Canadian asthma consensus report, 1999

OBJECTIVES: To provide physicians with current guidelines for the diagnosis and optimal management of asthma in children and adults, including pregnant women and the elderly, in office, emergency department, hospital and clinic settings. OPTIONS: The consensus group considered the roles of education, avoidance of provocative environmental and other factors, diverse pharmacotherapies, delivery devices and emergency and in-hospital management of asthma. OUTCOMES: Provision of the best control of asthma by confirmation of the diagnosis using objective measures, rapid achievement and maintenance of control and regular follow-up. EVIDENCE: The key diagnostic and therapeutic recommendations are based on the 1995 Canadian guidelines and a critical review of the literature by small groups before a full meeting of the consensus group. Recommendations are graded according to 5 levels of evidence. Differences of opinion were resolved by consensus following discussion. VALUES: Respirologists, immunoallergists, pediatricians and emergency and family physicians gave prime consideration to the achievement and maintenance of optimal control of asthma through avoidance of environmental inciters, education of patients and the lowest effective regime of pharmacotherapy to reduce morbidity and mortality. BENEFITS, HARMS AND COSTS: Adherence to the guidelines should be accompanied by significant reduction in patients'' symptoms, reduced morbidity and mortality, fewer emergency and hospital admissions, fewer adverse side-effects from medications, better quality of life for patients and reduced costs. RECOMMENDATIONS: Recommendations are included in each section of the report. In summary, after a diagnosis of asthma is made based on clinical evaluation, including demonstration of variable airflow obstruction, and contributing factors are identified, a treatment plan is established to obtain and maintain optimal asthma control. The main components of treatment are patient education, environmental control, pharmacotherapy tailored to the individual and regular follow-up. VALIDATION: The recommendations were distributed to the members of the Canadian Thoracic Society Asthma and Standards Committees, as well as members of the board of the Canadian Thoracic Society. In addition, collaborating groups representing the Canadian Association of Emergency Physicians, the Canadian College of Family Physicians, the Canadian Paediatric Society and the Canadian Society of Allergy and Immunology were asked to validate the recommendations. The recommendations were discussed at regional meetings throughout Canada. They were also compared with the recommendations of other similar groups in other countries. DISSEMINATION AND IMPLEMENTATION: An implementation committee has established a strategy for disseminating these guidelines to physicians, other health professionals and patients and for developing tools and means that will help integrate the recommendations into current asthma care. The plan is outlined in this report.     

To strengthen consensus, consult the stakeholders

CIOMS has been criticised for not adequately consulting stakeholders about its revised ethical guidelines regarding medical research. Political and logistical issues that arise in democratic processes and open exchange of information probably contributed to this exclusion. What might CIOMS have done to be more inclusive and attain broader consensus on its proposed revisions? Consensus is dynamic, and evolves as a community digests new information and perspectives. Engaging the public (and particularly the stakeholders) in discussion about the revisions would have generated broader consensus. It would have encouraged more stakeholders (i.e. researchers, potential research participants, research institutions, or governments) to buy in. CIOMS needs a process to encourage dialogue and stakeholder input. The CIOMS guidelines themselves promote stakeholder consultation and capacity building, but CIOMS has done relatively little to distribute or promote its own guidelines. CIOMS should do more to promote its revised guidelines, and engage stakeholders in dialogue. This paper explores the bioethics debate about universal and relative values to illustrate the value of consultation and consensus building. It concludes that like research sponsors, CIOMS and similar organisations have an ethical responsibility to facilitate capacity building in less developed areas, and to participate more actively in consensus building.     

Neonatal screening: trends, debates and consensus

This study focuses on the social and political implications of the substantial expansion of genetic tests and neonatal screening. The introduction of neonatal screening for cystic fibrosis is one of the significant developments that have fuelled debate on their appropriateness. It has raised a series of questions on the pros and cons, the role of evidence in biomedicine, and the articulation between the therapeutic approach and foetal selection. In this respect France provides an ideal research field as it was one of the first countries to generalize this screening, launched in January 2002. Several questions arise: What were the terms of the debate in France and their underlying logics? How was consensus reached? More generally, what does this screening tell us about policies on life forms today?     

