Variety Of Approaches (variety + of_approach)

Distribution by Scientific Domains

Selected Abstracts

Consistent Tests for Stochastic Dominance

ECONOMETRICA, Issue 1 2003
Garry F. Barrett
Methods are proposed for testing stochastic dominance of any pre,specified order, with primary interest in the distributions of income. We consider consistent tests, that are similar to Kolmogorov,Smirnov tests, of the complete set of restrictions that relate to the various forms of stochastic dominance. For such tests, in the case of tests for stochastic dominance beyond first order, we propose and justify a variety of approaches to inference based on simulation and the bootstrap. We compare these approaches to one another and to alternative approaches based on multiple comparisons in the context of a Monte Carlo experiment and an empirical example. [source]

A cautionary note on the use of species presence and absence data in deriving sediment criteria

Katherine Von Stackelberg
Abstract In recent years, a variety of approaches to deriving sediment quality guidelines have been developed. One approach relies on establishing an empirical relationship between the concentration of a contaminant in sediment and the condition of some biological indicator, for example, combining measured sediment concentrations of contaminants combined with data on colocated benthic species to measure in situ community effects of contamination. Biological threshold concentrations derived in this manner are being considered or have already been adopted by some regulatory agencies as a means for deriving sediment guidelines (e.g., Canada's Provincial Sediment Quality Guidelines). In order to test the validity of this method, we constructed several Monte Carlo simulations to illustrate that the methodology used to develop these guidelines is flawed by the effects of sampling and statistical artifacts that emerge from undersampling a lognormal density function. As a case study, this paper will present the screening level concentration method used by the Ontario Ministry of the Environment (Toronto, ON, Canada) and provide the results of several probabilistic exercises highlighting these issues. We present a word of caution on the applicability of methods that rely exclusively on statistical and mathematical relationships between invertebrate data and sediment concentrations to derive sediment quality guidelines. [source]

The inpatient management of physical activity in young people with anorexia nervosa

Sarah Davies
Abstract This study investigates the management of physical activity in young inpatients with anorexia nervosa. Through telephone interviews and postal surveys inpatient units across the UK were asked about written documents regarding physical activity management, how they viewed healthy exercise, how they assessed physical fitness to engage in activity, the management approaches taken, provision of education and support around this issue and range of activities provided. Results indicated that a variety of approaches were taken, with little consensus between units, although the majority of approaches did involve some form of restriction, frequently determined by weight criteria. There were few substantial written documents to guide practice and a range of interpretations of healthy exercise. The findings are discussed and suggestions made for research to explore this area further and to inform the development of effective interventions. Copyright © 2007 John Wiley & Sons, Ltd and Eating Disorders Association. [source]

Ethics Seminars: Teaching Professionalism to "Problem" Residents

Catherine A. Marco MD
Abstract Professional skills, which include communication, compassion, honesty, integrity, altruism, service, commitment, suspension of self-interest, commitment to excellence, authority, and accountability, are essential skills that should be taught during residency. A variety of approaches can be used, which include didactic teaching, bedside teaching, leadership, evaluation, and individualized mentorship. Deficiencies in professional skills should be identified early in the residency program, and should be addressed on an individual level. [source]

Candidate gene studies in the 21st century: meta-analysis, mediation, moderation

M. R. MunafÚ
The results of a large body of candidate gene studies of behavioural and psychiatric phenotypes have been largely inconclusive, with most findings failing to replicate reliably. A variety of approaches that augment the ,traditional' candidate gene approach are discussed, including the use of meta-analysis to combine findings from existing published reports, the investigation of mediating variables (including the use of intermediate phenotypes or endophenotypes) and the awareness of possible moderating influences (such as sex or ethnicity) and gene,environment interactions on genetic associations, possibly via epigenetic mechanisms. Advances in genotyping technology will also allow the routine use of haplotype analysis and linkage disequilibrium mapping. Examples of how these approaches may improve our understanding of how genetic associations with behavioural and psychiatric phenotypes obtain are given. [source]


ABSTRACT. The origin of two ridges on the eastern slopes of Mt Allen, southern Stewart Island, has remained equivocal, with differences of opinion over the exact process-mechanisms of formation. A variety of approaches was used to test a number of possible hypotheses about the origin of the ridges. These include topographic and spatial positioning, geomorphology, sedimentology and palaeoclimatological extrapolations to reconstruct two small former cirque glaciers with equilibrium line altitudes (ELAs) of c. 600 m. It would appear the two ridges reflect a glacial origin, the glaciers interpreted as forming during the Last Glacial Maximum (LGM) in New Zealand. Whilst glaciation during this time (18,19 ka) was extensive in the Southern Alps, the restricted nature of glaciation on Mt Allen suggests the low altitude restricted glaciation to niche sites on the lee side of upland areas. [source]

