Economic benefits from instream flow in a Colorado mountain stream

Submitted to Office of Water Research and Technology, U.S. Department of Interior.Bibliography: pages [131]-135.OWRT project no. A-035-COLO and OWRT project no. A-040-COLO

Role of spinon and spinon singlet pair excitations on phase transitions in d−waved-wave superconductors

We examine the roles of massless Dirac spinon and spin singlet pair excitations on the phase transition in $d-wave$ superconductors. Although the massless spinon excitations in the presence of the spin singlet pair excitations do not alter the nature of the phase transition at $T = 0$, that is, the XY universality class, they are seen to induce an additional attractive interaction potential between vortices, further stabilizing vortex-antivortex pairs at low temperature for lightly doped high $T_c$ samples.Comment: 5 pages, 1 figur

On the Interstellar Medium and Star Formation Demographics of Galaxies in the Local Universe

We present a demographic analysis of integrated star formation and gas properties for a sample of galaxies representative of the overall population at z~0. This research was undertaken in order to characterise the nature of star formation and interstellar medium behaviour in the local universe, and test the extent to which global star formation rates can be seen as dependent on the interstellar gas content. Archival 21 cm derived HI data are compiled from the literature, and are combined with CO (J=1-0) derived H_2 masses to calculate and characterise the total gas content for a large sample of local galaxies. The distribution in stellar mass-normalised HI content is found to exhibit the noted characteristic transition at stellar masses of ~3x10^10 M_sun, turning off towards low values, but no such transition is observed in the equivalent distribution of molecular gas. H-alpha based star formation rates and specific star formation rates are also compiled for a large (1110) sample of local galaxies. We confirm two transitions as found in previous work: a turnover towards low SFRs at high luminosities, indicative of the quenching of SF characteristic of the red sequence; and a broadening of the SF distribution in low-luminosity dwarf galaxies, again to extremely low SFRs of < 0.001 M_sun/yr. However, a new finding is that while the upper luminosity transition is mirrored by the turn over in HI content, suggesting that the low SFRs of the red sequence result from a lack of available gas supply, the transition towards a large spread of SFRs in the least luminous dwarf galaxies is not matched by a prominent increase in scatter in gas content. Possible mass-dependent quenching mechanisms are discussed, along with speculations that in low mass galaxies, the H-alpha luminosity may not faithfully trace the SFR.Comment: 15 pages, 12 figures; accepted for publication in MNRA

Fluctuation-dissipation relations in plaquette spin systems with multi-stage relaxation

We study aging dynamics in two non-disordered spin models with multi-spin interactions, following a sudden quench to low temperature. The models are relevant to the physics of supercooled liquids. Their low temperature dynamics resemble those of kinetically constrained models, and obey dynamical scaling, controlled by zero-temperature critical points. Dynamics in both models are thermally activated, resulting in multi-stage relaxation towards equilibrium. We study several two-time correlation and response functions. We find that equilibrium fluctuation-dissipation relations are generically not satisfied during the aging regime, but deviations from them are well described by fluctuation-dissipation ratios, as found numerically in supercooled liquids. These ratios are purely dynamic objects, containing information about the nature of relaxation in the models. They are non-universal, and can even be negative as a result of activated dynamics. Thus, effective temperatures are not well-defined in these models.Comment: 29 pages, 10 fig

Daily to decadal modulation of jet variability

The variance of a jet’s position in latitude is found to be related to its average speed: when a jet becomes stronger its variability in latitude decreases. This relationship is shown to hold for observed midlatitude jets around the world and also across a hierarchy of numerical models. North Atlantic jet variability is shown to be modulated on decadal timescales, with decades of a strong, steady jet being interspersed with decades of a weak, variable jet. These modulations are also related to variations in the basin-wide occurrence of high-impact blocking events. A picture emerges of complex multidecadal jet variability in which recent decades do not appear unusual. We propose an underlying barotropic mechanism to explain this behaviour, related to the change in refractive properties of a jet as it strengthens, and the subsequent effect on the distribution of Rossby wave breaking

Galactic Globular and Open Clusters in the Sloan Digital Sky Survey. I. Crowded Field Photometry and Cluster Fiducial Sequences in ugriz

