Boycotts are among the most frequent forms of consumer expression against unethical or egregious acts by firms. Most current research explains consumers' decisions to participate in a boycott using a ...universal cost-benefit model that mixes instrumental and expressive motives. To date, no conceptual framework accounts for the distinct behavioral motives for boycotting though. This article focuses on motivational heterogeneity among consumers. By distinguishing two stable behavioral models—a self-regarding type and a strongly reciprocal type—we introduce the notion of strong reciprocity to the boycott literature. We argue that the presence of strongly reciprocal consumers can enhance boycott success. First, in interactions with the target firm, strongly reciprocal consumers perceive higher levels of egregiousness and are more willing to engage in boycotting behavior, even in unfavorable strategic conditions, which provides a stable basis for boycotting. Second, in interactions with self-regarding consumers, strongly reciprocal consumers are willing to sanction those others, according to whether they participate in the boycott, which increases overall participation in and the likelihood of success of a consumer boycott. These findings have implications for further research, as well as for firms, nongovernmental organizations, and boycotters.
We analyze the suitability of cross-sector partnerships as an effective mechanism for private environmental governance. By focusing on the interaction between firms within cross-sector partnerships, ...we analyze how competition between firms affects partnership effectiveness. Marrying insights from the private governance literature with institutional theory and the resource-based view, we identify under which conditions firm-level competition for legitimacy and capabilities, respectively, undermines or enhances effectiveness of cross-sector partnerships to address environmental issues. In doing so, our argument develops the various factors that moderate the relationship between competition and effectiveness for different types of partnerships. We contend that the effectiveness of cross-sector partnerships for governing global environmental issues depends considerably on whether competitive forces at the firm level are aligned with the collective benefits of partnerships. We discuss the consequences for designing effective cross-sector partnerships as well as the implications of a firm perspective on private governance.
•A non-stoichiometric adsorption model for IEC chromatography is derived.•Adsorption is governed by electrostatic interactions inside an interaction force boundary layer.•The model accounts ...explicitly for ionic strength and pH based on the protein primary structure.•Model parameters are theoretically valid on different stationary phases.•Effect of post-translational modifications on protein adsorption can be simulated.
Mechanistic modeling of protein adsorption has gained increasing importance in the development of ion-exchange (IEX) chromatography processes. The most common adsorption models use a stoichiometric representation of the adsorption process based on the law of mass action. Despite the importance of these models in model-based development, the stoichiometric representation of the adsorption process is not accurate for the description of long-range electrostatic interactions in IEX chromatography, limiting the application and mechanistic extension of these models.
In this work an adsorption model is introduced describing the non-stoichiometric electrostatic interaction in IEX chromatography based on the linear Poisson–Boltzmann equation and a simplified colloidal representation of the protein. In contrast to most recent non-stoichiometric models, the introduced model accounts for charge regulation during the adsorption process. Its capability of describing the adsorption equilibrium is demonstrated by simulating partitioning coefficients of multiple proteins on different adsorber systems as a function of ionic strength and pH. Despite model simplifications the physical meaning and predictive value of the model could be preserved. By transferring model parameters of a monoclonal antibody (mAb) from one adsorber system to another, it could be demonstrated that protein parameters are theoretically not only valid on a specific adsorber system but freely transferable to other adsorbers. The predictive value of the mechanistic model on the new adsorber system was highlighted by predicting the elution behavior of charge variants of the mAb.
•A mechanistic chromatography model for a bispecific antibody format was developed.•Guidelines for good modeling practice were applied throughout.•Charge variants were found to be essential to model ...the elution profile.•Over-parameterization, parameter correlations and systematic errors were discussed.•Critical process parameters and acceptable operating ranges were assessed in silico.
In the biopharmaceutical industry, development and characterization of chromatography processes is typically based on statistical models. Although these approaches are easy to apply, the resulting models may fail to predict non-linear behavior in preparative chromatography with complex protein feed streams. An alternative to empirical methods are mechanistic models. In chemical engineering, mechanistic modeling has been a standard method for decades. As mechanistic models continue their advance in the biopharmaceutical industry, this study underlines the need of a standardized methodology for mechanistic model calibration.
A lumped rate model was applied to the polishing chromatography of a bispecific antibody. Following guidelines for good modeling practice, the model was thoroughly analyzed. Potential limitations such as over-parameterization, parameter correlations, imprecise parameter estimates or systematic errors were considered by evaluation of parameter confidence intervals, visual sensitivity analysis and model validation across different scales. Application of simulations for identification of critical process parameters will be discussed.
