This laboratory study was conducted to evaluate the effects of oyster shell by-product (OSB) on the characteristics of Hanwoo cow manure and emitted gases. For the treated groups, 0.5% and 1% OSB were applied to 200 g of Hanwoo cow manure in a container box with three replications each per group with a group without OSB (0%) as a control group. All samples were stored at room temperature to analyze pH, volatile basic nitrogen (VBN), volatile fatty acid (VFA), and gas emissions (NH3 and H2S) from Hanwoo manure on 0, 2, 4, and 8 days. No group exhibited a significant (p>0.05) effect on VBN, acetate, and propionate values during the 8 days. On day 0, pH increased by 1% OSB application, but no effects on the other days. Iso-butyrate concentration increased (p<0.05) on day 0 by OSB application, but deceased (p<0.05) on day 8. The NH3 gas emission on day 2 decreased (p<0.05) in all treatments applied OSB. However, either NH3 or H2S gases in all treatments were below 0.25 ppm on days 4 and 8, which were no differences (p>0.05) among treatments. Thus, this lab study indicated that the inclusion of OSB application in Hanwoo cow manure had a beneficial effect on NH3 gas emission, but no longer than for 2 days.

Osteoclasts are multinucleated cells with bone resorbing activity and differentiated from hematopoietic cell lineages of monocyte/macrophages in the presence of receptor activator of NF-xB ligand (RANKL) and M-CSF. However, the exact molecular mechanisms through which RANKL stimulates osteoclastogenesis remain to be elucidated. Here we report that activation of cAMP-response elementbinding protein (CREB) is not involved in osteoclastogenesis from osteoclast precursors in response to RANKL. RANKL induced CREB activation in osteoclast precursors. Using pharmacological inhibitors, we found that RANKL-induced CREB activation is dependent on p38 MAPK pathways. We also found that ectopic expressions of wild type and dominant negative forms of CREB in osteoclast precursors did not affect RANKL-induced osteoclast formation and bone resorbing activity. Furthermore, dominant negative forms of CREB did not alter the expression levels of osteoclast-specific marker genes. Taken together, these data suggest that CREB is dispensable for differentiation and resorbing activity of osteoclasts.