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New Strain (new + strain)
Selected AbstractsNew severe strains of Melon necrotic spot virus: symptomatology and sequencingPLANT PATHOLOGY, Issue 5 2005C. Kubo New strains of Melon necrotic spot virus (MNSV), designated MNSV-YS and MNSV-KS, caused much more severe growth retardation on melon plants than MNSV-NH, which was previously reported as the most severe strain of MNSV in Japan. MNSV-YS spread much more quickly than MNSV-NH in infected plants, and induced more severe growth retardation, even though the appearance of necrotic lesions on inoculated cotyledons was much slower. MNSV-KS had properties intermediate between those of the other two strains. The results suggest that faster-spreading strains can multiply more rapidly as a result of lower levels of activity in inducing necrotic lesions in melon plants. The complete sequences of MNSV-YS and MNSV-KS were determined, and an RT,PCR,RFLP method based on these sequences was successfully developed to detect and discriminate between the three strains. [source] Optimization of culture conditions for glucose oxidase production by a Penicillium chrysogenum SRT 19 strainENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 1 2010Ragini G. Bodade Abstract The enzyme glucose oxidase (GOD) has been used for a variety of biotechnological applications in food and pharmaceutical industries. In this study, the optimization of extracellular GOD production was carried out in a Penicillium chrysogenum SRT 19 strain isolated from contaminated and decaying cheese samples. Maximum GOD production was attained at pH 6 and 20°C in fermentation broth after 72,h of incubation. The effects of metal ions and sugars were screened for the induction of higher GOD production. The results revealed that glucose and lactose give the highest production of enzyme (0.670 and 0.552,U/mL, respectively) as compared with other sugars (sucrose, cellulose, mannitol and fructose). Out of the seven metal ions studied, CaCO3 (1.123,U/mL) and FeSO4 (0.822,U/mL) act as modulators, while MgSO4 (0.535,U/mL), CuSO4 (0.498,U/mL), HgCl2 (0.476,U/mL), ZnSO4 (0.457,U/mL) and BaSO4 (0.422,U/mL) yield lower production. The study therefore suggests that a strain of P. chrysogenum SRT 19 can be used as a new strain for GOD production. [source] A new method for assessing high-temperature crack growthFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 9 2005A. J. FOOKES ABSTRACT Experimental creep crack growth (CCG) test data are obtained by following standards that characterize CCG rates using the C* parameter. Such data are then used in high-temperature failure assessment procedures. An alternative approach to defect assessment at high-temperature failure is an extension of the R6 failure assessment diagram (FAD). At high temperature, creep toughness, Kcmat, can be estimated from CCG tests and replaces low-temperature toughness in R6. This approach has the advantage that it is not necessary to establish a creep fracture regime, such as small-scale, primary or widespread creep. Also, a new strain-based FAD has been developed, potentially allowing variations of stress and temperature to be accommodated. In this paper, the results of a series of crack growth tests performed on ex-service 316H stainless steel at 550 °C are examined in the light of the limitations imposed by ASTM for CCG testing. The results are then explored in terms of toughness and presented in FADs. [source] Environmental factors shaping the ecological niches of ammonia-oxidizing archaeaFEMS MICROBIOLOGY REVIEWS, Issue 5 2009Tuba H. Erguder Abstract For more than 100 years it was believed that bacteria were the only group responsible for the oxidation of ammonia. However, recently, a new strain of archaea bearing a putative ammonia monooxygenase subunit A (amoA) gene and able to oxidize ammonia was isolated from a marine aquarium tank. Ammonia-oxidizing archaea (AOA) were subsequently discovered in many ecosystems of varied characteristics and even found as the predominant causal organisms in some environments. Here, we summarize the current knowledge on the environmental conditions related to the presence of AOA and discuss the possible site-related properties. Considering these data, we deduct the possible niches of AOA based on pH, sulfide and phosphate levels. It is proposed that the AOA might be important actors within