Mineralogy and Oxygen Isotope Compositions of an Unusual Hibonite-Perovskite Refractory Inclusion from Allende

NASA Technical Reports Server (NTRS)

Keller, L. P.; Snead, C.; Rahman, Z.; McKeegan, K. D.

2012-01-01

Hibonite-rich Ca- and Al-rich inclusions (CAIs) are among the earliest formed solids that condensed in the early nebula. We discovered an unusual refractory inclusion from the Allende CV3 chondrite (SHAL) containing an approx 500 micron long single crystal of hibonite and co-existing coarse-grained perovskite. The mineralogy and petrography of SHAL show strong similarities to some FUN inclusions, especially HAL. Here we report on the mineralogy, petrography, mineral chemistry and oxygen isotopic compositions in SHAL.

Origin of unusual bandgap shift and dual emission in organic-inorganic lead halide perovskites

PubMed Central

Dar, M. Ibrahim; Jacopin, Gwénolé; Meloni, Simone; Mattoni, Alessandro; Arora, Neha; Boziki, Ariadni; Zakeeruddin, Shaik Mohammed; Rothlisberger, Ursula; Grätzel, Michael

2016-01-01

Emission characteristics of metal halide perovskites play a key role in the current widespread investigations into their potential uses in optoelectronics and photonics. However, a fundamental understanding of the molecular origin of the unusual blueshift of the bandgap and dual emission in perovskites is still lacking. In this direction, we investigated the extraordinary photoluminescence behavior of three representatives of this important class of photonic materials, that is, CH3NH3PbI3, CH3NH3PbBr3, and CH(NH2)2PbBr3, which emerged from our thorough studies of the effects of temperature on their bandgap and emission decay dynamics using time-integrated and time-resolved photoluminescence spectroscopy. The low-temperature (<100 K) photoluminescence of CH3NH3PbI3 and CH3NH3PbBr3 reveals two distinct emission peaks, whereas that of CH(NH2)2PbBr3 shows a single emission peak. Furthermore, irrespective of perovskite composition, the bandgap exhibits an unusual blueshift by raising the temperature from 15 to 300 K. Density functional theory and classical molecular dynamics simulations allow for assigning the additional photoluminescence peak to the presence of molecularly disordered orthorhombic domains and also rationalize that the unusual blueshift of the bandgap with increasing temperature is due to the stabilization of the valence band maximum. Our findings provide new insights into the salient emission properties of perovskite materials, which define their performance in solar cells and light-emitting devices. PMID:27819049

Origin of unusual bandgap shift and dual emission in organic-inorganic lead halide perovskites.

PubMed

Dar, M Ibrahim; Jacopin, Gwénolé; Meloni, Simone; Mattoni, Alessandro; Arora, Neha; Boziki, Ariadni; Zakeeruddin, Shaik Mohammed; Rothlisberger, Ursula; Grätzel, Michael

2016-10-01

Emission characteristics of metal halide perovskites play a key role in the current widespread investigations into their potential uses in optoelectronics and photonics. However, a fundamental understanding of the molecular origin of the unusual blueshift of the bandgap and dual emission in perovskites is still lacking. In this direction, we investigated the extraordinary photoluminescence behavior of three representatives of this important class of photonic materials, that is, CH 3 NH 3 PbI 3 , CH 3 NH 3 PbBr 3 , and CH(NH 2 ) 2 PbBr 3 , which emerged from our thorough studies of the effects of temperature on their bandgap and emission decay dynamics using time-integrated and time-resolved photoluminescence spectroscopy. The low-temperature (<100 K) photoluminescence of CH 3 NH 3 PbI 3 and CH 3 NH 3 PbBr 3 reveals two distinct emission peaks, whereas that of CH(NH 2 ) 2 PbBr 3 shows a single emission peak. Furthermore, irrespective of perovskite composition, the bandgap exhibits an unusual blueshift by raising the temperature from 15 to 300 K. Density functional theory and classical molecular dynamics simulations allow for assigning the additional photoluminescence peak to the presence of molecularly disordered orthorhombic domains and also rationalize that the unusual blueshift of the bandgap with increasing temperature is due to the stabilization of the valence band maximum. Our findings provide new insights into the salient emission properties of perovskite materials, which define their performance in solar cells and light-emitting devices.

Biophysical and biochemical characteristics of cutin, a plant barrier biopolymer.

PubMed

Heredia, Antonio

2003-03-17

Cutin is a support biopolyester involved in waterproofing the leaves and fruits of higher plants, regulating the flow of nutrients among various plant cells and organs, and minimizing the deleterious impact of pathogens. Despite the complexity and intractable nature of this biopolymer, significant progress in chemical composition, molecular architecture and, more recently, biosynthesis have been made in the past 10 years. This review is focused in the description of these advances and their physiological impacts to improve our knowledge on plant cutin, an unusual topic in most plant physiology and biochemistry books and reviews.

Atomically thin two-dimensional organic-inorganic hybrid perovskites.

PubMed

Dou, Letian; Wong, Andrew B; Yu, Yi; Lai, Minliang; Kornienko, Nikolay; Eaton, Samuel W; Fu, Anthony; Bischak, Connor G; Ma, Jie; Ding, Tina; Ginsberg, Naomi S; Wang, Lin-Wang; Alivisatos, A Paul; Yang, Peidong

2015-09-25

Organic-inorganic hybrid perovskites, which have proved to be promising semiconductor materials for photovoltaic applications, have been made into atomically thin two-dimensional (2D) sheets. We report the solution-phase growth of single- and few-unit-cell-thick single-crystalline 2D hybrid perovskites of (C4H9NH3)2PbBr4 with well-defined square shape and large size. In contrast to other 2D materials, the hybrid perovskite sheets exhibit an unusual structural relaxation, and this structural change leads to a band gap shift as compared to the bulk crystal. The high-quality 2D crystals exhibit efficient photoluminescence, and color tuning could be achieved by changing sheet thickness as well as composition via the synthesis of related materials. Copyright © 2015, American Association for the Advancement of Science.

Unusual features of fibrillarin cDNA and gene structure in Euglena gracilis: evolutionary conservation of core proteins and structural predictions for methylation-guide box C/D snoRNPs throughout the domain Eucarya.

PubMed

Russell, Anthony G; Watanabe, Yoh-ichi; Charette, J Michael; Gray, Michael W

2005-01-01

Box C/D ribonucleoprotein (RNP) particles mediate O2'-methylation of rRNA and other cellular RNA species. In higher eukaryotic taxa, these RNPs are more complex than their archaeal counterparts, containing four core protein components (Snu13p, Nop56p, Nop58p and fibrillarin) compared with three in Archaea. This increase in complexity raises questions about the evolutionary emergence of the eukaryote-specific proteins and structural conservation in these RNPs throughout the eukaryotic domain. In protists, the primarily unicellular organisms comprising the bulk of eukaryotic diversity, the protein composition of box C/D RNPs has not yet been extensively explored. This study describes the complete gene, cDNA and protein sequences of the fibrillarin homolog from the protozoon Euglena gracilis, the first such information to be obtained for a nucleolus-localized protein in this organism. The E.gracilis fibrillarin gene contains a mixture of intron types exhibiting markedly different sizes. In contrast to most other E.gracilis mRNAs characterized to date, the fibrillarin mRNA lacks a spliced leader (SL) sequence. The predicted fibrillarin protein sequence itself is unusual in that it contains a glycine-lysine (GK)-rich domain at its N-terminus rather than the glycine-arginine-rich (GAR) domain found in most other eukaryotic fibrillarins. In an evolutionarily diverse collection of protists that includes E.gracilis, we have also identified putative homologs of the other core protein components of box C/D RNPs, thereby providing evidence that the protein composition seen in the higher eukaryotic complexes was established very early in eukaryotic cell evolution.

Abiotic tooth enamel

NASA Astrophysics Data System (ADS)

Yeom, Bongjun; Sain, Trisha; Lacevic, Naida; Bukharina, Daria; Cha, Sang-Ho; Waas, Anthony M.; Arruda, Ellen M.; Kotov, Nicholas A.

2017-03-01

Tooth enamel comprises parallel microscale and nanoscale ceramic columns or prisms interlaced with a soft protein matrix. This structural motif is unusually consistent across all species from all geological eras. Such invariability—especially when juxtaposed with the diversity of other tissues—suggests the existence of a functional basis. Here we performed ex vivo replication of enamel-inspired columnar nanocomposites by sequential growth of zinc oxide nanowire carpets followed by layer-by-layer deposition of a polymeric matrix around these. We show that the mechanical properties of these nanocomposites, including hardness, are comparable to those of enamel despite the nanocomposites having a smaller hard-phase content. Our abiotic enamels have viscoelastic figures of merit (VFOM) and weight-adjusted VFOM that are similar to, or higher than, those of natural tooth enamels—we achieve values that exceed the traditional materials limits of 0.6 and 0.8, respectively. VFOM values describe resistance to vibrational damage, and our columnar composites demonstrate that light-weight materials of unusually high resistance to structural damage from shocks, environmental vibrations and oscillatory stress can be made using biomimetic design. The previously inaccessible combinations of high stiffness, damping and light weight that we achieve in these layer-by-layer composites are attributed to efficient energy dissipation in the interfacial portion of the organic phase. The in vivo contribution of this interfacial portion to macroscale deformations along the tooth’s normal is maximized when the architecture is columnar, suggesting an evolutionary advantage of the columnar motif in the enamel of living species. We expect our findings to apply to all columnar composites and to lead to the development of high-performance load-bearing materials.

A Carbonaceous Chondrite Based Simulant of Phobos

NASA Technical Reports Server (NTRS)

Rickman, Douglas L.; Patel, Manish; Pearson, V.; Wilson, S.; Edmunson, J.

2016-01-01

In support of an ESA-funded concept study considering a sample return mission, a simulant of the Martian moon Phobos was needed. There are no samples of the Phobos regolith, therefore none of the four characteristics normally used to design a simulant are explicitly known for Phobos. Because of this, specifications for a Phobos simulant were based on spectroscopy, other remote measurements, and judgment. A composition based on the Tagish Lake meteorite was assumed. The requirement that sterility be achieved, especially given the required organic content, was unusual and problematic. The final design mixed JSC-1A, antigorite, pseudo-agglutinates and gilsonite. Sterility was achieved by radiation in a commercial facility.

Variability in sinking fluxes and composition of particle-bound phosphorus in the Xisha area of the northern South China Sea

NASA Astrophysics Data System (ADS)

Dong, Yuan; Li, Qian P.; Wu, Zhengchao; Zhang, Jia-Zhong

2016-12-01

Export fluxes of phosphorus (P) by sinking particles are important in studying ocean biogeochemical dynamics, whereas their composition and temporal variability are still inadequately understood in the global oceans, including the northern South China Sea (NSCS). A time-series study of particle fluxes was conducted at a mooring station adjacent to the Xisha Trough in the NSCS from September 2012 to September 2014, with sinking particles collected every two weeks by two sediment traps deployed at 500 m and 1500 m depths. Five operationally defined particulate P classes of sinking particles including loosely-bound P, Fe-bound P, CaCO3-bound P, detrital apatite P, and refractory organic P were quantified by a sequential extraction method (SEDEX). Our results revealed substantial variability in sinking particulate P composition at the Xisha over two years of samplings. Particulate inorganic P was largely contributed from Fe-bound P in the upper trap, but detrital P in the lower trap. Particulate organic P, including exchangeable organic P, CaCO3-bound organic P, and refractory organic P, contributed up to 50-55% of total sinking particulate P. Increase of CaCO3-bound P in the upper trap during 2014 could be related to a strong El Niño event with enhanced CaCO3 deposition. We also found sediment resuspension responsible for the unusual high particles fluxes at the lower trap based on analyses of a two-component mixing model. There was on average a total mass flux of 78±50 mg m-2 d-1 at the upper trap during the study period. A significant correlation between integrated primary productivity in the region and particle fluxes at 500 m of the station suggested the important role of biological production in controlling the concentration, composition, and export fluxes of sinking particulate P in the NSCS.

NOAA declares string of seal deaths in New England an unusual mortality

Science.gov Websites

Alerts NOAA Organizations Working With NOAA Media & Constituents NOAA In Your State Emergency string of seal deaths in New England an unusual mortality event Public reminded to maintain safe distance the Working Group on Marine Mammal Unusual Mortality Events, a panel of international experts

Mechanical and thermal properties of planetologically important ices

NASA Technical Reports Server (NTRS)

Croft, Steven K.

1987-01-01

Two squences of ice composition were proposed for the icy satellites: a dense nebula model and a solar nebula model. Careful modeling of the structure, composition, and thermal history of satellites composed of these various ices requires quantitative information on the density, compressibility, thermal expansion, heat capacity, and thermal conductivity. Equations of state were fitted to the density data of the molecular ices. The unusual thermal and mechanical properties of the molecular and binary ices suggest a larger range of phenomena than previously anticipated, sufficiently complex perhaps to account for many of the unusual geologic phenomena found on the icy satellites.

Integrative analysis of the Caenorhabditis elegans genome by the modENCODE project.

PubMed

Gerstein, Mark B; Lu, Zhi John; Van Nostrand, Eric L; Cheng, Chao; Arshinoff, Bradley I; Liu, Tao; Yip, Kevin Y; Robilotto, Rebecca; Rechtsteiner, Andreas; Ikegami, Kohta; Alves, Pedro; Chateigner, Aurelien; Perry, Marc; Morris, Mitzi; Auerbach, Raymond K; Feng, Xin; Leng, Jing; Vielle, Anne; Niu, Wei; Rhrissorrakrai, Kahn; Agarwal, Ashish; Alexander, Roger P; Barber, Galt; Brdlik, Cathleen M; Brennan, Jennifer; Brouillet, Jeremy Jean; Carr, Adrian; Cheung, Ming-Sin; Clawson, Hiram; Contrino, Sergio; Dannenberg, Luke O; Dernburg, Abby F; Desai, Arshad; Dick, Lindsay; Dosé, Andréa C; Du, Jiang; Egelhofer, Thea; Ercan, Sevinc; Euskirchen, Ghia; Ewing, Brent; Feingold, Elise A; Gassmann, Reto; Good, Peter J; Green, Phil; Gullier, Francois; Gutwein, Michelle; Guyer, Mark S; Habegger, Lukas; Han, Ting; Henikoff, Jorja G; Henz, Stefan R; Hinrichs, Angie; Holster, Heather; Hyman, Tony; Iniguez, A Leo; Janette, Judith; Jensen, Morten; Kato, Masaomi; Kent, W James; Kephart, Ellen; Khivansara, Vishal; Khurana, Ekta; Kim, John K; Kolasinska-Zwierz, Paulina; Lai, Eric C; Latorre, Isabel; Leahey, Amber; Lewis, Suzanna; Lloyd, Paul; Lochovsky, Lucas; Lowdon, Rebecca F; Lubling, Yaniv; Lyne, Rachel; MacCoss, Michael; Mackowiak, Sebastian D; Mangone, Marco; McKay, Sheldon; Mecenas, Desirea; Merrihew, Gennifer; Miller, David M; Muroyama, Andrew; Murray, John I; Ooi, Siew-Loon; Pham, Hoang; Phippen, Taryn; Preston, Elicia A; Rajewsky, Nikolaus; Rätsch, Gunnar; Rosenbaum, Heidi; Rozowsky, Joel; Rutherford, Kim; Ruzanov, Peter; Sarov, Mihail; Sasidharan, Rajkumar; Sboner, Andrea; Scheid, Paul; Segal, Eran; Shin, Hyunjin; Shou, Chong; Slack, Frank J; Slightam, Cindie; Smith, Richard; Spencer, William C; Stinson, E O; Taing, Scott; Takasaki, Teruaki; Vafeados, Dionne; Voronina, Ksenia; Wang, Guilin; Washington, Nicole L; Whittle, Christina M; Wu, Beijing; Yan, Koon-Kiu; Zeller, Georg; Zha, Zheng; Zhong, Mei; Zhou, Xingliang; Ahringer, Julie; Strome, Susan; Gunsalus, Kristin C; Micklem, Gos; Liu, X Shirley; Reinke, Valerie; Kim, Stuart K; Hillier, LaDeana W; Henikoff, Steven; Piano, Fabio; Snyder, Michael; Stein, Lincoln; Lieb, Jason D; Waterston, Robert H

2010-12-24

We systematically generated large-scale data sets to improve genome annotation for the nematode Caenorhabditis elegans, a key model organism. These data sets include transcriptome profiling across a developmental time course, genome-wide identification of transcription factor-binding sites, and maps of chromatin organization. From this, we created more complete and accurate gene models, including alternative splice forms and candidate noncoding RNAs. We constructed hierarchical networks of transcription factor-binding and microRNA interactions and discovered chromosomal locations bound by an unusually large number of transcription factors. Different patterns of chromatin composition and histone modification were revealed between chromosome arms and centers, with similarly prominent differences between autosomes and the X chromosome. Integrating data types, we built statistical models relating chromatin, transcription factor binding, and gene expression. Overall, our analyses ascribed putative functions to most of the conserved genome.

Fetus-in-Fetu: An Unusual Cause for Abdominal Mass in Infancy

PubMed Central

Grosfeld, Jay L.; Stepita, Donald S.; Nance, Walter E.; Palmer, Catherine G.

1974-01-01

Fetus-in-fetu is an unusual cause of retroperitoneal abdominal mass in infants, which most likely arises from inclusion of a monozygotic, diamniotic twin. This entity is distinguished from teratoma by its embryological origin, its unusual location in the retroperitoneal space, its invariable benignity, and by the presence of vertebral organization with limb buds and well-developed organ systems. Diagnosis is made radiographically by the finding of a diminutive vertebral column on a plain abdominal film. The treatment of choice is total excision with special attention being given to the fetus' blood supply which may be directly from the host's superior mesenteric vessels. A well-documented example of this unusual entity that occurred in a six-week old infant male is presented. ImagesFig. 1.Fig. 2.Fig. 3. PMID:4471720

Chemical composition of HAL, an isotopically-unusual Allende inclusion

NASA Astrophysics Data System (ADS)

Davis, A. M.; Tanaka, T.; Grossman, L.; Lee, T.; Wasserburg, G. J.

1982-09-01

Samples of hibonite, black rim, and portions of friable rim from an unusual Allende inclusion, named HAL, were analyzed by INAA and RNAA for 37 major, minor, and trace elements. An unusually low amount of Ce was found in HAL, although it otherwise was highly enriched in REE compared to C1 chondrites. HAL is also depleted in Sr, Ba, U, V, Ru, Os, and Ir relative to other refractory elements. It is concluded that the distribution of REE between hibonite and rims was established when hibonite and other refractory minerals were removed at slightly different temperatures from a hot, oxidizing gas in which they previously coexisted as separate grains. Possible locations for the chemical and mass dependent isotopic fractionation are considered to be in ejecta from the low temperature helium-burning zone of a supernova and in the locally oxidizing environment generated by evaporation of interstellar grains of near-chondritic chemical composition.

Chemical composition of HAL, an isotopically-unusual Allende inclusion

NASA Technical Reports Server (NTRS)

Davis, A. M.; Tanaka, T.; Grossman, L.; Lee, T.; Wasserburg, G. J.

1982-01-01

Samples of hibonite, black rim, and portions of friable rim from an unusual Allende inclusion, named HAL, were analyzed by INAA and RNAA for 37 major, minor, and trace elements. An unusually low amount of Ce was found in HAL, although it otherwise was highly enriched in REE compared to C1 chondrites. HAL is also depleted in Sr, Ba, U, V, Ru, Os, and Ir relative to other refractory elements. It is concluded that the distribution of REE between hibonite and rims was established when hibonite and other refractory minerals were removed at slightly different temperatures from a hot, oxidizing gas in which they previously coexisted as separate grains. Possible locations for the chemical and mass dependent isotopic fractionation are considered to be in ejecta from the low temperature helium-burning zone of a supernova and in the locally oxidizing environment generated by evaporation of interstellar grains of near-chondritic chemical composition.

The Sentence-Composition Effect: Processing of Complex Sentences Depends on the Configuration of Common Noun Phrases versus Unusual Noun Phrases

ERIC Educational Resources Information Center

Johnson, Marcus L.; Lowder, Matthew W.; Gordon, Peter C.

2011-01-01

In 2 experiments, the authors used an eye tracking while reading methodology to examine how different configurations of common noun phrases versus unusual noun phrases (NPs) influenced the difference in processing difficulty between sentences containing object- and subject-extracted relative clauses. Results showed that processing difficulty was…

Composite structural materials

NASA Technical Reports Server (NTRS)

Ansell, G. S.; Loewy, R. G.; Wiberley, S. E.

1982-01-01

Research in the basic composition, characteristics, and processng science of composite materials and their constituents is balanced against the mechanics, conceptual design, fabrication, and testing of generic structural elements typical of aerospace vehicles so as to encourage the discovery of unusual solutions to problems. Detailed descriptions of the progress achieved in the various component parts of his program are presented.

Unusual organic osmolytes in deep-sea animals: adaptations to hydrostatic pressure and other perturbants.

PubMed

Yancey, Paul H; Blake, Wendy R; Conley, James

2002-11-01

Shallow-living marine invertebrates use free amino acids as cellular osmolytes, while most teleosts use almost no organic osmolytes. Recently we found unusual osmolyte compositions in deep-sea animals. Trimethylamine N-oxide (TMAO) increases with depth in muscles of some teleosts, skates, and crustaceans (up to 300 mmol/kg at 2900 m). Other deep-sea animals had high levels of (1). scyllo-inositol in echinoderms, gastropods, and polychaetes, (2). that polyol plus beta-alanine and betaine in octopods, (3). hypotaurine, N-methyltaurine, and unidentified methylamines in vestimentiferans from hydrothermal vents and cold seeps, and (4). a depth-correlated serine-phosphate osmolyte in vesicomyid clams from trench seeps. We hypothesize that some of these solutes counteract effects of hydrostatic pressure. With lactate dehydrogenase, actin, and pyruvate kinase, 250 mM TMAO (but not glycine) protected both ligand binding and protein stability against pressure. To test TMAO in living cells, we grew yeast under pressure. After 1 h at 71 MPa, 3.5 h at 71 MPa, and 17 h at 30 MPa, 150 mM TMAO generally doubled the number of cells that formed colonies. Sulfur-based osmolytes which are not correlated with depth, such as hypotaurine and thiotaurine, are probably involved in sulfide metabolism and detoxification. Thus deep-sea osmolytes may have at least two other roles beyond acting as simple compatible osmotica.

Unusual tumour ablations: report of difficult and interesting cases.

PubMed

Mauri, Giovanni; Nicosia, Luca; Varano, Gianluca Maria; Shyn, Paul; Sartori, Sergio; Tombesi, Paola; Di Vece, Francesca; Orsi, Franco; Solbiati, Luigi

2017-01-01

Image-guided ablations are nowadays applied in the treatment of a wide group of diseases and in different organs and regions, and every day interventional radiologists have to face more difficult and unusual cases of tumour ablation. In the present case review, we report four difficult and unusual cases, reporting some tips and tricks for a successful image-guided treatment.

Magnetic vortex excitation as spin torque oscillator and its unusual trajectories

NASA Astrophysics Data System (ADS)

Natarajan, Kanimozhi; Muthuraj, Ponsudana; Rajamani, Amuda; Arumugam, Brinda

2018-05-01

We report an interesting observation of unusual trajectories of vortex core oscillations in a spin valve pillar. Micromagnetic simulation in the composite free layer spin valve nano-pillar shows magnetic vortex excitation under critical current density. When current density is slightly increased and wave vector is properly tuned, for the first time we observe a star like and square gyration. Surprisingly this star like and square gyration also leads to steady, coherent and sustained oscillations. Moreover, the frequency of gyration is also very high for this unusual trajectories. The power spectral analysis reveals that there is a marked increase in output power and frequency with less distortions. Our investigation explores the possibility of these unusual trajectories to exhibit spin torque oscillations.

Biological Diversity Comprising Microbial Structures of Antarctic Ice Covered Lakes

NASA Astrophysics Data System (ADS)

Matys, E. D.

2015-12-01

Analysis of microbial membrane lipids is a rapid and non-selective method for evaluating the composition of microbial communities. To fully realise the diagnostic potential of these lipids, we must first understand their structural diversity, biological sources, physiological functions, and pathways of preservation. Particular environmental conditions likely prompt the production of different membrane lipid structures. Antarctica's McMurdo Dry Valleys host numerous ice-covered lakes with sharp chemical gradients that vary in illumination, geochemical structure, and benthic mat morphologies that are structured by nutrient availability and water chemistry. The lipid contents of these benthic mats have not received extensive study nor have the communities yet been thoroughly characterized. Accordingly, a combination of lipid biomarker and nucleic acid sequence data provides the means of assessing species diversity and environmental controls on the composition and diversity of membrane lipid assemblages. We investigated the richness and diversity of benthic microbial communities and accumulated organic matter in Lake Vanda of the McMurdo Dry Valleys. We have identified diverse glycolipids, aminolipids, and phospholipids in addition to many unknown compounds that may be specific to these particular environments. Light levels fluctuate seasonally, favoring low-light-tolerant cyanobacteria and specific lipid assemblages. Adaptations to nutrient limitations are reflected in contrasting intact polar lipid assemblages. For example, under P-limiting conditions, phospholipids are subsidiary to membrane-forming lipids that do not contain P (i.e. ornithine, betaine, and sulfolipids). The bacteriohopanepolyol (BHP) composition is dominated by bacteriohopanetetrol (BHT), a ubiquitous BHP, and 2-methylhopanoids. The relative abundance of 2-methylhopanoids is unprecedented and may reflect the unusual seasonal light regime of this polar environment. By establishing correlations between environmental conditions, microbial community composition and the lipid assemblages of microbial structures in ice-covered lakes of Antarctica's McMurdo Dry Valleys, our data provides important ecological and evolutionary insights into these unusual environments.

Single crystal, liquid crystal, and hybrid organic semiconductors

NASA Astrophysics Data System (ADS)

Twieg, Robert J.; Getmanenko, Y.; Lu, Z.; Semyonov, A. N.; Huang, S.; He, P.; Seed, A.; Kiryanov, A.; Ellman, B.; Nene, S.

2003-07-01

The synthesis and characterization of organic semiconductors is being pursued in three primary structure formats: single crystal, liquid crystal and organic-inorganic hybrid. The strategy here is to share common structures, synthesis methods and fabrication techniques across these formats and to utilize common characterization tools such as the time of flight technique. The single crystal efforts concentrate on aromatic and heteroaromatic compounds including simple benzene derivatives and derivatives of the acenes. The structure-property relationships due to incorporation of small substituents and heteroatoms are being examined. Crystals are grown by solution, melt or vapor transport techniques. The liquid crystal studies exploit their self-organizing properties and relative ease of sample preparation. Though calamitic systems tha deliver the largest mobilities are higher order smectics, even some unusual twist grain boundary phases are being studied. We are attempting to synthesize discotic acene derivatives with appropriate substitution patterns to render them mesogenic. The last format being examined is the hybrid organic-inorganic class. Here, layered materials of alternating organic and inorganic composition are designed and synthesized. Typical materials are conjugated aromatic compounds, usually functinalized with an amine or a pyridine and reacted with appropriate reactive metal derivatives to incorporate them into metal oxide or sulfide layers.

Polymer-directed crystallization of atorvastatin.

PubMed

Choi, Hyemin; Lee, Hyeseung; Lee, Min Kyung; Lee, Jonghwi

2012-08-01

Living organisms secrete minerals composed of peptides and proteins, resulting in "mesocrystals" of three-dimensional-assembled composite structures. Recently, this biomimetic polymer-directed crystallization technique has been widely applied to inorganic materials, although it has seldom been used with drugs. In this study, the technique was applied to the drowning-out crystallization of atorvastatin using various polymers. Nucleation and growth at optimized conditions successfully produced composite crystals with significant polymer contents and unusual characteristics. Atorvastatin composite crystals containing polyethylene glycol, polyacrylic acid, polyethylene imine, and chitosan showed a markedly decreased melting point and heat of fusion, improved stability, and sustained-release patterns. The use of hydroxypropyl cellulose yielded a unique combination of enhanced in vitro release and improved drug stability under a forced degradation condition. The formation hypothesis of unique mesocrystal structures was strongly supported by an X-ray diffraction pattern and substantial melting point reduction. This polymer-directed crystallization technique offers a novel and effective way, different from the solid dispersion approach, to engineer the release, stability, and processability of drug crystals. Copyright © 2012 Wiley Periodicals, Inc.

Comparison of the distribution of large magmatic centers on Earth, Venus, and Mars

NASA Technical Reports Server (NTRS)

Crumpler, L. S.

1993-01-01

Volcanism is widely distributed over the surfaces of the major terrestrial planets: Venus, Earth, and Mars. Anomalous centers of magmatic activity occur on each planet and are characterized by evidence for unusual concentrations of volcanic centers, long-lived activity, unusual rates of effusion, extreme size of volcanic complexes, compositionally unusual magmatism, and evidence for complex geological development. The purpose of this study is to compare the characteristics and distribution of these magmatic anomalies on Earth, Venus, and Mars in order to assess these characteristics as they may relate to global characteristics and evolution of the terrestrial planets.

Isolation of Mycobacterium avium from waterfowl with polycystic livers

USGS Publications Warehouse

Roffe, Thomas J.

1989-01-01

An unusual gross appearance of avian tuberculosis, where fluid-filled thin-walled cysts are produced and grossly apparent in preference to granulomas, is presented. Histopathology confirmed the granulomatous nature of the lesions and the presence of intracellular acid-fast organisms. Mycobacterium avium complex was cultured from affected organs. The unusual gross presentation in these cases indicates the need to consider tuberculosis in the differential of cystic diseases of avian livers.

Small organic solutes in sticky droplets from orb webs of the spider Zygiella atrica (Araneae; Araneidae): β-alaninamide is a novel and abundant component.

PubMed

Townley, Mark A; Pu, Qinglin; Zercher, Charles K; Neefus, Christopher D; Tillinghast, Edward K

2012-10-01

In northeastern North America, Zygiella atrica often build their orb webs near the ocean. We analyzed individual field-built Z. atrica webs to determine if organic low-molecular-mass solutes (LMM) in their sticky droplets showed any unusual features not previously seen in orb webs of other species living in less salty environments. While two of the three most abundant organic LMM (putrescine (butane-1,4-diamine) and GABamide (4-aminobutanamide)) are already well-known from webs of inland spiders, the third major LMM, β-alaninamide (3-aminopropanamide), a homolog of GABamide, has not been detected in sticky droplets from any other araneoid spiders (27 species). It remains to be established, however, whether or not use of β-alaninamide is related to proximity to saltwater. We observed variability in organic LMM composition in Z. atrica webs that appeared to be influenced more by an undetermined factor associated with different collecting locations and/or collection dates than by different genders or instars. Shifts in composition when adult females were transferred from the field to the laboratory were also observed. Structural similarities and inverse correlations among β-alaninamide, GABamide, and N-acetylputrescine suggest that they may form a series of LMM fulfilling essentially the same, as yet unknown, role in the webs of those species in which they occur. Copyright © 2012 Verlag Helvetica Chimica Acta AG, Zürich.

Evidence of Anomalously Low δ13C of Marine Organic Matter in an Arctic Fjord.

PubMed

Kumar, Vikash; Tiwari, Manish; Nagoji, Siddhesh; Tripathi, Shubham

2016-11-09

Accurate estimation of relative carbon deposition (marine vs. terrestrial) is required for understanding the global carbon budget, particularly in the Arctic region, which holds disproportionate importance with respect to global carbon cycling. Although the sedimentary organic matter (SOM) concentration and its isotopic composition are important tools for such calculations, uncertainties loom over estimates provided by organic-geochemical bulk parameters. We report carbon and nitrogen concentrations and isotopes (δ 13 C and δ 15 N) of SOM at an Arctic fjord namely Kongsfjorden. We find that the bound inorganic nitrogen (ammonium attached to the clay minerals) forms a significant proportion of total nitrogen concentration (~77% in the inner fjord to ~24% in the outer part). On removing the bound nitrogen, the C/N ratio shows that the SOM in the inner fjord is made up of terrestrial carbon while the outer fjord shows mixed marine-terrestrial signal. We further show that the marine organic matter is unusually more depleted in 13 C (~-24‰) than the terrestrial organic matter (~-22.5‰). This particular finding also helps explain high δ 13 C values of SOM as noted by earlier studies in central Arctic sediments despite a high terrestrial contribution.

The identification of two unusual types of homemade ammunition.

PubMed

Lee, Hsieh-Chang; Meng, Hsien-Hui

2012-07-01

Illegal homemade ammunition is commonly used by criminals to commit crimes in Taiwan. Two unusual types of homemade ammunition that most closely resembling genuine ammunition are studied here. Their genuine counterparts are studied as the control samples for the purpose of comparison. Unfired ammunition is disassembled, and the morphological, dimensional, and compositional features of the bullet and cartridge case are examined. Statistical tests are employed to distinguish the dimensional differences between homemade and genuine ammunitions. Manufacturing marks on head stamps of the cartridge case are carefully examined. Compositional features of propellant powders, primer mixtures, and gunshot residues are also analyzed. The results reveal that the morphological, dimensional, and compositional features of major parts of the ammunition can be employed to differentiate homemade cartridges from genuine ones. Among these features, tool marks on the head stamps left by the bunter can be used to trace the origin of ammunition. © 2012 American Academy of Forensic Sciences.

Can the fatty acid selectivity of plant lipases be predicted from the composition of the seed triglyceride?

PubMed

Hellyer, S A; Chandler, I C; Bosley, J A

1999-09-22

To address the question can the fatty acid selectivity of plant lipases be predicted from the composition of the seed triglyceride, we have characterised the selectivity of lipases from a wide range of oilseeds with diverse fatty acid compositions. For this study, a novel hydrolysis assay using a fully randomised oil, was developed. From some seed sources (e.g. Cinnamomum camphora), lipases show high preference for particular fatty acids, whilst from others (e.g. Brassica napus, Theobroma cacao80% saturated or 'unusual' fatty acids may contain lipases which exhibit selectivity. It therefore follows that since the majority of seeds are composed of unsaturated fatty acids, that highly selective lipases will be unusual in nature. However lipases from some species of the Cuphea genera show exceptionally high preference for particular fatty acids. For example, lipase from seeds of Cuphea procumbans has over 20-fold selectivity for C10:0.

Humidity Effects on Soluble Core Mechanical and Thermal Properties (Polyvinyl Alcohol/Microballoon Composite)

NASA Technical Reports Server (NTRS)

1993-01-01

This document constitutes the final report for the study of humidity effects and loading rate on soluble core (PVA/MB composite material) mechanical and thermal properties. This report describes test results, procedures employed, and any unusual occurrences or specific observations associated with this test program.

Ozone depletion, greenhouse gases, and climate change

NASA Technical Reports Server (NTRS)

Mooney, Harold A.; Baker, D. James, Jr.; Bretherton, Francis P.; Burke, Kevin C.; Clark, William C.; Davis, Margaret B.; Dickinson, Robert E.; Imbrie, John; Malone, Thomas F.; Mcelroy, Michael B.

