How Do Individuals in a Radical Echo Chamber React to Opposing Views? Evidence from a Content Analysis of Stormfront

Calls to “break up” radical echo chambers by injecting them with alternative viewpoints are common. Yet, thus far there is little evidence about the impact of such counter-messaging. To what extent and how do individuals who inhabit a radical echo chamber engage with messages that challenge their core beliefs? Drawing on data from the radical right forum Stormfront we address this question with a large-scale content and longitudinal analysis of users’ posting behavior, which analyses more than 35,000 English language contributions to the forum spanning 2011 through 2013. Our findings show that engaging with oppositional views is actually a core practice among Stromfront users which invites active participation and encourages engagement. Indeed, many “echoes” in the echo chamber we studied were not core beliefs being restated, but the sound of opposing viewpoints being undermined and marginalized. These findings underscore the limited potential for counter-messages to undermine radical echo chambers

Probiotic effects of lactic acid bacteria against Vibrio alginolyticus in Penaeus (Fenneropenaeus) indicus (H. Milne Edwards)

Cell free extracts of four strains of Lactic acid bacteria (LAB) viz. Lactobacillus. acidophilus, Streptococcus.cremoris, Lactobacillus bulgaricus –56 and Lactobacillus bulgaricus –57 inhibited growth of Vibrio alginolyticus in nutrient broth. The antagonism of LAB to Vibrio alginolyticus was further confirmed by streak plating wherein suppression of growth of Vibrio was obtained. Juveniles of Penaeus indicus (average weight 0.985 ± 0.1 g) on administering orally a moist feed base containing 5 × 106 cells·g of the four LAB probionts for a period of four weeks showed better survival (56 to 72%) when challenged with V. alginolyticus by intra-muscular injection of 0.1 ml containing 3 × 109 cells·ml. Animals maintained on a diet devoid of bacterial biomass exhibited 80% mortality

The RCB star V854 Cen is surrounded by a hot dusty shell

Aims : The hydrogen-deficient supergiants known as R Coronae Borealis (RCB) stars might be the result of a double-degenerate merger of two white dwarfs (WDs), or a final helium shell flash in a planetary nebula central star. In this context, any information on the geometry of their circumstellar environment and, in particular, the potential detection of elongated structures, is of great importance. Methods : We obtained near-IR observations of V854 Cen with the AMBER recombiner located at the Very Large Telescope Interferometer (VLTI) array with the compact array (B$\leq$35m) in 2013 and the long array (B$\leq$140m) in 2014. At each time, V854 Cen was at maximum light. The $H$- and $K$-band continua were investigated by means of spectrally dependant geometric models. These data were supplemented with mid-IR VISIR/VLT images. Results : A dusty slightly elongated over density is discovered both in the $H$- and $K$-band images. With the compact array, the central star is unresolved ($\Theta\leq2.5$\,mas), but a flattened dusty environment of $8 \times 11$ mas is discovered whose flux increases from about $\sim$20% in the $H$ band to reach about $\sim$50% at 2.3\micron, which indicates hot (T$\sim$1500\,K) dust in the close vicinity of the star. The major axis is oriented at a position angle (P.A.) of 126$\pm$29$\deg$. Adding the long-array configuration dataset provides tighter constraints on the star diameter ($\Theta\leq1.0$ mas), a slight increase of the overdensity to $12 \times 15$ mas and a consistent P.A. of 133$\pm$49$\deg$. The closure phases, sensitive to asymmetries, are null and compatible with a centro-symmetric, unperturbed environment excluding point sources at the level of 3% of the total flux in 2013 and 2014. The VISIR images exhibit a flattened aspect ratio at the 15-20% level at larger distances ($\sim$1\arcsec) with a position angle of 92$\pm$19$\deg$, marginally consistent with the interferometric observations. Conclusions : This is the first time that a moderately elongated structure has been observed around an RCB star. These observations confirm the numerous suggestions for a bipolar structure proposed for this star in the literature, which were mainly based on polarimetric and spectroscopic observations.Comment: Accepted by A\&A, new version after language editing, Astronomy and Astrophysics (2014