Biocultural linkages--cultural consensus, cultural consonance, and human biological research

Cultural consensus analysis tests for shared models of behavior in various cultural dimensions. Cultural consonance is used to assess the degree to which individuals behave in a way that is consistent with these cultural models. Results are presented from two studies using cultural consensus and consonance analysis (CCCA) on health risk in an African American population and on diet in a mixed sample from West Alabama. In the African American case study, cultural consonance in lifestyle and social support are demonstrated to have a significant effect on blood pressure. In the diet study, significant differences in cultural consonance on the health dimension of diet between groups espousing different dietary preferences were demonstrated in spite of all groups sharing the same model of healthy foods. These studies are used to argue that more sophisticated measures of culture in human biological research are readily available and accessible for most studies.     

Parsimony via consensus

The parsimony score of a character on a tree equals the number of state changes required to fit that character onto the tree. We show that for unordered, reversible characters this score equals the number of tree rearrangements required to fit the tree onto the character. We discuss implications of this connection for the debate over the use of consensus trees or total evidence and show how it provides a link between incongruence of characters and recombination.     

Total evidence, consensus, and bat phylogeny: A distance-based approach

Resolution of the total evidence (i.e., character congruence) versus consensus (i.e., taxonomic congruence) debate has been impeded by (1) a failure to employ validation methods consistently across both tree-building and consensus analyses, (2) the incomparability of methods for constructing as opposed to those for combining trees, and (3) indifference to aspects of trees other than their topologies. We demonstrate a uniform, distance-based approach which allows for comparability among the results of character- and taxonomic-congruence studies, whether or not an identical suite of taxa has been included in all contributing data sets. Our results indicate that total-evidence and consensus trees differ little in topology if branch lengths are taken into account when combining two or more trees. In addition, when character-state data are converted to distances, our method permits their combination with information produced by techniques which generate distances directly. Moreover, treating all data sets or trees as distance matrices avoids the problem that different numbers of characters in contributing studies may confound the conclusions of a total-evidence or consensus analysis. Our protocol is illustrated with an example involving bats, in which the three component studies based on serology, DNA hybridization, and anatomy imply distinct phylogenies. However, the total-evidence and consensus trees support a fourth, somewhat different, topology resolved at all but one node and which conforms closely to the currently accepted higher category classification of Chiroptera.     

Cryo-EM density maps adjustment for subtraction,consensus and sharpening

Electron cryomicroscopy (cryo-EM) has emerged as a powerful structural biology instrument to solve near-atomic three-dimensional structures. Despite the fast growth in the number of density maps generated from cryo-EM data, comparison tools among these reconstructions are still lacking. Current proposals to compare cryo-EM data derived volumes perform map subtraction based on adjustment of each volume grey level to the same scale. We present here a more sophisticated way of adjusting the volumes before comparing, which implies adjustment of grey level scale and spectrum energy, but keeping phases intact inside a mask and imposing the results to be strictly positive. The adjustment that we propose leaves the volumes in the same numeric frame, allowing to perform operations among the adjusted volumes in a more reliable way. This adjustment can be a preliminary step for several applications such as comparison through subtraction, map sharpening, or combination of volumes through a consensus that selects the best resolved parts of each input map. Our development might also be used as a sharpening method using an atomic model as a reference. We illustrate the applicability of this algorithm with the reconstructions derived of several experimental examples. This algorithm is implemented in Xmipp software package and its applications are user-friendly accessible through the cryo-EM image processing framework Scipion.     

Leadership,consensus decision making and collective behaviour in humans

This paper reviews the literature on leadership in vertebrate groups, including recent work on human groups, before presenting the results of three new experiments looking at leadership and decision making in small and large human groups. In experiment 1, we find that both group size and the presence of uninformed individuals can affect the speed with which small human groups (eight people) decide between two opposing directional preferences and the likelihood of the group splitting. In experiment 2, we show that the spatial positioning of informed individuals within small human groups (10 people) can affect the speed and accuracy of group motion. We find that having a mixture of leaders positioned in the centre and on the edge of a group increases the speed and accuracy with which the group reaches their target. In experiment 3, we use large human crowds (100 and 200 people) to demonstrate that the trends observed from earlier work using small human groups can be applied to larger crowds. We find that only a small minority of informed individuals is needed to guide a large uninformed group. These studies build upon important theoretical and empirical work on leadership and decision making in animal groups.     

Congruence, consensus, and the comparative phylogeography of codistributed species in California

Comparative phylogeography has emerged as a means of understanding the spatial patterns of genetic divergence of codistributed species. However, researchers are often frustrated because of the lack of appropriate statistical tests to assess concordancy of multiple phylogeographic trees. We develop a method for testing congruence across multiple species and synthesizing the data into a regional supertree. Nine phylogeographic data sets of species with different life histories and ecologies were statistically compared using maximum agreement subtrees (MAST) and showed a high degree of concordancy. A supertree combining the different phylogeographic trees was then computed using matrix representation with parsimony, and the groups defined by this supertree were tested against climatic data to investigate a potential mechanism driving divergence. Our data suggest that species and genetic lineages in California are shaped by climatic regimes. The supertree method in combination with MAST represents a new approach to test congruence hypotheses and detect common geographic signals in comparative phylogeography.     

Plant chitinase consensus sequences

Eighty-six plant chitinase sequences from 29 different species and one hybrid were obtained from the on-line GenBank nucleotide database. These sequences were grouped into five gene families based on previously published guidelines (Meins et al., 1994), and the amino-acid and nucleotide sequences of each gene family were aligned. Consensus amino-acid and nucleotide sequences were derived for each gene family based on the alignments. The consensus sequences were analyzed to determine, their amino-acid composition, hydropathy profiles, and codon usage.     

Arabidopsis consensus intron sequences

We have analysed 998 Arabidopsis intron sequences in the EMBL database. All Arabidopsis introns to adhere to the :GU...AG: rule with the exception of 1% of introns with :GC at their 5 ends. Virtually all of the introns contained a putative branchpoint sequence (YUNAN) 18 to 60 nt upstream of the 3 splice site. Although a polypyrimidine tract was much less apparent than in vertebrate introns, the most common nucleotide in the region upstream of the 3 splice site was uridine. Consensus sequences for 5 and 3 splice sites and branchpoint sequences for Arabidopsis introns are presented.     

Mexican radiationdermatitis management consensus

BackgroundRadiotherapy (RT) is an essential element in cancer treatment: 50–70% of cancer patients receive RT at some time of the course of their disease. Of these, almost 95% experience some grade of radiation dermatitis (RD). RD can affect patient’s quality of life during and after treatment. Consequently, the management of RD is important. There are few randomized controlled clinical trials on interventions used to prevent and treat RD and no standardized consensus on RD management. A panel of opinion leaders of the Mexican Society of Radiotherapy (SOMERA) took part in a study of oncologic practice in Mexico. The following clinical guide is referenced both by the national practice reality and international evidence.Materials and methodsThis RD management guide is based on input provided by 25 Mexican radiation oncologists, whose criteria were gathered using the Delphi Method and article review.ResultsTwenty-one questions about experience in RD treatment were voted. More than 80% of the panel agreed with: the use of dermocosmetics/medical device in prevention and in treatment of RD grades 1–2. As for grade 3, they recommend individualizing each case and dermatologist evaluation. Topical steroids should be used when there is skin itching or pain. Consider the use of natural soaking elements. Skin care must be continued to avoid or reduce severity of late radiation skin lesions.ConclusionThis consensus was developed as a supportive educational tool that can be adapted to individual clinical needs, useful for professionals involved in the treatment of RT patients.     

Majority-rule (+) consensus trees

The construction of a consensus tree to summarize the information of a given set of phylogenetic trees is now routinely a part of many studies in systematic biology. One popular method is the majority-rule consensus tree. In this paper we introduce and characterize a new consensus method that refines the majority-rule tree by adding certain compatible clusters satisfying a simple criterion.