Probiotic administration in congenital heart disease: a pilot study.

ObjectiveTo investigate the impact of probiotic Bifidobacterium longum ssp. infantis on the fecal microbiota and plasma cytokines in neonates with congenital heart disease.Study designSixteen infants with congenital heart disease were randomly assigned to receive either B. infantis (4.2 × 10(9) colony-forming units two times daily) or placebo for 8 weeks. Stool specimens from enrolled infants and from six term infants without heart disease were analyzed for microbial composition. Plasma cytokines were analyzed weekly in the infants with heart disease.ResultsHealthy control infants had increased total bacteria, total Bacteroidetes and total bifidobacteria compared to the infants with heart disease, but there were no significant differences between the placebo and probiotic groups. Plasma interleukin (IL)10, interferon (IFN)γ and IL1β levels were transiently higher in the probiotic group.ConclusionCongenital heart disease in infants is associated with dysbiosis. Probiotic B. infantis did not significantly alter the fecal microbiota. Alterations in plasma cytokines were found to be inconsistent

Impacts of meteoric sulfur in the Earth's atmosphere

A meteoric sulfur input function and a sulfur ion chemistry scheme have been incorporated into a chemistry-climate model, in order to study the speciation of sulfur between the stratosphere and the thermosphere (~20 – 120 km), and the impact of the sulfur input from ablation of cosmic dust. The simulations have been compared to rocket observations of SO+ between 85 and 110 km, MIPAS observations of SO2 between 20 and 45 km, and stratospheric balloon-borne measurements of H2SO4 vapor and sulfate aerosol. These observations constrain the present day global flux of meteoric sulfur to ≤ 1.0 t S d-1, i.e. 2 orders of magnitude smaller than the flux of S into the stratosphere from OCS photo-oxidation and explosive volcanic SO2 injection. However, the meteoric sulfur flux is strongly focused into the polar vortices by the meridional circulation, and therefore the contribution of SO2 of meteoric origin to the polar upper stratosphere during winter is substantial (~ 30% at 50 km for a flux of 1.0 t S d-1). The Antarctic spring sulfate aerosol layer is found to be very sensitive to a moderate increase of the input rate of meteoric sulfur, showing a factor of 2 enhancement in total sulfate aerosol number density at 30 km for an input of 3.0 t S d-1. The input rate estimate of 1.0 t S d-1 suggests an enrichment of sodium relative to sulfur of 2.7 ± 1.5 and is consistent with a total cosmic dust input rate of 44 t d-1

Controlled variation of monomer sequence-distribution in the synthesis of aromatic poly(ether ketone)s

The effects of varying the alkali metal cation in the high-temperature nucleophilic synthesis of a semi-crystalline, aromatic poly(ether ketone) have been systematically investigated, and striking variations in the sequence-distributions and thermal characteristics of the resulting polymers were found. Polycondensation of 4,4'-dihydroxybenzophenone with 1,3-bis(4-fluorobenzoyl)benzene in diphenylsulfone as solvent, in the presence of an alkali metal carbonate M2CO3 (M= Li, Na, K, or Rb) as base, affords a range of different polymers that vary in the distribution pattern of 2-ring and 3-ring monomer units along the chain. Lithium carbonate gives an essentially alternating and highly crystalline polymer, but the degree of sequence-randomisation increases progressively as the alkali metal series is descended, with rubidium carbonate giving a fully random and non-thermally-crystallisable polymer. Randomisation during polycondensation is shown to result from reversible cleavage of the ether linkages in the polymer by fluoride ions, and an isolated sample of alternating-sequence polymer is thus converted to a fully randomised material on heating with rubidium fluoride

Accelerating growth of HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane) in the atmosphere

We report the first measurements of 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), a substitute for ozone depleting compounds, in air samples originating from remote regions of the atmosphere and present evidence for its accelerating growth. Observed mixing ratios ranged from below 0.01 ppt in deep firn air to 0.59 ppt in the current northern mid-latitudinal upper troposphere. Firn air samples collected in Greenland were used to reconstruct a history of atmospheric abundance. Year-on-year increases were deduced, with acceleration in the growth rate from 0.029 ppt per year in 2000 to 0.056 ppt per year in 2007. Upper tropospheric air samples provide evidence for a continuing growth until late 2009. Furthermore we calculated a stratospheric lifetime of 370 years from measurements of air samples collected on board high altitude aircraft and balloons. Emission estimates were determined from the reconstructed atmospheric trend and suggest that current "bottom-up" estimates of global emissions for 2005 are too high by a factor of three

Four-Hundred-and-Ninety-Million-Year Record of Bacteriogenic Iron Oxide Precipitation at Sea-Floor Hydrothermal Vents

