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Kinds of Dataset Terms modified by Dataset Selected AbstractsFORECASTING AUSTRALIAN MACROECONOMIC VARIABLES USING A LARGE DATASETAUSTRALIAN ECONOMIC PAPERS, Issue 1 2010SARANTIS TSIAPLIAS This paper investigates the forecasting performance of the diffusion index approach for the Australian economy, and considers the forecasting performance of the diffusion index approach relative to composite forecasts. Weighted and unweighted factor forecasts are benchmarked against composite forecasts, and forecasts derived from individual forecasting models. The results suggest that diffusion index forecasts tend to improve on the benchmark AR forecasts. We also observe that weighted factors tend to produce better forecasts than their unweighted counterparts. We find, however, that the size of the forecasting improvement is less marked than previous research, with the diffusion index forecasts typically producing mean square errors of a similar magnitude to the VAR and BVAR approaches. [source] Patterns and trends in alcohol-related hospitalizations in Victoria, Australia, 1987/88,1995/96DRUG AND ALCOHOL REVIEW, Issue 4 2000KIRSTEN HANLIN Abstract The objective of this study was to examine patterns and yearly trends in alcohol-related hospitalization rates during the period 1987/88,1995/96 for men and women living in metropolitan and rural/remote Victoria. Alcohol-related hospitalizations were extracted from the Victorian Inpatient Minimum Dataset (VMD) for the years 1987/88,1995/96 (public hospitals) and 1993/94,1995/96 (private hospitals), and adjusted by the appropriate aetiological fractions. Sex-specific age-adjusted rates we expressed per 10000 residents/year. During 1993/94,1995/96, alcohol-related hospitalizations comprised 1.0% of all Victorian hospitalizations (about 12000/year), with men accounting for over two-thirds of alcohol-related hospitalizations. Approximately half of the alcohol-related hospitalizations were for disease conditions and the other half for external cause (injury) conditions. About 80% of all alcohol-related hospitalizations were to public hospitals, with the exception of alcohol dependence (63% to private hospitals). Alcohol-related hospitalization rates were generally higher for people living in rural/remote areas compared to urban areas. During 1987/88,1995/96, the age-adjusted alcohol-related hospitalization rates in public hospitals did not change significantly for disease conditions (14.8,14.7 for men and 6.3,6.4 for women) or female external cause conditions (6.7,6.1), but decreased for external cause conditions (18.4,15.5). In private hospitals during 1993/94,1995/96, the age-adjusted alcohol-related hospitalization rates for disease conditions decreased (5.4,4.1 for men and 3.7,3.0 for women) but increased for external cause conditions (1.8,2.4 for men and 1.0,1.2 for women). These patterns and time-trends in Victorian alcohol-related hospitalizations reflect a combination of alcohol-related morbidity levels, hospital admission practices and patterns and levels of service provision. They suggest a potential need to focus on services and programmes in rural/remote Victoria. [source] The epidemiology of cannabis use and cannabis-related harm in Australia 1993,2007ADDICTION, Issue 6 2010Amanda Roxburgh ABSTRACT Aims To examine trends in patterns of cannabis use and related harm in the Australian population between 1993 and 2007. Design Analysis of prospectively collected data from: (1) the National Drug Strategy Household Survey (NDSHS) and Australian Secondary Student Alcohol and Drug Survey (ASSADS); (2) the National Hospital Morbidity Database (NHMD); and (3) the Alcohol and Other Drug Treatment Services National Minimum Dataset (AODTS-NMDS). Participants Australians aged 14 years and over from the general population; students aged 12,17 years; public and private hospital in-patients; public and private in-patients and out-patients attending for drug treatment. Measurement Prevalence of 12-month cannabis use among the general population and secondary students. Proportions in the general population by age group reporting: daily cannabis use; difficulties in controlling cannabis use; and heavy cannabis use on each occasion. Number of hospital and treatment presentations for cannabis-related problems. Findings Prevalence of past-year cannabis use has declined in the Australian population since the late 1990s. Among those reporting past-year use, daily use is prevalent among 40,49-year-olds, while heavy patterns of use are prevalent among 14,19-year-olds. Hospital presentations for cannabis-related problems reflect similar trends. Past-year cannabis use has decreased among the 10,19-year age group, but those who are daily users in this age group report using large quantities of cannabis. Conclusions Despite declines in the prevalence of cannabis use, continued public health campaigns warning of the harms associated with cannabis use are essential, aimed particularly at users who are already experiencing problems. The increasing demand for treatment for cannabis problems in Australia suggests the need for more accessible and more effective interventions for cannabis use disorders. [source] Predicting and quantifying the structure of tropical dry forests in South Florida and the Neotropics using spaceborne imageryGLOBAL ECOLOGY, Issue 3 2006Thomas W. Gillespie ABSTRACT