Search results for "signaalit"
showing 10 items of 13 documents
Female sexual signaling in a capital breeder, the European glow-worm Lampyris noctiluca
2021
AbstractTheory predicts that because costs constrain female sexual signaling, females are expected to have a low signaling effort that is increased with passing time until mating is secured. This pattern of signaling is expected to result from females balancing the costs associated with a higher than optimal signaling effort and those costs associated with a low signaling effort that increase the likelihood of delayed mating. We tested whether this prediction applies in the common glow-worm Lampyris noctiluca (Coleoptera, Lampyridae), a capital breeding species in which females glow at night to attract males. Contrary to predictions, we found that the duration of female sexual signaling sig…
The structural effect between the output module and chromophore-binding domain is a two-way street via the hairpin extension.
2022
AbstractSignal transduction typically starts with either ligand binding or cofactor activation, eventually affecting biological activities in the cell. In red light-sensing phytochromes, isomerization of the bilin chromophore results in regulation of the activity of diverse output modules. During this process, several structural elements and chemical events influence signal propagation. In our study, we have studied the full-length bacteriophytochrome from Deinococcus radiodurans as well as a previously generated optogenetic tool where the native histidine kinase output module has been replaced with an adenylate cyclase. We show that the composition of the output module influences the stabi…
Content, cost, and context: A framework for understanding human signaling systems
2019
Humans frequently perform extravagant and seemingly costly behaviors, such as widely sharing hunted resources, erecting conspicuous monumental structures, and performing dramatic acts of religious devotion. Evolutionary anthropologists and archeologists have used signaling theory to explain the function of such displays, drawing inspiration from behavioral ecology, economics, and the social sciences. While signaling theory is broadly aimed at explaining honest communication, it has come to be strongly associated with the handicap principle, which proposes that such costly extravagance is in fact an adaptation for signal reliability. Most empirical studies of signaling theory have focused on…
Low-Noise Amplification and Frequency Conversion with a Multiport Microwave Optomechanical Device
2016
High-gain amplifiers of electromagnetic signals operating near the quantum limit are crucial for quantum information systems and ultrasensitive quantum measurements. However, the existing techniques have a limited gain-bandwidth product and only operate with weak input signals. Here we demonstrate a two-port optomechanical scheme for amplification and routing of microwave signals, a system that simultaneously performs high-gain amplification and frequency conversion in the quantum regime. Our amplifier, implemented in a two-cavity microwave optomechanical device, shows 41 dB of gain and has a high dynamic range, handling input signals up to $10^{13}$ photons per second, three orders of magn…
Geographic variation in the warning signals of the wood tiger moth (Parasemia plantaginis; Arctiidae)
2013
Many forms of the wood tiger moth (Parasemia plantaginis) : selective heterogeneity favours polymorphic warning signals
2013
Henkilöstövoimavarojen tuotantofunktion makro- sekä mikrotason tarkasteleminen
2013
Tutkimuksessa analysoidaan makro sekä mikro tasolla Kestin (2013) kehittelemää henki-löstövoimavarojen tuotantofunktiota. Sen avulla organisaatiot suunnittelevat resurssien (input) ja tuotosten (output) välistä suhdetta tiettynä ajanjaksona ja tietyllä teknologialla (Ollonqvist 1974, 3- 5; Saari 2006, 206; Vehmanen et al 1997, 43). Henkilöstövoimavaroihin rakentuva tuotantofunktio käsittää henkilöstömäärän ja työajankäytön lisäksi aineettoman henkilöstöpääoman hyödyntämisasteen eli työelämän laadun vaikutukset toimintakapasiteettiin. Henkilöstövoimavarojen tuotantofunktiossa liikevaihto tuotetaan henkilöstön tehollisella työajalla. Tehollisen työajan osuuden työn ääressä vietetystä ajasta m…
Methods for space-time parameter estimation in DS-CDMA arrays
2006
Rui Wu tutki väitöstyössään radiokanavan eri ominaisuuksien arviointia. Tietämys radiokanavan ominaisuuksista on monesti välttämätöntä, jotta radiovastaanottimen vastaanottama signaali voidaan purkaa ymmärrettävään muotoon. Wu tutki hajaspektrijärjestelmiä, joissa esimerkiksi puhe- tai datasignaalin kaistanleveys moninkertaistetaan radiolähettimessä. Näin tehdään muun muassa jo toiminnassa olevissa 3G-puhelimissa ja -tukiasemissa. Kaistanleveyden moninkertaistamisella pyritään satunnaistamaan muille järjestelmän käyttäjille aiheutetut häiriösignaalit, koska kyseisissä järjestelmissä signaalit etenevät samalla taajuuskaistalla yhtäaikaisesti. Se, miten kunkin järjestelmän käyttäjän signaali …