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PubMed2006

EEG transient event detection and classification using association rules.

In this paper, a methodology for the automated detection and classification of transient events in electroencephalographic (EEG) recordings is presented. It is based on association rule mining and classifies transient events into four categories: epileptic spikes, muscle activity, eye blinking activity, and sharp alpha activity. The methodology involves four stages: 1) transient event detection; 2) clustering of transient events and feature extraction; 3) feature discretization and feature subset selection; and 4) association rule mining and classification of transient events. The methodology is evaluated using 25 EEG recordings, and the best obtained accuracy was 87.38%. The proposed approach combines high accuracy with the ability to provide interpretation for the decisions made, since it is based on a set of association rules.

Algorithms↗
PubMed2002

Classification of finger activation for use in a robotic prosthesis arm.

Hand amputees would highly benefit from a robotic prosthesis, which would allow the movement of a number of fingers. In this paper we propose using the electromyographic signals recorded by two pairs of electrodes placed over the arm for operating such prosthesis. Multiple features from these signals are extracted whence the most relevant features are selected by a genetic algorithm as inputs for a simple classifier. This method results in a probability of error of less than 2%.

Adult↗
PubMed2005

Pose estimation for augmented reality applications using genetic algorithm.

This paper describes a genetic algorithm that tackles the pose-estimation problem in computer vision. Our genetic algorithm can find the rotation and translation of an object accurately when the three-dimensional structure of the object is given. In our implementation, each chromosome encodes both the pose and the indexes to the selected point features of the object. Instead of only searching for the pose as in the existing work, our algorithm, at the same time, searches for a set containing the most reliable feature points in the process. This mismatch filtering strategy successfully makes the algorithm more robust under the presence of point mismatches and outliers in the images. Our algorithm has been tested with both synthetic and real data with good results. The accuracy of the recovered pose is compared to the existing algorithms. Our approach outperformed the Lowe's method and the other two genetic algorithms under the presence of point mismatches and outliers. In addition, it has been used to estimate the pose of a real object. It is shown that the proposed method is applicable to augmented reality applications.

Algorithms↗
PubMed2007

Infective disorders of the gastrointestinal tract.

Gastrointestinal infections are a major cause of morbidity and mortality worldwide. Infectious organisms are often recovered by microbiological methods, but surgical pathologists may play a very valuable role in diagnosis. This review will focus on infective disorders of the gastrointestinal tract with an emphasis on enterocolitides caused by food- and water-borne pathogens. Diagnostic histological features of selected enteric infections will be emphasized, including those that mimic other inflammatory conditions of the gut (such as ischaemia or idiopathic inflammatory bowel disease), along with available diagnostic methods that can aid in diagnosis.

Colitis, Ischemic↗
PubMed1985

Influence of deamidation(s) in the 67-74 region of ribonuclease on its refolding.

The influence of chemical mutation featuring the selective conversion of asparagine or glutamine to aspartic or glutamic acid, respectively, on the kinetics of refolding of reduced RNase has been studied. The monodeamidated derivatives of RNase A, viz. RNase Aa1a, Aa1b, and Aa1c having their deamidations in the region 67-74, were found to regain nearly their original enzymatic activity. However, a marked difference in the kinetics of refolding is seen, the order of regain of enzymic activity being RNase A greater than Aa1c congruent to Aa1a greater than Aa1b. The similarities in the distinct elution positions on Amberlite XE-64, gel electrophoretic mobilities, and u.v. spectra of reoxidized and native derivatives indicated that the native structures are formed. The slower rate of reappearance of enzymic activity in the case of the monodeamidated derivatives appears to result from altered interactions in the early stages of refolding. The roles of some amino acid residues of the 67-74 region in the pathway of refolding of RNase A are discussed.

Amides↗
PubMed1995

Different susceptibility of protein kinases to staurosporine inhibition. Kinetic studies and molecular bases for the resistance of protein kinase CK2.

