The Computation of Surface Lightness in Simple and Complex Scenes

The present thesis examined how reflectance properties and the complexity of surface mesostructure (small-scale surface relief) influence perceived lightness in centresurround displays. Chapters 2 and 3 evaluated the role of surface relief, gloss, and interreflections on lightness constancy, which was examined across changes in background albedo and illumination level. For surfaces with visible mesostructure (“rocky” surfaces), lightness constancy across changes in background albedo was better for targets embedded in glossy versus matte surfaces. However, this improved lightness constancy for gloss was not observed when illumination varied. Control experiments compared the matte and glossy rocky surrounds to two control displays, which matched either pixel histograms or a phase-scrambled power spectrum. Lightness constancy was improved for rocky glossy displays over the histogram-matched displays, but not compared to phase-scrambled variants of these images with equated power spectrums. The results were similar for surfaces rendered with 1, 2, 3 and 4 interreflections. These results suggest that lightness perception in complex centre-surround displays can be explained by the distribution of contrast across space and scale, independently of explicit information about surface shading or specularity. The results for surfaces without surface relief (“homogeneous” surfaces) differed qualitatively to rocky surfaces, exhibiting abrupt steps in perceived lightness at points at which the targets transitioned from being increments to decrements. Chapter 4 examined whether homogeneous displays evoke more complex mid-level representations similar to conditions of transparency. Matching target lightness in a homogeneous display to that in a textured or rocky display required varying both lightness and transmittance of the test patch on the textured display to obtain the most satisfactory matches. However, transmittance was only varied to match the contrast of targets against homogeneous surrounds, and not to explicitly match the amount of transparency perceived in the displays. The results suggest perceived target-surround edge contrast differs between homogeneous and textured displays. Varying the mid-level property of transparency in textured displays provides a natural means for equating both target lightness and the unique appearance of the edge contrast in homogeneous displays

Success at the Base of the Pyramid: A relational view of competitive advantage

In this paper, we propose a new framework to measure the success of projects at the Base of the Pyramid (BoP), based on the relational view of strategy (Dyer and Singh, 1998; Lavie, 2006; Mesquita et al., 2008), and we test the framework using new case studies. We argue that the success of BoP projects depends on relation-specific resources and capabilities resulting from partnerships among participating organizations. Typical partners involved in a BoP project are firms that make a product or a service designed for BoP customers, a public or private agency that has local knowledge and presence, and a BoP community that uses the product. The relational view model can help assess the sustainable success of a BoP project because it examines unique interorganizational relationships and relation-specific combination of resources designed to create sustainable value (Dyer and Singh, 1998; Dyer, 1996). We apply this important model of strategic analysis to two new BoP projects

Guarded Kleene Algebra with Tests: Coequations, Coinduction, and Completeness

Guarded Kleene Algebra with Tests (GKAT) is an efficient fragment of KAT, as it allows for almost linear decidability of equivalence. In this paper, we study the (co)algebraic properties of GKAT. Our initial focus is on the fragment that can distinguish between unsuccessful programs performing different actions, by omitting the so-called early termination axiom. We develop an operational (coalgebraic) and denotational (algebraic) semantics and show that they coincide. We then characterize the behaviors of GKAT expressions in this semantics, leading to a coequation that captures the covariety of automata corresponding to these behaviors. Finally, we prove that the axioms of the reduced fragment are sound and complete w.r.t. the semantics, and then build on this result to recover a semantics that is sound and complete w.r.t. the full set of axioms

M&A Update and Cross-Border M&As: Considerations for Middle-Market Firms

Global activity in mergers and acquisitions (M&As) has weakened during the past year and a half. With continued concerns about the recovery of the global economy, many large companies were reluctant to close mega-deals. Economic and political events, such as increased fiscal crises in Europe, slowing economic growth in the BRIC countries, and political gridlock in Washington, reduced confidence among many dealmakers. Despite companies’ record cash reserves, many were reluctant to execute new M&A deals. In this article, we discuss global M&A activity in 2011 and the first half of 2012. The article concludes with a discussion of factors for middle-market companies to consider in pursuing cross-border M&As

2014 M&A Update

Market conditions for mergers and acquisitions (M&As) remained positive in 2013. Relative economic growth in the U.S. and within specific industry sectors, and positive economic developments in the emerging markets signaled an optimistic outlook for M&A activity. There was a decline in worldwide M&A transactions in the first half of 2013 following a modest gain in 2012 which resulted in an overall slowdown in M&A activities, yet there are positive signs for future M&A growth. Corporate executives and their boards were selective with their investment choices and sought many of their M&A opportunities in the middle market. In this article, we report on global M&A activity in 2012 and the first half of 2013, and conclude with a discussion on the board of directors’ role in mergers and acquisitions

Cell cycle progression or translation control is not essential for vesicular stomatitis virus oncolysis of hepatocellular carcinoma.

The intrinsic oncolytic specificity of vesicular stomatitis virus (VSV) is currently being exploited to develop alternative therapeutic strategies for hepatocellular carcinoma (HCC). Identifying key regulators in diverse transduction pathways that define VSV oncolysis in cancer cells represents a fundamental prerequisite to engineering more effective oncolytic viral vectors and adjusting combination therapies. After having identified defects in the signalling cascade of type I interferon induction, responsible for attenuated antiviral responses in human HCC cell lines, we have now investigated the role of cell proliferation and translation initiation. Cell cycle progression and translation initiation factors eIF4E and eIF2Bepsilon have been recently identified as key regulators of VSV permissiveness in T-lymphocytes and immortalized mouse embryonic fibroblasts, respectively. Here, we show that in HCC, decrease of cell proliferation by cell cycle inhibitors or siRNA-mediated reduction of G(1) cyclin-dependent kinase activities (CDK4) or cyclin D1 protein expression, do not significantly alter viral growth. Additionally, we demonstrate that translation initiation factors eIF4E and eIF2Bepsilon are negligible in sustaining VSV replication in HCC. Taken together, these results indicate that cellular proliferation and the initiation phase of cellular protein synthesis are not essential for successful VSV oncolysis of HCC. Moreover, our observations indicate the importance of cell-type specificity for VSV oncolysis, an important aspect to be considered in virotherapy applications in the future

Why do Gen Y students study abroad? Individual growth and the intent to study abroad

This paper proposes that Generation Y college students’ desire for individual growth is a critical factor that motivates them to express the intent to study abroad, and that five additional variables -- gender, parents’ educational level, prior international experience, age, and household income -- moderate the direct influence of the desire for individual growth on the intent to study abroad

Two-State Migration of DNA in a structured Microchannel

DNA migration in topologically structured microchannels with periodic cavities is investigated experimentally and with Brownian dynamics simulations of a simple bead-spring model. The results are in very good agreement with one another. In particular, the experimentally observed migration order of Lambda- and T2-DNA molecules is reproduced by the simulations. The simulation data indicate that the mobility may depend on the chain length in a nonmonotonic way at high electric fields. This is found to be the signature of a nonequilibrium phase transition between two different migration states, a slow one and a fast one, which can also be observed experimentally under appropriate conditions.Comment: Revised edition corresponding to the comments by the referees, submitted to Physical Review