Tale of J1328+2752 : a misaligned double-double radio galaxy hosted by a binary black-hole?

We present a radio and optical study of the double-double radio galaxy J1328+2752 based on new low-frequency Giant Metrewave Radio Telescope observations and Sloan Digital Sky Survey (SDSS) data. The radio data were used to investigate the morphology and to perform a spectral index analysis. In this source, we find that the inner double is misaligned by similar to 30 degrees from the axis of the outer diffuse structure. The SDSS spectrum shows that the central component has double-peaked line profiles with different emission strengths. The average velocity offset of the two components is 235 +/- 10.5 kms(-1). The misaligned radio morphology along with the double-peaked emission lines indicate that this source is a potential candidate binary supermassive black hole. This study further supports mergers as a possible explanation for repeated jet activity in radio sources

Cosmological Birefringence: an Astrophysical test of Fundamental Physics

We review the methods used to test for the existence of cosmological birefringence, i.e. a rotation of the plane of linear polarization for electromagnetic radiation traveling over cosmological distances, which might arise in a number of important contexts involving the violation of fundamental physical principles. The main methods use: (1) the radio polarization of radio galaxies and quasars, (2) the ultraviolet polarization of radio galaxies, and (3) the cosmic microwave background polarization. We discuss the main results obtained so far, the advantages and disadvantages of each method, and future prospects.Comment: To appear in the Proceedings of the JENAM 2010 Symposium "From Varying Couplings to Fundamental Physics", held in Lisbon, 6-10 Sept. 201

Betel nut and tobacco chewing; potential risk factors of cancer of oesophagus in Assam, India

Cancer of the oesophagus is the most commonly diagnosed cancer in males in Assam, in north-eastern India, and ranks second for females. The chewing of betel nut, with or without tobacco and prepared in various ways, is a common practice in the region and a case–control study has been designed to study the pattern of risk associated with different ways of preparing and chewing the nuts. 358 newly diagnosed male patients and 144 female have been interviewed together with 2 control subjects for each case chosen at random from among the attendants who accompanied patients to hospital. There were significant trends in risk ratios associated with the frequency of chewing each day, with the duration of chewing in years and with the age at which the habit was started that were apparent for both males and females and which remained significant after allowance was made for other known risk factors, notably tobacco smoking and alcohol consumption. The adjusted ratios, in comparison with non-chewers, were 13.3 M and 5.7 F for chewing more than 20 times a day, 10.6 M and 7.2 F for persons who had chewed for more than 20 years and 10.3 M and 5.3 F for those who had started before the age of 20. Among the different combinations of ingredients that were chewed the adjusted odds ratios were highest for those who had been using fermented betel nut with any form of tobacco (7.1 M and 3.6 F). The risk associated with tobacco smoking and alcohol consumption, which are high in some parts of the world, were less in Assam than those associated with the chewing of betel nut. © 2001 Cancer Research Campaign http://www.bjcancer.co

LeMMINGs. VI. Connecting nuclear activity to bulge properties of active and inactive galaxies: radio scaling relations and galaxy environment

