881 resultados para Communicative and pre-communicative tasks


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Seven hundred and thirty fishes and 276 crustaceans collected from various fish markets of Coimbatore, South India, over a period of 2 years (September 1990 to August 1992) were analysed for the prevalence of Salmonella. Fishes (14·25%) and 17·39% of crustaceans were found to be contaminated with Salmonella. Of the different fishes analysed, the highest incidence of Salmonella was seen in Scopelidae (28%) followed by Trachnidae (26·9%). Among crustaceans Portunus pelagicus (33·33%) showed the highest incidence followed by Scylla serrata (28·57%). A well-marked seasonal variation in the incidence pattern was observed in both fishes and crustaceans with a higher incidence during monsoon season followed by post-monsoon and pre-monsoon. The region of the body that showed frequent isolation was the alimentary canal in fishes (41·33%) and gills (35·06%) in crustaceans. Serotyping of the isolates revealed prevalence of Salmonella weltevreden, Salmonella typhi, Salmonella paratyphi B, Salmonella mgulani and Salmonella typhimurium in both fishes and crustaceans. Salmonella senftenberg was isolated only from crustaceans

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This paper discusses the salient features associated with the variation in the BODs and dissolved oxygen concentration in the Kadinamkulam Kayal based on fortnightly data from two selected stations from October1987toSeptember1988.The BODs ranged from 5.76 to 24.39 mg/l in the surface water and from 4.96 to 22.60mg!1 in the bottom waterat station-l whereas at station-2, it ranged from 0 to 3.74mg/1 in the surface water and from 0 to 3.40 mg!l in the bottom water. The dissolved oxygen concentration ranged from 0 to 0.72 mglI in the surface water and from 0 to 0.42 mg!l in the bottom waterat station-I, At station-2 it ranged from 2.69 to 6.21mg!1 in the surface waterand from 1.97 to 5.74 mg!1 in the bottom water. The pre-monsoom period showed the highest BODsof 16.68mg!I while the monsoon period showed the lowest of 0.61 mg!I. The dissolved oxygen concentration reached its peak during the monsoon period (5.52 mg/I). Long spells of anoxic condition during the post and pre-monsoon periods was a characteristic feature of the retting zone

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Present study focussed on the water quality status in relation to various anthropogenic activities in the Kodungallur- Azhikode Estuary (KAE). Average depth of the estuary was 3.6 ± 0.2 m with maximum of 4.3 ± 0.4 m in the estuarine mouth. Dissolved oxygen showed an average of 5.1±1 mg/l in the water column, whereas the highest BOD value was noticed during monsoon period (3.1 ± 0.8 mg/l) which could be due to high organic enrichment in the water column. pH displayed slightly alkaline condition in most of the stations and it varied from 7.2 ± 0.5 in Station 7 to 7.5 ± 0.5 in Station 1. Salinity in the estuary displayed mixo-mesohaline nature with clear vertical stratification. High river discharge could have resulted in nutrients and silt loading into the estuary, which makes a highly turbid water column particularly during the monsoon period, which limits light penetration and subsequent primary productivity. Turbidity in the water column showed an average of 20.2 ± 15.8 NTU. Estuary was nitrogen limited during post and pre monsoon periods. Nitrate-nitrogen content in the estuarine water gave negative correlation with ammonia.

