Giving subjects the eye and showing them the finger: socio-biological cues and saccade generation in the anti-saccade task.

Pointing with the eyes or the finger occurs frequently in social interaction to indicate direction of attention and one's intentions. Research with a voluntary saccade task (where saccade direction is instructed by the colour of a fixation point) suggested that gaze cues automatically activate the oculomotor system, but non-biological cues, like arrows, do not. However, other work has failed to support the claim that gaze cues are special. In the current research we introduced biological and non-biological cues into the anti-saccade task, using a range of stimulus onset asynchronies (SOAs). The anti-saccade task recruits both top ^ down and bottom^ up attentional mechanisms, as occurs in naturalistic saccadic behaviour. In experiment 1 gaze, but not arrows, facilitated saccadic reaction times (SRTs) in the opposite direction to the cues over all SOAs, whereas in experiment 2 directional word cues had no effect on saccades. In experiment 3 finger pointing cues caused reduced SRTs in the opposite direction to the cues at short SOAs. These findings suggest that biological cues automatically recruit the oculomotor system whereas non- biological cues do not. Furthermore, the anti-saccade task set appears to facilitate saccadic responses in the opposite direction to the cues

Change in Grassland Science: Implications for Training, Research and Grassland Societies

In most of the world the priority for production-oriented research has been succeeded by the need for grassland research to focus on systems which satisfy requirements relating to the stability and protection of land, water and atmospheric resources and to biodiversity, in addition to production efficiency. This dictates not only a new approach to research, but also new approaches for the organisation of research, the training and development of research scientists and the activities of Grassland Societies and associated organisations

Learning From Early Attempts to Generalize Darwinian Principles to Social Evolution

Copyright University of Hertfordshire & author.Evolutionary psychology places the human psyche in the context of evolution, and addresses the Darwinian processes involved, particularly at the level of genetic evolution. A logically separate and potentially complementary argument is to consider the application of Darwinian principles not only to genes but also to social entities and processes. This idea of extending Darwinian principles was suggested by Darwin himself. Attempts to do this appeared as early as the 1870s and proliferated until the early twentieth century. But such ideas remained dormant in the social sciences from the 1920s until after the Second World War. Some lessons can be learned from this earlier period, particularly concerning the problem of specifying the social units of selection or replication

Predictive learning, prediction errors, and attention: evidence from event-related potentials and eye tracking

Prediction error (‘‘surprise’’) affects the rate of learning: We learn more rapidly about cues for which we initially make incorrect predictions than cues for which our initial predictions are correct. The current studies employ electrophysiological measures to reveal early attentional differentiation of events that differ in their previous involvement in errors of predictive judgment. Error-related events attract more attention, as evidenced by features of event-related scalp potentials previously implicated in selective visual attention (selection negativity, augmented anterior N1). The earliest differences detected occurred around 120 msec after stimulus onset, and distributed source localization (LORETA) indicated that the inferior temporal regions were one source of the earliest differences. In addition, stimuli associated with the production of prediction errors show higher dwell times in an eyetracking procedure. Our data support the view that early attentional processes play a role in human associative learning

Pleural mesothelioma and lung cancer risks in relation to occupational history and asbestos lung burden.

BACKGROUND: We have conducted a population-based study of pleural mesothelioma patients with occupational histories and measured asbestos lung burdens in occupationally exposed workers and in the general population. The relationship between lung burden and risk, particularly at environmental exposure levels, will enable future mesothelioma rates in people born after 1965 who never installed asbestos to be predicted from their asbestos lung burdens. METHODS: Following personal interview asbestos fibres longer than 5 µm were counted by transmission electron microscopy in lung samples obtained from 133 patients with mesothelioma and 262 patients with lung cancer. ORs for mesothelioma were converted to lifetime risks. RESULTS: Lifetime mesothelioma risk is approximately 0.02% per 1000 amphibole fibres per gram of dry lung tissue over a more than 100-fold range, from 1 to 4 in the most heavily exposed building workers to less than 1 in 500 in most of the population. The asbestos fibres counted were amosite (75%), crocidolite (18%), other amphiboles (5%) and chrysotile (2%). CONCLUSIONS: The approximate linearity of the dose-response together with lung burden measurements in younger people will provide reasonably reliable predictions of future mesothelioma rates in those born since 1965 whose risks cannot yet be seen in national rates. Burdens in those born more recently will indicate the continuing occupational and environmental hazards under current asbestos control regulations. Our results confirm the major contribution of amosite to UK mesothelioma incidence and the substantial contribution of non-occupational exposure, particularly in women

