Fractionation and characterization of euchromatin isolated from mouse ascites sarcoma cells

Euchromatin specimen prepared by the usual method formed large clumps and had various shapes under electron microscopy. A method of separation of the euchromatin specimen into chromatin fractions having relatively homogeneous form was examined and partial characterization of these fractions was carried out. The heavy euchromatin fraction was a large network of thin fibrils (about 100 A in diameter) and various thick fibers. The intermediate euchromatin fraction consisted of relatively homogeneous networks of thick knobby fibers (about 250 A in diameter). The light euchromatin fraction had metworks of thick fibers. These chromatin fractions were quantitatively prepared from sonicated nuclei of mouse ascites sarcoma cells. Twenty-one or twenty-two bands of non-histone proteins besides histones were detected in these chromatin fractions by SDS-polyacrylamide gel electrophoresis. There were significant differences in the electrophoretic patterns of non-histone proteins among these chromatin fractions.</p

Molecular mechanisms of microtubule-dependent kinetochore transport toward spindle poles

In mitosis, kinetochores are initially captured by the lateral sides of single microtubules and are subsequently transported toward spindle poles. Mechanisms for kinetochore transport are not yet known. We present two mechanisms involved in microtubule-dependent poleward kinetochore transport in Saccharomyces cerevisiae. First, kinetochores slide along the microtubule lateral surface, which is mainly and probably exclusively driven by Kar3, a kinesin-14 family member that localizes at kinetochores. Second, kinetochores are tethered at the microtubule distal ends and pulled poleward as microtubules shrink (end-on pulling). Kinetochore sliding is often converted to end-on pulling, enabling more processive transport, but the opposite conversion is rare. The establishment of end-on pulling is partly hindered by Kar3, and its progression requires the Dam1 complex. We suggest that the Dam1 complexes, which probably encircle a single microtubule, can convert microtubule depolymerization into the poleward kinetochore-pulling force. Thus, microtubule-dependent poleward kinetochore transport is ensured by at least two distinct mechanisms

Effect of Thermoplastic Binder on Flow Deformation Behavior of Wood

AbstractA processing technique was recently developed to realize plastic deformation in wood impregnated with a thermoset binder. This paper proposes a new flow forming technique where a thermoplastic binder is used instead of a thermoset binder with the expectation that the formability and recyclability of the products will be improved. To clarify the effect of the thermoplastic binder on the flow deformation behavior of wood, capillary fluidity tests were performed using impregnated wood with various contents of thermoplastic binder (polymer). The extrusion load of the impregnated wood through the capillary decreased with an increase of the polymer content in the wood. Results of the second fluidity test using the first extruded material reveals that the recycled impregnated wood can flow again. The extrusion load of the second extrusion was equal to or lower than the first. These results indicate that the recyclability of the wood impregnated with a thermoplastic binder is highly promising. The internal configuration of the impregnated wood during extrusion was also dependent on the polymer content

Molding of wood powder with a natural binder

International Conference on the Technology of Plasticity, ICTP 2017, 17-22 September 2017, Cambridge, United KingdomThis paper describes the molding of wood powder using sucrose as a natural binder, as a means of fabricating products based on natural resources. The conditions, such as the temperature and binder content of the wood powder, were optimized in order to produce compacts successfully in the molding process. In experiments, the plasticization temperature of sucrose was initially investigated by thermogravimetric/differential thermal analysis for the prediction of the thermal flow temperature of the wood powder combined with sucrose. In addition, flow behavior of the mixture was evaluated for the temperature and the binder content by capillary flow tests. Based on these data, molding test of wood powder with sucrose was conducted to evaluate the injection moldabilty. As a result, the plasticization point of sucrose was found to be approximately 176 ºC, with a mass reduction onset at 200 ºC due to decomposition to volatile products. Wood powder mixed with sucrose flowed at temperatures above 180 ºC, although flow was restricted above 220 ºC due to the effect of gases evolved from the sucrose. The minimum sucrose content required for flow was 30 wt% within the temperature range of 180 to 200 ºC. The mixture was found to fill a mold under optimized conditions, forming compacts with good surface texture at a sucrose content of 30 wt% and 200 ºC. This method allows the fabrication of products from naturally occurring materials with minimal environmental impact

Influence of pulsive pressure waves on liquid penetration into wood in semi-opened container

The purpose of this paper was to confirm the influence of pulsive pressure waves on the liquid penetration into wood in the semi-opened container. Wood block sample was irradiated by the pulsive pressure waves in the semi-opened container filled with water used as a liquid. The irradiation was also performed in the closed container for the comparison. The water penetration into the sample was promoted by the pressure-wave irradiation. There was little difference in the degree of the penetration between the closed and the semi-opened containers. It was presumed from the measured hydraulic pressure that the pressure-wave energy irradiated on the sample in the closed container was higher than that in the semi-opened container. It was also presumed that the cavitation generation was promoted in the semi-opened container. This indicates that the cavitation as well as the pressure waves themselves affected the liquid penetration into wood. The compressive deformation of the sample irradiated in the semi-opened container was slightly smaller than that in the closed container. This indicates that the pulsive pressure-wave irradiation in the semi-opened container promoted the liquid penetration into wood with less compressive deformation

Early Spectral Evolution of the Rapidly Expanding Type Ia SN 2006X

We present optical spectroscopic and photometric observations of Type Ia supernova (SN) 2006X from --10 to +91 days after the $B$-band maximum. This SN exhibits one of the highest expansion velocity ever published for SNe Ia. At premaximum phases, the spectra show strong and broad features of intermediate-mass elements such as Si, S, Ca, and Mg, while the O{\sc i}$\lambda$7773 line is weak. The extremely high velocities of Si{\sc ii} and S{\sc ii} lines and the weak O{\sc i} line suggest that an intense nucleosynthesis might take place in the outer layers, favoring a delayed detonation model. Interestingly, Si{\sc ii}$\lambda$5972 feature is quite shallow, resulting in an unusually low depth ratio of Si{\sc ii}$\lambda$5972 to $\lambda$6355, $\cal R$(Si{\sc ii}). The low $\cal R$(Si{\sc ii}) is usually interpreted as a high photospheric temperature. However, the weak Si{\sc iii}$\lambda$4560 line suggests a low temperature, in contradiction to the low $\cal R$(Si{\sc ii}). This could imply that the Si{\sc ii}$\lambda$5972 line might be contaminated by underlying emission. We propose that $\cal R$(Si{\sc ii}) may not be a good temperature indicator for rapidly expanding SNe Ia at premaximum phases.Comment: 20 pages, 7 figures, (Received 2008 August 17; Accepted 2009 April 13

In vitro and in vivo assays for osteoclast apoptosis

Mature osteoclasts, multinucleated giant cells responsible for bone resorption, are terminally differentiated cells with a short life span. Recently, we have demonstrated that osteoclast apoptosis is regulated by ERK activity and Bcl-2 family member Bim. In this paper, we summarize the methods we used to study osteoclast apoptosis in vitro and in vivo. Using adenovirus and retrovirus vectors, we were able to introduce foreign genes into osteoclasts and examine their effects on osteoclast survival in vitro. In addition, we established the modified methods for in situ hybridization and BrdU labeling of bone sections from mice to study osteoclast survival in vivo. The detailed methods described here could be useful for studying the biological process in bone