• 아시안잔디학회지
• /
• 제10권3호
• /
• pp.213-230
• /
• 1996

A study of occurrence and distribution of cellular slime molds(CSMs) in forest soils of central areas of Korea was carried out. Samples for CSMs isolation were collected from 4 study sites; Mt.Kyeryong, Mt. Taebaek, Mt. Sobaek and Mt. Sokri. In Mt. Kyeryong, six species were found. These were Dictyostelium fasciculatum, D.firmibasis, D. mucoroides, D. minutum, D. brefeldianum and Polysphondylium pallidum. The average number of species isolated at one site was 0.75, and average density(clones /g soil) was 292. The results of soil sample analyses were that the concentration of Pb was higher than any other areas. In Mt. Taebaek, seven species were found; D. fasciculatum, D.firmibasis, D. mucoroides, D. miuutum, P.pallidum. P. violaceum, P. candidum. The average number of species isolated at one site was 2.3,and average density was 1,108. Based on importance values calculated from study sites within each of three elevation ranges, several of the more widely distributed and abundant species have distribution patterns that show a response to elevation. In Mt. Sobaek, eleven species were found. These were D. fasciculatum. D.firmibasis, D. mucoroides, D. miuutum, D. brefeldianum, D. crassicaule,D. deminutivum, D. implicatum, P. pallidum. P. violaceum and P. candidum. The average number of species isolated at one site was 3, and average density was 793. Species diversity appeared to be the highest in this area. In Mt. Sokri, six species were found. These were D. fasciculatum. D. mucoroides, D. minutum, D. purpureum, P. pallidum. and P. violaceum. The average number of species isolated at one site was 2.4 and average density was 858. It was noticeable that D.purpureum were much more comrnonly found in this pinus evergreen forest. Key words: Cellular slime molds(CSMs), Importance value, Elevation, Average number of species, Average density.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권10호
• /
• pp.1475-1478
• /
• 2005

Statistical analysis was conducted on sow stillbirth traits of three genotypes with 2,400 litters including the Erhualian, Large White and the $F_1$ cross of these two breeds. Number of stillborn piglets per litter in the Erhualian, Large White and the $F_1$ averaged 0.85, 0.31 and 0.70, and percentage born alive averaged 95.0%, 97.0% and 95.5%, respectively. Erhualian sows with a greater litter size also had a higher stillbirth rate. Results of analysis of variance indicated that genotype, parity, farrowing year${\times}$farrowing season interaction and total number born had highly significant effects on both number of stillborn piglets per litter and percentage born alive in sows (p<0.0001). Farrowing year had no significant effect on number of stillborn piglets per litter (p>0.05), and highly significant effect on percentage born alive (p<0.01). Farrowing season had highly significant effects on both number of stillborn piglets per litter and percentage born alive (p<0.01). From parity one to parity ten, least squares means for number of stillborn piglets per litter progressively increased with increasing parity and least squares means for percentage born alive progressively decreased with increasing parity. Sows that farrowed in winter had the highest number of stillborn piglets per litter and the lowest percentage born alive, sows that farrowed in autumn had the lowest number of stillborn piglets per litter and the highest percentage born alive. With increasing total number born, least squares means for number of stillborn piglets per litter markedly increased and least squares means for percentage born alive markedly decreased. Results from analysis of paternal half sibs indicated that the heritabilities for number of stillborn piglets per litter and percentage born alive were 0.110 and 0.124, and the genetic, phenotypic and environmental correlations between them were -0.989, -0.951 and -0.948, respectively. These results indicated that number of stillborn piglets per litter and percentage born alive were traits with the similar genetic background.

