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Methodology Used (methodology + used)
Selected AbstractsSimultaneous determination of nine endogenous steroids in human urine by polymeric-mixed micelle capillary electrophoresisELECTROPHORESIS, Issue 19 2010Sabrina Flor Abstract A new CE system based on the use of polymeric-mixed micelles (cholic acid, SDS and the poloxamine Tetronic® 1107) was developed for the simultaneous determination of nine steroids in human urine. This method allows the baseline separation and quantitation of cortisol, androstenedione, estriol, dehydroepiandrosterone sulfate, testosterone, dehydroepiandrosterone, estrone, progesterone and estradiol in less than 25,min showing to be sensitive enough to detect low concentrations of these steroids in urine samples (5,45,ng/mL). The optimized electrophoretic conditions were performed using a 50,cm×75,,m capillary, 18,kV, 25°C, with 44,mM cholic acid, 10,mM SDS, 0.05%,w/v tetronic® 1107, 2.5%,v/v methanol, 2.5%,v/v tetrahydrofuran in 5,mM borate , 5,mM phosphate buffer (pH=8.0) as a background electrolyte and a dual 210/254 UV-detection. The method can simultaneously determine 0.1,120,,g/mL, which corresponds to 5,6000,ng/mL of steroids in 2,mL urine. The recoveries ranged between 82.4 and 101.5%. Due to its simplicity, speed, accuracy and reliability, the proposed method could be a potential alternative to the traditional methodologies used with clinical purposes. [source] Soil metaproteomics: a review of an emerging environmental science.EUROPEAN JOURNAL OF SOIL SCIENCE, Issue 6 2009Significance, methodology, perspectives Summary Soil is a dynamic system in which microorganisms perform important tasks in organic matter transformations and nutrient cycles. Recently, some studies have started to focus on soil metaproteomics as a tool for understanding the function and the role of members of the microbial community. The aim of our work was to provide a review of soil proteomics by looking at the methodologies used in order to illustrate the challenges and gaps in this field, and to provide a broad perspective about the use and meaning of soil metaproteomics. The development of soil metaproteomics is influenced strongly by the extraction methods. Several methods are available but only a few provide an identification of soil proteins, while others extract proteins and are able to separate them by electrophoresis but do not provide an identification. The extraction of humic compounds together with proteins interferes with the latter's separation and identification, although some methods can avoid these chemical interferences. Nevertheless, the major problems regarding protein identification reside in the fact that soil is a poor source of proteins and that there is not enough sequence-database information for the identification of proteins by mass spectrometric analysis. Once these pitfalls have been solved, the identification of soil proteins may provide information about the biogeochemical potential of soils and pollutant degradation and act as an indicator of soil quality, identifying which proteins and microorganisms are affected by a degradation process. The development of soil metaproteomics opens the way to proteomic studies in other complex substrates, such as organic wastes. These studies can be a source of knowledge about the possibility of driven soil restoration in polluted and degraded areas with low organic matter content and even for the identification of enzymes and proteins with a potential biotechnological value. [source] Embryonic Stem Cells and Gene TargetingEXPERIMENTAL PHYSIOLOGY, Issue 6 2000Birgit Ledermann The development of gene targeting technology, the exchange of an endogenous allele of a target gene for a mutated copy via homologous recombination, and the application of this technique to murine embryonic stem cells has made it possible to alter the germ-line of mice in a predetermined way. Gene targeting has enabled researchers to generate mouse strains with defined mutations in their genome allowing the analysis of gene function in vivo. This review presents the essential tools and methodologies used for gene targeting that have been developed over the past decade. Special emphasis has been laid on the available embryonic stem cell lines and the importance of the genetic background. Also, the state-of-the art of gene targeting approaches in species other than mice will be discussed. [source] Structure of a human telomeric DNA sequence stabilized by 8-bromoguanosine substitutions, as determined by NMR in a K+ solutionFEBS JOURNAL, Issue 14 2007Akimasa Matsugami The structure of human telomeric DNA is controversial; it depends upon the sequence contexts and the methodologies used to determine it. The solution structure in the presence of K+ is particularly interesting, but the structure is yet to be elucidated, due to possible conformational heterogeneity. Here, a unique strategy is applied to stabilize one such structure in a K+ solution by substituting guanosines with 8-bromoguanosines at proper positions. The resulting spectra are cleaner and led to determination of the structure at a high atomic resolution. This demonstrates that the application of 8-bromoguanosine is a powerful tool to overcome the difficulty of nucleic