Aim, This research examines environmental theories and remote sensing methods that have been hypothesized to be associated with tropical dry forest structure. Location, Tropical dry forests of South Florida and the Neotropics. Methods, Field measurements of stand density, basal area and tree height were collected from 22 stands in South Florida and 30 stands in the Neotropics. In South Florida, field measurements were compared to climatic (temperature, precipitation, hurricane disturbance) and edaphic (rockiness, soil depth) variables, spectral indices (NDVI, IRI, MIRI) from Landsat 7 ETM+, and estimates of tree height from the Shuttle Radar Topography Mission (SRTM) and the National Elevation Dataset (NED). Environmental variables associated with tropical dry forest structure in South Florida were compared to tropical dry forest in other Neotropical sites. Results, There were significant correlations among temperature and precipitation, and stand density and tree height in South Florida. There were significant correlations between (i) stand density and mean NDVI and standard deviation of NDVI, (ii) MIRI and stand density, basal area and mean tree height, and (iii) estimates of tree height from SRTM with maximum tree height. In the Neotropics, there were no relationships between temperature or precipitation and tropical dry forest structure, however, Neotropical sites that experience hurricane disturbance had significantly shorter tree heights and higher stand densities. Main conclusions, It is possible to predict and quantify the forest structure characteristics of tropical dry forests using climatic data, Landsat 7 ETM+ imagery and SRTM data in South Florida. However, results based on climatic data are region-specific and not necessarily transferable between tropical dry forests at a continental spatial scale. Spectral indices from Landsat 7 ETM+ can be used to quantify forest structure characteristics, but SRTM data are currently not transferable to other regions. Hurricane disturbance has a significant impact on forest structure in the Neotropics. [source] Social assistance and minimum income benefits in old and new EU democraciesINTERNATIONAL JOURNAL OF SOCIAL WELFARE, Issue 4 2010Kenneth Nelson Nelson K. Social assistance and minimum income benefits in old and new EU democracies Int J Soc Welfare 2010: 19: 367,378 © 2009 The Author, Journal compilation © 2009 Blackwell Publishing Ltd and the International Journal of Social Welfare. In this article, social assistance developments are analysed in a large number of European Union (EU) member states, including European transition countries and the new democracies of southern Europe. The empirical analysis is based on the unique and recently established SaMip Dataset, which provides social assistance benefit levels for 27 countries from 1990 to 2005. It is shown that social assistance benefits have had a less favourable development than that of unemployment provision. Hardly any of the investigated countries provide social assistance benefits above the EU near-poverty threshold. Social assistance benefit levels have not converged in Europe. Instead, divergence can be observed, which is due mainly to lagging developments in eastern and southern Europe. [source] Announcements: Reconceptualizing International Borders Through the Application of GIS (Geographic Information Systems): A New Dataset on the "Nature" of BordersINTERNATIONAL STUDIES PERSPECTIVES, Issue 4 2001Harvey Starr No abstract is available for this article. [source] Reconceptualizing International Borders Through the Application of GIS (Geographic Information Systems): A New Dataset on the "Nature" of BordersINTERNATIONAL STUDIES PERSPECTIVES, Issue 4 2001Harvey Starr No abstract is available for this article. [source] Triage, treat and transfer: reconceptualising a rural practice model,JOURNAL OF CLINICAL NURSING, Issue 11-12 2010Elise Sullivan Aim., This article argues that the current model of emergency practice in rural Victorian hospitals, which relies heavily on visiting medical officers, needs to be reconceptualised if emergency services are to be supplied to rural communities. Background., Medical workforce shortages are manifesting in Victoria as a reduction in emergency care services from rural hospitals. The suggested alternative model of emergency care involves advancing nursing practice to enable a redistribution of clinical capacity across the health care team. Clinicians will need to work collaboratively and continuously negotiate their roles to meet the patient's and the clinical team's needs. Design., Systematic review. Methods., This article is based on a review of the Victorian and Australian literature on the subject of Victorian health services and policy, emergency care, collaboration, communication and rural nurse scope of practice and roles. Emergency care activity was drawn from data held in the Victorian Emergency Management Dataset and personal communications between one of the authors and hospital executives in a small selection of rural hospitals in Victoria. Results., The evidence reviewed suggests that the current emergency practice profile of rural hospitals in Victoria does not reflect the reconceptualised model of rural emergency practice. Instead, only a small proportion of non-urgent presentations is managed by nurses without medical support, and the data suggest that metropolitan nurses are more likely