First year growth in the lithodids Lithodes santolla and Paralomis granulosa reared at different temperatures

The southern king crab, Lithodes santolla Molina, and stone crab, Paralomis granulosa Jacquinot, inhabit the cold-temperate waters of southernmost South America (southern Chile and Argentina), where stocks of both species are endangered by overfishing. Recent investigations have shown that these crabs show life-cycle adaptations to scarcity of food and low temperatures prevailing in subantarctic regions, including complete lecithotrophy of all larval stages and prolonged periods of brooding and longevity. However, growth and development to maturity are slow under conditions of low temperatures, which may explain the particular vulnerability of subpolar lithodids to fisheries. In the present study, juvenile L. santolla and P. granulosa were individually reared in the laboratory at constant temperatures ranging from 3–15 °C, and rates of survival and development through successive instars were monitored throughout a period of about nine months from hatching. When the experiments were terminated, L. santolla had maximally reached juvenile instar IV (at 6 °C), V (9 °C), or VII (15 °C). In P. granulosa the maximum crab instar reached was II (at 3 °C), V (6 °C), V (9 °C), or VII (15 °C). The intermoult period decreased with increasing temperature, while it increased in successively later instars. In consequence, growth rate showed highly significant differences among temperatures (P<0.001). Growth-at-moult was highest at 9 °C. Rates of survival decreased significantly in juvenile P. granulosa with increasing temperature. Only at 15 °C in L. santolla, was a significantly enhanced mortality found compared with lower temperatures. Our results indicate that juvenile stages of L. santolla and P. granulosa are well adapted to 5–10°C, the range of temperatures typically prevailing in subantarctic marine environments. In spite of causing higher mortality rates, higher rearing temperatures (12–15 °C) should accelerate the rates of growth and maturation, which may be favourable for projects aiming at aquaculture or repopulation of overexploited king crab stocks

Competition and the Dynamics of Takeover Contests

This paper investigates the effect of potential competition on takeovers which we model as a bargaining game with alternating offers where calling an auction represents an outside option for each bidder at each stage of the game. The model describes a takeover process that is initiated by an unsolicited bidder, and it aims to answer three main questions: who wins the takeover and how? when? and how much is the takeover premium? Our results explain why the takeover premium resulting from a negotiated deal is not significantly different from that resulting from an auction, and why tender offers are rarely observed in reality. We also show that when the threat of the initial bidder to call a tender offer is not credible, the takeover process might end with a private auction organized by the target. Conversely, when the tender offer threat is credible, the takeover process ends with a deal negotiated bilaterally between the bidder and the target. The takeover premium always depends on the degree of potential competition, while it is affected by the target resistance only for weak initial bidders. Finally, the model allows us to draw conclusions on how other dimensions of the takeover process, such as termination fees, control benefits and tender offer costs, affect its dynamics and outcome

White Knights and the Corporate Governance of Hostile Takeovers

We analyze the dynamics of takeover contests where hostile raiders compete against white knights involved by a lead blockholder of the target firm (the incumbent). We assume that the incumbent has the power to bargain with the potential bidders to set a minimum takeover price. We characterize the conditions under which a white knight wins the takeover contest despite the smaller value of its synergies as compared to those of the hostile bidder. The paper provides a new explanation for the reason why we observe so few hostile takeovers in reality; moreover, it sheds some light on the effectiveness of white knights as an anti-takeover device and the role played by leading minority blockholders in the market for corporate control. ∗We would like to thank Vasso Ioannidou, Maria Fabiana Penas and Paul Sengmueller for their useful comments, as well as the seminar participants at the University of Groningen and the University of Tilburg

Preopening and equilibrium selection

Cahier de Recherche du Groupe HEC nº 927We introduce a form of pre-play communication that we call "preopening" for standard normal form, two player games. During the preopening players announce their strategy using a communication system which is subject to stochastic failures. Players payoffs depend on the action profile posted on the system at the end of the preopening. We show that the preopening allows players to coordinate on one pure strategy equilibrium of the game when the system failures hit the two players idiosyncratically. In such a case the preopening always leads the players to select the Pareto superior Nash equilibrium when this exhibits the maximum attainable payoff for each player. Moreover, in the class of two action games of conflicting interests the preopening leads to select the equilibrium preferred by the player with (i) the strongest preference over different equilibria, (ii) the lower cost of miscoordination or (iii) the less efficient posting system

Prenex Separation Logic with One Selector Field

International audienceWe show that infinite satisfiability can be reduced to finite satisfiabil-ity for all prenex formulas of Separation Logic with k ≥ 1 selector fields (SL k). This fact entails the decidability of the finite and infinite satisfiability problems for the class of prenex formulas of SL 1 , by reduction to the first-order theory of a single unary function symbol and an arbitrary number of unary predicate symbols. We also prove that the complexity of this fragment is not elementary recursive, by reduction from the first-order theory of one unary function symbol. Finally, we prove that the Bernays-Schönfinkel-Ramsey fragment of prenex SL 1 formulas with quantifier prefix in the language ∃ * ∀ * is PSPACE-complete

Verifying linearizability on TSO architectures

Linearizability is the standard correctness criterion for fine-grained, non-atomic concurrent algorithms, and a variety of methods for verifying linearizability have been developed. However, most approaches assume a sequentially consistent memory model, which is not always realised in practice. In this paper we define linearizability on a weak memory model: the TSO (Total Store Order) memory model, which is implemented in the x86 multicore architecture. We also show how a simulation-based proof method can be adapted to verify linearizability for algorithms running on TSO architectures. We demonstrate our approach on a typical concurrent algorithm, spinlock, and prove it linearizable using our simulation-based approach. Previous approaches to proving linearizabilty on TSO architectures have required a modification to the algorithm's natural abstract specification. Our proof method is the first, to our knowledge, for proving correctness without the need for such modification

Transient working lives : migrant women's everyday politics in London's hospitality industry

By bringing together trans-nationalism and labour process studies my research develops an understanding of migrant labour that re-evaluates the social and political potential of migrants’ everyday relationships in, across and beyond their workplaces. It shows that, although increasing casualisation of employment limits workers’ organisational resources, growing diversity and mobility also prompts alternative modes of resistance to improve the lives of transient workers. The challenges this research poses for unions include overcoming the persisting ‘masculine politics’ of organising models, expanding their coalitions beyond an ‘industry-based’ strategy, and engaging directly with migrants’ communities to promote self-organising through alternative educational tools.EThOS - Electronic Theses Online ServiceGBUnited Kingdo