Odehrání míče v tenise vyžaduje především prostorově-časovou informaci o dráze letu míče. Ve výzkumu jsme se zaměřili na časovou složku při riternu. Pomocí nahrávacího stroje jsme simulovali podání soupeře. Testované osoby měly na hlavě okluzní brýle Plató, které jim při nahrání míče z nahrávacího stroje zatemnily vidění na určitou dobu. Předem neznaly ani rychlost letícího míče, ani část dráhy jeho letu, která bude zatemněna. Zkoumali jsme pomocí okluzních brýlí vliv zatemnění určitých částí dráhy letu míče na načasování odehrání míče při riternu. Analýza nám ukázala, že největší problémy nastávaly při absenci informace o druhé třetině dráhy letu míče, kdy testované osoby dosahovaly největšího počtu časových chyb.

Ball-hitting in tennis involves spatio-temporal information about the ball's fl ight trajectory. We have focused on the temporal part of the information during returning a tennis serve that was simulated by a ball machine. The tested people had occlusion glasses placed on their eyes, which occluded their vision at the exact time, when the ball was being sent from the ball machine. The tested person did not know which part of the ball fl ight trajectory would be occluded, nor the ball speed. We examined the effect of part ball flight trajectory occlusion on the correct return timing of the ball. The analysis revealed that the greatest problems occurred while the second third of the ball fl ight trajectory had been occluded and reached most temporal errors at that time.

• Klíčová slova
• ritern, okluzní brýle,
• MeSH
• biomechanika MeSH
• dospělí MeSH
• financování organizované MeSH
• lidé MeSH
• mladý dospělý MeSH
• motorické dovednosti MeSH
• raketové sporty MeSH
• statistika jako téma MeSH
• tenis MeSH
• výzkumné techniky MeSH
• zrak fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH

Parameters in diffusion neuronal models are divided into two groups; intrinsic and input parameters. Intrinsic parameters are related to the properties of the neuronal membrane and are assumed to be known throughout the paper. Input parameters characterize processes generated outside the neuron and methods for their estimation are reviewed here. Two examples of the diffusion neuronal model, which are based on the integrate-and-fire concept, are investigated--the Ornstein--Uhlenbeck model as the most common one and the Feller model as an illustration of state-dependent behavior in modeling the neuronal input. Two types of experimental data are assumed-intracellular describing the membrane trajectories and extracellular resulting in knowledge of the interspike intervals. The literature on estimation from the trajectories of the diffusion process is extensive and thus the stress in this review is set on the inference made from the interspike intervals.

• MeSH
• modely neurologické MeSH
• neurony MeSH
• Publikační typ
• práce podpořená grantem MeSH
• přehledy MeSH

In image-guided percutaneous interventions, a precise planning of the needle path is a key factor to a successful intervention. In this paper we propose a novel method for computing a patient-specific optimal path for such interventions, accounting for both the deformation of the needle and soft tissues due to the insertion of the needle in the body. To achieve this objective, we propose an optimization method for estimating preoperatively a curved trajectory allowing to reach a target even in the case of tissue motion and needle bending. Needle insertions are simulated and regarded as evaluations of the objective function by the iterative planning process. In order to test the planning algorithm, it is coupled with a fast needle insertion simulation involving a flexible needle model and soft tissue finite element modeling, and experimented on the use-case of thermal ablation of liver tumors. Our algorithm has been successfully tested on twelve datasets of patient-specific geometries. Fast convergence to the actual optimal solution has been shown. This method is designed to be adapted to a wide range of percutaneous interventions.