Understanding the mechanisms and limitations of immune control of HIV

Miles P. Davenport
Summary:, A large number of experimental studies have been performed over the past decade in an attempt to develop a vaccine for human immunodeficiency virus (HIV). These studies have used a variety of approaches aimed at stimulating both antibody-mediated and cell-mediated immunity. Many of these experiments have been performed in macaque models of HIV. Analysis and modeling of the results of these studies provide the opportunity to investigate the mechanisms and limitations of viral control by humoral and cell-mediated immunity. These studies suggest that CD8+ T cells do ,too little too late' to prevent the establishment of viral infection and latency. By contrast, passively administered antibody acts extremely early to reduce the initial inoculum and slow viral growth. In both cases, reduction in peak viral load appears crucial to the maintenance of CD4+ T cells in acute infection and for effective long-term viral control. The insights gained from studies of simian human immunodeficiency virus infection have important implications for HIV vaccination. However, important questions remain as to whether differences in pathogenesis in HIV will lead to different ,rules of engagement' for immune control of virus. [source]

A survey of current architectures for connecting wireless mobile ad hoc networks to the Internet

Habib M. Ammari
Abstract Connecting wired and wireless networks, and particularly mobile wireless ad hoc networks (MANETs) and the global Internet, is attractive in real-world scenarios due to its usefulness and praticality. Because of the various architectural mismatches between the Internet and MANETs with regard to their communication topology, routing protocols, and operation, it is necessary to introduce a hybrid interface capable of connecting to the Internet using Mobile IP protocol and to MANETs owing to an ad hoc routing protocol. Specifically, the approaches available in the literature have introduced updated versions of Mobile IP agents or access points at the edge of the Internet to help MANET nodes get multi-hop wireless Internet access. The main differences in the existing approaches concern the type of ad hoc routing protocol as well as the switching algorithm used by MANET nodes to change their current Mobile IP agents based on specific switching criteria. This paper surveys a variety of approaches to providing multi-hop wireless Internet access to MANET nodes. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Effects of government programs to raise milk prices: Academic economists and public policy

Daniel A. Sumner
The Northeast Dairy Compact benefited milk suppliers (and allied input suppliers) and harmed those on the fluid milk demand side in the Compact region, while having opposite impacts on these groups outside the Compact region. These simulation results leave many questions unanswered, but seem relatively robust. Simulations require many assumptions, but so do all other approaches to policy analysis. The specific policy question addressed and available data determine the most promising approach. In some cases, as with the evaluating effects of the Compact, a variety of approaches to policy analysis are complementary. [EconLit citations: Q18, Q13, L10, L43]. © 2005 Wiley Periodicals, Inc. Agribusiness 21: 473,476, 2005. [source]

Predictive and correlative techniques for the design, optimisation and manufacture of solid dosage forms

Ian J. Hardy
ABSTRACT There is much interest in predicting the properties of pharmaceutical dosage forms from the properties of the raw materials they contain. Achieving this with reasonable accuracy would aid the faster development and manufacture of dosage forms. A variety of approaches to prediction or correlation of properties are reviewed. These approaches have variable accuracy, with no single technique yet able to provide an accurate prediction of the overall properties of the dosage form. However, there have been some successes in predicting trends within a formulation series based on the physicochemical and mechanical properties of raw materials, predicting process scale-up through mechanical characterisation of materials and predicting product characteristics by process monitoring. Advances in information technology have increased predictive capability and accuracy by facilitating the analysis of complex multivariate data, mapping formulation characteristics and capturing past knowledge and experience. [source]

Health Educators' Role in Promoting Health Literacy and Advocacy for the 21st Century

Marlene K. Tappe PhD
ABSTRACT: This article discusses the relationship between health literacy and advocacy for health and health education, cites achievement of advocacy as a critical outcome of health education, and identifies health advocacy competencies for both students and health educators. The paper also delineates a role for health education in developing health-literate citizens and in training health educators to advocate for health and health education. The article draws on recent initiatives in comprehensive school health education and coordinated school health programs to identify content and strategies for developing health advocacy skills among elementary, middle, and senior high school students. The article provides a variety of approaches and strategies for developing advocacy skills among preservice and inservice health educators. [source]

Analysis of longitudinal data with drop-out: objectives, assumptions and a proposal

Peter Diggle
Summary. The problem of analysing longitudinal data that are complicated by possibly informative drop-out has received considerable attention in the statistical literature. Most researchers have concentrated on either methodology or application, but we begin this paper by arguing that more attention could be given to study objectives and to the relevant targets for inference. Next we summarize a variety of approaches that have been suggested for dealing with drop-out. A long-standing concern in this subject area is that all methods require untestable assumptions. We discuss circumstances in which we are willing to make such assumptions and we propose a new and computationally efficient modelling and analysis procedure for these situations. We assume a dynamic linear model for the expected increments of a constructed variable, under which subject-specific random effects follow a martingale process in the absence of drop-out. Informal diagnostic procedures to assess the tenability of the assumption are proposed. The paper is completed by simulations and a comparison of our method and several alternatives in the analysis of data from a trial into the treatment of schizophrenia, in which approximately 50% of recruited subjects dropped out before the final scheduled measurement time. [source]

