• Journal of the Korean Mathematical Society
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• v.47 no.6
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• pp.1147-1165
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• 2010

In this paper we compare a torsion free sheaf F on $P^N$ and the free vector bundle $\oplus^n_{i=1}O_{P^N}(b_i)$ having same rank and splitting type. We show that the first one has always "less" global sections, while it has a higher second Chern class. In both cases bounds for the difference are found in terms of the maximal free subsheaves of F. As a consequence we obtain a direct, easy and more general proof of the "Horrocks' splitting criterion", also holding for torsion free sheaves, and lower bounds for the Chern classes $c_i$(F(t)) of twists of F, only depending on some numerical invariants of F. Especially, we prove for rank n torsion free sheaves on $P^N$, whose splitting type has no gap (i.e., $b_i{\geq}b_{i+1}{\geq}b_i-1$ 1 for every i = 1,$\ldots$,n-1), the following formula for the discriminant: $$\Delta(F):=2_{nc_2}-(n-1)c^2_1\geq-\frac{1}{12}n^2(n^2-1)$$. Finally in the case of rank n reflexive sheaves we obtain polynomial upper bounds for the absolute value of the higher Chern classes $c_3$(F(t)),$\ldots$,$c_n$(F(t)) for the dimension of the cohomology modules $H^iF(t)$ and for the Castelnuovo-Mumford regularity of F; these polynomial bounds only depend only on $c_1(F)$, $c_2(F)$, the splitting type of F and t.

• Archives of Pharmacal Research
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• v.26 no.5
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• pp.383-388
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• 2003

Bee venom is used as a traditional medicine for treatment of arthritis. The anti-inflammatory activity of the n-hexane, ethyl acetate, and aqueous partitions from bee venom (Apis mellifera) was studied using cyclooxygenase (COX) activity and pro-inflammatory cytokines (TNF-$\alpha and IL-1\beta$) production, in vitro. COX-2 is involved in the production of prostaglandins that mediate pain and support the inflammatory process. The aqueous partition of bee venom showed strong dose-dependent inhibitory effects on COX-2 activity ($IC_{50} = 13.1 \mu$ g/mL), but did not inhibit COX-1 activity. The aqueous partition was subfractionated into three parts by molecular weight differences, namely, B-F1 (above 20 KDa), B-F2 (between 10 KDa and 20 KDa) and BF-3 (below 10 KDa). B-F2 and B-F3 strongly inhibited COX-2 activity and COX-2 mRNA expression in a dose-dependent manner, without revealing cytotoxic effects. TNF-$\alpha and IL-1\beta$ are potent pro-inflammatory cytokines and are early indicators of the inflammatory process. We also investigated the effects of three subfractions on TNF-$\alpha and IL-1\beta$ production using ELISA method. All three subfractions, B-F1, B-F2 and B-F3, inhibited TNF-$\alpha and IL-1\beta$production. These results suggest the pharmacological activities of bee venom on anti-inflammatory process include the inhibition of COX-2 expression and the blocking of pro-inflammatory cytokines (TNF-$\alpha and IL-1\beta$) production.

• Communications of the Korean Mathematical Society
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• v.32 no.4
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• pp.959-970
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• 2017

In this paper, we investigate the transcendental meromorphic solutions with finite order of two different types of difference equations $${\sum\limits_{j=1}^{n}}a_jf(z+c_j)={\frac{P(z,f)}{Q(z,f)}}={\frac{{\sum_{k=0}^{p}}b_kf^k}{{\sum_{l=0}^{q}}d_lf^l}}$$ and $${\prod\limits_{j=1}^{n}}f(z+c_j)={\frac{P(z,f)}{Q(z,f)}={\frac{{\sum_{k=0}^{p}}b_kf^k}{{\sum_{l=0}^{q}}d_lf^l}}$$ that share three distinct values with another meromorphic function. Here $a_j$, $b_k$, $d_l$ are small functions of f and $a_j{\not{\equiv}}(j=1,2,{\ldots},n)$, $b_p{\not{\equiv}}0$, $d_q{\not{\equiv}}0$. $c_j{\neq}0$ are pairwise distinct constants. p, q, n are non-negative integers. P(z, f) and Q(z, f) are two mutually prime polynomials in f.

