122 research outputs found
Testing the predicted mass-loss bi-stability jump at radio wavelengths
In this study, we test the theoretically predicted mass-loss behaviour as a
function of stellar effective temperature across the so-called `bi-stability'
jump (BSJ). We gathered radio observations of 30 OB supergiants (O8-B3). We
derived the radio mass-loss rates and wind efficiencies, and compared our
results with Halpha mass-loss rates and predictions based on radiation-driven
wind models. he wind efficiency shows the possible presence of a local maximum
around an effective temperature of 21~000 K -- in qualitative agreement with
predictions. We also find that the radio mass-loss rates show good agreement
with empirical Halpha rates. However, the empirical mass-loss rates are larger
than the predicted rates from radiation-driven wind theory for objects above
the BSJ temperature, whilst they are smaller for the rest. A new wind
momenta-luminosity relation for O8-B0 stars has been derived.Comment: 13 pages, 13 figures, A&
Using a 3D virtual muscle model to link gene expression changes during myogenesis to protein spatial location in muscle
Background: Myogenesis is an ordered process whereby mononucleated muscle precursor cells (myoblasts) fuse into multinucleated myotubes that eventually differentiate into myofibres, involving substantial changes in gene expression and the organisation of structural components of the cells. To gain further insight into the orchestration of these structural changes we have overlaid the spatial organisation of the protein components of a muscle cell with their gene expression changes during differentiation using a new 3D visualisation tool: the Virtual Muscle 3D (VMus3D)
The First New Zealanders? An Alternative Interpretation of Stable Isotope Data from Wairau Bar, New Zealand.
PLOS ONE Volume 8 includes an article “The First New Zealanders: Patterns of Diet and Mobility Revealed through Isotope Analysis”. The paper proposes that burial groups within the settlement phase site of Wairau Bar differ in terms of dietary stable isotopes and 87Sr/86Sr. The authors argue this difference is probably due to one group being a founding population while the other burials are later. Here we review the work of Kinaston et al. and present an alternative analysis and interpretation of the isotopic data. Treating the isotope data independently from cultural and biological factors we find that sex best explains dietary variation. Our reassessment of 87Sr/86Sr confirms the authors original finding of high mobility of early New Zealanders but suggests a larger range of individuals should be considered ‘non-local’ on current evidence
Overexpression of extracellular superoxide dismutase reduces acute radiation induced lung toxicity
BACKGROUND: Acute RT-induced damage to the lung is characterized by inflammatory changes, which proceed to the development of fibrotic lesions in the late phase of injury. Ultimately, complete structural ablation will ensue, if the source of inflammatory / fibrogenic mediators and oxidative stress is not removed or attenuated. Therefore, the purpose of this study is to determine whether overexpression of extracellular superoxide dismutase (EC-SOD) in mice ameliorates acute radiation induced injury by inhibiting activation of TGFβ1 and downregulating the Smad 3 arm of its signal transduction pathway. METHODS: Whole thorax radiation (single dose, 15 Gy) was delivered to EC-SOD overexpressing transgenic (XRT-TG) and wild-type (XRT-WT) animals. Mice were sacrificed at 1 day, 1 week, 3, 6, 10 and 14 weeks. Breathing rates, right lung weights, total/differential leukocyte count, activated TGFβ1 and components of its signal transduction pathway (Smad 3 and p-Smad 2/3) were assessed to determine lung injury. RESULTS: Irradiated wild-type (XRT-WT) animals exhibited time dependent increase in breathing rates and right lung weights, whereas these parameters were significantly less increased (p < 0.05) at 3, 6, 10 and 14 weeks in irradiated transgenic (XRT-TG) mice. An inflammatory response characterized predominantly by macrophage infiltration was pronounced in XRT-WT mice. This acute inflammation was significantly attenuated (p < 0.05) in XRT-TG animals at 1, 3, 6 and 14 weeks. Expression of activated TGFβ1 and components of its signal transduction pathway were significantly reduced (p < 0.05) at later time-points in XRT-TG vs. XRT-WT. CONCLUSION: This study shows that overexpression of EC-SOD confers protection against RT-induced acute lung injury. EC-SOD appears to work, in part, via an attenuation of the macrophage response and also decreases TGFβ1 activation with a subsequent downregulation of the profibrotic TGFβ pathway
The Emergence of Shell Valuable Exchange in the New Guinea Highlands
Shell valuable exchange in the New Guinea Highlands has been a key
interest in anthropology, providing insight into economics, aesthetics, and social
stratification amongst banded communities. This paper describes how shell exchange
at ethnographic present reflects deeper historical processes. We trace the origins and
subsequent changes in shell use from the terminal Pleistocene to the Late Holocene at
the site of Kiowa in Chimbu Province, Papua New Guinea. Zooarchaeological and
technological analyses of Kiowa’s shell artifacts indicates riverine mussel was
procured locally from the terminal Pleistocene (9,500–10,000 years ago) and featured
as a minor component in the diet into the recent precolonial period. In contrast,
evidence for marine shell valuables only appears in the Late Holocene in the form of
Trochus armbands and Tegillarca granosa and Polymesoda cf. erosa multifunctional
tools. This challenges ideas that associate the gradual dispersal of marine shell into
the highlands with the spread of agriculture around the Wahgi Valley at the start of
the Holocene, and supports punctuated pulses of coastal contact. In doing so, we
formulate a testable model for the development of shell exchange into the highlands,
with implications for the emergence of stratification and the conduits between the
interior and coast
Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial
Background: The EMPA KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population. Methods: EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110. Findings: Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5–2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62–0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16–1·59), representing a 50% (42–58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1). Interpretation: In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease. Funding: Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council
The Appearance of Plant and Animal Domestication in New Guinea
search Station in the upper Wahgi valley, Western Highlands Province, Papua New Guinea, are interpreted as indicating the beginning of agriculture in the region at about 9 000 years BP. The deposits in the swamp register an episode of accelerated erosion in the catchments explained as due to forest clearance for gardening. A contemporary channel in the swamp basin is considered to be a man-made feature, designed to remove water and allow gardening in the basin itself. Archaeological features thought to be associated with this gardening are described. Amongst them are basins possibly resulting from the wallowing of pigs, animals not indigenous to New Guinea. The date of arrival of pigs in the island ultimately from Southeast Asia, at present a matter of dispute, is discussed in relation to the question of whether the earliest New Guinea agriculture was based on native New Guinea plants or already incorporated the allegedly Southeast Asian cultigens which are dominant in contemporary New Guinea, and Pacific, agriculture.Des matériaux obtenus au cours d'un programme de recherches archéologiques, géomorphologiques et paléobotaniques dans une zone marécageuse de la Kuk Agricultural Research Station dans la haute vallée de la Wahgi (Western Highlands Province, Papua New Guinea), sont interprétés comme indiquant le début de l'agriculture dans la région vers 9 000 avant le présent. Les dépôts du marécage révèlent un épisode d'érosion accélérée dans le captage des eaux, dû à des deforestations opérées pour l'agriculture. Un canal contemporain du bassin marécageux est estimé avoir été ouvert pour évacuer les eaux et permettre l'agriculture dans le bassin même. Les traits archéologiques supposés être associés à cette forme de culture sont décrits, dont des bassins résultant peut-être des bauges à cochons, animaux non autochtones en Nouvelle-Guinée. Le problème de la date d'introduction du cochon dans l'île à partir de l'Asie du Sud-Est — un sujet à controverse — est mis en rapport avec la question de savoir si l'agriculture originelle en Nouvelle-Guinée fut basée sur la domestication des plantes locales ou dépendit des cultigènes prétendument d'origine sud-est asiatique, dominants dans l'agriculture contemporaine de Nouvelle-Guinée et du Pacifique.Golson Jack, Hughes P. J. The Appearance of Plant and Animal Domestication in New Guinea. In: Journal de la Société des océanistes, n°69, tome 36, 1980. pp. 294-303
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