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Results for “Functional analysis”

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At least 145 records · Page 8Linked to original sources
PubMed1999

Functional analysis and treatment of problem behavior exhibited by elementary school children.

A functional analysis involving antecedent events was conducted with 4 students who had been identified as having behavior problems. Off-task behavior was measured while task difficulty and level of adult attention were manipulated during analogue sessions. Results revealed two patterns: Three students displayed higher rates of off-task behavior during difficult tasks, and 1 displayed higher rates of off-task behavior during sessions with low attention. Improved behavior was observed when students were taught an alternative behavior that matched the assessment results.

Attention↗
PubMed2002

Teacher acquisition of functional analysis methodology.

The current study examined methods for training teachers to use functional analysis methods. Teachers first received written and verbal instructions detailing attention and demand conditions. They then received training that included modeling, rehearsal, and performance feedback. Finally, probes were taken during ongoing class instruction. Results indicate that teachers acquired the skills and used them in classroom settings.

Behavior Therapy↗
PubMed1977

[Functional analysis in stomatology].

A survey of diagnostic details is made on which functional analysis is based. Symptoms connected with the temporo-mandibular joint, muscle palpation, radiological demonstration of the temporo-mandibular joint, and registration of the positional jaw relation are especially dealt with. The methods of examination which are prerequisite to a safe diagnosis are critically evaluated.

Dental Articulators↗
PubMed1983

Multiple discriminant function analysis of sex and race in the postcranial skeleton.

Terry Collection femora and innominates of 260 American Whites and Blacks (65 males and 65 females of each race) were analyzed by multiple discriminant function analysis. A stepwise procedure produced three optimal discriminant functions using 15 of our 32 measurements. These functions correctly identified 95% of the sample. The first two-one for sex and one for race-are statistically and biologically significant and form the basis of our analysis. The sexing function manifested both size and shape elements. Prominent among the former was joint size--acetabular diameter and epicondylar diameter of the femur. The shape elements included form of the greater sciatic notch and of the inferomedial aspect of the pubic body. The racing function highlighted a pattern of greater innominate dimensions, exclusive of the acetabular joint, in Whites. This was in contrast to the greater length of the Black femur. Overall, the function seems to express the established differences between the races in the ratio of lower limb length to torso length. While these functions have been applied successfully to forensic cases with confirmed identifications, questions regarding the breadth of applicability of discriminant functions make it desirable to validate our results on new material from the Terry and other collections.

Analysis of Variance↗
PubMed2001

Application of nano-diffraction to local atomic distribution function analysis of amorphous materials.

A method is proposed for the local atomic distribution function analysis of amorphous materials. This method is based on local halo-electron diffraction intensity analysis with nano-sized electron probes as small as 25 to approximately 3 nm, taking advantage of the intensity recording with imaging plate. Nanodiffraction and selected area electron diffraction (SAED) patterns from an amorphous SiNx (x approximately 4/3) thin film were taken using a conventional transmission electron microscope operated at 200 kV and recorded on imaging plates. An intensity correction to omit inelastic intensity was made using electron energy-loss spectroscopy. When a beam-convergence angle is larger than 1 x 10(-3) rad, the Wiener-filter deconvolution method becomes helpful in producing atomic pair distribution functions (PDFs) from the nano-diffraction intensity profiles that are more similar to the PDF from the SAED intensity. This technique was applied to the analysis of local amorphous structures of SiO2 layers formed by an oxygen-ion implantation into single crystal SiC.

Journal Article↗
PubMed1995

In vivo functional analysis of the Ras exchange factor son of sevenless.

The Son of sevenless (Sos) protein functions as a guanine nucleotide transfer factor for Ras and interacts with the receptor tyrosine kinase Sevenless through the protein Drk, a homolog of mammalian Grb2. In vivo structure-function analysis revealed that the amino terminus of Sos was essential for its function in flies. A molecule lacking the amino terminus was a potent dominant negative. In contrast, a Sos fragment lacking the Drk binding sites was functional and its activity was dependent on the presence of the Sevenless receptor. Furthermore, membrane localization of Sos was independent of Drk. A possible role for Drk as an activator of Sos is discussed and a Drk-independent interaction between Sos and Sevenless is proposed that is likely mediated by the pleckstrin homology domain within the amino terminus.