Fe oxide deposits are commonly found at hydrothermal vent sites at mid-ocean ridge and back-arc sea floor spreading centers, seamounts associated with these spreading centers, and intra-plate seamounts, and can cover extensive areas of the seafloor. These deposits can be attributed to several abiogenic processes and commonly contain micron-scale filamentous textures. Some filaments are cylindrical casts of Fe oxyhydroxides formed around bacterial cells and are thus unquestionably biogenic. The filaments have distinctive morphologies very like structures formed by neutrophilic Fe oxidizing bacteria. It is becoming increasingly apparent that Fe oxidizing bacteria have a significant role in the formation of Fe oxide deposits at marine hydrothermal vents. The presence of Fe oxide filaments in Fe oxides is thus of great potential as a biomarker for Fe oxidizing bacteria in modern and ancient marine hydrothermal vent deposits. The ancient analogues of modern deep-sea hydrothermal Fe oxide deposits are jaspers. A number of jaspers, ranging in age from the early Ordovician to late Eocene, contain abundant Fe oxide filamentous textures with a wide variety of morphologies. Some of these filaments are like structures formed by modern Fe oxidizing bacteria. Together with new data from the modern TAG site, we show that there is direct evidence for bacteriogenic Fe oxide precipitation at marine hydrothermal vent sites for at least the last 490 Ma of the Phanerozoic

Transit Timing and Duration Variations for the Discovery and Characterization of Exoplanets

Transiting exoplanets in multi-planet systems have non-Keplerian orbits which can cause the times and durations of transits to vary. The theory and observations of transit timing variations (TTV) and transit duration variations (TDV) are reviewed. Since the last review, the Kepler spacecraft has detected several hundred perturbed planets. In a few cases, these data have been used to discover additional planets, similar to the historical discovery of Neptune in our own Solar System. However, the more impactful aspect of TTV and TDV studies has been characterization of planetary systems in which multiple planets transit. After addressing the equations of motion and parameter scalings, the main dynamical mechanisms for TTV and TDV are described, with citations to the observational literature for real examples. We describe parameter constraints, particularly the origin of the mass/eccentricity degeneracy and how it is overcome by the high-frequency component of the signal. On the observational side, derivation of timing precision and introduction to the timing diagram are given. Science results are reviewed, with an emphasis on mass measurements of transiting sub-Neptunes and super-Earths, from which bulk compositions may be inferred.Comment: Revised version. Invited review submitted to 'Handbook of Exoplanets,' Exoplanet Discovery Methods section, Springer Reference Works, Juan Antonio Belmonte and Hans Deeg, Eds. TeX and figures may be found at https://github.com/ericagol/TTV_revie

Why do Particle Clouds Generate Electric Charges?

Grains in desert sandstorms spontaneously generate strong electrical charges; likewise volcanic dust plumes produce spectacular lightning displays. Charged particle clouds also cause devastating explosions in food, drug and coal processing industries. Despite the wide-ranging importance of granular charging in both nature and industry, even the simplest aspects of its causes remain elusive, because it is difficult to understand how inert grains in contact with little more than other inert grains can generate the large charges observed. Here, we present a simple yet predictive explanation for the charging of granular materials in collisional flows. We argue from very basic considerations that charge transfer can be expected in collisions of identical dielectric grains in the presence of an electric field, and we confirm the model's predictions using discrete-element simulations and a tabletop granular experiment

Teaching Evidence-Based Complementary and Alternative Medicine (EBCAM); Changing behaviours in the face of reticence: A cross-over trial

BACKGROUND: The effectiveness of teaching critical appraisal to students of Complementary and Alternative Medicine (CAM) has not been studied. In this study we attempt to determine if a workshop for final year students at a naturopathic college improved their ability to utilize critical appraisal concepts. METHODS: We assigned 83 Naturopathic Interns to two groups: Group A (n = 47) or Group B (n = 36). We conducted a baseline assessment of all subjects' critical appraisal skills. Group A was assigned to receive a 3 ½ hour workshop on Evidence Based Medicine (EBM) and Group B received a workshop on bioethics (control intervention). The groups critical appraisal skills were re-evaluated at this time. We then crossed over the intervention so that Group B received the EBM workshop while Group A received the bioethics workshop. Assessment of critical appraisal skills of the two groups was again performed. RESULTS: The students mean scores were similar in Group A (14.8) and Group B (15.0) after Group A had received the intervention and Group B had received the control (p = 0.75). Group scores were not significantly improved at the end of the trial compared to at the beginning of the study (Group A: 15.1 to 16.1) (Group B 15.6 to 15.9). Student's confidence in reading research papers also did not improve throughout the course of the study. CONCLUSION: The final year is a difficult but important time to teach critical appraisal and evidence skills. Single, short intervention programs will likely yield negligible results. A multi-factorial approach may be better suited to implementing EBCAM than single short interventions

Reading faces: differential lateral gaze bias in processing canine and human facial expressions in dogs and 4-year-old children

Sensitivity to the emotions of others provides clear biological advantages. However, in the case of heterospecific relationships, such as that existing between dogs and humans, there are additional challenges since some elements of the expression of emotions are species-specific. Given that faces provide important visual cues for communicating emotional state in both humans and dogs, and that processing of emotions is subject to brain lateralisation, we investigated lateral gaze bias in adult dogs when presented with pictures of expressive human and dog faces. Our analysis revealed clear differences in laterality of eye movements in dogs towards conspecific faces according to the emotional valence of the expressions. Differences were also found towards human faces, but to a lesser extent. For comparative purpose, a similar experiment was also run with 4-year-old children and it was observed that they showed differential processing of facial expressions compared to dogs, suggesting a species-dependent engagement of the right or left hemisphere in processing emotions