When the Weak are Mighty: A Two‐Sided Matching Approach to Alliance Performance

Research Summary Network centrality is an important determinant of alliance performance. However, estimating how each alliance member\u27s centrality affects alliance performance is challenging because the end market might value each partner\u27s contribution differently. We solve this empirical question with a two‐sided matching model that accounts for the partners\u27 endogenous selection and estimates the effect of each side\u27s centrality and input quality on performance. We implement the method in the novel context of the Thoroughbred horse industry, in foal‐sharing alliances between buyers and suppliers. We find that buyer centrality has a larger marginal effect on the alliance performance than the supplier centrality because buyers, who on average are less central in our context, are more likely to diffuse valuable information to the end market. Managerial Summary Alliance partners often struggle with identifying what their contributions and their partner\u27s contribution are to the alliance performance. We use a new method to identify each side\u27s contribution to their alliance. Our findings offer a few recommendations to firms forming similar alliances. First, we find that the less central partner in the business network has greater impact on the alliance performance due to their ability to diffuse more valuable information to the market. Second, our results suggest that product input quality that is relatively unknown impacts alliance performance more than low and average quality. Alliance partners may benefit more from experimenting with unknown inputs. Third, more central actors may reduce spending on mass communications if valuable information comes to the market through their less central partners

Limited Resection Versus Pancreaticoduodenectomy for Duodenal Gastrointestinal Stromal Tumors? Enucleation Interferes in the Debate: A European Multicenter Retrospective Cohort Study

Background The optimal surgical procedure for duodenal gastrointestinal stromal tumors (D-GISTs) remains poorly defined. Pancreaticoduodenectomy (PD) allows for a wide resection but is associated with a high morbidity rate. Objectives The aim of this study was to compare the short- and long-term outcomes of PD versus limited resection (LR) for D-GISTs and to evaluate the role of tumor enucleation (EN). Methods In this retrospective European multicenter cohort study, 100 patients who underwent resection for D-GIST between 2001 and 2013 were compared between PD (n = 19) and LR (n = 81). LR included segmental duodenectomy (n = 47), wedge resection (n = 21), or EN (n = 13). The primary objective was to evaluate disease-free survival (DFS) between the groups, while the secondary objectives were to analyze the overall morbidity and mortality, radicality of resection, and 5-year overall survival (OS) and recurrence rates between groups. Furthermore, the short- and long-term outcomes of EN were evaluated. Results Baseline characteristics were comparable between the PD and LR groups, except for a more frequent D2 tumor location in the PD group (68.3% vs. 29.6%; p = 0.016). Postoperative morbidity was higher after PD (68.4% vs. 23.5%; p < 0.001). OS (p = 0.70) and DFS (p = 0.64) were comparable after adjustment for D2 location and adjuvant therapy rate. EN was performed more in American Society of Anesthesiologists (ASA) stage III/IV patients with tumors < 5 cm and was associated with a 5-year OS rate of 84.6%, without any disease recurrences. Conclusions For D-GISTs, LR should be the procedure of choice due to lower morbidity and similar oncological outcomes compared with PD. In selected patients, EN appears to be associated with equivalent short- and long-term outcomes. Based on these results, a surgical treatment algorithm is proposed

L'adhésion thérapeutique : un nouveau challenge pour les mathématiques

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Mathematical modeling of the microtubule dynamic instability: a new approch of GTP-tubulin hydrolysis

Microtubules, components of the cytosqueleton, play an important role in cell division, cell migration and thus in the cancer proccess through dynamic instability. Therefore they are an important target for anti-cancer treatment. Proper modelling of dynamic instability is a crucial tool to understand the mechanism of action of microtubule targeting agents. In this paper, we propose a new concept for GTP-tubulin hydrolysis which allow the model to accurately reproduce microtubule dynamics observed in vitro or in cells. This approach will be more appropriate to take study the effects of drugs

Mathematical Modeling of Effect Of Microtubule-Targeted Agents On Microtubule Dynamic Instability

Microtubule-targeted agents (MTAs), widely used in chemotherapy, are molecules that are able to block cancer cell migration and division. Their effect on microtubule (MT) dynamic instability is measured by their influence on observable parameters of MT dynamics such as growth speed, time-based catastrophe frequency, time-based rescue fre- quency, etc. In this paper, we propose a new mathematical model that is able to reproduce MT dynamics with an appropriate estimation of the main observable parameters. Using the experimental data on paclitaxel effect in presence of EB proteins, we fitted param- eters of the model from several drug concentrations. It enable us to understand which non-observable model parameters are able to reproduce the effect of MTAs and thus to highlight a new potential mechanism of action associated with MTAs effect in presence of EB protein

