Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CHESS”

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.

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

At least 163 records · Page 9Linked to original sources
PubMed1990

[The impact of psychological stress on somatic and biochemical parameters in an atypical sports discipline].

The subject of our interest was to investigate the response of the organism to mental strain in an atypical sports discipline. To this end we examined 10 chess players. We assessed their pulse rate at rest, before a contest, immediately after the contest and after 5 mins. recovery. Statistical evaluation revealed an increased heart rate before the contest, as compared with rest at a level of significance of 0.01; after the contest as compared with the status before the contest at a level of 0.02; in the recovery stage, as compared with rest, at the 0.01 level. As a control group we examined 10 hockey players under the same conditions and the results were compared with the chess players. For scientific practice it is necessary to find a way to monitor the internal environment during a chess game (catecholamines, lactate, glucose, fatty acids, cholesterol and others). As soon as this will be possible without disturbing the reflection process of the chess player, we shall be able to obtain more information on the adaptation of the organism to mental strain during a game of chess.

Adolescent↗
PubMed2004

T2-weighted spine imaging with a fast three-point dixon technique: comparison with chemical shift selective fat suppression.

PURPOSE: To develop a phased-array coil-compatible, fast three-point Dixon (TPD) technique, and compare its performance in T2-weighted spine imaging with that of the standard chemical shift selective (CHESS) fat suppression technique. MATERIALS AND METHODS: We acquired T2-weighted spine images of 27 patients using essentially identical scanning parameters with the fast TPD technique and standard fast spin echo (FSE) with CHESS fat suppression. A phased-array coil-compatible image reconstruction algorithm was developed to generate separate water and fat images from the data acquired with the fast TPD technique. Three neuroradiologists independently scored the images from the two different techniques for uniformity of fat suppression and lesion conspicuity using a four-point system (1 = poor, 2 = fair, 3 = good, 4 = best). RESULTS: The reviewers' mean scores were 3.2 and 2.1 for the uniformity of fat suppression, and 3.0 and 2.0 for the lesion conspicuity for the fast TPD and the CHESS fat suppression techniques, respectively. The fast TPD technique was statistically superior to the CHESS technique at P < 0.0005. CONCLUSION: The fast TPD technique provides superior fat suppression and lesion conspicuity, and potentially can be used as an alternative to T2-weighted imaging of the spine.

Adult↗
PubMed1998

Expert memory: a comparison of four theories.

This paper compares four current theories of expertise with respect to chess players' memory: Chase and Simon's chunking theory, Holding's SEEK theory, Ericsson and Kintsch's long-term working memory theory, and Gobet and Simon's template theory (Chase, W.G., Simon, H.A., 1973a. Perception in chess. Cognitive Psychology 4, 55-81; Holding, D.H., 1985. The Psychology of Chess Skill. Erlbaum, Hillsdale, NJ; Ericsson, K.A., Kintsch, W., 1995. Long-term working memory. Psychological Review 102, 211-245; Gobet, F., Simon, H.A., 1996b. Templates in chess memory: a mechanism for recalling several boards. Cognitive Psychology 31, 1-40). The empirical areas showing the largest discriminative power include recall of random and distorted positions, recall with very short presentation times, and interference studies. Contrary to recurrent criticisms in the literature, it is shown that the chunking theory is consistent with most of the data. However, the best performance in accounting for the empirical evidence is obtained by the template theory. The theory, which unifies low-level aspects of cognition, such as chunks, with high-level aspects, such as schematic knowledge and planning, proposes that chunks are accessed through a discrimination net, where simple perceptual features are tested, and that they can evolve into more complex data structures (templates) specific to classes of positions. Implications for the study of expertise in general include the need for detailed process models of expert behavior and the need to use empirical data spanning the traditional boundaries of perception, memory, and problem solving.

Aptitude↗
PubMed2003

The role of constraints in expert memory.

A great deal of research has been devoted to developing process models of expert memory. However, K. J. Vicente and J. H. Wang (1998) proposed (a) that process theories do not provide an adequate account of expert recall in domains in which memory recall is a contrived task and (b) that a product theory, the constraint attunement hypothesis (CAH), has received a significant amount of empirical support. We compared 1 process theory (the template theory; TT; F. Gobet & H. A. Simon, 1996c) with the CAH in chess. Chess players (N=36) differing widely in skill levels were required to recall briefly presented chess positions that were randomized in various ways. Consistent with TT, but inconsistent with the CAH, there was a significant skill effect in a condition in which both the location and distribution of the pieces were randomized. These and other results suggest that process models such as TT can provide a viable account of expert memory in chess.

Achievement↗
PubMed1991

Combined chemical-shift and phase-selective imaging for fat suppression: theory and initial clinical experience.

