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PubMedDate not supplied

A survey approach for finding cases of epilepsy.

Identify persons with epilepsy by first looking for prescriptions for particular antiseizure drugs. Follow these prescriptions from the pharmacies to the physicians who wrote them for patients. Ask the physicians whether the patients have epilepsy. Finally, contact the patients who do have epilepsy to elicit information about the impact of that condition on their lives. With these steps, it may be possible to carry out successfully a probability survey of epilepsy in the United States population. To learn more about this approach, a field test was funded by the National Institute of Neurological and Communicative Disorders and Stroke (NINCDS) of the Public Health Service. From 1978 through 1982, the work was planned, carried out, and evaluated by Research Triangle Institute, Research Triangle Park, NC. Epilepsy is a sensitive topic to ask about in a survey. Also, the condition is sufficiently rare to render ordinary survey approaches inefficient. Even if rarity were not an issue, there would be the problem of response error because a person with epilepsy does not, as a rule, have much clinical information on his or her condition. Better information lies with the physician who provides the care, but many physicians are busy with their practices. Furthermore, their record systems are usually not designed for easy retrieval of information, unless the names of patients are available. In the survey approach considered here, the names of patients are obtained through a random sampling of prescriptions for antiseizure drugs. The field test was divided into three phases with special activities reserved for each. The most important problem confronted was how to safeguard the confidentiality of relationships between pharmacist and patient and between physician and patient.Special guidelines on confidentiality were put into effect for the data collection. These guidelines,however, contributed to serious problems of nonresponse-especially for physicians. This article provides a brief account of the field test, including a rationale for the survey strategy of finding cases of epilepsy through prescriptions for antiseizuredrugs.

Anticonvulsants↗
PubMed1996

Family physicians and smoking cessation. Survey of practices, opinions, and barriers.

OBJECTIVES: To assess what family physicians need to promote smoking cessation by looking at current knowledge, attitudes, and behaviours and to examine the barriers facing physicians in implementing an effective antismoking strategy. DESIGN: Cross-sectional study involving face-to-face interviews and mailed questionnaires. SETTING: Family practices in Kingston, Ont, and surrounding areas. PARTICIPANTS: All family physicians (n = 155) in the City of Kingston and the counties of Frontenac, Lennox, and Addington. MAIN OUTCOME MEASURES: Knowledge, attitudes, beliefs, and practices concerning smoking cessation; barriers and practices recommended in the literature. RESULTS: Response rate was 77%. Many physicians know about smoking cessation, and many actively counsel their patients to quit. Brief advice, nicotine replacement therapy, self-help materials, and follow-up appointments are the most common methods. Although many report that they are already knowledgeable, many are willing to learn more. Many physicians have unrealistically high estimates of the probability of success, and many find poor compliance among patients to be the greatest barrier. CONCLUSIONS: Family physicians in this are recognize the need to help their patients to quit and are identifying and counseling smokers in their practices. The main educational need could be to appreciate smoking as an addictive behaviour.

Cross-Sectional Studies↗
PubMed1998

[How does professional competence develop?].

The reality of medical practice demands not only proficiency but also educational provisions, an aspect which traditionally has been given little attention in medicine. The competence of a general practitioner does not consist solely of professional knowledge and practical skills; it consists to a large extent of personal (intuition and creativity based on personal experience) and communicative elements, both of which are necessary in managing the unpredictable complexity and the many controversies of general practice. Such competence is difficult to develop outside the practice. By sharing the experience of actual consultations with experienced colleagues, and reflecting upon this experience within a small group, general practitioners will probably develop better professional judgement and increased awareness of their learning needs, as well as of their limitations and potential. This article discusses these topics using the authors' personal experiences in the continuous medical education effort which is based on reciprocal practice visits among a small group of experienced general practitioners.

Clinical Competence↗
PubMed1995

Properties of evolutionarily stable learning rules.

Suppose a strategy for learning the optimal behavior in repeatedly played games is genetically determined. Then the animal is engaged in a learning game as well as the repeatedly played game. Harley (1981, J. theor. Biol. 89, 611-633) considers evolutionarily stable strategies in such learning games, called evolutionarily stable (ES) learning rules. Harley's work, though significant, is limited in that he does not establish the stochastic convergence of ES learning rules. Furthermore, his study of the relative payoff sum (RPS) approximation is limited to simulation experiments. Here, the stochastic convergence of ES learning rules and the RPS approximation is established. The ES learning rules and the RPS approximation were found to converge to the same quality, the so-called matching ratio, with probability one.

Animals↗
PubMed1999

Superordinate category formation in pigeons: association with a common delay or probability of food reinforcement makes perceptually dissimilar stimuli functionally equivalent.

