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Complex Situations (complex + situation)
Selected AbstractsTubular Piles , Buckling Design in a Complex SituationBAUTECHNIK, Issue 8 2008Anton Hübner Dr.-Ing. No abstract is available for this article. [source] Knowledge-sharing reward dynamics in knowledge management systems: Game theory,based empirical validationHUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 2 2010Xi Zhang Abstract There are several knowledge-sharing problems in knowledge-management system (KMS) contexts. Many organizations use rewards to motivate people to contribute knowledge, but there has been no conclusive evidence of the role of reward. We designed two game-theory models to explain why and how the different knowledge-sharing problems occur in a KMS and the effectiveness of rewards. We found that there are four types of Nash equilibriums in different knowledge-sharing situations (Perfect, Free-riding, Non-use, and Dormant). Complex situations also occur (e.g., the absence of consideration for knowledge quality leads to vicious cycles). People contribute low-quality knowledge that is not used, and thus the KMS spirals toward disuse. To provide proposition evidence, a case study in an enterprise resource planning vendor was conducted. Based on comparison with empirical evidence, proposition validity was ensured. To effectively facilitate knowledge sharing, our suggestion is that organizations not only add rewards but also apply some additional mechanisms, such as a quality-evaluating system, extended information technology support, and organizational policy. © 2010 Wiley Periodicals, Inc. [source] Bivariate association analyses for the mixture of continuous and binary traits with the use of extended generalized estimating equationsGENETIC EPIDEMIOLOGY, Issue 3 2009Jianfeng Liu Abstract Genome-wide association (GWA) study is becoming a powerful tool in deciphering genetic basis of complex human diseases/traits. Currently, the univariate analysis is the most commonly used method to identify genes associated with a certain disease/phenotype under study. A major limitation with the univariate analysis is that it may not make use of the information of multiple correlated phenotypes, which are usually measured and collected in practical studies. The multivariate analysis has proven to be a powerful approach in linkage studies of complex diseases/traits, but it has received little attention in GWA. In this study, we aim to develop a bivariate analytical method for GWA study, which can be used for a complex situation in which continuous trait and a binary trait are measured under study. Based on the modified extended generalized estimating equation (EGEE) method we proposed herein, we assessed the performance of our bivariate analyses through extensive simulations as well as real data analyses. In the study, to develop an EGEE approach for bivariate genetic analyses, we combined two different generalized linear models corresponding to phenotypic variables using a seemingly unrelated regression model. The simulation results demonstrated that our EGEE-based bivariate analytical method outperforms univariate analyses in increasing statistical power under a variety of simulation scenarios. Notably, EGEE-based bivariate analyses have consistent advantages over univariate analyses whether or not there exists a phenotypic correlation between the two traits. Our study has practical importance, as one can always use multivariate analyses as a screening tool when multiple phenotypes are available, without extra costs of statistical power and false-positive rate. Analyses on empirical GWA data further affirm the advantages of our bivariate analytical method. Genet. Epidemiol. 2009. © 2008 Wiley-Liss, Inc. [source] Location of a missing object and detection of its absence by infants: Contribution of an eye-tracking system to the understanding of infants' strategiesINFANT AND CHILD DEVELOPMENT, Issue 4 2004Roger Lécuyer Abstract Previous research has demonstrated infants' capacity to discriminate between situations in which all the objects successively hidden behind a screen are present, or not, after the removal of the screen. Two types of interpretation have been proposed: counting capacity or object memorization capacity. In the usual paradigm, the missing object in the impossible event is usually the last object which is placed behind the screen. Following this, a third interpretation can be offered: infants' exploration is first directed to this object's location, and its presence or absence is noticed. Two experiments using Wynn's (Nature 1992; 358:749) paradigm were performed to test the third hypothesis. The first experiment involved four objects (teddy bears) placed in four squares. Infants looked longer at the impossible event (3 objects, the last one missing) than at the possible event (4 objects) when the impossible event was presented first. No difference in looking duration was observed for the opposite order. In the second experiment, the four objects were disposed in a line and an eye-tracking system was used. No difference in the number of looks was observed between the impossible event (3 objects, the second one missing) and the possible event (4 objects). Therefore, it appears that at least in this complex situation (4 objects used instead of 2 usually), the location of the missing object is a key factor for event discrimination. Eye-tracking also indicated in the second experiment that infants looked less at the second location during an impossible event (object missing) than during the possible event (object present), indicating that the impossibility of the event was not a determining factor for looking durations. Altogether, the data indicate the potential usefulness of eye-tracking analysis in this type of situation. Copyright © 2004 John Wiley & Sons, Ltd. [source] From dynamic influence nets to dynamic Bayesian networks: A transformation algorithmINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 8 2009Sajjad Haider This paper presents an algorithm to transform a dynamic