Autori sa v príspevku zaoberajú problematikou klasifikácie skupín atletických disciplín ovplyvňuj-úcich športovú výkonnosť sedemboja žien. Na identifikáciu skupín boli využité ukazovatele najlepšíchsvetových výkonov sedemboja nad 6200 bodov podľa dostupných údajov z IAAF (N = 172). Z klasifi-kačných metód zhlukovania boli použité hierarchické modely ako Average linkage (Between & Within- group), Single Linkage - Nearest neigbor, Complete Linkage - Farthest neigbor, Centroid linkage,Median clustering, Ward ́s method.Všetkých sedem zhlukových metód sa zhodlo v dvoch skupinách zhlukov a v obsahu disciplínv 2. klastry [200 m, skok od diaľky, 800 m, 100 m prekážok, skok do výšky] [vrh guľou, hod oštepom].Test stability so štruktúrou zhlukov sedemboja na úrovni 2. klastra je 100 %. Najvyššiu stabilitu42,86 % javí vnútorná hierarchia disciplín [200 m, Skok do diaľky, 100 m prekážok, Skok do výšky,800 m] [Vrh guľou, Hod oštepom].Hierarchické modely umožnili identifikovať skupiny atletických disciplíny ovplyvňujúce športovývýkon v sedemboji žien. Poznanie štruktúry športového výkonu prispieva k zefektívneniu tréningovéhoprocesu a určeniu viacbojárskej typológie pretekárok svetovej výkonnosti.

Authors deals with the problematics of group classification of athletics disciplines, which influence thesports performance in the women's heptathlon. For the group identification, the indicators of the bestworld's performance in heptathlon above the 6200 points according to the data from IAAF (N = 172)were used. From the classification methods of clustering the hierarchical models as the Average linkage(Between & Within-group), Single Linkage - Nearest neighbor, Complete Linkage - Farthest neighbor,Centroid linkage, Median clustering, and Ward ́s method were used.All seven clustering methods agreed in two groups of clusters and in the content of disciplines in2 clusters [200 meters, Long jump, 800 meters, 100 meters hurdles, High jump] [Shot put, Javelinthrow]. The stability test with the cluster structure of heptathlon in the level of the second cluster is100 %. The highest stability, 42,86 %, shows the internal hierarchy of disciplines [200 meters, Longjump, 100 meters hurdles, High jump, 800 meters] [Shot put, Javelin throw].Hierarchical models allow identifying groups of athletics disciplines that influence the sports perfor-mance in women's heptathlon. Understanding the structure of sports performance contributes to thestreamlining the training process and determining the combined events typology of world performanceathletes.

• MeSH
• klasifikace MeSH
• lehká atletika klasifikace   MeSH
• lidé MeSH
• sporty klasifikace   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• srovnávací studie MeSH

Motivace: Infarkt myokardu a mozková mrtvice před- stavují závažný zdravotní problém ve většině rozvinutých zemí. Tato studie zkoumá genetickou dispozici pro akutní infarkt myokardu v české populaci. Metody a výsledky: Celogenomová studie genových ex- presí je spárovanou studií případů a kontrol. Vzorky peri- ferní krve kontrolních osob byly spárovány se vzorky paci- entů na základě pohlaví, věku, příznaku diabetes mellitus a kouření. Pacienti s infarktem byli rozděleni do dvou sku- pin podle toho, zda přežili období 6 měsíců od infarktu. Použili jsme metodu limma (Linear Models for Micro- array Data) pro identifikaci diferenciálních genových ex- presí. Metoda smrštěných centroidů pomohla identifikovat množiny diferenciálně exprimovaných genů s prediktivními vlastnostmi na nezávislých vzorcích. Prediktivní vlastnosti byly ověřeny pomocí bootstrapu. Ukazuje se, že 60 tran- skriptů je diferenciálně exprimováno z klinického i statis- tického hlediska mezi pacienty, kteří nepřežili šestiměsíční období, vzhledem ke kontrolním osobám. Přitom žádné ta- kové transkripty nebyly pozorovány mezi pacienty, kteří přežili. Mezi dvěma skupinami pacientů s infarktem vychází 14 di- ferenciálně exprimovaných transkriptů. Prediktivní mode- lování umožnilo vytipovat 16 ze 60 transkriptů, které nej- lépe diskriminují mezi kontrolami a pacienty, kteří zemřeli během šestiměsíčního období na kardiovaskulární onemoc- nění. Obdobný výběr nelze provést pro přeživší pacienty, protože pro ně vyšly všechny geny nesignifikantní. Za po- moci smrštěných centroidů bylo vytipováno 11 ze 14 tran- skriptů, které nejlépe diskriminují mezi oběma skupinami pacientů s infarktem. Závěry: Studie identifikovala geny asociované se zvýše- ným genetickým rizikem akutního infarktu myokardu, a to včetně genů asociovaných s úmrtím během šestiměsíčního období po výskytu infarktu.

