Proposal for a chaotic ratchet using cold atoms in optical lattices

We investigate a new type of quantum ratchet which may be realized by cold atoms in a double-well optical lattice, pulsed with unequal periods. The classical dynamics is chaotic and we find the classical diffusion rate D is asymmetric in momentum up to a finite time t(r). The quantum behavior produces a corresponding asymmetry in the momentum distribution which is "frozen-in" by dynamical localization provided the break time t* greater than or equal to t(r). We conclude that the cold atom ratchets require Db/(h) over bar similar to 1, where b is a small deviation from period-one pulses

Considering appropriate replication in the design of animal social network studies

© 2019, The Author(s). Social network analysis has increasingly been considered a useful tool to interpret the complexity of animal social relationships. However, group composition can affect the contact structure of the network resulting in variation between networks. Replication in contact network studies is rarely done but enables determination of possible variation in response across networks. Here we explore the importance of between-group variability in social behaviour and the impact of replication on hypothesis testing. We use an exemplar study of social contact data collected from six replicated networks of cattle before and after the application of a social disturbance treatment. In this replicated study, subtle but consistent changes in animal contact patterns were detected after the application of a social disturbance treatment. We then quantify both within- and between-group variation in this study and explore the importance of varying the number of replicates and the number of individuals within each network, on the precision of the differences in treatment effects for the contact behaviour of the resident cattle. The analysis demonstrates that reducing the number of networks observed in the study would reduce the probability of detecting treatment differences for social behaviours even if the total number of animals was kept the same

Modelling parasite transmission in a grazing system: the importance of host behaviour and immunity

Parasitic helminths present one of the most pervasive challenges to grazing herbivores. Many macro-parasite transmission models focus on host physiological defence strategies, omitting more complex interactions between hosts and their environments. This work represents the first model that integrates both the behavioural and physiological elements of gastro-intestinal nematode transmission dynamics in a managed grazing system. A spatially explicit, individual-based, stochastic model is developed, that incorporates both the hosts' immunological responses to parasitism, and key grazing behaviours including faecal avoidance. The results demonstrate that grazing behaviour affects both the timing and intensity of parasite outbreaks, through generating spatial heterogeneity in parasite risk and nutritional resources, and changing the timing of exposure to the parasites' free-living stages. The influence of grazing behaviour varies with the host-parasite combination, dependent on the development times of different parasite species and variations in host immune response. Our outputs include the counterintuitive finding that under certain conditions perceived parasite avoidance behaviours (faecal avoidance) can increase parasite risk, for certain host-parasite combinations. Through incorporating the two-way interaction between infection dynamics and grazing behaviour, the potential benefits of parasite-induced anorexia are also demonstrated. Hosts with phenotypic plasticity in grazing behaviour, that make grazing decisions dependent on current parasite burden, can reduce infection with minimal loss of intake over the grazing season. This paper explores how both host behaviours and immunity influence macro-parasite transmission in a spatially and temporally heterogeneous environment. The magnitude and timing of parasite outbreaks is influenced by host immunity and behaviour, and the interactions between them; the incorporation of both regulatory processes is required to fully understand transmission dynamics. Understanding of both physiological and behavioural defence strategies will aid the development of novel approaches for control

The incredible years therapeutic dinosaur programme to build social and emotional competence in welsh primary schools: study protocol for a randomised controlled trial

<p>Abstract</p> <p>Background</p> <p>School interventions such as the Incredible Years <it>Classroom </it>Dinosaur Programme targets pupil behaviour across whole classrooms, yet for some children a more intense approach is needed. The Incredible Years <it>Therapeutic </it>Dinosaur Programme is effective for clinically referred children by enhancing social, problem-solving skills, and peer relationship-building skills when delivered in a clinical setting in small groups.</p> <p>The aim of this trial is to evaluate the effectiveness of the Therapeutic Programme, delivered with small groups of children at high-risk of developing conduct disorder, delivered in schools already implementing the Classroom Programme.</p> <p>Methods/Design</p> <p>This is a pragmatic, parallel, randomised controlled trial.</p> <p>Two hundred and forty children (aged 4-8 years) rated by their teacher as above the 'borderline cut-off' for concern on the Strengths and Difficulties Questionnaire, and their parents, will be recruited.</p> <p>Randomisation is by individual within blocks (schools); 1:1 ratio, intervention to waiting list control.</p> <p>Twenty schools will participate in two phases. Two teachers per school will deliver the programme to six intervention children for 2-hours/week for 18 weeks between baseline and first follow-up. The control children will receive the intervention after first follow up.</p> <p>Phase 1 comprises three data collection points - baseline and two follow-ups eight months apart. Phase 2 includes baseline and first follow-up.</p> <p>The Therapeutic Programme includes elements on; Learning school rules; understanding, identifying, and articulating feelings; problem solving; anger management; how to be friendly; how to do your best in school.</p> <p>Primary outcomes are; change in child social, emotional and behavioural difficulties. Secondary outcomes are; teacher and parent mental wellbeing, child academic attainment, child and teacher school attendance. Intervention delivery will be assessed for fidelity.</p> <p>Intention to treat analyses will be conducted. ANCOVA, effect sizes, mediator and moderator analyses will be applied to establish differences between conditions, and for whom the intervention works best for and why.</p> <p>Discussion</p> <p>This trial will provide information on the delivery and effectiveness of a child centred, school-based intervention delivered in small groups of children, at risk of developing more severe conduct problems. The effects on child behaviour in school and home environments, academic attainment, peer interactions, parent and teacher mental health will be assessed.</p> <p>Trial Registration</p> <p>UK Clinical Research Network UKCRNID8615</p> <p>Current Controlled Trials <a href="http://www.controlled-trials.com/ISRCTN96803379">ISRCTN96803379</a></p

Solvent inhibition in the liquid-phase catalytic oxidation of 1,4-butanediol: Understanding the catalyst behaviour from NMR relaxation time measurements

Solvent inhibition over surfaces affects behaviour and performances of heterogeneous catalysts.Johnson Matthey, EvonikDegussa, Technology Strategy Board (Grant ID: TP/7/ZEE/6/I/N0262B), Engineering and Physical Sciences Research Council and CASTech consortium (Grant ID: EP/G011397/1), Wolfson College Cambridg