Missiological Education by Extension: A Case Study of the Course, “Foundations of the World Christian Movement”

This article is a case study of a simple online course created jointly by a mission agency and small university. It demonstrates how open source course management technology has been used to create a true sense of community among students from a variety of cultural backgrounds and locations. The content of the course was delivered through a blending of open source technology and self-directed adult learning facilitated through online dialog, which in turned engendered multi-cultural, respectful virtual community. Information is shared to enable others to obtain low-cost technological help for setting up other individual courses in Moodle

Saccades and drifts differentially modulate neuronal activity in V1: Effects of retinal image motion, position, and extraretinal influences

In natural vision, continuously changing input is generated by fast saccadic eye movements and slow drifts. We analyzed effects of fixational saccades, voluntary saccades, and drifts on the activity of macaque V1 neurons. Effects of fixational saccades and small voluntary saccades were equivalent. In the presence of a near-optimal stimulus, separate populations of neurons fired transient bursts after saccades, sustained discharges during drifts, or both. Strength, time course, and selectivity of activation by fast and slow eye movements were strongly correlated with responses to flashed or to externally moved stimuli. These neuronal properties support complementary functions for post-saccadic bursts and drift responses. Local post-saccadic bursts signal rapid motion or abrupt change of potentially salient stimuli within the receptive field; widespread synchronized bursts signal occurrence of a saccade. Sustained firing during drifts conveys more specific information about location and contrast of small spatial features that contribute to perception of fine detail. In addition to stimulus-driven responses, biphasic extraretinal modulation accompanying saccades was identified in one third of the cells. Brief perisaccadic suppression was followed by stronger and longer-lasting enhancement that could bias perception in favor of saccade targets. These diverse patterns of neuronal activation underlie the dynamic encoding of our visual world

Opinions of School Adminsatrators Concerning Selected Aspects of the Program of Vocational Agriculture in East Tennessee

Importance of the Study: Many people are responsible for conducting programs of vocational agriculture in East Tennessee. Some of the key personnel involved are the administrators of the school systems. Knowledge of their commendations and recommendations will be of considerable value to teachers of vocational agriculture, teacher trainers, and state supervisors of vocational agriculture in planning their programs. Their cooperation and backing can be more effectively sought with the knowledge of their appraisals, recommendations and understandings of the program. Proper application of this knowledge will make for a more effective vocational agriculture program in East Tennessee. It will serve as a guide for similar studies with the same or other personnel in the school systems. It has served as an invaluable means of in-service training for the writer in preparation for further teaching in the field of vocational agriculture

Effect of chemical control on insect populations infesting tomatoes : with notes on the behavior and larval development of Heliothis zea (Boddie)

Of the nine insecticides evaluated Ambush®, Cygon® and Pounce® most effectively suppressed aphid populations on tomatoes. Significantly lower fruitworm damage occurred on the carbamate and synthetic pyrethroid treatments than on the Cygon treatment or the untreated check. The tomato fruitworm migrated an average of 10 cm a day on tomato plants while 69% of observed feeding occurred on the fruit and 31% on the foliage. Larvae were unable to survive on a diet solely of tomato fruit, while larvae reared on tomato foliage were significantly smaller than larvae reared on artificial diet. Adult females preferred to deposit eggs on the underside of leaves and on fruit

Evangelical and Frontier Mission Perspectives on the Global Progress of the Gospel

As we reflect on the past century, then, the stories of the evangelical world church deserve to be heard. In this volume, we do not have space to even begin to scratch the surface. Being forced to choose an orientation, we collected stories and thinking related to the way evangelicals have idealized, operationalized and organized in light of the remaining frontiers of mission.https://scholar.csl.edu/edinburghcentenary/1005/thumbnail.jp

