The role of dyking and fault control in the rapid onset of eruption at Chaitén volcano, Chile

Rhyolite is the most viscous of liquid magmas, so it was surprising that on 2?May 2008 at Chaitén Volcano, located in Chile's southern Andean volcanic zone, rhyolitic magma migrated from more than 5?km depth in less than 4?hours (ref.?1) and erupted explosively with only two days of detected precursory seismic activity. The last major rhyolite eruption before that at Chaitén was the largest volcanic eruption in the twentieth century, at Novarupta volcano, Alaska, in 1912. Because of the historically rare and explosive nature of rhyolite eruptions and because of the surprisingly short warning before the eruption of the Chaitén volcano, any information about the workings of the magmatic system at Chaitén, and rhyolitic systems in general, is important from both the scientific and hazard perspectives. Here we present surface deformation data related to the Chaitén eruption based on radar interferometry observations from the Japan Aerospace Exploration Agency (JAXA) DAICHI (ALOS) satellite. The data on this explosive rhyolite eruption indicate that the rapid ascent of rhyolite occurred through dyking and that melt segregation and magma storage were controlled by existing faults.     

Human metabolic individuality in biomedical and pharmaceutical research

Genome-wide association studies (GWAS) have identified many risk loci for complex diseases, but effect sizes are typically small and information on the underlying biological processes is often lacking. Associations with metabolic traits as functional intermediates can overcome these problems and potentially inform individualized therapy. Here we report a comprehensive analysis of genotype-dependent metabolic phenotypes using a GWAS with non-targeted metabolomics. We identified 37 genetic loci associated with blood metabolite concentrations, of which 25 show effect sizes that are unusually high for GWAS and account for 10-60% differences in metabolite levels per allele copy. Our associations provide new functional insights for many disease-related associations that have been reported in previous studies, including those for cardiovascular and kidney disorders, type 2 diabetes, cancer, gout, venous thromboembolism and Crohn's disease. The study advances our knowledge of the genetic basis of metabolic individuality in humans and generates many new hypotheses for biomedical and pharmaceutical research.     

A Pluto-like radius and a high albedo for the dwarf planet Eris from an occultation

The dwarf planet Eris is a trans-Neptunian object with an orbital eccentricity of 0.44, an inclination of 44 degrees and a surface composition very similar to that of Pluto. It resides at present at 95.7 astronomical units (1?AU is the Earth-Sun distance) from Earth, near its aphelion and more than three times farther than Pluto. Owing to this great distance, measuring its size or detecting a putative atmosphere is difficult. Here we report the observation of a multi-chord stellar occultation by Eris on 6 November 2010 UT. The event is consistent with a spherical shape for Eris, with radius 1,163?±?6?kilometres, density 2.52?±?0.05 grams per cm(3) and a high visible geometric albedo, Pv = 0.96(+0.09)(-0.04). No nitrogen, argon or methane atmospheres are detected with surface pressure larger than ～1?nanobar, about 10,000 times more tenuous than Pluto's present atmosphere. As Pluto's radius is estimated to be between 1,150 and 1,200 kilometres, Eris appears as a Pluto twin, with a bright surface possibly caused by a collapsed atmosphere, owing to its cold environment. We anticipate that this atmosphere may periodically sublimate as Eris approaches its perihelion, at 37.8 astronomical units from the Sun.     

Red blood cells carry out T cell growth and survival bioactivities that are sensitive to cyclosporine A

Red blood cells (RBC) have emerged as a novel regulatory cell type endowed with bioactivities toward activated human T cells. Herein we show that the RBC bioactivities act on intracellular pathways initiated by T cell receptor (TCR)-dependent and -independent stimuli, including IL-2, IL-15, and the mixture of phorbol dibutyrate and ionomycin. The RBC bioactivities preserve the antioxidant status and are capable of rescuing activated T cells from cell death induced by serum deprivation. They are not mediated by glycosylphosphatidylinositol-linked receptors or sialic acids, and kinetic studies revealed that they hasten the entrance into the cell cycle. By using cyclosporine A (CsA) and rapamycin (Rapa) we show that the RBC bioactivities are calcineurin-dependent. Thus, treatment of T cells with CsA, but not Rapa, impaired RBC bioactivities, and preincubation of RBC with CsA completely abolished their bioactivities. We have demonstrated that RBC carry out bioactivities that are sensitive to CsA.     

The Perspective of the Instruments: Mediating Collectivity

Numerous studies in the fields of Science and Technology Studies (STS) and philosophy of technology have repeatedly stressed that scientific practices are collective practices that crucially depend on the presence of scientific technologies. Postphenomenology is one of the movements that aims to draw philosophical conclusions from these observations through an analysis of human–technology interactions in scientific practice. Two other attempts that try to integrate these insights into philosophy of science are Ronald Giere’s Scientific Perspectivism (2006) and Davis Baird’s Thing Knowledge (2004). In this paper, these two approaches will be critically discussed from the perspective of postphenomenology. We will argue that Giere and Baird problematically assume that scientific instruments (a) have a determined function, and (b) that all human members of a scientific collective have immediate access to this function. However, these assumptions also allow them to offer a clear answer to the question how scientists can collectively relate to scientific phenomena. Such an answer is not yet (explicitly) formulated within the postphenomenological perspective. By adding a postphenomenological touch to the semiotic approach in Actor-Network Theory, we offer an account of how different individual human–technology relations are integrated into larger scientific collectives. We do so by showing that scientific instruments not only help constitute scientific phenomena, but also the intersubjectivity within such collectives.     

Including the mitochondrial metabolism of <Emphasis Type="SmallCaps">l</Emphasis>-lactate in cancer metabolic reprogramming

Glucose avidity, high glycolysis and l-lactate production, regardless of oxygen availability, are the main traits of cancer metabolic reprogramming. The idea that mitochondria are dysfunctional in cancer, thus causing a glycolysis increase for ATP production and l-lactate accumulation as a dead-end product of glucose catabolism, has oriented cancer research for many years. However, it was shown that mitochondrial metabolism is essential for cancer cell proliferation and tumorigenesis and that l-lactate is a fundamental energy substrate with tumor growth-promoting and signaling capabilities. Nevertheless, the known ability of mitochondria to take up and oxidize l-lactate has remained ignored by cancer research. Beginning with a brief overview of the metabolic changes occurring in cancer, we review the present knowledge of l-lactate formation, transport, and intracellular oxidation and underline the possible role of l-lactate metabolism as energetic, signaling and anabolic support for cancer cell proliferation. These unexplored aspects of cancer biochemistry might be exploited for therapeutic benefit.