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1. HIMU geochemical signature originating from the transition zone

Author

Huang, S, Tschauner, O, Yang, S, Humayun, M, Liu, W, Gilbert Corder, SN, Bechtel, HA, and Tischler, J

Subjects
Geochemistry & Geophysics, Physical Sciences, Earth Sciences
Abstract

Plume volcanism may sample mantle sources deeper than mid-ocean ridge and arc volcanism. Ocean island basalts (OIBs) are commonly related to plume volcanism, and their diverse isotopic and elemental compositions can be described using a limited number of mantle endmembers. However, the origins and depths of these mantle endmembers are highly debated. Here we show that the HIMU (high μ, μ=238U/204Pb) endmember may reside in the transition zone. Specifically, we report the geochemical signature of a high-pressure multiphase diamond inclusion, entrapped at 420–440 km depth and 1450 ± 50 K, which matches exactly the geochemical patterns of the HIMU-rich OIBs. Since the HIMU component is variably sampled by almost all OIBs, our finding implies that the transition zone causes a major overprint of the geochemical features of mantle plumes. Some mantle plumes, like those feeding Bermuda, St Helena, Tubuai and Mangaia, appear to be dominated by this source. Furthermore, our finding highlights the importance of the transition zone in highly incompatible element budget of the mantle.

Published
2020

2. Environment-directed activation of the Escherichia coliflhDC operon by transposons.

Author

Zhang, Zhongge, Kukita, Chika, Humayun, M Zafri, and Saier, Milton H

Subjects
Flagella, Escherichia coli K12, Escherichia coli Proteins, Trans-Activators, DNA Transposable Elements, Gene Expression Regulation, Bacterial, Promoter Regions, Genetic, IS-mediated directed mutation, flagellar master regulator, FlhDC, transposon, gene activation, SIDD, Microbiology
Abstract

The flagellar system in Escherichia coli K12 is expressed under the control of the flhDC-encoded master regulator FlhDC. Transposition of insertion sequence (IS) elements to the upstream flhDC promoter region up-regulates transcription of this operon, resulting in a more rapid motility. Wang and Wood (ISME J 2011;5:1517-1525) provided evidence that insertion of IS5 into upstream activating sites occurs at higher rates in semi-solid agar media in which swarming behaviour is allowed as compared with liquid or solid media where swarming cannot occur. We confirm this conclusion and show that three IS elements, IS1, IS3 and IS5, transpose to multiple upstream sites within a 370 bp region of the flhDC operon control region. Hot spots for IS insertion correlate with positions of stress-induced DNA duplex destabilization (SIDD). We show that IS insertion occurs at maximal rates in 0.24 % agar, with rates decreasing dramatically with increasing or decreasing agar concentrations. In mixed cultures, we show that these mutations preferentially arise from the wild-type parent at frequencies of up to 3×10-3 cell-1 day-1 when the inoculated parental and co-existing IS-activated mutant cells are entering the stationary growth phase. We rigorously show that the apparent increased mutation frequencies cannot be accounted for by increased swimming or by increased growth under the selective conditions used. Thus, our data are consistent with the possibility that appropriate environmental conditions, namely those that permit but hinder flagellar rotation, result in the activation of a mutational pathway that involves IS element insertion upstream of the flhDC operon.

Published
2017

3. Hopping into a hot seat: Role of DNA structural features on IS5-mediated gene activation and inactivation under stress.

Author

Humayun, M Zafri, Zhang, Zhongge, Butcher, Anna M, Moshayedi, Aref, and Saier, Milton H

Subjects
Escherichia coli, DNA, DNA Transposable Elements, Base Sequence, Nucleic Acid Conformation, Mutation, Alleles, Operon, Promoter Regions, Genetic, Transcriptional Activation, General Science & Technology
Abstract

Insertion sequence elements (IS elements) are proposed to play major roles in shaping the genetic and phenotypic landscapes of prokaryotic cells. Recent evidence has raised the possibility that environmental stress conditions increase IS hopping into new sites, and often such hopping has the phenotypic effect of relieving the stress. Although stress-induced targeted mutations have been reported for a number of E. coli genes, the glpFK (glycerol utilization) and the cryptic bglGFB (β-glucoside utilization) systems are among the best characterized where the effects of IS insertion-mediated gene activation are well-characterized at the molecular level. In the glpFK system, starvation of cells incapable of utilizing glycerol leads to an IS5 insertion event that activates the glpFK operon, and enables glycerol utilization. In the case of the cryptic bglGFB operon, insertion of IS5 (and other IS elements) into a specific region in the bglG upstream sequence has the effect of activating the operon in both growing cells, and in starving cells. However, a major unanswered question in the glpFK system, the bgl system, as well as other examples, has been why the insertion events are promoted at specific locations, and how the specific stress condition (glycerol starvation for example) can be mechanistically linked to enhanced insertion at a specific locus. In this paper, we show that a specific DNA structural feature (superhelical stress-induced duplex destabilization, SIDD) is associated with "stress-induced" IS5 insertion in the glpFK, bglGFB, flhDC, fucAO and nfsB systems. We propose a speculative mechanistic model that links specific environmental conditions to the unmasking of an insertional hotspot in the glpFK system. We demonstrate that experimentally altering the predicted stability of a SIDD element in the nfsB gene significantly impacts IS5 insertion at its hotspot.