Incomplete fat suppression with a chemical-shift-selective (CHESS) or phase-selective (Dixon) technique is partially due to the olefinic fat component, which precesses at the same frequency as water. The authors developed a new method of fat suppression--the opposed-fat saturation (OP-ES) sequence--that combines both techniques to obtain superior fat saturation. Fat suppression was verified in phantom studies, which showed that the CHESS portion can eliminate most of the aliphatic fat signal except for a small residual component because of steady state effects and magnetic field imperfections. This residual component is cancelled by the olefinic fat with the phase-selective opposed portion of the sequence. Furthermore, this sequence was superior to another hybrid technique, chopper Dixon in combination with CHESS. When used in 10 healthy volunteers, the OP-FS sequence showed consistently better suppression of the subcutaneous and retroperitoneal fat compared with CHESS alone. Additional advantages for clinical abdominal imaging include its compatibility with respiratory compensation, use of a single excitation, and ease of implementation with gradient-echo imaging. Preliminary application in 10 patients illustrated other potential advantages, including clarification of fat-containing diseases and increasing conspicuity of some lesions.

Adipose Tissue↗
PubMed2001

Fast three-point dixon MR imaging using low-resolution images for phase correction: a comparison with chemical shift selective fat suppression for pediatric musculoskeletal imaging.

OBJECTIVE: The purpose of this study is to describe and to implement a new fast three-point Dixon MR imaging sequence with online image reconstruction, and to compare this sequence with conventional chemical shift selective (CHESS) suppression of fat in pediatric musculoskeletal imaging. SUBJECTS AND METHODS: A three-point Dixon technique using a fast spin-echo sequence with a new phase-correction algorithm providing online image reconstruction was implemented on a 1.5-T scanner. Twelve pediatric patients and young adults were imaged with both the new three-point Dixon and conventional CHESS sequences. Three radiologists un-aware of imaging parameters and clinical information independently scored the homogeneity of fat suppression and conspicuity of abnormality using a four-point system. An additional comparison between the two techniques was made using a phantom. RESULTS: The three-point Dixon method showed superior fat suppression and lesion conspicuity (p < 0.001), particularly in the hands and feet, where CHESS is prone to inconsistent fat suppression. The phantom study showed no significant difference in the ratio of suppressed fat signal to background noise and more homogeneous fat suppression using the three-point Dixon method. CONCLUSION: Compared with CHESS, the new fast three-point Dixon sequence with online image reconstruction provides superior fat suppression and lesion conspicuity and can be routinely used in pediatric musculoskeletal imaging.

Adolescent↗
PubMed1998

Analysis of outcome after thermotherapy using different classifications of bladder outlet obstruction.

The urodynamic profiles of 97 patients with benign prostatic hyperplasia undergoing low-energy transurethral microwave thermotherapy (TUMT) for lower urinary tract symptoms were analysed using the Abrams/Griffiths nomogram, the urethral resistance algorithm, the linPURR, Schäfer nomogram, and the CHESS classification. A significant clinical response was seen for the whole group, as shown by changes in symptom score, free flow rate, and residual urine. The best symptomatic response was identified in patients in whom obstruction was present, whatever the classification used. Only the two-dimensional CHESS classification was found to predict a group of patients with a better response in both symptoms and objective variables. Obviously, a better response from TUMT can only be predicted by a classification system that identifies the independent variables of footpoint and slope of the PURR. The CHESS classification was the only one of those studied that satisfactorily identified these two parameters and could be used as a system of case selection for this minimally invasive treatment.

Aged↗
PubMed2004

Selective missing pulse steady state free precession (MP-SSFP): inner volume and chemical shift selective imaging in a steady state sequence.

PURPOSE: To examine new sequences that restrict acquisition of spins to those excited by both of the RF pulses in missing pulse steady state free precession (MP-SSFP) MRI. MATERIALS AND METHODS: New MP-SSFP sequences were created by replacing one of the slice selective pulses (SSPs) with an orthogonal SSP for inner volume imaging, and with a chemical shift selective (CHESS) pulse for chemical shift imaging. The inner volume sequence was applied to a reduced field of view at the center of a resolution phantom; resulting images were evaluated for differences in the aliased signal. The CHESS sequence was applied to volunteers, as well as to and fat, water, and acetic acid phantoms. Results were evaluated with SNR measurements. RESULTS: The inner volume sequence eliminated the aliased signal, while nonselected fat and water levels were suppressed to that of noise by the CHESS sequence. CONCLUSION: Results suggest a novel steady state technique for rapid inner volume or chemical shift imaging.

