A novel model to explain dietary factors affecting hypocalcaemia in dairy cattle

Most dairy cows exhibit different degrees of hypocalcaemia around calving because the gestational Ca requirements shift to the disproportionately high Ca requirements of lactation. Ca homeostasis is a robust system that effectively adapts to changes in Ca demand or supply. However, these adaptations often are not rapid enough to avoid hypocalcaemia. A delay in the reconfiguration of intestinal Ca absorption and bone resorption is probably the underlying cause of this transient hypocalcaemia. Several dietary factors that affect different aspects of Ca metabolism are known to reduce the incidence of milk fever. The present review describes the interactions between nutrition and Ca homeostasis using observations from cattle and extrapolations from other species and aims to quantitatively model the effects of the nutritional approaches that are used to induce dry cows into an early adaptation of Ca metabolism. The present model suggests that reducing dietary cation–anion difference (DCAD) increases Ca clearance from the blood by dietary induction of systemic acidosis, which results in hypercalciuria due to the loss of function of the renal Ca transient receptor potential vanilloid channel TRPV5. Alternatively, reducing the gastrointestinal availability of Ca by reducing dietary Ca or its nutritional availability will also induce the activation of Ca metabolism to compensate for basal blood Ca clearance. Our model of gastrointestinal Ca availability as well as blood Ca clearance in the transition dairy cow allowed us to conclude that the most common dietary strategies for milk fever prevention may have analogous modes of action that are based on the principle of metabolic adaptation before calving

There's no Place Like Home: A Strategic Framework to Overcome Liability of Foreignness in the German Car Market

Globalization has led to exciting new business opportunities around the globe. Still, national and cultural boundaries have not evaporated into a "borderless world". Several studies have identified so-called liabilities of foreignness that arise from a lack of embeddedness and roots in the host market and subsequent competitive disadvantages. Countervailing strategies for these effects have remained scarce so far. We suggest that this is due to the lack of a viable approach to identify and quantify these effects and develop a conceptual framework to empirically estimate the individual degree of liability of foreignness of a firm from a market perspective. We suggest that disruptive changes in a society change the dynamics of liability of foreignness and generate opportunities for foreign companies to optimize their localization strategies. We apply our approach to a large mature market with established international competition : the German new car market. For a comprehensive sample of roughly 1,400 car models from 2003 we estimate the relative turnover disadvantage for all major foreign manufacturers. We find that most foreign producers have managed to overcome liabilities of foreignness in Germany through firm-specific advantages. Still, some face significant challenges. A submarket analysis shows that home market advantages are more deeply rooted in the Western part of Germany and that foreign competitors find a more accessible competitive environment in Eastern Germany. Therefore, East Germany is a superior platform for deploying effective and efficient countervailing strategies. Moreover, we identify a broader rationale to engage early and decisively in untapped but promising markets like China. --Liability of foreignness,automotive market,multinational strategy,seemingly unrelated regressions

Random Access Game and Medium Access Control Design

Motivated partially by a control-theoretic viewpoint, we propose a game-theoretic model, called random access game, for contention control. We characterize Nash equilibria of random access games, study their dynamics, and propose distributed algorithms (strategy evolutions) to achieve Nash equilibria. This provides a general analytical framework that is capable of modeling a large class of system-wide quality-of-service (QoS) models via the specification of per-node utility functions, in which system-wide fairness or service differentiation can be achieved in a distributed manner as long as each node executes a contention resolution algorithm that is designed to achieve the Nash equilibrium. We thus propose a novel medium access method derived from carrier sense multiple access/collision avoidance (CSMA/CA) according to distributed strategy update mechanism achieving the Nash equilibrium of random access game. We present a concrete medium access method that adapts to a continuous contention measure called conditional collision probability, stabilizes the network into a steady state that achieves optimal throughput with targeted fairness (or service differentiation), and can decouple contention control from handling failed transmissions. In addition to guiding medium access control design, the random access game model also provides an analytical framework to understand equilibrium and dynamic properties of different medium access protocols

There is no Place Like Home: A Strategic Framework to Overcome Liability of Foreignness in the German Car Market

Globalization has led to exciting new business opportunities around the globe. Still, national and cultural boundaries have not evaporated into a borderless world. Several studies have identified so-called liabilities of foreignness that arise from a lack of embeddedness and roots in the host market and subsequent competitive disadvantages. Countervailing strategies for these effects have remained scarce so far. We suggest that this is due to the lack of a viable approach to identify and quantify these effects and develop a conceptual framework to empirically estimate the individual degree of liability of foreignness of a firm from a market perspective. We suggest that disruptive changes in a society change the dynamics of liability of foreignness and generate opportunities for foreign companies to optimize their localization strategies. We apply our approach to a large mature market with established international competition: the German new car market. For a comprehensive sample of roughly 1,400 car models from 2003 we estimate the relative turnover disadvantage for all major foreign manufacturers. We find that most foreign producers have managed to overcome liabilities of foreignness in Germany through firm-specific advantages. Still, some face significant challenges. A submarket analysis shows that home market advantages are more deeply rooted in the Western part of Germany and that foreign competitors find a more accessible competitive environment in Eastern Germany. Therefore, East Germany is a superior platform for deploying effective and efficient countervailing strategies. Moreover, we identify a broader rationale to engage early and decisively in untapped but promising markets like China.Liability of foreignness, automotive market, multinational strategy, seemingly unrelated regressions

Decellularised extracellular matrix-derived peptides from neural retina and retinal pigment epithelium enhance the expression of synaptic markers and light responsiveness of human pluripotent stem cell derived retinal organoids

Tissue specific extracellular matrices (ECM) provide structural support and enable access to molecular signals and metabolites, which are essential for directing stem cell renewal and differentiation. To mimic this phenomenon in vitro, tissue decellularisation approaches have been developed, resulting in the generation of natural ECM scaffolds that have comparable physical and biochemical properties of the natural tissues and are currently gaining traction in tissue engineering and regenerative therapies due to the ease of standardised production, and constant availability. In this manuscript we report the successful generation of decellularised ECM-derived peptides from neural retina (decel NR) and retinal pigment epithelium (decel RPE), and their impact on differentiation of human pluripotent stem cells (hPSCs) to retinal organoids. We show that culture media supplementation with decel RPE and RPE-conditioned media (CM RPE) significantly increases the generation of rod photoreceptors, whilst addition of decel NR and decel RPE significantly enhances ribbon synapse marker expression and the light responsiveness of retinal organoids. Photoreceptor maturation, formation of correct synapses between retinal cells and recording of robust light responses from hPSC-derived retinal organoids remain unresolved challenges for the field of regenerative medicine. Enhanced rod photoreceptor differentiation, synaptogenesis and light response in response to addition of decellularised matrices from RPE and neural retina as shown herein provide a novel and substantial advance in generation of retinal organoids for drug screening, tissue engineering and regenerative medicine

Decision support for build-to-order supply chain management through multiobjective optimization

This paper aims to identify the gaps in decision-making support based on multiobjective optimization for build-to-order supply chain management (BTOSCM). To this end, it reviews the literature available on modelling build-to-order supply chains (BTO-SC) with the focus on adopting multiobjective optimization (MOO) techniques as a decision support tool. The literature has been classified based on the nature of the decisions in different part of the supply chain, and the key decision areas across a typical BTO-SC are discussed in detail. Available software packages suitable for supporting decision making in BTO supply chains are also identified and their related solutions are outlined. The gap between the modelling and optimization techniques developed in the literature and the decision support needed in practice are highlighted and future research directions to better exploit the decision support capabilities of MOO are proposed