Absorption and resonance Raman spectra of Pb2, Pb3 and Pb4 in xenon matrices

Lead metal was vaporized and trapped in solid xenon at 12K. Electronic absorption and resonance Raman spectra were recorded of the resulting matrix, which was shown to contain Pb2, Pb3, and possibly Pb4 molecular species. The vibrational frequency for Pb2 is determined to be 108/cm for the ground state, with a dissociation energy of 82000/cm. Ad3h symmetry is indicated for the Pb3 species, with nu sub 1=117/cm and nu sub 2 = 96 /cm. The existence of Pb4 is suggested by a fundamental and overtone of 111/cm spacing

A spectroscopic study of intermediates in the condensation of refractory smokes: Matrix isolation experiments SiO

The infrared and Raman spectra of N2 matrix isolated silicon oxides are investigated. The vibrational frequencies of SiO, Si2O2, and Si3O3 were identified and assigned on the basis of normal coordinate analyses. Heating the solid to 50 K (evaporating the matrix) leaves a residue whose infrared spectrum is identical to that of a smoke condensed at ambient temperatures. Further heating of the sample to 500 K leads to significant changes in the band shapes. Investigations of the infrared spectra at several stages of the diffusion process result in the proposal of a mechanism for the transition from molecular properties to those of the residue (bulk) material, which is characterized as Si2O3

Impact of water quality attributes and comparative study of icthyofaunal diversity of Asan lake and River Asan

The present study reported a total of 28 taxa with six families from Asan lake whereas only 18 taxa were reported from river Asan in Doon valley. The families identified were Cyprinidae, Chandadae, Belonidae, Cobitididae, Mastacembellidae, and Sisoridae. The impact of water quality parameters was quite evident on the fish diversity and density of Asan Lake and River Asan. Correlation between hydrological attributes showed good relationship in Asan lake and these parameters were found to be the most important variables in shaping fish assemblage.However, in River Asan the effect of physico-chemical factors were significant on fish diversity. The study showed that Asan lake supported considerable diversity of the fishes and is important for conservation. Its fish fauna is threatened being either vulnerable or endangered. The low fish diversity in river Asan indicated the disturbed habitat and ecological conditions of the river and the data generated from it would be useful for conservation planning and management and also for future assessment of this river

A Magnetically-Switched, Rotating Black Hole Model For the Production of Extragalactic Radio Jets and the Fanaroff and Riley Class Division

A model is presented in which both Fanaroff and Riley class I and II extragalactic jets are produced by magnetized accretion disk coronae in the ergospheres of rotating black holes. While the jets are produced in the accretion disk itself, the output power still is an increasing function of the black hole angular momentum. For high enough spin, the black hole triggers the magnetic switch, producing highly-relativistic, kinetic-energy-dominated jets instead of Poynting-flux-dominated ones for lower spin. The coronal mass densities needed to trigger the switch at the observed FR break power are quite small ($\sim 10^{-15} g cm^{-3}$), implying that the source of the jet material may be either a pair plasma or very tenuous electron-proton corona, not the main accretion disk itself. The model explains the differences in morphology and Mach number between FR I and II sources and the observed trend for massive galaxies to undergo the FR I/II transition at higher radio power. It also is consistent with the energy content of extended radio lobes and explains why, because of black hole spindown, the space density of FR II sources should evolve more rapidly than that of FR I sources. If the present model is correct, then the ensemble average speed of parsec-scale jets in sources distinguished by their FR I morphology (not luminosity) should be distinctly slower than that for sources with FR II morphology. The model also suggests the existence of a population of high-redshift, sub-mJy FR I and II radio sources associated with spiral or pre-spiral galaxies that flared once when their black holes were formed but were never again re-kindled by mergers.Comment: 14 pages, 2 figures, final version to appear in Sept Ap

Magnetic moment and local moment alignment in anionic and/or oxidized Fen clusters

First principles studies on the ground statestructure, binding energy, spin multiplicity, and the noncollinearity of local spin moments in Fen and Fen− clusters and their oxides, viz., FenO2and FenO2− have been carried out within a density functional formalism. The ground states of Fen and Fen− clusters have collinear spins with a magnetic moment of around 3.0 μB per atom. The O2 molecule is found to be dissociatively absorbed and its most significant effect on spin occurs in Fe2, where Fe2O2 and Fe2O2− show antiferromagnetic and noncollinear spin arrangements, respectively. The calculated adiabatic electron affinity and the vertical transitions from the anion to the neutral species are found to be in good agreement with the available negative ion photodetachment spectra, providing support to the calculated ground states including the noncollinear ones

Monitoring of ambient air quality in relation to traffic density in Bareilly City (U.P.), India

An ambient air quality study was undertaken in Bareilly city, U.P., India during the year 2010 and 2011. The seasonal air quality data was obtained from ten monitoring sites across the city considering sampling site of Cantt as control site. The maximum (713.06±55.64 µg/m3) suspended particulate matter (SPM), sulphur dioxide (SO2) (80.08±4.77 µg/m3) and nitrogen oxides (NOx) (64.98±3.53 µg/m3) level was found at Choupla during the winter 2011. Among the annual mean values of air pollutants were analyzed, SPM level was found to be above the National Ambient Air Quality Standards (NAAQS) (200 µg/m3) at all the polluted sites. SO2 and NOx levels were below the threshold limits (80 µg/m3) as per NAAQS. The ambient air quality was correlated with the traffic density in the city. The pollution level was observed to be positively correlated with traffic density which is the major source of air pollution in the city. The ambient air quality at different monitoring sites was categorized into different pollution level on the basis of Oak ridge air quality index (ORAQI). Light to moderate air pollution conditions were present at different sites. Sampling site of Choupla (SVII) observe maximum ORAQI of 64.48 and 70.81 and falls under category of moderate pollution