We present photometry for globular and open cluster stars observed with the Sloan Digital Sky Survey (SDSS). In order to exploit over 100 million stellar objects with r < 22.5 mag observed by SDSS, we need to understand the characteristics of stars in the SDSS ugriz filters. While star clusters provide important calibration samples for stellar colors, the regions close to globular clusters, where the fraction of field stars is smallest, are too crowded for the standard SDSS photometric pipeline to process. To complement the SDSS imaging survey, we reduce the SDSS imaging data for crowded cluster fields using the DAOPHOT/ALLFRAME suite of programs and present photometry for 17 globular clusters and 3 open clusters in a SDSS value-added catalog. Our photometry and cluster fiducial sequences are on the native SDSS 2.5-meter ugriz photometric system, and the fiducial sequences can be directly applied to the SDSS photometry without relying upon any transformations. Model photometry for red giant branch and main-sequence stars obtained by Girardi et al. cannot be matched simultaneously to fiducial sequences; their colors differ by ~0.02-0.05 mag. Good agreement (< ~0.02 mag in colors) is found with Clem et al. empirical fiducial sequences in u'g'r'i'z' when using the transformation equations in Tucker et al.Comment: 30 pages, 25 figures. Accepted for publication in ApJS. Version with high resolution figures available at http://www.astronomy.ohio-state.edu/~deokkeun/AnJohnson.pd

The On-Orbit Performance of the Galaxy Evolution Explorer

We report the first year on-orbit performance results for the Galaxy Evolution Explorer (GALEX), a NASA Small Explorer that is performing a survey of the sky in two ultraviolet bands. The instrument comprises a 50 cm diameter modified Ritchey-Chretien telescope with a 1.25 degree field of view, selectable imaging and objective grism spectroscopic modes, and an innovative optical system with a thin-film multilayer dichroic beam splitter that enables simultaneous imaging by a pair of photon counting, microchannel plate, delay line readout detectors. Initial measurements demonstrate that GALEX is performing well, meeting its requirements for resolution, efficiency, astrometry, bandpass definition and survey sensitivity.Comment: This paper will be published as part of the Galaxy Evolution Explorer (GALEX) Astrophysical Journal Letters Special Issu

Renal cell carcinoma in tuberous sclerosis complex

Renal cell carcinoma (RCC) occurs in 2% to 4% of patients with tuberous sclerosis complex (TSC). Previous reports have noted a variety of histologic appearances in these cancers, but the full spectrum of morphologic and molecular features has not been fully elucidated. We encountered 46 renal epithelial neoplasms from 19 TSC patients and analyzed their clinical, pathologic, and molecular features, enabling separation of these 46 tumors into 3 groups. The largest subset of tumors (n=24) had a distinct morphologic, immunologic, and molecular profile, including prominent papillary architecture and uniformly deficient succinate dehydrogenase subunit B (SDHB) expression prompting the novel term "TSC-associated papillary RCC (PRCC)." The second group (n=15) were morphologically similar to a hybrid oncocytic/chromophobe tumor (HOCT), whereas the last 7 renal epithelial neoplasms of group 3 remained unclassifiable. The TSC-associated PRCCs had prominent papillary architecture lined by clear cells with delicate eosinophilic cytoplasmic thread-like strands that occasionally appeared more prominent and aggregated to form eosinophilic globules. All 24 (100%) of these tumors were International Society of Urological Pathology (ISUP) nucleolar grade 2 or 3 with mostly basally located nuclei. Tumor cells from 17 of 24 TSC-associated PRCCs showed strong, diffuse labeling for carbonic anhydrase IX (100%), CK7 (94%), vimentin (88%), and CD10 (83%) and were uniformly negative for SDHB, TFE3, and AMACR. Gains of chromosomes 7 and 17 were found in 2 tumors, whereas chromosome 3p deletion and TFE3 translocations were not detected. In this study, we reported a sizable cohort of renal tumors seen in TSC and were able to identify them as different morphotypes, which may help to expand the morphologic spectrum of TSC-associated RCC

Triggerable tough hydrogels for gastric resident dosage forms

Systems capable of residing for prolonged periods of time in the gastric cavity have transformed our ability to diagnose and treat patients. Gastric resident systems for drug delivery, ideally need to be: ingestible, be able to change shape or swell to ensure prolonged gastric residence, have the mechanical integrity to withstand the forces associated with gastrointestinal motility, be triggerable to address any side effects, and be drug loadable and release drug over a prolonged period of time. Materials that have been primarily utilized for these applications have been largely restricted to thermoplastics and thermosets. Here we describe a novel set of materials, triggerable tough hydrogels, meeting all these requirement, supported by evaluation in a large animal model and ultimately demonstrate the potential of triggerable tough hydrogels to serve as prolonged gastric resident drug depots. Triggerable tough hydrogels may be applied in myriad of applications, including bariatric interventions, drug delivery, and tissue engineering.Bill & Melinda Gates Foundation (Grant OPP1096734)Bill & Melinda Gates Foundation (Grant OPP1139927)National Institutes of Health (U.S.) (Grant EB000244