• Korean Journal of Mathematics
• /
• 제7권2호
• /
• pp.227-233
• /
• 1999

Let $k$ be a real abelian field and $k_{\infty}={\bigcup}_{n{\geq}0}k_n$ be its $\mathbb{Z}_p$-extension for an odd prime $p$. For each $n{\geq}0$, we denote the class number of $k_n$ by $h_n$. The following is a well known theorem: Theorem. Suppose $p$ remains inert in $k$ and the prime ideal of $k$ above $p$ totally ramifies in $k_{\infty}$. Then $p{\nmid}h_0$ if and only if $p{\nmid}h_n$ for all $n{\geq}0$. The aim of this paper is to generalize above theorem: Theorem 1. Suppose $H^1(G_n,E_n){\simeq}(\mathbb{Z}/p^n\mathbb{Z})^l$, where $l$ is the number of prime ideals of $k$ above $p$. Then $p{\nmid}h_0$ if and only if $p{\nmid}h_n$. Theorem 2. Let $k$ be a real quadratic field. Suppose that $H^1(G_1,E_1){\simeq}(\mathbb{Z}/p\mathbb{Z})^l$. Then $p{\nmid}h_0$ if and only if $p{\nmid}h_n$ for all $n{\geq}0$.

• 한국식품조리과학회지
• /
• 제26권1호
• /
• pp.41-53
• /
• 2010

The purposes of this study were to: a) investigate personal and foodservice operational factors affecting job stress of school foodservice dietitians, b) analyze the contribution of emotional labor to job stress of school foodservice dietitians. A survey was conducted from May 2 to June 13, 2008 to collect data from school foodservice dietitians (N=546). 206 questionnaires were returned completed, and 15 improperly-completed questionnaires were excluded. Finally, 191 questionnaires were used for final statistical analysis (usage rate : 34.98%). The results of the study were as follows. First, personal variables significantly affecting dietitians' job stress were 'monthly bills(p<0.05)' and 'total length of time in school foodservice (p<0.05)'. Second, foodservice operational variables affecting dietitians' job stress were 'school level (p<0.05)', 'type of school foodservice management (p<0.01)', 'number of meal service times (p<0.05)', 'total number of meals served per day (p<0.001)', 'number of meals served per day for students (p<.001)', 'number of meals served per day for teachers (p<0.001)', and 'number of foodservice staff (p<0.001)'. Third, emotional labor was found to contribute significantly to the job stress of dietitians in school foodservice (p<0.001). It was found that as dietitians experience more emotional labor at work, more job stress is experienced. Stress management is a very important and meaningful contributor to foodservice quality as well as to personal well-being for workers in school foodservice. Therefore, it is proposed that management of emotional labor is essential for stress management. Further, emotional labor and job stress should no longer be considered a personal matter, but rather should be approached systematically in all aspects of a school foodservice organization.

• 한국작물학회지
• /
• 제60권4호
• /
• pp.412-420
• /
• 2015

Even though phosphorus (P) is essential element for plant growth and development, it is not enough for crop production in soil. To breed more P deficient tolerance rice, screening and selection in rice population is needed. We tried to develop more simple and rough screening method for breeding of P deficient tolerance rice. In P deficient condition, tiller number was dramatically decreased among yield components in rice. Though this result, we confirmed tiller number could be the best marker in screening of P deficient tolerance rice. 480 rice genetic resources were cultivated in rice bed tray filled with P deficient soil for four weeks and each dry weight was measured. Among them, the 55 kinds of genetic resource were selected then cultivated in paddy field with 3 fertilizer conditions. Plant dry weight and tiller number in ripening stage were shown significant difference according to P condition. Plant dry weight and tiller number in ripening stage was highly correlated especially in P deficient condition. Furthermore, the tiller number in ripening stage and plant dry weight in rough screening were shown high degree correlation. Though these results, we might expect measuring of plant dry weight after cultivation in rice bed tray filled with P deficient soil could be a simple and effective screening method in selection of P deficient tolerance rice.

• 호남수학학술지
• /
• 제31권3호
• /
• pp.437-449
• /
• 2009

In this paper, we calculate the number of points on elliptic curves $E^{a^3}_0:y^2=x^3+a^3$ over ${\mathbb{F}}_p$ mod 24 and $E^b_0:y^2=x^3+b$ over ${\mathbb{F}}_p$ mod 6, where b is cubic non-residue in ${\mathbb{F}}^*_p$. For example, if p ${\equiv}$ 1 (mod 12) is a prime, and a and a(2t - 3) are quadratic residues modulo p with $3t^2{\equiv}1$ (mod p), then the number of points in $E^{a^3}_0:y^2=x^3+a^3$ is congruent to 0 modulo 24.