to manage without medical support than rural nurses. Conclusion., Reconceptualising rural emergency care in Victoria will require significantly greater investment in rural nurses' knowledge and skills to enable them to operate confidently at a more advanced level. Clinical teams that deliver emergency service in rural hospitals will be expected increasingly to work collaboratively and interprofessionally. Relevance to clinical practice., This article offers some directions for advancing nursing practice and strategies for improving interprofessional collaboration in the delivery of rural emergency care. [source] Evaluation of gestational age and admission date assumptions used to determine prenatal drug exposure from administrative data,PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 12 2005Marsha A. Raebel PharmD Abstract Objective Our aim was to evaluate the 270-day gestational age and delivery date assumptions used in an administrative dataset study assessing prenatal drug exposure compared to information contained in a birth registry. Study Design and Setting Kaiser Permanente Colorado (KPCO), a member of the Health Maintenance Organization (HMO) Research Network Center for Education and Research in Therapeutics (CERTs), previously participated in a CERTs study that used claims data to assess prenatal drug exposure. In the current study, gestational age and deliveries information from the CERTs study dataset, the Prescribing Safely during Pregnancy Dataset (PSDPD), was compared to information in the KPCO Birth Registry. Sensitivity and positive predictive value (PPV) of the claims data for deliveries were assessed. The effect of gestational age and delivery date assumptions on classification of prenatal drug exposure was evaluated. Results The mean gestational age in the Birth Registry was 273 (median,=,275) days. Sensitivity of claims data at identifying deliveries was 97.6%, PPV was 98.2%. Of deliveries identified in only one dataset, 45% were related to the gestational age assumption and 36% were due to claims data issues. The effect on estimates of prevalence of prescribing during pregnancy was an absolute change of 1% or less for all drug exposure categories. For Category X, drug exposures during the first trimester, the relative change in prescribing prevalence was 13.7% (p,=,0.014). Conclusion Administrative databases can be useful for assessing prenatal drug exposure, but gestational age assumptions can result in a small proportion of misclassification. Copyright © 2005 John Wiley & Sons, Ltd. [source] Variations in hospitalizations for chronic obstructive pulmonary disease in rural and urban Victoria, AustraliaRESPIROLOGY, Issue 6 2007Zahid ANSARI Background and objective: Effective and timely management of COPD should reduce the risk of hospitalization. The purpose of this study was to describe variations in COPD hospital admission rates as an indicator of the adequacy of primary care services. Methods: Age- and gender-standardized hospital admission rates of COPD (2003,04) were computed using the Victorian Admitted Episodes Dataset. Potential predictors of COPD admission rates were identified from various sources of data. These included degree of remoteness, socio-economic status, number of general practitioners per population, percentage of Aboriginal or Torres Strait Islander people, percentage of smokers, and co-morbidities. These data were aggregated at the primary care partnership level, which are voluntary alliances of one or more local government areas in Victoria. Weighted least squares regression was used to identify the predictors of COPD admission rates. Results: Hospital admission rates for COPD were higher in rural than in metropolitan areas of Victoria. Multiple logistic regression analysis showed significant associations between COPD admission rates and socio-economic status, smoking rates and remoteness of the area. Conclusions: Small-area analyses of COPD admission rates highlighted significant differences between urban and rural areas. The influence of socio-economic status and degree of remoteness on COPD admission rates highlights opportunities for policymakers to develop targeted public health and health service interventions. [source] Graphic and haptic modelling of the oesophagus for VR-based medical simulationTHE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 3 2009Changmok Choi Abstract Background Medical simulators with vision and haptic feedback have been applied to many medical procedures in recent years, due to their safe and repetitive nature for training. Among the many technical components of the simulators, realistic and interactive organ modelling stands out as a key issue for judging the fidelity of the simulation. This paper describes the modelling of an oesophagus for a real-time laparoscopic surgical simulator. Methods For realistic simulation, organ deformation and tissue cutting in the oesophagus are implemented with geometric organ models segmented from the Visible Human Dataset. The tissue mechanical parameters were obtained from in vivo animal experiments and integrated with graphic and haptic devices into the laparoscopic surgical simulation system inside an abdominal mannequin. Results This platform can be used to demonstrate deformation and incision of the oesophagus by surgical instruments, where the user can haptically interact with the virtual soft tissues and simultaneously