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PubMed1998

Increase in Vdelta1+ gammadelta T cells in the peripheral blood and bone marrow as a selective feature of HIV-1 but not other virus infections.

Dysregulation of T-cell receptor (TCR) alphabeta bearing lymphocytes and an increase in Vdelta1+ gammadelta T cells are typical features of HIV-1 infection. However, the role of gammadelta T cells remains unclear. Therefore, peripheral blood mononuclear cells (PBMC) of 103 HIV-1-infected patients were investigated with respect to expression of Vdelta1. These results were compared to the Vdelta1 expression of bone marrow mononuclear cells (BMMC). In contrast to healthy controls, Vdelta1+ cells dominated among both PBMC and BMMC in HIV-1-infected patients. Analysis of the coexpression of CD25, CD8, HLA-DR and CD45RO revealed a high prevalence of Vdelta1/CD45RO and Vdelta1/HLA-DR double-positive PBMC only in HIV-1-infected patients but not in healthy donors. Furthermore, analysis of the gammadelta TCR repertoire in patients infected with hepatitis B virus, hepatitis C virus, herpes simplex virus (HSV)-1 and HSV-2 showed that the selective enhancement of Vdelta1+ cells was restricted to HIV infection and not observed in other virus diseases. Our data provide further support for the involvement of gammadelta T cells in immunosuppression and progression of HIV infection.

Adult↗
PubMed2002

Evaluation of selected features of Staphylococcus cohnii enabling colonization of humans.

Based on iron utilization, sensitivity to skin fatty acids, lipolytic and proteolytic activity the potential abilities of Staphylococcus cohnii strains to colonize humans were evaluated. The investigation included 60 strains that belong to both subspecies, viz. S. cohnii ssp. cohnii and S. cohnii ssp. urealyticus. Strains were isolated from different sources of the Intensive Care Unit and from non-hospital environment. Most of the strains were multiple antibiotic-resistant. Strains of both subspecies revealed a relatively low iron requirement. These strains were capable of utilizing iron bound in oxo acids and from host iron-binding proteins. S. cohnii ssp. urealyticus were more effective in iron uptake than S. cohnii ssp. cohnii. All investigated strains revealed sensitivity to skin fatty acids, but S. cohnii ssp. urealyticus strains were more resistant. Special features of strains of this subspecies promote colonization of humans.

Anti-Bacterial Agents↗
PubMed1987

Comparison of the ID3 algorithm versus discriminant analysis for performing feature selection.

Having obtained disappointing results in a small medical data set despite the fact that our data seemed to be well suited for induction via ID3, we decided to compare the performance of ID3 to discriminant analysis. Performance was gauged by the percentage of correct classification in a second, independent data set. Examples were obtained from a cardiology project on the accuracy of auscultation. There were 107 examples in the first data set and 67 cases in the second. We found that ID3 and discriminant analysis performed equally poorly, with ID3 classifying only 60% of the second set correctly and discriminant analysis classifying 66% of the second set correctly. Also, the ID3 probability statistic for estimating the accuracy of ID3 for classifying further cases was markedly optimistic compared to our actual second data set results. Moreover, with an increase in sample size, ID3 seemed to break down, producing a large, complex decision tree of dubious generality, whereas discriminant analysis, with a larger sample size, used more independent variables but maintained its first set accuracy. These data suggest that there is a need for more sophisticated algorithms than ID3, even at the risk of giving up some computational efficiency.

Adult↗
PubMed2005

Learning top-down gain control of feature selectivity in a recurrent network model of a visual cortical area.

We propose that the effects of attentional top-down modulations observed in the visual cortex reflect the simple strategy of strengthening currently relevant pathways in a task-dependent manner. To exemplify this idea, we set up a network model of a visual area and simulate the learning of a context-dependent 'go/no-go'-task. The model learns top-down gain-modulations of sensory representations based on reinforcements received from the environment. We also discuss how this idea relates to alternative interpretations like optimal coding hypotheses.

Adaptation, Physiological↗
PubMed2001

Rapid feature selective neuronal synchronization through correlated latency shifting.

Spontaneous brain activity could affect processing if it were structured. We show that neuron pairs in cat primary visual cortex exhibited correlated fluctuations in response latency, particularly when they had overlapping receptive fields or similar orientation preferences. Correlations occurred within and across hemispheres, but only when local field potentials (LFPs) oscillated in the gamma-frequency range (40-70 Hz). In this range, LFP fluctuations preceding response onset predicted response latencies; negative (positive) LFPs were associated with early (late) responses. Oscillations below 10 Hz caused covariations in response amplitude, but exhibited no columnar selectivity or coordinating effect on latencies. Thus, during high gamma activity, spontaneous activity exhibits distinct, column-specific correlation patterns. Consequently, cortical cells undergo coherent fluctuations in excitability that enhance temporal coherence of responses to contours that are spatially contiguous or have similar orientation. Because synchronized responses are more likely than dispersed responses to undergo rapid and joint processing, spontaneous activity may be important in early visual processes.

