About 70% of total honey products produced by Korean bee keepers was acacia honey. The remaining 30% was chestnut honey, jujube honey, snowbell honey, and another honey. False acacia, went down in payability since the middle 2000s because of simultaneous blooming etiolation chlorsis decreases productivity after aging. Therefore, substitution honey plants were necessary. This study estimated nectar secretion amount of each flower and productivity per ha at 14 medical herbs. Each flower, Codonopsis lanceloata, estimated a majority nectar secretion amount at 176.08 ul for each of the 14 medical herbs. Astragalus membranaceus estimated majority nectar secretion amount at 1273.3 L per ha for each of the 14 medical herbs. Medical herbs were hypothesized with valuable honey plants.

Jujube trees, herbal medicine material, produce not only their fruit but also jujube honey for bee and human’ food sources. Although jujube is an important honey plant after acacia bloom, the research was done with 15-year-old jujube trees grown in ChungDo-Gun, which there was no information on jujube floral nectar. According to the research, jujube nectar secretion mostly happens during dawn and morning for two days. The average number of inflorescence per tree is 638.1 according to the research. And also, the average number of flowers per inflorescence is 64.4. The amount of nectar secretion is 11.6 ul on average per flower, and hypothesized nectar secretion from 15-year-old tree per tree is 476.682 ul. Also,a jujube tree has 545.5ul hypothesized nectar secretion per ha by the research.

Differential capacity of the parthenogenetic embryonic stem cells (PESCs) is still under controversy and the mechanisms of its neural induction are yet poorly understood. Here we demonstrated neural lineage induction of PESCs by addition of insulin-like growth factor-2 (Igf2), which is an important factor for embryo organ development and a paternally expressed imprinting gene. Murine PESCs were aggregated to embryoid bodies (EBs) by suspension culture under the leukemia inhibitory factor-free condition for 4 days. To test the effect of exogenous Igf2, 30 ng/ml of Igf2 was supplemented to EBs induction medium. Then neural induction was carried out with serum-free medium containing insulin, transferrin, selenium, and fibronectin complex (ITSFn) for 12 days. Normal murine embryonic stem cells derived from fertilized embryos (ESCs) were used as the control group. Neural potential of differentiated PESCs and ESCs were analyzed by immunofluorescent labeling and real-time PCR assay (Nestin, neural progenitor marker; Tuj1, neuronal cell marker; GFAP, glial cell marker). The differentiated cells from both ESC and PESC showed heterogeneous population of Nestin, Tuj1, and GFAP positive cells. In terms of the level of gene expression, PESC showed 4 times higher level of GFAP expression than ESCs. After exposure to Igf2, the expression level of GFAP decreased both in derivatives of PESCs and ESCs. Interestingly, the expression level of Tuj1 increased only in ESCs, not in PESCs. The results show that IGF2 is a positive effector for suppressing over-expressed glial differentiation during neural induction of PESCs and for promoting neuronal differentiation of ESCs, while exogenous Igf2 could not accelerate the neuronal differentiation of PESCs. Although exogenous Igf2 promotes neuronal differentiation of normal ESCs, expression of endogenous Igf2 may be critical for initiating neuronal differentiation of pluripotent stem cells. The findings may contribute to understanding of the relationship between imprinting mechanism and neural differentiation and its application to neural tissue repair in the future.

The aim of this study was to determine the muscle activity of the abdominalis and erector spinae during bridging and unilateral bridging exercises on the firm surface, the sir-fit, and the foam roll. Eighteen healthy young subjects were recruited for this study. Surface electromyographic (EMG) activities were recorded from the both sides of the rectus abdominalis, external obliques, internal obliques, and erector spinae muscles during bridging and unilateral bridging-exercises. A one-way repeated analysis of variance was used to compare the EMG activity of each muscle according to the support surface condition. Differences in the EMG activities between the bridging and unilateral bridging exercises, and between the right and left side were assessed using a paired t-test. The study showed that the EMG activities of all of the muscles were significantly higher when the bridging exercise was performed using the foam roll or sit-fit than on the firm surface. The EMG activities of the right rectus abdominis, right external obliques, the right internal oblique, and both erector spinae were significantly higher during unilateral bridging ex exercise using the foam roll or the sit-fit than on the firm surface. The EMG activities of all of the muscles were significantly higher during the unilateral bridging exercise than during the bridging exercise. Based on these finding, performing the unilateral bridging exercise using the sit-fit or the foam roll is a useful method for facilitating trunk muscle strength and lumbar stability.