influence net (DIN) into a dynamic Bayesian network (DBN). The transformation aims to bring the best of both probabilistic reasoning paradigms. The advantages of DINs lie in their ability to represent causal and time-varying information in a compact and easy-to-understand manner. They facilitate a system modeler in connecting a set of desired effects and a set of actionable events through a series of dynamically changing cause and effect relationships. The resultant probabilistic model is then used to analyze different courses of action in terms of their effectiveness to achieve the desired effect(s). The major drawback of DINs is their inability to incorporate evidence that arrive during the execution of a course of action (COA). Several belief-updating algorithms, on the other hand, have been developed for DBNs that enable a system modeler to insert evidence in dynamic probabilistic models. Dynamic Bayesian networks, however, suffer from the intractability of knowledge acquisition. The presented transformation algorithm combines the advantages of both DINs and DBNs. It enables a system analyst to capture a complex situation using a DIN and pick the best (or close-to-best) COA that maximizes the likelihood of achieving the desired effect. During the execution, if evidence becomes available, the DIN is converted into an equivalent DBN and beliefs of other nodes in the network are updated. If required, the selected COA can be revised on the basis of the recently received evidence. The presented methodology is applicable in domains requiring strategic level decision making in highly complex situations, such as war games, real-time strategy video games, and business simulation games. © 2009 Wiley Periodicals, Inc. [source] The legal construction of the social security system of the Republic of KosovoINTERNATIONAL SOCIAL SECURITY REVIEW, Issue 1 2009Ma Lourdes Arastey Sahún Abstract Following the international community's unsuccessful attempts to broker an agreement between Serbia and Kosovo, the territory of Kosovo controversially declared independence on 17 February 2008. This article provides a description and analysis of the social protection system immediately after the declaration of independence. In the aftermath of conflict, and faced by enormous economic difficulties, Kosovo's society could not expect a complete restoration of the social security system. To date, the United Nations Mission has committed itself to building a minimum legal framework, seeking to give answers to main and essential challenges. But the core structure of the social security system is yet to be laid. Nonetheless, in a complex situation such as that of Kosovo, the realization of a social protection framework must be seen as an essential mechanism for reconstruction and peacekeeping. [source] SMIXTURE: strategy for mixture model clustering of multivariate imagesJOURNAL OF CHEMOMETRICS, Issue 11-12 2005Thanh N. Tran Abstract SMIXTURE, a novel strategy for mixture model clustering of multivariate images, has been developed. Most other clustering approaches require good guesses of the number of components (clusters) and the initial statistical parameters. In our approach, the initial parameters are determined by agglomerative clustering on homogenous regions, identified by region growing segmentation. SMIXTURE can be used in both a normal situation of mixture modeling, where the density of a cluster is modeled by a single normal distribution; and in a more complex situation, where the density of a single cluster is a mixture of several normal sub-clusters. The method has proven to be very robust to noise/outliers, overlapping clusters, is reasonably fast and is suitable for moderate to large images. Copyright © 2006 John Wiley & Sons, Ltd. [source] Practitioner assessments of ,good enough' parenting: factorial surveyJOURNAL OF CLINICAL NURSING, Issue 8 2009Julie Taylor Aim., The aim of this study was to measure health visitors' professional judgements on ,good enough' parenting and identify what factors and combinations of these are important when making such judgements. Background., The relationship between parenting and child health is unclear. Whilst agreement exists that ,good enough' parenting requires boundary setting, consistency and putting the child's needs first, attempting to define ,good enough' parenting in precise terms is complex. When faced with a complex situation, practitioners rely on relatively few factors to form judgements. Design., Factorial survey methods were employed using vignette techniques. Methods., Vignettes were constructed using previous research on those variables, which may influence nurses' judgements, for example, accommodation and child dentition. The level of factors was randomly varied. Two thousand vignettes were administered to a sample of 200 health visitors in two Health Boards who then made a judgement about this scenario. Analysis., Data were analysed through multiple regression with dummy variables and one-way analysis of variance. Regression equations for both good enough mothering and good enough parenting are reported. Results., The models used are significant predictors of parenting and mothering. Significant predictors on health visitor judgements' were boundary setting in sleep behaviours, type of housing inhabited and health behaviours. Although parenting and mothering are often conflated, health visitors appear to separate these aspects when making judgements based on type of housing. Conclusions., Most professionals can articulate what makes a ,good' parent, equally they may have strong views regarding what constitutes ,poor' parenting. The difficulty is in determining when parenting is ,good enough' to provide a child with a nurturing environment. Relevance to clinical practice., This study suggests that practitioners move their thresholds of what is ,good enough' depending on a narrow range of factors. Awareness of the factors, which influence individuals' judgements is important in safeguarding children. [source] Heart transplantation experiences: a phenomenological approachJOURNAL