Showing papers by "University of York published in 2000"

Empathy and Moral Development: Implications for Caring and Justice

Abstract: 1. Introduction and overview 2. Empathy, its arousal and prosocial functioning 3. Development of empathic distress 4. Empathic anger, sympathy, guilt, feeling of injustice 5. Guilt and moral internalization 6. From discipline to internalization 7. Relationship and other virtual guilts 8. Empathy's limitations: is empathy enough? 9. Empathy and moral principles 10. Development of empathy-based justice principles 11. Multiple- claimant and caring-versus-justice dilemmas 12. The universality and culture issue 13. Implications for intervention.

Plan 9 From Cyberspace: The Implications of the Internet for Personality and Social Psychology:

Abstract: Just as with most other communication breakthroughs before it, the initial media and popular reaction to the Internet has been largely negative, if not apocalyptic. For example, it has been described as “awash in pornography”, and more recently as making people “sad and lonely.” Yet, counter to the initial and widely publi cized claim that Internet use causes depression and social isolation, the body of ev idence (even in the initial study on which the claim was based) is mainly to the con trary. More than this, however, it is argued that like the telephone and television before it, the Internet by itself is not a main effect cause of anything, and that psy chology must move beyond this notion to an informed analysis of how social iden tity, social interaction, and relationship formation may be different on the Internet than in real life. Four major differences and their implications for self and identity, social interaction, and relationships are identified: one's greater anonymity, the greatly reduced i...

Cooperation in Groups: Procedural Justice, Social Identity, and Behavioral Engagement

Abstract: I. Overview. Introduction. The Design of This Study. II. The Antecedents of Cooperative Behavior. Why Study Cooperative Behavior in Groups. Instrumental Motivations for Engaging in Cooperative Behavior. Internally-driven Cooperative Behavior. III. The Influence of Justice: Procedual Justice and Cooperation. The Influence of Justice Based Judgments. Procedural Justice and Cooperative Behavior. IV. The Meaning of Procedual Justice: The Four Component Model. Relational Models of Procedual Justice. A Two Component Model of Procedural Justice: Quality of Decision-making and Quality of Treatment. Creating a Four Component Model of Procedural Justice: Adding the Distinction Between Formal and Informal Sources of Justice. V. Social Identity and Cooperative Behavior: Status and Psychological Engagement. Social Identity and Cooperative Behavior. Justice and Group Status: The Antecedents of Status Evaluations. Psychological Engagement with the Group. VI. Discussion Conclusion: Understanding Group Behavior From a Non-Instrumental Perspective. VII. References. VIII. Appendices

A Kingdom-Level Phylogeny of Eukaryotes Based on Combined Protein Data

Abstract: Current understanding of the higher order systematics of eukaryotes relies largely on analyses of the small ribosomal subunit RNA (SSU rRNA). Independent testing of these results is still limited. We have combined the sequences of four of the most broadly taxonomically sampled proteins available to create a roughly parallel data set to that of SSU rRNA. The resulting phylogenetic tree shows a number of striking differences from SSU rRNA phylogeny, including strong support for most major groups and several major supergroups.

Stable-isotope probing as a tool in microbial ecology

Abstract: Microorganisms are responsible for driving the biogeochemical cycling of elements on Earth Despite their importance and vast diversity1, the taxonomic identity of the microorganisms involved in any specific process has usually been confined to that small fraction of the microbiota that has been isolated and cultivated The recent coupling of molecular biological methods with stable-isotope abundance in biomarkers has provided a cultivation-independent means of linking the identity of bacteria with their function in the environment2,3 Here we show that 13C-DNA, produced during the growth of metabolically distinct microbial groups on a 13C-enriched carbon source, can be resolved from 12C-DNA by density-gradient centrifugation DNA isolated from the target group of microorganisms can be characterized taxonomically and functionally by gene probing and sequence analysis Application of this technique to investigate methanol-utilizing microorganisms in soil demonstrated the involvement of members of two phylogenetically distinct groups of eubacteria; the α-proteobacterial and Acidobacterium lineages Stable-isotope probing thus offers a powerful new technique for identifying microorganisms that are actively involved in specific metabolic processes under conditions which approach those occurring in situ

Angiogenesis in Wound Healing

Abstract: During wound healing, angiogenic capillary sprouts invade the fibrin/fibronectin-rich wound clot and within a few days organize into a microvascular network throughout the granulation tissue. As collagen accumulates in the granulation tissue to produce scar, the density of blood vessels diminishes. A dynamic interaction occurs among endothelial cells, angiogenic cytokines, such as FGF, VEGF, TGF-β, angiopoietin, and mast cell tryptase, and the extracellular matrix (ECM) environment. Specific endothelial cell ECM receptors are critical for these morphogenetic changes in blood vessels during wound repair. In particular, αvβ3, the integrin receptor for fibrin and fibronectin, appears to be required for wound angiogenesis: αvβ3 is expressed on the tips of angiogenic capillary sprouts invading the wound clot, and functional inhibitors of αvβ3 transiently inhibit granulation tissue formation. Recent investigations have shown that the wound ECM can regulate angiogenesis in part by modulating integrin receptor expression. mRNA levels of αvβ3 in human dermal microvascular endothelial cells either plated on fibronectin or overlaid by fibrin gel were higher than in cells plated on collagen or overlaid by collagen gel. Wound angiogenesis also appears to be regulated by endothelial cell interaction with the specific three-dimensional ECM environment in the wound space. In an in vitro model of human sprout angiogenesis, three-dimensional fibrin gel, simulating early wound clot, but not collagen gel, simulating late granulation tissue, supported capillary sprout formation. Understanding the molecular mechanisms that regulate wound angiogenesis, particularly how ECM modulates ECM receptor and angiogenic factor requirements, may provide new approaches for treating chronic wounds.

Event-related potential (ERP) studies of memory encoding and retrieval: a selective review.

Abstract: As event-related brain potential (ERP) researchers have increased the number of recording sites, they have gained further insights into the electrical activity in the neural networks underlying explicit memory. A review of the results of such ERP mapping studies suggests that there is good correspondence between ERP results and those from brain imaging studies that map hemodynamic changes. This concordance is important because the combination of the high temporal resolution of ERPs with the high spatial resolution of hemodynamic imaging methods will provide a greatly increased understanding of the spatio-temporal dynamics of the brain networks that encode and retrieve explicit memories.

Impaired recognition and experience of disgust following brain injury.

Abstract: Huntington's disease can particularly affect people's recognition of disgust from facial expressions, and functional neuroimaging research has demonstrated that facial expressions of disgust consistently engage different brain areas (insula and putamen) than other facial expressions. However, it is not known whether these particular brain areas process only facial signals of disgust or disgust signals from multiple modalities. Here we describe evidence, from a patient with insula and putamen damage, for a neural system for recognizing social signals of disgust from multiple modalities.

Global Warming and Terrestrial Ecosystems: A Conceptual Framework for Analysis

Abstract: raise global mean temperature over the next century by 1.0–3.5 °C (Houghton et al. 1995, 1996). Ecologists from around the world have begun experiments to investigate the effects of global warming on terrestrial ecosystems, the aspect of global climate change that attracts the most public attention (Woodwell and McKenzie 1995, Walker and Steffen 1999). The effort to understand response to warming builds on a history of investigations of the effects of elevated CO 2 on plants and ecosystems (Koch and Mooney 1996, Schulze et al. 1999). There are important differences, however, between increases in atmospheric CO 2 and temperature change, both in the temporal and spatial patterns of change and in how they affect ecosystems. The scientists involved in temperature change research have had to face new technical and conceptual challenges in designing and interpreting their experiments (Schulze et al. 1999). In this paper we describe these challenges and present a conceptual framework for interpreting experimental results and predicting effects of warming on ecosystems.

An approach to multi-copy search in molecular replacement.

Abstract: The molecular-replacement method has been extended to a simultaneous search for multiple copies of the macromolecule in the unit cell. The central point of this approach is the construction of a multi-copy search model from the properly oriented monomers using a special translation function. The multi-copy search method has been implemented in the program MOLREP and successfully tested using experimental data.

Temporal construal and time-dependent changes in preference

Abstract: Five studies tested the predictions of temporal construal theory and time-discounting theories regarding evaluation of near future and distant future options (outcomes, activities, products). The options had abstract or goal-relevant features (called high-level construal features) as well as more concrete or goal-irrelevant features (called low-level construal features). The studies varied the valence (positive vs. negative) and the type of valence (affective vs. cognitive) of the low-level and high-level construal features. The results show that the weight of high-level construal features, compared with the weight of low-level construal features, is greater in determining distant future preferences than near future preferences. The implications of the results for extant theories of time-dependent changes in preference are discussed.

The collective construction of work group moods.

Abstract: This research examines mood as a collective property of work groups We argue that work group members experience group moods when they can detect and display mood information through observable beh

A serotonin transporter gene promoter polymorphism (5-HTTLPR) and prefrontal cortical binding in major depression and suicide.

