1,881 research outputs found
Monumental burials and memorial feasting: an example from the southern Brazilian highlands
© 2008 Antiquity PublicationsWhat happened at the sites of prehistoric burial mounds after they were erected? In the southern highlands of Brazil and Argentina the pre-Hispanic mounds of the twelfth-thirteenth centuries AD are surrounded by large circular enclosures with avenues leading to their centre. The authors discovered that the banks of the surrounding enclosure were built up over several generations of time, accompanied by a succession of ovens. Ethnohistoric observations of more recent peoples in the same region suggested an explanation: the cremation of a chief was followed by periodic feasts at his mound, where meat was steamed and maize beer prepared at the edge of the gathering.Research at site PM01 was funded by grants from the National Geographic Committee
for Research and Exploration (CRE 7853-05) and the University of Exeter Exploration Fund
Populations dynamics in Northern Eurasian forests: a long-term perspective from Northeast Asia
The âNorthern Eurasian Greenbeltâ (NEG) is the northern forest zone stretching from the Japanese Archipelago to Northern Europe. The NEG has created highly productive biomes for humanity to exploit since the end of the Pleistocene. This research explores how the ecological conditions in northern Eurasia contributed to and affected human migrations and cultural trajectories by synthesizing the complimentary viewpoints of environmental archaeology, Geographic Information Science (GIS), genetics and linguistics. First, the environmental archaeology perspective raises the possibility that the NEG functioned as a vessel fostering people to develop diverse cultures and engage in extensive cross-cultural exchanges. Second, geographical analysis of genomic data on mitochondrial DNA using GIS reveals the high probability that population dynamics in the southeastern NEG promoted the peopling of the Americas at the end of the Pleistocene. Finally, a linguistic examination of environmental- and landscape-related vocabulary of the proto-Turkic language groups enables the outline of their original cultural landscape and natural conditions, demonstrating significant cultural spheres, i.e. from southern Siberia to eastern Inner Mongolia during Neolithization. All of these results combine to suggest that the ecological complex in the southern edge of the NEG in northeast Asia played a significant role in peopling across the continents during prehistory.- Introduction: Northern Eurasian Greenbelt - Methodology: synthesizing environmental archaeology, genetic-geography and linguistics - Environmental archaeology: socio-ecological background of the NEG -- Long huntingâgathering traditions -- Environmental setting -- Hypothesis: the NEG as a trans-continental cultural system - A geneticâgeographical perspective -- Cultural, physical and bio-geographical evidence -- Supporting archaeological evidence -- The genomic evidence -- Discussion - Historical linguistics: the origin of the Turkic family and its early dispersal via the NEG -- The Proto-Turkic homeland -- Proto-Turkic vocabulary of the natural and cultural environments -- Early Turkic migrations and cultural transmission via the NEG - Early Turkic migrations and cultural transmission via the NE
âWhatdunit?â Developmental changes in children\u27s syntactically based sentence interpretation abilities and sensitivity to word order
Aim 1 of this study was to examine the developmental changes in typically developing English-speaking childrenâs syntactically-based sentence interpretation abilities and sensitivity to word order. Aim 2 was to determine the psychometric standing of the novel sentence interpretation task developed for this study, as we wish to use it later with children with Specific Language Impairment (SLI). Children listened to semantically implausible sentences in which noun animacy and the natural affordance between the nouns were removed, thus controlling for event probability. Using this novel âwhatdunit?â agent selection task, 256 children 7-11 years listened to two structures with canonical word order and two with non-canonical word order. After each sentence, children selected as quickly as possible the picture of the noun they believed was âdoing the action.â Children interpreted sentences with canonical word order with greater accuracy and speed than those with non-canonical word order. Older children (AgeM = 10:8) were more accurate and faster than younger children (AgeM = 8:1) across all sentence forms. Both older and younger children demonstrated similar error patterns across sentence type. The âwhatdunit?â task also proved to have strong validity and reliability, making it suitable for studies with children with SLI
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Intensive archaeological survey of the F/H Surface Enhancement Project Area, Savannah River Site, Aiken and Barnwell Counties, South Carolina
