ABSTRACT
The present paper utilizes entropy theory and Google earth engine cloud computing technique to investigate system state and river recovery potential in two large sub-basins of the Mahanadi River, India. The cross-sectional intensity entropy (CIE) is computed for the post-monsoon season (October-March) along the selected reaches. Further, a normalized river recovery indicator (NRRI) is formulated to assess the temporal changes in river health. Finally, NRRI is related to a process-based variable-LFE (low flow exceedance) to comprehend the dominating system dynamics and evolutionary adjustments. The results highlight the existence of both threshold-modulated and filter-dominated systems based on CIE and NRRI variabilities. In addition, the gradual decline in CIE and subsequent stabilization of vegetated landforms can develop an 'event-driven' state, where floods exceeding the low-flow channel possess a direct impact on the river recovery trajectory. Finally, this study emphasizes the presence of instream vegetation as an additional degree of freedom, which further controls the hierarchy of energy dissipation and morphological continuum in the macrochannel settings.
Subject(s)
Floods , Rivers , Cross-Sectional Studies , Environmental Monitoring , India , SeasonsABSTRACT
There have been remarkable improvements in our understanding of cancer biology. However, therapeutic improvements, with a few exceptions, have been minimal. Also, significant challenges remain in translating fundamental discoveries in cancer biology and genetics into effective drugs and cures. Traditional two-dimensional monolayer cell cultures lack predictive value, resulting in a >90% failure rate of compounds in clinical trials. A developing cancer is a symbiotic tissue consisting of cancer cells, including cancer stem cells (CSCs), and cohabitating with the components of its environment to form a tumor microenvironment (TME) niche. Throughout the process of tumorigenesis, ubiquitous autocrine and paracrine signaling between the cellular and noncellular components of the TME dictates the milieu and structure of this niche. Arising out of such interactions are the cancer cell's phenotypic characteristics, such as stemness, epithelial mesenchymal transformation (EMT), and drug resistance which in turn greatly affect the response of these cells to drug therapy. For these reasons, in order to delineate the mechanism of tumorigenesis and in the process discover drugs that will have greatest impact on tumor growth, it becomes imperative to study the cancer cell in context of its microenvironment. In the present review, we enumerate the advantages of three- and four-dimensional (3D and 4D) cell cultures and describe the various cell culture platforms that are being used to study tumorigenesis in vitro. These culture systems will not only aid in the study of tumor progression complexities in a cost-effective and rapid manner; they also are expected to facilitate the discovery and delivery of therapeutic regimens that will have more success making it to the clinic.