A systematic analysis reveals that out of 20 protein kinases examined, specific for either Ser/Thr or Tyr, the majority are extremely sensitive to staurosporine, with IC50 values in the low nanomolar range. A few of them however, notably protein kinases CK1 and CK2, mitogen-activated protein (MAP) kinase and protein-tyrosine kinase CSK, are relatively refractory to staurosporine inhibition, exhibiting IC50 values in the micromolar range. With all protein kinases tested, namely PKA, CK1, CK2, MAP kinase (ERK-1), c-Fgr, Lyn, CSK and TPK-IIB/p38Syk, staurosporine inhibition was competitive with respect to ATP, regardless of its inhibitory power. In contrast, either uncompetitive or noncompetitive kinetics of inhibition with respect to the phosphoacceptor substrate were exhibited by Ser/Thr and Tyr-specific protein kinases, respectively, consistent with a different mechanism of catalysis by these two sub-families of kinases. Computer modeling based on PKA crystal structure in conjunction with sequence analysis suggest that the low sensitivity to staurosporine of CK2 may be accounted for by the bulky nature of three residues, Val66, Phe113 and Ile174 which are homologous to PKA Ala70, Met120 and Thr183, respectively. In contrast these PKA residues are either conserved or replaced by smaller ones in protein kinases highly sensitive to staurosporine inhibition. On the other hand, His160 which is homologous to PKA Glu170, appears to be responsible for the unique behaviour of CK2 with respect to a staurosporine derivative (CGP44171A) bearing a negatively charged benzoyl substituent: while CGP44171A is 10- 100-fold less effective than staurosporine against PKA and most of the other protein kinases tested, it is actually more effective than staurosporine for CK2 inhibition, but it looses part of its efficacy if it is tested on a CK2 mutant (H160D) in which His160 has been replaced by Asp. It can be concluded from these data that the catalytic sites of protein kinases are divergent enough as to allow a competitive inhibitor like staurosporine to be fairly selective, a feature that can be enhanced by suitable modifications designed based on the structure of the catalytic site of the kinase.

Alkaloids↗
PubMed2005

Studies of relationships between the GLUT10 Ala206Thr polymorphism and impaired insulin secretion.

AIMS: This study aimed to investigate if the previously observed association between the GLUT10 Ala206Thr polymorphism and variation in fasting and oral glucose-induced serum insulin concentrations could be replicated in a large-scale population-based cohort of Danish whites. METHODS: The GLUT10 Ala206Thr polymorphism was genotyped in a case-control study of 880 Type 2 diabetic patients and 4372 glucose-tolerant control subjects. The latter group was also enrolled in an assessment of fasting and post-OGTT circulating levels of plasma glucose and serum insulin in relation to genotype. The variant was genotyped by analysis of PCR-generated primer extension by matrix-assisted laser desorption/ionization time-of-flight analysis. RESULTS: The Ala206Thr variant was equally frequent among Type 2 diabetic patients and glucose-tolerant subjects (P = 0.9) and there was no difference in the distribution of genotype groups (P = 1.0). In the 4372 glucose-tolerant subjects there was no statistically significant association between the polymorphism and levels of fasting and post-oral glucose tolerance test plasma glucose and serum insulin along with the insulinogenic index and the homeostasis model of assessment for insulin resistance and insulin secretion. Likewise, in an age-stratified subgroup comprising 1264 subjects, we observed no relationships between the GLUT10 polymorphism and the selected metabolic features. CONCLUSIONS: The GLUT10 Ala206Thr polymorphism is not associated with Type 2 diabetes in the Danish population. Furthermore, in the present large-scale cohort, the polymorphism does not associate with phenotypes such as fasting and oral glucose-induced levels of plasma glucose and serum insulin.

Adult↗
PubMed2005

The late Nd reflects a memory trace containing amodal spatial information.

The early Nd reflects the analysis of simple features of selectively attended auditory stimuli, but the precise nature of the more complex processing reflected by the late Nd is unclear. The late but not the early Nd is sensitive to interference from a concurrently presented visual spatial attention switching task. This experiment investigated whether the late Nd is also sensitive to deeper visual attention switching. Twenty-one subjects performed a dichotic listening task concurrently with either visual spatial or visual letter matching attention switching tasks. Late Nd amplitude was reduced by the spatial but not the letter matching task, indicating insensitivity to deeper attention switching. P300 amplitude was reduced by both tasks. Reductions in N100 and P200 were uncorrelated. We propose that, in part, the late Nd reflects an amodal memory trace containing spatial information, possibly involving a "where" rather than a "what" auditory pathway.

Adolescent↗
PubMed2006

Mapping uptake of prenatal diagnosis for Down syndrome and other chromosome abnormalities across Victoria, Australia.

OBJECTIVE: To investigate geodemographic characteristics of women having prenatal diagnosis for Down syndrome and other fetal chromosome abnormalities in Victoria, Australia. METHODS: A descriptive analysis of population-based data on all confinements, amniocenteses and chorionic villus sampling for 1998 and 2002 was undertaken. Multivariate logistic regression analysis of 2002 data investigated geographical differences, including selected maternal features and a socioeconomic status measure that may be associated with uptake of diagnostic testing. RESULTS: After adjusting for age, parity of three or more children was associated with a significantly decreased likelihood of testing (P<0.001). Women from Africa were 61% less likely to have testing than women born in Australia (P<0.01). While overall uptake of testing was lower than average in rural regions, only the Loddon Mallee had a significantly decreased likelihood of testing (OR 0.71 (0.53, 0.95), P=0.02). A socioeconomic index of place of residence showed no association with uptake. Metropolitan and rural women giving birth in private hospitals were 31 and 60% more likely to have a test than women giving birth in public hospitals (P<0.01). CONCLUSION: Geographical differences influence uptake of prenatal diagnosis, probably related to access to services. However, other maternal demographic factors also play a role in uptake. To ensure equity in access and autonomy in women's reproductive choices, reasons for exceptionally low uptake in certain localities or within certain subgroups of pregnant women should be investigated further, followed by appropriate changes in service provision.

Adult↗
PubMed1992

A review of sutures and suturing techniques.

The ideal suture is strong, handles easily, and forms secure knots. It causes minimal tissue inflammation and does not promote infection. It stretches and accommodates wound edema. Although no single suture possesses all of these features, proper selection of sutures helps achieve better results in skin surgery. Proper suturing technique is essential for obtaining good cosmetic results and avoiding scarring and poor wound healing. Techniques that must be mastered include good eversion of skin edges, avoiding suture marks, maintaining uniform tensile strength along the skin edges, and precise approximation along skin edges.

Humans↗
PubMed1986

Premenstrual changes and changes in gonadal hormones.

Changes in plasma levels of estradiol and progesterone and their temporal relationship with changes in mood and behavior were studied along the menstrual cycle in 17 normal women with a wide range of severity and types of premenstrual changes (PMC). Emphasizing changes in hormonal levels over time as well as their rates of change, selective clinical features of premenstrual changes were found to be positively associated with peak levels of progesterone, its rate of decrease over time, and the ratio between the rates of decrease-over-time of progesterone and estradiol levels. A time-lag of 4-7 days between changes in plasma levels of progesterone and changes in clinical features was also found. Rate of change of estradiol was somewhat associated with clinical PMC. It is suggested that the association between gonadal hormones, other biological changes, and mood should be further studied as a diversified, dynamic, time-related process.

Adult↗
PubMed1987

Patterns of outpatient consultation: a survey of outpatients attending a metropolitan psychiatric hospital.

