Christopher Pierce
University of California, Davis, Anthropology, Department Member
- Cleveland Clinic, Clinical Invetigations, Department MemberCleveland Clinic, Registries and Research, Department MemberPortland State University, Anthropology, Department Memberadd
- Archaeological Science, Geoarchaeology, Archaeological Theory, Experimental Archaeology, Human Evolution, Archaeology, and 13 moreSouthwestern Archaeology, Evolutionary Theory (Archaeology), Clinical Research & Data Management, Clinical Research Informatics, Archaeological Method & Theory, Evolutionary Archaeology, Archaeology of the U.S. Southwest, Ceramic Analysis (Archaeology), Chaco Canyon, Southwestern United States (Archaeology in North America), Fired Cracked Rock, Pottery (Archaeology), and Californian archaeologyedit
Archaeologists commonly encounter traces of burrowing animals, usually in the form of filled burrows visible as differences in the color or consistency of the sediment, and occasionally in the form of loosened dirt deposited on the... more
Archaeologists commonly encounter traces of burrowing animals, usually in the form of filled burrows visible as differences in the color or consistency of the sediment, and occasionally in the form of loosened dirt deposited on the surface or in excavation units through active burrowing. While working as an archaeologist in California in the late 1970s, I became curious about how all that burrowing may have affected the archaeological record. This paper presents my personal journey, trying to understand this issue. My goals are threefold: First, I want to provide an account of how a scientist works on solving a problem. Too often we are presented with only the finished product of years of work, including false starts, compromises, and dead ends, which gives people the generally false impression that insights just appear fully formed. I think it is important to show the complex path that scientific research usually takes. Second, archaeologists still tend to overlook the importance of understanding the archaeological record as both a product of past human behavior AND ongoing geological and biological processes. By diving deeper into my experience with trying to unravel the impacts of sustained burrowing on archaeological deposits, I hope to inspire more archaeologists to take this kind of work seriously. Finally, I take the opportunity here to publish the code and documentation for my burrowing simulation produced as part of this research; it is attached as an appendix to this paper. Although I have published results of using the simulation in multiple contexts and made the simulation available online for others to run, I never published the actual code.
Research Interests:
Historical, meteorological, archaeological, and geological evidence support detailed reconstructions of how Spanish land-use practices affected the environment around the inland Chumash village of Talepop in the Santa Monica Mountains of... more
Historical, meteorological, archaeological, and geological evidence support detailed reconstructions of how Spanish land-use practices affected the environment around the inland Chumash village of Talepop in the Santa Monica Mountains of southern California. Initiation of Spanish farming and grazing around Talepop in 1801 followed by droughts between 1807 and 1810 defoliated the hillsides and triggered dustbowl-like conditions. Heavy rains in 1811 eroded the barren hills leading to massive floods in the valleys below. Chumash at Talepop adjusted to Spanish occupation by incorporating non-native plants and animals into their diet, but ultimately the changes overwhelmed them, and they abandoned the village.
Research Interests: Environmental History, California Indians, Californian archaeology, California History, Formation processes (Geoarchaeology), and 10 moreSpanish Colonial Archaeology, Culture Contact, Land Use History, California Archaeology, Early California History, Spanish Colonialism, California Coast and Channel Islands Archaeology, California Ethnohistory/Ethnology and Archaeology, History of Southern California, and Southern California
BACKGROUND: Data from 3 institutions revealed an abrupt increase in HeartMate II (Thoratec) pump thrombosis starting in 2011, associated with 48% mortality at 6 months without transplantation or pump exchange. We sought to discover if the... more
BACKGROUND: Data from 3 institutions revealed an abrupt increase in HeartMate II (Thoratec) pump thrombosis starting in 2011, associated with 48% mortality at 6 months without transplantation or pump exchange. We sought to discover if the increase occurred nationwide in Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) data, and if so (1) determine if accelerated risk continued, (2) identify predictors, (3) investigate institutional variability, and (4) assess mortality after pump thrombosis.
METHODS: From April 2008 to June 2014, 11,123 HeartMate II devices were implanted at 146 institutions. Machine learning, non-parametric Random Forests for Survival was used to explore riskadjusted thrombosis based on 87 pre-implant and implant variables, including implant date.
RESULTS: A total of 995 pumps thrombosed, with risk peaking within weeks of implant. The riskadjusted increase in pump thrombosis began in 2010, reached a maximum in 2012, and then plateaued at a level that was 3.3-times higher than pre-2010. Pump exchange, younger age, and larger body mass index were important predictors, and institutional variability was largely explained by implant date, patient profile, and duration of support. The probability of death within 3 months after pump thrombosis was 24%.
CONCLUSIONS: Accelerated risk of HeartMate II thrombosis was confirmed by Interagency Registry for Mechanically Assisted Circulatory Support data, with risk subsequently leveling at a riskadjusted rate higher than observed pre-2010. This elevated thrombosis risk emphasizes the need for improved mechanical circulatory support systems and post-market surveillance of adverse events. Clinicians cognizant of these new data should incorporate them into their and their patients’ expectations and understanding of risks relative to those of transplantation and continued medical
therapy.
METHODS: From April 2008 to June 2014, 11,123 HeartMate II devices were implanted at 146 institutions. Machine learning, non-parametric Random Forests for Survival was used to explore riskadjusted thrombosis based on 87 pre-implant and implant variables, including implant date.
RESULTS: A total of 995 pumps thrombosed, with risk peaking within weeks of implant. The riskadjusted increase in pump thrombosis began in 2010, reached a maximum in 2012, and then plateaued at a level that was 3.3-times higher than pre-2010. Pump exchange, younger age, and larger body mass index were important predictors, and institutional variability was largely explained by implant date, patient profile, and duration of support. The probability of death within 3 months after pump thrombosis was 24%.
