Knels L, Valtink M, Roehlecke C, Lupp A, de la Vega J, Mehner M, Funk RH.Consequences of oxidative stress in age-related macular degeneration. Human melanopsin forms a pigment maximally sensitive to blue light (λmax ≈ 479 nm) supporting activation of G(q/11) and G(i/o) signalling cascades.
Also, the morning light of 488nm (Bailes and Lucas 2013) is not impeded for the wakening effect, to maintain our circadian rhythm. On the other hand, this blocking does not significantly affect the natural impression of our color vision. Thus, it is very useful to block HEV light of 400nm – 420 nm, because the light can trigger harmful processes for the eye. Also, HEV light can alter the eye lens in its composition, which can lead to cataract formation via radicals and oxidative stress (Roberts 2011). These events can also happen in the human retina as one of the factors which accelerates the development of Age-related Macular Degeneration (AMD) (Wu et al. Furthermore, the Funk (2011b) group demonstrated that after exposure to 411nm light the retina gets distorted (Fig. The group of Funk (2011a) showed in standardized laboratory experiments that neuronal retinal cells after exposure to short wavelength light of 411nm begins to die from higher stress than after exposure to 470nm light.
People after cataract surgery and with implantation of colorless plastic lenses can also be injured by the harmful light coming through their clear, artificial lens.Īccording to recent studies, it was shown that HEV light can cause oxidative stress within different layers of the retina (see Fig.2). Especially, HEV light is more harmful for younger individuals up to about 20 years old, who play and enjoy outside under sunlight, because their eye lenses are very transparent. Through the cornea or the eye lens (see Fig.2), HEV light is harmfully transmitted onto the retina, which is the most delicate and vulnerable tissue of the eye. Because the shorter wavelength light of 400nm-420nm, which we call high energy violet (HEV) light, possesses much more energy than longer wavelengths (red end of the spectrum), it can also elicit more physiochemical reactions within the eye. It is well-known that our eyes should be protected from damage by ultraviolet (UV) rays, which are one part of the shorter wavelength light in sunlight in Fig. This gradual change in salinity contrasts with the prompt transgression which would have taken ∼400 a to occur.Regardless of weather, sunny or cloudy, our eyes are constantly damaged by sunlight. Mass colonisation of the Black Sea by Mediterranean taxa did not occur until salinity had risen sufficiently, a process which took 1000 a or more from the initial transgressive event. Basin-wide radiocarbon ages on peat indicate a prompt increase in water-level from that of the pre-existing and unconnected palaeo-lake during the earliest Holocene (9600–9200 cal a BP). Thus post-glacial outflow from the Black Sea occurred through a lowered or open Bosphorus seaway. However, the absence of AMS-dated mollusc ages from the shelves of this basin older than the Younger Dryas is suggestive of sub-aerial exposure of the shelves, and comparatively lower water-levels when the Younger Dryas began. shells indicate the water-level in the earlier lake phase continued, until the early Holocene, to be lower than the Bosphorus Sill after the Younger Dryas ended. A sea-level curve based on conventional and AMS radiocarbon ages on peat and AMS-based ages on Dreissena sp. These data combined with a review of previous radiocarbon ages has enabled a unique perspective on the post-glacial Black Sea. These data indicate infilling of the Black Sea during the early Holocene from an initial depth 107 m below sea-level, and 72 m below that of the Bosphorus Sill.
Here we present new 23 accelerator mass spectrometer (AMS) radiocarbon ages on peat and bivalve molluscs, supported by the first amino acid racemization (AAR) dating of bivalve molluscs ( n = 66) in the Black Sea. The exact mechanism and timing of the most recent connection between these water bodies is controversial with debate on the post-glacial history of the Black Sea being dependent on radiocarbon dating for numerical ages. The restricted environment of the Black Sea is particularly sensitive to climatic and oceanographic fluctuations, owing to its connection with the Mediterranean Sea via the narrow Bosphorus Strait.