see the corresponding organ deformation on the visual display. Conclusions Current laparoscopic surgical training has been transformed from the traditional apprenticeship model to simulation-based methods. The outcome of the model could replace conventional training systems and could be useful in effectively transferring surgical skills to novice surgeons. Copyright © 2009 John Wiley & Sons, Ltd. [source] Estimating the costs of drug-related hospital separations in AustraliaAUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 2 2008Steven Riddell Abstract Objective: To estimate the total hospital costs of drug-related separations in Australia from 1999/2000 to 2004/05, and separate costs for the following illicit drug classes: opioids, amphetamine, cannabis and cocaine. Methods: Australian hospital separations between 1999/2000 to 2004/05 from the National Hospital Morbidity Dataset (NHMD) with a principal diagnosis of opioids, amphetamine, cannabis or cocaine were included, as were indirect estimates of additional ,drug-caused' separations using aetiological fractions. The costs were estimated using the year-specific case weights and costs for each respective Diagnostic Related Group (DRG). Results: Total constant costs decreased from $50.8 million in 1999/2000 to $43.8 million in 2002/03 then increased to $46.7 million in 2004/05. The initial decrease was driven by a decline in numbers of opioid-related separations (with costs decreasing by $11.5 million) between 1999/2000 and 2001/02. Decreases were evident in separations within the opioid use, dependence and poisoning DRGs. Increases in costs were observed between 1999/00 and 2004/05 for amphetamine (an increase of $2.4 million), cannabis ($1.8 million) and cocaine ($330,000) related separations. Several uncommon but very expensive drug-related separations constituted 12.7% of the total drug-related separations. Conclusions and Implications: Overall, the costs of drug-related hospital separations have decreased by $4.1 million between 1999 and 2005, which is primarily attributable to fewer opioid-related separations. Small reductions in the number of costly separations through harm reduction strategies have the potential to significantly reduce drug-related hospital costs. [source] CONGESTIVE CARDIAC FAILURE: URBAN AND RURAL PERSPECTIVES IN VICTORIAAUSTRALIAN JOURNAL OF RURAL HEALTH, Issue 6 2003Mohammad Z. Ansari ABSTRACT Objective:,Effective and timely care for congestive cardiac failure (CCF) should reduce the risks of hospitalisation. The purpose of this study is to describe variations in rates of hospital admissions for CCF in Victoria as an indicator of the adequacy of primary care services. Detailed analyses identify trends in hospitalisations, urban/rural differentials and variations by the Primary Care Partnerships (PCP). Setting:,Acute care hospitals in Victoria. Design:,Routine analyses of age and sex standardised admission rates of CCF in Victoria using the Victorian Admitted Episodes Dataset from 1993,1994 to 2000,2001. Subjects:,All patients admitted to acute care hospitals in Victoria with the principal diagnosis of CCF between 1993,1994 and 2000,2001. Results:,There were 8359 admissions for CCF in Victoria with an average of 7.37 bed days in 2000,2001. There was a significantly higher admission rate for CCF in rural areas compared to metropolitan in 2000/2001 ,(2.53/1000 (2.44,2.62) and 1.80/1000 (1.75,1.85)) , respectively. Small area analyses identified 17 PCP (14 of which were rural) with significantly higher admission rate ratios of CCF compared to Victoria. Conclusion:,Small area analyses of CCF have identified significant gaps in the management of CCF in the community. This may be a reflection of deficit in primary care availability, accessibility, or appropriateness. Detailed studies may be needed to determine the relative importance of these factors in Victoria for targeting specific interventions at the PCP level. What does this study add?:,Congestive cardiac failure is a major public health problem. In Australia, there is a lack of studies identifying long-term hospitalisation trends of CCF, as well as small area analyses, especially in regard to rural and urban variations. This study has identified significant variations over an eight year period in admission rates of CCF in rural and urban Victoria. Small area analyses (e.g. at the level of primary care partnerships) have identified rural communities with significantly higher admission rates of CCF compared to the Victorian average. For the first time in Australia, this study has provided a new approach for generating evidence on quality of primary care services in rural and urban areas, and offers opportunities for targeting public health and health services interventions that can decrease access barriers, improve the adequacy of primary care, and reduce demand on the hospital system in Victoria. [source] The new World Health Organization classification of haematopoietic and lymphoid tumours: a dermatopathological perspectiveBRITISH JOURNAL OF DERMATOLOGY, Issue 4 2002D.N. Slater Summary The World Health Organization (WHO) has published a new consensus classification of tumours of haematopoietic and lymphoid tissue, based on recognizable disease entities defined by clinical and scientific criteria. The WHO does not support the use of stand-alone organ-related classifications, such as for skin. The Royal