5,215 research outputs found

    Analysis of the Tank 5F Feed and Bleed Residual Solids

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    Savannah River Remediation (SRR) is preparing Tank 5F for closure. As part of Tank 5F Closure Mechanical Cleaning, SRR conducted a 'Feed and Bleed' process in Tank 5F. Following this 'Feed and Bleed' Mechanical Cleaning in Tank 5F, SRR collected two tank heel samples (referred to as sample 1 and sample 2) under Riser 5 to determine the composition of the material remaining in the tanks. This document describes sample analysis results. The conclusions from this analysis follow. (1) The anions measured all had a concentration less than 250 mg/kg, except for oxalate, which had a concentration of 2100-2400 mg/kg. (2) The measured cations with the highest concentration were iron (432,000-519,000 mg/kg), nickel (54,600-69,300 mg/kg), and manganese (35,200-42,100 mg/kg). All other cations measured less than 13,000 mg/kg. (3) The radionuclides present in the highest concentration are {sup 90}Sr (3.0 x 10{sup 10} dpm/g), {sup 137}Cs (6.8 x 10{sup 8} dpm/g), and {sup 241}Am (1.4 x 10{sup 8} - 1.8 x 10{sup 8} dpm/g). (4) The particle size analysis shows a large fraction of particles greater than 100 {micro}

    Toward a New Diversity and the Revitalization of hte Campus Spirit: A Bandung 2000 Conference for Students, Staff and Faculty

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    In this session, New Diversity programs are designed and proposed, aimed at enabling minority staff, students and faculty the kind of cultural inoculation needed to be able to address the concerns which plague most campuses

    On parity functions in conformal field theories

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    We examine general aspects of parity functions arising in rational conformal field theories, as a result of Galois theoretic properties of modular transformations. We focus more specifically on parity functions associated with affine Lie algebras, for which we give two efficient formulas. We investigate the consequences of these for the modular invariance problem.Comment: 18 pages, no figure, LaTeX2

    The structures of Hausdorff metric in non-Archimedean spaces

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    For non-Archimedean spaces X X and Y, Y, let M(X),M(VW) \mathcal{M}_{\flat } (X), \mathfrak{M}(V \rightarrow W) and D(X,Y) \mathfrak{D}_{\flat }(X, Y) be the ballean of X X (the family of the balls in X X ), the space of mappings from X X to Y, Y, and the space of mappings from the ballen of X X to Y, Y, respectively. By studying explicitly the Hausdorff metric structures related to these spaces, we construct several families of new metric structures (e.g., ρ^u,β^X,Yλ,β^X,Yλ \widehat{\rho } _{u}, \widehat{\beta }_{X, Y}^{\lambda }, \widehat{\beta }_{X, Y}^{\ast \lambda } ) on the corresponding spaces, and study their convergence, structural relation, law of variation in the variable λ, \lambda, including some normed algebra structure. To some extent, the class β^X,Yλ \widehat{\beta }_{X, Y}^{\lambda } is a counterpart of the usual Levy-Prohorov metric in the probability measure spaces, but it behaves very differently, and is interesting in itself. Moreover, when X X is compact and Y=K Y = K is a complete non-Archimedean field, we construct and study a Dudly type metric of the space of K K-valued measures on X. X. Comment: 43 pages; this is the final version. Thanks to the anonymous referee's helpful comments, the original Theorem 2.10 is removed, Proposition 2.10 is stated now in a stronger form, the abstact is rewritten, the Monna-Springer is used in Section 5, and Theorem 5.2 is written in a more general for

    Public Investment in Infrastructure in Latin America: Is Debt the Culprit?

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    Panel data for seven Latin American countries are used to assess the influence of public indebtedness on public investment in infrastructure in the period 1987-2001. Debt increases are associated with higher public infrastructure investment, an effect that is robust to the inclusion of many other fiscal and macroeconomic variables. This paper also finds some evidence of complementarity between public and private investment and of the negative effect of IMF adjustment loans on infrastructure expenditures. No evidence is found that debt defaults affect public investment in infrastructure

    Phosphotyrosine Signaling Analysis in Human Tumors Is Confounded by Systemic Ischemia-Driven Artifacts and Intra-Specimen Heterogeneity

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    Tumor protein phosphorylation analysis may provide insight into intracellular signaling networks underlying tumor behavior, revealing diagnostic, prognostic or therapeutic information. Human tumors collected by The Cancer Genome Atlas program potentially offer the opportunity to characterize activated networks driving tumor progression, in parallel with the genetic and transcriptional landscape already documented for these tumors. However, a critical question is whether cellular signaling networks can be reliably analyzed in surgical specimens, where freezing delays and spatial sampling disparities may potentially obscure physiologic signaling. To quantify the extent of these effects, we analyzed the stability of phosphotyrosine (pTyr) sites in ovarian and colon tumors collected under conditions of controlled ischemia and in the context of defined intratumoral sampling. Cold-ischemia produced a rapid, unpredictable, and widespread impact on tumor pTyr networks within 5 minutes of resection, altering up to 50% of pTyr sites by more than 2-fold. Effects on adhesion and migration, inflammatory response, proliferation, and stress response pathways were recapitulated in both ovarian and colon tumors. In addition, sampling of spatially distinct colon tumor biopsies revealed pTyr differences as dramatic as those associated with ischemic times, despite uniform protein expression profiles. Moreover, intratumoral spatial heterogeneity and pTyr dynamic response to ischemia varied dramatically between tumors collected from different patients. Overall, these findings reveal unforeseen phosphorylation complexity, thereby increasing the difficulty of extracting physiologically relevant pTyr signaling networks from archived tissue specimens. In light of this data, prospective tumor pTyr analysis will require appropriate sampling and collection protocols to preserve in vivo signaling features.National Institutes of Health (U.S.) (Grant U24 CA159988