OF CLINICAL NURSING, Issue 7b 2008Maria Lúcia Araújo Sadala PhD Aim., The aim of this study was to understand the heart transplantation experience based on patients' descriptions. Background., To patients with heart failure, heart transplantation represents a possibility to survive and improve their quality of life. Studies have shown that more quality of life is related to patients' increasing awareness and participation in the work of the healthcare team in the post-transplantation period. Deficient relationships between patients and healthcare providers result in lower compliance with the postoperative regimen. Method., A phenomenological approach was used to interview 26 patients who were heart transplant recipients. Patients were interviewed individually and asked this single question: What does the experience of being heart transplanted mean? Participants' descriptions were analysed using phenomenological reduction, analysis and interpretation. Results., Three categories emerged from data analysis: (i) the time lived by the heart recipient; (ii) donors, family and caregivers and (iii) reflections on the experience lived. Living after heart transplant means living in a complex situation: recipients are confronted with lifelong immunosuppressive therapy associated with many side-effects. Some felt healthy whereas others reported persistence of complications as well as the onset of other pathologies. However, all participants celebrated an improvement in quality of life. Health caregivers, their social and family support had been essential for their struggle. Participants realised that life after heart transplantation was a continuing process demanding support and structured follow-up for the rest of their lives. Conclusion., The findings suggest that each individual has unique experiences of the heart transplantation process. To go on living participants had to accept changes and adapt: to the organ change, to complications resulting from rejection of the organ, to lots of pills and food restrictions. Relevance to clinical practice., Stimulating a heart transplant patients spontaneous expression about what they are experiencing and granting them the actual status of the main character in their own story is important to their care. [source] Introgressive hybridization in southern African baboons shapes patterns of mtDNA variationAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2010C. Keller Abstract Species, as main evolutionary units have long been considered to be morphological entities with limited hybridization potential. The occurrence of taxa which maintain morphological distinctness despite extensive hybridization is an interesting phenomenon. To understand the evolution of these taxa, descriptions of contemporary morphological and genetic variation are essential, also to reconstruct sound phylogenies. Baboons, with their wide geographic range, variant morphotypes, and extensive hybridization offer an intriguing model for those studies. We focus on the complex situation in southern Africa that, in contrast to east Africa, has been neglected in terms of baboon hybridization history. We aim to clarify the distribution and identify possible overlapping zones between different, previously described mitochondrial (mt) DNA clades of baboons that do not match with the ranges of traditionally recognized species. On the basis of the widespread sampling and mitochondrial cytochrome b gene sequencing, we constructed a phylogenetic tree that separates representatives of the two southern African baboon species, yellow and chacma baboons, into six clades: southern, northern and eastern chacmas, Kinda baboons and southern and Luangwa yellow baboons. The ranges of the chacma clades come into close contact or overlap in two regions in the Republic of South Africa and Namibia. Our phylogenetic reconstruction reveals mitochondrial paraphyly for chacma and yellow baboons, which is probably caused by introgressive hybridization and subsequent nuclear swamping, whereby males of the chacma morphotype population from the south invaded the yellow morphotype population in the north bringing their morphotype into a population that maintained its yellow baboon mtDNA. Am J Phys Anthropol 2010. © 2009 Wiley-Liss, Inc. [source] Score Tests for Exploring Complex Models: Application to HIV Dynamics ModelsBIOMETRICAL JOURNAL, Issue 1 2010Julia Drylewicz Abstract In biostatistics, more and more complex models are being developed. This is particularly the case in system biology. Fitting complex models can be very time-consuming, since many models often have to be explored. Among the possibilities are the introduction of explanatory variables and the determination of random effects. The particularity of this use of the score test is that the null hypothesis is not itself very simple; typically, some random effects may be present under the null hypothesis. Moreover, the information matrix cannot be computed, but only an approximation based on the score. This article examines this situation with the specific example of HIV dynamics models. We examine the score test statistics for testing the effect of explanatory variables and the variance of random effect in this complex situation. We study type I errors and the statistical powers of this score test statistics and we apply the score test approach to a real data set of HIV-infected patients. [source] Learning from James: Lessons about Policy and Practice for Schools' Special Provision in the Area of Literacy DifficultiesBRITISH JOURNAL OF SPECIAL EDUCATION, Issue 2 2004Janice Wearmouth Janice Wearmouth is a senior lecturer in the Faculty of Education and Language Studies at the Open University in the UK. She has many years' experience of teaching and research in mainstream secondary schools and of developing and leading postgraduate development courses for teachers in the area of special and inclusive education. In this article, she argues that successive Governments in England, Wales and Northern Ireland have adopted policies in relation to special educational provision that are