Twelve archaeological sites and four artifact occurrences were located by intensive survey of two tracts of land for the F and H Surface Enhancement Project on the Savannah River Site, Aiken and Barnwell Counties, South Carolina. Fieldwork in the 480-acre project area included surface reconnaissance of 3.6 linear kilometers of transects, 140 shovel tests along 4.2 linear kilometers of transects, an additional 162 shovel tests at sites and occurrences, and the excavation of six l {times} 2 m test units. All but one of the sites contained artifacts of the prehistoric era; the twelfth site consists of the remains of a twentieth-century home place. The historic site and six of the prehistoric sites consist of limited and/or disturbed contexts of archaeological deposits that have little research potential and are therefore considered ineligible for nomination to the National Register of Historic Places (NRHP). The remaining five sites have sufficient content and integrity to yield information important to ongoing investigations into upland site use. These sites (38AK146, 38AK535, 38AK539, 38AK541, and 38AK543) are thus deemed eligible for nomination to the NRHP and the Savannah River Archaeological Research Program (SRARP) recommends that they be preserved through avoidance or data recovery
Di-Calcium Phosphate and Phytosphingosine as an Innovative Acid-Resistant Treatment to Occlude Dentine Tubules
The present investigation evaluated the ability of an experimental di-calcium phosphate (DCP) desensitising agent used alone or combined with phytosphingosine (PHS) to occlude dentine tubules and resist a citric acid (CA) or artificial saliva (AS) challenge. Three groups of human dentine specimens (DS) were treated with the following: (1) PHS alone, (2) DCP or (3) a combination of PHS and DCP. Dentine hydraulic conductance of DS was evaluated using a digital flow sensor at 6.9 kPa. The average fluid volume for each of the treated DS was used to calculate the total dentine permeability reduction (%P) prior to and following CA immersion for 1 min or AS immersion for 4 weeks. The treated DS were subjected to both scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy analysis. Statistically significant differences (%P) were identified between the groups by ANOVA and Fisher's multiple comparison test (p 0.05) or show any evidence of occlusion of the dentine tubules. DCP can be used alone or combined with PHS to decrease the dentine permeability as well as to resist a CA and AS challenge. These results would, therefore, suggest that DCP may be a suitable treatment option for dentine hypersensitivity
Interdental and subgingival microbiota may affect the tongue microbial ecology and oral malodour in health, gingivitis and periodontitis.
BACKGROUND AND OBJECTIVE: Oral malodour is often observed in gingivitis and chronic periodontitis patients, and the tongue microbiota is thought to play a major role in malodorous gas production, including volatile sulphur compounds (VSCs) such as hydrogen sulphide (H2 S) and methanethiol (CH3 SH). This study aimed to examine the link between the presence of VSCs in mouth air (as a marker of oral malodour) and the oral bacterial ecology in the tongue and periodontal niches of healthy, gingivitis and periodontitis patients. METHODS: Participants were clinically assessed using plaque index, bleeding on probing (BOP) and periodontal probing depths, and VSC concentrations in their oral cavity measured using a portable gas chromatograph. Tongue scrapings, subgingival and interdental plaque were collected from healthy individuals (n = 22), and those with gingivitis (n = 14) or chronic periodontitis (n = 15). The bacterial 16S rRNA gene region V3-V4 in these samples was sequenced, and the sequences were analysed using the minimum entropy decomposition pipeline. RESULTS: Elevated VSC concentrations and CH3 SH:H2 S were observed in periodontitis compared with health. Significant ecological differences were observed in the tongue microbiota of healthy subjects with high plaque scores compared to low plaque scores, suggesting a possible connection between the microbiota of the tongue and the periodontium and that key dysbiotic changes may be initiated in the clinically healthy individuals who have higher dental plaque accumulation. Greater subgingival bacterial diversity was positively associated with H2 S in mouth air. Periodontopathic bacteria known to be prolific VSC producers increased in abundance on the tongue associated with increased bleeding on probing (BOP) and total percentage of periodontal pockets >6 mm, supporting the suggestion that the tongue may become a reservoir for periodontopathogens. CONCLUSION: This study highlights the importance of the periodontal microbiota in malodour and has detected dysbiotic changes in the tongue microbiota in periodontitis
Creative and Stylistic Devices Employed by Children During a Storybook Narrative Task: A Cross-Cultural Study
Purpose: The purpose of this study was to analyze the effects of culture on the creative and stylistic features children employ when producing narratives based on wordless picture books.