CONCLUSIONS: Accelerated risk of HeartMate II thrombosis was confirmed by Interagency Registry for Mechanically Assisted Circulatory Support data, with risk subsequently leveling at a riskadjusted rate higher than observed pre-2010. This elevated thrombosis risk emphasizes the need for improved mechanical circulatory support systems and post-market surveillance of adverse events. Clinicians cognizant of these new data should incorporate them into their and their patients’ expectations and understanding of risks relative to those of transplantation and continued medical
therapy.
Research Interests:
Semantic Web technologies offer the potential to revolutionize management of health care data by increasing interoperability and reusability while reducing the need for redundant data collection and storage. From 1998 through 2010,... more
Semantic Web technologies offer the potential to revolutionize management of health care data by increasing interoperability and reusability while reducing the need for redundant data collection and storage. From 1998 through 2010, Cleveland Clinic sponsored a project designed to explore and develop this potential. The product of this effort, SemanticDB, is a suite of software tools and knowledge resources built to facilitate the collection, storage and use of the diverse data needed to conduct clinical research and health care quality reporting. SemanticDB consists of three main components: 1) a content repository driven by a meta-model that facilitates collection and integration of data in an XML format and automatically converts the data to RDF; 2) an inference-mediated, natural language query interface designed to identify patients who meet complex inclusion and exclusion criteria; and 3) a data production pipeline that uses inference to generate customized views of the repository content for statistical analysis and reporting. Since 2008, this system has been used by the Cleveland Clinic's Heart and Vascular Institute to support numerous clinical investigations, and in 2009 Cleveland Clinic was certified to submit data produced in this manner to national quality monitoring databases sponsored by the Society of Thoracic Surgeons and the American College of Cardiology.
Research Interests:
A system includes a metadata model arranged to express concepts in a domain as a domain model. The domain model includes domain elements and at least one hierarchical relationship between domain elements. The system also includes at least... more
A system includes a metadata model arranged to express concepts in a domain as a domain model. The domain model includes domain elements and at least one hierarchical relationship between domain elements. The system also includes at least one given instance representation of the domain model, which includes instance data stored in a repository. A user interface is associated with the domain model and configured to at least create, view and modify at least one given instance representation of the domain model.
Link to document: http://www.freepatentsonline.com/y2007/0198564.html
Link to document: http://www.freepatentsonline.com/y2007/0198564.html
To understand the effects of European contact on the organization, size, and mobility of Pueblo populations in the Southwest requires detailed knowledge of the occupational histories of the aggregated settlements that typify the late... more
To understand the effects of European contact on the organization, size, and mobility of Pueblo populations in the Southwest requires detailed knowledge of the occupational histories of the aggregated settlements that typify the late prehistoric and early historic record. Unfortunately, such understanding is generally lacking because the methods used to document occupational histories of settlements tend to either obscure fine- grained temporal distinctions or necessitate costly, and politically objectionable, large- scale excavations. To overcome these difficulties, we use surface expressions to analyze the occupational and population history of San Marcos Pueblo (LA98), an aggregated, late prehistoric site in the Galisteo Basin of New Mexico that persisted to the Pueblo Revolt of 1680. Field methods include detailed mapping of the settlement and systematic surface collections of middens. Frequency seriation, correspondence analysis, and mean ceramic dates of decorated ceramic rims comprise our principal analytic methods and demonstrate that the pueblo was abandoned four times before 1680. Causes of abandonment are discussed. Relative scale measures of population show demographic fluctuations with maximum aggregation during the fifteenth century. Despite demographic pulses, the pueblo remained vital until the terminal abandonment.
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Barriers to Patient-Oriented Research Innovation in clinical research and bioinformatics has been severely hampered in part by the fragmented gathering and storing of data, reflecting the compartmentalization of medical science and... more
Barriers to Patient-Oriented Research
Innovation in clinical research and bioinformatics has been severely hampered in part by the fragmented gathering and storing of data, reflecting the compartmentalization of medical science and practice. It has also been hampered by the programmatic necessity of keeping up with medical advances, which has led within every discipline to a multiplicity of special-purpose databases. Neither seamless integration nor simple extensibility of data stores is the norm. Yet to answer ad hoc questions cutting across disparate domains, clinical knowledge housed in isolated silos needs to be integrated. To make matters worse, typically clinical knowledge is expressed in ambiguous, idiosyncratic terminology. This is especially problematic for longitudinal patient data that can feasibly span multiple, geographically separated sources—pharmacies, local practices, group practices, and primary, secondary, and tertiary hospitals—and disciplines such as genetics, pathology, cardiology, etc. Without aid of a well-defined, standardized knowledge representation, the expense of ad hoc integration is formidable to impossible.
Semantic Web Value Proposition
Semantic Web technology, and its various engineering specifications, seeks to remove some of these barriers. It combines a highly-distributable addressing and naming mechanism (Uniform Resource Identifiers: URIs) with a formal knowledge representation (RDF and OWL), a mechanism for rendering document dialects in this knowledge representation (GRDDL), and a common query language (SPARQL). The multifaceted nature of URIs alleviates some of the accessibility challenges associated with physically separated components. The common knowledge representation empowers domain experts with a language for capturing clinical terminology formally and with little ambiguity. Assertions can be added at a later point with no impact to the organization of physical storage and minimal impact on existing terminology. SPARQL provides a common query language for accessing assertions expressed in such terminology. Finally, GRDDL bridges gaps between messaging dialects (such as HL7 RIM) and more expressive terminologies (such as SNOMED-CT).
Innovation in clinical research and bioinformatics has been severely hampered in part by the fragmented gathering and storing of data, reflecting the compartmentalization of medical science and practice. It has also been hampered by the programmatic necessity of keeping up with medical advances, which has led within every discipline to a multiplicity of special-purpose databases. Neither seamless integration nor simple extensibility of data stores is the norm. Yet to answer ad hoc questions cutting across disparate domains, clinical knowledge housed in isolated silos needs to be integrated. To make matters worse, typically clinical knowledge is expressed in ambiguous, idiosyncratic terminology. This is especially problematic for longitudinal patient data that can feasibly span multiple, geographically separated sources—pharmacies, local practices, group practices, and primary, secondary, and tertiary hospitals—and disciplines such as genetics, pathology, cardiology, etc. Without aid of a well-defined, standardized knowledge representation, the expense of ad hoc integration is formidable to impossible.