Discovering new invertebrate neuropeptides using mass spectrometry

Amanda B. Hummon
Abstract Neuropeptides are a complex set of messenger molecules controlling a wide array of regulatory functions and behaviors within an organism. These neuromodulators are cleaved from longer protein molecules and often experience numerous post-translational modifications to achieve their bioactive form. As a result of this complexity, sensitive and versatile analysis schemes are needed to characterize neuropeptides. Mass spectrometry (MS) through a variety of approaches has fueled the discovery of hundreds of neuropeptides in invertebrate species in the last decade. Particularly successful are direct tissue and single neuron analyses by matrix-assisted laser desorption/ionization (MALDI) MS, which has been used to elucidate approximately 440 neuropeptides, and examination of neuronal homogenates by electrospray ionization techniques (ESI), also leading to the characterization of over 450 peptides. Additional MS methods with great promise for the discovery of neuropeptides are MS imaging and large-scale peptidomics studies in combination with a sequenced genome. © 2005 Wiley Periodicals, Inc. [source]

Reshaping their views: Science as liberal arts

Judith Bramble
General-education science courses should provide students with a foundation of knowledge about how the natural world works, a clear understanding of the nature of science and scientific inquiry, and an appreciation for the relationship between science and society. This chapter suggests a variety of approaches to engage students in their own learning and, with appropriate reflection, help them construct more scientific worldviews. [source]

Current concepts in periodontal bioengineering

M Taba Jr
Abstract Authors ,, Taba Jr M, Jin Q, Sugai JV, Giannobile WV Repair of tooth supporting alveolar bone defects caused by periodontal and peri-implant tissue destruction is a major goal of reconstructive therapy. Oral and craniofacial tissue engineering has been achieved with limited success by the utilization of a variety of approaches such as cell-occlusive barrier membranes, bone substitutes and autogenous block grafting techniques. Signaling molecules such as growth factors have been used to restore lost tooth support because of damage by periodontal disease or trauma. This paper will review emerging periodontal therapies in the areas of materials science, growth factor biology and cell/gene therapy. Several different polymer delivery systems that aid in the targeting of proteins, genes and cells to periodontal and peri-implant defects will be highlighted. Results from preclinical and clinical trials will be reviewed using the topical application of bone morphogenetic proteins (BMP-2 and BMP-7) and platelet-derived growth factor-BB (PDGF) for periodontal and peri-implant regeneration. The paper concludes with recent research on the use of ex vivo and in vivo gene delivery strategies via gene therapy vectors encoding growth promoting and inhibiting molecules (PDGF, BMP, noggin and others) to regenerate periodontal structures including bone, periodontal ligament and cementum. [source]

Biochemical and functional analysis of CTR1, a protein kinase that negatively regulates ethylene signaling in Arabidopsis

Yafan Huang
Summary CTR1 encodes a negative regulator of the ethylene response pathway in Arabidopsis thaliana. The C-terminal domain of CTR1 is similar to the Raf family of protein kinases, but its first two-thirds encodes a novel protein domain. We used a variety of approaches to investigate the function of these two CTR1 domains. Recombinant CTR1 protein was purified from a baculoviral expression system, and shown to possess intrinsic Ser/Thr protein kinase activity with enzymatic properties similar to Raf-1. Deletion of the N-terminal domain did not elevate the kinase activity of CTR1, indicating that, at least in vitro, this domain does not autoinhibit kinase function. Molecular analysis of loss-of-function ctr1 alleles indicated that several mutations disrupt the kinase catalytic domain, and in vitro studies confirmed that at least one of these eliminates kinase activity, which indicates that kinase activity is required for CTR1 function. One missense mutation, ctr1,8, was found to result from an amino acid substitution within a new conserved motif within the N-terminal domain. Ctr1,8 has no detectable effect on the kinase activity of CTR1 in vitro, but rather disrupts the interaction with the ethylene receptor ETR1. This mutation also disrupts the dominant negative effect that results from overexpression of the CTR1 amino-terminal domain in transgenic Arabidopsis. These results suggest that CTR1 interacts with ETR1 in vivo, and that this association is required to turn off the ethylene-signaling pathway. [source]

