867 research outputs found
Singing Actors and Dancing Singers
This article looks at two recent and widely recognized productions of Henry Purcell's Dido and Aeneas (by choreographer Sasha Waltz, Berlin 2005, and theatre director Sebastian NĂźbling, Basel 2006) and discusses three main aspects: 1. Genre: coming from a Tanztheater (Waltz) and a Sprechtheater (NĂźbling) background, each director renegotiates conventions of the operatic genre and consciously evades expectations in pursuit of a new and challenging experience for both the performers and their audience. 2. Physicality: both productions place the performers' bodies at the forefront of the mise-en-scne they remap the singing, dancing, acting body by questioning conventions and expectations commonly found in the production and reception process. 3. Adaptation: both productions take unconventional liberties by adapting in a domain where notions of Werktreue (fidelity to the original work or score) still reign. Adopting ideas from Nicholas Cook and Mikhail Bakhtin, I will argue that the conceptual, musical and theatrical implications of both productions indicate a renegotiation of the social and performative relevance of operatic performance
Unravelling the controls on the molybdenum isotopic composition of rivers
Formation and crystallisation of the Lunar Magma Ocean (LMO) was one of the most incisive events during the early evolution of the Moon. Lunar Magma Ocean solidification concluded with the coeval formation of K-, REE- and P-rich components (KREEP) and an ilmenite-bearing cumulate (IBC) layer. Gravitational overturn of the lunar mantle generated eruptions of basaltic rocks with variable Ti contents, of which their δ49Ti variations may now reflect variable mixtures of ambient lunar mantle and the IBC. To better understand the processes generating the spectrum of lunar low-Ti and high-Ti basalts and the role of Ti-rich phases such as ilmenite, we determined the mass dependent Ti isotope composition of four KREEP-rich samples, 12 low-Ti, and eight high-Ti mare basalts by using a 47Ti-49Ti double spike. Our data reveal significant variations in δ49Ti for KREEP-rich samples (+0.117 to +0.296 â°) and intra-group variations in the mare basalts (-0.030 to +0.055 â° for low-Ti and +0.009 to +0.115 â° for high-Ti basalts). We modelled the δ49Ti of KREEP using previously published HFSE data as well as the δ49Ti evolution during fractional crystallisation of the LMO. Both approaches yield δ49TiKREEP similar to measured values and are in excellent agreement with previous studies. The involvement of ilmenite in the petrogenesis of the lunar mare basalts is further evaluated by combining our results with element ratios of HFSE, U and Th, revealing that partial melting in an overturned lunar mantle and fractional crystallisation of ilmenite must be the main processes accounting for mass dependent Ti isotope variations in lunar basalts. Based on our results we can also exclude formation of high-Ti basalts by simple assimilation of ilmenite by ascending melts from the depleted lunar mantle. Rather, our data are in accord with melting of these basalts from a hybrid mantle source formed in the aftermath of gravitational lunar mantle overturn, which is in good agreement with previous Fe isotope data
Unravelling the controls on the molybdenum isotope ratios of river waters
The molybdenum (Mo) isotope ratios (δ98/95Mo) of river waters control the δ98/95Mo values of seawater and impact on the use of Mo isotope ratios as a proxy of past redox conditions. The δ98/95Mo values of river waters vary by more than 2 â°, yet the relative roles of lithology versus fractionation during weathering remain contested. Here, we combine measurements from river waters (δ98/95Modiss), river bed materials (δ98/95MoBM) and soils from locations with contrasting lithology. The δ98/95Mo values of river bed materials (δ98/95MoBM), set by rock type, vary by ~1 â° between rivers in New Zealand, the Mackenzie Basin, and Iceland. However, the difference between dissolved and solid phase Mo isotopes (Î98/95Modiss-BM) varies from +0.3 â° to +1.0 â°. We estimate Mo removal from solution using the mobile trace element rhenium and find that it correlates with Î98/95Modiss-BM across the sample set. The adsorption of Mo to Fe-Mn-(oxyhydr)oxides can explain the observed fractionation. Together, the amount of Mo released through dissolution and taken up by (oxyhydr)oxide formation on land may cause changes in the δ98/95Mo values of rivers, driving long term changes in the Mo isotope ratios of seawater
Distinguishing variation in referral accuracy from referral threshold: analysis of a national dataset of referrals for suspected cancer
Objectives: To distinguish between variation in referral threshold and variation in accurate
selection of patients for referral in fast-track referrals for possible cancer. To examine
factors associated with threshold and accuracy and model the effects of changing
thresholds.
Design: Analysis of national data on cancer referrals from general practices in England over
a five-year period. We developed a new method to estimate specificity of referral to
complement existing sensitivity. We used bivariate meta-analysis to produce summary
measures and described practices in relation to these.
Setting: 5479 GP practices with data relating to more than 50 cancer cases diagnosed over
the five years.
Outcomes: Number of practices whose 95% confidence regions for sensitivity and specificity
indicated that they were outliers in terms of either referral threshold or decision accuracy.
Results:
2019 practices (36.8%) were outliers in relation to referral threshold compared to 1205
practices (22.0%) in relation to decision accuracy. Practice age profile, cancer incidence,
and deprivation showed a modest association with decision accuracy but not with
thresholds. If all practices shared the referral behaviour of those in the highest quintile of
age-standardised referral rate there would be a 3.3% increase in cancers detected through
fast track pathways at the cost of a 36.9% increase in urgent referrals.
Conclusion: This new method permits variation in referral to be described more precisely
and quality improvement activities to be targeted. Changing referral thresholds without
increasing accuracy will result in modest effects on detection rates and a large increase in
demand on diagnostic services
Suppression of Mitochondrial Electron Transport Chain Function in the Hypoxic Human Placenta: A Role for miRNA-210 and Protein Synthesis Inhibition
Fetal growth is critically dependent on energy metabolism in the placenta, which drives active exchange of nutrients. Placental oxygen levels are therefore vital, and chronic hypoxia during pregnancy impairs fetal growth. Here we tested the hypothesis that placental hypoxia alters mitochondrial electron transport chain (ETS) function, and sought to identify underlying mechanisms. We cultured human placental cells under different oxygen concentrations. Mitochondrial respiration was measured, alongside levels of ETS complexes. Additionally, we studied placentas from sea-level and high-altitude pregnancies. After 4 d at 1% O2 (1.01 KPa), complex I-supported respiration was 57% and 37% lower, in trophoblast-like JEG3 cells and fibroblasts, respectively, compared with controls cultured at 21% O2 (21.24 KPa); complex IV-supported respiration was 22% and 30% lower. Correspondingly, complex I levels were 45% lower in placentas from high-altitude pregnancies than those from sea-level pregnancies. Expression of HIF-responsive microRNA-210 was increased in hypoxic fibroblasts and high-altitude placentas, whilst expression of its targets, iron-sulfur cluster scaffold (ISCU) and cytochrome c oxidase assembly protein (COX10), decreased. Moreover, protein synthesis inhibition, a feature of the high-altitude placenta, also suppressed ETS complex protein levels. Our results demonstrate that mitochondrial function is altered in hypoxic human placentas, with specific suppression of complexes I and IV compromising energy metabolism and potentially contributing to impaired fetal growth. \ua9 2013 Colleoni et al
Chronic myocardial infarction promotes atrial action potential alternans, afterdepolarisations and fibrillation
Generation of the Mt Kinabalu granite by crustal contamination of intraplate magma modelled by Equilibrated Major Element Assimilation with Fractional Crystallisation (EME-AFC)
New geochemical data are presented for the composite units of the Mount Kinabalu granitoid intrusion of Borneo and explore discrimination between crustal- and mantle-derived granitic magmas. The geochemical data demonstrate that the units making up this composite intrusion became more potassic through time. This was accompanied by an evolution of isotope ratios from a continental-affinity towards a slightly more mantle-affinity (87Sr/86Sri âź0.7078; 143Nd/144Ndi âź0.51245; 206Pb/204Pbi âź18.756 for the oldest unit compared to 87Sr/86Sri âź0.7065, 143Nd/144Ndi âź0.51250 and 206Pb/204Pbi âź18.721 for the younger units). Oxygen isotope ratios (calculated whole-rock δ18O ofâ+â6.5â9.3â°) do not show a clear trend with time. The isotopic data indicate that the magma cannot result only from fractional crystallisation of a mantle-derived magma. Alkali metal compositions show that crustal anatexis is also an unsuitable process for genesis of the intrusion. The data indicate that the high-K units were generated by fractional crystallisation of a primary, mafic magma, followed by assimilation of the partially melted sedimentary overburden. We present a new, Equilibrated Major Element â Assimilation with Fractional Crystallisation (EME-AFC) approach for simultaneously modelling the major element, trace element, and radiogenic and oxygen isotope compositions during such magmatic differentiation; addressing the lack of current AFC modelling approaches for felsic, amphibole- or biotite-bearing systems. We propose that Mt Kinabalu was generated through low degree melting of upwelling fertile metasomatised mantle driven by regional crustal extension in the Late Miocene
