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At least 523 records · Page 29Linked to original sources
PubMed2006

Web based distance learning at Faculty of Medicine of Sarajevo University.

The time in which we live is defined by the significant influence of the information technologies on our lives, changes and development of society and the efficacy of all the organization systems. Increase and development of distance learning (DL) technologies over the past decade has exposed the potential and the efficiency of new technologies. Number of events has organized by teaching staff from Cathedrae for Medical Informatics in order to promote distance learning and web based education are very extensive: professional-scientific events, workshops and congresses, first tele-exam at the Medical Faculty, Introducing of Distance learning in curriculum at biomedical faculties, etc. At the University in Sarajevo in year 2003 was opened the e-learning center for the support to the faculties the distance studies by use of the information technology. At Medical Faculty of University of Sarajevo at Cathedrae for Medical Informatics since 2002 is in progress realization of the project named: "Possibilities of introducing distance learning in medical curriculum", approved by the Federal and the Cantonal ministry of science and education. Pilot project was realized during three past school years, theoretical and practical education of subject Medical informatics are adapted to the new concepts of education using world trends of education from the distance. One group of students was included in the project finalized by electronic exam registration and electronic exam on 20 June 2005, publicly, in the Physiology amphitheatre of the Medical Faculty in Sarajevo.

Bosnia and Herzegovina↗
PubMed1992

Sign- versus goal-tracking: effects of conditioned-stimulus-to-unconditioned-stimulus distance.

Three pigeons were exposed sequentially across experimental phases to five different distances between the conditioned stimulus and the site of the unconditioned stimulus in a sign-/goal-tracking procedure. A computer-controlled tracking system provided a continuous record of the bird's position by continuously monitoring the location of the bird's head in three-dimensional space. It was found that birds sign-tracked (i.e., approached the conditioned stimulus) when the conditioned stimulus was closest to the site of the unconditioned stimulus, goal-tracked (i.e., approached the site of the unconditioned stimulus in the presence of the conditioned stimulus) when the conditioned stimulus was farthest from the site of the unconditioned stimulus, and engaged in both sign- and goal-tracking (or something intermediate) at intermediate conditioned-stimulus-to-unconditioned-stimulus distances. When both sign- and goal-tracking occurred, the former tended to occur in the first half and the latter in the second half of the interval in which the conditioned stimulus was present. The results suggest (a) whether sign- or goal-tracking (or both) occurs is a function of the distance of the conditioned stimulus from the site of the unconditioned stimulus, (b) the fact that pigeons but not rats have been found to sign-track consistently throughout the duration of the conditioned stimulus may be due to quantitatively rather than qualitatively different effects of conditioned-stimulus-to-unconditioned-stimulus distance across species (i.e., a "short" conditioned-stimulus-to-unconditioned-stimulus distance for a pigeon may be a "long" one for a rat), and (c) sign- and goal-tracking may be competing behavioral tendencies that can (e.g., at intermediate conditioned-stimulus-to-unconditioned-stimulus distances) cancel each other out. The findings lend support to theories that specify an interaction between phylogenetic and reinforcement variables in determining whether sign- or goal-tracking will occur in any given experimental preparation.

Animals↗
PubMed1979

Estimation of distance and Preferred State Theory.

This paper describes the application of Preferred State Theory to provide quantitative predictions of a variety of psychological effects, including the prothetic-metathetic distinction, and the expected form of the matching functions between physical stimuli and the estimates produced by magnitude and category subjective estimation methods. The subjective distance from a midwestern university campus to each of 24 American cities was judged by 157 male and female undergraduates. It was hypothesized on the basis of the theory that subjects would process short geographical distances as a metathetic continuum and longer distances as a prothetic continuum. This hypothesis was supported for the method of category judgments but not for the method of magnitude estimation. Based on the theory, the matching functions between physical and subjective distances for short distances were expected to be more nearly linear than for long distances for both judgment methods. The data do not support this hypothesis for either method.

Adolescent↗
PubMed2005

Dissociation of the distance effect and size effect in one-digit numbers.

Magnitude comparison of single digits is robustly characterized by a distance effect (close numbers are more difficult to compare than numbers further apart) and a size effect (for a given distance, comparison difficulty increases with increasing size). The distance effect indicates access to the mental number line (Dehaene, 1997), and the size effect is usually interpreted as indicating that the mental number line represents larger numbers more vaguely than smaller ones. In contrast, we have argued earlier (Verguts, Fias, & Stevens, 2005) that for symbolic numbers (Arabic or verbal notation), the size effect does not originate from the mental number line but, instead, originates from mappings to relevant output components that are specific for magnitude comparison. If the latter is true, it should be possible to dissociate the distance effect from the size effect in tasks other than magnitude comparison. In two experiments, we observed a robust distance effect in same/different judgments, which implies access to the mental number line. Yet the size effect was absent. Consistent with our prediction, this finding establishes a dissociation between the size effect and the distance effect.

Adult↗
PubMed1995

Does perceived size depend on perceived distance? An argument from extended haptic perception.

Two experiments were directed at the comparison between two perspectives on the perception of size achieved by probing the gap between two occluded distal surfaces by means of a hand-held rod. One perspective was the classical size-distance invariance hypothesis developed for the problem of visual size perception with a central role for perceived distance; the other was the hypothesis that the extended haptic perception of gap size is specific to a physical invariant lambda of the dynamics of probing. Experiment 1 examined the relation between hepatically perceived gap size and haptically perceived gap distance. No causal connection between the two was found, and all the variance in perceived size was accounted for by lambda. Experiment 2 manipulated the rotational inertia of the probe. Its effect was different for the two perceptions of size and distance, underscoring their independence. The indifference of perceived size to perceived distance was discussed in reference to identifying invariants for both the haptic and the visual perception of size at a distance.

Adult↗
PubMed1992

Size-distance invariance: kinetic invariance is different from static invariance.

The static form of the size-distance invariance hypothesis asserts that a given proximal stimulus size (visual angle) determines a unique and constant ratio of perceived object size to perceived object distance. A proposed kinetic invariance hypothesis asserts that a changing proximal stimulus size (an expanding or contracting solid visual angle) produces a constant perceived size and a changing perceived distance such that the instantaneous ratio of perceived size to perceived distance is determined by the instantaneous value of visual angle. The kinetic invariance hypothesis requires a new concept, an operating constraint, to mediate between the proximal expansion or contraction pattern and the perception of rigid object motion in depth. As a consequence of the operating constraint, expansion and contraction patterns are automatically represented in consciousness as rigid objects. In certain static situations, the operation of this constraint produces the anomalous perceived-size-perceived-distance relations called the size-distance paradox.

Depth Perception↗
PubMed1997

Time-distance relations in shifting attention between locations on one's body.

Does the time to discriminate the presence or absence of a tactile stimulus depend on its distance from the bodily location to which one has been attending? Subjects were tested by the presentation of air puffs at four of eight possible locations on the body. In each trial of Experiment 1, (1) subjects attended auditorily to an announcement of one of the eight locations; (2) 2 sec later, a second location was announced and, simultaneously, air puffs were presented at a randomly selected four of the eight locations; (3) the subjects reported as quickly as possible on whether or not air puffs had been presented at the second-announced location. Overall, reaction times increased with the distance between the just-attended and the tested locations. Experiment 2 was undertaken to determine whether the operative distance was distance through the subject's body or directly through three-dimensional space. The subjects were tested as in Experiment 1, but with their arms and legs either side-by-side in front or spread out to each side. Reaction times then depended more on straight-line distance in space than on distance through the body.

Adult↗
PubMed2006

Using performance-based assessments to evaluate parity between a campus and distance education pathway.

OBJECTIVES: To compare the performance of campus-based students with that of distance students during the first 2 years of a doctor of pharmacy program to evaluate parity between the pathways. METHODS: Twelve cases were created for each year of the program along with performance criteria. The cases were converted into computer-based simulations for programmatic assessment at the end of the 2002-2003 and 2003-2004 school years. All first-professional year (P1) and second-professional year (P2) students participated in the assessments. Overall class means were calculated and used to compare student performances between campus and distance education pathways. RESULTS: Overall scores for the 2003 P1 class were 56.4% for the campus-based students and 62.4% for the distance students, (p = 0.002); overall scores for the 2003 P2 class were 48.8% and 55.5%, respectively (p < 0.0001). The 2004 overall scores for P1 campus and distance students were 59.0% and 65.7%, respectively, (p = 0.001); and for 2004 P2 scores the results were 51.8% and 56.5%, respectively (p = 0.049). CONCLUSIONS: Students receiving their pharmacy education via a distance pathway scored higher on performance-based assessments compared with students receiving their pharmacy education via the traditional campus-based pathway. This indicates that distance students are receiving at least an equivalent curricular experience in the P1 and P2 years compared to that received by campus-based students.

Education, Distance↗
PubMed2003

Transatlantic medical education: preliminary data on distance-based high-fidelity human patient simulation training.

Advanced training using Human Patient Simulators (HPS) is, for the large part, unavailable for the majority of healthcare providers in rural, remote, and less developed regions of the world--either due to their separation from the major medical education centers or significant fiscal austerity. Remote access to HPS based on the Applications Software Provider principles may provide the solution to this problem. The medical ASP (MED-ASP) concept proposed and developed by MedSMART has been subjected to an extensive qualitative and quantitative international test conducted among France, Italy, and USA. Two SimMan HPSs (Laerdal, Norway) were used, with one unit based in Ann Arbor, MI, USA, and one in Laval, France. While the French site had both remote and hands-on access to the simulator, the Italian site could access the HPS only remotely. Simulator visualization was provided by 4 remotely operated cameras (Sony, zoom, pan, tilt) at each HPS site. HPS-generated vital signs were transmitted to each site together with the interactive simulator control panel using a communications hub at the MedSMART facility in Ann Arbor. All remote interactions were performed via the Internet (TCP/IP) using ISDN and/or ADSL connections at minimum 128 Kbps. During the course of training, the trainees were exposed to 3 emergency scenarios with the remote expert providing instruction. Interventions were performed either remotely (Italy) or remotely and hands-on (France). Quantitative measurement of the efficiency of training was performed at the Italian site based on the evaluation of video recordings of each session and the assessment of several performance measures. At the end of the training program, a Likert scale-based assessment test was also given. The trainees showed statistically significant (p<0.03 - 0.05) improvement in all testing measures. The Likert scale questionnaire revealed overwhelming satisfaction with the simulation-based distance training even when the access to the simulator was only remote (Italy). Confidence was also significantly improved. The trainees indicated the optimal frequency of distance training as one 2 hour-long session twice a month. In conclusion, simulation-based distance medical training proved to be a highly effective tool in improving emergency medical skills of junior physician trainees and, despite initial reservations, neither distance nor language and cultural differences posed significant obstacles. The present and historical data from our previous work confirm the concept of MED-ASP as a highly efficient tool in both national and international medical education and training. Moreover, we now validate for the first time the concept of simulation-based, fully interactive transatlantic medical ADL that we have proposed in our previous theoretical papers. The present experiments prove that training based on advanced technologies transcends barriers of distance, time, and national medical guidelines. Hence, international simulation-based distance training may ultimately provide the most realistic platform for a large-scale training of emergency medical personnel in less developed countries and in rural/remote regions of the globe.

Education, Distance↗
PubMed2005

Distance learning at biomedical faculties in bosnia & herzegovina.

Increase and development of distance learning technologies over the past decade has exposed the potential and the efficiency of new technologies. Benefit and use of contemporary information technologies is the area where medical informatics got the most on understanding and importance. Definition of distance learning as "use of technologies based on health care delivered on distance" covers areas such as electronic health, tele-health (e-health), telematics, telemedicine, tele-education, etc. For the need of e-health, telemedicine, tele-education and distance learning there are various technologies and communication systems from standard telephone lines to the system of transmission digitalized signals with modem, optical fiber, satellite links, wireless technologies, etc. Tele-education represents health education on distance, using Information Communication Technologies(ICT), as well as continuous education of a health system beneficiaries and use of electronic libraries, data bases or electronic data with data bases of knowledge. In this paper authors described activities on introduction of distance learning in teaching process at Medical faculty, University of Sarajevo, Bosnia and Herzegovina. Internet was not really meant to be a means of human communication at first; but the clearly the Net become a main piece of human communication.

Bosnia and Herzegovina↗
PubMed1982

Infants' sensitivity to familiar size as information for distance.

2 experiments tested the effectiveness of familiar size as information for perceived distance. In Experiment 1, under monocular viewing conditions, adults judged the distances to large and small (34.2 cm and 16.9 cm high) photographs of faces and to large and small checkerboard ovals equal to the faces in size. Familiar size influenced subjects' distance estimates. The small faces were judged to be more than twice the distance of the large faces. No significant difference was found between the judged distances to large and small checkerboards. In Experiment 2, the same displays were presented to 5- and 7-month-old infants. Faces were viewed either monocularly or binocularly; checkerboards were viewed monocularly. Duration of reaching was observed as a measure of perceived distance. 7-month-olds gave clear evidence of sensitivity to familiar size. In the monocular-face condition, the difference in duration of reaching to the large and small faces was significantly larger than in either the binocular-face condition or the monocular-checkerboard condition. This indicates that infants were not simply reaching to large faces or large objects without regard to spatial information. Rather, these results indicate that they perceived the large faces to be within reach and the small faces to be beyond reach in the monocular condition. 5-month-olds failed to provide evidence of sensitivity to familiar size.

Age Factors↗
PubMed1995

Distance between the tonsillar fossa and internal carotid artery in children.

OBJECTIVE: Obtain normative data on the distance from the tonsillar fossa to the internal carotid artery in children, and relate this distance to age and weight parameters. DESIGN: A prospective study of 100 children undergoing magnetic resonance imaging studies for pathology unrelated to the upper aerodigestive tract. The torus tubarius corresponds to the lateral extent of the tonsillar fossa and was used as the reference site for measurements. One hundred children (aged 7 days to 18 years; median, 6 years) were consecutively entered into the study. Exclusion criteria included any preexisting abnormalities of the upper aerodigestive tract. The study defined the distance from the tonsillar fossa to the internal carotid artery. Relationships of this distance were defined for both age and weight parameters. RESULTS: With increasing age and weight, the distance between the tonsillar fossa and the internal carotid artery increases in a regular fashion to a value approaching 25 mm. Both relationships are exponential with asymptotes being achieved by 56 kg (correlation coefficient, 0.8616; R2 value, 0.7423) or 12 years of age (correlation coefficient, 0.8452; R2 value, 0.7143). CONCLUSION: Age and weight parameters can be used to predict the distance from the tonsillar fossa to the internal carotid artery in children.

Adolescent↗
PubMed1999

Population substructure and isolation by distance in three continental regions.

Isolation by distance and divergence from a shared population history are two sources of population substructure. Isolation by distance erases population history as populations approach migration-drift equilibrium, while diverging populations descended from a single ancestral population will accumulate genetic differences with time. Here I investigate how much of the worldwide genetic diversity from Jorde et al.'s ([1997] Proc. Natl. Acad. Sci. USA 94:3100-3103) 60 tetranucleotide short tandem repeat (STR) data can be explained by isolation by distance. I use Slatkin's measure of population substructure, R(ST), principal components analyses, and Mantel tests to investigate the pattern of genetic diversity at both the intercontinental and intracontinental levels. Geographic distance accounts for almost 60% of world-wide interpopulation genetic relationships. Within continents, the correlations are less, although not significantly so because of wide confidence intervals. These results suggest that populations have not reached migration-drift equilibrium and that there is information in STR data to reconstruct population history. The level of population substructure worldwide is consistent with previous observations, but at the intracontinental level substructure is less. When one examines diversity against distance from the centroid, one sees excess heterozygosity in Africa, a pattern also noted by Stoneking et al. ([1998] Genome Research 7:1061-1071). A larger effective population size in Africa could explain the excess diversity. Greater gene flow in Africa is an unlikely explanation because the African R(ST) value is slightly larger than the Asian and European R(ST)s, pointing to less gene flow and greater substructure among African populations. Furthermore, there are differences in patterns between heterozygosity and allele size variance. Heterozygosity has a higher correlation with distance from the centroid than does allele size variance, and this may reflect demographic history. Kimmel et al. ([1998] Genetics 148:1921-1930) have shown that after a population expansion heterozygosity returns to equilibrium more quickly than does allele size variance. The contrasting patterns between heterozygosity and allele size variance may reflect different times after an expansion. However, simulations and further work need to be done to more thoroughly investigate the possibility that these data reflect population expansions.

Alleles↗
PubMed2000

Seed dispersal by woolly monkeys (Lagothrix lagothricha) at Tinigua National Park, Colombia: dispersal distance, germination rates, and dispersal quantity.

The purpose of this study was to describe seed dispersal patterns of woolly monkeys (Lagothrix lagothricha) in terms of dispersal quantity and two factors related to dispersal quality: germination rates of dispersed seeds and the distance of dispersal to parental trees. The possible influence of retention time, travel distance, seed size, activity patterns, and fruit abundance on dispersal distance was also analyzed. Observations on activity, diet, daily movements, and seed dispersal were made on focal individuals of a group of woolly monkeys at a tropical rain forest in Tinigua National Park (Colombia). Sixty hours of focal samples per month were completed during 1 year. A total of 753 depositions were collected during the study. Each dropping contained seeds from an average of 2.68 different species (range 0 to 9). Collected depositions contained an underestimated total of 50,168 seeds (>1 mm). Given a population density of 30 individuals/km2, the woolly monkeys in the study area disperse more than 25,000 seeds/km2/day. These seeds belong to 112 different plant species. Germination rates of dispersed seeds are usually similar or higher than those of non-swallowed seeds. It was possible to determine dispersal distance in 264 cases when the focal animal was continuously followed from ingestion at the parental tree to deposition. Only 1% of these depositions landed in close proximity (<15 m) of the parental tree. It was very common that the droppings were deposited between 100 and 500 m from the parent tree, and up to 1.5 km. Higher retention times and longer travel distances were not correlated with increased dispersal distance. Two main reasons for this result were the prolonged and variable passage rates (avg=11.2 hr+/-6.5 SD.) and the circuitous routes of monkeys in this forest.

Animals↗
PubMed2007

Exploring immature-to-mother social distances in Mexican mantled howler monkeys at Los Tuxtlas, Mexico.

We analyzed immature-to-mother social distance (juveniles and non-nursing infants) in two Mexican mantled howler monkey (Alouatta palliata) troops inhabiting a tropical rainforest fragment (40 ha) at Los Tuxtlas, Veracruz, Mexico. During July and August of 2000 and 2001 we applied an instantaneous sampling method (317 hr) to record the behaviors of the immatures and their mothers, as well as distances (ordinal scale) between immatures and their mothers (IMD), and between immatures and nonmother individuals (INMD). Immatures were generally less than 5 m away from any individual of the troop. Social distance was influenced by the different behaviors of both mothers and immatures, with the shortest distances occurring during rest (IMD <5 m in 94% of all instantaneous samples) and the longest during exploration (21% > or =10 m) and play (26% > or =10 m). When IMD increased, we found a higher percentage of records <5 m to other individuals, particularly with the probable father. When the variation in distance to the mother and to other individuals in the troop was considered, the immature animals' distance to other troop members depended on the immatures' age and type of behavior. Overall, these results suggest that in this low-activity species the development of the immature is associated with a complex set of relationships with other troop members.

