Selective Recovery of β-Galactosidase With Charged Fusion Tails Using Ion-Exchange Membranes

We explored the feasibility of attaching charged tails to a target protein, in this case β-galactosidase, for selective recovery. In this process, an ion-exchange membrane was used for selective binding and release of β-galactosidase with the attached purification fusions. Strength of binding and purity of eluate increased with increasing tail length. In addition, activity yield was improved with the implementation of an intermediate partial elution recycle procedure

Partitioning Schemes and Non-Integer Box Sizes for the Box-Counting Algorithm in Multifractal Analysis

We compare different partitioning schemes for the box-counting algorithm in the multifractal analysis by computing the singularity spectrum and the distribution of the box probabilities. As model system we use the Anderson model of localization in two and three dimensions. We show that a partitioning scheme which includes unrestricted values of the box size and an average over all box origins leads to smaller error bounds than the standard method using only integer ratios of the linear system size and the box size which was found by Rodriguez et al. (Eur. Phys. J. B 67, 77-82 (2009)) to yield the most reliable results.Comment: 10 pages, 13 figure

On the Representation Theory of an Algebra of Braids and Ties

We consider the algebra ${\cal E}_n(u)$ introduced by F. Aicardi and J. Juyumaya as an abstraction of the Yokonuma-Hecke algebra. We construct a tensor space representation for ${\cal E}_n(u)$ and show that this is faithful. We use it to give a basis for ${\cal E}_n(u)$ and to classify its irreducible representations.Comment: 24 pages. Final version. To appear in Journal of Algebraic Combinatorics

The Efficiency of Grain Alignment in Dense Interstellar Clouds: A Reassessment of Constraints from Near Infrared Polarization

A detailed study of interstellar polarization efficiency toward molecular clouds is used to attempt discrimination between grain alignment mechanisms in dense regions of the ISM. Background field stars are used to probe polarization efficiency in quiescent regions of dark clouds, yielding a dependence on visual extinction well-represented by a power law. No significant change in this behavior is observed in the transition region between the diffuse outer layers and dense inner regions of clouds, where icy mantles are formed, and we conclude that mantle formation has little or no effect on the efficiency of grain alignment. Young stellar objects generally exhibit greater polarization efficiency compared with field stars at comparable extinctions, displaying enhancements by factors of up to 6. Of the proposed alignment mechanisms, that based on radiative torques appears best able to explain the data. The attenuated external radiation field accounts for the observed polarization in quiescent regions, and radiation from the embedded stars themselves may enhance alignment in the lines of sight to YSOs. Enhancements in polarization efficiency observed in the ice features toward several YSOs are of greatest significance, as they demonstrate efficient alignment in cold molecular clouds associated with star formation

Genetic partitioning of interleukin-6 signalling in mice dissociates Stat3 from Smad3-mediated lung fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal disease that is unresponsive to current therapies and characterized by excessive collagen deposition and subsequent fibrosis. While inflammatory cytokines, including interleukin (IL)-6, are elevated in IPF, the molecular mechanisms that underlie this disease are incompletely understood, although the development of fibrosis is believed to depend on canonical transforming growth factor (TGF)-beta signalling. We examined bleomycin-induced inflammation and fibrosis in mice carrying a mutation in the shared IL-6 family receptor gp130. Using genetic complementation, we directly correlate the extent of IL-6-mediated, excessive Stat3 activity with inflammatory infiltrates in the lung and the severity of fibrosis in corresponding gp130757F mice. The extent of fibrosis was attenuated in B lymphocyte-deficient gp130757F;mu MT-/- compound mutant mice, but fibrosis still occurred in their Smad3-/- counterparts consistent with the capacity of excessive Stat3 activity to induce collagen 1a1 gene transcription independently of canonical TGF-beta/Smad3 signalling. These findings are of therapeutic relevance, since we confirmed abundant STAT3 activation in fibrotic lungs from IPF patients and showed that genetic reduction of Stat3 protected mice from bleomycin-induced lung fibrosis

Population density, water supply, and the risk of dengue fever in Vietnam: cohort study and spatial analysis.