Method: Participants included 60 first- and second-grade African American, Latino American, and Caucasian children. A subset of narratives based on wordless picture books collected as part of a larger study was coded and analyzed for the following creative and stylistic conventions: organizational style (topic centered, linear, cyclical), dialogue (direct, indirect), reference to character relationships (nature, naming, conduct), embellishment (fantasy, suspense, conflict), and paralinguistic devices (expressive sounds, exclamatory utterances).
Results: Many similarities and differences between ethnic groups were found. No significant differences were found between ethnic groups in organizational style or use of paralinguistic devices. African American children included more fantasy in their stories, Latino children named their characters more often, and Caucasian children made more references to the nature of character relationships.
Conclusion: Even within the context of a highly structured narrative task based on wordless picture books, culture influences childrenâs production of narratives. Enhanced understanding of narrative structure, creativity, and style is necessary to provide ecologically valid narrative assessment and intervention for children from diverse cultural backgrounds
Vitamin D deficiency and prognostics among patients with pancreatic adenocarcinoma
BACKGROUND: The prevalence of vitamin D deficiency among patients with cancer has been previously reported. Because vitamin D is fat soluble, patients with pancreatic adenocarcinoma may have an especially high risk of vitamin D deficiency in association with ongoing and varying degrees of malabsorption. However, little is known about the correlation between vitamin D status and prognosis in these patients. METHODS: We conducted a retrospective review of vitamin D status in patients with pancreatic adenocarcinoma who were treated at Siteman Cancer Center. Patientsâ demographic information, clinical staging at the time of vitamin D assessment, vitamin D levels, and survival data were collected. Vitamin D deficiency was defined as a serum 25-hydroxyvitamin D (25[OH]D) level of less than 20Â ng/mL, and vitamin D insufficiency was defined as a 25(OH)D level of between 20Â ng/mL and 30Â ng/mL. RESULTS: Between December 2007 and June 2011, 178 patients with pancreatic adenocarcinoma had their vitamin D levels checked at the time of initial visit at this center. Of these 178 patients, 87 (49%) had vitamin D deficiency, and 44 (25%) had vitamin D insufficiency. The median 25(OH)D level was significantly lower among nonwhite patients and among patients with stage I and II disease. A 25(OH)D level of less than 20Â ng/mL was found to be associated with poor prognosis (pâ=â0.0019) in patients with stage III and IV disease. CONCLUSIONS: Vitamin D insufficiency and deficiency were prevalent among patients with pancreatic adenocarcinoma. The vitamin D level appears to be prognostic for patients with advanced pancreatic adenocarcinoma, and its effects should be further examined in a prospective study
A new echocardiographic model for quantifying three-dimensional endocardial surface area
A new technique for quantitatively mapping the three-dimensional left ventricular endocardial surface was developed, using measurements from standard cross-sectional echocardiographic images. To validate the accuracy of this echocardiographic mapping technique in an animal model, the endocardial areas of 15 excised canine ventricles were calculated using measurements made from echocardiographic studies of the hearts and compared with areas determined with latex casts of the same ventricles. Close correlation (r = 0.87, p < 0.001) between these two measures of endocardial area provided preliminary confirmation of the accuracy of the maps.To further characterize the mapping algorithm, it was translated into computer format and used to map the surfaces of idealized hemiellipsoids. Areas measured with this mapping technique closely approximated the actual areas of idealized surfaces with a wide spectrum of shapes; maps were particularly accurate for ellipsoids with shapes similar to those of undistorted human ventricles. Also, the accuracies of area calculations were relatively insensitive to deviation from the assumed positions of the echocardiographic short-axis planes. Finally, although the accuracy of the mapping technique improved as data from more transverse planes were added, the procedure proved reliable for estimating surface areas when data from only three planes were used. These studies confirm the accuracy of the echocardiographic mapping technique, and they suggest that the resulting planar plots might be useful as templates for localizing and quantifying the overall extent of abnormal wall motion
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