A Method of Drusen Measurement Based on the Geometry of Fundus Reflectance

BACKGROUND: The hallmarks of age-related macular degeneration, the leading cause of blindness in the developed world, are the subretinal deposits known as drusen. Drusen identification and measurement play a key role in clinical studies of this disease. Current manual methods of drusen measurement are laborious and subjective. Our purpose was to expedite clinical research with an accurate, reliable digital method. METHODS: An interactive semi-automated procedure was developed to level the macular background reflectance for the purpose of morphometric analysis of drusen. 12 color fundus photographs of patients with age-related macular degeneration and drusen were analyzed. After digitizing the photographs, the underlying background pattern in the green channel was leveled by an algorithm based on the elliptically concentric geometry of the reflectance in the normal macula: the gray scale values of all structures within defined elliptical boundaries were raised sequentially until a uniform background was obtained. Segmentation of drusen and area measurements in the central and middle subfields (1000 μm and 3000 μm diameters) were performed by uniform thresholds. Two observers using this interactive semi-automated software measured each image digitally. The mean digital measurements were compared to independent stereo fundus gradings by two expert graders (stereo Grader 1 estimated the drusen percentage in each of the 24 regions as falling into one of four standard broad ranges; stereo Grader 2 estimated drusen percentages in 1% to 5% intervals). RESULTS: The mean digital area measurements had a median standard deviation of 1.9%. The mean digital area measurements agreed with stereo Grader 1 in 22/24 cases. The 95% limits of agreement between the mean digital area measurements and the more precise stereo gradings of Grader 2 were -6.4 % to +6.8 % in the central subfield and -6.0 % to +4.5 % in the middle subfield. The mean absolute differences between the digital and stereo gradings 2 were 2.8 +/- 3.4% in the central subfield and 2.2 +/- 2.7% in the middle subfield. CONCLUSIONS: Semi-automated, supervised drusen measurements may be done reproducibly and accurately with adaptations of commercial software. This technique for macular image analysis has potential for use in clinical research

Fixation in patients with juvenile macular disease

Purpose. The instability of fixation with central scotoma has been mainly studied in patients with age-related macular diseases (MDs). However, early macular lesions can lead to different characteristics of fixation. The aim of this work was to study fixation in patients with juvenile MD. Methods. Eye movements of 10 patients and 10 controls were monitored during fixation. Visual fields were assessed by static perimetry to determine the extent of the field defects. Eye movements were separated into saccades and drifts, with fixation stability assessed by bivariate contour ellipse area (BCEA). To quantify the number and location of preferred retinal loci (PRL), the kernel density estimator and expectation maximization for mixtures of gaussians were used. Results. Patients have worse fixation stability than controls and large BCEAs resulted in more than one PRL. It was found that central field defects (10°) have negative correlation with the size of BCEA. In addition, the meridian of saccades during fixation was correlated with the meridian inter-PRL. Conclusions. Patients with juvenile MDs have large BCEAs, frequently associated with two PRL. Similar results had been found for patients with age-related MDs. Also, the meridian of involuntary saccades during fixation was found to be correlated with the location of PRLs, suggesting a useful role of these movements in alternating between them

A perspective on color vision in platyrrhine monkeys

AbstractStudies carried out over the past two decades show that many platyrrhine (New World) monkeys have polymorphic color vision. This condition results from the sorting of allelic versions of X-chromosome cone opsin genes at a single gene site, yielding a mixture of dichromatic and trichromatic phenotypes in the population. Two genera of platyrrhine monkey are known to deviate significantly from this pattern. Examination of color vision, photopigments, and photopigment genes of all of these monkeys have stimulated a renewed interest in understanding the evolution of primate color vision

Changes in color vision with decreasing light level: separating the effects of normal aging from disease.

The purpose of this study was to obtain additional information about the health of the retina (HR) by measuring the rate of loss of chromatic sensitivity with decreasing light level. The HR(index) is introduced to separate the effects of normal aging from early stage disease. For normal subjects the HR(index is largely independent of age (r(2)~0.1), but ~11% of clinically normal, asymptomatic, older subjects exhibit values below the 2σ limit. The HR(index provides a single number that captures how light level affects chromatic sensitivity irrespective of age and can be used to screen for preclinical signs of retinal disease