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PubMed1992

On the existence and the role of chaotic processes in the nervous system.

Chaos theory is a rapidly growing field. As a technical term, "chaos" refers to deterministic but unpredictable processes being sensitively dependent upon initial conditions. Neurobiological models and experimental results are very complicated and some research groups have tried to pursue the "neuronal chaos". Babloyantz's group has studied the fractal dimension (d) of electroencephalograms (EEG) in various physiological and pathological states. From deep sleep (d = 4) to full awakening (d > 8), a hierarchy of "strange" attractors paralles the hierarchy of states of consciousness. In epilepsy (petit mal), despite the turbulent aspect of a seizure, the attractor dimension was near to 2. In Creutzfeld-Jacob disease, the regular EEG activity corresponded to an attractor dimension less than the one measured in deep sleep. Is it healthy to be chaotic? An "active desynchronisation" could be favourable to a physiological system. Rapp's group reported variations of fractal dimension according to particular tasks. During a mental arithmetic task, this dimension increased. In another task, a P300 fractal index decreased when a target was identified. It is clear that the EEG is not representing noise. Its underlying dynamics depends on only a few degrees of freedom despite yet it is difficult to compute accurately the relevant parameters. What is the cognitive role of such a chaotic dynamics? Freeman has studied the olfactory bulb in rabbits and rats for 15 years. Multi-electrode recordings of a few mm2 showed a chaotic hierarchy from deep anaesthesia to alert state. When an animal identified a previously learned odour, the fractal dimension of the dynamics dropped off (near limit cycles).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2001

[Therapy of venous thromboembolism].

Deep venous thrombosis and lung embolism are often considered as two different variants of the same disease. This is evident not only in the same pathogenesis but also in a comparable prognosis and therapy. Therefore the term "venous thromboembolism" is used in recent literature. The main therapy of venous thromboembolism is anticoagulation and initially consists of (low molecular weight) heparin followed by a regimen with oral anticoagulants--the duration depending on the indication. Pharmacokinetic advantages of low molecular weight heparin (LMWH) allow weight-adapted dosing with daily subcutaneous injections in most patients. LMWH do not require any laboratory controls. Therefore outpatient treatment should be possible for about 75% of patients with venous thromboembolism. Outpatient treatment of lung embolism, however, is still being studied and therefore not recommended apart from clinical trials. In cases of massive venous thromboembolism additional treatment with thrombolytic agents or surgery is needed. Adequately fit compression stockings can reduce the risk of post-thrombotic syndrome after deep venous thrombosis. Patients on long-term oral anticoagulation may learn to measure their INR with a portable coagulation monitor and adjust the dosage of the anticoagulants themselves--this method is called patient self-management of oral anticoagulation.

Ambulatory Care↗

PubMed2005

Post-training stimulation of the basolateral amygdala improves spatial learning in rats with lesion of the fimbria-fornix.

PURPOSE: To evaluate the capacity of amygdala stimulation to improve neural plasticity in animals bearing lesions of the fimbria-fornix (FF) system. METHODS: The animals were lesioned under narcosis (chloral hydrate, 420 mg/kg ip.) using a bilateral transection of the FF procedure. During the same surgery some animals were implanted with an electrode in the right basolateral amygdala (BLA) to allow the electrical stimulation of this structure. Training was carried out one week after surgery using a Morris water maze. Animals were trained in four consecutive days (8 trials/day) in the non-visible platform condition except in the fourth day in which only 4 trials were performed followed by a probe trial in which the escape platform was removed. On day 5 of training 8 trials with visible platform were performed. After each of the first 3 training days one group of animals received trains of electrical stimulation to the BLA, while control groups were not stimulated. A group of non-lesioned animals served as control. The location of the electrode was confirmed histologically after the end of the experiments. RESULTS: The learning capacity of the lesioned animals was improved by the electrical stimulation of the amygdala. The latency to find the submerged platform within this group approaches that of the non lesioned animals in the course of training (2-way ANOVA with repeated measures), while other lesioned animals continued to show severely impaired learning abilities. CONCLUSIONS: This is the first evidence that stimulating the BLA can positively influence the learning abilities of lesioned animals. Further experiments should contribute to improve the stimulation paradigms to make it more effective, if possible.

