In natural geological and archaeological environments, the ionizing radiation comes naturally from the immediate surroundings of the minerals. A glow curve of light bulb due to the second heating of the sample to a high temperature.
Advantages of OSL over TL
As an illustration, the main emissions for quartz and feldspar are in the near-ultraviolet (356 nm) and violet (410 nm) regions of the electromagnetic spectrum. Thus, the filters used when analyzing quartz and feldspar have windows in those respective regions, but exclude the wavelengths used for excitation, for example, blue for quartz and near-infrared for feldspar.
Luminescence properties of some common minerals
- Quartz
- Feldspar
- Calcite
- Zircon
In terms of emission wavelengths, K-rich feldspars have been reported [67] to show maxima in the range 390–440 nm (violet to blue). Conversely, emissions for some plagioclase feldspars have been reported to occur in the 550-560 nm (blue-green) range.
Paleodose and dose rate determination
Paleodose determination
Measuring the signal at the end of the storage period and comparing it to the natural signal obtained by the initial measurement allows for a calibration that gives the age of the natural signal. The main methods used to determine the equivalent dose. a) When using the additive dose method, incremental doses are given in addition to the natural dose, which are then measured.
Determination of the dose rate
Lower and upper age limits in luminescence dating
This is depicted in curves of luminescence growth from a plateau of the obtained signal with increasing dose and is often expressed using a saturating exponential function. Correction for anomalous feldspar fading at such high doses (>100–200 Gy) using standard methods [66], however, becomes problematic.
Sample collection and preparation for analysis
Sample grain size
If the dose rates are given as annual values, the equation gives the age in calendar years. Similarly, when coarse-grained feldspar is dated, potassium-40 isotopes in K-feldspar form an additional source of beta particles to be considered in the dose rate calculation.
Sample collection and preparation 1. Sample collection
The beta dose rate has been discounted by 0.9 as a correction for the grain size and the etching that removes the outer rim that has also received a beta dose [50, 51]. HF etching to remove the outer edge of the grains is not usually used in mid-grain dating.
On what materials can luminescence dating be applied?
Heated materials
In all cases, dating the materials using luminescence methods allows the age of the eruption to be approximated [100]. A final category of substances that can be dated using luminescence methods after being cooled by elevated temperatures are materials associated with meteorite impacts.
Dating of sediments reset by sunlight
Of all classes of geological materials that can be dated by luminescence methods, wind-deposited (eolian) sediments are the most ideal. Coarse as well as fine-grained sediments deposited by water have also been investigated using luminescence methods.
Current and future trends in luminescence dating
Author details
Geochronology of Pleistocene deposits exposed at Washock, northern Holy Cross Mts. A preliminary study of the thermoluminescence of quartz dust in loess and the determination of the age of loess layers. Single-grain optical dating of grave fill associated with human burials at Lake Mungo, Australia.
The effect of thermal transfer on the luminescence quenching of quartz from recent glaciofluvial sediments.
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Bioluminescent Fishes and their Eyes
Introduction
The eyes of all animals on the planet are adapted to the light regime of the habitat in which they are supposed to function [5] and bioluminescent fish are no exception. The visual abilities of oceanic fish are adapted not only to the spectral properties and intensity of incident sunlight at the depths in which fish live, but also to bioluminescence in their environment [6]. Vision and bioluminescence (at least in fish) likely share a common evolutionary history, which is reflected in the ontogeny, behavior, and ecology of bioluminescent fish.
Taxonomy of luminous fishes
- Dubious species
Also, the arrangement of light organs is generally similar within a family, but there are exceptions, namely families where all species are luminous. Although this method is more common in shallow-water species such as those of the families Leiognathidae and Apogonidae [19], it can also be found in some fishes of greater depths, such as those of the families Opisthoproctidae [12] and Evermannellidae [2]. The batoid Benthobatis moresbyi [20] is one of the most dubious examples of bioluminescence reported in fish.
Ti reperensia [21] ket mangibilang ti luminescence kadagiti sebbangan dagiti pamilia ti Halosauridae ken Brotulidae ken ti henero ti Ruvettus a kas mapagduaduaan.
Habitat dispersal of luminous fishes
Only faint light from the short-wavelength spectrum of the blue-green component of sunlight (but not moonlight) reaches the mesopelagic zone [30]. This is the oceanic 'bioluminescent hotspot' where more than 80% of the species present are bioluminescent [ 32 , 36 ] and biological light reaches its greatest brilliance in the diversity and complexity of structures and purposes [ 37 ]. In the depths where the distinction of silhouettes is of visual importance, it is no wonder that most species of bioluminescent fish inhabit this realm.
The colors of the fish at greater depths are a reflection of the different light environment.
Bioluminescence purposes in fishes
- Light organs and control
- Functions of light organs and likely roles of the emitted lights
However, blood supply has also been suggested to play a role, at least in the control of the intrinsically luminous barbs of the linophrynid [41]. Light spectra of the emitted light usually peak in the blue-green, but are variable to some extent, usually in relation to depth. Some shallow water fish such as anomalopids and leiognathids can control the angle of light emitted [41, 50].
The same luminal tissue can serve many types of functions, and the locations of the light organs generally correlate with the roles that the emitted lights are expected to play.
Vision in bioluminescent fishes
- Eye (structure, size and position)
- Lens, pupils and gaps
- Tapeta
- Retina
The majority of bioluminescent fish have typical single-lens, camera-type eyes, but some mesopelagic fish have tubular eyes. The latter are cylindrical eyes located at the top of the head and, due to their position, allow the fish to distinguish silhouettes against downward sunlight. Fish lenses offer little spherical aberration and a gradient of refractive index with the highest value in the middle guarantees that the focus of the light is sharp [4].
