• MeSH
• lineární modely MeSH
• statistika jako téma MeSH

• Konspekt
• Statistika
• NLK Obory
• statistika, zdravotnická statistika

We have developed a method to longitudinally classify subjects into two or more prognostic groups using longitudinally observed values of markers related to the prognosis. We assume the availability of a training data set where the subjects' allocation into the prognostic group is known. The proposed method proceeds in two steps as described earlier in the literature. First, multivariate linear mixed models are fitted in each prognostic group from the training data set to model the dependence of markers on time and on possibly other covariates. Second, fitted mixed models are used to develop a discrimination rule for future subjects. Our method improves upon existing approaches by relaxing the normality assumption of random effects in the underlying mixed models. Namely, we assume a heteroscedastic multivariate normal mixture for random effects. Inference is performed in the Bayesian framework using the Markov chain Monte Carlo methodology. Software has been written for the proposed method and it is freely available. The methodology is applied to data from the Dutch Primary Biliary Cirrhosis Study.

• MeSH
• biliární cirhóza farmakoterapie   MeSH
• biologické markery analýza   MeSH
• cholagoga a choleretika terapeutické užití   MeSH
• diskriminační analýza MeSH
• interpretace statistických dat MeSH
• kyselina ursodeoxycholová terapeutické užití   MeSH
• lidé MeSH
• lineární modely MeSH
• longitudinální studie MeSH
• počítačová simulace MeSH
• progrese nemoci MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Muscle strength and postural control are essential components for performing daily living activities, particularly in older adults, and can therefore serve as screening tools for assessing fall risk in this population. METHODS: The aim of this quasi-experimental study was to evaluate the impact of a 12-week exercise intervention followed by a 2-week detraining period on lower limb strength and postural stability in older adults. The study involved 38 community-dwelling participants of Central European origin over 60 years of age. Participants underwent the measurements consisting of assessments of knee flexors and extensors strength (isokinetic dynamometer, 90° range of motion, 60°/s angular velocity, Humac Norm CSMI, Stoughton MA, USA), toe grip strength (toe grip dynamometer, Takei Scientific Instruments, Niigata, Japan), and postural stability (narrow stand, 30 s, Kistler, Switzerland). Testing was repeated three times during the study (pre-intervention, post-intervention, and post-detraining). Participants were separated into 3 groups according to the type of training: resistance training group (n = 13), proprioceptive training group (n = 14), and endurance training group (n = 11). The intervention program lasted 12 weeks, two 60-min sessions per week. A linear mixed model (LMM) predicted a change in postural stability after the resistance, proprioceptive, and endurance exercise interventions were applied. RESULTS: Results showed that knee extensor strength normalized to body mass significantly increased in the resistance training group post-intervention (p = 0.01). Toe grip strength was significantly higher after the intervention in the endurance training group (p = 0.02). A statistically significant increase in knee flexor strength was observed in the proprioceptive training group (p = 0.01). The 2-weeks detraining period revealed no statistically significant loss in training gains. The LMM found different predictions of postural stability changes related to knee extensor strength after each type of training intervention. The final LMM model explains well the variability of the dependent variable R2 = 0.866. CONCLUSIONS: These results highlight the unique characteristics of specific exercise interventions in enhancing muscular strength and postural stability, which are critical for fall prevention among older adults.

• MeSH
• časové faktory MeSH
• cvičení * fyziologie   MeSH
• dolní končetina * fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• lineární modely MeSH
• odporový trénink * metody   MeSH
• posturální rovnováha * fyziologie   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• svalová síla * fyziologie   MeSH
• terapie cvičením * metody   MeSH
• úrazy pádem prevence a kontrola   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• statistika jako téma MeSH