V838 Monocerotis: the central star and its environment a decade after outburst

Aims. V838 Monocerotis erupted in 2002, brightened in a series of outbursts, and eventually developed a spectacular light echo. A very red star emerged a few months after the outburst. The whole event has been interpreted as the result of a merger. Methods. We obtained near-IR and mid-IR interferometric observations of V838 Mon with the AMBER and MIDI recombiners located at the Very Large Telescope Interferometer (VLTI) array. The MIDI two-beam observations were obtained with the 8m Unit Telescopes between October 2011 and February 2012. The AMBER three-beam observations were obtained with the compact array (B$\leq$m) in April 2013 and the long array (B$\leq$140m) in May 2014, using the 1.8m Auxiliary Telescopes. Results. A significant new result is the detection of a compact structure around V838 Mon, as seen from MIDI data. The extension of the structure increases from a FWHM of 25 mas at 8 {\mu}m to 70 mas at 13 {\mu}m. At the adopted distance of D = 6.1 $\pm$ 0.6 kpc, the dust is distributed from about 150 to 400 AU around V838 Mon. The MIDI visibilities reveal a flattened structure whose aspect ratio increases with wavelength. The major axis is roughly oriented around a position angle of -10 degrees, which aligns with previous polarimetric studies reported in the literature. This flattening can be interpreted as a relic of the 2002 eruption or by the influence of the currently embedded B3V companion. The AMBER data provide a new diameter for the pseudo-photosphere, which shows that its diameter has decreased by about 40% in 10yrs, reaching a radius R$_*$ = 750 $\pm$ 200 R$_{\odot}$ (3.5 $\pm$ 1.0 AU). Conclusions. After the 2002 eruption, interpreted as the merging of two stars, it seems that the resulting source is relaxing to a normal state. The nearby environment exhibits an equatorial over-density of dust up to several hundreds of AU.Comment: Astronomy and Astrophysics (2014) Will be set by the publishe

Inhibitory compound produced by Pseudomonas with effectiveness on Vibrio harveyi

Persistence of the antivibrio property of the potential antagonistic probiotics, Pseudomonas MCCB 102 and 103, at di¡erent temperatures, pH and in organic solvents was studied. The antivibrio compound was extracted, puri¢ed and characterized using thin-layer chromatography, high-pressure liquid chromatography, liquid chromatography-mass spectroscopy, UV^ Vis and nuclear magnetic resonance spectroscopy and identi¢ed as N-methyl-1-hydroxyphenazine, a phenazine antibiotic. The toxicity of the compound was tested in Penaeus monodon haemocyte culture and the IC50 valuewas found to be1.4 _ 0.31mg L_1. The compound was found to be bacteriostatic at 0.5mg L_1. Its stability to varying temperature, pH, organic solvents, prolonged shelf-life and vibriostatic nature point to its suitability for prophylatic aquaculture application

Total column CO_2 measurements at Darwin, Australia – site description and calibration against in situ aircraft profiles

An automated Fourier Transform Spectroscopic (FTS) solar observatory was established in Darwin, Australia in August 2005. The laboratory is part of the Total Carbon Column Observing Network, and measures atmospheric column abundances of CO_2 and O_2 and other gases. Measured CO_2 columns were calibrated against integrated aircraft profiles obtained during the TWP-ICE campaign in January–February 2006, and show good agreement with calibrations for a similar instrument in Park Falls, Wisconsin. A clear-sky low airmass relative precision of 0.1% is demonstrated in the CO2 and O2 retrieved column-averaged volume mixing ratios. The 1% negative bias in the FTS X_(CO_2) relative to the World Meteorological Organization (WMO) calibrated in situ scale is within the uncertainties of the NIR spectroscopy and analysis

A brackishwater isolate of Pseudomonas PS-102, a potential antagonistic bacterium against pathogenic vibrios in penaeid and non-penaeid rearing systems

A Pseudomonas sp PS-102 recovered from Muttukkadu brackish water lagoon, situated south of Chennai, showed significant activity against a number of shrimp pathogenic vibrios. Out of the 112 isolates of bacterial pathogens comprising Vibrio harveyi, V. vulnificus, V. parahaemolyticus, V. alginolyticus, V. fluvialis, and Aeromonas spp, 73% were inhibited in vitro by the cell-free culture supernatant of Pseudomonas sp PS-102 isolate. The organism produced yellowish fluorescent pigment on King's B medium, hydrolysed starch and protein, and produced 36.4% siderophore units by CAS assay and 32 μM of catechol siderophores as estimated by Arnow's assay. The PS-102 isolate showed wide ranging environmental tolerance with, temperatures from 25 to 40 °C, pH from 6 to 8, salinity from 0 to 36 ppt, while the antagonistic activity peaked in cultures grown at 30 °C, pH 8.0 and at 5 ppt saline conditions. The antagonistic activity of the culture supernatant was evident even at 30% v / v dilution against V. harveyi. The preliminary studies on the nature of the antibacterial action indicated that the antagonistic principle as heat stable and resistant to proteolytic, lipolytic and amylolytic enzymes. Pseudomonas sp PS 102 was found to be safe to shrimp when PL-9 stage were challenged at 107 CFU ml− 1 and by intramuscular injection into of 5 g sub-adults shrimp at 105 to 108 CFU. Further, its safety in a mammalian system, tested by its pathogenicity to mice, was also determined and its LD50 to BALB/c mice was found to be 109 CFU. The results of this study indicated that the organism Pseudomonas sp PS 102 could be employed as a potential probiont in shrimp and prawn aquaculture systems for management and control of bacterial infections

Automated Identification of Oceanic Fronts for Operational Generation of Potential Fishing Zone (PFZ) Advisories

PFZs, are essentially the frontal structures as identified from the satellite images of Sea Surface Temperature (SST) and chlorophyll concentration. These regions are known for fish aggregation and provide cost-effectiveness in offshore fishing operations. Subjective identification of fronts may lead to human-errors, non-negotiable beyond a limit. To overcome this, we propose utilization of tools that help automated identification of the frontal structures. This approach not only removes the errors, but also helps shorten the time period of the operational process-chai

Engineered carbon-nanomaterial-based electrochemical sensors for biomolecules

The study of electrochemical behavior of bioactive molecules has become one of the most rapidly developing scientific fields. Biotechnology and biomedical engineering fields have a vested interest in constructing more precise and accurate voltammetric/amperometric biosensors. One rapidly growing area of biosensor design involves incorporation of carbon-based nanomaterials in working electrodes, such as one-dimensional carbon nanotubes, two-dimensional graphene, and graphene oxide. In this review article, we give a brief overview describing the voltammetric techniques and how these techniques are applied in biosensing, as well as the details surrounding important biosensing concepts of sensitivity and limits of detection. Building on these important concepts, we show how the sensitivity and limit of detection can be tuned by including carbon-based nanomaterials in the fabrication of biosensors. The sensing of biomolecules including glucose, dopamine, proteins, enzymes, uric acid, DNA, RNA, and H2O2 traditionally employs enzymes in detection; however, these enzymes denature easily, and as such, enzymeless methods are highly desired. Here we draw an important distinction between enzymeless and enzyme-containing carbon-nanomaterial-based biosensors. The review ends with an outlook of future concepts that can be employed in biosensor fabrication, as well as limitations of already proposed materials and how such sensing can be enhanced. As such, this review can act as a roadmap to guide researchers toward concepts that can be employed in the design of next generation biosensors, while also highlighting the current advancements in the field.ope