Search results for "beta"
showing 10 items of 3374 documents
Reliģiski-filozofiski raksti, XXIV
2018
Par labirintiem un Ariadnes pavedienu Labirinta iziešana kā garīgs rituāls daudziem no mums ir svarīgs arī tagadnē. Taču diez vai tas saista mūs ar senā iniciācijas rita nozīmi. Drīzāk mēs šodien saredzam tajā nevis ceļu, kas ved mūs no savas sākotnes zaudēšanas uz tās no jauna atrašanu, bet gan psiholoģisku iespēju kādu brīdi aizmirst par racionālu domāšanu, ļaujoties labirinta centrā esošās dvēseles balsij, citiem vārdiem, bezapzinātā vēstījumam jeb savai intuīcijai, vai gluži otrādi, pārbaudīt savu loģiku un orientēšanās spējas. Iespējams, vēl vienkāršāk – mūsdienu cilvēkam labirints ir vien veids, kā uz brīdi aizmirst par ikdienas stresu. Ne jau velti visbiežāk mūsdienu labirinti ir daļ…
Teacher-Student Relations in Two Tibetan Buddhist Groups in Helsinki
2017
AbstractBased on sixteen interviews with members of two Tibetan Buddhist groups in Helsinki, Finland, this article investigates how the role of the guru, power imbalance and power abuse are perceived by the students. This qualitative study aims at understanding what shape the reverence to the Vajrayana teacher takes in the egalitarian environment of a European country, where Buddhism is a relatively new phenomenon. The interviews show that while teachers are not losing importance, ways of choosing and paying respect to them changes. They also reveal confusion in defining abuse, and emphasis on personal agency and teachers’ accountability for avoiding it.
Pigment organization and energy transfer dynamics in isolated photosystem I (PSI) complexes from Arabidopsis thaliana depleted of the PSI-G, PSI-K, P…
2002
Abstract Green plant photosystem I (PSI) consists of at least 18 different protein subunits. The roles of some of these protein subunits are not well known, in particular those that do not occur in the well characterized PSI complexes from cyanobacteria. We investigated the spectroscopic properties and excited-state dynamics of isolated PSI-200 particles from wild-type and mutant Arabidopsis thaliana plants devoid of the PSI-G, PSI-K, PSI-L, or PSI-N subunit. Pigment analysis and a comparison of the 5K absorption spectra of the various particles suggests that the PSI-L and PSI-H subunits together bind approximately five chlorophyll a molecules with absorption maxima near 688 and 667nm, that…
Aβ Oligomers and Fibrillar Aggregates Induce Different Apoptotic Pathways in LAN5 Neuroblastoma Cell Cultures
2009
Fibril deposit formation of amyloid beta-protein (Abeta) in the brain is a hallmark of Alzheimer's disease (AD). Increasing evidence suggests that toxicity is linked to diffusible Abeta oligomers, which have been found in soluble brain extracts of AD patients, rather than to insoluble fibers. Here we report a study of the toxicity of two distinct forms of recombinant Abeta small oligomers and fibrillar aggregates to simulate the action of diffusible Abeta oligomers and amyloid plaques on neuronal cells. Different techniques, including dynamic light scattering, fluorescence, and scanning electron microscopy, have been used to characterize the two forms of Abeta. Under similar conditions and …
Erythropoietin mediates tissue protection through an erythropoietin and common beta-subunit heteroreceptor
2004
The cytokine erythropoietin (Epo) is tissue-protective in preclinical models of ischemic, traumatic, toxic, and inflammatory injuries. We have recently characterized Epo derivatives that do not bind to the Epo receptor (EpoR) yet are tissue-protective. For example, carbamylated Epo (CEpo) does not stimulate erythropoiesis, yet it prevents tissue injury in a wide variety ofin vivoandin vitromodels. These observations suggest that another receptor is responsible for the tissue-protective actions of Epo. Notably, prior investigation suggests that EpoR physically interacts with the common β receptor (βcR), the signal-transducing subunit shared by the granulocyte-macrophage colony stimulating fa…
