929 resultados para Cognitive ability


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Objective: To study the episodic memory, semantic memory, cognitive planning ability and inhibition ability in MHD patients. Method: Neuropsychological research methods such as Action memory of verb-object phrase, Trail Making Test (A and B), Verbal Fluency Test, Go-No/Go test and Stroop Color Naming Task were used to investigate Episodic Memory 、Semantic Memory、Executive Function of 40 MHD and 40 NC. Self-Rating Anxiety Scale (SAS), Self-Rating Depression Scale(SDS), Social Support Scale, Life Satisfaction Scale, and biochemical examination were applied and their relationships with cognitive function were analized. The mean age and education level of MHD group and NC group have no significant difference. Result: 1.Action memory of verb-object phrase differed significantly between MHD group and NC group. 2.Two tests of Verbal Fluency differed significantly between MHD group and NC group. 3.Trail Making Test A, Trail Making Test B, the baseline condition of Go-No/Go Test and Stroop Color Naming Test differed significantly between MHD group and NC group. 4.There is no significant difference between MHD group and NC group on the correct rate of No/Go Test and the baseline condition. Both groups showed Stroop Effect in Go-No/Go test, but MHD group performed significantly worse. 5.In Stroop Color Naming Task Test, NC group showed Stroop Effect, significant Repeated Distraction Promotion Effect and significant Negative Priming Effect,while MHD group showed only Stroop Effect and no Repeated Distraction Promotion Effect and no Negative Priming Effect. There is significant difference in Stroop Effect between MHD group and NC group. Conclusion: 1.Comparing with NC group, episodic memory, semantic memory, cognitive planning ability, and inhibition ability of MHD group were impaired significantly. 2.The pathological aging of Executive Function in MHD group showed: executive Function should be a unitary system. 3.Cognitive impairment is negatively correlated with serum creatinine, blood pressure and anxiety score in MHD patients; and is related with hemoglobin, hematocrit, social support and life satisfaction. Keyword: maintenance hemodialysis, episodic memory, semantic memory, cognitive planning, inhibition ability.

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To test preschoolers’ development of cognitive flexibility--an ability to solve a problem in one way and to then switch solution strategies, and the mechanism involved in the development, 3-5-year-olds are asked to perform switching tasks in which the experimenter manipulates the way the stimuli are presented: consecutive or simultaneous; the way the switching happens: between dimensions or within a dimension; the conceptual domains involved: shape, color, number and direction; the specific labels used. The main results of this work are presented below: (1) 3-5-year-olds’ cognitive flexibility develops with age, yet its development is not of the same speed in extra-dimensional switch tasks and inter-dimensional reversal tasks. 3-year-olds manifest some cognitive flexibility, but their performance is significantly worse than that of 4- and 5-year-olds. For the 3-year-olds, in reversal tasks, although 80% of the children passed the post-switch phrase in color task; less then 60% children passed the post-switch phrase in shape, number and direction tasks. In extra-dimensional tasks, 3-year-olds performance is worse than that in the reversal tasks. Less than 50% of the children passed the tasks. Children’s cognitive flexibility develops fast from 3-year-olds to 4-year-olds. Both 4-year-olds and 5-year-olds demonstrate high flexibility without significant difference between them. (2) Children’s flexibility in the conceptual domains of shape, color, number and direction follows different developing patterns. In inter-dimensional reversal tasks, 3-year-olds’ performance is not the same in the 4 conceptual domains, but the difference among the domains is insignificant in 4-and-5-year-olds. In extra-dimensional switching tasks, children’s performance on the 4 domain tasks is significantly different from one another in 3-, 4-, and 5-year-olds. (3) The way the stimuli are presented affects children’s development of cognitive flexibility. In inter-dimensional reversal tasks, 3-year-olds’ performance in consecutive presentation is significantly better than that in simultaneous presentation. 4- and 5-year-olds’ performance in the 2 presentations is not significantly different from each other. In extra-dimensional switch tasks, 3-, 4-, and 5-year-olds’ performance in the consecutive presentation is not significantly better than that in the simultaneous presentation (4) 3-, 4-, and 5-year-olds’ self-issued labeling aids their performance on the switching tasks. Children’ performance in the labeling condition is significantly better than that of no labeling. (5) 3-5-year-olds’ cognitive flexibility is highly correlated with their working memory and inhibition. Children’ development of cognitive flexibility is a process that involves activation of working memory and inhibition, in which the complexity of the task also plays a role.