• MeSH
• ablace MeSH
• algoritmy * MeSH
• anatomické modely * MeSH
• chirurgie s pomocí počítače metody   MeSH
• játra patofyziologie   chirurgie   MeSH
• lidé MeSH
• nádory jater chirurgie   MeSH
• počítačová simulace * MeSH
• předoperační období * MeSH
• uživatelské rozhraní počítače MeSH
• zobrazování trojrozměrné MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

PURPOSE: To evaluate the impact of MR gradient system imperfections and limitations for the quantitative mapping of short T2* signals performed by ultrashort echo time (UTE) acquisition approach. MATERIALS AND METHODS: The measurement of short T2* signals from a phantom and a healthy volunteer study (8 subjects of average age 28 ± 4 years) were performed on a 3T scanner. The characteristics of the gradient system were obtained using calibration method performed directly on the measured subject or phantom. This information was used to calculate the actual sampling trajectory with the help of a parametric eddy current model. The actual sample positions were used to reconstruct corrected images and compared with uncorrected data. RESULTS: Comparison of both approaches, i.e., without and with correction of k-space sampling trajectories revealed substantial improvement when correction was applied. The phantom experiments demonstrate substantial in-plane signal intensity variations for uncorrected sampling trajectories. In the case of the volunteer study, this led to significant differences in relative proton density (RPD) estimation between the uncorrected and corrected data (P = 0.0117 by Wilcoxon matched-pairs test) and provides for about ~15% higher values for short T2* components of white matter (WM) in the case of uncorrected images. CONCLUSION: The imperfection of the applied gradients could induce errors in k-space data sampling which further propagates into the fidelity of the UTE images and jeopardizes precision of quantification. However, the study proved that measurement of gradient errors together with correction of sample positions can contribute to increased accuracy and unbiased characterization of short T2* signals.

• MeSH
• bílá hmota anatomie a histologie   MeSH
• dospělí MeSH
• fantomy radiodiagnostické MeSH
• kalibrace MeSH
• lidé MeSH
• magnetická rezonanční tomografie metody   MeSH
• mladý dospělý MeSH
• počítačové zpracování obrazu metody   MeSH
• protony MeSH
• referenční hodnoty MeSH
• zdraví dobrovolníci pro lékařské studie MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Tento článek s využitím sekundární analýzy kvalitativního výzkumu nesezdaných párů s dětmi zkoumá rodičovství v nesezdaném soužití z perspektivy destandardizace a individualizace rodinných drah. Na základě rozlišení situace a postojů nesezdaných párů v době před narozením dítěte a v současnosti identifikuje rozmanitost pohledů nesezdaných rodičovských párů na pozici nesezdaného soužití v rámci jejich rodinných drah. Analýza odhaluje pět dimenzí individualizace představ nesezdaných o procesu formování rodiny: 1) diverzifikace představ o vhodném časování vstupu do manželství s ohledem na věk i na délku soužití; 2) důraz na existenci situačních bariér vstupu do manželství; 3) oslabování vlivu původní rodiny; 4) zvažování výhod a nevýhod právního postavení manželů a nesezdaných partnerů; 5) různé vnímání symbolického významu manželství a nesezdaného soužití a postavení manželů a nesezdaných partnerů.

Based on a secondary analysis of data from qualitative research of unmarried parental couples, this article explores childbearing in unmarried cohabitation from the perspective of de-standardisation and individualization of family trajectories. Drawing upon a differentiation of their situation at the moment around childbirth and their actual attitudes, it distinguishes heterogeneity of views of unmarried parents on the position of an unmarried cohabitation with child in their family trajectories. Overall, the analysis identifies five dimensions of individualization of attitudes in family formation processes: (1) diversification of views on timing of entry to marriage in terms of age and length of unmarriedcoha­bitation, (2) an emphasis on situational barriers to entry into marriage, (3) weakening of influence of the family of orientation, (4) a consideration of views on the legal (dis)advantages of marriage, and (5) different symbolic meanings attached to marriage and unmarried cohabitation and to the status of married and unmarried partners.

