• Title/Summary/Keyword: Species associations

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Life History of a Colonial Spider Philoponella prominens (Araneae: Uloboridae) in Korea

  • Tae Soon Park;Jun Namkung;Jae Chun Choe
    • Animal cells and systems
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    • v.3 no.2
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    • pp.167-172
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    • 1999
  • We report for the first time the life history of a 'social' spider, Philoponella prominens, living in a temperate region. Philoponella prominens hibernated as immatures or subadults for 7-8 months in 1995 and 1996 from September-October to April-May in central Korea. When they emerged from their winter hibernation, a majority began their lives as commensals in the webs of other species. As the mating season approached, however, commensal spiders switched to become colonial or solitary. The mating season began in early June and lasted until early August. Newly-hatched spiderlings began to appear in the field in late June. They formed a colony by building their webs connected to the mother's by using pan of the mother's web as supporting substrates. As the season progressed, however, some of the colonial spiderlings became commensal or solitary individuals. Our field observations suggest that Philoponella prominens form colonies or commensal associations to reduce the web-building cost.

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Interspecific Association on a Native Grasslands (야초지 식생의 상관분석)

  • 박봉규
    • Journal of Plant Biology
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    • v.21 no.1_4
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    • pp.1-6
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    • 1978
  • Species lists were recorded for 100 quadrats in Kwang Neung, Kyung-gy Province, in which native grassland occurs. Among several methods, Agnew's method and Goodall's method were used for interspecific associations. As a result, plant community was divided into 3 or 6 homogeneous groups by each method.

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Phase Behavior of Reversibly Associating Star Copolymer-like Polymer Blends

  • June Huh;Kim, Seung-Hyun;Jo, Won-Ho
    • Macromolecular Research
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    • v.10 no.1
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    • pp.18-23
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    • 2002
  • We theoretically consider blends of two monodisperse one-end-functionalized homopolymers (denoted by A and B) capable of forming clusters between functional groups (stickers) using weak segregation theory. In this model system resulting molecular architectures via clustering resemble star copolymers having many A- and B-arms. Minimizing the total free energy with respect the cluster distribution, the equilibrium distribution of clusters is obtained and used for RPA (Random Phase Approximation) equations as input. For the case that polymers are functionalized by only one kind of sticker, the phase diagrams show that the associations promote the macrophase separation. When there is strong affinity between stickers belonging to the different polymer species, on the other hand, the phase diagram show a suppression of the macrophase separation at the range of high temperature regime, as well as the phase coexistence between a disordered and a mesoscopic phase at the relatively lower temperatures.

Studies on the Environmental Changes with the Urbanization of Ansan City (안산시의 도시화에 따른 환경변화에 관한 연구)

  • Yim, Yang-Jai;Jeyong Kang
    • The Korean Journal of Ecology
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    • v.11 no.4
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    • pp.201-212
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    • 1988
  • Ansan city in the coastal area of the mid-western Korea is known as a newly industrialized city(73.44$Km^2$, 127, 000 persons), with the increase rate of 27.8% in population and mean density of 1, 732 persons/$Km^2$. According to the census of the city(1986), it consists of cultivated field(36.8%), forest(34.2%), industrial area(7.4%), residential area(4.1%) and others(12.5%). The forest vegetation in the city is composed of four associations and two subassociations as follows; Pinus rigida, Pinus densiflora-Rhododendron mucronulatum, Quercus mongolica-Rhododendron mucronulatum and Robinia pseudo-acacia asociation, and Quercus mongolica-Corylus sieboldiana var. mandshurica and Robinia pseudoacacia-Alnus hirsuta subassociation. Various environmental conditions have been changed with the progress of urbanization of the city, since 1977. For example, a heat island phenomenon, which is the air temperature of 2 or 3$^{\circ}C$ higher in the central area than that of the boundary area, and floral changes caused by air pollutants such as decreasing bryophyte species along increasing SO$_2$ concentration.

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Is the MDR1 C3435T Polymorphism Responsible for Oral Mucositis in Children with Acute Lymphoblastic Leukemia?