Published
2017

9. Association of Body Mass Index with the Severity of SARS-COVID-19 Pneumonia in Hospitalized Patients.

Author

Zafar, Zara, Alamgir, Wasim, Zill-e-Humayun, M., Rehman, Aayesha, Ul Ain, Qurat, and Ilyas, Sumaira

Subjects
BODY mass index, HOSPITAL patients, COVID-19, MILITARY hospitals, PNEUMONIA
Abstract

Objective: To determine the association of body mass index with the severity of COVID-19 pneumonia in hospitalized patients. Study Design: Cross-sectional study. Place and Duration of Study: Pak Emirates Military Hospital, Rawalpindi Pakistan, form May to Jun 2021. Methodology: Patients diagnosed with COVID-19 pneumonia on PCR and chest imaging and admitted to our hospital were included in the study. Body mass index was calculated on the first day of hospital admission, and they were followed up for two weeks during the disease. Increased oxygen demand, duration of admission, CT severity score and use of non-invasive ventilation were compared in patients with normal and increased body mass index. Results: A total of 800 COVID-19 patients admitted to the hospital were included in the final analysis. The mean age of the study participants was 41.36±4.55 years. Out of 800 patients, 337(42.1%) had normal BMI, 420(52.5%) were classed in the category of overweight and 43(5.4%) were obese. Furthermore, it was seen that increased demand for oxygen, high CT severity score and longer duration of hospital admission had a statistically significant relationship (p-value<0.05) with high body mass index. Conclusion: More than half of the patients admitted after diagnosis of COVID-19 had higher than normal body mass index. A significant association was found between increased demand for oxygen, high CT severity score, longer hospital admission duration, and high body mass index. [ABSTRACT FROM AUTHOR]

Published
2022
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14. Origin and age of the earliest Martian crust from meteorite NWA 7533

Author

Humayun, M., Nemchin, A., Zanda, B., Hewins, R.H., Grange, M., Kennedy, A., Lorand, J.-P., Gopel, C., Fieni, C., Pont, S., and Deldicque, D.

Subjects
Astrogeology -- Research, Meteorites -- Properties -- Origin, Mars (Planet) -- Natural history, Breccia -- Properties -- Origin, Earth -- Crust, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

The ancient cratered terrain of the southern highlands of Mars is thought to hold clues to the planet's early differentiation (1,2), but until now no meteoritic regolith breccias have been recovered from Mars. Here we show that the meteorite Northwest Africa (NWA) 7533 (paired with meteorite NWA 7034 (3)) is a polymict breccia consisting of a fine-grained interclast matrix containing clasts of igneous-textured rocks and fine-grained clast-laden impact melt rocks. High abundances of meteoritic siderophiles (for example nickel and iridium) found throughout the rock reach a level in the fine-grained portions equivalent to 5 per cent CI chondritic input, which is comparable to the highest levels found in lunar breccias. Furthermore, analyses of three leucocratic monzonite clasts show a correlation between nickel, iridium and magnesium consistent with differentiation from impact melts. Compositionally, all the fine-grained material is alkalic basalt, chemically identical (except for sulphur, chlorine and zinc) to soils from Gusev crater. Thus, we propose that NWA 7533 is a Martian regolith breccia. It contains zircons for which we measured an age of 4,428 ± 25 million years, which were later disturbed 1,712 ± 85 million years ago. This evidence for early crustal differentiation implies that the Martian crust, and its volatile inventory (4), formed in about the first 100 million years of Martian history, coeval with earliest crust formation on the Moon (5) and the Earth (6). In addition, incompatible element abundances in clast-laden impact melt rocks and interclast matrix provide a geochemical estimate of the average thickness of the Martian crust (50 kilometres) comparable to that estimated geophysically (2,7)., NWA 7533 is a polymict breccia, characterized by a variety of clasts set in a fine-grained (~1 mm) interclast crystalline matrix (ICM) (Fig. 1). The main clast component consists of [...]

Published
2013

15. A large meteoritic event over Antarctica ca. 430 ka ago inferred from chondritic spherules from the Sør Rondane Mountains

Author

van Ginneken, M., Goderis, S., Artemieva, N., Debaille, V., Decrée, S., Harvey, R. P., Huwig, K. A., Hecht, L., Yang, S., Kaufmann, F. E. D., Soens, B., Humayun, M., Van Maldeghem, F., Genge, M. J., Claeys, P., van Ginneken, M., Goderis, S., Artemieva, N., Debaille, V., Decrée, S., Harvey, R. P., Huwig, K. A., Hecht, L., Yang, S., Kaufmann, F. E. D., Soens, B., Humayun, M., Van Maldeghem, F., Genge, M. J., and Claeys, P.

Abstract

Large airbursts, the most frequent hazardous impact events, are estimated to occur orders of magnitude more frequently than crater-forming impacts. However, finding traces of these events is impeded by the difficulty of identifying them in the recent geological record. Here, we describe condensation spherules found on top of Walnumfjellet in the Sør Rondane Mountains, Antarctica. Affinities with similar spherules found in EPICA Dome C and Dome Fuji ice cores suggest that these particles were produced during a single-asteroid impact ca. 430 thousand years (ka) ago. The lack of a confirmed crater on the Antarctic ice sheet and geochemical and 18O-poor oxygen isotope signatures allow us to hypothesize that the impact particles result from a touchdown event, in which a projectile vapor jet interacts with the Antarctic ice sheet. Numerical models support a touchdown scenario. This study has implications for the identification and inventory of large cosmic events on Earth.

Published
2021

16. Wafer-level parylene packaging with integrated RF electronics for wireless retinal prostheses

Author

Li, W., Rodger, D. C., Meng, E., Weiland, J. D., Humayun, M. S., and Tai, Y.-C.

Subjects
Microelectromechanical systems -- Design and construction, Parylenes -- Electric properties, Parylenes -- Thermal properties, Embedded systems -- Design and construction, Embedded system, System on a chip, Engineering and manufacturing industries, Science and technology
Published
2010

18. A large meteoritic event over Antarctica ca. 430 ka ago inferred from chondritic spherules from the Sør Rondane Mountains

Author

Van Ginneken, M., primary, Goderis, S., additional, Artemieva, N., additional, Debaille, V., additional, Decrée, S., additional, Harvey, R. P., additional, Huwig, K. A., additional, Hecht, L., additional, Yang, S., additional, Kaufmann, F. E. D., additional, Soens, B., additional, Humayun, M., additional, Van Maldeghem, F., additional, Genge, M. J., additional, and Claeys, P., additional

Published
2021
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19. 40Ar/39Ar ages of Northwest Africa 7034 and Northwest Africa 7533

Author

Lindsay, F. N., primary, Delaney, J. S., additional, GÖpel, C., additional, Herzog, G. F., additional, Hewins, R., additional, Humayun, M., additional, Nagao, K., additional, Nyquist, L. E., additional, Park, J., additional, Setera, J. B., additional, Shih, C.‐Y., additional, Swisher, C. C., additional, Zanda, B., additional, and Turrin, B. D., additional

