Stable isotopes, chronology and Bayesian models for the Viking archaeology of north-east Iceland

This paper reviews the results of a long-term research project that used stable isotope analyses (δ13C, δ15N, δ34S) and Bayesian mixing models to better model the chronology for a presumed Viking Age cemetery at Hofstaðir, near Lake Mývatn in north-east Iceland. δ13C and radiocarbon dating indicated that many of the individuals consumed a large amount of marine protein, which results in a marine reservoir effect (MRE), making ages older than expected. In addition to the MRE, geological activity in the region has the potential to introduce massive quantities of radioactive ‘dead’ carbon into the freshwater system, resulting in a very large freshwater reservoir effect (FRE) that can offset radiocarbon ages on the order of a few thousand years. The radiocarbon dates of organisms that derive an unknown proportion of their carbon from both marine and freshwater reservoirs are extremely difficult to ‘correct’, or, more appropriately, model. The research not only highlights the complexities of dealing with multiple reservoirs, but also how important it is to develop models that are temporally and geographically relevant to the site under study. Finally, it shows how this data can be used to inform the development of chronological models for refining the dating for archaeological activity

Radiocarbon dates from the Highland Jar and Coffin burial site of Phnom Khnang Peung, Cardamom Mountains, Cambodia

The Cardamom Mountain Jar and Coffin burial site of Phnom Khnang Peung is the most extensive example of the distinctive burial ritual first reported by Beavan et al. (2012a). The 40 intact Mae Nam Noi and late Angkorian-era ceramic jars used as burial vessels held a total of up to 152 individuals, representing the largest corpus of skeletal remains of any of the 10 known Jar and Coffin burial sites that have been discovered in the eastern ranges of the Cardamom Mountains of Cambodia. We report here on the radiocarbon dating of this site and notable burial phenomena, using a Bayesian approach to model the start and end date of activity as well as its overall span. The results of the dating and Bayesian analyses indicate that the Phnom Khnang Peung site’s earliest burials began cal AD 1420–1440 (95% probability). Interestingly, the concen- tration of burial activity spans only 15–45 years (95% probability), despite the large number of inhumations at the site. The 14C chronology presented for the site places the Highland burial ritual coincident with a period of economic, political, and societal transformations in the lowland Angkorian polity, but the unique burial practice and trade relationships evidenced by the burial goods and maritime trade ware ceramics employed in the burial ritual suggest these Highland people were a culture apart from Angkorian cultural influences

Research in progress: Assessing marine radiocarbon reservoir effect variation in greater Utqiaġvik, Alaska

No abstract available

Drivers of Microbial Risk for Direct Potable Reuse and de Facto Reuse Treatment Schemes: The Impacts of Source Water Quality and Blending.

Although reclaimed water for potable applications has many potential benefits, it poses concerns for chemical and microbial risks to consumers. We present a quantitative microbial risk assessment (QMRA) Monte Carlo framework to compare a de facto water reuse scenario (treated wastewater-impacted surface water) with four hypothetical Direct Potable Reuse (DPR) scenarios for Norovirus, Cryptosporidium, and Salmonella. Consumer microbial risks of surface source water quality (impacted by 0-100% treated wastewater effluent) were assessed. Additionally, we assessed risks for different blending ratios (0-100% surface water blended into advanced-treated DPR water) when source surface water consisted of 50% wastewater effluent. De facto reuse risks exceeded the yearly 10-4 infections risk benchmark while all modeled DPR risks were significantly lower. Contamination with 1% or more wastewater effluent in the source water, and blending 1% or more wastewater-impacted surface water into the advanced-treated DPR water drove the risk closer to the 10-4 benchmark. We demonstrate that de facto reuse by itself, or as an input into DPR, drives microbial risks more so than the advanced-treated DPR water. When applied using location-specific inputs, this framework can contribute to project design and public awareness campaigns to build legitimacy for DPR

CONSUMER ATTITUDES TOWARD ORGANICALLY GROWN LETTUCE

This research shows that approximately 29 percent of lettuce purchases in California expect to purchase an organically grown lettuce product in the future. Organic lettuce purchasers are more likely to be female, have a higher household income and a higher level of education. Consumers are concerned with the freshness, quality, price, and environmental impact of the lettuce they purchase.Consumer/Household Economics,

Matrilines in Neolithic cattle from Orkney, Scotland reveals complex husbandry patterns of ancestry

mtDNA, isotopic and archaeozoological analyses of cattle teeth and bones from the Late Neolithic site of Links of Noltland, Orkney, Scotland revealed these animals followed similar grazing regimes but displayed diverse genetic origins and included one cattle skull that carried an aurochs (wild cattle) genetic haplotype. Morphometric analyses indicate the presence of some cattle larger than published dimensions of Neolithic domestic cattle. Several explanations for these finding are possible but may be the evidence of a complex pattern of domestic cattle introductions into Neolithic Orkney and interbreeding between domestic and wild cattle

Sequential measurement of δ15N, δ13C and δ34S values in archaeological bone collagen at the Scottish Universities Environmental Research Centre (SUERC): a new analytical frontier

Rationale: The use of multi‐isotopic analysis (δ15N, δ13C and δ34S values) of archaeological bone collagen to assist in the interpretation of diet, movement and mobility of prehistoric populations is gradually increasing, yet many researchers have traditionally avoided investigating sulphur due to its very low concentrations (<0.3%) in mammalian collagen. For this reason, and as a consequence of analytical detection limits, sulphur is usually measured separately from carbon and nitrogen, which leads to longer analytical times and higher costs. Methods: A Thermo ScientificTM EA IsoLinkTM IRMS system, with the ability to rapidly heat a gas‐chromatography (GC) column and concentrate the sample gas online without cryo‐trapping, was used at the Radiocarbon Laboratory at SUERC. Optimisation of the GC temperature and carrier gas flow rate in the elemental analyser resulted in improved signal‐to‐noise ratio and sensitivity for SO2. This allowed for routine sequential N2, CO2 and SO2 measurements on small samples of bone collagen. Results: Improvements in sample gas transfer to the mass spectrometer allows for sequential δ15N, δ13C and δ34S values to be measured in 1–1.5 mg samples of bone collagen. Moreover, the sensitivity and signal‐to‐noise ratio of the sample gas, especially SO2, is improved, resulting in precisions of ±0.15‰ for δ15N values, ±0.1‰ for δ13C values and ±0.3‰ for δ34S values. Previous instrumentation allowed for the analysis of ~30 unknown samples before undertaking maintenance; however, ~150 unknown samples can now be measured, meaning a 5‐fold increase in sample throughput. Conclusions: The ability to sequentially measure δ15N, δ13C and δ34S values rapidly in archaeological bone collagen is an attractive option to researchers who want to build larger, more succinct datasets for their sites of interest, at a much‐reduced analytical cost and without destroying larger quantities of archaeological material

Deciphering diet and monitoring movement: multiple stable isotope analysis of the Viking Age settlement at Hofstaðir, Lake Mývatn, Iceland

Objectives: A previous multi-isotope study of archaeological faunal samples from Skútustaðir, an early Viking age settlement on the southern shores of Lake Mývatn in north-east Iceland, demonstrated that there are clear differences in δ34S stable isotope values between animals deriving their dietary protein from terrestrial, freshwater, and marine reservoirs. The aim of this study was to use this information to more accurately determine the diet of humans excavated from a nearby late Viking age churchyard. Materials and Methods: δ13C, δ15N, and δ34S analyses were undertaken on terrestrial animal (n = 39) and human (n = 46) bone collagen from Hofstaðir, a high-status Viking-period farmstead ∼10 km north-west of Skútustaðir. Results: δ34S values for Hofstaðir herbivores were ∼6‰ higher relative to those from Skútustaðir (δ34S: 11.4 ± 2.3‰ versus 5.6 ± 2.8‰), while human δ13C, δ15N, and δ34S values were broad ranging (−20.2‰ to −17.3‰, 7.4‰ to 12.3‰, and 5.5‰ to 14.9‰, respectively). Discussion: Results suggest that the baseline δ34S value for the Mývatn region is higher than previously predicted due to a possible sea-spray effect, but the massive deposition of Tanytarsus gracilentus (midges) (δ34S: −3.9‰) in the soil in the immediate vicinity of the lake is potentially lowering this value. Several terrestrial herbivores displayed higher bone collagen δ34S values than their contemporaries, suggesting trade and/or movement of animals to the region from coastal areas. Broad ranging δ13C, δ15N, and δ34S values for humans suggest the population were consuming varied diets, while outliers within the dataset could conceivably have been migrants to the area

Examining the Relationship Between Park Neighborhoods, Features, Cleanliness, and Condition With Observed Weekday Park Usage and Physical Activity: A Case Study

Background. Little research has comprehensively explored how park features, quality indicators, and neighborhood environments are associated with observed park usage and physical activity (PA). This case study examined whether weekday park usage and PA differ by neighborhood type, across numerous categories of park features, and according to park feature condition and cleanliness. Methods. Direct observation was used to capture the number of users and PA levels within 143 park features in 6 parks (3 urban, 3 suburban) over the course of six weeks. Audits of park environments assessed the type, condition, and cleanliness of all features and amenities. Results. Urban parks experienced greater usage, but a higher proportion of sedentary users than suburban parks. Usage and PA levels differed across types of park features, with splash pads, pools, paths, and play structures having the greatest proportion of active users. Usage did not differ by park feature condition and cleanliness, but greater condition and cleanliness were generally associated with higher PA levels. Conclusions. Factors such as neighborhood context, types of park features, and condition and cleanliness can impact park usage and PA levels and should be targets for researchers and planners aiming to foster more user-friendly and active neighborhood park environments

Adverse effect of increased left ventricular wall thickness on five year outcomes of patients with negative dobutamine stress

<p>Abstract</p> <p>Background</p> <p>To determine if patients without dobutamine induced left ventricular wall motion abnormalities (WMA) but an increased LV end-diastolic wall thickness (EDWT) exhibit a favorable cardiac prognosis.</p> <p>Results</p> <p>Between 1999 and 2001, 175 patients underwent a dobutamine stress cardiovascular magnetic resonance (DCMR) procedure utilizing gradient-echo cines. Participants had a LV ejection fraction >55% without evidence of an inducible WMA during peak dobutamine/atropine stress. After an average of 5.5 years, all participants were contacted and medical records were reviewed to determine the post-DCMR occurrence of cardiac death, myocardial infarction (MI), and unstable angina (USA) or congestive heart failure (CHF) warranting hospitalization.</p> <p>In a multivariate analysis, that took into account Framingham and other risk factors associated with cardiac events, a cine gradient-echo derived LV EDWT ≥12 mm was associated independently with an increase in cardiac death and MI (HR 6.0, p = 0.0016), and the combined end point of MI, cardiac death, and USA or CHF warranting hospitalization (HR 3.0, p = 0.0005).</p> <p>Conclusion</p> <p>Similar to echocardiography, CMR measures of increased LV wall thickness should be considered a risk factor for cardiac events in individuals receiving negative reports of inducible ischemia after dobutamine stress. Additional prognostic studies of the importance of LV wall thickness and mass measured with steady-state free precession techniques are warranted.</p