Speciation through entrepreneurial spin-off: The Acorn-ARM story

Can the concept of speciation explain evidence on how technologies branch and advance? Can evidence on innovation through spin-off usefully inform the concept of speciation? These questions are addressed through a case study of detailed processes enabling the shift of technology to new domains of application. An innovative IT firm developed its own semiconductor technology to remedy supplier deficiencies but it required a joint venture with a completely new business model to adapt and move the technology into new market domains. We propose the concept of techno-organizational speciation to delineate this phenomenon. Competing perspectives on speciation (compatibility, niche and lineage approaches) are found to illuminate the evidence, while complementarities between these conceptual dimensions are revealed by the case. Causal processes uncovered include the following: (1) Techno-organizational speciation through spin-off may be needed to launch a dominant technical standard, compatible with multiple applications. (2) This can be achieved through niche creation from which develops a new business ecosystem. (3) Inherited knowledge together with organizationally based learning foster the branching and renewal of technological lineage

The Regulation of Rat Liver Xanthine Oxidase CONVERSION IN VITRO OF THE ENZYME ACTIVITY FROM DEHYDROGENASE (TYPE D) TO OXIDASE (TYPE O)

Abstract The aerobic oxidation of xanthine by rat liver supernatant was greatly stimulated by the addition of methylene blue or of NAD+: the latter was reduced during the reaction. Storage of the supernatant at -20° brought about an enhancement of the xanthine oxidation rate measured without addition of cofactors. A similar "activation" was caused by prior incubation at 37° of the unfractionated liver homogenate, or of the supernatant separated after sonic disruption of the homogenate. The same effect was obtained by treatment with solvents, or by prior incubation at 37° of the supernatant in the presence of proteolytic enzymes or under anaerobic conditions. The presence of xanthine accelerated the effect of proteolytic enzymes and of anaerobiosis. Only the changes caused by anaerobiosis could be reversed by incubating the supernatant in air before the assay. The reaction rate was apparently unaffected by these treatments if activity of the enzyme was measured in the presence of methylene blue or of NAD+. The latter, however, was not reduced during the oxidation of xanthine by "activated" supernatants stored at -20° if the reaction was run in the presence of oxygen. If the reaction was in anaerobiosis, uric acid and a corresponding amount of NADH were formed by fresh, supernatant, and by supernatants activated at -20° or by prior incubation in anaerobiosis, but not by supernatant activated by trypsin. The hypothesis is formulated that most of the xanthine oxidase of rat liver supernatant is a dehydrogenase (Type D), and may be converted (activated) into an oxidase (Type O)

A DEEP SPACE HABITAT FOR EXPLORATION

The paper describes a habitable module to be used for long duration space exploration missions. The Deep Space Habitat (DSH) is conceived as a cis-lunar orbital infrastructure and a space-ship for deep space exploration missions. It will represent the first outpost beyond LEO, being deployed at the first Earth-Moon Lagrangian point (EML1), and is envisaged as a human-tended infrastructure with crew visits periodically foreseen. The DSH has to be firstly used as a platform for research and to demonstrate a set of critical technologies and associated operations required to perform a deep space human exploration mission (e.g. to a NEO). In this regard, placing the module at EML1 allows reproducing conditions that would be encountered during a travel to an asteroid (or to Mars), thus guaranteeing the possibility to test specific technologies in a more significant environment with respect to what possible on ground or in LEO (e.g. effects of radiations on human body outside the protection of the Van Allen belts and radiation protection system test). Besides being a technology test bed, the DSH will support lunar human exploration missions, providing a staging post and a safe haven for crew working on the Moon surface. The overall architecture of the DSH has derived from a set of system trade-off performed accordingly to the objectives to be accomplished: the most important features are described within the paper. The DSH deployed at EML1 can be seen as a first unit to be utilized as a precursor for a habitation module to be actually adopted for hosting the crew during a deep space mission (to a NEO or to Mars). Indeed, a second unit is envisaged, which exploits the experience gained through its precursor, having a common core with it and implementing technologies previously tested on it. Only minor changes shall be envisioned due to the peculiarities of the mission for which it is used. In particular, the description of the second unit presented in the paper refers to a specific reference mission to a NEO lasting one year. The first part of the paper focuses on the main performed trade-offs, as well as the obtained results, in terms of both system architecture and operations, highlighting the major differences between the two envisioned units. The second part is devoted to the critical and enabling technologies, with particular attention to advanced regenerative ECLSS, rapid prototyping and radiation protection syste

A model of discriminant analysis on the basis of descriptor variables for the ampelography of Vitis sp.