Published
2021
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20. ADVERSE EVENTS OF THE ARGUS II RETINAL PROSTHESIS: Incidence, Causes, and Best Practices for Managing and Preventing Conjunctival Erosion

Author

Rizzo, Stanislao, Barale, P. -O., Ayello-Scheer, S., Devenyi, R. G., Delyfer, M. -N., Korobelnik, J. -F., Rachitskaya, A., Yuan, A., Jayasundera, K. T., Zacks, D. N., Handa, J. T., Montezuma, S. R., Koozekanani, D., Stanga, P. E., da Cruz, L., Walter, P., Augustin, A. J., Chizzolini, M., Olmos de Koo, L. C., Ho, A. C., Kirchhof, B., Hahn, P., Vajzovic, L., Iezzi, R., Gaucher, D., Arevalo, J. F., Gregori, N. Z., Grisanti, S., Ozmert, E., Yoon, Y. H., Kokame, G. T., Lim, J. I., Szurman, P., de Juan, E., Rezende, F. A., Salzmann, J., Richard, G., Huang, S. S., Merlini, F., Patel, U., Cruz, C., Greenberg, R. J., Justus, S., Cinelli, L., Humayun, M. S., Rizzo S. (ORCID:0000-0001-6302-063X), Rizzo, Stanislao, Barale, P. -O., Ayello-Scheer, S., Devenyi, R. G., Delyfer, M. -N., Korobelnik, J. -F., Rachitskaya, A., Yuan, A., Jayasundera, K. T., Zacks, D. N., Handa, J. T., Montezuma, S. R., Koozekanani, D., Stanga, P. E., da Cruz, L., Walter, P., Augustin, A. J., Chizzolini, M., Olmos de Koo, L. C., Ho, A. C., Kirchhof, B., Hahn, P., Vajzovic, L., Iezzi, R., Gaucher, D., Arevalo, J. F., Gregori, N. Z., Grisanti, S., Ozmert, E., Yoon, Y. H., Kokame, G. T., Lim, J. I., Szurman, P., de Juan, E., Rezende, F. A., Salzmann, J., Richard, G., Huang, S. S., Merlini, F., Patel, U., Cruz, C., Greenberg, R. J., Justus, S., Cinelli, L., Humayun, M. S., and Rizzo S. (ORCID:0000-0001-6302-063X)

Abstract

PURPOSE: To analyze and provide an overview of the incidence, management, and prevention of conjunctival erosion in Argus II clinical trial subjects and postapproval patients. METHODS: This retrospective analysis followed the results of 274 patients treated with the Argus II Retinal Prosthesis System between June 2007 and November 2017, including 30 subjects from the US and European clinical trials, and 244 patients in the postapproval phase. Results were gathered for incidence of a serious adverse event, incidence of conjunctival erosion, occurrence sites, rates of erosion, and erosion timing. RESULTS: Overall, 60% of subjects in the clinical trial subjects versus 83% of patients in the postapproval phase did not experience device- or surgery-related serious adverse events. In the postapproval phase, conjunctival erosion had an incidence rate of 6.2% over 5 years and 11 months. In 55% of conjunctival erosion cases, erosion occurred in the inferotemporal quadrant, 25% in the superotemporal quadrant, and 20% in both. Sixty percent of the erosion events occurred in the first 15 months after implantation, and 85% within the first 2.5 years. CONCLUSION: Reducing occurrence of conjunctival erosion in patients with the Argus II Retinal Prosthesis requires identification and minimization of risk factors before and during implantation. Implementing inverted sutures at the implant tabs, use of graft material at these locations as well as Mersilene rather than nylon sutures, and accurate Tenon's and conjunctiva closure are recommended for consideration in all patients.

Published
2020

21. Hypotony and the Argus II retinal prosthesis: Causes, prevention and management

Author

Rizzo, Stanislao, Barale, P. -O., Ayello-Scheer, S., Devenyi, R. G., Delyfer, M. N., Korobelnik, J. -F., Rachitskaya, A., Yuan, A., Jayasundera, K. T., Zacks, D. N., Handa, J. T., Montezuma, S. R., Koozekanani, D., Stanga, P., Da Cruz, L., Walter, P., Augustin, A. J., Olmos De Koo, L. C., Ho, A. C., Kirchhof, B., Hahn, P., Vajzovic, L., Iezzi, R., Gaucher, D., Arevalo, J. F., Gregori, N. Z., Wiedemann, P., Ozmert, E., Lim, J. I., Rezende, F. A., Huang, S. S., Merlini, F., Patel, U., Greenberg, R. J., Justus, S., Bacherini, D., Cinelli, L., Humayun, M. S., Rizzo S. (ORCID:0000-0001-6302-063X), Rizzo, Stanislao, Barale, P. -O., Ayello-Scheer, S., Devenyi, R. G., Delyfer, M. N., Korobelnik, J. -F., Rachitskaya, A., Yuan, A., Jayasundera, K. T., Zacks, D. N., Handa, J. T., Montezuma, S. R., Koozekanani, D., Stanga, P., Da Cruz, L., Walter, P., Augustin, A. J., Olmos De Koo, L. C., Ho, A. C., Kirchhof, B., Hahn, P., Vajzovic, L., Iezzi, R., Gaucher, D., Arevalo, J. F., Gregori, N. Z., Wiedemann, P., Ozmert, E., Lim, J. I., Rezende, F. A., Huang, S. S., Merlini, F., Patel, U., Greenberg, R. J., Justus, S., Bacherini, D., Cinelli, L., Humayun, M. S., and Rizzo S. (ORCID:0000-0001-6302-063X)

Abstract

NA

Published
2020

22. The origin of iron silicides in ureilite meteorites

Author

Ross, A.J., Downes, Hilary, Herrin, J.S., Mittlefehldt, D.W., Humayun, M., and Smith, C.

Subjects
es
Abstract

Ureilite meteorites contain iron silicide minerals including suessite (Fe,Ni)3Si, hapkeite (Fe2Si) and xifengite (Fe5Si3). Despite occurring mostly in brecciated varieties presumed to be derived from the regolith of the ureilite parent asteroid, suessite has also been confirmed in one lithology of a dimict ureilite (NWA 1241). In contrast, Si-bearing Fe-metals occur in both brecciated and unbrecciated ureilites, implying that they were formed throughout the ureilite parent asteroid. We examined major, minor and trace element data of Fe-metals in seven brecciated ureilites (DaG 319, DaG 999, DaG 1000, DaG 1023, DaG 1047, EET 83309, and EET 87720) in addition to the dimict ureilite NWA 1241.\ud \ud In this study we show that the silicides and Si-bearing metals in ureilites have similar siderophile trace element patterns; therefore, the precursors to the silicides were indigenous to the ureilite parent body. Si-free kamacite grains in brecciated ureilites show flatter, more chondritic siderophile element patterns. They may also be derived from the interior of the ureilite parent body, but some may be of exogenous origin (impactor debris), as are rare taenite grains.\ud \ud On Earth, iron silicides are often formed under high-temperature and strongly reducing conditions (e.g. blast furnaces, lightning strikes). On the Moon, hapkeite (Fe2Si) and other silicides have been found in the regolith where they were formed by impact-induced space weathering. In the Stardust aerogel, iron silicides derived from comet Wild2 were also formed by an impact-related reduction process. Silicides in ureilite regolith breccias may have formed by similar processes but ureilites additionally contain abundant elemental carbon which probably acted as a reducing agent, thus larger and more abundant silicide grains were formed than in the lunar regolith or cometary material. The origin of suessite in NWA 1241 may be analogous to that of reduced lithologies in the terrestrial mantle, although a regolith origin may also be possible since this sample is shown here to be a dimict breccia.

Published
2019

24. Escherichia coli cells bearing a ribosomal ambiguity mutation in rpsD have a mutator phenotype that correlates with increased mistranslation

Author

Balashov, Sergey and Humayun, M. Zafri

Subjects
Gene expression -- Physiological aspects, Ribosomes -- Genetic aspects, Genetic transcription -- Physiological aspects, Cells -- Genetic aspects, Bacterial proteins -- Physiological aspects, Gene mutations -- Physiological aspects, Escherichia coli -- Genetic aspects, Bacteriology -- Research, Biological sciences
Abstract

Escherichia coli cells bearing certain mutations in rpsD (coding for the 30S ribosomal protein S4) show a ribosomal ambiguity (Ram) phenotype characterized by increased translational error rates. Here we show that spontaneous mutagenesis increases in Ram cells bearing the rpsD14 allele, suggesting that the recently described translational stress-induced mutagenesis pathway is activated in Ram cells.

Published
2003

27. Requirement for homologous recombination functions for expression of the mutA mistranslator tRNA-induced mutator phenotype in Escherichia coli

Author

Ren, Li, Al Mamun, Amar M., and Humayun, M. Zafri

Subjects
Genetic recombination -- Analysis, Cellular signal transduction -- Genetic aspects, DNA polymerases -- Genetic aspects, Escherichia coli -- Research, Biological sciences
Abstract

Results indicate that mutA phenotype of Escherichia coli depends on homologous recombination and RecA protein and RecBCD nuclease are components of this system. Data reveal that the recBCD is a component of the signal pathway in mutA cells.

Published
2000

28. SOS and UVM pathways have lesion-specific additive and competing effects on mutation fixation at replication-blocking DNA lesions

Author

Rahman, M. Sayeedur and Humayun, M. Zafri

Subjects
DNA damage -- Research, Gene mutations -- Research, Chromosome replication -- Research, Biological sciences
Abstract

Research was conducted to examine the relative contributions of two genetically distinct DNA damage-inducible pathways to mutagenesis at two non-instructive DNA lesions. The method of uncoupling SOS induction from DNA damage by expressing SOS mutagenesis genes under the control of a heterologous promoter was chosen. Results demonstrate that DNA damage activates multiple pathways that have lesion-specific additive and suppressive effects on mutation fixation.

Published
1999

30. The Rochechouart 2017-Cores Rescaled: Major Features

Author

Lambert, P., Alwmark, C., Baratoux, D., Bouley, S., Brack, A., Bruneton, P., Buchner, E., Dence, M. R., Courtin Nomade, A., Duhamel Achin, I., Floch, J. P., French, B. M., Fudge, C., Gattacceca, J., Gibson, R. L., Goderis, S., Grieve, R. A. F., Hauser, N., Hodges, K. V., Hörz, F., Humayun, M., Jourdan, F., Kelley, S. P., Kenkmann, T., Kring, D. A., Langenhorst, F., Lebreton, J. P., Lee, M. R., Lindgren, P., Lofi, J., Lorand, J. P., Luais, B., Masaitis, V., Meunier, A., Moore, C. B., Ormö, J., Osinski, G. R., Petit, S., Pezard, P. R., Pölchau, M., Pohl, J., Quesnel, Y., Jamboz, C., Reeves, H., Reimold, U. W., Rochette, P., Sapers, H. M., Schmieder, M., Schultz, P. H., Susanne Petra Schwenzer, Sharp, T., Schoemaker, C. S., Simpson, S. L., Stöffler, D., Sturkell, E., Trumel, H., Walton, E., Westall, F., Wittmann, A., Wünnemann, K., Ecosystèmes aquatiques et changements globaux (UR EABX), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Centre International de Recherches et de Restitution sur les Impacts et sur Rochechouart (CIRIR), Department of Geology [Lund], Lund University [Lund], Géosciences Environnement Toulouse (GET), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Centre de biophysique moléculaire (CBM), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Département Géosciences (AREVA-BU Mines), Groupe AREVA, Analytical, Environmental and Geo- Chemistry, Vrije Universiteit Brussel (VUB), Geological Survey of Canada [Ottawa] (GSC Central & Northern Canada), Geological Survey of Canada - Office (GSC), Natural Resources Canada (NRCan)-Natural Resources Canada (NRCan), Université de Limoges (UNILIM), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Smithsonian Institution, Arizona State University [Tempe] (ASU), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of the Witwatersrand [Johannesburg] (WITS), University of Western Ontario (UWO), University of Brasilia [Brazil] (UnB), NASA Johnson Space Center (JSC), NASA, Florida State University [Tallahassee] (FSU), School of Earth and Planetary Sciences [Perth], Curtin University [Perth], Planning and Transport Research Centre (PATREC)-Planning and Transport Research Centre (PATREC), The Open University [Milton Keynes] (OU), Department of Geosciences - Earth Sciences [Fribourg], University of Fribourg, Lunar and Planetary Institute [Houston] (LPI), Friedrich-Schiller-Universität = Friedrich Schiller University Jena [Jena, Germany], Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), School of Geographical and Earth Sciences [Univ Glasgow], University of Glasgow, Géosciences Montpellier, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), A. P. Karpinsky Russian Geological Research Institute (VSEGEI), Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Center for Meteorite Studies [Tempe], Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Ludwig-Maximilians-Universität München (LMU), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut des Sciences de la Terre d'Orléans - UMR7327 (ISTO), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Métallogénie - UMR7327, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Laboratoire Pierre Süe (LPS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Brown University, Arizona Geological Survey, CSIRO Land and Water, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Museum für Naturkunde [Berlin], Department of Earth Sciences [Gothenburg], University of Gothenburg (GU), CEA Le Ripault (CEA Le Ripault), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), University of Alberta, LUAIS, Béatrice, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Vrije Universiteit [Brussels] (VUB), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), School of Geosciences, University of the Witwatersrand, Johannesburg, South Africa, Friedrich Schiller University Jena [Jena, Germany], Laboratoire de physique et chimie de l'environnement et de l'Espace (LPC2E), UMR 7328 CNRS/Université d'Orléans, Université d'Orléans (UO), School of Geographical and Earth Sciences [Glasgow], Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique UMR6112 (LPG), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Université de Poitiers-Centre National de la Recherche Scientifique (CNRS), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Spain] (CSIC), PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), CEA-CNRS UMR 9956, CEA Saclay, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CIRIR, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Université de Fribourg = University of Fribourg (UNIFR)

