SEARCH · Search PubMed

Results for “Automatism”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31Linked to original sources

PubMed1979

[Automatic adder mixer for photometric cells: application to superprecipitation of myosin B. (author's transl)].

An automatic adder mixer for photometric cells was newly developed in our laboratory and was applied in experiments of superprecipitation of myosin B. The mixer has a reciprocating blade-type impeller with a pit for loading samples. The pit was cut so as to be just above the meniscus of the solution in a cell at the top dead point of the cam mechanism and so as to enter the solution at the bottom dead point. When 10 microliter of methylene blue solution was added, the mixing time was 0.6 sec. Myosin B was extracted from rabbit white muscle. Adding ATP (1 mM) to myosin B suspension and mixing was carried out by hand, using a mixing plunger, and also using the automatic adder mixer. The recordings obtained were then compared. Continuous recording of the initial reaction was successfully obtained only when the automatic adder mixer was used. Excellent results were also obtained with respect to reproducibility. The automatic adder mixer is easy to make, inexpensive, and can be utilized in conjunction with conventional spectrophotometers.

Chemical Precipitation↗

PubMed2004

A digital subtraction radiography scheme based on automatic multiresolution registration.

OBJECTIVES: To establish a digital subtraction radiography scheme for aligning clinical in vivo radiographs based on the implementations of an automatic geometric registration method and a contrast correction technique. METHODS: Thirty-five pairs of in vivo dental radiographs from four clinical studies were used in this work. First, each image pair was automatically aligned by applying a multiresolution registration strategy using the affine transformation followed by the implementation of the projective transformation at full resolution. Then, a contrast correction technique was applied in order to produce subtraction radiographs and fused images for further clinical evaluation. The performance of the proposed registration method was assessed against a manual method based on the projective transformation. RESULTS: The qualitative assessment of the experiments based on visual inspection has shown advantageous performance of the proposed automatic registration method against the manual method. Furthermore, the quantitative analysis showed statistical difference in terms of the root mean square (RMS) error estimated over the whole images and specific regions of interest. CONCLUSIONS: The proposed automatic geometric registration method is capable of aligning radiographs acquired with or without rigorous a priori standardization. The methodology is pixel-based and does not require the application of any segmentation process prior to alignment. The employed projective transformation provides a reliable model for registering intraoral radiographs. The implemented contrast correction technique sequentially applied provides subtraction radiographs and fused images for clinical evaluation regarding the evolution of a disease or the response to a therapeutic scheme.

Algorithms↗

PubMed1993

Hearing status and language fluency as predictors of automatic word and sign recognition.

In previous studies, evidence concerning the extent of automatic word recognition in deaf children and the influence of language fluency on word and sign recognition (as indexed by the Stroop task) has been contradictory. This study examined the effects of English and sign language fluency in the automatic word and sign recognition of deaf and hearing adults. Results indicated that responding in sign took longer and created more Stroop interference than responding orally. Two groups of certified interpreters revealed this finding to be independent of hearing status. Most important, deaf subjects showed greater automaticity in recognizing signs than words, whereas hearing subjects showed greater automaticity in recognizing words than signs. This pattern was unaffected by language fluency. The findings clarify the results of previous studies both theoretically and methodologically.

Adolescent↗

PubMed2001

Unreliability of automatic scoring of MESAM 4 in assessing patients with complicated obstructive sleep apnea syndrome.

BACKGROUND: Portable devices are used for unattended recording of patients with suspected obstructive sleep apnea syndrome (OSAS). The MESAM 4 (MAP; Martinsried, Germany) is a computerized ambulatory polysomnographic system that records four parameters: breathing noise, heart rate, arterial oxygen saturation (SaO(2)), and body position. DESIGN AND METHOD: We evaluated the reliability of the oxygen desaturation index (ODI) automatically calculated by the MESAM 4 device in evaluating patients with "complicated" OSAS. These patients present SaO(2) drops due to apneas associated with a fall in baseline SaO(2) during sleep, as occurs in the "overlap syndrome." Ten patients with complicated OSAS underwent nocturnal MESAM 4 recordings, and we compared the visual and automatic scorings of the ODI. RESULTS: The ODI obtained with visual scoring was significantly higher than ODI automatically calculated by the MESAM 4 in all patients. In some patients, this difference was so significant that it could bias clinical judgment of OSAS severity. We demonstrated that the system did not identify those desaturation events that were superimposed on a fall in baseline SaO(2). The error depends on the algorithm by which the device recognizes the desaturation events and calculates the baseline SaO(2). CONCLUSION: Automatic analysis of MESAM 4 recordings may be misleading in evaluating OSAS patients who have a fall in baseline SaO(2) during sleep. In this case, visual scoring performed by a trained polysomnographer is recommended.

Adult↗

PubMed1985

Evaluation of an automatic mixing system for an addition silicone impression material.

The automatic mixing system of an addition silicone impression material yields mixes and set material that comply with ADA specification no. 19 when testing is started at 0.5 minute rather than the specified 1.5 minutes. This change is reasonable because there is zero mixing time rather than the usual 45-60 second needed for standard two-paste rubber impression materials. Uniform mixing of base and catalyst occurs with the automatic system, with a fourth to a fifth as many bubbles in the mix as for comparable mixes obtained by hand spatulation. The automatic feature of the system simplifies mixing and nearly eliminates the training of assistants in the mixing of rubber impression material. The automatic mixing system is economical as it wastes only a third as much material as a typical hand-dispensing and mixing system. The properties and accuracy of the system are excellent and typical of addition silicones, including excellent recovery from deformation, low dimensional change on setting, and low flow. A wash or two-phase impression technique may be used with equal clinical accuracy.

Dental Impression Materials↗

PubMed2005

Changes in brain activation during the acquisition of a multifrequency bimanual coordination task: from the cognitive stage to advanced levels of automaticity.

Little is known about activation changes reflecting overlearning, i.e., extensive motor training beyond asymptotic performance. Here we used functional magnetic resonance imaging to trace the neural shifts from an initial to a skilled (learning) and finally overlearned stage (automatization). Scanning occurred before training (PRE) and after 1 (MID) and 2 weeks (POST) of intensive practice on a new bimanual coordination task (>10,500 cycles). Kinematics revealed major improvements between PRE and MID sessions, whereas MID to POST session performance leveled off, indicative of learning and automatization, respectively. Imaging findings showed that activation decreased in bilateral opercular areas, bilateral ventrolateral prefrontal cortex, the right ventral premotor and supramarginal gyrus, and the anterior cingulate sulcus during the learning stage and in the supplementary motor area during the automatization stage. These changes are hypothesized to reflect decreases in attention-demanding sensory processing, as well as suppression of preferred coordination tendencies as a prelude to acquiring new coordination modes. Conversely, learning-related increases were observed in the primary motor cortex (M1), posterior cingulate zone (PCZ), putamen, and right anterior cerebellum. Importantly, both M1 and PCZ activation decreased again to initial level (PRE) during automated performance (POST). Only the putamen and anterior cerebellum remained more activated across both learning and automatization stages, supporting their crucial role in long-term motor memory formation for coordination tasks.

Adult↗

PubMed2005

The neural correlates of motor skill automaticity.

Acquisition of a new skill is generally associated with a decrease in the need for effortful control over performance, leading to the development of automaticity. Automaticity by definition has been achieved when performance of a primary task is minimally affected by other ongoing tasks. The neural basis of automaticity was examined by testing subjects in a serial reaction time (SRT) task under both single-task and dual-task conditions. The diminishing cost of dual-task performance was used as an index for automaticity. Subjects performed the SRT task during two functional magnetic imaging sessions separated by 3 h of behavioral training over multiple days. Behavioral data showed that, by the end of testing, subjects had automated performance of the SRT task. Before behavioral training, performance of the SRT task concurrently with the secondary task elicited activation in a wide network of frontal and striatal regions, as well as parietal lobe. After extensive behavioral training, dual-task performance showed comparatively less activity in bilateral ventral premotor regions, right middle frontal gyrus, and right caudate body; activity in other prefrontal and striatal regions decreased equally for single-task and dual-task conditions. These data suggest that lateral and dorsolateral prefrontal regions, and their corresponding striatal targets, subserve the executive processes involved in novice dual-task performance. The results also showed that supplementary motor area and putamen/globus pallidus regions showed training-related decreases for sequence conditions but not for random conditions, confirming the role of these regions in the representation of learned motor sequences.

Adult↗

PubMed1977

[Maintenance of mice in automatic rearing system. I. Rearing tests with ICR mice (author's transl)].

