University of California

About: University of California is a education organization based out in Oakland, California, United States. It is known for research contribution in the topics: Population & Layer (electronics). The organization has 55175 authors who have published 52933 publications receiving 1491169 citations. The organization is also known as: UC & University of California System.

Sunlight-Mediated Inactivation of MS2 Coliphage via Exogenous Singlet Oxygen Produced by Sensitizers in Natural Waters

Abstract: Pathogens in sunlit surface waters can be damaged directly by UVB light. Indirect inactivation by reactive oxygen species (ROS) generated by sunlight interacting with external sensitizer molecules may also be important, but this mechanism has not been conclusively demonstrated. To better understand the role of ROS, we investigated the inactivation of MS2 coliphage, a commonly used surrogate for human enteric viruses, in water samples irradiated with a solar simulator and containing different types of sensitizers: waste stabilization pond (WSP) constituents, Fluka humic acid (FHA), and Suwannee River humic acid (SRHA). Inactivation of MS2 by the indirect mechanism was significant for all three sensitizers, and the efficiency of the sensitizers at inactivating MS2 was FHA > SRHA > WSP. Both dissolved and particulate fractions in the WSP water contributed to inactivation. In the WSP water, the indirect process was quantitatively more important than direct damage by UVB light, due to the rapid attenuation of...

Co-Operative Action

Abstract: 1. Introduction Part I. Co-operative Accumulative Action: 2. Co-operative accumulation as a pervasive feature of the organization of action 3. The co-operative organization of emerging action 4. Chil and his resources 5. Building complex meaning and action with a three word vocabulary: inhabiting and reshaping the actions of others through accumulative transformation 6. The distributed speaker Part II. Intertwined Semiosis: 7. Intertwined knowing 8. Building action by combining different kinds of materials 9. Intertwined actors 10. Projection and the interactive organization of unfolding experience 11. Projecting upcoming events to accomplish co-operative action Part III. Embodied Interaction: 12. Action and co-operative embodiment in girls' hopscotch 13. Practices of color classification 14. Creating professional vision co-operatively 15. Environmentally coupled gestures Part IV. Co-operative Action with Predecessors: Sedimented Landscapes for Knowledge and Action: 16. Co-operative action with predecessors 17. The accumulation of diversity through co-operative action 18. Seeing in depth 19. Co-operative action as the source of, and solution to, the task faced by every community of creating new, culturally competent members with specific forms of knowledge and skill Part V. Professional Vision, Transforming Sensory Experience into Types, and the Creation of Competent Inhabitants: 20. The emergence of conventionalized signs within the natural world 21. Calibrating experience and knowledge by touching the world 22. The blackness of black: color categories as situated practice 23. Environmentally coupled gestures and the social calibration of professional vision 24. Professional vision 25. Conclusion.

Probes labelled with energy transfer coupled dyes

Abstract: Compositions are provided comprising sets of fluorescent labels carrying pairs of donor and acceptor dye molecules, designed for efficient excitation of the donors at a single wavelength and emission from the acceptor in each of the pairs at different wavelengths. The different molecules having different donor-acceptor pairs can be modified to have substantially the same mobility under separation conditions, by varying the distance between the donor and acceptor in a given pair. Particularly, the fluorescent compositions find use as labels in sequencing nucleic acids.

Differential sensitivity to regional-scale drought in six central US grasslands

Abstract: Terrestrial ecosystems often vary dramatically in their responses to drought, but the reasons for this are unclear. With climate change forecasts for more frequent and extensive drought in the future, a more complete under- standing of the mechanisms that determine differential eco- system sensitivity to drought is needed. In 2012, the Central US experienced the fourth largest drought in a century, with a regional-scale 40 % reduction in growing season precipi- tation affecting ecosystems ranging from desert grassland to mesic tallgrass prairie. This provided an opportunity to assess ecosystem sensitivity to a drought of common mag- nitude in six native grasslands. We tested the prediction that drought sensitivity is inversely related to mean annual precipitation (MAP) by quantifying reductions in above- ground net primary production (ANPP). Long-term ANPP data available for each site (mean length = 16 years) were used as a baseline for calculating reductions in ANPP, and drought sensitivity was estimated as the reduction in ANPP

A family of starch-active polysaccharide monooxygenases

Abstract: The recently discovered fungal and bacterial polysaccharide monooxygenases (PMOs) are capable of oxidatively cleaving chitin, cellulose, and hemicelluloses that contain β(1→4) linkages between glucose or substituted glucose units. They are also known collectively as lytic PMOs, or LPMOs, and individually as AA9 (formerly GH61), AA10 (formerly CBM33), and AA11 enzymes. PMOs share several conserved features, including a monocopper center coordinated by a bidentate N-terminal histidine residue and another histidine ligand. A bioinformatic analysis using these conserved features suggested several potential new PMO families in the fungus Neurospora crassa that are likely to be active on novel substrates. Herein, we report on NCU08746 that contains a C-terminal starch-binding domain and an N-terminal domain of previously unknown function. Biochemical studies showed that NCU08746 requires copper, oxygen, and a source of electrons to oxidize the C1 position of glycosidic bonds in starch substrates, but not in cellulose or chitin. Starch contains α(1→4) and α(1→6) linkages and exhibits higher order structures compared with chitin and cellulose. Cellobiose dehydrogenase, the biological redox partner of cellulose-active PMOs, can serve as the electron donor for NCU08746. NCU08746 contains one copper atom per protein molecule, which is likely coordinated by two histidine ligands as shown by X-ray absorption spectroscopy and sequence analysis. Results indicate that NCU08746 and homologs are starch-active PMOs, supporting the existence of a PMO superfamily with a much broader range of substrates. Starch-active PMOs provide an expanded perspective on studies of starch metabolism and may have potential in the food and starch-based biofuel industries.