BACKGROUND: Aedes aegypti, the major vector of dengue viruses, often breeds in water storage containers used by households without tap water supply, and occurs in high numbers even in dense urban areas. We analysed the interaction between human population density and lack of tap water as a cause of dengue fever outbreaks with the aim of identifying geographic areas at highest risk. METHODS AND FINDINGS: We conducted an individual-level cohort study in a population of 75,000 geo-referenced households in Vietnam over the course of two epidemics, on the basis of dengue hospital admissions (n = 3,013). We applied space-time scan statistics and mathematical models to confirm the findings. We identified a surprisingly narrow range of critical human population densities between around 3,000 to 7,000 people/km² prone to dengue outbreaks. In the study area, this population density was typical of villages and some peri-urban areas. Scan statistics showed that areas with a high population density or adequate water supply did not experience severe outbreaks. The risk of dengue was higher in rural than in urban areas, largely explained by lack of piped water supply, and in human population densities more often falling within the critical range. Mathematical modeling suggests that simple assumptions regarding area-level vector/host ratios may explain the occurrence of outbreaks. CONCLUSIONS: Rural areas may contribute at least as much to the dissemination of dengue fever as cities. Improving water supply and vector control in areas with a human population density critical for dengue transmission could increase the efficiency of control efforts. Please see later in the article for the Editors' Summary

Self-Organization of the Escherichia coli Chemotaxis Network Imaged with Super-Resolution Light Microscopy

Photoactivated localization microscopy analysis of chemotaxis receptors in bacteria suggests that the non-random organization of these proteins results from random self-assembly of clusters without direct cytoskeletal involvement or active transport

Polarization in Disks

This white paper discusses how disk polarization observations can be used to study disk and grain properties during the planet formation process. Such studies require very sensitive and high resolution multi-wavelength observations.Fil: Stephens, Ian W.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Li, Zhi Yun. University of Virginia; Estados UnidosFil: Yang, Haifeng. Tsinghua University; ChinaFil: Kataoka, Akimasa. National Astronomical Observatory of Japan; JapónFil: Looney, Leslie. University of Illinois at Urbana; Estados UnidosFil: Hull, Charles L. H.. National Astronomical Observatory Of Japan; JapónFil: Fernandez Lopez, Manuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Sadavoy, Sarah. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Kwon, Woojin. Korea Astronomy And Space Science Institute; Corea del SurFil: Satoshi, Ohashi. Riken Cluster For Pioneering Research; JapónFil: Tazaki, Ryo. Tohoku University; JapónFil: Li, Dan. National Optical Astronomy Observatory; Estados UnidosFil: Hoang, Thiem. Korea Astronomy And Space Science Institute; Corea del SurFil: Bertrang, Gesa H. M.. Max Planck Institute For Extraterrestrial Physics; AlemaniaFil: Carrasco Gonzalez, Carlos Eugenio. Instituto de Radioastronomía y Astrofísica; MéxicoFil: Dent, William. Atacama Large (sub)millimeter Array; ChileFil: Takahashi, Satoko. National Institutes Of Natural Sciences - National Astronomical Observatory Of Japan; JapónFil: Bacciotti, Francesca. Istituto Nazionale di Astrofisica; ItaliaFil: Alves, Felipe O.. Max Planck Institute For Extraterrestrial Physics; AlemaniaFil: Girart, Josep M.. Instituto de Ciencias del Espacio; España. Consejo Superior de Investigaciones Científicas; EspañaFil: Zhang, Qizhou. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Rao, Ramprasad. Academia Sinica; ChinaFil: Pohl, Adriana. Max Planck Institute For Extraterrestrial Physics; AlemaniaFil: Padovani, Marco. Istituto Nazionale di Astrofisica; ItaliaFil: Galli, Daniele. Istituto Nazionale di Astrofisica; ItaliaFil: Lee, Chin Fei. Academia Sinica; ChinaFil: Segura Cox, Dominique. Max Planck Institute For Extraterrestrial Physics; AlemaniaAstro2020: APC Science White PapersEstados UnidosAmerica Astronomical Societ