Abstract: Background Major depression and suicide are associated with fewer serotonin transporter (5-HTT) sites. The 5′-flanking promoter region of the 5-HTT gene has a biallelic insertion/deletion (5-HTTLPR). We assayed prefrontal cortical (PFC) 5-HTT binding in major depression and suicide and examine the relationship to the 5-HTTLPR allele. Methods Postmortem brain samples from 220 individuals were genotyped for the 5-HTTLPR polymorphism. Binding of 5-HTT was assayed by quantitative autoradiography in the PFC of a subset of subjects (n = 159). Clinical information, including DSM-III-R Axis I diagnoses, was obtained by psychological autopsy and medical chart review. Results Binding to 5-HTT was lower in the ventral PFC of suicides compared with nonsuicides and was lower throughout the PFC of subjects with a history of major depression. The 5-HTTLPR genotype was associated with major depression but not with suicide or 5-HTT binding. Conclusions A diffuse reduction of 5-HTT binding in the PFC of individuals with major depression may reflect a widespread impairment of serotonergic function consistent with the range of psychopathologic features in major depression. The localized reduction in 5-HTT binding in the ventral PFC of suicides may reflect reduced serotonin input to that brain region, underlying the predisposition to act on suicidal thoughts. The 5-HTTLPR genotype was not related to the level of 5-HTT binding and does not explain why 5-HTT binding is lower in major depression or suicide.

Computational principles of mobile robotics

Abstract: Mobile robotics is a multidisciplinary field involving both computer science and engineering. Addressing the design of automated systems, it lies at the intersection of artificial intelligence, computational vision, and robotics. This textbook for advanced undergraduates and graduate students emphasizes algorithms for a range of strategies for locomotion, sensing, and reasoning. It concentrates on wheeled and legged mobile robots but discusses a variety of other propulsion systems. The new edition includes advances in robotics and intelligent machines over the last ten years, including significant coverage of SLAM (simultaneous localization and mapping) and multi-robot systems. It includes additional mathematical background and an extensive list of sample problems. Various mathematical techniques that were assumed in the first edition are now briefly introduced in appendices at the end of the text to make the book more self-contained. Researchers as well as students in the field of mobile robotics will appreciate this comprehensive treatment of state-of-the-art methods and key technologies.

Is preschool language impairment a risk factor for dyslexia in adolescence

Abstract: The literacy skills of 56 school leavers from the Bishop and Edmundson (1987) cohort of preschoolers with specific language impairment (SLI) were assessed at 15 years. The SLI group performed worse on tests of reading, spelling, and reading comprehension than age-matched controls and the literacy outcomes were particularly poor for those with Performance IQ less than 100. The rate of specific reading retardation in the SLI group had increased between the ages of 8 1/2 and 15 years and there had been a substantial drop in reading accuracy, relative to age. However, over 35% had reading skills within the normal range and those who had had isolated impairments of expressive phonology had a particularly good outcome. Our findings highlight the limitations of discrepancy definitions of dyslexia that do not take account of the changing demands of reading over time. We argue that children's phonological difficulties place them at risk of literacy failure at the outset of reading and that later, impairments of other language skills compromise development to adult levels of fluency.

Systematic review of water fluoridation.

Abstract: Objective: To review the safety and efficacy of fluoridation of drinking water. Design: Search of 25 electronic databases and world wide web. Relevant journals hand searched; further information requested from authors. Inclusion criteria were a predefined hierarchy of evidence and objectives. Study validity was assessed with checklists. Two reviewers independently screened sources, extracted data, and assessed validity. Main outcome measures: Decayed, missing, and filled primary/permanent teeth. Proportion of children without caries. Measure of effect was the difference in change in prevalence of caries from baseline to final examination in fluoridated compared with control areas. For potential adverse effects, all outcomes reported were used. Results: 214 studies were included. The quality of studies was low to moderate. Water fluoridation was associated with an increased proportion of children without caries and a reduction in the number of teeth affected by caries. The range (median) of mean differences in the proportion of children without caries was −5.0% to 64% (14.6%). The range (median) of mean change in decayed, missing, and filled primary/permanent teeth was 0.5 to 4.4 (2.25) teeth. A dose-dependent increase in dental fluorosis was found. At a fluoride level of 1 ppm an estimated 12.5% (95% confidence interval 7.0% to 21.5%) of exposed people would have fluorosis that they would find aesthetically concerning. Conclusions: The evidence of a beneficial reduction in caries should be considered together with the increased prevalence of dental fluorosis. There was no clear evidence of other potential adverse effects.

