Factor analysis of mixed data Dotaz Zobrazit nápovědu
The visual evaluation of data derived from screening and optimization experiments in the development of new analytical methods poses a considerable time investment and introduces the risk of subjectivity. This study presents a novel approach to processing such data, based on factor analysis of mixed data and hierarchical clustering - multivariate techniques implemented in the R programming language. The methodology is demonstrated in the early-stage screening and optimization of the chromatographic separation of 15 structurally diverse drugs that affect the central nervous system, using a custom R Language script. The presented explorative approach enabled the identification of key parameters affecting the separation and significantly reduced the time required to evaluate the comprehensive dataset from the screening experiments. Based on the data analysis results, the optimal combination of stationary phase and mobile phase composition was selected, considering retention, overall resolution, and peak shape of compounds. Additionally, compounds vulnerable to changes in selected chromatographic conditions were identified. As a complement to the presented R Language script, a web-based application ChromaFAMDeX has been developed to offer an intuitive interface that enhances the accessibility of the used statistical methods. Accompanying the publication, the R script and the link to the standalone application are provided, enabling replication and adaptation of the methodology.
Instantaneous phases extracted from multivariate time series can retain information about the relationships between the underlying mechanisms that generate the series. Although phases have been widely used in the study of nondirectional coupling and connectivity, they have not found similar appeal in the study of causality. Herein, we present a new method for phase-based causality analysis, which combines ideas from the mixed embedding technique and the information-theoretic approach to causality in coupled oscillatory systems. We then use the introduced method to investigate causality in simulated datasets of bivariate, unidirectionally paired systems from combinations of Rössler, Lorenz, van der Pol, and Mackey-Glass equations. We observe that causality analysis using the phases can capture the true causal relation for coupling strength smaller than the analysis based on the amplitudes can capture. On the other hand, the causality estimation based on the phases tends to have larger variability, which is attributed more to the phase extraction process than the actual phase-based causality method. In addition, an application on real electroencephalographic data from an experiment on elicited human emotional states reinforces the usefulness of phases in causality identification.
- MeSH
- časové faktory MeSH
- elektroencefalografie * MeSH
- kauzalita MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Recently developed methods of longitudinal discriminant analysis allow for classification of subjects into prespecified prognostic groups using longitudinal history of both continuous and discrete biomarkers. The classification uses Bayesian estimates of the group membership probabilities for each prognostic group. These estimates are derived from a multivariate generalised linear mixed model of the biomarker's longitudinal evolution in each of the groups and can be updated each time new data is available for a patient, providing a dynamic (over time) allocation scheme. However, the precision of the estimated group probabilities differs for each patient and also over time. This precision can be assessed by looking at credible intervals for the group membership probabilities. In this paper, we propose a new allocation rule that incorporates credible intervals for use in context of a dynamic longitudinal discriminant analysis and show that this can decrease the number of false positives in a prognostic test, improving the positive predictive value. We also establish that by leaving some patients unclassified for a certain period, the classification accuracy of those patients who are classified can be improved, giving increased confidence to clinicians in their decision making. Finally, we show that determining a stopping rule dynamically can be more accurate than specifying a set time point at which to decide on a patient's status. We illustrate our methodology using data from patients with epilepsy and show how patients who fail to achieve adequate seizure control are more accurately identified using credible intervals compared to existing methods.