acid structure determination arising from conformational heterogeneity. The obtained structure is a mixed-parallel/antiparallel quadruplex. The structure of telomeric DNA was recently reported in another study, in which stabilization was brought about by mutation and resultant additional interactions [Luu KN, Phan AT, Kuryavyi V, Lacroix L & Patel DJ (2006) Structure of the human telomere in K+ solution: an intramolecular (3+1) G-quadruplex scaffold. J Am Chem Soc 128, 9963,9970]. The structure of the guanine tracts was similar between the two. However, a difference was seen for loops connecting guanine tracts, which may play a role in the higher order arrangement of telomeres. Our structure can be utilized to design a small molecule which stabilizes the quadruplex. This type of molecule is supposed to inhibit a telomerase and thus is expected to be a candidate anticancer drug. [source] The Effects of Weather and Climate on the Seasonality of Influenza: What We Know and What We Need to KnowGEOGRAPHY COMPASS (ELECTRONIC), Issue 7 2010Christopher Fuhrmann Influenza is one of the most deadly of all airborne and upper-respiratory infections. On average, 22,000 deaths and over 3 million hospitalizations in USA are attributed to influenza each year. The distinct seasonality of influenza suggests a climate connection, but the wide range of methodologies used to explore this connection makes it difficult to elucidate a definitive relationship. Much of what is known about the effects of weather and climate on the seasonality of influenza stems from research conducted by members of the public health and medical communities, with few contributions from other physical and social science fields. Most of these studies are either based on experiments conducted under controlled laboratory conditions or on the broad-scale patterns of morbidity and mortality and their relationship to large-scale climate signals. What remains largely unknown is the suitability of these results for the development of early warning systems and for determining the dynamics of viral transmission on multiple space and time scales. [source] Performance on Stroop-like assessments of inhibitory control by 4- and 5-year-old childrenINFANT AND CHILD DEVELOPMENT, Issue 3 2010Dave S. Pasalich Abstract The rapid development of an aspect of executive functioning (EF), inhibitory control (IC), between the ages of 3- and 5-years, leads to an increase in a child's capacity to suppress inappropriate responding and therefore activate the necessary resources to carry-out goal-directed activity (Psychological Bulletin, 1997, 121, 65,94). To measure EF in children, tasks administered clinically to adults are adapted. The Day,Night Stroop (DNS) is a pictorial modification of the Stroop Test (Journal of Experimental Psychology, 1935, 18, 642,662), developed for pre-literate children. Although suitable as a measure of IC in 3- to 4-year-old children, ceiling effects have been reported on the DNS in slightly older preschoolers. The present study attempted to overcome this limitation by examining the suitability of two modified versions of the DNS in 4- to 5-year-old preschoolers. To investigate the executive demands made by both Stroop-like tasks, their associations with another measure of IC (stop-signal task) and a measure of working memory were examined. Counter to expectations, no significant association was found in performance between the two Stroop-like tasks; however, the modified DNS developed in this study showed significant relationships with the other executive tasks. The results are discussed in relation to the different methodologies used by these Stroop measures. Implications of this study suggest that researchers should consider more test-specific factors when assessing EF in young children. Copyright © 2010 John Wiley & Sons, Ltd. [source] Understanding and meeting the challenges of consumer/tourist experience researchINTERNATIONAL JOURNAL OF TOURISM RESEARCH, Issue 2 2009J. R. Brent Ritchie Abstract This paper seeks to provide a framework that will help us identify and better understand the major challenges we face in consumer/tourist experience research. These challenges have both theoretical and managerial dimensions. Based on an extensive and comprehensive review of the current literature in the field, we have categorised extant knowledge into six main streams of theoretical thinking and empirical research. These streams were identified as the fundamentals of the experience, experience-seeking behaviours, methodologies used in experience research, the nature of specific tourism experiences, managerial issues in the design and delivery of experiences, and the evolutionary trail of experience thinking. Copyright © 2009 John Wiley & Sons, Ltd. [source] Agricultural Growth and Inter-Sectoral Linkages in a Developing EconomyJOURNAL OF AGRICULTURAL ECONOMICS, Issue 3 2000N. Gemmell Does growth in the manufacturing sector of an economy spillover to agriculture, or do sectors share similar growth rates only when they share some common exogenous stimuli? The limited number of investigations of this issue, for cross-sections of countries, have found some evidence in favour of spillovers, though the methodologies used cannot readily separate correlation from causation. Adapting