32 research outputs found

    Information Sharing in Joint Research and Development

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    In today's science-driven industries, such as the semiconductor industry, firms are increasingly engaged in across-firm research and development projects in the form of a research consortium or a strategic alliance. Those collaboration processes, however, have complex aspects due to the competing relationship of the firms in product markets and will not be successful unless the participating firms have enough incentives to reveal their private information and to exert sufficient efforts. The paper attempts to explore the conditions under which firms have enough incentives to reveal their information and/or to expend collaborative efforts. Three existing economic models are examined for this purpose. It is argued that those incentives depend upon the nature of competition in the product markets, information structure, and the way that each firm's private information affects this competition. The models examined in the paper suggest that some mechanism is necessary to evaluate private technical information of each firm and to convey it to the other firms without distortion. This conclusion coincides with the observed fact that a neutral third-party plays an indispensable role in a successful research consortium.

    A single amino acid polymorphism in a conserved effector of the multihost blast fungus pathogen expands host-target binding spectrum

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    Accelerated gene evolution is a hallmark of pathogen adaptation and specialization following host-jumps. However, the molecular processes associated with adaptive evolution between host-specific lineages of a multihost plant pathogen remain poorly understood. In the blast fungus Magnaporthe oryzae (Syn. Pyricularia oryzae), host specialization on different grass hosts is generally associated with dynamic patterns of gain and loss of virulence effector genes that tend to define the distinct genetic lineages of this pathogen. Here, we unravelled the biochemical and structural basis of adaptive evolution of APikL2, an exceptionally conserved paralog of the well-studied rice-lineage specific effector AVR-Pik. Whereas AVR-Pik and other members of the six-gene AVR-Pik family show specific patterns of presence/absence polymorphisms between grass-specific lineages of M. oryzae, APikL2 stands out by being ubiquitously present in all blast fungus lineages from 13 different host species. Using biochemical, biophysical and structural biology methods, we show that a single aspartate to asparagine polymorphism expands the binding spectrum of APikL2 to host proteins of the heavy-metal associated (HMA) domain family. This mutation maps to one of the APikL2-HMA binding interfaces and contributes to an altered hydrogen-bonding network. By combining phylogenetic ancestral reconstruction with an analysis of the structural consequences of allelic diversification, we revealed a common mechanism of effector specialization in the AVR-Pik/APikL2 family that involves two major HMA-binding interfaces. Together, our findings provide a detailed molecular evolution and structural biology framework for diversification and adaptation of a fungal pathogen effector family following host-jumps

    Nephrotoxicity with VCM and Nephrotoxins

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    There is a growing concern about the relationship between vancomycin-associated nephrotoxicity (VAN) and concomitant use of nephrotoxins. We examined this relationship by combined retrospective analyses of two real-world databases. Initially, the FDA Adverse Event Reporting System (FAERS) was analyzed for the effects of concomitant use of one or more nephrotoxins on VAN and the types of combinations of nephrotoxins that exacerbate VAN. Next, electronic medical records (EMRs) of patients who received vancomycin (VCM) at Tokushima University Hospital between January 2006 and March 2019 were examined to confirm the FAERS analysis. An elevated reporting odds ratio (ROR) was observed with increases in the number of nephrotoxins administered (VCM + one nephrotoxin, adjusted ROR (95% confidence interval [CI]) 1.67 [1.51–1.85]; VCM + ≥ 2 nephrotoxins, adjusted ROR [95% CI] 1.54 [1.37–1.73]) in FAERS. EMRs analysis showed that the number of nephrotoxins was associated with higher incidences of VAN [odds ratio: 1.99; 95% CI: 1.42–2.78]. Overall, concomitant use of nephrotoxins was associated with an increased incidence of VAN, especially when at least one of those nephrotoxins was a renal hypoperfusion medication (furosemide, non-steroidal anti-inflammatory drugs, and vasopressors). The concomitant use of multiple nephrotoxins, especially including renal hypoperfusion medication, should be avoided to prevent VAN

    Concomitant Use of Multiple Nephrotoxins including Renal Hypoperfusion Medications Causes Vancomycin-Associated Nephrotoxicity: Combined Retrospective Analyses of Two Real-World Databases

