933 resultados para immediate implants
Resumo:
Maintaining the health of a construction project can help to achieve the desired outcomes of the project. An analogy is drawn to the medical process of a human health check where it is possible to broadly diagnose health in terms of a number of key areas such as blood pressure or cholesterol level. Similarly it appears possible to diagnose the current health of a construction project in terms of a number of Critical Success Factors (CSFs) and key performance indicators (KPIs). The medical analogy continues into the detailed investigation phase where a number of contributing factors are evaluated to identify possible causes of ill health and through the identification of potential remedies to return the project to the desired level of health. This paper presents the development of a model that diagnoses the immediate health of a construction project, investigates the factors which appear to be causing the ill health and proposes a remedy to return the project to good health. The proposed model uses the well-established continuous improvement management model (Deming, 1986) to adapt the process of human physical health checking to construction project health.
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Adolescent idiopathic scoliosis (AIS) is the most common form of spinal deformity in paediatrics, prevalent in approximately 2-4% of the general population. While it is a complex three-dimensional deformity, it is clinically characterised by an abnormal lateral curvature of the spine. The treatment for severe deformity is surgical correction with the use of structural implants. Anterior single rod correction employs a solid rod connected to the anterior spine via vertebral body screws. Correction is achieved by applying compression between adjacent vertebral body screws, before locking each screw onto the rod. Biomechanical complication rates have been reported as high as 20.8%, and include rod breakage, screw pull-out and loss of correction. Currently, the corrective forces applied to the spine are unknown. These forces are important variables to consider in understanding the biomechanics of scoliosis correction. The purpose of this study was to measure these forces intra-operatively during anterior single rod AIS correction.
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The healing process for bone fractures is sensitive to mechanical stability and blood supply at the fracture site. Most currently available mechanobiological algorithms of bone healing are based solely on mechanical stimuli, while the explicit analysis of revascularization and its influences on the healing process have not been thoroughly investigated in the literature. In this paper, revascularization was described by two separate processes: angiogenesis and nutrition supply. The mathematical models for angiogenesis and nutrition supply have been proposed and integrated into an existing fuzzy algorithm of fracture healing. The computational algorithm of fracture healing, consisting of stress analysis, analyses of angiogenesis and nutrient supply, and tissue differentiation, has been tested on and compared with animal experimental results published previously. The simulation results showed that, for a small and medium-sized fracture gap, the nutrient supply is sufficient for bone healing, for a large fracture gap, non-union may be induced either by deficient nutrient supply or inadequate mechanical conditions. The comparisons with experimental results demonstrated that the improved computational algorithm is able to simulate a broad spectrum of fracture healing cases and to predict and explain delayed unions and non-union induced by large gap sizes and different mechanical conditions. The new algorithm will allow the simulation of more realistic clinical fracture healing cases with various fracture gaps and geometries and may be helpful to optimise implants and methods for fracture fixation.
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It's hard to be dispassionate about Reyner Banham. For me, and for the plethora of other people with strong opinions about Banham, his writing is compelling, and one’s connection to him as a figure quite personal. For me, frankly, he rocks. As a landscape architect, I gleaned most of my knowledge about Modern architecture from Banham. His Theory and Design in the First Machine Age, along with Rowe and Koetter’s Collage City and Venturi’s Complexity and Contradiction in Architecture were the most influential books in my library, by far. Later, as a budding “real scholar”, I was disappointed to find that, while these authors had serious credibility, the writings themselves were regarded as “polemical” – when in fact what I admired about them most was their ability and willingness to make rough groupings and gross generalizations, and to offer fickle opinions. It spoke to me of a real personal engagement and an active, participatory reading of the architectural culture they discussed. They were at their best in their witty, cutting, but generally pithy, creative prose, such as in Rowe’s extrapolation of the modern citizen as the latest “noble savage”, or Banham railing against conservative social advocates and their response to high density housing: “those who had just re-discovered ‘community’ in the slums would fear megastructure as much as any other kind of large-scale renewal program, and would see to it that the people were never ready.” Any reader of Banham will be able to find a gem that will relate, somehow, personally, to what they are doing right now. For Banham, it was all personal, and the gaps in his scholarship, rather, were the dispassionate places: “Such bias is essential – an unbiased historian is a pointless historian – because history is an essentially critical activity, a constant re-scrutiny and rearrangement of the profession.” Reyner Banham: Historian of the Immediate Future, Nigel Whiteley’s recent “intellectual biography” (the MIT Press, 2002), allowed me to revisit Banham’s passionate mode of criticism and to consider what his legacy might be. The book examines Banham’s body of work, grouped according to his various primary fascinations, as well as his relationship to contemporaneous theoretical movements, such as postmodernism. His mode of practice, as a kind of creative critic, is also considered in some depth. While there are points where the book delves into Banham’s personal life, on the whole Whiteley is very rigorous in considering and theorizing the work itself: more than 750 articles and twelve books. In academic terms, this is good practice. However, considering the entirely personal nature of Banham’s writing itself, this separation seems artificial. Banham, as he himself noted, “didn’t mind a gossip”, and often when reading the book I was curious about what was happening to him at the time. Banham’s was an amazing type of intellectual practice, and one that academics (a term he hated) could do well to learn from. While Whiteley spends a lot of time arguing for his practice to be regarded as such, and makes strong points about both the role of the critic, and the importance of journalism, rather than scholarly publishing, I found myself wondering what his study looked like. What books he had in his library. Did he smoke when he wrote? What sort of teaching load did he have? He is an inspiration to design writers and thinkers, and I, personally, wanted to know how he did it.
