COCHLIOBOLUS SATIVUS: III. EFFECT OF ULTRAVIOLET RADIATION

1960 ◽  
Vol 38 (3) ◽  
pp. 275-282 ◽  
Author(s):  
R. D. Tinline ◽  
J. F. Stauffer ◽  
J. G. Dickson
Keyword(s):  
Ultraviolet Radiation ◽  
Ultraviolet Light ◽  
Aerial Mycelium ◽  
Mutagenic Effect ◽  
Cochliobolus Sativus ◽  
Highly Pathogenic ◽  
Wheat Seedlings ◽  
Rate Of Growth ◽  
High Doses ◽  
Sporulation Rate

The lethal and mutagenic effect of ultraviolet light on two isolates of Cochliobolus sativus was studied. Conidia of a dark-spored strain were considerably more resistant to high doses of radiation than those of a white-spored strain. Ultraviolet radiation increased the frequency of mutation in the fungus. Mutants were recovered that differed from their parents in degree of sporulation, rate of growth, pigmentation, amount of aerial mycelium, topography and consistency of colony, and pathogenicity to wheat seedlings. Tetrads from crosses between weakly and highly pathogenic strains indicated that pathogenicity was not a clearly segregating character.

COCHLIOBOLUS SATIVUS: IV. DRUG-RESISTANT, COLOR, AND NUTRITIONALLY EXACTING MUTANTS

1961 ◽  
Vol 39 (7) ◽  
pp. 1695-1704 ◽  
Author(s):  
R. D. Tinline
Keyword(s):  
Ultraviolet Radiation ◽  
Spontaneous Mutation ◽  
Resistant Mutant ◽  
Cochliobolus Sativus ◽  
Nutritional Deficiencies ◽  
Drug Resistant ◽  
Wild Type ◽  
Wheat Seedlings ◽  
Isolation Technique ◽  
Hyphal Tip

Auxotrophic mutants of Cochliobolus sativus were obtained from survivors of ultraviolet radiation by a modified total-isolation technique. Five or six hyphal tip isolations made from each survivor were tested for nutritional deficiencies. Although 0.48% of the survivors yielded auxotrophs, only about one-third of the hyphal tip isolations from these survivors were auxotrophic. Apparently, mutation in a multinucleate propagule resulted in a heterokaryotic culture and only some of the isolations from a culture were homokaryotic for the mutation. Some of the mutants were morphologically distinct from their parent and one, a methionineless strain, had white spores. Results indicated that recurrent requirements for growth occurred at different mutational sites.A strain resistant to the antibiotic anisomycin appeared as a spontaneous mutation. This strain grew at 1500 and its spores germinated at 1750 p.p.m.; wild-type isolates grew only at 75 and their spores germinated at 100 p.p.m. of the drug. The resistant mutant was pathogenic to wheat seedlings.

The influence of acridine dyes and caffeine on recovery from ultraviolet damage in Eudorina elegans

1975 ◽  
Vol 21 (11) ◽  
pp. 1849-1854 ◽  
Author(s):  
C. L. Kemp ◽  
K. M. Malloy
Keyword(s):  
Dna Synthesis ◽  
Acridine Orange ◽  
Ultraviolet Light ◽  
Ultraviolet Irradiation ◽  
Repair Process ◽  
Repair System ◽  
Acridine Dyes ◽  
Dark Survival ◽  
High Doses ◽  
Ultraviolet Damage

Caffeine and the acridine dyes, acridine orange and acriflavine, were used to examine the repair potential in Eudorina elegans following ultraviolet irradiation. Acridines blocked photoreactivation primarily as a result of absorption of photoreactivating wavelengths, but acridines did not influence dark survival. Therefore, an acridine-sensitive excision–resynthesis–repair process is absent in Eudorina.Caffeine decreased both dark and light survival, the latter only after relatively high doses of ultraviolet light were used for inactivation. The caffeine-sensitive repair process appears to function most actively when the organisms are engaged in DNA synthesis, indicating that a postreplication–repair system exists in Eudorina. However, the data suggest that a repair system not associated with the DNA synthetic phases may also exist.