Training associated pairs of perceptually dissimilar stimulus classes with a common delay or probability of food reinforcement in pigeons. Then, different choice responses were trained to 1 component class in each pair. In a choice test, the untrained class in each pair occasioned the same response as did the choice-trained class. In a 3rd experiment, 2 classes had reinforcement delays of 1 s and 15 s, respectively, and 2 other classes had reinforcement probabilities of 0.1 and 0.9. Then, 1 choice response was reinforced to a class previously associated with a better condition of reinforcement (e.g., 1-s delay or 1.0 probability), and a different response was reinforced to a class previously associated with a worse condition of reinforcement (0.1 probability or 0-s delay). Testing with all classes suggested that categorization was based on the relative reinforcement or hedonic value and not on the parametric details of reinforcement.

Animals↗
PubMedDate not supplied

The learning department, Part two.

Whether you want to move deliberately toward becoming a learning department or not, the kind of organization that is described here is probably appealing and a little frightening. The staff is more self-reliant, there is a higher level of motivation, communication is more open, there is a dedication to continuous improvement, and there is more intentional, "smart" risk-taking. At the beginning of our last column ("The Learning Department, Part One"), we listed the five trends that we believe will shape the clinical laboratory of the future: 1. increased automation and the attendant reduction and shift in the technical skills required 2. chronic shortages of qualified staff 3. changes in the legislation that affects credentialing and regulation 4. expanded uses of molecular diagnostics 5. emergence of the lab as a major contributor to the hospital's bottom line. It is hard to imagine surviving these turbulent trends without instilling many of the characteristics of a learning department in your organization. What are the most important steps to take? Open communications, schedule debriefs to learn from your experiences, and stay curious!

Career Mobility↗
PubMed2006

Heightened false memory: a long-term sequela of severe closed head injury.

Declarative memory impairment is a common long-term sequela of severe closed head injury (CHI). Although veridical memory performance following severe CHI has received attention in the literature, little is known about false memory production in this population. Within the present study, both long-term survivors of severe CHI and matched control participants studied and were tested on six 12-items word lists from the Deese Roediger McDermott (DRM) paradigm. Word lists from the DRM are composed of words that are strongly semantically associated to a non-presented word (i.e., the critical lure). Prior studies have shown that healthy young adults show a high level of false recall and recognition memory for the critical lures, and it was hypothesized individuals with severe CHI would show heightened susceptibility to false memory compared to control participants due to difficulty with monitoring of memory. It was further hypothesized that severe CHI participants would show high confidence in their false memories. Consistent with hypotheses, results indicated that although severe CHI participants remembered fewer actual list items, they made more semantically related intrusion errors (recall) and false-positive responses (recognition) than the control participants. Severe CHI participants also showed greater confidence in their false memories than did control participants. The results are interpreted in the context of theoretical accounts of false memory, and possible structural and functional brain changes that might account for the Severe CHI group's memory performance are discussed.

Adolescent↗
PubMed1980

Damages to cortical associative areas: effects on visual discrimination learning in cats.

Participation of the parietal and frontal cortical areas in pattern discrimination learning was studied in cats. Extirpation of the parietal cortex (fields 5 or 7) produced a deficit of visual discrimination of simultaneously presented patterns, but the animals were able to relearn the task. Postoperative learning of simultaneous discrimination was abolished, although successive discrimination of the same stimuli was still possible. The parietal associative areas probably participate in the organization of spatially and visually controlled movements. The frontal lobe ablation eliminated pattern but not brightness discrimination learning. The lesion of the frontal lobe is apparently connected with the occulomotor mechanism of pattern discrimination.

Animals↗
PubMed2000

On-line learning in RBF neural networks: a stochastic approach.

The on-line learning of Radial Basis Function neural networks (RBFNs) is analyzed. Our approach makes use of a master equation that describes the dynamics of the weight space probability density. An approximate solution of the master equation is obtained in the limit of a small learning rate. In this limit, the on line learning dynamics is analyzed and it is shown that, since fluctuations are small, dynamics can be well described in terms of evolution of the mean. This allows us to analyze the learning process of RBFNs in which the number of hidden nodes K is larger than the typically small number of input nodes N. The work represents a complementary analysis of on-line RBFNs, with respect to the previous works (Phys. Rev. E 56 (1997a) 907; Neur. Comput. 9 (1997) 1601), in which RBFNs with N >> K have been analyzed. The generalization error equation and the equations of motion of the weights are derived for generic RBF architectures, and numerically integrated in specific cases. Analytical results are then confirmed by numerical simulations. Unlike the case of large N > K we find that the dynamics in the case N < K is not affected by the problems of symmetric phases and subsequent symmetry breaking.