A survey of all outpatients (n = 1135) attending a regional psychiatric hospital during a 3-month period. Psychoses constituted 72% and non-psychotic disorders 25%. Psychoses had a greater proportion of long-term attenders while non-psychotic disorders, though frequent (43%) among recent attenders, showed a high attrition rate. Demographic characteristics, patterns of attendance, selected clinical features, level of functioning and difficulties of management of the different diagnostic groups are presented and discussed. Reasons are adduced to explain why patients who were deemed suitable for transfer to other care had not been discharged from hospital. Steps taken to reduce the patient load and increase the efficiency of the services are described.

Adolescent↗
PubMed1995

Infectious Disease in Ecuador.

The republic of Ecuador, which has a population of 10 million, is one of the smallest of the Andean countries in South America. Although it covers only an area of 110,000 square miles, it yields an extraordinary diversity of infectious diseases. Public health problems reflect socioeconomic realities and uniquely diverse climates, cultures, and geography. Equador extends from the Galapagos Islands 600 miles to the west, to inhabited Andean highlands with altitudes over 15,000 feet, and to both the coastal and Amazonian rain forests. Health statistics in Ecuador are widely variable by western standards. Life expectancy is 64-68 years, and infant mortality rates are up to 60 per 1000. The physical and geographic barriers to health care facilities are highly variable in different provinces. This was evidenced dramatically by recent death rates from cholera in 1991-92, which ranged from 0% in Guayaquil to over 50% in isolated highland villages or in the Oriente (eastern provinces). Major cities, provincial borders, and selected topographic features are illustrated in the accompanying map of Ecuador (Fig. 1.) This review reports data on some of the major infectious diseases existent in Ecuador. Emphasis is on the viral, bacterial, protozoal, or helminthic diseases, which are uncommon elsewhere in the world, but which are prevalent, or especially important to public health officials in Ecuador. Table 1 lists reportable disease categories in Ecuador, 1986-1993. Recognition of the diversity of infectious agents endemic to Ecuador may prove useful for diagnosis, treatment, and prevention of infectious diseases in international travelers.

Journal Article↗
PubMed1998

[Clinical analysis of patients with severe pneumonia requiring mechanical ventilation].

To clarify the clinical features and select the appropriate antibiotic therapy for patients with severe pneumonia requiring mechanical ventilation, we performed a clinical analysis of 65 patients with this condition. The following results were obtained. The majority of the patients were elderly males, whose performance status was poor (PS 2.2) and who had an underying disease. Abnormal physical signs included tachypnea, tachycardia and consciousness disturbance. Abnormal laboratory findings included hypoalbuminemia, and liver and renal dysfunction. The causative microorganisms were isolated from half of these patients. A number of antibiotics were administered and steroid pulse therapy was also performed for half of these patients. Nevertheless the prognosis was poor because the percentage of deaths was high (50.8%).

Adult↗
PubMed2006

Temporal subtraction in chest radiography: automated assessment of registration accuracy.

Radiologists routinely compare multiple chest radiographs acquired from the same patient over time to more completely understand changes in anatomy and pathology. While such comparisons are achieved conventionally through a side-by-side display of images, image registration techniques have been developed to combine information from two separate radiographic images through construction of a "temporal subtraction image." Although temporal subtraction images provide a powerful mechanism for the enhanced visualization of subtle change, errors in the clinical evaluation of these images may arise from misregistration artifacts that can mimic or obscure pathologic change. We have developed a computerized method for the automated assessment of registration accuracy as demonstrated in temporal subtraction images created from radiographic chest image pairs. The registration accuracy of 150 temporal subtraction images constructed from the computed radiography images of 72 patients was rated manually using a five-point scale ranging from "5-excellent" to "1-poor;" ratings of 3, 4, or 5 reflected clinically acceptable subtraction images, and ratings of 1 or 2 reflected clinically unacceptable images. Gray-level histogram-based features and texture measures are computed at multiple spatial scales within a "lung mask" region that encompasses both lungs in the temporal subtraction images. A subset of these features is merged through a linear discriminant classifier. With a leave-one-out-by-patient training/testing paradigm, the automated method attained an A(z) value of 0.92 in distinguishing between temporal subtraction images that demonstrated clinically acceptable and clinically unacceptable registration accuracy. A second linear discriminant classifier yielded an A(z) value of 0.82 based on a feature subset selected from an independent database of digitized film images. These methods are expected to advance the clinical utility of temporal subtraction images for chest radiography.

