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Assumptions
Kinds of Assumptions Terms modified by Assumptions Selected AbstractsTESTING ASSUMPTIONS OF NEUTRON ACTIVATION ANALYSIS: COMMUNITIES, WORKSHOPS AND PASTE PREPARATION IN YUCATAN, MEXICO,ARCHAEOMETRY, Issue 2 2000D. E. ARNOLD Contemporary pottery and raw materials (N= 170) from three workshops in Ticul, Yucatán, were analysed by neutron activation to test the hypothesis that individual workshops that used their own clay sources could be identified by their pottery. Although the data failed to confirm the hypothesis, the results reinforced previous conclusions about the relationship of local communities of potters to the chemical patterning of pottery made in these communities. [source] Implications for Asset Pricing Puzzles of a Roll-over Assumption for the Risk-Free Asset,INTERNATIONAL REVIEW OF FINANCE, Issue 3-4 2008GEOFFREY J. WARREN ABSTRACT The equity risk premium and risk-free rate puzzles are largely resolved by combining persistent uncertainty over the long-term consumption growth rate with analysis of the risk-free asset on a ,roll-over' basis. Under these conditions, cash equivalents are evaluated as a multi-period investment strategy that hedges against adverse growth rate outcomes. The premium on the risky asset is raised and the risk-free rate lowered due to their respective relation with multi-period consumption risk. Historical average asset returns are matched at plausible risk aversion. [source] Sacred Places, Domestic Spaces: Material Culture, Church, and Home at Our Lady of the Assumption and St. BrigittaJOURNAL FOR THE SCIENTIFIC STUDY OF RELIGION, Issue 3 2009Mary Ellen Konieczny The relationship between the material culture of public worship and congregants' homes is explored in a study of two Catholic parishes,theologically liberal St. Brigitta and conservative Our Lady of Assumption. At St. Brigitta, congregants' worship space is almost devoid of religious art and ritual objects are plain, but worshippers' homes are rich in decorative objects. By contrast, masses at Our Lady of the Assumption take place in a church filled with devotional art and ornate objects, but worshippers' homes are spare, neutrally furnished, and display few decorations. Distinct congregational logics surrounding the making of the self help to explain the material culture differences: St. Brigitta parishioners value individualized self-expression whereas Assumption's members subordinate individuality to family and church identities. Individuals use material objects not only for self-expression, but also to explicitly shape identities and make the self. [source] The historical biogeography of co-evolution: emerging infectious diseases are evolutionary accidents waiting to happenJOURNAL OF BIOGEOGRAPHY, Issue 8 2005Daniel R. Brooks Abstract Ecological fitting refers to interspecific associations characterized by ecologically specialized, yet phylogenetically conservative, resource utilization. During periods of biotic expansion, parasites and hosts may disperse from their areas of origin. In conjunction with ecological fitting, this sets the stage for host switching without evolving novel host utilization capabilities. This is the evolutionary basis of emerging infectious diseases (EIDs). Phylogenetic analysis for comparing trees (PACT) is a method developed to delineate both general and unique historically reticulated and non-reticulated relationships among species and geographical areas, or among parasites and their hosts. PACT is based on ,Assumption 0', which states that all species and all hosts in each input phylogeny must be analysed without modification, and the final analysis must be logically consistent with all input data. Assumption 0 will be violated whenever a host or area has a reticulated history with respect to its parasites or species. PACT includes a Duplication Rule, by which hosts or areas are listed for each co-evolutionary or biogeographical event affecting them, which satisfies Assumption 0 even if there are reticulations. PACT maximizes the search for general patterns by using Ockam's Razor , duplicate only enough to satisfy Assumption 0. PACT applied to the host and geographical distributions of members of two groups of parasitic helminths infecting anthropoid primates indicates a long and continuous association with those hosts. Nonetheless, c. 30% of the host associations are due to host switching. Only one of those involves non-primate hosts, suggesting that most were constrained by resource requirements that are phylogenetically conservative among primates (ecological fitting). In addition, most of the host switches were associated with episodes of biotic expansion, also as predicted by the ecological fitting view of EIDs. [source] Cladistic biogeography and the art of discoveryJOURNAL OF BIOGEOGRAPHY, Issue 4 2002Malte C. Ebach Aims Cladistic biogeography is about discovering geographical congruence. The agreement of several taxon-area cladograms (TACs) rarely yields a perfect result. Areas may overlap, taxa may not be evenly distributed, and thus, ambiguity may be prevalent in the data. Ambiguity is incongruence and may be resolved by reducing paralogy and resolving potential information. Recently, several new approaches in cladistic biogeography [i.e. Brooks parsimony analysis (BPA), Assumption 0] interpret ambiguity as congruence. These methods are problematic, as they are generational. Methods constructed under the generation paradigm are flawed concepts that are immunized from falsifying evidence. A critique of modified BPA reveals that taking an evolutionary stance in biogeography leads to flaws in implementation. Methods Area cladistics is a new development in cladistic biogeography. Area cladistics adopts paralogy-free subtree analysis using Assumption 2, to discover the relative positions of continents through time. Results Geographical congruence is the result of allopatric (geographical) speciation. Vicariance, dispersal and combinations of both, are recognized causes for allopatric speciation. Area cladistics highlights the concept that all these events occur in response to geological changes (e.g. continental drift) either directly, by geographical boundaries, or indirectly, at the level of ocean currents. Samples of chosen examples all respond to the geological process. The examples include Ordovician,Silurian and Lower Devonian trilobites to yield a general areagram which is a representational branching diagram that depicts the relationships of areas. Main conclusion Finding one common biogeographical pattern from several unrelated groups is a qualitative approach to interpret the positions of continental margins through time. Area cladistics is not a substitute for palaeomaps that are derived from palaeomagnetic data, but general areagrams adding to the body of knowledge that yields more precise interpretations of the earth's past. [source] Sano di Pietro's Assunta polyptych for the Convent of Santa Petronilla in SienaRENAISSANCE STUDIES, Issue 4 2005Diana Norman Since its incorporation into Siena's first public art collection early in the nineteenth century, the provenance of Sano di Pietro's polyptych of The Virgin of the Assumption with Saints has been recognised as the Clarissan church of Santa Petronilla. To date, however, there has been very little comment as to the significance of the provenance of the altarpiece, particularly in relation to the choice of subject matter. This essay explores the complex history of this major Clarissan foundation in Siena, identifying its first location beyond Siena's principal northern gate of Porta Camollia and then describing its subsequent removal during the mid sixteenth century into the safety of the city itself and to the church where the altarpiece was discovered in 1810. Recognising that the presence of a Clarissan donor figure on the central painting of the polyptych provides plausible evidence that the altarpiece was commissioned for the original convent church, the essay further demonstrates how the circumstances of the foundation of Santa Petronilla in the second decade of the thirteenth century provide a key for the principal subject matter of the altarpiece. The remaining imagery of the altarpiece is then discussed in terms of its general relevance for a fifteenth-century community of Clarissan nuns and for the particular devotional concerns of the nuns of Santa Petronilla. It is argued that this late fifteenth-century Sienese altarpiece offers a revealing example of the way in which art commissioned by enclosed orders of female religious within Renaissance Italy could be closely related to their own concerns and priorities. (pp. 433,457) [source] Mathematical model for mixing index in gas,solid fluidized bed: an analysisASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 4 2010Abanti Sahoo Abstract An available theoretical model for mixing index in gas-solid fluidized bed has been analyzed for further modification and improvement. Assumption of 50% bed material moving in the upward direction and rest 50% in the downward direction considered for the above model (the counter-flow circulation model) has been analyzed for optimum result. A computer program was run for different bed conditions by varying operating parameters, namely, the mixture composition, fractions of bed materials, minimum fluidization velocity of the jetsam particles and that of the bed materials (i.e. mixture of the jetsam and the flotsam particles). The developed model was solved by finite difference (central differencing). Fraction of the bed material moving in the upward direction was varied from 0 to 100% and the minimum fluidization velocity was varied within the Umf of the flotsam to that of the jetsam particles (i.e. 0.465,1.0335 m/s). Optimum fraction of bed materials with respect to its distribution (as per the earlier proposed model) in the upward and downward streams during the fluidization process was found to be 20 and 80%, respectively. The modified model was validated by conducting experiments on fluidization and studying the mixing characteristics of regular homogeneous materials (sago) in a 15 × 100 cm cylindrical column. Fairly good agreement was observed between the values of mixing index obtained from the proposed modified model and the experimental observations. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Escaping the matrix: a new algorithm for phylogenetic comparative studies of co-evolutionCLADISTICS, Issue 4 2004Maggie Wojcicki An algorithm for generating host cladograms from parasite-host cladograms derived from parasite phylogenies, Phylogenetic Analysis for Comparing Trees (PACT), is described. PACT satisfies Assumption 0, that all the information in each parasite-host cladogram must be used in a co-evolutionary analysis, and that the host relationships depicted in the final host cladogram must be logically consistent with the phylogenetic relationships depicted in every part of every parasite-host cladogram used to construct the host cladogram. It accounts for cases of speciation by host switching and expansion of host range, and reticulated host relationships, in addition to co-speciation, sympatric speciation, and extinction in all input parasite-host cladograms, and does so without a priori weighting schemes and without a posteriori manipulation of the data. [source] Evolution Is Not a Necessary Assumption of CladisticsCLADISTICS, Issue 1 2000Andrew V.Z. Brower Although the point has already been emphasized by various authors that the assumption of descent with modification is not required to justify cladistics, recent debate suggests that there is still confusion surrounding the necessary and sufficient background knowledge underlying the method. Three general axioms necessary to justify cladistics,the discoverability of characters, hierarchy, and parsimony,are reviewed. Although the assumption of evolution is sufficient to justify cladistics, it is also sufficient to justify competing approaches like maximum likelihood, which suggests that the philosophical support for the cladistic approach is strengthened by purging reference to descent with modification altogether. [source] Managing Stock Option Expense: The Manipulation of Option-Pricing Model Assumptions,CONTEMPORARY ACCOUNTING RESEARCH, Issue 2 2006Derek Johnston Abstract This paper examines whether firms that voluntarily recognize stock option expense in their financial statements manage that expense downward more than firms that do not recognize the expense by adjusting option-pricing model assumptions. To examine this issue, I collect option-pricing model assumptions from fiscal year 2002 for both a sample of firms that voluntarily recognize stock option expense ("recognizing firms") and a sample of control firms that do not ("disclosing firms"). The empirical results suggest that recognizing firms manage the recognized stock-based compensation expense reported in their financial statements downward more than do firms that only disclose the expense. Additional analyses reveal that recognizing firms assume a lower level of volatility than disclosing firms in the option-pricing model calculations; however, I find no evidence that recognizing firms manage the dividend yield and risk-free interest rate assumptions more than disclosing firms. The Financial Accounting Standards Board (FASB) recently issued Statement of Financial Accounting Standards No. 123(R), which requires the expensing of the fair value of stock options, so these results may be of interest to capital-market participants and the FASB as they assess the reliability of stock option expense as determined by option-pricing models. [source] Differences between European birthweight standards: impact on classification of ,small for gestational age'DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 11 2006K Hemming PhD We describe a quantitative and comparative review of a selection of European birthweight standards for gestational age for singletons, to enable appropriate choices to be made for clinical and research use. Differences between median values at term across standards in 10 regions and misclassification of 'small for gestational age'(SGA), were studied. Sex and parity differences, exclusion criteria, and methods of construction were considered. There was wide variation between countries in exclusion criteria, methods of calculating standards, and median birthweight at term. The lightest standards (e.g. France's medians are 255g lower than Norway's medians) were associated with fewer exclusion criteria. Up to 20% of the population used in the construction of the Scottish standard would be classified as SGA using the Norwegian standard. Substantial misclassification of SGA is possible. Assumptions about variation used in the construction of some standards were not justified. It is not possible to conclude that there are real differences in birthweight