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Research on naïve physics investigates children’s intuitive understanding of physical objects, phenomena and processes. Children, and also many adults, were found to have a misconception of inertia, called impetus theory. In order to investigate the development of this naïve concept and the mechanism underlying it, four age groups (5-year-olds, 2nd graders, 5th graders, and 8th graders) were included in this research. Modified experimental tasks were used to explore the effects of daily experience, perceptual cues and general information-processing ability on children’s understanding of inertia. The results of this research are: 1) Five- to thirteen-year-olds’ understanding of inertia problems which were constituted by two ogjects moving at the same spped undergoes an L-shaped developmental trend; Children’s performance became worse as they got older, and their performance in the experiment did not necessarily ascend with the improvement of their cognitive abilities. 2) The L-shaped developmental curve suggests that children in different ages used different strategies to solve inertia problems: Five- to eight-year-olds only used heuristic strategy, while eleven- to thirteen-year-olds solved problems by analyzing the details of inertia motion. 3) The different performance between familiar and unfamiliar problems showed that older children were not able to spontaneously transfer their knowledge and experience from daily action and observation of inertia to unfamiliar, abstract inertia problems. 4) Five- to eight-year-olds showed straight and fragmented pattern, while more eleven- to thirteen-year-olds showed standard impetus theory and revised impetus theory pattern, which showed that younger children were influenced by perceptual cues and their understanding of inertia was fragmented, while older children had coherent impetus theory. 5) When the perceptual cues were controlled, even 40 percent 5 years olds showed the information-processing ability to analyze the distance, speed and time of two objects traveling in two different directions at the same time, demonstrating that they have achieved a necessary level to theorize their naïve concept of inertia.

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The relationship between working memory (WM) and attention has attracted many researchers. In his embedded-processes model of WM, Cowan (1999, 2001) uses the term focus of attention to refer to the core component of WM, and proposes that the focus of attention of WM and that of perception have the same span, which is a fixed number. This hypothesis about the scope of attention has seldom been tested, although considerable studies have revealed that WM and attention have overlapping mechanisms. The present dissertation tests this hypothesis by examining the dual-task interference between Corsi Blocks Task (CBT) and Mutilple Object Tracking (MOT) and the findings demenstrate that Cowan’s hypothesis is not exactly true. The results of our first study show that the interference effect of MOT on CBT is a reliable indicator of whether and to which extent the attentional resoureces of WM and perception overlap. In the second study we find that the capacity of the common resources is not a fixed number but varies with the difficulty of control of attention. And the third study indicates that attentional resources used in WM and perception are partly independent, the overlapping part can attend to only one or two items or locations at a time. These findings can contribute to future studies on the capacity limitation of different cognitive functions, and to the development of relevant ability tests.

