Asymmetry, fluctuating

An initial widespread scepticism over fluctuating asymmetry has had to be re-appraised in the light of many demonstrations (e.g. for insects, birds, and humans) that symmetry is associated with various facets of sexual behaviour. Almost universally, for a whole range of animals, it has been found that males who are more symmetrical are faster,... 

Manning, J. T. and Ockenden, L. (1994). Fluctuating asymmetry in racehorses. Nature, London 370, 185-186. 

Mailer, A. P. and Pomiankowski, A. (1993). Fluctuating asymmetry and sexual selection. Cenetica 89, 267-279. 

Thornhill, R. and Gangestad, S. W. (1994). Fluctuating asymmetry and human sexual behaviour. Psychological Science 5, 297-302. 

Thornhill, R., Gangestad, S. W. and Comer, R. (1995). Human female orgasm and mate fluctuating asymmetry. Animal Behaviour 50, 1601-1615. 

YOUNG F K, WHEELER p and THORGAARD G (2009) No increase in developmental deformities or fluctuating asymmetry in rainbow trout (Oncorhynchus mykiss) produced with cryopreserved sperm. Aquaculture, 289,13-18. 

Kokko, E.G., Floate, K.D., Colwell, D.D. and Lee, B. (1996) Measurement of fluctuating asymmetry in insect wings using image analysis. Annals of the Entomological Society of America, 89 398-404. 

Smith, D.R., Crespi, B.J. and Bookstein, F.L. (1997) Fluctuating asymmetry in the honey bee. Apis mellifera effects of ploidy and hybridization. Journal of Evolutionary Biology, 10 551-574. 

Figure 6 compares the electroabsorption spectra of the three type of LB films in the wavelength range that corresponds to the absorption due to the transition moment in the direction of the long molecular axis. The applied field was 3.2 x 10s Vcm1 in each case. In the Y-type deposition film, a small Stark signal is observed nevertheless, the Y-type film is assumed to possess a symmetrical molecular orientation. The reason for this weak signal may be that the fluctuation of molecular orientation across the films induced a small asymmetry in the multilayer structure. 

For the fluctuating plume model, the simple addition of the solutions for sources at altitudes h and —h will not accomplish reflection because the asymmetries due to plume meandering must also be reflected in the fictitious image source at -h. The correct reflection for the fluctuating plume model is... 

C. The Chaos-Transport Formula Time Asymmetry in Dynamical Randomness A. Randomness of Fluctuations in NonequiUbrium Steady States... 

The plan of this chapter is the following. Section II gives a summary of the phenomenology of irreversible processes and set up the stage for the results of nonequilibrium statistical mechanics to follow. In Section III, it is explained that time asymmetry is compatible with microreversibility. In Section IV, the concept of Pollicott-Ruelle resonance is presented and shown to break the time-reversal symmetry in the statistical description of the time evolution of nonequilibrium relaxation toward the state of thermodynamic equilibrium. This concept is applied in Section V to the construction of the hydrodynamic modes of diffusion at the microscopic level of description in the phase space of Newton s equations. This framework allows us to derive ab initio entropy production as shown in Section VI. In Section VII, the concept of Pollicott-Ruelle resonance is also used to obtain the different transport coefficients, as well as the rates of various kinetic processes in the framework of the escape-rate theory. The time asymmetry in the dynamical randomness of nonequilibrium systems and the fluctuation theorem for the currents are presented in Section VIII. Conclusions and perspectives in biology are discussed in Section IX. 

It is most remarkable that the entropy production in a nonequilibrium steady state is directly related to the time asymmetry in the dynamical randomness of nonequilibrium fluctuations. The entropy production turns out to be the difference in the amounts of temporal disorder between the backward and forward paths or histories. In nonequilibrium steady states, the temporal disorder of the time reversals is larger than the temporal disorder h of the paths themselves. This is expressed by the principle of temporal ordering, according to which the typical paths are more ordered than their corresponding time reversals in nonequilibrium steady states. This principle is proved with nonequilibrium statistical mechanics and is a corollary of the second law of thermodynamics. Temporal ordering is possible out of equilibrium because of the increase of spatial disorder. There is thus no contradiction with Boltzmann s interpretation of the second law. Contrary to Boltzmann s interpretation, which deals with disorder in space at a fixed time, the principle of temporal ordering is concerned by order or disorder along the time axis, in the sequence of pictures of the nonequilibrium process filmed as a movie. The emphasis of the dynamical aspects is a recent trend that finds its roots in Shannon s information theory and modem dynamical systems theory. This can explain why we had to wait the last decade before these dynamical aspects of the second law were discovered. 

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