Multiwavelength studies indicate that nuclear activity and bulge properties are closely related, but the details remain unclear. To study this further, we combine Hubble Space Telescope bulge structural and photometric properties with 1.5 GHz, e-MERLIN nuclear radio continuum data from the LeMMINGs survey for a large sample of 173 'active' galaxies (LINERs and Seyferts) and 'inactive' galaxies (H IIs and absorption line galaxies, ALGs). Dividing our sample into active and inactive, they define distinct (radio core luminosity)-(bulge mass), LR,core − M∗,bulge, relations, with a mass turnover at M∗,bulge ∼ 109.8±0.3M☉ (supermassive blackhole mass MBH ∼ 106.8±0.3M☉), which marks the transition from AGN-dominated nuclear radio emission in more massive bulges to that mainly driven by stellar processes in low-mass bulges. None of our 10/173 bulge-less galaxies host an AGN. The AGN fraction increases with increasing M∗,bulge such that foptical_AGN ∝ M∗,bulge0.24±0.06 and fradio_AGN ∝ M∗,bulge0.24±0.05. Between M∗,bulge ∼ 108.5 and 1011.3M☉, foptical_AGN steadily rises from 15 ± 4 to 80 ± 5 per cent. We find that at fixed bulge mass, the radio loudness, nuclear radio activity, and the (optical and radio) AGN fraction exhibit no dependence on environment. Radio-loud hosts preferentially possess an early-type morphology than radio-quiet hosts, the two types are however indistinguishable in terms of bulge Sérsic index and ellipticity, while results on the bulge inner logarithmic profile slope are inconclusive. We finally discuss the importance of bulge mass in determining the AGN triggering processes, including potential implications for the nuclear radio emission in nearby galaxies

LeMMINGs III. The e-MERLIN legacy survey of the Palomar sample: exploring the origin of nuclear radio emission in active and inactive galaxies through the [O iii] – radio connection

What determines the nuclear radio emission in local galaxies? To address this question, we combine optical [O III] line emission, robust black hole (BH) mass estimates, and high-resolution e-MERLIN 1.5-GHz data, from the LeMMINGs survey, of a statistically complete sample of 280 nearby optically active (LINER and Seyfert) and inactive [H II and absorption line galaxies (ALGs)] galaxies. Using [O III] luminosity (⁠L[OIII]⁠) as a proxy for the accretion power, local galaxies follow distinct sequences in the optical–radio planes of BH activity, which suggest different origins of the nuclear radio emission for the optical classes. The 1.5-GHz radio luminosity of their parsec-scale cores (Lcore) is found to scale with BH mass (MBH) and [O III] luminosity. Below MBH ∼ 106.5 M⊙, stellar processes from non-jetted H II galaxies dominate with Lcore∝M0.61±0.33BH and Lcore∝L0.79±0.30[OIII]⁠. Above MBH ∼ 106.5 M⊙, accretion-driven processes dominate with Lcore∝M1.5−1.65BH and Lcore∝L0.99−1.31[OIII] for active galaxies: radio-quiet/loud LINERs, Seyferts, and jetted H II galaxies always display (although low) signatures of radio-emitting BH activity, with L1.5GHz≳1019.8 W Hz−1 and MBH ≳ 107 M⊙, on a broad range of Eddington-scaled accretion rates (⁠m˙⁠). Radio-quiet and radio-loud LINERs are powered by low-m˙ discs launching sub-relativistic and relativistic jets, respectively. Low-power slow jets and disc/corona winds from moderately high to high-m˙ discs account for the compact and edge-brightened jets of Seyferts, respectively. Jetted H II galaxies may host weakly active BHs. Fuel-starved BHs and recurrent activity account for ALG properties. In conclusion, specific accretion–ejection states of active BHs determine the radio production and the optical classification of local active galaxies

Microwave assisted solvent free synthesis of 1,3-diphenylpropenones

<p>Abstract</p> <p>Background</p> <p>1,3-Diphenylpropenones (chalcones) are well known for their diverse array of bioactivities. Hydroxyl group substituted chalcones are the main precursor in the synthesis of flavonoids. Till date various methods have been developed for the synthesis of these very interesting molecules. Continuing our efforts for the development of simple, eco-friendly and cost-effective methodologies, we report here a solvent free condensation of aryl ketones and aldehydes using iodine impregnated alumina under microwave activation. This new protocol has been applied to a variety of substituted aryl carbonyls with excellent yield of substituted 1,3-diphenylpropenones.</p> <p>Results</p> <p>Differently substituted chalcones were synthesized using iodine impregnated neutral alumina as catalyst in 79-95% yield in less than 2 minutes time under microwave activation without using any solvent. The reaction was studied under different catalytic conditions and it was found that molecular iodine supported over neutral alumina gives the best yield. The otherwise difficult single step condensation of hydroxy substituted aryl carbonyls is an attractive feature of this protocol to obtain polyhydroxychalcones in excellent yields. In order to find out the general applicability of this new endeavor it was successfully applied for the synthesis of 15 different chalcones including highly bioactive prenylated hydroxychalcone xanthohumol.</p> <p>Conclusion</p> <p>A new, simple and solvent free method was developed for the synthesis of substituted chalcones in environmentally benign way. The mild reaction conditions, easy work-up, clean reaction profiles render this approach as an interesting alternative to the existing methods.</p

