Advances in drug potency and tailored therapeutics are promoting pharmaceutical manufacturing to transition from a traditional batch paradigm to more flexible continuous processing. Here we report ...the development of a multistep continuous-flow CGMP (current good manufacturing practices) process that produced 24 kilograms of prexasertib monolactate monohydrate suitable for use in human clinical trials. Eight continuous unit operations were conducted to produce the target at roughly 3 kilograms per day using small continuous reactors, extractors, evaporators, crystallizers, and filters in laboratory fume hoods. Success was enabled by advances in chemistry, engineering, analytical science, process modeling, and equipment design. Substantial technical and business drivers were identified, which merited the continuous process. The continuous process afforded improved performance and safety relative to batch processes and also improved containment of a highly potent compound.
Research Summary
In ecosystems, tensions between value creation and appropriation can arise when complementors form relationships with a partner that benefits from network effects. While creating ...value collectively, these relationships strengthen the network effects, which increase the partner's ability to appropriate value. We posit that complementors strategize their product offerings to benefit from the relationship with the partner while preserving bargaining power by keeping relationships with other partners as outside options. We examine book publishers' product portfolios in the Amazon Kindle e‐book and the printed book ecosystems. Our results illuminate specific product offering decisions by large publishers that are more protective of the printed book ecosystem and less conducive to Kindle's success. This research adds to the literature on interorganizational relationships, platform ecosystems, and managing digital innovations.
Managerial Summary
How do book publishers deal with Amazon? This paper compares book publishers' product offerings on Amazon's Kindle digital platform and in the physical print channel. We find that publishers offer high demand products as e‐books on Kindle to benefit from logistics savings. Yet, relative to small publishers, large publishers product decisions that support Kindle less, such as withholding some of their greatest revenue generating books. Such decisions could both limit Kindle's attractiveness to the consumers and preserve the economic viability of the print channel as an outside option. These findings improve our understanding of how companies can leverage their product portfolios to both benefit from digital technology efficiencies and maintain their bargaining power vis‐à‐vis digital platforms.
The use of silver nanoparticles (AgNPs) in antimicrobial applications, including a wide range of consumer goods and apparel, has attracted attention because of the unknown health and environmental ...risks associated with these emerging materials. Of particular concern is whether there are new risks that are a direct consequence of their nanoscale size. Identifying those risks associated with nanoscale structure has been difficult due to the fundamental challenge of detecting and monitoring nanoparticles in products or the environment. Here, we introduce a new strategy to directly monitor nanoparticles and their transformations under a variety of environmental conditions. These studies reveal unprecedented dynamic behavior of AgNPs on surfaces. Most notably, under ambient conditions at relative humidities greater than 50%, new silver nanoparticles form in the vicinity of the parent particles. This humidity-dependent formation of new particles was broadly observed for a variety of AgNPs and substrate surface coatings. We hypothesize that nanoparticle production occurs through a process involving three stages: (i) oxidation and dissolution of silver from the surface of the particle, (ii) diffusion of silver ion across the surface in an adsorbed water layer, and (iii) formation of new, smaller particles by chemical and/or photoreduction. Guided by these findings, we investigated non-nanoscale sources of silver such as wire, jewelry, and eating utensils that are placed in contact with surfaces and found that they also formed new nanoparticles. Copper objects display similar reactivity, suggesting that this phenomenon may be more general. These findings challenge conventional thinking about nanoparticle reactivity and imply that the production of new nanoparticles is an intrinsic property of the material that is not strongly size dependent. The discovery that AgNPs and CuNPs are generated spontaneously from manmade objects implies that humans have long been in direct contact with these nanomaterials and that macroscale objects represent a potential source of incidental nanoparticles in the environment.
METHANESULFONATE-SENSITIVE21 (MMS21) ligases having critical roles in stress protection and DNA endoreduplication/repair, respectively. To help identify their corresponding targets in Arabidopsis ...thaliana, we used siz1 and mms21 mutants for proteomic analyses of SUMOylated proteins enriched via an engineered SUMO1 isoform suitable for mass spectrometric studies. Through multiple data sets from seedlings grown at normal temperatures or exposed to heat stress, we identified over 1000 SUMO targets, most of which are nuclear localized. Whereas no targets could be assigned to MMS21, suggesting that it modifies only a few low abundance proteins, numerous targets could be assigned to SIZ1, including major transcription factors, coactivators/repressors, and chromatin modifiers connected to abiotic and biotic stress defense, some of which associate into multisubunit regulatory complexes. SIZ1 itself is also a target, but studies with mutants protected from SUMOylation failed to uncover a regulatory role. The catalog of SIZ1 substrates indicates that SUMOylation by this ligase provides stress protection by modifying a large array of key nuclear regulators.
Research Summary
We study product digitization as an impetus for firm strategy change. Product digitization can erode a firm's ability to differentiate through physical product attributes and prompts ...them to increase emphasis on nonphysical product attributes to sustain their competitive advantage. We expect this effect is pronounced among firms that have pursued a physical differentiation strategy prior to the digital age. However, we expect that countervailing forces exist such that the internal supply cost of and the external market demand for the nonphysical differentiator mitigate this effect. Evidence from publishers in the Amazon Kindle e‐book ecosystem supports our hypotheses. This study bridges the growing digital strategy literature and the classical competitive strategy literature. We discuss how our findings are relevant to a range of industries.
