The effect of a multispecies probiotic on the composition of the faecal microbiota and bowel habits in chronic obstructive pulmonary disease patients treated with antibiotics

Short-term antibiotic treatment profoundly affects the intestinal microbiota, which may lead to sustained changes in microbiota composition. Probiotics may restore such a disturbance. The objective of the present study was to investigate the effect of a multispecies probiotic on the faecal microbiota during and after antibiotic intake in patients with a history of frequent antibiotic use. In this randomised, placebo-controlled, double-blind study, thirty chronic obstructive pulmonary disease (COPD) patients treated with antibiotics for a respiratory tract infection received 5 g of a multispecies probiotic or placebo twice daily for 2 weeks. Faecal samples were collected at 0, 7, 14 and 63 d. Changes in the composition of the dominant faecal microbiota were determined by PCR-denaturing gradient gel electrophoresis (DGGE). Changes in bacterial subgroups were determined by quantitative PCR and culture. Bowel movements were scored daily according to the Bristol stool form scale. During and after antibiotic treatment, DGGE-based similarity indices (SI) were high ( >/= 84 %) and band richness was relatively low, both remaining stable over time. No difference in SI was observed between patients with and without diarrhoea-like bowel movements. The multispecies probiotic had a modest effect on the bacterial subgroups. Nevertheless, it affected neither the composition of the dominant faecal microbiota nor the occurrence of diarrhoea-like bowel movements. The dominant faecal microbiota was not affected by antibiotics in this COPD population, suggesting an existing imbalance of the microbiota, which may also have contributed to the lack of effect by probiotic intak

New approaches to probing Minkowski functionals

We generalize the concept of the ordinary skew-spectrum to probe the effect of non-Gaussianity on the morphology of cosmic microwave background (CMB) maps in several domains: in real space (where they are commonly known as cumulant-correlators), and in harmonic and needlet bases. The essential aim is to retain more information than normally contained in these statistics, in order to assist in determining the source of any measured non-Gaussianity, in the same spirit as Munshi & Heavens skew-spectra were used to identify foreground contaminants to the CMB bispectrum in Planck data. Using a perturbative series to construct the Minkowski functionals (MFs), we provide a pseudo-C based approach in both harmonic and needlet representations to estimate these spectra in the presence of a mask and inhomogeneous noise. Assuming homogeneous noise, we present approximate expressions for error covariance for the purpose of joint estimation of these spectra. We present specific results for four different models of primordial non-Gaussianity local, equilateral, orthogonal and enfolded models, as well as non-Gaussianity caused by unsubtracted point sources. Closed form results of nextorder corrections to MFs too are obtained in terms of a quadruplet of kurt-spectra. We also use the method of modal decomposition of the bispectrum and trispectrum to reconstruct the MFs as an alternative method of reconstruction of morphological properties of CMB maps. Finally, we introduce the odd-parity skew-spectra to probe the odd-parity bispectrum and its impact on the morphology of the CMB sky. Although developed for the CMB, the generic results obtained here can be useful in other areas of cosmology

A strong web presence can equalize the playing field for long shot candidates in Presidential party nominations

While few would doubt that the Internet is now an important component in any election, especially the presidential, what effects does a candidates’ web presence have on their electoral chances, and is this something that they are able to influence? Using data from the 2008 presidential nominations, Dino P. Christenson, Corwin D. Smidt and Costas Panagopoulos investigate how candidate’s web presence differs from traditional indicators of campaign performance and if it can help them to gain greater financial and electoral support. They find that campaign frontrunners have a limited ability to control their web presence, but that outsider candidates can have more success. They also show that candidates with a greater web presence see greater successes in fundraising

CMB Constraints on Primordial non-Gaussianity from the Bispectrum (f_{NL}) and Trispectrum (g_{NL} and \tau_{NL}) and a New Consistency Test of Single-Field Inflation

We outline the expected constraints on non-Gaussianity from the cosmic microwave background (CMB) with current and future experiments, focusing on both the third (f_{NL}) and fourth-order (g_{NL} and \tau_{NL}) amplitudes of the local configuration or non-Gaussianity. The experimental focus is the skewness (two-to-one) and kurtosis (two-to-two and three-to-one) power spectra from weighted maps. In adition to a measurement of \tau_{NL} and g_{NL} with WMAP 5-year data, our study provides the first forecasts for future constraints on g_{NL}. We describe how these statistics can be corrected for the mask and cut-sky through a window function, bypassing the need to compute linear terms that were introduced for the previous-generation non-Gaussianity statistics, such as the skewness estimator. We discus the ratio A_{NL} = \tau_{NL}/(6f_{NL}/5)^2 as an additional test of single-field inflationary models and discuss the physical significance of each statistic. Using these estimators with WMAP 5-Year V+W-band data out to l_{max}=600 we constrain the cubic order non-Gaussianity parameters \tau_{NL}, and g_{NL} and find -7.4 < g_{NL}/10^5 < 8.2 and -0.6 < \tau_{NL}/10^4 < 3.3 improving the previous COBE-based limit on \tau_{NL} < 10^8 nearly four orders of magnitude with WMAP.Comment: 15 pages. 14 figure