LeMMINGs - I. The eMERLIN legacy survey of nearby galaxies. 1.5-GHz parsec-scale radio structures and cores

We present the first data release of high-resolution ($\leq0.2$ arcsec) 1.5-GHz radio images of 103 nearby galaxies from the Palomar sample, observed with the eMERLIN array, as part of the LeMMINGs survey. This sample includes galaxies which are active (LINER and Seyfert) and quiescent (HII galaxies and Absorption line galaxies, ALG), which are reclassified based upon revised emission-line diagrams. We detect radio emission $\gtrsim$ 0.2 mJy for 47/103 galaxies (22/34 for LINERS, 4/4 for Seyferts, 16/51 for HII galaxies and 5/14 for ALGs) with radio sizes typically of $\lesssim$100 pc. We identify the radio core position within the radio structures for 41 sources. Half of the sample shows jetted morphologies. The remaining half shows single radio cores or complex morphologies. LINERs show radio structures more core-brightened than Seyferts. Radio luminosities of the sample range from 10$^{32}$ to 10$^{40}$ erg s$^{-1}$: LINERs and HII galaxies show the highest and the lowest radio powers respectively, while ALGs and Seyferts have intermediate luminosities. We find that radio core luminosities correlate with black hole (BH) mass down to $\sim$10$^{7}$ M$_{\odot}$, but a break emerges at lower masses. Using [O III] line luminosity as a proxy for the accretion luminosity, active nuclei and jetted HII galaxies follow an optical fundamental plane of BH activity, suggesting a common disc-jet relationship. In conclusion, LINER nuclei are the scaled-down version of FR I radio galaxies; Seyferts show less collimated jets; HII galaxies may host weak active BHs and/or nuclear star-forming cores; and recurrent BH activity may account for ALG properties

Interferon-Induced Ifit2/ISG54 Protects Mice from Lethal VSV Neuropathogenesis

Interferon protects mice from vesicular stomatitis virus (VSV) infection and pathogenesis; however, it is not known which of the numerous interferon-stimulated genes (ISG) mediate the antiviral effect. A prominent family of ISGs is the interferon-induced with tetratricopeptide repeats (Ifit) genes comprising three members in mice, Ifit1/ISG56, Ifit2/ISG54 and Ifit3/ISG49. Intranasal infection with a low dose of VSV is not lethal to wild-type mice and all three Ifit genes are induced in the central nervous system of the infected mice. We tested their potential contributions to the observed protection of wild-type mice from VSV pathogenesis, by taking advantage of the newly generated knockout mice lacking either Ifit2 or Ifit1. We observed that in Ifit2 knockout (Ifit2−/−) mice, intranasal VSV infection was uniformly lethal and death was preceded by neurological signs, such as ataxia and hind limb paralysis. In contrast, wild-type and Ifit1−/− mice were highly protected and survived without developing such disease. However, when VSV was injected intracranially, virus replication and survival were not significantly different between wild-type and Ifit2−/− mice. When administered intranasally, VSV entered the central nervous system through the olfactory bulbs, where it replicated equivalently in wild-type and Ifit2−/− mice and induced interferon-β. However, as the infection spread to other regions of the brain, VSV titers rose several hundred folds higher in Ifit2−/− mice as compared to wild-type mice. This was not caused by a broadened cell tropism in the brains of Ifit2−/− mice, where VSV still replicated selectively in neurons. Surprisingly, this advantage for VSV replication in the brains of Ifit2−/− mice was not observed in other organs, such as lung and liver. Pathogenesis by another neurotropic RNA virus, encephalomyocarditis virus, was not enhanced in the brains of Ifit2−/− mice. Our study provides a clear demonstration of tissue-, virus- and ISG-specific antiviral action of interferon