Recent Progress in Artificial Organ Research at Tohoku University

Tomoyuki Yambe
Abstract: Tohoku University has developed various artificial organs over the last 30 years. Pneumatic driven ventricular assist devices with a silicone ball valve have been designed by the flow visualization method, and clinical trials have been performed in Tohoku University Hospital. On the basis of these developments, a pneumatic driven total artificial heart has been developed and an animal experimental evaluation was conducted. The development of artificial organs in Tohoku University has now progressed to the totally implantable type using the transcutaneous energy transmission system with amorphous fibers for magnetic shielding. Examples of implantable systems include a vibrating flow pump for ventricular assist device, an artificial myocardium by the use of shape memory alloy with Peltier elements, and an artificial sphincter for patients with a stoma. An automatic control system for artificial organs had been developed for the ventricular assist devices including a rotary blood pump to avoid suction and to maintain left and right heart balance. Based upon the technology of automatic control algorithm, a new diagnostic tool for evaluating autonomic nerve function has been developed as a branch of artificial organ research and this new machine has been tested in Tohoku University Hospital. Tohoku University is following a variety of approaches aimed at innovation in artificial organs and medical engineering fields. [source]

The missing link: self-assessment and continuing professional development

C Redwood
Abstract The purpose of this paper is to review current understanding of the role of self-assessment in continuing education, particularly in the health professions, and to examine how this knowledge can assist in more effective continuing education. The ongoing debate over compulsory continuing professional development (CPD) has seen a variety of approaches proposed. CPD programmes are expected to foster self-assessing and self-directed practitioners, but the common structure is reported to be largely ineffectual in modifying behaviour. If dentistry is to maintain the rights and privileges of a self-regulating profession, then it must ensure that the development and judgement of ongoing competence is meaningful. Improving practitioners' knowledge of the how and why of effective self-assessment should improve participation in, and outcomes of, CPD. An oft-repeated observation is that the least competent are the most confident. If this is the case, then the idea that dentists should be able, or entitled, to choose the path of their continuing professional development must be open to question. We propose that development of the ability of practitioners to self-assess their ongoing requirements for CPD is essential if all stakeholders are to get the maximum return for effort. [source]

From 3D to 2D: A Review of the Molecular Imprinting of Proteins

Nicholas W. Turner
Molecular imprinting is a generic technology that allows for the introduction of sites of specific molecular affinity into otherwise homogeneous polymeric matrices. Commonly this technique has been shown to be effective when targeting small molecules of molecular weight <1500, while extending the technique to larger molecules such as proteins has proven difficult. A number of key inherent problems in protein imprinting have been identified, including permanent entrapment, poor mass transfer, denaturation, and heterogeneity in binding pocket affinity, which have been addressed using a variety of approaches. This review focuses on protein imprinting in its various forms, ranging from conventional bulk techniques to novel thin film and monolayer surface imprinting approaches. [source]

A Fluorous, Pummerer Cyclative-Capture Strategy for the Synthesis of N-Heterocycles

Abstract A fluorous, cyclative-capture strategy based on a new Pummerer cyclization process allows rapid access to tagged, heterocyclic frameworks. Convenient modification of the fluorous, heterocyclic scaffolds by using a variety of approaches including Pd-catalyzed cross-couplings is possible. Traceless, reductive cleavage of the fluorous-phase tag or oxidative cleavage and further elaboration, completes a strategy for the high-throughput, fluorous-phase synthesis of a diverse range of N-heterocycles. [source]

Effects of an alternate dissection schedule on gross anatomy laboratory practical performance

David L. McWhorter
Abstract The current medical curricula reform that is taking place in many medical schools throughout the world has resulted in less time for gross anatomy laboratory instruction. In response, anatomists are using a variety of approaches (e.g., peer teaching, prosections, plastinated anatomical models, etc.) to adapt to these changes. To accommodate recent curricular reform at the University of Health Sciences College of Osteopathic Medicine, an alternating dissection schedule was implemented. The purpose of this study is to examine the effects of the alternating schedule on gross anatomy laboratory practical performance. Using a Mann-Whitney Rank Sum test, back and upper limb (back-upper limb), and lower extremity laboratory practical performance for students who dissected in every laboratory (EL group; n = 227) is compared to students who dissected in every other laboratory (EOL group; n = 254). For the back-upper limb part of the anatomy laboratory practical, the mean percentage scores for the EL and EOL groups were 74.5% and 68.1%, respectively (P < 0.001). The mean percentage scores for the EL and EOL groups on the lower limb portion of the anatomy lab practical were 75.9% and 75.6%, respectively (P = 0.994). These data suggest that the use of an alternating dissection schedule had an equivocal effect on the students' gross anatomy laboratory practical performance for these two sections. The reasons for these conflicting results may have been related to regional complexity or volume of information, and the sequence in which the regions were taught. Clin. Anat. 17:144,148, 2004. © 2004 Wiley-Liss, Inc. [source]