  • Bektas-Kayhan, Kivanc;Kucukhuseyin, Ozlem;Karagoz, Gizem;Unur, Meral;Ozturk, Oguz;Unuvar, Aysegul;Devecioglu, Omer;Yilmaz-Aydogan, Hulya
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.10
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    • pp.5251-5255
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    • 2012
  • Background and Aim: Although the functional consequences of MDR-1 polymorphisms have been the subject of numerous studies, to the best to our knowledge, associations with clinical side effects of anticancer drugs have yet to be assessed. Our aim was to clarify any role of the C3435T polymorphism of the MDR1 gene in oral mucositis and its relation with elevated reactive oxygen species (ROS) levels, in children with acute lymphoblastic leukemia (ALL). Materials and Methods: The distribution of the MDR-1 C3435T polymorphism in 47 patients with ALL was determined by RFLP and compared with that of 68 healthy controls. Results: There were no association in distribution of genotypes of MDR-1 C3435T polymorphism and the risk of ALL. Oral mucositis were detected in 78.7% (n=37) of the patients and significantly related to the MDR-1 CT genotype (p=0.042), as confirmed by logistic regression analysis. Conclusion: Our preliminary data suggest that children carrying the CT genotype are more prone to develop oral mucositis, which might mean that the heterozygous genotype leads to accumulation of more reactive oxygen species. Since a limited number of patients was investigated, further studies are needed to confirm these findings.

Chewing Lice of Swan Geese (Anser cygnoides): New Host-Parasite Associations

  • Choi, Chang-Yong;Takekawa, John Y.;Prosser, Diann J.;Smith, Lacy M.;Ely, Craig R.;Fox, Anthony D.;Cao, Lei;Wang, Xin;Batbayar, Nyambayar;Natsagdorj, Tseveenmayadag;Xiao, Xiangming
    • Parasites, Hosts and Diseases
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    • v.54 no.5
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    • pp.685-691
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    • 2016
  • Chewing lice (Phthiraptera) that parasitize the globally threatened swan goose Anser cygnoides have been long recognized since the early 19th century, but those records were probably biased towards sampling of captive or domestic geese due to the small population size and limited distribution of its wild hosts. To better understand the lice species parasitizing swan geese that are endemic to East Asia, we collected chewing lice from 14 wild geese caught at 3 lakes in northeastern Mongolia. The lice were morphologically identified as 16 Trinoton anserinum (Fabricius, 1805), 11 Ornithobius domesticus Arnold, 2005, and 1 Anaticola anseris (Linnaeus, 1758). These species are known from other geese and swans, but all of them were new to the swan goose. This result also indicates no overlap in lice species between older records and our findings from wild birds. Thus, ectoparasites collected from domestic or captive animals may provide biased information on the occurrence, prevalence, host selection, and host-ectoparasite interactions from those on wild hosts.

Nigrospora Species Associated with Various Hosts from Shandong Peninsula, China

  • Hao, Yuanyuan;Aluthmuhandiram, Janith V.S.;Chethana, K.W. Thilini;Manawasinghe, Ishara S.;Li, Xinghong;Liu, Mei;Hyde, Kevin D.;Phillips, Alan J.L.;Zhang, Wei
    • Mycobiology
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    • v.48 no.3
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    • pp.169-183
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    • 2020
  • Nigrospora is a monophyletic genus belonging to Apiosporaceae. Species in this genus are phytopathogenic, endophytic, and saprobic on different hosts. In this study, leaf specimens with disease symptoms were collected from host plants from the Shandong Peninsula, China. The fungal taxa associated with these leaf spots were studied using morphology and phylogeny based on ITS, TEF1, and TUB2 gene regions. In this article, we report on the genus Nigrospora with N. gorlenkoana, N. oryzae, N. osmanthi, N. rubi, and N. sphaerica identified with 13 novel host associations including crops with economic importance such as bamboo and Chinese rose.

Phospholipase and Aspartyl Proteinase Activities of Candida Species Causing Vulvovaginal Candidiasis in Patients with Type 2 Diabetes Mellitus