1989-01-01

This symposium was organized to study the unusual convergence of a number of observations, both short and long term that defy an integrated explanation. Of particular importance are surface temperature observations and observations of upper atmospheric temperatures, which have declined significantly in parts of the stratosphere. There has also been a dramatic decline in ozone concentration over Antarctica that was not predicted. Significant changes in precipitation that seem to be latitude dependent have occurred. There has been a threefold increase in methane in the last 100 years; this is a problem because a source does not appear to exist for methane of the right isotopic composition to explain the increase. These and other meteorological global climate changes are examined in detail.

Compositional analyses and shelf-life modeling of njangsa (ricinodendron heudelotii)seed oil using the weibull hazard method

USDA-ARS?s Scientific Manuscript database

This study investigated the compositional characteristics and shelf-life of Njangsa seed oil (NSO). Oil from Njangsa had a high polyunsaturated fatty acid (PUFA) content of which alpha eleosteric acid (alpha-ESA), an unusual conjugated linoleic acid was the most prevalent (about 52%). Linoleic acid...

Processing and property evaluation of metal matrix superconducting materials

NASA Technical Reports Server (NTRS)

Rao, Appajosula S.

1995-01-01

Metal - superconductor (YBCO) systems have been prepared and characterized by resistivity, ac susceptibility and dc SQUID magnetic moment measurements. The silver composites showed superconducting transition for all the composites processed and the superconducting transition temperature tends to depend upon the concentration of the silver in the composite. Aluminum composites showed an unusual resistivity results with two transitions around 90 K and 120 K. The superconducting property of silver composites can be explained qualitatively in terms of the proximity theory that has been suggested for the low temperature superconductors.

Composite structural materials

NASA Technical Reports Server (NTRS)

Loewy, R.; Wiberley, S. E.

1986-01-01

Overall emphasis is on basic long-term research in the following categories: constituent materials, composite materials, generic structural elements, processing science technology; and maintaining long-term structural integrity. Research in basic composition, characteristics, and processing science of composite materials and their constituents is balanced against the mechanics, conceptual design, fabrication, and testing of generic structural elements typical of aerospace vehicles so as to encourage the discovery of unusual solutions to present and future problems. Detailed descriptions of the progress achieved in the various component parts of this comprehensive program are presented.

TOPICAL REVIEW: Electrical transport modelling in organic electroluminescent devices

NASA Astrophysics Data System (ADS)

Walker, A. B.; Kambili, A.; Martin, S. J.

2002-10-01

Organic electroluminescent devices (OEDs) emit light when an electric current is applied to a thin film section. They arise from two main technology branches - small molecules and light emitting polymers. Apart from the insight offered into the fundamentals of their physics, which is relevant to topics such as electrical transport in biological systems and molecular computers, understanding how the mobilities in these systems vary with morphology and composition enables the design of improved materials for technological requirements, e.g. fast switching speeds for active matrix displays and polymer field effect transistors. In this review, we have focussed on the models of transport in OEDs that address the unusual nature of this transport and underpin device design. The review concludes with the following point: as new materials for use in OEDs continue to appear, modelling is essential for the prediction of their transport properties, which in turn leads to the establishment of fundamental trends in the behaviour of devices employing them.

Particulate organic matter delta C-13 variations across the Drake Passage

NASA Technical Reports Server (NTRS)

Rau, G. H.; Takahashi, T.; Des Marais, D. J.; Sullivan, C. W.

1991-01-01

Particulate organic matter (POM) was sampled during two cruise transects across the Drake Passage during March 1986 to investigate the unusual C-13 depletion in high-latitude Southern Ocean plankton. This POM delta C-13 transition from -23.2 o/oo at 53.3 deg S to values as low as -30.3 o/oo at above 62 deg S does not track previously reported abrupt changes in water chemistry and plankton species composition associated with the Polar Front Zone. The north-south isotopic trend is not accompanied by significant changes in POM carbon or nitrogen concentrations, or in POM C/N. Differences in plankton standing crop or biochemistry (e.g. lipid content) do not appear responsible for the isotopic trends observed. The latitudinal change in POM delta C-13 is highly correlated with water temperature and with the calculated concentration of CO2 (aq) at equilibrium with atmospheric CO2. These observations are consistent with the hypothesis that CO2 (aq) significantly influences POM delta C-13 in ocean surface waters.

Composition of microbial communities in aerosol, snow and ice samples from remote glaciated areas (Antarctica, Alps, Andes)

NASA Astrophysics Data System (ADS)

Elster, J.; Delmas, R. J.; Petit, J.-R.; Řeháková, K.

2007-06-01

Taxonomical and ecological analyses were performed on micro-autotrophs (cyanobacteria and algae together with remnants of diatom valves), micro-fungi (hyphae and spores), bacteria (rod, cocci and red clusters), yeast, and plant pollen extracted from various samples: Alps snow (Mt. Blank area), Andean snow (Illimani, Bolivia), Antarctic aerosol filters (Dumont d'Urville, Terre Adélie), and Antarctic inland ice (Terre Adélie). Three methods for ice and snow sample's pre-concentration were tested (filtration, centrifugation and lyophilisation). Afterwards, cultivation methods for terrestrial, freshwater and marine microorganisms (micro-autotrophs and micro-fungi) were used in combination with liquid and solid media. The main goal of the study was to find out if micro-autotrophs are commonly transported by air masses, and later stored in snow and icecaps around the world. The most striking result of this study was the absence of culturable micro-autotrophs in all studied samples. However, an unusual culturable pigmented prokaryote was found in both alpine snow and aerosol samples. Analyses of many samples and proper statistical analyses (PCA, RDA- Monte Carlo permutation tests) showed that studied treatments highly significantly differ in both microbial community and biotic remnants composition F=9.33, p=0.001. In addition, GLM showed that studied treatments highly significantly differ in numbers of categories of microorganisms and remnants of biological material F=11.45, p=0.00005. The Antarctic aerosol samples were characterised by having red clusters of bacteria, the unusual prokaryote and yeasts. The high mountain snow from the Alps and Andes contained much more culturable heterotrophs. The unusual prokaryote was very abundant, as were coccoid bacteria, red clusters of bacteria, as well as yeasts. The Antarctic ice samples were quite different. These samples had higher numbers of rod bacteria and fungal hyphae. The microbial communities and biological remnants of analysed samples comprises two communities, without a sharp boundary between them: i) the first community includes ubiquitous organisms including contaminants, ii) the second community represents individuals frequently occurring in remote terrestrial cold or hot desert/semi-desert and/or marginal soil-snow-ice ecosystems.

Evidence of Anomalously Low δ13C of Marine Organic Matter in an Arctic Fjord

PubMed Central

Kumar, Vikash; Tiwari, Manish; Nagoji, Siddhesh; Tripathi, Shubham

2016-01-01

Accurate estimation of relative carbon deposition (marine vs. terrestrial) is required for understanding the global carbon budget, particularly in the Arctic region, which holds disproportionate importance with respect to global carbon cycling. Although the sedimentary organic matter (SOM) concentration and its isotopic composition are important tools for such calculations, uncertainties loom over estimates provided by organic-geochemical bulk parameters. We report carbon and nitrogen concentrations and isotopes (δ13C and δ15N) of SOM at an Arctic fjord namely Kongsfjorden. We find that the bound inorganic nitrogen (ammonium attached to the clay minerals) forms a significant proportion of total nitrogen concentration (~77% in the inner fjord to ~24% in the outer part). On removing the bound nitrogen, the C/N ratio shows that the SOM in the inner fjord is made up of terrestrial carbon while the outer fjord shows mixed marine-terrestrial signal. We further show that the marine organic matter is unusually more depleted in 13C (~−24‰) than the terrestrial organic matter (~−22.5‰). This particular finding also helps explain high δ13C values of SOM as noted by earlier studies in central Arctic sediments despite a high terrestrial contribution. PMID:27827457

The Upward Progress of Unusually Good Ideas in a Four-Tier Hierarchy.

ERIC Educational Resources Information Center

Dunning, Robert Scott; Sincoff, Michael Z.

In long established research organizations, it is necessary to safeguard good research ideas originating at lower organizational levels. The upward progress of unusually good ideas in an organizational hierarchy may be compared with that of ordinary ideas by means of a mathematical model, with the assumption that ideas follow a Poisson…

Were the original eubacteria thermophiles?

NASA Technical Reports Server (NTRS)

Achenbach-Richter, L.; Gupta, R.; Stetter, K. O.; Woese, C. R.; Johnson, P. C. (Principal Investigator)

1987-01-01

Thermotoga maritima is one of the more unusual eubacteria: It is highly thermophilic, growing at temperatures higher than any other eubacterium; its cell wall appears to have a unique structure and its lipids a unique composition; and the organism is surrounded by a loose-fitting sheath of unknown function. Its phenotypic uniqueness is matched by its phylogenetic position; Thermotoga maritima represents the deepest known branching in the eubacterial line of descent, as measured by ribosomal RNA sequence comparisons. T. maritima also represents the most slowly evolving of eubacterial lineages. The fact that the two deepest branchings in the eubacterial line of descent (the other, the green non-sulfur bacteria and relatives, i.e. Chloroflexus, Thermomicrobium, etc.) are both basically thermophilic and slowly evolving, strongly suggests that all eubacteria have ultimately arisen from a thermophilic ancestor.

Mid-Infrared Study of Samples from Multiple Stones from the Sutters Mill Meteorite

NASA Technical Reports Server (NTRS)

Sandford, S. A.; Nuevo, M.; Flynn, G. J.; Wirick, S.

2013-01-01

The Sutter's Mill meteorite fell in N. California on April 22, 2012 and numerous pieces have been recovered and studied. We present Fourier transform infrared (FTIR) spectra of fragments from several stones of the meteorite. Methods and analysis: Infrared spectra of the samples were recorded with a Nicolet iN10 MX FTIR microscope in the mid-IR range (4000-675/cm; spectral resolution 4/cm). All samples were deposited on a clean glass slide, crushed with a stainless steel roller tool, and placed directly on the focal plane of the microscope. IR spectra were collected by averaging 128 scans. Results: Preliminary IR spectra of the non-fusion crust samples show mineral compositions that are dominated by phyllosilicates, carbonates, or mixtures of both [2]. The carbonates display a dominant, broad band centered at 1433/cm, with additional bands at 2515/cm, 1797/cm, 882/cm, and 715/cm). Features associated with phyllosilicates include a symmetric Si-O stretching mode band centered at 1011/cm and several O-H stretching mode bands. The O-H shows up in two forms (1) a broadband centered at 3415/cm that is probably largely due to adsorbed H2O and (2) a much weaker, narrower feature centered near 3680/cm due to structural -OH. Features observed in the 2985-2855/cm range suggest the presence of aliphatic -CH3 and -CH2- groups. The relative intensities of the bands in this range are somewhat unusual. Typically, the asymmetric aliphatic CH stretching bands are stronger than the symmetric stretching bands, but in this case the reverse is true. This unusual pattern is well matched by the aliphatic features seen in the spectrum of a terrestrial calcite (CaCO3) standard. This observation, and the fact that the strength of the carbonate and aliphatic bands seem to correlate, suggest the organics are associated with the carbonates. Conclusions: IR spectra of samples from the Sutter's Mill meteorite show absorption features associated with carbonates, phyllosilicates, and organics. Both the unusual band profile of the aliphatic C-H stretching mode bands and their correlation with the strength of the carbonate bands suggests the organics and the carbonates are associated in some manner.

Stable isotope study of a new chondrichthyan fauna (Kimmeridgian, Porrentruy, Swiss Jura): an unusual freshwater-influenced isotopic composition for the hybodont shark Asteracanthus

NASA Astrophysics Data System (ADS)

Leuzinger, L.; Kocsis, L.; Billon-Bruyat, J.-P.; Spezzaferri, S.; Vennemann, T.

2015-12-01

Chondrichthyan teeth (sharks, rays, and chimaeras) are mineralized in isotopic equilibrium with the surrounding water, and parameters such as water temperature and salinity can be inferred from the oxygen isotopic composition (δ18Op) of their bioapatite. We analysed a new chondrichthyan assemblage, as well as teeth from bony fish (Pycnodontiformes). All specimens are from Kimmeridgian coastal marine deposits of the Swiss Jura (vicinity of Porrentruy, Ajoie district, NW Switzerland). While the overall faunal composition and the isotopic composition of bony fish are generally consistent with marine conditions, unusually low δ18Op values were measured for the hybodont shark Asteracanthus. These values are also lower compared to previously published data from older European Jurassic localities. Additional analyses on material from Solothurn (Kimmeridgian, NW Switzerland) also have comparable, low-18O isotopic compositions for Asteracanthus. The data are hence interpreted to represent a so far unique, freshwater-influenced isotopic composition for this shark that is classically considered a marine genus. While reproduction in freshwater or brackish realms is established for other hybodonts, a similar behaviour for Asteracanthus is proposed here. Regular excursions into lower salinity waters can be linked to the age of the deposits and correspond to an ecological adaptation, most likely driven by the Kimmeridgian transgression and by the competition of the hybodont shark Asteracanthus with the rapidly diversifying neoselachians (modern sharks).

Stable isotope study of a new chondrichthyan fauna (Kimmeridgian, Porrentruy, Swiss Jura): an unusual freshwater-influenced isotopic composition for the hybodont shark Asteracanthus

NASA Astrophysics Data System (ADS)

Leuzinger, L.; Kocsis, L.; Billon-Bruyat, J.-P.; Spezzaferri, S.; Vennemann, T.

2015-08-01

Chondrichthyan teeth (sharks, rays and chimaeras) are mineralised in isotopic equilibrium with the surrounding water, and parameters such as water temperature and salinity can be inferred from the oxygen isotopic composition (δ18Op) of their bioapatite. We analysed a new chondrichthyan assemblage, as well as teeth from bony fish (Pycnodontiformes). All specimens are from Kimmeridgian coastal marine deposits of the Swiss Jura (vicinity of Porrentruy, Ajoie district, NW Switzerland). While the overall faunal composition and the isotopic composition of bony fish are consistent with marine conditions, unusually low δ18Op values were measured for the hybodont shark Asteracanthus. These values are also lower compared to previously published data from older European Jurassic localities. Additional analyses on material from Solothurn (Kimmeridgian, NW Switzerland) also have comparable, low-18O isotopic compositions for Asteracanthus. The data are hence interpreted to represent a so far unique, freshwater-influenced isotopic composition for this shark that is classically considered as a marine genus. While reproduction in freshwater or brackish realms is established for other hybodonts, a similar behaviour for Asteracanthus is proposed here. Regular excursions into lower salinity waters can be linked to the age of the deposits and correspond to an ecological adaptation, most likely driven by the Kimmeridgian transgression and by the competition of the primitive shark Asteracanthus with the rapidly diversifying neoselachians (modern sharks).

The oligocene Lund Tuff, Great Basin, USA: A very large volume monotonous intermediate

USGS Publications Warehouse

Maughan, L.L.; Christiansen, E.H.; Best, M.G.; Gromme, C.S.; Deino, A.L.; Tingey, D.G.

2002-01-01

Unusual monotonous intermediate ignimbrites consist of phenocryst-rich dacite that occurs as very large volume (> 1000 km3) deposits that lack systematic compositional zonation, comagmatic rhyolite precursors, and underlying plinian beds. They are distinct from countless, usually smaller volume, zoned rhyolite-dacite-andesite deposits that are conventionally believed to have erupted from magma chambers in which thermal and compositional gradients were established because of sidewall crystallization and associated convective fractionation. Despite their great volume, or because of it, monotonous intermediates have received little attention. Documentation of the stratigraphy, composition, and geologic setting of the Lund Tuff - one of four monotonous intermediate tuffs in the middle-Tertiary Great Basin ignimbrite province - provides insight into its unusual origin and, by implication, the origin of other similar monotonous intermediates. The Lund Tuff is a single cooling unit with normal magnetic polarity whose volume likely exceeded 3000 km3. It was emplaced 29.02 ?? 0.04 Ma in and around the coeval White Rock caldera which has an unextended north-south diameter of about 50 km. The tuff is monotonous in that its phenocryst assemblage is virtually uniform throughout the deposit: plagioclase > quartz ??? hornblende > biotite > Fe-Ti oxides ??? sanidine > titanite, zircon, and apatite. However, ratios of phenocrysts vary by as much as an order of magnitude in a manner consistent with progressive crystallization in the pre-eruption chamber. A significant range in whole-rock chemical composition (e.g., 63-71 wt% SiO2) is poorly correlated with phenocryst abundance. These compositional attributes cannot have been caused wholly by winnowing of glass from phenocrysts during eruption, as has been suggested for the monotonous intermediate Fish Canyon Tuff. Pumice fragments are also crystal-rich, and chemically and mineralogically indistinguishable from bulk tuff. We postulate that convective mixing in a sill-like magma chamber precluded development of a zoned chamber with a rhyolitic top or of a zoned pyroclastic deposit. Chemical variations in the Lund Tuff are consistent with equilibrium crystallization of a parental dacitic magma followed by eruptive mixing of compositionally diverse crystals and high-silica rhyolite vitroclasts during evacuation and emplacement. This model contrasts with the more systematic withdrawal from a bottle-shaped chamber in which sidewall crystallization creates a marked vertical compositional gradient and a substantial volume of capping-evolved rhyolite magma. Eruption at exceptionally high discharge rates precluded development of an underlying plinian deposit. The generation of the monotonous intermediate Lund magma and others like it in the middle Tertiary of the western USA reflects an unusually high flux of mantle-derived mafic magma into unusually thick and warm crust above a subducting slab of oceanic lithosphere. ?? 2002 Elsevier Science B.V. All rights reserved.

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2013-08-09

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FE and MG Isotopic Analyses of Isotopically Unusual Presolar Silicate Grains

NASA Technical Reports Server (NTRS)

Nguyen, A. N.; Messenger, S.; Ito, M.; Rahman, Z.

2011-01-01

Interstellar and circumstellar silicate grains are thought to be Mg-rich and Fe-poor, based on astronomical observations and equilibrium condensation models of silicate dust formation in stellar outflows. On the other hand, presolar silicates isolated from meteorites have surprisingly high Fe contents and few Mg-rich grains are observed. The high Fe contents in meteoritic presolar silicates may indicate they formed by a non-equilibrium condensation process. Alternatively, the Fe in the stardust grains could have been acquired during parent body alteration. The origin of Fe in presolar silicates may be deduced from its isotopic composition. Thus far, Fe isotopic measurements of presolar silicates are limited to the Fe-54/Fe-56 ratios of 14 grains. Only two slight anomalies (albeit solar within error) were observed. However, these measurements suffered from contamination of Fe from the adjacent meteorite matrix, which diluted any isotopic anomalies. We have isolated four presolar silicates having unusual O isotopic compositions by focused ion beam (FIB) milling and obtained their undiluted Mg and Fe isotopic compositions. These compositions help to identify the grains stellar sources and to determine the source of Fe in the grains.

Parallels between UNUSUAL FLORAL ORGANS and FIMBRIATA, genes controlling flower development in Arabidopsis and Antirrhinum.

PubMed

Ingram, G C; Goodrich, J; Wilkinson, M D; Simon, R; Haughn, G W; Coen, E S

1995-09-01

The unusual floral organs (ufo) mutant of Arabidopsis has flowers with variable homeotic organ transformations and inflorescence-like characteristics. To determine the relationship between UFO and previously characterized meristem and organ identity genes, we cloned UFO and determined its expression pattern. The UFO gene shows extensive homology with FIMBRIATA (FIM), a gene mediating between meristem and organ identity genes in Antirrhinum. All three UFO mutant alleles that we sequenced are predicted to produce truncated proteins. UFO transcripts were first detected in early floral meristems, before organ identity genes had been activated. At later developmental stages, UFO expression is restricted to the junction between sepal and petal primordia. Phenotypic, genetic, and expression pattern comparisons between UFO and FIM suggest that they are cognate homologs and play a similar role in mediating between meristem and organ identity genes. However, some differences in the functions and genetic interactions of UFO and FIM were apparent, indicating that changes in partially redundant pathways have occurred during the evolutionary divergence of Arabidopsis and Antirrhinum.

Spin dynamics of light-induced charge separation in composites of semiconducting polymers and PC60BM revealed using Q-band pulse EPR.

PubMed

Lukina, E A; Suturina, E; Reijerse, E; Lubitz, W; Kulik, L V

2017-08-23

Light-induced processes in composites of semiconducting polymers and fullerene derivatives have been widely studied due to their usage as active layers of organic solar cells. However the process of charge separation under light illumination - the key process of an organic solar cell is not well understood yet. Here we report a Q-band pulse electron paramagnetic resonance study of composites of the fullerene derivative PC 60 BM ([6,6]-phenyl-C 61 -butyric acid methyl ester) with different p-type semiconducting polymers regioregular and regiorandom P3HT (poly(3-hexylthiophene-2,5-diyl), MEH-PPV (poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]), PCDTBT (poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)]), PTB7 (poly({4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl}))), resulting in a detailed description of the in-phase laser flash-induced electron spin echo (ESE) signal. We found that in organic donor-acceptor composites the laser flash simultaneously induces species of two types: a polymer˙ + /fullerene˙ - spin-correlated polaron pair (SCPP) with an initial singlet spin state and (nearly) free polymer˙ + and fullerene˙ - species with non-equilibrium spin polarization. Species of the first type (SCPP) are well-known for polymer/fullerene blends and are usually associated with a charge-separated state. Also, spin polarization of long-living free species (polarons in deep traps) is affected by the laser flash, which is the third contribution to the flash-induced ESE signal. A protocol for extracting the in-phase ESE signal of the SCPP based on the dependence of the microwave nutation frequency on the strength of the spin coupling within the polaron pair was developed. Nutation experiments revealed an unusual pattern of the SCPP in RR-P3HT/PC 60 BM composites, from which the strength of the exchange interaction between the polymer˙ + and fullerene˙ - was extracted. In composites with low-efficient polymers the contribution of the SCPP to the in-phase ESE signal is high, while in composites with high-efficient polymers it is low. This finding can be used as a selection criterion of charge separation efficiency in the polymer/fullerene composites.

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2013-07-09

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Isolation, purification and chemical composition of insoluble collagen from Guerin epithelioma.

PubMed

Bańkowski, E; Galasiński, W; Gindzieẃski, A; Rzeczycki, W

1975-01-01

1. The insoluble collagen from Guerin epithelioma was isolated and its chemical composition was determined. The unusually high histidine content is accompanied in tumour collagen by a relatively small amount of lysine and arginine. 2. The isolated protein was strongly bound to glycoprotein, which could not be removed by EDTA treatment unless this procedure was preceded by digestion of the complex with trypsin.

Nano-structured calcite produced by micro-organisms in ancient and modern loess in Chinese Loess Plateau

NASA Astrophysics Data System (ADS)

Xu, H.; Chen, T.; Lu, H.; Wang, X.

2005-12-01

The results from transmission electron microscopy (TEM) and field emission gun scanning microscopy (FEG-SEM) investigation show that there are calcite nano-fibers (CNFs) formed during pedogenic process. The CNFs are widely distributed in the loess and red clay samples of Caoxian, Luochuan, Lingtai, Lantian, and Xifeng profiles as well as the samples of modern surface loess soils in Chinese Loess Plateau. Diameters of all the NFCs are about 40 nm, the length of the CNFs ranges from tens nanometer to several micrometers. Elongation direction of NFCs is unusual near parallel (105)* or (115)*. Crystals of NFCs arrange as bird net like and lattice-like frameworks. X-ray EDS spectra show the weak peaks of magnesium, phosphorous, and sulfur. Our investigation indicates that CNFs are in pore space of loess and paleosol and made up most of carbonate except for caliche nodular layers. Concentration of NFCs in the loess layers are significantly higher than those of paleosol layers because of leaching of carbonate in the paleosol forming environment (warn and wet paleoclimate). The "nanobacteria-like CNFs are well crystalline calcite single crystals with smoothes surfaces. The morphologies of CNFs are very unusual and different from the calcite single crystals observed in most geological environments. The CNFs are directly related to microbial activities in both ancient and modern loess. It is proposed that the intervention of organic compounds derived from microbial activities control the formation of the calcite nano-fibers. Both morphology and bulk composition of CNFs indicate that the formation of the CNFs involves bio-organics derived from microorganisms in loess deposit environment. Formation conditions of the calcite nano-fibers may information about paleoclimate, paleo-environment and paleoecology. So, the discovery of CNFs in loess-paloesol sequences can provide a new route for reconstruct paleoclimate by oxygen and carbon isotope from the CNFs.

Who Can You Trust? Protecting Your Organization from Internal Fraud.

ERIC Educational Resources Information Center

Lukaszewski, Thomas E.

1997-01-01

Discusses how to protect a child care organization from employee fraud. Differentiates employee and management fraud and examines reasons fraud is committed. Suggests procedures for protecting an organization from fraud, including establishing an effective internal control system, paying attention to unusual employee behavior, reviewing expense…

High Field Remagnetization of Hematite Concretions from Utah, USA and Czech Republic

NASA Astrophysics Data System (ADS)

Adachi, T.; Kletetschka, G.; Chan, M.; Mikula, V.; Adamovic, J.; Pruner, P.; Schnabl, P.; Wasilewski, P.

2007-03-01

Terrestrial hematite concretions of the Navajo Sandstone have been discussed as analogues to the blueberries on Mars. Magnetic investigation of terrestrial concretions showed unusual behavior of antiferromagnetic hematite-goethite composition that may mem

Distant Galaxies in Goods North

NASA Image and Video Library

2014-01-07

The view is a composite of images taken in visible and near-infrared light by NASA Hubble Space Telescope. Researchers have circled four unusually red objects that appear as they existed just 500 million years after the big bang.

Multimaterial magnetically assisted 3D printing of composite materials.

PubMed

Kokkinis, Dimitri; Schaffner, Manuel; Studart, André R

2015-10-23

3D printing has become commonplace for the manufacturing of objects with unusual geometries. Recent developments that enabled printing of multiple materials indicate that the technology can potentially offer a much wider design space beyond unusual shaping. Here we show that a new dimension in this design space can be exploited through the control of the orientation of anisotropic particles used as building blocks during a direct ink-writing process. Particle orientation control is demonstrated by applying low magnetic fields on deposited inks pre-loaded with magnetized stiff platelets. Multimaterial dispensers and a two-component mixing unit provide additional control over the local composition of the printed material. The five-dimensional design space covered by the proposed multimaterial magnetically assisted 3D printing platform (MM-3D printing) opens the way towards the manufacturing of functional heterogeneous materials with exquisite microstructural features thus far only accessible by biological materials grown in nature.

Multimaterial magnetically assisted 3D printing of composite materials

NASA Astrophysics Data System (ADS)

Kokkinis, Dimitri; Schaffner, Manuel; Studart, André R.

2015-10-01

3D printing has become commonplace for the manufacturing of objects with unusual geometries. Recent developments that enabled printing of multiple materials indicate that the technology can potentially offer a much wider design space beyond unusual shaping. Here we show that a new dimension in this design space can be exploited through the control of the orientation of anisotropic particles used as building blocks during a direct ink-writing process. Particle orientation control is demonstrated by applying low magnetic fields on deposited inks pre-loaded with magnetized stiff platelets. Multimaterial dispensers and a two-component mixing unit provide additional control over the local composition of the printed material. The five-dimensional design space covered by the proposed multimaterial magnetically assisted 3D printing platform (MM-3D printing) opens the way towards the manufacturing of functional heterogeneous materials with exquisite microstructural features thus far only accessible by biological materials grown in nature.

Modelling the development of defects during composite reinforcements and prepreg forming

PubMed Central

Hamila, N.; Madeo, A.

2016-01-01

Defects in composite materials are created during manufacture to a large extent. To avoid them as much as possible, it is important that process simulations model the onset and the development of these defects. It is then possible to determine the manufacturing conditions that lead to the absence or to the controlled presence of such defects. Three types of defects that may appear during textile composite reinforcement or prepreg forming are analysed and modelled in this paper. Wrinkling is one of the most common flaws that occur during textile composite reinforcement forming processes. The influence of the different rigidities of the textile reinforcement is studied. The concept of ‘locking angle’ is questioned. A second type of unusual behaviour of fibrous composite reinforcements that can be seen as a flaw during their forming process is the onset of peculiar ‘transition zones’ that are directly related to the bending stiffness of the fibres. The ‘transition zones’ are due to the bending stiffness of fibres. The standard continuum mechanics of Cauchy is not sufficient to model these defects. A second gradient approach is presented that allows one to account for such unusual behaviours and to master their onset and development during forming process simulations. Finally, the large slippages that may occur during a preform forming are discussed and simulated with meso finite-element models used for macroscopic forming. This article is part of the themed issue ‘Multiscale modelling of the structural integrity of composite materials’. PMID:27242300

Modelling the development of defects during composite reinforcements and prepreg forming.

PubMed

Boisse, P; Hamila, N; Madeo, A

2016-07-13

Defects in composite materials are created during manufacture to a large extent. To avoid them as much as possible, it is important that process simulations model the onset and the development of these defects. It is then possible to determine the manufacturing conditions that lead to the absence or to the controlled presence of such defects. Three types of defects that may appear during textile composite reinforcement or prepreg forming are analysed and modelled in this paper. Wrinkling is one of the most common flaws that occur during textile composite reinforcement forming processes. The influence of the different rigidities of the textile reinforcement is studied. The concept of 'locking angle' is questioned. A second type of unusual behaviour of fibrous composite reinforcements that can be seen as a flaw during their forming process is the onset of peculiar 'transition zones' that are directly related to the bending stiffness of the fibres. The 'transition zones' are due to the bending stiffness of fibres. The standard continuum mechanics of Cauchy is not sufficient to model these defects. A second gradient approach is presented that allows one to account for such unusual behaviours and to master their onset and development during forming process simulations. Finally, the large slippages that may occur during a preform forming are discussed and simulated with meso finite-element models used for macroscopic forming. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'. © 2016 The Author(s).

Diagnosis of systemic lupus erythematosus in an unusual presentation: what a primary care physician should know.

PubMed

Pramanik, Bimalendu

2014-01-01

Systemic Lupus Erythematosus (SLE) is a multisystem autoimmune disease affecting millions of people worldwide. It can affect any organ systems of the body. However, all systems may not be involved initially rather than they may be affected gradually, sometimes over years. Diagnosis depends on characteristic clinical features and laboratory test results. Some features such as skin rash, joint symptoms and oral ulcers are common in SLE. But initial presentation of many patients is unusual because either they do not have these common features of the disease or the presentation mimics other illnesses. As a result, delayed diagnosis and misdiagnosis are common. Therefore, high index of initial suspicion of SLE is critical. In clinical practice, SLE should be suspected in any patient presenting with an unexplained disease process involving two or more organ systems. To make a diagnosis in an unusual presentation, thorough clinical evaluation with details history of both present and past illnesses as well as laboratory tests for SLE should be performed. Usually primary-care physicians first evaluate SLE patients; but there is no single article, where all the information on when to suspect SLE in an unusual presentation, is available in an integrated form. In this article, a list of conditions, when SLE should be suspected in an unusual presentation, has been given and some relatively common areas with diagnostic challenges of SLE have been briefly described. To prepare this manuscript, most articles have been identified through 'Pubmed' search using keywords-atypical/ unusual presentation of SLE, case reports on SLE, gastrointestinal manifestations of SLE, neuropsychiatric SLE, diagnostic challenges with SLE, etc. Selected most articles are from currently medline-indexed journals.

Hierarchical mesostructured titanium phosphonates with unusual uniform lines of macropores.

PubMed

Ma, Tian-Yi; Lin, Xiu-Zhen; Zhang, Xue-Jun; Yuan, Zhong-Yong

2011-04-01

Organic-inorganic hybrid materials of mesostructured titanium phosphonates with unusual uniform lines of macropores were synthesized by using bis(hexamethylenetriamine) penta(methylenephosphonic acid) (BHMTPMP) as the coupling molecule, through a one-pot hydrothermal process without any surfactant assistance. A wormhole-like mesostructure and many uniform parallel lines of macropores divided by solid ridges in the same direction were confirmed by N(2) sorption, SEM and TEM observations. This novel macropore architecture has never been observed in other metal phosphonate materials, which may be directly related to the structure nature of BHMTPMP with extra long alkyl chains. The structural characterization of FT-IR and MAS NMR revealed the integrity of organic groups inside the hybrid framework. The hybrid materials were also used as adsorbents for heavy metal ions and CO(2), in order to clarify the impacts of the organic contents and organic types on the physicochemical properties of the synthesized hierarchical macro-/mesoporous phosphonate materials.

Cadmium and zinc isotopes of organic-rich marine sediments during Oceanic Anoxic Event 2

NASA Astrophysics Data System (ADS)

Sweere, T.; Dickson, A. J.; Jenkyns, H. C.; Porcelli, D.; Henderson, G. M.; van den Boorn, S.

2017-12-01

Mesozoic Oceanic Anoxic Events (OAEs) are characterized by widespread deposition of organic-rich sediments and the spread of low-oxygen marine environments. To drive and sustain unusually efficient carbon-burial during these events requires high export productivity rates, which has to be supported by an abundance of nutrients in the surface ocean. The presence of redox-sensitive bio-essential micronutrients may be particularly important, and potentially bio-limiting, during such events as they may be drawn down into sediment under low-oxygen conditions. Cadmium and zinc isotopes have potential as tracers for past (micro)nutrient dynamics considering their nutrient-like distribution in the modern ocean and isotope fractionation with uptake by primary producers. The modern deep ocean is generally well mixed for Cd and Zn while short-term cycling of these elements in the surface ocean imposes regional variation. Additional regional variation may be caused by sulfide formation and associated isotope fractionation in euxinic environments. The impact of such regional environmental conditions on the Cd- and Zn-isotope composition of the sediment therefore needs to be addressed in order to explore the use of these elements as a proxy for past nutrient conditions. Here we present an extensive dataset of cadmium- and zinc-isotope compositions of organic-rich marine sediments from different basins deposited during OAE 2 (Late Cretaceous). This comparison highlights regional differences in Cd- and Zn-isotope compositions. However, despite regional environmental controls, a correlation between δ114Cd and δ66Zn across the different sites is observed, which implies a largely similar control on the two isotope systems. When regional environmental controls are accounted for, the data may provide insight in the δ66Zn and δ114Cd evolution of global seawater during OAE 2 as well as information on the global cycling of redox-sensitive micronutrients during the event

A biopolymer-like metal enabled hybrid material with exceptional mechanical prowess

DOE PAGES

Zhang, Junsong; Cui, Lishan; Jiang, Daqiang; ...

