520 research outputs found
Carbon isotope ratios of Sterkfontein fossils indicate a marked shift to open environments c.1.7 Myr ago
Sterkfontein straddles a period in the Plio-Pleistocene in which the effects of global-scale climate shifts on continental environments and biota are not yet well understood. Reconstructions based on faunal indicators have suggested incremental shifts from relatively closed, mesic landscapes to open, arid environments at this time. We examined environmental shifts from ~2.5 to 1.7 million years ago (Myr) using a C3 / C4 index derived from 13C / 12C data on bovid fossils from Sterkfontein. Data for Member 4 and the Member 5 East infill indicate persistence of a wooded to moderately wooded environment until about 2.0-1.8 Myr. Data indicating a marked shift to open environments are observed only for the younger Member 5 West infill. We conclude that the major shift to open environments occurred near 1.7 Myr rather than at c. 2.5 Myr
Animal diets in the Waterberg based on stable isotopic composition of faeces
Faecal analysis of diet in free-ranging mammals can provide insight into local habitat conditions by reflecting the resources actually utilized. Here we used stable light isotope analysis of faeces to qualify, as well as quantify, certain aspects of mammal food selection in a recovering, nutrient-poor, savanna habitat in the Waterberg. Stable carbon isotope ratios in faeces reflect proportions of C3-foods (browse) to C4-foods (grass) consumed, whereas stable nitrogen isotope ratios reflect a combination of trophic behaviour, protein intake, and water and nutritional stress. Percentage nitrogen indicates the nutritional quality of the diet, at least in terms of crude protein intake. We used these data to reconstruct and compare the diets of various mammal species from two reserves in the Waterberg: the Welgevonden Private Game Reserve and Zoetfontein Private Game Farm
Of cattle and feasts: multi-isotope investigation of animal husbandry and communal feasting at Neolithic Makriyalos, northern Greece
The aim of this study is to investigate livestock husbandry and its relationship to the mobilization
of domestic animals for slaughter at large communal feasting events, in Late Neolithic
Makriyalos, northern Greece. A multi-isotope approach is built that integrates analysis of:
1. ÎŽ13C and ÎŽ15N values of human and animal bone collagen for understanding long-term dietary
behavior,
2. Incremental ÎŽ13C and ÎŽ18O values of domestic animal tooth enamel carbonate for assessing
seasonal patterns in grazing habits and mobility, and
3. 87Sr/86Sr ratios of cattle tooth enamel for examining the possibility that some of the animals
consumed at the site were born outside the local environment.
The findings indicate that cattle had isotopically more variable diets than sheep, which
may reflect grazing over a wider catchment area in the local landscape. Cattle products did
not make a significant contribution to the long-term dietary protein intake of the humans,
which may indicate that they were primarily consumed during episodic feasting events.
There is no indication that pasturing of livestock was pre-determined by their eventual context
of slaughter (i.e. large-scale feasting vs. more routine consumption events). Two nonlocal
cattle identified among those deposited in a feasting context may have been brought to
the site as contributions to these feasts. The evidence presented provides a more detailed
insight into local land use and into the role of livestock and feasting in forging social relationships
within the regional human population
Upper Body-Based Power Wheelchair Control Interface for Individuals with Tetraplegia
Many power wheelchair control interfaces are not sufficient for individuals with severely limited upper limb mobility. The majority of controllers that do not rely on coordinated arm and hand movements provide users a limited vocabulary of commands and often do not take advantage of the user's residual motion. We developed a body-machine interface (BMI) that leverages the flexibility and customizability of redundant control by using high dimensional changes in shoulder kinematics to generate proportional control commands for a power wheelchair. In this study, three individuals with cervical spinal cord injuries were able to control a power wheelchair safely and accurately using only small shoulder movements. With the BMI, participants were able to achieve their desired trajectories and, after five sessions driving, were able to achieve smoothness that was similar to the smoothness with their current joystick. All participants were twice as slow using the BMI however improved with practice. Importantly, users were able to generalize training controlling a computer to driving a power wheelchair, and employed similar strategies when controlling both devices. Overall, this work suggests that the BMI can be an effective wheelchair control interface for individuals with high-level spinal cord injuries who have limited arm and hand control
Madagascar corals track sea surface temperature variability in the Agulhas Current core region over the past 334 years
