Evolution of size and pattern in the social amoebas

A fundamental goal of biology is to understand how novel phenotypes evolved through changes in existing genes. The Dictyostelia or social amoebas represent a simple form of multicellularity, where starving cells aggregate to build fruiting structures. This review summarizes efforts to provide a framework for investigating the genetic changes that generated novel morphologies in the Dictyostelia. The foundation is a recently constructed molecular phylogeny of the Dictyostelia, which was used to examine trends in the evolution of novel forms and in the divergence of genes that shape these forms. There is a major trend towards the formation of large unbranched fruiting bodies, which is correlated with the use of cyclic AMP (cAMP) as a secreted signal to coordinate cell aggregation. The role of cAMP in aggregation arose through co-option of a pathway that originally acted to coordinate fruiting body formation. The genotypic changes that caused this innovation and the role of dynamic cAMP signaling in defining fruiting body size and pattern throughout social amoeba evolution are discussed. BioEssays 29:635–644, 2007. © 2007 Wiley Periodicals, Inc

Toward Strategy Implementation Success: An Empirical Study of the Role of Senior-Level Leaders in the Nevada Gaming Industry

The study is an investigation of the relationship between effective leadership behavior and successful strategy implementation in the Nevada casino industry. The study\u27s findings mostly agree with earlier research on the concept of strategy implementation and reaffirm the role that strategic consensus plays in the strategy implementation process. The study also reinforces findings that frequent communication up and down the organization structure enhances strategic consensus through the fostering of shared attitudes and values. In addition, it reaffirms the concept that an organization which ties rewards to the success of the strategy employed is rewarded with higher levels of organizational performance and concludes that strategy implementation plans must be clearly developed, indicating particular tasks for individuals, with clear-cut time frames, and identifying the people responsible for task completion

Innovation dialogue - Being strategic in the face of complexity - Conference report

The Innovation Dialogue on Being Strategic in the Face of Complexity was held in Wageningen on 31 November and 1 December 2009. The event is part of a growing dialogue in the international development sector about the complexities of social, economic and political change. It builds on two previous events hosted the Innovation Dialogue on Navigating Complexity (May 2009) and the Seminar on Institutions, Theories of Change and Capacity Development (December 2008). Over 120 people attended the event coming from a range of Dutch and international development organizations. The event was aimed at bridging practitioner, policy and academic interests. It brought together people working on sustainable business strategies, social entrepreneurship and international development. Leading thinkers and practitioners offered their insights on what it means to "be strategic in complex times". The Dialogue was organized and hosted by the Wageningen UR Centre for Development Innovation working with the Chair Groups of Communication & Innovation Studies, Disaster Studies, Education & Competence Studies and Public Administration & Policy as co; organisers. The theme of the Dialogue aligns closely with Wageningen UR’s interest in linking technological and institutional innovation in ways that enable ‘science for impact’

Aminopeptidase C of Aspergillus niger is a Novel Phenylalanine Aminopeptidase

A novel enzyme with a specific phenylalanine aminopeptidase activity (ApsC) from Aspergillus niger (CBS 120.49) has been characterized. The derived amino acid sequence is not similar to any previously characterized aminopeptidase sequence but does share similarity with some mammalian acyl-peptide hydrolase sequences. ApsC was found to be most active towards phenylalanine beta-naphthylamide (F-betaNA) and phenylalanine para-nitroanilide (F-betaNA), but it also displayed activity towards other amino acids with aromatic side chains coupled to betaNA; other amino acids with nonaromatic side chains coupled to either pNA or betaNA were not hydrolyzed or were poorly hydrolyzed. ApsC was not able to hydrolyze N-acetylalanine-pNA, a substrate for acyl-peptide hydrolases

Continuous Fields and Discrete Samples: Reconstruction through Delaunay Tessellations

Here we introduce the Delaunay Density Estimator Method. Its purpose is rendering a fully volume-covering reconstruction of a density field from a set of discrete data points sampling this field. Reconstructing density or intensity fields from a set of irregularly sampled data is a recurring key issue in operations on astronomical data sets, both in an observational context as well as in the context of numerical simulations. Our technique is based upon the stochastic geometric concept of the Delaunay tessellation generated by the point set. We shortly describe the method, and illustrate its virtues by means of an application to an N-body simulation of cosmic structure formation. The presented technique is a fully adaptive method: automatically it probes high density regions at maximum possible resolution, while low density regions are recovered as moderately varying regions devoid of the often irritating shot-noise effects. Of equal importance is its capability to sharply and undilutedly recover anisotropic density features like filaments and walls. The prominence of such features at a range of resolution levels within a hierarchical clustering scenario as the example of the standard CDM scenario is shown to be impressively recovered by our scheme.Comment: 4 pages, 2 figures, accepted for publication in Astronomy & Astrophysics Letter

The vertical extent and kinematics of the HI in NGC 2403

The neutral hydrogen line profiles along the major axis of the nearby spiral galaxy NGC 2403 show a wing towards the sytemic velocity. This asymmetry can be explained with the presence of an abnormally thick HI disk (FWHM ~ 5 kpc) or with a two-component structure: a thin disk and a slowly rotating, thicker (1-3 kpc) HI layer. The latter model gives a better representation of the observations. These results throw a new light on the disk-halo connection. In particular, the decrease of rotational velocity with height above the plane may be the result of a galactic fountain flow. A vertically extended, slowly rotating HI layer may be common among spiral galaxies with high levels of star formation.Comment: 4 pages, 2 figures, accepted for publication in Astronomy and Astrophysics Letter

Making Claims for Migrant Workers: Human Rights and Citizenship

Migrant workers claims for greater protection in a globalized world are typically expressed either in the idiom of international human rights or citizenship. Instead of contrasting these two normative frames, the paper explores the extent to which human rights and citizenship discourses intersect when it comes to claims by migrant workers. An analysis of the international human and labour rights instruments that are specifically designed for migrant workers reveals how neither discourse questions the assumption of territorial state sovereignty. Drawing upon sociological and political approaches to human rights claims, I evaluate the Arendtian-inspired critique of international human rights, which is that they ignore the very basis ‘right to have rights’. In doing so, I discuss the different dimensions of citizenship and conclude that international rights can be used by migrant workers to assert right claims that reinforce a conception of citizenship that, although different from national citizenship, has the potential to address their distinctive social location