Managerial Summary
Many companies invest in superior physical product attributes to increase a customer's willingness‐to‐pay and entice purchase. However, when products become digitized—such as music streaming displacing CDs or e‐books replacing printed books—the effectiveness of physical product differentiation is diminished. We examine how book publishers manage this challenge at the advent of Amazon's Kindle e‐book technology. We find that publishers that have emphasized physical product attributes turn to emphasizing nonphysical product differentiation, namely, through offering more content. Yet, the extent of the strategy change is limited by the internal development cost of and the external demand for the nonphysical differentiator. We discuss how our findings are relevant to a range of settings, including both product and service companies.
A proteoform is a defined form of a protein derived from a given gene with a specific amino acid sequence and localized post‐translational modifications. In top‐down proteomic analyses, proteoforms ...are identified and quantified through mass spectrometric analysis of intact proteins. Recent technological developments have enabled comprehensive proteoform analyses in complex samples, and an increasing number of laboratories are adopting top‐down proteomic workflows. In this review, some recent advances are outlined and current challenges and future directions for the field are discussed.
Networks of no-take marine reserves (NTMRs) are widely advocated for preserving exploited fish stocks and for conserving biodiversity. We used underwater visual surveys of coral reef fish and benthic ...communities to quantify the short- to medium-term (5 to 30 years) ecological effects of the establishment of NTMRs within the Great Barrier Reef Marine Park (GBRMP). The density, mean length, and biomass of principal fishery species, coral trout (Plectropomus spp., Variola spp.), were consistently greater in NTMRs than on fished reefs over both the short and medium term. However, there were no clear or consistent differences in the structure of fish or benthic assemblages, non-target fish density, fish species richness, or coral cover between NTMR and fished reefs. There was no indication that the displacement and concentration of fishing effort reduced coral trout populations on fished reefs. A severe tropical cyclone impacted many survey reefs during the study, causing similar declines in coral cover and fish density on both NTMR and fished reefs. However, coral trout biomass declined only on fished reefs after the cyclone. The GBRMP is performing as expected in terms of the protection of fished stocks and biodiversity for a developed country in which fishing is not excessive and targets a narrow range of species. NTMRs cannot protect coral reefs directly from acute regional-scale disturbance but, after a strong tropical cyclone, impacted NTMR reefs supported higher biomass of key fishery-targeted species and so should provide valuable sources of larvae to enhance population recovery and long-term persistence.
•Expansion of a GBR reserve network led to substantial increases in coral trout stocks•A large tropical cyclone impacted the reserve network, causing widespread damage•Impacts on coral trout biomass were smaller inside NTMRs compared to fished reefs•NTMRs may provide greater potential for replenishment after disturbances
No-take marine reserves (NTMRs) are widely advocated for conserving exploited fish stocks and biodiversity. Emslie et al. show that expanding NTMR networks had clear benefits for fishery target, but not non-target, species. A cyclone caused widespread degradation, but target species biomass was retained within NTMRs, with greater recovery potential.
The covalent attachment of SUMO (small ubiquitin-like modifier) to other intracellular proteins affects a broad range of nuclear processes in yeast and animals, including chromatin maintenance, ...transcription, and transport across the nuclear envelope, as well as protects proteins from ubiquitin addition. Substantial increases in SUMOylated proteins upon various stresses have also implicated this modification in the general stress response. To help understand the role(s) of SUMOylation in plants, we developed a stringent method to isolate SUMO-protein conjugates from Arabidopsis thaliana that exploits a tagged SUMO1 variant that faithfully replaces the wild-type protein. Following purification under denaturing conditions, SUMOylated proteins were identified by tandem mass spectrometry from both nonstressed plants and those exposed to heat and oxidative stress. The list of targets is enriched for factors that direct SUMOylation and for nuclear proteins involved in chromatin remodeling/repair, transcription, RNA metabolism, and protein trafficking. Targets of particular interest include histone H2B, components in the LEUNIG/TOPLESS corepressor complexes, and proteins that control histone acetylation and DNA methylation, which affect genome-wide transcription. SUMO attachment site(s) were identified in a subset of targets, including SUMO1 itself to confirm the assembly of poly-SUMO chains. SUMO1 also becomes conjugated with ubiquitin during heat stress, thus connecting these two posttranslational modifications in plants. Taken together, we propose that SUMOylation represents a rapid and global mechanism for reversibly manipulating plant chromosomal functions, especially during environmental stress.
Fear is a graded central motive state ranging from mild to intense. As threat intensity increases, fear transitions from discriminative to generalized. The circuit mechanisms that process threats of ...different intensity are not well resolved. Here, we isolate a unique population of locally projecting neurons in the central nucleus of the amygdala (CeA) that produce the neuropeptide corticotropin-releasing factor (CRF). CRF-producing neurons and CRF in the CeA are required for discriminative fear, but both are dispensable for generalized fear at high US intensities. Consistent with a role in discriminative fear, CRF neurons undergo plasticity following threat conditioning and selectively respond to threat-predictive cues. We further show that excitability of genetically isolated CRF-receptive (CRFR1) neurons in the CeA is potently enhanced by CRF and that CRFR1 signaling in the CeA is critical for discriminative fear. These findings demonstrate a novel CRF gain-control circuit and show separable pathways for graded fear processing.
•CRF neurons in the CeA are critical for discriminative fear•CRF neurons in the CeA are not required for generalized fear•CRF neurons project locally to enhance excitatory synaptic transmission•CRF provides gain control for fear processing
Sanford et al. demonstrate that a unique population of CRF-producing neurons in the central nucleus of the amygdala (CeA) provides a modulatory gain control signal within the CeA that operates at low threat levels to facilitate learning through the release of CRF.
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