Introduction: Revisiting the Roles and Responsibilities of Trade Associations

We explain that the reasons for this Dialog stem from the enduring gaps in our understanding of what trade associations are, how they work, and what impact they have on members, industries, markets, and societies. The Dialog includes an opening paper by Thomas Lawton, Tazeeb Rajwani and Amy Minto and is followed by contributions from Michael Barnett, Steven Kahl, Lyn Spillman, and Howard Aldrich. Building on previous and ongoing research, each author reflected on the key questions driving this Dialogue: Do trade associations matter and if so, how? We argue that not only do they matter but more attention needs to be given to their roles and responsibilities

Why Trade Associations Matter: Exploring Function, Meaning, and Influence

We explore the organizational characteristics of trade associations (TAs) and suggest theoretical approaches for undertaking research into or involving TAs in management and organization studies. Through emphasizing the role of TAs within and between industries and at the interface of business and society, we consider how TAs generate meaning and influence

On QBF Proofs and Preprocessing

QBFs (quantified boolean formulas), which are a superset of propositional formulas, provide a canonical representation for PSPACE problems. To overcome the inherent complexity of QBF, significant effort has been invested in developing QBF solvers as well as the underlying proof systems. At the same time, formula preprocessing is crucial for the application of QBF solvers. This paper focuses on a missing link in currently-available technology: How to obtain a certificate (e.g. proof) for a formula that had been preprocessed before it was given to a solver? The paper targets a suite of commonly-used preprocessing techniques and shows how to reconstruct certificates for them. On the negative side, the paper discusses certain limitations of the currently-used proof systems in the light of preprocessing. The presented techniques were implemented and evaluated in the state-of-the-art QBF preprocessor bloqqer.Comment: LPAR 201

High levels of the adhesion molecule CD44 on leukemic cells generate acute myeloid leukemia relapse after withdrawal of the initial transforming event

Multiple genetic hits are detected in patients with acute myeloid leukemia (AML). To investigate this further, we developed a tetracycline-inducible mouse model of AML, in which the initial transforming event, overexpression of HOXA10, can be eliminated. Continuous overexpression of HOXA10 is required to generate AML in primary recipient mice, but is not essential for maintenance of the leukemia. Transplantation of AML to secondary recipients showed that in established leukemias, ∼80% of the leukemia-initiating cells (LICs) in bone marrow stopped proliferating upon withdrawal of HOXA10 overexpression. However, the population of LICs in primary recipients is heterogeneous, as ∼20% of the LICs induce leukemia in secondary recipients despite elimination of HOXA10-induced overexpression. Intrinsic genetic activation of several proto-oncogenes was observed in leukemic cells resistant to inactivation of the initial transformation event. Interestingly, high levels of the adhesion molecule CD44 on leukemic cells are essential to generate leukemia after removal of the primary event. This suggests that extrinsic niche-dependent factors are also involved in the host-dependent outgrowth of leukemias after withdrawal of HOXA10 overexpression event that initiates the leukemia

Ageing and entrepreneurial preferences

Previous research on age and entrepreneurship assumed homogeneity and downplayed age-related differences in the motives and aims underlying enterprising behaviour. We argue that the heterogeneity of entrepreneurship influences how the level of entrepreneurial activity varies with age. Using a sample of 2566 respondents from 27 European countries we show that entrepreneurial activity increases almost linearly with age for individuals who prefer to only employ themselves (self-employers), whereas it increases up to a critical threshold age (late 40s) and decreases thereafter for those who aspire to hire workers (owner-managers). Age has a considerably smaller effect on entrepreneurial behaviour for those who do not prefer self-employment but are pushed into it by lack of alternative employment opportunities (reluctant entrepreneurs). Our results question the conventional wisdom that entrepreneurial activity declines with age and suggest that effective responses to demographic changes require policy makers to pay close attention to the heterogeneity of entrepreneurial preferences