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Among the decapod crustaceans, brachyuran crabs or the true crabs occupy a very significant position due to their ecological and economic value. Crabs support a sustenance fishery in India, even though their present status is not comparable to that of shrimps and lobsters. They are of great demand in the domestic market as well as in the foreign markets. In addition to this, brachyuran crabs are of great ecological importance. They form the conspicuous members of the mangrove ecosystems and play a significant role in detritus formation, nutrient recycling and dynamics of the ecosystem. Considering all these factors, crabs are often considered to be the keystone species of the mangrove ecosystem. Though several works have been undertaken on brachyuran crabs world –wide as well as within the country, reports on the brachyuran crabs of Kerala waters are very scanty. Most of the studies done on brachyuran fauna were from the east coast of India and a very few works from the west coast. Among the edible crabs, mud crabs belonging to genus Scylla forms the most important due to their large size and taste. They are being exported on a large scale to the foreign markets like Singapore, Malaysia and Hong Kong. Kerala is the biggest supplier of live mud crabs and Chennai is the major centre of live mud crab export. However, there exists considerable confusion regarding the identification of mud crabs because of the subtle morphological differences between the species.In this context, an extensive study was undertaken on the brachyuran fauna of Cochin Backwaters, Kerala, India, to have a basic knowledge on their diversity, habitat preference and systematics. The study provides an attempt to resolve the confusion pertaining in the species identification of mud crabs belonging to Genus Scylla. Diversity study revealed the occurrence of 23 species of brachyuran crabs belonging to 16 genera and 8 families in the study area Cochin Backwaters. Among the families, the highest number of species was recorded from Family Portunidae .Among the 23 crab species enlisted from the Cochin backwaters, 5 species are of commercial importance and contribute a major share to the crustacean fishery of the Cochin region. It was observed that, the Cochin backwaters are invaded by certain marine migrant species during the Post monsoon and Pre monsoon periods and they are found to disappear with the onset of monsoon. The study reports the occurrence of the ‘herring bow crab’ Varuna litterata in the Cochin backwaters for the first time. Ecological studies showed that the substratum characteristics influence the occurrence, distribution and abundance of crabs in the sampling stations rather than water quality parameters. The variables which affected the crab distribution the most were Salinity, moisture content in the sediment, organic carbon and the sediment texture. Besides the water and sediment quality parameters, the most important factor influencing the distribution of crabs is the presence of mangroves. The study also revealed that most of the crabs encountered from the study area preferred a muddy substratum, with high organic carbon content and high moisture content. In the present study, an identification key is presented for the brachyuran crabs occurring along the study area the Cochin backwaters and the associated mangrove patches, taking into account the morphological characters coupled with the structure of third maxillipeds, first pleopods of males and the shape of male abdomen. Morphological examination indicated the existence of a morphotype which is comparable with the morphological features of S. tranquebarica, the morphometric study and the molecular analyses confirmed the non existence of S. tranquebarica in the Cochin backwaters.

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In this article we compare regression models obtained to predict PhD students’ academic performance in the universities of Girona (Spain) and Slovenia. Explanatory variables are characteristics of PhD student’s research group understood as an egocentered social network, background and attitudinal characteristics of the PhD students and some characteristics of the supervisors. Academic performance was measured by the weighted number of publications. Two web questionnaires were designed, one for PhD students and one for their supervisors and other research group members. Most of the variables were easily comparable across universities due to the careful translation procedure and pre-tests. When direct comparison was not possible we created comparable indicators. We used a regression model in which the country was introduced as a dummy coded variable including all possible interaction effects. The optimal transformations of the main and interaction variables are discussed. Some differences between Slovenian and Girona universities emerge. Some variables like supervisor’s performance and motivation for autonomy prior to starting the PhD have the same positive effect on the PhD student’s performance in both countries. On the other hand, variables like too close supervision by the supervisor and having children have a negative influence in both countries. However, we find differences between countries when we observe the motivation for research prior to starting the PhD which increases performance in Slovenia but not in Girona. As regards network variables, frequency of supervisor advice increases performance in Slovenia and decreases it in Girona. The negative effect in Girona could be explained by the fact that additional contacts of the PhD student with his/her supervisor might indicate a higher workload in addition to or instead of a better advice about the dissertation. The number of external student’s advice relationships and social support mean contact intensity are not significant in Girona, but they have a negative effect in Slovenia. We might explain the negative effect of external advice relationships in Slovenia by saying that a lot of external advice may actually result from a lack of the more relevant internal advice

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Near isogenic lines (NILs) varying for genes for reduced height (Rht) and photoperiod insensitivity (Ppd-D1a) in a cv. Mercia background (rht (tall), Rht-B1b, Rht-D1b, Rht-B1c, Rht8c + Ppd-D1a, Rht-D1c, Rht12) were compared at one field site but within contrasting ('organic' vs. 'conventional') rotational and agronomic contexts, in each of 3 years. In the final year, further NILs (rht (tall), Rht-B1b, Rht-D1b, Rht-B1c, Rht-B1b + Rht-D1b, Rht-D1b + Rht-B1c) in both Maris Huntsman and Maris Widgeon backgrounds were added together with 64 lines of a doubled haploid (DH) population [Savannah (Rht-D1b) x Renesansa (Rht-8c + Ppd-D1a)]. Assessments included laboratory tests of germination and coleoptile length, and various field measurements of crop growth between emergence and pre jointing [plant population, tillering, leaf length, ground cover (GC), interception of photosynthetically active radiation (PAR), crop dry matter (DM) and nitrogen accumulation (N), far red: red reflectance ratio (FR:R), crop height, and weed dry matter]. All of the dwarfing alleles except Rht12 in the Mercia background and Rht8c in the DHs were associated with reduced coleoptile length. Most of the dwarfing alleles (depending on background) reduced seed viability. Severe dwarfing alleles (Rht-B1c, Rht-D1c and Rht12) were routinely associated with fewer plant numbers and reduced early crop growth (GC, PAR, DM, N, FR:R), and in 1 year, increased weed DM. In the Mercia background and the DHs the semi-dwarfing allele Rht-D1b was also sometimes associated with reductions in early crop growth; no such negative effects were associated with the marker for Rht8c. When significant interactions between cropping system and genotype did occur it was because differences between lines were more exaggerated in the organic system than in the conventional system. Ppd-D1a was associated positively with plant numbers surviving the winter and early crop growth (GC, FR:R, DM, N, PAR, height), and was the most significant locus in a QTL analysis. We conclude that, within these environmental and system contexts, genes moderating development are likely to be more important in influencing early resource capture than using Rht8c as an alternative semi-dwarfing gene to Rht-D1b.

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Research shows that poor indoor air quality (IAQ) in school buildings can cause a reduction in the students’ performance assessed by short-term computer-based tests; whereas good air quality in classrooms can enhance children's concentration and also teachers’ productivity. Investigation of air quality in classrooms helps us to characterise pollutant levels and implement corrective measures. Outdoor pollution, ventilation equipment, furnishings, and human activities affect IAQ. In school classrooms, the occupancy density is high (1.8–2.4 m2/person) compared to offices (10 m2/person). Ventilation systems expend energy and there is a trend to save energy by reducing ventilation rates. We need to establish the minimum acceptable level of fresh air required for the health of the occupants. This paper describes a project, which will aim to investigate the effect of IAQ and ventilation rates on pupils’ performance and health using psychological tests. The aim is to recommend suitable ventilation rates for classrooms and examine the suitability of the air quality guidelines for classrooms. The air quality, ventilation rates and pupils’ performance in classrooms will be evaluated in parallel measurements. In addition, Visual Analogue Scales will be used to assess subjective perception of the classroom environment and SBS symptoms. Pupil performance will be measured with Computerised Assessment Tests (CAT), and Pen and Paper Performance Tasks while physical parameters of the classroom environment will be recorded using an advanced data logging system. A total number of 20 primary schools in the Reading area are expected to participate in the present investigation, and the pupils participating in this study will be within the age group of 9–11 years. On completion of the project, based on the overall data recommendations for suitable ventilation rates for schools will be formulated.

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Previous studies of the Stroop task propose two key mediators: the prefrontal and cingulate cortices but hints exist of functional specialization within these regions. This study aimed to examine the effect of task modality upon the prefrontal and cingulate response by examining the response to colour, number, and shape Stroop tasks whilst BOLD fMRI images were acquired on a Siemens 3 T MRI scanner. Behavioural analyses indicated facilitation and interference effects and a noticeable effect of task difficulty. Some modular effects of modality were observed in the prefrontal cortex that survived exclusion of task difficulty related activations. No effect of task-relevant information was observed in the anterior cingulate. Future comparisons of the mediation of selective attention need to consider the effects of task context and task difficulty. (c) 2005 Elsevier Inc. All rights reserved.

