Multiple scattering and attenuation corrections in Deep Inelastic Neutron Scattering experiments

Multiple scattering and attenuation corrections in Deep Inelastic Neutron Scattering experiments are analyzed. The theoretical basis is stated, and a Monte Carlo procedure to perform the calculation is presented. The results are compared with experimental data. The importance of the accuracy in the description of the experimental parameters is tested, and the implications of the present results on the data analysis procedures is examined.Comment: 19 pages, 8 figure

Celadonite and smectite formation in the Úrkút Mn-carbonate ore deposit (Hungary)

Synsedimentary and early diagenetic oxygen levels are estimated by evaluating celadonitesmectite formation in marine Jurassic black shale-hosted manganese-carbonates. Celadonite formed under suboxic-dysaerobic conditions, Al-rich Fe-smectite formed at suboxic-anaerobic conditions, and nontronite formed at anoxic-anaerobic conditions during sedimentary burial. A genetic pathway by direct precipitation from solution is proposed for the enormous mass of celadonite, based on mineral and textural evidence. Lamination of the manganese ore is independent of clay-mineral composition and was given by a series of mineralized microbial Ferich biomats

MarcoPolo-R: Near-Earth Asteroid sample return mission selected for the assessment study phase of the ESA program cosmic vision

This paper presents the sample return mission to a primitive Near-Earth Asteroid (NEA) MarcoPolo-R proposed to the European Space Agency in December 2010. MarcoPolo-R was selected in February 2011 with three other missions addressing different science objectives for the two-year Assessment Phase of the Medium-Class mission competition of the Cosmic Vision 2 program for launch in 2022. The baseline target of MarcoPolo-R is the binary NEA (175706) 1996 FG3, which offers an efficient operational and technical mission profile. A binary target also provides enhanced science return. The choice of a binary target allows several scientific investigations to occur more easily than through a single object, in particular regarding the fascinating geology and geophysics of asteroids. MarcoPolo-R will rendezvous with a primitive, organic-rich NEA, scientifically characterize it at multiple scales, and return a bulk sample to Earth for laboratory analyses. The MarcoPolo-R sample will provide a representative sample from the surface of a known asteroid with known geologic context, and will contribute to the inventory of primitive material that is probably missing from the meteorite collection. The MarcoPolo-R samples will thus contribute to the exploration of the origin of planetary materials and initial stages of habitable planet formation, to the identification and characterization of the organics and volatiles in a primitive asteroid and to the understanding of the unique geomorphology, dynamics and evolution of a binary asteroid that belongs to the Potentially Hazardous Asteroid (PHA) population

Inflation Physics from the Cosmic Microwave Background and Large Scale Structure

Fluctuations in the intensity and polarization of the cosmic microwave background (CMB) and the large-scale distribution of matter in the universe each contain clues about the nature of the earliest moments of time. The next generation of CMB and large-scale structure (LSS) experiments are poised to test the leading paradigm for these earliest moments---the theory of cosmic inflation---and to detect the imprints of the inflationary epoch, thereby dramatically increasing our understanding of fundamental physics and the early universe. A future CMB experiment with sufficient angular resolution and frequency coverage that surveys at least 1 of the sky to a depth of 1 uK-arcmin can deliver a constraint on the tensor-to-scalar ratio that will either result in a 5-sigma measurement of the energy scale of inflation or rule out all large-field inflation models, even in the presence of foregrounds and the gravitational lensing B-mode signal. LSS experiments, particularly spectroscopic surveys such as the Dark Energy Spectroscopic Instrument, will complement the CMB effort by improving current constraints on running of the spectral index by up to a factor of four, improving constraints on curvature by a factor of ten, and providing non-Gaussianity constraints that are competitive with the current CMB bounds

Both \u3ci\u3eLymantria dispar\u3c/i\u3e Nucleopolyhedrovirus \u3ci\u3eEnhancin\u3c/i\u3e Genes Contribute to Viral Potency

Enhancins are a group of proteins first identified in granuloviruses (GV) that have the ability to enhance nuclear polyhedrosis virus potency. We had previously identified an enhancin gene (E1) in the Lymantria dispar multinucleocapsid nucleopolyhedrovirus (LdMNPV) (D. S. Bischoff and J. M. Slavicek, J. Virol. 71:8133–8140, 1997). Inactivation of the E1 gene product within the viral genome lowered viral potency by an average of 2.9-fold. A second enhancin gene (E2) was identified when the entire genome of LdMNPV was sequenced (Kuzio et al., Virology 253:17–34, 1999). The E2 protein exhibits approximately 30% amino acid identity to the LdMNPV E1 protein as well as the enhancins from Trichoplusia ni GV, Pseudaletia unipuncta GV, Helicoverpa armigera GV, and Xestia c-nigrum GV. Northern analysis of viral RNA indicated that the E2 gene transcripts are expressed at late times postinfection from a consensus baculovirus late promoter. The effect of the enhancin proteins on viral potency was investigated through bioassay using two recombinant viruses, one with a deletion in the E2 gene (E2del) and a second with deletion mutations in both enhancin genes (E1delE2del). The enhancin gene viral constructs were verified by Southern analysis and shown not to produce enhancin gene transcripts by Northern analysis. The E2del virus exhibited an average decrease in viral potency of 1.8-fold compared to wild-type virus. In the same bioassays, the recombinant virus E1cat, which does not produce an E1 gene transcript, exhibited an average decrease in viral potency of 2.3-fold compared to control virus. The E1delE2del virus exhibited an average decrease in viral potency of 12-fold compared to wild-type virus. Collectively, these results suggest that both LdMNPV enhancin genes contribute to viral potency, that each enhancin protein can partially compensate for the lack of the other protein, and that both enhancin genes are necessary for wild-type viral potency

Activity-based enrichment of matrix metalloproteinases using reversible inhibitors as affinity ligands

Matrix metalloproteinases (MMPs) are zinc dependent metalloproteases characterized by the ability to cleave extracellular matrix and many other extracellular proteins. MMP activity is tightly regulated but disturbances in this regulation can contribute to various disease processes characterized by a progressive destruction of the extracellular matrix. The ability to profile classes of enzymes based on functionally related activities would greatly facilitate research about the involvement of MMPs in physiological and/or pathological states. Here we describe the characterization of an affinity sorbent using an immobilized reversible inhibitor as a stationary phase for the activity-based enrichment of MMPs from biological samples. With a ligand density of 9.8 mM and binding constant of 58 mumol/l towards MMP-12, the capturing power of the affinity sorbent was strong enough to extract MMP-12 spiked into serum with high selectivity from relatively large sample volumes. Experiments with endogenous inhibitors revealed that MMP-12 extraction is strictly activity-dependent, offering powerful means to monitor NIMP activities in relation to physiological and/or pathological events by using affinity extraction as a first step in an MMP profiling method. (C) 2003 Elsevier B.V. All rights reserved