the nitrogen cycle in low-nutrient, low-pH, and sulfide-containing environments. [source] Biological and Molecular Characterization of Melon-Infecting Kyuri Green Mottle Mosaic Virus in IndonesiaJOURNAL OF PHYTOPATHOLOGY, Issue 10 2005B. S. Daryono Abstract Melon (Cucumis melo L.) plants showing fruit deformation and mosaic symptoms were found in Java, Indonesia, in 2001. Leaf dips of the symptomatic melon tissue revealed rod-shaped viral particles 300 × 18 nm in size. Biological and serological data described in this study indicate that the virus belonged to the genus tobamovirus and was related to the kyuri green mottle mosaic virus (KGMMV). The genome of the virus has been completely sequenced, consisting of 6512 nucleotides and was compared in detail with KGMMV-C1 and KGMMV-Y. The sequence of their 5,- and 3,- non-coding regions (NCRs) were 91% and 94% identical to KGMMV-C1, and only 82% and 95% identical to KGMMV-Y respectively. The amino acid sequence of the shorter and longer RNA replicase components, movement protein and coat protein were 94%, 91%, 95% and 94% identical to KGMMV-C1 and 93%, 89%, 91% and 85% identical of KGMMV-Y respectively. The results from phylogenetic analysis of the coding regions revealed that KGMMV-YM is a new strain of KGMMV. This is the first report of the complete nucleotide sequence and analysis of genome organization for KGMMV isolated in anywhere in South-East Asia. [source] Characterization of a strain of Apple stem grooving virus in Actinidia chinensis from ChinaPLANT PATHOLOGY, Issue 3 2003G. R. G. Clover A new strain of Apple stem grooving virus (ASGV) has been identified in Actinidia chinensis imported from China. The leaves of these plants exhibited a variety of symptoms including interveinal mottling, chlorotic mosaics and ringspots. Capillovirus-like particles were observed under the electron microscope, and the virus could be mechanically transmitted to a range of herbaceous indicators. The virus was detected using ELISA with antisera raised against ASGV. Sequencing of the virus revealed that it had more than 95% amino acid identity with ASGV in the putative coat and movement proteins. From the morphological, transmission, serological and molecular evidence, it was concluded that the virus is a strain of ASGV. It is not known how this strain of ASGV is transmitted, other than by grafting, nor is it known what effect the virus has on the growth of infected vines. The Actinidia -infecting strain of ASGV does not occur in New Zealand, and infected plants will not be released from quarantine. The detection methods used during the research will assist quarantine and the safe movement of breeding material. [source] Cultivation of methanotrophic bacteria in opposing gradients of methane and oxygenFEMS MICROBIOLOGY ECOLOGY, Issue 3 2006Ingeborg Bussmann Abstract In sediments, methane-oxidizing bacteria live in opposing gradients of methane and oxygen. In such a gradient system, the fluxes of methane and oxygen are controlled by diffusion and consumption rates, and the rate-limiting substrate is maintained at a minimum concentration at the layer of consumption. Opposing gradients of methane and oxygen were mimicked in a specific cultivation set-up in which growth of methanotrophic bacteria occurred as a sharp band at either c. 5 or 20 mm below the air-exposed end. Two new strains of methanotrophic bacteria were isolated with this system. One isolate, strain LC 1, belonged to the Methylomonas genus (type I methantroph) and contained soluble methane mono-oxygenase. Another isolate, strain LC 2, was related to the Methylobacter group (type I methantroph), as determined by 16S rRNA gene and pmoA sequence similarities. However, the partial pmoA sequence was only 86% related to cultured Methylobacter species. This strain accumulated significant amounts of formaldehyde in conventional cultivation with methane and oxygen, which may explain why it is preferentially enriched in a gradient cultivation system. [source] Molecular characterization of adenovirus circulating in Central and South America during the 2006,2008 periodINFLUENZA AND OTHER RESPIRATORY VIRUSES, Issue 6 2009Josefina García Background, Human Adenoviruses are recognized pathogens, causing a broad spectrum of diseases. Serotype identification is critical for epidemiological surveillance, detection of new strains and understanding of HAdvs