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At least 793 records · Page 44Linked to original sources
PubMed1996

Horizontal and vertical distance perception: the discorded-orientation theory.

We sought the conditions where the horizontal-vertical illusion (HVI) takes place outdoors in an open field. Longitudinal distance from a subject to a building wall was adjusted to appear equal to the vertical or horizontal distance on the wall. To examine validity of previous theories (physiology, frame, depth, and gravity theories), boundary of visual field (ellipse and circle), bodily orientation (upright and lying), and orientation of visual objects (normal, 90 degrees-tilted, and inverse) were manipulated in eight experiments. These three independent variables affected the HVI effects, but their effects were not explained by the previous theories. We therefore proposed a model on the basis of discord among the retinal, visual, and gravitational orientations. We also found that longitudinal distance was adjusted as being consistently larger than the standard distance. This result was explained by the reduction of cues to distance and the HVI effect.

Attention↗
PubMed2001

Professional socialization of baccalaureate nursing students: can students in distance nursing programs become socialized?

Distance education programs may have difficulty socializing nursing students due to limited face-to-face student-faculty interaction. Socialized attitudes toward the nursing profession were assessed using two measures with three groups--senior BSN students enrolled at campus-based programs, senior BSN students enrolled in distance programs, and non-nursing students. The purpose of this analysis was to determine whether nursing students enrolled in distance programs had professional socialization outcomes comparable to nursing students enrolled in campus-based programs, and to examine the psychometric properties of two popular measures of professional socialization. Results indicated that students in the distance programs had higher scores than the campus-based nursing students, who, in turn, had higher scores than non-nursing students. A statistical interaction of RN status by program type indicated that health care experience was a critical factor in the socialization process. Of the two socialization measures examined, one had acceptable psychometric properties. These data suggest that health care and preceptorship experiences are important determinants of professional socialization and that students who opt for distance nursing programs graduate with socialization outcomes that are at least comparable to those of students who attend traditional programs.

Analysis of Variance↗
PubMed2001

Perspective transformation in RN-to-BSN distance education.

This study examines perspective transformation (or professional resocialization) in RN-to-BSN students obtaining their degree by distance education. A socialization scale was used to compare newly admitted and graduating RN-to-BSN students who had taken their courses onsite, by distance education, or a mixture of the two methods. The scores of entering and graduating RN-to-BSN students also were compared to those of graduates from the generic program to identify if program and experience are factors in scores achieved. Results indicate that all BSN graduates had significantly higher scores than the diploma-prepared nurses entering the RN-to-BSN program. RN-to-BSN graduates who had used distance education had the highest scores, followed by the onsite RN-to-BSN students. Students who had taken a mixture of distance and onsite courses had scores similar to those of generic program graduates. Experience and full-time employment status were significantly associated with higher scores among graduating RN-to-BSN students. Implications for nurse educators working with RN-to-BSN students who use distance education are discussed.

Adult↗
PubMedDate not supplied

The evolution of a distance education initiative into a major telehealth project.

After a five-year collaboration in distance learning, the University of Texas Medical Branch in Galveston School of Nursing and the Lamar University Department of Nursing in Beaumont, Texas, opened discussions during the mid-1990s about working together to establish a cutting-edge telehealth clinic. Other participants in this dialogue were the UTMB Division of Pediatric Special Services (DPSS) and the East Texas Area Health Education Center (ETAHEC). DPSS hoped to provide telehealth services for children who had to commute routinely to receive comprehensive health care. ETAHEC, which specializes in building community-academic partnerships to improve the health of populations in its service region, had already worked with members of the team, providing support for the distance education collaboration between UTMB and LU. Several meetings between representatives from the two universities and ETAHEC resulted in the decision by LU to establish an infrastructure for distance learning that could also support telehealth activities. UTMB, which offered family nurse practitioner education at LU through the earlier distance learning initiative, had extensive experience in both distance education and telehealth. It provided the expertise to ensure that the two types of technology could be provided on the LU campus. Eventually, a third university came on board, and the program expanded to provide services in six public schools. A single telehealth clinic, in operation for two years with over 112 client visits, has grown into a major telehealth initiative linking an academic health science center, universities, and school districts in Texas.

