β-Glucan is a major growth substrate for human gut bacteria related to Coprococcus eutactus

A clone encoding carboxymethyl cellulase activity was isolated during functional screening of a human gut metagenomic library using Lactococcus lactis MG1363 as heterologous host. The insert carried a glycoside hydrolase family 9 (GH9) catalytic domain with sequence similarity to a gene from Coprococcus eutactus ART55/1. Genome surveys indicated a limited distribution of GH9 domains among dominant human colonic anaerobes. Genomes of C. eutactus-related strains harboured two GH9-encoding and four GH5-encoding genes, but the strains did not appear to degrade cellulose. Instead, they grew well on β-glucans and one of the strains also grew on galactomannan, galactan, glucomannan and starch. Coprococcus comes and Coprococcus catus strains did not harbour GH9 genes and were not able to grow on β-glucans. Gene expression and proteomic analysis of C. eutactus ART55/1 grown on cellobiose, β-glucan and lichenan revealed similar changes in expression in comparison to glucose. On β-glucan and lichenan only, one of the four GH5 genes was strongly upregulated. Growth on glucomannan led to a transcriptional response of many genes, in particular a strong upregulation of glycoside hydrolases involved in mannan degradation. Thus, β-glucans are a major growth substrate for species related to C. eutactus, with glucomannan and galactans alternative substrates for some strains

Spectral Analysis of the Chandra Comet Survey

We present results of the analysis of cometary X-ray spectra with an extended version of our charge exchange emission model (Bodewits et al. 2006). We have applied this model to the sample of 8 comets thus far observed with the Chandra X-ray observatory and ACIS spectrometer in the 300-1000 eV range. The surveyed comets are C/1999 S4 (LINEAR), C/1999 T1 (McNaught-Hartley), C/2000 WM1 (LINEAR), 153P/2002 (Ikeya-Zhang), 2P/2003 (Encke), C/2001 Q4 (NEAT), 9P/2005 (Tempel 1) and 73P/2006-B (Schwassmann-Wachmann 3) and the observations include a broad variety of comets, solar wind environments and observational conditions. The interaction model is based on state selective, velocity dependent charge exchange cross sections and is used to explore how cometary X-ray emission depend on cometary, observational and solar wind characteristics. It is further demonstrated that cometary X-ray spectra mainly reflect the state of the local solar wind. The current sample of Chandra observations was fit using the constrains of the charge exchange model, and relative solar wind abundances were derived from the X-ray spectra. Our analysis showed that spectral differences can be ascribed to different solar wind states, as such identifying comets interacting with (I) fast, cold wind, (II), slow, warm wind and (III) disturbed, fast, hot winds associated with interplanetary coronal mass ejections. We furthermore predict the existence of a fourth spectral class, associated with the cool, fast high latitude wind.Comment: 16 pages, 16 figures, and 7 Tables; accepted A&A (Due to space limits, this version has lower resolution jpeg images.

Seelische Belastung bei Menschen mit umweltbezogenen Störungen: Ein Vergleich zwischen Selbstbild und Fremdeinschätzung

Zusammenfassung: Umweltbezogene Gesundheitsstörungen stellen wissenschaftlich und klinisch ein diagnostisches und therapeutisches Konfliktfeld dar. Ein hoher subjektiver Leidensdruck, ein somatisches Krankheitsmodell sowie das Festhalten an einer Umweltursache gefährden die therapeutische Beziehung, wenn die Krankheitsmodelle von Arzt und Patient nicht übereinstimmen. Unsere Untersuchung greift diese empirisch noch kaum erforschte Diskrepanz auf, indem sie die Selbsteinschätzung von Patienten mit umweltbezogenen Krankheitsstörungen (n=61) systematisch der Fremdeinschätzung durch ein multidisziplinäres Expertenteam gegenüberstellt. Die Resultate weisen darauf hin, dass in Selbst- und Fremdeinschätzung psychisch unauffällige Probanden wenig psychiatrische Störungen zeigen, über stabile psychische Strukturen verfügen und v.a. unter umweltbedingten oder medizinischen Ursachen leiden. Wenn Selbst- und Fremdeinschätzung beide eine psychische Auffälligkeit beschreiben, sind entsprechend psychiatrische Störungen gehäuft, psychische Strukturen labil, und die Beschwerden werden psychiatrisch verursacht. Divergieren Selbst- und Fremdeinschätzung, erlaubt die Fremdeinschätzung akkuratere Aussagen bezüglich der psychiatrischen Diagnosen, der innerpsychischen Struktur und der Ursachenzuschreibun

Phosphorylation but Not Oligomerization Drives the Accumulation of Tau with Nucleoporin Nup98

Tau is a neuronal protein that stabilizes axonal microtubules (MTs) in the central nervous system. In Alzheimer’s disease (AD) and other tauopathies, phosphorylated Tau accumulates in intracellular aggregates, a pathological hallmark of these diseases. However, the chronological order of pathological changes in Tau prior to its cytosolic aggregation remains unresolved. These include its phosphorylation and detachment from MTs, mislocalization into the somatodendritic compartment, and oligomerization in the cytosol. Recently, we showed that Tau can interact with phenylalanine-glycine (FG)-rich nucleoporins (Nups), including Nup98, that form a diffusion barrier inside nuclear pore complexes (NPCs), leading to defects in nucleocytoplasmic transport. Here, we used surface plasmon resonance (SPR) and bio-layer interferometry (BLI) to investigate the molecular details of Tau:Nup98 interactions and determined how Tau phosphorylation and oligomerization impact the interactions. Importantly, phosphorylation, but not acetylation, strongly facilitates the accumulation of Tau with Nup98. Oligomerization, however, seems to inhibit Tau:Nup98 interactions, suggesting that Tau-FG Nup interactions occur prior to oligomerization. Overall, these results provide fundamental insights into the molecular mechanisms of Tau-FG Nup interactions within NPCs, which might explain how stress-and disease-associated posttranslational modifications (PTMs) may lead to Tau-induced nucleocytoplasmic transport (NCT) failure. Intervention strategies that could rescue Tau-induced NCT failure in AD and tauopathies will be further discussed