College of Pathologists (London) has adopted the WHO classification in its minimum dataset for the histopathological reporting of lymphoma and this will be used in the National Health Service Skin Cancer Dataset. The purpose of this review is to highlight the principal primary and secondary cutaneous haematopoietic and lymphoid tumours that are defined in the WHO classification. The review also discusses selected problematical areas in the WHO classification relevant to the skin and contains suggestions to encourage a unified approach in the use of the WHO coded summary. These represent an attempt to facilitate future progress and research in the field of cutaneous lymphoma. They are perceived as possible building-blocks for wider discussion and not as alterations to the classification. The WHO classification has been compared with a road map that indicates directions for future clinical and scientific research. [source] Detecting New Forms of Network Intrusion Using Genetic ProgrammingCOMPUTATIONAL INTELLIGENCE, Issue 3 2004Wei Lu How to find and detect novel or unknown network attacks is one of the most important objectives in current intrusion detection systems. In this paper, a rule evolution approach based on Genetic Programming (GP) for detecting novel attacks on networks is presented and four genetic operators, namely reproduction, mutation, crossover, and dropping condition operators, are used to evolve new rules. New rules are used to detect novel or known network attacks. A training and testing dataset proposed by DARPA is used to evolve and evaluate these new rules. The proof of concept implementation shows that a rule generated by GP has a low false positive rate (FPR), a low false negative rate and a high rate of detecting unknown attacks. Moreover, the rule base composed of new rules has high detection rate with low FPR. An alternative to the DARPA evaluation approach is also investigated. [source] Rule Quality Measures for Rule Induction Systems: Description and EvaluationCOMPUTATIONAL INTELLIGENCE, Issue 3 2001Aijun An A rule quality measure is important to a rule induction system for determining when to stop generalization or specialization. Such measures are also important to a rule-based classification procedure for resolving conflicts among rules. We describe a number of statistical and empirical rule quality formulas and present an experimental comparison of these formulas on a number of standard machine learning datasets. We also present a meta-learning method for generating a set of formula-behavior rules from the experimental results which show the relationships between a formula's performance and the characteristics of a dataset. These formula-behavior rules are combined into formula-selection rules that can be used in a rule induction system to select a rule quality formula before rule induction. We will report the experimental results showing the effects of formula-selection on the predictive performance of a rule induction system. [source] GPU-based interactive visualization framework for ultrasound datasetsCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 1 2009Sukhyun Lim Abstract Ultrasound imaging is widely used in medical areas. By transmitting ultrasound signals into the human body, their echoed signals can be rendered to represent the shape of internal organs. Although its image quality is inferior to that of CT or MR, ultrasound is widely used for its speed and reasonable cost. Volume rendering techniques provide methods for rendering the 3D volume dataset intuitively. We present a visualization framework for ultrasound datasets that uses programmable graphics hardware. For this, we convert ultrasound coordinates into Cartesian form. In ultrasound datasets, however, since physical storage and representation space is different, we apply different sampling intervals adaptively for each ray. In addition, we exploit multiple filtered datasets in order to reduce noise. By our method, we can determine the adequate filter size without considering the filter size. As a result, our approach enables interactive volume rendering for ultrasound datasets, using a consumer-level PC. Copyright © 2009 John Wiley & Sons, Ltd. [source] The Craniofacial Reconstruction from the Local Structural Diversity of SkullsCOMPUTER GRAPHICS FORUM, Issue 7 2008Yuru Pei Abstract The craniofacial reconstruction is employed as an initialization of the identification from skulls in forensics. In this paper, we present a two-level craniofacial reconstruction framework based on the local structural diversity of the skulls. On the low level, the holistic reconstruction is formulated as the superimposition of the selected tissue map on the novel skull. The crux is the accurate map registration, which is implemented as a warping guided by the 2D feature curve patterns. The curve pattern extraction under an energy minimization framework is proposed for the automatic feature labeling on the skull depth map. The feature configuration on the warped tissue map is expected to resemble that on the novel skull. In order to make the reconstructed faces personalized, on the high level, the local facial features are estimated from the skull measurements via a RBF model. The RBF model is learnt from a dataset of the skull and the face feature pairs extracted from the head volume data. The experiments demonstrate the facial outlooks can be reconstructed feasibly