pathogenesis. Little data is available about HAdvs subtypes in Latin America. Methods, In this study, we have molecularly characterized 213 adenoviruses collected from ILI presenting patients, during 2006-08, in Central and South America. Results, Our results indicate that 161(76%) adenoviruses belong to subgroup C, 45 (21%) to subgroup B and 7 (3%) to subtype E4. [source] Teasing Out the Lessons of the 1960s: Family Diversity and Family PrivilegeJOURNAL OF MARRIAGE AND FAMILY, Issue 3 2000Stephen R. Marks The tumult of the 1960s brought new strains of cultural relativism. I survey the continuing impact of some of these strains on family studies, focusing especially on the study of family diversity as an offshoot of the relativistic project. A dominant discourse still drives much of our work, however, and I illustrate it with some recent examples. The diversity agenda is hampered too often by unintended erasures of large categories of people in nondominant family arrangements. As a corrective to this tendency, I propose an agenda to study family privilege and entitlement, that is, to treat it as a "social problem" much as we treat poverty or juvenile delinquency. I illustrate with my own narrative of how I learned privilege and entitlement growing up male in a White, Jewish, upper-middle-class family. I end with some recommendations about how we might bring this agenda into our research and writing. [source] Molecular epidemiology of hepatitis A in St. Petersburg, Russia, 1997,2003JOURNAL OF MEDICAL VIROLOGY, Issue 6 2007Irja Davidkin Abstract The molecular epidemiology of hepatitis A virus (HAV) strains circulating in the St. Petersburg and Karelia regions was studied during 1997,2003. Hepatitis A virus RNA was isolated from both clinical samples (stools or sera) and environmental samples (sewage water). RT-PCR was carried out using different primer pairs from the VP1/2A and VP1 genomic regions, the variable parts of the HAV genome. PCR products were sequenced and 306 nucleotides from the VP1/2A and 332 nucleotides from the VP1 region were used for phylogenetic analysis. The results show that the IA subtype was the most common during the follow-up period: >90% of the isolated HAV strains belonged to that subtype. The HAV strains found in intravenous drug users belonged to subtypes IA and IIIA. Only one out of a total of 88 sequenced strains was of the IB subtype. The subtypes IB and IIIA were found only in 2001,2003, which suggests that new strains were introduced into the endemic situation. The results indicate the usefulness of molecular epidemiological methods in studying changes in the circulating HAV strains and in tracing transmission routes. J. Med. Virol. 79: 657,662, 2007. © 2007 Wiley-Liss, Inc. [source] Different transmission patterns of hepatitis A virus for two main risk groups as evidenced by molecular cluster analysis,JOURNAL OF MEDICAL VIROLOGY, Issue 5 2007Grace Tjon Abstract Men who have sex with men and traveling children are the most important risk groups for transmission of hepatitis A virus (HAV) in Amsterdam, The Netherlands. Between these two risk groups, different HAV genotypes are found. In this study the patterns of introduction and transmission of HAV were investigated in the two groups. HAV sequences from Amsterdam patients were divided according to risk: (I) travelers and their contacts, (II) homosexual men and their contacts. The sequences in each risk group were then grouped into clusters based on the genetic distances between the sequences. Among travelers many sporadic cases were found, the clusters were small, and introduced frequently into the population, mostly in the second half of each calendar year, indicating a seasonal pattern of introduction and transmission after the summer holidays. Among men who have sex with men the clusters were bigger and remained present for a longer time; sporadic cases were few, and introduction of new strains occurred only occasionally but throughout the year. Our findings indicate that new HAV strains are frequently imported into Amsterdam by travelers, but they are limited in the extent and season of their spread. In contrast, HAV is only occasionally imported into the male homosexual and bisexual population, but remains endemic and spreads to a large number of individuals without a seasonal pattern. J. Med. Virol. 79:488,494, 2007. © 2007 Wiley-Liss, Inc. [source] | ||||||||||