Search

Muscodor albus is an endophytic fungus, represented by a number of isolates from tropical tree and vine species in several of the world's rainforests, that produces volatile organic compounds (VOCs) with antibiotic activity. A new isolate, E-6, of this organism, with unusual biochemical and biological properties, has been obtained from the branches of a mature Guazuma ulmifolia (Sterculiaceae) tree growing in a dry tropical forest in SW Ecuador. This unique organism produces many VOCs not previously observed in other M. albus isolates, including butanoic acid, 2-methyl-; butanoic acid, 3-methyl-; 2-butenal, 2-methyl-; butanoic acid, 3-methylbutyl ester; 3-buten-1-ol, 3-methyl; guaiol; 1-octene, 3-ethyl-; formamide, N-(1-methylpropyl); and certain azulene and naphthalene derivatives. Some compounds usually seen in other M. albus isolates also appeared in the VOCs of isolate E-6, including caryophyllene; phenylethyl alcohol; acetic acid, 2-phenylethyl ester; bulnesene; and various propanoic acid, 2-methyl- derivatives. The biological activity of the VOCs of E-6 appears different from the original isolate of this fungus, CZ-620, since a Gram-positive bacterium was killed, and Sclerotinia sclerotiorum and Rhizoctonia solani were not. Scanning electron micrographs of the mycelium of isolate E-6 showed substantial intertwining of the hyphal strands. These strands seemed to be held together by an extracellular matrix accounting for the strong mat-like nature of the mycelium, which easily lifts off the agar surface upon transfer, unlike any other isolate of this fungus. The ITS-5.8S rDNA partial sequence data showed 99% similarity to the original M. albus strain CZ-620. For the first time, successful establishment of M. albus into its natural host, followed by recovery of the fungus, was accomplished in seedlings of G. ulmifolia. Overall, isolates of M. albus, including E-6, have chemical, biological and structural characteristics that make them potentially useful in medicine, agricultural and industrial applications.

Muscodor albus, an endophytic fungus originally isolated from Cinnamomum zeylanicum, produces a mixture of volatile organic compounds (VOCs) in culture and its spectrum of antimicrobial activity is broad. Using the original isolate of M. albus as a selection tool, it has been possible to find other culturally and biochemically unique wild-type isolates of this organism existing as endophytes in a variety of other plant species, including Grevillea pterifolia (fern-leafed grevillea), Kennedia mgriscans (snake vine) and Terminalia prostrata (nanka bakarra) growing in the northern reaches of the Northern Territory of Australia. Interestingly, none of the new isolates had a culture morphology that was identical to the original isolate, nevertheless each possessed hyphal characteristics that resembled that isolate. Furthermore, their ITS-5-8S rDNA sequences were 96-99 % identical to that of M. albus and the isolates were considered M. albus on the basis of the DNA sequence data. However, the VOCs produced by these new isolates greatly differed in quality from the original strain by virtue of the production of naphthalene, naphthalene, 1,1'-oxybis-, and one or more other compounds. In bioassays with a range of test micro-organisms, including fungi and bacteria, each isolate possessed biological activity but the range of activity was great. Artificial mixtures of some of the VOCs mimicked the effects of the VOCs of the fungus. The value of these observations to the biology and practical uses of M. albus in agriculture and other applications is discussed.

Theorem 4.1 Let HT ht be the free nilpotent group on n elements. Lemma 2.10 The set HT ht is a HT ht -Lie algebra. By definition, it is enough to show that it is closed under multiplication of scalars from HT ht . 4 The free cases In this section, we sketch a more straightforward proof to Corollary 1.5 in the special case where HT ht is a free nilpotent group on n elements, a proof which does not refer either to the CSP or to the strong approximation for unipotent groups. [Extracted from the article]