and efficiently. [source] Illustrative Hybrid Visualization and Exploration of Anatomical and Functional Brain DataCOMPUTER GRAPHICS FORUM, Issue 3 2008W. M. Jainek Abstract Common practice in brain research and brain surgery involves the multi-modal acquisition of brain anatomy and brain activation data. These highly complex three-dimensional data have to be displayed simultaneously in order to convey spatial relationships. Unique challenges in information and interaction design have to be solved in order to keep the visualization sufficiently complete and uncluttered at the same time. The visualization method presented in this paper addresses these issues by using a hybrid combination of polygonal rendering of brain structures and direct volume rendering of activation data. Advanced rendering techniques including illustrative display styles and ambient occlusion calculations enhance the clarity of the visual output. The presented rendering pipeline produces real-time frame rates and offers a high degree of configurability. Newly designed interaction and measurement tools are provided, which enable the user to explore the data at large, but also to inspect specific features closely. We demonstrate the system in the context of a cognitive neurosciences dataset. An initial informal evaluation shows that our visualization method is deemed useful for clinical research. [source] Progressive Simplification of Tetrahedral Meshes Preserving All Isosurface TopologiesCOMPUTER GRAPHICS FORUM, Issue 3 2003Yi-Jen Chiang In this paper, we propose a novel technique for constructing multiple levels of a tetrahedral volume dataset whilepreserving the topologies of all isosurfaces embedded in the data. Our simplification technique has two majorphases. In the segmentation phase, we segment the volume data into topological-equivalence regions, that is, thesub-volumes within each of which all isosurfaces have the same topology. In the simplification phase, we simplifyeach topological-equivalence region independently, one by one, by collapsing edges from the smallest to the largesterrors (within the user-specified error tolerance, for a given error metrics), and ensure that we do not collapseedges that may cause an isosurface-topology change. We also avoid creating a tetrahedral cell of negative volume(i.e., avoid the fold-over problem). In this way, we guarantee to preserve all isosurface topologies in the entiresimplification process, with a controlled geometric error bound. Our method also involves several additionalnovel ideas, including using the Morse theory and the implicit fully augmented contour tree, identifying typesof edges that are not allowed to be collapsed, and developing efficient techniques to avoid many unnecessary orexpensive checkings, all in an integrated manner. The experiments show that all the resulting isosurfaces preservethe topologies, and have good accuracies in their geometric shapes. Moreover, we obtain nice data-reductionrates, with competitively fast running times. [source] Fast Volume Rendering and Data Classification Using Multiresolution in Min-Max OctreesCOMPUTER GRAPHICS FORUM, Issue 3 2000Feng Dong Large-sized volume datasets have recently become commonplace and users are now demanding that volume-rendering techniques to visualise such data provide acceptable results on relatively modest computing platforms. The widespread use of the Internet for the transmission and/or rendering of volume data is also exerting increasing demands on software providers. Multiresolution can address these issues in an elegant way. One of the fastest volume-rendering alrogithms is that proposed by Lacroute & Levoy 1 , which is based on shear-warp factorisation and min-max octrees (MMOs). Unfortunately, since an MMO captures only a single resolution of a volume dataset, this method is unsuitable for rendering datasets in a multiresolution form. This paper adapts the above algorithm to multiresolution volume rendering to enable near-real-time interaction to take place on a standard PC. It also permits the user to modify classification functions and/or resolution during rendering with no significant loss of rendering speed. A newly-developed data structure based on the MMO is employed, the multiresolution min-max octree, M 3 O, which captures the spatial coherence for datasets at all resolutions. Speed is enhanced by the use of multiresolution opacity transfer functions for rapidly determining and discarding transparent dataset regions. Some experimental results on sample volume datasets are presented. [source] Determination of skin irritation potential in the human 4-h patch testCONTACT DERMATITIS, Issue 1 2004David A. Basketter Recently adopted legislation in Europe has increased the focus that must be placed on the development of in vitro alternatives to the traditional toxicology tests employed to identify the human health hazards associated with chemicals. Included in these is the rabbit skin-irritation test which is used to discriminate those substances which possess significant acute skin irritation potential from those which are of more limited irritation potential. So far, the considerable efforts to replace this assay with in vitro alternatives have not been successful, which may in part be due to the relatively poor quality of the existing in vivo dataset. To help address this problem, we have elected to present our complete database of