  • Bassyouni, Rasha H.;Wegdan, Ahmed Ashraf;Abdelmoneim, Abdelsamie;Said, Wessam;AboElnaga, Fatma
    • Journal of Microbiology and Biotechnology
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    • v.25 no.10
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    • pp.1734-1741
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    • 2015
  • Few research had investigated the secretion of phospholipase and aspartyl proteinase from Candida spp. causing infection in females with type 2 diabetes mellitus. This research aimed to investigate the prevalence of vulvovaginal candidiasis (VVC) in diabetic versus non-diabetic women and compare the ability of identified Candida isolates to secrete phospholipases and aspartyl proteinases with characterization of their genetic profile. The study included 80 females with type 2 diabetes mellitus and 100 non-diabetic females within the child-bearing period. Candida strains were isolated and identified by conventional microbiological methods and by API Candida. The isolates were screened for their extracellular phospholipase and proteinase activities by culturing them on egg yolk and bovine serum albumin media, respectively. Detection of aspartyl proteinase genes (SAP1 to SAP8) and phospholipase genes (PLB1, PLB2) were performed by multiplex polymerase chain reaction. Our results indicated that vaginal candidiasis was significantly higher among the diabetic group versus nondiabetic group (50% versus 20%, respectively) (p = 0.004). C. albicans was the most prevalent species followed by C. glabrata in both groups. No significant association between diabetes mellitus and phospholipase activities was detected (p = 0.262), whereas high significant proteinase activities exhibited by Candida isolated from diabetic females were found (82.5%) (p = 0.000). Non-significant associations between any of the tested proteinase or phospholipase genes and diabetes mellitus were detected (p > 0.05). In conclusion, it is noticed that the incidence of C. glabrata causing VVC is increased. The higher prevalence of vaginal candidiasis among diabetics could be related to the increased aspartyl proteinase production in this group of patients.

Managing Red Oak (Quercus rubra L.) Reduces Sensitivity to Climatic Stress

  • Chhin, Sophan
    • Journal of Forest and Environmental Science
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    • v.34 no.4
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    • pp.338-351
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    • 2018
  • This study was conducted in a long-term experimental forest in the central hardwoods region of southwestern Michigan to retrospectively examine the role of past forest management practices and climate on red oak (Quercus rubra L.) productivity. Initially, in 1971, plots within the experimental forest were treated separately with a clearcut and shelterwood regeneration harvest in an attempt to increase red oak regeneration. From 1987-1989, a new study was initiated within a portion of the clearcut and shelterwood plots to evaluate the effectiveness of additional oak crop tree release using mechanical and chemical applications. Cumulative diameter and mortality rates of 719 red oaks were monitored across the four silvicultural treatments: Clearcut-A (clearcut without additional release treatment), Clearcut-B (clearcut with additional release treatment), Shelterwood-A (shelterwood without additional release), and Shelterwood-B (shelterwood with additional release) plus an untreated control. Increment cores were obtained from red oak trees and neighboring competitor species. Tree-ring analyses (dendrochronology) were applied to examine the effect of these silvicultural treatments and climatic factors (temperature and precipitation) on red oak productivity. The results indicated that crop tree release following a clearcut or shelterwood harvest reduced mortality rates and thus increased survival of red oak. Red oak in control plots or plots only receiving the initial regeneration harvesting treatment and no additional competition release were negatively affected by climatic stress, which included summer moisture stress. In contrast, red oak in plots that received the competition release treatment from shade tolerant tree species not only had higher tree level productivity (i.e., tree basal area) and lower mortality rates, but were also relatively more resilient to climatic stress by showing limited or no associations between climate and growth.

Analysis of the Plant Community Structure in Gayasan National Park by the Ordination and Classification Technique (Ordination 및 Classification 방법에 의한 가야산지구의 식물군집구조분석)

  • 이경재;조재창;우종서
    • Korean Journal of Environment and Ecology
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    • v.3 no.1
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    • pp.28-41
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    • 1989
  • A survey of Hongryu-Dong and Chi-in district. Gaya National Park, was conducted using 40 sample sites of 500$m^2$ size. TWINSPAN classification confirmed a complex pattern of both local and geographical variation in the vegetation: Dry and wet community types. Within dry community types, two floristic assocation of Pinus densiflora were defined according to local variation. Within wet community types. two floristic association were defined according to altitude. Those associations can be further subdivided floristically into eight subassociation. The vegetation pattern presented by DCA ordination corresponds to one of TWINSPAN at the first two division. The DCA ordination was successful in separating Pinus densiflora from broad leaf forest. Ordination of samples produced arrangements reflectly environmental gradient of soil. The correlation between the first axe of DCA and soil moisture, soil acid, altitude, maximum species diversity and species diversity was significantly negative. The similarity index between each community was very low level.

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