237 research outputs found
Morphological Variation in Cephalogonimus americanus (Trematoda: Cephalogonimidae) from Amphibians in Colorado
A collection of western toads, Bufo boreas Baird and Girard, 1852, and neotenic tiger salamanders, Ambystoma tigrinum (Green) from Sheep Lake, Horseshoe Park, Rocky Mountain National Park, Colorado, were examined for helminths in the spring of 1966. Oswaldo-Cruzia subauricularis (Rudolphi, 1819) was found in Bufo boreas and Ophiotaenia filarioides (LaRue, 1909) in Ambystoma tigrinum. In addition, both hosts harbored Spironoura pretiosa Ingles, 1936, Phylloclistomum bufonis Frandsen, 1957 and Cephalogonimus americanus. The last species differed greatly in appearance in the two hosts and these differences are reported herein
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Analysis of Artificial Radiocarbon in Different Skeletal and Dental Tissue Types to Evaluate Date of Death
Radiocarbon dating, with special reference to the modern bomb-curve, can provide useful information to elucidate the date of death of skeletonized human remains. Interpretation can be enhanced with analysis of different types of tissues within a single skeleton because of the known variability of formation times and remodeling rates. Analysis of radiocarbon content of teeth, especially the enamel in tooth crowns provides information about the date of formation in the childhood years and in consideration of the known timing of tooth formation can be used to estimate the birth date after 1950 A.D. Radiocarbon analysis of modern cortical and trabecular bone samples from the same skeleton may allow proper placement on the pre-1963 or post-1963 sides of the bomb-curve since most trabecular bone generally undergoes more rapid remodeling than does most cortical bone. Pre-1963 bone formation would produce higher radiocarbon values for most trabecular bone than for most cortical bone. This relationship is reversed for formation after 1963. Radiocarbon analysis was conducted in this study on dental, cortical and trabecular bone samples from two adult individuals of known birth (1925 and 1926) and death dates (1995 and 1959). As expected, the dental results correspond to pre-bomb bomb-curve values reflecting conditions during the childhoods of the individuals. The curve radiocarbon content of most bone samples reflected the higher modern bomb-curve values. Within the bone sample analyses, the values of the trabecular bone were higher than those of cortical bone and supported the known placement on the pre-1963 side of the bomb-curve
Evaluating elbow osteoarthritis within the prehistoric Tiwanaku state using generalized estimating equations (GEE).
OBJECTIVES:Studies of osteoarthritis (OA) in human skeletal remains can come with scalar problems. If OA measurement is noted as present or absent in one joint, like the elbow, results may not identify specific articular pathology data and the sample size may be insufficient to address research questions. If calculated on a per data point basis (i.e., each articular surface within a joint), results may prove too data heavy to comprehensively understand arthritic changes, or one individual with multiple positive scores may skew results and violate the data independence required for statistical tests. The objective of this article is to show that the statistical methodology Generalized Estimating Equations (GEE) can solve scalar issues in bioarchaeological studies. MATERIALS AND METHODS:Using GEE, a population-averaged statistical model, 1,195 adults from the core and one colony of the prehistoric Tiwanaku state (AD 500-1,100) were evaluated bilaterally for OA on the seven articular surfaces of the elbow joint. RESULTS:GEE linked the articular surfaces within each individual specimen, permitting the largest possible unbiased dataset, and showed significant differences between core and colony Tiwanaku peoples in the overall elbow joint, while also pinpointing specific articular surfaces with OA. Data groupings by sex and age at death also demonstrated significant variation. A pattern of elbow rotation noted for core Tiwanaku people may indicate a specific pattern of movement. DISCUSSION:GEE is effective and should be encouraged in bioarchaeological studies as a way to address scalar issues and to retain all pathology information
Release of Lungworm Larvae from Snails in the Environment: Potential for Alternative Transmission Pathways
Background: Gastropod-borne parasites may cause debilitating clinical conditions in animals and humans following the consumption of infected intermediate or paratenic hosts. However, the ingestion of fresh vegetables contaminated by snail mucus and/or water has also been proposed as a source of the infection for some zoonotic metastrongyloids (e.g., Angiostrongylus cantonensis). In the meantime, the feline lungworms Aelurostrongylus abstrusus and Troglostrongylus brevior are increasingly spreading among cat populations, along with their gastropod intermediate hosts. The aim of this study was to assess the potential of alternative transmission pathways for A. abstrusus and T. brevior L3 via the mucus of infected Helix aspersa snails and the water where gastropods died. In addition, the histological examination of snail specimens provided information on the larval localization and inflammatory reactions in the intermediate host.
