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Systematic Evaluation (systematic + evaluation)
Selected AbstractsSystematic Evaluation of Pancreas Allograft Quality, Outcomes and Geographic Variation in UtilizationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2010D. A. Axelrod Pancreas allograft acceptance is markedly more selective than other solid organs. The number of pancreata recovered is insufficient to meet the demand for pancreas transplants (PTx), particularly for patients awaiting simultaneous kidney-pancreas (SPK) transplant. Development of a pancreas donor risk index (PDRI) to identify factors associated with an increased risk of allograft failure in the context of SPK, pancreas after kidney (PAK) or pancreas transplant alone (PTA), and to assess variation in allograft utilization by geography and center volume was undertaken. Retrospective analysis of all PTx performed from 2000 to 2006 (n = 9401) was performed using Cox regression controlling for donor and recipient characteristics. Ten donor variables and one transplant factor (ischemia time) were subsequently combined into the PDRI. Increased PDRI was associated with a significant, graded reduction in 1-year pancreas graft survival. Recipients of PTAs or PAKs whose organs came from donors with an elevated PDRI (1.57,2.11) experienced a lower rate of 1-year graft survival (77%) compared with SPK transplant recipients (88%). Pancreas allograft acceptance varied significantly by region particularly for PAK/PTA transplants (p < 0.0001). This analysis demonstrates the potential value of the PDRI to inform organ acceptance and potentially improve the utilization of higher risk organs in appropriate clinical settings. [source] Systematic Evaluation of Substituted Cyclopentadienyl Ruthenium Complexes, [(,5 -C5MenH5,n)RuCl(cod)], for Catalytic Cycloadditions of DiynesCHEMISTRY - AN ASIAN JOURNAL, Issue 4 2010Yoshihiko Yamamoto Prof. Abstract A series of ,5 -cyclopentadienylruthenium complexes, [(,5 -C5MenH5,n)RuCl(cod)] (cod=1,5-cyclooctadiene), are evaluated as catalysts for the cycloaddition of 1,6-diynes with alkynes. As a result, we unexpectedly found that the complex bearing the 1,2,4-Me3Cp ligand is the most efficient catalyst in terms of turnover number (TON) for the cycloaddition of a bulky diiododiyne with acetylene, recording the highest TON of 970 with a catalyst loading of 0.1,mol,%. To obtain insight into this result, we evaluate the electron richness of all complexes by cyclic voltammetric analyses, which indicate that the electron density of the ruthenium center increases with an increase in methyl substitution on the Cp, ligands. The initial rate (up to 10,% conversion) of the cycloaddition was then measured using 1H,NMR spectroscopy. The initial rate is found to decrease as the number of methyl substituents increases. According to these results, we assumed that the optimum catalytic performance exhibited by the 1,2,4-trimethylcyclopentadienyl complex can be attributed to its robustness under the catalytic cycloaddition conditions. The steric and electronic effects of the Cp, ligands are also investigated in terms of the regioselectivity of the cycloaddition of an unsymmetrical diyne and in terms of the chemoselectivity in the cycloaddition of a 1,6-heptadiyne with norbornene. [source] Systematic evaluation of the effect of common SNPs on pre-mRNA splicing,HUMAN MUTATION, Issue 4 2009Abdou ElSharawy Abstract The evolutionary and biomedical importance of differential mRNA splicing is well established. Numerous studies have assessed patterns of differential splicing in different genes and correlated these patterns to the genotypes for adjacent single-nucleotide polymorphisms (SNPs). Here, we have chosen a reverse approach and screened dbSNP for common SNPs at either canonical splice sites or exonic splice enhancers (ESEs) that would be classified as putatively splicing-relevant by bioinformatic tools. The 223 candidate SNPs retrieved from dbSNP were experimentally tested using a previously established panel of 92 matching DNAs and cDNAs. For each SNP, 16 cDNAs providing a balanced representation of the genotypes at the respective SNP were investigated by nested RT-PCR and subsequent sequencing. Putative allele-dependent splicing was verified by the cloning of PCR products. The positive predictive value of the bioinformatics tools turned out to be low, ranging from 0% for ESEfinder to 9% (in the case of acceptor-site SNPs) for a recently reported neural network. The results highlight the need for a better understanding of the sequence characteristics of functional splice-sites to improve our ability to predict in silico the splicing relevance of empirically observed DNA sequence variants. Hum Mutat 0, 1,9, 2009. © 2009 Wiley-Liss, Inc. [source] Systematic evaluation of the highest current threshold for regional anaesthesia in a porcine modelACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2010T. STEINFELDT Background: The purpose of this study was to determine systematically the highest minimal stimulation current threshold for regional anaesthesia in pigs. Methods: In an established pig model for regional anaesthesia, needle placements applying electric nerve stimulation were performed. The primary outcome was the frequency of close needle to nerve placements as assessed by resin injectates and subsequent anatomical evaluation. Following a statistical model (continual reassessment method), the applied output currents were selected to limit the necessary number of punctures, while providing guidance towards the highest output current range. Results: Altogether 186 punctures were performed in 11 pigs. Within the range of 0.3,1.4 mA, no distant needle to nerve placement was found. In the range of 1.5,4.1 mA, 43 distant needle to nerve placements occurred. The range of 1.2,1.4 mA was the highest interval that resulted in a close needle to nerve placement rate of ,95%. Conclusions: In the range of 0.3,1.4 mA, all resin deposition was found to be adjacent to nerve epineurium. The application of minimal current intensities up to 1.4 mA does not obviously lead to a reduction of epineural injectate contacts in pigs. These findings suggest that stimulation current thresholds up to 1.4 mA result in equivalent needle tip localisation in pigs. [source] Systematic