Action Potentials↗
PubMed1976

Elicited imitation of selected features of two american English dialects in Head Start children.

Three measures were used to check the bidialectal imitative facility of 100 black, white, and Spanish-speaking Head Start children. In general, blacks and Spanish-speaking subjects performed more accurately on black English markers than on Standard English markers and whites, the reverse. When the children did make an error on the feature marker they usually substituted the opposing dialectal marker. Blacks and Spanish-speaking subjects were more apt to be accurate on the total sentence when it was given in black English. Several explanations are offered for group similarities and differences.

Black or African American↗
PubMed2025

BISON: bi-clustering of spatial omics data with feature selection.

MOTIVATION: The advent of next-generation sequencing-based spatially resolved transcriptomics (SRT) techniques has reshaped genomic studies by enabling high-throughput gene expression profiling while preserving spatial and morphological context. Understanding gene functions and interactions in different spatial domains is crucial, as it can enhance our comprehension of biological mechanisms, such as cancer-immune interactions and cell differentiation in various regions. It is necessary to cluster tissue regions into distinct spatial domains and identify discriminating genes (DGs) that elucidate the clustering result, referred to as spatial domain-specific DGs. Existing methods for identifying these genes typically rely on a two-stage approach, which can lead to the phenomenon known as double-dipping. RESULTS: To address the challenge, we propose a unified Bayesian latent block model that simultaneously detects a list of DGs contributing to spatial domain identification while clustering these DGs and spatial locations. The efficacy of our proposed method is validated through a series of simulation experiments, and its capability to identify DGs is demonstrated through applications to benchmark SRT datasets. AVAILABILITY AND IMPLEMENTATION: The R/C++ implementation of BISON is available at https://github.com/new-zbc/BISON.

Software↗
PubMed2003

Unsupervised feature selection via two-way ordering in gene expression analysis.

MOTIVATION: Selection of genes most relevant and informative for certain phenotypes is an important aspect in gene expression analysis. Most current methods select genes based on known phenotype information. However, certain set of genes may correspond to new phenotypes which are yet unknown, and it is important to develop novel effective selection methods for their discovery without using any prior phenotype information. RESULTS: We propose and study a new method to select relevant genes based on their similarity information only. The method relies on a mechanism for discarding irrelevant genes. A two-way ordering of gene expression data can force irrelevant genes towards the middle in the ordering and thus can be discarded. Mechanisms based on variance and principal component analysis are also studied. When applied to expression profiles of colon cancer and leukemia, the unsupervised method outperforms the baseline algorithm that simply uses all genes, and it also selects relevant genes close to those selected using supervised methods. SUPPLEMENT: More results and software are online: http://www.nersc.gov/~cding/2way.

Algorithms↗
PubMed1983

Selected features of copper metabolism in the cat.

In separate experiments, domestic short hair kittens were fed diets based on soy or egg white protein containing from 1.98 to 9.64 or 0.58 to 9.8 micrograms Cu/g diet, respectively. Moreover, kittens were also nursed from queens fed diets containing either 0.58 or 12 micrograms Cu/g of diet. In each experiment, copper was analyzed in liver, spleen, lung, heart, muscle and brain samples. The liver copper concentration was the most responsive to changes in dietary copper intake. For example, in weanling kittens fed 0.58 or 9.8 micrograms Cu/g diet, the liver copper concentration was 24 or 45 micrograms/g wet weight, respectively. Likewise, the levels of hepatic Cu,Zn-superoxide dismutase were reduced in kittens fed the low copper diet. However, the concentrations of zinc, iron and manganese in liver, lung, spleen, brain, muscle and kidney were not consistently changed in response to low copper intakes. Anemia was also not a consistent feature in the copper-deficient cat or kitten, but signs of connective tissue lesions were observed in kittens born to and weaned from queens fed diets containing less than 1 micrograms Cu/g diet. Based on these observations and data for changes in growth in response to the differing levels of dietary copper, the copper requirement for the kitten was estimated to be 4-5 micrograms/g of diet (energy content approximately 5 kcal or 21 kJ per gram).

Age Factors↗
PubMed2004

Relevant, irredundant feature selection and noisy example elimination.