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    There is a growing concern about the relationship between vancomycin-associated nephrotoxicity (VAN) and concomitant use of nephrotoxins. We examined this relationship by combined retrospective analyses of two real-world databases. Initially, the FDA Adverse Event Reporting System (FAERS) was analyzed for the effects of concomitant use of one or more nephrotoxins on VAN and the types of combinations of nephrotoxins that exacerbate VAN. Next, electronic medical records (EMRs) of patients who received vancomycin (VCM) at Tokushima University Hospital between January 2006 and March 2019 were examined to confirm the FAERS analysis. An elevated reporting odds ratio (ROR) was observed with increases in the number of nephrotoxins administered (VCM + one nephrotoxin, adjusted ROR (95% confidence interval [CI]) 1.67 [1.51-1.85]; VCM + ≥2 nephrotoxins, adjusted ROR [95% CI] 1.54 [1.37-1.73]) in FAERS. EMRs analysis showed that the number of nephrotoxins was associated with higher incidences of VAN [odds ratio: 1.99; 95% CI: 1.42-2.78]. Overall, concomitant use of nephrotoxins was associated with an increased incidence of VAN, especially when at least one of those nephrotoxins was a renal hypoperfusion medication (furosemide, non-steroidal anti-inflammatory drugs, and vasopressors). The concomitant use of multiple nephrotoxins, especially including renal hypoperfusion medication, should be avoided to prevent VAN

    Disentangling the complex gene interaction networks between rice and the blast fungus identifies a new pathogen effector

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    Studies focused solely on single organisms can fail to identify the networks underlying host–pathogen gene-for-gene interactions. Here, we integrate genetic analyses of rice (Oryza sativa, host) and rice blast fungus (Magnaporthe oryzae, pathogen) and uncover a new pathogen recognition specificity of the rice nucleotide-binding domain and leucine-rich repeat protein (NLR) immune receptor Pik, which mediates resistance to M. oryzae expressing the avirulence effector gene AVR-Pik. Rice Piks-1, encoded by an allele of Pik-1, recognizes a previously unidentified effector encoded by the M. oryzae avirulence gene AVR-Mgk1, which is found on a mini-chromosome. AVR-Mgk1 has no sequence similarity to known AVR-Pik effectors and is prone to deletion from the mini-chromosome mediated by repeated Inago2 retrotransposon sequences. AVR-Mgk1 is detected by Piks-1 and by other Pik-1 alleles known to recognize AVR-Pik effectors; recognition is mediated by AVR-Mgk1 binding to the integrated heavy metal-associated (HMA) domain of Piks-1 and other Pik-1 alleles. Our findings highlight how complex gene-for-gene interaction networks can be disentangled by applying forward genetics approaches simultaneously to the host and pathogen. We demonstrate dynamic coevolution between an NLR integrated domain and multiple families of effector proteins

    Multiple Translocation of the AVR-Pita Effector Gene among Chromosomes of the Rice Blast Fungus Magnaporthe oryzae and Related Species

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    Magnaporthe oryzae is the causal agent of rice blast disease, a devastating problem worldwide. This fungus has caused breakdown of resistance conferred by newly developed commercial cultivars. To address how the rice blast fungus adapts itself to new resistance genes so quickly, we examined chromosomal locations of AVR-Pita, a subtelomeric gene family corresponding to the Pita resistance gene, in various isolates of M. oryzae (including wheat and millet pathogens) and its related species. We found that AVR-Pita (AVR-Pita1 and AVR-Pita2) is highly variable in its genome location, occurring in chromosomes 1, 3, 4, 5, 6, 7, and supernumerary chromosomes, particularly in rice-infecting isolates. When expressed in M. oryzae, most of the AVR-Pita homologs could elicit Pita-mediated resistance, even those from non-rice isolates. AVR-Pita was flanked by a retrotransposon, which presumably contributed to its multiple translocation across the genome. On the other hand, family member AVR-Pita3, which lacks avirulence activity, was stably located on chromosome 7 in a vast majority of isolates. These results suggest that the diversification in genome location of AVR-Pita in the rice isolates is a consequence of recognition by Pita in rice. We propose a model that the multiple translocation of AVR-Pita may be associated with its frequent loss and recovery mediated by its transfer among individuals in asexual populations. This model implies that the high mobility of AVR-Pita is a key mechanism accounting for the rapid adaptation toward Pita. Dynamic adaptation of some fungal plant pathogens may be achieved by deletion and recovery of avirulence genes using a population as a unit of adaptation
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