• Konspekt
• Statistika
• NLK Obory
• statistika, zdravotnická statistika

OBJECTIVE: To develop a preoperative risk model, using endometrial biopsy results and clinical and ultrasound variables, to predict the individual risk of lymph-node metastases in women with endometrial cancer. METHODS: A mixed-effects logistic regression model for prediction of lymph-node metastases was developed in 1501 prospectively included women with endometrial cancer undergoing transvaginal ultrasound examination before surgery, from 16 European centers. Missing data, including missing lymph-node status, were imputed. Discrimination, calibration and clinical utility of the model were evaluated using leave-center-out cross validation. The predictive performance of the model was compared with that of risk classification from endometrial biopsy alone (high-risk defined as endometrioid cancer Grade 3/non-endometrioid cancer) or combined endometrial biopsy and ultrasound (high-risk defined as endometrioid cancer Grade 3/non-endometrioid cancer/deep myometrial invasion/cervical stromal invasion/extrauterine spread). RESULTS: Lymphadenectomy was performed in 691 women, of whom 127 had lymph-node metastases. The model for prediction of lymph-node metastases included the predictors age, duration of abnormal bleeding, endometrial biopsy result, tumor extension and tumor size according to ultrasound and undefined tumor with an unmeasurable endometrium. The model's area under the curve was 0.73 (95% CI, 0.68-0.78), the calibration slope was 1.06 (95% CI, 0.79-1.34) and the calibration intercept was 0.06 (95% CI, -0.15 to 0.27). Using a risk threshold for lymph-node metastases of 5% compared with 20%, the model had, respectively, a sensitivity of 98% vs 48% and specificity of 11% vs 80%. The model had higher sensitivity and specificity than did classification as high-risk, according to endometrial biopsy alone (50% vs 35% and 80% vs 77%, respectively) or combined endometrial biopsy and ultrasound (80% vs 75% and 53% vs 52%, respectively). The model's clinical utility was higher than that of endometrial biopsy alone or combined endometrial biopsy and ultrasound at any given risk threshold. CONCLUSIONS: Based on endometrial biopsy results and clinical and ultrasound characteristics, the individual risk of lymph-node metastases in women with endometrial cancer can be estimated reliably before surgery. The model is superior to risk classification by endometrial biopsy alone or in combination with ultrasound. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

• MeSH
• dospělí MeSH
• endometroidní karcinom diagnostické zobrazování   sekundární   MeSH
• kohortové studie MeSH
• lidé středního věku MeSH
• lidé MeSH
• lineární modely MeSH
• lymfatické metastázy MeSH
• lymfatické uzliny MeSH
• nádory endometria diagnostické zobrazování   patologie   MeSH
• prospektivní studie MeSH
• rizikové faktory MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• senzitivita a specificita MeSH
• staging nádorů MeSH
• ultrasonografie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

KEY MESSAGE: Linear modelling approaches detected significant gradients in organ growth and patterning across early flowers of the Arabidopsis inflorescence and uncovered evidence of new roles for gibberellin in floral development. Most flowering plants, including the genetic model Arabidopsis thaliana, produce multiple flowers in sequence from a reproductive shoot apex to form a flower spike (inflorescence). The development of individual flowers on an Arabidopsis inflorescence has typically been considered as highly stereotypical and uniform, but this assumption is contradicted by the existence of mutants with phenotypes visible in early flowers only. This phenomenon is demonstrated by mutants partially impaired in the biosynthesis of the phytohormone gibberellin (GA), in which floral organ growth is retarded in the first flowers to be produced but has recovered spontaneously by the 10th flower. We presently lack systematic data from multiple flowers across the Arabidopsis inflorescence to explain such changes. Using mutants of the GA 20-OXIDASE (GA20ox) GA biosynthesis gene family to manipulate endogenous GA levels, we investigated the dynamics of changing floral organ growth across the early Arabidopsis inflorescence (flowers 1-10). Modelling of floral organ lengths identified a significant, GA-independent gradient of increasing stamen length relative to the pistil in the wild-type inflorescence that was separable from other, GA-dependent effects. It was also found that the first flowers exhibited unstable organ patterning in contrast to later flowers and that this instability was prolonged by exogenous GA treatment. These findings indicate that the development of individual flowers is influenced by hitherto unknown factors acting across the inflorescence and also suggest novel functions for GA in floral patterning.

• MeSH
• Arabidopsis genetika   růst a vývoj   MeSH
• fenotyp MeSH
• gibereliny metabolismus   farmakologie   MeSH
• inflorescentia genetika   růst a vývoj   MeSH
• květy genetika   růst a vývoj   MeSH
• lineární modely MeSH
• meristém genetika   růst a vývoj   MeSH
• mutace MeSH
• oxygenasy se smíšenou funkcí genetika   metabolismus   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• regulátory růstu rostlin metabolismus   farmakologie   MeSH
• signální transdukce MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Fleas infecting northern white-breasted hedgehogs, Erinaceus roumanicus (Barrett-Hamilton), collected from 2009-2011 in Budapest (Hungary) were studied. A total of 305 white-breasted hedgehogs were captured and 1,251 fleas were collected. The flea community comprised two species, the hedgehog flea Archaeopsylla erinacei (Bouche, 1835) and the dog flea Ctenocephalides canis (Curtis, 1826), although the latter was only found on three hedgehogs. Fleas were found on half of the host specimens (51%; n = 156) where their distribution was strongly aggregated. The sex ratio of A. erinacei was biased towards females and was correlated with host size. Interestingly, the sex ratio of fleas became more equal on heavier hosts. It had been expected that, under high competition, the sex ratio would be female biased because it is known that female ectoparasites dominate on poorer hosts. The body size of a random sample of 200 fleas (100 female and 100 male) was measured under a microscope. The analyses showed directional asymmetry in two features - the distance between the top of the head and the eye, and head length. In this two body traits the left side was significantly greater than right side in both sexes of A. erinacei. Our data shed light on the complex nature of the flea population infecting northern white-breasted hedgehogs in an urban area.

• MeSH
• infestace blechami parazitologie   veterinární   MeSH
• ježkovití parazitologie   MeSH
• koinfekce veterinární   MeSH
• lineární modely MeSH
• Siphonaptera anatomie a histologie   klasifikace   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Maďarsko MeSH

The aim of the article is to examine the stability of grapheme-colour matchings in adulthood. We carried out a panel study using computerized tests to measure short-term and long-term consistency. We conducted three testing rounds during 1 year and a half with a resulting sample of 26 synaesthetes. Our results suggest that the colours associated with individual graphemes can change substantially (e.g. from "salmon" to "aquamarine") even during this relatively short time period. Based on a linear mixed model, we further argue that short-term and long-term consistency should be distinguished because these scores tend to differ. These results thus complement previous findings on the issue of grapheme-colour consistency and have important consequences for the study of synaesthesia in the future.

• MeSH
• časové faktory MeSH
• dospělí MeSH
• lidé MeSH
• lineární modely MeSH
• percepční poruchy psychologie   MeSH
• synestezie MeSH
• vnímání barev fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• epidemiologická měření MeSH
• infekční nemoci MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• infekční lékařství
• epidemiologie

PURPOSE: With the increasing use of proton therapy, there is a growing emphasis on including radiation quality, often quantified by linear energy transfer, as a treatment plan optimization factor. The Timepix detectors offer energy-sensitive particle tracking useful for the characterization of proton linear energy transfer. To improve the detector's performance in mixed radiation fields produced in proton therapy, we customized the detector settings and performed the per-pixel energy calibration. METHODS: The detection threshold and per-pixel signal shaping time (IKrum current) were customized, and energy calibration was performed for MiniPIX Timepix3. The detector calibration was verified using α source and clinical proton beams, as well as Monte Carlo simulations. The effects on the detector's performance, in terms of spectral saturation and pixel occupancy, were evaluated. RESULTS: Measurements with proton beams showed a good agreement with simulations. With the customized settings, the measurable energy range in the detector data-driven mode was extended, and the signal duration time was reduced by 80%, while the yield of pixel time occupancy reduction depends on the number of occupied pixels. For performed measurements with proton beams, the number of occupied pixels was further reduced up to 40% due to the increased threshold. CONCLUSIONS: Customized detector configuration of the Timepix3 detector allowed for reduced pixel occupancy and mitigation of signal saturation in a data-driven mode without significantly interfering with the energy deposition measurement. The presented approach enables the extension of the operational range, including higher intensities and mixed-radiation fields in particle radiotherapy environments.

• MeSH
• kalibrace MeSH
• lineární přenos energie MeSH
• metoda Monte Carlo * MeSH
• protonová terapie * přístrojové vybavení   MeSH
• Publikační typ
• časopisecké články MeSH