Algorithms↗
PubMed2006

[Effect of yizhi jiannao granule on the behavior and neuron apoptosis in SAMP/8 mice].

OBJECTIVE: To investigate the effect of yizhi jiannao granule concentration fluid (YCF) on the behavior, the apoptosis rate of hippocampus neuron and the expression of apoptosis gene Bcl-2, Bax in senescence accelerated mice Senile-Prone/8 (SAMP/8), and to discuss some mechanism of traditional chinese medicine YCF in improving the capability of learning and memory. METHODS: Forty 6-month old SAMP/8 mice were randomly divided into the old group, huperzine A (Hup-A) group and YCF group. Ten 4-month old SAMP/8 mice were served as a young control group. Four groups were given different drugs for 8 weeks, their behavior changes were observed, and the hippocampus were taken out to examine the apotosis rate by flow cytomeutry (FCM) and the expression of Bcl-2, Bax mRNA by RT-PCR. RESULTS: In the YCF group, the escape latency was significantly shortened, the time of swim in the platform quadrant significantly increased, the apoptosis rate of hippocampus neural decreased; the level of Bcl-2 mRNA and the rate of Bcl-2/Bax increased, and the level of Bax mRNA decreased. CONCLUSION: Yizhi jiannao granule can decrease the neuron apoptosis rate and the Bax level, increase the Bcl-2 level, and modulate the rate of Bcl-2/Bax in SAMP/8 brain, which is probably part of the mechanisms of inhibiting the apoptosis and improving learning and memory.

Aging↗
PubMed2003

Rat models of dementia based on reductions in regional glucose metabolism, cerebral blood flow and cytochrome oxidase activity.

Three models are described in rats which attempt to mimic morphological and behavioural pathology of Alzheimer's dementia; intracerebroventricular injection of streptozotocin (STZ), permanent bilateral carotid artery occlusion (2VO) and brain mitochondrial cytochrome oxidase inhibition by sodium azide. Learning and memory are impaired within 4 weeks in all models. This probably involves a reduction in cortical and/or hippocampal cholinergic neurotransmission. STZ causes microglial activation and specific damage to myelinated tracts in the fornix through generation of oxidative stress, thereby disrupting connections between the septum and hippocampus. 2VO results in damage to myelin and CA1 cells in hippocampus and in abnormal processing of APP to beta-amyloid. It is not known if microglial activation and neuronal damage occur after sodium azide administration. Memory and learning can be improved in the STZ and 2VO models by estradiol, melatonin and cholinesterase inhibitors. Antioxidants and neuroprotective agents may also decrease memory deficits by preventing inflammation and neurodegeneration.

Animals↗
PubMed1976

Tay-Sachs screening: motives for participating and knowledge of genetics and probability.

A highly-educated, socially aware group of persons presented themselves for Tay-Sachs screening having learned about it mainly from friends, newspapers, radio, and television but not from physicians or rabbis. After learning that screening was possible and deciding that it is in principle a good idea, and after discussing it with relatives and friends but not with physicians and rabbis, they presented themselves for the test. Although the participants knew that Tay-Sachs is a serious disease and that Jews are vulnerable, few of them knew much about the genetics of the disease, its frequency, or the incidence of the carrier state. This experience of screening for Tay-Sachs carriers suggests the need for physicians to learn the relation of genetics to preventive medicine, and for the public to learn more about the biology of man.

Adult↗
PubMed1985

An infrared system for the detection of a pigeon's pecks at alphanumeric characters on a TV screen: the dependency of letter detection on the predictability of one letter by another.

Three pigeons pecked at letters of the alphabet and at the symbol "?" displayed on a computer-driven cathode ray screen. A 4 by 4 matrix of infrared emitting and detecting diodes and associated circuitry identified the location of a pigeon's responses to the screen. Responses at the target letter T were probabilistically reinforced with food whenever T appeared in a string of three letters in the middle of the screen. Responses at the symbol "?" appearing below this string were probabilistically reinforced whenever T did not appear. The letter F anywhere in the three-character string either strongly predicted the occurrence of the target letter T, in two conditions, or predicted its nonoccurrence, in a third. This manipulation of the frequency with which the familiar letter F predicted T was shown to change the function relating probability of a correct peck at the symbol "?" to the number of Fs in the string. This effect may be interpreted as an instance of the phenomenon where an organism's acquired knowledge changes what it sees.

Animals↗
PubMed2026

Discovery and validation of a multi-protein panel for predicting non-fatal major adverse cardiovascular events in diabetic kidney disease.