Methodology/Principal Findings: Twenty-four specimens of H. aspersa received ~500 L1 of A. abstrusus and T. brevior, and were assigned to six study groups. Snails were subjected to different mechanical and chemical stimuli throughout 20 days in order to elicit the production of mucus. At the end of the study, gastropods were submerged in tap water and the sediment was observed for lungworm larvae for three consecutive days. Finally, snails were artificially digested and recovered larvae were counted and morphologically and molecularly identified. The anatomical localization of A. abstrusus and T. brevior larvae within snail tissues was investigated by histology. L3 were detected in the snail mucus (i.e., 37 A. abstrusus and 19 T. brevior) and in the sediment of submerged specimens (172 A. abstrusus and 39 T. brevior). Following the artificial digestion of H. aspersa snails, a mean number of 127.8 A. abstrusus and 60.3 T. brevior larvae were recovered. The number of snail sections positive for A. abstrusus was higher than those for T. brevior.
Conclusions: Results of this study indicate that A. abstrusus and T. brevior infective L3 are shed in the mucus of H. aspersa or in water where infected gastropods had died submerged. Both elimination pathways may represent alternative route(s) of environmental contamination and source of the infection for these nematodes under field conditions and may significantly affect the epidemiology of feline lungworms. Considering that snails may act as intermediate hosts for other metastrongyloid species, the environmental contamination by mucus-released larvae is discussed in a broader context
New insights into Eastern Beringian mortuary behavior: A terminal Pleistocene double infant burial at Upward Sun River
Here we report on the discovery of two infant burials dating to 11,500 calibrated years (cal) B.P. at the Upward Sun River site in central Alaska. The infants were interred in a pit feature with associated organic and lithic grave goods, including the earliest known North American hafted bifaces with decorated antler foreshafts. Skeletal and dental analyses indicate that Individual 1 died shortly after birth and Individual 2 was a late-term fetus, making these the youngest-aged late Pleistocene individuals known for the Americas and the only known prenate, offering, to our knowledge, the first opportunity to explore mortuary treatment of the youngest members of a terminal Pleistocene North American population. This burial was situated 40 cm directly below a cremated 3-y-old child previously discovered in association with a central hearth of a residential feature. The burial and cremation are contemporaneous, and differences in body orientation, treatment, and associated grave goods within a single feature and evidence for residential occupation between burial episodes indicate novel mortuary behaviors. The human remains, grave goods, and associated fauna provide rare direct data on organic technology, economy, seasonality of residential occupations, and infant/child mortality of terminal Pleistocene Beringians
Puberty in the Bronze Age: First application of a puberty estimation method to a prehistoric population
This is the peer reviewed version of the following article: Doe, Danielle M., et al. "Puberty in the Bronze Age: First application of a puberty estimation method to a prehistoric population". International Journal of Osteoarchaeology 29.6 (2019): 1091-1099, which has been published in final form at https://doi.org/10.1002/oa.2822. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsPuberty and adolescence represent a significant period of physical growth and maturation and a critical life stage in which children transition into adults within their societies. Numerous studies have observed a secular trend and have determined that puberty is now occurring earlier than in the past. This investigation represents the first application of a methodology for assessing the pubertal status of osteological remains to a prehistoric skeletal sample. Six Bronze Age adolescent skeletons from the Cerro de La Encantada archaeological site (Ciudad Real, Spain) were analysed. Prepubescence was observed at age 9 and the transition phase of the pubertal growth spurt at 15Â years of age. These results were similar to those obtained from medieval, Industrial Revolution, and modern populations, both within and outside of the Iberian Peninsula. The similarity in the development of the Bronze Age adolescents to that of other past and contemporary populations suggests that the pubertal process has remained essentially unchanged across millennia until recent times. However, other interpretations, including the influence of a subpar developmental environment and potential methodological artefacts, are possible. Nevertheless, studies of this type provide important information about a crucial transitory period in human developmentThe Laboratorio de Poblaciones del Pasado (LAPP) has been supported by Projects HAR2016â78036âP, HAR2016â74846âP, HAR2017â82755âP, and HAR2017â83004âP (Spanish Government) and a grant (Ref. 38360) from the Leakey Foundatio
