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At least 883 records · Page 49Linked to original sources
PubMed2006

Metabolomic discrimination of different grades of pine-mushroom (Tricholoma matsutake Sing.) using 1H NMR spectrometry and multivariate data analysis.

Metabolomic analysis of raw and cooked pine-mushrooms (Tricholoma matsutake Sing.) of different grades was performed using (1)H nuclear magnetic resonance (NMR) spectrometry and principal component analysis (PCA). PCA of the (1)H NMR spectra of aqueous fractions allowed different grades of raw pine-mushroom to be discriminated by a combination of principal component (PC) 1 and PC 2, which accounted cumulatively for 94.1% of the variation in all variables. The major peaks in the (1)H NMR spectra that contributed to discrimination of raw mushrooms were assigned to choline, trehalose, threonine, leucine/isoleucine, succinic acid, alanine, and fumaric acid. The combination of PC 1 (70.8%) and PC 3 (7.5%) allowed different grades of cooked pine-mushroom to be discriminated, and the major peaks in the (1)H NMR spectra that contributed to discrimination of cooked mushrooms were assigned to succinic acid, trehalose, and fumaric acid. This metabolomic analysis-based method allows different grades of pine-mushroom to be distinguished without any prepurification.

Agaricales↗
PubMed2000

[Categorizing variables in the statistical analysis of data: consequences for interpreting the results].

Frequently during the process of data analysis in epidemiological studies, the scale of one or more continuous variables is changed. The objective of this paper was to assess the consequences of categorizing variables during data analysis. We studied three situations with different scenarios for statistical analysis with regression models. The results show that dichotomizing continuous variables can substantially modify the relationships between dependent and independent variables. Thus, for example, in epidemiological studies trying to evaluate the effect of an exposure on a response, the magnitude and/or the direction of this effect can be biased by dichotomizing a variable. We therefore recommend avoiding, as much as possible, the categorization of variables when doing analyses.

Analysis of Variance↗
PubMed1976

Multivariate analysis: data reduction and treatment evaluation.

In a recent article, Everitt (1975) discussed several problems with multivariate techniques. However, two useful applications of multivariate techniques were not covered. The present paper describes the use of factor analysis to reduce a large array of outcome variables to a statistically manageable number, and multivariate analysis of variance to determine the relative effectiveness of several treatment regimes where a single outcome variable cannot be specified. It is concluded that the advantages of a multivariate approach out-weigh the disadvantages, provided the researcher is careful in interpreting and reporting his results.

Alcoholism↗
PubMed1977

Computer processing of fatty acid analysis data.

A Fortran computer program for the processing of fatty acid data from the anlysis of fats and oils by gas-liquid chromatography is described. The analytical method and calculations are described primarily for the analysis of butterfat and margaine fat, but with minor changes could be adapted to suit other fats and oils. The program computes the concentration of each fatty acid as weight % and mole %, the percentage glycerol, the theoretical iodine value, and other relevant combinations of fatty acids.

Chemical Phenomena↗
PubMed2006

Computer programs for population genetics data analysis: a survival guide.

The analysis of genetic diversity within species is vital for understanding evolutionary processes at the population level and at the genomic level. A large quantity of data can now be produced at an unprecedented rate, requiring the use of dedicated computer programs to extract all embedded information. Several statistical packages have been recently developed, which offer a panel of standard and more sophisticated analyses. We describe here the functionalities, special features and assumptions of more than 20 such programs, indicate how they can interoperate, and discuss new directions that could lead to improved software and analyses.

Computers↗
PubMed1993

Teacher use of descriptive analysis data to implement interventions to decrease students' problem behaviors.

We conducted two field studies using a behavioral consultation approach to reduce children's problem behaviors in public school settings. The first study consisted of a descriptive analysis in which the students and their teachers were observed during naturally occurring classroom activities. The results of the descriptive analysis provided hypotheses regarding the operant function of the students' problem behaviors. The hypotheses were tested in the second experiment directly through a modified experimental analysis and indirectly through an evaluation of the treatment effects. The interventions were designed to disrupt the inappropriate response-reinforcer relation by discontinuing contingent reinforcement (i.e., extinction), providing the reinforcer contingent on appropriate play behaviors, and teaching the students verbal skills functionally equivalent to the inappropriate response. The classroom teachers were trained to implement the interventions and conduct the experimental analyses during classroom activities in which the problem behaviors occurred most frequently. The interventions were effective in decreasing the students' problem behaviors while concurrently increasing their appropriate verbal skills.

