לוח שנה משולב

Motion of endogenous objects within cells is often observed to exhibit fluctuations that are strongly reminiscent of the motion of thermally induced Brownian particles. Here I show that this motion is instead due to the effects of molecular motors with cells that lead to fluctuations that are completely non-equilibrium in character. In addition, I describe the effects of cell volume on this motion.

Atmospheric aerosol forcing remains the least understood element of the Earth’s climate system. Assessment of aerosol radiative effect on climate heavily relies on models that often assume aerosols as external mixture of spherical homogeneous particles. This may not represent diversity of aerosol compositions and shapes and provide uncertainty in aerosol absorption and scattering ability, as well as influence on properties of clouds. The climate models can be tuned by measurements; however, the measurements themselves have limited sensitivity to aerosol chemical composition, mixing state and non-sphericity. Resent achievements in satellites and ground-based aerosol optical measurements show clear tendency of increasing amount of measured spectral, angular and polarimetric information resulting in a larger number of the derived aerosol characteristics, including those related to chemical composition, mixing state and shape. In my work I examine influence of aerosol composition, external and internal mixtures and non-sphericity effect on accurate assessment of climatic radiative forcing. In parallel, the efforts are dedicated to development of numerical tools and measurement approaches that will provide information about aerosol composition and mixing state on large scales using space-borne or ground-based optical observations. Parameterization of aerosol optical characteristics in these developments implies involvement of knowledge on aerosol chemistry and microphysics available from laboratory studies and in situ sampling.