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Currently, well-established clinical therapeutic approaches for bone reconstruction are restricted to the transplantation of autografts and allografts, and the implantation of metal devices or ceramic-based implants to assist bone regeneration. Bone grafts possess osteoconductive and osteoinductive properties, however they are limited in access and availability and associated with donor site morbidity, haemorrhage, risk of infection, insufficient transplant integration, graft devitalisation, and subsequent resorption resulting in decreased mechanical stability. As a result, recent research focuses on the development of alternative therapeutic concepts. The field of tissue engineering has emerged as an important approach to bone regeneration. However, bench to bedside translations are still infrequent as the process towards approval by regulatory bodies is protracted and costly, requiring both comprehensive in vitro and in vivo studies. The subsequent gap between research and clinical translation, hence commercialization, is referred to as the ‘Valley of Death’ and describes a large number of projects and/or ventures that are ceased due to a lack of funding during the transition from product/technology development to regulatory approval and subsequently commercialization. One of the greatest difficulties in bridging the Valley of Death is to develop good manufacturing processes (GMP) and scalable designs and to apply these in pre-clinical studies. In this article, we describe part of the rationale and road map of how our multidisciplinary research team has approached the first steps to translate orthopaedic bone engineering from bench to bedside byestablishing a pre-clinical ovine critical-sized tibial segmental bone defect model and discuss our preliminary data relating to this decisive step.
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Psychologists investigating dreams in non-Western cultures have generally not considered the meanings of dreams within the unique meaning-structure of the person in his or her societal context. The majority of dream studies in African societies are no exception. Researchers approaching dreams within rural Xhosa and Zulu speaking societies have either adopted an anthropological or a psychodynamic orientation. The latter approach particularly imposes a Western perspective in the interpretation of dream material. There have been no comparable studies of dream interpretation among urban blacks participating in the African Independent Church Movement. The present study focuses on the rural Xhosa speaking people and the urban black population who speak one of the Nguni languages and identify with the African Independent Church Movement. The study is concerned with understanding the meanings of dreams within the cultural context in which they occur. The specific aims of the study are: 1. To explicate the indigenous system of dream interpretation as revealed by acknowledged dream experts. 2. To examine the commonalities and the differences between the interpretation of dreams in two groups, drawn from a rural and urban setting respectively. 3. To elaborate upon the life-world of the participants by the interpretations gained from the above investigation. One hundred dreams and interpretations are collected from two categories of participants referred to as the Rural Group and the Urban Group. The Rural Group is made up of amagqira [traditional healers] and their clients, while the Urban Group consists of prophets and members of the African Independent Churches. Each group includes acknowledged dream experts. A phenomenological methodology is adopted in explicating the data. The methodological precedure involves a number of rigorous stages of expl ication whereby the original data is reduced to Constituent Profiles leading to the construction of a Thematic Index File. By searching and reflect ing upon the data, interpretative themes are identified. These themes are explicated to provide a rigorous description of the interpretative-reality of each group. Themes explicated w i thin the Rural Group are: the physiognomy of the dreamer's life-world as revealed by ithongo, the interpretation of ithongo as revealed through action, the dream relationship as an anticipatory mode-of-existence, iphupha as disclosing a vulnerable mode-of-being, human bodiliness as revealed in dream interpretations and the legitimation of the interpretative-reality within the life-world. Themes explicated within the Urban Group are: the phys iognomy of the dreamer's life-world revealed in their dream-existence, the interpretative-reality revealed through the enaction of dreams, tension between the newer Christian-based cosomology and the traditional cultural-based cosmology, a moral imperative, prophetic perception and human bodiliness, as revealed in dream interpretations and the legitimation of the interpretative-reality within the life-world. The essence of the interpretative-reality of