251 research outputs found
Extragalactic Results from the Infrared Space Observatory
More than a decade ago the IRAS satellite opened the realm of external
galaxies for studies in the 10 to 100 micron band and discovered emission from
tens of thousands of normal and active galaxies. With the 1995-1998 mission of
the Infrared Space Observatory the next major steps in extragalactic infrared
astronomy became possible: detailed imaging, spectroscopy and
spectro-photometry of many galaxies detected by IRAS, as well as deep surveys
in the mid- and far- IR. The spectroscopic data reveal a wealth of detail about
the nature of the energy source(s) and about the physical conditions in
galaxies. ISO's surveys for the first time explore the infrared emission of
distant, high-redshift galaxies. ISO's main theme in extragalactic astronomy is
the role of star formation in the activity and evolution of galaxies.Comment: 106 pages, including 17 figures. Ann.Rev.Astron.Astrophys. (in
press), a gzip'd pdf file (667kB) is also available at
http://www.mpe.mpg.de/www_ir/preprint/annrev2000.pdf.g
The rise and fall of methanotrophy following a deepwater oil-well blowout
The blowout of the Macondo oil well in the Gulf of Mexico in April 2010 injected up to 500,000 tonnes of natural gas, mainly methane, into the deep sea1. Most of the methane released was thought to have been consumed by marine microbes between July and August 20102, 3. Here, we report spatially extensive measurements of methane concentrations and oxidation rates in the nine months following the spill. We show that although gas-rich deepwater plumes were a short-lived feature, water column concentrations of methane remained above background levels throughout the rest of the year. Rates of microbial methane oxidation peaked in the deepwater plumes in May and early June, coincident with a rapid rise in the abundance of known and new methane-oxidizing microbes. At this time, rates of methane oxidation reached up to 5,900 nmol lâ1 dâ1âthe highest rates documented in the global pelagic ocean before the blowout4. Rates of methane oxidation fell to less than 50 nmol lâ1 dâ1 in late June, and continued to decline throughout the remainder of the year. We suggest the precipitous drop in methane consumption in late June, despite the persistence of methane in the water column, underscores the important role that physiological and environmental factors play in constraining the activity of methane-oxidizing bacteria in the Gulf of Mexico
Measurement of D-s(+) and D-s(*+) production in B meson decays and from continuum e(+)e(-) annihilation at âs=10.6 GeV
This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APSNew measurements of Ds+ and Ds*+ meson production rates from B decays and from qqÌ
continuum events near the ΄(4S) resonance are presented. Using 20.8 fb-1 of data on the ΄(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(BâDs+X)=(10.93±0.19±0.58±2.73)% and B(BâDs*+X)=(7.9±0.8±0.7±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+âÏÏ+ branching fraction uncertainty. The production cross sections Ï(e+e-âDs+X)ĂB(Ds+âÏÏ+)=7.55±0.20±0.34pb and Ï(e+e-âDs*±X)ĂB(Ds+âÏÏ+)=5.8±0.7±0.5pb are measured at center-of-mass energies about 40 MeV below the ΄(4S) mass. The branching fractions ÎŁB(BâDs(*)+D(*))=(5.07±0.14±0.30±1.27)% and ÎŁB(BâDs*+D(*))=(4.1±0.2±0.4±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4±0.1±0.3MeV/c2 is also measured.This work was supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the Swiss NSF, A. P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
Capsaicin- resistant arterial baroreceptors
BACKGROUND: Aortic baroreceptors (BRs) comprise a class of cranial afferents arising from major arteries closest to the heart whose axons form the aortic depressor nerve. BRs are mechanoreceptors that are largely devoted to cardiovascular autonomic reflexes. Such cranial afferents have either lightly myelinated (A-type) or non-myelinated (C-type) axons and share remarkable cellular similarities to spinal primary afferent neurons. Our goal was to test whether vanilloid receptor (TRPV1) agonists, capsaicin (CAP) and resiniferatoxin (RTX), altered the pressure-discharge properties of peripheral aortic BRs. RESULTS: Periaxonal application of 1 ÎŒM CAP decreased the amplitude of the C-wave in the compound action potential conducting at <1 m/sec along the aortic depressor nerve. 