The performance of the OTT second-generation Particle Size Velocity (PARSIVEL2) laser weather sensor is evaluated by comparing it with a collocated two-dimensional video disdrometer (2DVD) and rain gauges using data collected over a total of 36 rain events. A comparison of raindrop size distributions (DSDs) between the 2DVD and two PARSIVEL2 reveals good agreement for weak rainfall rates below approximately 10 mm h−1 and for midsize drops with diameters between 0.6 and 4.0 mm irrespective of rainfall rates, whereas the PARSIVEL2 produces overestimations of large drops with diameters above 4 mm during heavy rainfall above approximately 20 mm h−1. The resultant DSD parameters of the PARSIVEL2 present overestimations of the mean diameter Dm in the normalized gamma function and the maximum drop diameter Dmax, and underestimations of the intercept parameter Nw and total number of drops NT. Furthermore, how the characteristics of DSDs from the PARSIVEL2 affect the polarimetric radar variables, such as differential reflectivity ZDR and specific differential phase KDP, is examined, as well as how these characteristics affect empirical relations required in radar hydrometeorological applications such as quantitative rainfall estimations. Based on these examinations, it can be concluded that the OTT PARSIVEL2 still produces overestimations of large drops and underestimations of small drops during heavy rainfall, similar to older models of PARSIVEL, despite significant improvements to the PARSIVEL2 system, and furthermore that the uses of PARSIVEL2 measurements can act as a source of error in radar hydrometeorological applications such as radar rainfall estimations.

Cranial sutures are important growth sites of the skull. During suture closure, the dura mater is one of the most important sources of various positive and negative regulatory signals. Previous results indicate that TGF-beta2 from dura mater strongly accelerates suture closure, however, its exact regulatory mechanism is still unclear. In this study, we confirmed that removal of dura mater in calvarial organ culture strongly accelerates sagittal suture closure and that this effect is further enhanced by TGF-beta2 treatment. TGF-beta2 stimulated cell proliferation in the MC3T3-E1 cell line. Similarly, it stimulated the proliferation of cells in the sutural space in calvarial organ culture. Furthermore, TGF-beta2-mediated enhanced cell proliferation and suture closure were almost completely inhibited by an Erk-MAPK blocker, PD98059. These results indicate that TGF-beta2-induced activation of Erk-MAPK is an important signaling component that stimulates cell proliferation to enrich osteoprogenitor cells, thereby promoting their differentiation into osteoblasts to achieve a rapid calvarial bone expansion.

The Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) measures reflectivity downward from space and provides observations of the vertical distributions of precipitation over land as well as the ocean. It overpasses the southern part of the Korean Peninsula where (i) a dense network of operational S-band scanning radars is available and (ii) various types of precipitation occur. By utilizing a 3D reflectivity composite from the ground S-band radar (GR) observations, this paper shows a comparison of reflectivity profiles observed with both PR and GR focusing on their vertical structure. For four cases of widespread rain, visual and statistical analyses show that PR attenuation-corrected reflectivity agrees closely with reflectivity observed from the GR composite below the melting layer. Above and within the melting layer, PR is affected critically by its sensitivity while GR beam broadening at far ranges causes systematic differences in the PR-GR comparisons. For four cases of convective rain, PR underestimates the mean reflectivities by 1-3 dB compared with those from GR at low levels where precipitation attenuation is significant toward the ground. In these cases, the low sensitivity of PR results in a small number of matched points for weak echoes. Also, the PR-GR discrepancy for the convective case is more affected by time mismatching.

For studies on the aryl hydrocarbon receptor (AhR)-dependent toxicity of the mycotoxins alternariol (AOH) and alternariol methyl ether (AME), three mouse hepatoma (Hepa-1) cell lines with intact and with compromised AhR signaling were compared with respect to their activities for hydroxylation, methylation, and glucuronidation. Whereas the activities of cytochrome P450-mediated monooxygenase and catechol-O-methyl transferase were very low and did not differ between the three cell lines, a pronounced difference was observed for UDP-glucuronosyl transferase activity, which was much higher in Hepa-1c1c4 than in c1c7 and c1c12 cells. In all three cell types, the rate of glucuronidation of AOH was about four times higher than that of AME. Whereas AME caused a concentration-dependent G2/M arrest in each cell line, AOH arrested Hepa-1c1c7 and c1c12 cells but not c1c4 cells. However, Hepa-1c1c4 cells were arrested by AOH when β-glucuronidase was added to the incubation medium in order to reverse the formation of AOH glucuronides. We conclude that the failure of AOH to cause cell cycle inhibition in Hepa-1c1c4 cells is due to its efficient glucuronidation. The considerable UDP-glucuronosyl transferase activity of Hepa-1c1c4 cells should be taken into account when other compounds are studied in this cell line. Moreover, we demonstrate that differences in glucuronide formation between cell types can be overcome by the addition of β-glucuronidase to the cell culture medium.

No abstract