Pan-Arctic distribution of bioavailable dissolved organic matter and linkages with productivity in ocean margins

Rapid environmental changes in the Arctic Ocean affect plankton productivity and the bioavailability of dissolved organic matter (DOM) that supports microbial food webs. We report concentrations of dissolved organic carbon (DOC) and yields of amino acids (indicators of labile DOM) in surface waters across major Arctic margins. Concentrations of DOC and bioavailability of DOM showed large pan-Arctic variability that corresponded to varying hydrological conditions and ecosystem productivity, respectively. Widespread hot spots of labile DOM were observed over productive inflow shelves (Chukchi and Barents Seas), in contrast to oligotrophic interior margins (Kara, Laptev, East Siberian, and Beaufort Seas). Amino acid yields in outflow gateways (Canadian Archipelago and Baffin Bay) indicated the prevalence of semilabile DOM in sea ice covered regions and sporadic production of labile DOM in ice-free waters. Comparing these observations with surface circulation patterns indicated varying shelf subsidies of bioavailable DOM to Arctic deep basins.Published version2019-07-3

Mach-Zehnder Interferometry in a Strongly Driven Superconducting Qubit

We demonstrate Mach-Zehnder-type interferometry in a superconducting flux qubit. The qubit is a tunable artificial atom, whose ground and excited states exhibit an avoided crossing. Strongly driving the qubit with harmonic excitation sweeps it through the avoided crossing two times per period. As the induced Landau-Zener transitions act as coherent beamsplitters, the accumulated phase between transitions, which varies with microwave amplitude, results in quantum interference fringes for n=1...20 photon transitions. The generalization of optical Mach-Zehnder interferometry, performed in qubit phase space, provides an alternative means to manipulate and characterize the qubit in the strongly-driven regime.Comment: 14 pages, 6 figure

Taste-Odor Integration in Espresso Coffee

Espresso coffee samples were freshly prepared with 10% sucrose, 0.0143% sucralose (equivalent in sweetness to 10% sucrose), or unsweetened, each with and without nondairy creamer. A sensory panel rated the intensities of "malty,” "caramel,” "roasty,” and "coffee-like.” The concentrations of flavor chemicals associated with the latter three sensations (Furaneol, 2-ethyl-3,5-dimethyl [EDM] pyrazine, and 2-furfuryl thiol, respectively) were determined by gas chromatography, using solid-phase microextraction sampling of coffee headspace. Furaneol and furfuryl thiol were essentially unaffected by creamer addition, but the more nonpolar EDM pyrazine was greatly reduced. The malty, caramel, roasty, and coffee-like flavor intensities were not significantly affected by creamer addition. This appears to be a case of disconnect between the absence of an odorant and perception. Furaneol, furfuryl thiol, and EDM pyrazine concentrations were unaffected by adding either sweetener. The malty sensation was the same with and without added sweetener. The roasty and coffee-like ratings both decreased to similar extents in the samples with the two added sweeteners. The ratings for caramel were considerably increased, again to a similar extent, by both sweeteners. Since the added sweeteners were both nonvolatile, this is clearly a case where taste affected odor perceptio

Polysaccharide-Degrading Complex Produced in Wood and in Liquid Media by the Brown-Rot Fungus Poria Placenta

The polysaccharide-degrading enzymes produced by Poria placenta in decayed wood and liquid media were compared qualitatively and quantitatively. A single carbohydrate-degrading complex was isolated and purified from wood and liquid cultures that was active on both polysaccharides and glycosides. Quantitative differences in enzyme activities from decayed wood versus liquid media were observed. However, the purified extracellular carbohydrate-degrading complex isolated from decayed wood and from liquid cultures must be structurally similar because of similar isoelectric points, electrophoretic properties, and molecular sieving properties

Generation of an expandable intermediate mesoderm restricted progenitor cell line from human pluripotent stem cells.

The field of tissue engineering entered a new era with the development of human pluripotent stem cells (hPSCs), which are capable of unlimited expansion whilst retaining the potential to differentiate into all mature cell populations. However, these cells harbor significant risks, including tumor formation upon transplantation. One way to mitigate this risk is to develop expandable progenitor cell populations with restricted differentiation potential. Here, we used a cellular microarray technology to identify a defined and optimized culture condition that supports the derivation and propagation of a cell population with mesodermal properties. This cell population, referred to as intermediate mesodermal progenitor (IMP) cells, is capable of unlimited expansion, lacks tumor formation potential, and, upon appropriate stimulation, readily acquires properties of a sub-population of kidney cells. Interestingly, IMP cells fail to differentiate into other mesodermally-derived tissues, including blood and heart, suggesting that these cells are restricted to an intermediate mesodermal fate

Beyond the Brim of the Hat: Kinematics of Globular Clusters out to Large Radius in the Sombrero Galaxy

We have obtained radial velocity measurements for 51 new globular clusters around the Sombrero galaxy. These measurements were obtained using spectroscopic observations from the AAOmega spectrograph on the Anglo-Australian Telescope and the Hydra spectrograph at WIYN. Combined with our own past measurements and velocity measurements obtained from the literature we have constructed a large database of radial velocities that contains a total of 360 confirmed globular clusters. Previous studies' analyses of the kinematics and mass profile of the Sombrero globular cluster system have been constrained to the inner ~9' (~24 kpc or ~5 effective radii), but our new measurements have increased the radial coverage of the data, allowing us to determine the kinematic properties of M104 out to ~15' (~41 kpc or ~9 effective radii). We use our set of radial velocities to study the GC system kinematics and to determine the mass profile and V-band mass-to-light profile of the galaxy. We find that the V-band mass-to-light ratio increases from 4.5 at the center to a value of 20.9 at 41 kpc (~9 effective radii or 15'), which implies that the dark matter halo extends to the edge of our available data set. We compare our mass profile at 20 kpc (~4 effective radii or ~7.4') to the mass computed from x-ray data and find good agreement. We also use our data to look for rotation in the globular cluster system as a whole, as well as in the red and blue subpopulations. We find no evidence for significant rotation in any of these samples.Comment: Accepted for publication in the Astronomical Journal; 23 pages, 14 figures, and 2 table

The Ursinus Weekly, May 14, 1956

Results of men\u27s voting announced; Rheiner is prexy • U.C. classes vote for new officers; Results released • Marge and Ruth write open letter of thanks • FTA to hold meeting Tuesday • W.C. group presents vespers • M. W. Armstrong is editor of new book; To be on TV • Awards presented at WAA banquet • Tuesday night set for women\u27s government banquet • Traditional May Day program presented Saturday; Featured pageant, concert, play: Spring play given Thurs., Fri., Sat.; Award is given; UC Band presents concert with the Meistersingers; May Day pageant presented to huge crowd Saturday • Recipients of honorary degrees announced • IRC elects new officers • Winner of silver contest • Tau Kappa Alpha debating society accepts members • Girls\u27 day study election • Pi Nu chooses officers • Student leaders to plan new calendar • Editorial: Less room for more; And a good time was had by all • APO: National service fraternity • Liberal means free • Letters to the editor • Review of Charley\u27s Aunt • SWC has outdoor service; Final vespers to be Sun. • Bruin rackets stop Drexel, PMC • Belles top Garnets for fifth victory • Belles crush CJC; Lose to W. Chester • Cindermen take first victory in romp over Lebanon Valley, 99-26 • Bruins stop Haverford, Drew; Edged in Moravian tilt, 4-2 • Second term finals schedule • Men to pick rooms Mon., Wed., Fri. • Chi Alpha holds electionshttps://digitalcommons.ursinus.edu/weekly/1452/thumbnail.jp

Resonant Readout of a Persistent Current Qubit

We have implemented a resonant circuit that uses a SQUID as a flux-sensitive Josephson inductor for qubit readout. In contrast to the conventional switching current measurement that generates undesired quasi-particles when the SQUID switches to the voltage state, our approach keeps the readout SQUID biased along the supercurrent branch during the measurement. By incorporating the SQUID inductor in a high-Q resonant circuit, we can distinguish the two flux states of a niobium persistent-current (PC) qubit by observing a shift in the resonant frequency of both the magnitude and the phase spectra. The readout circuit was also characterized in the nonlinear regime to investigate its potential use as a nonlinear amplifier.Comment: 4 pages, 2004 ASC Proceeding