Subjects
[SDU] Sciences of the Universe [physics], [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, [SDU]Sciences of the Universe [physics], [SDU.STU] Sciences of the Universe [physics]/Earth Sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, [SDU.STU.PL] Sciences of the Universe [physics]/Earth Sciences/Planetology, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2019

32. Escherichia coli cells expressing a mutant glyV (glycine tRNA) gene have a UVM-constitutive phenotype: implications for mechanisms underlying the mutA or mutC mutator effect

Author

Murphy, Holly S. and Humayun, M. Zafri

Subjects
Escherichia coli -- Genetic aspects, Gene expression -- Research, Phenotype -- Research, Mutagenesis -- Research, Glycine -- Research, Biological sciences
Abstract

Research was conducted to test whether the UVM-constitutive phenotype in mutA and mutC cells was associated with the expression of a mutant glycine tRNA gene in Escherichia coli. Background mutation frequency was determined from the number of rifampin-resistant mutants while plasmid pHM11 was established by cloning a 122-bp-long chemically synthesized tRNA gene. Results suggested that the UVM-constitutive phenotype displayed by mutaA or mutC cells is influenced by the same mechanism responsible for the mutator phenotype.

Published
1997

34. Role of mismatch repair in the Escherichia coli UVM response

Author

Murphy, Holly S., Palejwala, Vaseem A., Rahman, M. Sayeedur, Dunman, Paul M., Wang, Ge, and Humayun, M. Zafri

Subjects
Mutagenesis -- Research, Escherichia coli -- Genetic aspects, DNA repair -- Analysis, Ultraviolet radiation -- Genetic aspects, Biological sciences
Abstract

The ultraviolet modulation of mutagenesis (UVM) in Escherichia coli was analyzed to determine the presence of deoxyribonucleic acid (DNA) mismatch repair during UVM response. UVM induction in Escherichia coli GW3773F, D6432F and GM4271F strains after N-methyl-N'-nitro-N-nitrosoguanidine treatment indicated the presence of inefficient methyl-directed mismatch repair in the D6432F strain. However, UVM reactivation was detected from all the Escherichia coli strains. The reactivation of UVM indicates that UVM response in Escherichia coli is not dependent on DNA mismatch repair systems.

Published
1996

35. The potential science and engineering value of samples delivered to Earth by Mars sample return: International MSR Objectives and Samples Team (iMOST)

Author

Beaty, D. W., Grady, M. M., McSween, H. Y., Sefton-Nash, E., Carrier, B. L., Altieri, F., Amelin, Y., Ammannito, E., Anand, M., Benning, L. G., Bishop, J. L., Borg, L. E., Boucher, D., Brucato, J. R., Busemann, H., Campbell, K. A., Czaja, A. D., Debaille, V., Des Marais, D. J., Dixon, M., Ehlmann, B. L., Farmer, J. D., Fernandez-Remolar, D. C., Filiberto, J., Fogarty, J., Glavin, D. P., Goreva, Y. S., Hallis, L. J., Harrington, A. D., Hausrath, E. M., Herd, C. D.K., Horgan, B., Humayun, M., Kleine, T., Kleinhenz, J., Mackelprang, R., Mangold, N., Mayhew, L. E., McCoy, J. T., McCubbin, F. M., McLennan, S. M., Moser, D. E., Moynier, F., Mustard, J. F., Niles, P. B., Ori, G. G., Raulin, F., Rettberg, P., Schmitz, N., ten Kate, I. L., Beaty, D. W., Grady, M. M., McSween, H. Y., Sefton-Nash, E., Carrier, B. L., Altieri, F., Amelin, Y., Ammannito, E., Anand, M., Benning, L. G., Bishop, J. L., Borg, L. E., Boucher, D., Brucato, J. R., Busemann, H., Campbell, K. A., Czaja, A. D., Debaille, V., Des Marais, D. J., Dixon, M., Ehlmann, B. L., Farmer, J. D., Fernandez-Remolar, D. C., Filiberto, J., Fogarty, J., Glavin, D. P., Goreva, Y. S., Hallis, L. J., Harrington, A. D., Hausrath, E. M., Herd, C. D.K., Horgan, B., Humayun, M., Kleine, T., Kleinhenz, J., Mackelprang, R., Mangold, N., Mayhew, L. E., McCoy, J. T., McCubbin, F. M., McLennan, S. M., Moser, D. E., Moynier, F., Mustard, J. F., Niles, P. B., Ori, G. G., Raulin, F., Rettberg, P., Schmitz, N., and ten Kate, I. L.