Semantic Web Value Proposition
Semantic Web technology, and its various engineering specifications, seeks to remove some of these barriers. It combines a highly-distributable addressing and naming mechanism (Uniform Resource Identifiers: URIs) with a formal knowledge representation (RDF and OWL), a mechanism for rendering document dialects in this knowledge representation (GRDDL), and a common query language (SPARQL). The multifaceted nature of URIs alleviates some of the accessibility challenges associated with physically separated components. The common knowledge representation empowers domain experts with a language for capturing clinical terminology formally and with little ambiguity. Assertions can be added at a later point with no impact to the organization of physical storage and minimal impact on existing terminology. SPARQL provides a common query language for accessing assertions expressed in such terminology. Finally, GRDDL bridges gaps between messaging dialects (such as HL7 RIM) and more expressive terminologies (such as SNOMED-CT).
Research Interests:
OBJECTIVE: To (1) characterize atrial fibrillation complicating lung cancer resection, (2) evaluate its temporal relationship to other postoperative complications, and (3) assess its economics. METHODS: From January 1998 to August... more
OBJECTIVE: To (1) characterize atrial fibrillation complicating lung cancer resection, (2) evaluate its temporal relationship to other postoperative complications, and (3) assess its economics.
METHODS: From January 1998 to August 2002, 604 patients underwent anatomic lung cancer resection. Atrial fibrillation prevalence, onset, and temporal associations with other postoperative complications were determined. Propensity matching was used to assess economics.
RESULTS: Atrial fibrillation occurred in 113 patients (19%), peaking on postoperative day 2. Older age, male gender, heart failure, clamshell incision, and right pneumonectomy were risk factors (P < .01). Although atrial fibrillation was solitary in 75 patients (66%), other postoperative complications occurred in 38. Respiratory and infectious complications were temporally linked with atrial fibrillation onset. In 91 propensity-matched pairs, patients developing atrial fibrillation had more other postoperative complications (30% vs. 9%, P < .0004), had longer postoperative stays (median 8 vs 5 days, P < .0001), incurred higher costs (cost ratio 1.8, 68% confidence limits 1.6-2.1), and had higher in-hospital mortality (8% vs 0%, P = .01). Even when atrial fibrillation was a solitary complication, hospital stay was longer (median 7 vs 5 days, P < .0001), and cost was higher (cost ratio 1.5, 68% confidence limits 1.2-1.6).
CONCLUSION: Atrial fibrillation occurs in 1 in 5 patients after lung cancer resection, with peak onset on postoperative day 2. Risk factors are both patient and procedure related, and atrial fibrillation may herald other serious complications. Although often solitary, atrial fibrillation is associated with longer hospital stay and higher cost. It therefore requires prompt treatment and should stimulate investigation for other problems.
METHODS: From January 1998 to August 2002, 604 patients underwent anatomic lung cancer resection. Atrial fibrillation prevalence, onset, and temporal associations with other postoperative complications were determined. Propensity matching was used to assess economics.
RESULTS: Atrial fibrillation occurred in 113 patients (19%), peaking on postoperative day 2. Older age, male gender, heart failure, clamshell incision, and right pneumonectomy were risk factors (P < .01). Although atrial fibrillation was solitary in 75 patients (66%), other postoperative complications occurred in 38. Respiratory and infectious complications were temporally linked with atrial fibrillation onset. In 91 propensity-matched pairs, patients developing atrial fibrillation had more other postoperative complications (30% vs. 9%, P < .0004), had longer postoperative stays (median 8 vs 5 days, P < .0001), incurred higher costs (cost ratio 1.8, 68% confidence limits 1.6-2.1), and had higher in-hospital mortality (8% vs 0%, P = .01). Even when atrial fibrillation was a solitary complication, hospital stay was longer (median 7 vs 5 days, P < .0001), and cost was higher (cost ratio 1.5, 68% confidence limits 1.2-1.6).
CONCLUSION: Atrial fibrillation occurs in 1 in 5 patients after lung cancer resection, with peak onset on postoperative day 2. Risk factors are both patient and procedure related, and atrial fibrillation may herald other serious complications. Although often solitary, atrial fibrillation is associated with longer hospital stay and higher cost. It therefore requires prompt treatment and should stimulate investigation for other problems.
Research Interests:
Ceramic cooking pots throughout the world vary in exterior surface treatment from smooth to roughly textured. An intriguing example of this variation occurred in the Puebloan region of the southwestern United States where cooking pots... more
Ceramic cooking pots throughout the world vary in exterior surface treatment from smooth to roughly textured. An intriguing example of this variation occurred in the Puebloan region of the southwestern United States where cooking pots changed from scraped plain to highly textured, corrugated vessels between the seventh and eleventh centuries AD, and then reverted back to plain-surfaced by the fifteenth century. To investigate potential cost and performance differences between plain and corrugated cooking pots, a set of controlled experiments were performed, which document manufacturing costs, cooking effectiveness, and vessel durability. These experiments indicate that while corrugation may have increased manufacturing costs, neck corrugations improved vessel handling, upper body corrugations yielded greater control over cooking, and basal corrugations extended vessel use-life. Discerning the explanatory significance of these results for cooking pot change in the Southwest and elsewhere requires additional data on the contexts in which these pots were made and used.