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Subjects with Broca's aphasia have been shown to display difficulties in on-line and off-line tasks involving personal pronouns and reflexives. Off-line tasks have indicated more errors with pronouns than with reflexives while the reverse has been found in on-line studies. In the present off-line study, the comprehension of sentences containing personal pronouns and reflexives is examined in a group of 10 agrammatic participants. Results indicate that subjects had difficulties with both pronouns and reflexives, particularly with reflexives in sentences that contained a quantificational antecedent, as well as with pronouns in exceptional case marking constructions. It is argued that the low performance that subjects exhibited as a group in pronouns and reflexives indicates two distinct impairments, one that concerns coreference and one that concerns A-dependencies, the latter being a manifestation of a general processing failure to link positions. Poor performance on exceptional case marking constructions compared to simple transitive sentences is claimed to be interpreted within theories for reference assignment that distinguish between the two sentence types. (c) 2007 Elsevier Ltd. All rights reserved.

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The aim of this study was to compare the prosodic profiles of English and Spanish-speaking children with WS, examining cross-linguistic differences. Two groups of children with WS, English and Spanish, of similar chronological and nonverbal mental age, were compared on performance in expressive and receptive prosodic tasks from the Profiling Elements of Prosody in Speech-Communication (PEPS-C) battery in its English or Spanish version. Differences between the English and Spanish WS groups were found regarding the understanding of affect through prosodic means,using prosody to make words more prominent, and imitating different prosodic patterns. Such differences between the two WS groups on function prosody tasks mirrored the cross-linguistic differences already reported in typically developing children.

