Simulator experiments: effects of NPP operator experience on performance

During the FY83 research, a simulator experiment was conducted at the control room simulator for a GE Boiling Water Reactor (BWR) NPP. The research subjects were licensed operators undergoing requalification training and shift technical advisors (STAs). This experiment was designed to investigate the effects of senior reactor operator (SRO) experience, operating crew augmentation with an STA and practice, as a crew, upon crew and individual operator performance, in response to anticipated plant transients. Sixteen two-man crews of licensed operators were employed in a 2 x 2 factorial design. The SROs leading the crews were split into high and low experience groups on the basis of their years of experience as an SRO. One half of the high- and low-SRO experience groups were assisted by an STA. The crews responded to four simulated plant casualties. A five-variable set of content-referenced performance measures was derived from task analyses of the procedurally correct responses to the four casualties. System parameters and control manipulations were recorded by the computer controlling the simulator. Data on communications and procedure use were obtained from analysis of videotapes of the exercises. Questionnaires were used to collect subject biographical information and data on subjective workload during each simulated casualty. For four of the five performance measures, no significant differences were found between groups led by high (25 to 114 months) and low (1 to 17 months as an SRO) experience SROs. However, crews led by low experience SROs tended to have significantly shorter task performance times than crews led by high experience SROs. The presence of the STA had no significant effect on overall team performance in responding to the four simulated casualties. The FY84 experiments are a partial replication and extension of the FY83 experiment, but with PWR operators and simulator

Visual search for facing and non-facing people: the effect of actor inversion

In recent years, there has been growing interest in how human observers perceive, attend to, and recall, social interactions viewed from third-person perspectives. One of the interesting findings to emerge from this new literature is the search advantage for facing dyads. When hidden amongst pairs of individuals facing in the same direction, pairs of individuals arranged front-to-front are found faster in visual search tasks than pairs of individuals arranged back-to-back. Interestingly, the search advantage for facing dyads appears to be sensitive to the orientation of the people depicted. While front-to-front target pairs are found faster than back-to-back targets when target and distractor pairings are shown upright, front-to-front and back-to-back targets are found equally quickly when pairings are shown upside-down. In the present study, we sought to better understand why the search advantage for facing dyads is sensitive to the orientation of the people depicted. To begin, we show that the orientation sensitivity of the search advantage is seen with dyads constructed from faces only, and from bodies with the head and face occluded. We replicate these effects using two different visual search paradigms. We go on to show that individual faces and bodies, viewed in profile, produce strong attentional cueing effects when shown upright, but not when presented upside-down. Together with recent evidence that arrows arranged front-to-front also produce the search advantage for facing dyads, these findings support the view that the search advantage is a by-product of the ability of constituent elements to direct observers’ visuo-spatial attention

Nonlinear transduction of emotional facial expression

To create neural representations of external stimuli, the brain performs a number of processing steps that transform its inputs. For fundamental attributes, such as stimulus contrast, this involves one or more nonlinearities that are believed to optimise the neural code to represent features of the natural environment. Here we ask if the same is also true of more complex stimulus dimensions, such as emotional facial expression. We report the results of three experiments combining morphed facial stimuli with electrophysiological and psychophysical methods to measure the function mapping emotional expression intensity to internal response. The results converge on a nonlinearity that accelerates over weak expressions, and then becomes compressive for stronger expressions, similar to the situation for lower level stimulus properties. We further demonstrate that the nonlinearity is not attributable to the morphing procedure used in stimulus generation

Does developmental prosopagnosia impair identification of other-ethnicity faces?

Current approaches to the diagnosis of developmental prosopagnosia emphasise the perception and identification of same-ethnicity faces. This convention ensures that perceptual impairment arising from developmental prosopagnosia can be distinguished from problems arising from a lack of visual experience with particular facial ethnicities – the so-called ‘Other-Ethnicity Effect’. The present study sought to determine whether the perceptual difficulties seen in developmental prosopagnosia – diagnosed using same-ethnicity faces – extend to other-ethnicity faces. First, we sought to determine whether a group of Caucasian developmental prosopagnosics (N = 15) and typical Caucasian controls (N = 30) had similar experience with same- and other-ethnicity faces during development. All participants therefore completed a contact questionnaire that enquired about their experience of Caucasian, Black, and East Asian faces, at different developmental stages. Importantly, the two groups described very similar levels of visual experience with other-ethnicity faces. Second, we administered a sequential matching task to measure participants’ ability to discriminate same- (Caucasian) and other-ethnicity (Black, East Asian) faces. Relative to the experience-matched controls, the prosopagnosics were less accurate at discriminating both same- and other-ethnicity faces, and we found no evidence of disproportionate impairment for same-ethnicity faces. Given that the prosopagnosics and controls had similar opportunity to develop visual expertise for other-ethnicity faces, these results indicate that developmental prosopagnosia impairs recognition of both same- and other-ethnicity faces. The fact that developmental prosopagnosia affects the perception of both same- and other-ethnicity faces suggests that different facial ethnicities engage similar visual processing mechanisms. Our findings support the view that susceptibility to developmental prosopagnosia, and a lack of contact with other-ethnicity faces, contribute independently to the poor recognition of other-ethnicity faces

Ação de reguladores vegetais no crescimento de tomateiro (Lycopersicon esculentum Mill. cv. «Miguel Pereira»)

This research deals with the effects of exogenous growth regulators on development of the tomato cultivar «Miguel Pereira». Observations of tomato plants treated with (2-chloroethyl) trimethylammonium chloride (2,000 ppm) and succinic acid -2,2-d:methyi-hydrazide (3,000 ppm) showed that growth regulators induced little variation in plant height. Gibberellic acid (100 ppm) caused greater variation in height.Estudaram-se em condições de casa de vegetação, os efeitos da aplicação de reguladores vegetais no crescimento do tomateiro cultivar "Miguel Pereira". Além do tratamento controle, aplicou-se, 44 dias após a semeadura, cloreto de (2-cloroetil) trimetilamônio 2.000 ppm, ácido succínico -2,2-dimetilhidrazida 3.000 ppm e ácido giberélico 100 ppm. Observou-se que o GA promoveu maior crescimento, em relação ao controle. O crescimento do tomateiro mostrou-se mais reduzido nas plantas tratadas com CCC e SADH, com relação àquelas pulverizadas com GA e plantas controle

Is developmental prosopagnosia best characterised as an apperceptive or mnemonic condition?

Traditionally, developmental prosopagnosia (DP) has been thought of as an apperceptive condition that hinders individuals’ ability to encode face structure. However, several authors have recently raised the possibility that many DPs may be able to form accurate percepts, but be unable to maintain those percepts over time. The present study sought to distinguish these possibilities. In our first experiment 16 DPs and 22 typical controls completed a delayed match-to-sample task with face and car stimuli, with a retention interval of 1-second (low demand) or 6-seconds (high demand). As expected, the participants with DP were worse than the controls at face matching, and were disproportionately impaired at matching faces relative to cars. However, the relative degree of impairment seen in the DPs did not interact with retention interval; they exhibited similar levels of impairment when matching faces with 1- and 6-second delays. Next, we compared the performance of 72 DPs and 54 typical controls on the Cambridge Face Perception Test (CFPT), a task that measures face perception ability in a way that minimises the memory demands. As expected, we found that the DPs were impaired at the group level. This difference was not attributable to a few individuals with an apperceptive profile; rather we found evidence that the distribution of CFPT scores seen in the DP sample was shifted relative to that of typical controls. Some heterogeneity is likely in any neurodevelopmental population, and DP is no different. Generally, however, these findings suggest that selective STFM impairment may be relatively uncommon in this population. Instead, deficits of perceptual encoding may play a larger role in DP than currently acknowledged

Energetic particle influence on the Earth's atmosphere

This manuscript gives an up-to-date and comprehensive overview of the effects of energetic particle precipitation (EPP) onto the whole atmosphere, from the lower thermosphere/mesosphere through the stratosphere and troposphere, to the surface. The paper summarizes the different sources and energies of particles, principally galactic cosmic rays (GCRs), solar energetic particles (SEPs) and energetic electron precipitation (EEP). All the proposed mechanisms by which EPP can affect the atmosphere are discussed, including chemical changes in the upper atmosphere and lower thermosphere, chemistry-dynamics feedbacks, the global electric circuit and cloud formation. The role of energetic particles in Earth’s atmosphere is a multi-disciplinary problem that requires expertise from a range of scientific backgrounds. To assist with this synergy, summary tables are provided, which are intended to evaluate the level of current knowledge of the effects of energetic particles on processes in the entire atmosphere

Measurement of the cross section for isolated-photon plus jet production in pp collisions at √s=13 TeV using the ATLAS detector

The dynamics of isolated-photon production in association with a jet in proton–proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb−1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon–jet invariant mass and the scattering angle in the photon–jet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements