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Rigorous Methods (rigorous + methods)
Selected AbstractsThe sedimentary records in Mediterranean rockshelters and caves: Archives of environmental changeGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 4 2001Jamie C. Woodward It is important to develop rigorous methods and robust conceptual models for the interpretation of rockshelter and cave sediment records so that the cultural sequences they contain can be considered in their proper environmental context. Much of what we know about the prehistory of the Mediterranean region and adjacent areas has largely been pieced together from materials excavated from sedimentary sequences in these environments. The rockshelters and caves of the region form important environmental and sedimentary archives. Recent work has begun to consider if the remarkable climatic variability evident in the high resolution lacustrine and ice core records is manifest in the rockshelter and cave sediment records of the area. In this context, the two main characteristics of a rockshelter or cave site which control its usefulness as an archive of environmental change are the temporal resolution of the sedimentary record and the environmental sensitivity of the site. Many rockshelters and caves can be described as either Active Karst Settings (AKS) or Passive Karst Settings (PKS) and site type is an important influence on climatic sensitivity with a direct influence upon the usefulness of the sedimentary sequence as a proxy record of climate change. It is now clear that some sites may preserve detailed paleoclimatic records and the climatic signal may be represented by distinctive suites of micromorphological features, by variations in the input of allogenic sediment, or by fluctuations in the mineral magnetic properties of the fine sediment fraction. It can be argued that data derived from the analysis of bulk coarse-grained samples often lacks the stratigraphic resolution and environmental sensitivity that can be obtained from other approaches. The most favorable sites for detailed paleoclimatic reconstruction appear to be in active karst settings such as Theopetra Cave (Greece) and Pigeon Cave (Morocco) where micromorphological analyses offer insights into the stratigraphic record that are not otherwise obtainable. The temporal resolution of a site can only be established through a rigorous stratigraphic analysis and a comprehensive dating program. These are fundamental considerations in the study of rockshelter sediment records, especially when attempting to correlate between sites and draw comparisons with other proxy records of environmental change derived from sedimentary environments with rather different characteristics. Rockshelters and caves are part of a wider sediment system, and their investigation must be accompanied by detailed geomorphological, sedimentological, paleoecological, and geochronological studies of the off-site Quaternary record. © 2001 John Wiley & Sons, Inc. [source] Application of equality constraints on variables during alternating least squares proceduresJOURNAL OF CHEMOMETRICS, Issue 12 2002Mark H. Van Benthem Abstract We describe several methods of applying equality constraints while performing procedures that employ alternating least squares. Among these are mathematically rigorous methods of applying equality constraints, as well as approximate methods, commonly used in chemometrics, that are not mathematically rigorous. The rigorous methods are extensions of the methods described in detail in Lawson and Hanson's landmark text on solving least squares problems, which exhibit well-behaved least squares performance. The approximate methods tend to be easy to use and code, but they exhibit poor least squares behaviors and have properties that are not well understood. This paper explains the application of rigorous equality-constrained least squares and demonstrates the dangers of employing non-rigorous methods. We found that in some cases, upon initiating multivariate curve resolution with the exact basis vectors underlying synthetic data overlaid with noise, the approximate method actually results in an increase in the magnitude of residuals. This phenomenon indicates that the solutions for the approximate methods may actually diverge from the least squares solution. Copyright © 2002 John Wiley & Sons, Ltd. [source] Sleep problems, sleepiness and daytime behavior in preschool-age childrenTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 12 2009Beth Goodlin-Jones Background:, Sleep problems are a common complaint of parents of preschool children. Children with neurodevelopmental disorders have even more disrupted sleep than typically developing children. Although disrupted nighttime sleep has been reported to affect daytime behavior, the pathway from sleep disruption to sleep problems, to impairments in daytime performance or behavior is not clear. This multi-method, preliminary study assessed this path in 68 children with autism, matched to 57 children with developmental delay without autism and 69 children developing typically. Methods:, Actigraphy, structured questionnaires, laboratory assessments, and parent reports were obtained in 194 children. Results:, Controlling for diagnosis and developmental age of the child, nighttime sleep problems determined by parent reports were significantly associated with decrements in daytime behavior, also measured by parent report instruments. However, actigraph-defined sleep problems and objective measures of daytime sleepiness were not associated with decrements in daytime performance. Conclusions:, Parent report measures substantiate relationships between disrupted sleep patterns and waking behavior. Further understanding of the pathway from sleep disorders to daytime sleepiness and decrements in waking performance, however, may require more rigorous methods of assessment such as polysomnography and the multiple sleep latency test. [source] Managing alcohol-related problems among Indigenous Australians: what the literature tells usAUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 2010Dennis Gray Abstract Objective: To contextualise and provide an overview of two review papers , prepared as part of a larger research program , dealing with different aspects of the treatment of Indigenous Australians with alcohol-related problems. Method: The papers were reviewed thematically and compared to identify key issues raised in them. Findings: Together, the papers highlight the paucity of the evidence base for the provision of treatment for Indigenous Australians with alcohol-related problems. Among the key issues identified are: the need to engage with clients in culturally safe ways; practitioner, organisational and client barriers to engagement; the contexts in which Indigenous drinking and treatment take place; the need to develop rigorous methods of evaluation more appropriate to Indigenous cultural and service provision settings; and the importance of effective partnerships in the provision of services. Conclusion: For those working in the field, the reviews direct attention to the need to review and interrogate our current practice. They also provide clear directions for future research. [source] Endodontic imaging as an aid to forensic personal identificationAUSTRALIAN ENDODONTIC JOURNAL, Issue 2 2010Alexander Stewart Forrest MDSc, FICD Abstract Identification by dental comparison between records of a missing person and the dentition of a deceased individual depends on recognition of concordant features common to both with no unexplained discrepancies. While written dental records are commonly used for this task, we believe they should not be the preferred basis of comparison because they do not derive directly from an individual and are potentially prone to errors, inaccuracies and misinterpretation. Images, however, are a direct representation of a physical item, and are an objective method of recording information. Radiographs are images that capture the unique morphological features of teeth, surrounding structures and physical detail of past dental treatment resulting in changes to a dentition. Taking post-mortem radiographs in such a way as to duplicate as closely as possible the conditions under which the ante-mortem radiographs were produced, permits demonstrably rigorous methods of comparison, raising the probative value of the outcome. In this context post-treatment endodontic radiographs present a particularly rich source of features on which individuation can be achieved, especially considering that alteration of endodontic restorations happens less frequently than is the case with intra-coronal restorations. We illustrate various techniques with a series of cases and discuss the parameters for success. [source] | ||||||||||