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Full-Text Articles in Life Sciences

Rab35 Centered Membrane Trafficking Pathway Directs Apical Constriction During Drosophila Gastrulation, Hui Miao Jan 2021

Rab35 Centered Membrane Trafficking Pathway Directs Apical Constriction During Drosophila Gastrulation, Hui Miao

Electronic Theses and Dissertations

Force generation in epithelial tissues is often pulsatile, with actomyosin networks generating high-tension contractile forces at the cell cortex before cyclically disassembling. This pulsed nature of cytoskeletal forces implies that there must be cellular processes to extract unidirectional changes that drive processive transformations in cell shape. During Drosophila melanogastergastrulation, the invagination of the prospective mesoderm is driven by the pulsed constriction of apical surfaces. Here, we address the mechanisms by which the irreversibility of pulsed events is achieved while also permitting uniform epithelial behaviors to emerge. We use MSD-based analyses to identify contractile steps and find that when a …


Hedging To Safety: A Political Economy Of Derivatives, Risk And Agriculture In The Developing World, Sasha Coler Breger Bush Jan 2009

Hedging To Safety: A Political Economy Of Derivatives, Risk And Agriculture In The Developing World, Sasha Coler Breger Bush

Electronic Theses and Dissertations

It has become common for researchers and international development institutions to recommend the use of derivative instruments to developing country farmers and policymakers as a means of insuring agricultural incomes against the threats posed by volatile global commodity prices. Despite such enthusiasm, very little research to date examines whether or not derivative instruments actually can deliver income support to agricultural producers who face commodity price risk. This dissertation evaluates these recommendations, focusing upon the potential income security benefits of hedging with futures instruments for coffee farmers in Mexico, Brazil and Uganda during the 1998-2002 coffee crisis. The three-part quantitative and …