Here, heterologous expression of plant cellulose synthase (CESA) and its purification has remained a challenge for decades impeding detailed biophysical, biochemical and structural characterization ...of this key enzyme. An in-depth knowledge of structure and function of CESA proteins would enable us to better understand the hierarchical structure of the plant cell wall. Here, we report a detailed, and reproducible method of purification of catalytic domain of CESA1 from Arabidopsis thaliana that was recombinantly expressed in Escherichia coli. The method relies on a two stage purification procedure to obtain the catalytic domain in monomer and trimer forms. The biochemical and biophysical data including low resolution structures of the protein have been published. Currently the crystallization studies of this protein are underway.
Abstract African-American (AA) individuals have a higher risk for late-onset Alzheimer's disease (LOAD) than Americans of primarily European ancestry (EA). Recently, the largest genome-wide ...association study in AAs to date confirmed that six of the Alzheimer's disease (AD)–related genetic variants originally discovered in EA cohorts are also risk variants in AA; however, the risk attributable to many of the loci (e.g., APOE, ABCA7 ) differed substantially from previous studies in EA. There likely are risk variants of higher frequency in AAs that have not been discovered. We performed a comprehensive analysis of genetically determined local and global ancestry in AAs with regard to LOAD status. Compared to controls, LOAD cases showed higher levels of African ancestry, both globally and at several LOAD relevant loci, which explained risk for AD beyond global differences. Exploratory post hoc analyses highlight regions with greatest differences in ancestry as potential candidate regions for future genetic analyses.
In contrast to prior investigations using between-subjects designs to infer the existence of rigidity in decision behaviors, this research used a within-subject design to directly measure rigidity. ...We also extended previous examinations by distinguishing between semantic and episodic informational cues. Finally, we used a computer process-tracing technique that allows validity assessments of tests and keeps researcher intrusion to a minimum. Our results, based on data from three different groups of business analysts and two studies, suggest the inappropriateness of arguing that individuals show either exclusively rigid or non-rigid decision behaviors.
The literature on corporate diversification suggests a relationship between the relatedness of merging firms and risk. We tested that notion by classifying 297 large mergers into four relatedness ...categories and by using three measures of risk: unsystematic, systematic, and total. The findings show that risk reduction may be a valid rationale for mergers but not for the reasons often cited. Specifically, all types of mergers are associated with significant increases in unsystematic risk. Related mergers, however, are associated with a significant decline in systematic and total risk. The possible contributions to the results made by market conditions and leverage were explored.
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