11 research outputs found
Shape analysis of a synthetic diamond
Two-dimensional images of synthetic industrial diamond particles were obtained
using a camera, framegrabber and PC-based image analysis software. Various
methods for shape quantification were applied, including two-dimensional shape
factors, Fourier series expansion of radius as a function of angle, boundary fractal
analysis, polygonal harmonics, and corner counting methods. The shape parameter
found to be the most relevant was axis ratio, defined as the ratio of the minor axis to
the major axis of the ellipse with the same second moments of area as the particle.
Axis ratio was used in an analysis of the sorting of synthetic diamonds on a vibrating
table. A model was derived based on the probability that a particle of a given axis
ratio would travel to a certain bin. The model described the sorting of bulk material
accurately but it was found not to be applicable if the shape mix of the feed material
changed dramatically. This was attributed to the fact that the particle-particle
interference was not taken into account.
An expert system and a neural network were designed in an attempt to classify
particles by a combination of four shape parameters. These systems gave good results
when discriminating between particles from bin I and bin 9 but not for neighbouring
bins or for more than two classes.
The table sorting process was discussed in light of the findings and it was
demonstrated that the shape distributions of sorted diamond fractions can be quantified in a useful and meaningful way
Psr1p interacts with SUN/sad1p and EB1/mal3p to establish the bipolar spindle
Regular Abstracts - Sunday Poster Presentations: no. 382During mitosis, interpolar microtubules from two spindle pole bodies (SPBs) interdigitate to create an antiparallel microtubule array for accommodating numerous regulatory proteins. Among these proteins, the kinesin-5 cut7p/Eg5 is the key player responsible for sliding apart antiparallel microtubules and thus helps in establishing the bipolar spindle. At the onset of mitosis, two SPBs are adjacent to one another with most microtubules running nearly parallel toward the nuclear envelope, creating an unfavorable microtubule configuration for the kinesin-5 kinesins. Therefore, how the cell organizes the antiparallel microtubule array in the first place at mitotic onset remains enigmatic. Here, we show that a novel protein psrp1p localizes to the SPB and plays a key role in organizing the antiparallel microtubule array. The absence of psr1+ leads to a transient monopolar spindle and massive chromosome loss. Further functional characterization demonstrates that psr1p is recruited to the SPB through interaction with the conserved SUN protein sad1p and that psr1p physically interacts with the conserved microtubule plus tip protein mal3p/EB1. These results suggest a model that psr1p serves as a linking protein between sad1p/SUN and mal3p/EB1 to allow microtubule plus ends to be coupled to the SPBs for organization of an antiparallel microtubule array. Thus, we conclude that psr1p is involved in organizing the antiparallel microtubule array in the first place at mitosis onset by interaction with SUN/sad1p and EB1/mal3p, thereby establishing the bipolar spindle.postprin