Background: Myocardial infarction and stroke represent a major public health problem in most developing coun- tries. This study explores genetic predisposition of acute myocardial infarction in the Czech population. Methods and Results: Genome-wide expression study used matched case-control design. Peripheral blood sam- ples of the controls were matched to those of cases based on gender, age, status of diabetes mellitus and smoking status. Six months cardiovascular survival status of the cases was used to identify two distinct subgroups among the cases. Linear models for microarray data were em- ployed to identify differential gene expression. Shrunken centroids technique helped in identifying the subsets of differentially expressed genes with predictive properties in independent samples. Predictive properties were evaluated using bootstrap sampling. Sixty transcripts were found to be both clinically and statistically differentially expressed among the cases not surviving the six months follow-up period relative to controls, while no such transcripts were observed among other surviving cases. The two subgroups of cases exhibited fourteen differen- tially expressed transcripts. Predictive modeling indicated sixteen out of sixty transcripts to best discriminate be- tween the controls and cases that died during the follow-up period from cardiovascular causes, while for the surviving cases the already non-significant set of transcripts could not be further reduced. Eleven out of fourteen transcripts were found to best discriminate between the two groups of cases using shrunken centroids. Conclusions: The study identified genes associated with excess genetic risk of acute myocardial infarction, including those associated with the six months fatality of the cases.

• Klíčová slova
• prediktivní modelování,
• MeSH
• akutní nemoc MeSH
• celogenomová asociační studie * metody   statistika a číselné údaje   MeSH
• exprese genu MeSH
• genetická predispozice k nemoci * genetika   MeSH
• genetické markery MeSH
• genetické testování metody   statistika a číselné údaje   MeSH
• infarkt myokardu * genetika   mortalita   MeSH
• lidé MeSH
• lineární modely MeSH
• mikročipová analýza MeSH
• senzitivita a specificita MeSH
• studie případů a kontrol MeSH
• Check Tag
• lidé MeSH

INTRODUCTION: This study aimed to evaluate changes in facial size and shape in children and their relationship to the changes in height and weight. METHODS: One hundred and thirteen healthy children aged between 6 and 13 years were followed annually for 2 consecutive years. The facial morphology was captured in 12-month intervals (from T1 to T2 and from T2 to T3) using a 3-dimensional stereophotogrammetric optical scanner; the body height and weight were recorded simultaneously. The changes in facial size and shape were analyzed with geometric morphometrics. Multiple regression mixed-effects models were exploited for evaluation of the association between the changes of facial size or shape and age at the beginning of the observation, gender, and change of height and weight. RESULTS: The centroid size (reflecting facial size) increased from T1 to T2 and T2 to T3 in boys and girls. In contrast, the facial shape did not change during both 12-month observation periods (T1 to T2 and T2 to T3) either in boys or girls. Of 2 multiple regression mixed-effects models, only the model with the change of natural logarithm of centroid size as a dependent variable was statistically significant (P <0.001; adjusted r2 = 0.29). It showed that height and weight changes were associated with a change of the facial size (with weight change having a greater effect than height change: adjusted r2 = 0.25 for weight change and adjusted r2 = 0.106 for height change). CONCLUSIONS: Most changes in the facial morphology observed in our cohort were associated with increasing facial size. In contrast, the shape of the face remained relatively constant. Body height and weight gains were associated with the change of the facial size only. However, only 29% of the variation in facial size was explained by height or weight changes during growth.

• MeSH
• dítě MeSH
• fotogrammetrie MeSH
• hmotnostní přírůstek MeSH
• lidé MeSH
• mladiství MeSH
• následné studie MeSH
• obličej * anatomie a histologie   diagnostické zobrazování   MeSH
• tělesná výška * MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

People are remarkably good at remembering photographs. To further investigate the nature of the stored representations and the fidelity of human memories, it would be useful to evaluate the visual similarity of stimuli presented in experiments. Here, we explored the possible use of convolutional neural networks (CNN) as a measure of perceptual or representational similarity of visual scenes with respect to visual memory research. In Experiment 1, we presented participants with sets of nine images from the same scene category and tested whether they were able to detect the most distant scene in the image space defined by CNN. Experiment 2 was a visual variant of the Deese-Roediger-McDermott paradigm. We asked participants to remember a set of photographs from the same scene category. The photographs were preselected based on their distance to a particular visual prototype (defined as centroid of the image space). In the recognition test, we observed higher false alarm rates for scenes closer to this visual prototype. Our findings show that the similarity measured by CNN is reflected in human behavior: people can detect odd-one-out scenes or be lured to false alarms with similar stimuli. This method can be used for further studies regarding visual memory for complex scenes.

• MeSH
• lidé MeSH
• neuronové sítě MeSH
• paměť * MeSH
• rozpomínání * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The current investigation evaluates the efficiency of the trifocal toric Liberty 677MTY intraocular lens (IOL) in correcting preoperative corneal astigmatism in cataract patients demanding spectacle independence. The retrospective evaluation included 28 eyes of 15 patients with preoperative corneal astigmatism of at least 1.0 Dioptre (D). All patients were followed up for one year postoperatively. Residual refractive errors and visual acuities at multiple distances were measured. Binocular visual acuity and contrast sensitivity defocus curves were plotted. Visual functions and patient satisfaction were assessed. The efficiency of astigmatism correction was determined using the vector analysis method. The mean spherical equivalent refraction (SEQ) improved from 2.72 ± 1.62 D to 0.10 ± 0.48 D. The cylindric refraction decreased from 1.18 ± 0.45 D to 0.16 ± 0.31 D. Vector analysis proved efficient astigmatism correction with a centroid of 0.10 ± 0.34 D at 161°. Ninety-two percent of eyes resulted within 0.5 D from the target refraction. Visual acuities were 0.1 logMAR or better from +1.0 to -3.5 D defocus values. Visual tasks could be performed without major difficulties. Our patients were highly satisfied. Refractive and visual outcomes with the investigated presbyopia-correcting toric IOL are predictable and the lens provides excellent trifocal vision.

• Publikační typ
• časopisecké články MeSH

We investigated a combination of three classification algorithms, namely the modified maximum uncertainty linear discriminant analysis (mMLDA), the centroid method, and the average linkage, with three types of features extracted from three-dimensional T1-weighted magnetic resonance (MR) brain images, specifically MR intensities, grey matter densities, and local deformations for distinguishing 49 first episode schizophrenia male patients from 49 healthy male subjects. The feature sets were reduced using intersubject principal component analysis before classification. By combining the classifiers, we were able to obtain slightly improved results when compared with single classifiers. The best classification performance (81.6% accuracy, 75.5% sensitivity, and 87.8% specificity) was significantly better than classification by chance. We also showed that classifiers based on features calculated using more computation-intensive image preprocessing perform better; mMLDA with classification boundary calculated as weighted mean discriminative scores of the groups had improved sensitivity but similar accuracy compared to the original MLDA; reducing a number of eigenvectors during data reduction did not always lead to higher classification accuracy, since noise as well as the signal important for classification were removed. Our findings provide important information for schizophrenia research and may improve accuracy of computer-aided diagnostics of neuropsychiatric diseases.

• MeSH
• algoritmy MeSH
• diagnóza počítačová metody   MeSH
• diskriminační analýza MeSH
• dospělí MeSH
• lidé MeSH
• magnetická rezonanční tomografie metody   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• schizofrenie diagnóza   MeSH
• senzitivita a specificita MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Typical time intervals between acquisitions of three-dimensional (3-D) images of the same cell in live cell imaging are in the orders of minutes. In the meantime, the live cell can move in a water basin on the stage. This movement can hamper the studies of intranuclear processes. We propose a fast point-based image registration method for the suppression of the movement of a cell as a whole in the image data. First, centroids of certain intracellular objects are computed for each image in a time-lapse series. Then, a matching between the centroids, which have the maximal number of pairs, is sought between consecutive point sets by a 3-D extension of a two-dimensional fast point pattern matching method, which is invariant to rotation, translation, local distortion, and extra/missing points. The proposed 3-D extension assumes rotations only around the z axis to retain the complexity of the original method. The final step involves computing the optimal fully 3-D transformation between images from corresponding points in the least-squares manner. The robustness of the method was evaluated on generated data. The results of the simulations show that the method is very precise and its correctness can be estimated. This article also presents two practical application examples, namely the registration of images of HP1 domains and the registration of images of telomeres. More than 97% of time-consecutive images were successfully registered. The results show that the method is very well suited to live cell imaging.