Over the last two decades, corporate sustainability has been established as a legitimate research topic among management and organization scholars. This introductory article explores potential ...avenues for advances in research on corporate sustainability by readdressing some of the fundamental aspects of the sustainability debate and approaching some novel perspectives and insights from outside the corporate sustainability field. This essay also sketches out how each of the six articles of this special issue contribute to the literature by going back to some of the conceptual roots of sustainability and/or by offering novel perspectives for research on corporate sustainability. As these six articles and the outlook on future research opportunities show, broadening the inquiry of corporate sustainability in terms of topics, theories, and methodologies holds considerable potential to improve our understanding of how decision makers and organizations respond to sustainability.
HER2/neu is an oncogene that facilitates neoplastic transformation due to its ability to transduce growth signals in a ligand-independent manner, is over-expressed in 20-30% of human breast cancers ...correlating with aggressive disease and has been successfully targeted with trastuzumab (Herceptin®). Because trastuzumab alone achieves only a 15-30% response rate, it is now commonly combined with conventional chemotherapeutic drugs. While the combination of trastuzumab plus chemotherapy has greatly improved response rates and increased survival, these conventional chemotherapy drugs are frequently associated with gastrointestinal and cardiac toxicity, bone marrow and immune suppression. These drawbacks necessitate the development of new, less toxic drugs that can be combined with trastuzumab. Recently, we reported that orally administered alpha-tocopheryloxyacetic acid (α-TEA), a novel ether derivative of alpha-tocopherol, dramatically suppressed primary tumor growth and reduced the incidence of lung metastases both in a transplanted and a spontaneous mouse model of breast cancer without discernable toxicity.
In this study we examined the effect of α-TEA plus HER2/neu-specific antibody treatment on HER2/neu-expressing breast cancer cells in vitro and in a HER2/neu positive human xenograft tumor model in vivo.
We show in vitro that α-TEA plus anti-HER2/neu antibody has an increased cytotoxic effect against murine mammary tumor cells and human breast cancer cells and that the anti-tumor effect of α-TEA is independent of HER2/neu status. More importantly, in a human breast cancer xenograft model, the combination of α-TEA plus trastuzumab resulted in faster tumor regression and more tumor-free animals than trastuzumab alone.
Due to the cancer cell selectivity of α-TEA, and because α-TEA kills both HER2/neu positive and HER2/neu negative breast cancer cells, it has the potential to be effective and less toxic than existing chemotherapeutic drugs when used in combination with HER2/neu antibody.
Price momentum is a well‐documented anomaly in many of the world’s equity markets, and refers to the excess returns due to buying (selling) past winner (loser) stocks. Industry momentum refers to the ...excess returns due to buying (selling) stocks from past winner (loser) industries, and has been demonstrated to be more profitable than individual stock momentum in the United States. We investigate whether industry momentum can be captured by investing with sector exchange‐traded funds (ETFs). The performance of sector ETF‐based industry momentum is very different to stock momentum, and the strong performance of an unexpected group of sector ETF momentum portfolios remains robust after controlling for risk.
•A mechanistic model for HIC is derived by considering the water structure on hydrophobic surfaces.•Model parameters for three proteins were identified using both column and batch experiments ...independently.•Predictions for gradient elution runs beyond the calibration space were validated in the laboratory.
Mechanistic models are successfully used for protein purification process development as shown for ion-exchange column chromatography (IEX). Modeling and simulation of hydrophobic interaction chromatography (HIC) in the column mode has been seldom reported. As a combination of these two techniques is often encountered in biopharmaceutical purification steps, accurate modeling of protein adsorption in HIC is a core issue for applying holistic model-based process development, especially in the light of the Quality by Design (QbD) approach.
In this work, a new mechanistic isotherm model for HIC is derived by consideration of an equilibrium between well-ordered water molecules and bulk-like ordered water molecules on the hydrophobic surfaces of protein and ligand.
The model's capability of describing column chromatography experiments is demonstrated with glucose oxidase, bovine serum albumin (BSA), and lysozyme on Capto™ Phenyl (high sub) as model system. After model calibration from chromatograms of bind-and-elute experiments, results were validated with batch isotherms and prediction of further gradient elution chromatograms.
PDF
