870 research outputs found
When on Mars
While mining for ore on Mars, earth settlers found evidence of a ancient civilization that apparently flourished for centuries and then suddenly disappeared
Versatile toolbox for high throughput biochemical and functional studies with fluorescent fusion proteins
Fluorescent fusion proteins are widely used to study protein localization and interaction dynamics in living cells. However, to fully characterize proteins and to understand their function it is crucial to determine biochemical characteristics such as enzymatic activity and binding specificity. Here we demonstrate an easy, reliable and versatile medium/high-throughput method to study biochemical and functional characteristics of fluorescent fusion proteins. Using a new system based on 96-well micro plates comprising an immobilized GFP-binding protein (GFP-mulitTrap), we performed fast and efficient one-step purification of different GFP- and YFP-fusion proteins from crude cell lysate. After immobilization we determined highly reproducible binding ratios of cellular expressed GFP-fusion proteins to histone-tail peptides, DNA or selected RFP-fusion proteins. In particular, we found Cbx1 preferentially binding to di-and trimethylated H3K9 that is abolished by phosphorylation of the adjacent serine. DNA binding assays showed, that the MBD domain of MeCP2 discriminates between fully methylated over unmethylated DNA and protein-protein interactions studies demonstrate, that the PBD domain of Dnmt1 is essential for binding to PCNA. Moreover, using an ELISA-based approach, we detected endogenous PCNA and histone H3 bound at GFP-fusions. In addition, we quantified the level of H3K4me2 on nucleosomes containing different histone variants. In summary, we present an innovative medium/high-throughput approach to analyse binding specificities of fluroescently labeled fusion proteins and to detect endogenous interacting factors in a fast and reliable manner in vitro
Coming Clean: The Health Revolution of 1890-1920 and Its Impact on Infant Mortality
The purpose of this thesis is to document the change in attitudes and behaviors pertaining to public and personal hygiene habits at the turn of the nineteenth century. Public utilities, such as municipal water supplies, sanitary sewage systems, and refuse disposal reduced the incidence of communicable diseases. Access to potable water and sewage disposal encouraged a Health Revolution in the United States and the United Kingdom during the era 1890-1920.
Advertisers began (in 1890 and continuing into the 1920s) to employ the fear of contagious diseases, as well as the virtue of beauty, to target consumers and to promote the sale of products. Soap advertisements, specifically, used these persuasive tactics. The newly emerging national magazines, in particular, were the preferred vehicles through which these advertisements changed the consumers\u27 perception of personal cleanliness. Bathing was no longer an activity reserved for the eclectic and very wealthy. Within a few decades, personal cleanliness was normative.
During the quarter decade 1890-1915, infant mortality rates declined significantly. This is particularly true for gastroenteritis. It can be demonstrated that the shift in opinions about hygiene was responsible for saving countless infant lives from diarrhea
Dependence of Maximum Trappable Field on Superconducting Nb3Sn Cylinder Wall Thickness
Uniform dipole magnetic fields from 1.9 to 22.4 kOe were permanently trapped,
with high fidelity to the original field, transversely to the axes of hollow
Nb3Sn superconducting cylinders. These cylinders were constructed by helically
wrapping multiple layers of superconducting ribbon around a mandrel. This is
the highest field yet trapped, the first time trapping has been reported in
such helically wound taped cylinders, and the first time the maximum trappable
field has been experimentally determined as a function of cylinder wall
thickness.Comment: 8 pages, 4 figures, 1 table. PACS numbers: 74.60.Ge, 74.70.Ps,
41.10.Fs, 85.25.+
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