Nerve growth factor/p75 neurotrophin receptor–mediated sensitization of rat sensory neurons depends on membrane cholesterol

Nerve growth factor (NGF) is an important mediator in the initiation of the inflammatory response and NGF via activation of the p75 neurotrophin receptor (p75(NTR)) and downstream sphingomyelin signaling leads to significant enhancement of the excitability of small-diameter sensory neurons. Because of the interaction between sphingomyelin and cholesterol in creating membrane liquid-ordered domains known as membrane or lipid rafts, we examined whether neuronal NGF-induced sensitization via p75(NTR) was dependent on the integrity of membrane rafts. Here, we demonstrate that the capacity of NGF to enhance the excitability of sensory neurons may result from the interaction of p75(NTR) with its downstream signaling partner(s) in membrane rafts. Two agents known to disrupt membrane rafts, edelfosine and methyl-β-cyclodextrin (MβCD), block the increase in excitability produced by NGF. In contrast, treatment with MβCD containing saturated amounts of cholesterol does not alter the capacity of NGF to augment excitability. In addition, adding back MβCD with cholesterol restored the NGF-induced sensitization in previously cholesterol-depleted neurons, suggesting that cholesterol and the structural integrity of rafts are key to promoting NGF-mediated sensitization. Using established protocols to isolate detergent-resistant membranes, both p75(NTR) and the neuronal membrane raft marker, flotillin, localize to raft fractions. These results suggest that downstream signaling partners interacting with p75(NTR) in sensory neurons are associated with membrane raft signaling platforms

Gastrointestinal symptom severity in irritable bowel syndrome, inflammatory bowel disease and the general population

BackgroundIrritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) patients report similar gastrointestinal (GI) symptoms, yet comparisons of symptom severity between groups and with the general population (GP) are lacking.MethodsWe compared Patient‐Reported Outcomes Measurement Information System (PROMIS®) GI symptom scales measuring gastro‐esophageal reflux (GER), disrupted swallowing, diarrhea, bowel incontinence, nausea/vomiting, constipation, belly pain, and gas/bloating in: (i) USA GP sample, (ii) IBS patients, and (iii) IBD patients from tertiary care and community populations. Symptom severity scores were based on T‐score metric with mean 50±10 (standard deviation) relative to the GP.Key ResultsOf 1643 patients enrolled, there were 253 IBS patients (68% F, mean age 45±15 years), 213 IBD patients (46% F, mean age 41±14 years), and 1177 GP subjects (57% F, mean age 46±16 years). IBS patients reported greater severity of GER, disrupted swallowing, nausea/vomiting, belly pain, gas/bloating, and constipation symptoms than their IBD counterparts (all P<.05). Compared to the GP, IBD patients had worse belly pain, gas/bloating, diarrhea, and bowel incontinence, but less severe GER and disrupted swallowing (all P<.05), and IBS patients had more severe nausea/vomiting, belly pain, gas/bloating, and constipation (all P<.05). Women had more severe belly pain and gas/bloating than men, whereas men had more severe bowel incontinence (all P<.05).Conclusion & InferencesIBS and IBD are associated with more severe GI symptoms compared to the GP excluding esophageal symptoms. Unlike IBD, IBS is not characterized by observable GI inflammation but patients report more severe upper and lower GI symptoms.The PROMIS GI scales were used to determine gastrointestinal symptoms severity in patients. Unlike IBD, IBS is not characterized by observable gastrointestinal inflammation, but patients report more severe upper and lower gastrointestinal symptoms.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136712/1/nmo13003.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136712/2/nmo13003_am.pd

The structure of black hole magnetospheres. I. Schwarzschild black holes

We introduce a multipolar scheme for describing the structure of stationary, axisymmetric, force-free black-hole magnetospheres in the ``3+1'' formalism. We focus here on Schwarzschild spacetime, giving a complete classification of the separable solutions of the stream equation. We show a transparent term-by-term analogy of our solutions with the familiar multipoles of flat-space electrodynamics. We discuss electrodynamic processes around disk-fed black holes in which our solutions find natural applications: (a) ``interior'' solutions in studies of the Blandford-Znajek process of extracting the hole's rotational energy, and of the formation of relativistic jets in active galactic nuclei and ``microquasars'', and, (b) ``exterior'' solutions in studies of accretion disk dynamos, disk-driven winds and jets. On the strength of existing numerical studies, we argue that the poloidal field structures found here are also expected to hold with good accuracy for rotating black holes, except for maximum possible rotation rates. We show that the closed-loop exterior solutions found here are not in contradiction with the Macdonald-Thorne theorem, since these solutions, which diverge logarithmically on the hole's horizon $\cal H$, apply only to those regions which exclude $\cal H$.Comment: 6 figures. Accepted for publication by MNRA