New ventures on the search for viable business models: Taking into account levels of uncertainty / ambiguity.

There exists evidence that most initial selections of business models by new ventures have to be adapted later on and that minor this need for adaptation stems from the high degrees of uncertainty and ambiguity new ventures are confronted with, both on the technology and the market level. The main research question of this paper is whether different levels of uncertainty and ambiguity have an effect on the appropriateness of different search strategies new ventures can use to adapt their business model; and if yes, what this effect is. We first present the relevant literature. We then put forward a simulation model - based on the model developed by Kauffman (1989, 1993) - as a formal basis for addressing our research question and analyze the simulation results. To conclude, these results are discussed in the light of existing research on entrepreneurship and innovation and some limitations of our research methodology are presented.Innovation; Market; Model; Models; Research; Selection; Simulation; Strategy; Technology; Uncertainty;

Flow instabilities of magnetic flux tubes II. Longitudinal flow

Flow-induced instabilities are relevant for the storage and dynamics of magnetic fields in stellar convection zones and possibly also in other astrophysical contexts. We continue the study started in the first paper of this series by considering the stability properties of longitudinal flows along magnetic flux tubes. A linear stability analysis was carried out to determine criteria for the onset of instability in the framework of the approximation of thin magnetic flux tubes. In the non-dissipative case, we find Kelvin-Helmholtz instability for flow velocities exceeding a critical speed that depends on the Alfv{\'e}n speed and on the ratio of the internal and external densities. Inclusion of a friction term proportional to the relative transverse velocity leads to a friction-driven instability connected with backward (or negative energy) waves. We discuss the physical nature of this instability. In the case of a stratified external medium, the Kelvin-Helmholtz instability and the friction-driven instability can set in for flow speeds significantly lower than the Alfv{\'e}n speed. Dissipative effects can excite flow-driven instability below the thresholds for the Kelvin-Helmholtz and the undulatory (Parker-type) instabilities. This may be important for magnetic flux storage in stellar convection zones and for the stability of astrophysical jets.Comment: accepted by Astronomy & Astrophysic

Expanding Local to Global through ESRI Story Maps

For decades, the “expanding communities” model has dominated the elementary classroom, sustained by notions that young children need to first understand their local communities before they can understand the broader world. As proponents of this approach value how it supports young learners developmentally, critics fault its narrow scope. How will children become global thinkers if they fail to explore the world beyond their home? Instead of separating local and global perspectives and topics, we set out to integrate them, to teach children about the world through their local communities. We created Community Story Maps as an inquiry-driven project where students learn about local history through the lenses of history, civics, economics, and geography and compare their surroundings to geographically different places and regions. The Community Story Maps project illustrates how an online resource—Esri Story Maps—can be used to deepen historical and geospatial thinking and make connections between the local and global

Preparing Preservice Secondary Social Studies Teachers for Common Core

For history and social studies educators, the Common Core standards present a new challenge, asking teachers explicitly to integrate literacy skills into their instruction. As K-12 and higher education institutions think about how to support teachers to meet this charge (Gewertz, 2012b; Sawchuk, 2012), this study uses the work of preservice teachers to examine how they address and fail to address Common Core standards. Our findings are based on qualitative analysis of unit plans (105 lessons) from preservice secondary history teachers. Analysis was completed on individual lessons and then on each unit holistically. Finally the units were analyzed collectively in order to draw more generalized findings. This study identifies specific aspects of the standards where educators are more likely to struggle with implementation of the Common Core ELA standards and provides suggestions on how teacher educators can better prepare preservice secondary history teachers to attend to the framework

Background Measurements in the Gran Sasso Underground Laboratory

The gamma background flux below 3000 keV in the Laboratori Nazionali del Gran Sasso (LNGS), Italy, has been measured using a 3" diameter NaI(Tl) detector at different underground positions: In hall A, hall B, the interferometer tunnel, and inside the Large Volume Detector (LVD). The integrated flux is 0.3--0.4 s$^{-1}$cm$^{-2}$ at the first three locations, and is lower by two orders of magnitude inside LVD. With the help of Monte Carlo simulations for every location, the contribution of the individual primordial isotopes to the background has been determined. Using an 11" diameter NaI(Tl) detector, the background neutron flux in the LNGS interferometer tunnel has been estimated. Within the uncertainties, the result agrees with those from other neutron measurements in the main halls.Comment: 6 pages, 6 figures, accepted versio

Transverse oscillations of two parallel coronal loops

Context. Collective oscillations of two or more coronal magnetic loops are observed very often. Aims. We study the eigenmodes of oscillations of a system consisting of two parallel magnetic loops. Methods. The linearised MHD equations for a cold plasma are solved analytically in bicylindrical coordinates using the longwavelength approximation. A dispersion equation determining the frequencies of eigenmodes is derived and solved analytically. Results. Two solutions of the dispersion relation were found. The higher frequency corresponds to the antisymmetric mode polarised in the direction parallel to the line connecting the loop centres, and the symmetric mode polarised in the perpendicular direction. Depending on the polarisation of modes corresponding to the lower frequency, the systems of two parallel loops are classified as standard and anomalous. In standard systems the lower frequency corresponds to the symmetric mode polarised in the direction parallel to the line connecting the loop centres, and the antisymmetric mode polarised in the perpendicular direction. In anomalous systems the lower frequency corresponds to the antisymmetric mode polarised in the direction parallel to the line connecting the loop centres, and the symmetric mode polarised in the perpendicular direction. The limiting case of two identical loops is studied. The results for this case are compared with recent numerical results

Flow focusing through gels as a tool to generate 3D concentration profiles in hydrogel-filled microfluidic chips

Laminar flow patterning is an iconic microfluidic technology used to deliver chemicals to specific regions on a two-dimensional surface with high spatial fidelity. Here we present a novel extension of this technology using Darcy flow within a three-dimensional (3D) hydrogel. Our test device is a simple 3-inlet microfluidic channel, totally filled with collagen, a cured biological hydrogel, where the concentration profiles of solutes are manipulated via the inlet pressures. This method allows solutes to be delivered with 50 micron accuracy within the gel, as we evidence by controlling concentration profiles of 40 kDa and 1 kDa fluorescent polysaccharide dyes. Furthermore, we design and test a 3D-printed version of our device with an extra two inlets for control of the vertical position of the concentration profile, demonstrating that this method is easily extensible to control of the concentration profile in 3D

Advanced glycation end products:An emerging biomarker for adverse outcome in patients with peripheral artery disease

AbstractPatients with peripheral artery disease (PAD) suffer from widespread atherosclerosis. Partly due to the growing awareness of cardiovascular disease, the incidence of PAD has increased considerably during the past decade. It is anticipated that algorithms to identify high risk patients for cardiovascular events require being updated, making use of novel biomarkers. Advanced glycation end products (AGEs) are moieties formed non-enzymatically on long-lived proteins under influence of glycemic and oxidative stress reactions. We elaborate about the formation and effects of AGEs, and the methods to measure AGEs. Several studies have been performed with AGEs in PAD. In this review, we evaluate the emerging evidence of AGEs as a clinical biomarker for patients with PAD