Group navigation and the "many-wrongs principle" in models of animal movement.

Journal ArticleResearch Support, Non-U.S. Gov'tTraditional studies of animal navigation over both long and short distances have usually considered the orientation ability of the individual only, without reference to the implications of group membership. However, recent work has suggested that being in a group can significantly improve the ability of an individual to align toward and reach a target direction or point, even when all group members have limited navigational ability and there are no leaders. This effect is known as the "many-wrongs principle" since the large number of individual navigational errors across the group are suppressed by interactions and group cohesion. In this paper, we simulate the many-wrongs principle using a simple individual-based model of movement based on a biased random walk that includes group interactions. We study the ability of the group as a whole to reach a target given different levels of individual navigation error, group size, interaction radius, and environmental turbulence. In scenarios with low levels of environmental turbulence, simulation results demonstrate a navigational benefit from group membership, particularly for small group sizes. In contrast, when movement takes place in a highly turbulent environment, simulation results suggest that the best strategy is to navigate as individuals rather than as a group.Marine Institute and the Marine RTDI Measure, Productive Sector Operational Programme, National Development Plan 2000–2006

The structure and function of the cervix during pregnancy

The structure of the cervix is integral to the maintenance of pregnancy, keeping the developing baby in utero and forming a barrier to the ascent of microorganisms from the vagina. Weakness of the cervix may lead to deficiency of this barrier and is associated with subsequent preterm birth. The underlying cause of this structural weakness is poorly understood. In this paper we review the structure and function of the cervix before and during pregnancy. The causes of mechanical failure of the cervix during pregnancy are described, with a specific focus on the internal cervical os. We highlight the role of the internal cervical os in causing preterm birth and discuss research techniques that may provide further insight into its function during pregnancy. It is hoped that clinical translation of this knowledge will enable the early and appropriate identification of women who will benefit from strategies to reinforce the internal os and so reduce the incidence of preterm birth

Sedimentation, re-sedimentation and chronologies in archaeologically-important caves: problems and prospects

Excavations in the photic zones of caves have provided cornerstone archaeological sequences in many parts of the world. Before the appearance of modern dating techniques, cave deposits provided clear evidence for the antiquity, relative ages and co-occurrence of ancient human remains, material culture and fauna. Earlier generations of archaeologists had generally rather limited understanding of taphonomic and depositional processes, but the twentieth century saw considerable improvement in excavation and analytical techniques. The advent of modern dating and chronological methodologies offers very powerful tools for the analysis of cave fill deposits and this has resulted in the recognition of chronological incoherence in parts of some sites, with consequent re-evaluation of previous archaeological disputes. Obtaining multiple dates per context provides a means to assess the integrity and coherence of the archaeological and environmental records from cave fills. In the case of the Haua Fteah (Libya), this technique allowed the recognition of chronological coherence in low-energy depositional environments and limited recycling in high-energy contexts. We provide a conceptual model of the relationship between recycling, sedimentation rate and process energy. High-resolution investigation enables recognition of the complexity of the formation of cave sequences, thus an increasingly sophisticated understanding of human behaviour and environmental relationships in the past, and potentially gives a new life to old data

Sedimentation, re-sedimentation and chronologies in archaeologically-important caves: problems and prospects

Excavations in the photic zones of caves have provided cornerstone archaeological sequences in many parts of the world. Before the appearance of modern dating techniques, cave deposits provided clear evidence for the antiquity, relative ages and co-occurrence of ancient human remains, material culture and fauna. Earlier generations of archaeologists had generally rather limited understanding of taphonomic and depositional processes, but the twentieth century saw considerable improvement in excavation and analytical techniques. The advent of modern dating and chronological methodologies offers very powerful tools for the analysis of cave fill deposits and this has resulted in the recognition of chronological incoherence in parts of some sites, with consequent re-evaluation of previous archaeological disputes. Obtaining multiple dates per context provides a means to assess the integrity and coherence of the archaeological and environmental records from cave fills. In the case of the Haua Fteah (Libya), this technique allowed the recognition of chronological coherence in low-energy depositional environments and limited recycling in high-energy contexts. We provide a conceptual model of the relationship between recycling, sedimentation rate and process energy. High-resolution investigation enables recognition of the complexity of the formation of cave sequences, thus an increasingly sophisticated understanding of human behaviour and environmental relationships in the past, and potentially gives a new life to old data

Drivers of social cognitive development in human and non-human primate infants

From prosocial behavior to cultural learning and belief understanding, social cognitive skills are important for engagement in social interactions and learning from others. In this chapter, we review some probable foundational skills of social cognitive development in human and non-human primate (NHP) infants. We selectively discuss capacities that are early-emerging and shared across species, with the goal of illustrating the value of a comparative developmental approach in advancing our understanding of early social cognitive development. In particular, this chapter focuses on exploring the role that a comparative developmental approach may play in identifying foundational social cognitive abilities and the drivers of these early-emerging skills in human infants

Neonatal imitation and its sensorimotor mechanism

In the present chapter, we propose that aspects of early social development—sensorimotor matching skills, social motivation, and temperament—may explain variability in neonatal imitation. We suggest that the presence of an action-perception mechanism at birth can be better understood by taking into account the complex interactions occurring during development between infants' social competences, in part a cause and consequence of their sensorimotor skills, and the effects of different experiences and environmental inputs on individual differences already present from birth (e.g., social interest temperament). We also present some findings and propose future directions aimed at testing these possibilities by examining individual differences related to imitative skill