I of the Vortex: From Neurons to Self

Abstract: A highly original theory of how the mind-brain works, based on the author's study of single neuronal cells. In I of the Vortex, Rodolfo Llinas, a founding father of modern brain science, presents an original view of the evolution and nature of mind. According to Llinas, the "mindness state" evolved to allow predictive interactions between mobile creatures and their environment. He illustrates the early evolution of mind through a primitive animal called the "sea squirt." The mobile larval form has a brainlike ganglion that receives sensory information about the surrounding environment. As an adult, the sea squirt attaches itself to a stationary object and then digests most of its own brain. This suggests that the nervous system evolved to allow active movement in animals. To move through the environment safely, a creature must anticipate the outcome of each movement on the basis of incoming sensory data. Thus the capacity to predict is most likely the ultimate brain function. One could even say that Self is the centralization of prediction. At the heart of Llinas's theory is the concept of oscillation. Many neurons possess electrical activity, manifested as oscillating variations in the minute voltages across the cell membrane. On the crests of these oscillations occur larger electrical events that are the basis for neuron-to-neuron communication. Like cicadas chirping in unison, a group of neurons oscillating in phase can resonate with a distant group of neurons. This simultaneity of neuronal activity is the neurobiological root of cognition. Although the internal state that we call the mind is guided by the senses, it is also generated by the oscillations within the brain. Thus, in a certain sense, one could say that reality is not all "out there," but is a kind of virtual reality.

Counteractive self-control in overcoming temptation.

Abstract: How do anticipated short-term costs affect the likelihood of engaging in an activity that has long-term benefits. Five studies investigated the factors that determine (a) how anticipated short-term costs elicit self-control efforts and (b) how self-control efforts eventually diminish the influence of short-term costs on behavior. The studies manipulated short-term costs (e.g., painful medical procedures) and assessed a variety of self-control strategies (e.g., self-imposed penalties for failure to undergo a test). The results show that short-term costs elicit self-control strategies for self rather than others, before rather than after behavior, when long-term benefits are important rather than unimportant and when the costs are moderate rather than extremely small or large. The results also show that the self-control efforts help people act according to their long-term interests. People sometimes know what they prefer but feel uncertain that this is what they will actually do. This uncertainty often reflects feasibility constraints such as lack of opportunity, freedom of choice, or prerequisite skills. In some cases, however, people may know that what they prefer is entirely feasible but may nevertheless suspect that when faced with the actual choice they will be

The effectiveness and cost-effectiveness of prophylactic removal of wisdom teeth.

Abstract: Background: Removal of wisdom teeth is one of the most common surgical procedures performed in the UK. Little controversy surrounds the removal of impacted third molars when they are associated with pathological changes such as infection, non-restorable carious lesions, cysts, tumours, and destruction of adjacent teeth and bone. However, the justification for prophylactic removal of impacted third molars is less certain and has been debated for many years. Objectives: To provide a summary of existing evidence on prophylactic removal of impacted wisdom teeth, in terms of the incidence of surgical complications associated with prophylactic removal, and the morbidity associated with retention. Methods: A systematic review of the research literature was undertaken. METHODS - DATA SOURCES: An existing review formed the basis of this report, and additional literature searches were undertaken, including searches of electronic databases (MEDLINE, 1984-99; EMBASE, 1984-99; Science Citation Index, Cochrane Controlled Trials Register, National Research Register; Database of Abstracts of Reviews of Effectiveness), paper sources (including Clinical Evidence), and web-based resources. Relevant organisations and professional bodies were contacted for further information. Methods - study selection: Studies were selected for inclusion if they met the following criteria: (1) design - randomised controlled trials (RCTs), literature reviews, or decision analyses; (2) participants - people with unerupted or impacted third molars, or those undergoing surgical removal of third molars either as prophylaxis or due to associated pathological changes; (3) reported outcomes - either the pathological changes associated with retention of third molars, or post-operative complications following extraction. There were no language restrictions on study selection. METHODS - DATA EXTRACTION AND SYNTHESIS: Data from included studies were extracted into structured tables and individual study validity was assessed against methodological checklists. Data were summarised descriptively. Decisions relating to study selection, data extraction and validity assessment were made by two independent reviewers, and disagreements were resolved by discussion. For non-English papers, translators were recruited to assist with study selection and data extraction. Results: Forty studies were included in the review: two RCTs, 34 literature reviews, and four decision analysis studies. One RCT in the UK focused on the effects of retained third molars on incisor crowding (predominantly a cosmetic problem) in patients who had previously undergone orthodontic treatment. The results of this trial suggested that the removal of third molars to prevent late incisor crowding cannot be justified. Another on-going RCT in Denmark compares the effects and costs of prophylactic removal of third molars with removal according to morbidity. So far, this trial has recruited 200 participants, and preliminary results indicate that watchful waiting may be a promising strategy. However, more data and longer follow-up of patients are needed to conclude which treatment strategy is the most cost-effective. It is also known that a trial is on-going in the USA but no results are available so far. The methodological quality of the literature reviews was generally poor, and none of the reviews was systematic. Conclusions from nine reviews on anterior crowding suggested that there was only a weak association between retention of third molars and crowding. Six out of 21 reviews with a more general scope also concluded that the prophylactic removal of third molars was unjustified. Twelve general reviews did not conclude with a clear message about the management of third molars. Three reviews suggested that prophylactic removal of third molars is appropriate, but these reviews were of poorer methodological quality than the majority of other reviews. Three out of four papers focusing on surgical management expressed

