Search results for "otos"
showing 10 items of 857 documents
Optical storage in doped microstructures of alkali halides
2002
Peculiarities of colour centres production and their recombination in photostimulated processes in doped alkali halide microstructures were examined in connection with their practical use as active photostimulable media in miniaturised optoelectronic and photonic devices. The specific interaction of unrelaxed H-centres and electrons with the dopants in different valence and electronic states open a way for widening the scope of multifunctional (logical and mathematical) optical data processing and transfer.
Baltā Lotosa sekta un tās politiskās aktivitātes
2015
Kopsavilkums latviski Šī bakalaura darba tēma ir „Baltā Lotosa sekta un tās politiskās aktivitātes”. Tēma izvēlēta turpmākai izpētei, jo Baltā Lotosa sektas ietekme Ķīnas vēsturē bijusi ievērojama. Lotosa sekta vairāku gadsimtu garumā piedalījās politikas veidošanā, rīkoja sacelšanās pret valsti, kas gan ietekmēja valsts ideoloģiju, gan sabiedrības viedokli un vispārējo situāciju valstī. Baltās Lotosa sektas pārveidošanās no reliģiskas biedrības par politiski aktīvu sektu ir tipiska parādība Ķīnas vēsturē, kas pamato valsts ideoloģijas nostādnes arī mūsdienās. Darba mērķis ir izpētīt Baltā Lotosa sektas izcelsmi un vēsturisko attīstību saistībā ar politiskajiem notikumiem Ķīnā. Šī mērķa sas…
Seawater carbonate chemistry and kelp densities and coral coverages at three study locations and photosynthesis and calcification of corals measured …
2021
Ocean warming is altering the biogeographical distribution of marine organisms. In the tropics, rising sea surface temperatures are restructuring coral reef communities with sensitive species being lost. At the biogeographical divide between temperate and tropical communities, warming is causing macroalgal forest loss and the spread of tropical corals, fishes and other species, termed “tropicalization”. A lack of field research into the combined effects of warming and ocean acidification means there is a gap in our ability to understand and plan for changes in coastal ecosystems. Here, we focus on the tropicalization trajectory of temperate marine ecosystems becoming coral-dominated systems…
Macroalgal responses to ocean acidification depend on nutrient and light levels
2015
Ocean acidification may benefit algae that are able to capitalize on increased carbon availability for photosynthesis, but it is expected to have adverse effects on calcified algae through dissolution. Shifts in dominance between primary producers will have knock-on effects on marine ecosystems and will likely vary regionally, depending on factors such as irradiance (light vs. shade) and nutrient levels (oligotrophic vs. eutrophic). Thus experiments are needed to evaluate interactive effects of combined stressors in the field. In this study, we investigated the physiological responses of macroalgae near a CO2 seep in oligotrophic waters off Vulcano (Italy). The algae were incubated in situ …
Seagrass ecosystem response to long-term high CO2 in a Mediterranean volcanic vent
2014
We examined the long-term effect of naturally acidified water on a Cymodocea nodosa meadow growing at a shallow volcanic CO2 vent in Vulcano Island (Italy). Seagrass and adjacent unvegetated habitats growing at a low pH station (pH = 7.65 ± 0.02) were compared with corresponding habitats at a control station (pH = 8.01 ± 0.01). Density and biomass showed a clear decreasing trend at the low pH station and the below- to above-ground biomass ratio was more than 10 times lower compared to the control. C content and delta 13C of leaves and epiphytes were significantly lower at the low pH station. Photosynthetic activity of C. nodosa was stimulated by low pH as seen by the significant increase in…
Síndrome de Cockayne: Informe de un caso: revisión de la literatura
2006
El Síndrome de Cockayne (CS) es un desorden genético con un patrón de herencia autosómico recesivo que fue descrito por primera vez en 1936 por Cockayne. Los pacientes con este síndrome presentan detención del crecimiento, talla baja, envejecimiento prematuro, anormalidades neurológicas, fotosensibilidad, retraso en la erupción de los dientes primarios, ausencia congénita de dientes permanentes, macrodoncia parcial, atrofia de los procesos alveolares y caries dental. Puede ser causado por mutación en dos genes, el CKN1 (ERCC8) y el ERCC6, localizados en los cromosomas 5 y 10 respectivamente; originando dos tipos: CS-A que tienen mutación en ERCC8 y CS-B con mutación en ERCC6, este último pr…
Progress of Phototherapy Applications in the Treatment of Bone Cancer
2021
Bone cancer including primary bone cancer and metastatic bone cancer, remains a challenge claiming millions of lives and affecting the life quality of survivors. Conventional treatments of bone cancer include wide surgical resection, radiotherapy, and chemotherapy. However, some bone cancer cells may remain or recur in the local area after resection, some are highly resistant to chemotherapy, and some are insensitive to radiotherapy. Phototherapy (PT) including photodynamic therapy (PDT) and photothermal therapy (PTT), is a clinically approved, minimally invasive, and highly selective treatment, and has been widely reported for cancer therapy. Under the irradiation of light of a specific wa…
Navigating the translational roadblock: Towards highly specific and effective all-optical interrogations of neural circuits
2020
AbstractTwo-photon (2-P) all-optical approaches combine in vivo 2-P calcium imaging and 2-P optogenetic modulations and have the potential to build a framework for network-based therapies, e.g. for rebalancing maladaptive activity patterns in preclinical models of neurological disorders. Here, our goal was to tailor these approaches for this purpose: Firstly, we combined in vivo juxtacellular recordings and GCaMP6f-based 2-P calcium imaging in layer II/III of mouse visual cortex to tune our detection algorithm towards a 100 % specific identification of AP-related calcium transients. False-positive-free detection was achieved at a sensitivity of approximately 73 %. To further increase specif…
Doped Alkali Halide Thin Films as Active Media for Information Storage and Retrieval
1997
Ultraviolet-induced paramagnetic centers and absorption changes in singlemode Ge-doped optical fibers
2009
We investigated the laser-energy-density dependence of absorption changes and paramagnetic centers induced by a cw Ar+ laser operating at 5.1 eV, in both unloaded and H-2-loaded single mode Ge-doped optical fibers. The induced absorption is measured in the blue and near ultraviolet spectral range by using the 3.1 eV photoluminescence, ascribed to Ge lone pair center (GLPC), as an in situ probe source. We find that the Ge (1) center (GeO4-) is induced upon UV exposure by electron trapping on GeO4 precursors, where the free electrons are most likely produced by ionization of GLPC. Ge (1) is responsible of optical transmission loss of the fiber in the investigated range. Hydrogen loading stron…