2015-02-10

In this study, the design principles for naturally occurring biological materials have inspired us to develop next-generation engineering materials with remarkable performance. Nacre, commonly referred to as nature's armor, is renowned for its unusual combination of strength and toughness. Nature's wisdom in nacre resides in its elaborate structural design and the judicious placement of a unique organic biopolymer with intelligent deformation features. However, up to now, it is still a challenge to transcribe the biopolymer's deformation attributes into a stronger substitute in the design of new materials. In this study, we propose a new design strategy that employs shape memorymore » alloy to transcribe the "J-curve'' mechanical response and uniform molecular/atomic level deformation of the organic biopolymer in the design of high-performance hybrid materials. This design strategy is verified in a TiNi-Ti 3Sn model material system. The model material demonstrates an exceptional combination of mechanical properties that are superior to other high-performance metal-based lamellar composites known to date. Our design strategy creates new opportunities for the development of high-performance bio-inspired materials.« less

A biopolymer-like metal enabled hybrid material with exceptional mechanical prowess

PubMed Central

Zhang, Junsong; Cui, Lishan; Jiang, Daqiang; Liu, Yinong; Hao, Shijie; Ren, Yang; Han, Xiaodong; Liu, Zhenyang; Wang, Yunzhi; Yu, Cun; Huan, Yong; Zhao, Xinqing; Zheng, Yanjun; Xu, Huibin; Ren, Xiaobing; Li, Xiaodong

2015-01-01

The design principles for naturally occurring biological materials have inspired us to develop next-generation engineering materials with remarkable performance. Nacre, commonly referred to as nature's armor, is renowned for its unusual combination of strength and toughness. Nature's wisdom in nacre resides in its elaborate structural design and the judicious placement of a unique organic biopolymer with intelligent deformation features. However, up to now, it is still a challenge to transcribe the biopolymer's deformation attributes into a stronger substitute in the design of new materials. In this study, we propose a new design strategy that employs shape memory alloy to transcribe the “J-curve” mechanical response and uniform molecular/atomic level deformation of the organic biopolymer in the design of high-performance hybrid materials. This design strategy is verified in a TiNi-Ti3Sn model material system. The model material demonstrates an exceptional combination of mechanical properties that are superior to other high-performance metal-based lamellar composites known to date. Our design strategy creates new opportunities for the development of high-performance bio-inspired materials. PMID:25665501

A biopolymer-like metal enabled hybrid material with exceptional mechanical prowess.

PubMed

Zhang, Junsong; Cui, Lishan; Jiang, Daqiang; Liu, Yinong; Hao, Shijie; Ren, Yang; Han, Xiaodong; Liu, Zhenyang; Wang, Yunzhi; Yu, Cun; Huan, Yong; Zhao, Xinqing; Zheng, Yanjun; Xu, Huibin; Ren, Xiaobing; Li, Xiaodong

2015-02-10

The design principles for naturally occurring biological materials have inspired us to develop next-generation engineering materials with remarkable performance. Nacre, commonly referred to as nature's armor, is renowned for its unusual combination of strength and toughness. Nature's wisdom in nacre resides in its elaborate structural design and the judicious placement of a unique organic biopolymer with intelligent deformation features. However, up to now, it is still a challenge to transcribe the biopolymer's deformation attributes into a stronger substitute in the design of new materials. In this study, we propose a new design strategy that employs shape memory alloy to transcribe the "J-curve" mechanical response and uniform molecular/atomic level deformation of the organic biopolymer in the design of high-performance hybrid materials. This design strategy is verified in a TiNi-Ti3Sn model material system. The model material demonstrates an exceptional combination of mechanical properties that are superior to other high-performance metal-based lamellar composites known to date. Our design strategy creates new opportunities for the development of high-performance bio-inspired materials.

The architecture of the joint head cuticle and its transition to the arthrodial membrane in the terrestrial crustacean Porcellio scaber.

PubMed

Ruangchai, Sukhum; Reisecker, Christian; Hild, Sabine; Ziegler, Andreas

2013-04-01

The cuticle of terrestrial isopods is an interesting model for the study of structure-function relationships in biological composite materials. Its organic matrix has a hierarchically organised structure, and type and phase of the mineral compound can vary. The cuticle forms functionally diverse skeletal elements whose properties are adapted to their specific functions. In order to better understand the relation between structure, composition and function of isopod cuticle, we studied the structure and composition of the joint head that is part of the pereiopod's basis. It consists of a central region, whose shape fits well into the joint socket, and an edge region that is connected to the soft arthrodial membrane and protects the central region from mechanical load. The cuticle architecture of the joint head has local variations in structure and composition. In the central region the cuticle is similar to the previously published tergite cuticle. High concentrations of amorphous calcium phosphate are located in the endocuticle suggesting a coexistence with amorphous calcium carbonate. The edge region has an unexpected organisation characterised by thickening of the epi- and exocuticle and an unusual unidirectional orientation of chitin-protein fibrils within the endocuticle. The concentrations of phosphate are considerably higher than in the central region. The overall differentiation in the cuticular architecture of the edge in comparison to the central region reflects the adaptation to mechanical strains the cuticle has to sustain during contraction of extensor muscles, and to the structural and compositional transition from the edge to the connecting arthrodial membrane. Copyright © 2013 Elsevier Inc. All rights reserved.

Evidence from in vivo manipulations of lipid composition in mutants that the delta 3-trans-hexadecenoic acid-containing phosphatidylglycerol is involved in the biogenesis of the light-harvesting chlorophyll a/b-protein complex of Chlamydomonas reinhardtii.

PubMed

Dubertret, G; Mirshahi, A; Mirshahi, M; Gerard-Hirne, C; Tremolieres, A

1994-12-01

The phosphatidylglycerol containing the unusual delta 3-trans hexadecenoic fatty acid is specifically found in photosynthetic membranes of eukaryotic organisms. Its involvement in the biogenesis and the structure of the light-harvesting chlorophyll a/b-protein complex has been evidenced by in vivo targeting this lipid to photosynthetic membranes of Chlamydomonas reinhardtii mutants lacking this lipid. In the mf1 and mf2 mutants, this deficiency results in (a) the absence of the oligomeric light-harvesting complex of photosystem 2; (b) an extensive destacking of thylakoid membranes; (c) a very low 77-K fluorescence emission in the photosystem-2 region. We show in this paper that these deficiencies result from modifications in the pigment and polypeptide compositions of the photosystem-2 light-harvesting complex; it contains less chlorophyll b and some of its constitutive polypeptides are absent or reduced in amount, while immunologically related polypeptides of lower molecular mass accumulate. The direct involvement of the lack of trans-C16: 1-phosphatidylglycerol in these deficiencies is evidenced by the partial restoration of normal characteristics of the light-harvesting complex (pigment and polypeptide composition, oligomerization) after liposome-mediated, in vivo incorporation of this lipid into the photosynthetic membranes of the mf2 mutant. Trans-C16:1-phosphatidylglycerol, therefore, is involved in the biogenesis of the photosystem-2 light-harvesting chlorophyll a/b-protein complex through a mechanism that may prevent degradation processes. Its contribution to the structural conformation of neosynthesized monomers and to their organization into stable oligomeric form is discussed.

Hydra actinoporin-like toxin-1, an unusual hemolysin from the nematocyst venom of Hydra magnipapillata which belongs to an extended gene family.

PubMed

Glasser, Eliezra; Rachamim, Tamar; Aharonovich, Dikla; Sher, Daniel

2014-12-01

Cnidarians rely on their nematocysts and the venom injected through these unique weaponry systems to catch prey and protect themselves from predators. The development and physiology of the nematocysts of Hydra magnipapillata, a classic model organism, have been intensively studied, yet the composition and biochemical activity of their venom components are mostly unknown. Here, we show that hydra actinoporin-like toxins (HALTs), which have previously been associated with Hydra nematocysts, belong to a multigene family comprising six genes, which have diverged from a single common ancestor. All six genes are expressed in a population of Hydra magnipapillata. When expressed recombinantly, HALT-1 (Δ-HYTX-Hma1a), an actinoporin-like protein found in the stenoteles (the main penetrating nematocysts used in prey capture), reveals hemolytic activity, albeit about two-thirds lower than that of the anemone actinoporin equinatoxin II (EqTII, Δ-AITX-Aeq1a). HALT-1 also differs from EqTII in the size of its pores, and likely does not utilize sphingomyelin as a membrane receptor. We describe features of the HALT-1 sequence which may contribute to this difference in activity, and speculate on the role of this unusual family of pore-forming toxins in the ecology of Hydra. Copyright © 2014 Elsevier Ltd. All rights reserved.

Provenance and composition of unusually chrome and nickel-rich bucket-shaped pottery from Rogaland (southwestern Norway)

NASA Astrophysics Data System (ADS)

Zimmermann, Udo; Kristoffersen, Elna Siv; Fredriksen, Per Ditlef; Bertolino, Silvana A. R.; Andò, Sergio; Bersani, Danilo

2016-05-01

We report results from FE-SEM-EDS, geochemical, mineralogical analyses and Raman spectroscopy of pottery of bucket-shaped ceramic from Rogaland (southwestern Norway) dated between the 5th and 6th Century. The study reveals a very rare pottery composition including asbestos-group minerals and an unusual enrichment in compatible elements like Cr (8-27 × Post Archean average shale (PAS), McLennan et al., 2006), Ni (2-8 × normal shale) and Co (2-3 × PAS). X-Rray diffraction and Raman spectroscopy could pinpoint that Ni is introduced by specific Ni-rich talc mineral and chlorite minerals and Cr occurs in a rare Cr-rich talc, and possibly in a Cr-chlorite, these minerals are the most abundant in the pottery, which is supported by strong enrichment in Mg (10-20 × PAS). The addition of Mg, Cr, Ni and Co and other compatible trace elements is to our current knowledge not caused by anthropogenic activity but related to the used materials, which are alteration products of mafic and ultramafic rocks or genetically related to mafic and ultramafic rocks. Rocks of this type are exposed in vicinity of the sampling areas in a region called Karmøy, hosting a world famous ophiolite complex, which is identified as the major source for the mafic and ultramafic component, as the next succession of a similar composition is far further north located in Norway and a number of rock types on Karmøy matches the chemical composition of the pottery. The here reported composition is spectacular and extremely rare - if ever found - in pottery. Our study shows that unusual material sources have been used in pottery production, and this opens for discussion whether the materials were deliberately selected by the manufacturers, thereby expressing a specific social function, in a time period where more functional clay types and additives, and certainly functional and sufficient for use in pottery, where abundant in areas of Rogaland closer to where the pots were found.

Particle size effect on strength, failure, and shock behavior in polytetrafluoroethylene-Al-W granular composite materials

NASA Astrophysics Data System (ADS)

Herbold, E. B.; Nesterenko, V. F.; Benson, D. J.; Cai, J.; Vecchio, K. S.; Jiang, F.; Addiss, J. W.; Walley, S. M.; Proud, W. G.

2008-11-01

The variation of metallic particle size and sample porosity significantly alters the dynamic mechanical properties of high density granular composite materials processed using a cold isostatically pressed mixture of polytetrafluoroethylene (PTFE), aluminum (Al), and tungsten (W) powders. Quasistatic and dynamic experiments are performed with identical constituent mass fractions with variations in the size of the W particles and pressing conditions. The relatively weak polymer matrix allows the strength and fracture modes of this material to be governed by the granular type behavior of agglomerated metal particles. A higher ultimate compressive strength was observed in relatively high porosity samples with small W particles compared to those with coarse W particles in all experiments. Mesoscale granular force chains of the metallic particles explain this unusual phenomenon as observed in hydrocode simulations of a drop-weight test. Macrocracks forming below the critical failure strain for the matrix and unusual behavior due to a competition between densification and fracture in dynamic tests of porous samples were also observed. Numerical modeling of shock loading of this granular composite material demonstrated that the internal energy, specifically thermal energy, of the soft PTFE matrix can be tailored by the W particle size distribution.

Eco-Friendly Magnetic Iron Oxide Pillared Montmorillonite for Advanced Catalytic Degradation of Dichlorophenol

EPA Science Inventory

Eco-friendly pillared montmorillonites, in which the pillars consist of iron oxide are expected to have interesting and unusual magnetic properties that are applicable for environmental decontamination. Completely “green” and effective composite was synthesized using mild reactio...

AN UNUSUAL POLYUNSATURATED C27 HYDROCARBON FROM THE MARINE DINOFLAGELLATE PYROCYSTIS LUNULA

EPA Science Inventory

Studies of the lipids of different algal species have revealed a diversity of fatty acids, sterols, and hydrocarbons, of which several are considered useful biomarkers, with potential for characterizing phytoplankton community composition. To extend this approach and characterize...

European external quality control study on the competence of laboratories to recognize rare sequence variants resulting in unusual genotyping results.

PubMed

Márki-Zay, János; Klein, Christoph L; Gancberg, David; Schimmel, Heinz G; Dux, László

2009-04-01

Depending on the method used, rare sequence variants adjacent to the single nucleotide polymorphism (SNP) of interest may cause unusual or erroneous genotyping results. Because such rare variants are known for many genes commonly tested in diagnostic laboratories, we organized a proficiency study to assess their influence on the accuracy of reported laboratory results. Four external quality control materials were processed and sent to 283 laboratories through 3 EQA organizers for analysis of the prothrombin 20210G>A mutation. Two of these quality control materials contained sequence variants introduced by site-directed mutagenesis. One hundred eighty-nine laboratories participated in the study. When samples gave a usual result with the method applied, the error rate was 5.1%. Detailed analysis showed that more than 70% of the failures were reported from only 9 laboratories. Allele-specific amplification-based PCR had a much higher error rate than other methods (18.3% vs 2.9%). The variants 20209C>T and [20175T>G; 20179_20180delAC] resulted in unusual genotyping results in 67 and 85 laboratories, respectively. Eighty-three (54.6%) of these unusual results were not recognized, 32 (21.1%) were attributed to technical issues, and only 37 (24.3%) were recognized as another sequence variant. Our findings revealed that some of the participating laboratories were not able to recognize and correctly interpret unusual genotyping results caused by rare SNPs. Our study indicates that the majority of the failures could be avoided by improved training and careful selection and validation of the methods applied.

GENOME ANALYSIS OF BURKHOLDERIA CEPACIA AC1100

EPA Science Inventory

Burkholderia cepacia is an important organism in bioremediation of environmental pollutants and it is also of increasing interest as a human pathogen. The genomic organization of B. cepacia is being studied in order to better understand its unusual adaptive capacity and genome pl...

γ-Tubulin complex in Trypanosoma brucei: molecular composition, subunit interdependence and requirement for axonemal central pair protein assembly.

PubMed

Zhou, Qing; Li, Ziyin

2015-11-01

γ-Tubulin complex constitutes a key component of the microtubule-organizing center and nucleates microtubule assembly. This complex differs in complexity in different organisms: the budding yeast contains the γ-tubulin small complex (γTuSC) composed of γ-tubulin, gamma-tubulin complex protein (GCP)2 and GCP3, whereas animals contain the γ-tubulin ring complex (γTuRC) composed of γTuSC and three additional proteins, GCP4, GCP5 and GCP6. In Trypanosoma brucei, the composition of the γ-tubulin complex remains elusive, and it is not known whether it also regulates assembly of the subpellicular microtubules and the spindle microtubules. Here we report that the γ-tubulin complex in T. brucei is composed of γ-tubulin and three GCP proteins, GCP2-GCP4, and is primarily localized in the basal body throughout the cell cycle. Depletion of GCP2 and GCP3, but not GCP4, disrupted the axonemal central pair microtubules, but not the subpellicular microtubules and the spindle microtubules. Furthermore, we showed that the γTuSC is required for assembly of two central pair proteins and that γTuSC subunits are mutually required for stability. Together, these results identified an unusual γ-tubulin complex in T. brucei, uncovered an essential role of γTuSC in central pair protein assembly, and demonstrated the interdependence of individual γTuSC components for maintaining a stable complex. © 2015 John Wiley & Sons Ltd.

The γ-tubulin complex in Trypanosoma brucei: molecular composition, subunit interdependence and requirement for axonemal central pair protein assembly

PubMed Central

Zhou, Qing; Li, Ziyin

2015-01-01

The γ-tubulin complex constitutes a key component of the microtubule-organizing center and nucleates microtubule assembly. This complex differs in complexity in different organisms: the budding yeast contains the γ-tubulin small complex (γTuSC) composed of γ-tubulin, GCP2 and GCP3, whereas animals contain the γ-tubulin ring complex (γTuRC) composed of γTuSC and three additional proteins, GCP4, GCP5 and GCP6. In Trypanosoma brucei, the composition of the γ-tubulin complex remains elusive, and it is not known whether it also regulates assembly of the subpellicular microtubules and the spindle microtubules. Here we report that the γ-tubulin complex in T. brucei is composed of γ-tubulin and three GCP proteins, GCP2-GCP4, and is primarily localized in the basal body throughout the cell cycle. Depletion of GCP2 and GCP3, but not GCP4, disrupted the axonemal central pair microtubules, but not the subpellicular microtubules and the spindle microtubules. Furthermore, we showed that the γTuSC is required for assembly of two central pair proteins and that γTuSC subunits are mutually required for stability. Together, these results identified an unusual γ-tubulin complex in T. brucei, uncovered an essential role of γTuSC in central pair protein assembly, and demonstrated the interdependence of individual γTuSC components for maintaining a stable complex. PMID:26224545

Complete duplication of bladder and urethra in a sagittal plane in a male infant: case report and literature review.

PubMed

Coker, Alisa M; Allshouse, Michael J; Koyle, Martin A

2008-08-01

Complete duplication of the bladder and urethra is a rare entity. It may occur in the coronal and sagittal planes, and is often associated with other organ system anomalies, in particular of the gastrointestinal tract. We report an unusual variant of sagittal duplication of the bladder, in a male, associated with rudimentary hindgut duplication, and review the literature pertaining to this unusual anomaly.

Unusual Synchronous Presentation of Maxillary Sinus Fibrosarcoma and Gemistocytic Astrocytoma with a Complication Called Leukocytoclastic Vasculitis: A Case Report

PubMed Central

Cadir, Bilge; Karahan, Nermin; Nasir, Serdar; Aydin, M. Asim; Turkaslan, S. Suha

2009-01-01

Fibrosarcoma of the paranasal sinuses is extremely rare pathology and there is limited report in the literature. We report synchronous presentation of maxillary sinus fibrosarcoma and gemistocytic astrocytoma which is, to our knowledge, unique in the literature. Both tumors metastases to other organ rarely and the metastatic spread of gemistocytic astrocytoma to fibrosarcoma or vice versa have also not been reported in the literature yet. This report discusses the clinical course of the disease, outcome of the treatment approach and survival as well as an unusual occurrence of leukocytoclastic vasculitis during the course of radiotherapy in such unusual presentation. PMID:19756200

Acidophilic Halophilic Microorganisms in Fluid Inclusions in Halite from Lake Magic, Western Australia

PubMed Central

Conner, Amber J.

2013-01-01

Abstract Lake Magic is one of the most extreme of hundreds of ephemeral acid-saline lakes in southern Western Australia. It has pH as low as 1.7, salinity as high as 32% total dissolved solids, temperatures ranging from 0°C to 50°C, and an unusually complex aqueous composition. Optical petrography, UV-vis petrography, and laser Raman spectrometry were used to detect microorganisms and organic compounds within primary fluid inclusions in modern bedded halite from Lake Magic. Rare prokaryotes appear as 1–3 μm, bright cocci that fluoresce green with UV-vis illumination. Dimpled, 5–7 μm yellow spherules that fluoresce blue with UV-vis illumination are interpreted as Dunaliella algae. Yellow-orange beta-carotene crystals, globules, and coatings are characterized by orange-red fluorescence and three distinct Raman peaks. Because acid saline lakes are good Mars analogues, the documentation of prokaryotes, eukaryotes, and organic compounds preserved in the halite here has implications for the search for life on Mars. Missions to Mars should incorporate such in situ optical and chemical examination of martian evaporites for possible microorganisms and/or organic compounds in fluid inclusions. Key Words: Acid—Extremophiles—Western Australia—Fluid inclusions—Lake Magic—Dunaliella. Astrobiology 13, 850–860. PMID:23971647

An Unusual Coronal Mass Ejection: First Solar Wind Electron, Proton, Alpha Monitor (SWEPAM) Results from the Advanced Composition Explorer. Appendix 6

NASA Technical Reports Server (NTRS)

McComas, D. J.; Bame, S. J.; Barker, P. L.; Delapp, D. M.; Gosling, J. T.; Skoug, R. M.; Tokar, R. L.; Riley, P.; Feldman, W. C.; Santiago, E.

2001-01-01

This paper reports the first scientific results from the Solar Wind Electron Proton Alpha Monitor (SWEPAM) instrument on board the Advanced Composition Explorer (ACE) spacecraft. We analyzed a coronal mass ejection (CME) observed in the solar wind using data from early February, 1998. This event displayed several of the common signatures of CMEs, such as counterstreaming halo electrons and depressed ion and electron temperatures, as well as some unusual features. During a portion of the CME traversal, SWEPAM measured a very large helium to proton abundance ratio. Other heavy ions, with a set of ionization states consistent with normal (1 to 2x10(exp 6) K) coronal temperatures, were proportionately enhanced at this time. These observations suggest a source for at least some of the CME material, where heavy ions are initially concentrated relative to hydrogen and then accelerated up into the solar wind, independent of their mass and first ionization potential.

High-performance liquid chromatographic enantioseparation of unusual isoxazoline-fused 2-aminocyclopentanecarboxylic acids on macrocyclic glycopeptide-based chiral stationary phases.

PubMed

Sipos, László; Ilisz, István; Nonn, Melinda; Fülöp, Ferenc; Pataj, Zoltán; Armstrong, Daniel W; Péter, Antal

2012-04-06

The enantiomers of four unusual isoxazoline-fused 2-aminocyclopentanecarboxylic acids were directly separated on chiral stationary phases containing macrocyclic glycopeptide antibiotics teicoplanin (Astec Chirobiotic T and T2), teicoplanin aglycone (Chirobiotic TAG), vancomycin (Chirobiotic V) and vancomycin aglycone (Chirobiotic VAG) as chiral selectors. The effects of the mobile phase composition, the structure of the analytes and temperature on the separations were investigated. Experiments were performed at constant mobile phase compositions in the temperature range 5-45 °C to study the effects of temperature, and thermodynamic parameters were calculated from plots of lnk or lnα versus 1/T. Some mechanistic aspects of the chiral recognition process are discussed with respect to the structures of the analytes. It was found that the enantiomeric separations were in most cases enthalpy-driven. The sequence of elution of the enantiomers was determined in all cases. Copyright © 2011 Elsevier B.V. All rights reserved.

Fossilized venom: the unusually conserved venom profiles of Heloderma species (beaded lizards and gila monsters).

PubMed

Koludarov, Ivan; Jackson, Timothy N W; Sunagar, Kartik; Nouwens, Amanda; Hendrikx, Iwan; Fry, Bryan G

2014-12-22

Research into snake venoms has revealed extensive variation at all taxonomic levels. Lizard venoms, however, have received scant research attention in general, and no studies of intraclade variation in lizard venom composition have been attempted to date. Despite their iconic status and proven usefulness in drug design and discovery, highly venomous helodermatid lizards (gila monsters and beaded lizards) have remained neglected by toxinological research. Proteomic comparisons of venoms of three helodermatid lizards in this study has unravelled an unusual similarity in venom-composition, despite the long evolutionary time (~30 million years) separating H. suspectum from the other two species included in this study (H. exasperatum and H. horridum). Moreover, several genes encoding the major helodermatid toxins appeared to be extremely well-conserved under the influence of negative selection (but with these results regarded as preliminary due to the scarcity of available sequences). While the feeding ecologies of all species of helodermatid lizard are broadly similar, there are significant morphological differences between species, which impact upon relative niche occupation.

Formation of the world's largest REE deposit through protracted fluxing of carbonatite by subduction-derived fluids

PubMed Central

Ling, Ming-Xing; Liu, Yu-Long; Williams, Ian S.; Teng, Fang-Zhen; Yang, Xiao-Yong; Ding, Xing; Wei, Gang-Jian; Xie, Lu-Hua; Deng, Wen-Feng; Sun, Wei-Dong

2013-01-01

Rare Earth Elements (REE) are essential to modern society but the origins of many large REE deposits remain unclear. The U-Th-Pb ages, chemical compositions and C, O and Mg isotopic compositions of Bayan Obo, the world's largest REE deposit, indicate a protracted mineralisation history with unusual chemical and isotopic features. Coexisting calcite and dolomite are in O isotope disequilibrium; some calcitic carbonatite samples show highly varied δ26Mg which increases with increasing Si and Mg; and ankerite crystals show decreases in Fe and REE from rim to centre, with highly varied REE patterns. These and many other observations are consistent with an unusual mineralisation process not previously considered; protracted fluxing of calcitic carbonatite by subduction-released high-Si fluids during the closure of the Palaeo-Asian Ocean. The fluids leached Fe and Mg from the mantle wedge and scavenged REE, Nb and Th from carbonatite, forming the deposit through metasomatism of overlying sedimentary carbonate.

High-rate nano-crystalline Li 4Ti 5O 12 attached on carbon nano-fibers for hybrid supercapacitors

NASA Astrophysics Data System (ADS)

Naoi, Katsuhiko; Ishimoto, Shuichi; Isobe, Yusaku; Aoyagi, Shintaro

A lithium titanate (Li 4Ti 5O 12)-based electrode which can operate at unusually high current density (300 C) was developed as negative electrode for hybrid capacitors. The high-rate Li 4Ti 5O 12 electrode has a unique nano-structure consisting of unusually small nano-crystalline Li 4Ti 5O 12 (ca. 5-20 nm) grafted onto carbon nano-fiber anchors (nc-Li 4Ti 5O 12/CNF). This nano-structured nc-Li 4Ti 5O 12/CNF composite are prepared by simple sol-gel method under ultra-centrifugal force (65,000 N) followed by instantaneous annealing at 900 °C for 3 min. A model hybrid capacitor cell consisting of a negative nc-Li 4Ti 5O 12/CNF composite electrode and a positive activated carbon electrode showed high energy density of 40 Wh L -1 and high power density of 7.5 kW L -1 comparable to conventional EDLCs.

Analysis of New Composite Architectures

NASA Technical Reports Server (NTRS)

Whitcomb, John D.

1996-01-01

Efficient and accurate specialty finite elements methods to analyze textile composites were developed and are described. Textile composites present unique challenges to the analyst because of the large, complex 'microstructure'. The geometry of the microstructure is difficult to model and it introduces unusual free surface effects. The size of the microstructure complicates the use of traditional homogenization methods. The methods developed constitute considerable progress in addressing the modeling difficulties. The details of the methods and attended results obtained therefrom, are described in the various chapters included in Part 1 of the report. Specific conclusions and computer codes generated are included in Part 2 of the report.

Ar-39 - Ar-40 Dating of Unusual Eucrite NWA-011: Is it from Vesta?

NASA Technical Reports Server (NTRS)

Bogard, D. D.; Garrison, D. H.

2004-01-01

Basaltic meteorite NWA-011 is similar to eucrites in many aspects, but its oxygen isotopic composition lies far off the oxygen fractionation line defined by eucrites. It was suggested that NWA011 may have derived from a different parent body from that of eucrites, which are thought to derive from the asteroid Vesta. Some other eucrites also show small anomalous oxygen compositions. This suggests that for all eucrites to derive from Vesta, it must be compositionally inhomogeneous. Some workers have speculated whether early, large impactors on Vesta might have contributed the anomalous oxygen.

Formation of Adsorbed Oxygen Radicals on Minerals at the Martian Surface and the Decomposition of Organic Molecules

NASA Technical Reports Server (NTRS)

Yen, A. S.; Kim, S. S.; Freeman, B. A.; Hecht, M. H.

2000-01-01

We present experimental evidence that superoxide ions form on mineral grains at the martian surface and show that these adsorbates can explain the unusual reactivity of the soil as well as the apparent absence of organic molecules.

Urchin-like TiO₂@C core-shell microspheres: coupled synthesis and lithium-ion battery applications.

PubMed

Liu, Zhenyu; Liu, Jing; Liu, Junfeng; Wang, Li; Zhang, Guoxin; Sun, Xiaoming

2014-05-21

Carbon coated urchin-like TiO2 microspheres were prepared through coupled hydrolysis of titanium tetrachloride and catalyzed carbonization of glucose. Carbon coating endowed the composite with unusual structural stability at high temperature and reasonable Li-ion battery performance.

Unusual larval habitats and life history of chironomid (Diptera) genera

USGS Publications Warehouse

Hudson, Patrick L.

1987-01-01

Ninety-three genera, representing all subfamilies of Chironomidae, are organized into 9 categories of unusual habitats or life history including hygropetric, riparian (bank, floodplain, upland), hyporheic, symbiotic, and intertidal; others live in water held in plants or mine into unusual substrates. In riparian zones precise location of optimum habitat is difficult to determine as is definition of habitat within the continuum from shoreline to upland areas. The ecological importance of the riparian group appears to lie in its processing of coarse particulate matter along the floodplain of streams and rivers. All riparian genera are zoogeographically useful and can be used in reconstructing evolutionary dispersal pathways because they are adapted to unique habits that have remained largely undisturbed by human activities.

Unusual chemical compositions of noctilucent-cloud particle nuclei

NASA Technical Reports Server (NTRS)

Hemenway, C. L.

1973-01-01

Two sounding rocket payloads were launched from the ESRO range in Sweden during a noctilucent cloud display. Large numbers of submicron particles were collected, most of which appear to be made up of a high density material coated with a low density material. Typical electron micrographs are shown. Particle chemical compositions have been measured by use of dispersive X-ray analysis equipment attached to an electron microscope and have revealed that most of the high density particle nuclei have atomic weights greater than iron.

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2013-06-04

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Rare Orbital Infections ~ State of the Art ~ Part II

PubMed Central

Hamed-Azzam, Shirin; AlHashash, Islam; Briscoe, Daniel; Rose, Geoffrey E; Verity, David H.

2018-01-01

Infections of the orbit and periorbita are relatively frequent. Identifying unusual organisms is crucial because they can cause severe local and systemic morbidity, despite their rarity. Opportunistic infections of the orbit should be considered mainly in debilitated or immunocompromised patients. The key to successful management includes a high index of suspicion, prompt diagnosis, and addressing the underlying systemic disease. This review summarizes unusual infectious processes of the orbit, including mycobacterial, fungal, and parasitic infections, as well as their pathophysiology, symptoms, signs, and treatment. PMID:29719648

Aortic root repair for thoracic aorta false aneurysm following Bentall procedure.

PubMed

Kumar, Sanjay; Jones, Steve; Sivananthan, U M; McGoldrick, J P

2008-08-01

The Bentall procedure for aortic root replacement in Marfan's syndrome is safe and durable. We describe successful repair of periprosthetic valvular leak, 12 years following Bentall repair with composite graft. The aim of this report is to analyse and evaluate technical factors leading to this unusual occurrence.

Structure, histochemistry and phytochemical profile of the bark of the sobol and aerial stem of Tontelea micrantha (Celastraceae - Hippocrateoideae).

PubMed

Mercadante-Simões, Maria Olívia; Mazzottini-Dos-Santos, Hellen C; Nery, Lays A; Ferreira, Peracio R B; Ribeiro, Leonardo M; Royo, Vanessa A; de Oliveira, Dario A

2014-09-01

The bark of the underground stem of Tontelea micrantha (Mart. ex. Schult.) A. C. Sm., a native Brazilian Cerrado species, is used in folk medicine for treating kidney ailments. The structures of the underground and the aerial stems were examined and their barks were analyzed for the presence of secondary metabolites. Bark fragments were processed according to conventional techniques in plant anatomy and their chemical compositions examined using histochemical and phytochemical tests, thin layer chromatography, and high-efficiency liquid chromatography. The underground stem is a sobol with unusual cambial activity. Laticifers that secrete terpenoids were present in the cortex and phloem of both organs and can contribute to the identification of the species in field. Druses were present in both barks, but mono-crystals were only observed in the sobol. Tannins, flavonoids, alkaloids, and terpenoids occurred in both types of bark, but carotenoids were only detected in the sobol. The similarities between these two organs indicate that the aerial stem bark has potential medicinal use and represents a plausible alternative to harvesting the sobol, which could contribute to the preservation of natural populations of this species.

Genetic Analysis of Collective Motility of Paenibacillus sp. NAIST15-1

PubMed Central

Kobayashi, Kazuo; Kanesaki, Yu

2016-01-01

Bacteria have developed various motility mechanisms to adapt to a variety of solid surfaces. A rhizosphere isolate, Paenibacillus sp. NAIST15-1, exhibited unusual motility behavior. When spotted onto 1.5% agar media, Paenibacillus sp. formed many colonies, each of which moved around actively at a speed of 3.6 μm/sec. As their density increased, each moving colony began to spiral, finally forming a static round colony. Despite its unusual motility behavior, draft genome sequencing revealed that both the composition and organization of flagellar genes in Paenibacillus sp. were very similar to those in Bacillus subtilis. Disruption of flagellar genes and flagellar stator operons resulted in loss of motility. Paenibacillus sp. showed increased transcription of flagellar genes and hyperflagellation on hard agar media. Thus, increased flagella and their rotation drive Paenibacillus sp. motility. We also identified a large extracellular protein, CmoA, which is conserved only in several Paenibacillus and related species. A cmoA mutant could neither form moving colonies nor move on hard agar media; however, motility was restored by exogenous CmoA. CmoA was located around cells and enveloped cell clusters. Comparison of cellular behavior between the wild type and cmoA mutant indicated that extracellular CmoA is involved in drawing water out of agar media and/or smoothing the cell surface interface. This function of CmoA probably enables Paenibacillus sp. to move on hard agar media. PMID:27764113

Appliance Science.

ERIC Educational Resources Information Center

McGhee, James

1984-01-01

Ordinary household appliances can be used in the classroom to inspire unusual research, artwork, and problem solving. Suggestions on how to organize and collect materials to develop an appliance science unit are offered. (DF)

The complete mitochondrial genome of the stomatopod crustacean Squilla mantis

PubMed Central

Cook, Charles E

2005-01-01

Background Animal mitochondrial genomes are physically separate from the much larger nuclear genomes and have proven useful both for phylogenetic studies and for understanding genome evolution. Within the phylum Arthropoda the subphylum Crustacea includes over 50,000 named species with immense variation in body plans and habitats, yet only 23 complete mitochondrial genomes are available from this subphylum. Results I describe here the complete mitochondrial genome of the crustacean Squilla mantis (Crustacea: Malacostraca: Stomatopoda). This 15994-nucleotide genome, the first described from a hoplocarid, contains the standard complement of 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and a non-coding AT-rich region that is found in most other metazoans. The gene order is identical to that considered ancestral for hexapods and crustaceans. The 70% AT base composition is within the range described for other arthropods. A single unusual feature of the genome is a 230 nucleotide non-coding region between a serine transfer RNA and the nad1 gene, which has no apparent function. I also compare gene order, nucleotide composition, and codon usage of the S. mantis genome and eight other malacostracan crustaceans. A translocation of the histidine transfer RNA gene is shared by three taxa in the order Decapoda, infraorder Brachyura; Callinectes sapidus, Portunus trituberculatus and Pseudocarcinus gigas. This translocation may be diagnostic for the Brachyura. For all nine taxa nucleotide composition is biased towards AT-richness, as expected for arthropods, and is within the range reported for other arthropods. Codon usage is biased, and much of this bias is probably due to the skew in nucleotide composition towards AT-richness. Conclusion The mitochondrial genome of Squilla mantis contains one unusual feature, a 230 base pair non-coding region has so far not been described in any other malacostracan. Comparisons with other Malacostraca show that all nine genomes, like most other mitochondrial genomes, share a bias toward AT-richness and a related bias in codon usage. The nine malacostracans included in this analysis are not representative of the diversity of the class Malacostraca, and additional malacostracan sequences would surely reveal other unusual genomic features that could be useful in understanding mitochondrial evolution in this taxon. PMID:16091132

On the Merits of "Unusual Field Trips."