Child Health Services↗
PubMed2001

[Effect of the configuration of a route on distance perception].

Numerous studies have been carried out to investigate the knowledge of route distance in environmental space. Evidence suggests that the knowledge of distance is influenced by the environmental features and structures of the route. The purpose of this study was to investigate the factors that affect this knowledge. In particular, the aim was to determine the role of the structure versus that of characteristic environmental features along the route. In two experiments, it was found that the knowledge of distance was not affected by the structure alone. Rather it was determined by the environmental features along the route. Participants seem to infer the environmental distance between two locations indirectly using successively perceived and stored retrievable features. It could be shown in a third experiment that in an intentional learning condition--in contrast to an incidental condition--, the number of environmental features does not seem to influence distance knowledge. In this condition, a direct retrieval of information appears to be possible. The experiments took place in a virtual environment.

Adult↗
PubMed2002

[Distance learning in postgraduate training of professionals. Example of occupational medicine specialization].

The rapid development of science, technology, economy and the society has one along with the wide recognition of lifelong education and learning society concepts. Scientific centres worldwide conduct research how the access to the information and multimedia technology could bring about positive changes in our lives including improvement in education and the learning environment. Mankind development in conformity with social progress and sustainable development faces a new educational concept of learning society and open education in the information age, supported with multimedia and data processing technology. Constrains in resources availability for broadening the access to education had led to search for alternative, more time and cost-effective systems of education. One of them is distance learning, applied with success in many countries. The benefits of distance learning are well proven and can be extended to occupational medicine. Major advantages include: the integration of studies with work experience, flexibility, allowing studies to be matched to work requirements, perceived work and leisure timing, continuity of career progression. Likewise is in Poland this form of education becomes more and more popular. The distance education systems have been seen as an investment in human resource development. The vast variety of courses and educational stages makes possible the modern method of knowledge to be easily accessible. Experience of the School of Public Health in Łódź in distance learning had shown remarkable benefits of the method with comparable quality of intramural and distance learning in respect of the knowledge and experience gained by students.

Clinical Competence↗
PubMedDate not supplied

[Estimation by toads of the distance to the moving objects and their true size: neuroethological and comparative aspects].

In two sets of experiments, studies have been made on the parameters by which the toad Bufo bufo estimates the neighbour and remote moving objects. In absence of the structural surrounding, a dark target with a diameter 17.2 degrees (3 cm at a distance of 10 cm) and with the rate of movement 36, 72 and 145 degrees/sec evoked in toads only feeding turns; at the rates 72 and 145 degrees/sec, together with these turns, animals usually fired with their tongues to the direction of the target, revealing evident underestimation of the distance and real size of the object. Under the same experimental conditions, a target with a diameter 1.2 degrees (0.25 cm at a distance of 12 cm) and the rate of movement 0.6 and 3 degrees/sec produced mainly frightful reaction, which indicates overestimation of the distance to the object and its size. The same object moving at a structural background evoked only feeding reactions, i.e. the animals correctly estimated the distance to the target and its size.

Animals↗
PubMed1993

Two roads diverged: young children's ability to judge distance.

In the present studies, we investigated 4- and 5- to 6-year-old's ability to compare the distances covered by a direct route to a location and an indirect route to the same location. The distances ranged between 16 and 22 feet. The routes were visible from a single vantage point, and objects serving as landmarks were sometimes located along the routes. We found clear demonstrations of the two classic Piagetian distance errors--the direct-indirect error, in which children judge that a direct route and an indirect route cover the same distance, and the interposed object error, in which children judge that a route is shorter when it is segmented by an object located somewhere along the route. The interposed object error occurred because children focused on only one segment of the route, which was consistent with Piaget's explanation of the error. However, in contrast to Piaget, we found that about 40% of 4-year-olds could successfully avoid the direct-indirect error, and in addition, when the routes were visually displayed, they could also avoid the interposed object error. It is important that they also gave correct explanations for why the indirect route was longer, by referring to the fact that it was not straight. For these children at least, the interposed object error was due to difficulty they had representing routes, rather than to a misconception of distance. We suggest that future research should examine whether that may also be true for younger children.