evaluation of rating scales for impairment and disability in Parkinson's diseaseMOVEMENT DISORDERS, Issue 5 2002Claudia Ramaker MD Abstract We assessed the clinometric characteristics of rating scales used for the evaluation of motor impairment and disability of patients with Parkinson's disease (PD), conducting a systematic review of PD rating scales published from 1960 to the present. Thirty studies describing clinometrics of 11 rating scales used for PD were identified. Outcome measures included validity (including factor structure), reliability (internal consistency, inter-rater, and intrarater) and responsiveness. We traced three impairment scales (Webster, Columbia University Rating Scale [CURS] and Parkinson's Disease Impairment Scale), four disability scales (Schwab and England, Northwestern University Disability Scale [NUDS], Intermediate Scale for Assessment of PD, and Extensive Disability Scale), and four scales evaluating both impairment and disability (New York University, University of California Los Angeles, Unified Parkinson's Disease Rating Scale [UPDRS], and Short Parkinson Evaluation Scale). The scales showed large differences in the extent of representation of items related to signs considered responsive to dopaminergic treatment or to those signs that appear late in the disease course and lack responsiveness to treatment. Regardless of the scale, there was a conspicuous lack of consistency concerning inter-rater reliability of bradykinesia, tremor, and rigidity. Overall disability items displayed moderate to good inter-rater reliability. The available evidence shows that CURS, NUDS, and UPDRS have moderate to good reliability and validity. In contrast to their widespread clinical use for assessment of impairment and disability in PD, the majority of the rating scales have either not been subjected to an extensive clinometric evaluation or have demonstrated clinometric shortcomings. The CURS, NUDS, and UPDRS are the most evaluated, valid, and reliable scales currently available. © 2002 Movement Disorder Society [source] Annotation: The use of psychotropic medications in children: a British viewTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 2 2003David Bramble Background: Prescribing practices relating to the use of psychotropic medication with mentally disordered children have changed significantly in Britain over recent years. Methods: I conducted a review of the modest body of empirical data available relating to the prescribing practices of child psychiatrists, paediatricians and general practitioners (primary care physicians). The data were obtained primarily from postal questionnaire studies but also from British drug studies and a government-sponsored evaluation of the efficacy of stimulant medication. Postgraduate training guidelines for the three principal clinical disciplines are also discussed. Results: Systematic evaluation of prescribing practices has a relatively short history. All the studies reviewed demonstrated consistent methodological weaknesses, the most important of which was reliance upon retrospective reports of prescribing practices from clinicians with no analysis of actual prescription data. No studies relating to the general use of psychotropic medication by paediatricians were found. Child psychiatrists and general practitioners appear to be using a range of drugs for a range of conditions; however, there was evidence of intra- and interdisciplinary variations in practice. It was also evident from the general practitioner data that drug treatments were frequently used for conditions best managed with behavioural methods (e.g., common sleep problems and enuresis). Government prescription data relating to methylphenidate use in ADHD reveal a dramatic rise over the past ten years. Currently, most child psychiatrists use this treatment compared to approximately half the profession only seven years ago. The use of newer antipsychotic agents as well as the SSRI antidepressants appears to be growing in child psychiatric practice. A majority of clinicians surveyed believed that medication was an important treatment modality but also felt that they were relatively unskilled in the field and requested further training. Conclusions: Overall, a picture of both a growing and better informed use of psychotropic medication is emerging in Britain despite shortcomings in postgraduate training. Future research needs to evaluate prescribing practice in a more objective manner in order to improve training and also service developments in the field. [source] Animated instructional software for mechanics of materials: Implementation and assessmentCOMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 1 2006Timothy A. Philpot Abstract During the past 3 years, the Basic Engineering Department at the University of Missouri, Rolla has been developing a second-generation suite of instructional software called MecMovies for the Mechanics of Materials course. The MecMovies suite consists of over 110 animated example problems, drill-and-practice games, and interactive exercises. Students generally respond favorably to software of this type; however, much of the data that has been gathered to assess the effectiveness of similar software has been anecdotal. The method by which instructional software is incorporated into the engineering class is partly responsible for this lack of systematic evaluation. Often, software packages have been implemented in the classroom as supplemental material,recommended but not required. In the Fall 2003 semester, MecMovies was integrated thoroughly into the course assignments for one of the six UMR Mechanics of Materials sections. Four professors were involved in the study, and student performance in the experimental MecMovies section was compared to performance in the five control sections through a common final exam. At the end of the semester, students who used the MecMovies software also completed a survey questionnaire consisting of a number of subjective rating items. This paper presents a comparison of student performance in the experimental and control sections along with discussion of student qualitative ratings and comments. © 2006 Wiley Periodicals, Inc. Comput Appl Eng Educ 14: 31,43, 2006; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20065 [source] Robust Transportation Network Design Under Demand UncertaintyCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 1 2007Satish V. Ukkusuri The origin,destination trip matrices are taken as random variables with known probability distributions. Instead of finding optimal network design solutions for a given future scenario, we are concerned with solutions that are in some sense "good" for a variety of demand realizations. We introduce a definition of robustness accounting for the planner's required degree of robustness. We propose a formulation of the robust network design problem (RNDP) and develop a methodology based on genetic algorithm (GA) to solve the RNDP. The proposed model generates globally near-optimal network design solutions, f, based on the planner's input for robustness. The study makes two important contributions to the network design literature. First, robust network design solutions are significantly different from the deterministic NDPs and not accounting for them could potentially underestimate the network-wide impacts. Second, systematic evaluation of the performance of the model and solution algorithm is conducted on different test networks and budget levels to explore the efficacy of this approach. The results highlight the importance of accounting for robustness in transportation planning and the proposed approach is capable of producing high-quality solutions. [source] A patch test study of 27 crude drugs commonly used in Chinese topical medicamentsCONTACT DERMATITIS, Issue 1 2003Hsuan-Hsiang Chen Chinese topical medicaments (CTMs) are commonly used in Taiwan and in Southeast Asia. However, a systematic evaluation of contact sensitization potential from CTM has not been carried out to our knowledge. This study was undertaken to investigate the incidence of contact sensitivity to the components of CTM in patients with contact dermatitis from CTM. A screening series of 27 crude drugs most commonly used in CTM as well as a modified European standard series was patch tested in 30 patients. The herbs with the most frequent positive reactions were Flos Caryophylli ( ), Radix Angelicae Pubescentis ( ), Cortex Cinnamomi ( ), Cortex Radix Acanthopanacis ( ), Caulis Impatientis ( ), Resina Draconis/Sanguis Draconis ( ), Fructus Cnidii ( ), Radix Gentiana Macrophyllae ( ), and Rhizoma Ligustici Chuanxiong ( ). Concomitant allergy to colophonium was found in most of these positive reactions. Reducing the concentration and simplifying the compositions of these components, as well as replacement with those of low allergenicity in CTM, such as Rhizoma Arisaematis ( ), Herba Lycopodii ( ), Radix Cyathulae Officinalis ( ), Rhizoma Pinelliae ( ), Radix Angelicae Dahuricae ( ), Herba Dendrobii ( ), Secretio Moschus ( ), and Stigmata Croci ( ), may be advocated. A precise labelling of the dosage of each component and the exact chemical compounds in CTM products could further improve the safety and therapeutic effects of CTM in the future. [source] Polyamines and hair: a couple in search of perfectionEXPERIMENTAL DERMATOLOGY, Issue 9 2010Yuval Ramot Please cite this paper as: Polyamines and hair: a couple in search of perfection. Experimental Dermatology 2010; 19: 784,790. Abstract:, Polyamines (spermidine, putrescine and spermine) are multifunctional cationic amines that are indispensable for cellular proliferation; of key significance in the growth of rapidly regenerating tissues and tumors. Given that the hair follicle (HF) is one of the most highly proliferative organs in mammalian biology, it is not surprising that polyamines are crucial to HF growth. Indeed, growing (anagen) HFs show the highest activity of ornithine decarboxylase (ODC), the rate-limiting enzyme of polyamine biosynthesis, while inhibition of ODC, using eflornithine, results in a decreased rate of excessive facial hair growth in vivo and inhibits human scalp hair growth in organ culture. In sheep, manipulation of dietary intake of polyamines also results in altered wool growth. Polyamine-containing nutraceuticals have therefore been proposed as promoters of human hair growth. Recent progress in polyamine research, coupled with renewed interest in the role of polyamines in skin biology, encourages one to revisit their potential roles in HF biology and highlights the need for a systematic evaluation of their mechanisms of action and clinical applications in the treatment of hair disorders. The present viewpoint essay outlines the key frontiers in polyamine-related hair research and defines the major open questions. Moreover, it argues that a renaissance in polyamine research in hair biology, well beyond the inhibition of ODC activity in hirsutism therapy, is important for the development of novel therapeutic strategies for the manipulation of human hair growth. Such targets could include the manipulation of polyamine biosynthesis and the topical administration of selected polyamines, such as spermidine. [source] Seawater Mg/Ca controls polymorph mineralogy of microbial CaCO3: A potential proxy for calcite-aragonite seas in Precambrian timeGEOBIOLOGY, Issue 2 2008J. B. RIES ABSTRACT A previously published hydrothermal brine-river water mixing model driven by ocean crust production suggests that the molar Mg/Ca ratio of seawater (mMg/Casw) has varied significantly (~1.0,5.2) over Precambrian time, resulting in six intervals of aragonite-favouring seas (mMg/Casw > 2) and five intervals of calcite-favouring seas (mMg/Casw < 2) since the Late Archaean. To evaluate the viability of microbial carbonates as mineralogical proxy for Precambrian calcite-aragonite seas, calcifying microbial marine biofilms were cultured in experimental seawaters formulated over the range of Mg/Ca ratios believed to have characterized Precambrian seawater. Biofilms cultured in experimental aragonite seawater (mMg/Casw = 5.2) precipitated primarily aragonite with lesser amounts of high-Mg calcite (mMg/Cacalcite = 0.16), while biofilms cultured in experimental calcite seawater (mMg/Casw = 1.5) precipitated exclusively lower magnesian calcite (mMg/Cacalcite = 0.06). Furthermore, Mg/Cacalcite varied proportionally with Mg/Casw. This nearly abiotic mineralogical response of the biofilm CaCO3 to altered Mg/Casw is consistent with the assertion that biofilm calcification proceeds more through