Technology platform strategies offer a novel way to orchestrate a rich portfolio of contributions made by the many independent actors who form an ecosystem of heterogeneous complementors around a ...stable platform core. This form of organising has been successfully used in smartphone, gaming, commercial software, and industrial sectors. Technology ecosystems require stability and homogeneity to leverage common investments in standard components, but they also need variability and heterogeneity to meet evolving market demand. Although the required balance between stability and evolvability in the ecosystem has been addressed conceptually in the literature, we have less understanding of its underlying mechanics or appropriate governance. Through an extensive case study of a business software ecosystem consisting of a major multinational manufacturer of enterprise resource planning software at the core and a heterogeneous system of independent implementation partners and solution developers on the periphery, our research identifies three salient tensions that characterize the ecosystem: standard–variety, control–autonomy, and collective–individual. We then highlight the specific ecosystem governance mechanisms designed to simultaneously manage desirable and undesirable variance across each tension. Paradoxical tensions may manifest as dualities, where tensions are framed as complementary and mutually enabling. Alternatively, they may manifest as dualisms, where actors are faced with contradictory and disabling “either…or” decisions. We identify conditions where latent, complementary tensions become manifest as salient, contradictory tensions. By identifying conditions in which complementary logics are overshadowed by contradictory logics, our study further contributes to the understanding of the dynamics of technology ecosystems, as well as the effective design of technology ecosystem governance that can explicitly embrace paradoxical tensions toward generative outcomes.
Sporothrix schenckii is the species responsible for sporotrichosis, a fungal infection caused by the traumatic implantation of this dimorphic fungus. Recent molecular studies have demonstrated that ...this species constitutes a complex of numerous phylogenetic species. Since the delineation of such species could be of extreme importance from a clinical point of view, we have studied a total of 127 isolates, most of which were received as S. schenckii, including the available type strains of species currently considered synonyms, and also some close morphological species. We have phenotypically characterized all these isolates using different culture media, growth rates at different temperatures, and numerous nutritional tests and compared their calmodulin gene sequences. The molecular analysis revealed that Sporothrix albicans, S. inflata, and S. schenckii var. luriei are species that are clearly different from S. schenckii. The combination of these phenetic and genetic approaches allowed us to propose the new species Sporothrix brasiliensis, S. globosa, and S. mexicana. The key phenotypic features for recognizing these species are the morphology of the sessile pigmented conidia, growth at 30, 35, and 37°C, and the assimilation of sucrose, raffinose, and ribitol.
Pseudallescheria boydii (anamorph Scedosporium apiospermum) is the species responsible for human scedosporiosis, a fungal infection with a high mortality rate and which is difficult to treat. ...Recently, it has been demonstrated that high genetic variation exists within this species. We have performed a morphological and molecular study involving numerous strains of clinical or environmental origins and from different countries. The analysis of partial sequences of the {szligbeta}-tubulin (two loci) and calmodulin genes and the internal transcribed spacer region of the rRNA gene has demonstrated that P. boydii is a species complex. The combined analysis of the sequences of the four loci of 60 strains has showed the presence of 44 haplotypes in the ingroup. Three species morphologically related to P. boydii sensu stricto, i.e., Pseudallescheria angusta, Pseudallescheria ellipsoidea, and Pseudallescheria fusoidea, which had previously been considered synonyms, could be differentiated genetically from P. boydii in our study. It is relevant that two of the three strains now included in P. ellipsoidea have caused invasive infections. The species Pseudallescheria minutispora and Scedosporium aurantiacum are clearly phylogenetically separated from the other species studied and are here proposed as new. Morphological features support this proposal. All the strains included in S. aurantiacum species have a clinical origin, while those included in P. minutispora are environmental. Further studies are needed to demonstrate whether all the species included in the P. boydii complex have different clinical spectra and antifungal susceptibility.
Based on the morphological, physiologic, and molecular (β-tubulin gene) study of 141 isolates of the Pseudallescheria boydii species complex (including several synonyms) and relatives, the new ...species Scedosporium dehoogii is proposed. Scedosporium apiospermum and P. boydii are considered two different species and the new name Scedosporium boydii is proposed for the anamorph of the latter species. A summary of the key morphological and physiological features for distinguishing the species of Pseudallescheria/Scedosporium is provided.
Abstract The in vitro antifungal susceptibility of a set of 99 clinical isolates of Curvularia was tested against 9 drugs using a reference microdilution method. The isolates had been identified ...previously to species level by comparing their ITS rDNA and glyceraldehyde-3-phosphate dehydrogenase gene sequences with those of reference strains. We were able to reliably identify 73.2% of the isolates, the most frequent species being Curvularia aeria , Curvularia geniculata / Curvularia senegalensis , Curvularia lunata , Curvularia inaequalis , Curvularia verruculosa , and Curvularia borreriae . Most of these isolates had been recovered from nasal sinus, which is generally considered one of the most frequent sites of infection by these fungi. In addition, at least 3 phylogenetic species that have not yet been formally described were detected. The most active drugs were the echinocandins, amphotericin B, and posaconazole, whereas voriconazole and itraconazole showed poor activity.
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