Ingestive Behavior of Fistulated and Intact Sheep Grazing Grass and Legumes Indoors and Outdoors

Components of short-term ingestive behaviour were recorded for fistulated and intact sheep grazing turves in indoor crates, and for esophageal-fistulated sheep grazing swards in situ in outdoor cages. Perennial ryegrass, orchard grass and white clover at vegetative and reproductive growth stages were offered to the sheep. Bite weight, depth, area and volume did not differ between sheep grazing indoors and outdoors, nor between intact and fistulated sheep. Bite rate of fistulated sheep was slower indoors than outdoors (25.3 versus 32.1 bites/min), and intact sheep had a higher biting rate (36.7 versus 25.3 bites/min) than fistulated sheep. Bite weight was over-estimated using extrusa collection, the average DM recovery coefficient being 1.32

Effect of Defoliation Intensity on the Absolute and Relative Growth Rates of \u27Grasslands Puna\u27 Chicory

The response of absolute and relative growth of \u27Grasslands Puna\u27 chicory (Cichorium intybus L.) to defoliation intensity was examined in a glasshouse. Five defoliation intensities (0, 50, 100, 150 and 200 mm above media level), at 3 week intervals with 4 replications were arranged in a completely randomised design. The aboveground relative growth rate of Puna chicory increased exponentially as defoliation intensity increased, resulting in defoliation intensity not decreasing average absolute growth rate until weeks 9-12. However, there were significant differences in belowground mass between defoliation intensities from week 6 onwards. Defoliation above 150 mm, with 3 week intervals, is suggested to maintain aboveground absolute growth rate and belowground mass

Rooted Plantlet Production in a Vegetatively Reproductive Red Clover (\u3ci\u3eTrifolium pratense\u3c/i\u3e L.) cv. Astred

Vegetatively reproductive cultivars of red clover (Trifolium pratense L.) can produce clonal daughter plantlets under certain management and environmental conditions, which may improve sward persistency. Six trials involving spaced plants, pure swards or grazed mixed swards were conducted near Massey University, Palmerston North, New Zealand, from 1995 to 1998. Rooted plantlets counted in autumn of each year ranged from 5.8±1.6 to 43±5.1 rooted plantlets/parent plant for ungrazed spaced plants, and 0 to 1.8 rooted plantlets/parent plant for pure and mixed swards under grazing management. It is concluded that clonal, rooted plantlet production is highly variable in Astred depending on grazing management, environmental conditions and companion species, but offers a feasible replacement mechanism for maintaining red clover persistence in mixed and pure swards

Bite Depth Penetration Patterns of Dairy Cows Foraging on Complex Swards

Sward height was the dominant cue used by dairy cattle to determine the depth of penetration on young vegetative swards. On more complex swards, bite depth penetration was controlled by variations in the depth of regrowth. Evidence showed that cattle grazed to the pseudostem:lamina interface, but sward height exerted a stronger effect on bite depth than pseudostem height. Modelling efforts to predict how the herbivore places bites in space in the vertical dimension across sward states are currently being restricted by the absence of detailed canopy structure descriptions. We argue that the contrast between strata is an important determinant of bite depth penetration through the conditioning effect on biting resistance, and that the “constant proportionality” concept of bite depth control should be treated with caution. Furthermore, we demonstrate that bite depth penetration is continuously being conditioned through information gained on a bite-by-bite basis, and that patch appraisal begins a new cycle at every patch