Female ICR:JCL mice were reared in wire-mesh cages with nozzles for automatic water supply on a battery with an automatic washing system, and the evaluation of this system was made in comparison with the conventional feeding system with water bottles, alumite cages and changes of the bedding. In weight gains, feed intakes, water consumption, leucocyte and erythrocyte counts, hematocrit values or vaious organ weights during the period from 3 to 14 weeks of age, animals maintained by the automatic rearing system showed no significant difference as compared with those maintained by the conventional system, providing evidence for a conspicuous labor saving with the automatic control system.

Animals↗

PubMed1979

[Comparison of different types automatic water-supply system for mouse rearing (author's transl)].

Rearing and breeding scores were compared between groups of mice (JCL : ICR and ddN strains) raised with two different types of automatic water-supply systems; the Japanese type and the American type, using manual water-supply system as control. The mice raised with the manual water-supply system were superior in body weight gain as compared to those with two automatic water-supply systems. As to the survival rate, however, the m; anual water-supply system and the Japanese type gave better results than the American type. As to weanling rate in the breeding test, the manual water-supply system gave somewhat better result than either of the two automatic types. Accidental water leaks, which are serious problems of automatic systems, occurred frequently only when the American type was used. Only one defect of the Japanese type revealed was that it was unfavorable for mice with smaller size (e.g., young ddN mice), resulting in lower body weight gain as well as lower breeding scores.

Animals↗

PubMed2003

A cautionary note: survival of nymphs of two species of ticks (Acari: Ixodidae) among clothes laundered in an automatic washer.

Host-seeking ticks often remain on clothing of persons returning home from work or recreation in tick habitats, and can pose at least a temporary risk to people and pets in these homes. Laundering clothing has been one of the recommendations to reduce tick exposure. Host-seeking lone star tick, Amblyomma americanum (L.), and blacklegged tick, Ixodes scapularis Say, nymphs confined in polyester mesh packets, were included with laundry in cold, warm, and hot wash cycles of an automatic clothes washer. Ticks were also placed with washed clothing and subjected to drying in an automatic clothes dryer set on high heat and on air only (unheated). Most nymphs (> or = 90%) of both species survived the cold and warm washes, and 95% of A. americanum nymphs survived the hot wash. At the time of their removal from the washer, I. scapularis nymphs were clearly affected by the hot wash, but 65% were considered alive 20-24 h later. Large percentages of nymphs of both species survived hot washes in which two other detergents (a powder containing a nonchlorine bleach and a liquid) were used. All ticks were killed by the 1 h cycle at high heat in the clothes dryer, but with unheated air some nymphs of both species survived the 1 h cycle in the dryer. Given the laundering recommendations of clothing manufacturers and variation in the use automatic clothes washers, laundry washed in automatic washers should not be considered free of living ticks.

Animals↗

PubMed2003

Automatic generation of finite element meshes from computed tomography data.

A major obstacle for a broader adoption of the finite element method (FEM) in clinical biomedical applications is the generation of the model, frequently too slow for the times imposed by the clinical practice. The algorithms for automatic mesh generation have greatly improved, but their adoption by the biomedical community is still limited. The aim of this work is to review the principal algorithms for automatic mesh generation and to critically discuss them with particular reference to their applicability in the biomedical field. Specialized literature on numerical methods was reviewed in order to identify the main theoretical approaches currently available for automatic mesh generation. Then, published methods for the automatic generation of finite element models of organs from computed tomography data were reviewed and classified with a proposed taxonomy. Each method was reconnected to a theoretical approach described in the specialized literature whenever possible. Last, each method was critically reviewed with respect to its applicability to the clinical practice. None of the methods described satisfy all the requirements in terms of automation, generality, accuracy, and robustness imposed by a clinical application. However, some of these methods can already be successfully used in various application contexts, and a few guidelines are drawn.

Algorithms↗

PubMedDate not supplied

High complication rate of an automatic Tru-Cut biopsy gun device for liver biopsy in cats.

