Perceptual outcomes as reinforcers

The paucity of basic behavioral research with humans was highlighted almost 40 years ago (Findley, 1966). A recent search of the basic behavioral research journals by the present authors indicated that this situation remains, with only approximately 15% of the research using human participants. It may seem surprising that so few studies use human participants given the apparent practical advantages of doing so. Human participants are readily available, extensively pre-trained, can use a range of complex apparatus and require no feeding or housing. In reality, however, the use of human participants involves a number of practical difficulties: humans generally will not agree to participate in research involving a large number of sessions or sessions lasting more than two to three hours; it is difficult to gain within-session compliance as a result of the often repetitive and simplistic nature of the tasks; and it is often unclear whether the experimental results are a product of the experimentally-arranged contingencies or the instructions given to the participants. Another difficulty, that which is addressed here, lies in the identification of a suitable experimental outcome that will serve as a reinforcer

Field dependence of electronic recoil signals in a dual-phase liquid xenon time projection chamber

We present measurements of light and charge signals in a dual-phase time projection chamber at electric fields varying from 10 V/cm up to 500 V/cm and at zero field using 511 keV gamma rays from a $^{22}$Na source. We determine the drift velocity, electron lifetime, diffusion constant, and light and charge yields at 511 keV as a function of the electric field. In addition, we fit the scintillation pulse shape to an effective exponential model, showing a decay time of 43.5 ns at low field that decreases to 25 ns at high fields.Comment: 14 pages, 8 figure

A Review on the Invasion Ecology of Amur Honeysuckle (Lonicera maackii, Caprifoliaceae), A Case Study of Ecological Impacts at Multiple Scales

Invasive species are of global importance because of their impacts on ecological communities, habitat structure, native community dynamics, and ecosystem processes and function. Scientists and conservation managers are increasingly focusing on the biological impacts of invasive species and on devising management practices that emphasize the health of ecosystems based on measured biological processes. Amur honeysuckle (Lonicera maackii (Rupr.) Herder) is a highly successful invasive shrub in forests of eastern North America. The scientific literature surrounding this species has grown in the past several decades as researchers have investigated L. maackii impacts across multiple ecological scales. In this review we synthesized literature on (a) the key traits related to this species\u27 invasion success, (b) the impacts this invasive species has at various ecological scales, (c) the outcomes of restoration efforts for this species, and (d) the connections of this weed to invasion ecology theories. Lonicera maackii impacts are complex and vary across ecosystems and spatial scales; we report findings from studies demonstrating a wide range of effects on species composition, community structure, ecosystem function, and successional trajectories. We end by providing a working ecological framework that may help guide future research and conservation efforts

Investigation of prediction methods for the loads and stresses of Apollo type spacecraft parachutes. Volume 1: Loads

An analysis was conducted with the objective of upgrading and improving the loads, stress, and performance prediction methods for Apollo spacecraft parachutes. The subjects considered were: (1) methods for a new theoretical approach to the parachute opening process, (2) new experimental-analytical techniques to improve the measurement of pressures, stresses, and strains in inflight parachutes, and (3) a numerical method for analyzing the dynamical behavior of rapidly loaded pilot chute risers

A penny for your thoughts:athletes’ and trainee sport psychologists’ internal dialogue during consultations

The purpose of this study was to explore the internal dialogue of trainee sport psychologists (TSPs) and athletes immediately following athlete–practitioner consultations. TSPs (four male and three female, age 22–32 years) and athletes (four male, three female, age 19–29 years) completed a thought-listing procedure twice, while watching video recordings of their previous consultations. The thought-listing procedure involved participants’ pausing the video to record the in-session internal dialogue they had experienced during the consultation. Participants’ responses were categorized into six dimensions: time, place, focus, locus, orientation, and mode. TSPs’ and athletes’ retrospective accounts provided evidence that their in-session internal dialogue was (a) present focused, (b) about in-session material, (c) about the athletes or themselves, (d) about internal and external events, (e) professional (i.e., related to the session), and (f) neutral. Findings provide trainees and inexperienced practitioners with insights into the thought content of TSPs and athletes to guide their own athlete interactions

Turbulence structure of open channel flows over permeable and impermeable beds : A comparative study

Peer reviewedPublisher PD

What Happens When the Party is Over?:Sustaining Physical Activity Behaviors after Intervention Cessation

Although extensive research suggests that behavior change interventions can improve physical activity (PA) over the course of an intervention, the maintenance of these improvements beyond intervention termination is less clear. The purpose of this study was to determine, through meta-analysis, whether behavior change interventions produce sustained improvements in PA after interventions conclude. Studies were retrieved from a recent (2019) meta-analysis of 224 interventions. Studies that measured PA at baseline, post-intervention, and a follow-up timepoint were included in this updated review. We examined the effects of these interventions in terms of changes in PA from baseline to post-intervention, baseline to follow-up, and post-intervention to follow-up (relative to control groups). We also examined whether the inclusion of theory and behavior change techniques (BCTs) within interventions as well as the length of time between PA assessments moderated these effects. Thirty-nine interventions (17% of interventions from the previous review) from 31 studies were included in the meta-analysis. Significant improvements in PA were found from baseline to follow-up (d = 0.32). In general, these effects resulted from significant increases in PA from baseline to post-intervention (d = 0.46), followed by significant decreases from post-intervention to follow-up (d = −0.18). Effect sizes did not vary between theory-based and no-stated-theory interventions. The positive effects from baseline to post-intervention and negative effects from post-intervention to follow-up were more pronounced as the length of time between assessments increased. In conclusion, behavior change interventions improve PA over the course of the intervention; however, these improvements are generally not sustained after the intervention concludes.</p

Theories of physical activity behaviour change:A history and synthesis of approaches

Rebar, A ORCiD: 0000-0003-3164-993XBackground: Most people in developed countries are not physically active enough to reap optimal health benefits so effective promotion strategies are warranted. Theories of behaviour change are essential to understand physical activity and provide an organizing framework for effective intervention. The purpose of this paper was to provide a narrative historical overview of four key theoretical frameworks (social cognitive, humanistic, dual process, socioecological) that have been applied to understand and change physical activity over the last three decades. Methods: Our synthesis of research included the brief history, basic efficacy, strengths, and potential weaknesses of these approaches when applied to physical activity. Results: The dominant framework for understanding physical activity has been in the social cognitive tradition, and it has provided valuable information on key constructs linked to physical activity. The humanistic framework for understanding physical activity has seen a surge in research in the last decade and has demonstrated initial effectiveness in both explaining and intervening on behaviour. The most recent and understudied framework for understanding physical activity is dual process models, which may have promise to provide a broader perspective of motivation by considering non-conscious and hedonic determinants of physical activity. Finally, the individual-level focus of all three of these approaches is contrasted by the socioecological framework, which has seen considerable research attention in the last 15 years and has been instrumental in understanding the role of the built environment in physical activity behaviour and critical to shaping public health policy in government. Conclusions: Despite the strengths of all four frameworks, we noted several weaknesses of each approach at present and highlight several newer applications of integrated models and dynamic models that may serve to improve our understanding and promotion of physical activity over the next decade. © 2018 Elsevier Lt