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The paper focuses on the history of origination and development of iridology. The basic stages of formation of iridology as a science in Ukraine are analyzed. Due emphasis is given to the role of iridology as an easy-to-learn method of rapid diagnosis of high informative value. Efficiency is shown of iridodiagnosis as exemplified in Chernobyl accident victims. Iridology is claimed to be a science of much promise in Ukraine.
During a study of eosinophil-predominant gallbladder disease, an image analysis (IA) technique was developed for quantification of eosinophils and lymphocytes in routine formalin-fixed tissue sections. Alternating sections were stained with hematoxylin and eosin for eosinophils and with monoclonal CD45 antibody visualized with diaminobenzidine by an avidin-biotin procedure for lymphocytes. A protocol was then developed using a commercially available image analyzer and two well-defined macro routines. The system was validated with cell block sections prepared from peripheral blood samples with known eosinophil and lymphocyte counts. The eosinophil counts obtained by this IA technique showed excellent correlation with the absolute counts from a peripheral blood analyzer (r2 = 0.987). The lymphocyte counts obtained by IA showed good correlation with the absolute counts (r2 = 0.820). This IA-based technique provides a sensitive, reproducible, and substantiated means of quantifying inflammatory cells in tissue sections. This rapid and easily learned technique adds quantification as a complementary dimension to the subjective assessment of tissue morphology.
Research on avian song learning has traditionally been based on an instructional model, as exemplified by the sensorimotor model of song development. Several large-scale, species-wide field studies of learned birdsongs have revealed that variation is narrowly restricted to certain aspects of song structure. Other aspects are sufficiently stereotyped and so widely shared by species' members that they qualify as species-specific universals. The limitations on natural song variation are difficult to reconcile with a fully open, instructive model of song learning. An alternative model based on memorization by selection postulates a system of innate neural templates that facilitate the recognition and rapid memorization of conspecific song patterns. Behavioral evidence compatible with this model includes learning preferences, rapid conspecific song learning, and widespread ocurrence of species-specific song universals that are recognized innately but fail to develop in songs of social isolates. A third model combines instruction, in the memorization phase, with selection during song production. An overproduced repertoire of plastic songs previously memorized by instruction is winnowed by selection imposed during social interactions at the time of adult song crystallization. Selection during production is well established as a factor in the song development of several species, in the form of action-based learning. The possible role of selective processes in song memorization merits further neurobiological investigation.
Children with learning problems often cannot discriminate rapid acoustic changes that occur in speech. In this study of normal children and children with learning problems, impaired behavioral discrimination of a rapid speech change (/dalpha/versus/galpha/) was correlated with diminished magnitude of an electrophysiologic measure that is not dependent on attention or a voluntary response. The ability of children with learning problems to discriminate another rapid speech change (/balpha/versus/walpha/) also was reflected in the neurophysiology. These results indicate that some children's discrimination deficits originate in the auditory pathway before conscious perception and have implications for differential diagnosis and targeted therapeutic strategies for children with learning disabilities and attention disorders.
We have previously shown that several brain areas are activated both during sequence learning at wake and during subsequent rapid-eye-movements (REM) sleep (Nat. Neurosci. 3 (2000) 831-836), suggesting that REM sleep participates in the reprocessing of recent memory traces in humans. However, the nature of the reprocessed information remains open. Here, we show that regional cerebral reactivation during posttraining REM sleep is not merely related to the acquisition of basic visuomotor skills during prior practice of the serial reaction time task, but rather to the implicit acquisition of the probabilistic rules that defined stimulus sequences. Moreover, functional connections between the reactivated cuneus and the striatum--the latter being critical for implicit sequence learning--are reinforced during REM sleep after practice on a probabilistic rather than on a random sequence of stimuli. Our results therefore support the hypothesis that REM sleep is deeply involved in the reprocessing and optimization of the high-order information contained in the material to be learned. In addition, we show that the level of acquisition of probabilistic rules attained prior to sleep is correlated to the increase in regional cerebral blood flow during subsequent REM sleep. This suggests that posttraining cerebral reactivation is modulated by the strength of the memory traces developed during the learning episode. Our data provide the first experimental evidence for a link between behavioral performance and cerebral reactivation during REM sleep.