BACKGROUND: Liver biopsies taken with an automatic Tru-Cut biopsy gun device caused unexpected fatal shock reactions in cats. The goal of the present study was to determine if this biopsy device caused more frequent fatal complications than did a semiautomatic device. ANIMALS: All cats referred to the Utrecht University, between October 1, 2002, and October 31, 2004, in which ultrasound-guided Tru-Cut liver biopsies were taken. The indications for liver biopsy were increased liver enzyme activity, increased bile acid concentrations, ultrasonographic abnormalities of the liver, ultrasonographic abnormalities of the bile ducts, or some combination of these findings. Coagulation parameters were normal. METHODS: From October 1, 2002, until October 31, 2003, 26 cats were biopsied with an automatic biopsy device. Between November 1, 2003, and October 31, 2004, 19 cats underwent liver biopsy with a semiautomatic biopsy device. RESULTS: In the first period. 5 of the 26 cats (19%) developed severe shock within 15 minutes. Resuscitation was not successful. In the second period, none of the 19 cats experienced any major adverse effect. There were no significant differences between the 2 groups with respect to diagnosis, clinical signs, clinicopathologic findings, or the use of anesthetics. CONCLUSIONS AND CLINICAL IMPORTANCE: We conclude that the difference in complication rate is explained by the biopsy technique used. The pressure wave, which occurs when firing the automatic device, may have caused intense vagotonia and shock. Use of this automatic biopsy device should be avoided in cats because of the high risk of fatal complications.

Animals↗

PubMed1997

Characteristics of automatic or semiautomatic firearm ownership in the United States.

OBJECTIVES: This study examined ownership patterns of automatic/ semiautomatic firearms in the United States. METHODS: Data were derived from a national random-digit-dialing telephone survey of 800 gun owners. RESULTS: Sixty percent of gun owners reported owning an automatic or semiautomatic firearm. In comparison with other gun owners, owners of automatics or semiautomatics were more likely to be male, live in the South, own a gun for protection, and have a gun for work. They were also more likely to report binge drinking. CONCLUSIONS: Owners of automatic or semiautomatic firearms differ from other gun owners in several respects, including frequency of binge drinking.

Adult↗

PubMed1986

Depolarization-induced automaticity in the myocardium: its ionic mechanisms and relation to excitability changes.

The characteristics of depolarization-induced automaticity in myocardium and the mechanisms presumably responsible for their occurrence and maintenance were discussed in relation to ionic channels and ion transport systems of the cell membrane. The initiating mechanisms of automaticity were subdivided into oscillatory potentials of increasing amplitude, spontaneous slow depolarization and sustained depolarization of the membrane, and various possible causes of these potential changes were described. As for the mechanisms responsible for the maintenance of automaticity, phase 4 depolarization, after depolarization and triggered activity were considered with special reference given to the excitability recovery characteristics during the diastolic period. Thus, various factors were responsible for modifying the automaticity. Also, intracellular Ca fluctuations which induce oscillatory potentials, afterdepolarizations, or even supernormal periods of excitability appear to play a cardinal role. Clarification of the intracellular Ca metabolism in relation to internal membrane systems such as the sarcoplasmic reticulum and mitochondria should yield pertinent information resulting in a better understanding of these events.

Animals↗

PubMed1982

Evaluation of a new mobile automatic exposure control device.

Mobile chest radiographs obtained with manual technique and with an automatic exposure control device were compared in 50 patients requiring three radiographs within a 48 hr period. Parameters evaluated were overall quality, internal consistency, film latitude, lung field (consistency and quality), cardiac contour, hilar anatomy, pulmonary vascularity, mediastinum, tracheobronchial tree, and tubes and appliances. Radiographs obtained with the automatic exposure control system demonstrated better overall quality, consistency, film latitude, and lung field consistency and quality than manual technique. There was no definite advantage of the automatic exposure control device in the visualization of the hila, pulmonary vascularity, heart, or mediastinum. Tubes and appliances were seen equally well with both techniques. The automatic exposure control device has the potential to increase the quality and consistency of mobile radiographs, particularly in those critically ill patients who are radiographed at least on a daily basis.

Adult↗

PubMed1987

Evaluation of radiation dose, focal spot, and automatic exposure of newer film-screen mammography units.

