Actin remodeling to facilitate membrane fusion

AbstractActin and its associated proteins participate in several intracellular trafficking mechanisms. This review assesses recent work that shows how actin participates in the terminal trafficking event of membrane bilayer fusion. A recent flurry of reports defines a role for Rho proteins in membrane fusion and also demonstrates that this role is distinct from any vesicle transport mechanism. Rho proteins are well known to govern actin remodeling, which implicates this process as a condition of membrane fusion. A small but significant body of work examines actin-regulated events of intracellular membrane fusion, exocytosis and endocytosis. In general, actin has been shown to act as a negative regulator of exocytosis. Cortical actin filaments act as a barrier that requires transient removal to allow vesicles to undergo docking at the plasma membrane. However, once docked, F-actin synthesis may act as a positive regulator to give the final stimulus to drive membrane fusion. F-actin synthesis is clearly needed for endocytosis and intracellular membrane fusion events. What may seem like dissimilar results are perhaps snapshots of a single mechanism of membranous actin remodeling (i.e. dynamic disassembly and reassembly) that is universally needed for all membrane fusion events

Against the Ivory Tower: An Apologia for "Popular" Historical Documentaries

What makes a documentary good? What makes one bad? These two little questions account for probably eighty-five percent of the ink that has flowed in discussion of documentaries in general and historical documentaries in particular-both in academic circles and in the popular press. These questions continue to provoke strong disagreements. It is a safe bet that they are in no danger of a speedy resolution. Nonetheless, when it comes to the practical matter of doing things with historical documentaries -using them in the classroom, at conferences, in our writing- they are questions that insist upon answers. I do not have any all-purpose answers. I would like to make a case, however, concerning how we ought to approach the questions.What makes a documentary good? What makes one bad? These two little questions account for probably eighty-five percent of the ink that has flowed in discussion of documentaries in general and historical documentaries in particular-both in academic circles and in the popular press. These questions continue to provoke strong disagreements. It is a safe bet that they are in no danger of a speedy resolution. Nonetheless, when it comes to the practical matter of doing things with historical documentaries -using them in the classroom, at conferences, in our writing- they are questions that insist upon answers. I do not have any all-purpose answers. I would like to make a case, however, concerning how we ought to approach the question

The role of fungal lifestyle and secreted effectors in complex phyllosphere microbial communities

In nature plants are challenged by several pathogenic organisms but are also colonized by numerous commensal microbes. Those microbes establish a network of interactions with their host and amongst each other. They can influence the plants health status by altering plant immune responses or directly antagonizing microbial pathogens. In wild Arabidopsis thaliana populations, the oomycete pathogen Albugo laibachii was identified as a hub organism and plays an essential role in structuring the leaf phyllosphere microbial network. In this thesis it was shown that the epiphytic yeast Moesziomyces bullatus ex Albugo (Mba) is an antagonistic member of the A. thaliana phyllosphere. While it is a close relative of pathogenic smut fungi, it stays mainly apathogenic in nature. This work provides new insights into the evolution of epiphytic basidiomycete yeasts in comparison to their pathogenic relatives. Genetic manipulation of Mba showed that it still holds the potential to switch to pathogenic growth in vitro. Loss of pathogenicity in this strain is most likely the result of a mating type bias leading to death of one mating type in nature. Nevertheless, its genetic background makes it highly compatible in its epiphytic form. Mba reduces infections of A. thaliana by A. laibachii and antagonizes several bacterial members of the A. thaliana phyllosphere community. To functionally investigate the antimicrobial interactions of Mba, a high-quality annotated genome sequence and an efficient transformation system were established. The combination of transcriptomics, reverse genetics and recombinant protein production identified a GH25 hydrolase with lysozyme activity as a major effector of this microbial antagonism. Those findings are important to strengthen the understanding of microbial interactions within the A. thaliana phyllosphere and can be used in the future to develop novel strategies of microbiota-mediated disease protection

A VILLAGE IN INDIA: AN APPLICATION OF THE THEORY OF INCREASING SCALE OF SOCIETAL ORGANIZATION

http://web.ku.edu/~starjrn

Dilemmas of Diversification: Regional Economic Development and Business-Industrial Clusters in China and Kazakhstan

Both China and Kazakhstan have established sovereign wealth funds and financial state holding companies, where diversified asset management can move beyond Western financial markets to take multiple stakes in other emerging market businesses, including international private equity, commodities, and real estate. Faced with uncertain returns in the West, China and Kazakhstan are increasingly poised to evolve separate yet mutually cooperative investment projects to further diversify their own state portfolios away from Western capital markets. For instance, China’s financial conglomerate CITIC (China International Trust and Investment Corporation) acquired shares of Kazakhstan’s sovereign wealth fund Samruk-Kazyna. As similar projects emerge in the future, the spillover of knowledge and information will accompany asset-sharing

Improved ultrasonic standard reference blocks

A program to improve the quality, reproducibility and reliability of nondestructive testing through the development of improved ASTM-type ultrasonic reference standards is described. Reference blocks of aluminum, steel, and titanium alloys were considered. Equipment representing the state-of-the-art in laboratory and field ultrasonic equipment was obtained and evaluated. Some RF and spectral data on ten sets of ultrasonic reference blocks were taken as part of a task to quantify the variability in response from nominally identical blocks. Techniques for residual stress, preferred orientation, and microstructural measurements were refined and are applied to a reference block rejected by the manufacturer during fabrication in order to evaluate the effect of metallurgical condition on block response