standards between European countries. Country-based standards control for some population features but add misclassification due to the differing ways in which standards are derived. Standards should be chosen to reflect clinical or research need. If standards stratified by sex or parity are not available, adjustments should be made. In multinational studies, comparisons should be made between results using both a common standard and country-based standards. [source] Applying species-sensitivity distributions in ecological risk assessment: Assumptions of distribution type and sufficient numbers of species,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2000Michael C. Newman Abstract Species-sensitivity distribution methods assemble single-species toxicity data to predict hazardous concentrations (HCps) affecting a certain percentage (p) of species in a community. The fit of the lognormal model and required number of individual species values were evaluated with 30 published data sets. The increasingly common assumption that a lognormal model best fits these data was not supported. Fifteen data sets failed a formal test of conformity to a lognormal distribution; other distributions often provided better fit to the data than the lognormal distribution. An alternate bootstrap method provided accurate estimates of HCp without the assumption of a specific distribution. Approximate sample sizes producing HC5 estimates with minimal variance ranged from 15 to 55, and had a median of 30 species-sensitivity values. These sample sizes are higher than those suggested in recent regulatory documents. A bootstrap method is recommended that predicts with 95% confidence the concentration affecting 5% or fewer species. [source] Couples' Relationships: Questioning Assumptions, Beliefs, and ValuesFAMILY PROCESS, Issue 2 2005Evan Imber-Black I want to express my deep appreciation to Howard J. Markman and Kim Halford for their excellent work as guest editors of the special section, Couple Relationship Education in an International Context. [source] International Organizations in Transfer of Infectious Diseases: Iterative Loops of Adoption, Adaptation, and MarketingGOVERNANCE, Issue 2 2004Gill Walt Over the past few years increasing attention has been given to the role of international organizations in the diffusion of policy ideas and promotion of particular macro-level policies. Much of the attention has been on the ideological driving forces behind such policies, and on the extent to which the policies are externally imposed. There has been limited discussion on the bread-and-butter, technical policies of international organizations, and how they devise, adopt, adapt, and then promote what come to be seen as policies of global "best practice." This paper seeks to redress this gap by looking at the process of transfer of two infectious disease policies between international and national levels. It demonstrates that international organizations play different roles in policy transfer at particular stages in the process. The paper suggests that health policy transfer is a long adaptive process, made up of several iterative loops, as research and clinical practices developed in one or more countries are adopted, adapted, and taken up by international organizations which then mobilize support for particular policies, market, and promote them. Assumptions that new ideas about policies flow "rationally" into existing decision making are challenged by the processes analyzed here. Policy transfer, given the experience of these infectious diseases policies, goes through separate, "bottom-up," research-oriented, and "top-down" marketing-oriented loops. Individuals and different configurations of networks play key roles linking these loops. In the process, complex, context-specific policies are repackaged into simplified guidelines for global best practice, leading to considerable contestation within the policy networks. [source] Governance Reform in Thailand: Questionable Assumptions, Uncertain OutcomesGOVERNANCE, Issue 3 2000Bidhya Bowornwathana This article examines the nature of governance reform in Thailand. The argument is that Thai citizens are not especially benefiting from the public reform initiatives of Thai governments because government reformers made fourquestionable assumptions about reform which have in turn produced uncertain outcomes and provided the opportunity for government reformers to avoid responsibility for their reform choices. First, the reformers support the belief that a global reform paradigm with ready-made reform packages exists which can be easily transplanted in the Thai public sector. Second, the reformers prefer to define success largely as reform output rather than reform outcomes or long term reform consequences. Third, Thai government reformers have overemphasized the efficiency aspects of the new public management at the expense of other governance goals. Fourth, governance reform in Thailand has been portrayed as