Sediment Dynamics and Morphology of a Boulder-Bed Ephemeral Stream

Very few studies investigated the geomorphological and sedimen-tological processes of modern very coarse-grained, ephemeral streams. A field study on such topics is carried out on the Golina river, a sandy boulder-bed ephemeral stream of the Kobo basin in northern Ethiopia, subjected to intermittent flow generated by isolated, high intensity rainfall. The main gemorphological characteristics of the study reach channels are only apparently similar to those of perennial counterparts, in fact, a detailed analysis shows macroforms such as bars, riffles and pools and their sedimentary structures resuls from very different depo-sitional/erosion processes. A conceptual model based on the superimposition of coarse-grained bedload sheets, with the characteristics described by Whiting et al. (1988), and subsequent dissection during the receding flood flow is proposed. This model was found to well explain the morphological and sedimentological features of the study river reach

Using a neurocomputational autobiographical memory model to study memory loss

Autobiographical memory (AM) is a core component of human life and plays an important role in self-identification. Various conceptual models have been proposed to explain its functionalities and describe its dynamics. However, most existing computational AM models do not distinguish AM from other long-term memory. Specifically, during model design, the unique features and the memory encoding, storage, and retrieval procedures of AM were not taken into consideration in prior models. In this chapter, we introduce our neurocomputational AM model, which is consistent with Conway and Pleydell-Pearce’s model in terms of both the network structure and dynamics.We further propose how to apply our parameterized computational model to quantitatively study memory loss in people of different age groups. As such, we provide a suitable tool to evaluate the effect of different memory loss phases in a rapid and quantitative manner, which may be difficult or impossible in experimental studies on human subjects