Abstract

Return of samples from the surface of Mars has been a goal of the international Mars science community for many years. Affirmation by NASA and ESA of the importance of Mars exploration led the agencies to establish the international MSR Objectives and Samples Team (iMOST). The purpose of the team is to re-evaluate and update the sample-related science and engineering objectives of a Mars Sample Return (MSR) campaign. The iMOST team has also undertaken to define the measurements and the types of samples that can best address the objectives. Seven objectives have been defined for MSR, traceable through two decades of previously published international priorities. The first two objectives are further divided into sub-objectives. Within the main part of the report, the importance to science and/or engineering of each objective is described, critical measurements that would address the objectives are specified, and the kinds of samples that would be most likely to carry key information are identified. These seven objectives provide a framework for demonstrating how the first set of returned Martian samples would impact future Martian science and exploration. They also have implications for how analogous investigations might be conducted for samples returned by future missions from other solar system bodies, especially those that may harbor biologically relevant or sensitive material, such as Ocean Worlds (Europa, Enceladus, Titan) and others. Summary of Objectives and Sub-Objectives for MSR Identified by iMOST: Objective 1 Interpret the primary geologic processes and history that formed the Martian geologic record, with an emphasis on the role of water. Intent To investigate the geologic environment(s) represented at the Mars 2020 landing site, provide definitive geologic context for collected samples, and detail any characteristics that might relate to past biologic processesThis objective is divided into five sub-objectives that would apply at different landing site

Published
2019

36. 182W evidence for core-mantle interaction in the source of mantle plumes

Author

Rizo, H. (Hanika), Andrault, D. (D.), Bennett, N.R. (N. R.), Humayun, M. (M.), Brandon, A. (A.), Vlastelic, I. (I.), Moine, B. (B.), Poirier, A. (A.), Bouhifd, M.A. (M. A.), Murphy, D.T. (D. T.), Rizo, H. (Hanika), Andrault, D. (D.), Bennett, N.R. (N. R.), Humayun, M. (M.), Brandon, A. (A.), Vlastelic, I. (I.), Moine, B. (B.), Poirier, A. (A.), Bouhifd, M.A. (M. A.), and Murphy, D.T. (D. T.)

Abstract

Tungsten isotopes are the ideal tracers of core-mantle chemical interaction. Given that W is moderately siderophile, it preferentially partitioned into the Earth's core during its segregation, leaving the mantle depleted in this element. In contrast, Hf is lithophile, and its short-lived radioactive isotope 182Hf decayed entirely to 182W in the mantle after metal-silicate segregation. Therefore, the 182W isotopic composition of the Earth's mantle and its core are expected to differ by about 200 ppm. Here, we report new high precision W isotope data for mantle-derived rock samples from the Paleoarchean Pilbara Craton, and the Réunion Island and the Kerguelen Archipelago hotspots. Together with other available data, they reveal a temporal shift in the 182W isotopic composition of the mantle that is best explained by core-mantle chemical interaction. Core-mantle exchange might be facilitated by diffusive isotope exchange at the core-mantle boundary, or the exsolution of W-rich, Si-Mg-Fe oxides from the core into the mantle. Tung-sten-182 isotope compositions of mantle-derived magmas are similar from 4.3 to 2.7 Ga and decrease afterwards. This change could be related to the onset of the crystallisation of the inner core or to the initiation of post-Archean deep slab subduction that more efficiently mixed the mantle.

Published
2019
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37. The potential science and engineering value of samples delivered to Earth by Mars sample return: International MSR Objectives and Samples Team (iMOST)

Author

Petrology, Beaty, D. W., Grady, M. M., McSween, H. Y., Sefton-Nash, E., Carrier, B. L., Altieri, F., Amelin, Y., Ammannito, E., Anand, M., Benning, L. G., Bishop, J. L., Borg, L. E., Boucher, D., Brucato, J. R., Busemann, H., Campbell, K. A., Czaja, A. D., Debaille, V., Des Marais, D. J., Dixon, M., Ehlmann, B. L., Farmer, J. D., Fernandez-Remolar, D. C., Filiberto, J., Fogarty, J., Glavin, D. P., Goreva, Y. S., Hallis, L. J., Harrington, A. D., Hausrath, E. M., Herd, C. D.K., Horgan, B., Humayun, M., Kleine, T., Kleinhenz, J., Mackelprang, R., Mangold, N., Mayhew, L. E., McCoy, J. T., McCubbin, F. M., McLennan, S. M., Moser, D. E., Moynier, F., Mustard, J. F., Niles, P. B., Ori, G. G., Raulin, F., Rettberg, P., Schmitz, N., ten Kate, I. L., Petrology, Beaty, D. W., Grady, M. M., McSween, H. Y., Sefton-Nash, E., Carrier, B. L., Altieri, F., Amelin, Y., Ammannito, E., Anand, M., Benning, L. G., Bishop, J. L., Borg, L. E., Boucher, D., Brucato, J. R., Busemann, H., Campbell, K. A., Czaja, A. D., Debaille, V., Des Marais, D. J., Dixon, M., Ehlmann, B. L., Farmer, J. D., Fernandez-Remolar, D. C., Filiberto, J., Fogarty, J., Glavin, D. P., Goreva, Y. S., Hallis, L. J., Harrington, A. D., Hausrath, E. M., Herd, C. D.K., Horgan, B., Humayun, M., Kleine, T., Kleinhenz, J., Mackelprang, R., Mangold, N., Mayhew, L. E., McCoy, J. T., McCubbin, F. M., McLennan, S. M., Moser, D. E., Moynier, F., Mustard, J. F., Niles, P. B., Ori, G. G., Raulin, F., Rettberg, P., Schmitz, N., and ten Kate, I. L.