• Journal of Plant Biology
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• v.33 no.4
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• pp.237-242
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• 1990

Geographical distribution of diploid plant with AA genome (2n=16) and allotetraploid with AABB genome (2n=34) of Scilla scilloides Complex from Korea has been studied. The composition and frequencies of B chromosomes ere also investigated. Plants with AABB genome were predominant over AA genome plants. A mixed population of AA and AABB genome plants was found for the first time. Aneuploid plants have not been found. Chromosomes of AA genome were composed of three pairs of metacentric, two pairs of submetacentric, two pairs of subtlocentric and one pair of telocentric chromosomes, whereas BB genome was four pairs of metacentric and five pairs of subtelocentric chromosomes. B chromosomes were classified into two categories, isochromosome (F) and chromosome fragment (f). The frequencies of B chromosomes were 43% in AA genome plants and 44% in AABB genome plants. The number of B chromosome ranged from 1 to 3 and 1 to 7 in AA and AABB genome plants, respectively. B chromosome combinations were F and F+f in AA genome plants and F, F+f and f in AABB genome plants.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.3
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• pp.481-485
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• 1992

In order to upgrade native sheep, Rambouillet (R) rams were mated to Kaghani (K) ewes to generate F1 ($R{\times}K$) crossbred ewes. Crossbred ewes were backcrossed to Rambouillet rams to produce B1 ($R{\times}F1$), B2 ($R{\times}B1$) and B3 ($R{\times}B2$) genotypes. Weaning weight of 2605 lambs and wool weight of 2378 mature ewe records, representing R, K, F1, B1, B2 and B3 genotypes, were analyzed to compare genetic variation among genotypes produced during upgrading process and identify genotypes of the highest performance. Performance of Rambouillets was also evaluated under semi-temperate climate. Data were adjusted for yearly variation considering Rambouillet as a control. Genotypes influenced lambs weaning weight (p<.01). B1 lambs were heaviest (18.4 kg) followed in order by B2, F1, B3, R and K lambs (18.3, 17.9, 16.9, 16.8 and 13.2 kg, respectively). The highest wool production was 2.5 kg from R ewes followed by B2 (2.3), B3 (2.3), F1 (2.0) and K (1.2) ewes (p < .01). Ewe mating weight, reproduction, growth and wool production of Rambouillets deteriorated significantly after the first decade of their importation. Compared with the first phase (1959-1971), ewe mating weight, litter size, birth weight, lamb weaning weight and wool production declined by 20, 23, 32 and 36%, respectively, in the second phase (1972-1988).

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.1
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• pp.63-75
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• 2009

The aim of this study was to elucidate the antimelanogenic effect of Dokhwalkisaeng-tang(Duohujisheng-tang) in B16F10 melanoma cells. Dokhwalkisaeng-tang(DKT) was used to develop the effective prescription of inhibition of melanin production. We determined inhibitory effects of DKT on melanin-release, melanin production, and tyrosinase activity in B16F10 melanoma cells. And to explicate the action-mechanism of DKT, melanin-related gene expressions were determined using RT-PCR and real time RT PCR technique in B16F10 melanoma cells. DKT inhibited melanin-release, melanin production in B16F10 melanoma cells considerably. DKT inhibited tyrosinase activity in vitro and in B16F10 melanoma cells. DKT inhibited the expression of tyrosinase, TRP-1, TRP-2 in B16F10 melanoma cells. DKT inhibited the expression of PKA, PKC, MMP-2 and MITF in B16F10 melanoma cells. On the other hand, DKT increased the expression of ERK-1, ERK-2, AKT-1 in B16F10 melanoma cells. From these results, we propose that DKT may have effect on the antimelanogenesis.