Factors Influencing the Effectiveness of Wildlife Underpasses in Banff National Park, Alberta, Canada

Abstract: Wildlife crossing structures are intended to increase permeability and habitat connectivity across roads. Few studies, however, have assessed the effectiveness of these mitigation measures in a multispecies or community level context. We used a null model to test whether wildlife crossing structures serve large mam- mal species equally or whether such structures limit habitat connectivity across roads in species-specific ways. We also modeled species responses to 14 variables related to underpass structure, landscape features, and hu- man activity. Species performance ratios (observed crossing frequency to expected crossing frequency) were evaluated for four large carnivore and three ungulate species in 11 underpass structures in Banff National Park, Alberta, Canada. Observed crossing frequencies were collected in 35 months of underpass monitoring. Expected frequencies were developed from three independent models: radio telemetry, pellet counts, and hab- itat-suitability indices. The null model showed that species responded to underpasses differently. In the pres- ence of human activity carnivores were less likely to use underpasses than were ungulates. Apart from hu- man activity, carnivore performance ratios were better correlated to landscape variables, and ungulate performance ratios were better correlated to structural variables. We suggest that future underpasses de- signed around topography, habitat quality, and location will be minimally successful if human activity is not managed.

Capitation, salary, fee-for-service and mixed systems of payment: effects on the behaviour of primary care physicians.

Abstract: Background It is widely believed that the method of payment of physicians may affect their clinical behaviour. Although payment systems may be used to achieve policy objectives (e.g. cost containment or improved quality of care), little is known about the effects of different payment systems in achieving these objectives. Objectives To evaluate the impact of different methods of payment (capitation, salary, fee for service and mixed systems of payment) on the clinical behaviour of primary care physicians (PCPs). Search methods We searched the Cochrane Effective Practice and Organisation of Care Group specialised register; the Cochrane Controlled Trials Register; MEDLINE (1966 to October 1997); BIDS EMBASE (1980 to October 1997); BIDS ISI (1981 to October 1997); EconLit (1969 to October 1997); HealthStar (1975 to October 1997) Helmis (1984 to October 1997); health economics discussion paper series of the Universities of York, Aberdeen, Sheffield, Bristol, Brunel, and McMaster; Swedish Institute of Health Economics; RAND corporation; and reference lists of articles. Selection criteria Randomised trials, controlled before and after studies and interrupted time series analyses of interventions comparing the impact of capitation, salary, fee for service (FFS) and mixed systems of payment on primary care physician satisfaction with working environment; cost and quantity of care; type and pattern of care; equity of care; and patient health status and satisfaction. Data collection and analysis Two reviewers independently extracted data and assessed study quality. Main results Four studies were included involving 640 primary care physicians and more than 6400 patients. There was considerable variation in study setting and the range of outcomes measured. FFS resulted in more primary care visits/contacts, visits to specialists and diagnostic and curative services but fewer hospital referrals and repeat prescriptions compared with capitation. Compliance with a recommended number of visits was higher under FFS compared with capitation payment. FFS resulted in more patient visits, greater continuity of care, higher compliance with a recommended number of visits, but patients were less satisfied with access to their physician compared with salaried payment. Authors' conclusions It is noteworthy that so few studies met the inclusion criteria. There is some evidence to suggest that the method of payment of primary care physicians affects their behaviour, but the findings' generalisability is unknown. More evaluations of the effect of payment systems on PCP behaviour are needed, especially in terms of the relative impact of salary versus capitation payments.