The mutagenic effect of ultraviolet radiation and nitrous acid onMycobacterium phlei

1966 ◽  
Vol 11 (3) ◽  
pp. 163-168 ◽  
Author(s):  
Miluše Radochová ◽  
J. Koníček ◽  
I. Málek
Keyword(s):  
Ultraviolet Radiation ◽  
Nitrous Acid ◽  
Mutagenic Effect

Mutagenic effect of ultraviolet radiation on the non-acid-fast strain ofMycobacterium phlei

1968 ◽  
Vol 13 (4) ◽  
pp. 282-287 ◽  
Author(s):  
J. Koníček ◽  
I. Málek
Keyword(s):  
Ultraviolet Radiation ◽  
Mutagenic Effect ◽  
Strain Ofmycobacterium

Damage Due to Solar Ultraviolet Radiation in the Brittlestar Ophioderma Brevispinum (Echinodermata: Ophiuroidea)

1998 ◽  
Vol 78 (2) ◽  
pp. 681-684 ◽  
Author(s):  
Sönke Johnsen ◽  
William M. Kier
Keyword(s):  
North Carolina ◽  
Ultraviolet Radiation ◽  
Ultraviolet Light ◽  
Control Treatment ◽  
Solar Ultraviolet Radiation ◽  
Field Station ◽  
The North ◽  
North Carolina Coast ◽  
Behavioural Characteristics ◽  
Solar Ultraviolet

Many morphological, chemical, and behavioural characteristics of echinoderms have been implicated as defences against ultraviolet light, though no studies have investigated whether adult echinoderms are damaged by this form of radiation. This study tests whether the brittlestar Ophioderma brevispinum (Ophiuroidea: Echinodermata) is damaged by solar ultraviolet radiation. Specimens of O. brevispinum were exposed to sunlight at a field station on the North Carolina coast. After 4 d of exposure, 12 out of 13 animals were dead and the remaining animal was moderately damaged. The animals in the control treatment, protected by a UV-opaque filter, suffered almost no damage.

scholarly journals Application of the CIE L*a*b* method for the evaluation of the colour of fried products from potato tubers exposed to C band ultraviolet light

2019 ◽  
Vol 132 ◽  
pp. 02004 ◽  
Author(s):  
Piotr Nawara ◽  
Tomasz Jakubowski ◽  
Zygmunt Sobol
Keyword(s):  
Statistical Analysis ◽  
Ultraviolet Radiation ◽  
Ultraviolet Light ◽  
Raw Material ◽  
Potato Tubers ◽  
Significance Level ◽  
B Method ◽  
Technological Treatment ◽  
Potato Products ◽  
Qualitative Changes

Colour evaluation, using its numerous parameters, is applied to assess qualitative changes of products resulting from the use of specific technological treatment. The study investigates the possibility of using the CIE L*a*b* method to determine selected colour coefficients of fried potato products. Statistical analysis of the results was performed at the assumed significance level of α = 0.05. It was demonstrated that the method proposed (CIE L*a*b*) is effective in evaluating the colour of French fries modified with the use of raw material exposed to ultraviolet radiation in the C band.

Study on Anti-Ultraviolet Radiation Aging Property of TiO2 Modified Asphalt

2011 ◽  
Vol 306-307 ◽  
pp. 951-955 ◽  
Author(s):  
Shi Shuang Sun ◽  
Yan Min Wang ◽  
Ai Qin Zhang
Keyword(s):  
Ultraviolet Radiation ◽  
Ultraviolet Light ◽  
Softening Point ◽  
Radiation Environment ◽  
Modified Asphalt ◽  
Performance Indexes ◽  
Before And After ◽  
Aging Property ◽  
Modify Asphalt

