Bifunctional antibody-Renilla luciferase fusion protein for in vivo optical detection of tumors

An anti-carcinoembryonic antigen (CEA) antibody fragment, the anti-CEA diabody, was fused to the bioluminescence enzyme Renilla luciferase (RLuc) to generate a novel optical imaging probe. Native RLuc or one of two stabilized variants (RLucC124A, RLuc8) was used as the bioluminescent moiety. A bioluminescence ELISA showed that diabody-luciferase could simultaneously bind to CEA and emit light. In vivo optical imaging of tumor-bearing mice demonstrated specific targeting of diabody-RLuc8 to CEA-positive xenografts, with a tumor:background ratio of 6.0 +/- 0.8 at 6 h after intravenous injection, compared with antigen-negative tumors at 1.0 +/- 0.1 (P = 0.05). Targeting and distribution was also evaluated by microPET imaging using (124)I-diabody-RLuc8 and confirmed that the optical signal was due to antibody-mediated localization of luciferase. Renilla luciferase, fused to biospecific sequences such as engineered antibodies, can be administered systemically to provide a novel, sensitive method for optical imaging based on expression of cell surface receptors in living organisms.     

Mapping interactions within the evolving science of science and innovation policy community

The Science of Science and Innovation Policy (SciSIP) program at the National Science Foundation (NSF) supports research designed to advance the scientific basis of science and innovation policy. The program was established at NSF in 2005 in response to a call from Dr. John Marburger III, then science advisor to the U.S. President, for a “science” of science policy. As of January 2011, it has co-funded 162 awards that aim to develop, improve, and expand data, analytical tools, and models that can be directly applied in the science policy decision making process. The long-term goals of the SciSIP program are to provide a scientifically rigorous and quantitative basis for science policy and to establish an international community of practice. The program has an active listserv that, as of January 2011, has almost 700 members from academia, government, and industry. This study analyzed all SciSIP awards (through January 2011) to identify existing collaboration networks and co-funding relations between SciSIP and other areas of science. In addition, listserv data was downloaded and analyzed to derive complementary discourse information. Key results include evidence of rich diversity in communication and funding networks and effective strategies for interlinking researcher and science policy makers, prompting discussion, and resource sharing.     

Melbourne—Is there Life after Florida?1

This article reports on participation in local community groups from a postal survey of residents of four socio-economically contrasting suburbs in metropolitan Adelaide. A hierarchical logistic regression model was fitted to examine the socio-economic and neighbourhood-related determinants of participation in community groups within the local neighbourhood. In the final model, higher level of education, being female, longer length living in the neighbourhood, not being employed full time and having children under age 15 were significantly associated with local community group participation. Perceived social cohesion and higher ratings for local shops and recreational facilities were also associated with an increased likelihood of local community group participation. The implications for policies and initiatives that are designed to build ‘social capital’ within neighbourhoods are discussed.     

Laccase-catalyzed removal of bisphenol-A from water: protective effect of PEG on enzyme activity

The feasibility of using the enzyme laccase to treat synthetic wastewater containing bisphenol-A (BPA) was examined. Optimization of pH, laccase concentration, polyethylene glycol (PEG) as an additive for >95% conversion and precipitation of BPA over 3 h of reaction period was determined through colorimetric assay and HPLC. PEG reduced enzyme inactivation, allowing a 5.2-fold reduction in the amount of laccase required for >95% removal of BPA in the range of 0.1-1 mM over 3 h. The fate of PEG after the reaction was also monitored. Linear relationships were found between the concentration of BPA (0.1-1 mM) and the optimum concentrations of laccase and PEG. Little PEG remained in the solution when up to 75 mg/L of PEG was used to treat 0.5 mM BPA. Beyond this level, PEG concentration increased linearly in the supernatant. It is inferred that an interaction between PEG and the polymeric products resulted in the protection of laccase.     

Sky-High Promise (and Potential Pitfalls) of Drones

Few technologies today raise as many interesting legal issues as the use of unmanned aircraft systems, known as UASs or (less formally) “drones.”     

Testing Models of Media Performance in Wartime: U.K. TV News and the 2003 Invasion of Iraq

Debate over media coverage of foreign affairs has been dominated by a range of theoretical positions, here characterized as the 'elite-driven,'independent' and 'oppositional' models. In this article, we explore the relative cogency of these theoretical positions in the context of British media coverage of the 2003 Iraq War. We find that coverage generally conformed to the elite-driven model, reinforcing the coalition. Nevertheless, our analysis also provides evidence to support the independent and oppositional models. Regarding casualties and the humanitarian situation, we find significant levels of coverage which support the oppositional model and the notion of event-driven news. Overall, our study points toward a more nuanced understanding of media-state relations than is suggested by the existing elite-driven paradigm.     