10 ÎŒM CAP eliminated the C-wave while leaving intact the A-wave conducting in the A-ÎŽ range (<12 m/sec). These whole nerve results suggest that TRPV1 receptors are expressed along the axons of C- but not A-conducting BR axons. In an aortic arch â aortic nerve preparation, intralumenal perfusion with 1 ÎŒM CAP had no effect on the pressure-discharge relations of regularly discharging, single fiber BRs (A-type) â including the pressure threshold, sensitivity, frequency at threshold, or maximum discharge frequency (n = 8, p > 0.50) but completely inhibited discharge of an irregularly discharging BR (C-type). CAP at high concentrations (10â100 ÎŒM) depressed BR sensitivity in regularly discharging BRs, an effect attributed to non-specific actions. RTX (†10 ÎŒM) did not affect the discharge properties of regularly discharging BRs (n = 7, p > 0.18). A CAP-sensitive BR had significantly lower discharge regularity expressed as the coefficient of variation than the CAP-resistant fibers (p < 0.002). CONCLUSION: We conclude that functional TRPV1 channels are present in C-type but not A-type (A-ÎŽ) myelinated aortic arch BRs. CAP has nonspecific inhibitory actions that are unlikely to be related to TRV1 binding since such effects were absent with the highly specific TRPV1 agonist RTX. Thus, CAP must be used with caution at very high concentrations
Arabidopsis leucine-rich repeat receptorâlike kinase NILR1 is required for induction of innate immunity to parasitic nematodes
Plant-parasitic nematodes are destructive pests causing losses of billions of dollars annually. An effective plant defence against pathogens relies on the recognition of pathogen-associated molecular patterns (PAMPs) by surface-localised receptors leading to the activation of PAMP-triggered immunity (PTI). Extensive studies have been conducted to characterise the role of PTI in various models of plant-pathogen interactions. However, far less is known about the role of PTI in roots in general and in plant-nematode interactions in particular. Here we show that nematode-derived proteinaceous elicitor/s is/are capable of inducing PTI in Arabidopsis in a manner dependent on the common immune co-receptor BAK1. Consistent with the role played by BAK1, we identified a leucine-rich repeat receptor-like kinase, termed NILR1 that is specifically regulated upon infection by nematodes. We show that NILR1 is essential for PTI responses initiated by nematodes and nilr1 loss-of-function mutants are hypersusceptible to a broad category of nematodes. To our knowledge, NILR1 is the first example of an immune receptor that is involved in induction of basal immunity (PTI) in plants or in animals in response to nematodes. Manipulation of NILR1 will provide new options for nematode control in crop plants in future
A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)
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The role of cinnamon as a modulator of the expression of genes related to antioxidant activity and lipid metabolism of laying quails
Since cinnamon has vitamins and minerals in addition to antioxidants compounds in its chemical composition studies have shown the potential of cinnamon supplementation on some important characteristics in the performance of birds. Thus, this study was conducted under the hypothesis that the inclusion of cinnamon in the laying quail diet could influence the performance of the birds through the expression of genes related to antioxidant activity and lipid metabolism. To test this hypothesis, 144 Japanese quail (Coturnix japonica) with an initial age of 18 weeks and average weight of 133g were distributed in a completely randomized design with two treatments: no cinnamon supplementation (NCSâcontrol group) and with supplementation of 9g/kg of cinnamon powder (CPS). The experiment lasted for 84 days. At the end of the experimental period, six animals from each treatment were euthanized by cervical dislocation, blood was collected and organs weighed. Liver tissue was collected for gene expression and biochemical analyses. We observed a significant effect of cinnamon inclusion on the weight of the pancreas (P = 0.0418), intestine (P = 0.0209) and ovary (P = 0.0389). Lower weights of the pancreas and intestine, and a higher ovary weight was observed in birds receiving the CPS diet. Quails fed with cinnamon supplementation also had better feed conversion per egg mass (2.426 g /g, P = 0.0126), and higher triglyceride (1516.60 mg/dL, P = 0.0207), uric acid (7.40 mg/dL, P = 0.0003) and VLDL (300.40 mg/dL, P = 0.0252) contents. A decreased content of thiobarbituric acid reactive substances (TBARS) and lower catalase activity was observed in the liver of quails from the CPS diet (0.086 nmoles/mg PTN, and 2.304 H2O2/min/mg PTN, respectively). Quails from the CPS group presented significantly greater expression of FAS (fatty acid synthase, 36,03 AU), ACC (Acetyl-CoA Carboxylase, 31.33 AU), APOAI (apolipoprotein A-I, 803,9 AU), ESR2 (estrogen receptor 2, 0.73 AU) SOD (superoxide dismutase, 4,933.9 AU) and GPx7 (glutathione peroxidase 7, 9.756 AU) than quails from the control group. These results allow us to suggest that cinnamon powder supplementation in the diet of laying quails can promote balance in the metabolism and better performance through the modulation of antioxidant activity and the expression of genes related to lipid metabolism
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