• 천문학회보
• /
• 제44권1호
• /
• pp.40.3-40.3
• /
• 2019

There is growing evidence for the dependence of Type Ia supernova (SN Ia) luminosities on the environments. The origin of this correlation, however, is under debate. In order to explore the physical origin of the trend in detail, we analyze SN Ia light-curves by combining a sample of 1231 SNe Ia over a wide redshift range (0.01 < z < 1.37) in various SN surveys and employing two independent light-curve fitters of SALT2 and MLCS2k2. Although SALT2 is the most widely used fitter in the SN community, MLCS2k2 has a novelty in the context of an investigation of the luminosity evolution of SNe Ia. For this reason we use both fitters and analyze them separately. We also determine a stellar mass and a star formation rate (SFR) for a sample of ~600 host galaxies. In addition, because recent low-redshift studies suggest that this dependence manifests itself most strongly when using the local SFR at the SN location, we introduce a new method to infer the local environments by restricting the SN Ia sample in globally star-forming host galaxies to a low-mass host galaxy subset (${\leq}10^{10}M_{\odot}$). We find that SNe Ia in low-mass and star-forming host galaxies are fainter than those in high-mass and passive hosts, after light-curve corrections. Especially, for the first time in host studies, we show that SNe Ia in locally star-forming environments are $0.081{\pm}0.018$ mag fainter ($4.5{\sigma}$) than those in locally passive environments from the sample including SNe at the high-redshift range. Considering the significant difference in the mean stellar population age between these environments, the result would suggest that the origin of the environmental dependence is the luminosity evolution of SNe Ia.

• 한국균학회지
• /
• 제15권1호
• /
• pp.48-69
• /
• 1987

외생균근(外生菌根)버섯의 기주범위(寄主範圍)와 기주선택성(寄主選擇注)을 구명(究明)하고 주요(主要) 조림수종(造林樹種)의 균근균(菌根菌) 선택성(選擇性)을 상호비교(相互比較)하기 위하여 1981년(年)부터 1986년(年)까지 전국(全國)의 여러 곳에서 12개수종(個樹種)의 순림(純林)(소나무, 리기다소나무, 잣나무, 종비나무, 일본잎갈나무, 젓나무, 현사시, 밤나무, 갈참나무, 상수리나무, 신갈나무, 자작나무)를 대상(對象)으로 균근(菌根)버섯을 채집(採集)하여 분석(分析)을 비교(比較)하였다. 6년(年)동안 총(總) 48리(履) 196종(種) 8 품종(品種)의 균근(菌根) 버섯을 동정(同定)하였으며 그 중 Russla가 31종(種) 1 품종(品種), Amanita가 22종(種) 5 품종(品種), Lactarius가 18종(種) 1 품종(品種)이었다. 기주범위(寄主範圍)가 넓은 종(種)은 Russula, Amanita, Lactarius, Laccaria, Cantharellus 속(屬)에 속(屬)해 있있다. Laccaria Laccata는 12개조사수종중(個調査樹種中)에서 12개수종전분의 임분(林分)에서, Amanita vaginata group은 11개수종(個樹種)에서, Labtarius gerardii와 Russula sororia는 9 개수종(個樹種)에 서, Amanita agglutinata, Cantharellus cibarius, Russula bella, Russula bella, Russula virescens는 8개수종(個樹種)의 침개엽수임분(針開葉樹林分)에서 채집(採集)되어 기주(寄主)의 범위(範圍)가 넓은 버섯으로 분류(分類)되었다. Amanita citrina, Boletus bicolor, Boletus erythropus, Lactarius piperatus, L. subzonarius, Russula pseudodelica는 침개활수(針葉闊樹)의 $4{\sim}5$개수종(個樹種)에서 채집(採集)되어 기주(寄主)의 범위(範圍)가 중간(中間)정도(程度)인 버섯으로 분류(分類)되었으며 특히 Suillus grevillei는 잎갈나무에서서만 채집(採集)되어 기주(寄主)의 범위(範圍)가 가장 좁은 버섯으로 판명(判明)되었다. 12개수종(個樹種)의 임분중(林分中)에서 균근(菌根)버섯의 종류(種類)가 가장 많은 젓나무림(林)으로써 83종(重)의 균근(菌根)버섯을 채집(採集)했으며, 소나무(赤松)림(林)에서 66종(重)을, 리기다소나무림(林)에서 50종(種)을, 잣나무림(林)에서 49종(重)을, 갈참나무림(林)에서 46종(種)을 채집(採集)했다. 일본잎갈나무림(林)에서는 23종(種)의 균근(菌根)버섯을 채집(採集)했는데 다른 임분(林分)과 달리 Amanita, Lactarius, Russula 는 적고 대신 Laccaria 가 많이 관찰(觀察)되었다. 본(本) 실험(實驗)에서 조사(調査)된 12개수종(個樹種)의 대부분(大部分)은 다양(多樣)한 균근(菌根)버섯과 공생(共生)하는 듯하며 균선택성(菌選擇性)이 적은 것으로 사료(思料)된다.