Simultaneous Swift X-ray and UV views of comet C/2007 N3 (Lulin)

We present an analysis of simultaneous X-Ray and UV observations ofcomet C/2007 N3 (Lulin) taken on three days between January 2009 and March 2009 using the Swift observatory. For our X-ray observations, we used basic transforms to account for the movement of the comet to allow the combination of all available data to produce an exposure-corrected image. We fit a simple model to the extracted spectrum and measured an X-ray flux of 4.3+/-1.3 * 10^-13 ergs cm-2 s-1 in the 0.3 to 1.0 keV band. In the UV, we acquired large-aperture photometry and used a coma model to derive water production rates given assumptions regarding the distribution of water and its dissociation into OH molecules about the comet's nucleus. We compare and discuss the X-ray and UV morphology of the comet. We show that the peak of the cometary X-ray emission is offset sunward of the UV peak emission, assumed to be the nucleus, by approximately 35,000 km. The offset observed, the shape of X-ray emission and the decrease of the X-ray emission comet-side of the peak, suggested that the comet was indeed collisionally thick to charge exchange, as expected from our measurements of the comet's water production rate (6--8 10^28 mol. s-1). The X-ray spectrum is consistent with solar wind charge exchange emission, and the comet most likely interacted with a solar wind depleted of very highly ionised oxygen. We show that the measured X-ray lightcurve can be very well explained by variations in the comet's gas production rates, the observing geometry and variations in the solar wind flux.Comment: Paper accepted for publication in Astronomy and Astrophysics, 6 March 2012, 12 pages, 8 colour figures, one tabl

Winery website loyalty: the role of sales promotion and service attributes

Purpose: toward buying wine on mobile phones and m-commerce website loyalty by examining a) the mediating role of sales promotion and b) the moderating role of service attributes of the m-commerce websites in influencing the mediation. Design/methodology/approach: A total of 3,318 completed surveys were collected. Drawing on a large non-probability criterion based purposive sample across six countries (France, Germany, Greece, South Africa, United States and Canada) mediation analysis was performed to examine hypothesized relationships. Findings: Results show that sales promotion mediates the relationship between feelings towards buying wine on mobile phones and m-commerce website loyalty. Moderated mediation reveals that the indirect pathways (sales promotion) through which feelings towards buying wine over mobile exert its effect on m-commerce website loyalty is dependent on the value of service (wine delivery) attributes of the website. The results demonstrate that sales promotion and service are of paramount importance to wineries and wine marketers. Research implications/limitations: Wine producers and retailers should consider the use of sales promotion to enhance sales and loyalty to m-commerce websites. Practical implications: Wine producers and retailers should consider use sales promotion (such as SMS or push notifications) to enhance sales and influence consumer feelings and hence their loyalty. Originality/value: Wine m-commerce studies are limited, especially with an international perspective comparing 6 different countries: 3 from the old world (such as France, Germany and Greece) and 3 from the New World (North America with USA and Canada; and South Africa). Altogether those 6 countries represent around 40% of the world consumption

Don't believe the hype: a grounded exploratory six country wine purchasing study

The purpose of this exploratory study was to understand the extent that consumers report purchasing wine on mobile devices and to empirically examine potential drivers of m-wine purchasing across six countries to guide theoretical research enquiry moving forward. Purposive sampling was employed. An online survey involving 2853 respondents from France, Germany, Greece, Canada, US and South Africa forms the basis for the current study. The results of the study indicate that though mobile phone usage, wine consumption and purchasing rates are high, mobile-wine purchasing prevalence is low within all six countries. While technology hype has us believe an online presence is essential for business revenue growth and performance; the current study indicates wineries should carefully consider consumer readiness towards mobile-wine purchasing. Limitations and recommendations for future research are identified

Microtubules gate tau condensation to spatially regulate microtubule functions.

Tau is an abundant microtubule-associated protein in neurons. Tau aggregation into insoluble fibrils is a hallmark of Alzheimer's disease and other types of dementia1, yet the physiological state of tau molecules within cells remains unclear. Using single-molecule imaging, we directly observe that the microtubule lattice regulates reversible tau self-association, leading to localized, dynamic condensation of tau molecules on the microtubule surface. Tau condensates form selectively permissible barriers, spatially regulating the activity of microtubule-severing enzymes and the movement of molecular motors through their boundaries. We propose that reversible self-association of tau molecules, gated by the microtubule lattice, is an important mechanism of the biological functions of tau, and that oligomerization of tau is a common property shared between the physiological and disease-associated forms of the molecule

Many-body approach to proton emission and the role of spectroscopic factors

The process of proton emission from nuclei is studied by utilizing the two-potential approach of Gurvitz and Kalbermann in the context of the full many-body problem. A time-dependent approach is used for calculating the decay width. Starting from an initial many-body quasi-stationary state, we employ the Feshbach projection operator approach and reduce the formalism to an effective one-body problem. We show that the decay width can be expressed in terms of a one-body matrix element multiplied by a normalization factor. We demonstrate that the traditional interpretation of this normalization as the square root of a spectroscopic factor is only valid for one particular choice of projection operator. This causes no problem for the calculation of the decay width in a consistent microscopic approach, but it leads to ambiguities in the interpretation of experimental results. In particular, spectroscopic factors extracted from a comparison of the measured decay width with a calculated single-particle width may be affected.Comment: 17 pages, Revte