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International Perspective The development of GM technology continues to expand into increasing numbers of crops and conferred traits. Inevitably, the focus remains on the major field crops of soybean, maize, cotton, oilseed rape and potato with introduced genes conferring herbicide tolerance and/or pest resistance. Although there are comparatively few GM crops that have been commercialised to date, GM versions of 172 plant species have been grown in field trials in 31 countries. European Crops with Containment Issues Of the 20 main crops in the EU there are four for which GM varieties are commercially available (cotton, maize for animal feed and forage, and oilseed rape). Fourteen have GM varieties in field trials (bread wheat, barley, durum wheat, sunflower, oats, potatoes, sugar beet, grapes, alfalfa, olives, field peas, clover, apples, rice) and two have GM varieties still in development (rye, triticale). Many of these crops have hybridisation potential with wild and weedy relatives in the European flora (bread wheat, barley, oilseed rape, durum wheat, oats, sugar beet and grapes), with escapes (sunflower); and all have potential to cross-pollinate fields non-GM crops. Several fodder crops, forestry trees, grasses and ornamentals have varieties in field trials and these too may hybridise with wild relatives in the European flora (alfalfa, clover, lupin, silver birch, sweet chestnut, Norway spruce, Scots pine, poplar, elm, Agrostis canina, A. stolonifera, Festuca arundinacea, Lolium perenne, L. multiflorum, statice and rose). All these crops will require containment strategies to be in place if it is deemed necessary to prevent transgene movement to wild relatives and non-GM crops. Current Containment Strategies A wide variety of GM containment strategies are currently under development, with a particular focus on crops expressing pharmaceutical products. Physical containment in greenhouses and growth rooms is suitable for some crops (tomatoes, lettuce) and for research purposes. Aquatic bioreactors of some non-crop species (algae, moss, and duckweed) expressing pharmaceutical products have been adopted by some biotechnology companies. There are obvious limitations of the scale of physical containment strategies, addressed in part by the development of large underground facilities in the US and Canada. The additional resources required to grow plants underground incurs high costs that in the long term may negate any advantage of GM for commercial productioNatural genetic containment has been adopted by some companies through the selection of either non-food/feed crops (algae, moss, duckweed) as bio-pharming platforms or organisms with no wild relatives present in the local flora (safflower in the Americas). The expression of pharmaceutical products in leafy crops (tobacco, alfalfa, lettuce, spinach) enables growth and harvesting prior to and in the absence of flowering. Transgenically controlled containment strategies range in their approach and degree of development. Plastid transformation is relatively well developed but is not suited to all traits or crops and does not offer complete containment. Male sterility is well developed across a range of plants but has limitations in its application for fruit/seed bearing crops. It has been adopted in some commercial lines of oilseed rape despite not preventing escape via seed. Conditional lethality can be used to prevent flowering or seed development following the application of a chemical inducer, but requires 100% induction of the trait and sufficient application of the inducer to all plants. Equally, inducible expression of the GM trait requires equally stringent application conditions. Such a method will contain the trait but will allow the escape of a non-functioning transgene. Seed lethality (‘terminator’ technology) is the only strategy at present that prevents transgene movement via seed, but due to public opinion against the concept it has never been trialled in the field and is no longer under commercial development. Methods to control flowering and fruit development such as apomixis and cleistogamy will prevent crop-to-wild and wild-to-crop pollination, but in nature both of these strategies are complex and leaky. None of the genes controlling these traits have as yet been identified or characterised and therefore have not been transgenically introduced into crop species. Neither of these strategies will prevent transgene escape via seed and any feral apomicts that form are arguably more likely to become invasives. Transgene mitigation reduces the fitness of initial hybrids and so prevents stable introgression of transgenes into wild populations. However, it does not prevent initial formation of hybrids or spread to non-GM crops. Such strategies could be detrimental to wild populations and have not yet been demonstrated in the field. Similarly, auxotrophy prevents persistence of escapes and hybrids containing the transgene in an uncontrolled environment, but does not prevent transgene movement from the crop. Recoverable block of function, intein trans-splicing and transgene excision all use recombinases to modify the transgene in planta either to induce expression or to prevent it. All require optimal conditions and 100% accuracy to function and none have been tested under field conditions as yet. All will contain the GM trait but all will allow some non-native DNA to escape to wild populations or to non-GM crops. There are particular issues with GM trees and grasses as both are largely undomesticated, wind pollinated and perennial, thus providing many opportunities for hybridisation. Some species of both trees and grass are also capable of vegetative propagation without sexual reproduction. There are additional concerns regarding the weedy nature of many grass species and the long-term stability of GM traits across the life span of trees. Transgene stability and conferred sterility are difficult to trial in trees as most field trials are only conducted during the juvenile phase of tree growth. Bio-pharming of pharmaceutical and industrial compounds in plants Bio-pharming of pharmaceutical and industrial compounds in plants offers an attractive alternative to mammalian-based pharmaceutical and vaccine production. Several plantbased products are already on the market (Prodigene’s avidin, β-glucuronidase, trypsin generated in GM maize; Ventria’s lactoferrin generated in GM rice). Numerous products are in clinical trials (collagen, antibodies against tooth decay and non-Hodgkin’s lymphoma from tobacco; human gastric lipase, therapeutic enzymes, dietary supplements from maize; Hepatitis B and Norwalk virus vaccines from potato; rabies vaccines from spinach; dietary supplements from Arabidopsis). The initial production platforms for plant-based pharmaceuticals were selected from conventional crops, largely because an established knowledge base already existed. Tobacco and other leafy crops such as alfalfa, lettuce and spinach are widely used as leaves can be harvested and no flowering is required. Many of these crops can be grown in contained greenhouses. Potato is also widely used and can also be grown in contained conditions. The introduction of morphological markers may aid in the recognition and traceability of crops expressing pharmaceutical products. Plant cells or plant parts may be transformed and maintained in culture to produce recombinant products in a contained environment. Plant cells in suspension or in vitro, roots, root cells and guttation fluid from leaves may be engineered to secrete proteins that may be harvested in a continuous, non-destructive manner. Most strategies in this category remain developmental and have not been commercially adopted at present. Transient expression produces GM compounds from non-GM plants via the utilisation of bacterial or viral vectors. These vectors introduce the trait into specific tissues of whole plants or plant parts, but do not insert them into the heritable genome. There are some limitations of scale and the field release of such crops will require the regulation of the vector. However, several companies have several transiently expressed products in clinical and pre-clinical trials from crops raised in physical containment.