- Klíčová slova
- allocation scheme, credible intervals, longitudinal discriminant analysis,
- MeSH
- Bayesova věta * MeSH
- diskriminační analýza MeSH
- epilepsie diagnóza terapie MeSH
- indukce remise MeSH
- klasifikace metody MeSH
- lidé MeSH
- lineární modely MeSH
- longitudinální studie MeSH
- multivariační analýza MeSH
- počítačová simulace MeSH
- pravděpodobnost * MeSH
- prognóza MeSH
- rozhodování MeSH
- senzitivita a specificita MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
When drugs are poorly soluble then, instead of the potentiometric determination of dissociation constants, pH-spectrophotometric titration can be used along with nonlinear regression of the absorbance response surface data. Generally, regression models are extremely useful for extracting the essential features from a multiwavelength set of data. Regression diagnostics represent procedures for examining the regression triplet (data, model, method) in order to check (a) the data quality for a proposed model; (b) the model quality for a given set of data; and (c) that all of the assumptions used for least squares hold. In the interactive, PC-assisted diagnosis of data, models and estimation methods, the examination of data quality involves the detection of influential points, outliers and high leverages, that cause many problems when regression fitting the absorbance response hyperplane. All graphically oriented techniques are suitable for the rapid estimation of influential points. The reliability of the dissociation constants for the acid drug silybin may be proven with goodness-of-fit tests of the multiwavelength spectrophotometric pH-titration data. The uncertainty in the measurement of the pK (a) of a weak acid obtained by the least squares nonlinear regression analysis of absorption spectra is calculated. The procedure takes into account the drift in pH measurement, the drift in spectral measurement, and all of the drifts in analytical operations, as well as the relative importance of each source of uncertainty. The most important source of uncertainty in the experimental set-up for the example is the uncertainty in the pH measurement. The influences of various sources of uncertainty on the accuracy and precision are discussed using the example of the mixed dissociation constants of silybin, obtained using the SQUAD(84) and SPECFIT/32 regression programs.
- MeSH
- antioxidancia analýza chemie MeSH
- časové faktory MeSH
- chemické modely MeSH
- koncentrace vodíkových iontů MeSH
- léčivé přípravky chemie MeSH
- metoda nejmenších čtverců * MeSH
- regresní analýza * MeSH
- senzitivita a specificita MeSH
- silibinin MeSH
- silymarin analýza chemie MeSH
- spektrofotometrie metody MeSH
- stabilita léku MeSH
- titrace metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antioxidancia MeSH
- léčivé přípravky MeSH
- silibinin MeSH
- silymarin MeSH
INTRODUCTION: Amphetamine-type stimulants (ATS) including amphetamine, methylenedioxymethamphetamine/'ecstasy', methamphetamine, synthetic cathinones and 'Ritalin' are the second most commonly used illicit drugs globally. Yet, there is little evidence on which factors are associated with the development of different patterns of ATS use over the life course. This study aims to examine which individual, social and environmental factors shape different pathways and trajectories of ATS consumption. The study will be conducted in five European countries: Germany, the Netherlands, Poland, Czech Republic and the UK. METHODS AND ANALYSIS: We will use a sequential mixed-methods study design to investigate the multiple factors (familial, social and occupational situation, critical life events, general risk behaviour, mental and physical health, satisfaction with life) that shape individual ATS use pathways. A systematic literature review will be performed to provide an overview of the current academic literature on the topic. In module 1, qualitative semistructured interviews (n=ATS users and non-users) will be conducted to explore individual experiences of, and perspectives on, dynamics of change in stimulant consumption patterns. In module 2, structured questionnaires (n=2000 ATS users and non-users) will be administered via tablet computers to validate and enhance the generalisability of the interview findings. Data integration will take place at two key points. First, during the study, where the findings from the first qualitative interviews will inform the design of the structured questionnaire. Second, at the end of the study, where mixed methods data will be brought together to generate an in-depth, contextualised understanding of the research topic. ETHICS AND DISSEMINATION: The study has been approved by the respective responsible ethics committee in each participating country. Data will be treated confidentially to ensure participants' anonymity. Findings will be disseminated in peer-reviewed scientific journals, national and international conferences, and in briefings for policy and practice.
- Klíčová slova
- amphetamine-type stimulants, drug use trajectory, life course, study protocol,
- MeSH
- hodnocení rizik MeSH
- lidé MeSH
- multicentrické studie jako téma MeSH
- poruchy spojené s užíváním psychoaktivních látek epidemiologie psychologie MeSH
- rizikové faktory MeSH
- stimulanty centrálního nervového systému aplikace a dávkování MeSH
- systematický přehled jako téma MeSH
- výzkumný projekt * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa epidemiologie MeSH
- Názvy látek
- stimulanty centrálního nervového systému MeSH
BACKGROUND: Pineoblastoma is a rare pineal region brain tumor. Treatment strategies have reflected those for other malignant embryonal brain tumors. PATIENTS AND METHODS: Original prospective treatment and outcome data from international trial groups were pooled. Cox regression models were developed considering treatment elements as time-dependent covariates. RESULTS: Data on 135 patients with pineoblastoma aged 0.01-20.7 (median 4.9) years were analyzed. Median observation time was 7.3 years. Favorable prognostic factors were age ≥4 years (hazard ratio [HR] for progression-free survival [PFS] 0.270, P < .001) and administration of radiotherapy (HR for PFS 0.282, P < .001). Metastatic disease (HR for PFS 2.015, P = .006), but not postoperative residual tumor, was associated with unfavorable prognosis. In 57 patients <4 years old, 5-year PFS/overall survival (OS) were 11 ± 4%/12 ± 4%. Two patients survived after chemotherapy only, while 3 of 16 treated with craniospinal irradiation (CSI) with boost, and 3 of 5 treated with high-dose chemotherapy (HDCT) and local radiotherapy survived. In 78 patients aged ≥4 years, PFS/OS were 72 ± 7%/73 ± 7% for patients without metastases, and 50 ± 10%/55 ± 10% with metastases. Seventy-three patients received radiotherapy (48 conventionally fractionated CSI, median dose 35.0 [18.0-45.0] Gy, 19 hyperfractionated CSI, 6 local radiotherapy), with (n = 68) or without (n = 6) chemotherapy. The treatment sequence had no impact; application of HDCT had weak impact on survival in older patients. CONCLUSION: Survival is poor in young children treated without radiotherapy. In these patients, combination of HDCT and local radiotherapy may warrant further evaluation in the absence of more specific or targeted treatments. CSI combined with chemotherapy is effective for older non-metastatic patients.
- Klíčová slova
- high-dose chemotherapy, pediatric, pineoblastoma, radiotherapy, treatment,
- MeSH
- antitumorózní látky terapeutické užití MeSH
- databáze faktografické MeSH
- dítě MeSH
- dospělí MeSH
- epifýza mozková účinky léků patologie účinky záření MeSH
- kojenec MeSH
- kombinovaná terapie MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- nádory mozku farmakoterapie mortalita radioterapie terapie MeSH
- pinealom farmakoterapie mortalita radioterapie terapie MeSH
- předškolní dítě MeSH
- přežití po terapii bez příznaků nemoci MeSH
- prospektivní studie MeSH
- výsledek terapie MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa MeSH
- Spojené státy americké MeSH
- Názvy látek
- antitumorózní látky MeSH
- MeSH
- akutní lymfatická leukemie genetika MeSH
- DNA primery MeSH
- DNA vazebné proteiny genetika MeSH
- genetická vazba MeSH
- genetické markery MeSH
- histonlysin-N-methyltransferasa MeSH
- krysa rodu Rattus genetika MeSH
- lidé MeSH
- lidské chromozomy, pár 11 genetika MeSH
- mapování chromozomů * MeSH
- molekulární sekvence - údaje MeSH
- polymorfismus délky restrikčních fragmentů MeSH
- protoonkogenní protein MLL MeSH
- protoonkogeny * MeSH
- restrikční endonukleasy typu II metabolismus MeSH
- transkripční faktory * MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus genetika MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, P.H.S. MeSH
- Názvy látek
- CYCGRG-specific type II deoxyribonucleases MeSH Prohlížeč
- DNA primery MeSH
- DNA vazebné proteiny MeSH
- genetické markery MeSH
- histonlysin-N-methyltransferasa MeSH
- KMT2A protein, human MeSH Prohlížeč
- Mllt1 protein, rat MeSH Prohlížeč
- protoonkogenní protein MLL MeSH
- restrikční endonukleasy typu II MeSH
- transkripční faktory * MeSH
At present, no standardized tool to measure therapeutic outcomes of a central European traditional healing system called Ethicotherapy exists. Ethicotherapy focuses on the relationship between physical health and moral health. The aim was to develop and validate the Ethicotherapy quality of life questionnaire (EQLQ) using a sequential exploratory mixed-method study design. An EQLQ with good psychometric properties was developed. An exploratory factor analysis identified eight domains consisting of 30 items. Future research investigating a relationship between EQLQ, health, and physical illness in different populations and cultural settings is recommended.