both groups is very similar and is expressed in the notion of relatedness to a cosmic mode-of-being. The cosmic mode-of-being includes a numinous dimension which is expressed through divine presence in the form of ancestors, Holy Spirit or God. These notions cannot be apprehended by theoretical constructs alone but may be grasped and given form in meaning-disclosing intuitions which are expressed in the lifeworld in terms of bodiliness, revelatory knowledge, action and healing. Some differences b e tween the two groups are evident and reveal some conflict between the monotheistic Christian cosmology and the traditional cosmology. Unique aspects of the interpetative-reality of the Urban Group are expressed in terms of difficulties in the urban social environment and the notion of a moral imperative. It is observed that cul tural self-expression based upon traditional ideas continues to play a significant role in the urban environment. The apparent conflict revealed between the respective cosmologies underlies an integration of the aditional meanings with Christian concepts. This finding is consistent with the literature suggesting that the African Independent Church is a syncretic movement. The life-world is based upon the immediate and vivid experience of the numinous as revealed in the dream phenomenon. The participants' approach to dreams is not based upon an explicit theory, but upon an immediate and pathic understanding of the dream phenomenon. The understanding is based upon the interpreter's concrete understanding of the life-world, which includes the possibility of cosmic integration and continuity between the personal and transpersonal realms of being. The approach is characterized as an expression of man's primordial attunement with the cosmos. The approach of the participants to dreams may not b e consistent with a Western rational orientation, but neverthele ss, it is a valid approach . The validity is based upon the immediate life-world of experience which is intelligible, coherent, and above all, it is meaning-giving in revealing life-possibility within the context of human existence.
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President’s Report Hello fellow AITPM members, Welcome to the first edition of the AITPM National Newsletter for 2009! I trust we all had a relaxing break and managed to lose track of all things transport for just a little while. I know I had trouble doing so when hunting for a car space at the shopping centre, and experiencing new projects such as the Tugun Bypass – the new gateway between New South Wales and Queensland. Byron Bay is now as close as Noosa for those high profile beach goers of Brisbane. There was also my experience of the reduced posted speed of 90km/h on the Bruce Highway around the troublesome Gympie stretch, when returning from a short Fraser Coast holiday. I expect that this relatively inexpensive safety improvement will pay substantial dividends in terms of crash reduction. The Newsletter took its annual leave last month and is refreshed and ready for a new year to keep us all informed of the latest in traffic and transport engineering, planning and management. I would like to take this opportunity to acknowledge the ongoing significant contributions of many volunteers in the Newsletter’s production. Mr Andrew Hulse, AITPM’s Immediate Past National President, serves as the Editorial Coordinator on behalf of the Institute. Each Branch Committee also includes a Newsletter Coordinator and committee members frequently contribute as well. And the ongoing contributions of readers enable us to offer the Newsletter as a vehicle for dialogue and debate around our sector. If you would like to contribute please email AITPM’s administration officer Josephine Mitton at aitpm@aitpm.com or through your local Branch Committee. I would also like to welcome back on deck our Editor, Mr David Brown of Driven Media, who creates a fantastic package for us each month. Lastly, members would have received the Call for Papers for the AITPM 2009 National Conference, Traffic Beyond Tomorrow, to be held at the Adelaide Convention Centre between 5 – 7 August. Abstracts will be accepted up to 20 February 2009. We look forward to seeing everyone at this, our flagship event for the year. To all a good year ahead, Jon Bunker Post Script: We all will have seen through the media the enormous scale and nature of the two natural disasters Australia is experiencing at present. AITPM’s thoughts are with all of those members, family and friends who may be experiencing hardship as a result of the Victorian bushfires and North Queensland floods. AITPM is a not for profit organisation however the National Executive has taken the decision to donate in measure to the Red Cross Victorian Bushfire Disaster Relief fund and the Queensland Premier’s Disaster Relief fund as a gesture to support our fellow Australians in their time of need. Details about these funds can be found via the Victorian and Queensland Governments’ websites.
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Introduction and Aims: Remote delivery of interventions is needed to address large numbers of people with alcohol use disorders who are spread over large areas. Previous correspondence trials typically examined its effects as stand-alone treatment. This study aimed to test whether adding postal treatment to general practitioner (GP) support would lower alcohol use more than GP intervention alone. Design and Methods: A single-blind, randomised controlled trial with a crossover design was conducted over 12 months on 204 people with alcohol use disorders. Participants in an immediate correspondence condition received treatment over the first 3 months; those receiving delayed treatment received it in months 3–6. Results: Few participants were referred from GPs, and little intervention was offered by them. At 3 months, 78% of participants remained in the study. Those in immediate treatment showed greater reductions in alcohol per week, drinking days, anxiety, depression and distress than those in the delayed condition. However, post-treatment and follow-up outcomes still showed elevated alcohol use, depression, anxiety and distress. Greater baseline anxiety predicted better alcohol outcomes, although more mental distress at baseline predicted dropout. Discussion and Conclusions: The study gave consistent results with those from previous research on correspondence treatments, and showed that high levels of participant engagement over 3 months can be obtained. Substantial reductions in alcohol use are seen, with indications that they are well maintained. However, many participants continue to show high-risk alcohol use and psychological distress.
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Australia’s National Review of Visual Education (DEEWR, 2009) asserts the primacy of visual language ability, or ‘visuacy” in problem-solving. This paper reports on a recent university/schools research project with ‘at risk’ middle school students in which visuacy was promoted as a primary medium for obtaining data relating to issues of immediate concern to the students. Using a students-as-researchers approach, the project investigated middle school students’ perspectives on school engagement and disengagement. In this project, novice researchers used a variety of data gathering methods including photography, video interviews and drawn images as well as more traditional verbal methods, such as interviews, and quantitative methods, such as questionnaires. Engaging student imagination was a key focus of the approach taken by the project, acknowledging that student participants may be reluctant to enter dialogue with teachers and researchers on matters to which they have previously had little input. Students who have previously been marginalized and prevented from contributing their voices to educational forums often have difficulty in adjusting to the novelty of collaborative research with adults (Rudduck, 2003) and may be uncertain of their own place in the relationship that defines teacher/student interactions. It is argued that the project’s promotion of visuacy, alongside more traditional literacies and numeracy in education research, helped to overcome these concerns, engaged the imaginations of the student researchers, and provided a medium for the expression of the voices of marginalised young people.
Resumo:
The provision of accessible and cost-effective treatment to a large number of problem drinkers is a significant challenge to health services. Previous data suggest that a correspondence intervention may assist in these efforts. We recruited 277 people with alcohol abuse problems and randomly allocated them to immediate cognitive behavioral treatment by correspondence (ICBT), 2 months in a waiting list (WL2-CBT), self-monitoring (SM2-CBT), or extended self-monitoring (SM6-CBT). Everyone received correspondence CBT after the control period. Over 2 months later, no drop in alcohol intake occurred in the waiting list, and CBT had a greater impact than SM. No further gains from SM were seen after 2 months. Effects of CBT were well maintained and were equivalent, whether it was received immediately or after 2 to 6 months of self-monitoring. Weekly alcohol intake fell 48% from pretreatment to 18.6 alcohol units at 12 months. Our results confirmed that correspondence CBT for alcohol abuse was accessible and effective for people with low physical dependence.
Resumo:
There is little evidence that workshops alone have a lasting impact on the day-to-day practice of participants. The current paper examined a strategy to increase generalization and maintenance of skills in the natural environment using pseudo-patients and immediate performance feedback to reinforce skills acquisition. A random half of pharmacies (N=30) took part in workshop training aimed at optimizing consumers' use of nonprescription analgesic products. Pharmacies in the training group also received performance feedback on their adherence to the recommended protocol. Feedback occurred immediately after a pseudo-patient visit in which confederates posed as purchasers of analgesics, and combined positive and corrective elements. Trained pharmacists were significantly more accurate at identifying people who misused the medication (P<0.001). The trained pharmacists were more likely than controls to use open-ended questions (P<0.001), assess readiness to change problematic use (P <0.001), and to deliver a brief intervention that was tailored to the person's commitment to alter his/her usage (P <0.001). Participants responded to the feedback positively. Results were consistent with the hypothesis that when workshop is combined with on-site performance feedback, it enhances practitioners' adherence to protocols in the natural setting.
