Measuring Spatial Dynamics in Metropolitan Areas

This paper introduces a new approach to measuring neighborhood change. Instead of the traditional method of identifying “neighborhoods†a priori and then studying how resident attributes change over time, our approach looks at the neighborhood more intrinsically as a unit that has both a geographic footprint and a socioeconomic composition. Therefore, change is identified when both as- pects of a neighborhood transform from one period to the next. Our approach is based on a spatial clustering algorithm that identifies neighborhoods at two points in time for one city. We also develop indicators of spatial change at both the macro (city) level as well as local (neighborhood) scale. We illustrate these methods in an application to an extensive database of time-consistent census tracts for 359 of the largest metropolitan areas in the US for the period 1990-2000.

Heterogeneity of wheat endosperm proteolipids (CM proteins)

Proteins extracted with CHCl3-MeOH from wheat endosperm have been fractionated by Sephadex G-100 and the 15 000–20 000 MW range fraction, designated CM protein, has been examined by combined electrofocusing (pH range 5–8) and electrophoresis (pH 3.2) and the heterogeneity of the electrophoretic components has been ascertained. It has been shown by joint mapping and by sequential extraction that CM proteins are extracted by 70% EtOH but not by H2O, although they can be made water-soluble after dialysis against an acid buffer, pH 3.2, 3 M urea, without losing their solubility in CHCl3-MeOH mixtures. It is concluded that CM proteins fit the definition of a Folch—Lees proteolipid. The Triticum aestivum (genomes ABD) map can be reconstructed by mixing T. durum (AB) and Aegilops squarrosa (D). The low intragenomic variability of CM protein is confirmed

Towards a quantitative phase-field model of two-phase solidification

We construct a diffuse-interface model of two-phase solidification that quantitatively reproduces the classic free boundary problem on solid-liquid interfaces in the thin-interface limit. Convergence tests and comparisons with boundary integral simulations of eutectic growth show good accuracy for steady-state lamellae, but the results for limit cycles depend on the interface thickness through the trijunction behavior. This raises the fundamental issue of diffuse multiple-junction dynamics.Comment: 4 pages, 2 figures. Better final discussion. 1 reference adde

Uncertain Uncertainty: Spatial Variation in the Quality of American Community Survey Estimates

The U.S. Census Bureau's American Community Survey (ACS) is the foundation of social science research, much federal resource allocation and the development of public policy and private sector decisions. However, the high uncertainty associated with some of the ACS's most frequently used estimates can jeopardize the accuracy of inferences based on these data. While there is high level understanding in the research community that problems exist in the data, the sources and implications of these problems have been largely overlooked. Using 2006-2010 ACS median household income at the census tract scale as the test case (where a third of small-area estimates have higher than recommend errors), we explore the patterns in the uncertainty of ACS data. We consider various potential sources of uncertainty in the data, ranging from response level to geographic location to characteristics of the place. We find that there exist systematic patterns in the uncertainty in both the spatial and attribute dimensions. Using a regression framework, we identify the factors that are most frequently correlated with the error at national, regional and metropolitan area scales, and find these correlates are not consistent across the various locations tested. The implication is that data quality varies in different places, making cross-sectional analysis both within and across regions less reliable. We also present general advice for data users and potential solutions to the challenges identified

Formation of octapod MnO nanoparticles with enhanced magnetic properties through kinetically-controlled thermal decomposition of polynuclear manganese complexes

Polynuclear manganese complexes are used as precursors for the synthesis of manganese oxide nanoparticles (MnO NPs). Altering the thermal decomposition conditions can shift the nanoparticle product from spherical, thermodynamically-driven NPs to unusual, kinetically-controlled octapod structures. The resulting increased surface area profoundly alters the NP's surface-dependent magnetism and may have applications in nanomedicine

Single-Electron Spectroscopy

Contains research goals and objectives, reports on four research projects and a list of publications.Joint Services Electronics Program Contract DAAL03-92-C-0001Joint Services Electronics Program Grant DAAH04-95-1-0038National Science Foundation Young Investigator AwardPackard FoundationU.S. Navy - Office of Naval Researc

In-beam internal conversion electron spectroscopy with the SPICE detector

The SPectrometer for Internal Conversion Electrons (SPICE) has been commissioned for use in conjunction with the TIGRESS $\gamma$-ray spectrometer at TRIUMF's ISAC-II facility. SPICE features a permanent rare-earth magnetic lens to collect and direct internal conversion electrons emitted from nuclear reactions to a thick, highly segmented, lithium-drifted silicon detector. This arrangement, combined with TIGRESS, enables in-beam $\gamma$-ray and internal conversion electron spectroscopy to be performed with stable and radioactive ion beams. Technical aspects of the device, capabilities, and initial performance are presented

Production of two novel laccase isoforms by a thermotolerant strain of Pycnoporus sanguineus isolated from an oil-polluted tropical habitat

A thermotolerant and halotolerant strain of Pycnoporus sanguineus was isolated from an oil-polluted site in a tropical area located in Veracruz, Mexico. This strain was able to grow at 47ºC and in culture medium containing 500 mM NaCl. The strain was also tolerant to the presence of 30,000 ppm of crude Maya oil. A 68-kDa protein purified submerged cultures exhibited laccase activity towards 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), guaiacol, syringaldazine and o-dianisidine, for which it presented the highest affinity (Km = 43 µM). Two-dimensional gel electrophoresis analysis showed that, unusual for laccases, the enzyme has two active isoforms, with isoelectric points of 7.00 and 7.08. The purified enzyme showed high thermostability, retaining 40% of its original activity after 3 h at 60ºC. This property seems to correlate with a long “shelf-life”, given that at 40ºC enzyme activity was only gradually lost over a 5-day period incubation. Both, the fungus and its laccase aer likely to have high potential for biotechnological applications