Improving customer retention in financial services using kinship network information

This study investigates the advantage of social network mining in a customer retention context. A company that is able to identify likely churners in an early stage can take appropriate steps to prevent these potential churners from actually churning and subsequently increase profit. Academics and practitioners are constantly trying to optimize their predictive-analytics models by searching for better predictors. The aim of this study is to investigate if, in addition to the conventional sets of variables (socio-demographics, purchase history, etc.), kinship network based variables improve the predictive power of customer retention models. Results show that the predictive power of the churn model can indeed be improved by adding the social network (SNA-) based variables. Including network structure measures (i.e. degree, betweenness centrality and density) increase predictive accuracy, but contextual network based variables turn out to have the highest impact on discriminating churners from non-churners. For the majority of the latter type of network variables, the importance in the model is even higher than the individual level counterpart variable.     

Ambient contracts: verifying and enforcing ambient object compositions à la carte

Current programming languages do not offer adequate abstractions to discover and compose heterogenous objects over unreliable networks. This forces programmers to discover objects one by one, compose them manually, and keep track of their individual connectivity state at all times. In this paper we propose Ambient Contracts, a novel programming abstraction to deal with the difficulties of composing objects connected over unreliable networks. Ambient Contracts provide declarative heterogenous group discovery and composition while dealing with the unreliability of the network. An ambient contract allows runtime verification and enforcement of the messages sent between the participants in the contract. The use of our abstraction significantly reduces the code base and allows programmers to focus on the core functionality of their application. Our claims are reinforced by comparing the implementation of an example scenario in our contracts with a Java implementation using M2MI.     

Low‐Voltage Electro‐Optic Modulation Using Amorphous Polycarbonate Host Material

The selection process leading to the development of a guest–host electro‐optic material based on an amorphous polycarbonate (APC) is described. The optical loss at 1300 nm of this material system is under 2 dB/cm, which is the confidence limit of the slab measurement used. A Mach–Zehnder modulator fabricated using the push–pull poling technique has a low switching voltage (V_π) of 1.2 V.     

An indicator approach to sustainable urban freight transport

Several indicators have been established to monitor and evaluate the sustainability of cities. Logistics and related transportation activities are underrepresented in these established frameworks despite the substantial negative impact of urban freight transport (UFT) on the environment, society and economy. The result is the lack of an understanding of freight flows’ impact on the liveability of cities. This paper fills this gap by introducing a comprehensive set of freight transport related indicators with an operational target in policy support and urban planning. It provides a discussion of its hierarchical design and 45 indicators. Using this indicator set, local authorities can assess and enhance UFT sustainability.     

3D Microstructured Carbon Nanotube Electrodes for Trapping and Recording Electrogenic Cells

Electrogenic cells such as cardiomyocytes and neurons rely mainly on electrical signals for intercellular communication. Microelectrode arrays (MEAs) have been developed for long‐term recording of cell signals and stimulation of electrogenic cells under low‐cell‐stress conditions, providing new insights in the behavior of electrogenic cells and the operation of the brain. To date, MEAs are relying on flat or needle‐shaped electrode surfaces, mainly due to limitations in the lithographic processes. This paper relies on a previously reported elasto‐capillary aggregation process to create 3D carbon nanotube (CNT) MEAs. This study shows that CNTs aggregate in well‐shaped structures of similar size as cardiomyocytes are particularly interesting for MEA applications. This is because i) CNT microwells of the right diameter preferentially trap individual cardiomyocytes, which facilitates single cell recording without the need for clamping cells or signal deconvolution, and ii) once the cells are trapped inside of the CNT wells, this 3D CNT structure is used as an electrode surrounding the cell, which increases the cell–electrode contact area. As a result, this study finds that the recorded output voltages increase significantly (more than 200%). This fabrication process paves the way for future study of complex interactions between electrogenic cells and 3D recording electrodes.     