Humans↗
PubMed1995

Mapping the biodistribution and catabolism of 5-fluorouracil in tumor-bearing rats by chemical-shift selective 19F MR imaging.

A chemical-shift selective (CHESS) 19F MR imaging technique was used to map selectively the antineoplastic drug 5-fluorouracil (5-FU) and its major catabolite alpha-fluoro-beta-alanine (FBAL) in tumor-bearing rats. The pulse sequence employed a CHESS RF saturation pulse to suppress either the 5-FU or the FBAL resonance before the other component in the two-line 19F MR spectra was measured. Selective 5-FU and FBAL images with a spatial resolution of 10 x 10 x 15 mm3 (1.5 ml) were obtained in 40 min from six ACl rats with implanted Morris hepatoma. Because the transmitter frequency could always be set to the Larmor frequency of the 19F resonance employed for imaging, the images were free of chemical-shift artifacts in readout and slice-selection direction. Whereas FBAL appeared only in the liver, the kidneys, and the bladder, 5-FU could also be detected in all major organs and in the muscular system. In the Morris hepatomas, a small 5-FU uptake and no FBAL accumulation were measured. The CHESS 19F MRI technique provides useful physiological and biochemical data on the biodistribution of the antineoplastic drug 5-FU and on the different catabolic activities of the tissues.

Animals↗
PubMed1992

The Council for Health and Environmental Safety of Soils.

The Council for Health and Environmental Safety of Soils (CHESS) was organized in 1987 to develop a consensus soil risk assessment methodology to be used as a framework for establishing standards for soil contamination to protect the environment and public health. The wide range of contaminating substances of possible health concern in soil is affecting land use and development, causing excessive economic expenditures, and the regulatory approaches for control are disperse. The International Society of Regulatory Toxicology and Pharmacology agreed to sponsor the Council and through a Governing Board composed of experienced scientists from the federal government, state departments of public health and environmental protection, academia, and the private sector including industry and environmental organizations. The Board was created to support the goals of CHESS, its mode of operation, and to establish funding policies and directions. A technical council agreed to develop a peer-reviewed consensus methodology to assess public health risks from contaminated soil by technical committees composed of recognized experts in the area of soil contamination and other relevant disciplines. This methodology would then be made available to federal and state agencies, the private sector, and the scientific community at large. After extensive study, a final decision was made to develop a decision-tree framework to be used at the state and local levels for application to all types of soil contamination. Following extensive studies it was agreed the ubiquitous nature of petroleum contamination in soil has direct and immediate public health implications and CHESS therefore directed its first efforts to this area.(ABSTRACT TRUNCATED AT 250 WORDS)

Environmental Pollution↗
PubMed2006

Visuomotor priming of a manual reaching movement during a perceptual decision task.

This paper deals with the mental simulation of manual movement that sometimes accompanies the visual perception of an object. Previous studies investigated how visual objects prime the grasping manual movement they afford. The principal purpose of the present experiment was to determine if such visuomotor priming also concerns the reaching manual movement that visual objects afford. During a perceptual decision task, 32 subjects were asked to grasp a proximal or distal switch, as fast and accurately as possible, depending on the color of a chess piece displayed on a computer screen. Results showed an effect on the reaction times of the interaction between the position of the chess piece on the chessboard and the manual response, suggesting that subjects mentally simulated a manual reaching movement toward the perceived chess piece.

Adult↗
PubMed2006

Superior performance and neural efficiency: the impact of intelligence and expertise.

Superior cognitive performance can be viewed from an intelligence perspective, emphasising general properties of the human information processing system (such as mental speed and working memory), and from an expertise perspective, highlighting the indispensable role of elaborated domain-specific knowledge and acquired skills. In exploring its neurophysiological basis, recent research has provided considerable evidence of the neural efficiency hypothesis of intelligence, indicating lower and more focussed brain activation in brighter individuals. The present EEG study investigates the impacts of intelligence and expertise on cognitive performance and the accompanying cortical activation patterns in the domain of tournament chess. Forty-seven tournament chess players of varying intelligence and expertise level worked on tasks drawing on mental speed, memory, and reasoning. Half of the tasks were representative for chess, while the other half was not. The cortical activation was quantified by means of event-related desynchronisation (ERD) in the upper alpha band. Independent effects of expertise and intelligence emerged at both, the performance and the neurophysiological level. Brighter participants performed better than less intelligent ones which was associated with more efficient brain functioning (lower ERD) across all tasks. Additionally, a high expertise level was beneficial for good task performance but exerted a topographically differentiated influence on the cortical activation patterns. The findings suggest that superior cognitive performance and the underlying cortical activation are not only a function of knowledge and domain-specific competences but also of the general efficiency of the information processing system.