a managerial problem instead of a political one. The author supports his arguments by drawing on theoretical debates in the international literature on administrative reform, and relating these debates to the Thai case. Governance reform in Thailand is still at an early stage, but the role of unintended consequences is important to administrative reform. Furthermore, the Thai case may reflect governance reform in other countries as well. [source] On the Governing Equations and Model Assumptions for Multiphase Flow in Porous MediaGROUND WATER, Issue 4 2000Amir Gamliel No abstract is available for this article. [source] Implications of system expansion for the assessment of well-to-wheel CO2 emissions from biomass-based transportationINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 13 2010Elisabeth Wetterlund Abstract In this paper we show the effects of expanding the system when evaluating well-to-wheel (WTW) CO2 emissions for biomass-based transportation, to include the systems surrounding the biomass conversion system. Four different cases are considered: DME via black liquor gasification (BLG), methanol via gasification of solid biomass, lignocellulosic ethanol and electricity from a biomass integrated gasification combined cycle (BIGCC) used in a battery-powered electric vehicle (BPEV). All four cases are considered with as well as without carbon capture and storage (CCS). System expansion is used consistently for all flows. The results are compared with results from a conventional WTW study that only uses system expansion for certain co-product flows. It is shown that when expanding the system, biomass-based transportation does not necessarily contribute to decreased CO2 emissions and the results from this study in general indicate considerably lower CO2 mitigation potential than do the results from the conventional study used for comparison. It is shown that of particular importance are assumptions regarding future biomass use, as by expanding the system, future competition for biomass feedstock can be taken into account by assuming an alternative biomass usage. Assumptions regarding other surrounding systems, such as the transportation and the electricity systems are also shown to be of significance. Of the four studied cases without CCS, BIGCC with the electricity used in a BPEV is the only case that consistently shows a potential for CO2 reduction when alternative use of biomass is considered. Inclusion of CCS is not a guarantee for achieving CO2 reduction, and in general the system effects are equivalent or larger than the effects of CCS. DME from BLG generally shows the highest CO2 emission reduction potential for the biofuel cases. However, neither of these options for biomass-based transportation can alone meet the needs of the transport sector. Therefore, a broader palette of solutions, including different production routes, different fuels and possibly also CCS, will be needed. Copyright © 2009 John Wiley & Sons, Ltd. [source] Modelling lifetime QALYs and health care costs from different drinking patterns over time: a Markov modelINTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 2 2010Carolina Barbosa Abstract The negative health consequences of alcohol use and its treatment account for significant health care expenditure worldwide. Long-term modelling techniques are developed in this paper to establish a link between drinking patterns, health consequences and alcohol treatment effectiveness and cost-effectiveness. The overall change in health related quality and quantity of life which results from changes in health-related behaviour is estimated. Specifically, a probabilistic lifetime Markov model is presented where alcohol consumption in grams of alcohol per day and drinking history are used for the categorization of patients into four Markov states. Utility weights are assigned to each drinking state using EQ-5D scores. Mortality and morbidity estimates are state, gender and age specific, and are alcohol-related and non-alcohol-related. The methodology is tested in a case study. This represents a major development in the techniques traditionally used in alcohol economic models, in which short-term costs and outcomes are assessed, omitting potential longer term cost savings and improvements in health related quality of life. Assumptions and implications of the approach are discussed. Copyright © 2010 John Wiley & Sons, Ltd. [source] A Change of Climate Provokes a Change of Paradigm: Taking Leave of Two Tacit Assumptions about Physical Lake ForcingINTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 4-5 2008David M. Livingstone Abstract Physically, lakes have traditionally been viewed as individual systems forced by statistically stationary local weather. This view implies that the physical response of a lake to external physical forcing is unique and stationary. Recent recognition of the importance of large-scale climatic forcing in driving physical lake processes, combined with the