essentially technicist in character. These policies proceed from assumptions that are made about the clear and unproblematic nature of the issues and the responses that need to be made. In this model, difficulties in learning can be ,fixed' by selecting the most appropriate ,tool' in the most efficient and cost-effective way. The current focus on competency-based teacher education can be seen as a corollary of this approach. Drawing upon a personal account of the experience of having difficulties in literacy acquisition, this article presents a contrary view. Janice Wearmouth argues that the area of special educational needs in schools, including literacy difficulties, is fraught with uncertainty and conflicting viewpoints. Given this complex situation, the technicist responses of recent Governments in the UK seem inappropriate and inadequate, Janice Wearmouth suggests. She proposes that practice in relation to special educational needs in general, and literacy difficulties in particular, can be most effectively understood from the perspective of a reflective practitioner. Her article closes with a call for practitioner professional development to be reconceptualised in these terms. [source] Snap: A time critical decision-making framework for MOUT simulationsCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 3-4 2008Shang-Ping Ting Abstract Deliberative reasoning based on the rational analysis of various alternatives often requires too much information and may be too slow in time critical situations. In these situations, humans rely mainly on their intuitions rather than some structured decision-making processes. An important and challenging problem in Military Operations on Urban Terrain (MOUT) simulations is how to generate realistic tactical behaviors for the non-player characters (also known as bots), as these bots often need to make quick decisions in time-critical and uncertain situations. In this paper, we describe our work on Snap, a time critical decision-making framework for the bots in MOUT simulations. The novel features of Snap include case-based reasoning (CBR) and thin slicing. CBR is used to make quick decisions by comparing the current situation with past experience cases. Thin slicing is used to model human's ability to quickly form up situation awareness under uncertain and complex situations using key cues from partial information. To assess the effectiveness of Snap, we have integrated it into Twilight City, a virtual environment for MOUT simulations. Experimental results show that Snap is very effective in generating quick decisions during time critical situations for MOUT simulations. Copyright © 2008 John Wiley & Sons, Ltd. [source] Use of mutually inductive coupling in probe design,CONCEPTS IN MAGNETIC RESONANCE, Issue 4 2002D.I. Hoult Abstract An analysis is presented of mutually inductive coupling in probe design. It is assumed that near field couplings predominate and that lumped constants may therefore be employed. Using three published designs as examples, analytic techniques are presented for assessing B1 field strength, losses, and signal-to-noise ratio in increasingly complex situations. The perturbing effect of the B1 field from a matching coil is examined and it is shown that if the coil is too close to the sample there can be an asymmetry introduced in the rotating frame B1 field. It is then shown that such asymmetries are potentially a general feature of inductively coupled, loaded coils. The importance of suppressing unwanted resonances is highlighted if tuning and matching are to be orthogonal, a potential advantage of mutually inductive matching. Finally, a lumped-constant simulation is briefly described for those situations where an analytic approach becomes too cumbersome. © 2002 Wiley Periodicals, Inc. Concepts in Magnetic Resonance (Magn Reson Engineering) 15: 262,285, 2002 [source] Applications of cone-beam computed tomography in fractures of the maxillofacial complexDENTAL TRAUMATOLOGY, Issue 4 2009Werner H. Shintaku Several studies support the use of conventional two-dimensional imaging for traumas involving mainly the mandible, but for more complex situations advanced imaging modalities such as computed tomography (CT) and magnetic resonance imaging have higher indication. Nowadays, besides CT, cone-beam computed tomography (CBCT) has appeared as a reasonable and reliable alternative considering radiation dosage, image quality and comfort for the patient. The purpose of this study was to review the fracture patterns involving the maxillofacial complex, provide a technical and practical comparison between CT and CBCT, and finally present the potential applications of CBCT illustrated with clinical examples. [source] Entering the Twilight Zone: The Local Complexities of Pay and Employment Equity in New ZealandGENDER, WORK & ORGANISATION, Issue 5 2009Deborah Jones This article introduces the recent pay and employment equity situation in the New Zealand state sector through a discussion of research carried out for a Pay and Employment Equity Taskforce. It investigates the twilight zone of pay and employment equity , the murky situations where pay and employment equity programmes already exist, but progress for senior women has stalled for no obvious reasons. Qualitative research is necessary to make sense of these complex situations and to complement labour-market level studies. The example used is a study of teachers in New Zealand schools, where a range of complex reasons, including lack of support, gendered job designs and intense workloads, creates a bottleneck for women at senior levels. The authors argue that highly decentralized human resources practices work against progress in equal employment opportunity in the state sector. [source] From dynamic influence nets to dynamic Bayesian networks: A transformation algorithmINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 8 2009Sajjad Haider This paper presents an algorithm to transform a dynamic influence net (DIN) into a dynamic Bayesian network (DBN). The transformation aims to bring the best of both