Research Interests:
Archaeological research has documented the broad outlines of the development of corrugated utility pottery from plain and neck-banded antecedents. However, a reliance on typological descriptions has obscured the technological details of... more
Archaeological research has documented the broad outlines of the development of corrugated utility pottery from plain and neck-banded antecedents. However, a reliance on typological descriptions has obscured the technological details of this development. An attribute analysis of six well-dated utility-ware assemblages from southwestern Colorado indicates that corrugation appeared first in this region during the eighth century A. D. as wide, non-overlapping coils left unsmoothed around jar necks. During the ninth and tenth centuries, the variety and frequency of neck-banding increased with the introduction of narrower coils, overlapping of adjacent coils, and incising and indenting of coil surfaces. By the early eleventh century, one recent neck-banding variant, narrow, substantially overlapped and indented coils, replaced almost all others, and was extended over the entire exterior surface of jars for the first time. Performance benefits of this full-body, indented corrugation may explain its rapid adoption in southwestern Colorado.
Research Interests:
OBJECTIVES: Surgical staging and resection of lung cancer may be done as 1 operation (combined) or 2 (staged). This study evaluates the safety and efficiency of these treatment strategies. METHODS: From 1998 to July 2001, 343 patients... more
OBJECTIVES: Surgical staging and resection of lung cancer may be done as 1 operation (combined) or 2 (staged). This study evaluates the safety and efficiency of these treatment strategies.
METHODS: From 1998 to July 2001, 343 patients underwent bronchoscopy, mediastinoscopy, and thoracotomy without induction chemoradiotherapy by 3 surgeons. Fifty-seven patients were staged and 286 combined. Staged patients had higher clinical stage (P < .001). Propensity-matched groups were compared to adjust for this and other differences. Factors associated with safety and efficiency were identified by propensity-adjusted multivariable analysis.
RESULTS: Mortality and morbidity were similar for both strategies. Efficiency, measured by shorter operative time (1.2 hours) and lower cost (25%), was better for combined strategy (P < .001). Hospital stay was similar, but revenue was 12% higher for the staged strategy (P < .001). In propensity-matched comparisons excluding surgeon, results were similar to the above. Comparisons including surgeon demonstrated similar cost and revenue for both strategies. Increased mortality and morbidity were associated only with patient and tumor characteristics: male gender, worsening Eastern Cooperative Oncology Group performance status, and increasing pathological node classification. All measures of efficiency worsened with increasing pathological classifications. Staged strategy was associated with increased operative time and revenue, while one surgeon and patient smoking history were associated with increased hospital stay and costs.
CONCLUSIONS: The combined strategy provides efficient, safe health care for clinically operable lung cancer patients, but it may not be as financially rewarding as the staged strategy. Treatment strategy is only 1 of many determinants of efficiency.
METHODS: From 1998 to July 2001, 343 patients underwent bronchoscopy, mediastinoscopy, and thoracotomy without induction chemoradiotherapy by 3 surgeons. Fifty-seven patients were staged and 286 combined. Staged patients had higher clinical stage (P < .001). Propensity-matched groups were compared to adjust for this and other differences. Factors associated with safety and efficiency were identified by propensity-adjusted multivariable analysis.
RESULTS: Mortality and morbidity were similar for both strategies. Efficiency, measured by shorter operative time (1.2 hours) and lower cost (25%), was better for combined strategy (P < .001). Hospital stay was similar, but revenue was 12% higher for the staged strategy (P < .001). In propensity-matched comparisons excluding surgeon, results were similar to the above. Comparisons including surgeon demonstrated similar cost and revenue for both strategies. Increased mortality and morbidity were associated only with patient and tumor characteristics: male gender, worsening Eastern Cooperative Oncology Group performance status, and increasing pathological node classification. All measures of efficiency worsened with increasing pathological classifications. Staged strategy was associated with increased operative time and revenue, while one surgeon and patient smoking history were associated with increased hospital stay and costs.
CONCLUSIONS: The combined strategy provides efficient, safe health care for clinically operable lung cancer patients, but it may not be as financially rewarding as the staged strategy. Treatment strategy is only 1 of many determinants of efficiency.
Research Interests:
The scale, intensity, and character of interaction among Pueblo people during the 13th century A.D. likely played an important role in the processes and events leading to the abandonment of the Northern San Juan region in the 1280s.... more
The scale, intensity, and character of interaction among Pueblo people during the 13th century A.D. likely played an important role in the processes and events leading to the abandonment of the Northern San Juan region in the 1280s. Characteristics of pottery production and distribution in the Sand Canyon locality provide one means of investigating these interactions. Variation among Pueblo III settlements in the use of temper and available raw clay sources, and the distribution of pottery production tools demonstrate the existence of at least two production areas within the locality. The nature of the boundary between these production areas indicates a complex pattern of settlement and community interaction that challenges models based on settlement proximity. Further, an almost complete lack of extra-regional pottery at Pueblo III settlements suggests that the Northern San Juan region may have been economically isolated from other regions inhabited by Pueblo people. Available at http://webdataworks.com/PiercePotDist2002.html
Research Interests:
"Corrugated pottery is a unique utility ware made by leaving construction coils unobliterated, and manipulating these exposed coils to produce a rough exterior surface. Ancestral Puebloan populations in the American Southwest made this... more
"Corrugated pottery is a unique utility ware made by leaving construction coils unobliterated, and manipulating these exposed coils to produce a rough exterior surface. Ancestral Puebloan populations in the American Southwest made this pottery in various forms between AD 650 and 1450. Although archaeologists have tried to explain corrugation for over 100 years, none of these explanations has proven satisfactory. I employ an evolutionary approach in an attempt to explain the rise and fall of corrugated pottery.
Using analyses of ancient pottery, experiments with modern replicas, and syntheses of published data, I document that corrugation developed gradually from plain ware through a series of innovations in the size of coils and how they were applied and manipulated. Initially, corrugation appeared in the southern Mogollon region as wide, filleted, and unindented bands on jar necks, and spread north into the Anasazi areas of the Colorado Plateau. The development of overlapped and indented neck bands during the ninth and tenth centuries ultimately led to the use of these techniques over the entire exterior surface during the eleventh century producing full-body, indented corrugation. Full-body corrugation spread rapidly across a large area of the Colorado Plateau, and remained dominant until the fifteenth century when a return to plain pottery occurred. The development of corrugation coincided with an increase in the use of these vessels to cook food.