• MeSH
• dospělí MeSH
• kvalitativní výzkum MeSH
• lidé MeSH
• manželství * trendy   MeSH
• postoj MeSH
• rodičovství MeSH
• rodina MeSH
• sběr dat MeSH
• statistika jako téma MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH

Objectives: Evidence suggests that renal function increasingly deteriorates in patients with apparently treatment-resistant hypertension (ATRH) in comparison with those who have non-resistant arterial hypertension (NAH). We aimed to assess the long-term decline in renal function between these patient groups and identify specific risk factors contributing to the progression of renal dysfunction. Methods: Data for 265 patients with ATRH and NAH in a hypertension excellence centre were retrospectively evaluated. Demographic characteristics, co-morbidities, laboratory findings, secondary causes of hypertension, medication and exposure to contrast agents were assessed. To address differences between groups, adjustment with linear mixed-effect models was used. Results: Data from the first 4 years of follow-up were evaluated. After adjustment for age and diabetes, which were identified as independent risk factors for renal dysfunction progression in the study cohort, the mean decrease in estimated glomerular filtration rate per year was steeper with ATRH than with NAH (-1.49 vs. -0.65 mL/min/1.73 m2 per year; difference in slope, 0.83 mL/min/1.73 m2 per year; 95% confidence interval [CI]: 0.25-1.41, p = 0.005). In subgroup analyses, without Holm-Bonferroni correction, the prescription of MRA indicated a faster decline in renal function in ATRH. Following correction, no specific therapeutic risk factor was associated with faster progression of renal dysfunction. Conclusions: Renal function declines twice as fast with ATRH compared with NAH, independently of age and diabetes. Larger studies are needed to reveal risk factors for renal dysfunction in patients with hypertension.

• MeSH
• antihypertenziva terapeutické užití   MeSH
• hodnoty glomerulární filtrace * MeSH
• hypertenze * patofyziologie   farmakoterapie   komplikace   MeSH
• ledviny patofyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• následné studie MeSH
• progrese nemoci MeSH
• retrospektivní studie MeSH
• rizikové faktory MeSH
• senioři MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

PURPOSE: To examine the influence of growth and maturation in the trajectory of stretch-shortening cycle capability. METHOD: Using a mixed-longitudinal design, absolute and relative leg stiffness and reactive strength index (RSI) were measured 3 times over a 3-year period in 44 youth team-sport players. Maturation was determined as maturity offset and included within the Bayesian inference analysis as a covariate alongside chronological age. RESULTS: Irrespective of age and maturation, there was no change in absolute leg stiffness, however relative leg stiffness decreased over time. Maturation and age reduced this decline, but the decline remained significant (Bayesian factor [10] = 5097, model averaged R2 = .61). The RSI increased over time and more so in older more mature youth players (Bayesian factor [10] = 9.29e8, model averaged R2 = .657). CONCLUSION: In youth players who are at/post peak height velocity, relative leg stiffness appears to decline, which could have an impact on both performance and injury risk. However, RSI increases during this period, and these data reinforce that leg stiffness and RSI reflect different components of stretch-shortening cycle capability. Practitioners should consider these differences when planning training to maximize stretch-shortening cycle capability during growth and maturation in athletes on the developmental performance pathway.

• MeSH
• Bayesova věta MeSH
• bérec fyziologie   MeSH
• kosterní svaly fyziologie   MeSH
• lidé MeSH
• longitudinální studie MeSH
• mladiství MeSH
• sport pro děti a mládež MeSH
• sportovci * MeSH
• svalová kontrakce * MeSH
• svalová síla MeSH
• týmové sporty MeSH
• Check Tag
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Several natural history studies on primary progressive multiple sclerosis (PPMS) patients detected a consistent heterogeneity in the rate of disability accumulation. OBJECTIVES: To identify subgroups of PPMS patients with similar longitudinal trajectories of Expanded Disability Status Scale (EDSS) over time. METHODS: All PPMS patients collected within the MSBase registry, who had their first EDSS assessment within 5 years from onset, were included in the analysis. Longitudinal EDSS scores were modeled by a latent class mixed model (LCMM), using a nonlinear function of time from onset. LCMM is an advanced statistical approach that models heterogeneity between patients by classifying them into unobserved groups showing similar characteristics. RESULTS: A total of 853 PPMS (51.7% females) from 24 countries with a mean age at onset of 42.4 years (standard deviation (SD): 10.8 years), a median baseline EDSS of 4 (interquartile range (IQR): 2.5-5.5), and 2.4 years of disease duration (SD: 1.5 years) were included. LCMM detected three different subgroups of patients with a mild ( n = 143; 16.8%), moderate ( n = 378; 44.3%), or severe ( n = 332; 38.9%) disability trajectory. The probability of reaching EDSS 6 at 10 years was 0%, 46.4%, and 81.9% respectively. CONCLUSION: Applying an LCMM modeling approach to long-term EDSS data, it is possible to identify groups of PPMS patients with different prognosis.

