141 research outputs found
Bulk Level to Individual Particle Level Chemical Composition of Atmospheric Dust Aerosols (PM5) over a Semi-Arid Urban Zone of Western India (Rajasthan)
Mineral dust particles in the lower atmosphere may significantly influence radiative and optical budgets, along with the net chemical balance, through their interactions with ambient chemicals. Their ability to absotb/scatter incoming radiation strongly depends on their chemical composition (i.e., distribution of major crustal elements), but as yet there is no adequate regional database with regard to this for the Indian region. To create a regional database of background mineral dust from a semi-arid zone of western India, we measured the chemical composition of ambient particles (with aerodynamic diameter <= 5 mu m; PM5), collected from seven locations of Jaipur city (in the vicinity of Thar Desert; Rajasthan) at varying altitudes, during late-winter of 2012. The chemical compositions of the sampled particles at both bulk and individual levels were measured using X-ray fluorescence (XRF) and Scanning Electron Microscope equipped with Energy Dispersive X-ray (SEM-EDX) techniques, respectively. Significant differences in chemical compositions were observed among the seven sites, yet the bulk chemical compositions of the particles were broadly consistent with those of individual particles. Average elemental ratios of Mg/Al, Si/Al, K/Al, Ca/Al, Mn/Al, Fe/Al were found to be 0.44 +/- 0.22, 1.96 +/- 0.90, 0.65 +/- 0.22, 1.52 +/- 0.40, 0.84 and 1.54 +/- 1.67, respectively. We also estimated the complex refractive index (RIs at 550 nm wavelength) for the studied sites, yielding an average n and k (the real and imaginary parts of RI, respectively) of (1.56 +/- 0.03) + (6.5 +/- 4.6) x 10(-3)i, with the aerosols collected from Kukas Hill area (27.02 degrees N, 75.85 degrees E) having the highest iron (Fe) mass fraction (similar to 43%). Non-crustal elements e.g., Cu, S, C, Ag and Pb were found only in aerosols over the main city Birla Temple (Jaipur) at ground level (26.89 degrees N, 75.81 degrees E)
Multiplicity Distributions and Charged-neutral Fluctuations
Results from the multiplicity distributions of inclusive photons and charged
particles, scaling of particle multiplicities, event-by-event multiplicity
fluctuations, and charged-neutral fluctuations in 158 GeV Pb+Pb
collisions are presented and discussed. A scaling of charged particle
multiplicity as and photons as have been observed, indicating violation of naive wounded nucleon model.
The analysis of localized charged-neutral fluctuation indicates a
model-independent demonstration of non-statistical fluctuations in both charged
particles and photons in limited azimuthal regions. However, no correlated
charged-neutral fluctuations are observed.Comment: Talk given at the International Symposium on Nuclear Physics
(ISNP-2000), Mumbai, India, 18-22 Dec 2000, Proceedings to be published in
Pramana, Journal of Physic
Elliptic emission of K+ and pi(+) in 158 A center dot GeV Pb + Pb collisions
An event-by-event analysis of the azimuthal angular correlation with respect to the reaction plane has been carried out for K+ and pi(+) emission near mid-rapidity in 158 A . GeV Pb + Pb collisions. In semi-central collisions, K+ mesons are found to be preferentially emitted out of the reaction plane, while pi(+) mesons are emitted in the reaction plane. The results suggest that the kaon emission is influenced by in-medium potential effects in addition to collective flow effects. (C) 1999 Published by Elsevier Science B.V. All rights reserved
Delta(++) production in 158 A GeV Pb-208+Pb-208 interactions at the CERN SPS
The Delta(++)-resonance production in central 158 A GeV Pb-208 + Pb-208 collisions at the CERN SPS has been studied. The Delta(++) production was estimated from the invariant mass spectrum of p pi(+)-pairs by subtracting a mixed event background. The measured Delta(++) abundance is compared with the results from other experiments at lower energies, and with a model calculation assuming thermal and chemical equilibrium. (C) 2000 Elsevier Science B.V. All rights reserved
Loss of function mutations in GEMIN5 cause a neurodevelopmental disorder.
GEMIN5, an RNA-binding protein is essential for assembly of the survival motor neuron (SMN) protein complex and facilitates the formation of small nuclear ribonucleoproteins (snRNPs), the building blocks of spliceosomes. Here, we have identified 30 affected individuals from 22 unrelated families presenting with developmental delay, hypotonia, and cerebellar ataxia harboring biallelic variants in the GEMIN5 gene. Mutations in GEMIN5 perturb the subcellular distribution, stability, and expression of GEMIN5 protein and its interacting partners in patient iPSC-derived neurons, suggesting a potential loss-of-function mechanism. GEMIN5 mutations result in disruption of snRNP complex assembly formation in patient iPSC neurons. Furthermore, knock down of rigor mortis, the fly homolog of human GEMIN5, leads to developmental defects, motor dysfunction, and a reduced lifespan. Interestingly, we observed that GEMIN5 variants disrupt a distinct set of transcripts and pathways as compared to SMA patient neurons, suggesting different molecular pathomechanisms. These findings collectively provide evidence that pathogenic variants in GEMIN5 perturb physiological functions and result in a neurodevelopmental delay and ataxia syndrome
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