Although most of the innovations appeared first as decorative elaborations, some also affected the cost and performance of the vessels. The use of narrower and overlapped coils increased the time required to form a vessel over the earlier plain vessels. However, the extension of the textured surface to the upper body and basal parts of vessels significantly improved control over cooking and the use-life of vessels respectively.
Explanations of corrugation emphasize how the environment with which corrugated pottery interacted changed through time, and how these changes affected innovation rates, and the selection or drift of particular corrugation variants. In formulating explanations, I address four problems: the advent of neck banding, experimentation with neck banding, the rapid adoption of full-body corrugation, and the return to plain-surfaced pottery."
Available at http://webdataworks.com/dissTitle.html
Using analyses of ancient pottery, experiments with modern replicas, and syntheses of published data, I document that corrugation developed gradually from plain ware through a series of innovations in the size of coils and how they were applied and manipulated. Initially, corrugation appeared in the southern Mogollon region as wide, filleted, and unindented bands on jar necks, and spread north into the Anasazi areas of the Colorado Plateau. The development of overlapped and indented neck bands during the ninth and tenth centuries ultimately led to the use of these techniques over the entire exterior surface during the eleventh century producing full-body, indented corrugation. Full-body corrugation spread rapidly across a large area of the Colorado Plateau, and remained dominant until the fifteenth century when a return to plain pottery occurred. The development of corrugation coincided with an increase in the use of these vessels to cook food.
Although most of the innovations appeared first as decorative elaborations, some also affected the cost and performance of the vessels. The use of narrower and overlapped coils increased the time required to form a vessel over the earlier plain vessels. However, the extension of the textured surface to the upper body and basal parts of vessels significantly improved control over cooking and the use-life of vessels respectively.
Explanations of corrugation emphasize how the environment with which corrugated pottery interacted changed through time, and how these changes affected innovation rates, and the selection or drift of particular corrugation variants. In formulating explanations, I address four problems: the advent of neck banding, experimentation with neck banding, the rapid adoption of full-body corrugation, and the return to plain-surfaced pottery."
Available at http://webdataworks.com/dissTitle.html
Research Interests:
Research Interests: Archaeology, Spatial Analysis, Landscape Archaeology, Archaeological Science, Archaeological Method & Theory, and 9 moreArchaeometry, Southeastern Archaeology (Archaeology in North America), Weaving Technology, Prehistory, Southeastern Archaic (Archaeology in North America), Poverty Point, Artifact Analysis, Late Archaic, and Morphometric Analyses
Documenting variation and change in the use of particular plants and plant parts for fuel in ancient households contributes to an understanding of settlement location, local and regional abandonments and resource depletion. Chemical... more
Documenting variation and change in the use of particular plants and plant parts for fuel in ancient households contributes to an understanding of settlement location, local and regional abandonments and resource depletion. Chemical analysis of ash surviving in hearths and other thermal features to determine the kinds and relative amounts of fuels consumed may be less biased by formation processes than the macrofossil record currently employed to document ancient fuel use. Our studies indicate that it is possible to distinguish, chemically, ash of common fuel taxa and tissue types (bark, wood, etc.) in both modern and ancient samples of fuels found in the northern Colorado Plateau region of the American Southwest. However, the chemical signatures of the ancient and modern material of the same taxon differ, indicating possible alteration by post-depositional processes. Although multiple regression performs well in determining the relative contributions of different fuels to modern ash mixtures, possible post-depositional alterations and incomplete characterization of the range of within-taxon variation, currently limit our confidence in applications of this approach to ancient ash from Pueblo III settlements in south-west Colorado.
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This chapter presents information on the portable artifacts recovered and analyzed from the 13 sites investigated during the Site Testing Program. These artifacts include pottery, stone tools and manufacturing debris, modified bone, and... more
This chapter presents information on the portable artifacts recovered and analyzed from the 13 sites investigated during the Site Testing Program. These artifacts include pottery, stone tools and manufacturing debris, modified bone, and shell. Analytical methods and results for each of these general categories of artifacts are discussed in separate sections of this chapter.
The construction of burrows and movement of sediment by pocket gophers alter archaeological deposits by causing vertical size-sorting of artifacts, destruction of fragile artifacts, disruption of sedimentary structures, and organic... more
The construction of burrows and movement of sediment by pocket gophers alter archaeological deposits by causing vertical size-sorting of artifacts, destruction of fragile artifacts, disruption of sedimentary structures, and organic enrichment of the subsurface. To evaluate the long-term effects of exposure to burrowing, a simulation was developed based on quantitative information on pocket gopher burrows and rates of sediment movement. Simulation results indicate the development of a distinct stone zone composed predominantly of particles greater than 6 cm after 4000-5000 years, and a logarithmic pattern to the rate of strata disruption. The patterns produced by the simulation compare well with patterns exhibited by actual archaeological deposits belonging to California's Milling Stone Horizon. These results suggest that current notions concerning the Milling Stone Horizon and other aspects of California prehistory may require revision, and that more emphasis must be placed on formation process research in such settings.
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For the past decade, several archaeologists have advocated the development of middle-range theory as a way to give objective meaning to the archaeological record (e.g., Bettinger 1987; Binford 1977, 1983b; Thomas 1983, 1989; Torrence... more
For the past decade, several archaeologists have advocated the development of middle-range theory as a way to give objective meaning to the archaeological record (e.g., Bettinger 1987; Binford 1977, 1983b; Thomas 1983, 1989; Torrence 1986). They argue that we must translate the static archaeological record into behaviorally dynamic terms by documenting causal linkages between relevant behaviors and their static material by-products.