    Filtration rates of the non-native Chinese mystery snail (Bellamya chinensis) and potential impacts on microbial communities

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    Invasive species in the phylum Mollusca, including gastropods and bivalves, have caused substantial impacts in freshwater ecosystems. The Chinese mystery snail, Bellamya chinensis, is a large viviparid snail native to Southeastern Asia and widely introduced throughout United States and parts of Canada and Europe. B. chinensis is a facultative filter-feeding detritivore that can both graze epiphytic diatoms using its radula and filter-feed its breathing water. Despite mounting concern associated with the expanding range and increasing abundance of B. chinensis in many parts of its invaded range, the potential ecological impacts of this non-native species remain largely unknown. Here, we used a series of laboratory experiments to assess filtration rates of B. chinensis and quantify its effects on microbial communities. According to both microcosm (24-hour, 4-L suspension) and mesocosm (5-day, 90-L suspension) experimental trials, B. chinensis exhibited an average filtration rate of 106-113 mL snail-1h-1(1.45 mL mg DW-1h-1) and an individual maximum of 471 mL snail-1h-1(6.15 mL mg DW-1h-1). These values are comparable to reported filtration rates for high-profile invasive, freshwater bivalves. Relationships between snail size and filtration rate relationship suggests that B. chinensis display an ontogenetic shift in feeding behavior from primarily radular grazing to increased filter-feeding at threshold size of approximately 44 mm shell height. Our experiments also revealed that high snail densities can result in small, significant shifts in bacterial community composition. These results suggest that B. chinensis may influence microbial communities either directly by using bacteria as a food source or indirectly by producing sufficiently large quantities of fecal and pseudo-fecal material to affect bacterial activity and growth. The overall ecological effects and importance of B. chinensis filtration behavior remain unclear, but our experimental results suggest that these impacts may be large and should be further investigated to better understand its potential role in coupling benthic and pelagic food webs in lake ecosystems.Las especies invasoras del phyllum Mollusca, incluyendo los gasterópodos y bivalvos, han causado impactos importantes en los ecosistemas dulceacuícolas. Bellamya chinensis, es un vivíparo de gran tamaño, nativo del sureste de Asia y ampliamente introducido a lo largo de los Estados Unidos y parte de Canadá y Europa. B. chinensis es una especie detritivora- filtradora facultativa, que puede tanto ramonear diatomeas epifitas usando su rádula como filtrar el agua que respiran. A pesar de la creciente preocupación asociada al incremento en la abundancia y rango de distribución de B. chinensis en las regiones ya colonizadas, el potencial impacto ecológico de esta especie introducida permanece ampliamente desconocido. En este estudio, usamos series de experimentos de laboratorio para evaluar las tasas de filtración de B. chinensis y cuantificar su efecto en las comunidades microbianas. De acuerdo con los experimentos realizados tanto en los microcosmos (24-hour, 4-L suspensión) como en los mesocosmos (5-day, 90-L suspensión), B. chinensis mostró una tasa promedio de filtración de 106-113 mL caracol-1h-1(1.45 mL mg peso seco-1h-1) y un máximo por individuo de 471 mL caracol-1h-1(6.15 mL mg peso seco-1h-1). Estos valores son comparables a otros reportados para especies de bivalvos dulceacuícolas altamente invasivas. La relación entre el tamaño de los caracoles y las tasas de filtración sugieren que B. chinensis muestra un cambio ontogénico en la manera de alimentarse, de ramoneo a una mayor alimentación por filtración, a partir de un umbral de tamaño de la concha de aproximadamente 44 mm de altura. Nuestros experimentos también revelan que altas densidades de caracoles generan pequeños cambios pero significativos en las comunidades microbianas. Estos resultados sugieren que B. chinensis afectaría las comunidades microbianas de forma directa usando las bacterias como fuente de alimentación o indirectamente al producir una cantidad de materia fecal o seudo-fecal, suficiente para afectar la actividad y crecimiento bacteriano. El impacto ecológico global y el comportamiento como filtrador de B. chinensis aún no son claros, pero nuestros resultados experimentales sugieren que estos impactos pueden ser importantes y se deben investigar mejor para entender más su papel potencial en el acoplamiento de las redes tróficas bentónicas y pelágicas en los sistemas lacustres

    Recent Advances Concerning Certain Class of Geophysical Flows

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    This paper is devoted to reviewing several recent developments concerning certain class of geophysical models, including the primitive equations (PEs) of atmospheric and oceanic dynamics and a tropical atmosphere model. The PEs for large-scale oceanic and atmospheric dynamics are derived from the Navier-Stokes equations coupled to the heat convection by adopting the Boussinesq and hydrostatic approximations, while the tropical atmosphere model considered here is a nonlinear interaction system between the barotropic mode and the first baroclinic mode of the tropical atmosphere with moisture. We are mainly concerned with the global well-posedness of strong solutions to these systems, with full or partial viscosity, as well as certain singular perturbation small parameter limits related to these systems, including the small aspect ratio limit from the Navier-Stokes equations to the PEs, and a small relaxation-parameter in the tropical atmosphere model. These limits provide a rigorous justification to the hydrostatic balance in the PEs, and to the relaxation limit of the tropical atmosphere model, respectively. Some conditional uniqueness of weak solutions, and the global well-posedness of weak solutions with certain class of discontinuous initial data, to the PEs are also presented.Comment: arXiv admin note: text overlap with arXiv:1507.0523
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