• 대한수학회논문집
• /
• 제13권2호
• /
• pp.233-242
• /
• 1998

Let $k = Q(\sqrt{m})$ be a real quadratic field. In this paper, the following theorems on p-divisibility of the class number h of k are studied for each prime pp. Theorem 1. If the discriminant of k has at least three distinct prime divisors, then 2 divides h. Theorem 2. If an odd prime p divides h, then p divides $B_{a,\chi\omega^{-1}}$, where $\chi$ is the nontrivial character of k, and $\omega$ is the Teichmuller character for pp. Theorem 3. Let $h_n$ be the class number of $k_n$, the nth layer of the $Z_p$-extension $k_\infty$ of k. If p does not divide $B_{a,\chi\omega^{-1}}$, then $p \notmid h_n$ for all $n \geq 0$.

• 미생물학회지
• /
• 제25권4호
• /
• pp.255-261
• /
• 1987

Five independent Actinomycetes harboring plasmids were isolated from soil. Molecular weight of these plasmids was 55kb, 6.2kb, 4.4kb, 55kb and 7.0kb, respectively. Among them small and apprent high copy number plasmids, pJY501 of 4.4kb and pHY711 of 7.0kb, were selected. The plasmids purified by CsCl-EtBr density gradient centrifugation preserved the conformation of supercoiled covalently closed circular molecule, and an apparent copy number was estivated about 150 and about 35 per chromosome. The isolates carrying plasmids were assigned to the genus Streptomyces. For the purpose of introducing selection markers into the isolated plasmids, the tsr fragmemt of pIJ702 was inserted into the BclI site of pJY 501 and pJY711. And the recombinant plasmids constructed designated as pJY502 and pJY712 respectively.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2009년 춘계학술대회논문집
• /
• pp.245-251
• /
• 2009

Numerical algorithms for solving the incompressible Navier-Stokes equations using P2P1 finite element are compared regarding the eigenvalues of matrices. P2P1 element allocates pressure at vertex nodes and velocity at both vertex and mid nodes. Therefore, compared to the P1P1 element, the number of pressure variables in the P2P1 element decreases to 1/4 in the case of two-dimensional problems and to 1/8 in the three-dimensional problems. Fully-implicit-integrated, semi-implicit- integrated and semi-segregated finite element formulations using P2P1 element are compared in terms of elapsed time, accuracy and eigenvlue distribution (condition number). For the comparison,they have been applied to the well-known benchmark problems. That is, the two-dimensional unsteady flows around a fixed circular cylinder and decaying vortex flow are adopted to check spatial accuracy.

• Reproductive and Developmental Biology
• /
• 제28권4호
• /
• pp.227-233
• /
• 2004

This study was conducted to investigate the effect of various addition and exclusion time of glucose (Control: no addition, A: 24～72 h, B: 24～48 h, C: 48～72 h, D: 0～72 h, E: 0～48 h, F: 0～24 h and 48～72 h, G: 0～24 h) on embryonic developmental capacity of 2-cell embryos in mice. Developed blastocysts were assessed for mean cell number by differential staining. The zona-intact blastocyst (ZiB) rates were higher (p<0.05) in group B than control. However, the zona-escape blastocyst (ZeB) rates were not significantly different in all groups. At 72 h, total blastocyst (ZiB + ZeB) formation rates were not significantly different in all groups. The mean cell number was not significantly different among all groups. The inner cell mass (ICM) cell number was higher (p<0.05) in group F than control, group A, B and G. The trophectoderm (TE) cell number was higher (p<0.05) in control than group A and D. The %ICM was higher (p<0.05) in group C, D and F than control. The ICM : TE ratio was not significantly different in all groups. Between control and glucose group, no significant difference was observed in the total blastocysts (ZiB + ZeB) formation rates. Also, no significant difference was observed in the mean cell number, ICM cell number and ICM : TE ratio. However the TE cell number was higher (p<0.05) in control than glucose group and %ICM was higher (p<0.05) in glucose group than control. In conclusion, glucose added in culture medium was not inhibitory on blastocyst formation but glucose added for 48 ～72 h in culture medium increases %ICM of blastocysts in mice.