Animals↗
PubMed1997

Functional analysis of immunoreceptor tyrosine-based activation motif (ITAM)-mediated signal transduction: the two YxxL segments within a single CD3zeta-ITAM are functionally distinct.

Functional analysis of the immunoreceptor tyrosine-based activation motif (ITAM) derived from the membrane-proximal ITAM of CD3zeta demonstrates that mutations at either the tyrosine or leucine residues in the N-terminal YxxL segment of the ITAM abolish all signal transduction functions of this ITAM. In contrast, mutations at the tyrosine or leucine residues in the C-terminal YxxL segment abrogate signals for interleukin (IL)-2 production but do not prevent tyrosine phosphorylation of the N-terminal tyrosine of the ITAM, lck association with the ITAM, activation of phospholipase C-gamma1 or calcium mobilization. Cross-linking of chimeric receptors containing a C-terminal YxxL leucine mutation induces tyrosine phosphorylation of ZAP70 but without stable binding to the phosphorylated ITAM. These results indicate that the two YxxL segments in an ITAM are functionally distinct and that both are essential for ZAP70 binding and IL-2 production. Furthermore, tyrosine phosphorylation of ZAP70 per se is not sufficient to trigger the downstream events leading to IL-2 production. Substitution of an alanine for the bulky side chain at the Y+1 position of the N-terminal YxxL segment reduces the receptor cross-linking requirement necessary to achieve cellular activation and the absolute dependence on lck in this process. Our results reveal that both the number of ITAM as well as the specific amino acid residues within a single ITAM determine the extent of chimeric receptor cross-linking required to trigger tyrosine phosphorylation-dependent signaling events.

Amino Acid Sequence↗
PubMed1992

Functional analysis of human papillomavirus type 16 E7 by complementation with adenovirus E1A mutants.

Functional analysis of human papillomavirus type 16 E7 protein by complementation with adenovirus E1A mutants in baby rat kidney cells has shown that the retinoblastoma gene product (RB)-binding region of E7 can substitute in trans for that of E1A. An N-terminal E7 mutant was unable to complement an E1A mutant unable to bind p300, indicating that the two mutants were defective for functionally equivalent activities. E7 proteins with mutations within the RB-binding region were also unable to complement either the non-p300-binding E1A mutant or the N-terminal E7 mutant, suggesting that these mutations affect more than just RB binding.

Adenovirus Early Proteins↗
PubMed1998

Drug-induced phenotypes provide a tool for the functional analysis of yeast genes.

The post-genome sequencing era of Saccharomyces cerevisiae is defined by the analysis of newly discovered open reading frames of unknown function. In this report, we describe a genetic method for the rapid identification and characterisation of genes involved in a given phenotype. This approach is based on the ability of overexpressed genomic DNA fragments to cure an induced phenotype in yeast. To validate this concept, yeast cells carrying a yeast DNA library present on multicopy plasmid vectors were screened for resistance to the antifungal drug ketoconazole. Among 1.2 million colonies 13 clones tested positive, including those expressing the lanosterol C-14 demethylase, known to be a cellular target for azole drugs, and the cytochrome-c oxidase of mitochondria, regulating the respiratory chain electron transport. Several other resistant clones were identified, which code for yeast proteins of so far unknown function. These genes may represent potential candidates for antifungal drug effects. Together with the availability of the entire yeast genome sequence, the described genetic screening method is a powerful tool for the effective functional analysis of yeast genes.

Antifungal Agents↗
PubMed1994

Functional analysis of transcription of the Mycobacterium tuberculosis 16S rDNA-encoding gene.

