Search results for "MRI."
showing 10 items of 591 documents
Kritiskās domāšanas attīstība vecākajā pirmsskolas vecumā
2021
Darba autore: Liene Gribuste Bakalaura darba tēma: Kritiskās domāšanas attīstība vecākajā pirmsskolas vecumā Studiju programma: Profesionālā bakalaura studiju programma ‘’Pirmsskolas un sākumskolas skolotājs’’ Darba zinātniskais vadītājs: Docente Dr. Paed. Inese Freiberga Bakalaura darbā tiek pētīts / analizēts: Vecākā pirmsskolas vecuma bērna kritiskās domāšanas attīstība. Darba mērķis: Izpētīt kritiskās domāšanas attīstības iespējas vecākajā pirmsskolas vecumā, sniedzot bērniem iespējas pašiem spriest un analizēt, pieņemt lēmumus un secināt sava lēmuma rezultātu, kā arī izmantojot problēmrisināšanas metodi. Darba uzdevumi: 1. Pētīt pedagoģijas un psiholoģijas zinātnieku teorijas par kriti…
Skolēnu radošās darbības veicināšana matemātikas mācībā 3.klasei
2022
Bakalaura darba nosaukums: Skolēnu radošās darbības veicināšana matemātikas mācībā 3.klasei. Darba autore: Sevda Latkovska Darba vadītāja: Asoc.prof., Dr.paed Ineta Helmane Bakalaura darba mērķis ir pētīt un praktiski pārbaudīt skolēnu radošās darbības veicināšanu matemātikas mācībā 3. klasei. Bakalaura darbs sastāv no teorētiskās un empīriskās daļas, secinājumiem un ieteikumiem. Teorētiskajā daļā analizēta un apkopota pedagoģijas un psiholoģijas zinātniskā literatūra, žurnāli un pētījumi par radošas darbības būtību, matemātikas mācību sākumskolā, skolēnu radošas darbības veicināšanu. Empīriskajā daļā veikts pētījums divos posmos. Katrā posmā tiek īstenotas 5 nodarbības. Pētījuma hipotēze i…
Iron oxides nanoparticles and titanate nanotubes dedicated to multimodal imaging and anticancer therapy
2013
The new implementations of nanoparticles in the medical field are one of the essential factors of the medical progress expected at the beginning of this XXIst century. Thus, the domain of the medical imaging is also affected by this technological evolution. This work consisted in developing theranostic probes with iron oxides nanoparticles (SPIO) and titanate nanotubes (TiONts) for multimodal imaging (magnetic/nuclear or magnetic/optical) and also possessing a therapeutic effect (hyperthermia/PDT or radiosensitization/PDT).The titanate nanotubes of this study have an average length of about 150 nm and were obtained by Kasuga's hydrothermal synthesis. These nanotubes present an outside diame…
ICA of full complex-valued fMRI data using phase information of spatial maps.
2015
Background ICA of complex-valued fMRI data is challenging because of the ambiguous and noisy nature of the phase. A typical solution is to remove noisy regions from fMRI data prior to ICA. However, it may be more optimal to carry out ICA of full complex-valued fMRI data, since any filtering or voxel-based processing may disrupt information that can be useful to ICA. New method We enable ICA of the full complex-valued fMRI data by utilizing phase information of estimated spatial maps (SMs). The SM phases are first adjusted to properly represent spatial phase changes of all voxels based on estimated time courses (TCs), and then these are used to segment the voxels into BOLD-related and unwant…
Coupling of Action-Perception Brain Networks during Musical Pulse Processing: Evidence from Region-of-Interest-Based Independent Component Analysis
2017
Our sense of rhythm relies on orchestrated activity of several cerebral and cerebellar structures. Although functional connectivity studies have advanced our understanding of rhythm perception, this phenomenon has not been sufficiently studied as a function of musical training and beyond the General Linear Model (GLM) approach. Here, we studied pulse clarity processing during naturalistic music listening using a data-driven approach (independent component analysis; ICA). Participants’ (18 musicians and 18 controls) functional magnetic resonance imaging (fMRI) responses were acquired while listening to music. A targeted region of interest (ROI) related to pulse clarity processing was defined…
Noise-assisted persistence and recovery of memory state in a memristive spiking neuromorphic network
2021
Abstract We investigate the constructive role of an external noise signal, in the form of a low-rate Poisson sequence of pulses supplied to all inputs of a spiking neural network, consisting in maintaining for a long time or even recovering a memory trace (engram) of the image without its direct renewal (or rewriting). In particular, this unique dynamic property is demonstrated in a single-layer spiking neural network consisting of simple integrate-and-fire neurons and memristive synaptic weights. This is carried out by preserving and even fine-tuning the conductance values of memristors in terms of dynamic plasticity, specifically spike-timing-dependent plasticity-type, driven by overlappi…
Towards peptide-based tunable multistate memristive materials
2021
Development of new memristive hardware is a technological requirement towards widespread neuromorphic computing. Molecular spintronics seems to be a fertile field for the design and preparation of this hardware. Within molecular spintronics, recent results on metallopeptides demonstrating the interaction between paramagnetic ions and the chirality induced spin selectivity effect hold particular promise for developing fast (ns–μs) operation times. [R. Torres-Cavanillas et al., J. Am. Chem. Soc., 2020, DOI: 10.1021/jacs.0c07531]. Among the challenges in the field, a major highlight is the difficulty in modelling the spin dynamics in these complex systems, but at the same time the use of inexp…
Can histographic analysis of apparent diffusion coefficient help discriminate between benign and malignant nodes in head and neck squamous cell carci…
2011
Objective: To investigate histographic analysis of apparent diffusion coefficient (ADC) measurements as discriminators of benign from malignant lymph nodes in patients with head and neck (H&N) squamous cell carcinoma (SCC) Materials and Methods: Seventeen patients with H&N SCC staged for nodal disease using anatomical MRI, contrast enhanced CT and ultrasound ± fine needle aspiration gave informed consent for additional MR diffusion weighted imaging (DWI). Axial DWI was performed by short tau inversion recovery (STIR) echo planar imaging and trace weighted images obtained b 0, 50, 100, 300, 600 and 1000. Image analysis was conducted using Jim 5.0. Nodal disease and contralateral benign nodal…
Importance of the Window Function Choice for the Predictive Modelling of Memristors
2021
Window functions are widely employed in memristor models to restrict the changes of the internal state variables to specified intervals. Here, we show that the actual choice of window function is of significant importance for the predictive modelling of memristors. Using a recently formulated theory of memristor attractors, we demonstrate that whether stable fixed points exist depends on the type of window function used in the model. Our main findings are formulated in terms of two memristor attractor theorems, which apply to broad classes of memristor models. As an example of our findings, we predict the existence of stable fixed points in Biolek window function memristors and their absenc…
Dynamical attractors of memristors and their networks
2018
It is shown that the time-averaged dynamics of memristors and their networks periodically driven by alternating-polarity pulses may converge to fixed-point attractors. Starting with a general memristive system model, we derive basic equations describing the fixed-point attractors and investigate attractors in the dynamics of ideal, threshold-type and second-order memristors, and memristive networks. A memristor potential function is introduced, and it is shown that in some cases the attractor identification problem can be mapped to the problem of potential function minimization. Importantly, the fixed-point attractors may only exist if the function describing the internal state dynamics dep…