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Self-regulation has recently become an important topic in cognitive and developmental domain. According to previous theories and experimental studies, it is shown that self-regulation consist of both a personality (or social) aspect and a behavioral cognitive aspect of psychology. Self-regulation can be divided into self-regulation personality and self-regulation ability. In the present study researches have been carried out from two perspectives: child development and individual differences. We are eager to explore the characteristics of self-regulation in terms of human cognitive development. In the present study, we chose two groups of early adolescences one with high intelligence and the other with normal intelligence. In Study One Questionnaires were used to compare whether the highly intelligent group had had better self-regulation personality than the normal group. In Study Two experimental psychology tasks were used to compare whether highly intelligent children had had better self-regulation cognitive abilities than their normal peers. Finally, in Study Three we combined the results of Study One and Study Two to further explore the neural mechanisms for highly intelligent children with respect to their good self-regulation abilities. Some main results and conclusions are as follows: (1) Questionnaire results showed that highly intelligent children had better self-regulation personalities, and they got higher scores on the personalities related to self-regulation such as, self-reliance, stability, rule-consciousness. They also got higher scores on self-consciousness which meant that they could know their own self better than the normal children. (2) Among the three levels of cognitive difficulties in self-regulation abilities, the highly intelligent children had faster reaction speed than normal children in the primary self-regulation tasks. In the intermediate self-regulation tasks, highly intelligent children’s inhibition processing and executive processing were both better than their normal peers. In the advanced self-regulation tasks, highly intelligent children again had faster reaction speed and more reaction accuracy than their normal peers when facing with conflict and inconsistency experimental conditions,. Regression model’s results showed that primary and advanced self-regulation abilites had larger predictive power than intermediate self-regualation ability. (3) Our neural experiments showed that highly intelligent children had more efficient neural automatic processing ability than normal children. They also had better, faster and larger neural reaction to novel stimuli under pre-attentional condition which made good and firm neural basis for self-regualation. Highly intelligent children had more mature frontal lobe and pariental functions for inhibition processing and executive processing. P3 component in ERP was closely related to executive processing which mainly activated pariental function. There were two time-periods for inhibition processing—first it was the pariental function and later it was the coordination function of frontal and pariental lobes. While conflict control task had pariental N2 and frontal-pariental P3 neural sources, highly intelligent children had much smaller N2 and shorter P3 latency than normal children. Inconsistency conditions induced larger N2 than conditions without inconsistency, and conditions without inconsistency (or Conflict) induced higher P3 amplitudes than with Inconsistency (or Conflict) conditions. In conclusion, the healthy development of self-regulation was very important for children’s personality and cognition maturity, and self-regulation had its own specific characteristics in ways of presentation and ways of development. Better understanding of self-regulation can further help the exploration of the nature of human intelligence and consciousness.

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Classification is a kind of basic cognitive process, and category is an important way for human beings to define the world. At the same time, categories are organized in a hierarchical way, which makes it possible for human beings to process information efficiency. For those reasons, the development of classification ability is always one of the foci in developmental psychology. By using the methods of spontaneous and trained classification of both familiar stimuli materials and artificial concepts, this research explored the 4-6 year old children's classification criteria. And by the artificial concept system formed in these classification criteria experiments, the mastery degree of class hierarchy in these young children was analyzed. The main results and conclusions are: 1) The classification ability increases quickly among kindergarteners from 4 to 6 year old: the 4 year old children seemed unable to classify objects by classificatory criteria, however, the 6 year ones had shown the ability in many experimental conditions. But the main basis of classificatory criteria in these young children, including 6 year old ones, was the functional relation of the objects but the conceptual relations, and their classification criteria was not consistent because they seem to be easily affected by experimental conditions. 2) The age of 5 is a more sensitive period of classification ability development: for the children of 5 year old, it was found that their classification ability was easily enhanced by training. The zone of proximal development in classification ability by category standard could probably lie in this period of age. 3) Knowledge is an important factor that affects young children's classification ability, meanwhile, their classification activity are affected by cognitive processing ability: young children exhibited different classification ability as they had different understanding of stimuli materials. Kindergarteners of different age were significantly different in their classification ability as the difference in cognitive processing ability, even if they had the same knowledge about the stimuli materials. 4) Different properties of class hierarchy are different in difficulty for young children: the 5-6 year old children showed that the could master the transitivity of the class hierarchy. No matter under what learning condition, they could answer most of the transitivity questions correctly and infer the property of the sub-class according to that of the super-class. The young children at 5-6 years old had mastered the branching property of class hierarchy at a relative high level, but their answers were easily affected by the hints in the questions. However, it seemed that the asymmetry of class hierarchy was difficult for young children to learn. Because young children could not understand the class inclusion relation, they always drew wrong conclusions about super-class from sub-class in their classification.