ERIC Educational Resources Information Center

Howarth, Dean E.

1999-01-01

Describes the organization and completion of a scientific field trip for a group of high school physics students that was organized primarily around a study of the Manhattan Project. The group visited the Trinity site, Los Alamos, several museums, and the National Radio Astronomy Observatory Very Large Array. Contact information for the various…

An unusual case of calcineurine inhibitor pain syndrome.

PubMed

Nickavar, Azar; Mehrazma, Mitra; Hallaji, Farideh

2014-09-01

Cyclosporine induced pain syndrome (CIPS) is a newly diagnosed complication of calcineurine inhibitors, mainly observed in solid organ and hematopoetic transplantations. The present case is a male child with steroid resistant nephrotic syndrome on low therapeutic level cyclosporine treatment. He presented with intractable and debilitating leg pain, with no reported history of previous injury or trauma. The pain was reluctant to antimicrobial and sedative treatment. MRI revealed bone marrow and soft tissue edema in the mid shaft of patient's right leg. Inspite of unusual manifestations, CIPS was suggested and cyclosporine discontinued. However, the pain did not improve and was resistant to calcium blocker. Subsequently, core decompression was performed as an unusual treatment of CIPS, revealing normal bone morphology. The pain improved rapidly and the patient was discharged a few days later.

Geochemical constraints on volatile sources and subsurface conditions at Mount Martin, Mount Mageik, and Trident Volcanoes, Katmai Volcanic Cluster, Alaska

NASA Astrophysics Data System (ADS)

Lopez, T.; Tassi, F.; Aiuppa, A.; Galle, B.; Rizzo, A. L.; Fiebig, J.; Capecchiacci, F.; Giudice, G.; Caliro, S.; Tamburello, G.

2017-11-01

We use the chemical and isotopic composition of volcanic gases and steam condensate, in situ measurements of plume composition and remote measurements of SO2 flux to constrain volatile sources and characterize subvolcanic conditions at three persistently degassing and seismically active volcanoes within the Katmai Volcanic Cluster (KVC), Alaska: Mount Martin, Mount Mageik and Trident. In situ plume measurements of gas composition were collected at all three volcanoes using MultiGAS instruments to calculate gas ratios (e.g. CO2/H2S, SO2/H2S and H2O/H2S), and remote measurements of SO2 column density were collected from Mount Martin and Mount Mageik by ultraviolet spectrometer systems to calculate SO2 fluxes. Fumaroles were directly sampled for chemical and isotopic composition from Mount Mageik and Trident. Mid Ocean Ridge Basalt (MORB)-like 3He/4He ratios ( 7.2-7.6 Rc/RA) within Mount Mageik and Trident's fumarole emissions and a moderate SO2 flux ( 75 t/d) from Mount Martin, combined with gas compositions dominated by H2O, CO2 and H2S from all three volcanoes, indicate magma degassing and active hydrothermal systems in the subsurface of these volcanoes. Mount Martin's gas emissions have the lowest CO2/H2S ratio ( 2-4) and highest SO2 flux compared to the other KVC volcanoes, indicative of shallow magma degassing. Geothermometry techniques applied to Mount Mageik and Trident's fumarolic gas compositions suggest that their hydrothermal reservoirs are located at depths of 0.2 and 4 km below the surface, respectively. Observations of an unusually reducing gas composition at Trident and organic material in the near-surface soils suggest that thermal decomposition of sediments may be influencing gas composition. When the measured gas compositions from Mount Mageik and Trident are compared with previous samples collected in the late 1990's, relatively stable magmatic-hydrothermal conditions are inferred for Mount Mageik, while gradual degassing of residual magma and contamination by shallow crustal fluids is inferred for Trident. The isotopic composition of volcanic gases emitted from Mount Mageik and Trident reflect mixing of subducted slab, mantle and crustal volatile sources, with organic sediment and carbonate being the predominant sources. Considering the close proximity of the target volcanoes in comparison with the depth to the subducted slab we speculate that Aleutian Arc volatiles are fed by a relatively homogeneous subducted fluid and that much of the apparent variability in volatile provenance can be explained by shallow crustal volatile sources and/or processes.

Aqueous alteration and brecciation in Bells, an unusual, saponite-bearing, CM chondrite

NASA Astrophysics Data System (ADS)

Brearley, Adrian J.

1995-06-01

The petrological and mineralogical characteristics of the unusual CM2 chondrite, Bells, have been investigated in detail by scanning electron microscopy (SEM), electron microprobe analysis (EPMA), and transmission electron microscopy (TEM). Bells is a highly brecciated chondrite which contains few intact chondrules, a very low abundance of refractory inclusions, and is notable in having an unusually high abundance of magnetite, which is disseminated throughout the fine-grained matrix. Fragmental olivines and pyroxenes are common and, based on compositional data, appear to have been derived from chondrules as a result of extensive brecciation. The fine-grained mineralogy of matrix in Bells differs considerably from other CM chondrites and has closer affinities to matrix in CI chondrites. The dominant phases are fine-grained saponite interlayered with serpentine, and phases such as tochilinite and cronstedtite, which are typical of CM chondrite matrices, are entirely absent. Pentlandite, pyrrhotite, magnetite, anhydrite, calcite, and rare Ti-oxides also occur as accessory phases. Based on its oxygen and noble gas isotopic compositions (Zadnik, 1985; Rowe et al., 1994), Bells can be considered to be a CM2 chondrite, although its bulk composition shows some departures from the typical range exhibited by this group. However, these variations in bulk chemistry are entirely consistent with the observed mineralogy of Bells. The unusual fine-grained mineralogy of Bells matrix can be reasonably attributed to the combined effects of aqueous alteration and advanced brecciation in a parent body environment. Extensive brecciation has assisted aqueous alteration by reducing chondrules and mineral grains into progressively smaller grains with high surface areas, which are more susceptible to dissolution reactions involving aqueous fluids. This has resulted in the preferential dissolution of Fe-rich chondrule olivines, which are now completely absent in Bells although present in other CM chondrites. The formation of saponite in Bells probably resulted from the dissolution of relatively silica-rich phases, such as pyroxene and olivine, that were derived from chondrules. The result of such dissolution reactions would be to increase the activity of silica in the fluid phase, at least on a localized scale, stabilizing saponite in preference to serpentine. An increase in aSiO 2 would also have destabilized preexisting cronstedtite which may have reacted to form magnetite and MgFe serpentine under conditions of constant ƒO 2 .

The Intrinsically X-Ray-weak Quasar PHL 1811. II. Optical and UV Spectra and Analysis

NASA Astrophysics Data System (ADS)

Leighly, Karen M.; Halpern, Jules P.; Jenkins, Edward B.; Casebeer, Darrin

2007-11-01

This is the second of two papers reporting observations and analysis of the unusually bright (mb=14.4), luminous (MB=-25.5), nearby (z=0.192) narrow-line quasar PHL 1811. The first paper reported that PHL 1811 is intrinsically X-ray-weak and presented a spectral energy distribution (SED). Here we present HST STIS optical and UV spectra, and ground-based optical spectra. The optical and UV line emission is very unusual. There is no evidence for forbidden or semiforbidden lines. The near-UV spectrum is dominated by very strong Fe II and Fe III, and unusual low-ionization lines such as Na I D and Ca II H and K are observed. High-ionization lines are very weak; C IV has an equivalent width of 6.6 Å, a factor of ~5 smaller than measured from quasar composite spectra. An unusual feature near 1200 Å can be deblended in terms of Lyα, N V, Si II, and C III* using the blueshifted C IV profile as a template. Photoionization modeling shows that the unusual line emission can be explained qualitatively by the unusually soft SED. Principally, a low gas temperature results in inefficient emission of collisionally excited lines, including the semiforbidden lines generally used as density diagnostics. The emission resembles that of high-density gas; in both cases this is a consequence of inefficient cooling. PHL 1811 is very unusual, but we note that quasar surveys may be biased against finding similar objects. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with proposal 9181. Based on observations obtained at Kitt Peak National Observatory, a division of the National Optical Astronomy Observatories, which is operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation.

Factors associated with the decline disease of sugar maple on the Allegheny Plateau

Treesearch

Stephen B. Horsley; Robert P. Long; Scott W. Bailey; Richard A. Hallett; Thomas J. Hall

2000-01-01

Mortality of sugar maple (Acer saccharum Marsh.) has reached unusually high levels across northern Pennsylvania since the early to mid-1980s. We evaluated the influence of glaciation, topographic position, foliage chemistry, defoliation history, and stand characteristics (species composition, structure, density) on the health of sugar maple in 43...

78 FR 11553 - Special Conditions: Embraer S.A., Model EMB-550 Airplane; Electronic Flight Control System...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-19

... metal with composite empennage and control surfaces. The Model EMB-550 airplane is designed for 8...; Electronic Flight Control System: Control Surface Awareness and Mode Annunciation AGENCY: Federal Aviation... Embraer S.A. Model EMB-550 airplane. This airplane will have a novel or unusual design feature(s...

Assessment of oil content and fatty acid composition variability in two economically important Hibiscus species.

USDA-ARS?s Scientific Manuscript database

The Hibiscus genus encompasses more than 300 species, but kenaf (H. cannabinus L.) and roselle (H. sabdariffa L.) are the two most economically important species within the genus. Seeds from these two Hibiscus species contain a relatively high amount of oil with two unusual fatty acids: dihydrosterc...

Massive shelf dense water flow influences plankton community structure and particle transport over long distance.

PubMed

Bernardi Aubry, Fabrizio; Falcieri, Francesco Marcello; Chiggiato, Jacopo; Boldrin, Alfredo; Luna, Gian Marco; Finotto, Stefania; Camatti, Elisa; Acri, Francesco; Sclavo, Mauro; Carniel, Sandro; Bongiorni, Lucia

2018-03-14

Dense waters (DW) formation in shelf areas and their cascading off the shelf break play a major role in ventilating deep waters, thus potentially affecting ecosystem functioning and biogeochemical cycles. However, whether DW flow across shelves may affect the composition and structure of plankton communities down to the seafloor and the particles transport over long distances has not been fully investigated. Following the 2012 north Adriatic Sea cold outbreak, DW masses were intercepted at ca. 460 km south the area of origin and compared to resident ones in term of plankton biomass partitioning (pico to micro size) and phytoplankton species composition. Results indicated a relatively higher contribution of heterotrophs in DW than in deep resident water masses, probably as result of DW-mediated advection of fresh organic matter available to consumers. DWs showed unusual high abundances of Skeletonema sp., a diatom that bloomed in the north Adriatic during DW formation. The Lagrangian numerical model set up on this diatom confirmed that DW flow could be an important mechanism for plankton/particles export to deep waters. We conclude that the predicted climate-induced variability in DW formation events could have the potential to affect the ecosystem functioning of the deeper part of the Mediterranean basin, even at significant distance from generation sites.

SOLAR WIND HEAVY IONS OVER SOLAR CYCLE 23: ACE/SWICS MEASUREMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lepri, S. T.; Landi, E.; Zurbuchen, T. H.

2013-05-01

Solar wind plasma and compositional properties reflect the physical properties of the corona and its evolution over time. Studies comparing the previous solar minimum with the most recent, unusual solar minimum indicate that significant environmental changes are occurring globally on the Sun. For example, the magnetic field decreased 30% between the last two solar minima, and the ionic charge states of O have been reported to change toward lower values in the fast wind. In this work, we systematically and comprehensively analyze the compositional changes of the solar wind during cycle 23 from 2000 to 2010 while the Sun movedmore » from solar maximum to solar minimum. We find a systematic change of C, O, Si, and Fe ionic charge states toward lower ionization distributions. We also discuss long-term changes in elemental abundances and show that there is a {approx}50% decrease of heavy ion abundances (He, C, O, Si, and Fe) relative to H as the Sun went from solar maximum to solar minimum. During this time, the relative abundances in the slow wind remain organized by their first ionization potential. We discuss these results and their implications for models of the evolution of the solar atmosphere, and for the identification of the fast and slow wind themselves.« less

Chandra Observations of Comet 2P/Encke 2003: First Detection of a Collisionally Thin, Fast Solar Wind Charge Exchange System

NASA Technical Reports Server (NTRS)

Lisse, C. M.; Christian, D. J.; Deneri, K.; Wolk, S. J.; Bodewits, D.; Hoekstra, R.; Combi, M. R.; Makinen, T.; Dryer, M.; Fry, C. D.;

Proanthocyanidin profile of cowpea (Vigna unguiculata) reveals catechin-O-glucoside as the dominant compound.

PubMed

Ojwang, Leonnard O; Yang, Liyi; Dykes, Linda; Awika, Joseph

2013-08-15

Proanthocyanidin (PA) profile and content can have important nutritional and health implications on plant foods. Six diverse cowpea phenotypes (black, red, green, white, light-brown and golden-brown) were investigated for PA composition using normal-phase HPLC and reversed-phase UPLC-TQD-MS. Catechin and (epi)afzelechin were the major flavan-3-ol units. Unusual composition was observed in all cowpea phenotypes with significant degrees of glycosylation in the monomers and dimers. The PA content of cowpea (dry basis) ranged between 2.2 and 6.3 mg/g. Monomeric flavan-3-ols were the largest group of PA (36-69%) in cowpea, with catechin-7-O-glucoside accounting for most (about 88%) of the monomers. The oligomers with degree of polymerization (DP) 2-4 ranged from 0.41 to 1.3 mg/g (15-20%), whereas DP>10 polymers accounted for only 13.5% of PA. Future studies that highlight the impact of the unusual cowpea PA profile on nutritional and bioactive properties of this important legume are warranted. Copyright © 2013 Elsevier Ltd. All rights reserved.

Synthetic biology meets tissue engineering

PubMed Central

Davies, Jamie A.; Cachat, Elise

2016-01-01

Classical tissue engineering is aimed mainly at producing anatomically and physiologically realistic replacements for normal human tissues. It is done either by encouraging cellular colonization of manufactured matrices or cellular recolonization of decellularized natural extracellular matrices from donor organs, or by allowing cells to self-organize into organs as they do during fetal life. For repair of normal bodies, this will be adequate but there are reasons for making unusual, non-evolved tissues (repair of unusual bodies, interface to electromechanical prostheses, incorporating living cells into life-support machines). Synthetic biology is aimed mainly at engineering cells so that they can perform custom functions: applying synthetic biological approaches to tissue engineering may be one way of engineering custom structures. In this article, we outline the ‘embryological cycle’ of patterning, differentiation and morphogenesis and review progress that has been made in constructing synthetic biological systems to reproduce these processes in new ways. The state-of-the-art remains a long way from making truly synthetic tissues, but there are now at least foundations for future work. PMID:27284030

Aerogel: Tile Composites Toughen a Brittle Superinsulation

NASA Technical Reports Server (NTRS)

White, Susan; Rasky, Daniel; Arnold, James O. (Technical Monitor)

1998-01-01

Pure aerogels, though familiar in the laboratory for decades as exotic lightweight insulators with unusual physical properties, have had limited industrial applications due to their low strength and high brittleness. Composites formed of aerogels and the ceramic fiber matrices like those used as space shuttle tiles bypass the fragility of pure aerogels and can enhance the performance of space shuttle tiles in their harsh operating environment. Using a layer of aerogel embedded in a tile may open up a wide range of applications where thermal insulation, gas convection control and mechanical strength matter.

Aerogel: Tile Composites Toughen a Brittle Superinsulation

NASA Technical Reports Server (NTRS)

White, Susan; Rasky, Daniel; Arnold, James O. (Technical Monitor)

1998-01-01

Pure aerogels, though familiar in the laboratory for decades as exotic lightweight insulators with unusual physical properties, have had limited industrial applications due to their low strength and high brittleness. Composites formed of aerogels and the ceramic fiber matrices used as space shuttle tiles bypass the fragility of pure aerogels and can enhance the performance of space shuttle tiles in their harsh operating environment. Using a layer of aerogel embedded in a tile may open up a wide range of applications where thermal insulation, gas convection control and mechanical strength matter.

Legionella feeleii: an unusual organism associated with cutaneous infection in an immunocompromised patient.

PubMed

Verykiou, S; Goodhead, C; Parry, G; Meggitt, S

2018-04-01

We report a 23-year-old immunocompromised woman who, following cardiac transplantation, presented with an unusual cutaneous eruption. She developed a widespread pustular rash, systemic symptoms and a high temperature with raised inflammatory markers. The diagnosis was reached when a skin biopsy was cultured onto Legionella agar (buffered charcoal yeast extract) and Legionella feeleii was isolated. The patient was treated with 6 weeks of moxifloxacin and her cutaneous lesions gradually resolved. Cutaneous Legionella infections are uncommon and usually affect immunocompromised patients. © 2017 British Association of Dermatologists.

Unusual Thermoelectric Behavior Indicating a Hopping to Bandlike Transport Transition in Pentacene

NASA Astrophysics Data System (ADS)

Germs, W. Chr.; Guo, K.; Janssen, R. A. J.; Kemerink, M.

2012-07-01

An unusual increase in the Seebeck coefficient with increasing charge carrier density is observed in pentacene thin film transistors. This behavior is interpreted as being due to a transition from hopping transport in static localized states to bandlike transport, occurring at temperatures below ˜250K. Such a transition can be expected for organic materials in which both static energetic disorder and dynamic positional disorder are important. While clearly visible in the temperature and density dependent Seebeck coefficient, the transition hardly shows up in the charge carrier mobility.

Design strategies of sea urchin teeth: structure, composition and micromechanical relations to function.

PubMed

Wang, R Z; Addadi, L; Weiner, S

1997-04-29

The teeth of sea urchins comprise a variety of different structural entities, all of which are composed of magnesium-bearing calcite together with a small amount of organic material. The teeth are worn down continuously, but in such a way that they remain sharp and functional. Here we describe aspects of the structural, compositional and micromechanical properties of the teeth of Paracentrotus lividus using scanning electron microscopy, infrared spectrometry, atomic absorption. X-ray diffraction and microindentation. The S-shaped single crystalline calcitic fibres are one of the main structural elements of the tooth. They extend from the stone part to the keel. The diameter of the fibres increases gradually from less than 1 micron at the stone tip to about 20 microns at the keel end, while their MgCO3 contents decrease from about 13 mol% to about 4.5 mol%. Each fibre is coated by a thin organic sheath and surrounded by polycrystalline calcitic discs containing as much as 35 mol% MgCO3. This structure constitutes a unique kind of gradient fibre-reinforced ceramic matrix composite, whose microhardness and toughness decrease gradually from the stone part to the keel. Primary plates are also important structural elements of the tooth. Each primary plate has a very unusual sandwich-like structure with a calcitic envelope surrounding a thin apparently amorphous CaCO3 layer. This central layer, together with the primary plate/disc interface, improves the toughness of this zone by stopping and blunting cracks. The self-sharpening function of the teeth is believed to result from the combination of the geometrical shape of the main structural elements and their spatial arrangement, the interfacial strength between structural elements, and the hardness gradient extending from the working stone part to the surrounding zones. The sea urchin tooth structure possesses an array of interesting functional design features, some of which may possibly be applicable to materials science.

Biosourced polymetallic catalysis: A surprising and efficient means to promote the Knoevenagel condensation

NASA Astrophysics Data System (ADS)

Deyris, Pierre-Alexandre; Bert, Valérie; Diliberto, Sébastien; Boulanger, Clotilde; Petit, Eddy; Legrand, Yves-Marie; Grison, Claude

2018-03-01

Zn hyperaccumulator (Arabidobsis halleri) and Zn accumulator Salix ‘Tordis’ (Salix schwerinii x S. viminalis) have shown their interest in the phytoextraction of polluted brownfields. Herein, we explore an innovative methodology based on the chemical valorization of Zn-rich biomass produced by these metallophyte plants. The approach is based on the direct use of polymetallic salts derived from plants as “Lewis acid” catalysts in organic chemistry. The formed ecocatalysts were characterized via ICP-MS, XRD, FT-IR in order to elucidate the chemical composition, structure and behavior of the formed materials. The Doebner-Knoevenagel reaction was chosen as model reaction to study their synthetic potential. Significant differences to conventional catalysts such as zinc (II) chloride are observed. They can principally be related to a mixture of unusual mineral species. DFT calculations were carried out on these salts in the context of the Gutmann theory. They allow the rationalization of experimental results. Finally, these new bio-based polymetallic catalysts illustrated the interest of this concept for green and sustainable catalysis.

Spectroscopic characterization of zirconium(IV) and hafniumf(IV) gallate phthalocyanines in monolithic silica gels obtained by sol gel method

NASA Astrophysics Data System (ADS)

Gerasymchuk, Y. S.; Chernii, V. Ya.; Tomachynski, L. A.; Legendziewicz, J.; Radzki, St.

2005-07-01

The Zr(IV) and Hf(IV) phthalocyanines, with gallate as axial ligand coordinated to the central metal atom of phthalocyanine, were incorporated in silica gels during sol-gel process with using tetraethyl orthosilicate (TEOS) as precursor. The obtained mixed inorganic-organic composites were transparent and homogeneous. The absorption and emission properties of these materials in comparison with the spectra of the Zr(IV) and Hf(IV) phthalocyanines in various solvents were investigated. The spectra were correlated with various stage of the sol-gel process. It was established that in the gels concurrence of the monomer and dimer form is different in sol, alco-, hydro- and xerogels. The intensive 700-725 nm fluorescence emission upon relatively long-wavelength excitation and unusually large (about 45 nm) Stokes shift in the Q region, suggest that Zr(IV) and Hf(IV) phthalocyanines could be considered as photosensitizers in the PDT method (photodynamic therapy).

Gas-separation process

DOEpatents

Toy, Lora G.; Pinnau, Ingo; Baker, Richard W.

1994-01-01

A process for separating condensable organic components from gas streams. The process makes use of a membrane made from a polymer material that is glassy and that has an unusually high free volume within the polymer material.

High elongation elastomers

NASA Technical Reports Server (NTRS)

Brady, V. L.; Reed, R.; Merwin, L.; Nissan, R.

1994-01-01

A new class of liquid curable elastomers with unusual strength and elasticity has been developed at the Naval Air Warfare Center Weapons Division, China Lake. Over the years, studies have been conducted on polymer structure and its influence on the mechanical properties of the ensuing composites. Different tools, including nuclear magnetic resonance, have been used. This paper presents a summary of the factors controlling the mechanical behavior of composites produced with the new liquid curable elastomers, including the effects of plasticizers. It also provides an overview of the nuclear magnetic resonance study on polymer structure, the composition and properties of some live and inert formulations produced at China Lake, and some possible peace-time applications for these new elastomeric materials.

Preparation and Characterization of InP/Poly(methyl methacrylate) Nanocomposite Films.

PubMed

Kwon, Younghoon; Kim, Jongsung

2017-04-01

Quantum dots (QDs) are nanocrystalline semiconductors with many unusual optical properties. They exhibit very high fluorescence intensities and possess exceptional stability against photo-bleaching. In this study, we report the preparation of InP QDs-poly(methyl methacrylate) (PMMA) hybrids by fabricating QDs via a thermal decomposition reaction, followed by radical polymerization. The InP QDs were synthesized using indium(III) chloride and tris(dimethylamino)phosphine. Flexible composite films were obtained by radical polymerization using methyl methacrylate (MMA) as the monomer and 2,2′-azobis(2-methylpropionitrile) (AIBN) as a radical initiator. The PL intensity of the QDs was lowered upon composite formation with PMMA. However, the composites exhibited higher thermal stability than pure PMMA.

Results of initial analyses of the salt (macro) batch 9 tank 21H qualification samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, T. B.

2015-10-01

Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Interim Salt Disposition Project (ISDP) Salt (Macro) Batch 9 for processing through the Actinide Removal Process (ARP) and the Modular Caustic-Side Solvent Extraction Unit (MCU). This document reports the initial results of the analyses of samples of Tank 21H. Analysis of the Tank 21H Salt (Macro) Batch 9 composite sample indicates that the material does not display any unusual characteristics or observations, such as floating solids, the presence of large amount of solids, or unusual colors. Further results on the chemistry and other tests willmore » be issued in the future.« less

Light triggered interfacial damage self-healing of poly(p-phenylene benzobisoxazole) fiber composites.

PubMed

Hu, Zhen; Shao, Qing; Huang, Yudong; Yu, Long; Zhang, Dayu; Xu, Xirong; Lin, Jing; Liu, Hu; Guo, Zhanhu

2018-05-04

The interfacial microcracks in the resin matrix composites are difficult to be detected and repaired. However, the self-healing concept provides opportunities to fabricate composites with unusual properties. In the present study, photothermal conversion Ag-Cu 2 S nanoparticles were immobilized onto poly(p-phenylene benzobisoxazole) (PBO) fibers via a polydopamine chemistry. Benefitting from the photothermal effects of Ag-Cu 2 S, the obtained PBO fibers (Ag-Cu 2 S-PBO) efficiently converted the light energy into heat under Xenon lamp irradiation. Then, single PBO fiber composites were prepared using thermoplastic polyurethane as the matrix. It was found that the interfacial damage caused by single fiber pull-out was simply self-healed by Xe light irradiation. This wonderful interfacial damage self-healing property was mainly attributed to the in situ heating generation via photothermal effects of Ag-Cu 2 S in the composite interface. This paper reports a novel strategy to construct advanced composites with light-triggered self-healing properties, which will provide inspiration for preparing high performance composite materials.

Bulk chemical compositions of Antarctic meteorites in the NIPR collection

NASA Astrophysics Data System (ADS)

Kimura, M.; Imae, N.; Yamaguchi, A.; Haramura, H.; Kojima, H.

2018-03-01

Bulk chemical compositions of meteorites were traditionally analyzed by wet chemical analysis, and NIPR has data for 1162 meteorites as of September 2017. We discuss the classification of meteorites on the basis of these data. Chondrite data are distributed in an anomalously wide range of compositions on the Urey-Craig diagram. One of the reasons for such wide distribution is terrestrial weathering producing Fe2O3-bearing phases from Fe-Ni metal and sulfides. Another important factor affecting the bulk compositional data is brecciation. Our observations indicate that many brecciated chondrites contain anomalously abundant opaque minerals, or are depleted in them, resulting in unusual compositions. In case of enstatite and some carbonaceous chondrites, the bulk compositions are distributed in wider ranges than reported before. The bulk compositions of HED meteorites are consistent with their mineralogy and classification. Our study suggests that wet chemical data are still significant for the meteorite classification. However, petrographic observation is indispensable for evaluating the bulk chemistry and classification of meteorites.

Light triggered interfacial damage self-healing of poly(p-phenylene benzobisoxazole) fiber composites

NASA Astrophysics Data System (ADS)

Hu, Zhen; Shao, Qing; Huang, Yudong; Yu, Long; Zhang, Dayu; Xu, Xirong; Lin, Jing; Liu, Hu; Guo, Zhanhu

2018-05-01

The interfacial microcracks in the resin matrix composites are difficult to be detected and repaired. However, the self-healing concept provides opportunities to fabricate composites with unusual properties. In the present study, photothermal conversion Ag-Cu2S nanoparticles were immobilized onto poly(p-phenylene benzobisoxazole) (PBO) fibers via a polydopamine chemistry. Benefitting from the photothermal effects of Ag-Cu2S, the obtained PBO fibers (Ag-Cu2S-PBO) efficiently converted the light energy into heat under Xenon lamp irradiation. Then, single PBO fiber composites were prepared using thermoplastic polyurethane as the matrix. It was found that the interfacial damage caused by single fiber pull-out was simply self-healed by Xe light irradiation. This wonderful interfacial damage self-healing property was mainly attributed to the in situ heating generation via photothermal effects of Ag-Cu2S in the composite interface. This paper reports a novel strategy to construct advanced composites with light-triggered self-healing properties, which will provide inspiration for preparing high performance composite materials.

77 FR 70941 - Special Conditions: Embraer S.A., Model EMB-550 Airplane; Interaction of Systems and Structures

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-28

... primary structure is metal with composite empennage and control surfaces. The Model EMB-550 airplane is...., Model EMB-550 Airplane; Interaction of Systems and Structures AGENCY: Federal Aviation Administration... conditions for the Embraer S.A. Model EMB-550 airplane. This airplane will have a novel or unusual design...

Polyhydroxyalkanoate synthesis in transgenic plants as a new tool to study carbon flow through beta-oxidation.

PubMed

Mittendorf, V; Bongcam, V; Allenbach, L; Coullerez, G; Martini, N; Poirier, Y

1999-10-01

Transgenic plants producing peroxisomal polyhydroxy- alkanoate (PHA) from intermediates of fatty acid degradation were used to study carbon flow through the beta-oxidation cycle. Growth of transgenic plants in media containing fatty acids conjugated to Tween detergents resulted in an increased accumulation of PHA and incorporation into the polyester of monomers derived from the beta-oxidation of these fatty acids. Tween-laurate was a stronger inducer of beta-oxidation, as measured by acyl-CoA oxidase activity, and a more potent modulator of PHA quantity and monomer composition than Tween-oleate. Plants co-expressing a peroxisomal PHA synthase with a capryl-acyl carrier protein thioesterase from Cuphea lanceolata produced eightfold more PHA compared to plants expressing only the PHA synthase. PHA produced in double transgenic plants contained mainly saturated monomers ranging from 6 to 10 carbons, indicating an enhanced flow of capric acid towards beta-oxidation. Together, these results support the hypothesis that plant cells have mechanisms which sense levels of free or esterified unusual fatty acids, resulting in changes in the activity of the beta-oxidation cycle as well as removal and degradation of these unusual fatty acids through beta-oxidation. Such enhanced flow of fatty acids through beta-oxidation can be utilized to modulate the amount and composition of PHA produced in transgenic plants. Furthermore, synthesis of PHAs in plants can be used as a new tool to study the quality and relative quantity of the carbon flow through beta-oxidation as well as to analyse the degradation pathway of unusual fatty acids.

The role of macromolecular crowding in the evolution of lens crystallins with high molecular refractive index.

PubMed

Zhao, Huaying; Magone, M Teresa; Schuck, Peter

2011-08-01

Crystallins are present in the lens at extremely high concentrations in order to provide transparency and generate a high refractive power of the lens. The crystallin families prevalent in the highest density lens tissues are γ-crystallins in vertebrates and S-crystallins in cephalopods. As shown elsewhere, in parallel evolution, both have evolved molecular refractive index increments 5-10% above those of most proteins. Although this is a small increase, it is statistically very significant and can be achieved only by very unusual amino acid compositions. In contrast, such a molecular adaptation to aid in the refractive function of the lens did not occur in crystallins that are preferentially located in lower density lens tissues, such as vertebrate α-crystallin and taxon-specific crystallins. In the current work, we apply a model of non-interacting hard spheres to examine the thermodynamic contributions of volume exclusion at lenticular protein concentrations. We show that the small concentration decrease afforded by the higher molecular refractive index increment of crystallins can amplify nonlinearly to produce order of magnitude differences in chemical activities, and lead to reduced osmotic pressure and the reduced propensity for protein aggregation. Quantitatively, this amplification sets in only at protein concentrations as high as those found in hard lenses or the nucleus of soft lenses, in good correspondence to the observed crystallin properties in different tissues and different species. This suggests that volume exclusion effects provide the evolutionary driving force for the unusual refractive properties and the unusual amino acid compositions of γ-crystallins and S-crystallins.

The role of macromolecular crowding in the evolution of lens crystallins with high molecular refractive index

PubMed Central

Zhao, Huaying; Magone, M. Teresa; Schuck, Peter

2011-01-01

Crystallins are present in the lens at extremely high concentrations in order to provide transparency and generate a high refractive power of the lens. The crystallin families prevalent in the highest density lens tissues are γ crystallins in vertebrates and S crystallins in cephalopods. In parallel evolution, both have evolved molecular refractive index increments 5 – 10 % above those of most proteins. Although this is a small increase, it is statistically very significant and can be achieved only by very unusual amino acid compositions. In contrast, such a molecular adaptation to aid in the refractive function of the lens did not occur in crystallins that are preferentially located in lower density lens tissues, such as vertebrate α crystallin and taxon specific crystallins. In the current work, we apply a model of non-interacting hard spheres to examine the thermodynamic contributions of volume exclusion at lenticular protein concentrations. We show that the small concentration decrease afforded by the higher molecular refractive index increment of crystallins can amplify nonlinearly to produce order of magnitude differences in chemical activities, and lead to reduced osmotic pressure and the reduced propensity for protein aggregation. Quantitatively, this amplification sets in only at protein concentrations as high as those found in hard lenses or the nucleus of soft lenses, in good correspondence to the observed crystalline properties in different tissues and different species. This suggests that volume exclusion effects provide the evolutionary driving force for the unusual refractive properties and the unusual amino acid compositions of γ crystallins and S crystallins. PMID:21566271

Isotope and fatty acid trends along continental shelf depth gradients: Inshore versus offshore hydrological influences on benthic trophic functioning

NASA Astrophysics Data System (ADS)

Chouvelon, T.; Schaal, G.; Grall, J.; Pernet, F.; Perdriau, M.; A-Pernet, E. J.; Le Bris, H.

2015-11-01

Anthropogenic activities and land-based inputs into the sea may influence the trophic structure and functioning of coastal and continental shelf ecosystems, despite the numerous opportunities and services the latter offer to humans and wildlife. In addition, hydrological structures and physical dynamics potentially influence the sources of organic matter (e.g., terrestrial versus marine, or fresh material versus detrital material) entering marine food webs. Understanding the significance of the processes that influence marine food webs and ecosystems (e.g., terrestrial inputs, physical dynamics) is crucially important because trophic dynamics are a vital part of ecosystem integrity. This can be achieved by identifying organic matter sources that enter food webs along inshore-offshore transects. We hypothesised that regional hydrological structures over wide continental shelves directly control the benthic trophic functioning across the shelf. We investigated this issue along two transects in the northern ecosystem of the Bay of Biscay (north-eastern Atlantic). Carbon and nitrogen stable isotope analysis (SIA) and fatty acid analysis (FAA) were conducted on different complementary ecosystem compartments that include suspended particulate organic matter (POM), sedimentary organic matter (SOM), and benthic consumers such as bivalves, large crustaceans and demersal fish. Samples were collected from inshore shallow waters (at ∼1 m in depth) to more than 200 m in depth on the offshore shelf break. Results indicated strong discrepancies in stable isotope (SI) and fatty acid (FA) compositions in the sampled compartments between inshore and offshore areas, although nitrogen SI (δ15N) and FA trends were similar along both transects. Offshore the influence of a permanently stratified area (described previously as a ;cold pool;) was evident in both transects. The influence of this hydrological structure on benthic trophic functioning (i.e., on the food sources available for consumers) was especially apparent across the northern transect, due to unusual carbon isotope compositions (δ13C) in the compartments. At stations under the cold pool, SI and FA organism compositions indicated benthic trophic functioning based on a microbial food web, including a significant contribution of heterotrophic planktonic organisms and/or of SOM, notably in stations under the cold pool. On the contrary, inshore and shelf break areas were characterised by a microalgae-based food web (at least in part for the shelf break area, due to slope current and upwelling that can favour fresh primary production sinking on site). SIA and FAA were relevant and complementary tools, and consumers better medium- to long-term system integrators than POM samples, for depicting the trophic functioning and dynamics along inshore-offshore transects over continental shelves.