Algorithms↗
PubMed1998

Selection and combination of acoustic features for the description of pathologic voices.

The glottal to noise excitation ratio (GNE) is an acoustic measure designed to assess the amount of noise in a pulse train generated by the oscillation of the vocal folds. So far its properties have only been studied for synthesized signals, where it was found to be independent of variations of fundamental frequency (jitter) and amplitude (shimmer). On the other hand, other features designed for the same purpose like NNE (normalized noise energy) or CHNR (cepstrum based harmonics-to-noise ratio) did not show this independence. This advantage of the GNE over NNE and CHNR, as well as its general applicability in voice quality assessment, is now tested for real speech using a large group of pathologic voices (n = 447). A set of four acoustic features is extracted from a total of 22 mostly well-known acoustic voice quality measures by correlation analysis, mutual information analysis, and principal components analysis. Three of these measures are chosen to assess primarily different aspects of signal aperiodicity, while the fourth one indicates the noise content of the signal. All analysis methods lead to the same feature set that consists of a measure of period correlation, jitter, shimmer, and GNE. The two-dimensional projection of this set named "hoarseness diagram" allows a graphical illustration of voice quality that can be easily interpreted.

Adolescent↗
PubMed1993

Glucose uptake and catabolite repression in dominant HTR1 mutants of Saccharomyces cerevisiae.

Growth and carbon metabolism in triosephosphate isomerase (delta tpi1) mutants of Saccharomyces cerevisiae are severely inhibited by glucose. By using this feature, we selected for secondary site revertants on glucose. We defined five complementation groups, some of which have previously been identified as glucose repression mutants. The predominant mutant type, HTR1 (hexose transport regulation), is dominant and causes various glucose-specific metabolic and regulatory defects in TPI1 wild-type cells. HTR1 mutants are deficient in high-affinity glucose uptake and have reduced low-affinity transport. Transcription of various known glucose transporter genes (HXT1, HXT3, and HXT4) was defective in HTR1 mutants, leading us to suggest that HTR mutations affect a negative factor of HXT gene expression. By contrast, transcript levels for SNF3, which encodes a component of high-affinity glucose uptake, were unaffected. We presume that HTR1 mutations affect a negative factor of HXT gene expression. Multicopy expression of HXT genes or parts of their regulatory sequences suppresses the metabolic defects of HTR1 mutants but not their derepressed phenotype at high glucose concentrations. This suggests that the glucose repression defect is not a direct result of the metabolically relevant defect in glucose transport. Alternatively, some unidentified regulatory components of the glucose transport system may be involved in the generation or transmission of signals for glucose repression.

Blotting, Northern↗
PubMed1965

TAXONOMY OF PSEUDOMONAS PISCICIDA (BEIN) BUCK, MEYERS, AND LEIFSON.

Hansen, A. J. (University of Idaho, Moscow), O. B. Weeks, and R. R. Colwell. Taxonomy of Pseudomonas piscicida (Bein) Buck, Meyers, and Leifson. J. Bacteriol. 89:752-761. 1965.-Twenty strains of marine bacteria showing the properties of pigmentation and icthyotoxicity were studied for selected physiological features. A quantitative taxonomic analysis with an electronic computer was performed. Eighteen species of Pseudomonas were included in the computer analysis as reference strains. The marine collection formed a homogeneous cluster, 80% similarity, and showed a 67 to 70% similarity to certain of the Pseudomonas species: P. atlantica, P. geniculata, P. synxantha, and P. taetrolens. The marine strains are treated as a phenon describing the species P. piscicida. The species was characterized by the hypothetical Median Organism concept; P. piscicida 14 corresponded most closely to the Median Organism.

Anti-Bacterial Agents↗