realisation that this forcing is undergoing a long-term trend as a result of climate change, has led to a shift in this paradigm. The new physical paradigm views lakes more in terms of a local response to large-scale climatic forcing modulated by the addition of local noise. A strong climate signal leads to large-scale spatial coherence in the physical lake response, while the existence of trends in large-scale climatic forcing associated with climate change means that both the forcing and the physical lake response are statistically non-stationary. Thus increasing realisation of the importance of climate and climate change is invalidating the tacit assumptions of individuality and stationarity that underlie the old conceptual framework, resulting in its gradual abandonment in favour of a new paradigm based on the concepts of spatial coherence and temporal non-stationarity. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Is Defibrillation Testing Still Necessary?JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2008A Decision Analysis, Markov Model Objective: To assess the impact of defibrillation threshold (DFT) testing of implanted cardioverter-defibrillators (ICDs) on survival. Background: DFT testing is generally performed during implantation of ICDs to assess sensing and termination of ventricular fibrillation. It is common clinical practice to defibrillate ventricular fibrillation twice at an output at least 10 J below the maximum output of the device, providing a 10 J safety margin. However, there are few data regarding impact of DFT testing on outcomes. Methods: Decision analysis and Monte Carlo simulation were used to assess expected outcomes of DFT testing. Survival of a hypothetical cohort of patients was assessed according to two strategies,routine DFT testing at time of ICD implant versus no DFT testing. Assumptions in the model were varied over a range of reasonable values to assess outcomes under a variety of scenarios. Results: Five-year survival with DFT and no-DFT strategies were similar at 59.72% and 59.36%, respectively. The results were not sensitive to changing risk estimates for arrhythmia incidence and safety margin. Results of the Monte Carlo simulation were qualitatively similar to the base case scenario and consistent with a small and nonsignificant survival advantage with routine DFT testing. Conclusions: The impact of DFT testing on 5-year survival in ICD patients, if it exists, is small. Survival appears higher with DFT testing as long as annual risk of lethal arrhythmia or the risk of a narrow safety margin is at least 5%, although the incremental benefit is marginal and 95% confidence intervals cross zero. A prospective randomized study of DFT testing in modern devices is warranted. [source] An Approach to Evaluating the Missing Data Assumptions of the Chain and Post-stratification Equating Methods for the NEAT DesignJOURNAL OF EDUCATIONAL MEASUREMENT, Issue 1 2008Paul W. Holland Two important types of observed score equating (OSE) methods for the non-equivalent groups with Anchor Test (NEAT) design are chain equating (CE) and post-stratification equating (PSE). CE and PSE reflect two distinctly different ways of using the information provided by the anchor test for computing OSE functions. Both types of methods include linear and nonlinear equating functions. In practical situations, it is known that the PSE and CE methods will give different results when the two groups of examinees differ on the anchor test. However, given that both types of methods are justified as OSE methods by making different assumptions about the missing data in the NEAT design, it is difficult to conclude which, if either, of the two is more correct in a particular situation. This study compares the predictions of the PSE and CE assumptions for the missing data using a special data set for which the usually missing data are available. Our results indicate that in an equating setting where the linking function is decidedly non-linear and CE and PSE ought to be different, both sets of predictions are quite similar but those for CE are slightly more accurate. [source] Insights into creation and use of prescribing documentation in the hospital medical recordJOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 5 2005Mary P. Tully PhD MRPharmS Abstract Rationale, aims and objectives, Extraction of prescribing data from medical records is a common, albeit flawed, research method. Yet little is known about the processes that result in those data. This study explores the creation and use of prescribing documentation in the medical record, from the perspective of the hospital doctors who both create and use it. Methods, Thirty-six hospital doctors were purposively selected for qualitative interviews, giving a maximum variability sample of grades of doctors across the range of major medical specialty areas and medical teams at a large teaching hospital in England. Results, The findings suggest a number of reasons why