A functional analysis of Mycobacterium tuberculosis 16S ribosomal RNA (rRNA) transcription and processing was undertaken in this study. RNA:DNA hybridizations indicated that the maximum transcriptional activity of rRNA-encoding genes (rDNA) corresponded to the earliest period of exponential growth. Transcription start points (tsp) were mapped by primer extension analysis of RNA from M. tuberculosis H37Rv and M. tuberculosis H37Ra. An identical pattern of rRNA transcription and processing was exhibited in laboratory-grown cultures of M. tuberculosis H37Rv and H37Ra. One promoter represents the structural equivalent of the Escherichia coli rrn P2 promoter. The precursor transcripts are processed into mature 16S rRNA through a pathway that includes recognition of RNA secondary structure by ribonuclease III (RNase III) in the stem structure surrounding the 16S rRNA indicating that at least this RNA processing step is conserved in mycobacteria and E. coli. The 16S rDNA promoter region from H37Rv was cloned upstream from the promoterless chloramphenicol (Cm) acetyltransferase (CAT)-encoding gene (cat) in a shuttle plasmid vector, pSD7. The promoter-fusion construct, pSD7.16S, was characterized by CAT assays, measurement of percent survival in Cm-containing medium and in vivo transcription analysis in M. smegmatis. The M. smegmatis transformant exhibited a CAT activity of 16,669 nmol/min per mg protein, suggesting that the 16S promoter was of exceptionally high strength. Two tsp utilized in M. tuberculosis were also employed in M. smegmatis. The cat mRNA synthesized under the direction of the ribosomal promoter was less stable, as compared to genome-derived rRNA.

Base Sequence↗
PubMed1989

A comparison of dummy variable versus traditional multiple discriminant function analysis.

The authors compare the use of dummy variable and traditional multiple discriminant function analysis when dealing with research questions where ratio or nominal scale independent variables can be used. A healthcare-related example of using dv MDF is given and the authors conclude that it is superior to traditional MDF for determining variable importance and developing market segment profiles.

Analysis of Variance↗
PubMed2001

Functional analysis and treatment of inappropriate verbal behavior.

The present study examined the possible function of inappropriate verbal behavior of an adult man who had been diagnosed with both mental retardation and psychosis. Results of a functional analysis indicated that inappropriate verbal utterances were maintained by attention. An intervention consisting of the differential reinforcement of appropriate verbal behavior effectively reduced the inappropriate behavior.

Adult↗
PubMed1984

[Importance of a structural and functional analysis of the fallopian epithelium in tubal pregnancy and endometrial adenocarcinoma].

The structural-functional analysis of the uterine tube epithelium is proposed as an additional indirect index of the ovarian hormonal activity. Several standard types of the tubal epithelium are distinguished (proliferative, secretory, gravidal, non-functional, proliferative-hyperplastic) which are characteristic of certain level of various sex hormones in the woman organism. The control data obtained are used for the evaluation of the hormonal background in women with tubal pregnancy and endometrial carcinoma. The signs of ovarian dysfunction were observed in 55.2 and 43.3% of cases respectively and these symptoms were reflected in the pathogenesis and clinical picture of the diseases studied.

Adenocarcinoma↗
PubMed1998

Cloning and functional analysis of human p51, which structurally and functionally resembles p53.

The p53 tumor suppressor gene, which is induced by DNA damage and/or stress stimuli, causes cells to undergo G1-arrest or apoptotic death; thus it plays an essential role in human carcinogenesis. We have searched for p53-related genes by using degenerate PCR, and have identified two cDNA fragments similar to but distinct from p53: one previously reported, p73, and the other new. We cloned two major splicing variants of the latter gene and named these p51A and p51B (a human homologue of rat Ket). The p51A gene encodes a 448-amino-acid protein with a molecular weight of 50.9 kDa; and p51B, a 641-amino-acid protein with a molecular weight of 71.9 kDa. In contrast with the ubiquitous expression of p53, expression of p51 mRNA was found in a limited number of tissues, including skeletal muscle, placenta, mammary gland, prostate, trachea, thymus, salivary gland, uterus, heart and lung. In p53-deficient cells, p51A induced growth-suppression and apoptosis, and upregulated p21waf-1 through p53 regulatory elements. Mutations in p51 were found in some human epidermal tumors.

Alternative Splicing↗
PubMed1998

The effect of reinforcer preference on functional analysis outcomes.