The UNUSUAL FLORAL ORGANS gene of Arabidopsis thaliana is an F-box protein required for normal patterning and growth in the floral meristem.

PubMed

Samach, A; Klenz, J E; Kohalmi, S E; Risseeuw, E; Haughn, G W; Crosby, W L

1999-11-01

Genetic and molecular studies have suggested that the UNUSUAL FLORAL ORGANS (UFO) gene, from Arabidopsis thaliana, is expressed in all shoot apical meristems, and is involved in the regulation of a complex set of developmental events during floral development, including floral meristem and floral organ identity. Results from in situ hybridization using genes expressed early in floral development as probes indicate that UFO controls growth of young floral primordia. Transgenic constructs were used to provide evidence that UFO regulates floral organ identity by activating or maintaining transcription of the class B organ-identity gene APETALA 3, but not PISTILLATA. In an attempt to understand the biochemical mode of action of the UFO gene product, we show here that UFO is an F-box protein that interacts with Arabidopsis SKP1-like proteins, both in the yeast two-hybrid system and in vitro. In yeast and other organisms both F-box proteins and SKP1 homologues are subunits of specific ubiquitin E3 enzyme complexes that target specific proteins for degradation. The protein selected for degradation by the complex is specified by the F-box proteins. It is therefore possible that the role of UFO is to target for degradation specific proteins controlling normal growth patterns in the floral primordia, as well as proteins that negatively regulate APETALA 3 transcription.

Unusual infrared absorption increases in photo-degraded organic films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shah, Satvik; Biswas, Rana; Koschny, Thomas

Degradation is among the most pressing problems facing organic materials, occurring through ingress of moisture and oxygen, and light exposure. We determine the nanoscale pathways underlying degradation by light-soaking organic films in an environmental chamber, and performing infrared spectroscopy, to identify atomic bonding changes. We utilize as a prototype the low band gap PTB7-PCBM blend. Films light-soaked in the presence of oxygen show unusual increased absorption at 1727 cm –1 attributable to increased C=O modes, and a broad increase at 3240 cm –1 attributable to hydroxyl (O–H) groups bonded within the organic matrix. Films exposed to oxygen in the dark,more » or light-soaked in an inert atmosphere, do not exhibit significant absorption changes, suggesting simultaneous exposure of oxygen and light that creates singlet excited oxygen is the detrimental factor. Our ab initio electronic structure simulations interpret these by oxidation at the α-C site of the alkyl chains in PTB7, with an irreversible rupture of the alkyl chain and formation of new C=O and C–O–H conformations at the α-C. Infrared spectroscopy coupled with ab initio simulation can provide a powerful tool for quantifying photo-structural atomic bonding changes. As a result, understanding nanoscale light-induced structural changes will open avenues to designing more stable organic materials for organic electronics.« less

Unusual infrared absorption increases in photo-degraded organic films

DOE PAGES

Shah, Satvik; Biswas, Rana; Koschny, Thomas; ...

2017-06-05

Degradation is among the most pressing problems facing organic materials, occurring through ingress of moisture and oxygen, and light exposure. We determine the nanoscale pathways underlying degradation by light-soaking organic films in an environmental chamber, and performing infrared spectroscopy, to identify atomic bonding changes. We utilize as a prototype the low band gap PTB7-PCBM blend. Films light-soaked in the presence of oxygen show unusual increased absorption at 1727 cm –1 attributable to increased C=O modes, and a broad increase at 3240 cm –1 attributable to hydroxyl (O–H) groups bonded within the organic matrix. Films exposed to oxygen in the dark,more » or light-soaked in an inert atmosphere, do not exhibit significant absorption changes, suggesting simultaneous exposure of oxygen and light that creates singlet excited oxygen is the detrimental factor. Our ab initio electronic structure simulations interpret these by oxidation at the α-C site of the alkyl chains in PTB7, with an irreversible rupture of the alkyl chain and formation of new C=O and C–O–H conformations at the α-C. Infrared spectroscopy coupled with ab initio simulation can provide a powerful tool for quantifying photo-structural atomic bonding changes. As a result, understanding nanoscale light-induced structural changes will open avenues to designing more stable organic materials for organic electronics.« less

Unusual MR spectroscopic imaging pattern of an astrocytoma: lack of elevated choline and high myo-inositol and glycine levels.

PubMed

Londoño, Ana; Castillo, Mauricio; Armao, Diane; Kwock, Lester; Suzuki, Kinuko

2003-05-01

We present the case of a patient with an MR imaging study showing an ill-defined intra-axial mass in the right insula and frontal lobe. The mass showed high signal intensity on T2-weighted and fluid-attenuated inversion recovery images and an unusual proton MR spectroscopic imaging pattern characterized by the presence of high levels of myo-inositol/glycine, no significant elevation of choline, and mildly reduced N-acetylaspartate. The histopathologic diagnosis was of diffuse astrocytoma with oligodendroglial components (World Health Organization grade II).

Elephant Moraine 96029, a very mildly aqueously altered and heated CM carbonaceous chondrite: Implications for the drivers of parent body processing

NASA Astrophysics Data System (ADS)

Lee, Martin R.; Lindgren, Paula; King, Ashley J.; Greenwood, Richard C.; Franchi, Ian A.; Sparkes, Robert

2016-08-01

Elephant Moraine (EET) 96029 is a CM carbonaceous chondrite regolith breccia with evidence for unusually mild aqueous alteration, a later phase of heating and terrestrial weathering. The presence of phyllosilicates and carbonates within chondrules and the fine-grained matrix indicates that this meteorite was aqueously altered in its parent body. Features showing that water-mediated processing was arrested at a very early stage include a matrix with a low magnesium/iron ratio, chondrules whose mesostasis contains glass and/or quench crystallites, and a gehlenite-bearing calcium- and aluminium-rich inclusion. EET 96029 is also rich in Fe,Ni metal relative to other CM chondrites, and more was present prior to its partial replacement by goethite during Antarctic weathering. In combination, these properties indicate that EET 96029 is one of the least aqueously altered CMs yet described (CM2.7) and so provides new insights into the original composition of its parent body. Following aqueous alteration, and whilst still in the parent body regolith, the meteorite was heated to ∼400-600 °C by impacts or solar radiation. Heating led to the amorphisation and dehydroxylation of serpentine, replacement of tochilinite by magnetite, loss of sulphur from the matrix, and modification to the structure of organic matter that includes organic nanoglobules. Significant differences between samples in oxygen isotope compositions, and water/hydroxyl contents, suggests that the meteorite contains lithologies that have undergone different intensities of heating. EET 96029 may be more representative of the true nature of parent body regoliths than many other CM meteorites, and as such can help interpret results from the forthcoming missions to study and return samples from C-complex asteroids.

Chemical and isotopic equilibrium between CO 2 and CH 4 in fumarolic gas discharges: Generation of CH 4 in arc magmatic-hydrothermal systems

NASA Astrophysics Data System (ADS)

Fiebig, Jens; Chiodini, Giovanni; Caliro, Stefano; Rizzo, Andrea; Spangenberg, Jorge; Hunziker, Johannes C.

2004-05-01

The chemical and isotopic composition of fumarolic gases emitted from Nisyros Volcano, Greece, and of a single gas sample from Vesuvio, Italy, was investigated in order to determine the origin of methane (CH 4) within two subduction-related magmatic-hydrothermal environments. Apparent temperatures derived from carbon isotope partitioning between CH 4 and CO 2 of around 340°C for Nisyros and 470°C for Vesuvio correlate well with aquifer temperatures as measured directly and/or inferred from compositional data using the H 2O-H 2-CO 2-CO-CH 4 geothermometer. Thermodynamic modeling reveals chemical equilibrium between CH 4, CO 2 and H 2O implying that carbon isotope partitioning between CO 2 and CH 4 in both systems is controlled by aquifer temperature. N 2/ 3He and CH 4/ 3He ratios of Nisyros fumarolic gases are unusually low for subduction zone gases and correspond to those of midoceanic ridge environments. Accordingly, CH 4 may have been primarily generated through the reduction of CO 2 by H 2 in the absence of any organic matter following a Fischer-Tropsch-type reaction. However, primary occurrence of minor amounts of thermogenic CH 4 and subsequent re-equilibration with co-existing CO 2 cannot be ruled out entirely. CO 2/ 3He ratios and δ 13C CO 2 values imply that the evolved CO 2 either derives from a metasomatized mantle or is a mixture between two components, one outgassing from an unaltered mantle and the other released by thermal breakdown of marine carbonates. The latter may contain traces of organic matter possibly decomposing to CH 4 during thermometamorphism.

Comparative Genomic and Transcriptomic Characterization of the Toxigenic Marine Dinoflagellate Alexandrium ostenfeldii

PubMed Central

Jaeckisch, Nina; Yang, Ines; Wohlrab, Sylke; Glöckner, Gernot; Kroymann, Juergen; Vogel, Heiko; Cembella, Allan; John, Uwe

2011-01-01

Many dinoflagellate species are notorious for the toxins they produce and ecological and human health consequences associated with harmful algal blooms (HABs). Dinoflagellates are particularly refractory to genomic analysis due to the enormous genome size, lack of knowledge about their DNA composition and structure, and peculiarities of gene regulation, such as spliced leader (SL) trans-splicing and mRNA transposition mechanisms. Alexandrium ostenfeldii is known to produce macrocyclic imine toxins, described as spirolides. We characterized the genome of A. ostenfeldii using a combination of transcriptomic data and random genomic clones for comparison with other dinoflagellates, particularly Alexandrium species. Examination of SL sequences revealed similar features as in other dinoflagellates, including Alexandrium species. SL sequences in decay indicate frequent retro-transposition of mRNA species. This probably contributes to overall genome complexity by generating additional gene copies. Sequencing of several thousand fosmid and bacterial artificial chromosome (BAC) ends yielded a wealth of simple repeats and tandemly repeated longer sequence stretches which we estimated to comprise more than half of the whole genome. Surprisingly, the repeats comprise a very limited set of 79–97 bp sequences; in part the genome is thus a relatively uniform sequence space interrupted by coding sequences. Our genomic sequence survey (GSS) represents the largest genomic data set of a dinoflagellate to date. Alexandrium ostenfeldii is a typical dinoflagellate with respect to its transcriptome and mRNA transposition but demonstrates Alexandrium-like stop codon usage. The large portion of repetitive sequences and the organization within the genome is in agreement with several other studies on dinoflagellates using different approaches. It remains to be determined whether this unusual composition is directly correlated to the exceptionally genome organization of dinoflagellates with a low amount of histones and histone-like proteins. PMID:22164224

76 FR 50796 - Self-Regulatory Organizations; Financial Industry Regulatory Authority, Inc.; Notice of Filing...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-16

... designed to minimize the potential for mini-manipulations and for corners or squeezes of the underlying... movements by automated surveillance techniques to identify unusual activity in both options and underlying...

Gas-separation process

DOEpatents

Toy, L.G.; Pinnau, I.; Baker, R.W.

1994-01-25

A process is described for separating condensable organic components from gas streams. The process makes use of a membrane made from a polymer material that is glassy and that has an unusually high free volume within the polymer material. 6 figures.

Wax Layers on Cosmos bipinnatus Petals Contribute Unequally to Total Petal Water Resistance1[OPEN

PubMed Central

Buschhaus, Christopher; Hager, Dana; Jetter, Reinhard

2015-01-01

Cuticular waxes coat all primary aboveground plant organs as a crucial adaptation to life on land. Accordingly, the properties of waxes have been studied in much detail, albeit with a strong focus on leaf and fruit waxes. Flowers have life histories and functions largely different from those of other organs, and it remains to be seen whether flower waxes have compositions and physiological properties differing from those on other organs. This work provides a detailed characterization of the petal waxes, using Cosmos bipinnatus as a model, and compares them with leaf and stem waxes. The abaxial petal surface is relatively flat, whereas the adaxial side consists of conical epidermis cells, rendering it approximately 3.8 times larger than the projected petal area. The petal wax was found to contain unusually high concentrations of C22 and C24 fatty acids and primary alcohols, much shorter than those in leaf and stem waxes. Detailed analyses revealed distinct differences between waxes on the adaxial and abaxial petal sides and between epicuticular and intracuticular waxes. Transpiration resistances equaled 3 × 104 and 1.5 × 104 s m−1 for the adaxial and abaxial surfaces, respectively. Petal surfaces of C. bipinnatus thus impose relatively weak water transport barriers compared with typical leaf cuticles. Approximately two-thirds of the abaxial surface water barrier was found to reside in the epicuticular wax layer of the petal and only one-third in the intracuticular wax. Altogether, the flower waxes of this species had properties greatly differing from those on vegetative organs. PMID:25413359

A new zinc-1,3,5-benzenetricarboxylate framework integrated three distinct subunits (SBUs)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Yi-Ming, E-mail: ymxie@fjirsm.ac.cn

2013-06-01

A new metal-organic framework (MOF) [Zn₅(btc)₃(H₂O)₀.₅(O)₀.₅(DMA)₃]·1.75(DMA) (1; btc=1,3,5-benzenetricarboxylate; DMA=N,N´-dimethyl acetamide) has been solvothermally synthesized. Unusually, three distinct subunits (SBUs), [Zn₂(CO₂)₄(DMA)₂], [(μ₃-H₂O)Zn₃(CO₂)₆(DMA)] and [(µ₄-O)Zn₄(CO₂)₆(DMA)₂] are observed in 1 simultaneously. The integration of three distinct SBUs leads to an interesting Zn-btc framework materials with unusual structural topology. - Graphical abstract: Presented here is a new zinc-1,3,5-benzenetricarboxylate framework integrated three distinct subunits (SBUs). - Highlights: • A new zinc-1,3,5-benzenetricarboxylate framework has been synthesized. • Three distinct subunits (SBUs) are observed in 1 simultaneously. • The integration of three distinct SBUs leads to an unusual structural topology.

Unusual benthic fauna associated with a whale fall in Monterey Canyon, California

NASA Astrophysics Data System (ADS)

Goffredi, Shana K.; Paull, Charles K.; Fulton-Bennett, Kim; Hurtado, Luis A.; Vrijenhoek, Robert C.

2004-10-01

On February 6, 2002, we discovered an unusual assemblage of deep-sea animals associated with a well-preserved carcass of a gray whale (Eschrichtius robustus) at 2891 m depth in the axis of Monterey Canyon, California. The 9-10 m long carcass was found approximately 31 km off shore, where it settled to the bottom against the northern wall of the canyon's sedimented floor. This carcass delivered approximately 20,000 kg of organic material to a typically food-limited seafloor. Particularly noteworthy were the low occurrence of large mobile scavengers, the large number of opportunistic deep-sea species, and an abundance of unusual polychaetes. Two of these polychaetes, a spionid and a siboglinid, are new to science. Since this discovery, we visited the whale fall on two subsequent occasions (March and October 2002) to document faunal community changes in one of the deepest large food falls known to date.

Fabricating porous materials using interpenetrating inorganic-organic composite gels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seo, Dong-Kyun; Volosin, Alex

Porous materials are fabricated using interpenetrating inorganic-organic composite gels. A mixture or precursor solution including an inorganic gel precursor, an organic polymer gel precursor, and a solvent is treated to form an inorganic wet gel including the organic polymer gel precursor and the solvent. The inorganic wet gel is then treated to form a composite wet gel including an organic polymer network in the body of the inorganic wet gel, producing an interpenetrating inorganic-organic composite gel. The composite wet gel is dried to form a composite material including the organic polymer network and an inorganic network component. The composite materialmore » can be treated further to form a porous composite material, a porous polymer or polymer composite, a porous metal oxide, and other porous materials.« less

Interlaminar fracture of random short-fiber SMC composite

NASA Technical Reports Server (NTRS)

Wang, S. S.; Suemasu, H.; Zahlan, N. M.

1984-01-01

In the experimental phase of the present study of the interlaminar fracture behavior of a randomly oriented short fiber sheet molding compound (SMC) composite, the double cantilever beam fracture test is used to evaluate the mode I interlaminar fracture toughness of different composite thicknesses. In the analytical phase of this work, a geometrically nonlinear analysis is introduced in order to account for large deflections and nonlinear load deflection curves in the evaluation of interlaminar fracture toughness. For the SMC-R50 material studied, interlaminar toughness is an order of magnitude higher than that of unreinforced neat resin, due to unusual damage mechanisms ahead of the crack tip, together with significant fiber bridging across crack surfaces. Composite thickness effects on interlaminar fracture are noted to be appreciable, and a detailed discussion is given on the influence of SMC microstructure.

An unusually strong Einstein ring in the radio source PKS1830 - 211

NASA Technical Reports Server (NTRS)

Jauncey, D. L.; Reynolds, J. E.; Tzioumis, A. K.; Murphy, D. W.; Preston, R. A.; Jones, D. L.; Meier, D. L.; Hoard, D. W.; Lobdell, E. T.; Skjerve, L.

1991-01-01

High-resolution radio images of PKS1830 - 211 are obtained to study the possibility that the double structure is a gravitationally lensed object. The VLBI observations, taken from interferometric radiotelescope networks, reveal an elliptical ring that connects two bright spots of similar composition. Because the lens and the lensed object are closely aligned, and because of the structure of the two spots, the source is concluded to be a radio Einstein ring. The source is found to be close to the galactic plane, and the lens and the lensed object are extragalactic. The source is also found to be unusually bright, suggesting that it is aligned with a bright background source or amplified by some mechanism related to a source that is not so bright.

Results of initial analyses of the salt (macro) batch 10 tank 21H qualification samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, T. B.

2017-01-01

Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Interim Salt Disposition Project (ISDP) Salt (Macro) Batch 10 for processing through the Actinide Removal Process (ARP) and the Modular Caustic-Side Solvent Extraction Unit (MCU). This document reports the initial results of the analyses of samples of Tank 21H. Analysis of the Tank 21H Salt (Macro) Batch 10 composite sample indicates that the material does not display any unusual characteristics or observations, such as floating solids, the presence of large amount of solids, or unusual colors. Further sample results will be reported in a futuremore » document. This memo satisfies part of Deliverable 3 of the Technical Task Request (TTR).« less

Results of initial analyses of the salt (macro) batch 11 Tank 21H qualification samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, T. B.

Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Interim Salt Disposition Project (ISDP) Salt (Macro) Batch 11 for processing through the Actinide Removal Process (ARP) and the Modular Caustic-Side Solvent Extraction Unit (MCU). This document reports the initial results of the analyses of samples of Tank 21H. Analysis of the Tank 21H Salt (Macro) Batch 11 composite sample indicates that the material does not display any unusual characteristics or observations, such as floating solids, the presence of large amounts of solids, or unusual colors. Further sample results will be reported in a futuremore » document. This memo satisfies part of Deliverable 3 of the Technical Task Request (TTR).« less

Synthesis of sodium polyhydrides at high pressures

NASA Astrophysics Data System (ADS)

Struzhkin, Viktor V.; Kim, Duck Young; Stavrou, Elissaios; Muramatsu, Takaki; Mao, Ho-Kwang; Pickard, Chris J.; Needs, Richard J.; Prakapenka, Vitali B.; Goncharov, Alexander F.

2016-07-01

The only known compound of sodium and hydrogen is archetypal ionic NaH. Application of high pressure is known to promote states with higher atomic coordination, but extensive searches for polyhydrides with unusual stoichiometry have had only limited success in spite of several theoretical predictions. Here we report the first observation of the formation of polyhydrides of Na (NaH3 and NaH7) above 40 GPa and 2,000 K. We combine synchrotron X-ray diffraction and Raman spectroscopy in a laser-heated diamond anvil cell and theoretical random structure searching, which both agree on the stable structures and compositions. Our results support the formation of multicenter bonding in a material with unusual stoichiometry. These results are applicable to the design of new energetic solids and high-temperature superconductors based on hydrogen-rich materials.

Biogeochemistry and nitrogen cycling in an Arctic, volcanic ecosystem

NASA Astrophysics Data System (ADS)

Fogel, M. L.; Benning, L.; Conrad, P. G.; Eigenbrode, J.; Starke, V.

2007-12-01

As part of a study on Mars Analogue environments, the biogeochemistry of Sverrefjellet Volcano, Bocfjorden, Svalbard, was conducted and compared to surrounding glacial, thermal spring, and sedimentary environments. An understanding of how nitrogen might be distributed in a landscape that had extinct or very cold adapted, slow- growing extant organisms should be useful for detecting unknown life forms. From high elevations (900 m) to the base of the volcano (sea level), soil and rock ammonium concentrations were uniformly low, typically less than 1- 3 micrograms per gm of rock or soil. In weathered volcanic soils, reduced nitrogen concentrations were higher, and oxidized nitrogen concentrations lower. The opposite was found in a weathered Devonian sedimentary soil. Plants and lichens growing on volcanic soils have an unusually wide range in N isotopic compositions from -5 to +12‰, a range rarely measured in temperate ecosystems. Nitrogen contents and isotopic compositions of volcanic soils and rocks were strongly influenced by the presence or absence of terrestrial herbivores or marine avifauna with higher concentrations of N and elevated N isotopic compositions occurring as patches in areas immediately influenced by reindeer, Arctic fox ( Alopex lagopus), and marine birds. Because of the extreme conditions in this area, ephemeral deposition of herbivore feces results in a direct and immediate N pulses into the ecosystem. The lateral extent and distribution of marine- derived nitrogen was measured on a landscape scale surrounding an active fox den. Nitrogen was tracked from the bones of marine birds to soil to vegetation. Because of extreme cold, slow biological rates and nitrogen cycling, a mosaic of N patterns develops on the landscape scale.

ABC triblock copolymer vesicles with mesh-like morphology.

PubMed

Zhao, Wei; Chen, Dian; Hu, Yunxia; Grason, Gregory M; Russell, Thomas P

2011-01-25

Polymer vesicles made from poly(isoprene-b-styrene-b-2-vinyl pyridine) (PI-b-PS-b-P2VP) triblock copolymer confined within the nanopores of an anodic aluminum oxide (AAO) membrane are studied. It was found that these vesicles have well-defined, nanoscopic size, and complex microphase-separated hydrophobic membranes, comprised of the PS and PI blocks, while the coronas are formed by the P2VP block. Vesicle formation was tracked using both transmission and scanning electron microscopy. A mesh-like morphology formed in the membrane at a well-defined composition of the three blocks that can be tuned by changing the copolymer composition. The nanoscale confinement, copolymer composition, and subtle molecular interactions contribute to the generation of these vesicles with such unusual morphologies.

Carbonate mineralization via an amorphous calcium carbonate (ACC) pathway: Tuning polymorph selection by Mg, pH, and mixing environment

NASA Astrophysics Data System (ADS)

Dove, P. M.; Blue, C.; Mergelsberg, S. T.; Giuffre, A. J.; Han, N.; De Yoreo, J. J.

2017-12-01

Mineral formation by nonclassical processes is widespread with many pathways that include aggregation of nanoparticles, oriented attachment of fully formed crystals, and sequential nucleation/transformation of amorphous phases (De Yoreo et al., 2015, Science). Field observations indicate amorphous calcium carbonate (ACC) can be the initial precipitate when local conditions promote high supersaturations for short time periods. Examples include microbial mats, marine porewaters that undergo pulses of increased alkalinity, closed basin lakes, and sabkhas. The crystalline products exhibit diverse morphologies and complex elemental and isotopic signatures. This study quantifies relationships between solution composition and the crystalline polymorphs that transform from ACC (Blue et al., GCA, 2017). Our experimental design synthesized ACC under controlled conditions for a suite of compositions by tuning input pH, Mg/Ca, and total carbonate concentration. ACC products were allowed to transform within output suspensions under stirred or quiescent mixing while characterizing the polymorph and composition of evolving solutions and solids. We find that ACC transforms to crystalline polymorphs with a systematic relationship to solution composition to give a quantitative framework based upon solution aMg2+/aCa2+ and aCO32-/aCa2+. We also measure a polymorph-specific evolution of pH and Mg/Ca during the transformation that indicates the initial polymorph to form. Pathway is further modulated by stirring versus quiescent conditions. The findings reconcile discrepancies among previous studies of ACC to crystalline products and supports claims that monohydrocalcite may be an overlooked, transient phase during formation of some aragonite and calcite deposits. Organic additives and extreme pH are not required to tune composition and polymorph. Insights from this study reiterate the need to revisit long-standing dogmas regarding controls on CaCO3 polymorph selection. Classical models assume thermodynamic equilibria but cannot provide a reliable predictor of compositions when kinetic factors are driving mineralization. Nonclassical pathways to mineralization may be the missing link to interpreting unusual CaCO3 polymorphs, compositions and textures in modern and ancient carbonates.

Synthetic biology meets tissue engineering.

PubMed

Davies, Jamie A; Cachat, Elise

2016-06-15

Classical tissue engineering is aimed mainly at producing anatomically and physiologically realistic replacements for normal human tissues. It is done either by encouraging cellular colonization of manufactured matrices or cellular recolonization of decellularized natural extracellular matrices from donor organs, or by allowing cells to self-organize into organs as they do during fetal life. For repair of normal bodies, this will be adequate but there are reasons for making unusual, non-evolved tissues (repair of unusual bodies, interface to electromechanical prostheses, incorporating living cells into life-support machines). Synthetic biology is aimed mainly at engineering cells so that they can perform custom functions: applying synthetic biological approaches to tissue engineering may be one way of engineering custom structures. In this article, we outline the 'embryological cycle' of patterning, differentiation and morphogenesis and review progress that has been made in constructing synthetic biological systems to reproduce these processes in new ways. The state-of-the-art remains a long way from making truly synthetic tissues, but there are now at least foundations for future work. © 2016 Authors; published by Portland Press Limited.

Agreement between Lakeshore Vocational, Technical and Adult Education District Board and Lakeshore Education Association, 1987-1989.

ERIC Educational Resources Information Center

1987

The agreement between the Lakeshore Vocational, Technical and Adult Education District Board and the Lakeshore Education Association is presented for the period 1987-1989. The articles in the agreement set forth provisions related to: (1) recognition and composition of the bargaining unit; (2) pay variations for various or unusual conditions; (3)…

In-situ characterization of highly reversible phase transformation by synchrotron X-ray Laue microdiffraction

DOE PAGES

Chen, Xian; Tamura, Nobumichi; MacDowell, Alastair; ...

2016-05-23

The alloy Cu 25 Au 30 Zn 45 undergoes a huge first-order phase transformation (6% strain) and shows a high reversibility under thermal cycling and an unusual martensitc microstructure in sharp contrast to its nearby compositions. We discovered this alloy by systematically tuning the composition so that its lattice parameters satisfy the cofactor conditions (i.e., the kinematic conditions of compatibility between phases). It was conjectured that satisfaction of these conditions is responsible for the enhanced reversibility as well as the observed unusual fluid-like microstructure during transformation, but so far, there has been no direct evidence confirming that these observed microstructuresmore » are those predicted by the cofactor conditions. In order to verify this hypothesis, we use synchrotron X-ray Laue microdiffraction to measure the orientations and structural parameters of variants and phases near the austenite/martensite interface. The areas consisting of both austenite and multi-variants of martensite are scanned by microLaue diffraction. The cofactor conditions have been examined from the kinematic relation of lattice vectors across the interface. The continuity condition of the interface is precisely verified from the correspondent lattice vectors between two phases.« less

Strain Hardening of Hadfield Manganese Steel

NASA Astrophysics Data System (ADS)

Adler, P. H.; Olson, G. B.; Owen, W. S.

1986-10-01

The plastic flow behavior of Hadfield manganese steel in uniaxial tension and compression is shown to be greatly influenced by transformation plasticity phenomena. Changes in the stress-strain (σ-ɛ) curves with temperature correlate with the observed extent of deformation twinning, consistent with a softening effect of twinning as a deformation mechanism and a hardening effect of the twinned microstructure. The combined effects give upward curvature to the σ-ɛ curve over extensive ranges of plastic strain. A higher strain hardening in compression compared with tension appears to be consistent with the observed texture development. The composition dependence of stacking fault energy computed using a thermodynamic model suggests that the Hadfield composition is optimum for a maximum rate of deformation twinning. Comparisons of the Hadfield steel with a Co-33Ni alloy exhibiting similar twinning kinetics, and an Fe-21Ni-lC alloy deforming by slip indicate no unusual strain hardening at low strains where deformation is controlled by slip, but an unusual amount of structural hardening associated with the twin formation in the Hadfield steel. A possible mechanism of anomalous twin hardening is discussed in terms of modified twinning behavior (pseudotwinning) in nonrandom solid solutions.

Impact of photoluminescence temperature and growth parameter on the exciton localized in BxGa1-xAs/GaAs epilayers grown by MOCVD

NASA Astrophysics Data System (ADS)

Hidouri, Tarek; Saidi, Faouzi; Maaref, Hassen; Rodriguez, Philippe; Auvray, Laurent

2016-10-01

In this work, BxGa1-xAs/GaAs epilayers with three different boron compositions were elaborated by metal organic chemical vapor deposition (MOCVD) on GaAs (001) substrate. Structural study using High resolution X-ray diffraction (HRXRD) spectroscopy and Atomic Force Microscopy (AFM) have been used to estimate the boron fraction. The luminescence keys were carried out as functions of temperature in the range 10-300 K, by the techniques of photoluminescence (PL). The low PL temperature has shown an abnormal emission appeared at low energy side witch attributed to the recombination through the deep levels. In all samples, the PL peak energy and the full width at half maximum (FWHM), present an anomalous behavior as a result of the competition process between localized and delocalized carriers. We propose the Localized-state Ensemble model to explain the unusual photoluminescence behaviors. Electrical carriers generation, thermal escape, recapture, radiative and non-radiative lifetime are taken into account. The temperature-dependent photoluminescence measurements were found to be in reasonable agreement with the model of localized states. We controlled the evolution of such parameters versus composition by varying the V/III ratio to have a quantitative and qualitative understanding of the recombination mechanisms. At high temperature, the model can be approximated to the band-tail-state emission.

Inorganic Phosphate Limitation Modulates Capsular Polysaccharide Composition in Mycobacteria.

PubMed

van de Weerd, Robert; Boot, Maikel; Maaskant, Janneke; Sparrius, Marion; Verboom, Theo; van Leeuwen, Lisanne M; Burggraaf, Maroeska J; Paauw, Nanne J; Dainese, Elisa; Manganelli, Riccardo; Bitter, Wilbert; Appelmelk, Ben J; Geurtsen, Jeroen

2016-05-27

Mycobacterium tuberculosis is protected by an unusual and highly impermeable cell envelope that is critically important for the successful colonization of the host. The outermost surface of this cell envelope is formed by capsular polysaccharides that play an important role in modulating the initial interactions once the bacillus enters the body. Although the bioenzymatic steps involved in the production of the capsular polysaccharides are emerging, information regarding the ability of the bacterium to modulate the composition of the capsule is still unknown. Here, we study the mechanisms involved in regulation of mycobacterial capsule biosynthesis using a high throughput screen for gene products involved in capsular α-glucan production. Utilizing this approach we identified a group of mutants that all carried mutations in the ATP-binding cassette phosphate transport locus pst These mutants collectively exhibited a strong overproduction of capsular polysaccharides, including α-glucan and arabinomannan, suggestive of a role for inorganic phosphate (Pi) metabolism in modulating capsular polysaccharide production. These findings were corroborated by the observation that growth under low Pi conditions as well as chemical activation of the stringent response induces capsule production in a number of mycobacterial species. This induction is, in part, dependent on σ factor E. Finally, we show that Mycobacterium marinum, a model organism for M. tuberculosis, encounters Pi stress during infection, which shows the relevance of our findings in vivo. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Atmospheric CO and hydrogen uptake and CO oxidizer phylogeny for miyake-jima, Japan volcanic deposits.

PubMed

King, Gary M; Weber, Carolyn F; Nanba, Kenji; Sato, Yoshinori; Ohta, Hiroyuki

2008-01-01

We have assayed rates of atmospheric CO and hydrogen uptake, maximum potential CO uptake and the major phylogenetic composition of CO-oxidizing bacterial communities for a variety of volcanic deposits on Miyake-jima, Japan. These deposits represented different ages and stages of plant succession, ranging from unvegetated scoria deposited in 1983 to forest soils on deposits >800 yr old. Atmospheric CO and hydrogen uptake rates varied from -2.0±1.8-6.3±0.1 mg CO m(-2) d(-1) and 0.0±0.4-2.0±0.2 mg H(2) m(-2) d(-1), respectively, and were similar to or greater than values reported for sites on Kilauea volcano, Hawaii, USA. At one of the forested sites, CO was emitted to the atmosphere, while two vegetated sites did not consume atmospheric hydrogen, an unusual observation. Although maximum potential CO uptake rates were also comparable to values for Kilauea, the relationship between these rates and organic carbon contents of scoria or soil indicated that CO oxidizers were relatively more abundant in Miyake-jima deposits. Phylogenetic analyses based on the large sub-unit gene for carbon monoxide dehydrogenase (coxL) indicated that many novel lineages were present on Miyake-jima, that CO-oxidizing Proteobacteria were prevalent in vegetated sites and that community structure appeared to vary more than composition among sites.

Composition and depositional environment of concretionary strata of early Cenomanian (early Late Cretaceous) age, Johnson County, Wyoming

USGS Publications Warehouse

Merewether, E.A.; Gautier, Donald L.