• MeSH
• analýza latentních tříd * MeSH
• Bayesova věta MeSH
• chronicko-progresivní roztroušená skleróza diagnóza   patologie   MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• longitudinální studie MeSH
• následné studie MeSH
• opožděná diagnóza MeSH
• postižení MeSH
• posuzování pracovní neschopnosti * MeSH
• prognóza MeSH
• progrese nemoci * MeSH
• prospektivní studie MeSH
• registrace * MeSH
• sexuální faktory MeSH
• věkové faktory MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND AND OBJECTIVES: The mental health of healthcare workers (HCWs) may have improved after the COVID-19 pandemic. We aimed to model the trajectories of psychological distress, depressive symptoms, and resilience during the COVID-19 pandemic and toward its end in HCWs in Czechia and investigate, which COVID-19 work stressors were associated with these trajectories. METHODS: The study included 322 HCWs from the Czech arm of the international HEROES Study who participated in an online questionnaire in two waves during the pandemic and one wave toward its end. Growth mixture modeling identified trajectory patterns of depressive symptoms (measured with Patient Health Questionnaire), distress (General Health Questionnaire), and resilience (Brief Resilience Scale). Logistic regression was applied to estimate the association of COVID-19 stressors with mental health trajectories, adjusting for baseline characteristics. RESULTS: Trajectory classes revealed both high and low depressive symptoms (high in 61% of participants), distress (high in 82% of participants), and resilience (low in 32% of participants). Depressive symptoms and distress trajectories demonstrated the same shape, first increasing during the pandemic and decreasing toward its end, while resilience remained constant. Exposure to COVID-19 stressors, in particular, the experience of stigmatization, discrimination, and violence, was associated with high depressive symptoms and distress trajectories, but not with resilience. CONCLUSIONS: Interventions provided to HCWs during crises such as pandemic should target distress and depressive symptoms and need to address stigmatization, discrimination, and violence.

• MeSH
• COVID-19 * psychologie   epidemiologie   MeSH
• deprese * psychologie   epidemiologie   MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• pracovní stres psychologie   epidemiologie   MeSH
• průzkumy a dotazníky MeSH
• psychická odolnost * MeSH
• psychický distres MeSH
• psychický stres psychologie   epidemiologie   MeSH
• SARS-CoV-2 MeSH
• zdravotnický personál * psychologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

This paper deals with a comparison of statistical and non-statistical classifi ers for thumb motion classifi cation. Presented work is a part of research of relation between brain and muscle activity. Th e thumb motion is represented by trajectory coordinates of special mark placed on the thumb. Motions are classifi ed using k-Means classifi er (non-statistical classifi cation, no prior information is needed) and Bayes classifi er (statistical models of classes are needed, classifi er training is necessary). Th e effi ciency of classifi ers is evaluated using the standard HTK parameters. Real testing data includes more than 900 stationary states which are used for classifi er testing. Th e classifi cation results are compared for both methods.

• MeSH
• audiovizuální záznam metody   přístrojové vybavení   využití   MeSH
• Bayesova věta MeSH
• elektroencefalografie metody   využití   MeSH
• financování organizované MeSH
• lidé MeSH
• mozek fyziologie   MeSH
• muskuloskeletální a nervový systém - fyziologické jevy MeSH
• palec ruky fyziologie   MeSH
• pohyb fyziologie   MeSH
• ruka fyziologie   MeSH
• shluková analýza MeSH
• statistika jako téma metody   MeSH
• studie pohybu a času MeSH
• svalová kontrakce fyziologie   MeSH
• Check Tag
• lidé MeSH