Analysis of Variance↗
PubMed1995

Distance cues for vertical vergence adaptation.

Vertical vergence can be trained to respond to vertical and/or horizontal conjugate eye position, horizontal vergence, and vertical head tilt. This cross-coupling is manifest as a vertical phoria aftereffect (monocular vertical vergence response) that varies with direction and distance of gaze. The function of the spatially dependent adaptation is to maintain the calibration between vertical eye alignment and intended placement of the two retinal images. Oculomotor adaptation stabilizes our sense of spatial localization and calibrates a body-referenced coordinate representation of visual space that is necessary for visually guided motor responses. We have tested the possible association of vertical phoria adaptation with perceptual cues to distance in the absence of any other associated motor activity. During adaptive training, vertical disparity vergence was associated with variations of perceptual distance cues (including loom, overlap, relative size, and relative motion), oculomotor distance cues (horizontal vergence), or a combination of both classes of cues. We observed that in a 2-h period the open-loop (monocular) vertical vergence response could not be trained to occur as an aftereffect in association with the perceptual cues to distance, whereas it could be trained in association with oculomotor cues. We conclude that the spatial specificity of vertical vergence aftereffects caused by short-term adaptation results from an associated cross-coupling with supranuclear sources of oculomotor activity.

Adaptation, Ocular↗
PubMed1998

Cognitive channels computing action distance and direction.

Visually guided, goal-directed reaching requires encoding action distance and direction from attributes of visual landmarks. We identified a cognitive mechanism that seemingly performs visual motor extension before action initiation and replicated and extended previous results that identified a mechanism for visual motor mental rotation. We find that humans systematically delay action onset while newly planning increasingly distant arm movements beyond a visual landmark, consistent with an internal representation for visual motor extension. Onset times also changed systematically during concurrent mental rotation and visual motor extension computations required to process new directions and distances. Visual motor extension associated with reaching slowed when participants needed to plan action direction within the same time frame, whereas mental rotation efficiency was unaffected by concurrent needs to prepare action distance. In contrast to parallel direction and distance computations needed for direct aiming to a visual target, the planning of new directions and distances likely occurs at distinct times. When considered with previous findings, the current results suggest the existence of an intermediate component of motor preparation that engages a covert mechanism of cognitive motor planning.

Adolescent↗
PubMedDate not supplied

A distance learning model in a physical therapy curriculum.

In response to the rural health initiative established in 1991, the University of Kentucky has developed an innovative distance learning program of physical therapy instruction that combines classroom lecture and discussion via compressed video technology with laboratory experiences. The authors describe the process of planning, implementing, and evaluating a specific distance learning course in pathomechanics for the professional-level master's-degree physical therapy students at the University of Kentucky. This presentation may serve as a model for teaching distance learning. Descriptions of optimal approaches to preclass preparation, scheduling, course delivery, use of audiovisual aids, use of handout material, and video production are given. Special activities that may enhance or deter the achievement of the learning objectives are outlined, and a problem-solving approach to common problems encountered is presented. An approach to evaluating and comparing course outcomes for the distance learnere is presented. For this particular course, there was no statistically significant difference in the outcome measures utilized to compare the distance learners with the on-site learners.

Computer-Assisted Instruction↗
PubMedDate not supplied

Role of depth in eye distance measurements: comparison of single and stereo-photogrammetry.