The deep inspiration breath-hold technique in the treatment of inoperable non–small-cell lung cancer

Abstract: Purpose: Conventional radiotherapeutic techniques are associated with lung toxicity that limits the treatment dose. Motion of the tumor during treatment requires the use of large safety margins that affect the feasibility of treatment. To address the control of tumor motion and decrease the volume of normal lung irradiated, we investigated the use of three-dimensional conformal radiation therapy (3D-CRT) in conjunction with the deep inspiration breath-hold (DIBH) technique. Methods and Materials: In the DIBH technique, the patient is initially maintained at quiet tidal breathing, followed by a deep inspiration, a deep expiration, a second deep inspiration, and breath-hold. At this point the patient is at approximately 100% vital capacity, and simulation, verification, and treatment take place during this phase of breath-holding. Results: Seven patients have received a total of 164 treatment sessions and have tolerated the technique well. The estimated normal tissue complication probabilities decreased in all patients at their prescribed dose when compared to free breathing. The dose to which patients could be treated with DIBH increased on average from 69.4 Gy to 87.9 Gy, without increasing the risk of toxicity Conclusions: The DIBH technique provides an advantage to conventional free-breathing treatment by decreasing lung density, reducing normal safety margins, and enabling more accurate treatment. These improvements contribute to the effective exclusion of normal lung tissue from the high-dose region and permit the use of higher treatment doses without increased risks of toxicity.

Response of root respiration to changes in temperature and its relevance to global warming

Abstract: Global warming over the next century is likely to be associated with a change in the extent to which atmospheric and soil temperatures fluctuate, on both a daily and a seasonal basis. The average annual temperature of the Earth's surface is expected to increase, as is the frequency of hot days. In this review, we explore what effects short-term and long-term changes in temperature are likely to have on root respiratory metabolism, and what impacts such changes will have on daily, seasonal and annual CO2 release by roots under field conditions. We demonstrate that Q10 values, and the degree of acclimation, differ between and within plant species. Changes in the temperature sensitivity of respiration with measuring temperature are highlighted. Temperature-dependent changes in adenylate control and substrate supply are likely to control the Q10 and degree of acclimation of root respiration. Limitations in respiration capacity are unlikely to control respiratory flux at most temperatures. The potential role of nonphosphorylating pathways such as the alternative oxidase in controlling Q10 values is highlighted. The possibility that potentially rapid changes in adenylate control might underlie the acclimation response (rather than slow changes in enzyme capacity) has implications for the total amount of CO2 respired by roots daily and annually. Our modelling suggests that rapid acclimation will result in near-perfect homeostasis of respiration rates and minimize annual CO2 release. However, annual CO2 release increases substantially if the speed of full acclimation is lower. Our modelling exercise also shows that high Q10 values have the potential to increase daily and annual CO2 release substantially, particularly if the frequency of hot days increases after global warming.

Precursors of literacy delay among children at genetic risk of dyslexia.

Abstract: This paper reports the literacy skills of 63 children selected as being at genetic risk of dyslexia compared with 34 children from families reporting no history of reading impairment. Fifty-seven per cent of the at-risk group were delayed in literacy development at 6 years compared with only 12% of controls. The “unimpaired” at-risk group were not statistically different from controls on most cognitive and language measures at 45 months, whereas the literacy-delayed group showed significantly slower speech and language development, although they did not differ from controls in nonverbal ability. Letter knowledge at 45 months was the strongest predictor of literacy level at 6 years. In addition, early speech and language skills predicted individual differences in literacy outcome and genetic risk accounted for unique variance over and above these other factors. The results are discussed in terms of an interactive developmental model in which semantic and phonological skills support early reading acquisition.

Communities of practice in the distributed international environment

Abstract: Modern commercial organisations are facing pressures which have caused them to lose personnel. When they lose people, they also lose their knowledge. Organisations also have to cope with the internationalisation of business forcing collaboration and knowledge sharing across time and distance. Knowledge management (KM) claims to tackle these issues. This paper looks at an area where KM does not offer sufficient support, that is, the sharing of knowledge that is not easy to articulate. The focus in this paper is on communities of practice in commercial organisations. We do this by exploring knowledge sharing in Lave and Wenger’s (1991) theory of communities of practice and investigating how communities of practice may translate to a distributed international environment. The paper reports on two case studies that explore the functioning of communities of practice across international boundaries.