Standard spectral density mapping protocols, well suited for the analysis of (15)N relaxation rates, introduce significant systematic errors when applied to (13)C relaxation data, especially if the dynamics is dominated by motions with short correlation times (small molecules, dynamic residues of macromolecules). A possibility to improve the accuracy by employing cross-correlated relaxation rates and on measurements taken at several magnetic fields has been examined. A suite of protocols for analyzing such data has been developed and their performance tested. Applicability of the proposed protocols is documented in two case studies, spectral density mapping of a uniformly labeled RNA hairpin and of a selectively labeled disaccharide exhibiting highly anisotropic tumbling. Combination of auto- and cross-correlated relaxation data acquired at three magnetic fields was applied in the former case in order to separate effects of fast motions and conformational or chemical exchange. An approach using auto-correlated relaxation rates acquired at five magnetic fields, applicable to anisotropically moving molecules, was used in the latter case. The results were compared with a more advanced analysis of data obtained by interpolation of auto-correlated relaxation rates measured at seven magnetic fields, and with the spectral density mapping of cross-correlated relaxation rates. The results showed that sufficiently accurate values of auto- and cross-correlated spectral density functions at zero and (13)C frequencies can be obtained from data acquired at three magnetic fields for uniformly (13)C-labeled molecules with a moderate anisotropy of the rotational diffusion tensor. Analysis of auto-correlated relaxation rates at five magnetic fields represents an alternative for molecules undergoing highly anisotropic motions.

• MeSH
• Algorithms * MeSH
• Data Interpretation, Statistical * MeSH
• Carbon-13 Magnetic Resonance Spectroscopy methods   MeSH
• Magnetic Fields MeSH
• RNA, Small Interfering analysis   chemistry   MeSH
• Signal Processing, Computer-Assisted * MeSH
• Reproducibility of Results MeSH
• Sensitivity and Specificity MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

BACKGROUND AND OBJECTIVE: Capturing the population variability of bone properties is of paramount importance to biomedical engineering. The aim of the present paper is to describe variability and correlations in bone mineral density with a spatial random field inferred from routine computed tomography data. METHODS: Random fields were simulated by transforming pairwise uncorrelated Gaussian random variables into correlated variables through the spectral decomposition of an age-detrended correlation matrix. The validity of the random field model was demonstrated in the spatiotemporal analysis of bone mineral density. The similarity between the computed tomography samples and those generated via random fields was analyzed with the energy distance metric. RESULTS: The random field of bone mineral density was found to be approximately Gaussian/slightly left-skewed/strongly right-skewed at various locations. However, average bone density could be simulated well with the proposed Gaussian random field for which the energy distance, i.e., a measure that quantifies discrepancies between two distribution functions, is convergent with respect to the number of correlation eigenpairs. CONCLUSIONS: The proposed random field model allows the enhancement of computational biomechanical models with variability in bone mineral density, which could increase the usability of the model and provides a step forward in in-silico medicine.

• MeSH
• Bone and Bones * MeSH
• Bone Density * MeSH
• Tomography, X-Ray Computed MeSH
• Publication type
• Journal Article MeSH

It has long been known that environmental conditions, particularly during development, affect morphological and functional properties of the brain including sensory systems; manipulating the environment thus represents a viable way to explore experience-dependent plasticity of the brain as well as of sensory systems. In this review, we summarize our experience with the effects of acoustically enriched environment (AEE) consisting of spectrally and temporally modulated complex sounds applied during first weeks of the postnatal development in rats and compare it with the related knowledge from the literature. Compared to controls, rats exposed to AEE showed in neurons of several parts of the auditory system differences in the dendritic length and in number of spines and spine density. The AEE exposure permanently influenced neuronal representation of the sound frequency and intensity resulting in lower excitatory thresholds, increased frequency selectivity and steeper rate-intensity functions. These changes were present both in the neurons of the inferior colliculus and the auditory cortex (AC). In addition, the AEE changed the responsiveness of AC neurons to frequency modulated, and also to a lesser extent, amplitude-modulated stimuli. Rearing rat pups in AEE leads to an increased reliability of acoustical responses of AC neurons, affecting both the rate and the temporal codes. At the level of individual spikes, the discharge patterns of individual neurons show a higher degree of similarity across stimulus repetitions. Behaviorally, rearing pups in AEE resulted in an improvement in the frequency resolution and gap detection ability under conditions with a worsened stimulus clarity. Altogether, the results of experiments show that the exposure to AEE during the critical developmental period influences the frequency and temporal processing in the auditory system, and these changes persist until adulthood. The results may serve for interpretation of the effects of the application of enriched acoustical environment in human neonatal medicine, especially in the case of care for preterm born children.