information on the skin irritation potential of some 65 substances, all of which have been tested in a standard human 4-h patch test. These provide a high quality dataset, generated in man (the goal of toxicologists' health protection-related activities). The data are presented in the context of results with a concurrent positive skin irritation control to ensure that results from individual experiments can be correlated. Consequently, in vitro or in silico alternatives which can identify the significant acute human skin irritants in this group may well represent suitable alternatives to the rabbit. [source] A chemical dataset for evaluation of alternative approaches to skin-sensitization testingCONTACT DERMATITIS, Issue 5 2004G. Frank Gerberick Allergic contact dermatitis resulting from skin sensitization is a common occupational and environmental health problem. In recent years, the local lymph node assay (LLNA) has emerged as a practical option for assessing the skin-sensitization potential of chemicals. In addition to accurate identification of skin sensitizers, the LLNA can also provide a reliable measure of relative sensitization potency, information that is pivotal in successful management of human health risks. However, even with the significant animal welfare benefits provided by the LLNA, there is interest still in the development of non-animal test methods for skin sensitization. Here, we provide a dataset of chemicals that have been tested in the LLNA and the activity of which correspond with what is known of their potential to cause skin sensitization in humans. It is anticipated that this will be of value to other investigators in the evaluation and calibration of novel approaches to skin-sensitization testing. The materials that comprise this dataset encompass both the chemical and biological diversity of known chemical allergens and provide also examples of negative controls. It is hoped that this dataset will accelerate the development, evaluation and eventual validation of new approaches to skin-sensitization testing. [source] What Do Shareholders' Coalitions Really Want?CORPORATE GOVERNANCE, Issue 2 2007Evidence from Italian voting trusts This paper studies the effects of having multiple large shareholders who share the control of firms, by analysing a unique dataset of Italian shareholders' agreements (voting trusts). We investigate the separation between ownership and control granted by such agreements, showing that, on average, a voting trust owning 52 per cent of the total company's cash-flow rights is able to exercise up to 87 per cent of the total board rights; the wedge is particularly beneficial to the largest shareholder within the voting trust who is able to get the majority of board rights despite owning only a minority fraction of the company's cash-flow rights. Then, an event-study analysis of a sample of voting trusts' announcements is performed. The results support the "entrenchment effects" hypothesis (Stulz, 1988) linking the ownership structure and the firm value, and are consistent with the view that, in Italy, voting trust agreements are mainly aimed at both protecting controlling shareholders from hostile takeovers and entrenching incumbent management. [source] Gender and Ethnic Diversity Among UK Corporate BoardsCORPORATE GOVERNANCE, Issue 2 2007Stephen Brammer This paper investigates the ethnic and gender diversity of the corporate board of UK companies, placing particular emphasis on links to board size and industry characteristics. We employ a novel dataset that covers a large sample of UK PLCs and describes a director's gender, ethnicity and position held. We find both ethnic and gender diversity to be very limited, and that diversity is somewhat less pronounced among executive positions. We find significant cross-sector variation in gender diversity, with an above average prevalence of women in Retail, Utilities, Media and Banking, while such variation in ethnic diversity is considerably less pronounced. Our evidence suggests that a close proximity to final consumers plays a more significant role in shaping board diversity than does the female presence among the industry's workforce. We argue that this shows that board diversity is influenced by a firm's external business environment and particularly an imperative to reflect corresponding diversity among its customers. [source] Unsupervised immunophenotypic profiling of chronic lymphocytic leukemiaCYTOMETRY, Issue 3 2006Luzette K. Habib Abstract Background Proteomics and functional genomics have revolutionized approaches to disease classification. Like proteomics, flow cytometry (FCM) assesses concurrent expression of many proteins, with the advantage of using intact cells that may be differentially selected during analysis. However, FCM has generally been used for incremental marker validation or construction of predictive models based on known patterns, rather than as a tool for unsupervised class discovery. We undertook a retrospective analysis of clinical FCM data to assess the feasibility of a cell-based proteomic approach to FCM by unsupervised cluster analysis. Methods Multicolor FCM data on peripheral blood (PB) and bone marrow (BM) lymphocytes from 140 consecutive patients with B-cell chronic lymphoproliferative disorders (LPDs), including 81 chronic lymphocytic leukemia (CLLs), were studied. Expression was normalized for CD19 totals, and recorded