988 research outputs found

    High modal number and triple trisomies are highly correlated favorable factors in childhood B-cell precursor high hyperdiploid acute lymphoblastic leukemia treated according to the NOPHO ALL 1992/2000 protocols.

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    To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.Between 1992 and 2008, 713 high hyperdiploid acute lymphoblastic leukemias in children aged 1-15 years were diagnosed and treated according to the Nordic Society for Pediatric Hematology and Oncology acute lymphoblastic leukemia 1992/2000 protocols. Twenty (2.8%) harbored t(1;19), t(9;22), der(11q23), or t(12;21). The median age of patients with "classic" high hyperdiploidy was lower than that of patients with translocation-positive high hyperdiploidy (P53/55 (P=0.020/0.024). In multivariate analyses, modal number and triple trisomies were significantly associated with superior event-free survival in separate analyses with age and white blood cell counts. When including both modal numbers and triple trisomies, only low white blood cell counts were significantly associated with superior event-free survival (P=0.009). We conclude that high modal chromosome numbers and triple trisomies are highly correlated prognostic factors and that these two parameters identify the same subgroup of patients characterized by a particularly favorable outcome.Swedish Childhood Cancer Foundation Swedish Cancer Society Swedish Research Counci

    A terminal assessment of stages theory : introducing a dynamic states approach to entrepreneurship

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    Stages of Growth models were the most frequent theoretical approach to understanding entrepreneurial business growth from 1962 to 2006; they built on the growth imperative and developmental models of that time. An analysis of the universe of such models (N=104) published in the management literature shows no consensus on basic constructs of the approach, nor is there any empirical confirmations of stages theory. However, by changing two propositions of the stages models, a new dynamic states approach is derived. The dynamic states approach has far greater explanatory power than its precursor, and is compatible with leading edge research in entrepreneurship

    Entrepreneurs’ age, institutions, and social value creation goals: a multi-country study

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    This study explores the relationship between an entrepreneur's age and his/her social value creation goals. Building on the lifespan developmental psychology literature and institutional theory, we hypothesize a U-shaped relationship between entrepreneurs’ age and their choice to create social value through their ventures, such that younger and older entrepreneurs create more social value with their businesses while middle age entrepreneurs are relatively more economically and less socially oriented with their ventures. We further hypothesize that the quality of a country’s formal institutions in terms of economic, social, and political freedom steepen the U-shaped relationship between entrepreneurs’ age and their choice to pursue social value creation as supportive institutional environments allow entrepreneurs to follow their age-based preferences. We confirm our predictions using multilevel mixed-effects linear regressions on a sample of over 15,000 entrepreneurs (aged between 18 and 64 years) in 45 countries from Global Entrepreneurship Monitor data. The findings are robust to several alternative specifications. Based on our findings, we discuss implications for theory and practice, and we propose future research directions

    Learning Sequences: Their Existence, Effect, and Evolution

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    Much is known about the importance of learning and some of the distinct learning processes that organizations use (e.g., trial-and-error learning, vicarious learning, experimental learning, and improvisational learning). Yet surprisingly little is known about whether these processes combine over time in ordered ways, because most research on learning explores one particular process. Using theory elaboration and theory-building methods and data on the accumulated country entries of entrepreneurial firms, we address this gap. Our core contribution is an emergent theoretical framework that develops the concept of learning sequences. We find that learning sequences exist and are influenced by initial conditions. We also find that learning sequences evolve in fundamentally distinct ways over time and with repeated use. Finally, data show how different learning sequences differentially affect both shorter- and longer-term performance, suggesting that it matters which learning processes are used and when. Overall, our findings on learning sequences have important implications for learning theory, international entrepreneurship, and the growing literature on process management