In many real-world situations, the method for computing the desired output from a set of inputs is unknown. One strategy for solving these types of problems is to learn the input-output functionality from examples in a training set. However, in many situations it is difficult to know what information is relevant to the task at hand. Subsequently, researchers have investigated ways to deal with the so-called problem of consistency of attributes, i.e., attributes that can distinguish examples from different classes. In this paper, we first prove that the notion of relevance of attributes is directly related to the consistency of attributes, and show how relevant, irredundant attributes can be selected. We then compare different relevant attribute selection algorithms, and show the superiority of algorithms that select irredundant attributes over those that select relevant attributes. We also show that searching for an "optimal" subset of attributes, which is considered to be the main purpose of attribute selection, is not the best way to improve the accuracy of classifiers. Employing sets of relevant, irredundant attributes improves classification accuracy in many more cases. Finally, we propose a new method for selecting relevant examples, which is based on filtering the so-called pattern frequency domain. By identifying examples that are nontypical in the determination of relevant, irredundant attributes, irrelevant examples can be eliminated prior to the learning process. Empirical results using artificial and real databases show the effectiveness of the proposed method in selecting relevant examples leading to improved performance even on greatly reduced training sets.

Journal Article↗
PubMed1987

Infective endocarditis in children with congenital heart disease: comparison of selected features in patients with surgical correction or palliation and those without.

The diagnostic and prognostic features of 44 episodes of infective endocarditis in 42 children with congenital heart disease were reviewed. Endocarditis occurred in 18 patients who had not had surgical correction or palliation of the defect (non-operated group). There were 26 episodes in 24 patients who had been treated surgically (operated group) (16 open and eight closed cardiac operations). Endocarditis occurred soon after open heart surgery in eight patients and as a late complication in the other 16. It recurred in two patients (operated group). Invasive monitoring and low cardiac output were consistent features in those patients who had endocarditis soon after open heart surgery whereas dental treatment was a common feature in non-operated cases and after closed cardiac operations. Late cases of endocarditis after open heart surgery had various microbiological features that were not typical of infection after dental problems. Gram positive infections occurred in non-operated patients and in those who had had closed cardiac operations. The group that had open heart surgery had infections caused by Gram positive, Gram negative, and anaerobic bacteria and fungi. Fever, anaemia, leucocytosis, and positive blood cultures were the only consistent findings. Vegetations were seen in nine of 12 patients at cross sectional echocardiography. All 12 (four non-operated, one closed, and seven open cases) needed acute surgical treatment. The mortality from infective endocarditis was 17% for non-operated cases, 0% for those who had had closed heart surgery, and 50% for those who had had open heart surgery. Infective endocarditis after open heart surgery differs from that in the other subgroups in terms of microbiology, source of infection, and outcome and its early diagnosis depends on a thorough investigation of minimal symptoms and signs.

Adolescent↗
PubMed2001

Selected features of nonendocrine pancreatic cancer.

We survey some interesting features of gene expression in nonendocrine pancreatic cancer, the response to some less widely known agents as they impact on pancreatic cell proliferation and programmed death, and several developing approaches to therapy. The proliferative and cellular suicide responses of Panc-1 cells to the free radical spin trap, NTBN, and to the 5-lipoxygenease inhibitor, MK 886, the latter assessed with CLONTECH Atlas Human cDNA Array 1, are reviewed. Difficulties in identifying those factors whose suppression or augmentation could result in inhibition of malignantly transformed cell properties are considered.

Animals↗
PubMed1978

Shedd's formulations concerning the hyperkinetic syndrome--an empirical test of selected features.

According to Shedd's (1968) formulations, one of the distinguishing characteristics of hyperkinetic children is the score pattern which they earn on different types of ability tests. Specifically, Shedd's work suggests that IQs from a picture vocabulary test, the WISC, and a drawing test should show the following order relationship: picture vocabulary greater than WISC greater than drawing. This hypothesis was investigated for 62 overactive children (47 boys and 15 girls) enrolled in classes for learning disabled. The findings support Shedd's since IQs from the Ammons' test were significantly higher than WISC IQs which were significantly higher than IQs from the Goodenough-Harris. The magnitudes of the mean differences in scores for the three tests were within the range indicated by Shedd and 51 of the 62 children showed the order of scores he specified.

Adolescent↗
PubMed2001

Exclusion from participation in medicare and medicaid: some selected features and distinctions from state and federal law.

The sanction of exclusion of a practitioner from participation in government funded healthcare programs because of his own health program offenses has existed since 1977 under federal laws and 1997 under state statutes. Now, severe Civil Monetary Penalties can be assessed in addition to exclusion; and, practitioners can be severely fined, as well as themselves excluded, if they hire someone excluded while at other employment, if that new employee's services are reimbursed, directly or indirectly, by a federal health care program even if that excluded employee does not furnish direct patient care to the government program beneficiary.

Health Services Misuse↗