Fake slits can improve sensitivity by capturing light from specific oblique areas of the field of view [3, 4].
Evolution of bioluminescence and vision
- Bioluminescence evolution
- Visual adaptation to bioluminescence
A good example of this tendency is the bathypelagic myctophid of the genus Taaningichthys, in which only the deepest living species, T. Whether we are dealing with cases of intrinsic or symbiotic bioluminescence in fish, the acquisition of the bioluminescence had to be on a stage in evolutionary history. On the other hand, we have the symbiotic light fish, in which light-producing bacteria are responsible for the bioluminescent capacity of the host.
Moreover, evolutionary divergence in the bacterial species is unrelated to that of the host species [ 86 ].
Ontogeny of bioluminescence and vision
- Metamorphosis of eye and luminous tissues
- Ecology and ontogeny: vision and bioluminescence in young fishes
The eyes of most deep-sea species have high concentrations of rhodopsin giving them a broad sensitivity to the blue-green range of the spectrum [69], consisting of wavelengths that appear to be ideally suited for biolumin sensing. The larvae of the shallow-water species are spatially close to the adults, suggesting that bacteria can be released from the adult light organ and transferred to the hatchlings [39]. In teleosts, the development of luminous organs is also influenced by the changes in the photic environment and the behavior of the young fish.
For juveniles, light emission changes during growth and maturation [22]; ventral luminescence develops rapidly during that phase of the life of many teleosts.
Visual ecology
- Bioluminescence detection
- Intraspecific communication
- Hunting
- Predator avoidance
Photic lures to attract prey are one of the better known examples of luminous hunting devices. In the specific case of the dalatiid Squaliolus aliae, the shortwave sensitive pigments in its retina appear to be more adapted to prey emitting blue luminescence [65]. The method of defense and the view of the predator and prey are always involved.
The light spectrum of a luminescent species used in counter-illumination is not always a perfect match to the landing light [30].
Final remarks
- Methodology
- Future prospects
Spectral sensitivity peaks of the visual pigments obtained spectrophotometrically or electrophysiologically should be associated with chemical analyzes of the photopigments involved and opsing gene analyzes [36]. Evolutionary studies of vision are supported by research on the mutagenesis of the visual pigments [5] and genetics of nuclear and mitochondrial gene fragments can also be used in studies of phylogenetic relationships between species [17]. Often lacking first-hand direct observational evidence of vision/luminescence interactions in the natural environment, the next best approach would be realistic analyzes of the underwater transmission of bioluminescence in specific cases and ecological modeling, based on the available information.
Some questions have been answered regarding the eco-ethological roles of the relationship between bioluminescence and vision, but many more remain to be resolved.
Acknowledgements
Functional morphology of the luminescence system of Siphamia versicolor (Perciformes: Apogonidae), a bacterial glow coral reef fish. Histological observations on the eye of two luminescent fishes Photoblepharon palpebratus (Boddaert) and Anomalops katoptron (Blkr). Dynamics of the gold-spotted grenadier anchovy (Coilia dussumieri) along the northwest coast of India.
Rome: Food and Agriculture Organization of the United Nations and the American Society of Ichthyologists and Herpetologists.
Bioluminescence Microscopy: Design and Applications
Microscope design
- Imaging lens
- Vignetting
- Effective field area
- The bioluminescence microscope, LV200
Therefore, a microscope with a high NA' (short focal length imaging lens) makes it possible to achieve a higher NA and lower M without further improvement of the objective lens. OB, objective lens; AP, aperture; IM, imaging lens; fo, focal length of the objective lens; fi, focal length of the image lens. The images on the CCD chip show only a fraction of the light collected by the OB.
To show the spatial resolution of the bioluminescence images acquired using the LV200, organelle-targeted images were captured using a UPlanFLN 100× oil objective lens (Olympus) and ImagEM EM-CCD camera (C9100-13; Hamamatsu Photonics, Shizuoka, Japan) .
Applications
- Intracellular Ca 2+ imaging using obelin
- Imaging of clock gene promoter assays
- Three-dimensional imaging of Drosophila larva
NanoLuc-NLS accumulated in the nucleus of the cell, and CoxVIII-NanoLuc and calreticulin-NanoLuc-KDEL appeared in a meshwork pattern in the cytoplasm. The promoter region of the mouse Per2 clock gene was inserted into the luciferase promoter vector, pGL3 (Promega), and the vector was transfected into NIH3T3 cells. They observed that a critical light pulse drove cellular clocks to singularity behavior and proved that loss of the circadian rhythm of a cellular clock can be caused by the desynchronization of individual cells underlying singularity behavior by single-cell analysis.
Bioluminescence images of cold-treated anesthetized larvae were captured using an LV200 microscope with a UPlanFLN 60× OB (NA = 0.90) and iXon EM-CCD camera.
Conclusion
Real-time analysis of the transcriptional regulation of HIV and hCMV promoters in single mammalian cells. Bioluminescence imaging of individual fibroblasts reveals sustained, independently phased circadian rhythms of clock gene expression. Video rate bioluminescence imaging of secretory proteins in living cells: localization, secretory frequency and quantification.
Monitoring mitochondrial pyruvate carrier activity in real time using a BRET-based biosensor: investigation of the Warburg effect.