To evaluate the efficacy of rapid antigen detection for diagnosis of Group A streptococcal pyoderma, lesions on 129 children were swabbed for culture and for rapid antigen detection testing. Duplicate cultures and duplicate rapid antigen tests were performed in two laboratories. The sensitivity and the specificity of the test were high, supporting the validity of this technique in diagnosing streptococcal pyoderma. Of importance, however, was the documentation of a learning curve effect on the sensitivity and specificity. There was a significant difference between the early samples and the later samples in one laboratory which had less previous experience with the rapid antigen detection test. By the time the later samples were collected, the proficiency of the first laboratory was equal to that of the second laboratory for both sensitivity and specificity. Although a learning curve effect on sensitivity and specificity of rapid antigen detection tests for Group A streptococci has been suspected, this is the first documentation of such an effect. This finding has important clinical implications for using rapid antigen detection tests for Group A streptococcal infections.
Circulating estrogens affect the neural circuits that underlie learning and memory in several vertebrates via an influence on the hippocampus. In the songbird hippocampus local estrogen synthesis due to the abundant expression of aromatase may modulate hippocampal function including spatial memory performance. Here, we examined the effect of estradiol, testosterone, and dihydrotestosterone on the structure and function of the songbird hippocampus. Adult male zebra finches were castrated, implanted with one of these steroids or a blank implant, and trained on a spatial memory task. The rate of acquisition and overall performance on this task was recorded by direct observation. The size and density of cells in the hippocampus and its volume were measured. Estradiol-treated birds learned the task more rapidly than any other group. Although testosterone- and blank-implanted birds did learn the task, we found no evidence of learning in dihydrotestosterone-implanted subjects. Cells in the rostral hippocampus were larger in estradiol- and testosterone-treated birds relative to other groups. A corresponding decrease in the density of cells was apparent in estradiol-implanted subjects relative to all other groups. These data suggest that estradiol may accelerate the acquisition of a spatial memory task and increase the size of neurons in the rostral hippocampus. Since testosterone-mediated changes in acquisition and cell size were similar to those of estradiol, but not dihydrotestosterone, we conclude that neural aromatization of testosterone to estrogen is responsible for effects on the structure and function of the songbird hippocampus.
Experiments on imitation typically evaluate a student's ability to copy some feature of an expert's motor behavior. Here, we describe a type of observational learning in which a student copies a cognitive rule rather than a specific motor action. Two rhesus macaques were trained to respond, in a prescribed order, to different sets of photographs that were displayed on a touch-sensitive monitor. Because the position of the photographs varied randomly from trial to trial, sequences could not be learned by motor imitation. Both monkeys learned new sequences more rapidly after observing an expert execute those sequences than when they had to learn new sequences entirely by trial and error.
Quick changes on the field of informational communication technologies forces educational and other institutions to think about different ways of teaching and learning in both formal and informal environments. It addition it is well known that due to fast advancement of science and technology the knowledge gained in schools is getting out-of-date rapidly, so life long learning is becoming an essential alternative. As a consequence we are facing a rapid development and use of new educational approaches such as e-learning, simulations, virtual reality, etc. They brought a revolution to learning and instruction. But in general the empirical results of e-learning studies are somewhat disappointing. They cannot prove the superiority of e-learning processes over traditional learning in general, neither in specific areas like nursing. In our international study we proved that e-Learning can have many benefits and that it can enhance learning experience in nursing education, but it has to be provided in correct manner.
Learning and memory in humans rely upon several memory systems, which appear to have dissociable brain substrates. A fundamental question concerns whether, and how, these memory systems interact. Here we show using functional magnetic resonance imaging (FMRI) that these memory systems may compete with each other during classification learning in humans. The medial temporal lobe and basal ganglia were differently engaged across subjects during classification learning depending upon whether the task emphasized declarative or nondeclarative memory, even when the to-be-learned material and the level of performance did not differ. Consistent with competition between memory systems suggested by animal studies and neuroimaging, activity in these regions was negatively correlated across individuals. Further examination of classification learning using event-related FMRI showed rapid modulation of activity in these regions at the beginning of learning, suggesting that subjects relied upon the medial temporal lobe early in learning. However, this dependence rapidly declined with training, as predicted by previous computational models of associative learning.
The rapidity with which children acquire language is one of the mysteries of human cognition. A view held widely for the past 30 years is that children master language by means of a language-specific learning device. An earlier proposal, which has generated renewed interest, is that children make use of domain-general, associative learning mechanisms. However, our current lack of knowledge of the actual learning mechanisms involved during infancy makes it difficult to determine the relative contributions of innate and acquired knowledge. A recent approach to studying this problem exposes infants to artificial languages and assesses the resulting learning. In this article, we review studies using this paradigm that have led to a number of exciting discoveries regarding the learning mechanisms available during infancy. These studies raise important issues with respect to whether such mechanisms are general or specific to language, the extent to which they reflect statistical learning versus symbol manipulation, and the extent to which such mechanisms change with development. The fine-grained characterizations of infant learning mechanisms that this approach permits should result in a better understanding of the relative contributions of, and the dynamic between, innate and learned factors in language acquisition.
