Sum fraction terms can approximate multi-variable functions on the basis of discrete observations, replacing a partial differential equation definition with polynomial elementary data relation descriptions. Artificial neural networks commonly transform the weighted sum of inputs to describe overall similarity relationships of trained and new testing input patterns. Differential polynomial neural networks form a new class of neural networks, which construct and solve an unknown general partial differential equation of a function of interest with selected substitution relative terms using non-linear multi-variable composite polynomials. The layers of the network generate simple and composite relative substitution terms whose convergent series combinations can describe partial dependent derivative changes of the input variables. This regression is based on trained generalized partial derivative data relations, decomposed into a multi-layer polynomial network structure. The sigmoidal function, commonly used as a nonlinear activation of artificial neurons, may transform some polynomial items together with the parameters with the aim to improve the polynomial derivative term series ability to approximate complicated periodic functions, as simple low order polynomials are not able to fully make up for the complete cycles. The similarity analysis facilitates substitutions for differential equations or can form dimensional units from data samples to describe real-world problems.

• MeSH
• algoritmy MeSH
• interpretace statistických dat MeSH
• matematika * MeSH
• nelineární dynamika MeSH
• neuronové sítě * MeSH
• počasí MeSH
• počítačová simulace MeSH
• strojové učení MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Numerous physiological processes are cyclical, but sampling these processes densely enough to perform frequency decomposition and subsequent analyses can be challenging. Mathematical approaches for decomposition and reconstruction of sparsely and irregularly sampled signals are well established but have been under-utilized in physiological applications. We developed a basis pursuit denoising with polynomial detrending (BPWP) model that recovers oscillations and trends from sparse and irregularly sampled timeseries. We validated this model on a unique dataset of long-term inter-ictal epileptiform discharge (IED) rates from human hippocampus recorded with a novel investigational device with continuous local field potential sensing. IED rates have well established circadian and multiday cycles related to sleep, wakefulness, and seizure clusters. Given sparse and irregular samples of IED rates from multi-month intracranial EEG recordings from ambulatory humans, we used BPWP to compute narrowband spectral power and polynomial trend coefficients and identify IED rate cycles in three subjects. In select cases, we propose that random and irregular sampling may be leveraged for frequency decomposition of physiological signals. Trial Registration: NCT03946618.

• MeSH
• algoritmy MeSH
• elektroencefalografie metody   MeSH
• elektrokortikografie metody   MeSH
• epilepsie * patofyziologie   diagnóza   MeSH
• hipokampus patofyziologie   fyziologie   MeSH
• lidé MeSH
• modely neurologické MeSH
• počítačové zpracování signálu MeSH
• výpočetní biologie metody   MeSH
• záchvaty patofyziologie   diagnóza   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

The main aim of this article is to present a graphical approach to robust stability analysis for families of fractional order (quasi-)polynomials with complicated uncertainty structure. More specifically, the work emphasizes the multilinear, polynomial and general structures of uncertainty and, moreover, the retarded quasi-polynomials with parametric uncertainty are studied. Since the families with these complex uncertainty structures suffer from the lack of analytical tools, their robust stability is investigated by numerical calculation and depiction of the value sets and subsequent application of the zero exclusion condition.

• MeSH
• algoritmy MeSH
• nejistota * MeSH
• teoretické modely * MeSH
• Publikační typ
• časopisecké články MeSH

Objective: We aimed to identify the population in which encouraging participation in the general health check-up would be helpful using a prediction model based on a machine-learning method. A secondary analysis of data obtained from the health promotion program using a randomized controlled design, aimed at improving participation in the general health check-up, was performed. Methods: The retrospective analysis was conducted using data from a health promotion program in the Fukuoka branch of Japan Health Insurance Association, Japan, between November 2015 and March 2016. Subjects were extracted from dependents (family members) of insured persons aged 40-74 years who had participated in general health check-up at least once in the past five years (2010-2014). Subjects were divided into two groups; the intervention group received a printed reminder saying “you are due to general health check-up” through mail, while the control group received nothing. The participation rates of both groups for each participation probability group (participation probability was calculated by the prediction model) were assessed after 4 month follow-up. Results: The numbers in the intervention group and in the control group were 1,911 and 3,294, respectively. Regarding the prediction model, the AUC value for test data was 0.668 (95%CI: 0.635–0.701). With regard to the effectiveness of the intervention for each probability group, there was a significant difference between the groups only for the moderate participation probability groups as follows: 30-39% (P=0.005), 40-49% (P=0.003), 50-59% (P=0.004) and 60-69% (P=0.039). Conclusion: The intervention with printed reminder was effective for improving participation of general health check-up among the group with moderate participation probability. The targeting using the results of prediction model was useful for identifying appropriate intervention targets. Conclusions: More studies are needed to assess the cost and benefits of adopting a system like this and then the appropriate actions could be taken.