    Varieties of export-oriented entrepreneurship in Asia

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    This paper explores differences in the proportion of export-oriented early-stage entrepreneurial activity in 12 Asian countries. Drawing on varieties of capitalism theory, we find that Asian countries with high quality institutions are more likely to have higher proportions of young export-oriented firms. However, analysis on a 51 country data set indicates that Asian countries have significantly fewer young export-oriented firms than do non-Asian countries. Furthermore, the multi-country study reveals that countries with higher proportions of export-oriented entrepreneurial activity tend to have flexible industrial relations, high quality vocational training, and confrontational labor-employer relations, however the proportion of export-oriented new ventures is not related to the quality of corporate governance and inter-firm relations

    ‘Better late than never’: the interplay between green technology and age for firm growth

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    This paper investigates the relationship between green/non-green technologies and firm growth. By combining the literature on eco-innovations, industrial organisation and entrepreneurial studies, we examine the dependence of this relationship on the pace at which firms grow and the age of the firm. From a dataset of 5498 manufacturing firms in Italy for the period of 2000–2008, longitudinal fixed effects quantile models are estimated, in which the firm’s age is set to moderate the effects of green and non-green patents on employment growth. We find that the positive effect of green technologies on growth is greater than that of non-green technologies. However, this result does not apply to struggling and rapidly growing firms. With fast-growing (above the median) firms, age moderates the growth effect of green technologies. Inconsistent with the extant literature, this moderation effect is positive: firm experience appears important for the growth benefits of green technologies, possibly relative to the complexity of their management

    Determining Vertical Soil-Water Flux in Glaciated Terrains Using a Convective Heat Flux Model and Measured Transient Soil Thermal Properties

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    Presentation given at the American Geophysical Union Fall Meeting in New Orleans, LA, from Dec. 11-15, 2017.Several workers have applied water flux models based on convective heat-transfer principles and measured temperature profiles to quantify vertical water movement through unsaturated soils. However, flux estimates can vary significantly due to uncertainty in soil thermal properties such as thermal diffusivity, thermal conductivity, and soil volumetric heat capacity and their relationship to changing degrees of saturation. In this study, soil temperature profile data is combined with in situ measurements of soil thermal properties to estimate both upward and downward water fluxes through soils developed in glacial parent materials. A regression analysis of 1.2-m discrete depth in situ volumetric heat capacity and degree-of-saturation data indicates that there is a good correlation for sites underlain by coarse-grained diamicton, outwash, and alluvium (R = 0.66 – 0.87), whereas sites underlain by fine-grained glacial diamicton show little to no correlation and are therefore deemed unfit for the modelling approach. The results of the convective heat model for the outwash and alluvium sites are compared to water fluxes previously simulated using the one-dimensional Richard’s Equation. Preliminary results at a midwestern U.S. glacial outwash site indicate that daily downward flux results compare well with the previously published estimates after eliminating extreme values caused by temperature signal noise. At the coarse-grained diamicton and alluvium sites having lower hydraulic conductivities, the fluxes generally are temporally correlated, but the thermal model tends to overestimate flux by an order of magnitude. This ongoing work aims to refine the convective flux model while optimizing vadose-zone monitoring networks such that real-time percolation estimates are possible

    The graduation performance of technology business incubators in China's three tier cities: the role of incubator funding, technical support, and entrepreneurial mentoring

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    This study examines the effects of technology business incubator (TBI)’s funding, technical support and entrepreneurial mentoring on the graduation performance of new technology-based firms in China’s three tier cities. Using new dataset on all TBIs and incubated new technology-based firms from government surveys conducted over five consecutive years from 2009 to 2013 combined with archival and hand-collected data, we find the effects of incubator services on the early growth of new technology-based firms vary according to the local context. Technical support facilities and entrepreneurial mentoring from TBIs are found to have significantly and positively influenced the early development of the firms in the four most affluent tier 1 cities, whilst these effects become less pronounced for the tier 2 and tier 3 cities. These two services are also found to influence graduation performance in the government and university types of TBI respectively. Results support the notion that the effectiveness of an incubators services is shaped by the level of a city’s socio-economic development and that the city location of a TBI does impact the graduation performance of its incubatees
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