Description: The Late Bronze Age ‘Minoan’ eruption of Santorini, Greece occurred from within an existing caldera. Low-temperature pyroclastic flow emplacement on shallow slopes outside the caldera can only be consistent with the caldera being filled with eruption products that are not preserved. Field observations and seismic reflection surveys suggest that this missing material has been downfaulted. The volume of the caldera infill is estimated as 18–26 km3 dense rock equivalent (DRE), increasing the total of the Minoan eruption deposits to 78–86 km3 DRE and making it the largest known Holocene eruption. This study highlights a general mechanism whereby caldera eruption volumes could be significantly underestimated.

Description: Author(s): H. T. Nembach, T. J. Silva, J. M. Shaw, M. L. Schneider, M. J. Carey, S. Maat, and J. R. Childress X-ray diffraction (XRD), magnetometry, and ferromagnetic resonance (FMR) measurements were performed on sputtered thin films of the nominal Heusler alloy (Co 2 Mn) 1− x Ge x with varying Ge content and annealing temperatures. XRD indicates some degree of B2 alloy formation, with strong (110) texturing. FM... [Phys. Rev. B 84, 054424] Published Mon Aug 08, 2011

Description: Do infants learn to interpret others’ actions through their own experience producing goal-directed action, or does some knowledge of others’ actions precede first-person experience? Several studies report that motor experience enhances action understanding, but the nature of this effect is not well understood. The present research investigates what is learned...

Description: Discharge of volcanic gases in the marine environment can lead to local perturbations in ocean acidity, with consequences for biological communities and the potential for hazards related to depressurization and release of gases at the surface. Numerous hydrothermal vents in the crater of Kolumbo submarine volcano (Aegean Sea) are discharging virtually pure gaseous CO 2 together with clear fluids at temperatures up to 220 °C. Acoustic imaging of the ascending bubbles suggests that the gas is being dissolved into seawater within ~10 m above the crater floor (500 m below sea level). Dissolution of the gas likely causes local increases in water density that result in sequestration of CO 2 within the enclosed crater, and the accumulation of acidic seawater. Lack of macrofauna at the Kolumbo hydrothermal vents, occurrence of carbonate-poor sediment in the crater, and pH values as low as 5.0 in recovered water samples point to acidic conditions within the crater. Buildup of CO 2 -rich water in the bowl-shaped crater of Kolumbo may be producing conditions analogous to some African volcanic lakes (Lake Monoun and Lake Nyos, Cameroon) where overturn of gas-rich bottom waters led to abrupt releases of CO 2 at the surface. A minimum estimate of 2.0 x 10 5 m 3 (STP) of excess CO 2 may currently exist in the bottom 10 m of the Kolumbo crater.

Description: Objective— Bone morphogenetic proteins (Bmps) are important mediators of inflammation and atherosclerosis, though their mechanism of action is not fully understood. To better understand the contribution of the Bmp signaling pathway in vascular inflammation, we investigated the role of Bmper (Bmp endothelial cell precursor–derived regulator), an extracellular Bmp modulator, in an induced in vivo model of inflammation and atherosclerosis. Methods and Results— We crossed apolipoprotein E–deficient (ApoE –/– ) mice with mice missing 1 allele of Bmper (Bmper +/– mice used in the place of Bmper –/– mice that die at birth) and measured the development of atherosclerosis in mice fed a high-fat diet. Bmper haploinsufficiency in ApoE –/– mice (Bmper +/– ;ApoE –/– mice) led to a more severe phenotype compared with Bmper +/+ ;ApoE –/– mice. Bmper +/– ;ApoE –/– mice also exhibited increased Bmp activity in the endothelial cells in both the greater and lesser curvatures of the aortic arch, suggesting a role for Bmper in regulating Bmp-mediated inflammation associated with laminar and oscillatory shear stress. Small interfering RNA knockdown of Bmper in human umbilical vein endothelial cells caused a dramatic increase in the inflammatory markers intracellular adhesion molecule 1 and vascular cell adhesion molecule 1 at rest and after exposure to oscillatory and laminar shear stress. Conclusion— We conclude that Bmper is a critical regulator of Bmp-mediated vascular inflammation and that the fine-tuning of Bmp and Bmper levels is essential in the maintenance of normal vascular homeostasis.

