The archaeological literature warns against trusting the context of artifacts found within a vertisol due to the constant mixing of sediments caused by the shrink/swell properties of clays. These churning processes were thought to be the defining characteristic of vertisols until only the past few decades. It is now apparent that vertisols vary drastically based on a wide spectrum of variables and are fully capable of forming without churning processes. The Buttermilk Creek Site, Block A represents a prime example of a minimally developed vertisol. In addition, the site itself is a heavily occupied lithic quarry that has been almost continuously inhabited since Clovis and possibly Pre-Clovis times. This thesis takes a detailed look at the sediments and distribution of lithic artifacts from Block A of the Buttermilk Creek site to address the two following research objectives: 1) to determine if the archaeological context within the floodplain sediments at Block A has been disturbed by post-depositional processes, and 2) to identify discrete occupation surfaces within the vertic floodplain sediments at the site. These objectives are addressed using a variety of methods, including: 1) plotting the stratigraphic position of diagnostic artifacts, 2) determining the size distribution of debitage and artifact quantities throughout the floodplain deposits, 3) examining the distribution of cultural versus non-cultural lithic material, 4) recording the presence or absence of heat alteration in the deposits, 5) creating maps showing the degree of fissuring across the site, 6) analyzing differences in patination on artifacts, and 7) analyzing the presence of calcium carbonate on artifacts from all levels. Results from these analyses show that, despite the classification of sediments at Block A as a vertisol, vertical displacement of artifacts is largely absent. Chronologically ordered diagnostic points, consistently size sorted artifacts, and a lack of constant mixing of calcium carbonate throughout the profile suggest that artifacts found as deep as 20 cm below the Clovis-aged horizon represent intact cultural horizons. These oldest components found in Block A may represent some of the earliest known evidence of people in the New World.

This thesis covers more than thirty years of the author's research into the Paleoamerican period of the Middle Atlantic Region of North America, including the last 19+ years of focused work on the Cactus Hill site (44SX202) and replication of the Paleoamerican occupation discovered there. Using a landform and geology based predictive model derived from the Paleoamerican occupation at Cactus Hill, the author directed preliminary archaeological testing in three other areas of the same Nottoway River Valley, where Cactus Hill is located. These areas were the Barr site, located 11 miles (18 km.) downriver from Cactus Hill; the Chub Sandhill Natural Resource Conservation Area, located 19 miles (30 km.) downriver from Cactus Hill; and the Blueberry Hill site (44SX327), located approximately 1,000 feet (300 meters) east of Cactus Hill. The latter two produced OSL dated, pre-Younger-Dryas landforms, as predicted. The Rubis-Pearsall site (44SX360), located in the Chub Sandhill preserve also produced a buried Paleoamerican, Clovis age cultural level confirming the model. In addition to the OSL dates, Blueberry Hill also produced a distinct and apparently discrete activity surface with a possible pre-Clovis age Cactus Hill point at the same depth as the Paleoamerican levels at Cactus Hill and Rubis-Pearsall.

This dissertation addresses how Paleoindians used the karst drainage of the Aucilla River in northwestern Florida during the Pleistocene/Holocene transition (approximately 15-10,000 14C yr B.P.). I take a geoarchaeological approach to discuss Paleoindian land use by first defining the Late Pleistocene and Holocene geological record, and then by creating a model of site formation processes in the Aucilla River. Both underwater and terrestrial fieldwork were performed. Underwater fieldwork consisted of hand-driven cores and surface survey, vibrocoring, underwater 1 x 1 m unit excavation, and controlled surface collection. Terrestrial fieldwork consisted of shovel and auger test pits. Seventeen cores were collected from five different submerged sinkhole sites, which were used to select two sites for further study: Sloth Hole (8JE121), which had been previously excavated, and Wayne's Sink (8JE1508/TA280), which was recorded but not formally investigated. Five vibrocores and two 1 x 1m units were used, with previous research, to define the geological and geoarchaeological context of Sloth Hole. Fifteen vibrocores, six 1 x 1 m excavation units, and ten 1 x 1 m surface collection units were used to define the geological, geoarchaeological, and archaeological context of Wayne's Sink. A combination of 130 shovel and auger test pits was used to define the geological, geoarchaeological, and archaeological potential of the terrestrial landscape. Five new Holocene-aged terrestrial sites were recorded. All of these data were evaluated with archival data from previously-excavated sites to create models of site formation and Paleoindian land use in the lower Aucilla Basin. This research shows that there have been four major periods of sinkhole infill in the lower Aucilla basin. The first occurred prior to the Last Glacial Maximum, with each sinkhole containing peat deposits that date in excess of 21,000 calendar years ago (cal B.P.). These peats are overlain by sandy colluvium that dates to approximately 14,500 cal B.P. The colluvium is overlain by clays that contain evidence for soil formation. These soils vary in age, with radiocarbon dates of approximately 14,500-10,000 cal B.P. These clays are directly overlain by peats dating to 5,000-3,500 cal B.P., which are overlain by peats and clays that date to 2,500-0 cal B.P. Intact Paleoindian and Early Archaic deposits are possible in the late Pleistocene soils.