Trispectrum from Ghost Inflation

Ghost inflation predicts almost scale-invariant primordial cosmological perturbations with relatively large non-Gaussianity. The bispectrum is known to have a large contribution at the wavenumbers forming an equilateral triangle and the corresponding nonlinear parameter $f_{NL}^{equil}$ is typically of order $O(10^2)$. In this paper we calculate trispectrum from ghost inflation and show that the corresponding nonlinear parameter $\tau_{NL}$ is typically of order $O(10^4)$. We investigate the shape dependence of the trispectrum and see that it has some features different from DBI inflation. Therefore, our result may be useful as a template to distinguish ghost inflation from other models of inflation by future experiments.Comment: 25 pages, 10 figure

Microbial communities involved in anaerobic degradation of unsaturated-and saturated-LCFA in methanogenic bioreactors

Long chain fatty acids (LCFA) are frequently found in wastewaters as the main product of lipid hydrolysis. These compounds hold a high energetic potential and thus are attractive substrates for methane production. Insight into the microbial populations involved in anaerobic LCFA-degradation is important for the development and improvement of technologies for lipids/LCFA-rich wastewater valorisation. This study identifies putative LCFA-degrading bacteria by combining selective enrichments with molecular techniques. Two distinct enrichment series of anaerobic cultures growing on unsaturatedand saturated-LCFA were obtained by successive transfers in medium containing oleate (C18:1) and palmitate (C16:0), respectively, as the sole carbon and energy source. This procedure resulted in two stable and highly enriched cultures that could convert oleate and palmitate to acetate and methane. Changes in the microbial composition during the enrichment were analyzed by 16S rRNA gene PCRDGGE profiling. Upon enrichment a decrease in microbial diversity was observed. Prominent bands in the DGGE profiles of stable enriched cultures were identified by 16S rRNA gene sequencing, and nearly full sequences were compared using ARB software. A major part of the retrieved 16S rRNA gene sequences was most similar to those of uncultured bacteria. Organisms corresponding to dominant DGGE bands in oleate- and palmitate-enrichment cultures clustered with fatty-acid oxidizing syntrophic bacteria within Syntrophomonadaceae and Syntrophaceae families. Despite the absence of sulphate in the medium, a Desulfovibrio-like organism was detected as a dominant band in the DGGE profile of the oleate-enrichment culture. In other studies Desulfovibrio species have been detected in methanogenic reactors without added sulphate. They were proposed to grow acetogenically. The role of such bacteria in the oleate-enrichment culture is not clear yet, and this needs further investigation. A low methane yield (12%) was observed in the oleate-enrichment and acetate, produced according to the expected stoichiometry, was no further converted to methane. In the palmitate-enrichment culture, the acetate produced was completely mineralised and a total methane yield of about 83% was achieved from palmitate degradation. Furthermore, the oleate-enrichment culture was able to use palmitate without detectable changes in the DGGE profile. However, the palmitate-specialised consortia degraded oleate only after a lag phase of three months, after which the DGGE profile was changed. A dominant band appeared and sequence analysis showed affiliation with the Syntrophomonas genus. This band was also present in the oleate-enrichment culture, suggesting that this bacterium is important for oleate degradation, emphasizing possible differences between the degradation of unsaturated- and saturated-LCFA

Microbial communities involved in anaerobic degradation of unsaturated or saturated long-chain fatty acids

Anaerobic long-chain fatty acid (LCFA)-degrading bacteria were identified by combining selective enrichment studies with molecular approaches. Two distinct enrichment cultures growing on unsaturated and saturated LCFAs were obtained by successive transfers in medium containing oleate and palmitate, respectively, as the sole carbon and energy sources. Changes in the microbial composition during enrichment were analyzed by denaturing gradient gel electrophoresis (DGGE) profiling of PCR-amplified 16S rRNA gene fragments. Prominent DGGE bands of the enrichment cultures were identified by 16S rRNA gene sequencing. A significant part of the retrieved 16S rRNA gene sequences was most similar to those of uncultured bacteria. Bacteria corresponding to predominant DGGE bands in oleate and palmitate enrichment cultures clustered with fatty acid-oxidizing bacteria within Syntrophomonadaceae and Syntrophobacteraceae families. A low methane yield, corresponding to 9 to 18% of the theoretical value, was observed in the oleate enrichment, and acetate, produced according to the expected stoichiometry, was not further converted to methane. In the palmitate enrichment culture, the acetate produced was completely mineralized and a methane yield of 48 to 70% was achieved from palmitate degradation. Furthermore, the oleate enrichment culture was able to use palmitate without detectable changes in the DGGE profile. However, the palmitate- specialized consortia degraded oleate only after a lag phase of 3 months, after which the DGGE profile had changed. Two predominant bands appeared, and sequence analysis showed affiliation with the Syntrophomonas genus. These bands were also present in the oleate enrichment culture, suggesting that these bacteria are directly involved in oleate degradation, emphasizing possible differences between the degradation of unsaturated and saturated LCFAs.Fundação para a Ciência e a Tecnologia (FCT)Fundo Social Europeu (FSE) Wageningen Institute for Environmental and Climate Research (WIMEK)