Adolescent↗
PubMed2000

Panic disorder in Thailand: a report on the secondary data analysis.

Panic disorder (PD) is one of the most common psychiatric illnesses in Thailand but the picture of PD in Thailand is not clear. Therefore, the objective of this research was to review, summarize, and analyse data from research reports concerning the clinical aspects of PD in Thailand. Relevant papers were searched comprehensively. Four groups of data including prevalence and incidence rates, sex differences, clinical symptoms during panic attacks, and scores of the Hamilton anxiety scale (HAM-A) were extracted where available. Data thus obtained were then grouped and compared. It was found that 2.1 per cent to 12.4 per cent of patients who visited the psychiatric outpatient clinic for the first time were diagnosed as having PD. Males were affected at a similar rate to females with a ranging ratio of female:male from 1.3:1 to 0.67:1. The most common symptoms during panic attacks were palpitations, chest pain or discomfort, and dizziness or vertigo, similar to South American studies. Regarding scores of original HAM-A, mean somatic anxiety scores of PD patients who attended the cardiology clinic were significantly higher than generalized anxiety disorder patients (15.0 vs 9.8, p < 0.05). PD patients who attended the psychiatric clinic had higher mean scores of HAM-A when compared to PD patients who visited the cardiology clinic, but it was not statistically significant (27.7 vs 26.6, p > 0.05). However, the fear item of PD patients at the psychiatric clinic had significantly higher scores (2.1) than the other one (0.7). The difference between these findings and those of Western studies may be caused by cultural factors. Thai men tend to react more promptly to panic attacks and seek medical attention while women mostly attributed their symptoms to "Air Disease". However, incidence rates from other rural areas are lacking. Before conclusions can be drawn, research on epidemiologic data in the community should be further investigated.

Female↗
PubMed1980

[Statistical data analysis of physiologic parameters in patients with endomorphic-depressive phases. An attempt to explore the changeable effects between physiologic parameters, examination times during the phase and various experimental conditions].

Range-corrected (according to Lykken) physiological data from the parameters of heart rate (HF), respiratory rate (AF), skin potential (skin potential level; SPL; skin potential response, SPR) and skin resistance level, SRL; skin resistance response, SRR) were obtained under an acoustic activation paradigm in the course of a longitudinal investigation on 7 women with endomorph depression treated with thymoleptic medication. These data form the matrix for two- and threefold analyses of variance as well as for concordance analyses according to Kendall. During six measurements (three each taken in the morning and evening) one finds differing levels of activation: relatively low ones at the beginning and at the end, high ones during the 'labilization phase' of the treatment. The varying 'reactivity' to the diverse examination sequences of an acoustic activation program is little affected by the degree of these changes; patient-specific 'characteristics' of the course of the activation are just as recognizable throughout the course of the investigation as are 'stimulus-specific' reactions. Each of the parameters is appropriate for the estimation of different physiological variables; SPR seems rather to be a situation-specific variable, HF and AF are probably suitable for establishing the level of activation, while changes in SPL seem to represent patient-specific characteristics.

Adult↗
PubMed2002

Simultaneous classification and feature clustering using discriminant vector quantization with applications to microarray data analysis.

In many applications of supervised learning, automatic feature clustering is often desirable for a better understanding of the interaction among the various features as well as the interplay between the features and the class labels. In addition, for high dimensional data sets, feature clustering has the potential for improvement in classification accuracy and reduction in computational complexity. In this paper, a method is developed for simultaneous classification and feature clustering by extending discriminant vector quantization (DVQ), a prototype classification method derived from the principle of minimum description length using source coding techniques. The method incorporates feature clustering with classification performed by fusing features in the same clusters. To illustrate its effectiveness, the method has been applied to microarray gene expression data for human lymphoma classification. It is demonstrated that incorporating feature clustering improves classification accuracy, and the clusters generated match well with biological meaningful gene expression signature groups.