• MeSH
• formuláře a záznamy - kontrola a vedení MeSH
• lidé MeSH
• nemocniční záznamy * MeSH
• plošný screening MeSH
• průzkumy zdravotní péče MeSH
• statistické modely MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

• MeSH
• algoritmy MeSH
• časové faktory MeSH
• finanční podpora výzkumu jako téma MeSH
• klasifikace MeSH
• matematické výpočty počítačové MeSH
• modely neurologické MeSH
• neuronové sítě MeSH
• statistické modely MeSH

BACKGROUND: No universal solution, based on an approved pedagogical approach, exists to parametrically describe, effectively manage, and clearly visualize a higher education institution's curriculum, including tools for unveiling relationships inside curricular datasets. OBJECTIVE: We aim to solve the issue of medical curriculum mapping to improve understanding of the complex structure and content of medical education programs. Our effort is based on the long-term development and implementation of an original web-based platform, which supports an outcomes-based approach to medical and healthcare education and is suitable for repeated updates and adoption to curriculum innovations. METHODS: We adopted data exploration and visualization approaches in the context of medical curriculum innovations in higher education institutions domain. We have developed a robust platform, covering detailed formal metadata specifications down to the level of learning units, interconnections, and learning outcomes, in accordance with Bloom's taxonomy and direct links to a particular biomedical nomenclature. Furthermore, we used selected modeling techniques and data mining methods to generate academic analytics reports from medical curriculum mapping datasets. RESULTS: We present a solution that allows users to effectively optimize a curriculum structure that is described with appropriate metadata, such as course attributes, learning units and outcomes, a standardized vocabulary nomenclature, and a tree structure of essential terms. We present a case study implementation that includes effective support for curriculum reengineering efforts of academics through a comprehensive overview of the General Medicine study program. Moreover, we introduce deep content analysis of a dataset that was captured with the use of the curriculum mapping platform; this may assist in detecting any potentially problematic areas, and hence it may help to construct a comprehensive overview for the subsequent global in-depth medical curriculum inspection. CONCLUSIONS: We have proposed, developed, and implemented an original framework for medical and healthcare curriculum innovations and harmonization, including: planning model, mapping model, and selected academic analytics extracted with the use of data mining.

• MeSH
• kurikulum * MeSH
• lidé MeSH
• statistické modely * MeSH
• studium lékařství * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Spolehlivost, neboli reliabilita měření je mírou jeho opakovatelnosti za stejných podmínek. Klasický koncept reliability předpokládá, že se měření Y skládá ze skutečné hodnoty měřené vlastnosti T a chybové složky ?, dvou nezávislých náhodných veličin, Y = T + ?. Spolehlivost měření je pak definovaná jako podíl rozptylu skutečného skóru a rozptylu měření. Tento koncept nicméně není použitelný v modelech pro dichotomní měření, ve kterých nefigurují chybové složky, leč jsou definovány pomocí podmíněných pravděpodobností. V tomto článku zkoumáme obecnější definici spolehlivosti navrženou v [1], která je založena na rozkladu rozptylu v modelu se smíšenými efekty. Navržená definice splývá v klasické testové situaci s definicí klasickou, a navíc je použitelná také pro modely dichotomních měření. Nově jsou pro navrženou definici odvozeny předpoklady, za jejichž platnosti může být spolehlivost složeného měření vyjádřena pomocí spolehlivostí jediného měření (tzv. Spearmanova-Brownova formule) a je ukázána přibližná platnost Spearmanovy-Brownovy formule pro Raschův model. Na závěr zkoumáme tzv. logistické alfa – nový odhad spolehlivosti navržený v [2] coby modifikace klasického odhadu spolehlivosti založeném na Cronbachovu alfa. Simulace ukazují, že nový odhad nepodhodnocuje skutečnou spolehlivost tak často, jako Cronbachovo alfa. Logistické alfa se tak pro některé případy jeví být vhodnějším odhadem spolehlivosti. Nový odhad je použit na binární data získaná automatizovaným procesem diagnostiky prokrvení myokardu založeným na snímcích emisní protonové tomografie (SPECT).

Reliability of measurement is a measure of its reproducibility under replicate conditions. The classical concept of reliability assumes that measurement Y is composed out of true value T and error term ?, two independent random variables, Y = T + ? . Reliability of measurement is defined as the ratio of the variance of the true scores to the variance of the observed scores. However, this concept is not applicable in models for dichotomous measurements which do not consider error terms and are instead defined via conditional probabilities. In this paper we examine a more general definition of reliability proposed in [1], which is based on decomposition of variance in mixed effects model. Proposed definition covers the classical definition of reliability and it is, moreover, appropriate for dichotomous measurements, too. Newly, for the proposed definition assumptions are derived, under which the reliability of composite measurement can be predicted by reliability of single measurement (Spearman-Brown formula) and approximate validity of Spearman-Brown formula is shown for the Rasch model. Finally, as a modification of the classical estimate of reliability based on Cronbach’s alpha, we examine its counterpart logistic alpha introduced in [2], which appears to be more appropriate for composite dichotomous measurements in some cases. Simulations show that the new estimate does not tend to underestimate reliability as often as the Cronbach’s alpha does. The new estimate is used in binary data of computerized process of myocardial perfusion diagnosis from cardiac single proton emission computed tomography (SPECT).