Promotion of osteogenic cell response using quasicovalent immobilized fibronectin on titanium surfaces: introduction of a novel biomimetic layer syst…
2012
Purpose Despite the undeniable potential of cell adhesion molecules such as fibronectin to support osteogenic cell responses and consecutive dental implant healing, the most beneficial mode of application onto titanium implant surfaces still requires investigation. Unspecific fibronectin adsorption on titanium dioxide (TiO2) surfaces can result in low-loading, high-desorption rates and protein–metal interactions with impaired biologic activity. The aim of the present study was to monitor the osteogenic cell responses (cell adhesion, proliferation, and differentiation) specifically to fibronectin biofunctionalized TiO2. Materials and Methods An innovative biomimetic streptavidin-biotin layer…
A Raft-derived, Pak1-regulated Entry Participates in α2β1 Integrin-dependent Sorting to Caveosomes
2008
We have previously shown that a human picornavirus echovirus 1 (EV1) is transported to caveosomes during 2 h together with its receptor alpha2beta1 integrin. Here, we show that the majority of early uptake does not occur through caveolae. alpha2beta1 integrin, clustered by antibodies or by EV1 binding, is initially internalized from lipid rafts into tubulovesicular structures. These vesicles accumulate fluid-phase markers but do not initially colocalize with caveolin-1 or internalized simian virus 40 (SV40). Furthermore, the internalized endosomes do not contain glycosylphosphatidylinositol (GPI)-anchored proteins or flotillin 1, suggesting that clustered alpha2beta1 integrin does not enter…
Supercritical carbon dioxide extraction of seed oil from yellow horn (Xanthoceras sorbifolia Bunge.) and its anti-oxidant activity
2010
Supercritical fluid carbon dioxide (SF-CO(2)) extraction (SFE) of seed oil from yellow horn and its anti-oxidant activity were investigated. The effects of CO(2) flow rate and particle size were firstly optimized, and a central composite design (CCD) combined with response surface methodology was used to study the effects of extraction pressure, temperature and time on the extraction yields. A maximal extraction yield of 61.28% was achieved under optimal conditions of extraction pressure 30 MPa at 45.68 degrees C, 2.08 h and CO(2) flow rate 12 kg/h with 0.5mm particle size. By analyzing the chemical composition of the seed oil, we found that the content of unsaturated fatty acids was approx…
Cholesterol Modulates the Interaction of β-Amyloid Peptide with Lipid Bilayers
2009
The interaction of an amphiphilic, 40-amino acid beta-amyloid (Abeta) peptide with liposomal membranes as a function of sterol mole fraction (X(sterol)) was studied based on the fluorescence anisotropy of a site-specific membrane sterol probe, dehydroergosterol (DHE), and fluorescence resonance energy transfer (FRET) from the native Tyr-10 residue of Abeta to DHE. Without Abeta, peaks or kinks in the DHE anisotropy versus X(sterol) plot were detected at X(sterol) approximately 0.25, 0.33, and 0.53. Monomeric Abeta preserved these peaks/kinks, but oligomeric Abeta suppressed them and created a new DHE anisotropy peak at X(sterol) approximately 0.38. The above critical X(sterol) values coinci…
Glucocorticoid receptor regulates organic cation transporter 1 (OCT1, SLC22A1) expression via HNF4α upregulation in primary human hepatocytes
2013
Abstract Background Organic cation transporter 1 (OCT1, SLC22A1) is a membrane transporter that is important for therapeutic effect of the antidiabetic drug metformin. Its liver-specific expression in hepatocytes is strongly controlled by hepatocyte nuclear factor-4α (HNF4α). HNF4α expression and transcriptional activity have been demonstrated to be augmented by glucocorticoid receptor (GR) in human hepatocytes and rodent livers. Methods It was examined whether GR activation indirectly induces OCT1 gene expression via HNF4α up-regulation in primary human hepatocytes.We also examined which other transcription factors are involved in OCT1 gene expression and whether they are regulated by dexa…