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PubMed2004

Motivating learning, performance, and persistence: the synergistic effects of intrinsic goal contents and autonomy-supportive contexts.

Three field experiments with high school and college students tested the self-determination theory hypotheses that intrinsic (vs. extrinsic) goals and autonomy-supportive (vs. controlling) learning climates would improve students' learning, performance, and persistence. The learning of text material or physical exercises was framed in terms of intrinsic (community, personal growth, health) versus extrinsic (money, image) goals, which were presented in an autonomy-supportive versus controlling manner. Analyses of variance confirmed that both experimentally manipulated variables yielded main effects on depth of processing, test performance, and persistence (all ps <.001), and an interaction resulted in synergistically high deep processing and test performance (but not persistence) when both intrinsic goals and autonomy support were present. Effects were significantly mediated by autonomous motivation.

Adolescent↗

PubMedDate not supplied

Lower extremity venous imaging for the echocardiologist.

Cardiologists who are familiar with the techniques and the performance of echocardiography can easily learn how to study the lower extremity veins in their patients by using ultrasound imaging combined with pulsed-wave Doppler echocardiography (duplex scanning). In particular, duplex scanning is useful for diagnosing deep or superficial venous thrombosis, for assessing venous incompetence, and for mapping the superficial veins before surgical harvesting for bypass operations. Because questions about the veins arise frequently in the treatment of cardiovascular patients, the cardiologist who is knowledgeable about veins and venous disease can play a central role in the diagnostic workup and treatment of these patients.

Echocardiography, Doppler↗

PubMed1995

A review for pediatricians on limb lengthening and the Ilizarov method.

As recently as 1986, limb lengthening in children was considered by most North American orthopedic surgeons to be both dangerous and impractical. Previous attempts were plagued by unacceptably high rates of serious complications such as nerve palsy, deep infection, malunion, broken hardware, and stiff joints. With the recent introduction of the Russian Ilizarov method and apparatus for limb lengthening, a tremendous groundswell of interest has risen. Despite a steep learning curve, many Western centers have now reproduced Ilizarov's clinical results. The important advances over prior methods are partly biologic and partly hardware related. Ilizarov's principles require a minimally invasive, low-energy osteotomy, stable external fixation, a latency period before commencing distraction, and gradual lengthening of 1 mm/d in divided doses (0.25 mm four times per day). The article reviews the background of this new technique and provides an update on results reported over the past year. There is disagreement regarding precise indications for limb salvage (lengthening) of congenital limb deficiencies versus amputation. The role of extended lengthening in dwarfism also remains controversial.

Bone Lengthening↗

PubMed2006

Essentializing differences between women and men.

People represent many social categories, including gender categories, in essentialist terms: They see category members as sharing deep, nonobvious properties that make them the kinds of things they are. The present research explored the consequences of this mode of representation for social inferences. In two sets of studies, participants learned (a) that they were similar to a member of the other gender on a novel attribute, (b) that they were different from a member of the other gender on a novel attribute, or (c) just their own standing on a novel attribute. Results showed that participants made stronger inductive inferences about the attribute in question when they learned that it distinguished them from a member of the other gender than in the other conditions. We consider the implications of these results for the representation of social categories and for everyday social inference processes.

Adult↗

PubMed1993

In search of engrams.

The body of literature presented in this paper indicate, as Marr and Albus hypothesized, that the cerebellum is involved in the regulation of classical conditioning. At present, the most parsimonious hypothesis is that the essential memory traces for classical conditioning of eyelid closure, limb flexion, and other discrete responses learned with an aversive US are formed in cerebellar cortex and interpositus nucleus. Both sites contain neuronal elements which encode both conditioned and unconditioned stimuli. Recordings from both cerebellar cortex and the deep nuclei model the topography of the conditioned response and precede the response in time. Lesions of the cortex massively impair conditioning and lesions of the interpositus nucleus completely and permanently abolish the conditioned response without affecting reflex performance.

Animals↗

PubMed1993

Cartwheel and superficial stellate cells of the dorsal cochlear nucleus of mice: intracellular recordings in slices.