Mathematical modeling of the microtubule dynamic instability: a new approch of GTP-tubulin hydrolysis

Microtubules, components of the cytosqueleton, play an important role in cell division, cell migration and thus in the cancer proccess through dynamic instability. Therefore they are an important target for anti-cancer treatment. Proper modelling of dynamic instability is a crucial tool to understand the mechanism of action of microtubule targeting agents. In this paper, we propose a new concept for GTP-tubulin hydrolysis which allow the model to accurately reproduce microtubule dynamics observed in vitro or in cells. This approach will be more appropriate to take study the effects of drugs

Mathematical Modeling of Effect Of Microtubule-Targeted Agents On Microtubule Dynamic Instability★

Microtubule-targeted agents (MTAs), widely used in chemotherapy, are molecules that are able to block cancer cell migration and division. Their effect on microtubule (MT) dynamic instability is measured by their influence on observable parameters of MT dynamics such as growth speed, time-based catastrophe frequency, time-based rescue fre- quency, etc. In this paper, we propose a new mathematical model that is able to reproduce MT dynamics with an appropriate estimation of the main observable parameters. Using the experimental data on paclitaxel effect in presence of EB proteins, we fitted param- eters of the model from several drug concentrations. It enable us to understand which non-observable model parameters are able to reproduce the effect of MTAs and thus to highlight a new potential mechanism of action associated with MTAs effect in presence of EB protein

Using what you know: patented knowledge in incumbent firms and employee entrepreneurship

Prior studies have shown that the acquisition of relevant knowledge by employees in existing firms is associated with the creation of new firms through employee entrepreneruship. Some researchers propose that the transition to entrepreneurship may be explained by established firms undervaluing knowledge created by employees, whereas other scholars maintain that firm strategies may lead to the underutilization of knowledge. We ask the question of which of these drivers is more pronounced as an explanation of employee entrepreneurship and what technological factors matter in this relationship. Analyzing a unique data set, we find that the likelihood of employee entrepreneurship increases with the inventor’s assessment of the value of a patent for an invention developed while at the incumbent firm but dramatically decreases when the invention protected by the patent is commercialized by the firm, licensed to third parties, interdependent with other firms’ inventions protected by patents, or technologically broad. We also find that conditional on high valuation by the inventor, a matching high valuation by the firm further increases the likelihood of transitioning to entrepreneurship. In combination, we show that a situation when both the inventor and the firm consider the invention valuable but the firm ends up not commercializing the invention is more predictive of employee entrepreneurship than simple differences in assessing the value of the invention. The study refines our understanding of the drivers of entrepreneurship by underscoring the “strategic” explanation of employee entrepreneurship

Corporate governance practices and companies' R&D intensity: Evidence from European countries

This paper empirically investigates whether corporate governance practices implemented to align shareholders' and managers' interests affect the resources firms devote to R&D. Two databases - one on governance ratings and one on R&D investment - are merged to obtain a multi-country, multi-sector sample of 177 European companies involved in R&D activities. The results suggest that limitations of anti-takeover devices and voting rights restrictions, a financial performance-based remuneration system for managers and a higher shareholders' consensus at the annual general assembly are all negatively correlated with R&D intensity. In other words, governance practices that are designed to respond to the short-term expectations of financial markets might prove to be detrimental to long-term R&D investments.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Microtubules (MT) a key target in oncology: mathematical modeling of anti-MT agents on cell migration

Microtubules (MTs) are protein filaments found in all eukaryotic cells which are crucial for many cellular processes including cell movement, cell differentiation, and cell division, making them a key target for anti-cancer treatment. In particular, it has been shown that at low dose, MT targeted agents (MTAs) may induce an anti-migratory effect on cancer and endothelial cells, leading to new prospects in cancer therapy. In that context, we propose to better understand the role of MT dynamics and thus of MTAs on cell migration using a mathematical cell centered model of cell migration taking into account the action of microtubules in the process. The model use a fluid based approach that describes, through level-set techniques, the deformation of the membrane during cell migration. The fluid part of the model is mainly composed of Stokes equations and the biochemical state of the cell is described using Reaction-Diffusion equations. Microtubules act on the biochemical state by activating or inactivating proteins of the Rho-GTPases family. The numerical simulation of the model is performed using Discrete Duality Finite Volume techniques. We describe the different schemes used for the simulation, focusing on the adaptation of preexisting methods to our particular case. Numerical simulation are performed, showing a realistic behavior of the simulated cells in term of shape, speed and microtubules dynamics. Different strategies for a depolymerizing MTA (Vincristin) mechanisms are investigated and show the robutness of our model