Resumo:
Background: Exercise could contribute to weight loss by altering the sensitivity of the appetite regulatory system. Objective: The aim of this study was to assess the effects of 12 wk of mandatory exercise on appetite control. Design: Fifty-eight overweight and obese men and women [mean (±SD) body mass index (in kg/m2) = 31.8 ± 4.5, age = 39.6 ± 9.8 y, and maximal oxygen intake = 29.1 ± 5.7 mL · kg–1 · min–1] completed 12 wk of supervised exercise in the laboratory. The exercise sessions were designed to expend 2500 kcal/wk. Subjective appetite sensations and the satiating efficiency of a fixed breakfast were compared at baseline (week 0) and at week 12. An Electronic Appetite Rating System was used to measure subjective appetite sensations immediately before and after the fixed breakfast in the immediate postprandial period and across the whole day. The satiety quotient of the breakfast was determined by calculating the change in appetite scores relative to the breakfast's energy content. Results: Despite large variability, there was a significant reduction in mean body weight (3.2 ± 3.6 kg), fat mass (3.2 ± 2.2 kg), and waist circumference (5.0 ± 3.2 cm) after 12 wk. The analysis showed that a reduction in body weight and body composition was accompanied by an increase in fasting hunger and in average hunger across the day (P < 0.0001). Paradoxically, the immediate and delayed satiety quotient of the breakfast also increased significantly (P < 0.05). Conclusions: These data show that the effect of exercise on appetite regulation involves at least 2 processes: an increase in the overall (orexigenic) drive to eat and a concomitant increase in the satiating efficiency of a fixed meal.
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Nontuberculous mycobacteria are ubiquitous environmental organisms that have been recognised as a cause of pulmonary infection for over 50 years. Traditionally patients have had underlying risk factors for development of disease; however the proportion of apparently immunocompetent patients involved appears to be rising. Not all patients culture-positive for mycobacteria will have progressive disease, making the diagnosis difficult, though criteria to aid in this process are available. The two main forms of disease are cavitary disease (usually involving the upper lobes) and fibronodular bronchiectasis (predominantly middle and lingular lobes). For patients with disease, combination antibiotic therapy for 12-24 months is generally required for successful treatment, and this may be accompanied by drug intolerances and side effects. Published success rates range from 30-82%. As the progression of disease is variable, for some patients, attention to pulmonary hygiene and underlying diseases without immediate antimycobacterial therapy may be more appropriate. Surgery can be a useful adjunct, though is associated with risks. Randomised controlled trials in well described patients would provide stronger evidence-based data to guide therapy of NTM lung diseases, and thus are much needed.
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In children, joint hypermobility (typified by structural instability of joints) manifests clinically as neuro-muscular and musculo-skeletal conditions and conditions associated with development and organization of control of posture and gait (Finkelstein, 1916; Jahss, 1919; Sobel, 1926; Larsson, Mudholkar, Baum and Srivastava, 1995; Murray and Woo, 2001; Hakim and Grahame, 2003; Adib, Davies, Grahame, Woo and Murray, 2005:). The process of control of the relative proportions of joint mobility and stability, whilst maintaining equilibrium in standing posture and gait, is dependent upon the complex interrelationship between skeletal, muscular and neurological function (Massion, 1998; Gurfinkel, Ivanenko, Levik and Babakova, 1995; Shumway-Cook and Woollacott, 1995). The efficiency of this relies upon the integrity of neuro-muscular and musculo-skeletal components (ligaments, muscles, nerves), and the Central Nervous System’s capacity to interpret, process and integrate sensory information from visual, vestibular and proprioceptive sources (Crotts, Thompson, Nahom, Ryan and Newton, 1996; Riemann, Guskiewicz and Shields, 1999; Schmitz and Arnold, 1998) and development and incorporation of this into a representational scheme (postural reference frame) of body orientation with respect to internal and external environments (Gurfinkel et al., 1995; Roll and Roll, 1988). Sensory information from the base of support (feet) makes significant contribution to the development of reference frameworks (Kavounoudias, Roll and Roll, 1998). Problems with the structure and/ or function of any one, or combination of these components or systems, may result in partial loss of equilibrium and, therefore ineffectiveness or significant reduction in the capacity to interact with the environment, which may result in disability and/ or injury (Crotts et al., 1996; Rozzi, Lephart, Sterner and Kuligowski, 1999b). Whilst literature focusing upon clinical associations between joint hypermobility and conditions requiring therapeutic intervention has been abundant (Crego and Ford, 1952; Powell and Cantab, 1983; Dockery, in Jay, 1999; Grahame, 1971; Childs, 1986; Barton, Bird, Lindsay, Newton and Wright, 1995a; Rozzi, et al., 1999b; Kerr, Macmillan, Uttley and Luqmani, 2000; Grahame, 2001), there has been a deficit in controlled studies in which the neuro-muscular and musculo-skeletal characteristics of