12 research outputs found
Eight new Leptographium species associated with tree-infesting bark beetles in China
Leptographium spp. are anamorphs of Grosmannia residing in the order Ophiostomatales. These fungi are typically associated with bark-beetles and are common causal agents of sapstain in lumber and some are important tree pathogens. In this study, Leptographium spp. associated with bark beetles collected during a survey in Jilin and Yunnan provinces of China, were identified. Identifications were achieved using comparisons of morphological characters and DNA sequence data for the ITS2-partial LSU rDNA region, as well as the β-tubulin and EF-1α gene regions. Eight unknown species of Leptographium are recognised and described from conifer and hardwood hosts, associated with beetles including Ips subelongatus, Tomicus yunnanensis, Hylurgops minor, Polygraphus verrucifrons and a Pissodes sp. Six of the new species are morphologically and phylogenetically related to species known to occur in Asia such as G. yunnanense, L. bhutanense, L. bistatum and L. sinoprocerum. The remaining two taxa are related to those in a group containing G. americana and L. abietinum, found in North America. This study also provides the first report of L. pineti on Pinus kesiya in China
Modifications to PM-assisted Synchronous Reluctance Machine to Achieve Rare-Earth Free Heavy-duty Traction
Automotive applications require electrical machines designed for high torque density, wide speed range, and low cost. NdFeB magnets can achieve a high torque density and wide speed range, and however, they have a high cost. Therefore, this article explores the capability of rare-earth-free (REF) design through a PM-assisted synchronous reluctance (PM-SynRel) motor. A PM-SynRel design with NdFeB has been used in this study where the NdFeB magnets have been replaced with ferrite magnets. Then, several modifications on the rotor have been made to ensure mechanical safety. Thermal analysis has been conducted last to evaluate the temperatures in the different machine parts to avoid exceeding the required limits. Finally, a prototype has been made and tested to validate the simulation results
Parascedosporium and its relatives: phylogeny and ecological trends
The genus Scedosporium and its relatives comprising microascalean anamorphs with slimy conidia were studied. Graphium and Parascedosporium also belong to this complex, while teleomorphs are found in Pseudallescheria, Petriella, Petriellopsis, and Lophotrichus. Species complexes were clearly resolved by rDNA ITS sequencing. Significantly different ecological trends were observed between resolved species aggregates. The Pseudallescheria and Scedosporium prolificans clades were the only lineages with a marked opportunistic potential to mammals, while Petriella species were associated primarily with soil enriched by, e.g. dung. A consistent association with bark beetles was observed in the Graphium clade. The ex-type strain of Rhinocladium lesnei, CBS 108.10 was incorrectly implicated by Vuillemin (1910) in a case of human mycetoma; its sequence was identical to that of the ex-type strain of Parascedosporium tectonae, CBS 127.84
Barcoding and microcoding using "identiprimers" with Leptographium species
Leptographium species provide an ideal model to test the applications of a PCR microcoding system for differentiating species of other genera of ascomycetes. Leptographium species are closely related and share similar gross morphology. Probes designed for a PhyloChip for Leptographium have been transferred and tested as primers for PCR diagnostic against Leptographium species. The primers were combined with complementary universal primers to identify known and suspected undescribed species of Leptographium. The primer set was optimized for 56 species, including the three varieties of L. wageneri, then blind-tested against 10 random DNA samples. The protocols established in this study successfully identified species from the blind test as well as eight previously undescribed isolates of Leptographium. The undescribed isolates were identified as new species of Leptographium with the aid of the microcoding PCR identification system established in this study. The primers that were positive for each undescribed isolate were used to determine close relatives of these species and some of their biological characteristics. The transfer of oligonucleotides from a micro-array platform to a PCR diagnostic was successful, and the identification system is robust for both known and unknown species of Leptographium. © 2010 by The Mycological Society of America.Articl