Evidence-based Medicine and Mechanistic Evidence: The Case of the Failed Rollout of Efavirenz in Zimbabwe

Evidence-based medicine (EBM) has long deemphasized mechanistic reasoning and pathophysiological rationale in assessing the effectiveness of interventions. The EBM+ movement has challenged this stance, arguing that evidence of mechanisms and comparative studies should both be seen as necessary and complementary. Advocates of EBM+ provide a combination of theoretical arguments and examples of mechanistic reasoning in medical research. However, EBM+ proponents have not provided recent examples of how downplaying mechanistic reasoning resulted in worse medical results than would have occurred otherwise. Such examples are necessary to make the case that EBM+ responds to a problem in clinical practice that urgently demands a solution. In light of this, we examine the failed rollout of efavirenz as a first-line HIV treatment in Zimbabwe as evidence of the importance of mechanistic reasoning in improving clinical practice and public health policy decisions. We suggest that this case is analogous to examples commonly given to support EBM.

Nanotechnology for a Sustainable Future: Addressing Global Challenges with the International Network4Sustainable Nanotechnology

Nanotechnology has important roles to play in international efforts in sustainability. We discuss how current and future capabilities in nanotechnology align with and support the United Nations' Sustainable Development Goals. We argue that, as a field, we can accelerate the progress toward these goals both directly through technological solutions and through our special interdisciplinary skills in communication and tackling difficult challenges. We discuss the roles of targeting solutions, technology translation, the circular economy, and a number of examples from national efforts around the world in reaching these goals. We have formed a network of leading nanocenters to address these challenges globally and seek to recruit others to join us.

Endowing university spin-offs pre-formation: Entrepreneurial capabilities for scientist-entrepreneurs

University spin-offs are important mechanisms for creating and capturing value from scientific inventions. Academic scientists are uniquely positioned to shape such opportunities long before the university spin-off is founded. To better understand how science-based university spin-offs can be endowed for success, the pre-formation stage of 30 ventures co-founded over a 40 year period by a star-scientist-entrepreneur is analysed by matching his 363 co-invented US patents granted to 1476 co-authored publications and these 30 ventures. Employing the extended case method, including the analysis of extensive archival data, iterative interviews, and this unique, longitudinal, multi-level dataset, existing dynamic capabilities theory is confronted and extended with evidence as to how a star-scientist-entrepreneur senses and shapes and seizes opportunities to endow university spin-offs pre-formation. A process model is developed depicting four pre-formation entrepreneurial capabilities with which these science-based university spin-offs are endowed for success. Recommendations are made for scientist-entrepreneurs, investors, university leadership, and for innovation policymakers.

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The pre-formation stage of 30 ventures co-founded by a star-scientist-entrepreneur is analysed.

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363 co-invented US patents granted are matched to 1476 co-authored publications and to these 30 ventures.

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Dynamic capabilities theory is extended to show how a star-scientist-entrepreneur senses, shapes, and seizes opportunities.

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A process model is developed depicting four pre-formation entrepreneurial capabilities.

Knowledge Diversity in the Emerging Global Bio-Nano Sector

As scientists are able to understand and manipulate ever smaller scales of matter, research in the fields of biotechnology and nanotechnology has converged to enable such radical innovations as lab-on-a-chip devices, targeted drug delivery, and other forms of minimally invasive therapy and diagnostics. This paper provides a descriptive overview of the emerging bio-nano sector, identifying what types of firms are entering, from what knowledge base, where they are located, and their strategic choices in terms of technological diversity and R&D strategy. The firms engaged in bio-nano research and development span the range from start-up firm to multinational pharmaceutical, biotech, chemical, and electronics firms: two thirds of bio-nano firms are relatively young and relatively small. The United States dominates this sector, with more than half of all bio-nano firms located in the USA. Even within this sector which epitomizes the convergence of technology, there is a broad range of technological diversity, with the most diverse firms overall coming from a base in electronics, the most diverse start-up firms coming from a base in nanomaterials, and the most narrowly focused firms coming from a biotechnology/pharmaceutical base. We find that hybridization has been the dominant knowledge diversity strategy, with 93% of the bio-nano firms with nano-patents holding multiclass patents.

Analysis of the multiple roles of gld-1 in germline development: interactions with the sex determination cascade and the glp-1 signaling pathway

The Caenorhabditis elegans gene gld-1 is essential for oocyte development; in gld-1 (null) hermaphrodites, a tumor forms where oogenesis would normally occur. We use genetic epistasis analysis to demonstrate that tumor formation is dependent on the sexual fate of the germline. When the germline sex determination pathway is set in the female mode (terminal fem/fog genes inactive), gld-1 (null) germ cells exit meiotic prophase and proliferate to form a tumor, but when the pathway is set in the male mode, they develop into sperm. We conclude that the gld-1 (null) phenotype is cell-type specific and that gld-1(+) acts at the end of the cascade to direct oogenesis. We also use cell ablation and epistasis analysis to examine the dependence of tumor formation on the glp-1 signaling pathway. Although glp-1 activity promotes tumor growth, it is not essential for tumor formation by gld-1 (null) germ cells. These data also reveal that gld-1(+) plays a nonessential (and sex nonspecific) role in regulating germ cell proliferation before their entry into meiosis. Thus gld-1(+) may negatively regulate proliferation at two distinct points in germ cell development: before entry into meiotic prophase in both sexes (nonessential premeiotic gld-1 function) and during meiotic prophase when the sex determination pathway is set in the female mode (essential meiotic gld-1 function).

The 87A7 chromomere. Identification of novel chromatin structures flanking the heat shock locus that may define the boundaries of higher order domains

The chromatin fiber of eukaryotic chromosomes is thought to be organized into a series of discrete domains or loops. To learn more about these large-scale structures, we have examined the sequence and chromatin organization of the DNA segments surrounding the two hsp 70 genes at the Drosophila melanogaster cytogenetic locus 87A7. These studies indicate that this heat shock locus is flanked on both the proximal and distal sides by novel chromatin structures, which we have called, respectively, scs and scs' (specialized chromatin structures). Each structure is defined by two sets of closely spaced nuclease-hypersensitive sites arranged around a central nuclease-resistant segment. Our findings suggest that these two structures define the proximal and distal boundaries of the 87A7 chromomere and, hence, may be one of the first examples of anchor points for the organization of eukaryotic chromosomes into a series of discrete higher order domains. Moreover, these structures may provide focal points both for the decondensation of the chromomere when the hsp 70 genes are induced by heat shock and for the subsequent rewinding and condensation of the chromomere during recovery from heat shock.