Algorithms↗
PubMed2000

Real-time 3D echocardiographic data analysis for left ventricular volume estimation.

A new computerized semi-automatic method for left ventricular chamber segmentation is presented. The left ventricle is imaged by real-time three-dimensional echocardiography. This real-time data acquisition method allows accurate evaluation of chamber size and shape, even in case there are cavities with irregular geometry. The surface detection model is based on a partial differential equation that propagates interfaces with curvature dependent speeds. The equation is solved by applying numerical methods for conservation laws. The method consists of one step only. Initial conditions are manually established on a small subset of slices of the entire volume. The solution obtained is a surface corresponding to the surface between LV cavity and LV endocardium. This mathematical model is applied to sequences of frames of human hearts (volume range: 34-109 ml) imaged by real-time 3D echocardiography. Volume estimates show an excellent correlation with those obtained by manual tracing (r=0.99).

Cardiac Volume↗
PubMed2006

[Investigation on indication of fuzheng huayu capsule against hepatic fibrosis and its non-invasive efficacy evaluation parameters: data analysis of liver biopsy of 50 patients with chronic hepatitis B before and after treatment].

OBJECTIVE: To investigate the indication of Fuzheng Huayu Capsule (FHC) against hepatic fibrosis and its non-invasive efficacy evaluation parameters. METHODS: Data involving hepatic fibrotic patients received twice liver biopsy before and after FHC treatment were received from multi-center, randomized, double-blind, controlled clinical trials and analyzed. The changes of indexes related to inflammation of hepatic tissue and liver function, serological and virologic parameters of fibrosis, blood routine test, hepatic ultrasonic test as well as clinical symptoms and signs of patients were compared between patients alleviated (assigned to the effective group) and un-alleviated (assigned to the ineffective group) by the treatment. RESULTS: (1) The degree of liver fibrosis, ALT activity and the scores of symptoms of hypochondriac pain and dry mouth before treatment were remarkably higher in the effective group than those in the ineffective group. (2) Level of ALT activity decreased in both groups after treatment. In the effective group, the grading scores of hepatic inflammatory significantly decreased after treatment (P < 0.01), levels of AST and GGT decreased after 3 months' treatment, and levels of GGT and PT significantly decreased after treated for 6 months, as compared to those in the ineffective group, showing significant difference. (3) Levels of serum hyaluronic acid (HA) and collagen type III (P-III-P) remarkably decreased after 12 weeks' treatment in the effective group. (4) Symptoms and signs were improved at various degrees in the two groups, but the improvement in dim and blackish complexion was more significant in the effective group than that in the ineffective group. (5) The changes in virologic parameters of hepatitis B virus, blood routine and hepatic ultrasonic test between the two groups showed no significant difference respectively. CONCLUSIONS: (1) FHC showed better effect against hepatic fibrosis in patients of fibrotic stage around S3, with obvious active hepatic inflammation and symptoms of hypochondriac pain and dry mouth, which could be taken as a referential index in clinical practice for indication decision. (2) The increase of serum albumin, decrease of GGT, AST, PT, HA, and P-III-P as well as the improvement of signs of dim and blackish complexion could be regarded as the referential indexes of effectiveness of FHC against hepatic fibrosis. These parameters are valuable non-invasive indices for diagnosis of hepatic fibrosis and efficacy evaluation of its treatment.

Adult↗
PubMed2006

The cost-effectiveness of antiretroviral treatment in Khayelitsha, South Africa--a primary data analysis.