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Transfer of learning is one of the major concepts in educational psychology. As cognitive psychology develops, many researchers have found that transfer plays an important part in problem solving, and the awareness of the similarity of related problems is important in transfer. So they become more interested in researching the problem of transfer. But in the literature of transfer research, it has been found that many researchers do not hold identical conclusions about the influence of awareness of related problems during problem solving transfer. This dissertation is written on the basic of much of sub-research work, such as looking up literature concerning transfer of problem solving research, comparing the results of research work done recently and experimental researches. The author of this dissertation takes middle school students as subjects, geometry as materials, and adopts factorial design in his experiments. The influence of awareness of related problems on problem solving transfer is examined from three dimensions which are the degree of difficulty of transfer problems, the level of awareness of related problems and the characteristics of subjects themselves. Five conclusions have been made after the experimental research: (1) During the process of geometry problem solving, the level of awareness of related problems is one of the major factors that influence the effect of problem solving transfer. (2) Either more difficult or more easy of the transfer problems will hinder the influence of awareness of related problems during problem solving transfer, and the degree of difficulty of the transfer problems have interactions with the level of awareness of related problems in affecting transfer. (3) During geometry problems solving transfer, the level of awareness of related problems has interactions with the degree of student achievement. Compared with the students who have lower achievement, the influence of the level of the awareness is bigger in the students who have higher achievement. (4) There is positive correlation between geometry achievement and reasoning ability of the middle school students. The student who has higher reasoning ability has higher geometry achievement, while the level of awareness is raised, the transfer achievement of both can be raised significantly. (5) There is positive correlation between geometry achievement and cognitive style of the middle school students. The student who has independent field tendency of cognitive style has higher geometry achievement, while the level of awareness is raised, the transfer achievement of both can be raised significantly. At the end of the dissertation, the researcher offers two proposals concerning Geometry teaching on the basis of the research findings.

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This thesis study the problem of work group effectiveness and group job design according to extensive literature investigation and the analysis of realistic background. The whole research consists of four parts: (1) The evaluation of work group effectiveness, the aim is to search to criteria that can describe and analysis work group, and explore the cognitive dimensions of effectiveness of Chinese subjects; (2) The study on the relationship between group job characteristic and effectiveness, the aim is to find the general correlation between work group characteristic and effectiveness, and try to search the most important core variable; (3) The study on the preference for the way of group work; (4) The study of the relationship between group composition and group effectiveness, try to examine how different approaches of personnel selection influence work results. The results indicate: (1) The evaluation of group effectiveness mainly consists of two dimensions: performance and the employee's attitude and feelings toward the group, so we can use these two dimensions and corresponding criteria as the standard of effectiveness evaluation. (2) According to the analysis of related literature, we can determine work group characteristic from five aspects: job design, the interdependence among members, group composition, organizational background, group process. (3) Experimental study find that different group job characteristics have different relationship models with effectiveness criteria. Job design, the interdependence among group members, group composition have significant correlation relationships with two kinds of effectiveness criteria; organizational background mainly has relationships with satisfaction criteria; group process mainly has relationships with performance criteria. (4) The choice for people to select the way of group work has the consistency, that is people prefer to "Self--managed work groups"; but different groups have the difference, the main group dimension is the difference between group members and group leaders. (5) Work groups which were composed accordingly to interpersonal attraction have higher levels of communication, coordination, group cohesion and job satisfaction than ability--based groups based. But the performance evaluation under these two conditions has no difference. The thesis analysis and discuss the research results, also point out several questions that needed to be explored further and the possible research directions in the future. This study has some reference value in group--level performance appraisal and reward design, the content and method of group--level job design, and personnel selection of group, etc.