The aim of this article was to review the current knowledge relating to work-related musculoskeletal disorders (WRMDs) and non-fatal injuries in emergency medical technicians and paramedics (EMTs-Ps). A literature search was conducted in PubMed, Google Scholar, and Clinical Key. The annual prevalence of back pain ranged from 30% to 66%, and back injuries and contusions from 4% to 43%. Falls, slips, trips, and overexertion while lifting or carrying patients or instruments ranged from 10% to 56%, with overexertion being the most common injury. Risk factors were predominantly lifting, working in awkward postures, loading patients into the ambulance, and cardiopulmonary resuscitation procedures. Lack of job satisfaction and social support was associated with WRMDs and injuries. EMTs-Ps had the highest rate of worker compensation claim rates compared to other healthcare professionals. Positive ergonomic intervention results included electrically powered stretchers, backboard wheeler, descent control system, and the transfer sling. [ABSTRACT FROM AUTHOR]

Let F be a free pro- p non-abelian group, and let Δ be a commutative Noetherian complete local ring with a maximal ideal I such that char(Δ/I) = p > 0. Zubkov [Sibirsk. Mat. Zh. 28 (1987), pp. 64-69] showed that when p\neq 2, the pro- p congruence subgroup GL21(Δ) = ker (GL2(Δ) Δ → Δ/I → GL2(Δ/I)) admits a pro-p identity, i.e., there exists an element 1 ≠ w ∈ F that vanishes under any continuous homomorphism F → GL21(Δ). In this paper we investigate the case p = 2. The main result is that when char(Δ) = 2, the pro- 2 group GL21(Δ) admits a pro-2 identity. This result was obtained by the use of trace identities that originate in PI-theory. [ABSTRACT FROM AUTHOR]

BACKGROUND Sclerotium rolfsii is a soil‐borne phytopathogenic fungus that causes diseases in economically important crops. Eradication of the fungus is hampered by its wide range of hosts, as well as its capacity to form sclerotia. Recently, we have shown that the endophytic fungus Daldinia cf. concentrica emits biologically active volatile organic compounds (VOCs); we also demonstrated that one VOC, trans‐2‐octenal, was the most effective against various phytopathogenic fungi. Thus, the aim of this study was to examine the potential of this compound to control hyphae and sclerotia of S. rolfsii, both in vitro and in soil. RESULTS: We found that in vitro exposure of S. rolfsii mycelium to trans‐2‐octenal in air fully inhibits and kills the fungus. Elimination of sclerotia viability occurred at the same concentration, but direct contact between the sclerotia and the compound was needed. trans‐2‐Octenal also affected the viability of both hyphae and sclerotia of S. rolfsii in small pots containing loam soil. CONCLUSION: We suggest the use of trans‐2‐octenal as a novel compound to control S. rolfsii. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Mal Secco is a severe disease of citrus in which the fungus Plenodomus tracheiphilus (formerly Phoma tracheiphila) penetrates the vascular system of the host. In this study, we characterized the spatial dynamics of the disease in seven lemon orchards. A representative block of trees from each orchard was evaluated monthly during 3 consecutive years. In addition, scouts assessed disease severity in 75 orchards from three different geographical regions and tested for association between disease severity and measures of orchard management, environmental factors, cultural practices, and cultivar type. We assessed disease incidence and characteristics of spatial patterns using Ripley's K function and fitted logistic regression models for different neighboring tree structures followed by model selection methods to provide insight into the spatial and temporal dynamics of disease progress. We found different rates of disease spread in different orchards, which are most likely the result of differences in orchard management practices or less likely the result of differences in climatic conditions. There was an indication that agricultural tools contribute to spread of the disease within rows of trees. The results confirm that the lemon cultivar Interdonato is less susceptible compared with other citrus cultivars, and they suggest that the density of urban terrain surrounding each orchard is positively correlated with the severity of the disease. In contrast to our expectations, no correlation was found between the density of lemon orchards surrounding an orchard and the severity of the disease within it, which corroborates previous findings regarding the limited distribution of the disease. [ABSTRACT FROM AUTHOR]