• MeSH
• algoritmy MeSH
• artefakty MeSH
• financování organizované MeSH
• fluorescenční mikroskopie metody   MeSH
• interpretace obrazu počítačem metody   MeSH
• kultivované buňky cytologie   MeSH
• lidé MeSH
• pohyb buněk MeSH
• reprodukovatelnost výsledků MeSH
• rozpoznávání automatizované metody   MeSH
• senzitivita a specificita MeSH
• subtrakční technika MeSH
• ukládání a vyhledávání informací metody   MeSH
• umělá inteligence MeSH
• videomikroskopie metody   MeSH
• vylepšení obrazu metody   MeSH
• zobrazování trojrozměrné metody   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• hodnotící studie MeSH

PURPOSE: The optimal motion management strategy for patients receiving stereotactic arrhythmia radioablation (STAR) for the treatment of ventricular tachycardia (VT) is not fully known. We developed a framework using a digital phantom to simulate cardiorespiratory motion in combination with different motion management strategies to gain insight into the effect of cardiorespiratory motion on STAR. METHODS AND MATERIALS: The 4-dimensional (4D) extended cardiac-torso (XCAT) phantom was expanded with the 17-segment left ventricular (LV) model, which allowed placement of STAR targets in standardized ventricular regions. Cardiac- and respiratory-binned 4D computed tomography (CT) scans were simulated for free-breathing, reduced free-breathing, respiratory-gating, and breath-hold scenarios. Respiratory motion of the heart was set to population-averaged values of patients with VT: 6, 2, and 1 mm in the superior-inferior, posterior-anterior, and left-right direction, respectively. Cardiac contraction was adjusted by reducing LV ejection fraction to 35%. Target displacement was evaluated for all segments using envelopes encompassing the cardiorespiratory motion. Envelopes incorporating only the diastole plus respiratory motion were created to simulate the scenario where cardiac motion is not fully captured on 4D respiratory CT scans used for radiation therapy planning. RESULTS: The average volume of the 17 segments was 6 cm3 (1-9 cm3). Cardiac contraction-relaxation resulted in maximum segment (centroid) motion of 4, 6, and 3.5 mm in the superior-inferior, posterior-anterior, and left-right direction, respectively. Cardiac contraction-relaxation resulted in a motion envelope increase of 49% (24%-79%) compared with individual segment volumes, whereas envelopes increased by 126% (79%-167%) if respiratory motion also was considered. Envelopes incorporating only the diastole and respiration motion covered on average 68% to 75% of the motion envelope. CONCLUSIONS: The developed LV-segmental XCAT framework showed that free-wall regions display the most cardiorespiratory displacement. Our framework supports the optimization of STAR by evaluating the effect of (cardio)respiratory motion and motion management strategies for patients with VT.

• MeSH
• čtyřrozměrná počítačová tomografie MeSH
• dýchání * MeSH
• fantomy radiodiagnostické MeSH
• lidé MeSH
• pohyb těles MeSH
• srdce * diagnostické zobrazování   účinky záření   MeSH
• srdeční arytmie MeSH
• srdeční komory diagnostické zobrazování   účinky záření   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

AIMS: The aim of this study was to determine the relationship between electrical and mechanical activation in heart failure (HF) patients and whether electromechanical coupling is affected by scar. METHODS AND RESULTS: Seventy HF patients referred for cardiac resynchronization therapy or biological therapy underwent endocardial anatomo-electromechanical mapping (AEMM) and delayed-enhancement magnetic resonance (CMR) scans. Area strain and activation times were derived from AEMM data, allowing to correlate mechanical and electrical activation in time and space with unprecedented accuracy. Special attention was paid to the effect of presence of CMR-evidenced scar. Patients were divided into a scar (n = 43) and a non-scar group (n-27). Correlation between time of electrical and mechanical activation was stronger in the non-scar compared to the scar group [R = 0.84 (0.72-0.89) vs. 0.74 (0.52-0.88), respectively; P = 0.01]. The overlap between latest electrical and mechanical activation areas was larger in the absence than in presence of scar [72% (54-81) vs. 56% (36-73), respectively; P = 0.02], with smaller distance between the centroids of the two regions [10.7 (4.9-17.4) vs. 20.3 (6.9-29.4) % of left ventricular radius, P = 0.02]. CONCLUSION: Scar decreases the association between electrical and mechanical activation, even when scar is remote from late activated regions.

• MeSH
• jizva diagnostické zobrazování   MeSH
• lidé MeSH
• magnetická rezonance kinematografická MeSH
• srdeční komory diagnostické zobrazování   MeSH
• srdeční resynchronizační terapie * MeSH
• srdeční selhání * diagnostické zobrazování   terapie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH