23,058 research outputs found
On the Bayesian analysis of species sampling mixture models for density estimation
The mixture of normals model has been extensively applied to density estimation problems.
This paper proposes an alternative parameterisation that naturally leads to new forms
of prior distribution. The parameters can be interpreted as the location, scale and smoothness
of the density. Priors on these parameters are often easier to specify. Alternatively, improper
and default choices lead to automatic Bayesian density estimation. The ideas are extended to
multivariate density estimation
Nimbus Telemetry
Nimbus satellite - pulse-code-modulated telemetry subsyte
Domain interactions within Fzo1 oligomers are essential for mitochondrial fusion
Mitofusins are conserved GTPases essential for the fusion of mitochondria. These mitochondrial outer membrane proteins contain a GTPase domain and two or three regions with hydrophobic heptad repeats, but little is known about how these domains interact to mediate mitochondrial fusion. To address this issue, we have analyzed the yeast mitofusin Fzo1p and find that mutation of any of the three heptad repeat regions (HRN, HR1, and HR2) leads to a null allele. Specific pairs of null alleles show robust complementation, indicating that functional domains need not exist on the same molecule. Biochemical analysis indicates that this complementation is due to Fzo1p oligomerization mediated by multiple domain interactions. Moreover, we find that two non-overlapping protein fragments, one consisting of HRN/GTPase and the other consisting of HR1/HR2, can form a complex that reconstitutes Fzo1p fusion activity. Each of the null alleles disrupts the interaction of these two fragments, suggesting that we have identified a key interaction involving the GTPase domain and heptad repeats essential for fusion
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