Back to the Future – the Marginal Utility of History in Economics

Economics and economic history share many fundamental research problems and have a rich shared intellectual history. Still, works by economic historians are rarely read or referenced in economics. In this essay we attempt to identify the cost of this negligence. In particular, we argue that a restrictive understanding of the economic research programme excludes available evidence and precludes analysis of complex situational constraints on economic decision-making.

Semiconservative quasispecies equations for polysomic genomes: The general case

This paper develops a formulation of the quasispecies equations appropriate for polysomic, semiconservatively replicating genomes. This paper is an extension of previous work on the subject, which considered the case of haploid genomes. Here, we develop a more general formulation of the quasispecies equations that is applicable to diploid and even polyploid genomes. Interestingly, with an appropriate classification of population fractions, we obtain a system of equations that is formally identical to the haploid case. As with the work for haploid genomes, we consider both random and immortal DNA strand chromosome segregation mechanisms. However, in contrast to the haploid case, we have found that an analytical solution for the mean fitness is considerably more difficult to obtain for the polyploid case. Accordingly, whereas for the haploid case we obtained expressions for the mean fitness for the case of an analogue of the single-fitness-peak landscape for arbitrary lesion repair probabilities (thereby allowing for non-complementary genomes), here we solve for the mean fitness for the restricted case of perfect lesion repair.Comment: 16 pages, 3 figure

Under What Conditions Do Rural Schools Learn From their Partners? Exploring the Dynamics of Educational Infrastructure and Absorptive Capacity in Inter-Organisational Learning Leadership

This journal is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits any use, duplication, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.This case study was designed to explore the strategies and actions that high performing schools with sus-tainable results employ at the district level in arural part of Norway. The district subjected to the study is characterisedby small municipalities and a scattered population, with a few small school administrative units, which might be a challenging context for sustainability and improvement. In response, the districts developed collaborative structures to increase collective learning capacity. The research design involved a collective case study, and it draws on data from interviews with school leaders at the municipal level and local school policy documents. The findings suggest that Norwegian school district actorscan facilitate school improvement by shaping collaborating cultures, inter-organisationallearning processes and educa-tional infrastructures. Furthermore, the findings highlight the schools’ ability to recogniseand value new knowledge from external sources, such as academic institutions and partner schools, assimilate novelties across boundaries and,eventually,utilise thesefor strategic or operational endstoenhance an organisation’s absorptive capacity. Finally, the findings indicate that superintendents can play important roles through boundary-spanning and gatekeeping activities.publishedVersio

Evolutionary dynamics of adult stem cells: Comparison of random and immortal strand segregation mechanisms

This paper develops a point-mutation model describing the evolutionary dynamics of a population of adult stem cells. Such a model may prove useful for quantitative studies of tissue aging and the emergence of cancer. We consider two modes of chromosome segregation: (1) Random segregation, where the daughter chromosomes of a given parent chromosome segregate randomly into the stem cell and its differentiating sister cell. (2) ``Immortal DNA strand'' co-segregation, for which the stem cell retains the daughter chromosomes with the oldest parent strands. Immortal strand co-segregation is a mechanism, originally proposed by Cairns (J. Cairns, {\it Nature} {\bf 255}, 197 (1975)), by which stem cells preserve the integrity of their genomes. For random segregation, we develop an ordered strand pair formulation of the dynamics, analogous to the ordered strand pair formalism developed for quasispecies dynamics involving semiconservative replication with imperfect lesion repair (in this context, lesion repair is taken to mean repair of postreplication base-pair mismatches). Interestingly, a similar formulation is possible with immortal strand co-segregation, despite the fact that this segregation mechanism is age-dependent. From our model we are able to mathematically show that, when lesion repair is imperfect, then immortal strand co-segregation leads to better preservation of the stem cell lineage than random chromosome segregation. Furthermore, our model allows us to estimate the optimal lesion repair efficiency for preserving an adult stem cell population for a given period of time. For human stem cells, we obtain that mispaired bases still present after replication and cell division should be left untouched, to avoid potentially fixing a mutation in both DNA strands.Comment: 9 pages, 3 figure

Breaching the kinetic barrier to in vitro somatic stem cell propagation

ABSTRACT: Here we have reviewed the conventional definitions and fundamental characteristics of the two basic types of stem cells, embryonic stem cells (ESCs) and somatic stem cells (SSCs). By taking into account the often-overlooked asymmetric cell kinetics of SSCs, we consider the evidence that should SSCs retain these growth kinetics in vitro, a natural kinetic barrier to SSC propagation exists. Recent discoveries showing that the tumor suppressor gene p53 can act as a regulator of asymmetric cell kinetics provide a target pathway for in vitro SSC propagation strategies