2000-01-01

Unusual, concretion-bearing mudrocks of early Late Cretaceous age, which were deposited in an early Cenomanian epeiric sea, have been recognized at outcrops in eastern Wyoming and in adjoining areas of Montana, South Dakota, Nebraska, and Colorado. In Johnson County, Wyo., on the western flank of the Powder River Basin, these strata are in the lower part of the Belle Fourche Member of the Frontier Formation. At a core hole in south-central Johnson County, they are informally named Unit 2. These strata are about 34 m (110 ft) thick and consist mainly of medium- to dark-gray, noncalcareous, silty shale and clayey or sandy siltstone; and light-gray to grayish-red bentonite. The shale and siltstone are either bioturbated or interlaminated; the laminae are discontinuous, parallel, and even or wavy. Several ichnogenera of deposit feeders are common in the unit but filter feeders are sparse. The unit also contains marine and continental palynomorphs and, near the top, a few arenaceous foraminifers. No invertebrate macrofossils have been found in these rocks. Unit 2 conformably overlies lower Cenomanian shale in the lowermost Belle Fourche Member, informally named Unit 3, and is conformably overlain by lower and middle Cenomanian shale, siltstone, and sandstone within the member, which are informally named Unit 1. The mineral and chemical composition of the three Cenomanian units is comparable and similar to that of shale and siltstone in the Upper Cretaceous Pierre Shale, except that these units contain more SiO2 and less CaO, carbonate carbon, and manganese. Silica is generally more abundant and CaO is generally less abundant in river water than in seawater. The composition of Unit 2 contrasts significantly with that of the underlying and overlying units. Unit 2 contains no pyrite and dolomite and much less sulfur than Units 1 and 3. Sulfate is generally less abundant in river water than in seawater. Unit 2 also includes sideritic and calcitic concretions, whereas Units 1 and 3 contain neither concretions nor siderite and only sparse calcite. Carbon-sulfur-iron chemistry for the concretions suggests that sulfate availability was the limiting factor in pyrite formation and sulfide incorporation in Unit 2. Isotopic compositions of the carbon and oxygen in siderite and calcite from several concretions are variable and suggest cementation during early diagenesis in a variety of microenvironments. The isotopic composition of these carbonate minerals differs from that of Upper Cretaceous marine limestones. When considered in conjunction with the proportions of sulfur, organic carbon, and iron in Unit 2, major-element and micropaleontological data suggest that the composition of the original pore waters and of overlying waters in the late early Cenomanian sea was brackish to fresh. The mudrocks of Units 3 and 2, and a lower part of Unit 1, accumulated on a shelf at low to moderate rates of sedimentation in association with variable but generally weak current action. In Unit 2 and laterally equivalent rocks of the region, the sideritic and calcitic concretions probably indicate the extent of a body of brackish to fresh and oxygen-deficient water. Rates of precipitation in this region during the mid-Cretaceous could have been unusually high and the precipitation probably was seasonal. The organic matter in Unit 2 is humic-rich and would have been derived from continental environments. If the epeiric sea was brackish to fresh in the region of eastern Wyoming and contiguous areas, meteoric runoff from the adjoining lowlands must have been periodically large and the seaway north of the region probably was constricted. Seasonal changes in salinity might have been accompanied by changes in water temperature and oxygen content. The lower part of the Frontier Formation (Units 3, 2, and 1) in Wyoming records an intermittently and easterly prograding shoreline during late early and early middle Cenomanian time. Laterally equivalent strata in Nebraska

ATMOSPHERIC COMPOSITION OF WEAK G BAND STARS: CNO AND Li ABUNDANCES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adamczak, Jens; Lambert, David L., E-mail: adamczak@astro.as.utexas.edu

We determined the chemical composition of a large sample of weak G band stars-a rare class of G and K giants of intermediate mass with unusual abundances of C, N, and Li. We have observed 24 weak G band stars with the 2.7 m Harlan J. Smith Telescope at the McDonald Observatory and derived spectroscopic abundances for C, N, O, and Li, as well as for selected elements from Na-Eu. The results show that the atmospheres of weak G band stars are highly contaminated with CN-cycle products. The C underabundance is about a factor of 20 larger than for normalmore » giants and the {sup 12}C/{sup 13}C ratio approaches the CN-cycle equilibrium value. In addition to the striking CN-cycle signature the strong N overabundance may indicate the presence of partially ON-cycled material in the atmospheres of the weak G band stars. The exact mechanism responsible for the transport of the elements to the surface has yet to be identified but could be induced by rapid rotation of the main sequence progenitors of the stars. The unusually high Li abundances in some of the stars are an indicator for Li production by the Cameron-Fowler mechanism. A quantitative prediction of a weak G band star's Li abundance is complicated by the strong temperature sensitivity of the mechanism and its participants. In addition to the unusual abundances of CN-cycle elements and Li, we find an overabundance of Na that is in accordance with the NeNa chain running in parallel with the CN cycle. Apart from these peculiarities, the element abundances in a weak G band star's atmosphere are consistent with those of normal giants.« less

Atmospheric Composition of Weak G Band Stars: CNO and Li Abundances

NASA Astrophysics Data System (ADS)

Adamczak, Jens; Lambert, David L.

2013-03-01

We determined the chemical composition of a large sample of weak G band stars—a rare class of G and K giants of intermediate mass with unusual abundances of C, N, and Li. We have observed 24 weak G band stars with the 2.7 m Harlan J. Smith Telescope at the McDonald Observatory and derived spectroscopic abundances for C, N, O, and Li, as well as for selected elements from Na-Eu. The results show that the atmospheres of weak G band stars are highly contaminated with CN-cycle products. The C underabundance is about a factor of 20 larger than for normal giants and the 12C/13C ratio approaches the CN-cycle equilibrium value. In addition to the striking CN-cycle signature the strong N overabundance may indicate the presence of partially ON-cycled material in the atmospheres of the weak G band stars. The exact mechanism responsible for the transport of the elements to the surface has yet to be identified but could be induced by rapid rotation of the main sequence progenitors of the stars. The unusually high Li abundances in some of the stars are an indicator for Li production by the Cameron-Fowler mechanism. A quantitative prediction of a weak G band star's Li abundance is complicated by the strong temperature sensitivity of the mechanism and its participants. In addition to the unusual abundances of CN-cycle elements and Li, we find an overabundance of Na that is in accordance with the NeNa chain running in parallel with the CN cycle. Apart from these peculiarities, the element abundances in a weak G band star's atmosphere are consistent with those of normal giants.

Mg-spinel lithology: A new rock type on the lunar farside

USGS Publications Warehouse

Pieters, C.M.; Besse, S.; Boardman, J.; Buratti, B.; Cheek, L.; Clark, R.N.; Combe, J.-P.; Dhingra, D.; Goswami, J.N.; Green, R.O.; Head, J.W.; Isaacson, P.; Klima, R.; Kramer, G.; Lundeen, S.; Malaret, E.; McCord, T.; Mustard, J.; Nettles, J.; Petro, N.; Runyon, C.; Staid, M.; Sunshine, J.; Taylor, L.A.; Thaisen, K.; Tompkins, S.; Whitten, J.

2011-01-01

High-resolution compositional data from Moon Mineralogy Mapper (M 3) for the Moscoviense region on the lunar farside reveal three unusual, but distinctive, rock types along the inner basin ring. These are designated "OOS" since they are dominated by high concentrations of orthopyroxene, olivine, and Mg-rich spinel, respectively. The OOS occur as small areas, each a few kilometers in size, that are widely separated within the highly feldspathic setting of the basin rim. Although the abundance of plagioclase is not well constrained within the OOS, the mafic mineral content is exceptionally high, and two of the rock types could approach pyroxenite and harzburgite in composition. The third is a new rock type identified on the Moon that is dominated by Mg-rich spinel with no other mafic minerals detectable (<5% pyroxene, olivine). All OOS surfaces are old and undisturbed since basin formation. They are effectively invisible in image data and are only recognized by their distinctive composition identified spectroscopically. The origin of these unusual lithologies appears to be linked to one or more magmatic intrusions into the lower crust, perhaps near the crust-mantle interface. Processes such as fractional crystallization and gravity settling within such intrusions may provide a mechanism for concentrating the mafic components within zones several kilometers in dimension. The OOS are embedded within highly anorthositic material from the lunar crust; they may thus be near contemporaneous with crustal products from the cooling magma ocean. Copyright ?? 2011 by the American Geophysical Union.

Above detection limits - Prebiotic organics in comets and carbonaceous meteorites

NASA Astrophysics Data System (ADS)

Stern, J. C.; Elsila, J. E.; Callahan, M. P.; Glavin, D. P.; Martin, M. G.; Dworkin, J. P.

2009-12-01

The delivery of organic compounds such as amino acids and nucleobases by comets, asteroids, and their fragments may have contributed feedstock for prebiotic chemistry leading to the first self-replicating systems of the early Earth. In order to determine the isotopic composition, distribution, and abundance of prebiotic organic compounds in extraterrestrial samples we have recently optimized a highly sensitive liquid chromatography tandem quadupole mass spectrometer (LC-QqQ-MS) and a gas chromatography mass spectrometer coupled with an isotope ratio mass spectrometer (GC-MS/IRMS). This suite of instruments not only allows us to identify and quantify extremely trace amounts of organics of astrobiological interest, but also to confirm their extraterrestrial origins by stable isotopic measurements. The amino acid glycine was detected upon preliminary examinations of foils from NASA’s Stardust mission, which returned cometary material from comet 81P/Wild 2. To rule out the possibility of terrestrial contamination as the source of the glycine, the carbon isotopic ratio was measured. The δ13C value for glycine was determined to be +29 ± 6‰, well outside the terrestrial range for organic carbon of +6 ‰ to -40 ‰. The Stardust glycine δ13C value falls in the range previously reported for glycine (+22‰ to +41‰) in the carbonaceous meteorites Murchison and Orgueil. This represents the first detection of glycine or any other amino acid in a comet. Recent investigations of carbonaceous meteorite organic matter have revealed the presence of several nucleobases in the Murchison meteorite and several Antarctic CR meteorites never before analyzed for nucleobases using LC-QqQ-MS. This analytical tool is a sensitive and highly selective method for measuring the trace amounts of these organics in meteorites. In particular, the unusual Antarctic C2 meteorite, LON 94102, shows high abundances of guanine, hypoxanthine, and xanthine with concentrations ranging from 70 to 200 ppb. Nitrogen isotopic measurements will be made to determine the origin (extraterrestrial or terrestrial) of these compounds.

UNUSUAL FLORAL ORGANS Controls Meristem Identity and Organ Primordia Fate in Arabidopsis.

PubMed

Wilkinson, M. D.; Haughn, G. W.

1995-09-01

A novel gene that is involved in regulating flower initiation and development has been identified in Arabidopsis. This gene has been designated UNUSUAL FLORAL ORGANS (UFO), with five corresponding nuclear recessive alleles designated ufo[middot]1 to ufo[middot]5. Under short day-length conditions, ufo homozygotes generate more coflorescences than do the wild type, and coflorescences often appear apical to the first floral shoot, resulting in a period of inflorescence development in which regions of floral and coflorescence shoots are produced alternately. ufo enhances the phenotype of weak leafy alleles, and the double mutant Ufo-1 Apetala1-1 produces only coflorescence-like shoots, suggesting that these two genes control different aspects of floral initiation. Floral development was also altered in Ufo plants. Ufo flowers have an altered organ number in all whorls, and organs in the first, second, and third whorls exhibit variable homeotic transformations. Ufo single and double mutant phenotypes suggest that the floral changes result from reduction in class B floral homeotic gene expression and fluctuations in the expression boundaries of class C function and FLO10. Surprisingly, in situ hybridization analysis revealed no obvious differences in expression pattern or level in developing Ufo flowers compared with that of the wild type for any class B or C gene studied. We propose that UFO acts in concert with known floral initiation genes and regulates the domains of floral homeotic gene function.

A painful pulsatile abdominal mass in a young man with elevated blood pressures: an unusual presentation of phaeochromocytoma.

PubMed

Lee, B M K; Ti, L K

2002-08-01

We report an unusual presentation of phaeochromocytoma in a young man with a painful, pulsatile abdominal mass and elevated blood pressures. This led to a delay in diagnosis and resulted in the administration of triggers of catecholamine release, possibly causing a catecholamine surge. This caused the development of catecholamine-induced cardiomyopathy and multiple organ failure, requiring inotropic and ventilatory support, intra-aortic balloon pump and dialysis. Fortunately, his condition reversed with supportive treatment and alpha-adrenergic blockade. This illustrates the importance of having a high index of suspicion of phaeochromocytoma, especially in young patients with elevated blood pressures.

Segregation of liquid crystal mixtures in topological defects

DOE PAGES

Rahimi, Mohammad; Ramezani-Dakhel, Hadi; Zhang, Rui; ...

2017-04-28

The structure and physical properties of liquid crystal (LC) mixtures are a function of composition, and small changes can have pronounced effects on observables, such as phase-transition temperatures. Traditionally, LC mixtures have been assumed to be compositionally homogenous. The results of chemically detailed simulations presented here show that this is not the case; pronounced deviations of the local order from that observed in the bulk at defects and interfaces lead to significant compositional segregation effects. More specifically, two disclination lines are stabilized in this work by introducing into a nematic liquid crystal mixture a cylindrical body that exhibits perpendicular anchoring.more » Here, it is found that the local composition deviates considerably from that of the bulk at the interface with the cylinder and in the defects, thereby suggesting new assembly and synthetic strategies that may capitalize on the unusual molecular environment provided by liquid crystal mixtures.« less

Dipyridamole and paracetamol overdose resulting in multi-organ failure.

PubMed

Cullis, P S; Watson, D; Cameron, A; McKee, R F

2013-08-01

Dipyridamole intoxication is rare and few reports exist amongst the current literature. A case of dipyridamole and paracetamol overdose is described in a previously healthy 58-year-old woman, which resulted in multi-organ failure requiring dialysis, inotropic support, ventilation and extensive surgical intervention for small bowel ischaemia. This case highlights the dangers of an unusually large overdose of a commonly prescribed drug, and reviews current knowledge of dipyridamole intoxication.

Organization of testicular interstitial tissue of an Australian rodent, the spinifex hopping mouse, Notomys alexis.

PubMed

Peirce, E J; Breed, W G

1990-05-01

The organization of testicular interstitial tissue of the spinifex hopping mouse, Notomys alexis differs from that of other rodents. It comprises between 10.3% and 17.3% (average 15.0%) of the total testicular volume, and is variable in its organization both at different locations within the testis of the one animal and among different individuals. Abundant, closely packed Leydig cells are usually present; however, in some regions large, thick-walled blood vessels and extensive peritubular lymphatic spaces, often lacking an endothelium adjacent to the Leydig cells, are also prominent. The Leydig cells in contact with the large blood vessels and lymphatics, unlike those in regions where lymph is sparse, are not densely packed and sometimes contain numerous lipid droplets. Ultrastructure of Leydig cells is typical of steroid-producing cells; however, mitochondria are often extremely large, unusual in shape or bizarrely arranged in relation to one another. Also electron-dense bodies displaying a paracrystalline-like internal structure of parallel, electron-dense filaments arranged in a lattice pattern occur in the cytoplasm of many cells. The significance of these unusual ultrastructural features and the organization of the interstitial tissue remain to be determined conclusively, but may relate to steroid synthesis, secretion and uptake.

Synthesis of sodium polyhydrides at high pressures

DOE PAGES

Struzhkin, Viktor V.; Kim, Duck Young; Stavrou, Elissaios; ...

2016-07-28

Archetypal ionic NaH is the only known compound of sodium and hydrogen. Application of high pressure is known to promote states with higher atomic coordination, but extensive searches for polyhydrides with unusual stoichiometry have had only limited success in spite of several theoretical predictions. Here we report the first observation of the formation of polyhydrides of Na (NaH 3 and NaH 7) above 40 GPa and 2,000 K. Moreover, we combine synchrotron X-ray diffraction and Raman spectroscopy in a laser-heated diamond anvil cell and theoretical random structure searching, which both agree on the stable structures and compositions. Our results supportmore » the formation of multicenter bonding in a material with unusual stoichiometry. These results are applicable to the design of new energetic solids and high-temperature superconductors based on hydrogen-rich materials.« less

Clinical characterization of unusual cystic echinococcosis in southern part of Turkey.

PubMed

Akcam, Atlgan Tolga; Ulku, Abdullah; Koltas, Ismail Soner; Izol, Volkan; Bicer, Omer Sunkar; Kilicbagir, Emine; Sakman, Gurhan; Poyrazoglu, Hakan; Erman, Tahsin; Aridogan, Ibrahim Atilla; Parsak, Cem Kaan; Inal, Mehmet; Iskit, Serdar

2014-01-01

The incidence of primary extrahepatic cystic echinococcosis (CE) is rare. Generally, radiological and serological findings can help establish the diagnosis of hepatic and pulmonary CE, but a CE in an unusual location with atypical radiological findings may complicate the differential diagnosis. The objective of this study is to present the characteristics of cases with extrahepatic CE in respect of sites of involvement, clinical presentations, radiological findings, serological diagnostic evaluations, and outcomes of infected patients. A retrospective analysis of surgically treated CE was conducted between January 1993 and January 2014 in the General Surgery, Pediatric Surgery, Urology, Cardiovascular Surgery, Neurosurgery, and Orthopedics departments of University of Cukurova, Faculty of Medicine, Balcal Hospital. Among the 661 patients managed for CE, 134 had unusual sites of involvement. Radiological and serological examinations were used to differentiate CE from alveolar echinococcosis. Of 134 cases with unusual sites of involvement, 32 cases had liver CE (23.9%), 7 cases had lung CE (5.2%), and 2 cases had concomitant liver and lung CE (1.5%). In 93 (69.4%) cases, unusual organ involvement was isolated without any liver or lung involvement. The mean age was 45 years. Abdominal pain was the main symptom and was found in 104 patients. Thirty-one (23.1%) of 134 extrahepatic CE cases were evaluated as negative with indirect hemagglutination (IHA). However, positive results were obtained in 54 cases evaluated with Echinococcus granulosus IgG Western blot (WB), including 10 IHA-negative cases. CE with unusual localizations may cause serious problems of diagnostic confusion. The combination of clinical history, radiological findings, and serological test results (especially the WB) are valuable in diagnosing extrahepatic CE.

Magnetic field drift shell splitting - Cause of unusual dayside particle pitch angle distributions during storms and substorms

NASA Technical Reports Server (NTRS)

Sibeck, D. G.; Mcentire, R. W.; Lui, A. T. Y.; Lopez, R. E.; Krimigis, S. M.

1987-01-01

This paper presents a magnetic field drift shell-splitting model for the unusual butterfly and head-and-shoulder energetic (E greater than 25 keV) particle pitch angle distributions (PADs) which appear deep within the dayside magnetosphere during the course of storms and substorms. Drift shell splitting separates the high and low pitch angle particles in nightside injections as they move to the dayside magnetosphere, so that the higher pitch angle particles move radially away from earth. Consequently, butterfly PADs with a surplus of low pitch angle particles form on the inner edge of the injection, but head-and-shoulder PADs with a surplus of high pitch angle particles form on the outer edge. A similar process removes high pitch angle particles from the inner dayside magnetosphere during storms, leaving the remaining lower pitch angle particles to form butterfly PADs on the inner edge of the ring current. A detailed case and statistical study of Charge Composition Explorer/Medium-energy Particle Analyzer observations, as well as a review of previous work, shows most examples of unusual PADs to be consistent with the model.

Critical Heat Flux in Pool Boiling on Metal-Graphite Composite Surfaces

NASA Technical Reports Server (NTRS)

Zhang, Nengli; Yang, Wen-Jei; Chao, David F.; Chao, David F. (Technical Monitor)

2000-01-01

A study is conducted on high heat-flux pool boiling of pentane on micro-configured composite surfaces. The boiling surfaces are copper-graphite (Cu-Gr) and aluminum-graphite (Al-Gr) composites with a fiber volume concentration of 50%. The micro-graphite fibers embedded in the matrix contribute to a substantial enhancement in boiling heat-transfer performance. Correlation equations are obtained for both the isolated and coalesced bubble regimes, utilizing a mathematical model based on a metal-graphite, two-tier configuration with the aid of experimental data. A new model to predict the critical heat flux (CHF) on the composites is proposed to explain the fundamental aspects of the boiling phenomena. Three different factors affecting the CHF are considered in the model. Two of them are expected to become the main agents driving vapor volume detachment under microgravity conditions, using the metal-graphite composite surfaces as the heating surface and using liquids with an unusual Marangoni effect as the working fluid.

Assessing integrity of insect RNA

USDA-ARS?s Scientific Manuscript database

Assessing total RNA integrity is important for the success of downstream RNA applications. The 2100 Bioanalyzer system with the RNA Integrity Number (RIN) provides a quantitative measure of RNA degradation. Although RINs may not be ascertained for RNA from all organisms, namely those with unusual or...

High strength W/TiNi micro-laminated composite with transformation-mediated ductility

DOE PAGES

Shao, Yang; Yu, Kaiyuan; Jiang, Daqiang; ...

2016-06-06

A laminated W/TiNi composite is fabricated by hot pressing under vacuum and subsequent forging. The W and TiNi constituents are about 250 μm and 80 μm respectively in thicknesses and their interfaces are chemically sharp with negligible intermixing. The material exhibits two yielding plateaus and excellent strength-ductility combination during compression tests. In situ X-ray technique is employed to demonstrate that the unusual yielding phenomenon is related to the reversible thermoelastic phase transformation of TiNi layers. Furthermore, such mechanisms also contribute to the damage tolerance of the materials by inhibiting crack propagation in W.

The fatty acid composition of a Vibrio alginolyticus associated with the alga Cladophora coelothrix. Identification of the novel 9-methyl-10-hexadecenoic acid.

PubMed

Carballeira, N M; Sostre, A; Stefanov, K; Popov, S; Kujumgiev, A; Dimitrova-Konaklieva, S; Tosteson, C G; Tosteson, T R

1997-12-01

The fatty acid composition of a new strain of Vibrio alginolyticus, found in the alga Cladophora coelothrix, was studied. Among 38 different fatty acids, a new fatty acid, 9-methyl-10-hexadecenoic acid and the unusual 11-methyl-12-octadecenoic acid, were identified. Linear alkylbenzene fatty acids, such as 10-phenyldecanoic acid, 12-phenyldodecanoic acid and 14-phenyltetradecanoic acid, were also found in V. alginolyticus. The alga contained 43% saturated fatty acids, and 28% C16-C20 polyunsaturated fatty acids of the n-3 and n-6 families.

Ribonucleic Acid and Ribosomes of Bacillus stearothermophilus1

PubMed Central

Saunders, Grady F.; Campbell, L. Leon

1966-01-01

Saunders, Grady F. (University of Illinois, Urbana), and L. Leon Campbell. Ribonucleic acid and ribosomes of Bacillus stearothermophilus. J. Bacteriol. 91:332–339. 1966.—The ability of some thermophilic bacteria to grow at temperatures as high as 76 C emphasizes the remarkable thermal stability of their crucial macromolecules. An investigation of the ribonucleic acid (RNA) and ribosomes of Bacillus stearothermophilus was conducted. Washed log-phase cells were disrupted either by sonic treatment or by alumina grinding in 10−2m MgCl2–10−2m tris-(hydroxymethyl)aminomethane buffer, pH 7.4 (TM buffer). Ultracentrifugal analysis revealed peaks at 72.5S, 101S, and 135S, with the 101S peak being the most prominent. By lowering the Mg++ concentration to 10−3m, the ribosome preparation was dissociated to give 40S, 31S, and 54S peaks. These in turn were reassociated in the presence of 10−2m Mg++ to give the larger 73S and 135S particles. When heated in TM buffer, Escherichia coli ribosomes began a gradual dissociation at 58 C, and at 70 C underwent a large hyperchromic shift with a Tm at 72.8 C. In contrast, B. stearothermophilus ribosomes did not show a hyperchromic shift below 70 C; they had a Tm of 77.9 C. The thermal denaturation curves of the 4S, 16S, and 23S RNA from both organisms were virtually identical. The gross amino acid composition of B. stearothermophilus ribosomes showed no marked differences from that reported for E. coli ribosomes. These data suggest that the unusual thermal stability of B. stearothermophilus ribosomes may reflect either an unusual packing arrangement of the protein to the RNA or differences in the primary structure of the ribosomal proteins. Images PMID:5903099

Composites for removing metals and volatile organic compounds and method thereof

DOEpatents

Coronado, Paul R [Livermore, CA; Coleman, Sabre J [Oakland, CA; Reynolds, John G [San Ramon, CA

2006-12-12

Functionalized hydrophobic aerogel/solid support structure composites have been developed to remove metals and organic compounds from aqueous and vapor media. The targeted metals and organics are removed by passing the aqueous or vapor phase through the composite which can be in molded, granular, or powder form. The composites adsorb the metals and the organics leaving a purified aqueous or vapor stream. The species-specific adsorption occurs through specific functionalization of the aerogels tailored towards specific metals and/or organics. After adsorption, the composites can be disposed of or the targeted metals and/or organics can be reclaimed or removed and the composites recycled.

Organohalide respiration and bioremediation: harnessing biogeochemical cycles (Invited)

NASA Astrophysics Data System (ADS)

Edwards, E.; Hug, L.; Perez de Mora, A.

2013-12-01

Groundwater contamination is a serious threat to global health and prosperity. Chlorinated solvents are widely used as industrial degreasers, dry-cleaning agents and precursors in chemical synthesis, and therefore are common groundwater contaminants. Owing to their toxicity, even small spills render groundwater unsuitable for use, and cleanup is typically a costly and long-term undertaking. Dehalococcoides, Dehalobacter, Dehalogenimonas and other unusual microbes have been discovered that can dechlorinate many groundwater contaminants, in particular, the common solvents tetrachloroethene and trichloroethene to the benign product ethene. Remarkably, these organisms obtain energy for growth from dechlorination in a process termed organohalide respiration. The use of biostimulation and bioaugmentation is growing, even at sites with complex hydrogeology and high concentrations of contaminants. Molecular understanding of the unusual metabolism of these organisms is helping to design successful remediation strategies. Four aspects will be emphasized: 1) the nature of the remarkable enzymes that catalyze dechlorination reactions, 2) the role of the non-dechlorinating microbes in providing essential nutrients to dechlorinating organisms, 3) the effects of mixtures of contaminants and 4) the origins of organohalide respiration. Morevoer, the hunt is on to further explore nature's diversity to discover other unusual or novel microbes capable of detoxifying a broader range of contaminants. New molecular biology and genomic tools are helping us understand how these microbes make a living, and how we can take advantage of their abilities to clean up the environment. In this presentation I will review some of the current trends in bioremediation with particular focus on how molecular tools are helping with remediation design, scope and troubleshooting. I will draw from a number of examples from my own laboratory and elsewhere.

Photosynthetic Pigments in Diatoms

PubMed Central

Kuczynska, Paulina; Jemiola-Rzeminska, Malgorzata; Strzalka, Kazimierz

2015-01-01

Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvesting pigments such as chlorophyll a, chlorophyll c, and fucoxanthin, there is a group of photoprotective carotenoids which includes β-carotene and the xanthophylls, diatoxanthin, diadinoxanthin, violaxanthin, antheraxanthin, and zeaxanthin, which are engaged in the xanthophyll cycle. Additionally, some intermediate products of biosynthetic pathways have been identified in diatoms as well as unusual pigments, e.g., marennine. Marine algae have become widely recognized as a source of unique bioactive compounds for potential industrial, pharmaceutical, and medical applications. In this review, we summarize current knowledge on diatom photosynthetic pigments complemented by some new insights regarding their physico-chemical properties, biological role, and biosynthetic pathways, as well as the regulation of pigment level in the cell, methods of purification, and significance in industries. PMID:26389924

Biosourced Polymetallic Catalysis: A Surprising and Efficient Means to Promote the Knoevenagel Condensation

PubMed Central

Deyris, Pierre-Alexandre; Bert, Valérie; Diliberto, Sébastien; Boulanger, Clotilde; Petit, Eddy; Legrand, Yves-Marie; Grison, Claude

2018-01-01

Zn hyperaccumulator (Arabidobsis halleri) and Zn accumulator Salix “Tordis” (Salix schwerinii × Salix viminalis) have shown their interest in the phytoextraction of polluted brownfields. Herein, we explore a novel methodology based on the chemical valorization of Zn-rich biomass produced by these metallophyte plants. The approach is based on the use of polymetallic salts derived from plants as bio-based catalysts in organic chemistry. The formed ecocatalysts were characterized via ICP-MS, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) in order to precise the chemical composition, structure, and behavior of the formed materials. The Doebner-Knoevenagel reaction was chosen as model reaction to study their synthetic potential. Significant differences to usual catalysts such as zinc (II) chloride are observed. They can principally be related to a mixture of unusual mineral species. DFT calculations were carried out on these salts in the context of the Gutmann theory. They allow the rationalization of experimental results. Finally, these new bio-based polymetallic catalysts illustrated the interest of this concept for green and sustainable catalysis. PMID:29637065

Biosourced Polymetallic Catalysis: A Surprising and Efficient Means to Promote the Knoevenagel Condensation.

PubMed

Deyris, Pierre-Alexandre; Bert, Valérie; Diliberto, Sébastien; Boulanger, Clotilde; Petit, Eddy; Legrand, Yves-Marie; Grison, Claude

2018-01-01

Zn hyperaccumulator ( Arabidobsis halleri ) and Zn accumulator Salix "Tordis" ( Salix schwerinii × Salix viminalis ) have shown their interest in the phytoextraction of polluted brownfields. Herein, we explore a novel methodology based on the chemical valorization of Zn-rich biomass produced by these metallophyte plants. The approach is based on the use of polymetallic salts derived from plants as bio-based catalysts in organic chemistry. The formed ecocatalysts were characterized via ICP-MS, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) in order to precise the chemical composition, structure, and behavior of the formed materials. The Doebner-Knoevenagel reaction was chosen as model reaction to study their synthetic potential. Significant differences to usual catalysts such as zinc (II) chloride are observed. They can principally be related to a mixture of unusual mineral species. DFT calculations were carried out on these salts in the context of the Gutmann theory. They allow the rationalization of experimental results. Finally, these new bio-based polymetallic catalysts illustrated the interest of this concept for green and sustainable catalysis.

Nanobacteria-like calcite single crystals at the surface of the Tataouine meteorite

PubMed Central

Benzerara, Karim; Menguy, Nicolas; Guyot, François; Dominici, Christian; Gillet, Philippe

2003-01-01

Nanobacteria-like objects evidenced at the surface of the orthopyroxenes of the Tataouine meteorite in South Tunisia have been studied by scanning and transmission electron microscopies. A method of micromanipulation has been developed to ensure that exactly the same objects were studied by both methods. We have shown that the nanobacteria-like objects are spatially correlated with filaments of microorganisms that colonized the surface of the meteoritic pyroxene during its 70 years of residence in the aridic Tataouine soil. Depressions of a few micrometers in depth are observed in the pyroxene below the carbonates, indicating preferential dissolution of the pyroxene and calcite precipitation at these locations. The nanobacteria-like small rods that constitute calcium carbonate rosettes are well crystallized calcite single crystals surrounded by a thin amorphous layer of carbonate composition that smoothes the crystal edges and induces rounded shapes. Those morphologies are unusual for calcite single crystals observed in natural samples. A survey of recent literature suggests that the intervention of organic compounds derived from biological activity is likely in their formation. PMID:12792020

Self-assembly of mesoscopically ordered chromatic polydiacetylene/silica nanocomposites

NASA Technical Reports Server (NTRS)

Lu, Y.; Yang, Y.; Sellinger, A.; Lu, M.; Huang, J.; Fan, H.; Haddad, R.; Lopez, G.; Burns, A. R.; Sasaki, D. Y.;

Nanobacteria-like calcite single crystals at the surface of the Tataouine meteorite.

PubMed

Benzerara, Karim; Menguy, Nicolas; Guyot, Francois; Dominici, Christian; Gillet, Philippe

2003-06-24

Nanobacteria-like objects evidenced at the surface of the orthopyroxenes of the Tataouine meteorite in South Tunisia have been studied by scanning and transmission electron microscopies. A method of micromanipulation has been developed to ensure that exactly the same objects were studied by both methods. We have shown that the nanobacteria-like objects are spatially correlated with filaments of microorganisms that colonized the surface of the meteoritic pyroxene during its 70 years of residence in the aridic Tataouine soil. Depressions of a few micrometers in depth are observed in the pyroxene below the carbonates, indicating preferential dissolution of the pyroxene and calcite precipitation at these locations. The nanobacteria-like small rods that constitute calcium carbonate rosettes are well crystallized calcite single crystals surrounded by a thin amorphous layer of carbonate composition that smoothes the crystal edges and induces rounded shapes. Those morphologies are unusual for calcite single crystals observed in natural samples. A survey of recent literature suggests that the intervention of organic compounds derived from biological activity is likely in their formation.

From Syllabus To Diagnostic Exam: Learnings from the New Faculty Workshop Applied In the Intro Physics Classroom

NASA Astrophysics Data System (ADS)

Tanoff, Michael

2009-03-01

Kalamazoo College offers a ``one-size-fits-all'' concept-based introductory physics sequence. The widely varying demographic composition of the class --- including majors in biology, chemistry, pre-med, physics, and math, along with occasional humanities majors --- adds obvious challenges to the successful learning experience. As such, educational techniques that apply across the demographic are required. Several ideas presented at the Fall 2005 New Faculty Workshop apply to the needs of this broad range of students at Kalamazoo College, including an ``organic'' course syllabus that has been allowed to grow to whatever extent necessary to address recurring student concerns and misunderstandings about course expectations, policies, and guidelines, and to provide advice on recurring themes; peer instruction for maximizing classroom value; and hiring teaching assistants with first hand experience in the course and the labs. Details on implementing these techniques, including developing a syllabus with unusual section headings such as ``Attendance and Homework Dramas'' and ``Introductory Physics Survival Requirements,'' will be presented. Success of the techniques, as evidenced by performance on diagnostic exams, class attendance, and comments from course evaluations, will be discussed.

Enhancing non-refractory aerosol apportionment from an urban industrial site through receptor modeling of complete high time-resolution aerosol mass spectra

NASA Astrophysics Data System (ADS)

McGuire, M. L.; Chang, R. Y.-W.; Slowik, J. G.; Jeong, C.-H.; Healy, R. M.; Lu, G.; Mihele, C.; Abbatt, J. P. D.; Brook, J. R.; Evans, G. J.

2014-08-01

Receptor modeling was performed on quadrupole unit mass resolution aerosol mass spectrometer (Q-AMS) sub-micron particulate matter (PM) chemical speciation measurements from Windsor, Ontario, an industrial city situated across the Detroit River from Detroit, Michigan. Aerosol and trace gas measurements were collected on board Environment Canada's Canadian Regional and Urban Investigation System for Environmental Research (CRUISER) mobile laboratory. Positive matrix factorization (PMF) was performed on the AMS full particle-phase mass spectrum (PMFFull MS) encompassing both organic and inorganic components. This approach compared to the more common method of analyzing only the organic mass spectra (PMFOrg MS). PMF of the full mass spectrum revealed that variability in the non-refractory sub-micron aerosol concentration and composition was best explained by six factors: an amine-containing factor (Amine); an ammonium sulfate- and oxygenated organic aerosol-containing factor (Sulfate-OA); an ammonium nitrate- and oxygenated organic aerosol-containing factor (Nitrate-OA); an ammonium chloride-containing factor (Chloride); a hydrocarbon-like organic aerosol (HOA) factor; and a moderately oxygenated organic aerosol factor (OOA). PMF of the organic mass spectrum revealed three factors of similar composition to some of those revealed through PMFFull MS: Amine, HOA and OOA. Including both the inorganic and organic mass proved to be a beneficial approach to analyzing the unit mass resolution AMS data for several reasons. First, it provided a method for potentially calculating more accurate sub-micron PM mass concentrations, particularly when unusual factors are present, in this case the Amine factor. As this method does not rely on a priori knowledge of chemical species, it circumvents the need for any adjustments to the traditional AMS species fragmentation patterns to account for atypical species, and can thus lead to more complete factor profiles. It is expected that this method would be even more useful for HR-ToF-AMS data, due to the ability to understand better the chemical nature of atypical factors from high-resolution mass spectra. Second, utilizing PMF to extract factors containing inorganic species allowed for the determination of the extent of neutralization, which could have implications for aerosol parameterization. Third, subtler differences in organic aerosol components were resolved through the incorporation of inorganic mass into the PMF matrix. The additional temporal features provided by the inorganic aerosol components allowed for the resolution of more types of oxygenated organic aerosol than could be reliably resolved from PMF of organics alone. Comparison of findings from the PMFFull MS and PMFOrg MS methods showed that for the Windsor airshed, the PMFFull MS method enabled additional conclusions to be drawn in terms of aerosol sources and chemical processes. While performing PMFOrg MS can provide important distinctions between types of organic aerosol, it is shown that including inorganic species in the PMF analysis can permit further apportionment of organics for unit mass resolution AMS mass spectra.