This is accomplished, they argue, by making observations today that establish signature patterns allowing the unambiguous recognition of particular dynamics from their static by-products, and inferring past dynamics from identification of signature patterns in the archaeological record. Further, it has been emphasized that the operations and products of middle-range theory must remain logically independent of the general theory we use to explain the past to avoid automatically confirming our ideas about the past through a tautology. This approach to middle-range research is flawed in two major respects. First, the justification of inferences relies on the establishment of universal behavioral laws and unambiguous signature patterns to validate the use of uniformitarian assumptions, neither of which can be accomplished in the manner proposed. Second, the tautological relationship between description and explanation is not only an unavoidable, but also a necessary aspect of science. Solutions to these problems lie in using the physical characteristics of the archaeological record itself as our source of knowledge about the past rather than translating the record into untestable behavioral reconstructions.
This is accomplished, they argue, by making observations today that establish signature patterns allowing the unambiguous recognition of particular dynamics from their static by-products, and inferring past dynamics from identification of signature patterns in the archaeological record. Further, it has been emphasized that the operations and products of middle-range theory must remain logically independent of the general theory we use to explain the past to avoid automatically confirming our ideas about the past through a tautology. This approach to middle-range research is flawed in two major respects. First, the justification of inferences relies on the establishment of universal behavioral laws and unambiguous signature patterns to validate the use of uniformitarian assumptions, neither of which can be accomplished in the manner proposed. Second, the tautological relationship between description and explanation is not only an unavoidable, but also a necessary aspect of science. Solutions to these problems lie in using the physical characteristics of the archaeological record itself as our source of knowledge about the past rather than translating the record into untestable behavioral reconstructions.
Research Interests:
The Density Dependent Method consists of a coordinated group of techniques that are designed to measure large- and small-scale spatial variability contained in the archaeological record. This is accomplished with a series of nested... more
The Density Dependent Method consists of a coordinated group of techniques that are designed to measure large- and small-scale spatial variability contained in the archaeological record. This is accomplished with a series of nested sampling schemes that focuses on the individual artifact or feature in its environmental context. The primary objective of this paper os to present the details of the density-dependent method as it was developed to deal with the Archaic hunter-gatherer record in the northern Southwest. The method facilitiates quantiative analyses of the relationships between artifact spatial distributions and the local and regional resource framework as defined by a landform environment classificaiton.
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Research Interests:
In the early 11th century CE, the use of full body corrugated cooking pots spread rapidly through Ancestral Puebloan populations. This corrugation technology grew out of plain and neck-banded antecedents and was eventually replaced in the... more
In the early 11th century CE, the use of full body corrugated cooking pots spread rapidly through Ancestral Puebloan populations. This corrugation technology grew out of plain and neck-banded antecedents and was eventually replaced in the 15th century by a return to plain cooking pots. Several possible explanations have been proposed to account for this change, but none has garnered sustained support. During the 1990s while working at Crow Canyon Archaeological Center and as part of my Ph.D. research, Dr. Pierce performed extensive literature review, detailed technological analyses, and controlled experiments to further the understanding of the adoption of corrugated cooking pots. Dr. Pierce’s work identified the technological changes involved in the development of corrugation, documented the spread of these technologies across the northern Southwest, and demonstrated cost and performance differences between plain and corrugated vessels. In this presentation, Chris reviews the results of his earlier work, presents four new possible explanations for the adoption and eventual rejection of corrugated cooking pots, and evaluates evidence to test one of these hypotheses.
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The ability to identify patient populations for clinical research according to specific criteria is a critical component of clinical informatics. Traditionally, database systems that leverage relational databases are used to store and... more
The ability to identify patient populations for clinical research according to specific criteria is a critical component of clinical informatics. Traditionally, database systems that leverage relational databases are used to store and manage the data targeted for population identification. The process of starting with an abstract research question (posed in prose) and distilling it into the specific query plans and corresponding data structures necessary to answer such research questions is often significantly tedious and primarily driven by idiosyncrasies of how the data is stored rather than the underlying science that guides the intuition of the researcher. Contemporary clinical data management systems have yet to move beyond this approach. Cleveland Clinic and Cycorp Inc. have developed a state-of-the-art query interface that builds query fragments through natural language-driven interactions with an investigator. This interface targets a clinical research repository comprised o...
The ability to identify patient populations for clinical research according to specific criteria is a critical component of clinical informatics. Traditionally, database systems that leverage relational databases are used to store and... more
The ability to identify patient populations for clinical research according to specific criteria is a critical component of clinical informatics. Traditionally, database systems that leverage relational databases are used to store and manage the data targeted for population identification. The process of starting with an abstract research question (posed in prose) and distilling it into the specific query plans and corresponding data structures necessary to answer such research questions is often significantly tedious and primarily driven by idiosyncrasies of how the data is stored rather than the underlying science that guides the intuition of the researcher. Contemporary clinical data management systems have yet to move beyond this approach. Cleveland Clinic and Cycorp Inc. have developed a state-of-the-art query interface that builds query fragments through natural language-driven interactions with an investigator. This interface targets a clinical research repository comprised o...
Medical records come in many forms, including enterprise-wide electronic health records mandated by the 2009 federal stimulus package; lab and clinic-based data management systems; administrative databases for scheduling, billing and... more
Medical records come in many forms, including enterprise-wide electronic health records mandated by the 2009 federal stimulus package; lab and clinic-based data management systems; administrative databases for scheduling, billing and inventory control; and secondary databases for clinical research and quality reporting. Making meaningful use of these disparate data sources to improve the cost and quality of patient care turns on our ability to accurately model their complex semantics and exploit these semantics through machine processing. Since 2003, Cleveland Clinic has applied semantic technologies to making use of diverse data derived from the treatment of over 200,000 patients with cardiovascular disease over the past 30 years. This presentation outlines the practical issues and challenges faced, and describes how some of these issues have been overcome while others remain unsolved. Topics covered include: Domain ontology development and utilization Linking domain ontologies to ...