This dissertation focuses on two portions of the Clovis lithic assemblage recovered from Excavation Area 8 at the Gault site (41BL323) located in central Texas. Gault is a quarry-camp visited by hunter-gatherer groups for at least 13,000 years, with Paleoindian, Archaic, and Late Prehistoric occupations. Freshwater seep springs, a diverse array of floral and faunal resources, and an abundant outcrop of high-quality toolstone at the site created an ideal location for people who lived a mobile hunting-andgathering way of life. The site is currently the only locale with two stratigraphically separate Clovis components-a lower geologic unit designated 3a and an upper unit designated 3b. Both are represented in Excavation Area 8 where, in the spring of 2000, Texas A&M University (TAMU) excavated 22 1-m2 contiguous units. For this research, 3375 complete flakes were analyzed individually to characterize Clovis debitage as represented at Excavation Area 8 and to establish if there are technological differences between the debitage assemblages recovered from Units 3a and 3b. The two Clovis components are quite similar from a technological standpoint. Minor differences appear to be related to site formation processes and intensity of site use. The second objective was to determine if Clovis debitage has diagnostic technological traits that allow confident assignment to the Clovis era. To test whether Clovis debitage is distinctive, it was compared to debitage recovered from later cultural components at the site. No evidence of a true blade technology was observed in the post- Clovis Paleoindian or Early Archaic debitage assemblages, although biface manufacture continued through time. Technologically, few differences were observed between the Clovis, post-Clovis Paleoindian, and Early Archaic debitage related to biface reduction. While overshot flakes may be diagnostic of Clovis biface technology, biface thinning flakes and other non-distinctive debitage showed few differences between components. During debitage analysis pieces were selected in an attempt to identify edgemodified tools. Low- and high-power usewear analysis was employed to make determinations concerning the cultural modification or use of flakes. This study concluded post-depositional damage affected most of the collection and there was minimal usewear-or minimal observable usewear-on flakes. Taphonomic processes interfered to a great extent with drawing firm inferences on tool use and possibly hindered the identification of tools. Of the 3375 pieces of Clovis debitage originally analyzed, 26 specimens were classified as tools based mainly on invasive, patterned flaking with less reliance on microscopic use indicators. Of these, inference of use was assigned to nine tools.

Thesis (M.A.)--University of Wyoming, 2007. / Title from PDF title page (viewed on Feb. 11, 2009). Includes bibliographical references (p. 157-168).

Les fractures du fémur proximal de la personne âgée sont généralement fixées par des dispositifs d'ostéosynthèse. Pour les fractures particulières dites inter-trochantériennes, il est possible de fixer la fracture de manière intra-médullaire (à l'intérieur de l'os) ou de manière extra-médullaire (en dehors de l'os). Pour chaque type de traitement, les hôpitaux sont équipés des deux systèmes de fixation. Les différences de morphologie des individus impliquent l'existence de multiples références d'implants et donc de surcoûts en termes d'équipement. Dans ce travail de thèse, un implant original adaptable à la plupart des morphologies a été développé. Cet implant permettra non seulement d'offrir aux chirurgiens une souplesse au cours des interventions chirurgicales mais aussi de réduire de manière significative les stocks d'implants dans les hôpitaux. Le comportement mécanique de l'implant est étudié dans différents cas de fractures par deux approches complémentaires, une méthode numérique par Éléments Finis et une approche expérimentale mettant en oeuvre des techniques de stéréo-corrélation à partir d'images de caméras rapides. Les résultats des calculs numériques sont confrontés à ceux issus d'essais réalisés sur des fémurs synthétiques, puis cadavériques en laboratoire d'anatomie. Les comparaisons avec des implants existants montrent que ce nouveau concept d'implant permet une fixation plus stable des fragments osseux et une bonne compression du foyer de fracture.