Enhancing non-refractory aerosol apportionment from an urban industrial site through receptor modelling of complete high time-resolution aerosol mass spectra

NASA Astrophysics Data System (ADS)

McGuire, M. L.; Chang, R. Y.-W.; Slowik, J. G.; Jeong, C.-H.; Healy, R. M.; Lu, G.; Mihele, C.; Abbatt, J. P. D.; Brook, J. R.; Evans, G. J.

2014-02-01

Receptor modelling was performed on quadrupole unit mass resolution aerosol mass spectrometer (Q-AMS) sub-micron particulate matter (PM) chemical speciation measurements from Windsor, Ontario, an industrial city situated across the Detroit River from Detroit, Michigan. Aerosol and trace gas measurements were collected on board Environment Canada's CRUISER mobile laboratory. Positive matrix factorization (PMF) was performed on the AMS full particle-phase mass spectrum (PMFFull MS) encompassing both organic and inorganic components. This approach was compared to the more common method of analysing only the organic mass spectra (PMFOrg MS). PMF of the full mass spectrum revealed that variability in the non-refractory sub-micron aerosol concentration and composition was best explained by six factors: an amine-containing factor (Amine); an ammonium sulphate and oxygenated organic aerosol containing factor (Sulphate-OA); an ammonium nitrate and oxygenated organic aerosol containing factor (Nitrate-OA); an ammonium chloride containing factor (Chloride); a hydrocarbon-like organic aerosol (HOA) factor; and a moderately oxygenated organic aerosol factor (OOA). PMF of the organic mass spectrum revealed three factors of similar composition to some of those revealed through PMFFull MS: Amine, HOA and OOA. Including both the inorganic and organic mass proved to be a beneficial approach to analysing the unit mass resolution AMS data for several reasons. First, it provided a method for potentially calculating more accurate sub-micron PM mass concentrations, particularly when unusual factors are present, in this case, an Amine factor. As this method does not rely on a priori knowledge of chemical species, it circumvents the need for any adjustments to the traditional AMS species fragmentation patterns to account for atypical species, and can thus lead to more complete factor profiles. It is expected that this method would be even more useful for HR-ToF-AMS data, due to the ability to better understand the chemical nature of atypical factors from high resolution mass spectra. Second, utilizing PMF to extract factors containing inorganic species allowed for the determination of extent of neutralization, which could have implications for aerosol parameterization. Third, subtler differences in organic aerosol components were resolved through the incorporation of inorganic mass into the PMF matrix. The additional temporal features provided by the inorganic aerosol components allowed for the resolution of more types of oxygenated organic aerosol than could be reliably resolved from PMF of organics alone. Comparison of findings from the PMFFull MS and PMFOrg MS methods showed that for the Windsor airshed, the PMFFull MS method enabled additional conclusions to be drawn in terms of aerosol sources and chemical processes. While performing PMFOrg MS can provide important distinctions between types of organic aerosol, it is shown that including inorganic species in the PMF analysis can permit further apportionment of organics for unit mass resolution AMS mass spectra.

Characteristic of lipids and fatty acid compositions of the neon flying squid, Ommastrephes bartramii.

PubMed

Saito, Hiroaki; Ishikawa, Satoru

2012-01-01

The lipids and fatty acids of the neon flying squid (Ommastrephes bartramii) were an-alyzed to clarify its lipid physiology and health benefit as marine food. Triacylglycerols were the only major component in the digestive gland (liver). In all other organs (mantle, arm, integument, and ovary), sterols and phospholipids were the major components with noticeable levels of ceramide aminoethyl phosphonate and sphingomyelin. The significant levels of sphingolipids suggest the O. bartramii lipids is a useful source for cosmetics. Although the lipid content between the liver and all other tissues markedly differed from each other, the same nine dominant fatty acids in the triacylglycerols were found in all organs; 14:0, 16:0, 18:0, 18:1n-9, 20:1n-9, 20:1n-11, 22:1n-11, 20:5n-3 (icosapentaenoic acid, EPA), and 22:6n-3 (docosahexaenoic acid, DHA). Unusually high 20:1n-11 levels in the O. bartramii triacylglycerols were probably characteristic for western Pacific animal depot lipids, compared with non-detectable levels of 20:1n-11 reported in other marine animals. O. bartramii concurrently has high levels of DHA in their triacylglycerols. The major fatty acids in the phospholipids were 16:0, 18:0, 20:1n-9, EPA, and DHA without 20:1n-11. Markedly high levels of both EPA and DHA were observed in phosphatidylethanolamine, while only DHA was found as the major one in phosphatidylcholine. In particular, high levels of DHA were found both in its depot triacylglycerols and tissue phospholipids in all organs of O. bartramii, similar to that in highly migratory fishes. The high DHA levels in all its organs suggest that O. bartramii lipids is a healthy marine source for DHA supplements.

Sedimentary exhalative nickel-molybdenum ores in south China

USGS Publications Warehouse

Lott, D.A.; Coveney, R.M.; Murowchick, J.B.; Grauch, R.I.

1999-01-01

Unique bedded Ni-Mo ores hosted by black shales were discovered in localized paleobasins along the Yangzte platform of southern China in 1971. Textural evidence and radiometric dates imply ore formation during sedimentation of black shales that grade into readily combustible beds, termed stone coals, which contain 10 to 15 percent organic carbon. Studies of 427 fluid inclusions indicate extreme variation in hydrothermal brine salinities that were contained by Proterozoic dolostones underlying the ore zone in Hunan and Guizhou. Variations of fluid inclusion salinities, which range from 0.1 to 21.6 wt percent NaCl equiv, are attributed to differences in the compositions of brines in strata underlying the ore bed, complicated by the presence of seawater and dilute fluids that represent condensates of vapors generated by boiling of mineralizing fluids or Cambrian meteoric water. The complex processes of ore deposition led to scattered homogenization temperatures ranging from 100??to 187??C within the Hunan ore zone and from 65??to 183??C within the Guizhou ore zone. While living organisms probably did not directly accumulate metals in situ in sufficient amounts to explain the unusually high grades of the deposits, sulfur isotope ratios indicate that bacteria, now preserved as abundant microfossils, provided sufficient sulfide for the ores by reduction of seawater sulfate. Such microbiota may have depended on vent fluids and transported organic matter for key nutrients and are consistent with a sedex origin for the ores. Vent fluids interacted with organic remains, including rounded fragments of microbial mats that were likely transported to the site of ore deposition by the action of waves and bottom currents prior to replacement by ore minerals.

Wax layers on Cosmos bipinnatus petals contribute unequally to total petal water resistance.

PubMed

Buschhaus, Christopher; Hager, Dana; Jetter, Reinhard

2015-01-01

Cuticular waxes coat all primary aboveground plant organs as a crucial adaptation to life on land. Accordingly, the properties of waxes have been studied in much detail, albeit with a strong focus on leaf and fruit waxes. Flowers have life histories and functions largely different from those of other organs, and it remains to be seen whether flower waxes have compositions and physiological properties differing from those on other organs. This work provides a detailed characterization of the petal waxes, using Cosmos bipinnatus as a model, and compares them with leaf and stem waxes. The abaxial petal surface is relatively flat, whereas the adaxial side consists of conical epidermis cells, rendering it approximately 3.8 times larger than the projected petal area. The petal wax was found to contain unusually high concentrations of C(22) and C(24) fatty acids and primary alcohols, much shorter than those in leaf and stem waxes. Detailed analyses revealed distinct differences between waxes on the adaxial and abaxial petal sides and between epicuticular and intracuticular waxes. Transpiration resistances equaled 3 × 10(4) and 1.5 × 10(4) s m(-1) for the adaxial and abaxial surfaces, respectively. Petal surfaces of C. bipinnatus thus impose relatively weak water transport barriers compared with typical leaf cuticles. Approximately two-thirds of the abaxial surface water barrier was found to reside in the epicuticular wax layer of the petal and only one-third in the intracuticular wax. Altogether, the flower waxes of this species had properties greatly differing from those on vegetative organs. © 2015 American Society of Plant Biologists. All Rights Reserved.

Carbon and nitrogen isotopic compositions of particulate organic matter and biogeochemical processes in the eutrophic Danshuei Estuary in northern Taiwan.

PubMed

Liu, Kon-Kee; Kao, Shuh-Ji; Wen, Liang-Saw; Chen, Kuan-Lun

2007-08-15

The Danshuei Estuary is distinctive for the relatively short residence time (1-2 d) of its estuarine water and the very high concentration of ammonia, which is the dominant species of dissolved inorganic nitrogen in the estuary, except near the river mouth. These characteristics make the dynamics of nitrogen cycling distinctively different from previously studied estuaries and result in unusual isotopic compositions of particulate nitrogen (PN). The delta(15)N(PN) values ranging from -16.4 per thousand to 3.8 per thousand lie in the lower end of nitrogen isotopic compositions (-16.4 to +18.7 per thousand) of suspended particulate matter observed in estuaries, while the delta(13)C values of particulate organic carbon (POC) and the C/N (organic carbon to nitrogen) ratios showed rather normal ranges from -25.5 per thousand to -19.0 per thousand and from 6.0 to 11.3, respectively. There were three major types of particulate organic matter (POM) in the estuary: natural terrigenous materials consisting mainly of soils and bedrock-derived sediments, anthropogenic wastes and autochthonous materials from the aquatic system. During the typhoon induced flood period in August 2000, the flux-weighted mean of delta(13)C(POC) values was -24.4 per thousand, that of delta(15)N(PN) values was +2.3 per thousand and that of C/N ratio was 9.3. During non-typhoon periods, the concentration-weighted mean was -23.6 per thousand for delta(13)C(POC), -2.6 per thousand for delta(15)N(PN) and 8.0 for C/N ratio. From the distribution of delta(15)N(PN) values of highly polluted estuarine waters, we identified the waste-dominated samples and calculated their mean properties: delta(13)C(POC) value of -23.6+/-0.7 per thousand, delta(15)N(PN) value of -3.0+/-0.1 per thousand and C/N ratio of 8.0+/-1.4. Using a three end-member mixing model based on delta(15)N(PN) values and C/N ratios, we calculated contributions of the three major allochthonous sources of POC, namely, wastes, soils and bedrock-derived sediments, to the estuary. Their contributions were, respectively, 83%, 12% and 5% under non-typhoon conditions, and 9%, 63% and 28% under typhoon conditions. The autochthonous POM had the most varied isotopic compositions, encompassing the full ranges of delta(13)C(POC) (-25.5 to -19.1 per thousand), delta(15)N(PN) (-16.4-3.8 per thousand) and C/N ratio (6.0-11.3). The heavy end of the carbon isotopic composition reflected the typical marine condition and the lower end the estuarine condition, which probably had elevated concentrations of dissolved inorganic carbon with low delta(13)C values due to input from decomposition of organic matter. The lack of isotopically heavy PN, as found in larger estuaries, was attributed to isotopically light starting materials, namely, anthropogenic wastes, the slow phytoplankton growth within the estuary and the rather short residence time; the latter two factors made (15)N enrichment during ammonia consumption very limited. The most isotopically light PN likely originated from phytoplankton incorporating (15)N-depleted nitrate near the river mouth, where ammonia inhibition of nitrate uptake probably stopped.

Interacting and self-organized two-level states in tunnel barriers

NASA Technical Reports Server (NTRS)

Pesenson, L.; Robertazzi, R. P.; Buhrman, R. A.; Cypher, S. R.; Hunt, B. D.

1991-01-01

The excess low-frequency 1/f noise and discrete two-level resistance fluctuations (TLFs) were studied in small-area NbN-MgO-NbN tunnel junctions with a high, low-temperature density of active defects. Strong and evolving interactions between large TLFs indicate that these fluctuations result from the self-organization of interacting defect elements. In the low-T tunneling regime, an unusual slowing down of the rates and a decrease in amplitude with increasing T is sometimes observed indicative of a thermally induced change in the self-organized two-level state.

Unusual ZFC and FC magnetic behavior in thin Co multi-layered structure

NASA Astrophysics Data System (ADS)

Ben Dor, Oren; Yochelis, Shira; Felner, Israel; Paltiel, Yossi

2017-04-01

The observation of unusual magnetic phenomena in a Ni -based magnetic memory device ([4] O. Ben-Dor et al., 2013) encouraged us to conduct a systematic research on Co based multi-layered structure which contains a α-helix L polyalanine (AHPA-L) organic compound. The constant Co thickness is 7 nm and AHPA-L was also replaced by non-chiral 1-Decanethiol organic molecules. Both organic compounds were chemisorbed on gold by a thiol group. The dc magnetic field (H) was applied parallel and perpendicular to the surface layers. The perpendicular direction is the easy magnetization axis and along this orientation only, the zero-field-cooled (ZFC) plots exhibit a pronounced peak around 55-58 K. This peak is suppressed in the second ZFC and field-cooled (FC) runs performed shortly after the virgin ZFC one. Thus, around the peak position ZFC>FC a phenomenon seldom observed. This peak reappears after measuring the same material six months later. This behavior appears in layers with the non-chiral 1-Decanethiol and it is very similar to that obtained in sulfur doped amorphous carbon. The peak origin and the peculiar ZFC>FC case are qualitatively explained.

Diversity in a Hidden Community: Tardiagrades in Lichens.

ERIC Educational Resources Information Center

Shofner, Marcia; Vodopich, Darrell

1993-01-01

Describes an interesting field experiment examining the distribution and diversity of a single community using lichens and the animals living in them. Combining field experience and laboratory work reveals not only the biology of some unusual organisms, but also community ecology and diversity. (PR)

In situ solid-state NMR and XRD studies of the ADOR process and the unusual structure of zeolite IPC-6

NASA Astrophysics Data System (ADS)

Morris, Samuel A.; Bignami, Giulia P. M.; Tian, Yuyang; Navarro, Marta; Firth, Daniel S.; Čejka, Jiří; Wheatley, Paul S.; Dawson, Daniel M.; Slawinski, Wojciech A.; Wragg, David S.; Morris, Russell E.; Ashbrook, Sharon E.

2017-10-01

The assembly-disassembly-organization-reassembly (ADOR) mechanism is a recent method for preparing inorganic framework materials and, in particular, zeolites. This flexible approach has enabled the synthesis of isoreticular families of zeolites with unprecedented continuous control over porosity, and the design and preparation of materials that would have been difficult—or even impossible—to obtain using traditional hydrothermal techniques. Applying the ADOR process to a parent zeolite with the UTL framework topology, for example, has led to six previously unknown zeolites (named IPC-n, where n = 2, 4, 6, 7, 9 and 10). To realize the full potential of the ADOR method, however, a further understanding of the complex mechanism at play is needed. Here, we probe the disassembly, organization and reassembly steps of the ADOR process through a combination of in situ solid-state NMR spectroscopy and powder X-ray diffraction experiments. We further use the insight gained to explain the formation of the unusual structure of zeolite IPC-6.

Two intriguing hydroxy-copper(II) coordination polymers with bis(triazole) and bicarboxylate ligands: Syntheses, structures and photocatalytic degradation of organic dyes

NASA Astrophysics Data System (ADS)

Zhao, Shan; Zheng, Tian-Rui; Shi, Lu-Lu; Li, Ke; Li, Bao-Long; Li, Hai-Yan

2017-09-01

Two intriguing coordination polymers [Cu2(OH)(mbtx)(sip)(H2O)2]n (1) and {[Cu3(OH)2(mbtx)(nip)2]·H2O}n (2) were synthesized by the hydrothermal method and characterized by elementary analysis, IR, PXRD, diffuse reflectance spectra and single-crystal X-ray diffraction (mbtx = 1,3-bis(1,2,4-triazol-4-yl)benzene, sip = sulfoisophthalate, nip = 5-nitroisophthalate). 1 shows an unusual 3-connected 2D network based on the dimeric hydroxy-copper(II) cluster [Cu2(μ-OH)] with the point symbol of 63. 2 exhibits an unusual 3D network based on 1D hydroxyl-copper(II) chains [Cu3(OH)2]n. 1 and 2 are highly efficient and universal photocatalysts for the degradation of the organic dyes such as methyl orange (MO), methylene blue (MB) and rhodamine B (RhB) under UV irradiation. The photocatalytic mechanism was supposed.

Unusual chromosomal organization of telomeric sequences and expeditious karyotypic differentiation in the recently evolved Mus terricolor complex.

PubMed

Sharma, G G; Sharma, T

1998-01-01

The Mus terricolor complex displays a stable homozygous arrangement of autosomal heterochromatin variations in the form of accretion of definitive autosomal short arms among three nonoverlapping populations, in concert with an expeditious evolutionary differentiation into three chromosomal species: M. terricolor I, II, and III. In contrast to the highly conservative M. musculus-like chromosomes in the coexisting sibling species, M. booduga, reshuffling and differentiation of centric heterochromatin has occurred in harmony with a revision of centric configurations, resulting in acrocentric and submetacentric autosomes. The chromosomal distribution of the prevalent vertebrate telomeric sequence (TTAGGG)n was examined by fluorescence in situ hybridization to metaphase cells of M. terricolor I, II, and III. An unusual centric organization of internal telomeric sequences was detected in all the submetacentric and acrocentric autosomes. An auxiliary role of these presumably fragile, recombinogenic telomeric sequences in the evolutionary revision of centric configurations in the terricolor complex is hypothesized.

Sandstone type uranium deposits in the Ordos Basin, Northwest China: A case study and an overview

NASA Astrophysics Data System (ADS)

Akhtar, Shamim; Yang, Xiaoyong; Pirajno, Franco

2017-09-01

This paper provides a comprehensive review on studies of sandstone type uranium deposits in the Ordos Basin, Northwest China. As the second largest sedimentary basin, the Ordos Basin has great potential for targeting sandstone type U mineralization. The newly found and explored Dongsheng and Diantou sandstone type uranium deposits are hosted in the Middle Jurassic Zhilou Formation. A large number of investigations have been conducted to trace the source rock compositions and relationship between lithic subarkose sandstone host rock and uranium mineralization. An optical microscopy study reveals two types of alteration associated with the U mineralization: chloritization and sericitization. Some unusual mineral structures, with compositional similarity to coffinite, have been identified in a secondary pyrite by SEM These mineral phases are proposed to be of bacterial origin, following high resolution mapping of uranium minerals and trace element determinations in situ. Moreover, geochemical studies of REE and trace elements constrained the mechanism of uranium enrichment, displaying LREE enrichment relative to HREE. Trace elements such as Pb, Mo and Ba have a direct relationship with uranium enrichment and can be used as index for mineralization. The source of uranium ore forming fluids and related geological processes have been studied using H, O and C isotope systematics of fluid inclusions in quartz veins and the calcite cement of sandstone rocks hosting U mineralization. Both H and O isotopic compositions of fluid inclusions reveal that ore forming fluids are a mixture of meteoric water and magmatic water. The C and S isotopes of the cementing material of sandstone suggest organic origin and bacterial sulfate reduction (BSR), providing an important clue for U mineralization. Discussion of the ore genesis shows that the greenish gray sandstone plays a crucial role during processes leading to uranium mineralization. Consequently, an oxidation-reduction model for sandstone-type uranium deposit is proposed, which can elucidate the source of uranium in the deposits of the Ordos Basin, based on the role of organic materials and sulfate reducing bacteria. We discuss the mechanism of uranium deposition responsible for the genesis of these large sandstone type uranium deposits in this unique sedimentary basin.

Synthesis of Oxides Containing Transition Metals

DTIC Science & Technology

1990-07-09

metal oxide single crystals by the electrolysis of molten salts containing mixtures of the appropriate oxides. Andreiux and Bozon (33-34) were able to...examples of unusual transition metal oxides which can be prepared (usually as single crystals) by electrolysis of fused salts . Summary The methods of...ferrites with the composition MFe 204 involved the thermal decomposition of oxalate (3) or pyridinate salts (1). The synthesis of ferrites from mixed

Bomb Detection System Study

DTIC Science & Technology

1965-01-01

cause the reduction in vapor pressure. To determine whether an explosive can be detected thi ugh its * vapor, it is necessary to know the vapor pressures...Smokeless powders are explosives normally used in shotgun powders and can vary widely in composition. Nitrocellulose is the major :oomponent. Dinitrotoluene...will not be inclined to undertake the risky process except under very unusual circum- stances. Black powder is an obvious choice and has been so in

From Nanofibrillar to Nanolaminar Poly(butylene succinate): Paving the Way to Robust Barrier and Mechanical Properties for Full-Biodegradable Poly(lactic acid) Films.

PubMed

Xie, Lan; Xu, Huan; Chen, Jing-Bin; Zhang, Zi-Jing; Hsiao, Benjamin S; Zhong, Gan-Ji; Chen, Jun; Li, Zhong-Ming

2015-04-22

The traditional approach toward barrier property enhancement of poly(lactic acid) (PLA) is the incorporation of sheet-like fillers such as nanoclay and graphene, unfortunately leading to the sacrificed biocompatibility and degradability. Here we unveil the first application of a confined flaking technique to establish the degradable nanolaminar poly(butylene succinate) (PBS) in PLA films based on PLA/PBS in situ nanofibrillar composites. The combination of high pressure (10 MPa) and appropriate temperature (160 °C) during the flaking process desirably enabled sufficient deformation of PBS nanofibrils and retention of ordered PLA channels. Particularly, interlinked and individual nanosheets were created in composite films containing 10 and 20 wt % PBS, respectively, both of which presented desirable alignment and large width/thickness ratio (nanoscale thickness with a width of 428±13.1 and 76.9±8.2 μm, respectively). With the creation of compact polymer "nano-barrier walls", a dramatic decrease of 86% and 67% in the oxygen permeability coefficient was observed for the film incorporated with well-organized 20 wt % PBS nanosheets compared to pure PLA and pure PBS (1.4 and 0.6×10(-14) cm3·cm·cm(-2)·s(-1)·Pa(-1)), respectively. Unexpectedly, prominent increases of 21% and 28% were achieved in the tensile strength and modulus of composite films loaded 20 wt % PBS nanosheets compared to pure PLA films, although PBS intrinsically presents poor strength and stiffness. The unusual combination of barrier and mechanical performances established in the fully degradable system represent specific properties required in packaging beverages, food and medicine.

Raman, SEM-EDS and XRPD investigations on pre-Columbian Central America "estucado" pottery

NASA Astrophysics Data System (ADS)

Casanova Municchia, Annalaura; Micheli, Mario; Ricci, Maria Antonietta; Toledo, Michelle; Bellatreccia, Fabio; Lo Mastro, Sergio; Sodo, Armida

2016-03-01

Seventeen different colored fragments from six selected pre-Columbian estucado ceramics from El Salvador have been investigated by Raman spectroscopy, scanning electron microscope coupled to an energy dispersive spectrometer (SEM/EDS) and X-ray powder diffraction (XRPD). The peculiarity of this kind of ceramics consist of the unusual presence of a white engobe, traditionally termed stucco, between the ceramic body and the decoration elements, hence the name estucado ceramics. The aim of this work was to study the unusual manufacturing technique and to identify the chemical composition of the engobe and of the pigment palette. The results showed that the stucco layer is made of clay (kaolinite) with traces of titanium oxide (anatase). Remarkably, this is the same composition of the white pigments used for the decoration layer, thus excluding an early use of natural titanium oxide as a white pigment in the estucado productions as suggested in previous investigations. Moreover, the presence of kaolinite and anatase both in the stucco and in the decoration layer suggests a cold-working or low temperature technique. The red, yellow and green decorations were realized by the use of natural ochre, while in all the blue and gray decorations Maya blue pigment was identified. Finally, an amorphous carbon pigment of vegetal origin and manganese oxide were used to obtain black pigments.

An Analysis of Recent Major Breakups in he Low Earth Orbit Region

NASA Technical Reports Server (NTRS)

Liou, Jer-Chyi; Anz-Meador, P. D.

2010-01-01

Of the 190 known satellite breakups between 1961 and 2006, only one generated more than 500 cataloged fragments. The event was the explosion of the Pegasus Hydrazine Auxiliary Propulsion System in 1996, adding 713 fragments to the U.S. Satellite Catalog. Since the beginning of 2007; however, the near-Earth environment has been subjected to several major breakups, including the Fengyun-1C anti-satellite test and the explosion of Briz-M in 2007, the unusual breakup of Cosmos 2421 in 2008, and the collision between Iridium 33 and Cosmos 2251 in 2009. Combined, these events added more than 5000 large (> or equal 10 cm) fragments to the environment. Detailed analysis of the radar cross section measurements and orbit histories of the fragments from these major events reveals several unusual characteristics in their size and area-to-mass ratio distributions. The characteristics could be related to the material composition of the parent vehicles, the nature of the breakup, and the composition and physical property of the fragments. In addition, the majority of these fragments are expected to remain in orbit for at least decades. Their long-term impact to the environment is analyzed using the NASA orbital debris evolutionary model, LEGEND. Descriptions of these analyses and a summary are included in this paper.

Novel electrode systems for amperometric sensing: the case of titanium

NASA Astrophysics Data System (ADS)

Terzi, F.; Pigani, L.; Zanardi, C.; Zanfrognini, B.; Ruggeri, S.; Maccaferri, G.; Seeber, R.

2014-10-01

After working for years on organic materials, e.g., polythiophenes and relevant composites with metal nanoparticles, we shifted our attention to unusual metals, chosen as candidates to effective amperometric sensing on the basis of the atomic structure and crystalline properties. The present contribution aims at proposing an electrode material rarely employed in electroanalysis, namely Ti. We have experimented that the peculiar nature of Ti leads to electrochemical behavior quite different with respect to the conventional electrode materials, including those based on TiO2 (nano)particles. Our work focuses on the determination of strong oxidizing species, namely H2O2 and HClO, and noble metal ions, namely Au(III). Strong oxidizing species are commodity chemicals employed in a number of different industrial processes, in which usually high concentration levels should be monitored. The procedures proposed have been successfully applied also in complex matrices, such as detergent samples. As to Au(III) determination, it also constitutes a crucial tool in order to increase the efficiency of hydrometallurgic processes and of the recovery of precious materials from electronic waste. Ti electrodes allow the determination of dissolved Au species in the presence of other metal ions. In any cases the electrodes exhibit reproducible and repeatable electrochemical responses, even in the presence of high concentration of organic fouling species typical of bio-sorption processes.

Foraminiferal and calcareous nannofossil paleoecology across the Cenomanian/Turonian boundary in the western interior of North America

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diner, R.; Bralower, T.J.

1985-01-01

The Cenomanian-Turonian boundary is noted by a global positive excursion in the carbon isotopic signature. Sediments deposited during this interval in Europe are rich in organic carbon this interval in Europe are rich in organic carbon. These data suggest unusually high productivity which should be expressed within the composition of the plankton. The authors have examined samples from three sections in the Western Interior Seaway from Manitoba, Colorado, Arizona, that represent nearshore and offshore calcareous litho facies. They analyzed the foraminifera and calcareous nannofossils to determine how biostratigraphic and paleoecologic events affected the makeup of faunal and floral assemblages. Themore » extinction of the calcareous nannofossil P. albianus occurs at the first appearance of the planktonic foraminifer W. archeocretacea, which marks the base of the boundary interval. Nearshore foraminiferal assemblages that include planktonic taxa, characteristically contain a benthic fauna composed of both arenaceous and calcareous species. During these blooms though, planktonics disappear as does the calcareous component of the benthic fauna, most notably the nodosariids. Co-occurring shifts in the relative abundance of the planktonic foraminifera and the calcareous nannofossils in the more offshore facies are also evident. Finally when the authors compare the faunal data with the record of carbon and oxygen isotopes, they find that the timing of the biostratigraphic events already described is coincident with the positive excursion of the carbon isotope.« less

Warhead verification as inverse problem: Applications of neutron spectrum unfolding from organic-scintillator measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawrence, Chris C.; Flaska, Marek; Pozzi, Sara A.

2016-08-14

Verification of future warhead-dismantlement treaties will require detection of certain warhead attributes without the disclosure of sensitive design information, and this presents an unusual measurement challenge. Neutron spectroscopy—commonly eschewed as an ill-posed inverse problem—may hold special advantages for warhead verification by virtue of its insensitivity to certain neutron-source parameters like plutonium isotopics. In this article, we investigate the usefulness of unfolded neutron spectra obtained from organic-scintillator data for verifying a particular treaty-relevant warhead attribute: the presence of high-explosive and neutron-reflecting materials. Toward this end, several improvements on current unfolding capabilities are demonstrated: deuterated detectors are shown to have superior response-matrixmore » condition to that of standard hydrogen-base scintintillators; a novel data-discretization scheme is proposed which removes important detector nonlinearities; and a technique is described for re-parameterizing the unfolding problem in order to constrain the parameter space of solutions sought, sidestepping the inverse problem altogether. These improvements are demonstrated with trial measurements and verified using accelerator-based time-of-flight calculation of reference spectra. Then, a demonstration is presented in which the elemental compositions of low-Z neutron-attenuating materials are estimated to within 10%. These techniques could have direct application in verifying the presence of high-explosive materials in a neutron-emitting test item, as well as other for treaty verification challenges.« less

Warhead verification as inverse problem: Applications of neutron spectrum unfolding from organic-scintillator measurements

NASA Astrophysics Data System (ADS)

Lawrence, Chris C.; Febbraro, Michael; Flaska, Marek; Pozzi, Sara A.; Becchetti, F. D.

2016-08-01

Verification of future warhead-dismantlement treaties will require detection of certain warhead attributes without the disclosure of sensitive design information, and this presents an unusual measurement challenge. Neutron spectroscopy—commonly eschewed as an ill-posed inverse problem—may hold special advantages for warhead verification by virtue of its insensitivity to certain neutron-source parameters like plutonium isotopics. In this article, we investigate the usefulness of unfolded neutron spectra obtained from organic-scintillator data for verifying a particular treaty-relevant warhead attribute: the presence of high-explosive and neutron-reflecting materials. Toward this end, several improvements on current unfolding capabilities are demonstrated: deuterated detectors are shown to have superior response-matrix condition to that of standard hydrogen-base scintintillators; a novel data-discretization scheme is proposed which removes important detector nonlinearities; and a technique is described for re-parameterizing the unfolding problem in order to constrain the parameter space of solutions sought, sidestepping the inverse problem altogether. These improvements are demonstrated with trial measurements and verified using accelerator-based time-of-flight calculation of reference spectra. Then, a demonstration is presented in which the elemental compositions of low-Z neutron-attenuating materials are estimated to within 10%. These techniques could have direct application in verifying the presence of high-explosive materials in a neutron-emitting test item, as well as other for treaty verification challenges.

Differential diagnosis of an unusual shoulder articular lesion in an ancient domestic dog (Canis lupus familiaris L., 1758).

PubMed

Lawler, D F; Rubin, D A; Evans, R H; Hildebolt, C F; Smith, K E; Widga, C; Martin, T J; Siegel, M; Sackman, J E; Smith, G K; Patel, T K

2013-12-01

A proximal humeral articular surface from an ancient domestic dog deliberate burial was examined during survey of small mammal bones from a prehistoric early Late Woodland archeological site. An unusual lesion on the caudolateral articular surface prompted micro-computed tomography to define detailed structure. Results indicate cortical or immature woven bone arising subchondrally, replacing normal trabeculae, extending through a breach in the cortical surface, and having sharp transition with surrounding normal bone. Organized bone within the lesion indicates that the dog lived for months-to-years following insult. Differential diagnoses initially included: sharp penetrating trauma; intrinsic or extrinsic blunt fracturing force; osteochondrosis or complication of an osteochondral lesion; unusual osteoarthritis; and neoplasia. Computed tomography ruled out normal or unusual osteoarthritis, and neoplasia. The nature and small size of the lesion, relatively small size of the dog, and lack of evidence for complicating infection, suggest against sharp penetrating trauma as a sole cause. The most plausible differential diagnoses include: uncommon fracture-producing force in a companion animal, and blunt intrinsic or extrinsic force causing fracture at a weak point, such as an early osteochondral lesion, that was obliterated by healing. Combined gross examination, micro-computed tomography, and archeological-anthropological influences facilitated refinement of differential diagnosis. Copyright © 2013 Elsevier Inc. All rights reserved.

Sulfur-Containing Organic-Inorganic Hybrid Gel Compositions and Aerogels

NASA Technical Reports Server (NTRS)

Evans, Owen R (Inventor); Deshpande, Kiranmayi (Inventor); Dong, Wenting (Inventor)

2017-01-01

Methods and materials are described for preparing organic-inorganic hybrid gel compositions where a sulfur-containing cross-linking agent covalently links the organic and inorganic components. The gel compositions are further dried to provide porous gel compositions and aerogels. The mechanical and thermal properties of the dried gel compositions are also disclosed.

Sulfur-Containing Organic-Inorganic Hybrid Gel Compositions and Aerogels

NASA Technical Reports Server (NTRS)

Deshpande, Kiranmayi (Inventor); Evans, Owen R. (Inventor); Dong, Wenting (Inventor)

2015-01-01

Methods and materials are described for preparing organic-inorganic hybrid gel compositions where a sulfur-containing cross-linking agent covalently links the organic and inorganic components. The gel compositions are further dried to provide porous gel compositions and aerogels. The mechanical and thermal properties of the dried gel compositions are also disclosed.

Biogas Production from Protein-Rich Biomass: Fed-Batch Anaerobic Fermentation of Casein and of Pig Blood and Associated Changes in Microbial Community Composition

PubMed Central

Kovács, Etelka; Wirth, Roland; Maróti, Gergely; Bagi, Zoltán; Rákhely, Gábor; Kovács, Kornél L.

2013-01-01

It is generally accepted as a fact in the biogas technology that protein-rich biomass substrates should be avoided due to inevitable process inhibition. Substrate compositions with a low C/N ratio are considered difficult to handle and may lead to process failure, though protein-rich industrial waste products have outstanding biogas generation potential. This common belief has been challenged by using protein-rich substrates, i.e. casein and precipitated pig blood protein in laboratory scale continuously stirred mesophilic fed-batch biogas fermenters. Both substrates proved suitable for sustained biogas production (0.447 L CH4/g protein oDM, i.e. organic total solids) in high yield without any additives, following a period of adaptation of the microbial community. The apparent key limiting factors in the anaerobic degradation of these proteinaceous materials were the accumulation of ammonia and hydrogen sulfide. Changes in time in the composition of the microbiological community were determined by next-generation sequencing-based metagenomic analyses. Characteristic rearrangements of the biogas-producing community upon protein feeding and specific differences due to the individual protein substrates were recognized. The results clearly demonstrate that sustained biogas production is readily achievable, provided the system is well-characterized, understood and controlled. Biogas yields (0.45 L CH4/g oDM) significantly exceeding those of the commonly used agricultural substrates (0.25-0.28 L CH4/g oDM) were routinely obtained. The results amply reveal that these high-energy-content waste products can be converted to biogas, a renewable energy carrier with flexible uses that can replace fossil natural gas in its applications. Process control, with appropriate acclimation of the microbial community to the unusual substrate, is necessary. Metagenomic analysis of the microbial community by next-generation sequencing allows a precise determination of the alterations in the community composition in the course of the process. PMID:24146974

UNUSUAL FLORAL ORGANS Controls Meristem Identity and Organ Primordia Fate in Arabidopsis.

PubMed Central

Wilkinson, M. D.; Haughn, G. W.