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Background: American Heart Association (AHA) 2020 impact goals rely on valid primary and secondary metrics used for detection and/or surveillance of patients with non-fatal cardiovascular disease, including heart failure (CHF). We... more
Background: American Heart Association (AHA) 2020 impact goals rely on valid primary and secondary metrics used for detection and/or surveillance of patients with non-fatal cardiovascular disease, including heart failure (CHF). We assessed the feasibility and reliability of using an automated electronic method for corroborating detection of incident CHF events across existent sources of intra-institutional electronic health records.
Methods: Epic’s Clarity applications (AEEA): "Problem List Diagnosis Files" (PLDF) and "Encounter Diagnosis Administrative Files" (EDAF) were considered to be equally valid sources for detecting patients with CHF. We sought to validate the ability of the proposed method by detecting/following CHF in two different settings: cross-sectionally in the general patient population seen in clinic (S1), and longitudinally in cardiac patients at risk for CHF followed-up at our institution between 2002 and 2012 (S2). Results obtained using AEEA were compared against the "gold standard," defined as the standardized manual extraction of CHF diagnoses by experienced electronic data extractors using evidence-based guidelines established by the AHA.
Results: We compared the use of AEEA with the gold standard for 1000 patients in the S1 setting and 668 patients in the S2 setting. Use of AEEA for detecting CHF showed high specificity (0.99) and sensitivity (0.93) for patients in the S1 setting, but lower specificity (0.92) and sensitivity (0.89) in S2 patients (Table 1). Information found through the manual search of "Progress Notes" accounted for 40% of the false negative cases in S2 patients.
Conclusions: Use of automated electronic corroborating intra-institutional data is an effective method for identification and surveillance of CHF. Clarity applications targeting unified clinical notes, available with upgrades to Epic 2010, should be further explored as a means of increasing performance of automated wide-scale CHF surveillance.
Methods: Epic’s Clarity applications (AEEA): "Problem List Diagnosis Files" (PLDF) and "Encounter Diagnosis Administrative Files" (EDAF) were considered to be equally valid sources for detecting patients with CHF. We sought to validate the ability of the proposed method by detecting/following CHF in two different settings: cross-sectionally in the general patient population seen in clinic (S1), and longitudinally in cardiac patients at risk for CHF followed-up at our institution between 2002 and 2012 (S2). Results obtained using AEEA were compared against the "gold standard," defined as the standardized manual extraction of CHF diagnoses by experienced electronic data extractors using evidence-based guidelines established by the AHA.
Results: We compared the use of AEEA with the gold standard for 1000 patients in the S1 setting and 668 patients in the S2 setting. Use of AEEA for detecting CHF showed high specificity (0.99) and sensitivity (0.93) for patients in the S1 setting, but lower specificity (0.92) and sensitivity (0.89) in S2 patients (Table 1). Information found through the manual search of "Progress Notes" accounted for 40% of the false negative cases in S2 patients.
Conclusions: Use of automated electronic corroborating intra-institutional data is an effective method for identification and surveillance of CHF. Clarity applications targeting unified clinical notes, available with upgrades to Epic 2010, should be further explored as a means of increasing performance of automated wide-scale CHF surveillance.
Research Interests:
Experience in applying semantic web technology to clinical health care research has revealed the need for a more consistent approach to RDF data production. Data originating in diverse clinical systems, formats and data models... more
Experience in applying semantic web technology to clinical health care research has revealed the need for a more consistent approach to RDF data production.
Data originating in diverse clinical systems, formats and data models typically must be transformed to hub ontologies, merged, inferenced, selected and finally transformed to consuming applications' ontologies and data formats for productive use. The process is quite repetitive: similar transformations are often performed each day, week or month with only slight variations to the data windows and queries. Ad hoc data production scripts can be created to help automate this process, but they tend to be fragile, inefficient, difficult to maintain and hard to visualize.
This presentation describes a simple framework and ontology for cached RDF data production pipelines, based on RESTful HTTP and SPARQL. These pipelines are easily visualized, and incremental data changes automatically propagate through to consuming applications.
Data originating in diverse clinical systems, formats and data models typically must be transformed to hub ontologies, merged, inferenced, selected and finally transformed to consuming applications' ontologies and data formats for productive use. The process is quite repetitive: similar transformations are often performed each day, week or month with only slight variations to the data windows and queries. Ad hoc data production scripts can be created to help automate this process, but they tend to be fragile, inefficient, difficult to maintain and hard to visualize.
This presentation describes a simple framework and ontology for cached RDF data production pipelines, based on RESTful HTTP and SPARQL. These pipelines are easily visualized, and incremental data changes automatically propagate through to consuming applications.
Research Interests:
Hospitals have come under increasing pressure to report a wide variety of health care process and outcomes measures to various governmental and non-governmental agencies. Typically, the data needed for these reports are captured in... more
Hospitals have come under increasing pressure to report a wide variety of health care process and outcomes measures to various governmental and non-governmental agencies. Typically, the data needed for these reports are captured in separate, unconnected databases designed to fulfill the specific requirements of individual agencies. Although initially expedient, this approach to quality reporting has several drawbacks: 1) it can result in costly redundant data collection if different reports have overlapping requirements; 2) similar data collected in separate databases can produce discrepancies in the same measures reported to different agencies; 3) data targeting specific quality reports often are difficult to use for other purposes, such as clinical research; and 4) the particular data collected are subject to the changing requirements of individual agencies, making multi-year comparisons difficult.
To overcome these problems, Cleveland Clinic's Heart and Vascular Institute has adopted a semantic approach to quality reporting, which uses ontology and rule-based inference to derive specific reported values from core clinical facts collected in a common RDF data repository. We use SemanticDB to collect core clinical data for individual patients through feeds from other clinical systems, and manual, forms-based data entry. These core patient medical data are stored in named RDF graphs, which can be expanded through a combination of forward and backward inference to include new classes useful for generating specific quality reports. These reports are generated with an application built on the Cyc ontology and reasoner that align logical and physical schemas, formulate appropriate SPARQL queries of the expanded graphs, and transform results to the required format. With this approach, core clinical data can be collected in a highly reusable form with little or no redundancy. In addition, differences or changes in reporting requirements can often be handled by modifications of the ontologies and rules guiding the inferential expansion of patient graphs and SPARQL queries rather than the actual data collected.