• Journal of Microbiology
• /
• 제45권1호
• /
• pp.58-63
• /
• 2007

In this study, the relative synonymous codon and amino acid usage biases of the broad-host range phage, KVP40, were investigated in an attempt to understand the structure and function of its proteins/protein-coding genes, as well as the role of its tRNAs. Synonymous codons in KVP40 were determined to be AT-rich at the third codon positions, and their variations are dictated principally by both mutational bias and translational selection. Further analysis revealed that the RSCU of KVP40 is distinct from that of its Vibrio hosts, V. cholerae and V. parahaemolyticus. Interestingly, the expression of the putative highly expressed genes of KVP40 appear to be preferentially influenced by the abundant host tRNA species, whereas the tRNAs expressed by KVP40 may be required for the efficient synthesis of all its proteins in a diverse array of hosts. The data generated in this study also revealed that KVP40 proteins are rich in low molecular weight amino acid residues, and that these variations are influenced primarily by hydropathy, mean molecular weight, aromaticity, and cysteine content.

• Mycobiology
• /
• 제50권3호
• /
• pp.166-171
• /
• 2022

Virginia creeper (or five-leaved ivy; Parthenocissus quinquefolia) is one of the most popular and widely grown climbers worldwide. In September 2021, Virginia creeper leaves with typical rust symptom were found in an arboretum in Korea, with severe damage. Globally, there is no record of a rust disease on Virginia creeper. Using morphological investigation and molecular phylogenetic inferences, the rust agent was identified as Neophysopella vitis, which is a rust pathogen of other Parthenocissus spp. including Boston ivy (P. tricuspidata). Given that the two ivy plants, Virginia creeper and Boston ivy, have common habitats, especially on buildings and walls, throughout Korea, and that N. vitis is a ubiquitous rust species affecting Boston ivy in Korea, it is speculated that the host range of N. vitis may recently have expanded from Boston ivy to Virginia creeper. The present study reports a globally new rust disease on Virginia creeper, which could be a major threat to the ornamental creeper.

• 생약학회지
• /
• 제36권2호통권141호
• /
• pp.93-96
• /
• 2005

Mutagenicity of Gamgung-tang (GGT) was tested using in vitro S-9 mixture in vitro host-mediated assay with Salmonella typhimurium. In the previous reports, GGT was tested for the safety using Ames(-S-9), Bacillus subtilis Rec, and umu gene expression mutagenicity tests. Mutagenic activity in any assays we tested was not found. In this report, we further investigated safety of GGT after metabolic activation in vivo. Ames test with S-9 mixture and host-mediated assay with Salmonella typhimurium TA98 were used to identify metagenic property of GGT. GGT was administered 3 times with i.m. to Balb/c mice did not induced mutagenic effect in Salmonella typhimurium TA98 recovered from the liver after 3.5h with i.p. treatment. Over the entire dose range $(3{\sim}150mg/mouse)$ tested no toxicity was detected to the bacterial cells. These results suggest that there was no DNA damage and mutagenicity by GGT.