- Klíčová slova
- Development, Ethicotherapy, Psychometric properties, Questionnaire, Validation,
- MeSH
- faktorová analýza statistická MeSH
- kvalita života * MeSH
- lidé MeSH
- průzkumy a dotazníky * normy MeSH
- psychometrie MeSH
- reprodukovatelnost výsledků MeSH
- výzkumný projekt * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The ammonia-oxidizing bacterial community (AOB) was investigated in two types of laboratory-scale bioreactors performing partial oxidation of ammonia to nitrite or nitrate at high (80 mM) to extremely high (428 mM) concentrations of ammonium bicarbonate. At all conditions, the dominant AOB was affiliated to the Nitrosomonas europaea lineage as was determined by fluorescence in situ hybridization and polymerase chain reaction in combination with denaturing gradient gel electrophoresis. Molecular analysis of the mixed populations, based on the 16S rRNA and cbbL genes, demonstrated the presence of two different phylotypes of Nitrosomonas, while microbiological analysis produced a single phylotype, represented by three different morphotypes. One of the most striking features of the AOB populations encountered in the bioreactors was the domination of highly aggregated obligate microaerophilic Nitrosomonas, with unusual cellular and colony morphology, commonly observed in nitrifying bioreactors but rarely investigated by cultural methods. The latter is probably not an adaptation to stressful conditions created by high ammonia or nitrite concentrations, but oxygen seems to be a stressful factor in these bioreactors.
- MeSH
- amoniak metabolismus MeSH
- bakteriální proteiny genetika MeSH
- bioreaktory mikrobiologie MeSH
- DNA bakterií chemie genetika MeSH
- dusičnany metabolismus MeSH
- dusitany metabolismus MeSH
- fylogeneze MeSH
- hybridizace in situ fluorescenční MeSH
- hydrogenuhličitany metabolismus MeSH
- kultivační média chemie MeSH
- molekulární sekvence - údaje MeSH
- Nitrosomonas klasifikace genetika metabolismus MeSH
- oxidace-redukce MeSH
- polymerázová řetězová reakce MeSH
- ribozomální DNA chemie genetika MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční analýza DNA MeSH
- shluková analýza MeSH
- společenstvo * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- ammonium bicarbonate MeSH Prohlížeč
- amoniak MeSH
- bakteriální proteiny MeSH
- DNA bakterií MeSH
- dusičnany MeSH
- dusitany MeSH
- hydrogenuhličitany MeSH
- kultivační média MeSH
- ribozomální DNA MeSH
- RNA ribozomální 16S MeSH
Mixed cellular (MC) type of Hodgkin disease was studied in a group of 92 bioptic cases diagnosed before the start of treatment. A precise histological analysis showed one subtype with lower malignancy (MC 1) and a second one with higher malignancy (MC 2). Subtype MC 1 comprised 61 cases (66 per cent), subtype MC 2 31 cases (34 per cent). Histomorphological subtyping was brought into correlation with clinical data of survival available in 65 cases (44 cases of subtype MC 1,21 cases of subtype MC 2). Different survival in both subtypes had statistical significance and prognostic relevance. Suggested subtyping is simple, based on common histological slides, without need of special additional investigation.
- MeSH
- Hodgkinova nemoc patologie MeSH
- lidé MeSH
- prognóza MeSH
- retrospektivní studie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