for 10 additional B-cell markers. Data were subjected to hierarchical cluster analysis using complete linkage by Pearson's correlation. Analysis of CLL in PB samples (n = 63) discovered three major clusters. One cluster (14 patients) was skewed toward "atypical" CLL and was characterized by high CD20, CD22, FMC7, and light chain, and low CD23. The remaining two clusters consisted almost entirely (48/49) of cases recorded as typical BCLL. The smaller "typical" BCLL cluster differed from the larger cluster by high CD38 (P = 0.001), low CD20 (P = 0.001), and low CD23 (P = 0.016). These two typical BCLL clusters showed a trend toward a difference in survival (P = 0.1090). Statistically significant cluster stability was demonstrated by expanding the dataset to include BM samples, and by using a method of random sampling with replacement. Conclusions This study supports the concept that unsupervised immunophenotypic profiling of FCM data can yield reproducible subtypes of lymphoma/chronic leukemia. Expanded studies are warranted in the use of FCM as an unsupervised class discovery tool, akin to other proteomic methods, rather than as a validation tool. © 2006 International Society for Analytical Cytology [source] Revenue Mobilisation in Sub-Saharan Africa: Challenges from Globalisation I , Trade ReformDEVELOPMENT POLICY REVIEW, Issue 5 2010Michael Keen This is the first of two articles evaluating the nature and extent of, and possible responses to, two of the central challenges that globalisation poses for revenue mobilisation in sub-Saharan Africa: trade liberalisation, and corporate tax competition. Both articles use a new dataset with the features needed to address these issues meaningfully: a disentangling of tariff from commodity tax revenue, and a distinction between resource-related and other revenues. This first article describes that dataset, and provides a broad picture of revenue developments in the region between 1980 and 2005. Countries' experiences have varied, but the overall picture is of non-resource revenues having been essentially stagnant. Within this, however, and with exceptions, reductions in trade tax revenue have been largely offset by increased revenue from domestic sources. [source] Revenue Mobilisation in Sub-Saharan Africa: Challenges from Globalisation II , Corporate TaxationDEVELOPMENT POLICY REVIEW, Issue 5 2010Michael Keen This second article evaluates and discusses the challenges to government revenue in sub-Saharan Africa posed by developments in corporate taxation. Using the dataset described in the first article, it shows that, in broad terms, corporate tax revenues in the region have held up, despite a reduction in rates and evidence of substantial base-narrowing (mainly through the provision of tax holidays in Investment Codes and Free Zones). This is something of a puzzle. Options for dealing with the continuation and intensification of the challenges to these revenues, including through regional co-operation, are discussed. [source] Private Provision of Infrastructure in Emerging Markets: Do Institutions Matter?DEVELOPMENT POLICY REVIEW, Issue 2 2006Sudeshna Ghosh Banerjee Governments in developing countries have encouraged private sector investment to meet the growing demand for infrastructure. According to institutional theory, the role of institutions is paramount in private sector development. A longitudinal dataset of 40 developing economies between 1990 and 2000 is used to test empirically how different institutional structures affect private investment in infrastructure, in particular its volume and frequency. The results indicate that property rights and bureaucratic quality play a significant role in promoting private infrastructure investment. Interestingly, they also suggest that countries with higher levels of corruption attract greater private participation in infrastructure. [source] Fiber tracking using magnetic resonance diffusion tensor imaging and its applications to human brain developmentDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 3 2003Richard Watts Abstract Diffusion tensor imaging is unique in its ability to noninvasively visualize white matter fiber tracts in the human brain in vivo. Diffusion is the incoherent motion of water molecules on a microscopic scale. This motion is itself dependent on the micro-structural environment that restricts the movement of the water molecules. In white matter fibers there is a pronounced directional dependence on diffusion. With white matter fiber tracking or tractography, projections among brain regions can be detected in the three-dimensional diffusion tensor dataset according to the directionality of the fibers. Examples of developmental changes in diffusion, tracking of major fiber tracts, and examples of how diffusion tensor tractography and functional magnetic resonance imaging can be combined are provided. These techniques are complimentary and allow both the identification of the eloquent areas of the brain involved in specific functional tasks, and the connections between them. The noninvasive nature of magnetic resonance imaging will allow these techniques to be used in both longitudinal developmental and diagnostic studies. An overview of the technique and preliminary applications are presented, along with its current limitations. MRDD Research Reviews 2003;9:168,177. © 2003 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||