the Feder (1982) model of sectoral externalities to a time-series context, we examine how far agricultural output in Malaysia has been affected by inter-sectoral spillovers. Our results suggest that expansion of manufacturing output, though associated with reduced agricultural output in the short-run, is associated with agricultural expansion over the long-run. Service output growth on the other hand seems to have been inimical to agricultural growth in both the short- and long-runs, while causality testing supports the case for spillovers rather than "common causes". Evidence on sectoral productivity is consistent with neoclassical arguments suggesting that the benefits of higher productivity in manufacturing tend to spill over to agriculture, encouraging productivity convergence. [source] Research Methods in the Leading Small Business,Entrepreneurship Journals: A Critical Review with Recommendations for Future Research,JOURNAL OF SMALL BUSINESS MANAGEMENT, Issue 3 2009Michael R. Mullen Small business and entrepreneurship scholars have made significant progress toward advancing the field and gaining recognition as an important domain of scientific inquiry. However, the authors suggest that a strong methodological foundation built on state-of-the-art research technologies is necessary to support further paradigmatic growth and maturation. Using Chandler and Lyon's study as a benchmark for research methods through the 1990s, the study critiques research methodologies used by small business and entrepreneurship researchers over the ensuing years. The analysis includes all 665 papers published between 2001 and February of 2008 in the Journal of Small Business Management, Journal of Business Venturing, and Entrepreneurship Theory and Practice. The research outlines key methodological issues, assesses recent methodological practice, identifies current trends, and offers recommendations for researchers in adopting existing and emerging research technologies. [source] A critical review of methodologies used in determination of relative bio-availability ratio of RRR -,-tocopheryl acetate and all - rac -,-tocopheryl acetateJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2010Yueming Dersjant-Li Abstract Bio-availability of different ,-tocopherol forms in livestock animals is measured by the increase in plasma or tissue concentrations of ,-tocopherol after oral administration. It is generally accepted that RRR -,-tocopheryl acetate (natural source vitamin E derived from vegetable oil) has a higher bio-availability compared to all - rac -,-tocopheryl acetate (synthetic vitamin E, i.e. ,-tocopherol produced by chemical synthesis). However, different bio-availability ratios have been reported in the literature. The major reason for conflicting results in literature studies was the inability to separate the proportion of ,-tocopherol originating from test materials, from the proportion of ,-tocopherol originating from basal dietary ingredients and pre-feeding. This causes significant variability. For bio-availability determination, a baseline or control treatment is essential. The estimation of bio-availability without correction for basal vitamin E status will lead to incorrect interpretation of the results. When using proper methodologies, it is possible to correct for the impact of ,-tocopherol intake from basal ingredients and ,-tocopherol originating from pre-feeding, therefore yielding results reflecting the true relative bio-availability of different ,-tocopherol substances. When reviewing literature data a critical evaluation of the method used in determination of relative bio-availability is recommended. Copyright © 2010 Society of Chemical Industry [source] Cross-site comparison of herbivore impact on nitrogen availability in grasslands: the role of plant nitrogen concentrationOIKOS, Issue 11 2009E. S. Bakker Herbivores may influence the nitrogen (N) recycling rates and consequently increase or decrease the productivity of grasslands. Plant N concentration emerged as a critical parameter to explain herbivore effects from several conceptual models, which predict that herbivores decrease soil N availability when plant N concentration is low whereas they increase it when plant N concentration is high (Hobbs 1996, Ritchie et al. 1998, Pastor et al. 2006). However, a broader cross-site comparison among published studies to test these predictions is hampered by the different methodologies used to measure soil N availability or a proxy thereof, and a lack of measurements of plant N concentration. Therefore it remains unclear whether these model predictions are generally valid across a range of grasslands. We tested whether there is a relationship between plant N concentration and herbivore impact on soil N availability (measured with resin bags) with a study of replicate 6,8,year old exclosures (with an unfenced control) of vertebrate herbivores (>1,kg) established at each of seven grassland sites in North America and Europe. Contrary to model predictions, we found a negative relationship between the effect of herbivores on resin bag soil N availability and plant N concentration. Our study confirms the importance of plant N concentration as a predictor of herbivore effect on soil N availability across grasslands, but contradicts the models. A possible explanation may be that the results represent a transient situation as the exclosures were relatively young whereas the models may refer to an equilibrium state. Simultaneous measurements of both plant N concentration and herbivore effect on soil N availability from more grassland sites, preferably with contrasting plant N concentrations and including exclosures of different ages, should resolve the contrast between model predictions and our field measurements. [source] MORE THAN ONE WAY TO STUDY A BUILDING: APPROACHES TO PREHISTORIC HOUSEHOLD AND SETTLEMENT SPACEOXFORD JOURNAL OF ARCHAEOLOGY, Issue 3 2006MARION CUTTING Summary. This article reviews a number of research methodologies used to record household and settlement architecture and assesses their value in the investigation of the human use of prehistoric built space. It exemplifies, through case studies, five broad approaches to, and research techniques associated with, the investigation of such architecture. These approaches are: architectural form; the spatial distribution of activities; continuity and standardization; the relationship between built and non-built space; and human patterns of movement. Then, drawing mainly on Near Eastern, and particularly Anatolian, material, it shows how a sixth approach, the use of ethnographic observation and analogy, provides insights into functional and seasonal variations in spatial use, patterns of movement and social organization. It identifies seven categories of data collection and nine observations drawn from the ethnographic material which together provide an investigative and interpretative framework for the study of early farming communities in the Near East and elsewhere. [source] Towards harmonized approaches for mycotoxin analyses: an assessmentQUALITY ASSURANCE & SAFETY OF CROPS & FOOD, Issue 2 2009Anton J. Alldrick Abstract Mycotoxins (the poisonous metabolites of certain filamentous fungi) are potential contaminants of staple food commodities and, if uncontrolled, may present a significant public health hazard. In many jurisdictions, questions relating to mycotoxin contamination are addressed at both generic and specific levels by food-safety legislation. Key to the successful management of the mycotoxin question, both in terms of verifying food-safety measures by the agri-food businesses and ensuring compliance with statutory limits by enforcement agencies, is the use of reliable sampling and analytical methodology. Evidence from European Union Rapid Alert System for Food and Feed data suggest that harmonization of methodologies used to determine the mycotoxin content of foods would contribute to improved compliance at both regulatory and commercial levels. [source] A numerical evaluation of chamber methodologies used in measuring the ,13C of soil respirationRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 17 2009Nick Nickerson Measurement of the ,13C value of soil-respired CO2 (,r) has become a commonplace method through which ecosystem function and C dynamics can be better understood. Despite its proven utility there is currently no consensus on the most robust method with which to measure ,r. Static and dynamic chamber systems are both commonly used for this purpose; however, the literature on these methods provides evidence suggesting that measurements of ,r made with these chamber systems are neither repeatable (self-consistent) nor comparable across methodologies. Here we use a three-dimensional (3-D) numerical soil-atmosphere-chamber model to test these chamber systems in a ,surrogate reality'. Our simulations show that each chamber methodology is inherently biased and that no chamber methodology can accurately predict the true ,r signature under field conditions. If researchers intend to use ,r to study insitu ecosystem processes, the issues with these chamber systems need to be corrected either by using diffusive theory or by designing a new, unbiased ,r measurement system. Copyright © 2009 John Wiley & Sons, Ltd. [source] Lipidomic analysis of twenty-seven prostanoids and isoprostanes by liquid chromatography/electrospray tandem mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 20 2006Mojgan Masoodi Prostanoids are potent mediators of many physiological and pathophysiological processes. Of the many analytical methodologies used for their qualitative and quantitative analysis, electrospray tandem mass spectrometry coupled to liquid chromatography (LC/ESI-MS/MS) offers a rapid, sensitive and versatile system applicable to lipidomic analyses. We have developed an LC/ESI-MS/MS assay for twenty-seven mediators including prostaglandins, prostacyclines, thromboxanes, dihydroprostaglandins and isoprostanes. The assay was liner over the concentration range 1,100 pg/µL. The limits of detection and quantitation were 0.5,50 and 2,100 pg, respectively, whilst recoveries were from 83,116% depending on the metabolite. The assay can be applied to the profiling of prostanoids produced by a variety of biological fluids and extracts including brain, liver, plasma and urine, thus facilitating our understanding of the role of these lipid mediators in health and disease, as well as assisting in drug development. Copyright © 2006 John Wiley & Sons, Ltd. [source] A critical comparison of stratosphere,troposphere coupling indicesTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 644 2009Mark P. Baldwin Abstract Assessing stratosphere,troposphere coupling in observational data or model output requires a multi-level index with high time resolution. Ideally, such an index would (1) represent spatial patterns in the troposphere that are most strongly coupled with stratospheric variability and (2) be robust and computationally feasible in both observations and standard model output. Several of the indices used to diagnose extratropical stratosphere,troposphere coupling are based on the Northern and Southern Hemisphere annular modes. The annular mode indices are commonly defined as the leading empirical orthogonal functions (EOFs) of monthly-mean, hemispheric geopotential height. In the lowermost troposphere, the structure of the annular modes is defined as the leading EOF of the near-surface geopotential height field, and these patterns correspond well to the patterns of variability induced by stratospheric circulation changes. At pressure levels above the surface, the structure of the annular modes is typically found by either calculating the local EOF or regressing geopotential height data onto the leading principal component time series of near-surface geopotential height. Here we make a critical comparison of the existing methodologies used to diagnose stratosphere,troposphere coupling, including EOF-based indices as well as measures based on zonal-mean wind at a fixed latitude and geopotential height over the polar cap. We argue in favour of an alternative methodology based on EOFs of daily zonally-averaged geopotential. We find that (1) the daily evolution of stratosphere,troposphere coupling events is seen most clearly with this methodology, and (2) the methodology is robust and requires few subjective choices, making it readily applicable to climate model output available only in zonal-mean form. Copyright © 2009 Royal Meteorological Society [source] Review Article: A review of sex determination and searches for sex-specific markers in sturgeonAQUACULTURE RESEARCH, Issue 9 2010Saeed Keyvanshokooh Abstract The availability of monosex populations of caviar-producing female sturgeon would considerably enhance the economic viability of domestic caviar production systems. However, it is not possible to distinguish males from females by morphological characters at larval, juvenile and even adult stages. The mechanism of sex determination in sturgeons is poorly understood, and to date no sex-specific markers in sturgeon have been reported. This review concentrates on the methodologies used to elucidate the mode of sex determination in sturgeon species and provides information on the molecular tools used to determine genetic sex markers. [source] Nutrition and immunity: an updateAQUACULTURE RESEARCH, Issue 3 2010Viviane Verlhac Trichet Abstract Immunity encompasses all mechanisms and responses used by the organism to defend itself against bacteria, viruses or parasites. Adequate supply and balance of nutrients are required for proper efficiency of the host defences. Research has identified dietary factors that affect human and animal immune responses like amino acids, fatty acids, minerals and vitamins. Some of these nutrients have been proven to have specific actions on immunity when provided at pharmacological doses. This paper will review these nutrients and their current use in aquaculture. The immune system is an efficient but complex system. Its complexity has made the assessment of the effects of diets difficult. Nevertheless, the standardization of methodology as well as the use of new techniques at the cell or the gene level should help to better understand the mechanisms of immune modulation. This paper will review the major functions of fish and shrimp immune system and the methodologies used. Cellular and humoral functions including cytokines will be discussed in relation to potential means to modulate them and the underlying mechanism. A better understanding of the mechanisms of modulation of the immune functions should help in the discovery of new dietary factors to improve the immune status of the animal, leading to better disease resistance. [source] Using the implicit association test across cultures: A case of implicit self-esteem in Japan and CanadaASIAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 3 2009Andrew C. H. Szeto Previous research has suggested that implicit self-esteem might be universally positive. In the present study implicit self-esteem, as measured by the implicit association test (IAT), was found to be positive in both Japanese and Canadian participants. However, contrary to prior research, Japanese participants were found to have significantly lower implicit self-esteem than Canadians. Japanese participants also had lower scores on an exploratory measure of collective implicit self-esteem. In general, the results of the present study point to the complexities in the study of implicit self-esteem across cultures. Inconsistencies between the present and previous research might reflect divergent methodologies used in the IAT. The applicability of the IAT in a cross-cultural setting is discussed. [source] Modulation of aggressive behaviour by fighting experience: mechanisms and contest outcomesBIOLOGICAL REVIEWS, Issue 1 2006Yuying Hsu ABSTRACT Experience in aggressive contests often affects behaviour during, and the outcome of, later contests. This review discusses evidence for, variations in, and consequences of such effects. Generally, prior winning experiences increase, and prior losing experiences decrease, the probability of winning in later contests, reflecting modifications of expected fighting ability. We examine differences in the methodologies used to study experience effects, and the relative importance and persistence of winning and losing experiences within and across taxa. We review the voluminous, but somewhat disconnected, literature on the neuroendocrine mechanisms that mediate experience effects. Most studies focus on only one of a number of possible mechanisms without providing a comprehensive view of how these mechanisms are integrated into overt behaviour. More carefully controlled work on the mechanisms underlying experience effects is needed before firm conclusions can be drawn. Behavioural changes during contests that relate to prior experience fall into two general categories. Losing experiences decrease willingness to engage in a contest while winning experiences increase willingness to escalate a contest. As expected from the sequential assessment model of contest behaviour, experiences become less important to outcomes of contests that escalate to physical fighting. A limited number of studies indicate that integration of multiple experiences can influence current contest behaviour. Details of multiple experience integration for any species are virtually unknown. We propose a simple additive model for this integration of multiple experiences into an individual's expected fighting ability. The model accounts for different magnitudes of experience effects and the possible decline in experience effects over time. Predicting contest outcomes based on prior experiences requires an algorithm that translates experience differences into contest outcomes. We propose two general types of model, one based solely on individual differences in integrated multiple experiences and the other based on the probability contests reach the escalated phase. The difference models include four algorithms reflecting possible decision rules that convert the perceived fighting abilities of two rivals into their probabilities of winning. The second type of algorithm focuses on how experience influences the probability that a subsequent contest will escalate and the fact that escalated contests may not be influenced by prior experience. Neither type of algorithm has been systematically investigated. Finally, we review models for the formation of dominance hierarchies that assume that prior experience influences contest outcome. Numerous models have reached varied conclusions depending on which factors examined in this review are included. We know relatively little about the importance of and variation in experience effects in nature and how they influence the dynamics of aggressive interactions in social groups and random assemblages of individuals. Researchers should be very active in this area in the next decade. The role of experience must be integrated with other influences on contest outcome, such as prior residency, to arrive at a more complete picture of variations in contest outcomes. We expect that this integrated view will be important in understanding other types of interactions between individuals, such as mating and predator-prey interactions, that also are affected significantly by prior experiences. [source] Enhancing instructional design efficiency: Methodologies employed by instructional designersBRITISH JOURNAL OF EDUCATIONAL TECHNOLOGY, Issue 2 2010Margaret A. Roytek Instructional systems design (ISD) has been frequently criticised as taking too long to implement, calling for a reduction in cycle time,the time that elapses between project initiation and delivery. While instructional design research has historically focused on increasing learner efficiencies, the study of what instructional designers do to increase efficiency during the design of instruction, including web-based training, has not yet been fully examined. The purpose of this qualitative developmental study was to identify and understand the methodologies used by experienced instructional designers to increase the efficiency of the instructional design process. Data were gathered from 11 instructional designers working within two business and industry consulting firms that provide learning solutions to global clients. Results revealed 47 efficiency methodologies found within the four categories of design model, instructional design team member roles, instructional design processes and instructional design tools. Additionally, 14 supporting instructional designer competencies were found within the category of instructional designer knowledge, skills and attitudes. [source] Selection, teaching and training in ophthalmologyCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 5 2005Larry Benjamin FRCOphth Abstract This article examines the training requirements for ophthalmic surgical training, and the selection, assessment and training methodologies used for trainees, and also comments on the role of the surgical trainers. As an introduction to the article, a brief description of the current scheme in the UK is given. [source] Cardiovascular and renal phenotyping of genetically modified mice: A challenge for traditional physiologyCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 4 2003Sharyn M Fitzgerald Summary 1.,The advent of techniques to genetically modify experimental animals and produce directed mutations in both a conditional and tissue-specific manner has dramatically opened up new fields for physiologists in cardiovascular and renal research. 2.,A consequence of altering the genetic background of mice is the difficulty in predicting the phenotypic outcome of the genetic mutation. We therefore suggest that physiologists may need to change their current experimental paradigms to face this new era. Hence, our aim is to propose a complementary research philosophy for physiologists working in the post-genomic era. That is, instead of using strictly hypothesis-driven research philosophies, one will have to perform screening studies of mutant mice, within a field of interest, to find valuable phenotypes. Once a relevant phenotype is found, in-depth studies of the underlying mechanisms should be performed. These follow-up studies should be performed using a traditional hypothesis-driven research philosophy. 3.,The rapidly increasing availability of mutated mouse models of human disease also necessitates the development of techniques to characterize these various mouse phenotypes. In particular, the miniaturization and refinement of techniques currently used to study the renal and cardiovascular system in larger animals will be discussed in the present review. Hence, we aim to outline what techniques are currently available and should be present in a laboratory to screen and study renal and cardiovascular phenotypes in genetically modified mice, with particular emphasis on methodologies used in the intact, conscious animal. [source] Assessing Qualitative Television Audience Research: Incorporating Feminist and Anthropological Theoretical InnovationCOMMUNICATION THEORY, Issue 4 2000Amanda D. Lotz During the past 20 years qualitative audience researchers have produced respected theory and applied work in their studies of media audiences. Derived from roots in traditional anthropology, audience studies use methodologies that reproduce power differentials between researchers and participants. This article considers the application of feminist ethnography to the methodologies used in audience studies by exploring developments in recent anthropological approaches to ethnography. Shifting to a theoretical base incorporating feminist ethnography aids in identifying the power hierarchies between researcher and research participant and theorizes strategies to minimize these power differentials. In sum, this article queries the epistemological premises of current audience research practices and advocates a rethinking of this research based on the contributions of feminist ethnographic theory and other emergent anthropological developments. [source] Confidence Interval Calculation Methods Are Infrequently Reported in Emergency-medicine LiteratureACADEMIC EMERGENCY MEDICINE, Issue 1 2007Amy Marr MD Abstract Background There are many different confidence interval calculation methods, each providing different as well as in some cases inadequate interval estimates. Readers who know which method is used are better able to understand potentially significant limitations in study reports. Objectives To quantify how often confidence interval calculation methods are disclosed by authors in four peer-reviewed North American emergency-medicine journals. Methods The authors independently performed searches of four journals for all studies in which comparisons were made between means, medians, proportions, odds ratios, or relative risks. Case reports, editorials, subject reviews, and letters were excluded. Using a standardized abstraction form developed on a spreadsheet, the authors evaluated each article for the reporting of confidence intervals and evaluated the description of methodology used to calculate the confidence intervals. Results A total of 212 articles met the inclusion criteria. Confidence intervals were reported in 123 articles (58%; 95% CI = 51% to 64%); of these, a description of methodology was reported in 12 (9.8%; 95% CI = 5.7% to 16%). Conclusions Confidence interval methods of calculation are disclosed infrequently in emergency medicine literature. [source] Dynamic study of cerebral bioenergetics and brain function using in vivo multinuclear MRS approachesCONCEPTS IN MAGNETIC RESONANCE, Issue 2 2005Wei Chen Abstract One of the greatest merits of nuclear magnetic resonance (NMR) methodology used in biomedical research and clinical settings is its capability of measuring various physiological parameters in vivo. Besides MR imaging (MRI), which has been routinely applied to obtain vital information in living organs at normal and diseased states, in vivo MR spectroscopy (MRS) provides an invaluable tool for determining metabolites, chemical reaction rates, bioenergetics, and their dynamic changes in the human and animals noninvasively. These MRS capabilities are further enhanced at high/ultrahigh magnetic fields because of significant gain in NMR detection sensitivity and improvement in the spectral resolution. Recent progress has shown that in vivo MRS holds great promise in many biomedical research areas,in particular, brain research. This article provides a broad review of (i) in vivo multinuclear MRS approaches, (ii) advanced MRS methodologies, and (iii) MRS applications for determining cerebral metabolism as well as bioenergetics at resting brain state and their dynamic changes in response to brain activation. © 2005 Wiley Periodicals, Inc. Concepts Magn Reson Part A 27A: 84-121, 2005 [source] Reproducibility evaluation of gross and net walking efficiency in children with cerebral palsyDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 1 2007Merel-Anne Brehm MSc In evaluating energy cost (EC) of walking, referred to as walking efficiency, the use of net measurement protocols (i.e. net=gross-resting) has recently been recommended. However, nothing is known about the comparative reproducibility of net protocols and the commonly used gross protocols. Ten minutes of resting and 5 minutes of walking at a self-selected speed were used to determine gross and net EC in 13 children with spastic cerebral palsy (CP; seven males, six females; mean age 8y 7mo [SD 3y 4mo], range 4y 1mo,13y) and in 10 children (three males, seven females) with typical development. In the former, their Gross Motor Function Classification System levels ranged from Level I to Level III; and seven had hemiplegia and six diplegia. There were four repeated sessions on different days, with periods of 1 week between sessions. Reproducibility was assessed for speed, and gross and net EC, by using the standard error of measurement. The results of this preliminary study showed that EC measurements were more variable for children with CP than for children with typical development. Furthermore, in both groups there was considerably more variability in the net measurements than in the gross measurements. We conclude that, on the basis of the methodology used, the use of gross EC, rather than net EC, seems a more sensitive measure of walking efficiency to detect clinically relevant changes in an individual child with CP. [source] The use of GIS-based digital morphometric techniques in the study of cockpit karstEARTH SURFACE PROCESSES AND LANDFORMS, Issue 2 2007P. Lyew-Ayee Abstract Cockpit karst landscapes are among the most distinctive landscapes in the world, and have been the focus of long-standing scientific interest. Early researchers used largely descriptive techniques to categorize the terrain, and subsequent work has not attempted to critically re-evaluate descriptions of landscapes using more sophisticated methods. The distinctive surface topography of cockpit karst areas can be characterized in order to compare them with other karst as well as non-karst areas, and to determine geological and/or climatic conditions that are responsible for the observed terrain. Process models of the rate of karst denudation or evolution can only be accurate if the contemporary morphology of the landscape is quantitatively and unambiguously defined. A detailed analysis of cockpit karst terrain is carried out using the latest GIS-based digital morphometric techniques in order to assess the nature of such terrain and provide further information for subsequent modelling, as well as other non-geomorphological applications, such as environmental management and conservation issues. The paper presents the methodology used for the digital analysis of terrain and landforms in the distinctive Cockpit Country area of Jamaica and its environs. The results indicate that cockpit karst may be categorized based on its vertical, horizontal and shape characteristics, as well as by looking at the semivariogram, slope characteristics, and landscape relief scale, which combine measures of vertical and horizontal scales. Copyright © 2006 John Wiley & Sons, Ltd. [source] A cautionary note on the use of species presence and absence data in deriving sediment criteriaENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2002Katherine 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] Evaluation by dental students of a communication skills course using professional role-players in a UK school of dentistryEUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 1 2005P. Croft This paper reports student (n = 180) feedback on the role-play teaching methodology used in behavioural sciences teaching at The School of Dentistry in Birmingham (UK). The feedback received on this well-established (since 1995) educational programme was collected via questionnaire (100% response rate), requiring Likert scale and free text responses. Generally students reported that they had enjoyed and valued the session. Over two-thirds (69.7%) of students rated the role-players as ,very real' and over three-quarters (78.9%) rated their feedback as ,very fair'. The data collected from this study will inform future curriculum development. Student feedback was very positive and demonstrated that the cohort (86% of all students studying in years 1, 2 and 3) found the use of professional role-players involved in behavioural sciences teaching to be both acceptable and valuable. [source] | |||||||||||||||||||||||||||||||||||||