hospital doctors fail to record prescribing decisions in the medical record. There was no set standard, record keeping was not formally taught and the hurried environment of the ward gave little time for documentation. The doctors also acknowledged that there was no need for completeness, as colleagues would be able to ,fill in the gaps' via an inferential process. ,Assumptions ,were ,made ,and ,although ,this ,was ,not ,seen ,as ,ideal, it was recognized as necessary if work was to be done efficiently. Conclusion, These results reinforce the suggestion that, despite the large number of potential users, the medical record is created for those with the right privileged knowledge. This has profound implications for those without that insider knowledge who are using medical records for research purposes. Funding, This work was funded by a North West Regional National Health Service Postdoctoral Fellowship. [source] Mixture Interpretation: Defining the Relevant Features for Guidelines for the Assessment of Mixed DNA Profiles in Forensic Casework,JOURNAL OF FORENSIC SCIENCES, Issue 4 2009Bruce Budowle Ph.D. Abstract:, Currently in the United States there is little direction for what constitutes sufficient guidelines for DNA mixture interpretation. While a standardized approach is not possible or desirable, more definition is necessary to ensure reliable interpretation of results is carried out. In addition, qualified DNA examiners should be able to review reports and understand the assumptions made by the analyst who performed the interpretation. Interpretation of DNA mixture profiles requires consideration of a number of aspects of a mixed profile, many of which need to be established by on-site, internal validation studies conducted by a laboratory's technical staff, prior to performing casework analysis. The relevant features include: criteria for identification of mixed specimens, establishing detection and interpretation threshold values, defining allele peaks, defining nonallele peaks, identifying artifacts, consideration of tri-allelic patterns, estimating the minimum number of contributors, resolving components of a mixture, determining when a portion of the mixed profile can be treated as a single source profile, consideration of potential additive effects of allele sharing, impact of stutter peaks on interpretation in the presence of a minor contributor, comparison with reference specimens, and some issues related to the application of mixture calculation statistics. Equally important is using sensible judgment based on sound and documented principles of DNA analyses. Assumptions should be documented so that reliable descriptive information is conveyed adequately concerning that mixture and what were the bases for the interpretations that were carried out. Examples are provided to guide the community. Interpretation guidelines also should incorporate strategies to minimize potential bias that could occur by making inferences based on a reference sample. The intent of this paper is to promote more thought, provide assistance on many aspects for consideration, and to support that more formalized mixture interpretation guidelines are developed. [source] Models, Assumptions, and Stakeholders: Planning for Water Supply Variability in the Colorado River Basin,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 2 2008Dustin Garrick Abstract:, Declining reservoir storage has raised the specter of the first water shortage on the Lower Colorado River since the completion of Glen Canyon and Hoover Dams. This focusing event spurred modeling efforts to frame alternatives for managing the reservoir system during prolonged droughts. This paper addresses the management challenges that arise when using modeling tools to manage water scarcity under variable hydroclimatology, shifting use patterns, and institutional complexity. Assumptions specified in modeling simulations are an integral feature of public processes. The policymaking and management implications of assumptions are examined by analyzing four interacting sources of physical and institutional uncertainty: inflow (runoff), depletion (water use), operating rules, and initial reservoir conditions. A review of planning documents and model reports generated during two recent processes to plan for surplus and shortage in the Colorado River demonstrates that modeling tools become useful to stakeholders by clarifying the impacts of modeling assumptions at several temporal and spatial scales. A high reservoir storage-to-runoff ratio elevates the importance of assumptions regarding initial reservoir conditions over the three-year outlook used to assess the likelihood of reaching surplus and shortage triggers. An ensemble of initial condition predictions can provide more robust initial conditions estimates. This paper concludes that water managers require model outputs that encompass a full range of future potential outcomes, including best and worst cases. Further research into