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As a key issue in spatial cognitive developmental research, the coding of object location plays an important role in children's cognitive development. The development of location coding is a precondition for children's adaptation to their environments, and the development of corresponding ability could enhance children's adaptation ability and improve their synthetic diathesis. In this paper, under the improved paradigm of object searching, 7-, 9- and 11-year-olds of urban primary school students were involved in two studies including the total of four experiments. The children were examined upon the ability to encode target location in terms of the distance between two landmarks, three points on a line, the intersection of two lines, or the corresponding points on two parallel lines. The experiments were designed to explore the primary school children's cognitive developmental process upon spatial object location and the correlative restricting factors. From the studies, the following conclusions were drawn: 1)The ability of 7-year-olds to represent target location in terms of the relationships of points and lines is in the inceptive stage and appears unstable. Meanwhile, the same ability of 9-year-olds is in a state of fast developing. The 9-year-olds' performance depends on how difficult the task is. It is stable when task is easy while unstable when task becomes difficult. The ability of 11-year-olds reaches much-developed state and the group's performance is independent of the difficulty of tasks. 2) The correlate coefficient is significant between Raven Standard Inference ability levels and the performance of representing target location in terms of the relationships of points. Those children with good performance in Raven Standard Inference Test have good performance in target location coding. The case is true for all different age groups. As of the task in terms of the relationships of lines, the correlate coefficient between Raven Standard Inference ability levels and children's performance of representing target location is found significant only for the 7-year-olds' group. The case is not true for the groups of 9- and 11-year-olds. It is also found that the correlate coefficient is significant between the sum of performance and Raven Standard Inference ability levels, and that is true for all age groups. 3) Effects from task variable exist upon children's above-mentioned cognitive performance. The effects are different according to different difficulty levels of tasks. Also, they are different according to the different ages. 4) The subjects who failed in the 'no cues for encoding given' situation were able to improve their performances when the cues of encoding were given. Therefore it is possible to improve the primary school children's corresponding cognitive performance by providing the cues of encoding. 5) Two kinds of efficient strategies were used to solve the problem. They are trial-comparison strategy and anticipation-directed strategy.

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Since the middle of 1980's, the mechanisms of transfer of training between cognitive subskills rest on the same body of declarative knowledge has been highly concerned. The dominant theory is theory of common element (Singley & Anderson, 1989) which predict that there will be little or no transfer between subskills within the same domain when knowledge is used in different ways, even though the subskills might rest on a common body of declarative knowledge. This idea is termed as "principle of use specificity of knowledge" (Anderson, 1987). Although this principle has gained some empirical evidence from different domains such as elementary geometry (Neves & Anderson, 1981) and computer programming (McKendree & Anderson, 1987), it is challenged by some research (Pennington et al., 1991; 1995) in which substantially larger amounts of transfer of training was found between substills that rest on a shared declarative knowledge but share little procedures (production rules). Pennington et al. (1995) provided evidence that this larger amounts of transfer are due to the elaboration of declarative knowledge. Our research provide a test of these two different explanation, by considering transfer between two subskills within the domain of elementary geometry and elementary algebra respectively, and the inference of learning method ("learning from examples" and "learning from declarative-text") and subject ability (high, middle, low) on the amounts of transfer. Within the domain of elementary geometry, the two subskills of generating proofs" (GP) and "explaining proofs" (EP) which are rest on the declarative knowledge of "theorems on the characters of parallelogram" share little procedures. Within the domain of elementary algebra, the two subskills of "calculation" (C) and "simplification" (S) which are rest on the declarative knowledge of "multiplication of radical" share some more procedures. The results demonstrate that: 1. Within the domain of elementary geometry, although little transfer was found between the two subskills of GP and EP within the total subjects, different results occurred when considering the factor of subject's ability. Within the high level subjects, significant positive transfer was found from EP to GP, while little transfer was found on the opposite direction (i. e. from GP to EP). Within the low level subjects, significant positive transfer was found from EP to GP, while significant negative transfer was found on the opposite direction. For the middle level subject, little transfer was found between the two subskills. 2. Within the domain of elementary algebra, significant positive transfer was found from S to C, while significant negative transfer was found on the opposite direction (i. e. from C to S), when considering the total subjects. The same pattern of transfer occurred within the middle level subjects and low level subject. Within the high level subjects, no transfer was found between the two subskills. 3. Within theses two domains, different learning methods yield little influence on transfer of training between subskills. Apparently, these results can not be attributed to either common procedures or elaboration of declarative knowledge. A kind of synthetic inspection is essential to construct a reasonable explanation of these results which should take into account the following three elements: (1) relations between the procedures of subskills; (2) elaboration of declarative knowledge; (3) elaboration of procedural knowledge. 排Excluding the factor of subject, transfer of training between subskills can be predicted and explained by analyzing the relations between the procedures of two subskills. However, when considering some certain subjects, the explanation of transfer of training between subskills must include subjects' elaboration of declarative knowledge and procedural knowledge, especially the influence of the elaboration on performing the other subskill. The fact that different learning methods yield little influence on transfer of training between subskills can be explained by the fact that these two methods did not effect the level of declarative knowledge. Protocol analysis provided evidence to support these hypothesis. From this research, we conclude that in order to expound the mechanisms of transfer of training between cognitive subskills rest on the same body of declarative knowledge, three elements must be considered synthetically which include: (1) relations between the procedures of subskills; (2) elaboration of declarative knowledge; (3) elaboration of procedural knowledge.