1. Intracellular recordings were made from identified cartwheel and stellate cells in the molecular and fusiform cell layers of the murine dorsal cochlear nucleus (DCN). The aim of the study was to identify and characterize their synaptic inputs and to learn how synaptic inputs and intrinsic electrical properties interact to generate firing patterns. 2. Eight cells labeled by the intracellular injection of biocytin were cartwheel cells. Their axon terminals extended from the deep part of the molecular layer through the fusiform cell layer. Their dendrites extended through the molecular layer and had spines. Both the dendritic and axonal arbors were small, having diameters of approximately 150 microns in the parasagittal plane. 3. When depolarized, cartwheel cells often fired bursts of rapid action potentials superimposed on a slow depolarization. The peaks of action potentials were usually overshooting. Individually occurring action potentials were followed by two afterhyperpolarizations, as in other cells of the DCN. During bursts, action potentials did not have two distinct repolarizing phases. 4. Excitatory postsynaptic potentials (EPSPs) were recorded from cartwheel cells spontaneously and after shocks to the nerve root or to the ventral cochlear nucleus (VCN). The EPSPs rose slowly. When they were suprathreshold they evoked action potentials singly or in bursts. EPSPs evoked by shocks to the nerve root or to the VCN had long latencies, the rise of EPSPs beginning between 5 and 10 ms after the shock. No inhibitory synaptic potentials, either spontaneous or driven with electrical stimulation, were detected in cells whose resting potentials were between -50 and -70 mV. 5. The locations from which excitatory input can be driven electrically are consistent with cartwheel cells receiving excitatory synaptic input from granule cells. 6. One labeled cell was a superficial stellate cell. It had smooth, straight dendrites that radiated parallel to the layers of the DCN; its axonal arbor was also planar and was restricted to the molecular layer. Both the dendritic and axonal arbors of this stellate cell were large, > 500 microns diam in the parasagittal plane. 7. The superficial stellate cell fired trains of action potentials at regular intervals that, like other cells of the DCN, were overshooting and were followed by double undershoots. 8. Shocks to the nerve root and to the surface of the VCN evoked EPSPs after 3.5 and 2 ms, respectively, in the superficial stellate cell. Chemical stimulation of the VCN also evoked excitation. No inhibitory synaptic input, spontaneous or driven, was detected.

Animals↗

PubMed2002

Using "concept sorting" to study learning processes and outcomes.

PURPOSE: First, to evaluate "concept sorting" as a tool for assessing knowledge organization in the memories of first-year medical students, and second, to study the relationship between knowledge organization and examination performance. METHOD: During 2001, first-year medical students taking the Renal Course at the University of Calgary Faculty of Medicine were given a questionnaire on scheme use and were given a concept-sorting task in the domain of metabolic alkalosis. The sophistication of their concept sorting was graded using the number of physiology-based groups they formed. Review of the course's examination scores allowed correlation with concept-sorting scores. Statistical analyses used Fisher's exact test and the two-sample t-test. Pearson's correlation coefficient and the kappa statistic were used for correlation between raters. RESULTS: A total of 81 of 99 students completed the study. The concept-sorting score (mean +/- SEM) for students who used the scheme was higher than was the score for students who did not (2.5 +/- 0.14 versus 1.91 +/- 0.12, p =.016). Students who scored higher in the concept-sorting task, referred to as "deep learners," scored higher than did "surface learners" on exam questions on metabolic alkalosis (2.81 versus 2.29, p =.02). There was no difference in the overall examination performances between the two groups. CONCLUSIONS: Concept sorting may be a useful tool for studying the learning process. Scheme use by students produces a positive outcome on examination performance.

Education, Medical, Undergraduate↗

PubMed1985

The learning style of medical students.

Recent research indicates that students' learning styles and approaches to study may have a significant bearing on their academic success. A study was undertaken on first-, third- and final-year medical students to analyse their preferred learning styles and approaches to study, using the Lancaster Approaches to Learning Inventory. The results showed that students entering the medical school had preferences which were more similar to science students' than arts students'. The medical students had high scores on reproducing orientation (surface approach) in all years tested. The first-year students had low scores on meaning orientation (deep approach) but the scores from students in later years showed a progressive rise. The implications of these results with regard to selection, teaching and assessment are explored. However, this preliminary study does not allow us to differentiate between the effect of student preference and that of the context and the environment in which they study.

Australia↗

PubMed1993

Efferent projections from the anterior thalamic nuclei to the cingulate cortex in the rat.