In order to decrease the disadvantageous effect of ultraviolet light to asphalt, nano-scaled TiO2 was selected as modifier to modify asphalt. The photooxidation properties of the modified asphalt were examined in a home-made ultraviolet radiation environment box. By comparing the before and after performance indexes of asphalt, the anti-photooxidation aging property of modified asphalt and the blank asphalt were studied. And the results showed that the sample of 5% TiO2 modified asphalt possesses more stable ductility and smaller softening point changing ratio.TiO2 doping can actively enhance the photooxidation properties of asphalt and TiO2 modified asphalt is capable of resisting photooxidation aging.

scholarly journals Toxin-positive Clostridium difficile latently infect mouse colonies and protect against highly pathogenic C. difficile

Gut ◽  
2017 ◽  
Vol 67 (5) ◽  
pp. 860-871 ◽  
Author(s):  
Lucie Etienne-Mesmin ◽  
Benoit Chassaing ◽  
Oluwaseyi Adekunle ◽  
Lisa M Mattei ◽  
Frederic D Bushman ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Disease Burden ◽  
Virulence Genes ◽  
Highly Pathogenic ◽  
Germ Free ◽  
Growth Properties ◽  
High Doses ◽  
Similar Growth ◽  
Overt Disease

ObjectiveClostridium difficile is a toxin-producing bacterium and a leading cause of antibiotic-associated disease. The ability of C. difficile to form spores and infect antibiotic-treated persons at low multiplicity of infection (MOI) underlies its large disease burden. However, C. difficile-induced disease might also result from long-harboured C. difficile that blooms in individuals administered antibiotics.DesignMice purchased from multiple vendors and repeatedly testing negative for this pathogen by quantitative PCR bloomed C. difficile following antibiotic treatment. This endogenous C. difficile strain, herein termed LEM1, which formed spores and produced toxin, was compared with highly pathogenic C. difficile strain VPI10463.ResultsWhole-genome sequencing revealed that LEM1 and VPI10463 shared 95% of their genes, including all known virulence genes. In contrast to VPI10463, LEM1 did not induce overt disease when administered to antibiotic-treated or germ-free mice, even at high doses. Rather, blooms of LEM1 correlated with survival following VPI10463 inoculation, and exogenous administration of LEM1 before or shortly following VPI10463 inoculation prevented C. difficile-induced death. Accordingly, despite similar growth properties in vitro, LEM1 strongly outcompeted VPI10463 in mice even at 100-fold lower inocula.ConclusionsThese results highlight the difficulty of determining whether individual cases of C. difficile infection resulted from a bloom of endogenous C. difficile or a new exposure to this pathogen. In addition to impacting the design of studies using mouse models of C. difficile-induced disease, this study identified, isolated and characterised an endogenous murine spore-forming C. difficile strain able to decrease colonisation, associated disease and death induced by a pathogenic C. difficile strain.

Suppressive effect of preirradiation with blue light on near ultraviolet light induced conidiation in Alternaria tomato

1986 ◽  
Vol 64 (4) ◽  
pp. 896-899 ◽  
Author(s):  
Tadashi Kumagai
Keyword(s):  
Ultraviolet Radiation ◽  
Ultraviolet Light ◽  
Blue Light ◽  
Action Spectrum ◽  
Light Response ◽  
Suppressive Effect ◽  
Ultraviolet Region ◽  
Near Ultraviolet ◽  
Blue Light Response ◽  
A Minor

Conidiophore formation in Alternaria tomato (Cke.) Weber (ATCC 38852) was induced by irradiation with near ultraviolet light, and conidia formed in subsequent darkness. However, blue light applied before the inductive near ultraviolet radiation suppressed the induction. Preirradiation with blue light just before the inductive near ultraviolet radiation was most suppressive. An action spectrum for this suppression showed a peak around 447 nm, with a shoulder between 400 and 440 nm, a minor peak around 478 nm in the blue region, and another near 385 nm in the near ultraviolet region. This action spectrum is very similar to the ubiquitous blue light response (cryptochrome).

Sign in / Sign up

Export Citation Format

Share Document