Exploration and Exploitation within Firms: The Impact of CEOs' Cognitive Style on Incremental and Radical Innovation Performance

Previous studies have provided valuable insights into how environmental and organizational factors may influence levels of explorative and exploitative innovation in firms. At the same time, scholars suggest that individual characteristics, such as cognitive and behavioural inclinations of top executives, might also have significant impact on the ability of a firm to engage in explorative and exploitative activities. The importance of the CEO is of interest, especially in medium‐sized companies, where the CEO appears to be most influential. Very few studies, however, have quantitatively examined the relationship between individual characteristics of top managers and firm‐level exploration and exploitation. Most of the existing research focuses on observable managerial characteristics and the composition of top management teams. Therefore, some important psychological issues may have been bypassed. This study complements prior research in two fundamental ways. First, whereas previous studies focus on extrinsic organizational factors that influence individual exploration and exploitation, we rely on insights from cognitive psychology to hypothesize a relationship between intrinsic factors (i.e., cognitive style) and individuals' tendency for exploration versus exploitation. Second, whereas existing research remains silent on the implications of individual CEO characteristics for firm performance, we hypothesize a relationship between CEOs' tendency for exploration or exploitation and firm‐level innovation performance.     

Influence of the uterine environment on the development of in vitro-produced equine embryos

The necessity for early interaction between the embryo and the oviductal and/or uterine environment in the horse is reflected by several striking differences between equine embryos that develop in vivo and those produced in vitro. Better understanding of the salient interactions may help to improve the efficiency of in vitro equine embryo production. In an initial experiment, cleavage-stage in vitro-produced (IVP) equine embryos were transferred into the uterus of recipient mares that had ovulated recently to determine whether premature placement in this in vivo environment would improve subsequent development. In a second experiment, an important element of the uterine environment was mimicked by adding uterocalin, a major component of the endometrial secretions during early pregnancy, to the culture medium. Intrauterine transfer of cleavage-stage IVP equine embryos yielded neither ultrasonographically detectable pregnancies nor day 7 blastocysts, indicating that the uterus is not a suitable environment for pre-compact morula stage horse embryos. By contrast, exposure to uterocalin during IVP improved capsule formation, although it did not measurably affect the development or expression of a panel of genes known to differ between in vivo and in vitro embryos. Further studies are required to evaluate whether uterocalin serves purely as a carrier protein or more directly promotes improved capsule development.     

A blood group-related polymorphism of CD44 abolishes a hyaluronan-binding consensus sequence without preventing hyaluronan binding

CD44 is a widely expressed integral membrane protein that acts as a receptor for hyaluronan (HA) and is proposed to be important to cell-extracellular matrix interaction. The Indian (In) blood group antigens reside on CD44, and most individuals express the Inb antigen. Homozygosity for the Ina allele occurs as a rare event and is associated with production of alloantibody to the common Inb antigen after transfusion or pregnancy. The present study demonstrates that a single point mutation (G252 --> C) causes an Arg46 --> Pro substitution, which is responsible for the Inb/Ina polymorphism. Additional mutations were found in In(a+b-) cDNA but were not necessary to the antigenic phenotype as determined in site-directed mutagenesis studies. In studies using CD44 chimeric constructs, Arg46 has previously been shown to be crucial for maintenance of HA-binding ability to a CD44 peptide. However, the present study demonstrates that the Arg46 --> Pro substitution does not reduce HA binding to the intact CD44 protein, which contains two proposed extracellular HA-binding motifs. Down-regulation of HA binding to In(a+b-) CD44 by anti-CD44 monoclonal antibody (mAb) ligands, however, was weakened, although all mAbs tested bound In(a+b-) and In(a-b+) CD44 equally well. Competitive inhibition studies using human anti-Inb also showed that some mAbs that inhibit HA binding to CD44 may do so by interacting with a domain separate from, but affecting the structure of, the Inb epitope.     

Vertical fiber-to-waveguide coupling using adapted fibers with an angled facet fabricated by a simple molding technique

Vertical coupling between silicon-on-insulator waveguides and optical fibers is achieved using adapted fibers with an angled facet. The proposed coupling scheme is demonstrated for waveguides containing uniform one-dimensional grating couplers. A coupling efficiency of 32% and a 1 dB bandwidth of 32 nm are measured at a wavelength of 1550 nm. We demonstrate single-step fabrication of these fibers using a simple molding technique.