BACKGROUND: Given the size of the HIV epidemic in South Africa and other developing countries, scaling up antiretroviral treatment (ART) represents one of the key public health challenges of the next decade. Appropriate priority setting and budgeting can be assisted by economic data on the costs and cost-effectiveness of ART. The objectives of this research were therefore to estimate HIV healthcare utilisation, the unit costs of HIV services and the cost per life year (LY) and quality adjusted life year (QALY) gained of HIV treatment interventions from a provider's perspective. METHODS: Data on service utilisation, outcomes and costs were collected in the Western Cape Province of South Africa. Utilisation of a full range of HIV healthcare services was estimated from 1,729 patients in the Khayelitsha cohort (1,146 No-ART patient-years, 2,229 ART patient-years) using a before and after study design. Full economic costs of HIV-related services were calculated and were complemented by appropriate secondary data. ART effects (deaths, therapy discontinuation and switching to second-line) were from the same 1,729 patients followed for a maximum of 4 years on ART. No-ART outcomes were estimated from a local natural history cohort. Health-related quality of life was assessed on a sub-sample of 95 patients. Markov modelling was used to calculate lifetime costs, LYs and QALYs and uncertainty was assessed through probabilistic sensitivity analysis on all utilisation and outcome variables. An alternative scenario was constructed to enhance generalizability. RESULTS: Discounted lifetime costs for No-ART and ART were US$2,743 and US$9,435 over 2 and 8 QALYs respectively. The incremental cost-effectiveness ratio through the use of ART versus No-ART was US$1,102 (95% CI 1,043-1,210) per QALY and US$984 (95% CI 913-1,078) per life year gained. In an alternative scenario where adjustments were made across cost, outcome and utilisation parameters, costs and outcomes were lower, but the ICER was similar. CONCLUSION: Decisions to scale-up ART across sub-Saharan Africa have been made in the absence of incremental lifetime cost and cost-effectiveness data which seriously limits attempts to secure funds at the global level for HIV treatment or to set priorities at the country level. This article presents baseline cost-effectiveness data from one of the longest running public healthcare antiretroviral treatment programmes in Africa that could assist in enhancing efficient resource allocation and equitable access to HIV treatment.

Journal Article↗
PubMed2004

Algorithm for locating analytes of interest based on mass spectral similarity in GC x GC-TOF-MS data: analysis of metabolites in human infant urine.

The developed algorithm reported herein, referred to as "DotMap," addresses the need to rapidly identify analyte peak locations in gas chromatography x gas chromatography-time of flight mass spectrometry (GC x GC-TOF-MS) data. The third-order structure of GC x GC-TOF-MS data is such that at each point in the GC x GC chromatogram, a complete mass spectrum is measured. DotMap utilizes this third-order structure to search for the location of a given spectrum of interest in a complete data set, or in a user selected portion of the complete data set. The algorithm returns a contour plot indicating the location of signal(s) with the most similar mass spectra to the analyte of interest. A spectrum from the region indicated is then subjected to an automated mass spectral search to give immediate feedback on the accuracy of the analysis. This algorithm was investigated with a trimethylsilyl (TMS) derivatized human infant urine sample that contained organic acid metabolites. One hundred percent of 12 selected TMS derivatized organic acid metabolites in human infant urine were located with the DotMap algorithm. A typical automated DotMap analysis takes 30 s on a 1.6 GHz PC with 1024 MB of RAM. Vanillic acid (TMS) was located by DotMap, but also exhibited overlap with other organic acids. The presence of vanillic acid (TMS) was confirmed by subjecting the appropriate GC x GC region to chemometric signal deconvolution by PARAFAC to yield pure component information suitable for subsequent quantification.

Algorithms↗
PubMedDate not supplied

Influence of mass transfer and surface ligand heterogeneity on quantitative BIAcore binding data. Analysis of the interaction of NC10 Fab with an anti-idiotype Fab'.

The interaction of monovalent Fab fragments of NC10, an antiviral neuraminidase antibody, and the anti-idiotype antibody 3-2G12 has been used as a model system to demonstrate experimentally the influence of non-ideal binding effects on BIAcore binding data. Because the association rate constant for these two molecules was found to be relatively high (about 5 x 10(5) M-1 S-1), mass transfer was recognised as a potential source of error in the analysis of the interaction kinetics. By manipulation of the flow rate and the surface density of the immobilised ligand, however, the magnitude to this error was minimised. In addition, the application of site-specific immobilisation procedures was found to improve considerably the correlation of experimental binding data to the ideal 1:1 kinetic model such that the discrepancy between experimental and fitted curves was within the noise range of the instrument. Experiments performed to measure the equilibrium constant (KD) in solution resulted in a value of similar magnitude to those obtained from the ratio of the kinetic rate constants, even those measured with a heterogeneous ligand or with a significant mass transfer component. For this system, the experimental complexities introduced by covalent immobilisation did not lead to large errors in the KD values obtained using the BIAcore.

Animals↗