Timing Performance Error in Rewarded and Non-Rewarded Tasks

The literature on human and nonhuman animal interval timing disagrees about whether perceived time is a linear or power function of real time, and to what extent reward influences timing performance. Two competing computational learning and timing models, Temporal Difference (TD, Schultz, 2013) and Sometimes Competing Retrieval (SOCR, Stout & Miller, 2007) are reviewed. The present experiments investigate human interval timing error in both reward and non-reward conditions. The experiments were simulated by a computational model to identify both the function that describes the effect of interval duration on the distribution of variance (e.g., scalar or linear) and the relative predictive power of the SOCR and TD models, and the effects of reward on interval timing. Specifically, it was hypothesized that 1) timing variability is scalar, not linear, 2) that a modified SOCR model explains the data, and 3) that interval timing performance is less variable in rewarding situations than in non-rewarding situations. Timing trials involved the presentation of a reference duration; participants then produced their estimate of that duration while under cognitive load (random number generation and serial math tasks) through key presses on a computer. The results failed to support these hypotheses. However, reward produced a nonsignificant tendency towards early responding. Finally, suggestions for further research, including further computational modeling and investigation of the neural substrata of reward and timing are discussed

Internal reversing flow in a tailpipe offtake configuration for SSTOVL aircraft

A generic one-third scale model of a tailpipe offtake system for a supersonic short takeoff vertical landing (SSTOVL) aircraft was tested at LeRC Powered Lift Facility. The model consisted of a tailpipe with twin elbows, offtake ducts, and flow control nozzles, plus a small ventral nozzle and a blind flange to simulate a blocked cruise nozzle. The offtake flow turned through a total angle of 177 degrees relative to the tailpipe inlet axis. The flow split was 45 percent to each offtake and 10 percent to the ventral nozzle. The main test objective was to collect data for comparison to the performance of the same configuration predicted by a computational fluid dynamics (CFD) analysis. Only the experimental results are given - the analytical results are published in a separate paper. Performance tests were made with unheated air at tailpipe-to-ambient pressure ratios up to 5. The total pressure loss through the offtakes was as high as 15.5 percent. All test results are shown as graphs, contour plots, and wall pressure distributions. The complex flow patterns in the tailpipe and elbows at the offtake openings are described with traversing flow angle probe and paint streak flow visualization data

Characterisation of the Arabidopsis thaliana leucine-rich repeat receptor kinase subfamily XII in immune signalling.

Plant cells employ cell surface-localised receptors in order to perceive perturbations in their environment. One such context, central to plant survival, is the recognition of potential pathogens through pattern recognition receptors (PRRs). Upon recognition of apoplastic molecular patterns indicative of danger, PRRs induce pattern-triggered immunity. These molecular patterns can be of non-self (pathogen-associated molecular patterns; PAMPs) or modified-self (danger-associated molecular patterns; DAMPs) origins. Recognition of many PAMPs is lineage specific due to the phylogenetically restricted distribution of the cognate receptors. In general, PRRs can be transferred between angiosperm genomes to confer PAMP-recognition and induce quantitative, broad-spectrum disease resistance. As such, non-crop genomes represent a potential reservoir of exploitable PRRs to engineer resistance. Currently, this approach is constrained by the limited number of characterised PRRs. With this in mind, I sought to characterise additional members of the leucine-rich repeat receptor kinase subfamily XII from Arabidopsis thaliana; a known PRR-containing clade. I generated a range of genetic resources to screen a range of pathogens for gain- or loss-of-resistance. Within this subfamily, I focused on MIK2, whose mutants show defects in pollen tube guidance, salt stress tolerance, cell wall integrity sensing, Fusarium oxysporum resistance and root skewing. Our data revealed that loss of MIK2 leads to defects in basal ROS production and transcriptomic homeostasis. Moreover, we showed that mik2 mutants are differentially affected in elicitor-induced reactive oxygen species production, revealing an undescribed elicitor-based dichotomy. Through this work, I identified the recently described DAMP SCOOP12 is a likely ligand for MIK2. Furthermore, analysis of transcriptional changes in mik2 revealed a novel phytocytokine-like peptide, which is transcriptionally upregulated in mik2. The insights gained through this work further our understanding of how plants recognise and potentiate danger signals and integrate these into physiological responses

Development of a Cardiovascular Fitness Test for College Women Based on an Index of Work Equivalency

The problem with which this study was concerned was that of developing a valid and reliable physical fitness test for college women which could be readily administered to large groups in a short period of time

How the court politics of Covid-19 help us make sense of crisis responses

What explains the different responses of European countries to Covid-19? Drawing on a new study, John Boswell, Jack Corbett, Rod Rhodes and Heidi Houlberg Salomonsen set out a ‘court politics’ model of how governing elites have taken advice and made decisions during the pandemic

Managing the entanglement: complexity leadership in public sector systems

Complexity in public sector systems requires leaders to balance the administrative practices necessary to be aligned and efficient in the management of routine challenges and the adaptive practices required to respond to dynamic circumstances. Conventional notions of leadership in the field of public administration do not fully explain the role of leadership in balancing the entanglement of formal, top-down, administrative functions and informal, emergent, adaptive functions within public sector settings with different levels of complexity. Drawing on and extending existing complexity leadership constructs, this article explores how leadership is enacted over the duration of six urban regeneration projects representing high, medium, and low levels of project complexity. The article suggests that greater attention needs to be paid to the tensions inherent in enabling leadership if actors are to cope with the complex, collaborative, cross-boundary, adaptive work in which they are increasingly engage

A New Synthetic Amphidiploid in Cucumis from a C. sativus x C. hystrix F1 Interspecific Hybrid

CT. A synthetic amphidiploid was developed through organogenesis in tissue culturefrom an interspecific F1hybrid betweenCucumis sativus L. andC. hystrix Chakr. The resultsfrom flow cytometry indicated that, on average, 7.3% of the regenerants with unique morphology were chromosome-doubled F1hybrids. The 2C DNA content of the original F1hybrid was1.17 pg, and the 4C DNA content was 2.35 pg. Frequency of chromosome doubling between thetwo genotypes used in this study varied considerably

Composite isogrid structures for parabolic surfaces

The invention relates to high stiffness parabolic structures utilizing integral reinforced grids. The parabolic structures implement the use of isogrid structures which incorporate unique and efficient orthotropic patterns for efficient stiffness and structural stability