The Agulhas Current (AC) is the strongest western boundary current in the Southern Hemisphere and is key for weather and climate patterns, both regionally and globally. Its heat transfer into both the midlatitude South Indian Ocean and South Atlantic is of global significance. A new composite coral record (Ifaty and Tulear massive Porites corals), is linked to historical AC sea surface temperature (SST) instrumental data, showing robust correlations. The composite coral SST data start in 1660 and comprise 200 years more than the AC instrumental record. Numerical modelling exhibits that this new coral derived SST record is representative for the wider core region of the AC. AC SSTs variabilities show distinct cooling through the Little Ice Age and warming during the late 18th, 19th and 20th century, with significant decadal variability superimposed. Furthermore, the AC SSTs are teleconnected with the broad southern Indian and Atlantic Oceans, showing that the AC system is pivotal for inter-ocean heat exchange south of Africa
Diet and food strategies in a southern al-Andalusian urban environment during Caliphal period, ecija, Sevilla
The Iberian medieval period is unique in European history due to the widespread socio-cultural changes that took place after the
arrival of Arabs, Berbers and Islam in 711 AD. Recently, isotopic research has been insightful on dietary shifts, status, resource
availability and the impact of environment. However, there is no published isotopic research exploring these factors in southern
Iberian populations, and as the history of this area differs to the northern regions, this leaves a significant lacuna in our
knowledge. This research fills this gap via isotopic analysis of human (n = 66) and faunal (n = 13) samples from the 9th to the
13th century Ăcija, a town renowned for high temperatures and salinity. Stable carbon (ÎŽ13C) and nitrogen (ÎŽ15N) isotopes were
assessed from rib collagen, while carbon (ÎŽ13C) values were derived from enamel apatite. Human diet is consistent with C3 plant
consumption with a very minor contribution of C4 plants, an interesting feature considering the suitability of Ăcija to C4 cereal
production. ÎŽ15N values vary among adults, which may suggest variable animal protein consumption or isotopic variation within
animal species due to differences in foddering. Consideration of ÎŽ13C collagen and apatite values together may indicate sugarcane
consumption, while moderate ÎŽ15N values do not suggest a strong aridity or salinity effect. Comparison with other Iberian groups
shows similarities relating to time and location rather than by religion, although more multi-isotopic studies combined with
zooarchaeology and botany may reveal subtle differences unobservable in carbon and nitrogen collagen studies alone.OLC is funded by Plan Galego I2C mod.B (ED481D 2017/014). The research was partially funded by the projects âGalician Paleodietâ and by Consiliencia network (ED 431D2017/08) Xunta de GaliciaS
An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics
For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
A systematic review of correlates of sedentary behaviour in adults aged 18â65 years: a socio-ecological approach
Background: Recent research shows that sedentary behaviour is associated with adverse cardio-metabolic consequences even among those considered sufficiently physically active. In order to successfully develop interventions to address this unhealthy behaviour, factors that influence sedentariness need to be identified and fully understood. The aim of this review is to identify individual, social, environmental, and policy-related determinants or correlates of sedentary behaviours among adults aged 18-65 years. Methods: PubMed, Embase, CINAHL, PsycINFO and Web of Science were searched for articles published between January 2000 and September 2015. The search strategy was based on four key elements and their synonyms: (a) sedentary behaviour (b) correlates (c) types of sedentary behaviours (d) types of correlates. Articles were included if information relating to sedentary behaviour in adults (18-65 years) was reported. Studies on samples selected by disease were excluded. The full protocol is available from PROSPERO (PROSPERO 2014:CRD42014009823). Results: 74 original studies were identified out of 4041: 71 observational, two qualitative and one experimental study. Sedentary behaviour was primarily measured as self-reported screen leisure time and total sitting time. In 15 studies, objectively measured total sedentary time was reported: accelerometry (nâ=â14) and heart rate (nâ=â1). Individual level factors such as age, physical activity levels, body mass index, socio-economic status and mood were all significantly correlated with sedentariness. A trend towards increased amounts of leisure screen time was identified in those married or cohabiting while having children resulted in less total sitting time. Several environmental correlates were identified including proximity of green space, neighbourhood walkability and safety and weather. Conclusions: Results provide further evidence relating to several already recognised individual level factors and preliminary evidence relating to social and environmental factors that should be further investigated. Most studies relied upon cross-sectional design limiting causal inference and the heterogeneity of the sedentary measures prevented direct comparison of findings. Future research necessitates longitudinal study designs, exploration of policy-related factors, further exploration of environmental factors, analysis of inter-relationships between identified factors and better classification of sedentary behaviour domains
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