• Klíčová slova
• binární data, logistická regrese, Cronbachovo alfa, Raschův model, hodnocení perfuse myokardu,
• MeSH
• analýza rozptylu MeSH
• biometrie metody   MeSH
• regresní analýza MeSH
• statistické modely MeSH

Aortic stiffness is strongly related to age and mean arterial pressure (MAP). In the present analysis, we investigated whether antihypertensive treatment modulates the association of the aortic pulse wave velocity (PWV) with age and with MAP in the general population. In the Czech post-MONICA cross-sectional study, we measured the PWV in 735 subjects (mean age 61.2±7.8 years, 54.1% women, 44.3% on antihypertensive medication). We used a linear regression model to assess the effect of treatment on the PWV. The independent covariates in our analysis included sex, age, MAP, heart rate, body mass index, plasma glucose, low-density lipoprotein cholesterol, smoking and observer. The patients receiving treatment were older (64.1±6.7 vs. 58.9±7.8 years), had higher systolic blood pressure (135.9±16.2 vs. 130.1±16.5 mm Hg) and had higher pulse wave velocity (9.1±2.2 vs. 8.2±2.1 m s(-1); P for all <0.0001) than untreated subjects. After adjustment for MAP, the use of treatment modified the association between age and the PWV (regression equations, treated patients 9.68-0.009 × age vs. untreated subjects 6.98+0.020 × age, difference of regression slopes, F=11.2; P=0.0009). In analyses adjusted for age, treatment was associated with a smaller increase of the PWV with MAP (treated patients 9.63-0.006 × MAP vs. untreated subjects 7.18+0.010 × MAP, F=10.70; P=0.0001). These results were driven primarily by subjects whose blood pressure was below 140/90 mm Hg. In the cross-sectional analysis from a random sample of the general population, antihypertensive treatment was associated with a less steep increase in the PWV with age and the mean arterial pressure. Further longitudinal studies are needed to confirm this finding.

• MeSH
• analýza pulzové vlny MeSH
• antihypertenziva terapeutické užití   MeSH
• aorta účinky léků   fyziologie   MeSH
• dospělí MeSH
• hypertenze farmakoterapie   patologie   patofyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• průřezové studie MeSH
• průzkumy a dotazníky MeSH
• senioři MeSH
• stárnutí fyziologie   MeSH
• statistické modely MeSH
• tuhost cévní stěny účinky léků   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Temperature drives development in insects and other ectotherms because their metabolic rate and growth depends directly on thermal conditions. However, relative durations of successive ontogenetic stages often remain nearly constant across a substantial range of temperatures. This pattern, termed 'developmental rate isomorphy' (DRI) in insects, appears to be widespread and reported departures from DRI are generally very small. We show that these conclusions may be due to the caveats hidden in the statistical methods currently used to study DRI. Because the DRI concept is inherently based on proportional data, we propose that Dirichlet regression applied to individual-level data is an appropriate statistical method to critically assess DRI. As a case study we analyze data on five aquatic and four terrestrial insect species. We find that results obtained by Dirichlet regression are consistent with DRI violation in at least eight of the studied species, although standard analysis detects significant departure from DRI in only four of them. Moreover, the departures from DRI detected by Dirichlet regression are consistently much larger than previously reported. The proposed framework can also be used to infer whether observed departures from DRI reflect life history adaptations to size- or stage-dependent effects of varying temperature. Our results indicate that the concept of DRI in insects and other ectotherms should be critically re-evaluated and put in a wider context, including the concept of 'equiproportional development' developed for copepods.

• MeSH
• biologické modely * MeSH
• hmyz růst a vývoj   MeSH
• stadia vývoje * MeSH
• statistické modely * MeSH
• teplota * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Spectral fluences of neutrons generated in the heads of the radiotherapeutic linacs Varian Clinac 2100 C/D and Siemens ARTISTE were measured by means of the Bonner spheres spectrometer whose active detector of thermal neutrons was replaced by an activation detector, i.e. a tablet made of pure manganese. Measurements with different collimator settings reveal an interesting dependence of neutron fluence on the area defined by the collimator jaws. The determined neutron spectral fluences were used to derive ambient dose equivalent rate along the treatment coach. To clarify at which components of the linac neutrons are mainly created, the measurements were complemented with MCNPX calculations based on a realistic model of the Varian Clinac.

• MeSH
• analýza selhání vybavení MeSH
• částice - urychlovače přístrojové vybavení   MeSH
• dávka záření MeSH
• design s pomocí počítače MeSH
• design vybavení MeSH
• metoda Monte Carlo MeSH
• neutrony * MeSH
• počítačová simulace MeSH
• radiační rozptyl MeSH
• radiochirurgie přístrojové vybavení   MeSH
• radiometrie přístrojové vybavení   metody   MeSH
• statistické modely * MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH