Explaining cooperation is a challenge for evolutionary biology. Surprisingly, the role of extrinsic ecological parameters remains largely unconsidered. Disturbances are widespread in nature and have evolutionary consequences. We develop a mathematical model predicting that cooperative traits most readily evolve at intermediate disturbance. Under infrequent disturbance, cooperation breaks down t...

Recent measurements of the Cosmic Microwave Background Anisotropy have provided evidence for the presence of oscillations in the angular power spectrum. These oscillations are a wonderful confirmation of the standard cosmological scenario and allow us to derive constraints on many cosmological, astrophysical and inflationary parameters. If the discovery is confirmed by future experiments, oppor...

We report studies of the motion of cold atoms in a time-dependent optical potential. The dynamics of our system are that of the quantum kicked rotor, and exhibit a wide variety of phenomena. One purely quantum effect is the quantum resonance, which occurs for well-chosen initial conditions and specific values of the period between kicks. Distinctly nonclassical behavior, such as ballistic growt...

this work proposes a new algorithm to enhance the performance of the speaker verification over the communication systems based Multiple-Input Multiple-Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) techniques. The algorithm mainly tackles and overcomes the effect of the high Peak-to-Average Power Ratio problem that is found in OFDM systems, MIMOOFDM combination has been develop...

two multivariate calibration methods are compared for the simultaneous chromatographic determination and separation of sulfamethoxazole (smx) and phthalazine (phz) by high performance liquid chromatography (hplc). multivariate calibration techniques such as classical least squares (cls) and inverse least squares (ils) were introduced into hplc to determine the quantification by using uv detecto...