An In Situ Method for Sizing Insoluble Residues in Precipitation and Other Aqueous Samples

Particles are frequently incorporated into clouds or precipitation, influencing climate by acting as cloud condensation or ice nuclei, taking up coatings during cloud processing, and removing species through wet deposition. Many of these particles, particularly ice nuclei, can remain suspended within cloud droplets/crystals as insoluble residues. While previous studies have measured the soluble or bulk mass of species within clouds and precipitation, no studies to date have determined the number concentration and size distribution of insoluble residues in precipitation or cloud water using in situ methods. Herein, for the first time we demonstrate that nanoparticle tracking analysis (NTA) is a powerful in situ method for determining the total number concentration, number size distribution, and surface area distribution of insoluble residues in precipitation, both of rain and melted snow. The method uses 500 μL or less of liquid sample and does not require sample modification. Number concentrations for the insoluble residues in aqueous precipitation samples ranged from 2.0–3.0 (±0.3)?×?10⁸ particles cm^?3, while surface area ranged from 1.8 (±0.7)–3.2 (±1.0) × 10⁷ μm² cm^?3. Number size distributions peaked between 133 and 150 nm, with both single and multi-modal character, while surface area distributions peaked between 173 and 270 nm. Comparison with electron microscopy of particles up to 10 μm show that, by number, >97% residues are <1 μm in diameter, the upper limit of the NTA. The range of concentration and distribution properties indicates that insoluble residue properties vary with ambient aerosol concentrations, cloud microphysics, and meteorological dynamics. NTA has great potential for studying the role that insoluble residues play in critical atmospheric processes.

Copyright 2015 American Association for Aerosol Research     

Mapping the diffusion of scholarly knowledge among major U.S. research institutions

Summary This paper reports the results of a large scale data analysis that aims to identify the production, diffusion, and consumption of scholarly knowledge among top research institutions in the United States. A 20-year publication data set was analyzed to identify the 500 most cited research institutions and spatio-temporal changes in their inter-citation patterns. A novel approach to analyzing the dual role of institutions as producers and consumers of scholarly knowledge and to study the diffusion of knowledge among them is introduced. A geographic visualization metaphor is used to visually depict the production and consumption of knowledge. The highest producers and their consumers as well as the highest consumers and their producers are identified and mapped. Surprisingly, the introduction of the Internet does not seem to affect the distance over which scholarly knowledge diffuses as manifested by citation links. The citation linkages between institutions fall off with the distance between them, and there is a strong linear relationship between the log of the citation counts and the log of the distance. The paper concludes with a discussion of these results and future work.     

Differential Allocation of Seed-Borne Ergot Alkaloids During Early Ontogeny of Morning Glories (Convolvulaceae)

Ergot alkaloids are mycotoxins that can increase host plant resistance to above- and below-ground herbivores. Some morning glories (Convolvulaceae) are infected by clavicipitaceous fungi (Periglandula spp.) that produce high concentrations of ergot alkaloids in seeds—up to 1000-fold greater than endophyte-infected grasses. Here, we evaluated the diversity and distribution of alkaloids in seeds and seedlings and variation in alkaloid distribution among species. We treated half the plants with fungicide to differentiate seed-borne alkaloids from alkaloids produced de novo post-germination and sampled seedling tissues at the cotyledon and first-leaf stages. Seed-borne alkaloids in Ipomoea amnicola, I. argillicola, and I. hildebrandtii remained primarily in the cotyledons, whereas I. tricolor allocated lysergic acid amides to the roots while retaining clavines in the cotyledons. In I. hildebrandtii, almost all festuclavine was found in the cotyledons. These observations suggest differential allocation of individual alkaloids. Intraspecific patterns of alkaloid distribution did not vary between fungicide-treated and control seedlings. Each species contained four to six unique ergot alkaloids and two species had the ergopeptine ergobalansine. De novo production of alkaloids did not begin immediately, as total alkaloids in fungicide-treated and control seedlings did not differ through the first-leaf stage, except in I. argillicola. In an extended time-course experiment with I. tricolor, de novo production was detected after the first-leaf stage. Our results demonstrate that allocation of seed-borne ergot alkaloids varies among species and tissues but is not altered by fungicide treatment. This variation may reflect a response to selection for defense against natural enemies.