Alouatta↗
PubMed2002

Influence of lean body mass on performance differences of male and female distance runners in warm, humid environments.

The purpose of this investigation was to evaluate the influence of lean body mass (LBM) and body weight (BW) on the thermoregulatory responses and endurance performance of male and female athletes in warm, humid environments. Ten (5 males, 5 females) healthy, moderately trained athletes with varying physiques performed a self-paced 30-min run on a motorized treadmill in warm (30 degrees C), humid (60% relative humidity) conditions, with the aim of running the greatest distance possible. Males completed one trial, while females completed two trials, one in each of the follicular (Fol) and luteal (Lut) phases of the menstrual cycle in a randomized fashion. There were no significant differences among groups for distance run (males, 5.2 +/- 0.4 km; Fol, 4.9 +/- 0.1 km; Lut, 4.7 +/- 0.1 km). However, following analysis of covariance accounting for LBM and BW, the distances run were significantly different. The adjusted means for distance run after accounting for LBM were 3.4 km for males (P < 0.05), 5.9 km for Fol, and 5.6 km for Lut. Adjusted means accounting for BW resulted in run distances of 6.5 km for males (P < 0.05), 4.2 km for Fol, and 4.0 km for Lut. Thermoregulatory responses such as rectal and skin temperatures were similar among groups. Avenues of heat loss and gain were altered relative to the menstrual cycle phase. The results suggest that one reason for the disparity in performance between male and female athletes over similar race distances might in part be related to unequal body characteristics and in particular to differences in LBM.

Adult↗
PubMed1985

The solution structure of a B-DNA undecamer comprising a portion of the specific target site for the cAMP receptor protein in the gal operon. Refinement on the basis of interproton distance data.

A restrained least squares refinement of the solution structure of the double-stranded DNA undecamer 5'd(AAGTGT-GACAT).5'd(ATGTCACACTT) comprising a portion of the specific target site of the cAMP receptor protein in the gal operon is presented. The structure is refined on the basis of both distance and planarity restraints, 2331 in all. The distance restraints comprise 150 interproton distances determined from pre-steady state nuclear Overhauser enhancement measurements and 2159 other interatomic distances derived from idealized geometry (i.e., distances between covalently bonded atoms, between atoms defining fixed bond angles, and between atoms defining hydrogen bonding in AT and GC base pairs). Two refinements were carried out and in both cases the final RMS difference between the experimental and calculated interproton distances was 0.2 A. The difference between the two refined structures is small (overall RMS difference of 0.23 A) and represents the error in the refined coordinates. Although the refined structures have an overall B-type conformation there are large variations in many of the local conformational parameters including backbone and glycosidic bond torsion angles, helical twist and propellor twist, base roll and base tilt angles.

Base Sequence↗
PubMed2004

Cluster distance geometry of polypeptide chains.

Distance geometry has been a broadly useful tool for dealing with conformational calculations. Customarily each atom is represented as a point, constraints on the distances between some atoms are obtained from experimental or theoretical sources, and then a random sampling of conformations can be calculated that are consistent with the constraints. Although these methods can be applied to small proteins having on the order of 1000 atoms, for some purposes it is advantageous to view the problem at lower resolution. Here distance geometry is generalized to deal with distances between sets of points. In the end, much of the same techniques produce a sampling of different configurations of these sets of points subject to distance constraints, but now the radii of gyration of the different sets play an important role. A simple example is given of how the packing constraints for polypeptide chains combine with loose distance constraints to give good calculated protein conformers at a very low resolution.

Algorithms↗