Amygdala↗

PubMed2025

A Graph Contrastive Learning Method for Enhancing Genome Recovery in Complex Microbial Communities.

Accurate genome binning is essential for resolving microbial community structure and functional potential from metagenomic data. However, existing approaches-primarily reliant on tetranucleotide frequency (TNF) and abundance profiles-often perform sub-optimally in the face of complex community compositions, low-abundance taxa, and long-read sequencing datasets. To address these limitations, we present MBGCCA, a novel metagenomic binning framework that synergistically integrates graph neural networks (GNNs), contrastive learning, and information-theoretic regularization to enhance binning accuracy, robustness, and biological coherence. MBGCCA operates in two stages: (1) multimodal information integration, where TNF and abundance profiles are fused via a deep neural network trained using a multi-view contrastive loss, and (2) self-supervised graph representation learning, which leverages assembly graph topology to refine contig embeddings. The contrastive learning objective follows the InfoMax principle by maximizing mutual information across augmented views and modalities, encouraging the model to extract globally consistent and high-information representations. By aligning perturbed graph views while preserving topological structure, MBGCCA effectively captures both global genomic characteristics and local contig relationships. Comprehensive evaluations using both synthetic and real-world datasets-including wastewater and soil microbiomes-demonstrate that MBGCCA consistently outperforms state-of-the-art binning methods, particularly in challenging scenarios marked by sparse data and high community complexity. These results highlight the value of entropy-aware, topology-preserving learning for advancing metagenomic genome reconstruction.

canonical correlation analysis↗

PubMed2026

usiGrabber: automating the curation of proteomics spectra data at scale, making large datasets ready for use in machine learning systems.

MOTIVATION: An unprecedented amount of mass spectrometry-based proteomics data is publicly available through repositories such as the PRoteomics IDEntifications Database (PRIDE), and the field is increasingly leveraging machine-learning approaches. However, the available data is not ready to be reused in a scalable way beyond the original acquisition purpose. Existing machine learning models commonly rely on a few manually curated datasets that require deep domain expertise and tedious technical work to construct. Importantly, these datasets have not been updated in recent years, so that newly published data remains inaccessible. We present usiGrabber, a scalable framework for assembling large proteomic datasets. usiGrabber is designed around portability and extensibility. It extracts spectra identification data from mzIdentML files, stores additional project-level metadata retrieved through the PRIDE API, indexes raw spectra using Universal Spectrum Identifiers (USIs), and offers download utilities to retrieve spectra data at scale. RESULTS: Within 49 h, we parsed over 800 million peptide spectrum matches and corresponding USIs from over 1200 projects. As a proof of concept, we used usiGrabber to construct a phosphorylation-specific training dataset of nearly 11 million spectra in under 2 days and used it to retrain a binary phosphorylation classifier based on the AHLF model architecture. With a balanced accuracy of 0.78, our model achieves comparable performance to the original model on an independent test set, showing that automated data extraction is an alternative to manual curation of static datasets. AVAILABILITY AND IMPLEMENTATION: All code is available at https://github.com/usiGrabber/usiGrabber; the data are available at https://zenodo.org/records/18853258.

Machine Learning↗

PubMed1997

[Carving].

Using skis with a deep sidecut (as carving skis have it) it's not necessary to learn a new techniques. Different carving skis are developed for all target groups. They simplify the steering of turns on the ski-edge, but the skier needs some more muscle-effort as with usual skis. Lately physical researches proved that there's no higher risk of false cutting with carving skis than with common, normal sidecut skis. Mainly the condition of the ski-edge and the height of the skier's position over the ski do cause false cutting.

Acceleration↗

PubMed2006

Too much teaching, not enough learning: what is the solution?

