Shock avoidance by discrimination learning in the shore crab (Carcinus maenas) is consistent with a key criterion for pain

Nociception allows for immediate reflex withdrawal whereas pain allows for longer-term protection via rapid learning. We examine here whether shore crabs placed within a brightly lit chamber learn to avoid one of two dark shelters when that shelter consistently results in shock. Crabs were randomly selected to receive shock or not prior to making their first choice and were tested again over 10 trials. Those that received shock in trial 2, irrespective of shock in trial 1, were more likely to switch shelter choice in the next trial and thus showed rapid discrimination. During trial 1, many crabs emerged from the shock shelter and an increasing proportion emerged in later trials, thus avoiding shock by entering a normally avoided light area. In a final test we switched distinctive visual stimuli positioned above each shelter and/or changed the orientation of the crab when placed in the chamber for the test. The visual stimuli had no effect on choice, but crabs with altered orientation now selected the shock shelter, indicating that they had discriminated between the two shelters on the basis of movement direction. These data, and those of other recent experiments, are consistent with key criteria for pain experience and are broadly similar to those from vertebrate studies. © 2013. Published by The Company of Biologists Ltd.

Avoidance Techniques: State Related Defences in International Antitrust Cases

Despite its economic significance, competition law still remains fragmented, lacking an international framework allowing for dispute settlement. This, together with the growing importance of non-free-market economies in world trade require us to re-consider and re-evaluate the possibilities of bringing an antitrust suit against a foreign state. If the level playing field on the global marketplace is to be achieved, the possibility of hiding behind the bulwark of state sovereignty should be minimised. States should not be free to act in an anti-competitive way, but at present the legal framework seems ill-equipped to handle such challenges.

This paper deals with the defences available in litigation concerning transnational anti-competitive agreements involving or implicating foreign states. Four important legal doctrines are analysed: non-justiciability (political question doctrine), state immunity, act of state doctrine and foreign state compulsion. The paper addresses also the general problem of applicability of competition laws to a foreign state as such. This is a tale about repetitive unsuccessful efforts to sue OPEC and recent attempts in the US to deal with export cartels of Chinese state-owned enterprises

A downlink power control scheme for interference avoidance in femtocells

Femtocells being small low powered base stations provide sufficient increase in system capacity along with better indoor coverage. However, the dense deployment of femtocells face the main challenge of co channel interference with macrocell users. In this paper, this interference problem is addressed by proposing a novel downlink power control algorithm for femtocells. The proposed algorithm gradually reduces the downlink transmit power of femtocells when they are informed about a nearby macrocell user under interference. This information is given to the femtocells by the macrocell base station through a unidirectional downlink broadcast channel. Simulation results show that the algorithm causes the macrocell to accommodate large number of femtocells within its area, whereas at the same time protecting the macrocell users from any harmful interference.

A co-operative formation-based collision avoidance approach for a group of autonomous vehicles (Special Issue on Adaptive Control and Signal Processing in Marine System)

This paper employs a unique decentralised cooperative control method to realise a formation-based collision avoidance strategy for a group of autonomous vehicles. In this approach, the vehicles' role in the formation and their alert and danger areas are first defined, and the formation-based intra-group and external collision avoidance methods are then proposed to translate the collision avoidance problem into the formation stability problem. The extension–decomposition–aggregation formation control method is next employed to stabilise the original and modified formations, whilst manoeuvring, and subsequently solve their collision avoidance problem indirectly. Simulation study verifies the feasibility and effectiveness of the intra-group and external collision avoidance strategy. It is demonstrated that both formation control and collision avoidance problems can be simultaneously solved if the stability of the expanded formation including external obstacles can be satisfied.

Multiple robots formation manoeuvring and collision avoidance strategy

This paper presents a multiple robots formation manoeuvring and its collision avoidance strategy. The direction priority sequential selection algorithm is employed to achieve the raw path, and a new algorithm is then proposed to calculate the turning compliant waypoints supporting the multi-robot formation manoeuvre. The collision avoidance strategy based on the formation control is presented to translate the collision avoidance problem into the stability problem of the formation. The extension-decomposition-aggregation scheme is next applied to solve the formation control problem and subsequently achieve the collision avoidance during the formation manoeuvre. Simulation study finally shows that the collision avoidance problem can be conveniently solved if the stability of the constructed formation including unidentified objects can be satisfied.

No discrimination shock avoidance with sequential presentation of stimuli but shore crabs still reduce shock exposure

Insights into the potential for pain may be obtained from examination of behavioural responses to noxious stimuli. In particular, prolonged responses coupled with long-term motivational change and avoidance learning cannot be explained by nociceptive reflex but are consistent with the idea of pain. Here, we placed shore crabs alternately in two halves of a test area divided by an opaque partition. Each area had a dark shelter and in one repeated small electric shocks were delivered in an experimental but not in a control group. Crabs showed no specific avoidance of the shock shelter either during these trials or in a subsequent test in which both were offered simultaneously; however they often emerged from the shock shelter during a trial and thus avoided further shock. More crabs emerged in later trials and took less time to emerge than in early trials. Thus, despite the lack of discrimination learning between the two shelters they used other tactics to markedly reduce the amount of shock received. We note that a previous experiment using simultaneous presentation of two shelters demonstrated rapid discrimination and avoidance learning but the paradigm of sequential presentation appears to prevent this. Nevertheless, the data show clearly that the shock is aversive and tactics, other than discrimination learning, are used to avoid it. Thus, the behaviour is only partially consistent with the idea of pain.

Sex Education in Northern Ireland Schools: a Critical Evaluation.

To date there has been little research on young people and sexuality in Northern Ireland. This paper draws on the first major study in this area to analyse the delivery of formal sex education in schools. Both quantitative and qualitative methods were used to access young people's opinions about the quality of the sex education they had received at school. Overall, they reported high levels of dissatisfaction, with notable variations in relation to both gender and religious affiliation. In one sense their opinions mesh well with those of young people in other parts of these islands. At the same time the specificity of sexuality in Ireland plays a key role in producing the moral system that underlies much of formal sex education in schools. Underpinned by a particularly traditional and conservative strain of Christian morality, sex education in Northern Ireland schools is marked by conservatism and silence and by the avoidance of opportunities for informed choice in relation to sexuality on the part of young people.

What price harmony? Teachers' methods of delivering an ethos of tolerance and respect for diversity in an integrated school in Northern Ireland

The aim of the paper is to explore teachers’ methods of delivering an ethos of tolerance, respect
and mutual understanding in one integrated secondary school in Northern Ireland. Drawing on
interviews with teachers in the school, it is argued that most teachers make ‘critical choices’
which both reflect and reinforce a ‘culture of avoidance’, whereby politically or religiously contentious
issues are avoided rather than explored. Although teachers are well-intentioned in making
these choices, it is shown that they have the potential to create the conditions that maintain or even
harden psychological boundaries between Catholics and Protestants rather than dilute them.