Search results for " manipulation"
showing 10 items of 113 documents
Cycle-triggered averaging of respiration-related neuronal activity
1985
Abstract A computer system is presented which provides off-line computation of cycle-triggered histograms (CTH) of respiration-related neuronal activity. Binwidths of the histograms are freely selectable by software from 10 ms to 100 ms. For special evaluation purposes. CTHs can be standardized in different ways concerning cycle duration as well as amplitude. Time incidence of maximum frequency, center of gravity and expiration-to-inspiration phase transition within the respiratory cycle are computed. The system employs special hardware interfaces to an 8-bit microcomputer which are briefly described. Data acquisition, data manipulation and output handling of the results are performed by ch…
Roadmap on STIRAP applications
2019
STIRAP (stimulated Raman adiabatic passage) is a powerful laser-based method, usually involving two photons, for efficient and selective transfer of populations between quantum states. A particularly interesting feature is the fact that the coupling between the initial and the final quantum states is via an intermediate state, even though the lifetime of the latter can be much shorter than the interaction time with the laser radiation. Nevertheless, spontaneous emission from the intermediate state is prevented by quantum interference. Maintaining the coherence between the initial and final state throughout the transfer process is crucial. STIRAP was initially developed with applications in …
Coupling-assisted Landau-Majorana-Stückelberg-Zener transition in a system of two interacting spin qubits
2019
We analyse a system of two interacting spin-qubits subjected to a Landau-Majorana-Stuckelberg-Zener (LMSZ) ramp. We prove that LMSZ transitions of the two spin-qubits are possible without an external transverse static field since its role is played by the coupling between the spin-qubits. We show how such a physical effect could be exploited to estimate the strength of the interaction between the two spin-qubits and to generate entangled states of the system by appropriately setting the slope of the ramp. Moreover, the study of effects of the coupling parameters on the time-behaviour of the entanglement is reported. Finally, our symmetry-based approach allows us to discuss also effects stem…
Resetting of a planar superconducting quantum memory
2009
We consider and analyze a scheme for the reset of a M × N planar array of inductively coupled Josephson flux qubits. We prove that it is possible to minimize the resetting time of an arbitrary chosen row of qubits by properly switching on and off the coupling between pairs of qubits belonging to the same column. In addition, the analysis of the time evolution of the array allows us to single out the class of generalized W states which can be successfully reset.
Influence of dissipation on the extraction of quantum states via repeated measurements
2007
A quantum system put in interaction with another one that is repeatedly measured is subject to a non-unitary dynamics, through which it is possible to extract subspaces. This key idea has been exploited to propose schemes aimed at the generation of pure quantum states (purification). All such schemes have so far been considered in the ideal situations of isolated systems. In this paper, we analyze the influence of non-negligible interactions with environment during the extraction process, with the scope of investigating the possibility of purifying the state of a system in spite of the sources of dissipation. A general framework is presented and a paradigmatic example consisting of two inte…
Interspecific differences in carotenoid content and sensitivity to UVB radiation in three acanthocephalan parasites exploiting a common intermediate …
2011
9 pages; International audience; Few endoparasite species are pigmented. Acanthocephalans are an exception however, with several species being characterised by yellow to orange colouration both at the immature (cystacanth) and adult stages. However, the functional and adaptive significance of carotenoid-based colourations in acanthocephalans remains unclear. One possibility is that the carotenoid content of acanthocephalan cystacanths acts as a protective device against ultra-violet radiation (UVR) passing through the translucent cuticle of their crustacean hosts. Indeed, acanthocephalans often bring about behavioural changes in their aquatic intermediate hosts that can increase their expos…
Is the host or the parasite the most locally adapted in an amphipod–acanthocephalan relationship? A case study in a biological invasion context
2007
8 pages; International audience; Manipulative endoparasites with complex life cycles can alter their intermediate host immunity and behaviour in ways that increase survival probability within the host body cavity and enhance successful transmission to the definitive host. These parasitic manipulations are variable among and within parasite species and may result from co-evolutionary processes, in which the parasite is constrained for adaptation to the local intermediate host. Hence, arrival of a new host species in a local host population may promote local parasite maladaptation. This study tested the occurrence of local adaptation in two distantly located populations of the acanthocephalan…
Anxiété et manipulation parasitaire chez un invertébré aquatique : approches évolutive et mécanistique
2020
Trophically transmitted parasites induce changes in their host’s phenotype. These changes are supposed to increase transmission probability to definitive hosts through the predation of intermediate hosts. This phenomenon is known as ‘parasite manipulation’ has been hypothesized to be an adaptive trait of parasites for a long time. As manipulation involves predator-prey interactions, it is therefore necessary to understand how antipredatory behaviours are modulated by exogenous (predation pressure) and endogenous (infection, emotional state) factors. We tried to go into this phenomenon in depth, in amphipods, by responding toseveral questions : (1) what is the extent of the multidimensionali…
Facebook’s Emotional Contagion Experiment as a Challenge to Research Ethics
2016
This article analyzes the ethical discussion focusing on the Facebook emotional contagion experiment published by the <em>Proceedings of the National Academy of Sciences</em> in 2014. The massive-scale experiment manipulated the News Feeds of a large amount of Facebook users and was successful in proving that emotional contagion happens also in online environments. However, the experiment caused ethical concerns within and outside academia mainly for two intertwined reasons, the first revolving around the idea of research as manipulation, and the second focusing on the problematic definition of informed consent. The article concurs with recent research that the era of social med…
Immune depression induced by acanthocephalan parasites in their intermediate crustacean host: consequences for the risk of super-infection and links …
2009
9 pages; International audience; Parasite survival in hosts mainly depends on the capacity to circumvent the host immune response. Acanthocephalan infections in gammarids are linked with decreased activity of the prophenoloxidase (ProPO) system, suggesting an active immunosuppression process. Nevertheless, experimental evidence for this hypothesis is lacking: whether these parasites affect several immune pathways is unknown and the consequences of such immune change have not been investigated. In particular, the consequences for other pathogens are not known; neither are the links with other parasite-induced manipulations of the host. Firstly, using experimental infections of Pomphorhynchus…