The curriculum is packed with so much content that teachers resort to telling students what they know and students simply commit facts to memory. The packed curriculum leaves little time for students to acquire a deep understanding of the subject or to develop life-long skills such as critical thinking, problem solving, and communication. However, learning is not committing a set of facts to memory, but the ability to use resources to find, evaluate, and apply information. This paper addresses these concerns by discussing "how we learn" and reviewing the literature on what works to improve learning. It is clear that active processing of information, not passive reception of information, leads to learning. That is, students must construct their own understanding of concepts, relationships, and procedures. Teachers can encourage this process by carefully considering the type and organization of information as well as instructional strategies. Specifically, teachers should reduce the total amount of factual information students are expected to memorize, reduce our use of the passive lecture format, and devote much more effort to helping students become active, independent learners and problem solvers. Collaborative learning activities, interactive models, educational games, and establishing a culture of inquiry/scholarship are critical for achieving these goals.

Comprehension↗

PubMed1992

Irish brogue after stroke.

BACKGROUND: We describe a patient who presented a unique variation of the previously described acquired foreign accent syndrome. CASE DESCRIPTION: A 65-year-old women developed an Irish brogue immediately after a deep left hemisphere stroke. The newly accented speech possibly represented a previously learned speech pattern. CONCLUSIONS: Suppressed prosodic speech patterns may reemerge in the setting of brain injury.

Aged↗

PubMed1975

Multiple nervoid basal cell epithelioma, cysts of the jaw, and bifid rib syndrome: report of case.

A case of mutiple nevoid basal cell epithelium, cysts of the jaw, and bifid rib syndrome has been reported because of the large number of positive findings in a single patient. Symptoms were a simple manner with slow learning ability, frontal bossing, wide nasal root, hypertelorism, large superciliary ridge, deep-set eyes, bifid uvula, dentigerous keratocyst of the mandible, pectus excavatum, bilateral shortened metacarpals, multiple basal cell nevi, bilateral palmar pitting, hemivertebrae C2-3 and C7-T1, several bifid ribs, calcification of the falx cerebri, bridging of the sella turcica, and an open frontal suture. The need for establishing diagnosis has been emphasized.

Abnormalities, Multiple↗

PubMed1990

[Neurophysiological studies on group A xeroderma pigmentosum in early childhood].

Neurophysiological studies were performed on 8 patients with group A xeroderma pigmentosum during early childhood. EEG, ABR and NCV were normal during this period. In contrast, various sleep parameters detected by polysomnography showed abnormal findings even in the neurologically normal patient. Decreased % sleep REM was seen in a case, and decreased frequency of REMs were seen in another. Body movements were extremely high or low in frequency in 3 cases in whole night sleep. The distribution of body movements were abnormal; in control subjects, the frequency was higher in SREM and stage 1 than in slow wave sleep; in 7 cases, it was higher in slow wave sleep than in stage 1 or 2, or body movements were extremely frequent. Neurological examination revealed soft signs in various systems in early childhood. All cases except one showed hypotonia. Many cases were slow in learning to walk and the gait was unstable. Speech delay and decreased deep tendon reflexes, especially of patella, were seen in most cases. Since the neural deficits in XP may be related to the DNA repair defect, these findings indicate the possibility that some endogenous compounds distributing all over the nervous system might produce the DNA damages. Because the body movements during sleep are controlled by the nigrostriatal dopaminergic system, present data indicate that the basal ganglia might be one of the earliest degenerative systems in the CNS. Recently, some studies have suggested the possibility that oxygen radical mechanisms might be involved in the development of the dopamine neurodegenerative process in Parkinson's disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

PubMedDate not supplied

Acquisition of a new-latency conditioned nictitating membrane response--major, but not complete, dependence on the ipsilateral cerebellum.