The organization of projections from the anterior thalamic nuclei to the cingulate cortex was analyzed in the rat by the anterograde transport of Phaseolus vulgaris-leucoagglutinin. The rostral part of the anteromedial nucleus projects to layers I, V and VI of the anterior cingulate areas 1 and 2, layers I and III of the ventral orbital area, layers I, V and VI of area 29D of the retrosplenial area, and layers I and V of the caudal part of the retrosplenial granular and agranular areas. In contrast, the caudal part of the anteromedial nucleus projects to layer V of the frontal area 2, and layers I and V of the rostral part of the retrosplenial granular and agranular areas. The interanteromedial nucleus projects to layers I, III and V of the frontal area 2, layer V of the agranular insular area, and layers I, V and VI of area 29D. The anteroventral nucleus projects to layers I and IV of the retrosplenial granular area, whereas the anterodorsal nucleus projects to layers I, III and IV of the same area. Projections from the anteroventral and anterodorsal nuclei were, furthermore, organized such that their ventral parts project to the rostral part of the retrosplenial granular area, whereas their dorsal parts project to the more caudal part. The results suggest that the anterior thalamic nuclei project to more widespread areas and laminae of the cingulate cortex than was previously assumed. The projections are organized such that the anteromedial and interanteromedial nuclei project to layer I and the deep layers of the anterior cingulate and retrosplenial cortex, whereas the anteroventral and anterodorsal nuclei project to the superficial layers of the retrosplenial cortex. These thalamocortical projections may play important roles in behavioral learning such as discriminative avoidance behavior.

Animals↗

PubMed2005

Vibrotactile frequency discrimination in human hairy skin.

The human capacity for vibrotactile frequency discrimination has been compared directly for glabrous and hairy skin regions by means of a two-alternative, forced-choice psychophysical procedure in five subjects. Sinusoidal vibratory stimuli, delivered by means of a 4-mm-diam probe, were first used to obtain detection threshold values for the two skin sites, the finger tip and the dorsal forearm, at four standard frequencies, 20, 50, 100, and 200 Hz. Values confirmed previous results showing detection thresholds were markedly higher on hairy skin than on glabrous skin. For the discrimination task, each standard frequency, at an amplitude four times detection threshold, was paired with a series of comparison frequencies, and discrimination capacity then was quantified by deriving from psychometric function curves, measures of the discriminable frequency increment (Deltaf) and the Weber Fraction (Deltaf/f), which, when plotted as a function of the four standard frequencies, revealed similar capacities for frequency discrimination at the two skin sites at the standard frequencies of 20, 100, and 200 Hz but an equivocal difference at 50 Hz. Cutaneous local anesthesia produced a marked impairment in vibrotactile detection and discrimination at the low standard frequencies of 20 and 50 Hz but little effect at higher frequencies. In summary, the results reveal, first, a striking similarity in vibrotactile discriminative performance in hairy and glabrous skin despite marked differences in detection thresholds for the two sites, and, second, the results confirm that vibrotactile detection and discrimination in hairy skin depend on superficial receptors at low frequencies but depend on deep, probably Pacinian corpuscle, receptors for high frequencies.

Discrimination Learning↗

PubMedDate not supplied

A combined porcelain onlay/amalgam restoration for an endodontically treated posterior tooth.

This article describes a new method of fabricating an aesthetic restoration for an endodontically treated posterior tooth. The tooth is prepared with minimal reduction of sound tooth tissue. Amalgam is condensed into the orifices of the root canals, the pulp chamber, and the remainder of the cavity. The tooth and the amalgam core are then prepared to receive a porcelain onlay. Additional retention is provided by 1 mm deep holes cut in the amalgam floor of the preparation which is then microetched. The porcelain onlay with its margins remote from the gingiva is bonded with dual-cure composite cement. The learning objective of this article is to familiarize the reader with this new procedure.

Dental Amalgam↗

PubMed1998

Type 1 and type 2 cytokines: from basic science to fungal infections.

At the present time, it is clear that Th1 responses afford protection against the fungi; however, the development, maintenance and function of the protective immune responses are complex mechanisms and are influenced by multiple factors. The route of infection has been shown to affect initial cytokine production and, consequently, the induction of protective Th1 responses. The ability of different isolates of the same fungal agent to induce and sustain a protective response has also been emphasized. Protective immune responses have been shown to vary in genetically different mouse strains after infection. In addition, these protective responses, such as cellular influx and cytokine production, also vary within the same animal depending on the tissue infected. The functional dominance of certain cytokines over others in influencing development and maintenance of protective responses has been discussed. Certain cytokines may act differently in hosts lacking important components of their innate or immune repertoire. It is evident from these presentations that a more comprehensive understanding of the protective mechanisms against different fungal agents is emerging. However, there is still much to learn before cytokine modulatory therapy can be used effectively without risk in the human host.

Animals↗

PubMed2004

Laser,"closure", stents and other new technology in the treatment of venous disease.

New technology is transforming our approach to venous disease. Once considered taboo for fear of causing deep venous thrombosis, surgical or endovenous intervention in the deep venous system is now known to be safe. Newer techniques allow minimally invasive procedures, many carried out on an outpatient basis. Traditional conservative regimens to treat acute ilio-femoral DVT are yielding to more aggressive interventional approaches to minimize the high incidence of postthrombotic syndrome with the former. Stent technology can safely and effectively relieve many of the disabling symptoms of chronic venous obstruction. Stent patency is high and morbidity low. Knowledge of venous pathophysiology has also advanced, though much remains to be learned. The beneficiaries are the large patient population with DVT and chronic venous insufficiency, which is estimated to be at least three times as large as patients with arterial disease. Unlike arterial disease, venous pathology afflicts the younger working age population in large numbers at enormous direct and social costs. In the older patient, deep venous disease is common, but seldom suspected. The symptoms are often ascribed to systemic causes. A thorough venous investigation is the key to proper diagnosis and treatment. Often, a minimally invasive procedure such as EVLT or stent insertion can offer surprising symptom relief with significant improvement in the quality of life during the twilight years.

Angioplasty, Balloon, Laser-Assisted↗

PubMed2000

Neurodevelopmental profile of a new dysmorphic syndrome associated with submicroscopic partial deletion of 1p36.3.

We describe four children with dysmorphic syndrome with severe learning disability (SLD). Their chromosomes had been normal on conventional cytogenetic examination. However, screening using a multiprobe fluorescence in situ hybridisation (FISH) technique for subtelomeric abnormalities revealed a deletion of the p arm of chromosome 1. The physical features include body asymmetry, microcephaly, distinctive facies with deep-set eyes, sharply defined eye sockets, and mid-face hypoplasia; the neurodevelopmental profile was characterised by SLD, motor delay with hypotonia, markedly delayed visual maturation, and postural asymmetry together with epilepsy. This phenotype is consistent with that described for partial monosomy for 1p36.3.

Abnormalities, Multiple↗

PubMed2002

Temporal discrimination learning in abstinent chronic alcoholics.

BACKGROUND: Converging evidence from varied experimental paradigms has demonstrated that the cerebellum is involved in the timing of learned behavior. Given the documented neurological changes secondary to chronic alcoholism, particularly cerebellar degeneration, the ability of recovered chronic alcoholics to learn a temporal discrimination was assessed by using delayed eyeblink classical conditioning. METHODS: Twelve abstinent alcoholic participants and 12 matched control participants were randomly presented 2 clearly discriminable tone conditioned stimuli that were individually paired with 2 different interstimulus intervals. RESULTS: The data revealed a significant alteration in the abstinent alcoholics' peak latency measure at the long interstimulus intervals and an overall impairment in their level of acquisition of conditioned responses. No group differences in extinction were observed. CONCLUSIONS: It was speculated that cerebellar cortical atrophy caused by years of alcohol abuse resulted in the peak latency alteration and that atrophy extending into deep cerebellar nuclei caused the overall impairment in conditioned response acquisition.

Alcoholism↗

PubMed2004

One process is not enough! A speed-accuracy tradeoff study of recognition memory.

Speed-accuracy tradeoff (SAT) methods have been used to contrast single- and dual-process accounts of recognition memory. In these procedures, subjects are presented with individual test items and are required to make recognition decisions under various time constraints. In this experiment, we presented word lists under incidental learning conditions, varying the modality of presentation and level of processing. At test, we manipulated the interval between each visually presented test item and a response signal, thus controlling the amount of time available to retrieve target information. Study-test modality match had a beneficial effect on recognition accuracy at short response-signal delays (< or =300 msec). Conversely, recognition accuracy benefited more from deep than from shallow processing at study only at relatively long response-signal delays (> or =300 msec). The results are congruent with views suggesting that both fast familiarity and slower recollection processes contribute to recognition memory.

Auditory Perception↗

PubMed2001

[Laparoscopy assisted radical vaginal hysterectomy (LAVRH) for cervical carcinoma--perioperative parameters and complications].

OBJECTIVE: Presently we note a standardization of techniques for laparoscopy assisted radical vaginal hysterectomy (LARVH). Altgassen et al. pointed to this fact with their evaluation of 108 operations for cervical cancer. They considered the necessity to perform 100 such operations before standardizing this method. In our survey we compare a similar number of operations performed in our department in order to prove whether Altgassen's thesis is correct, taking peri- and postoperative parameters as well as complications into consideration. For this purpose we analyzed the number of operations necessary to develop and standardize laparoscopic pelvic lymphadenectomy combined with radical vaginal hysterectomy in women treated for cervical cancer. PATIENTS AND METHODS: Between 1st August 1993 and 31st January 1999, 80 patients with cervical cancer FIGO stage Ia2-IIb were selected for laparoscopy assisted radical vaginal hysterectomy. We were able to perform this operation in 71 patients. The operation reports and records of the postoperative period were evaluated retrospectively. RESULTS: The average duration of the operation increased from 380 minutes in cervix carcinoma Ia2 to 530 minutes in cervix carcinoma IIb. The average blood loss remained the same at 1,000 ml for each operation. Correspondingly the average decrease of hemoglobin was 3.5% for all operations. The number of pelvic lymph nodes removed unilaterally varied between 6 and 13. If the group of 37 patients with cervical cancer FIGO stage Ib--particularly homogenous as far as the spread of the tumor and the course of the operation are concerned--is divided up into one group up to the 50th operation and another group after the 50th operation, the regression analysis after the 50th operation shows a statistically significantly higher number of lymphnodes (11 compared to 25; Mann-Whitney-U-Test, p = 0.00014). However no differences were found for mean blood loss (800 ml compared to 700 ml) or duration of operation (400 minutes compared to 420) (Mann-Whitney-U-Test, p > 0.05). 5% of serious complications were associated with the laparoscopic part of the procedure--a blood vessel lesion, a ureter lesion, two postoperative intraperitoneal secondary hemorrhages. 7.5% serious complications in the area of the bladder and the ureter were associated with the vaginal part of the procedure. In 6% of our procedures we observed lymphedema in the lower extremities. Deep Compartment Syndrome was observed in 5% of our patients and associated with the duration of the procedure. CONCLUSION: To implement and standardize our technique of laparoscopic pelvic lymphadenectomy and radical vaginal hysterectomy a learning phase of 50 procedures was necessary.

Adult↗

PubMed1994

Computed tomographically guided biopsy of the spine.

STUDY DESIGN: Efficacy of the percutaneous biopsy of the spine under computed tomographic guidance was investigated. Seventy-five patients, ranging in age from 7 to 72 years, underwent this procedure. OBJECTIVES: To determine the usefulness of computed tomographically guided biopsies in the treatment of patients with spinal disorders. SUMMARY OF BACKGROUND DATA: The results of 68 biopsies (90.6%) were judged to be accurate insofar as the samples of tissue obtained could be diagnosed as specific types of neoplasm, infective lesions, reactive lesions of nonspecific type, or normal bone. METHODS: Biopsies that yielded a specific abnormality were categorized as true positives. The "normal" biopsies were followed for 6-18 months and were then deemed true negatives. Nondiagnostic ones were considered false negatives. RESULTS: The results are acceptable with an accuracy rate of 90.6%. It is a safe and simple procedure with a short learning curve. CONCLUSIONS: Computed tomographically guided biopsy of the spine is recommended as a procedure of choice, especially in cervical and thoracic lesions. Computed tomography is superior to fluoroscopy when dealing with small, deep-seated lesions especially in the cervical and thoracic regions and with lesions picked up on bone scan only, radiographs being negative. Needle biopsy under computed tomographic guidance is safe and precise.

Adolescent↗