8,017 research outputs found

    Winds as the origin of radio emission in z=2.5z=2.5 radio-quiet extremely red quasars

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    Most active galactic nuclei (AGNs) are radio-quiet, and the origin of their radio emission is not well-understood. One hypothesis is that this radio emission is a by-product of quasar-driven winds. In this paper, we present the radio properties of 108 extremely red quasars (ERQs) at z=2−4z=2-4. ERQs are among the most luminous quasars (Lbol∌1047−48L_{bol} \sim 10^{47-48} erg/s) in the Universe, with signatures of extreme (≫1000\gg 1000 km/s) outflows in their [OIII]λ\lambda5007 \AA\ emission, making them the best subjects to seek the connection between radio and outflow activity. All ERQs but one are unresolved in the radio on ∌10\sim 10 kpc scales, and the median radio luminosity of ERQs is ÎœLÎœ[6 GHz]=1041.0\nu L_\nu [{\rm 6\,GHz}] = 10^{41.0} erg/s, in the radio-quiet regime, but one to two orders of magnitude higher than that of other quasar samples. The radio spectra are steep, with a mean spectral index ⟚α⟩=−1.0\langle \alpha \rangle = -1.0. In addition, ERQs neatly follow the extrapolation of the low-redshift correlation between radio luminosity and the velocity dispersion of [OIII]-emitting ionized gas. Uncollimated winds, with a power of one per cent of the bolometric luminosity, can account for all these observations. Such winds would interact with and shock the gas around the quasar and in the host galaxy, resulting in acceleration of relativistic particles and the consequent synchrotron emission observed in the radio. Our observations support the picture in which ERQs are signposts of extremely powerful episodes of quasar feedback, and quasar-driven winds as a contributor of the radio emission in the intermediate regime of radio luminosity ÎœLÎœ=1039−1042\nu L_\nu = 10^{39}-10^{42} erg/s.Comment: accepted by MNRA

    Differential expression of aquaporin 3 in Triturus italicus from larval to adult epidermal conversion

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    By using immunohistochemical techniques applied to confocal microscopy, the presence of aquaporin 3 water channel in the epidermis of Triturus italicus (Amphibia, Urodela) has been shown. We analysed the expression of aquaporin 3 (AQP3) during the larval, pre-metamorphic and adult phases; we also showed the localization of the water-channel protein AQP3 in free-swimming conditions and during aestivation in parallel with histological analysis of the skin, focusing on the possible relationship between protein expression and terrestrial habitats. Our results indicate that aquaporin is produced as the epidermis modifies during the functional maturation phase starting at the climax. Moreover, our data suggest an increase in enzyme expression in aestivating newts emphasizing the putative functional importance of differential expression related to a distinct phase of the biological cycle

    ETHANOL PRODUCTION FROM A MEMBRANE PURIFIED HEMICELLULOSIC HYDROLYSATE DERIVED FROM SUGAR MAPLE BY PICHIA STIPITIS NRRL Y-7124

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    In an effort to devise inexpensive and sustainable production of ethanol fuel, experiments were conducted to establish conditions for Pichia stipitis NRRL Y-7124 to ferment a membrane treated wood hydrolysate derived from sugar maple to produce ethanol. The degree of aeration required to effectively utilize xylose, produce ethanol, and minimize xylitol formation as well as the optimal hydrolysate concentration were the conditions examined. P. stipitis produced the highest concentrations of ethanol in shake flasks at 150 rpm (14.3 g/L in 71 h), and 50% hydrolysate maximized ethanol yield (12.4 g/L in 51.5 h). In the 50% hydrolysate cultures, P. stipitis produced ethanol at a rate of 0.24 g/Lh with a yield of 0.41 g ethanol/g wood-derived carbohydrate

    Lubricin in synovial fluid of mild and severe temporomandibular joint internal derangements

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    To understand the molecular basis of temporomandibular joint (TMJ) pathologies, we aimed to investigate the lubricin levels in the TMJ synovial fluid (SF) of patients with mild to severe internal derangements (IDs). A total, 34 joints were the study group. Only patients, with a Wilkes stage of III, IV and V were included, in this sample. Control group consisted of SF from eight joints, from patients undergoing to orthognatic surgery. Concentrations of lubricin in the SF from both samples were measured using ELISA system. The mean lubricin concentration was 7.029 ± 0.21 ”g/mL in stage III patients; 5.64 ± 0.10 ”g/mL in stage IV patients, and 4.78 ± 0.11 ”g/mL in stage V patients. The lubricin levels from stage IV and stage V patients differed significantly (P ? 0.001) from those of control subjects. Lubricin levels were inversely correlated with age and to VAS score. The results of this cross-sectional study highlight the relationship between disease severity and the levels of lubricin in TMJ SF. Our findings suggest that novel biotherapeutic approaches, including the administration of recombinant lubricin in the joint cavity, for the treatment of TMJ diseases can be developed

    Detecting Lithium (Li) Mineralizations from Space: Current Research and Future Perspectives

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    Optical and thermal remote sensing data have been an important tool in geological exploration for certain deposit types. However, the present economic and technological advances demand the adaptation of the remote sensing data and image processing techniques to the exploration of other raw materials like lithium (Li). A bibliometric analysis, using a systematic review approach, was made to understand the recent interest in the application of remote sensing methods in Li exploration. A review of the application studies and developments in this field was also made. Throughout the paper, the addressed topics include: (i) achievements made in Li exploration using remote sensing methods; (ii) the main weaknesses of the approaches; (iii) how to overcome these difficulties; and (iv) the expected research perspectives. We expect that the number of studies concerning this topic will increase in the near future and that remote sensing will become an integrated and fundamental tool in Li exploration

    Host lifestyle affects human microbiota on daily timescales

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    Background: Disturbance to human microbiota may underlie several pathologies. Yet, we lack a comprehensive understanding of how lifestyle affects the dynamics of human-associated microbial communities. Results: Here, we link over 10,000 longitudinal measurements of human wellness and action to the daily gut and salivary microbiota dynamics of two individuals over the course of one year. These time series show overall microbial communities to be stable for months. However, rare events in each subjects’ life rapidly and broadly impacted microbiota dynamics. Travel from the developed to the developing world in one subject led to a nearly two-fold increase in the Bacteroidetes to Firmicutes ratio, which reversed upon return. Enteric infection in the other subject resulted in the permanent decline of most gut bacterial taxa, which were replaced by genetically similar species. Still, even during periods of overall community stability, the dynamics of select microbial taxa could be associated with specific host behaviors. Most prominently, changes in host fiber intake positively correlated with next-day abundance changes among 15% of gut microbiota members. Conclusions: Our findings suggest that although human-associated microbial communities are generally stable, they can be quickly and profoundly altered by common human actions and experiences.National Science Foundation (U.S.) (Grant 0821391
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