Classical conditioning of the nictitating membrane response (NMR) of rabbits is simple associative learning of a motor response. In several two-stage experiments, reversible inactivations of the deep cerebellar nuclei in stage 1 appeared to prevent acquisition of NMR conditioning in naive rabbits--no conditioned responses (CRs) were evident after inactivations were lifted in stage 2. Results of a three-stage experiment were different. When subjects were first trained with a light conditional stimulus (CS) in stage 1, reversible cerebellar inactivations during conditioning to a different, tone CS during stage 2 did not appear to prevent new learning because CRs to the tone CS were evident when the inactivation was lifted. Results from the two-stage experiments support the suggestion that the cerebellum is essential for the acquisition of NMR conditioning, but results from the three-stage experiment do not. Here, we use a three-stage design with different interstimulus intervals (ISIs) in stages 1 and 2. Because CRs develop with latencies-to-peak dependent on the ISI, learning during stage 1 can be dissociated from that accruing in stage 2. Complete inactivation of the ipsilateral cerebellar nuclei with muscimol substantially but not completely prevented learning with the second ISI during stage 2 because small CR peaks around the stage 2 ISI could be detected in some subjects after the inactivation had been lifted in stage 3. We suggest that the weak levels of conditioning possible during unilateral inactivation depend on the contralateral cerebellum or on extracerebellar circuitry and that these may be capable of supporting transfer of conditioning in a previous three-stage experiment. But, we confirm that normal NMR conditioning is critically dependent on the ipsilateral cerebellum.

Animals↗

PubMed1999

Cognitive outcome following staged bilateral pallidal stimulation for the treatment of Parkinson's disease.

As neurosurgical treatment of parkinsonian symptoms has become increasingly popular, concern about the cognitive morbidity which may result from such interventions has risen proportionately. Previous reports of cognitive difficulties associated with pallidotomy and thalamotomy, especially in bilateral cases, have provided the impetus for research into chronic electrical deep brain stimulation procedures which are believed to be safer than ablation. Given the lack of neurobehavioral research following bilateral deep brain stimulation procedures, this preliminary study of six Parkinson's disease patients undergoing staged bilateral pallidal stimulation was undertaken. A battery of tests assessing attention, executive function, visuomotor coordination, language, visuoperceptual function, learning memory and mood revealed no significant change in overall level of cognitive functioning after either unilateral or bilateral pallidal deep brain stimulation. No significant declines were observed about three months following bilateral stimulation, and in fact, significant gains in delayed recall and relief of anxiety symptoms were noted. It was concluded from this preliminary data that bilateral pallidal stimulation for the treatment of Parkinson's disease, at least in the absence of operative complications, offers a cognitively safe alternative to ablation.

Cognition↗

PubMed2000

Motor control problems in patients with spinal pain: a new direction for therapeutic exercise.

Recent research into muscle dysfunction in patients with low back pain has led to discoveries of impairments in deep muscles of the trunk and back. These muscles have a functional role in enhancing spinal segmental support and control. The muscle impairments are not those of strength but rather problems in motor control. These findings call for a different approach in therapeutic exercise, namely a motor learning exercise protocol. The specific exercise approach has an initial focus on retraining the cocontraction of the deep muscles (ie, the transversus abdominis and lumbar multi-fidus Initial clinical trials point to the effectiveness of the approach in patients with both acute and chronic low back pain in terms of reducing the neuromuscular impairment and in control of pain.

Exercise Therapy↗

PubMed1999

Review and Process Effects of Spontaneous Note-Taking on Text Comprehension.

This study examines how quantitative and qualitative differences in spontaneously taken notes are related to text comprehension in combination with reviewing or not reviewing previously made notes. High school graduates (N = 226) were allowed to take notes in any way they desired while reading a philosophical text. Approximately half the participants were told that they could review their notes during writing tasks designed to measure the ability to define, compare, and evaluate text content. The other half of the participants answered the subsequent questions without their notes. The process of taking notes was rated on the basis of note quality and quantity. The results revealed significant review and process effects in spontaneous note-taking. Reviewing the notes during essay-writing generally resulted in good performance in an exam calling for deep-level text comprehension. However, this review effect was mainly limited to detailed learning instead of making one's own inferences. Results pertaining to note quality indicated that the participants who summarized the content of the text resulted in better performance in all tasks in comparison with those who produced notes following the text order or verbatim notes. The amount of note-taking was also positively related to text comprehension. The discussion focuses upon the situational appropriateness of note-taking effects that pose challenges to educators. Copyright 1999 Academic Press.

Journal Article↗

PubMed1983

Bilingualism and brain functional asymmetry.

The task of the neural organization of the native language, acquired by a direct method and of another language, studied at school, performed correspondingly by the left and the right hemispheres, was studied in the bilingual patient after unilateral electroconvulsive therapy used in psychiatry. It was established that in such a bilingual type the right hemisphere is concerned with the formation of deep semantic structures of the native language while the left hemisphere is responsible for the formation of second language deep structures and of surface structures of both languages. The effect of language learning method on cerebral organization of bilingualism is postulated.

Adult↗

PubMedDate not supplied

Unsupervised Spike Sorting of extracellular electrophysiological recording in subthalamic nucleus of Parkinsonian patients.

The present study demonstrates the application of the Unsupervised Spike Sorting algorithm (USS) to separation of multi-unit recordings and investigation of neuronal activity patterns in the subthalamic nucleus (STN). This nucleus is the main target for deep brain stimulation (DBS) in Parkinsonian patients. The USS comprises a fast unsupervised learning procedure and allows sorting of multiple single units, if any, out of a bioelectric signal. The algorithm was tested on a simulated signal with different levels of noise and with application of Time and Spatial Adaptation (TSA) algorithm for denoising. The results of the test showed a good quality of spike separation and allow its application to investigation of neuronal activity patterns in a medical application. One hundred twenty-four single channel multi-unit records from STN of 6 Parkinsonian patients were separated with USS into 492 single unit trains. Auto- and crosscorrellograms for each unit were analyzed in order to reveal oscillatory, bursting and synchronized activity patterns. We analyzed separately two brain hemispheres. For each hemisphere the percentage of units of each activity pattern were calculated. The results were compared for the first and the second operated hemispheres of each patient and in total.

Action Potentials↗

PubMedDate not supplied

Some usual and unusual poisonings due to carbon monoxide.

Carbon monoxide poisoning is a frequent occurrence in both developed and under developed countries of the world. Carbon monoxide can be produced in fires, automobile engine exhausts and the incomplete combustion of organic matter. It is a "silent killer" that initially produces a mild progressive frontal headache, drowsiness and sleep that is usually ignored as common place. Continued low-level CO exposure for a long period of time in a confined space is cumulative and these accidental deaths are frequent but should be avoidable. Several usual and unusual poisonings are reported to illustrate its various forms of exposure. It all began many years ago when a bolt of lightening hit a fallen tree and produced a fire. Early cave man later learned to enjoy some of the benefits of this new discovery. They could now see at night, they could keep warm, keep the predators at bay, cook their food and make it taste better and be more gentle to their teeth. Also meat could be preserved and eaten at a later date especially if it were dried and smoked. They learned by trial and error that it was dangerous to bring their fire deep into their cave without a chimney. Carbon monoxide (CO) also can be easily produced by many other sources besides fire. Very common today is the incomplete combustion of gasoline in the engine of an automobile which can produce about 6% carbon monoxide.

Accidents↗

PubMed2004

Approaches to learning and studying in medical students: validation of a revised inventory and its relation to student characteristics and performance.

INTRODUCTION: Inventories to quantify approaches to studying try to determine how students approach academic tasks. Medical curricula usually aim to promote a deep approach to studying, which is associated with academic success and which may predict desirable traits postqualification. AIMS: This study aimed to validate a revised Approaches to Learning and Studying Inventory (ALSI) in medical students and to explore its relation to student characteristics and performance. METHODS: Confirmatory factor analysis was used to validate the reported constructs in a sample of 128 Year 1 medical students. Models were developed to investigate the effect of age, graduate status and gender, and the relationships between approaches to studying and assessment outcomes. RESULTS: The ALSI performed as anticipated in this population, thus validating its use in our sample, but a 4-factor solution had a better fit than the reported 5-factor one. Medical students scored highly on deep approach compared with other students in higher education. Graduate status and gender had significant effects on approach to studying and a deep approach was associated with higher academic scores. CONCLUSIONS: The ALSI is valid for use in medical students and can uncover interesting relationships between approaches to studying and student characteristics. In addition, the ALSI has potential as a tool to predict student success, both academically and beyond qualification.

Age Factors↗