Use of descriptor variables in ampelography is recommended to simplify recording of data and to enable useful comparisons. Parametric assumptions are, however, poorly satisfied especially with regard to statistical interference. In the paper some statistical procedures to improve the discriminant ability of descriptor variables are considered. The use of variances and covariances of variety by year interactions is suggested for the error matrix within a multiple discriminant analysis procedure. The adequacy of this model is verified in a 3-year experiment with Italian wine varieties. The discriminant power, as evaluated on the basis of the estimated distances among varieties, is satisfactory

Flat bidifferential ideals and semihamiltonian PDEs

In this paper we consider a class of semihamiltonian systems characterized by the existence of a special conservation law. The density and the current of this conservation law satisfy a second order system of PDEs which has a natural interpretation in the theory of flat bifferential ideals. The class of systems we consider contains important well-known examples of semihamiltonian systems. Other examples, like genus 1 Whitham modulation equations for KdV, are related to this class by a reciprocal trasformation.Comment: 18 pages. v5: formula (36) corrected; minor change

Bond strength of adhesive resin cement with different adhesive systems

To assess the immediate bond strength of a dual-cure adhesive resin cement to the hybridized dentin with different bonding systems. Fifty-six healthy human molars were randomly divided into 7 groups (n=8). After 3 longitudinal sections, the central cuts were included in PVC matrix and were submitted to dentin hybridization according to the groups: G1 - etch & rinse system with 3-step (Apder™ Scotchbond™ Multi-Purpose, 3M ESPE), G2 - etch & rinse system with 3-step (Optibond™ FL, Kerr), G3 - etch & rinse system with 3-step (All-Bond 3®, Bisco), G4 - etch & rinse simplified system (Adper™ Single Bond 2, 3M ESPE), G5 - self-etching system with one step (Bond Force, Tokuyama), G6 - universal system in moist dentin (Single Bond Universal, 3M ESPE), G7 - universal system in dry dentin (Single Bond Universal, 3M ESPE). Then all groups received the cementing of a self-adhesive resin cement cylinder (Duo-link, Bisco) made from a polypropylene matrix. In the evaluation of bond strength, the samples were subjected to the microshear test and evaluated according to the fracture pattern by optical microscopy. The Kruskal-Wallis test suggests a statistically significant difference between groups (p=0,039), and Tukey for multiple comparisons, indicating a statistically significant difference between G3 and G4 (p<0.05). It was verified high prevalence of adhesive failures, followed by mixed failure and cohesive in dentin. The technique and the system used to dentin hybridization are able to affect the immediate bond strength of resin cement dual adhesive

Differential Calculi on Associative Algebras and Integrable Systems

After an introduction to some aspects of bidifferential calculus on associative algebras, we focus on the notion of a "symmetry" of a generalized zero curvature equation and derive Backlund and (forward, backward and binary) Darboux transformations from it. We also recall a matrix version of the binary Darboux transformation and, inspired by the so-called Cauchy matrix approach, present an infinite system of equations solved by it. Finally, we sketch recent work on a deformation of the matrix binary Darboux transformation in bidifferential calculus, leading to a treatment of integrable equations with sources.Comment: 19 pages, to appear in "Algebraic Structures and Applications", S. Silvestrov et al (eds.), Springer Proceedings in Mathematics & Statistics, 202

Public engagement with climate change: what do we know and where do we go from here?

Climate change is an issue with fundamental implications for societies and individuals. These implications range from our everyday choices about resource use and lifestyles, through how we adjust to an unprecedented rate of environmental change, to our role in debating and enacting accompanying social transitions. This article outlines the various ways in which members of society (‘publics’) may be engaged in efforts to mitigate and adapt to climate change, and then provides a synthesis of lessons about public engagement which span both theoretical and practical insights. These include the diverse drivers of, and barriers to, engagement; the importance of multiple forms of engagement and messages; and a critical need to evaluate and identify successful examples of engagement. We conclude by outlining priorities for future research, policy and practice

Is a more aggressive COVID-19 case detection approach mitigating the burden on ICUs? Some reflections from Italy

No abstract availabl