Recent Zika Virus Isolates Induce Premature Differentiation of Neural Progenitors in Human Brain Organoids

The recent Zika virus (ZIKV) epidemic is associated with microcephaly in newborns. Although the connection between ZIKV and neurodevelopmental defects is widely recognized, the underlying mechanisms are poorly understood. Here we show that two recently isolated strains of ZIKV, an American strain from an infected fetal brain (FB-GWUH-2016) and a closely-related Asian strain (H/PF/2013), productively infect human iPSC-derived brain organoids. Both of these strains readily target to and replicate in proliferating ventricular zone (VZ) apical progenitors. The main phenotypic effect was premature differentiation of neural progenitors associated with centrosome perturbation, even during early stages of infection, leading to progenitor depletion, disruption of the VZ, impaired neurogenesis, and cortical thinning. The infection pattern and cellular outcome differ from those seen with the extensively passaged ZIKV strain MR766. The structural changes we see after infection with these more recently isolated viral strains closely resemble those seen in ZIKV-associated microcephaly.Peer reviewe

Innovation for sale: New perspectives on what motivates mergers and acquisitions

OBJECTIVES OF THE STUDY Contradicting the traditional view of innovativeness as a born-with quality, recent vision in the market argues for the option of buying into innovation. This thesis aims to contribute to the existing literature by providing empirical evidence on the motivational role of innovation in M&A decisions. Consequently, the purpose of this thesis is to examine the effect of acquisition activity and especially acquisitions of innovative targets on post-acquisition innovation and stock return performance of the acquirers. Furthermore, the main drivers behind the effect are examined. DATA AND METHODOLOGY This thesis utilizes patent data from the NBER Patent Citations Database and M&A data from the SDC Platinum mergers and acquisitions database. The final sample contains 478 non-U.S. companies with approximately 9 900 completed acquisitions between 1990 and 2006. In this thesis, the NBER database is exceptionally exploited in a study of innovation acquisitions of non-U.S. firms. My analysis is mainly based on ordinary least square regressions (OLS) of innovation and stock return performance as dependent variable and M&A Volume and characteristics of innovation acquisitions as independent variables. FINDINGS OF THE STUDY The findings suggest that M&A activity has a significant positive impact on the innovation performance of the acquirers in the high technology industries. Moreover, a positive phenomenon is found for the whole sample when the target in the acquisition is considered as innovative. The main drivers behind the positive effect seem to be the size of the target's knowledge base and the relatedness of the target's and acquirer's knowledge bases. The results of this thesis also lend support to the value creative nature of innovation acquisitions as acquirers of innovative targets experience significantly higher announcement returns than acquirers of non-innovative targets