To overcome these problems, Cleveland Clinic's Heart and Vascular Institute has adopted a semantic approach to quality reporting, which uses ontology and rule-based inference to derive specific reported values from core clinical facts collected in a common RDF data repository. We use SemanticDB to collect core clinical data for individual patients through feeds from other clinical systems, and manual, forms-based data entry. These core patient medical data are stored in named RDF graphs, which can be expanded through a combination of forward and backward inference to include new classes useful for generating specific quality reports. These reports are generated with an application built on the Cyc ontology and reasoner that align logical and physical schemas, formulate appropriate SPARQL queries of the expanded graphs, and transform results to the required format. With this approach, core clinical data can be collected in a highly reusable form with little or no redundancy. In addition, differences or changes in reporting requirements can often be handled by modifications of the ontologies and rules guiding the inferential expansion of patient graphs and SPARQL queries rather than the actual data collected.
1998 Invited presentation to workshop on "Modeling Complexity in Social Systems," Colorado Center for Chaos and Complexity, University of Colorado, Boulder.
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1998 Invited presentation, 63rd Annual Meeting of the Society for American Archaeology, Seattle, Wa.
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Research Interests:
Fire-altered rocks, as the name implies, are rocks that show signs of alteration resulting from exposure to extreme heat. These rocks are often referred to as "fire-cracked rocks" by archaeologists because cracking is a common and readily... more
Fire-altered rocks, as the name implies, are rocks that show signs of alteration resulting from exposure to extreme heat. These rocks are often referred to as "fire-cracked rocks" by archaeologists because cracking is a common and readily distinguishable form of alteration. The archaeological record in many areas of the world contains great quantities of fire-altered rocks and these rocks were recognized early on as artifacts. However, the lack of stylistic attributes of most fire-altered rocks lead, understandably, to their neglect by archaeologists devoted to working out culture histories. More recently, a growing concern with functional or analogous variation has lead some archaeologist, primarily in the past decade, to look more closely at fire-altered rocks as a source of information about the past (e.g., Ericson 1972; McDowell-Loudan 1983; Pierce 1982, 1988; Roll 1982; Thoms 1986; Van Dyke, et al 1980). Although these studies have served to increase the awareness of the potential of fire-altered rock studies in some areas, in general, archaeologists continue to ignore these artifacts. Consequently, we still know exceedingly little about the nature and significance of variation in fire-altered rocks.
My goal here is to demonstrate through two examples that fire-altered rocks possess considerable variation that is easily described and directly relevant to the kinds of functional questions asked by archaeologists today. In fact, as we will see, fire-altered rocks are ideally suited to functional studies because the class of artifacts is defined in terms that are directly related to a particular kind of use, that is the manipulation of heat energy. The examples will use are drawn from two different contexts. One includes data collected on rocks contained in six discrete concentrations or features exposed on the surface of a site. The other example focuses on fire-altered rocks recovered from test pits excavated in a shell midden where the rocks occur in varying amounts throughout the deposit rather than in discrete or recognizable features.
My goal here is to demonstrate through two examples that fire-altered rocks possess considerable variation that is easily described and directly relevant to the kinds of functional questions asked by archaeologists today. In fact, as we will see, fire-altered rocks are ideally suited to functional studies because the class of artifacts is defined in terms that are directly related to a particular kind of use, that is the manipulation of heat energy. The examples will use are drawn from two different contexts. One includes data collected on rocks contained in six discrete concentrations or features exposed on the surface of a site. The other example focuses on fire-altered rocks recovered from test pits excavated in a shell midden where the rocks occur in varying amounts throughout the deposit rather than in discrete or recognizable features.
Research Interests:
Research Interests:
In 1996, Dr. Ann Ramenofsky and Chris Pierce began discussions with the Archaeological Conservancy regarding the potential for long-term, significant research at San Marcos Pueblo (LA98). The site is located on a 60-acre Conservancy... more
In 1996, Dr. Ann Ramenofsky and Chris Pierce began discussions with the Archaeological Conservancy regarding the potential for long-term, significant research at San Marcos Pueblo (LA98). The site is located on a 60-acre Conservancy preserve adjacent to New Mexico State Highway 14 in the Galisteo Basin south of Santa Fe. At the time, the Conservancy was in the process of acquiring the entire parcel that included numerous room blocks and a mission-complex. Given the integrity of the site, the tourism potential, and the importance of the site for understanding a significant part of Rio Grande prehistory and history to the Pueblo Revolt, the Conservancy was interested and supportive of sustained archaeological field work at San Marcos.
The initial goal of the fieldwork was to produce modern, detailed planimetric and topographic maps of the pueblo. In addition to Nelson's plan maps, a group from the University of Colorado had produced a series of photogrammetric interpretations and surface maps of the pueblo (Eddy et al. 1996; Welker 1997; Welker and Carr 1995). We benefited from these previous efforts, and used them to familiarize ourselves with the surface complexity of the pueblo. None of the earlier maps were topographic, and the latter is an important tool for management and for archaeological surface and sub-surface research.
The initial goal of the fieldwork was to produce modern, detailed planimetric and topographic maps of the pueblo. In addition to Nelson's plan maps, a group from the University of Colorado had produced a series of photogrammetric interpretations and surface maps of the pueblo (Eddy et al. 1996; Welker 1997; Welker and Carr 1995). We benefited from these previous efforts, and used them to familiarize ourselves with the surface complexity of the pueblo. None of the earlier maps were topographic, and the latter is an important tool for management and for archaeological surface and sub-surface research.