How old are you now? A new ageing method for nonadults based on dental wear
The main aim of this study is to present a novel method of nonadult (ca. 1â19 years) ageâatâdeath estimation using the dental wear of deciduous, mixed deciduousâpermanent, and permanent dentitions, including the incisors, canines, premolars, and first and second molars. The stageâbased method is derived from degrees of dental wear in knownâage (n = 39) and estimatedâage (n = 11) nonadults containing 951 teeth from the predominately 19th century cemetery of Middenbeemster, The Netherlands. The need for such a method is warranted in cases where dental development and/or eruption cannot be assessed for ageâatâdeath estimation. As well, by establishing a baseline for normal ageârelated nonadult tooth wear, users may better document wear that could be due to extramasticatory behaviours. The regression analysis reveals a strong quadratic correlationâF(2, 47) = 555.1, p R2 = .95, standard error of the estimate = 1.14, residual sum of squares (RSS) = 68.89, predicted residual error sum of squares (PRESS) = 77.67âbetween age and wear and multivariate adaptive regression splines (R2 = .95, generalised cross validation = 1.67, RSS = 67.68, PRESS = 89.34), which are used to develop an Râpackage that users may employ to estimate ageâatâdeath from dental wear. The accuracy of this method (78â98%) is evaluated using leaveâoneâout crossâvalidation. Analyses of males versus females, deciduous versus permanent, upper versus lower, and anterior versus posterior teeth revealed no apparent reason to warrant separate methods for these groups of separated dentitions. This method fills a disciplinary gap in the understudied area of deciduous and nonadult dental wear and hopes to stimulate much future research. With the Râpackage, we also provide the foundation and framework for the development of additional reference populations across different spatiotemporal contexts, to make the method more widely applicable. Bioarchaeolog
Multidisciplinary investigations of the diets of two post-medieval populations from London using stable isotopes and microdebris analysis
This paper presents the first multi-tissue study of diet in post-medieval London using both the stable light isotope analysis of carbon and nitrogen and analysis of microdebris in dental calculus. Dietary intake was explored over short and long timescales. Bulk bone collagen was analysed from humans from the Queenâs Chapel of the Savoy (QCS) (n = 66) and the St Barnabas/St Mary Abbots (SB) (n = 25). Incremental dentine analysis was performed on the second molar of individual QCS1123 to explore childhood dietary intake. Bulk hair samples (n = 4) were sampled from adults from QCS, and dental calculus was analysed from four other individuals using microscopy. In addition, bone collagen from a total of 46 animals from QCS (n = 11) and the additional site of Prescot Street (n = 35) was analysed, providing the first animal dietary baseline for post-medieval London. Overall, isotopic results suggest a largely C3-based terrestrial diet for both populations, with the exception of QCS1123 who exhibited values consistent with the consumption of C4 food sources throughout childhood and adulthood. The differences exhibited in ÎŽ15Ncoll across both populations likely reflect variations in diet due to social class and occupation, with individuals from SB likely representing wealthier individuals consuming larger quantities of animal and marine fish protein. Microdebris analysis results were limited but indicate the consumption of domestic cereals. This paper demonstrates the utility of a multidisciplinary approach to investigate diet across long and short timescales to further our understanding of variations in social status and mobility
Colonial America
The first permanent British settlement in what became the United States was established in 1607, nearly 170 years prior to the American declaration of independence. This chapter examines the economic development of the British North American colonies that became the United States. As it describes, abundant natural resources and scarce labor and capital contributed to the remarkable growth in the size of the colonial economy, and allowed the free white colonial population to enjoy a relatively high standard of living. There was not, however, much improvement over time in living standards. Patterns of factor abundance also played an important role in shaping colonial institutions, encouraging reliance on indentured and enslaved labor as well as the development of representative government. For most of the colonial era, the colonists happily accepted their relationship to Britain. After 1763, however, changes in British policies following the end of the Seven Years War created growing tensions with the colonists and ultimately led to the colonies to declare their independence
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