Low-temperature gas from marine shales: wet gas to dry gas over experimental time

Marine shales exhibit unusual behavior at low temperatures under anoxic gas flow. They generate catalytic gas 300° below thermal cracking temperatures, discontinuously in aperiodic episodes, and lose these properties on exposure to trace amounts of oxygen. Here we report a surprising reversal in hydrocarbon generation. Heavy hydrocarbons are formed before light hydrocarbons resulting in wet gas at the onset of generation grading to dryer gas over time. The effect is moderate under gas flow and substantial in closed reactions. In sequential closed reactions at 100°C, gas from a Cretaceous Mowry shale progresses from predominately heavy hydrocarbons (66% C5, 2% C1) to predominantly light hydrocarbons (56% C1, 8% C5), the opposite of that expected from desorption of preexisting hydrocarbons. Differences in catalyst substrate composition explain these dynamics. Gas flow should carry heavier hydrocarbons to catalytic sites, in contrast to static conditions where catalytic sites are limited to in-place hydrocarbons. In-place hydrocarbons and their products should become lighter with conversion thus generating lighter hydrocarbon over time, consistent with our experimental results

Visualization and 3D Reconstruction of Flame Cells of Taenia solium (Cestoda)

BACKGROUND: Flame cells are the terminal cells of protonephridial systems, which are part of the excretory systems of invertebrates. Although the knowledge of their biological role is incomplete, there is a consensus that these cells perform excretion/secretion activities. It has been suggested that the flame cells participate in the maintenance of the osmotic environment that the cestodes require to live inside their hosts. In live Platyhelminthes, by light microscopy, the cells appear beating their flames rapidly and, at the ultrastructural, the cells have a large body enclosing a tuft of cilia. Few studies have been performed to define the localization of the cytoskeletal proteins of these cells, and it is unclear how these proteins are involved in cell function. METHODOLOGY/PRINCIPAL FINDINGS: Parasites of two different developmental stages of T. solium were used: cysticerci recovered from naturally infected pigs and intestinal adults obtained from immunosuppressed and experimentally infected golden hamsters. Hamsters were fed viable cysticerci to recover adult parasites after one month of infection. In the present studies focusing on flame cells of cysticerci tissues was performed. Using several methods such as video, confocal and electron microscopy, in addition to computational analysis for reconstruction and modeling, we have provided a 3D visual rendition of the cytoskeletal architecture of Taenia solium flame cells. CONCLUSIONS/SIGNIFICANCE: We consider that visual representations of cells open a new way for understanding the role of these cells in the excretory systems of Platyhelminths. After reconstruction, the observation of high resolution 3D images allowed for virtual observation of the interior composition of cells. A combination of microscopic images, computational reconstructions and 3D modeling of cells appears to be useful for inferring the cellular dynamics of the flame cell cytoskeleton

Production of K-S(,)0 K-*+/- (892) and phi(0) (1020) in minimum bias events and K-S(0) and Lambda(0) in jets in p (p)over-barcollisions at root S 1: 96 TeV

We report measurements of the inclusive transverse momentum (pT) distribution of centrally produced KS0, K±(892), and φ0(1020) mesons up to pT=10 GeV/c in minimum bias events, and KS0 and Λ0 particles up to pT=20 GeV/c in jets with transverse energy between 25 and 160 GeV in pp̄ collisions. The data were taken with the CDF II detector at the Fermilab Tevatron at √s=1.96 TeV. We find that as pT increases, the pT slopes of the three mesons (KS0, K±, and φ) are similar. And using our previous Λ0 results from minimum bias events, we show that the ratio of Λ0 to KS0 as a function of pT in minimum bias events becomes similar to the fairly constant ratio in jets at pT∼5 GeV/c. This suggests that the particles with pTâ‰35 GeV/c in minimum bias events are from "soft" jets, and that the pT slope of particles in jets is insensitive to light quark flavor (u, d, or s) and to the number of valence quarks. We also find that for pT≠24 GeV relatively more Λ0 baryons are produced in minimum bias events than in jets. © 2013 American Physical Society