Horizontal Transfer of a Nitrate Assimilation Gene Cluster and Ecological Transitions in Fungi: A Phylogenetic Study

High affinity nitrate assimilation genes in fungi occur in a cluster (fHANT-AC) that can be coordinately regulated. The clustered genes include nrt2, which codes for a high affinity nitrate transporter; euknr, which codes for nitrate reductase; and NAD(P)H-nir, which codes for nitrite reductase. Homologs of genes in the fHANT-AC occur in other eukaryotes and prokaryotes, but they have only been found clustered in the oomycete Phytophthora (heterokonts). We performed independent and concatenated phylogenetic analyses of homologs of all three genes in the fHANT-AC. Phylogenetic analyses limited to fungal sequences suggest that the fHANT-AC has been transferred horizontally from a basidiomycete (mushrooms and smuts) to an ancestor of the ascomycetous mold Trichoderma reesei. Phylogenetic analyses of sequences from diverse eukaryotes and eubacteria, and cluster structure, are consistent with a hypothesis that the fHANT-AC was assembled in a lineage leading to the oomycetes and was subsequently transferred to the Dikarya (Ascomycota+Basidiomycota), which is a derived fungal clade that includes the vast majority of terrestrial fungi. We propose that the acquisition of high affinity nitrate assimilation contributed to the success of Dikarya on land by allowing exploitation of nitrate in aerobic soils, and the subsequent transfer of a complete assimilation cluster improved the fitness of T. reesei in a new niche. Horizontal transmission of this cluster of functionally integrated genes supports the “selfish operon” hypothesis for maintenance of gene clusters

Plant-symbiotic fungi as chemical engineers: multi-genome analysis of the Clavicipitaceae reveals dynamics of alkaloid Loci

The fungal family Clavicipitaceae includes plant symbionts and parasites that produce several psychoactive and bioprotective alkaloids. The family includes grass symbionts in the epichloae clade (Epichloë and Neotyphodium species), which are extraordinarily diverse both in their host interactions and in their alkaloid profiles. Epichloae produce alkaloids of four distinct classes, all of which deter insects, and some—including the infamous ergot alkaloids—have potent effects on mammals. The exceptional chemotypic diversity of the epichloae may relate to their broad range of host interactions, whereby some are pathogenic and contagious, others are mutualistic and vertically transmitted (seed-borne), and still others vary in pathogenic or mutualistic behavior. We profiled the alkaloids and sequenced the genomes of 10 epichloae, three ergot fungi (Claviceps species), a morning-glory symbiont (Periglandula ipomoeae), and a bamboo pathogen (Aciculosporium take), and compared the gene clusters for four classes of alkaloids. Results indicated a strong tendency for alkaloid loci to have conserved cores that specify the skeleton structures and peripheral genes that determine chemical variations that are known to affect their pharmacological specificities. Generally, gene locations in cluster peripheries positioned them near to transposon-derived, AT-rich repeat blocks, which were probably involved in gene losses, duplications, and neofunctionalizations. The alkaloid loci in the epichloae had unusual structures riddled with large, complex, and dynamic repeat blocks. This feature was not reflective of overall differences in repeat contents in the genomes, nor was it characteristic of most other specialized metabolism loci. The organization and dynamics of alkaloid loci and abundant repeat blocks in the epichloae suggested that these fungi are under selection for alkaloid diversification. We suggest that such selection is related to the variable life histories of the epichloae, their protective roles as symbionts, and their associations with the highly speciose and ecologically diverse cool-season grasses