A nomological network of e-government evaluation

An emergent epistemology has been developing in the field of e-government evaluation as disparate attempts are made in the literature to evaluate and measure different aspects of e-government. To formalize it, this paper proposes a nomological network as an organizing concept for plotting e-government evaluation research. It proposes different forms of evaluation, pre-evaluation, ex-ante, in-itenere, and ex-post as fulfilling different and complementary roles in e-government evaluation. E-Government concepts such as agenda, strategy, processes, and performance are plotted within the nomological network with matching modes of evaluation

New insight into short wavelength solar wind fluctuations from Vlasov theory

The nature of solar wind (SW) turbulence below the proton gyroscale is a topic that is being investigated extensively nowadays. Although recent observations gave evidence of the dominance of Kinetic Alfv\'en Waves (KAW) at sub-ion scales with $\omega<{\omega_{ci}}$, other studies suggest that the KAW mode cannot carry the turbulence cascade down to electron scales and that the whistler mode (i.e., $\omega>\omega_{ci}$) is more relevant. Here, we propose to study key properties of the short wavelength plasma modes under realistic SW conditions, typically $\beta_i\gtrsim \beta_e\sim 1$ and for high oblique angles of propagation $80^\circ\leq \Theta_{\bf kB}<90^\circ$ as observed from the Cluster data. The linear properties of the plasma modes under these conditions are poorly known, which contrasts with the well-documented cold plasma limit and/or moderate oblique angles of propagation ($\Theta_{\bf kB} <80^\circ$). Based on linear solutions of the Vlasov kinetic theory, we discuss the relevance of each plasma mode (fast, Bernstein, KAW, whistler) in carrying the energy cascade down to electron scales. We show, in particular, that the shear Alfv\'en mode extends at scales $k\rho_i\gtrsim1$ following either a whistler mode ($\omega>\omega_{ci}$) or a KAW mode (with $\omega<\omega_{ci}$) depending on the anisotropy $k_\parallel/ k_\perp$. This contrasts with the well-accepted idea that the whistler branch develops as a continuation at high frequencies of the fast magnetosonic mode. We show, furthermore, that the whistler branch is more damped than the KAW one, which makes the latter a more relevant candidate to carry the energy cascade down to electron scales. We discuss how these new findings may facilitate resolution of the controversy concerning the nature of the small scale turbulence, and we discuss the implications for present and future spacecraft wave measurements in the SW.Comment: 11 pages, 12 figures, submitted to Astrophysical Journa