Photogrammetry has been used as an alternative to direct measurements to obtain facial distances for a variety of anthropometric applications. Taking measurements from photographs is less intrusive to subjects and reduces screening time, but measurements from single frontal photographs neglect depth information and may be inadequate for screening purposes. This study examined the role of depth in measurements of palpebral fissure length, interpupillary distance, inner canthal distance, and outer canthal distance using single- and stereo-photogrammetry; an operator selected landmarks on single and stereo digital photographs displayed on a computer monitor. Depth was not found to make a significant contribution to eye distances in an idealized system where the real-world coordinates of points on the eye were known from three-dimensional calibration of stereo photographs. However, the differences found between measurements taken from single frontal photographs and those from stereo-photogrammetry indicated that measurements from single photographs are prone to errors due to misalignment of the camera, the face, and the calibration instrument during image acquisition; if single photographs are to be used, the placement of these components should be carefully monitored.

Anthropometry↗
PubMed2002

Short bi-iliac distance in prenatal Ullrich-Turner syndrome.

The purpose of the present study is to evaluate the bi-iliac distance and the caudo-cranial position of the iliac bones in Ullrich-Turner syndrome (UTS) fetuses compared to recently published standards for normal fetuses. Whole-body radiographs in antero-posterior projections of 24 UTS fetuses (crown-rump lengths, 106-220 mm) were included in the study. From each radiograph, two horizontal (outer and inner bi-iliac distances) and two vertical (caudo-cranial) positions compared to the vertebral column were measured to estimate the position of the iliac bones. The present investigation revealed that both the outer and inner bi-iliac distances were significantly shorter in UTS fetuses than in normal fetuses. We also found that for the inner bi-iliac distance, the growth rate in UTS fetuses was significantly lower than in normal fetuses. This finding suggests not only a lesser growth but also a different growth pattern compared to normal fetuses. Regarding the caudo-cranial position of the iliac bones compared to the lower vertebral column, there was no significant difference for the lower caudo-cranial position, but the upper caudo-cranial position was significantly lower in UTS fetuses than in normal fetuses. The bi-iliac distance and the iliac bone position have not previously been described in Ullrich-Turner syndrome fetuses.

Fetal Diseases↗
PubMed1978

Empirical comparison of distance equations using discrete traits.

The use of the Grewal-Smith statistic in measuring biological distance among skeletal population samples has been questioned since it was first applied to human populations. Recently, in an attempt to stabilize the variance of the Grewal-Smith statistic for use with non-metric analysis, Sjøhivold ('73) and Green and Suchey ('76) have introduced corrections and alternative transformations which may enhance the meaning of biological distance among population samples. Their recommendations improve the statistics for specific variable ranges; i.e., small sample size and low trait frequencies. Thirteen equations representing Grewal-Smith, Freeman-Tukey, Anscombe, and Bartlett transformations and/or corrections, were compared using rank order correlation statistics on actual biological distances generated by real population data as presented in existing literature. Results from testing these actual distance models show little variation between equations based on the populational data sets used. Based on these findings, the distance model resulting from the Grewal-Smith statistic is not inferior to the more sophisticated models, although the latter may be superior allowing specific improvements for small sample size and/or low trait frequencies.

Bone and Bones↗
PubMed2002

Determination of intermolecular distance for a model peptide of Bombyx mori silk fibroin, GAGAG, with rotational echo double resonance.

Rotational echo double resonance NMR spectroscopy is applied for the determination of the distance of intermolecular chains of pentapeptide, GAGAG (G: Gly, A: Ala), a model typical of the crystalline domain in Bombyx mori silk fibroin. 1:4 mixture of G[1-(13)C]AGAG and GAG[(15)N]AG with antiparallel beta-sheet structure was used to determine the distance of intermolecular hydrogen bonding between adjacent molecules within pleated sheet and the (13)C-(15)N interatomic distance was determined to be 4.3 A. On the other hand, 1:4 mixture of GAG[1-(13)C]AG and GAG[(15)N]AG gave information on the interpleated sheet arrangement. When we assumed the same distances between two interpleated sheets, the distance was calculated to be 5.3 A and the angle (15)N-(13)C-(15)N was 180 degrees.

Animals↗
PubMed2003

Constant-distance mode scanning electrochemical microscopy (SECM)--Part I: Adaptation of a non-optical shear-force-based positioning mode for SECM tips.

A non-optical shear-force-based detection scheme for accurately controlling the tip-to-sample distance in scanning electrochemical microscopy (SECM) is presented. With this approach, the detection of the shear force is accomplished by mechanically attaching a set of two piezoelectric plates to the scanning probe. One of the plates is used to excite the SECM tip causing it to resonate, and the other acts as a piezoelectric detector of the amplitude of the tip oscillation. Increasing shear forces in close proximity to the sample surface lead to a damping of the vibration amplitude and a phase shift, effects that are registered by connecting the detecting piezoelectric plate to a dual-phase analogue lock-in amplifier. The shear force and hence distance-dependent signal of the lock-in amplifier is used to establish an efficient, computer-controlled closed feedback loop enabling SECM imaging in a constant-distance mode of operation. The details of the SECM setup with an integrated piezoelectric shear-force distance control are described, and approach curves are shown. The performance of the constant-distance mode SECM with a non-optical detection of shear forces is illustrated by imaging simultaneously the topography and conductivity of an array of Pt-band microelectrodes.

Journal Article↗
PubMed2006

Treatment of local breast carcinoma in Florida: the role of the distance to radiation therapy facilities.

BACKGROUND: Breast-conserving surgery combined with radiation (BCSR) is the recommended alternative treatment to mastectomy for local breast carcinoma. However, limited access to healthcare may result in more extensive surgical treatment. The effect of distance to radiation therapy facilities on the likelihood of receiving BCSR was examined in Florida. METHODS: Local breast carcinomas reported to Florida's statewide registry between July, 1997, and December, 2000 were linked to the Agency of Healthcare Administration inpatient and outpatient databases to supplement the registry's treatment data, resulting in 18,903 local breast carcinoma cases treated with BCSR or mastectomy. The odds of receiving BCSR were modeled as a function of distance to the closest radiation therapy facility, adjusting for health insurance, age, race/ethnicity, and marital status. RESULTS: Distance to the closest radiation therapy facility was negatively associated with BCSR, with the odds ratio (OR) decreasing by 3% per 5-mile increase in distance. Compared with the uninsured, privately insured women were 49% more likely to receive BCSR (OR of 1.49; 95% confidence interval [95% CI], 1.20-1.86) and Medicare patients were 37% more likely (OR of 1.37; 95% CI, 1.09-1.72). Age at diagnosis was negatively associated, reducing the odds of BCSR by 1% per year increase in age. Compared with white non-Hispanic, Hispanic women were 38% less likely to receive BCSR (OR of 0.62; 95% CI, 0.55-0.71). Married women were 23% more likely to receive BCSR compared with singles (OR of 1.23; 95% CI, 1.09-1.40); women who were separated, divorced, or widowed did not differ significantly from single women. CONCLUSIONS: Distance to radiation therapy facilities may negatively impact the likelihood of BCSR in Florida. Age at diagnosis, insurance type, race/ethnicity, and marital status were associated with BCSR. Future efforts should target the uninsured, Hispanics, the elderly, and the unmarried women to reduce disparities in the administration of BCSR for local breast carcinoma.

Adult↗
PubMed2001

Variation in reproductive traits is associated with short anogenital distance in female rats.

Anogenital distance was used as a biomarker for natural variation in prenatal androgenization of female rats and was associated with individual differences in a suite of reproductive characteristics. Females with short anogenital distances were likely to have first vaginal estrus earlier than females with longer anogenital distances and to have first vaginal estrus on the same day as vaginal opening. In young adulthood, females with short anogenital distances had shorter ovarian cycles and less intense lordosis reflexes in response to manual palpation than those with longer anogenital distances, but only when living individually, not in groups. Taken together, these findings indicate that prenatal androgenization affects reproductive traits throughout the life span.

Anal Canal↗