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This paper explores the relationships between a computation theory of temporal representation (as developed by James Allen) and a formal linguistic theory of tense (as developed by Norbert Hornstein) and aspect. It aims to provide explicit answers to four fundamental questions: (1) what is the computational justification for the primitive of a linguistic theory; (2) what is the computational explanation of the formal grammatical constraints; (3) what are the processing constraints imposed on the learnability and markedness of these theoretical constructs; and (4) what are the constraints that a linguistic theory imposes on representations. We show that one can effectively exploit the interface between the language faculty and the cognitive faculties by using linguistic constraints to determine restrictions on the cognitive representation and vice versa. Three main results are obtained: (1) We derive an explanation of an observed grammatical constraint on tense?? Linear Order Constraint??m the information monotonicity property of the constraint propagation algorithm of Allen's temporal system: (2) We formulate a principle of markedness for the basic tense structures based on the computational efficiency of the temporal representations; and (3) We show Allen's interval-based temporal system is not arbitrary, but it can be used to explain independently motivated linguistic constraints on tense and aspect interpretations. We also claim that the methodology of research developed in this study??oss-level" investigation of independently motivated formal grammatical theory and computational models??a powerful paradigm with which to attack representational problems in basic cognitive domains, e.g., space, time, causality, etc.

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This dissertation presents a model of the knowledge a person has about the spatial structure of a large-scale environment: the "cognitive map". The functions of the cognitive map are to assimilate new information about the environment, to represent the current position, and to answer route-finding and relative-position problems. This model (called the TOUR model) analyzes the cognitive map in terms of symbolic descriptions of the environment and operations on those descriptions. Knowledge about a particular environment is represented in terms of route descriptions, a topological network of paths and places, multiple frames of reference for relative positions, dividing boundaries, and a structure of containing regions. The current position is described by the "You Are Here" pointer, which acts as a working memory and a focus of attention. Operations on the cognitive map are performed by inference rules which act to transfer information among different descriptions and the "You Are Here" pointer. The TOUR model shows how the particular descriptions chosen to represent spatial knowledge support assimilation of new information from local observations into the cognitive map, and how the cognitive map solves route-finding and relative-position problems. A central theme of this research is that the states of partial knowledge supported by a representation are responsible for its ability to function with limited information of computational resources. The representations in the TOUR model provide a rich collection of states of partial knowledge, and therefore exhibit flexible, "common-sense" behavior.

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Mead, J., Gray, S., Hamer, J., James, R., Sorva, J., Clair, C. S., and Thomas, L. 2006. A cognitive approach to identifying measurable milestones for programming skill acquisition. SIGCSE Bull. 38, 4 (Dec. 2006), 182-194.

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Ioan Fazey, John A. Fazey, Joern Fischer, Kate Sherren, John Warren, Reed F. Noss, Stephen R. Dovers (2007) Adaptive capacity and learning to learn as leverage for social?ecological resilience. Frontiers in Ecology and the Environment 5(7),375-380. RAE2008

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Kingston-Smith, A. H., Bollard, A. L., Humphreys, M. O,, Theodorou, M. K. (2002). An assessment of the ability of the stay-green phenotype in Lolium species to provide an improved protein supply for ruminants. Annals of Botany, 89(6), 731-740. Sponsorship: BBSRC/MAFF/Milk Development Council/Meat and Livestock Commission/Industry. RAE2008