the elevation of , via metabolic removal of CO2 and/or H+, than through the elevation of Ca2+, which would alter the Mg/Ca ratio of the biofilm's calcifying fluid causing its pattern of CaCO3 polymorph precipitation (aragonite vs. calcite; Mg-incorporation in calcite) to deviate from that of abiotic calcification. If previous assertions are correct that the physicochemical properties of Precambrian seawater were such that Mg/Casw was the primary variable influencing CaCO3 polymorph mineralogy, then the observed response of the biofilms' CaCO3 polymorph mineralogy to variations in Mg/Casw, combined with the ubiquity of such microbial carbonates in Precambrian strata, suggests that the original polymorph mineralogy and Mg/Cacalcite of well-preserved microbial carbonates may be an archive of calcite-aragonite seas throughout Precambrian time. These results invite a systematic evaluation of microbial carbonate primary mineralogy to empirically constrain Precambrian seawater Mg/Ca. [source] Sources of information on adverse effects: a systematic reviewHEALTH INFORMATION & LIBRARIES JOURNAL, Issue 3 2010Su Golder Background:, Systematic reviews can provide accurate and timely information on adverse effects. An essential part of the systematic review process is a thorough search of the literature. This often requires searching many different sources. However, it is unclear which sources are most effective at providing information on adverse effects. Objective:, To identify and summarise studies that have evaluated sources of information on adverse effects. Methods:, Studies were located by searching in 10 databases as well as by reference checking, hand searching, citation searching and contacting experts. Results:, A total of 6218 citations were retrieved yielding 19 studies which met the inclusion criteria. The included studies tended to focus on the adverse effects of drug interventions and compare the relative value of different sources using the number of relevant references retrieved from searches of each source. However, few studies were conducted recently with a large sample of references. Conclusions:, This review suggests that embase, Derwent Drug File, medline and industry submissions may potentially provide the greatest number of relevant references for information on adverse effects of drugs. However, a systematic evaluation of the current value of different sources of information for adverse effects is urgently required. [source] Age of closure of the foramen of Huschke: an osteological studyINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 1 2006L. T. Humphrey Abstract The foramen of Huschke is a dehiscence in the antero-inferior surface of the tympanic plate, which forms during the normal post-natal development of the temporal bone. Closure of the foramen is generally reported to take place by 5 years of age, although a persistent foramen has been observed in 0,67% of adult crania depending on the population. A persistent foramen of Huschke in adult life may be involved in abnormalities of the external auditory canal and related structures, which can lead to otological complications. This paper examines age-related changes in the development of the tympanic plate from the perinatal to the adult condition using two osteological samples from Britain, and is the first systematic evaluation beyond the age of six years. The results suggest that the widely cited chronology for the closure of the foramen of Huschke is erroneous. Earlier stages of formation may be used for narrowing age estimation in fragmentary remains of juveniles in a skeletal collection of unknown age or in a forensic or clinical context. Copyright © 2005 John Wiley & Sons, Ltd. [source] A model for evaluating the effectiveness of middle managers' training courses: evidence from a major banking organization in GreeceINTERNATIONAL JOURNAL OF TRAINING AND DEVELOPMENT, Issue 4 2009Ekaterini Galanou Contemporary management thinking embraces the organizational training theory that sustainable success rests, to a great extent, upon a systematic evaluation of training interventions. However, the evidence indicates that few organizations take adequate steps to assess and analyse the quality and outcomes of their training. The authors seek to develop the existing literature on training evaluation by proposing a new model, specific to management training, which might encourage more and better evaluation by practitioners. Their thesis is that training evaluation is best if it can be based on criteria derived from the objectives of the training and they draw on the management effectiveness literature to inform their proposed model. The study seeks to examine the effect of six evaluation levels , reactions, learning, job behaviour, job performance, organizational team performance and some wider, societal effects , in measuring training interventions with regard to the alterations to learning, transfer and organizational impact. The model was tested with data obtained from 190 middle managers employed by a large banking organization in Greece and the results suggest that there is considerable consistency in the evaluation framework specified. The paper discusses these results and draws conclusions about their practical implications. The study's limitations are considered and some future research needs identified. [source] Development of a tool to assess fidelity to a psycho-educational interventionJOURNAL OF ADVANCED NURSING, Issue 3 2010Mi-Kyung Song song m.-k., happ m.b. & sandelowski m. (2010) Development of a tool to assess fidelity to a psycho-educational intervention. Journal of Advanced Nursing66(3), 673,682. Abstract Aim., This paper is a description of a method to develop and conduct a customized psycho-educational intervention fidelity assessment as part of pilot work for an efficacy study. A tool designed to assess treatment fidelity to a psycho-education intervention for patients with end-stage renal disease and their surrogate decision makers, Sharing the Patient's Illness Representations to Increase Trust, is presented as an illustration. Background., Despite the specificity and idiosyncrasy of individual interventions and the call to systematically evaluate treatment fidelity, how to accomplish this goal has not been clarified. Tools to adequately measure treatment fidelity are lacking. Methods., We developed the Sharing the Patient's Illness Representations to Increase Trust Treatment Fidelity Assessment tool by identifying elements that were idiosyncratic to the intervention and those that could be adapted from existing tools. The tool has four components: overall adherence to the intervention content elements; pacing of the intervention delivery; overall dyad responsiveness; and, overall quality index of intervention delivery. The study was undertaken between 2006 and 2008. Results., Inter-rater reliability ranged from 0·80 to 0·87 for the four components. The tool showed utility in training and monitoring, such as detecting unplanned content elements delivered and the use of proscribed communication behaviours. Conclusion., Psycho-educational interventions are one of the most common types of nursing interventions worldwide. Use of fidelity assessment tools customized to the individual interventions may enhance systematic evaluation of training and monitoring treatment fidelity. [source] Fall risk factors in older people with dementia or cognitive impairment: a systematic reviewJOURNAL OF ADVANCED NURSING, Issue 5 2009Jürgen Härlein Abstract Title.,Fall risk factors in older people with dementia or cognitive impairment: a systematic review. Aim., This paper is a report of a review conducted to identify and summarize specific risk factors for falls in older people with dementia or cognitive impairments as documented by prospective or case,control studies. Background., People with dementia have a doubled to threefold risk for falls, but the reasons for this have not yet been fully explained. Several integrative literature reviews discuss possible specific fall risk factors. However, there is lack of a systematic evaluation of studies. Data sources., The CINAHL, PubMed, EMBASE and PsychInfo databases were searched for the period between 1980 and May 2007. Review methods., A systematic review was conducted. Cohort or case,control studies published in English or German were included if they investigated risk factors for falls or fall-related injuries in a sample consisting of participants with dementia or cognitive impairment. Two reviewers independently assessed study quality. Results., Six prospective studies were included in the review. These differed concerning samples, settings, follow-up periods and examined variables. Therefore, meta-analysis was not possible. Eight categories of risk factors emerged: disease-specific motor impairments, impaired vision, type and severity of dementia, behavioural disturbances, functional impairments, fall history, neuroleptics and low bone mineral density. Conclusion., There is lack of sound studies examining fall risk factors in cognitively impaired elders. Well-known risk factors such as motor impairment show particular characteristics in people with dementia. In addition, behavioural disturbances contribute to their high risk for falls. Further prospective studies are needed. [source] A systematic evaluation of the benefits and hazards of variable selection in latent variable regression.JOURNAL OF CHEMOMETRICS, Issue 7 2002Part I. Search algorithm, simulations, theory Abstract Variable selection is an extensively studied problem in chemometrics and in the area of quantitative structure,activity relationships (QSARs). Many search algorithms have been compared so far. Less well studied is the influence of different objective functions on the prediction quality of the selected models. This paper investigates the performance of different cross-validation techniques as objective function for variable selection in latent variable regression. The results are compared in terms of predictive ability, model size (number of variables) and model complexity (number of latent variables). It will be shown that leave-multiple-out cross-validation with a large percentage of data left out performs best. Since leave-multiple-out cross-validation is computationally expensive, a very efficient tabu search algorithm is introduced to lower the computational burden. The tabu search algorithm needs no user-defined operational parameters and optimizes the variable subset and the number of latent variables simultaneously. Copyright © 2002 John Wiley & Sons, Ltd. [source] A systematic evaluation of the benefits and hazards of variable selection in latent variable regression.JOURNAL OF CHEMOMETRICS, Issue 7 2002Part II. Abstract Leave-multiple-out cross-validation (LMO-CV) is compared to leave-one-out cross-validation (LOO-CV) as objective function in variable selection for four real data sets. Two data sets stem from NIR spectroscopy and two from quantitative structure,activity relationships. In all four cases, LMO-CV outperforms LOO-CV with respect to prediction quality, model complexity (number of latent variables) and model size (number of variables). The number of objects left out in LMO-CV has an important effect on the final results. It controls both the number of latent variables in the final model and the prediction quality. The results of variable selection need to be validated carefully with a validation step that is independent of the variable selection. This step needs to be done because the internal figures of merit (i.e. anything that is derived from the objective function value) do not correlate well with the external predictivity of the selected models. This is most obvious for LOO-CV. LOO-CV without further constraints always shows the best internal figures of merit and the worst prediction quality. Copyright © 2002 John Wiley & Sons, Ltd. [source] Heart rate variability does not tap putative efficacy of Thought Field TherapyJOURNAL OF CLINICAL PSYCHOLOGY, Issue 10 2001John P. Kline Callahan (2001) has offered a series of case reports in an effort to validate the rationale and methods of Thought Field Therapy (TFT). These case reports employ subjective ratings, that is, the Subjective Units of Distress (SUD) rating scale as well as a gross measure of heart rate variability (HRV). My criticisms center around (a) inappropriately strong inferences given exclusive reliance on case reports, a potentially biased sample, and lack of appropriate controls; (b) misinterpretation of statistical artifact as systematic effect; (c) lack of systematic evaluation of HRV changes; and (d) erroneous interpretation of HRV. Callahan's article provides no evidence for the efficacy of TFT nor does it provide evidence for the credibility of TFT's rationale. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 1187,1192, 2001. [source] Systematic determination of ion score cutoffs based on calculated false positive rates: application for identifying ubiquitinated proteins by tandem mass spectrometryJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 3 2008Julian Vasilescu Abstract We report a simple approach for determining ion score cutoffs that permit the confident identification of ubiquitinated proteins by tandem mass spectrometry (MS/MS). Initial experiments involving the analysis of gel bands containing multi-Ubiquitin chains with quadrupole time-of-flight and quadrupole ion trap mass spectrometers revealed that standard ion score cutoffs used for database searching were not sufficiently stringent. We also found that false positive and false negative rates (FPR and FNR) varied significantly depending on the cutoff scores used and that appropriate cutoffs could only be determined following a systematic evaluation of false positive rates. When standard cutoff scores were used for the analysis of complex mixtures of ubiquitinated proteins, unacceptably high FPR were observed. Finally, we found that FPR for ubiquitinated proteins are affected by the size of the protein database that is searched. These observations may be applicable for the study of other post-translational modifications. Copyright © 2007 John Wiley & Sons, Ltd. [source] Towards a rational development of anti-endotoxin agents: novel approaches to sequestration of bacterial endotoxins with small moleculesJOURNAL OF MOLECULAR RECOGNITION, Issue 6 2001Sunil A. David Abstract Endotoxins, or lipopolysaccharides (LPS), present on the surface of Gram-negative bacteria, play a key role in the pathogenesis of septic shock, a common clinical problem and a leading cause of mortality in critically ill patients, for which no specific therapeutic modalities are available at the present time. The toxic moiety of LPS is a glycolipid called ,lipid A', which is composed of a bisphosphorylated diglucosamine backbone bearing up to seven acyl chains in ester and amide linkages. Lipid A is structurally highly conserved in Gram-negative bacteria, and is therefore an attractive target for developing anti-endotoxin molecules designed to sequester, and thereby neutralize, the deleterious effects of endotoxins. The anionic and amphipathic nature of lipid A enables the interaction of a wide variety of cationic amphiphiles with the toxin. This review describes the systematic evaluation of several structural classes of cationic amphiphiles, both peptides and non-peptidic small molecules, in the broader context of recent efforts aimed at developing novel anti-endotoxin strategies. The derivation of a pharmacophore for LPS recognition has led to the identification of novel, nontoxic, structurally simple small molecules, the lipopolyamines. The lipopolyamines bind and neutralize LPS in in vitro experiments as well as in animal models of endotoxicity, and thus present novel and exciting leads for rational, structure-based development of LPS-sequestering agents of potential clinical value. Copyright © 2001 John Wiley & Sons, Ltd. [source] Euclid: Strategic alternative assessment matrixJOURNAL OF MULTI CRITERIA DECISION ANALYSIS, Issue 2 2002Madjid Tavana Abstract The vast amount of information that must be considered to solve inherently ill-structured and complex strategic problems creates a need for tools to help decision makers (DMs) recognize the complexity of this process and develop a rational model for strategy evaluation. Over the last several decades, a philosophy and a body of intuitive and analytical methods have been developed to assist DMs in the evaluation of strategic alternatives. However, the intuitive methods lack a structured framework for the systematic evaluation of strategic alternatives while the analytical methods are not intended to capture intuitive preferences. Euclid is a simple and yet sophisticated multiobjective value analysis model that attempts to uncover some of the complexities inherent in the evaluation of strategic alternatives. The proposed model uses a series of intuitive and analytical methods including environmental scanning, the analytic hierarchy process (AHP), subjective probabilities, and the theory of displaced ideal, to plot strategic alternatives on a matrix based on their Euclidean distance from the ideal alternative. Euclid is further compared to the quantitative strategic planning matrix (QSPM) in a real world application. The information provided by the users shows that Euclid can significantly enhance decision quality and the DM's confidence. Euclid is not intended to replace the DMs, rather, it provides a systematic approach to support, supplement, and ensure the internal consistency of their judgments through a series of logically sound techniques. Copyright © 2003 John Wiley & Sons, Ltd. [source] Investigating intellectual disability: A genetic perspectiveJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 7 2003NK Poplawski Abstract: Intellectual disability (ID) is a common paediatric problem. Investigation focused on determining the aetiology of ID is warranted because a specific diagnosis may assist in prognostication, recurrence risk counselling, and identification of therapeutic and educational interventions. Three groups of screening investigations can be justified on the basis of expert opinion, common sense and the small body of published evidence-based medicine. First, investigations where current evidence justifies routine use in the investigation of ID; second, investigations which should be considered in all children with ID, although there is insufficient current evidence to support routine use; and finally, investigations which currently have an unclear role in children with ID and should be restricted to specific clinical situations unless further evidence suggesting otherwise emerges. There is a great need for systematic evaluation of the diagnostic yield of investigation templates based on this proposed stratification of investigations. [source] Stability profiles of drug products extended beyond labeled expiration datesJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 7 2006Robbe C. Lyon Abstract The American Medical Association has questioned whether expiration dating markedly underestimates the actual shelf life of drug products. Results from the shelf life extension program (SLEP) have been evaluated to provide extensive data to address this issue. The SLEP has been administered by the Food and Drug Administration for the United States Department of Defense (DOD) for 20 years. This program probably contains the most extensive source of pharmaceutical stability data extant. This report summarizes extended stability profiles for 122 different drug products (3005 different lots). The drug products were categorized into five groups based on incidence of initial extension failures and termination failures (extended lot eventually failed upon re-testing). Based on testing and stability assessment, 88% of the lots were extended at least 1 year beyond their original expiration date for an average extension of 66 months, but the additional stability period was highly variable. The SLEP data supports the assertion that many drug products, if properly stored, can be extended past the expiration date. Due to the lot-to-lot variability, the stability and quality of extended drug products can only be assured by periodic testing and systematic evaluation of each lot. © 2006 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 95: 1549,1560, 2006 [source] Computational study of stereoelectronic effects in fluorinated alkylamines,JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 11 2005Joseph J. Urban Abstract A systematic evaluation of the stereoelectronic effects in a series of fluorinated amine compounds has been carried out. A variety of computational methods have been employed, including molecular mechanics, semi-empirical, density functional and ab initio methods. An analysis of the natural bond orbital populations has been carried out and the effect of solvent was considered via the polarized continuum model (PCM). The results indicate a preference for conformations that result in an anti-periplanar arrangement between the nitrogen lone pair and the CX bond (XF or CF3). There are variations in geometry and natural bond orbital population, with conformation that are consistent with a stereoelectronic effect whereby electron density from the nitrogen lone pair is delocalized into the CX ,* orbital. Similar results are obtained for trifluoromethyl methylamines, although the magnitude of the stereoelectronic effect is attenuated resulting in greater expected conformational diversity for these compounds. The PCM results suggest that these preferences should persist in solution. Comparison among the computational methods used reveals that there is good agreement among the ab initio and density functional methods (at the HF/6-31,+,G(d), MP2/6-31,+,G(d), MP2/6-311,+,G(2d,p) and B3LYP/6-31,+,G(d) levels) and these methods agree well with the available experimental data for ethylmethylamine. Published in 2005 by John Wiley & Sons, Ltd. [source] CE ARTICLE: Recognizing and treating upper extremity lymphedema in postmastectomy/lumpectomy patients: A guide for primary care providersJOURNAL OF THE AMERICAN ACADEMY OF NURSE PRACTITIONERS, Issue 9 2010Eva Quirion MSN Abstract Purpose: To provide an overview of the lymphatics, physiology of lymphedema (LE), incidence, risks, and costs as well as a guide for the primary care provider on how to recognize the symptoms of LE, a review of current published treatment recommendations, and advice about making a referral to appropriate LE specialists. Data sources: Selected studies on diagnosing and treating LE in breast cancer patients following mastectomy/lumpectomy and evidence-based treatment guidelines. Conclusions: LE is the most common complication related to breast cancer treatment with an occurrence estimated between 10% and 60% depending on the parameters used for measurement. Most commonly, LE occurs within the first 3 years after breast cancer treatment, but the remaining cases happen beyond this period of time and can occur after many years. This means that significant numbers of patients with LE can present to primary care clinicians. Implications for practice: A patient who is treated for breast cancer will be followed for a time by the oncology team, but eventually, that patient will be discharged from the oncology practice and will be seen in primary care. Risk factors for developing LE include treatment-related (number of nodes removed and radiation to axilla), disease-related (stage and location of tumor), and patient-related (younger age, obesity, and comorbid conditions) factors. A systematic evaluation of any patient presenting with LE will assure accurate diagnosis and prompt treatment. [source] Quality assessment in general practice trainersMEDICAL EDUCATION, Issue 12 2000M J F J Vernooij-Dassen Introduction General practice trainers hold a key position in general practice training, especially through their provision of a role model. Their own competence in general practice care is important in this regard. The purpose of the study was to evaluate whether a quality assessment programme could identify the strengths and weaknesses of GP trainers in four main domains of general practice care. Methods The quality assessment programme comprised validated tests on four domains of general practice: general medical knowledge, knowledge of medical-technical skills, consultation skills and practice management. The criterion for the identification of relative strengths and weaknesses of GP trainers was a variation in the scores of trainers indicating higher and lower scores (strengths and weaknesses) within each domain. Results GP trainers (n=105) were invited to participate in the study and 90% (n=94) did so. The variation in scores allowed the indication of strengths and weaknesses. Main strengths were: general medical knowledge of the digestive system; knowledge of medical skills relating to the skin; consultation skills concerning empathy; practice management with regard to accessibility. Main weaknesses were: general medical knowledge of the neurological system; knowledge of the medical/technical skills relating to the endocrine metabolic and nutritional system; consultation skills regarding shared decision making; practice management involving cooperation with staff and other care providers. Discussion This first systematic evaluation of GP trainers identified their strengths and weaknesses. The weaknesses identified will be used in the improvement process as topics for collective improvement in the GP trainers' general curriculum and in individual learning plans. [source] Imaging FRET standards by steady-state fluorescence and lifetime methodsMICROSCOPY RESEARCH AND TECHNIQUE, Issue 12 2007Beatriz Domingo Abstract Imaging fluorescence resonance energy transfer (FRET) between molecules labeled with fluorescent proteins is emerging as a powerful tool to study changes in ions, ligands, and molecular interactions in their physiological cellular environment. Different methods use either steady-state fluorescence properties or lifetime to quantify the FRET rate. In addition, some provide the absolute FRET efficiency whereas others are simply a relative index very much influenced by the actual settings and instrumentation used, which makes the interpretation of a given FRET rate very difficult. The use and exchange of FRET standards in laboratories using these techniques would help to overcome this drawback. We report here the construction and systematic evaluation of FRET standard probes of varying FRET efficiencies. The standards for intramolecular FRET were protein fusions of the cyan and yellow variants of A. victoria green fluorescent protein (ECFP and citrine) joined by short linkers or larger protein spacers, or ECFP tagged with a tetracysteine motif and labeled with the biarsenical fluorochrome, FlAsH. Negative and positive controls of intermolecular FRET were also used. We compared these FRET standards with up to four FRET quantification methods: ratioing of acceptor to donor emission, donor intensity recovery upon acceptor photobleach, sensitized emission after spectral unmixing of raw images, and fluorescence lifetime imaging (FLIM). The latter was obtained with a frequency-domain setup able to provide high quality lifetime images in less than a second, and is thus very well suited for live cell studies. The FRET rates or indexes of the standards were in good agreement regardless of the method used. For the CFP-tetraCys/FlAsH pair, the rate calculated from CFP quenching was faster than that obtained by FLIM. Microsc. Res. Tech., 2007. © 2007 Wiley-Liss, Inc. [source] Reproducibility of tricuspid regurgitant jet velocity measurements in children and young adults with sickle cell disease undergoing screening for pulmonary hypertension,AMERICAN JOURNAL OF HEMATOLOGY, Issue 10 2010Robert I. Liem The reproducibility of tricuspid regurgitant jet velocity (TRJV) measurements by Doppler echocardiography has not been subjected to systematic evaluation among individuals with sickle cell disease (SCD) undergoing screening for pulmonary hypertension. We examined sources of disagreement associated with peak TRJV in children and young adults with SCD. Peak TRJV was independently measured and interpreted a week apart by separate sonographers and readers, respectively, in 30 subjects (mean age, 15.8 ± 3.3 years) who provided 120 observations. We assessed intra-/inter-reader, intra-/inter-sonographer, sonographer-reader, and within subject agreement using Intraclass Correlation Coefficient (ICC) and Cohen's kappa (,). Agreement was examined graphically using Bland-Altman plots. Although sonographers could estimate and measure peak TRJV in all subjects, readers designated tricuspid regurgitation nonquantifiable in 10,17% of their final interpretations. Intra-reader agreement was highest (ICC = 0.93 [95% CI 0.86, 0.97], P = 0.0001) and within subject agreement lowest (ICC = 0.36 [95% CI 0.02, 0.64], P = 0.021) for single TRJV measurements. Similarly, intra-reader agreement was highest (, = 0.74 [95% CI 0.53, 0.95], P = 0.0001) and within subject lowest (, = 0.14 [95% CI ,0.17, 0.46], P = 0.38) when sonographers and readers categorized TRJV measurements. On Bland-Altman plots, absolute differences in observations increased with higher mean TRJV readings for intra-/inter-reader agreement. Peak TRJV measurements in individual children and young adults with SCD are affected by several sources of disagreement, underscoring the need for methodological improvements that ensure reproducibility of this screening modality for making clinical decisions in this population. Am. J. Hematol., 2010. © 2010 Wiley-Liss, Inc. [source] The Brief Pain Inventory and Its "Pain At Its Worst in the Last 24 Hours" Item: Clinical Trial Endpoint ConsiderationsPAIN MEDICINE, Issue 3 2010Thomas M. Atkinson PhD Abstract Context., In 2006, the United States Food and Drug Administration (FDA) released a draft Guidance for Industry on the use of patient-reported outcomes (PRO) Measures in Medical Product Development to Support Labeling Claims. This draft guidance outlines psychometric aspects that should be considered when designing a PRO measure, including conceptual framework, content validity, construct validity, reliability, and the ability to detect clinically meaningful score changes. When finalized, it may provide a blueprint for evaluations of PRO measures that can be considered by sponsors and investigators involved in PRO research and drug registration trials. Objective., In this review we examine the short form of the Brief Pain Inventory (BPI) and particularly the "pain at its worst in the last 24 hours" item in the context of the FDA draft guidance, to assess its utility in clinical trials that include pain as a PRO endpoint. Results and Conclusions., After a systematic evaluation of the psychometric aspects of the BPI, we conclude that the BPI and its "pain at its worst in the last 24 hours" item generically satisfy most key recommendations outlined in the draft guidance for assessing a pain-reduction treatment effect. Nonetheless, when the BPI is being considered for assessment of pain endpoints in a registration trial, sponsors and investigators should consult with the appropriate FDA division early during research design to discuss whether there is sufficient precedent to use the instrument in the population of interest or whether additional evaluations of measurement properties are advisable. [source] | |||||||||||||||||||||||||||||||