Search results for "HALO"
showing 10 items of 2623 documents
Assessment of nonnegative matrix factorization algorithms for electroencephalography spectral analysis.
2020
AbstractBackgroundNonnegative matrix factorization (NMF) has been successfully used for electroencephalography (EEG) spectral analysis. Since NMF was proposed in the 1990s, many adaptive algorithms have been developed. However, the performance of their use in EEG data analysis has not been fully compared. Here, we provide a comparison of four NMF algorithms in terms of accuracy of estimation, stability (repeatability of the results) and time complexity of algorithms with simulated data. In the practical application of NMF algorithms, stability plays an important role, which was an emphasis in the comparison. A Hierarchical clustering algorithm was implemented to evaluate the stability of NM…
Mismatch negativity (MMN) in freely-moving rats with several experimental controls.
2014
Mismatch negativity (MMN) is a scalp-recorded electrical potential that occurs in humans in response to an auditory stimulus that defies previously established patterns of regularity. MMN amplitude is reduced in people with schizophrenia. In this study, we aimed to develop a robust and replicable rat model of MMN, as a platform for a more thorough understanding of the neurobiology underlying MMN. One of the major concerns for animal models of MMN is whether the rodent brain is capable of producing a human-like MMN, which is not a consequence of neural adaptation to repetitive stimuli. We therefore tested several methods that have been used to control for adaptation and differential exogenou…
Serratia marcescens infection or hypoxic-ischaemic encephalopathy in neonates: Is magnetic resonance imaging a problem-solving tool?
2017
To the Editor: We read with great interest the retrospective case series by A Madide and J Smith,[1] describing brain ultrasound (US) findings of neonates with Serratia marcescens hospital-acquired infections. S. marcescens is a Gram-negative organism that frequently colonises neonatal intensive care units (NICUs). This bacterium can cause severe brain infections in neonates, with irreversible neurological damage and long-term neurodevelopmental impairment. The authors conclude that in babies with acute onset of the illness, US scans allow doctors to highlight pathological changes in the brain immediately before the microbiological diagnosis of infection, and to follow the evolution of thos…
Dieta del delfín de Risso (Grampus griseus) en el Mediterráneo occidental
2006
DIETA DEL DELFÍN DE RISSO (GRAMPUS GRISEUS) EN EL MEDITERRÁNEO OCCIDENTAL. – Se ha analizado el contenido gastrointestinal de quince ejemplares de Grampus griseus varados en el Mediterráneo occidental entre 40º25’N 00º32’W y 37º35’N 00º45’E durante el período 1987 a 2003. Los resultados indican una dieta teutófaga, basada principalmente en cefalópodos oceánicos destacando los octópodos pelágicos, especialmente Argonauta argo, como la presa más abundante (media = 41,28%; SD±34,32). Algunas especies pertenecientes a las familias mmastrephidae, Histioteuthidae y Onychoteuthidae son también componentes frecuentes de la misma. La distribución batimétrica de los cefalópodos indica que el área de …
Thermodynamic correction of particle concentrations measured by underwing probes on fast-flying aircraft
2016
Particle concentration measurements with underwing probes on aircraft are impacted by air compression upstream of the instrument body as a function of flight velocity. In particular, for fast-flying aircraft the necessity arises to account for compression of the air sample volume. Hence, a correction procedure is needed to invert measured particle number concentrations to ambient conditions that is commonly applicable to different instruments to gain comparable results. In the compression region where the detection of particles occurs (i.e. under factual measurement conditions), pressure and temperature of the air sample are increased compared to ambient (undisturbed) conditions in certain …
Pairwise and higher-order measures of brain-heart interactions in children with temporal lobe epilepsy
2022
Abstract Objective. While it is well-known that epilepsy has a clear impact on the activity of both the central nervous system (CNS) and the autonomic nervous system (ANS), its role on the complex interplay between CNS and ANS has not been fully elucidated yet. In this work, pairwise and higher-order predictability measures based on the concepts of Granger Causality (GC) and partial information decomposition (PID) were applied on time series of electroencephalographic (EEG) brain wave amplitude and heart rate variability (HRV) in order to investigate directed brain-heart interactions associated with the occurrence of focal epilepsy. Approach. HRV and the envelopes of δ and α EEG activity re…
Modyfikowane ftalocyjaniny dla diagnozowania oraz terapii fotodynamicznej nowotworów
2016
Terapie przeciwnowotworowe powinny charakteryzować się wysoką skutecznością przy możliwie ograniczonych skutkach ubocznych. Obiecującą metodą wydaje się być terapia fotodynamiczna (PDT). Dobrą efektywność terapii uzyskuje się, stosując lipofilowe foto-uczulacze, kumulujące się w błonie komórkowej. Dodatkowo efektywność terapii fotodyn-amicznej można zwiększyć, stosując liposomy jako nośniki leków. Rolę fotouczulaczy (PS) dla terapii PDT mogą pełnić modyfikowane ftalocyjaniny (MPc). W pracy koncentrowano się na zbadaniu możliwości penetracji błony fosfolipidowej przez ftalocyjaninę miedzi o 4 podstawnikach 2,4-bis(1,1-dimetylopropylo)fenoksylowych (CuPc-TM), bezmetaliczną ftalocyjaninę o 4 p…
Cortical correlates of language perception : neuromagnetic studies in adults and children
2007
Kielen havaitsemisen päämääränä on ymmärtää kuullun tai luetun viestin sisältö. Itse havaitseminen on meille näennäisen vaivatonta. Puheen tunnistaminen ja lukeminen ovat kuitenkin tulos monimutkaisesta aivokuorella tapahtuvasta laskennasta, jonka lähtökohtana on silmän ja korvan vastaanottama fysikaalinen signaali.Tiina Parviainen tarkasteli väitöstutkimuksessaan kielen käsittelyn aivomekanismeja normaalisti lukevilla ja lukivaikeuksisilla aikuisilla sekä lukemaan opettelevilla lapsilla. Hän selvitti kirjoitetun ja puhutun kielen käsittelyyn liittyvää aktivaatioketjua aivoissa ja siinä esiintyviä eroja aikuisten ja lasten välillä. Kielen aivomekanismien kartoituksessa on keskeistä aktivaat…
When the Grafting of Double Decker Phthalocyanines on Si(100)-2 × 1 Partly Affects the Molecular Electronic Structure
2016
International audience; A combined X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), and density functional theory (DFT) study has been performed to characterize the adsorbate interaction of lutetium biphthalocyanine (LuPc2) molecules on the Si(100)-2 × 1 surface. Large molecule–substrate adsorption energies are computed and are found to compete with the molecule–molecule interactions of the double decker molecules. A particularly good matching between STM images and computed ones confirms the deformation of the molecule upon the absorption process. The comparison between DFT calculations and XP spectra reveals that the electronic distribution in the two plateaus …