children with joint hypermobility have been quantified and considered within the context of organization of postural control in standing balance and gait. This was the aim of this project, undertaken as three studies. The major study (Study One) compared the fundamental neuro-muscular and musculo-skeletal characteristics of 15 children with joint hypermobility, and 15 age (8 and 9 years), gender, height and weight matched non-hypermobile controls. Significant differences were identified between previously undiagnosed hypermobile (n=15) and non-hypermobile children (n=15) in passive joint ranges of motion of the lower limbs and lumbar spine, muscle tone of the lower leg and foot, barefoot CoP displacement and in parameters of barefoot gait. Clinically relevant differences were also noted in barefoot single leg balance time. There were no differences between groups in isometric muscle strength in ankle dorsiflexion, knee flexion or extension. The second comparative study investigated foot morphology in non-weight bearing and weight bearing load conditions of the same children with and without joint hypermobility using three dimensional images (plaster casts) of their feet. The preliminary phase of this study evaluated the casting technique against direct measures of foot length, forefoot width, RCSP and forefoot to rearfoot angle. Results indicated accurate representation of elementary foot morphology within the plaster images. The comparative study examined the between and within group differences in measures of foot length and width, and in measures above the support surface (heel inclination angle, forefoot to rearfoot angle, normalized arch height, height of the widest point of the heel) in the two load conditions. Results of measures from plaster images identified that hypermobile children have different barefoot weight bearing foot morphology above the support surface than non-hypermobile children, despite no differences in measures of foot length or width. Based upon the differences in components of control of posture and gait in the hypermobile group, identified in Study One and Study Two, the final study (Study Three), using the same subjects, tested the immediate effect of specifically designed custom-made foot orthoses upon balance and gait of hypermobile children. The design of the orthoses was evaluated against the direct measures and the measures from plaster images of the feet. This ascertained the differences in morphology of the modified casts used to mould the orthoses and the original image of the foot. The orthoses were fitted into standardized running shoes. The effect of the shoe alone was tested upon the non-hypermobile children as the non-therapeutic equivalent condition. Immediate improvement in balance was noted in single leg stance and CoP displacement in the hypermobile group together with significant immediate improvement in the percentage of gait phases and in the percentage of the gait cycle at which maximum plantar flexion of the ankle occurred in gait. The neuro-muscular and musculo-skeletal characteristics of children with joint hypermobility are different from those of non-hypermobile children. The Beighton, Solomon and Soskolne (1973) screening criteria successfully classified joint hypermobility in children. As a result of this study joint hypermobility has been identified as a variable which must be controlled in studies of foot morphology and function in children. The outcomes of this study provide a basis upon which to further explore the association between joint hypermobility and neuro-muscular and musculo-skeletal conditions, and, have relevance for the physical education of children with joint hypermobility, for footwear and orthotic design processes, and, in particular, for clinical identification and treatment of children with joint hypermobility.
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There is considerable evidence that working memory impairment is a common feature of schizophrenia. The present study assessed working memory and executive function in 54 participants with schizophrenia, and a group of 54 normal controls matched to the patients on age, gender and estimated premorbid IQ, using traditional and newer measures of executive function and two dual tasks—Telephone Search with Counting and the Memory Span and Tracking Task. Results indicated that participants with schizophrenia were significantly impaired on all standardised measures of executive function with the exception of a composite measure of the Trail Making Test. Results for the dual task measures demonstrated that while the participants with schizophrenia were unimpaired on immediate digit span recall over a 2-min period, they recalled fewer digit strings and performed more poorly on a tracking task (box-crossing task) compared with controls. In addition, participants with schizophrenia performed more poorly on the tracking task when they were required to simultaneously recall digits strings than when they performed this task alone. Contrary to expectation, results of the telephone search task under dual conditions were not significantly different between groups. These results may reflect the insufficient complexity of the tone-counting task as an interference task. Overall, the present study showed that participants with schizophrenia appear to have a restricted impairment of their working memory system that is evident in tasks in which the visuospatial sketchpad slave system requires central executive control.