Adolescent↗
PubMed1981

Aging and skilled problem solving.

Information-processing models of problem solving too often are based on restrictive age ranges. On the other hand, gerontologists have investigated few problem-solving tasks and have rarely generated explicit models. As this article demonstrates, both fields can benefit by closer collaboration. One major issue in gerontology is whether aging is associated with irreversible decrement or developmental plasticity. If both processes occur, then an appropriate strategy for investigating aging is to equate age groups for molar problem-solving performance and search for differences in the underlying components. This strategy was adopted to examine the relation of age and skill to problem solving in chess. Chess players were selected to vary widely in age and skill such that these variables were uncorrelated. Problem-solving and memory tasks were administered. Skill level was the only significant predictor for accuracy in both a choose-a-move task and a speeded end-game evaluation task. Age (negatively) and skill (positively) jointly determined performance in an unexpected recall task. Efficient chunking in recall was positively related to skill, though negatively related to age. Recognition confidence, though not accuracy, was negatively related to age. Thus despite age-related declines in encoding and retrieval of information, older players match the problem-solving performance of equivalently skilled younger players. Apparently, they can search the problem space more efficiently, as evidenced by taking less time to select an equally good move. Models of chess skill that stress that role of encoding efficiency, as indexed by chunking in recall, need to be modified to account for performance over the life span.

Adolescent↗
PubMed2005

Computer-aided organic synthesis.

It is tempting for those in the field of organic synthesis to liken the process of retrosynthesis to a game of chess. That the world chess champion was recently defeated by a computer leads us to think that perhaps new and powerful computing methods could be applied to synthetic problems. Here the analogy between synthesis and chess is outlined. Achievements in the 35-year history of computer-aided synthetic design are described, followed by some more recent developments.

Acrylonitrile↗
PubMed1984

Perceptual skill in the game of Othello.

Three experiments were conducted extending research on chess and Go to the game of Othello. Experiment 1 demonstrated that expert Othello players, in comparison to nonplayers of the game, are superior at recalling meaningful game configurations but are not better at recalling random positions. Experiment 2 demonstrated that expert players can learn a sequence of moves from an Othello game much more rapidly than nonplayers can. Experiment 3 examined chunking behavior and found that experts and nonplayers perceive different patterns of piece clusters in an Othello position. These results indicate that skill in Othello is cognitively organized in a manner similar to chess skill. Because Othello provides a less complex environment than chess and Go, efforts to model human skill in strategy games may be profitably pursued with Othello.

Concept Formation↗
PubMed1985

Chemical shift selective MR imaging using a whole-body magnet.

We have applied a new method for separating water and fat resonances in proton magnetic resonance (MR) imaging to human studies using a whole-body MR imaging system at 2.0 T. Chemical shift selective (CHESS) MR imaging provides either a water or fat image in a single experimental run within the same time needed for a conventional composite image. Although the technique requires a spectral resolution of about 1 ppm over the entire imaging region, first images of the human head and hip indicated that CHESS MR imaging is extremely promising for use in clinical investigations. Moreover, CHESS MR imaging can be combined arbitrarily with other imaging modalities and is easy to implement in any high-field MR imaging system.

Adipose Tissue↗
PubMedDate not supplied

[Visual evoked potentials in children with congenital glaucoma].

Phasic and established visual evoked potentials (VEP) to homogeneous light field and chess patterns were studied in 25 patients (48 eyes) aged 1.5 months to 9 years with different stages of congenital glaucoma and in 114 age-matched healthy children. Patients with almost absolute and far progressed stages of the disease presented with gross changes of VEP to both large- and small-cell chess patterns. In patients with the initial stages of decompensated congenital glaucoma VEP to mostly large-cell chess patterns were altered. These data evidence the usefulness of examining the VEP to stimuli with low spatial frequency for the early detection of congenital glaucoma.

Age Factors↗
PubMedDate not supplied

[Possibilities of the use of visual evoked potentials in the evaluation of visual acuity in congenital myopia in children].

Studies of visual evoked potentials (EP) to chess field reversion in 80 children (147 eyes) aged 5 to 16 with congenital myopia have demonstrated significant deviations from the reference values of the P100 component to all the stimuli. The clinical groups with various changes in the fundus oculi were found to differ by the P100 component amplitude when chess fields with cells 112 and 56 angular min in size were shown. The number of discrepancies between the clinical vision acuity and its assessment from the threshold EP grew from 19% when no changes in the fundus oculi were seen to 54 and 61% when myopic and non-myopic changes were detectable in the fundus oculi. These data evidence that EP amplitude to chess field reversion better reflects the status of the retino-cortical route than the central vision acuity.

Adolescent↗