probabilistic reasoning paradigms. The advantages of DINs lie in their ability to represent causal and time-varying information in a compact and easy-to-understand manner. They facilitate a system modeler in connecting a set of desired effects and a set of actionable events through a series of dynamically changing cause and effect relationships. The resultant probabilistic model is then used to analyze different courses of action in terms of their effectiveness to achieve the desired effect(s). The major drawback of DINs is their inability to incorporate evidence that arrive during the execution of a course of action (COA). Several belief-updating algorithms, on the other hand, have been developed for DBNs that enable a system modeler to insert evidence in dynamic probabilistic models. Dynamic Bayesian networks, however, suffer from the intractability of knowledge acquisition. The presented transformation algorithm combines the advantages of both DINs and DBNs. It enables a system analyst to capture a complex situation using a DIN and pick the best (or close-to-best) COA that maximizes the likelihood of achieving the desired effect. During the execution, if evidence becomes available, the DIN is converted into an equivalent DBN and beliefs of other nodes in the network are updated. If required, the selected COA can be revised on the basis of the recently received evidence. The presented methodology is applicable in domains requiring strategic level decision making in highly complex situations, such as war games, real-time strategy video games, and business simulation games. © 2009 Wiley Periodicals, Inc. [source] Hybrid learning architecture for fuzzy control of quadruped walking robotsINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 2 2005Huosheng Hu This article presents a hybrid learning architecture for fuzzy control of quadruped walking robots in the RoboCup domain. It combines reactive behaviors with deliberative reasoning to achieve complex goals in uncertain and dynamic environments. To achieve real-time and robust control performance, fuzzy logic controllers (FLCs) are used to encode the behaviors and a two-stage learning scheme is adopted to make these FLCs be adaptive to complex situations. The first stage is called structure learning, in which the rule base of an FLC is generated by a Q-learning scheme. The second stage is called parameter learning, in which the parameters of membership functions in input fuzzy sets are learned by using a real value genetic algorithm. The experimental results are provided to show the suitability of the architecture and effectiveness of the proposed learning scheme. © 2005 Wiley Periodicals, Inc. Int J Int Syst 20: 131,152, 2005. [source] Exploring nursing outcomes for patients with advanced cancer following intervention by Macmillan specialist palliative care nursesJOURNAL OF ADVANCED NURSING, Issue 6 2003Jessica Corner BSc PhD RGN OncCert Background.,Little information exists about the outcomes from nursing interventions, and few studies report new approaches to evaluating the complex web of effects that may result from specialist nursing care. Aims.,The aim of this study was to explore nursing outcomes for patients with advanced cancer that may be identified as resulting from the care of a Macmillan specialist palliative care nurse. Methods/instruments.,Seventy-six patients referred to 12 United Kingdom Macmillan specialist palliative care nursing services participated in a longitudinal study of their care over 28 days. Patients were interviewed and completed the European Organization for Research on Treatment of Cancer Quality of Life Scale and the Palliative Care Outcomes Scale at referral, and 3, 7 and 28 days following referral to a Macmillan specialist palliative care nursing service. A nominated carer was interviewed at baseline and 28 days. Notes recorded by Macmillan specialist palliative care nurses in relation to each patient case were analysed. Findings.,Significant improvements in emotional (P = 0·03) and cognitive functioning (P = 0·03) were identified in changes in patients' European Organization for Research on Treatment of Cancer Quality of Life Scale scores, and in Palliative Care Outcomes Scale patient anxiety scores (P = 0·003), from baseline to day 7. Analysis of case study data indicated that overall positive outcomes of care from Macmillan specialist palliative care nursing intervention were achieved in 42 (55%) cases. Study limitations.,Sample attrition due to patients' deteriorating condition limited the value of data from the quality of life measures. The method developed for evaluating nursing outcomes using data from patient and carer interviews and nursing records was limited by a lack of focus on outcomes of care in these data sources. Conclusions.,A method was developed for evaluating outcomes of nursing care in complex situations such as care of people who are dying. Positive outcomes of care for patients that were directly attributable to the care provided by Macmillan specialist palliative care nurses were found for the majority of patients. For a small number of patients, negative outcomes of care were identified. [source] Generalized marker regression and interval QTL mapping methods for binary traits in half-sib family designsJOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 5 2001H. N. Kadarmideen A Generalized Marker Regression Mapping (GMR) approach was developed for mapping Quantitative Trait Loci (QTL) affecting binary polygenic traits in a single-family half-sib design. The GMR is based on threshold-liability model theory and regression of offspring phenotype on expected marker genotypes at flanking marker loci. Using simulation, statistical power and bias of QTL mapping for binary traits by GMR was compared with full QTL interval mapping based on a threshold model (GIM) and with a linear marker regression mapping method (LMR). Empirical significance threshold values, power and estimates of QTL location and effect were identical for GIM and GMR when QTL mapping was restricted to within the marker interval. These