Background: The light organs of the splitfin flashlight fish Anomalops katoptron are necessary for schooling behavior, to determine nearest neighbor distance, and to feed on zooplankton under dim light conditions. Each behavior is coupled to context-dependent blink frequencies and can be regulated via mechanical occlusion of light organs. During shoaling in the laboratory individuals show moderate blink frequencies around 100 blinks per minute.
View Article and Find Full Text PDFFluorescence is a widespread phenomenon found in animals, bacteria, fungi, and plants. In marine environments fluorescence has been proposed to play a role in physiological and behavioral responses. Many fluorescent proteins and other molecules have been described in jellyfish, corals, and fish.
View Article and Find Full Text PDFBiol Rev Camb Philos Soc
August 2024
Fluorescence in marine animals has mainly been studied in Cnidaria but is found in many different phyla such as Annelida, Crustacea, Mollusca, and Chordata. While many fluorescent proteins and molecules have been identified, very little information is available about the biological functions of fluorescence. In this review, we focus on describing the occurrence of fluorescence in marine animals and the behavioural and physiological functions of fluorescent molecules based on experimental approaches.
View Article and Find Full Text PDFThis sharpens the result in the paper Jagers and Zuyev (J Math Biol 81:845-851, 2020): consider a population changing at discrete (but arbitrary and possibly random) time points, the conditional expected change, given the complete past population history being negative, whenever population size exceeds a carrying capacity. Further assume that there is an [Formula: see text] such that the conditional probability of a population decrease at the next step, given the past, always exceeds [Formula: see text] if the population is not extinct but smaller than the carrying capacity. Then the population must die out.
View Article and Find Full Text PDFThe schooling flashlight fish Anomalops katoptron can be found at dark nights at the water surface in the Indo-Pacific. Schools are characterized by bioluminescent blink patterns of sub-ocular light organs densely-packed with bioluminescent, symbiotic bacteria. Here we analyzed how blink patterns of A.
View Article and Find Full Text PDFJ Math Biol
September 2020
Consider a population whose size changes stepwise by its members reproducing or dying (disappearing), but is otherwise quite general. Denote the initial (non-random) size by [Formula: see text] and the size of the nth change by [Formula: see text], [Formula: see text]. Population sizes hence develop successively as [Formula: see text] and so on, indefinitely or until there are no further size changes, due to extinction.
View Article and Find Full Text PDFHow long does it take for an initially advantageous mutant to establish itself in a resident population, and what does the population composition look like then? We approach these questions in the framework of the so called Bare Bones evolution model (Klebaner et al. in J Biol Dyn 5(2):147-162, 2011. https://doi.
View Article and Find Full Text PDFReal time, or quantitative, PCR typically starts from a very low concentration of initial DNA strands. During iterations the numbers increase, first essentially by doubling, later predominantly in a linear way. Observation of the number of DNA molecules in the experiment becomes possible only when it is substantially larger than initial numbers, and then possibly affected by the randomness in individual replication.
View Article and Find Full Text PDFThe analysis and functional characterization of ectopically expressed human olfactory receptors (ORs) is becoming increasingly important, as many ORs have been identified in several healthy and cancerous tissues. OR activation has been demonstrated to have influence on cancer cell growth and progression. Here, ORs were identified using RNA-Seq analyses and RT-PCR.
View Article and Find Full Text PDFBioluminescence is a fascinating phenomenon occurring in numerous animal taxa in the ocean. The reef dwelling splitfin flashlight fish (Anomalops katoptron) can be found in large schools during moonless nights in the shallow water of coral reefs and in the open surrounding water. Anomalops katoptron produce striking blink patterns with symbiotic bacteria in their sub-ocular light organs.
View Article and Find Full Text PDFComprehensive models of stochastic, clonally reproducing populations are defined in terms of general branching processes, allowing birth during maternal life, as for higher organisms, or by splitting, as in cell division. The populations are assumed to start small, by mutation or immigration, reproduce supercritically while smaller than the habitat carrying capacity but subcritically above it. Such populations establish themselves with a probability wellknown from branching process theory.
View Article and Find Full Text PDFFirst a population model with one single type of individuals is considered. Individuals reproduce asexually by splitting into two, with a population-size-dependent probability. Population extinction, growth and persistence are studied.
View Article and Find Full Text PDFNuclear energy can play a role in carbon free production of electrical energy, thus making it interesting for tomorrow's energy mix. However, several issues have to be addressed. In fission technology, the design of so-called fourth generation reactors show great promise, in particular in addressing materials efficiency and safety issues.
View Article and Find Full Text PDFIt is argued that biological populations are finite and consisting of individuals with varying life span and reproduction, and that they should be thus modelled. Modern probability theory provides tools for this.
View Article and Find Full Text PDFPopulations can die out in many ways. We investigate one basic form of extinction, stable or intrinsic extinction, caused by individuals on the average not being able to replace themselves through reproduction. The archetypical such population is a subcritical branching process, i.
View Article and Find Full Text PDFEven though the efficiency of the polymerase chain reaction (PCR) reaction decreases, analyses are made in terms of Galton-Watson processes, or simple deterministic models with constant replication probability (efficiency). Recently, Schnell and Mendoza have suggested that the form of the efficiency, can be derived from enzyme kinetics. This results in the sequence of molecules numbers forming a stochastic process with the properties of a branching process with population size dependence, which is supercritical, but has a mean reproduction number that approaches one.
View Article and Find Full Text PDF