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Three bruchid pest species, Callosobruchus maculatus, Callosobruchus chinensis and Callosobruchus rhodesianus, were studied for their response to insecticide toxicity taking into account the separate and interactive effects of temperature and pre-adult food. The food types used were cowpea (Vigna unguiculata) and mungbean (Vigna radiata). Callosobruchus maculatus was the most tolerant to malathion and the least affected by temperature change while C. rhodesianus was the least tolerant. Over a 4 C range (23, 25, 27 C), there was generally a significant impact of temperature on the tolerance of the three species to the insecticide. The food type on which the insects developed influenced considerably the degree of insecticide tolerance. Callosobruchus maculatus and C. chinensis populations reared onmungbean had higher tolerance to malathion than their counterparts reared on cowpea, but the opposite was observed in C. rhodesianus populations. The food influence in this study suggested an ancestral cause or fitness cost depending on the species. The interaction of food-by-temperature had no significant effect on malathion toxicity to this genus. Correlation analysis showed C. chinensis to be relatively less sensitive to insecticide concentration over the range studied compared with the other two species.

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Although the curriculum subject of English is continually reviewed and revised in all English speaking countries, the status of literature is rarely questioned i.e. that it is of high cultural value and all students should be taught about it. The concerns of any review, in any country, are typically about what counts as literature, especially in terms of national heritage and then how much of the curriculum should it occupy. This article reports on three inter-related pieces of research that examine the views of in-service, and pre-service, English teachers about their experiences of teaching literature and their perceptions of its ‘status’ and significance at official level and in the actual classroom; it draws attention to how England compares to some other English speaking countries and draws attention to the need to learn from the negative outcomes of political policy in England. The findings suggest that the nature of engagement with literature for teachers and their students has been distorted by official rhetorics and assessment regimes and that English teachers are deeply concerned to reverse this pattern.

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Field experiments were conducted in northern Greece in 2003 and 2004 to evaluate effects of tillage regimes (moldboard plowing, chisel plowing, and rotary tilling), cropping sequences(continuous cotton, cotton-sugar beet rotation,and continuous tobacco) and herbicide treatments with inter-row hand hoeing on weed population densities. Total weed densities were not affected by tillage treatment except that of barnyardgrass (Echinochloa crus-galli), which increased only in moldboard plowing treated plots during 2003. Redroot pigweed (Amaranthus retroflexus)and black nightshade (Solanum nigrum) densities were reduced in continuous cotton, while purple nutsedge (Cyperus rotundus), E. crus-galli, S. nigrum, and johnsongras(Sorghum halepense) densities were reduced in tobacco. A. retroflexus and S. nigrum were effectively controlled by all herbicide treatments with inter-row hand hoeing,whereas E. crus-galli was effectively reduced by herbicides applied to cotton and tobacco. S. halepense density reduction was a result of herbicide applied to tobacco with inter-row hand hoeing. Yield of all crops was higher under moldboard plowing and herbicide treatments. Pre-sowing and pre-emergence herbicide treatments in cotton and pre-transplant in tobacco integrated with inter-row cultivation resulted in efficient control of annual weed species and good crop yields. These observations are of practical relevance to crop selection by farmers in order to maintain weed populations at economically acceptable densities through the integration of various planting dates, sustainable herbicide use and inter-row cultivation; tools of great importance in integrated weed management systems. Keywords: cropping sequence, herbicide, integrated weed management, inter-row cultivation,tillage.

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Cluttering is a rate-based disorder of fluency, the scope of whose diagnostic criteria currently remains unclear. This paper reports preliminary findings from a larger study which aims to determine whether cluttering can be associated with language disturbances as well as motor and rate based ones. Subtests from the Mt Wilga High Level Language Test (MWHLLT) were used to determine whether people who clutter (PWC) have word finding difficulties, and use significantly more maze behaviours compared to controls, during story re-telling and simple sequencing tasks. Independent t tests showed that PWC were significantly slower than control participants in lexical access and sentence completion tasks, but returned mixed findings when PWCs were required to name items within a semantic category. PWC produced significantly more maze behaviour than controls in a task where participants were required to explain how to undertake commonly performed actions, but no difference in use of maze behaviour was found between the two groups when retelling a story from memory. The implications of these findings are discussed