• 농업과학연구
• /
• 제35권2호
• /
• pp.177-182
• /
• 2008

Type I Interferons (IFNs) are potent antiviral cytokines that modulate both innate immunity and adaptive immunity. Type I IFNs are immediately induced by viral infection, and stimulate production of a broad range of gene products such as double-stranded RNA-activated protein kinase (PKR), 2' 5'-oligoadenylate synthetase (OAS)/RNaseL and Mx GTPases. These proteins inhibit viral replication in host cells. Type I IFNs, in turn, lead to antiviral state at early phase of viral infection. We provide an overview of the knowledge of IFN-inducible antiviral proteins conserved in vertebrates.

• World Technopolis Review
• /
• 제1권1호
• /
• pp.27-41
• /
• 2012

The science and technology park movement has been developing for over 60 years. The first developments simply relied on the co-location of tenant companies and the park's host to encourage technology transfer. This is in contrast with their modern counter parts which offer a range of active links between tenant companies and host organisations as well as a raft of business development services to support technology commercialisation. Many of these sites have also become important centres in regional innovation plans. In these cases they are supported by a range of local, regional and national policies that are aimed at establishing a business, technology and social environment which support innovation. The paper examines both the business development programmes developed by science and technology parks to support technology commercialisation and the macro conditions that are now being developed to support innovation.

• BMB Reports
• /
• 제29권1호
• /
• pp.63-67
• /
• 1996

In order to elucidate the molecular mechanism of plasmid incompatibility of broad host-range plasmid R1162, the plasmid-encoded replication protein RepIB was purified and tested for binding to the 20 bp direct repeat (DR) DNA sequence which is reiterated 3 and 1/2 times within the replicative origin of the plasmid. The RepIB protein specifically binds to the DR DNA. Point mutations in the DR which affect expression of plasmid incompatibility also coordinately affect binding. These results indicate that the incompatibility of broad host-range plasmid R1162 is exerted by the DR DNA by titrating the essential replication protein RepIB.

• The Plant Pathology Journal
• /
• 제16권2호
• /
• pp.79-82
• /
• 2000

No Abstract.See Full-text

• The Plant Pathology Journal
• /
• 제24권2호
• /
• pp.101-111
• /
• 2008

The fungal genus Alternaria is comprised of many saprophytic and endophytic species, but is most well known as containing many notoriously destructive plant pathogens. There are over 4,000 Alternaria/host associations recorded in the USDA Fungal Host Index ranking the genus 10th among nearly 2,000 fungal genera based on the total number of host records. While few Alternaria species appear to have a sexual stage to their life cycles, the majority lack sexuality altogether. Many pathogenic species of Alternaria are prolific toxin producers, which facilitates their necrotrophic lifestyle. Necrotrophs must kill host cells prior to colonization, and thus these toxins are secreted to facilitate host cell death often by triggering genetically programmed apoptotic pathways or by directly causing cell damage resulting in necrosis. While many species of Alternaria produce toxins with rather broad host ranges, a closely-related group of agronomically important Alternaria species produce selective toxins with a very narrow range often to the cultivar level. Genes that code for and direct the biosynthesis of these host-specific toxins for the Alternaria alternata sensu lato lineages are often contained on small, mostly conditionally dispensable, chromosomes. Besides the role of toxins in Alternaria pathogenesis, relatively few genes and/or gene products have been identified that contribute to or are required for pathogenicity. Recently, the completion of the A. brassicicola genome sequencing project has facilitated the examination of a substantial subset of genes for their role in pathogenicity. In this review, we will highlight the role of toxins in Alternaria pathogenesis and the use of A. brassicicola as a model representative for basic virulence studies for the genus as a whole. The current status of these research efforts will be discussed.