We combined functional analyses and concurrent-schedule assessments to identify reinforcer preference during situations in which problem behavior may have been multiply controlled. Participants were 3 children with developmental delays who engaged in problem behavior during toy play with another child and one adult present, suggesting that problem behavior may have been maintained by adult attention or access to tangible reinforcement. Thus, conditions were designed to test attention and access-to-toys hypotheses. Initial functional analyses suggested multiple control. Subsequent concurrent-schedule assessments identified preference between the reinforcers, and treatments were based on these findings. Findings are discussed regarding the assessment of potentially multiply controlled problem behavior.

Adult↗
PubMed1991

Structure-function analysis of the histidine permease and comparison with cystic fibrosis mutations.

Traffic ATPases constitute a superfamily of transporters that include prokaryotic permeases and medically important eukaryotic proteins, such as the multidrug resistance P-glycoprotein and the cystic fibrosis gene product. We present a structure-function analysis of a member of this superfamily, the prokaryotic histidine permease, using mutations generated both in vitro and in vivo, and assaying several biochemical functions. The analysis supports a previously predicted structural model and allows the assignment of specific functions to several predicted structural features. Mutations in the secondary structure features which form the nucleotide-binding pocket in general cause the loss of ATP binding activity. Mutations in the helical domain retain ATP binding activity. Several mutations have been identified which may affect the signaling mechanism between ATP hydrolysis and membrane translocation. We relate our findings to those emerging from the recent biochemical and genetic analyses of cystic fibrosis mutations.

ATP-Binding Cassette Transporters↗
PubMed1991

Transfer function analysis of the circulation: unique insights into cardiovascular regulation.

We have demonstrated previously that transfer function analysis can be used to precisely characterize the respiratory sinus arrhythmia (RSA) in normal humans. To further investigate the role of the autonomic nervous system in RSA and to understand the complex links between respiratory activity and arterial pressure, we determined the transfer functions between respiration, heart rate (HR), and phasic, systolic, diastolic, and pulse arterial pressures in 14 healthy subjects during 6-min periods in which the respiratory rate was controlled in a predetermined but erratic fashion. Pharmacological autonomic blockade with atropine, propranolol, and both, in combination with changes in posture, was used to characterize the sympathetic and vagal contributions to these relationships, as well as to dissect the direct mechanical links between respiration and arterial pressure from the effects of the RSA on arterial pressure. We found that 1) the pure sympathetic (standing + atropine) HR response is characterized by markedly reduced magnitude at frequencies greater than 0.1 Hz and a phase delay, whereas pure vagal (supine + propranolol) modulation of HR is characterized by higher magnitude at all frequencies and no phase delay; 2) both the mechanical links between respiration and arterial pressure and the RSA contribute significantly to the effects of respiration on arterial pressure; 3) the RSA contribution to arterial pressure fluctuations is significant for vagal but not for sympathetic modulation of HR; 4) the mechanical effects of respiration on arterial pressure are related to the negative rate of change of instantaneous lung volume; 5) the mechanical effects have a higher magnitude during systole than during diastole; and 6) the mechanical effects are larger in teh standing than the supine position. Most of these findings can be explained by a simple model of circulatory control based on previously published experimental transfer functions from our laboratory.

Adult↗
PubMed2000

The mouse Psma1 gene coding for the alpha-type C2 proteasome subunit: structural and functional analysis, mapping, and colocalization with Pde3b on mouse chromosome 7.

We have isolated and functionally characterized the mouse gene for the C2 subunit of the 20S proteasome. The gene contains 10 exons distributed over a region of 12 kb on the distal end of mouse chromosome 7. Its exon-intron structure differs from those of the other few known proteasome genes. Transfection assays revealed that 1.5 kb of 5' flanking sequence is active as promoter in cultured myoblasts. Deletion reporter constructs narrowed this presumptive promoter region to within 450 bp upstream of the translation initiation site. Several consensus motifs for transcription factor binding sites were identified in this upstream region of the gene. Psma1 was mapped to mouse chromosome 7 using the interspecific backcross DNA panels from The Jackson Laboratory. Additional mapping studies showed that the mouse genes Psma1 and Pde3b are closely linked, residing between cM 53 and 53.3 in a region syntenic to human chromosome 11p15. Our results extend the structural and functional analysis of genes encoding the 20S proteasome subunits and provide the basis for the study of their regulation.

3',5'-Cyclic-AMP Phosphodiesterases↗