Description: We present Submillimeter Array (SMA)  = 0.88 and 1.3 mm broad-band observations, and Very Large Array (VLA) observations in NH 3 ( J , K ) = (1,1) up to (5,5), H 2 O and CH 3 OH maser lines towards the two most massive molecular clumps in infrared dark cloud (IRDC) G11.11–0.12. Sensitive high-resolution images reveal hierarchical fragmentation in dense molecular gas from the ~1 pc clump scale down to ~0.01 pc condensation scale. At each scale, the mass of the fragments is orders of magnitude larger than the Jeans mass. This is common to all four IRDC clumps we studied, suggesting that turbulence plays an important role in the early stages of clustered star formation. Masers, shock heated NH 3 gas, and outflows indicate intense ongoing star formation in some cores while no such signatures are found in others. Furthermore, chemical differentiation may reflect the difference in evolutionary stages among these star formation seeds. We find NH 3 ortho/para ratios of 1.1 ± 0.4, 2.0 ± 0.4, and 3.0 ± 0.7 associated with three outflows, and the ratio tends to increase along the outflows downstream. Our combined SMA and VLA observations of several IRDC clumps present the most in-depth view so far of the early stages prior to the hot core phase, revealing snapshots of physical and chemical properties at various stages along an apparent evolutionary sequence.

Description: Cross-cultural studies suggest that access to a conventional language containing words that can be used for counting is essential to develop representations of large exact numbers. However, cultures that lack a conventional counting system typically differ from cultures that have such systems, not only in language but also in many other ways. As a result, it is difficult to isolate the effects of language on the development of number representations. Here we examine the numerical abilities of individuals who lack conventional language for number (deaf individuals who do not have access to a usable model for language, spoken or signed) but who live in a numerate culture (Nicaragua) and thus have access to other aspects of culture that might foster the development of number. These deaf individuals develop their own gestures, called homesigns, to communicate. We show that homesigners use gestures to communicate about number. However, they do not consistently extend the correct number of fingers when communicating about sets greater than three, nor do they always correctly match the number of items in one set to a target set when that target set is greater than three. Thus, even when integrated into a numerate society, individuals who lack input from a conventional language do not spontaneously develop representations of large exact numerosities.

Description: Herschel far-infrared continuum data obtained as part of the Hi-GAL survey have been used, together with the GLIMPSE 8 μm and MIPSGAL 24 μm data, to attempt the first 3D-decomposition of dust emission associated with atomic, molecular and ionized gas at 15 arcmin angular resolution. Our initial test case is a 2 2 square degrees region centred on ( l , b ) = (30°, 0°), a direction that encompasses the origin point of the Scutum–Crux Arm at the tip of the Galactic Bar. Coupling the IR maps with velocity maps specific for different gas phases (H i 21cm, 12 CO and 13 CO, and radio recombination lines), we estimate the properties of dust blended with each of the gas components and at different Galactocentric distances along the line of sight (LOS). A statistical Pearson's coefficients analysis is used to study the correlation between the column densities estimated for each gas component and the intensity of the IR emission. This analysis provides evidence that the 2 2 square degree field under consideration is characterized by the presence of a gas component not accounted for by the standard tracers, possibly associated with warm H 2 and cold H i . We demonstrate that the IR radiation in the range 8 〈  〈 500 μm is systematically dominated by emission originating within the Scutum–Crux Arm. By applying an inversion method, we recover the dust emissivities associated with atomic, molecular and ionized gas. Using the DustEM model, we fit the spectral energy distributions for each gas phase, and find average dust temperatures of T d,H i  = 18.82 ± 0.47 K, T d,H 2  = 18.84 ± 1.06 K and T d,H ii  = 22.56 ± 0.64 K, respectively. We also obtain an indication for polycyclic aromatic hydrocarbons depletion in the diffuse ionized gas. We demonstrate the importance of including the ionized component in 3D-decompositions of the total IR emission. However, the main goal of this work is to discuss the impact of the missing column density associated with the dark gas component on the accurate evaluation of the dust properties, and to shed light on the limitations of the inversion method approach when this is applied to a small section of the Galactic plane and when the working resolution allows sufficient de-blending of the gas components along the LOS.