• MeSH
• Acoustic Stimulation * MeSH
• Acoustics MeSH
• Inferior Colliculi growth & development   physiology   MeSH
• Rats MeSH
• Humans MeSH
• Neurons physiology   MeSH
• Neuronal Plasticity * physiology   MeSH
• Animals, Newborn MeSH
• Auditory Pathways * growth & development   physiology   MeSH
• Auditory Perception MeSH
• Auditory Cortex * growth & development   physiology   MeSH
• Age Factors MeSH
• Environment MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

This book represents a concise summary of non-relativistic quantum mechanics on the level suitable for university students of physics. It covers, perhaps even slightly exceeds, a one-year course of about 50 lectures, requiring basic knowledge of calculus, algebra, classical mechanics and a bit of motivation for the quantum adventure.The exposition is succinct, with minimal narration, but with a maximum of explicit and hierarchically structured mathematical derivations. The text covers all essential topics of university courses of quantum mechanics - from general mathematical formalism to specific applications. The formulation of quantum theory is accompanied by illustrations of the general concepts of elementary quantum systems. Some subtleties of mathematical foundations are overviewed, but the formalism is used in an accessible, intuitive way. Besides the traditional topics of non-relativistic quantum mechanics, such as single-particle dynamics, symmetries, semiclassical and perturbative approximations, density-matrix formalism, scattering theory, theory of angular momentum, description of many-particle systems - the course also touches upon some modern issues, including quantum entanglement, decoherence, measurement, nonlocality, and quantum information. Historical context and chronology of basic achievements is outlined in brief remarks. The book is intended for beginners as a supplement to lectures, however, it may also be used by more advanced students as a compact and comprehensible overview of elementary quantum theory.

• MeSH
• Physical Phenomena MeSH
• Magnetic Resonance Imaging MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• radiologie, nukleární medicína a zobrazovací metody
• NML Publication type
• kolektivní monografie

• MeSH
• Physics MeSH

• Conspectus
• Fyzika
• Učební osnovy. Vyučovací předměty. Učebnice
• NML Fields
• fyzika, biofyzika
• NML Publication type
• učebnice vysokých škol

• MeSH
• Physics MeSH

• Conspectus
• Přírodní vědy. Matematické vědy
• NML Fields
• přírodní vědy
• NML Publication type
• učebnice vysokých škol

• MeSH
• Diagnostic Imaging MeSH
• Radiography * instrumentation   MeSH
• Technology, Radiologic MeSH
• Publication type
• Monograph MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• radiologie, nukleární medicína a zobrazovací metody

• MeSH
• Image Interpretation, Computer-Assisted MeSH

• Conspectus
• Lékařské vědy. Lékařství
• NML Fields
• lékařská informatika

The structure of neurons in the central auditory system is vulnerable to various kinds of acoustic exposures during the critical postnatal developmental period. Here we explored long-term effects of exposure to an acoustically enriched environment (AEE) during the third and fourth weeks of the postnatal period in rat pups. AEE consisted of a spectrally and temporally modulated sound of moderate intensity, reinforced by a behavioral paradigm. At the age of 3-6 months, a Golgi-Cox staining was used to evaluate the morphology of neurons in the inferior colliculus (IC), the medial geniculate body (MGB), and the auditory cortex (AC). Compared to controls, rats exposed to AEE showed an increased mean dendritic length and volume and the soma surface in the external cortex and the central nucleus of the IC. The spine density increased in both the ventral and dorsal divisions of the MGB. In the AC, the total length and volume of the basal dendritic segments of pyramidal neurons and the number and density of spines on these dendrites increased significantly. No differences were found on apical dendrites. We also found an elevated number of spines and spine density in non-pyramidal neurons. These results show that exposure to AEE during the critical developmental period can induce permanent changes in the structure of neurons in the central auditory system. These changes represent morphological correlates of the functional plasticity, such as an improvement in frequency tuning and synchronization with temporal parameters of acoustical stimuli.

• MeSH
• Acoustic Stimulation MeSH
• Inferior Colliculi cytology   physiology   MeSH
• Dendritic Spines physiology   MeSH
• Dendrites physiology   MeSH
• Rats MeSH
• Geniculate Bodies cytology   physiology   MeSH
• Neurons cytology   physiology   MeSH
• Neuronal Plasticity physiology   MeSH
• Animals, Newborn MeSH
• Rats, Long-Evans MeSH
• Auditory Pathways cytology   physiology   MeSH
• Auditory Cortex cytology   physiology   MeSH
• Cell Shape physiology   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH