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Rigorous Assessment (rigorous + assessment)
Selected AbstractsA conceptual framework for the colonisation of urban areas: the blackbird Turdus merula as a case studyBIOLOGICAL REVIEWS, Issue 3 2010Karl L. Evans Despite increasing interest in urban ecology the factors limiting the colonisation of towns and cities by species from rural areas are poorly understood. This is largely due to the lack of a detailed conceptual framework for this urbanisation process, and of sufficient case studies. Here, we develop such a framework. This draws upon a wide range of ecological and evolutionary theory and the increasing number of studies of how the markedly divergent conditions in urban and rural areas influence the traits of urban populations and the structure of urban assemblages. We illustrate the importance of this framework by compiling a detailed case study of spatial and temporal variation in the urbanisation of the blackbird Turdus merula. Our framework identifies three separate stages in the urbanisation process: (i) arrival, (ii) adjustment, and (iii) spread. The rate of progress through each stage is influenced by environmental factors, especially human attitudes and socio-economic factors that determine the history of urban development and the quality of urban habitats, and by species' ecological and life-history traits. Some traits can positively influence progression through one stage, but delay progression through another. Rigorous assessment of the factors influencing urbanisation should thus ideally pay attention to the different stages. Urbanisation has some similarities to invasion of exotic species, but the two clearly differ. Invasion concerns geographic range expansion that is external to the species' original geographic range, whilst urbanisation typically relates to filling gaps within a species' original range. This process is exemplified by the blackbird which is now one of the commonest urban bird species throughout its Western Palearctic range. This is in stark contrast to the situation 150 years ago when the species was principally confined to forest. Blackbird urbanisation was first recorded in Germany in 1820, yet some European cities still lack urban blackbirds. This is especially so in the east, where urbanisation has spread more slowly than in the west. The timing of blackbird urbanisation exhibits a marked spatial pattern, with latitude and longitude explaining 76% of the variation. This strong spatial pattern contrasts with the weaker spatial pattern in timing of urbanisation exhibited by the woodpigeon Columba palumbus (with location explaining 39% of the variation), and with the very weak spatial pattern in timing of black-billed magpie Pica pica urbanisation (in which location explains 12% of the variation). Strong spatial patterns in timing of urbanisation are more compatible with the leap-frog urbanisation model, in which urban adapted or imprinted birds colonise other towns and cities, than with the independent urbanisation model, in which urban colonisation events occur independently of each other. Spatial patterns in isolation do not, however, confirm one particular model. Factors relating to the arrival and adjustment stages appear particularly likely to have influenced the timing of blackbird urbanisation. Spatial variation in the occurrence of urban populations and the timing of their establishment creates opportunities to assess the factors regulating urbanisation rates, and how the composition of urban assemblages develops as a result. These are major issues for urban ecology. [source] Performance-based seismic analysis and design of suspension bridgesEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 4-5 2005Serafim Arzoumanidis Abstract This paper presents a performance-based seismic analysis and design of a large suspension bridge, the new Tacoma Narrows Parallel Crossing in the State of Washington. The scope of the project included establishment of design criteria, extensive analysis and validation of the design. The analysis was performed using detailed three-dimensional models that included geometric and material non-linearity. The target post-earthquake level of service was verified using stress, deformation and ductility criteria. In the absence of well-established criteria, which relate the structural response of tower shafts to specific levels of performance, capacity analyses were performed to demonstrate that the design fulfills the performance objectives. The seismic analysis and design of this bridge was reviewed throughout the design process. An independent check team also performed separate analysis and validation of the design. Thus, this bridge constitutes an example of a large-scale design project where the performance-based seismic design procedures underwent rigorous assessment. This work demonstrated that the performance-based approach for seismic design is an appropriate way for designing earthquake-resistant structures. Further data that relate the structural response with the performance objectives are necessary. Copyright © 2005 John Wiley & Sons, Ltd. [source] Capillary electrophoresis of amphipathic ,-helical peptide diastereomersELECTROPHORESIS, Issue 1 2004Traian V. Popa Abstract We have made a rigorous assessment of the ability of capillary electrophoresis to resolve peptide diastereomers through its application to the separation of a series of synthetic 18-residue, amphipathic ,-helical monomeric peptide analogues, where a single site in the centre of the hydrophobic face of the ,-helix is substituted by 19 L - or D -amino acids. Such L - and D -peptide pairs have the same mass-to-charge ratio, amino acid sequence and intrinsic hydrophobicity, varying only in the stereochemistry of one residue. CE approaches assessed in their ability to separate diastereomeric peptide pairs included capillary zone electrophoresis (uncoated capillary), micellar electrokinetic chromatography (uncoated capillary in the presence of 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate, CHAPS), open-tubular capillary electrochromatography (C8 -coated capillary in the presence of 25% 2,2,2-trifluoroethanol (TFE) or 25% ethanol). Overall, the OT-CEC methods were the most effective at separating the most peptide pairs, particularly for those containing hydrophilic side chains. However, the MEKC approach proved most effective for separation of peptide pairs containing hydrophobic or aromatic side chains. [source] High within-individual variation in total mercury concentration in seabird feathersENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2008Alexander L. Bond Abstract To our knowledge, no rigorous assessment of the variation in mercury concentrations within individual seabirds has been made using multiple body feathers. We analyzed five feathers from individual Arctic terns (Sterna paradisaea Pontoppidan), common terns (Sterna hirundo L.), and Leach's storm-petrels (Oceanodroma leucorhoa Veillot) and found levels of within-individual variability higher than population or time-series variation. Using a randomization procedure, we found a large range of possible mercury concentrations if only one feather per individual had been sampled. Researchers should report within-individual variability in future studies. [source] Influences of habitat complexity on the diversity and abundance of epiphytic invertebrates on plantsFRESHWATER BIOLOGY, Issue 4 2003Hiromi Taniguchi SUMMARY 1. The compound influence of habitat complexity and patch size on stream invertebrate assemblages associated with submerged macrophytes was investigated through field sampling of two natural macrophyte species with contrasting leaf morphologies (complex, Ranunculus yezoensis; simple, Sparganium emersum) and an experiment with two artificial plants with different levels of morphological complexity. 2. The artificial plant experiment was designed to separate the effects of habitat area (patch size) and habitat complexity, thus enabling a more rigorous assessment of complexity per se than in previous studies where only a single patch size was used. Simple and complex artificial plants were established with five different patch sizes corresponding to the range found in natural plants. 3. Invertebrates occurred on both complex and simple forms of natural and artificial plants at similar abundances with dipterans and ephemeropterans being predominant. Taxon richness was higher on structurally complex Ranunculus than on simple Sparganium and was similarly higher on the complex artificial plant than on the simple one, over the entire range of habitat patch sizes. Thus, architectural complexity affected the taxon richness of epiphytic invertebrates, independently of habitat scale. 4. On the natural plants there was no difference in the abundance (both number of individuals and biomass) of invertebrates between simple and complex forms, while on artificial plants more invertebrates occurred on complex than on simple forms. The amount of particulate organic matter, >225 ,m (POM) and chlorophyll a showed mixed patterns on natural and artificial plants, suggesting that the availability of these resources is not an overriding proximate factor controlling invertebrate abundance on plants. The difficulty of extrapolating from experimental results involving use of artificial plants is discussed, especially when considering the relationship between habitat structure and the occurrence of epiphytic invertebrates on natural plants. [source] "Unknown Risks" of non-steroid topical medications for atopic dermatitisINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 6 2007Anne Marie McNeill PhD Introduction, Tacrolimus ointment is a nonsteroid treatment for atopic dermatitis which is both effective and has a minimal side-effect profile. However, some clinicians may be reluctant to use tacrolimus ointment due to the "unknown risks", meaning those that have not been uncovered in human studies conducted thus far. Therefore, the available animal data regarding the "unknown risks" of topical tacrolimus therapy are reviewed, and a discussion of the interpretation of this available but limited data is presented. Animal studies, Some of the fear on the part of clinicians regarding the use of topical tacrolimus may come from the results of animal studies which showed an increase in lymphoma and UV-induced skin cancer after treatment with topical tacrolimus in animal models of carcinogenesis. However, rigorous assessment of these studies suggest that it is somewhat likely that these represent a species-specific response to tacrolimus in an animal already predisposed to tumor formation, and therefore may not be relevant in assessing the possibility of an increased human health risk. Conclusions, Animal and human studies suggest that topical tacrolimus is a safe alternative to topical steroids, with the major known adverse effect being a transient burning sensation, compared with the known adverse effects of topical steroids, including long-lasting ones. Therefore, in the opinion of the authors, currently available data, including animal studies, does not suggest that "unknown risks" of topical tacrolimus need be any more concerning than the known side-effects of the topical steroids. [source] International Relations Theory and the Second Korean WarINTERNATIONAL STUDIES QUARTERLY, Issue 3 2003David C. Kang Ever since the first Korean war in 1950, scholars and policymakers have been predicting a second one, started by an invasion from the North. Whether seen as arising from preventive, preemptive, desperation, or simple aggressive motivations, the predominant perspective in the west sees North Korea as likely to instigate conflict. Yet for fifty years North Korea has not come close to starting a war. Why were so many scholars so consistently wrong about North Korea's intentions? Social scientists can learn as much from events that did not happen as from those that did. The case of North Korea provides a window with which to examine these theories of conflict initiation, and reveals how the assumptions underlying these theories can become mis-specified. Either scholars misunderstood the initial conditions, or they misunderstood the theory, and I show that scholars have made mistakes in both areas. Social science moves forward from clear statement of a theory, its causal logic, and its predictions. However, just as important is the rigorous assessment of a theory, especially if the predictions fail to materialize. North Korea never had the material capabilities to be a serious contender to the U.S.,ROK alliance, and it quickly fell further behind. The real question has not been whether North Korea would preempt as South Korea caught up, but instead why North Korea might fight as it fell further and further behind. The explanation for a half-century of stability and peace on the Korean peninsula is actually quite simple: deterrence works. [source] World Commission on Dams: implications for food and irrigation1,IRRIGATION AND DRAINAGE, Issue 2 2001Chris Perry barrages; l'irrigation; securité d'alimentation Abstract The World Commission on Dams has now published its report. Insights into the workings and conclusions of the Commission were published in the last edition of this Journal. While the WCD report brings together a number of important existing and new recommendations on ameliorating the negative impacts of large dams, it pays inadequate attention to the impacts in the major area (food production and security) for which dams have been built. Consideration of data presented by the WCD would suggest a more positive impact, and a brief review of national and world trends in food production suggests that irrigation , of which large dams are an intrinsic and central component , has underlain if not dominated the vast improvement in food availability that occurred in the second half of the last century. With water in crisis in many countries, planners, policymakers and politicians will continue to face challenging decisions on the allocation of limited freshwater supplies, and demands to increase the level of water resources development. Some guidance from the WCD is helpful, and some is flawed. Most importantly, much is missing, and to be useful, guidance must reflect rational and balanced, expert and rigorous assessment of all the impacts of the available options. Copyright © 2001 John Wiley & Sons, Ltd. La Commission Globale des Barrages a maintenant publiée son rapport. Quelques apercus sur les méthodes et les conclusions de la commission ont été données dans la dernière edition de ce journal. Quant le rapport CGB a se rassemblé quelques recommendations nouveaux et actuels pour amèliorer les impacts négatifs des grands barrages, il n'y a pas d'attention suffisante donnés aux impacts sur les questions importantes (comme le production et la sécurité d'alimentation) pour qui les barrages ont étés construits. Penser aux donnés du CGB suggère un impact plus positif et un critique des tendances nationale et globale du production d'alimentation denote que l'irrigation (dont les grands barrages sont un composant central et intrinsèque) a soutienne si non dominée l'immense amélioration de la disponibililité d'alimentation dans la dernière partie du XXe siècle. Avec la crise actuèlle de l'eau en beaucoup de pays, les planificateurs, les dirigants de politique et les politiciens se continuent de faire face aux decisions difficile sur les questions d'allocation d'eau limitée et les demands pour une augmentation de développement des resources en eau. Quelques conseils du CGB sont util mais quelques uns sont en défaut. Les plus importantes problèmes sont que le rapport manque beaucoup de choses et que, pour être utile, les conseils doivent réfléchir les impactes de tous les choix dans une façon rationale et équilibrée avec une évaluation experte et rigoureuse. Copyright © 2001 John Wiley & Sons, Ltd. [source] Population growth and mass mortality of an estuarine fish, Acanthopagrus butcheri, unlawfully introduced into an inland lakeAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 1 2009Kimberley Smith Abstract 1.In 2006, two periods of hypoxia resulted in the death of approximately 35 tonnes of black bream (Acanthopagrus butcheri) in Lake Indoon, a small inland lake in Western Australia. 2.Acanthopagrus butcheri was the first fish species to be recorded in this lake, along with the mosquitofish (Gambusia holbrooki) which was also observed during sampling in 2006. Acanthopagrus butcheri appears to have been introduced to Lake Indoon between 1998 and 2003 and formed a self-sustaining population. It is believed to have been deliberately introduced for the purpose of creating a recreational fishery, despite the existence of substantial penalties for illegal translocation of fish in Western Australia. 3.Recent human-induced environmental changes, including rising groundwater and salinization, have probably aided the establishment of both species in Lake Indoon. The importance of salinity to recruitment success by A. butcheri was indicated by the presence of only two age classes in 2006, with estimated recruitment dates coinciding with the years of highest recorded salinity in the lake. 4.The ,fish kills' provided an opportunity to examine aspects of A. butcheri biology in a relatively low salinity environment which is atypical for this estuarine species. In particular, the recruitment period in Lake Indoon was delayed until autumn/winter, rather than spring/summer as seen in other populations. Biological responses in Lake Indoon have implications for natural populations living in estuaries with modified salinity regimes. 5.The ecological, social and economic impacts potentially arising from the introduction of fish to Lake Indoon, which is an important migratory bird habitat and a recreational amenity for local residents and tourists, illustrate the complexities of fish translocation and the need for rigorous assessment before stocking to identify potential costs and benefits. Copyright © 2008 John Wiley & Sons, Ltd. [source] National guidelines for the control and prevention of methicillin-resistant Staphylococcus aureus,what do they tell us?CLINICAL MICROBIOLOGY AND INFECTION, Issue 9 2007H. HumphreysArticle first published online: 30 JUN 200 Abstract Guidelines to control and prevent methicillin-resistant Staphylococcus aureus (MRSA) infection are available in many countries. Infection control and prevention teams determine local strategies using such national guidelines, but not all guidelines involve a rigorous assessment of the literature to determine the strength of the recommendations. Available guidelines drafted by national agencies or prominent professional organisations in Germany, New Zealand, North America, The Netherlands, Ireland and the UK were reviewed. Significant literature reviews were a component of guidelines from the UK and North America. Recommendations were not graded on the strength of the evidence in guidelines from New Zealand and The Netherlands. The Netherlands, a country with a very low prevalence of MRSA, had the simplest set of guidelines. Few of the recommendations in any of the guidelines achieved the highest grading, i.e., based on well-designed, experimental, clinical or epidemiological studies, even though the logic of the proposed measures is clear. The onset of community-acquired MRSA is reflected in the recent publication of guidelines from North America. New developments, such as rapid testing and mathematical modelling, are of importance in helping to control MRSA in settings of both low and high endemicity. National guidelines are increasingly evidence-based, although good scientific studies concerning some aspects of MRSA control are lacking. However, general principles, e.g., early detection and isolation, are recommended by all guidelines. There is still a role for consensus and the opinion of experts in devising national guidelines. [source] Serious case reviews: learning to use expertiseCHILD ABUSE REVIEW, Issue 3 2005Marian Brandon Abstract While undertaking an analysis of 20 serious case reviews for the Welsh Assembly Government, the authors became aware of important, largely unexplored, practice issues with implications for training, service delivery and the role of the lead professional. The reviews were studied using a ,layered reading' methodology to ensure that emerging themes were grounded entirely in the reports. In looking beyond the familiar recurring themes and practice failings, findings emerged about the use of expertise in its widest sense. The need for more skilled use of expertise was identified, from external specialists and child protection specialists, and from children, siblings and parents. Professionals from agencies who contribute less routinely to the process of safeguarding children should be consulted as experts and be empowered to play a fuller part. Consultation could often be used prior to, or in place of referral. The barrier to the collation and analysis of relevant information often appeared to be a failure to recognize and understand expertise rather than a lack of communication as often postulated in review reports. Skilled use of expertise and consultation in a coordinated manner could result in more rigorous assessments and promote greater professional trust, confidence and challenge. Copyright © 2005 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||