• Korean Journal of Microbiology
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• v.32 no.2
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• pp.120-125
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• 1994

The genes, trpB, trpA and 3’ trpC(F) of Vibrio metschnikovii strain RH530 were cloned and sequenced. The trpB and trpA genes had open reading frames of 1,173 bp and 804 bp encoding 391 and 268 amino acids, respectively. The trpB and trpA genes had conventional ribosome-binding sequences and overlapped with each other by one nucleotide, suggesting that these two genes are translationally coupled. 115 nucleotide upstream the trpB start codon, tjere was an incomplete open reading frame of the 3’-end of the trpC(F). The amino acid sequences of trpB, trpA and trpC(F) of V. metschnikovii RH530 had identities of 64.2%, 82.4% and 73.7% respectively, for those of V. parahaemolyticus; 58.7%, 72.3% and 54.9%, respectively, for Salmonella typhimurium; and 42.6%. 54.1% and 12.5%, respectively, for brevibacterium lactofermentum. The genetic organization of these genes, especially in the noncoding region between trpC(F) and trpB, was distinct from that of Enterobacteriaceae.

• Journal of agriculture & life science
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• v.46 no.6
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• pp.1-8
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• 2012

This study was carried out to determine the genic values of taste of Korean hot pepper (Capsicum annuum L.) in practical genetic resources of using to breed them. The two breeding materials of pepper, '#1803' ($P_1$) of prefer tastes and '#1532' ($P_2$) of ordinary taste, and their $F_1$, $F_2$ generations were used in this study. By using partitioning method it was possible to estimate, from the $F_2$ generation, the number of effective factor pairs differentiating the two parents. There were found to be differentiated by two effective factor pairs. In practical genetic resource of using to breed the Korean hot pepper, the heritance of pepper tastes showed that the $F_1$ was better than excellent parent by reason of over dominant, but some $F_2$ was better than both parent by transgressive segregation. As the result, the magnitude of genic effects of A-a gene in pepper tastes was 0.36, and B-b gene was 0.64. The tastes of Korean hot pepper showed a complex inheritance by interaction effect on the two non-allelic factors of 0.94 and secondary effect of 2.86 at the most.

• Korean Journal of Pharmacognosy
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• v.52 no.4
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• pp.212-218
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• 2021

Fatsia japonica is grown wild to Eastern Asia, including Korea, Japan, and Taiwan and it is known as ornamental plant, and it is also known that pharmacological action. In this study, we have selected the stem of F. japonica with consideration about biological activities and amount of yield. In addition, four compounds (1-4) were isolated from the stem of F. japonica. Extensive spectroscopic and chemical studies established the structures of these compounds as maltose (1), begoniifolide A (2), leiyemudanoside B (3), leonticin F (4). All of the compounds were investigated for their anti-inflammatory, anti-neuroinflammatory, and neuro-protective effects on RAW264.7, BV2, and HT22 cells. However, among four compounds, there were no effects by maltose (1), begoniifolide A (2), leiyemudanoside B (3), leonticin F (4) on the anti-inflammatory, anti-neuroinflammatory, and neuro-protective action. This is the first report on the isolation of maltose (1), begoniifolide A (2), leiyemudanoside B (3), leonticin F (4) from the stem of F. japonica. Begoniifolide A (2), leiyemudanoside B (3), leonticin F (4) were isolated for the first time from this plant. It might be necessary to continue the further studies to find the biological active compounds isolated from the stem of F. japonica.

• Communications of the Korean Mathematical Society
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• v.10 no.1
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• pp.133-135
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• 1995

In this note, we will investigate the radial symmetry of some kind of solutions of nonlinear ellipitic equations $$ \Delta U = f(U) $$ $$ (1.1) U = 0 in B $$ $$ U \in C^2 (\bar{B}) on \partial B$$ Here f is $C^1$ and B denotes a n-dimensional unit ball in $R^n$.