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The landmark discrimination learning test can be used to assess the ability to utilize allocentric spatial information to locate targets. The present experiments examined the role of various factors on performance of a landmark discrimination learning task in beagle dogs. Experiments 1 and 2 looked at the effects of age and food composition. Experiments 3 and 4 were aimed at characterizing the cognitive strategies used in performance on this task and in long-term retention. Cognitively equivalent groups of old and young dogs were placed into either a test group maintained on food enriched with a broad-spectrum of antioxidants and mitochondrial cofactors, or a control group maintained on a complete and balanced food formulated for adult dogs. Following a wash-in period, the dogs were tested on a series of problems, in which reward was obtained when the animal responded selectively to the object closest to a thin wooden block, which served as a landmark. In Experiment 1, dogs were first trained to respond to a landmark placed directly on top of coaster, landmark 0 (L0). In the next phase of testing, the landmark was moved at successively greater distances (1, 4 or 10 cm) away from the reward object. Learning varied as a function of age group, food group, and task. The young dogs learned all of the tasks more quickly than the old dogs. The aged dogs on the enriched food learned L0 significantly more rapidly than aged dogs on control food. A higher proportion of dogs on the enriched food learned the task, when the distance was increased to 1cm. Experiment 2 showed that accuracy decreased with increased distance between the reward object and landmark, and this effect was greater in old animals. Experiment 3 showed stability of performance, despite using a novel landmark, and new locations, indicating that dogs learned the landmark concept. Experiment 4 found age impaired long-term retention of the landmark task. These results indicate that allocentric spatial learning is impaired in an age-dependent manner in dogs, and that age also affects performance when the distance between the landmark and target is increased. In addition, these results both support a role of oxidative damage in the development of age-associated cognitive dysfunction and indicate that short-term administration of a food enriched with supplemental antioxidants and mitochondrial cofactors can partially reverse the deleterious effects of aging on cognition.
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Verbal and nonverbal forms of developmental learning disabilities have been reported. Whereas there are several instruments for evaluating children for the presence of verbal learning disabilities at school, no screening tool is available to identify children who have nonverbal learning disabilities. This study aimed at devising and validating a short screening questionnaire that can be used by teachers in primary schools to identify those children who need to be referred for clinical services because they have a visuospatial learning disability (VSLD). An 18-item Shortened Visuospatial Questionnaire (SVS) was derived from an earlier, longer version. Its validation procedure was twofold and was achieved by (a) verifying that children who had been identified with the SVS questionnaire as having a VSLD actually showed visuospatial deficits on psychometric evaluation and by (b) rating with the SVS a clinically identified population of children with VSLD. The results of the validation procedure showed that the SVS is a quick, reliable, and valid instrument that may be helpful in identifying children with VSLD in primary school.
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Tallal hypothesized that reading disabled children have a domain-general deficit in processing rapidly occurring auditory stimuli that degrades speech perception, thereby limiting phonologic awareness and thus reading acquisition. She predicted they would be disproportionately affected by rapidly presented auditory stimuli. In this study, one hundred 7- to 11-year-old children with learning impairment (LI) and 243 non-learning impaired (NLI) children were evaluated on a two-tone auditory discrimination paradigm. LI committed more errors, but effects of timing were comparable. The same result was obtained for a subsample of good and poor readers. Task performance predicted reading, spelling, and calculation. Neural processes underlying perception of speech and other auditory stimuli may be less effective in poor readers; however, contrary to Tallal's hypothesis, rate may not be specifically affected.
The relationship of sleep to memory and learning is complex. Sleep affects memory, and memory must be present for learning to occur. A number of studies have been conducted to increase our understanding of their relationship. In addition to the numerous scientific investigations of each concept separately, sleep, memory, and learning have been studied together to determine (a) the effect of sleep on memory and learning, (b) the effect of sleep deprivation in general on memory and learning, (c) the effect of rapid eye movement (REM) sleep deprivation on memory and learning, (d) the effect of memory and learning on REM sleep, and (e) the effect of non-REM sleep loss on memory and learning. Neuroanatomic correlates have been pursued as well with most attention to the hippocampus. Despite considerable efforts to date, many of the studies reveal contradictory or inconclusive findings. Much remains unknown, and additional work is needed. Implications for nursing include those that have a direct effect on the patient, the nurse, and nursing science.