results show that the theory of the marker regression method for QTL mapping is also applicable to binary traits and possibly for traits with other non-normal distributions. The linear and threshold models based on marker regression (LMR and GMR) also resulted in similar estimates and power for large progeny group sizes, indicating that LMR can be used for binary data for balanced designs with large families, as this method is computationally simpler than GMR. GMR may have a greater potential than LMR for QTL mapping for binary traits in complex situations such as QTL mapping with complex pedigrees, random models and models with interactions. Generalisierte Marker Regression und Intervall QTL Kartierungsmethoden für binäre Merkmale in einem Halbgeschwisterdesign Es wurde ein Ansatz zur generalisierten Marker Regressions Kartierung (GMR) entwickelt, um quantitative Merkmalsloci (QTL) zu kartieren, die binäre polygenetische Merkmale in einem Einfamilien-Halbgeschwisterdesign beeinflussen. Das GMR basiert auf der Theorie eines Schwellenwertmodells und auf der Regression des Nachkommenphänotyps auf den erwarteten Markergenotyp der flankierenden Markerloci. Mittels Simulation wurde die statistische Power und Schiefe der QTL Kartierung für binäre Merkmale nach GMR verglichen mit vollständiger QTL Intervallkartierung, die auf einem Schwellenmodell (GIM) basiert, und mit einer Methode zur linearen Marker Regressions Kartierung (LMR). Empirische Signifikanzschwellenwerte, Power und Schätzer für die QTL Lokation und der Effekt waren für GIM und GMR identisch, so lange die QTL Kartierung innerhalb des Markerintervalls definiert war. Diese Ergebnisse zeigen, dass die Theorie der Marker Regressions-Methode zur QTL Kartierung auch für binäre Merkmale und möglicherweise auch für Merkmale, die keiner Normalverteilung folgen, geeignet ist. Die linearen und Schwellenmodelle, die auf Marker Regression (LMR und GMR) basieren, ergaben ebenfalls ähnliche Schätzer und Power bei großen Nachkommengruppen, was schlussfolgern lässt, dass LMR für binäre Daten in einem balancierten Design mit großen Familien genutzt werden kann. Schließlich ist diese Methode computertechnisch einfacher als GMR. GMR mag für die QTL Kartierung bei binären Merkmalen in komplexen Situationen ein größeres Potential haben als LMR. Ein Beispiel dafür ist die QTL Kartierung mit komplexen Pedigrees, zufälligen Modellen und Interaktionsmodellen. [source] Management implications of the Macquarie Island trophic cascade revisited: a reply to Dowding et al. (2009)JOURNAL OF APPLIED ECOLOGY, Issue 5 2009Dana M. Bergstrom Summary 1. The management of non-indigenous species is not without its complications. In Bergstrom et al.'s (2009) study, we demonstrated that feral cats Felis catus on sub-Antarctic Macquarie Island were exerting top-down control on the feral rabbit Oryctolagus cuniculus population, and that the eradication of the cats led to a substantial increase in rabbit numbers and an associated trophic cascade. 2. Dowding et al. (2009) claim our modelling was flawed for various reasons, but primarily that a reduction in the application of the rabbit control agent, Myxoma virus, coinciding with cat removal, was a major driver of rabbit population release. 3. We explore this proposition (as well as others) by examining rates of Myxoma viral release between 1991 and 2006 (with an attenuation factor for the years, 2003,2006) in association with presence/absence of cats against two estimates of rabbit population size. Myxoma viral release was a significant factor in the lower estimates of rabbit population, but the effect was small, and was not significant for higher rabbit population estimates. By contrast, the presence or absence of cats remained highly significant for both estimates. 4.Synthesis and applications. We re-affirm our position that top-down control of rabbit numbers by cats, prior to their eradication, was occurring on Macquarie Island. Nonetheless, we agree with Dowding et al. (2009) that systems with multiple invasive species represent complex situations that require careful scrutiny. Such scrutiny should occur in advance of, during, and following management interventions. [source] Controlling coverage of D-optimal onion designs and selectionsJOURNAL OF CHEMOMETRICS, Issue 12 2004Ing-Marie Olsson Abstract Statistical molecular design (SMD) is a powerful approach for selection of compound sets in medicinal chemistry and quantitative structure,activity relationships (QSARs) as well as other areas. Two techniques often used in SMD are space-filling and D-optimal designs. Both on occasions lead to unwanted redundancy and replication. To remedy such shortcomings, a generalization of D-optimal selection was recently developed. This new method divides the compound candidate set into a number of subsets (,layers' or ,shells'), and a D-optimal selection is made from each layer. This improves the possibility to select representative molecular structures throughout any property space independently of requested sample size. This is important in complex situations where any given model is unlikely to be valid over the whole investigated domain of experimental conditions. The number of selected molecules can be controlled by varying the number of subsets or by altering the complexity of the model equation in each layer and/or the dependency of previous layers. The new method, called D-optimal onion design (DOOD), will allow the user to choose the model equation complexity independently of sample size while still avoiding unwarranted redundancy. The focus of the present work is algorithmic improvements of DOOD in comparison with classical D-optimal design. As illustrations, extended DOODs have been generated for two applications by in-house programming, including some modifications of the D-optimal algorithm. The performances of the investigated approaches are expected to differ depending on the number of principal properties of the compounds in the design, sample sizes and the investigated model, i.e. the aim of the design. QSAR models have been generated from the