Organizational Knowledge Transfer: Introducing A Multi-Level Perspective

Posten inneholder presentasjon og tilhørende artikkel presentert på Academy of Management Annual Meeting i 2010Research on organizational knowledge transfer is burgeoning, due to the critical role of external knowledge as a source of advantages for firms as well as public sector organizations. Our study investigates knowledge transfer in the context of a Norwegian benchmarking project in which a majority of the country‟s municipality organizations participated over a period of two years. The explicit purpose of the project was to encourage the project groups to learn from the experiences of their partner organizations. A field sample of 82 benchmarking groups and 274 individual municipality managers were examined to test antecedents to knowledge transfer in this setting. Specifically, the relationships between knowledge transfer and group autonomy, group intensity of effort, absorptive capacity and cognitive distance were hypothesized in the current study, and possible moderator effects from group autonomy were tested on an exploratory basis. Our study was deliberately conducted using a composite multi-level design, in order to test individual and group level relationships simultaneously. The study detected a positive relationship between group intensity, group autonomy and knowledge transfer as well as a negative relationship between individual cognitive distance and knowledge transfer

Combining capacity for instructional leadership with individual core practices in the Norwegian policy context

This article is distributed under the terms of the Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/) which permits any use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (https://us.sagepub.com/en-us/nam/open-access-at-sage).This study explores how Norwegian school leaders develop their capacity for instructional leadership, a leadership style that is strongly related to school effectiveness and school improvement across a range of national school systems. The concept captures important aspects of Norwegian school leaders’ task preferences. To gain further insight into the process of developing the capacity for instructional leadership, this study links instructional leadership to school leaders’ core practices. The multidimensional concept of core practices views school leaders as goal oriented and actively involved in teachers’ collaboration and professional development, observation, and supervision. Moreover, the concept covers school leaders’ efforts to redesign and improve their schools’ instructional programs. In this study, school leaders assessed instructional leadership related to three distinctive core practices: observation and supervision, collaborative learning engagement, and time allocation for data use. Multiple regression analyses were conducted, and overall, the regression model, with all the predictors included as a set, was significant. 28.5% of the variance in school leader’s capacity for instructional leadership is explained by the three distinct factors. The results indicate that when school leaders adapt core practices of leadership to their work context, their capacity as instructional leaders increases. The findings and implications will be discussed.publishedVersio

Nordiske skolechefer: Agenter i en brudt kæde

I bogen analyseres skolechefernes positioner og relationer inden for de kommunale forvaltninger i de nordiske lande. Det kommunale styre af institutionerne er placeret i New Public Management og statslige omstruktureringer og udfoldes i en blanding af bløde styringsteknologier og hårde reguleringer

When should you consider implanted nerve stimulators for lower back pain?

Patients can gain more pain relief from spinal cord stimulation (SCS) than from reoperation (strength of recommendation [SOR]: A, 2 randomized controlled trials [RCTs]). SCS can also treat chronic low back pain effectively (SOR: B, cohort studies). It's indicated when conservative measures have failed (SOR: C, expert opinion). The side effects and failure rates of SCS are well documented and should be considered before recommending the therapy to patients (SOR: A, systematic review of RCTs and cohort studies)

Susceptibility for lupus nephritis by low copy number of the FCGR3B gene is linked to increased levels of pathogenic autoantibodies

Low copy number (CN) of the FCGR3B gene reduces FCGR3B membrane expression on neutrophils and results in clearance of a smaller amount of immune complex. We investigated FCGR3B CN in relation to the clinical phenotype in a Caucasian SLE cohort (n = 107). FCGR3B CN was determined by three different qPCR parameter estimations (Ct-, Cy0, and cpD1) and confirmed by the FCGR2C/FCGR2A paralog ratio test. Clinical and serological data were then analyzed for their association with FCGR3B CN. Low FCGR3B CN (2). In multivariate analyses, LN was independently associated with anti-C1q-Ab levels (P = 0.03) and low FCGR3B CN (P = 0.09). We conclude that the susceptibility for LN in patients with low FCGR3B CN is linked to increased levels of pathogenic autoantibodies.Johannes C. Nossent, Andrea Becker-Merok, Maureen Rischmueller, and Sue Leste