Published
2019

38. The potential science and engineering value of samples delivered to Earth by Mars sample return

Author

Beaty, David D.W., Grady, Monica, McSween, H. Y., Sefton-Nash, E., Carrier, B., Altieri, F., Ammannito, E., Amelin, Yuri, Anand, Mahesh, Benning, Liane G, Bishop, J. L., Borg, L. E., Boucher, D., Brucato, John Robert, Buseman, H., Campbell, K., Czaja, A. D., Debaille, Vinciane, Des Marais, D. J., Dixon, M., Ehlmann, B. L., Farmer, J. D., Fernandez-Remolar, D. C., Filiberto, J., Fogarty, J., Glavin, D. P., Goreva, Y. S., Hallis, L. J., Harrington, Andrea A. D., Hausrath, E. M., Herd, C. D. K., Horgan, B., Humayun, M., Kleine, Thorsten, Kleinhenz, J., Mangold, Nicolas, Mayhew, L. E., McCoy, Tim, McCubbin, Francis M., McLennan, Scott M., Moser, Desmond, Moynier, Frédéric, Mustard, John Fraser, Niles, P. B., Ori, G. G., Raulin, F., Rettberg, Petra, Rucker, M. A., Schmitz, Nicole, Schwenzer, Susanne P., Septhon, M. A., Shaheen, R., Sharp, Z. D., Shuster, D. L., Siljeström, S., Smith, Caroline L., Spry, J. A., Steele, Andrew, Swindle, T. D., Ten Kate, Inge Loes, Tosca, N. J., Usui, Tomohiro, Van Kranendonk, M. J., Wadhwa, Meenakshi, Weiss, Benjamin P., Werner, Stephanie C., Westall, Frances, Wheeler, R. M., Zipfel, Jutta, Zorzano, M. P., Beaty, David D.W., Grady, Monica, McSween, H. Y., Sefton-Nash, E., Carrier, B., Altieri, F., Ammannito, E., Amelin, Yuri, Anand, Mahesh, Benning, Liane G, Bishop, J. L., Borg, L. E., Boucher, D., Brucato, John Robert, Buseman, H., Campbell, K., Czaja, A. D., Debaille, Vinciane, Des Marais, D. J., Dixon, M., Ehlmann, B. L., Farmer, J. D., Fernandez-Remolar, D. C., Filiberto, J., Fogarty, J., Glavin, D. P., Goreva, Y. S., Hallis, L. J., Harrington, Andrea A. D., Hausrath, E. M., Herd, C. D. K., Horgan, B., Humayun, M., Kleine, Thorsten, Kleinhenz, J., Mangold, Nicolas, Mayhew, L. E., McCoy, Tim, McCubbin, Francis M., McLennan, Scott M., Moser, Desmond, Moynier, Frédéric, Mustard, John Fraser, Niles, P. B., Ori, G. G., Raulin, F., Rettberg, Petra, Rucker, M. A., Schmitz, Nicole, Schwenzer, Susanne P., Septhon, M. A., Shaheen, R., Sharp, Z. D., Shuster, D. L., Siljeström, S., Smith, Caroline L., Spry, J. A., Steele, Andrew, Swindle, T. D., Ten Kate, Inge Loes, Tosca, N. J., Usui, Tomohiro, Van Kranendonk, M. J., Wadhwa, Meenakshi, Weiss, Benjamin P., Werner, Stephanie C., Westall, Frances, Wheeler, R. M., Zipfel, Jutta, and Zorzano, M. P.

Abstract

Executive summary provided in lieu of abstract., SCOPUS: no.j, info:eu-repo/semantics/published

Published
2019

39. Effect of optical fiber core diameter on Brillouin scattering loss.

Author

Humayun, M. A., Hasan, M. N., Rashid, M. A., Kuwana, A., and Kobayashi, H.

Subjects
*BRILLOUIN scattering, *OPTICAL fibers, *OPTICAL fiber communication, *OPTICAL fiber detectors, *OPTICAL communications, *PLASTIC fibers, *CABLES, *PLASTIC optical fibers
Abstract

This paper reports the effect of core diameter of optical fiber cables on stimulated Brillouin scattering loss, which is one of the major loss characteristics of an optical fiber communication system. Analysis of this loss characteristic at three windows of the operating wavelength of a laser has been carried out through a numerical approach. Among different types of optical fiber cables, multi-mode step index silica fiber, multimode graded index silica fiber and plastic fibers have been considered for the numerical analysis. The numerical analysis has been performed using MATLAB in this research work. Through the comparative analysis, it has been ascertained that the Brillouin scattering loss is not only affected by the operating wavelength, but also by the core diameter of the different type of the cable. From the investigation of the comparative analysis, it is revealed that Brillouin scattering loss declines with the application of multimode graded index silica fiber. However, in the plastic fiber category, plastic step index fiber offers better performance. [ABSTRACT FROM AUTHOR]

Published
2021
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40. Functional recA, lexA, umuD, umuC, polA, and polB genes are not required for the Escherichia coli UVM response

Author

Palejwala, Vaseem A., Wang, Ge, Murphy, Holly S., and Humayun, M. Zafri

Subjects
Escherichia coli -- Genetic aspects, Radiogenetics -- Research, Ultraviolet radiation -- Physiological aspects, Biological sciences
Abstract

Experiments show that ultraviolet-induced mutagenesis (UVM) in Escherichia coli is not caused by a recA-independent alternative induction pathway for SOS genes and that neither DNA polymerase I nor DNA polymerase II are necessary. The findings indicate that UVM is not caused simply by the inhibition of the repair ability but by mechanisms which impair base insertion. UVM seems to affect base insertion at noncoding lesions.

Published
1995

41. Alkylating agents induce UVM, a recA-independent inducible mutagenic phenomenon in Escherichia coil

Author

Wang, Ge, Palejwala, Vaseem A., Dunman, Paul M., Aviv, Daniel H., Murphy, Holly S., Rahman, M. Sayeedur, and Humayun, M. Zafri

Subjects
Mutagenesis -- Causes of, Alkylating agents -- Research, Escherichia coli -- Research, Ultraviolet radiation -- Genetic aspects, Biological sciences
Abstract

Noninstructive DNA damage in Escherichia coli induces SOS functions hypothesized to be required for mutagenesis and translesion DNA synthesis at noncoding DNA lesions. We have recently demonstrated that in E. coli cells incapable of SOS induction, prior UV-irradiation nevertheless strongly enhances mutagenesis at a noninstructive lesion borne on M13 DNA. Here, we address the question whether this effect, named UVM for UV modulation of mutagenesis, can be induced by other DNA damaging agents. Exponentially growing [delta]recA cells were pretreated with alkylating agents before transfection with M13 single-stranded DNA bearing a site-specific ethenocytosine residue. Effect of cell pretreatment on survival of the transfected DNA was determined as transfection efficiency. Mutagenesis at the ethenocytosine site in pretreated or untreated cells was analyzed by multiplex DNA sequencing, a phenotype-independent technology. Our data show that 1-methyl-3-nitro-1-nitrosoguanidine, N-nitroso-N-methylurea and dimethylsulfate, but not methyl iodide, are potent inducers of UVM. Because alkylating agents induce the adaptive response to defend against DNA alkylation, we asked if the genes constituting the adaptive response are required for UVM. Our data show that MNNG induction UVM is independent of ada, alkA and alkB genes and define UVM as an inducible mutagenic phenomenon distinct from the E. coli adaptive and SOS responses.

Published
1995

47. The Potential Science and Engineering Value of Samples Delivered to Earth by Mars Sample Return - Final Report (white paper)

Author

International MSR Objectives and Samples Team, iMOST, Beaty, D. W., Grady, M. M., McSween, H. Y., Sefton-Nash, E., Carrier, B. L., Altieri, F., Amelin, Y., Ammannito, E., Anand, M., Benning, L. G., Bishop, J. L., Borg, L. E., Boucher, D., Brucato, J. R., Busemann, H., Campbell, K. A., Czaja, A. D., Debaille, V., Des Marais, D. J., Dixon, M., Ehlmann, B. L., Farmer, J. D., Fernandez-Remolar, D. C., Filiberto, J., Fogarty, J., Glavin, D. P., Goreva, Y. S., Hallis, L. J., Harrington, A. D., Hausrath, E. M., Herd, C. D. K., Horgan, B., Humayun, M., Kleine, T., Kleinhenz, J., Mackelprang, R., Mangold, N., Mayhew, L. E., McCoy, J. T., McCubbin, F. M., McLennan, S. M., Moser, D. E., Moynier, F., Mustard, J. F., Niles, P. B., Ori, G. G., Raulin, F., Rettberg, Petra, Rucker, M. A., Schmitz, N., Schwenzer, S. P., Sephton, M. A., Shaheen, R., Sharp, Z. D., Shuster, D. L., Siljeström, S., Smith, C. L., Spry, J. A., Steele, A., Swindle, T. D., ten Kate, I. L., Tosca, N. J., Usui, T., Van Kranendonk, M. J., Wadhwa, M., Weiss, B. P., Werner, S. C., Westall, F., Wheeler, R. M., Zipfel, J., Zorzano, M. P., co-chair: Beaty, D. W., co-chair: Grady, M. M., co-chair: McSween, H. Y., co-chair: Sefton-Nash, E., documentarian: Carrier, B.L., and plus 66 co-authors, .

Subjects
Strahlenbiologie, Mars sample return, iMOST
Abstract

Executive Summary: Return of samples from the surface of Mars has been a goal of the international Mars science community for many years. Affirmation by NASA and ESA of the importance of Mars exploration led the agencies to establish the international MSR Objectives and Samples Team (iMOST). The purpose of the team is to re-evaluate and update the sample-related science and engineering objectives of a Mars Sample Return (MSR) campaign. The iMOST team has also undertaken to define the measurements and the types of samples that can best address the objectives. Seven objectives have been defined for MSR, traceable through two decades of previously published international priorities. The first two objectives are further divided into sub-objectives. Within the main part of the report, the importance to science and/or engineering of each objective is described, critical measurements that would address the objectives are specified, and the kinds of samples that would be most likely to carry key information are identified. These seven objectives provide a framework for demonstrating how the first set of returned martian samples would impact future martian science and exploration. They also have implications for how analogous investigations might be conducted for samples returned by future missions from other solar system bodies, especially those that may harbor biologically relevant or sensitive material, such as Ocean Worlds (Europa, Enceladus, Titan) and others.

Published
2018

48. WHAT COULD BE LEARNED ABOUT THE GEOCHRONOLOGY OF MARS FROM SAMPLES COLLECTED BY M-2020

Author

Humayun, M. and the iMOST-Team and Rettberg, Petra

Subjects
Strahlenbiologie, Mars Sample Return campaign, iMOST study, Mars
Abstract

Based on meteoritic evidence, Mars accreted as early as 2 Ma after the formation of the first solids in the solar system [1] from material with an OTi-Cr-Ni isotopic provenance distinct from the EarthMoon system [2]. It likely formed a magma ocean within ~100 Ma after solar system formation [3], from which the martian core last equilibrated with its mantle at pressures of ~14 GPa [4]. The formation of most of the mass of the Martian crust is constrained to have occurred by 4.35 Ga [5,6]. Remanent magnetization in martian meteorite ALH 84001 demonstrates a dynamo had initiated on Mars at or before 4.1 Ga [7]. Sample return is necessary because meteorites lack geologic context and their orientation with respect to the paleomagnetic field is not known [8].

Published
2018

49. ROCHECHOUART 2017-DRILLING CAMPAIGN: FIRST RESULTS

Author

Lambert, P., Alwmark, C., Baratoux, D., Bouley, S., Brack, A., Bruneton, P., Buchner, E., Claeys, P., Dence, M.R., Courtin Nomade, A., Duhamel Achin, I., Floch, J.P., French, B.M., Fudge, C., Gattacceca, J., Gibson, R.L., Goderis, S., Grieve, R.A.F., Hodges, K.V., Hörz, F., Humayun, M., Jourdan, F., Kelley, S.P., Kenkmann, T., Kring, D.A., Langenhorst, F., Lee, M.R., Lindgren, P., Lofi, J., Lorand, J.P., Luais, B., Masaitis, V., Meunier, A., Moore, C.B., Ormö, J., Osinski, G.R., Petit, S., Pezard, P.A., Poelchau, M., Pohl, J., Quesnel, Y., Ramboz, C., Reeves, H., Rochette, P., Sapers, H.M., Schmieder, M., Schultz, P.H., Schwenzer, S.P., Sharp, T., Shoemaker, C.S., Simpson, S.L., Stöffler, D., Sturkell, E., Trumel, H., Walton, E., Westall, F., Wittmann, A., Wünnemann, K., Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), and Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)

Subjects
[SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology
Abstract

International audience; Characteristics and initial description of the 18 holes and 515m of cores recovered (cumulative length) at Rochechouart.

Published
2018

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