selected compound sets, and root mean squared error of prediction (RMSEP) values have been used as measures of performance of the different designs. Copyright © 2005 John Wiley & Sons, Ltd. [source] From competence to capability: a study of nurse practitioners in clinical practiceJOURNAL OF CLINICAL NURSING, Issue 2 2008Anne Gardner BA, MRCNA Aims and objectives., This research aimed to understand the level and scope of practice of the nurse practitioner in Australia and New Zealand further using a capability framework. Background., The original study, from which the present paper was developed, sought to identify competency standards for the extended role of the nurse practitioner in Australia and New Zealand. In doing so the researchers became aware that while competencies described many of the characteristics of the nurse practitioner they did not manage to tell the whole story. In a search of the literature, the concept of capability appeared to provide a potentially useful construct to describe the attributes of the nurse practitioner that went beyond competence. Design., A secondary analysis of data obtained from interviews with nurse practitioners working in Australia and New Zealand was undertaken. These data had previously been obtained in a study to identify nurse practitioner competencies. The analysis described in this paper investigated whether or not the components of capability would adequately explain the characteristics of the nurse practitioner. Methods., Fifteen nurse practitioners were interviewed from Australia and New Zealand. A secondary (deductive) analysis of interview data using capability as a theoretical framework was conducted. Results., The analysis showed that capability and its dimensions is a useful model for describing the advanced level attributes of nurse practitioners. Thus, nurse practitioners described elements of their practice that involved: using their competences in novel and complex situations as well as the familiar; being creative and innovative; knowing how to learn; having a high level of self-efficacy; and working well in teams. Conclusions., This study suggests that both competence and capability need to be considered in understanding the complex role of the nurse practitioner. Relevance to clinical practice., The dimensions of capability need to be considered in the education and evaluation of nurse practitioners. [source] The Often-Forgotten Nonfuneral Consumer Grief for the GrievingJOURNAL OF CONSUMER AFFAIRS, Issue 3 2008ELIZABETH TAYLOR QUILLIAM Consumer protection advocates and resulting government regulation of the death care industry tend to focus on the most obvious problems, those caused by deceptive sales practices of funeral service providers. However, a spotlight on the funeral's large expenses overshadows the myriad of other consumption activities that heirs must undertake. Survivors must navigate confusing complex situations for which they are unprepared, at a time when grief increases their vulnerability. [source] A General Misspecification Test for Spatial Regression Models: Dependence, Heterogeneity, and NonlinearityJOURNAL OF REGIONAL SCIENCE, Issue 2 2001Thomas De Graaff There is an increasing awareness of the potentials of nonlinear modeling in regional science. This can be explained partly by the recognition of the limitations of conventional equilibrium models in complex situations, and also by the easy availability and accessibility of sophisticated computational techniques. Among the class of nonlinear models, dynamic variants based on, for example, chaos theory stand out as an interesting approach. However, the operational significance of such approaches is still rather limited and a rigorous statistical-econometric treatment of nonlinear dynamic modeling experiments is lacking. Against this background this paper is concerned with a methodological and empirical analysis of a general misspecification test for spatial regression models that is expected to have power against nonlinearity, spatial dependence, and heteroskedasticity. The paper seeks to break new research ground by linking the classical diagnostic tools developed in spatial econometrics to a misspecification test derived directly from chaos theory,the BDS test, developed by Brock, Dechert, and Scheinkman (1987). A spatial variant of the BDS test is introduced and applied in the context of two examples of spatial process models, one of which is concerned with the spatial distribution of regional investments in The Netherlands, the other with spatial crime patterns in Columbus, Ohio. [source] Informal reasoning regarding socioscientific issues: A critical review of researchJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 5 2004Troy D. Sadler Socioscientific issues encompass social dilemmas with conceptual or technological links to science. The process of resolving these issues is best characterized by informal reasoning which describes the generation and evaluation of positions in response to complex situations. This article presents a critical review of research related to informal reasoning regarding socioscientific issues. The findings reviewed address (a) socioscientific argumentation; (b) relationships between nature of science conceptualizations and socioscientific decision making; (c) the evaluation of information pertaining to socioscientific issues, including student ideas about what counts as evidence; and (d) the influence of an individual's conceptual understanding on his or her informal reasoning. This synthesis of the current state of socioscientific issue research provides a comprehensive framework from which future research can be motivated and decisions about the design and implementation of socioscientific curricula can be made. The implications for future research and classroom applications are discussed. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 513,536, 2004 [source] Field primatology of today: current ethical issuesAMERICAN JOURNAL OF PRIMATOLOGY, Issue 9 2010K.C. MacKinnon Abstract As members of professional organizations such as American Society of Primatologists (ASP) and the International Primatological Society (IPS), primatologists must adhere to a set of nonhuman primate-focused principles outlined in resolutions and policy statements on, for example, the ethical treatment of nonhuman primates. Those of us that work in the field must also address issues such as the protection of primate health in the wild and the conservation of wild primate populations. Moreover, we increasingly find ourselves in complex situations where we must balance human and nonhuman primate needs and interests. The selection of commentary pieces in this edition of the American Journal of Primatology originated from presentations given in the symposium, Field Primatology of Today: Navigating the Ethical Landscape, held at the 32nd Annual Meeting of the American Society of Primatologists (ASP) in September 2009. The goals of that symposium and these resulting commentary pieces are threefold: (1) to revive a discussion of key contemporary ethical issues faced by field primatologists, (2) to highlight the need for centrally placed ethical considerations in various facets of our professional lives, particularly research and teaching, and (3) to consider what a comprehensive ethical code that addresses all of these issues might look like. Am. J. Primatol. 72:749,753, 2010. © 2010 Wiley-Liss, Inc. [source] Patient assessment and diagnosis in implant treatmentAUSTRALIAN DENTAL JOURNAL, Issue 2008NU Zitzmann Abstract As in any dental treatment procedure, a thorough patient assessment is a prerequisite for adequate treatment planning including dental implants. The literature was searched for references to patient assessment in implant treatment up to September 2007 in Medline via PubMed and an additional handsearch was performed. Patient assessment included the following aspects: (1) evaluation of patient's history, his/her complaints, desires and preferences; (2) extra-and intra-oral examination with periodontal and restorative status of the remaining dentition; (3) obligatory prerequisites were a panoramic radiograph and periapical radiographs (at least from the adjacent teeth) for diagnosis and treatment planning. Additional tomographs are required depending on the anatomic situation and the complexity of the planned restoration; (4) study casts are needed especially in more complex situations also requiring a diagnostic set-up, which can be tried-in and transferred into a provisional restoration as well as into a radiographic and surgical template. The current review clearly revealed the necessity for a thorough, structured patient assessment. Following an evaluation, a recommendation is given for implant therapy or, if not indicated, conventional treatment alternatives can be presented. [source] The strategic leadership of complex practice: opportunities and challengesCHILD ABUSE REVIEW, Issue 5 2010Tony Morrison Abstract This paper addresses the issue of how strategic-level partnerships, such as Local Safeguarding Children Boards, know about and learn from practice. The death of Baby Peter in Haringey exposed the dangers of reliance on numerical performance data alone to inform leaders about the true state of practice. The drivers for, and impact of, regulatory, media and political pressures on front-line practice and partnership behaviour are discussed with reference to the rise of organisational risk management and ,rule-based' responses (Munro, 2009). These are exacerbated by an overload of negative data about child protection systems which results in contagious ,attention cascades' which lead to over-simplification of complex issues and the rush to quick-fix solutions. This results in compliance-based responses designed to avoid ,blame', based on individualistic analyses of complex situations. Under these conditions, ,learning', such as from serious case reviews, can become regressive (how to avoid future culpability) rather than progressive (how to improve knowledge skills and practice). It is argued that understanding and improving practice require strategic partnerships to have engaged with front-line staff in order to access practice narratives as well as performance numbers, and to achieve an accurate and systemic analysis of the state of practice and how it can be improved. This calls for collective forms of knowing and reflecting and the paper concludes by describing examples. Copyright © 2010 John Wiley & Sons, Ltd. [source] An independent person in action under the Children Act 1989 complaints procedureCHILDREN & SOCIETY, Issue 4 2001Gillian Bridge Under Section 26 (4) of the Children Act 1989, local authorities are obliged to appoint independent people to participate in investigations at stage two of the complaints procedure. The nature of their role and tasks were ill defined by the Department of Health Guidance (1991), and hitherto there has been little research in this area. Using the author's experiences, this discussion paper examines some of the dilemmas of undertaking this role, and raises questions about how independent people are meeting legal requirements. From the material discussed here, it appears that the system of including independent people in complaints' investigations is not meeting the intended objectives of ensuring that complaints by young people themselves benefit from impartial scrutiny. Instead, independent people are mainly engaged with investigating officers in unravelling complex situations, many with long histories of serious breakdowns in communication between parents, carers and local authority children's services. In the light of these findings, the Department of Health's recent consultation paper, Listening to People is welcome, although rather disappointing in restricting its attention largely to procedural issues. In this paper the author promotes greater attention to the growing expertise of independent people currently investigating complaints. Additionally it is recommended that a more accessible means for young people to complain should be devised. Copyright © 2001 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||