OBJECTIVE: To identify plasma protein biomarkers associated with incident non-fatal major adverse cardiovascular events (MACE) in diabetic kidney disease (DKD) patients. RESEARCH DESIGN AND METHODS: We analyzed 317 DKD patients from the UK Biobank. Plasma proteomics and clinical data (demographics, metabolism, renal function) were integrated. In an exploratory discovery phase, three sequential Cox regression models (crude, socio-demographic-adjusted, socio-demographic-metabolic adjusted) screened non-fatal MACE-associated proteins. To prevent information leakage, the cohort was then randomly split into training (70%) and testing (30%) sets; machine-learning feature selection, hyperparameter optimization, and final model development were performed exclusively within the training set. The associated proteins were input into the four-step machine-learning pipeline (LASSO-Cox, random survival forest, Boruta, XGBoost-Cox). Predictive performance was validated using Kaplan-Meier survival analyses, longitudinal trajectory modeling, and ROC benchmarking. An interactive web application was deployed for clinical implementation. RESULTS: Of 1,463 plasma proteins, 561 were associated with non-fatal MACE across Cox models, with 14 overlapping proteins. Nine core proteins (ANG, IL1R1, CXCL14, ESAM, PTGDS, HAVCR1, FGFR2, IGSF8, CCL3) were validated: ANG showed the strongest non-fatal MACE association (HR&#xa0;=&#xa0;3.88, 95%CI 2.33-6.48, p<0.001), and all high-expression groups had elevated non-fatal MACE risk. GO/KEGG enrichment highlighted inflammatory-immune pathways like positive regulation of MAPK cascade, Cytokine-cytokine receptor interaction and PI3K-Akt signaling pathway as key mechanisms. The model integrating proteins, demographic factors, and clinical variables achieved the highest predictive performance across non-fatal MACE (AUC&#xa0;=&#xa0;0.768), myocardial infarction (MI) (0.808), and stroke (0.816) outcomes, with superior stability in cross-validation. CoxBoost + Elastic Net framework was selected as the optimal framework via benchmarking of 101 algorithms. The model demonstrated favorable calibration in high-risk patients and yielded positive net clinical benefit across decision thresholds of 5% to 45%. The web tool (https://jiangli2941.github.io/MACE-prediction-v2/) enables input of 28 variables, outputs non-fatal MACE risk status, risk probability, and highlights abnormal indicators. CONCLUSION: Plasma proteomics combined with machine learning identifies robust non-fatal MACE predictors in DKD.

Humans↗
PubMed2002

Learning to recognize three-dimensional objects.

A learning account for the problem of object recognition is developed within the probably approximately correct (PAC) model of learnability. The key assumption underlying this work is that objects can be recognized (or discriminated) using simple representations in terms of syntactically simple relations over the raw image. Although the potential number of these simple relations could be huge, only a few of them are actually present in each observed image, and a fairly small number of those observed are relevant to discriminating an object. We show that these properties can be exploited to yield an efficient learning approach in terms of sample and computational complexity within the PAC model. No assumptions are needed on the distribution of the observed objects, and the learning performance is quantified relative to its experience. Most important, the success of learning an object representation is naturally tied to the ability to represent it as a function of some intermediate representations extracted from the image. We evaluate this approach in a large-scale experimental study in which the SNoW learning architecture is used to learn representations for the 100 objects in the Columbia Object Image Library. Experimental results exhibit good generalization and robustness properties of the SNoW-based method relative to other approaches. SNoW's recognition rate degrades more gracefully when the training data contains fewer views, and it shows similar behavior in some preliminary experiments with partially occluded objects.

Artificial Intelligence↗
PubMed1979

Residual sensory capacities of the deaf: a signal detection analysis of a visual discrimination task.

This experiment compared the visual sensory sensitivity of deaf and hearing subjects in a signal detection paradigm. Subjects (ns = 6) were required to give forced-choice responses to a brightness discrimination task under three stimulus probability conditions (0.25, 0.50, and 0.75). A total of 1,800 trials were given to each subject and utilized to construct isosensitivity functions and d' and Beta, indices for sensory sensitivity and response bias, respectively. The results showed that no enhanced sensory sensitivity is present for these deaf children and questions the classical sensory compensation hypothesis. Furthermore, the deaf subjects responded in a relatively bias-free manner to variations in stimulus probability.

Attention↗
PubMed1964

TIME FACTORS IN INTERHEMISPHERIC TRANSFER OF LEARNING.

Single-trial interhemispheric transfer of a discrimination task engram was studied by eliciting spreading depression unilaterally during acquisition of the discrimination. Complete transfer to the untrained side occurred after one trial with both hemispheres functional, if 10 minutes elapsed between this trial and the elicitation of spreading depression in the trained side. If depression was elicited 15 seconds after the trial no transfer occurred. correct response highly probable.

Brain↗