Fifteen recently introduced mammographic units representing eight different models and manufacturers were evaluated to see whether the equipment performance equaled claims made by the manufacturers. Focal-spot size was measured by pinhole and slit methods. Eight automatic exposure control systems on five models were tested by measuring the optical density produced by imaging at 28 and 30 kVp, with and without a grid and with test objects of varying thicknesses of BR12 epoxy material. Comparable mean glandular dose for a 4-cm-thick BR12 test object was measured for 13 of the units under manual or automatic exposures. Nominal focal-spot size was larger than stated for six of the 15 large focal spots and for seven of the 12 microfocal spots. Comparable doses under automatic exposure control varied more than 100% between units from different manufacturers, while the doses of units from the same manufacturer varied less than 20%. Automatic exposure control systems were operational in eight of the 15 units, but four of these eight were found to be out of calibration. There are considerable performance variations that need to be evaluated before acceptance and use of new mammographic equipment.

Breast↗

PubMed2003

Automatic-controlled information processing and error detection in a simulated pharmacy-verification task.

The relationships between attentional variables and information-processing demands of pharmacy dispensing tasks that contribute to difficulties in cognitive performance are not well-known. In the present study, a psychological approach to medical dispensing errors, the cognitive-systems performance model of Grasha, was employed to evaluate the contributions of individual differences in attention and alterations in visual task information on simulated pharmacy-verification performance, perceived workload, and self-reported stress. 73 college-age volunteers completed a pretest battery containing psychological measures of automatic and controlled information processing, and one-week later spent 265 min. completing the end visual-inspection process for 200 simulated prescriptions, 27% of which contained artificially inserted errors. Evidence suggesting that both automatic and controlled processes underlie performance of a simulated pharmacy-verification task was obtained. Individual differences in controlled information processing were mildly predictive of detection accuracy, while contrary to expectations, automatic processing scores did not produce significant relationships. Detection associated with experimental alterations in font size (12-pt. vs 6-pt.) of critical prescription label information was partially in line with expectations from the cognitive-systems performance model, while additional visual enhancements via a magnification/illumination device yielded mixed results. Finally, reports of perceived workload (NASA Task Load Index) and specific patterns of self-reported stress (Dundee Stress State Questionnaire) were consistent with a three-tier behavioral framework offered recently by Matthews, Davies, Westerman, and Stammers for predicting behaviors along the automatic-controlled continuum.

Adult↗

PubMed2007

The profitability of automatic milking on Dutch dairy farms.

Several studies have reported on the profitability of automatic milking based on different simulation models, but a data-based study using actual farm data has been lacking. The objective of this study was to analyze the profitability of dairy farms having an automatic milking system (AMS) compared with farms using a conventional milking system (CMS) based on real accounting data. In total, 62 farms (31 using an AMS and 31 using a CMS) were analyzed for the year 2003 in a case control study. Differences between the years 2002 and 2003 also were analyzed by comparing a subgroup of 16 farms with an AMS and 16 farms with a CMS. Matching was based on the time of investment in a milking system (same year), the total milk production per year, and intensity of land use (kg/ha). Results from 2003 showed that the farms with an AMS used, on average, 29% less labor than farms with a CMS. In contrast, farms using a CMS grew faster (37,132 kg of milk quota and 5 dairy cows) than farms with an AMS (-3,756 kg milk quota and 0.5 dairy cows) between 2002 and 2003. Dairy farmers with a CMS had larger (euro7,899) revenues than those with an AMS. However, no difference in the margin on dairy production was detected, partly because of numerically greater (euro6,822) variable costs on CMS farms. Dairy farms were compared financially based on the amount of money that was available for rent, depreciation, interest, labor, and profit (RDILP). The CMS farms had more money (euro15,566) available for RDILP than the AMS farms. This difference was caused by larger fixed costs (excluding labor) for the AMS farms, larger contractor costs (euro6,422), and larger costs for gas, water, and electricity (euro1,549). Differences in costs for contractors and for gas, water, and electricity were statistically significant. When expressed per full-time employee, AMS farms had greater revenues, margins, and gross margins per full-time employee than did CMS farms. This resulted in a substantially greater (but not statistically significant) RDILP per full-time employee (euro12,953) for AMS farms compared with CMS farms. Depreciation and interest costs for automatic milking were not available but were calculated based on several assumptions. Assuming larger purchase costs and a shorter depreciation time for AMS than for CMS, costs for depreciation and interest were larger for AMS farms than for CMS farms. Larger fixed costs should be compensated for by the amount of labor that has become available after introducing the milking robot. Therefore, farm managers should decide whether the extra time acquired by automatic milking balances against the extra costs associated with an AMS.

Animals↗