Fast coarsening in unstable epitaxy with desorption
Homoepitaxial growth is unstable towards the formation of pyramidal mounds
when interlayer transport is reduced due to activation barriers to hopping at
step edges. Simulations of a lattice model and a continuum equation show that a
small amount of desorption dramatically speeds up the coarsening of the mound
array, leading to coarsening exponents between 1/3 and 1/2. The underlying
mechanism is the faster growth of larger mounds due to their lower evaporation
rate.Comment: 4 pages, 4 PostScript figure
Low meteorological influence found in 2019 Amazonia fires
Technical note. The sudden increase in Amazon fires early in the 2019 fire season made global headlines. While it has been heavily speculated that the fires were caused by deliberate human ignitions or human-induced landscape changes, there have also been suggestions that meteorological conditions could have played a role. Here, we ask two questions: were the 2019 fires in the Amazon unprecedented in the historical record, and did the meteorological conditions contribute to the increased burning? To answer this, we take advantage of a recently developed modelling framework which optimises a simple fire model against observations of burnt area and whose outputs are described as probability densities. This allowed us to test the probability of the 2019 fire season occurring due to meteorological conditions alone. The observations show that the burnt area was higher than in previous years in regions where there is already substantial deforestation activity in the Amazon. Overall, 11â% of the area recorded the highest early season (JuneâAugust) burnt area since the start of our observational record, with areas in Brazil's central arc of deforestation recording the highest ever monthly burnt area in August. However, areas outside of the regions of widespread deforestation show less burnt area than the historical average, and the optimised model shows that this low burnt area would have extended over much of the eastern Amazon region, including in Brazil's central arc of deforestation with high fire occurrence in 2019. We show that there is a 9â% likelihood of the observed August fires being caused by meteorological conditions alone, decreasing to 6â%â7â% along the agriculturalâhumid forest interface in Brazil's central states and 8â% in Paraguay and Bolivia dry forests. Our results suggest that changes in land use, cover or management are the likely drivers of the substantial increase in the 2019 early fire season burnt area, especially in Brazil. Burnt area for September in the arc of deforestation had a 14â%â26â% probability of being caused by meteorological conditions, potentially coinciding with a shift in fire-related policy from South American governments
Kinetics of plasma cellâfree DNA and creatine kinase in a canine model of tissue injury
Background:
Cellâfree DNA (cfDNA) comprises short, doubleâstranded circulating DNA sequences released from damaged cells. In people, cfDNA concentrations correlate well with disease severity and tissue damage. No reports are available regarding cfDNA kinetics in dogs.
Objectives/Hypothesis:
Cellâfree DNA will have a short biological halfâlife and would be able to stratify mild, moderate, and severe tissue injury. Our study aims were to determine the kinetics and biological halfâlife of cfDNA and to contrast them with those of creatine kinase (CK).
Animals:
Three groups of 10 dogs undergoing open ovariohysterectomy, surgery for cranial cruciate ligament rupture (CCLR), or hemilaminectomy.
Methods:
Plasma for cfDNA and CK analysis was collected at admission, at induction of anesthesia, postsurgery (time 0) and at 6, 12, 24, 36, 48, 60, and 72 hours after surgery.
Results:
The biological halfâlife of plasma cfDNA and CK were 5.64 hours (95% confidence interval [CI 95], 4.36â7.98 hours) and 28.7 hours (CI95, 25.3â33.3 hours), respectively. In the hemilaminectomy group, cfDNA concentrations differed significantly from admission at 6â12 hours after surgery. Creatine kinase activity differed among the surgical groups and reached a peak 6 hours after surgery. In the ovariohysterectomy and CCLR groups, plasma CK activity 72 hours after surgery did not differ from admission activity of the ovariohysterectomy group. In contrast, in the hemilaminectomy group, plasma CK activity after 72 hours did not return to the ovariohysterectomy group admission activity.
Conclusions and Clinical Importance:
Plasma CK activity has a longer biological halfâlife than previously thought. In contrast to plasma CK activity, cfDNA has a short halfâlife and could be a useful marker for peracute severe tissue injury
- âŚ