Abundance of planktonic thraustochytrids and bacteria and the concentration of particulate ATP in the Greenland and Norwegian Seas

Surface water samples were collected at 15 sites in the Greenland and Norwegian Seas, and total planktonic thraustochytrids and bacteria were directly counted by epifluorescence microscopy. Particulate (>0.2 μm) adenosine 5\u27-triphosphate (ATP) was also determined by bioluminescence photometry. Abundance of planktonic thraustochytrids varied from below the detection limit (<8.1×102 l^(-1)) to 2.3×105 l^(-1) with an overall average of 3.1×104 l^(-1). Abundance of bacterioplankton ranged from 2.2×107 l^(-1) at the northernmost site to 6.0×108 l^(-1) at the southernmost site with an overall average of 2.1×108 l^(-1). Particulate ATP concentration ranged from 79 pmol to 676 pmol at the mid-transect (68°N) and southernmost (62°N) sites, respectively, with an overall average of 222 pmol. The measured ATP concentrations were too low to account for the abundance of thraustochytrids and bacteria estimated from total counts and carbon-per-cell factors. However, particulate ATP was correlated with the abundance of bacterioplankton, but not that of planktonic thraustochytrids. These differing relationships suggest different physiological and biochemical strategies of starvation survival and differing substrate availability in the Arctic and sub-Arctic surface waters

Photoresponse of La1.85_{1.85}Sr0.15_{0.15}CuO4_{4} nanostrip

We report the fabrication and photoresponse of 5 nm thick La$_{1.85}$Sr$_{0.15}$CuO$_{4}$ nanostrip with a width of 100nm. The I-V characteristics of the nanostrip show a hysteresis and a sharp voltage jump at $I_{c}$. The $J_{c}$(3K) of the nanostrip is 2.3 x 10$^{7}$ A/cm$^{2}$. The nanostrip exhibits photoresponse signals when illuminated by a pulse laser at 1560 nm wavelength with a bias current just below $I_{c}$. The height of the signal reduces as the optical intensity decreases and disappears below -10 dBm. The signal also decreases as the temperature increases, but it exists up to 30 K. These results suggest the possibility of La$_{1.85}$Sr$_{0.15}$CuO$_{4}$ nanostrip as single-photon detector (SSPD, SNSPD) working at high temperature by further reducing the cross-section of the strip

In-situ epitaxial growth of superconducting La-based bilayer cuprate thin films

We investigate the epitaxial growth of bilayer cuprate La2CaCu2O6+\delta using pure ozone as an oxidant, and find that even the crystal with parent composition without cation substitution can show metallic behavior with the aid of epitaxial strain effect. The hole concentration is controlled simply by excess-oxygen doping, and the films grown under the optimum conditions exhibit superconductivity below 30 K. This is the first result on the superconductivity of bilayer La2CaCu2O6+\delta induced purely by the excess oxygen.Comment: 5 pages, 3 figures, To appear in Phys. Rev. B, Rapid Communication

Enhanced Superconductivity in Sr2CuO4-v

A critical review of previous investigations of the superconductivity with enhanced Tc ~ 95K found in Sr2CuO4-v shows that new physics occurs in a highly overdoped region of the cuprate phase diagram. Moreover, evidence is adduced from the literature that 30% of the oxygen sites in the CuO2 layers are vacant, a conclusion which is at odds with the universally made assumption that superconductivity originates in stoichiometric CuO2 layers. While further research is needed in order to identify the pairing mechanism(s) responsible for the enhanced Tc, we suggest possible candidates

In-situ angle-resolved photoemission study of MBE-grown (La, Ce)2CuO4 thin films

We have performed in-situ angle-resolved photoemission spectroscopy on the electron doped cuprate superconductor La2-xCexCuO4 (x = 0.1) using high-quality films grown by molecular beam epitaxy. The obtained photoemission spectra were free from dirt peaks. In addition, the time evolution of the spectra due to impurity adsorption is rather gradual, and the sample surface is stable even at ambient temperature, which is in contrast with previous reports on bulk Nd2-xCexCuO4 (NCCO) single crystals. The energy distribution curves show clear dispersions near the Fermi energy (EF) with some EF crossings. The resultant Fermi surface is hole-like and centered around (pi, pi), which essentially agrees with that predicted for NCCO by band calculations and also with the experimentally determined Fermi surface of optimally doped NCCO (x = 0.15).Comment: to be published in Physica C (Proceedings of ISS2003

Substitution for Cu in the electron-doped infinite-layer superconductor Sr0.9La0.1CuO2, Ni reduces Tc much faster than Zn

We report on the effect of substitution for Cu on Tc of electron-doped infinite-layer superconductors Sr0.9La0.1Cu1-xRxO2, R = Zn and Ni. We found that Tc was nearly constant until x = 0.03 for R = Zn, while superconductivity was nearly suppressed for x = 0.02 with dTc/dx = 20 K/% for R = Ni. This behavior is very similar to that of conventional superconductors. These findings are discussed in terms of the superconducting gap symmetry in the cuprate superconductors including another electron-doped superconductor, (Nd,Ce)2CuO4-y.Comment: 5 pages and 2 EPS figures, [email protected] for material reques

Review on Superconducting Materials

Short review of the topical comprehension of the superconductor materials classes Cuprate High-Temperature Superconductors, other oxide superconductors, Iron-based Superconductors, Heavy-Fermion Superconductors, Nitride Superconductors, Organic and other Carbon-based Superconductors and Boride and Borocarbide Superconductors, featuring their present theoretical understanding and their aspects with respect to technical applications.Comment: A previous version of this article has been published in \" Applied Superconductivity: Handbook on Devices and Applications \", Wiley-VCH ISBN: 978-3-527-41209-9. The new extended and updated version will be published in \" Encyclopedia of Applied Physics \", Wiley-VC

3 to 5- Not Years But Climate Star Rating

The journey of C.B. Watson Primary has been a struggle but we are proud of our story and would like to share it with you with the hopes of you learning that the “struggle is real” everywhere and how we overcame those obstacles. Now, students are able to learn and teachers are able to teach without students’ behaviors controlling the day. The mindset of the teachers needed to change in order for the behaviors of the students to change. Come and hear our story on how PBIS changed our school from a 3 star to a 5 star school

The Honolulu Zoo-- A Center Of Learning

In Hawaii the Honolulu Zoo is one of the few recreational facilities besides the beach parks which is open to the public with no admission charge. Being free of charge it has been the place where school children are taken for the purpose of eating lunch after the major portion of the day's excursion has been completed. Little attempt has been made to use the zoo as an educational facility. I sincerely feel that the zoo should be regarded as a recreational facility as well as an educational facility. In 1968 the Honolulu Zoo took a major step toward increasing the educational value of the zoo visits by organizing an educational program. The zoo was able to develop the program with the assistance of the Junior League of Honolulu and community volunteers and hence, the present program is a product of hard working, dedicated volunteers. Today under the leadership of Mrs. Tanya Waros, the Honolulu Zoo's education coordinator, the program is continually being upgraded and refined