Vitreous Substitutes: Old and New Materials in Vitreoretinal Surgery

Recent developments in vitreoretinal surgery have increased the need for suitable vitreous substitutes. A successful substitute should maintain all the physical and biochemical properties of the original vitreous, be easy to manipulate, and be long lasting. Substitutes can be gaseous or liquid, both of which have associated advantages and disadvantages related to their physical properties and use. Furthermore, new surgical techniques with smaller vitreoretinal instruments have driven the use of more viscous substitutes. In this review, we analyze and discuss the most frequently used vitreous substitutes and look ahead to future alternatives. We classify these compounds based on their composition and structure, discuss their clinical use with respect to their associated advantages and disadvantages, and analyze how new vitreoretinal surgical techniques have modified their use

Competitive strategies in the motion picture industry: An ABM to study investment decisions

We study a parsimonious competition setting whereby two studio producers launch their movies simultaneously. They compete deciding about the positioning of their movies, as they can position close to or far from the mainstream, and investing in advertising and in quality. We study our competitive setting with an analytical model and solve it using a standard game-theoretical technique. Next, we use an agent-based model (ABM) to relax several assumptions of the analytical model and investigate more realistic market situations, such as symmetric as well as asymmetric positioning, competitions among big and/or small studios, settings with more than two competitors, and studios that use weighted and evolving decision rules. Our results explain interesting dynamics behind the scenes of the competition. They indicate the drivers of studios' behaviors and shed light on some important aspects of their strategic competition. In this sense, our results offer relevant theoretical and practical implications

1,3-Butanediol Administration Increases β-Hydroxybutyrate Plasma Levels and Affects Redox Homeostasis, Endoplasmic Reticulum Stress, and Adipokine Production in Rat Gonadal Adipose Tissue

Ketone bodies (KBs) are an alternative energy source under starvation and play multiple roles as signaling molecules regulating energy and metabolic homeostasis. The mechanism by which KBs influence visceral white adipose tissue physiology is only partially known, and our study aimed to shed light on the effects they exert on such tissue. To this aim, we administered 1,3-butanediol (BD) to rats since it rapidly enhances β-hydroxybutyrate serum levels, and we evaluated the effect it induces within 3 h or after 14 days of treatment. After 14 days of treatment, rats showed a decrease in body weight gain, energy intake, gonadal-WAT (gWAT) weight, and adipocyte size compared to the control. BD exerted a pronounced antioxidant effect and directed redox homeostasis toward reductive stress, already evident within 3 h after its administration. BD lowered tissue ROS levels and oxidative damage to lipids and proteins and enhanced tissue soluble and enzymatic antioxidant capacity as well as nuclear erythroid factor-2 protein levels. BD also reduced specific mitochondrial maximal oxidative capacity and induced endoplasmic reticulum stress as well as interrelated processes, leading to changes in the level of adipokines/cytokines involved in inflammation, macrophage infiltration into gWAT, adipocyte differentiation, and lipolysis

Control and contract design in research collaborations: A complete contracts perspective

Incumbent firms, especially in high-tech industries, often contract and collaborate with small research units on single projects. A delicate resulting contracting decision thus is how to allocate control. This paper considers the incumbent's problem to design a research contract that specifies: the allocation of control; the unit's research input, and its monetary compensation. Contracting is complicated by the unit's private information about its technological skills; research outputs also are not verifiable. Control affects the distribution of the private benefits from research and can be shared. From a complete contracts perspective, an allocation of control that is contingent on the unit's reported information provides the incumbent an additional instrument for designing the incentives. Control can generate countervailing incentives and mitigate the limitations of contracts in research environments, to the point of extracting the full surplus. The analysis further clarifies when control is centralized by the incumbent, when it is shared between the parties, and when it is delegated to the unit

Strategic interaction in alliances

This article studies strategic interactions between firms that form alliances to exploit synergistic benefits. Firms cooperate to create value, but they can also compete to capture value. Fundamental questions rarely addressed by strategy scholars relate to how the configuration of control over resources influences firms’ strategies, the potential for termination, and the emergence of cooperation and trust. The formal results reveal crucial aspects of the interorganizational rent-generating process and yield testable implications. With greater synergistic benefits, firms invest more, but they also compete more intensively to capture more value. With symmetric control, more value gets created, which limits the potential for termination but also exacerbates the competition for value; from a relational perspective, this form of control augments the calculative rationale of cooperation and trust

Second best

This article offers a brief overview of second best reasoning, sketches the theory and provides an example that illustrates the mechanics behind. The theory aims to identify the distortions generated by an economic friction that restraints a decision maker, using a three-step procedure: (i) compute the optimal choice of a decision maker in a frictionless environment (the first best solution); (ii) compute the optimal choice when an additional constraint due to the friction is added to the analysis (the second best solution); (iii) determine the disturbing effects of the friction by comparing the two solutions

Bargaining models

Negotiation is a pervasive feature of social exchange. Bargaining theory and the related models examine the problem of rational individuals that pursue their own interest and must reach an agreement to divide the gains from cooperating. This article sketches two pillars of the literature on bargaining: the axiomatic solution of Nash (1950) and the solution of Rubinstein’s (1982) bargaining game with alternating offers. It also comments briefly on the recent applications of bargaining and cooperative game theory to strategy

Value creation, value appropriation, and cooperation in team production

We propose a theoretical framework and develop a game-theoretical analysis to advance understanding of the cooperation dilemma in team production. We conceptualize team production as a process where productive and appropriative activities coexist, shifting the focus from whether team members cooperate to what type of cooperative behavior they are willing to adopt. Depending on the extent to which members cooperate to create value and compete to appropriate value, we can observe scenarios of full, partial, and no cooperation. After characterizing member behavior in the different scenarios, we study which form of cooperation can be sustained through repeated interaction, mutual monitoring, and reciprocity. To do so, we allow for different deviations from cooperation, which are then accompanied by different reactions according to an equivalent retaliation strategy. Our focus is on how member behavior and incentives to cooperate relate to teamsize. We also introduce conceptual elements that describe teamproduction in organizational teams as well as interorganizational relationships