methods of representing and communicating about hydrologic and institutional uncertainty in model outputs will help water managers and other stakeholders to assess tradeoffs when planning for water supply variability. [source] Kinds of Assumptions and Their Truth: Shaking an Untwisted F-TwistKYKLOS INTERNATIONAL REVIEW OF SOCIAL SCIENCES, Issue 3 2000Uskali Mäki In an insightful article published in this journal, Alan Musgrave (1981) has argued that once we distinguish between three types of assumptions, Milton Friedman's F-twist , according to which the truth of the assumptions of an economic theory is irrelevant to its acceptability , can be untwisted. It is shown that once we bring in more clarity on the formal identity of the different kinds of assumptions, Musgrave's contribution can be further defined: distinctions can be drawn between detectability and negligibility assumptions, and between domain and acceptability assumptions; the suggested gap between as-if assumptions and other kinds can be removed; another type, that of joint neglibility assumption, can be introduced; the untwisting of the F-twist can be accepted in all cases except in the case of early-step (heuristic) assumptions; and the art of paraphrase is shown to constitute the basis for Musgrave's strategy and to have limits. [source] Learning, literacy, and identityNEW DIRECTIONS FOR ADULT & CONTINUING EDUCATION, Issue 106 2005Lyn Tett Assumptions about learner identity are often based on a deficit view of the working classes. This chapter illustrates an alternative discourse that shows how one family literacy program in Scotland generated useful knowledge. [source] Indian Giver or Nobel Savage: Duping, Assumptions of Identity, and Other Double Entendres in Rigoberta Menchú Turn's Stoll/En PastAMERICAN ETHNOLOGIST, Issue 2 2001Diane M. Nelson I address the emotional debate over David Stoll's claims that parts of Nobel Laureate Rigoberta Menchu Turn's testimonial are untrue. Rather than arguing for or against either "side", I negotiate the double entendre of "Indian giver" and the assumptions that structure the arguments that make up the debate. I track how such assumptions of identity involve a detour through gendered, ethnic, and transnational difference. Transactions such as gifting, joking, and stereotyping are ecstatic and pleasurable, and vacillate with threatening to suggest that the vacillation itself, the exchange, is essential to identification and that the empiricist promise of being "nonduped" is an error. [identity, violence, globalization, consciousness, Mayan organizing, gender, U.S. anthropology] [source] Casting the Riace Bronzes: Modern Assumptions and Ancient FactsOXFORD JOURNAL OF ARCHAEOLOGY, Issue 2 2002Herbert Hoffmann This article argues that classical archaeologists have seriously underestimated the output of heat required to melt a large quantity of bronze and therefore have wrongly reconstructed the ancient casting process. The idea that sufficient metal for casting a bronze of monumental proportions could be heated in a crucible with a charcoal fire ventilated by bellows is not realistic. The following observations are based on solid foundry experience: Nigel Konstam, a bronze sculptor, for many years supervised the casting of monumental bronzes comparable in size to those from Riace. This article has been written by Herbert Hoffmann drawing on Konstam's notes [source] Immigration Assumptions in Projecting the US Social Security BurdenPOPULATION AND DEVELOPMENT REVIEW, Issue 4 2008Article first published online: 5 DEC 200 First page of article [source] Evaluation of Needle Exchange ProgramsPUBLIC HEALTH NURSING, Issue 2 2004Cheryl Delgado M.S.N. Abstract Needle exchange programs exist in every major population area in the United States and in many other countries. Some operate legally under emergency health decrees issued by local departments of health, with the stated intention of risk reduction through the removal of used injection equipment from use by injection drug users. It is theorized that this results in a reduced transmission of human immunodeficiency virus, hepatitis, and, possibly, other blood-borne diseases. Needle exchange programs also offer access to drug treatment programs for the participants. It is a difficult but necessary task to evaluate these programs. This article examines examples of evaluations attempted in the past and discusses the challenges of such evaluations. Experimental evaluations, economic program analysis, legal aspects, and risk,benefit assessment along with ethical aspects are considered. An outline of program evaluation is proposed. Needle exchange programs offer an opportunity to encourage risk reduction and to offer counseling and access to health care for individuals at high risk. It is essential that such programs demonstrate their effectiveness. Assumptions of efficacy are insufficient for health care in the twenty-first century. [source] | |||||||||||||||||||||||||||||||||||||||||||