1995-01-01

A novel gene that is involved in regulating flower initiation and development has been identified in Arabidopsis. This gene has been designated UNUSUAL FLORAL ORGANS (UFO), with five corresponding nuclear recessive alleles designated ufo[middot]1 to ufo[middot]5. Under short day-length conditions, ufo homozygotes generate more coflorescences than do the wild type, and coflorescences often appear apical to the first floral shoot, resulting in a period of inflorescence development in which regions of floral and coflorescence shoots are produced alternately. ufo enhances the phenotype of weak leafy alleles, and the double mutant Ufo-1 Apetala1-1 produces only coflorescence-like shoots, suggesting that these two genes control different aspects of floral initiation. Floral development was also altered in Ufo plants. Ufo flowers have an altered organ number in all whorls, and organs in the first, second, and third whorls exhibit variable homeotic transformations. Ufo single and double mutant phenotypes suggest that the floral changes result from reduction in class B floral homeotic gene expression and fluctuations in the expression boundaries of class C function and FLO10. Surprisingly, in situ hybridization analysis revealed no obvious differences in expression pattern or level in developing Ufo flowers compared with that of the wild type for any class B or C gene studied. We propose that UFO acts in concert with known floral initiation genes and regulates the domains of floral homeotic gene function. PMID:12242408

Meningitis due to Moraxella nonliquefaciens in a paediatric patient: a case report and review of the literature

PubMed Central

Szymczak, Wendy; Munjal, Iona

2017-01-01

Introduction. Moraxella nonliquefaciens is an unusual organism to be isolated from cerebral spinal fluid (CSF) and there exists only one case report of M. nonliquefaciens meningitis from a neonate. Moraxella species normally exist as part of the human upper respiratory tract flora and rarely cause invasive human disease. There are only a handful of case reports implicating the organism as a cause of endocarditis, bacteraemia, septic arthritis and endophthalmitis. Identification to the species level based on routine laboratory techniques has been challenging, with final identification often made through 16S rRNA sequencing. With the use of a newer diagnostic tool, matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) MS, we were able to rapidly identify the organism and initiate appropriate treatment. Case presentation. We present a rare care of M. nonliquefaciens meningitis in a paediatric patient with an underlying cranial anatomical defect due to Crouzon syndrome. She had been admitted to hospital 3 months previously with Streptococcus pneumoniae meningitis and mastoiditis, and returned to the emergency department with meningismus. CSF culture grew M. nonliquefaciens. She was treated with ceftriaxone with rapid improvement and eventually was taken for endoscopic surgical repair of a right encephalocele defect. Conclusion. The use of MALDI-TOF MS allowed for the rapid identification of the organism. The patient recovered with appropriate antimicrobial therapy and eventual surgical correction. An underlying anatomical defect should be considered in all patients who present with meningitis due to this unusual organism. PMID:28348808

Atmospheric Fragmentation of the Canyon Diablo Meteoroid

NASA Technical Reports Server (NTRS)

Pierazzo, E.; Artemieva, N. A.

2005-01-01

About 50 kyr ago the impact of an iron meteoroid excavated Meteor Crater, Arizona, the first terrestrial structure widely recognized as a meteorite impact crater. Recent studies of ballistically dispersed impact melts from Meteor Crater indicate a compositionally unusually heterogeneous impact melt with high SiO2 and exceptionally high (10 to 25% on average) levels of projectile contamination. These are observations that must be explained by any theoretical modeling of the impact event. Simple atmospheric entry models for an iron meteorite similar to Canyon Diablo indicate that the surface impact speed should have been around 12 km/s [Melosh, personal comm.], not the 15-20 km/s generally assumed in previous impact models. This may help explaining the unusual characteristics of the impact melt at Meteor Crater. We present alternative initial estimates of the motion in the atmosphere of an iron projectile similar to Canyon Diablo, to constraint the initial conditions of the impact event that generated Meteor Crater.

Finnish wallpaper pigments in the 18th-19th century: Presence of KFe3(CrO4)2(OH)6 and odd pigment mixtures

NASA Astrophysics Data System (ADS)

Castro, Kepa; Knuutinen, Ulla; Vallejuelo, Silvia Fdez-Ortiz de; Irazola, Mireia; Madariaga, Juan Manuel

2013-04-01

Several Finish wallpapers from the 18th and 19th century were analysed by using Raman spectroscopy assisted with EDXRF instrumentation, in an attempt of determine the pigments used in their manufacture process as well as of trying to date some of the samples through pigment composition. All pigments present in samples were determined and surprisingly the unusual and strange iron (III) chromate yellow pigment was found. Besides, unusual mixtures were found to obtain fashionable colours, especially in blue and green areas, where more than one blue pigments were mixed with green and yellow pigments. Blue verditer, ultramarine blue, Prussian blue, chrome yellow, calcite, lead white, red and yellow iron oxide, gypsum and carbon black were identified. The presence of the risky and poisonous emerald green must be highlighted. The results were compared with those found in other wallpapers from Spain and France.

Anisotropic superconductivity and elongated vortices with unusual bound states in quasi-one-dimensional nickel-bismuth compounds

NASA Astrophysics Data System (ADS)

Wang, Wen-Lin; Zhang, Yi-Min; Lv, Yan-Feng; Ding, Hao; Wang, Lili; Li, Wei; He, Ke; Song, Can-Li; Ma, Xu-Cun; Xue, Qi-Kun

2018-04-01

We report low-temperature scanning tunneling microscopy and spectroscopy studies of Ni-Bi films grown by molecular beam epitaxy. Highly anisotropic and twofold symmetric superconducting gaps are revealed in two distinct composites, Bi-rich NiBi3 and near-equimolar NixBi , both sharing quasi-one-dimensional crystal structure. We further reveal axially elongated vortices in both phases, but Caroli-de Gennes-Matricon states solely within the vortex cores of NiBi3. Intriguingly, although the localized bound state splits energetically off at a finite distance ˜10 nm away from a vortex center along the minor axis of elliptic vortex, no splitting is found along the major axis. We attribute the elongated vortices and unusual vortex behaviors to the combined effects of twofold superconducting gap and Fermi velocity. The findings provide a comprehensive understanding of the electron pairing and vortex matter in quasi-one-dimensional superconductors.

Characterization of the Mysteriously Cool Brown Dwarf HD 4113

NASA Astrophysics Data System (ADS)

Ednie, Michaela; Follette, Katherine; Ward-Duong, Kimberly

2018-01-01

Characterizing the physical properties of brown dwarfs is necessary to expand and improve our understanding of low mass companions, including exoplanets. Systems with both close radial velocity companions and distant directly imaged companions are particularly powerful in understanding planet formation mechanisms. Early in 2017, members of the SPHERE team discovered a companion brown dwarf in the HD 4113 system, which also contains a known RV planet. Atmospheric model fits to the Y and J-band spectra and H2/H3 photometry of the brown dwarf suggested it is unusually cool. We obtained new Magellan data in the Z and K’ bands in mid-2017. This data will help us to complete a more detailed atmospheric and astrometric characterization of this unusually cool companion. Broader wavelength coverage will help in accurate spectral typing and estimations of luminosity, temperature, surface gravity, radius, and composition. Additionally, a second astrometric epoch will help constrain the architecture of the system.

On the occurrence and origin of anthropogenic radionuclides found in a fragment of the Chelyabinsk (LL5) meteorite

NASA Astrophysics Data System (ADS)

Querfeld, Rebecca; Tanha, Mohammad R.; Heyer, Lars; Renz, Franz; Guggenberger, Georg; Brandstätter, Franz; Ferrière, Ludovic; Koeberl, Christian; Steinhauser, Georg

2017-06-01

A piece of the 2013 Chelyabinsk meteorite was investigated for its content of anthropogenic radionuclides. In addition to traces of cesium-137 that had been previously reported for this particular fragment, we found an unusually high amount of strontium-90, which indicates that the source of this contamination was the Kyshtym accident (1957). A high Sr-90/Cs-137 activity ratio is characteristic for Kyshtym-derived contaminations. Based on the cesium-137 content in the soil from the finding site, it is estimated that the fragment was contaminated with soil particles in the milligram range upon impact. Investigation of the soil revealed very unusual ferromagnetic characteristics and an iron-rich chemical composition. Mössbauer spectroscopy indicated the presence of steel components in this soil, suggesting that the investigated meteorite fragment was found in an industrial dumping site rather than natural soil.

Hingganite-(Y) from a small aplite vein in granodiorite from Oppach, Lusatian Mts., E-Germany

NASA Astrophysics Data System (ADS)

Thomas, Rainer; Davidson, Paul

2017-12-01

Crystals of hingganite-(Y) occur co-trapped in quartz crystals from miarolitic cavities in an aplite vein in the Cadomian granodiorite from Oppach/Lusatian, Germany. We describe the chemical composition and provide a reference Raman spectrum of this mineral, for which little useful spectral data has been published. In addition, we provide some inferences as to the genesis of this mineral in relationship to melt and fluid inclusions in quartz. The paragenetic sequence of minerals conserved only as small crystal inclusions in quartz, demonstrates an unusual occurrence in the Lusatian aplites, characterized by an unusual, extremely water-rich, near-supercritical melt-fluid system with high concentrations in alkali carbonates and sulfates. We propose that a sulfate-rich system was responsible for the fixation of Be and REE as hingganite-(Y), rather than the more common beryl + REE mineral assemblage. This may provide an explanation for the formation of this otherwise rare mineral

An All-Organic Composite System for Resistive Change Memory via the Self-Assembly of Plastic-Crystalline Molecules.

PubMed

Cha, An-Na; Lee, Sang-A; Bae, Sukang; Lee, Sang Hyun; Lee, Dong Su; Wang, Gunuk; Kim, Tae-Wook

2017-01-25

An all-organic composite system was introduced as an active component for organic resistive memory applications. The active layer was prepared by mixing a highly polar plastic-crystalline organic molecule (succinonitrile, SN) into an insulating polymer (poly(methyl methacrylate), PMMA). As increasing concentrations of SN from 0 to 3.0 wt % were added to solutions of different concentrations of PMMA, we observed distinguishable microscopic surface structures on blended films of SN and PMMA at certain concentrations after the spin-casting process. The structures were organic dormant volcanos composed of micron-scale PMMA craters and disk type SN lava. Atomic force microscopy (AFM), cross-sectional transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive X-ray spectrometer (EDX) analysis showed that these structures were located in the middle of the film. Self-assembly of the plastic-crystalline molecules resulted in the phase separation of the SN:PMMA mixture during solvent evaporation. The organic craters remained at the surface after the spin-casting process, indicative of the formation of an all-organic composite film. Because one organic crater contains one SN disk, our system has a coplanar monolayer disk composite system, indicative of the simplest composite type of organic memory system. Current-voltage (I-V) characteristics of the composite films with organic craters revealed that our all-organic composite system showed unipolar type resistive switching behavior. From logarithmic I-V characteristics, we found that the current flow was governed by space charge limited current (SCLC). From these results, we believe that a plastic-crystalline molecule-polymer composite system is one of the most reliable ways to develop organic composite systems as potential candidates for the active components of organic resistive memory applications.

Vibrational energy distribution in aniline scattered from surfaces covered with organized organic monolayers

NASA Astrophysics Data System (ADS)

Paz, Y.; Naaman, R.

1990-08-01

Energy distribution in aniline molecules scattered from organized organic monolayers was investigated using a resonance-enhanced two-photon ionization technique. Two type of monolayers were used, one exposing a floppy unsubstituted aliphatic chain (OTS, n-octadecyltrichlorosilane), and the second having a perfluorinated tail (PFDA, perfluorodecanoic acid). The dependence of the internal and translational energy of the scattered aniline is monitored as a function of collision energy and surface properties. The data reveal an unusually high propensity for excitation of the NH 2 inversion mode in aniline. Vibrationally excited molecules are scattered with a narrower time-of-flight (TOF) distribution than those in the ground vibrational state.

Shape-preserving transformations of organic matter and compositions thereof

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaehr, Bryan J.; Meyer, Kristin; Townson, Jason L.

The present invention relates to methods of transforming organic matter into organic-inorganic composites, inorganic replicas, or conductive replicas. Organic matter, such as biological cells and tissue and organs, can be converted into such composites and replicas using the methods described herein. In particular, such methods transform organic matter (into inorganic, organic-inorganic, or conductive constructs), while simultaneously preserving microscopic and/or macroscopic structural detail.

Organic contaminant separator

DOEpatents

Del Mar, P.

1993-12-28

A process is presented of sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium by (a) passing an initial aqueous medium including a minor amount of the organic contaminant through a composite tube comprised of a blend of a polyolefin and a polyester, the composite tube having an internal diameter of from about 0.1 to about 2.0 millimeters and being of sufficient length to permit the organic contaminant to adhere to the composite tube, (b) passing a solvent through the composite tube. The solvent is capable of separating the adhered organic contaminant from the composite tube. Further, an extraction apparatus is presented for sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium. The apparatus includes a composite tube comprised of a blend of a polyolefin and a polyester. The composite tube has an internal diameter of from about 0.1 to about 2.0 millimeters and has sufficient length to permit an organic contaminant contained within an aqueous medium passed therethrough to adhere to the composite tube. 2 figures.

PARACOCCIDIOIDOMYCOSIS IN A RENAL TRANSPLANT RECIPIENT

PubMed Central

GÓES, Heliana Freitas de Oliveira; DURÃES, Sandra Maria Barbosa; LIMA, Caren dos Santos; de SOUZA, Mariana Boechat; VILAR, Enoi Aparecida Guedes; DALSTON, Marcos Olivier

2016-01-01

Paracoccidioidomycosis (PCM) is the most common endemic mycosis in Latin America. The etiological agents, which comprise two species, Paracoccidioides brasiliensis and P. lutzii, are thermodimorphic fungi that usually affect previously healthy adults. They primarily involve the lungs and then disseminate to other organs. Such mycosis is rare in organ transplant recipients; there have been only three cases reported in literature, until now. We report a case of PCM in a renal transplant recipient with an unusual dermatological presentation. PMID:26910451

Army Aviation in Operation Just Cause

DTIC Science & Technology

1992-04-15

DECLASSIFICATION/DOWNGRAD-ING iCHEDULE is unlimited. 4. PERFORMING ORGANIZATION REPORT NUMBER( S ) 5. MONITORING ORGANIZATiON REPORT NUMBER( S ; 6a. VAME OF...AUTHOR( S ) 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Year,"Month, Day) 15. PAGE COUNT Individual Study FROM TO__ 15 April 1992 157 16...were unable to take the children home until 1900 hours." S Again, Army aviation units displayed unusual flexibility and capability to respond on short

Contrast-enhanced ultrasound and computed tomography findings of granulomatosis with polyangiitis presenting with multiple intrarenal microaneurysms: A case report.

PubMed

Kim, Youe Ree; Lee, Young Hwan; Lee, Jong-Ho; Yoon, Kwon-Ha

Granulomatosis with polyangiitis (GPA) is a systemic disorder that affects small- and medium- sized vessels in many organs. Although the kidneys are the second most commonly involved organ in patients with GPA, its manifestation as multiple intrarenal aneurysms is rare. We report an unusual manifestation of GPA with multiple intrarenal microaneurysms, as demonstrated by contrast-enhanced ultrasound and computed tomography. Copyright © 2017 Elsevier Inc. All rights reserved.

Two Decades of Negative Thermal Expansion Research: Where Do We Stand?

PubMed Central

Lind, Cora

2012-01-01

Negative thermal expansion (NTE) materials have become a rapidly growing area of research over the past two decades. The initial discovery of materials displaying NTE over a large temperature range, combined with elucidation of the mechanism behind this unusual property, was followed by predictions that these materials will find use in various applications through controlled thermal expansion composites. While some patents have been filed and devices built, a number of obstacles have prevented the widespread implementation of NTE materials to date. This paper reviews NTE materials that contract due to transverse atomic vibrations, their potential for use in controlled thermal expansion composites, and known problems that could interfere with such applications. PMID:28817027

CCE plasma wave observations during the storm of September 4, 5, 1984. [Charge Composition Explorer

NASA Technical Reports Server (NTRS)

Scarf, F. L.

1985-01-01

Near 0700 on September 4, 1984 a series of interplanetary discontinuities arrived at earth when the AMPTE Charge Composition Explorer (CCE) was near apogee. During the next few hours the spacecraft passed in and out of the magnetosheath. At the magnetopause boundary, the CCE wave instrument detected strong electron plasma oscillations, weaker electromagnetic waves at the electron plasma frequency, and broadband electrostatic waves. During the subsequent perigee passes on September 4 and 5, the wave observations of upper hybrid resonance emissions, continuum radiation, electrostatic noise bands and unusual low latitude auroral kilometic radiation were used to monitor significant variations in the magnetospheric characteristics as the main storm phases developed.

Morphology-Dependent Hardness of Cr7C3-Ni-Rich Alloy Composite vs Orientation Independent Hardness of Cr7C3 Primary Phase in a Laser Clad Microstructure

NASA Astrophysics Data System (ADS)

Venkatesh, Lakshmi Narayanan; Suresh Babu, Pitchuka; Gundakaram, Ravi Chandra; Doherty, Roger D.; Joshi, Shrikant V.; Samajdar, Indradev

2017-04-01

Microstructural evolution with superheating was studied in chromium carbide-nickel coatings deposited by laser cladding. At lower superheating, selective growth of <0001> direction from the high density of Cr7C3 grains nucleated resulted in a columnar structure with (0001) texture. Increased superheating lead to the loss of columnar structure as well as the (0001) texture. The hexagonal Cr7C3 showed an unusual isotropic nanoindentation hardness evidently correlated with its low c/ a ratio. However, the rod-like morphology of the carbide dendrites resulted in significant anisotropy in the hardness of the composite.

Fighting Back: Negotiating under the Radar

ERIC Educational Resources Information Center

Starr, Gary E.; Henry, Roderick; Kolnick, Jeff

2009-01-01

This January, the Inter Faculty Organization, the union representing nearly 3,300 faculty members at the seven Minnesota state universities, took the unusual step of making an offer that broke dramatically with past practice and with typical union negotiating. The Minnesota faculty offered to accept a pay freeze while holding current contract…

75 FR 36725 - Self-Regulatory Organizations; International Securities Exchange, LLC; Notice of Filing of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-28

..., entitled ``Numerical Guidelines Applicable to Volatile Market Opens'' with a new paragraph, entitled...) of Rule 2128 to eliminate the ability of the Exchange to deviate from the Numerical Guidelines... Numerical Guidelines or Reference Prices in various ``Unusual Circumstances.'' The Exchange proposes to...

Broad Ligament Perivascular Epithelioid Cell Tumor (PEComa) of Uncertain Malignant Potential.

PubMed

Mathew, Mary; Nayal, Bhavna; Rao, Lakshmi; Nagel, Bhawna

2016-01-01

PEComas are uncommon mesenchymal tumors often involving the pelvic organs. They have an unpredictable behavior. Accurate diagnosis and long-term follow-up is therefore essential in these patients. We report this case of PEComa of uncertain malignant potential in an unusual location with excellent prognosis.

Improving Public Debate with Television and Social Organization

ERIC Educational Resources Information Center

Magnuson, Osgood T.

1970-01-01

"Town Meeting, an unusual experiment in using television for improving citizen participation in the American democratic process, has given viewers in Minnesota and South Dakota an opportunity to hear about issues and to join in the decision-making." Based on remarks made to the Kettering Conference on Public Television Programming.…

A non-multimacrocyclic heteroditopic receptor that cooperatively binds and effectively extracts KAcO salt.

PubMed

Zakrzewski, Maciej; Kwietniewska, Natalia; Walczak, Wojciech; Piątek, Piotr

2018-06-06

Prepared in only three synthetic steps, a non-multimacrocyclic heteroditopic receptor binds potassium salts of halides and carboxylates with unusually high cooperativity, suggesting salt binding as associated ion-pairs. Unprecedented extraction of highly hydrophilic KAcO salt from water to organic solution is also demonstrated.

42 CFR 422.113 - Special rules for ambulance services, emergency and urgently needed services, and maintenance and...

Code of Federal Regulations, 2011 CFR

2011-10-01

... means of transportation would endanger the beneficiary's health. (b) Emergency and urgently needed... temporarily absent from the MA plan's service (or, if applicable, continuation) area (or, under unusual and... organization's provider network is temporarily unavailable or inaccessible) when the services are medically...

Effect of Chemical Structure and Network Formation on Physical Properties of Di(Cyanate Ester) Thermosets (Post Print)

DTIC Science & Technology

2012-02-06

with glass or polyethylene reinforcements for use in radomes and antenna structures,4 where their unusually low dielectric constant and low moisture ...are prized for their elevated glass transition temperature, good adhesion to metals, resistance to degradation by moisture , and excellent flame...on the performance of cyanate ester resins and composites. Cyanate ester monomers, particularly when catalyzed, may react with adventitious moisture to

CRREL (Cold Regions Research and Engineering Laboratory) Technical Publications. Supplement

DTIC Science & Technology

1986-09-01

Utilization for Fresh Water Production, ROAD. CHIMCAL COMPOSITION OF DUST nical memorandum~ Mar. 1976, No. 116, Muske Re- Weather Modilicationt, and...it appeared in a J-9 core Commes a i elon teo kEvromna 516 on an unusual boundary layer showing in th core andaa PV.e sEvromns assessment of the...SEA ICE IN at lowbtrquencinsfroad nttrsnsmtterseadofthelnductive 37.4035 THE 50-15 MHZ RANGEL coupling between two loop ntennaus are describsed

Method for hydrogen production and metal winning, and a catalyst/cocatalyst composition useful therefor

DOEpatents

Dhooge, Patrick M.

1987-10-13

A catalyst/cocatalyst/organics composition of matter is useful in electrolytically producing hydrogen or electrowinning metals. Use of the catalyst/cocatalyst/organics composition causes the anode potential and the energy required for the reaction to decrease. An electrolyte, including the catalyst/cocatalyst composition, and a reaction medium composition further including organic material are also described.

Unusually Low Snow Cover in the U.S.

NASA Technical Reports Server (NTRS)

2002-01-01

New maps of snow cover produced by NASA's Terra satellite show that this year's snow line stayed farther north than normal. When combined with land surface temperature measurements, the observations confirm earlier National Oceanic and Atmospheric Administration reports that the United States was unusually warm and dry this past winter. The above map shows snow cover over the continental United States from February 2002 and is based on data acquired by the Moderate-Resolution Imaging Spectroradiometer (MODIS). The amount of land covered by snow during this period was much lower than usual. With the exception of the western mountain ranges and the Great Lakes region, the country was mostly snow free. The solid red line marks the average location of the monthly snow extent; white areas are snow-covered ground. Snow was mapped at approximately 5 kilometer pixel resolution on a daily basis and then combined, or composited, every eight days. If a pixel was at least 50 percent snow covered during all of the eight-day periods that month, it was mapped as snow covered for the whole month. For more information, images, and animations, read: Terra Satellite Data Confirm Unusually Warm, Dry U.S. Winter Image by Robert Simmon, based on data from the MODIS Snow/Ice Global Mapping Project

Bioorganic/inorganic hybrid composition of sponge spicules: matrix of the giant spicules and of the comitalia of the deep sea hexactinellid Monorhaphis.

PubMed

Müller, Werner E G; Wang, Xiaohong; Kropf, Klaus; Ushijima, Hiroshi; Geurtsen, Werner; Eckert, Carsten; Tahir, Muhammad Nawaz; Tremel, Wolfgang; Boreiko, Alexandra; Schlossmacher, Ute; Li, Jinhe; Schröder, Heinz C

2008-02-01

The giant basal spicules of the siliceous sponges Monorhaphis chuni and Monorhaphis intermedia (Hexactinellida) represent the largest biosilica structures on earth (up to 3m long). Here we describe the construction (lamellar organization) of these spicules and of the comitalia and highlight their organic matrix in order to understand their mechanical properties. The spicules display three distinct regions built of biosilica: (i) the outer lamellar zone (radius: >300 microm), (ii) the bulky axial cylinder (radius: <75 microm), and (iii) the central axial canal (diameter: <2 microm) with its organic axial filament. The spicules are loosely covered with a collagen net which is regularly perforated by 7-10 microm large holes; the net can be silicified. The silica layers forming the lamellar zone are approximately 5 microm thick; the central axial cylinder appears to be composed of almost solid silica which becomes porous after etching with hydrofluoric acid (HF). Dissolution of a complete spicule discloses its complex structure with distinct lamellae in the outer zone (lamellar coating) and a more resistant central part (axial barrel). Rapidly after the release of the organic coating from the lamellar zone the protein layers disintegrate to form irregular clumps/aggregates. In contrast, the proteinaceous axial barrel, hidden in the siliceous axial cylinder, is set up by rope-like filaments. Biochemical analysis revealed that the (dominant) molecule of the lamellar coating is a 27-kDa protein which displays catalytic, proteolytic activity. High resolution electron microscopic analysis showed that this protein is arranged within the lamellae and stabilizes these surfaces by palisade-like pillars. The mechanical behavior of the spicules was analyzed by a 3-point bending assay, coupled with scanning electron microscopy. The load-extension curve of the spicule shows a biphasic breakage/cracking pattern. The outer lamellar zone cracks in several distinct steps showing high resistance in concert with comparably low elasticity, while the axial cylinder breaks with high elasticity and lower stiffness. The complex bioorganic/inorganic hybrid composition and structure of the Monorhaphis spicules might provide the blueprint for the synthesis of bio-inspired material, with unusual mechanical properties (strength, stiffness) without losing the exceptional properties of optical transmission.

Familial pseudoxanthoma elasticum associated with multiple comedones.

PubMed

Maarouf, Melody; Sharon, Victoria R; Sivamani, Raja K; Prakash, Neha; Bipin, T H; Davis, Tracy; Shi, Vivian Y

2017-09-15

Pseudoxanthoma elasticum (PXE) is an autosomal recessive disorder characterized by atypical elastic fibers that causes connective tissue abnormalities of the skin, eyes, and heart, among other organs. The disorder is rare, with a classic presentation of yellow-orange cobblestone-like papules on flexural areas, lax skin, ocular degeneration, and moribund vasculature in multiple organs. There is wide variability in the presentation of the affected organs [1]. We present two sisters with classic cutaneous findings of PXE with the additional unusual findings of numerous open comedones on the neck. To our knowledge, this is the first report of numerous open comedones in familial PXE.

Generation of a composite grid for turbine flows and consideration of a numerical scheme

NASA Technical Reports Server (NTRS)

Choo, Y.; Yoon, S.; Reno, C.

1986-01-01

A composite grid was generated for flows in turbines. It consisted of the C-grid (or O-grid) in the immediate vicinity of the blade and the H-grid in the middle of the blade passage between the C-grids and in the upstream region. This new composite grid provides better smoothness, resolution, and orthogonality than any single grid for a typical turbine blade with a large camber and rounded leading and trailing edges. The C-H (or O-H) composite grid has an unusual grid point that is connected to more than four neighboring nodes in two dimensions (more than six neighboring nodes in three dimensions). A finite-volume lower-upper (LU) implicit scheme to be used on this grid poses no problem and requires no special treatment because each interior cell of this composite grid has only four neighboring cells in two dimensions (six cells in three dimensions). The LU implicit scheme was demonstrated to be efficient and robust for external flows in a broad flow regime and can be easily applied to internal flows and extended from two to three dimensions.

The composite nature of the peculiar star HR 6560 (HD 159870)

NASA Technical Reports Server (NTRS)

Wegner, Gary; Cowley, Charles R.

1992-01-01

Ground-based high-dispersion photographic spectra and ultraviolet spectra obtained with the IUE satellite are described and employed to determine the nature of the peculiar star HR 6560 (HD 159870). Previously this object had been described as both a composite system and as a strong Fm star. The UBVRI, Stromgren, and ultraviolet colors of HR 6560 are compared with objects classified composite from the Bright Star Catalogue and normal dwarfs and giants. The colors of HR 6560 are not unusual for a composite and are consistent with a late-A dwarf, combined with a late-G or early-K giant. The ultraviolet satellite clearly shows the presence of an A component, but its precise spectral type is difficult to assign. The IUE and TD-1 data suggest that the ultraviolet is dominated by light from an A5 V secondary and the visual from a GO III primary. This does not agree well with the most plausible model that fits the visual photometry. The peculiar nature of HR 6560's spectrum is most likely due to its composite nature.

Outbreak of meningitis in weaner pigs caused by unidentified asaccharolytic gram-negative bacterium.

PubMed Central

Mohan, K; Holmes, B; Kock, N; Muvavarirwa, P

1996-01-01

Several organisms are known to cause outbreaks of meningitis in pigs, with Haemophilus species being the most frequently implicated. We report such an outbreak in which necropsied pigs manifested an unusual combination of meningitis, tracheitis, and bronchitis. The causative agent appeared to be an asaccharolytic gram-negative nonfermentative bacterium whose classification has yet to be determined. The organism was isolated from the brain and was extremely capnophilic, growing in air only after several serial subcultures. PMID:8815112

[Muscular system of the Microphallus pygmaeus metacercaria (Trematoda: microphallidae)].

PubMed

Krupenko, D Iu

2010-01-01

The musculature of body wall, attachment organs (oral and ventral suckers), and internal organs (alimentary tract, excretory bladder, and ducts of reproductive system) of the Microphallus pygmaeus metacercaria are described. An unusual arrangement of longitude and diagonal muscles was found in the hind part of the metacercaria body. Longitude fibers of dorsal and lateral body surfaces are bow-shaped and bend round the excretory pore along its ventral margin. An additional group of diagonal fibers is situated in the hind part of ventral body surface.

Asplenic fulminant sepsis secondary to a dog bite complicated by toxic epidermal necrolysis/Stevens-Johnson syndrome.

PubMed

Teo, Ken G; Anavekar, Namrata S; Yazdabadi, Anosha; Ricketts, Sophie

2012-07-29

We report a case of asplenic fulminant sepsis in Australia following a dog bite which was complicated by toxic epidermal necrolysis/Stevens-Johnson syndrome (TENS/SJS). Capnocytophaga canimorsus, the infective organism, is a rare cause of septicaemia: a high degree of suspicion of this unusual organism and its early aggressive management is paramount. The diagnostic and management difficulties of TENS/SJS in the context of a patient with fulminant sepsis, DIC and on inotropes are also highlighted.

Development of Improved Environmental Resistant Organic-Reinforced Materials Systems

DTIC Science & Technology

1975-11-01

Advanced composites , graphite and boron reinforced laminates, moisture resistance, environmental resistance, organic matrix composites . 20. ABSTRACT...in November 1975 for publication. Efforts at TOD were conducted within the Advanced Composites Engineering Departmfntrunde; L technical...weight makes^organic matrix advanced composites hardware extremely attractive for today s modern Air Force weapons systems. Accordingly, such

Correlated nanoscale characterization of a unique complex oxygen-rich stardust grain: Implications for circumstellar dust formation

NASA Astrophysics Data System (ADS)

Leitner, J.; Hoppe, P.; Floss, C.; Hillion, F.; Henkel, T.

2018-01-01

We report the light to intermediate-mass element abundances as well as the oxygen, magnesium, silicon, and titanium isotope compositions of a unique and unusually large (0.8 μm × 3.75 μm) presolar O-rich grain from the Krymka LL3.2 chondrite. The O-, Al-, and Ti-isotopic compositions are largely compatible with an origin from an asymptotic giant branch (AGB) star of 1.5 solar masses with a metallicity that is 15% higher than the solar metallicity. The grain has an elevated 17O/16O ratio (8.40 ± 0.16 × 10-4) compared to solar, and slightly sub-solar 18O/16O ratio (1.83 ± 0.03 × 10-3). It shows evidence for the presence of initial 26Al, suggesting formation after the first dredge-up, during one of the early third dredge-up (TDU) episodes. Titanium isotopic data indicate condensation of the grain before significant amounts of material from the He-burning shell were admixed to the stellar surface with progressive TDUs. We observed a small excess in 30Si (δ30Si = 41 ± 5‰), which most likely is inherited from the parent star's initial Si-isotopic composition. For such stars stellar models predict a C/O-ratio < 1 even after the onset of TDU, thus allowing the condensation of O-rich dust. The grain is an unusual complex presolar grain, consisting of an Al-Ca-Ti-oxide core, surrounded by an Mg-Ca-silicate mantle, and resembles the condensation sequence for a cooling gas of solar composition at pressures and dust/gas ratios typically observed for circumstellar envelopes around evolved stars. We also report the first observation of phosphorus in a presolar grain, although the origin of the P-bearing phase remains ambiguous.

Organic-Inorganic Composites Toward Biomaterial Application.

PubMed

Miyazaki, Toshiki; Sugawara-Narutaki, Ayae; Ohtsuki, Chikara

2015-01-01

Bioactive ceramics are known to exhibit specific biological affinities and are able to show direct integration with surrounding bone when implanted in bony defects. However, their inadequate mechanical properties, such as low fracture toughness and high Young's modulus in comparison to natural bone, limit their clinical application. Bone is a kind of organic-inorganic composite where apatite nanocrystals are precipitated onto collagen fibre networks. Thus, one way to address these problems is to mimic the natural composition of bone by using bioactive ceramics via material designs based on organic-inorganic composites. In this chapter, the current research on the development of the various organic-inorganic composites designed for biomaterial applications has been reviewed. Various compounds such as calcium phosphate, calcium sulphate and calcium carbonate can be used for the inorganic phases to design composites with the desired mechanical and biological properties of bone. Not only classical mechanical mixing but also coating of the inorganic phase in aqueous conditions is available for the fabrication of such composites. Organic modifications using various polymers enable the control of the crystalline structure of the calcium carbonate in the composites. These approaches on the fabrication of organic-inorganic composites provide important options for biomedical materials with novel functions. © 2015 S. Karger AG, Basel.

Source Evolution After Subduction Initiation as Recorded in the Izu-Bonin-Mariana Fore-arc Crust

NASA Astrophysics Data System (ADS)

Shervais, J. W.; Reagan, M. K.; Pearce, J. A.; Shimizu, K.

2015-12-01

Drilling in the Izu-Bonin-Mariana (IBM) fore-arc during IODP Expedition 352 and DSDP Leg 60 recovered consistent stratigraphic sequences of volcanic rocks reminiscent of those found in many ophiolites. The oldest lavas in these sections are "fore-arc basalts" (FAB) with ~51.5 Ma ages. Boninites began eruption approximately 2-3 m.y. later (Ishizuka et al., 2011, EPSL; Reagan et al., 2013, EPSL) and further from the trench. First results from IODP Expedition 352 and preliminary post-cruise data suggest that FAB at Sites U1440 and U1441 were generated by decompression melting during near-trench sea-floor spreading, and that fluids from the subducting slab were not involved in their genesis. Temperatures appear to have been unusually high and pressures of melting appear to have been unusually low compared to mid-ocean ridges. Spreading rates at this time appear to have been robust enough to maintain a stable melt lens. Incompatible trace element abundances are low in FAB compared to even depleted MORB. Nd and Hf Isotopic compositions published before the expedition suggest that FAB were derived from typical MORB source mantle. Thus, their extreme deletion resulted from unusually high degrees of melting immediately after subduction initiation. The oldest boninites from DSDP Site 458 and IODP Sites U1439 and U1442 have relatively high concentrations of fluid-soluble elements, low concentrations of REE, and light depleted REE patterns. Younger boninites, have even lower REE concentrations, but have U-shaped REE patterns. Our first major and trace element compositions for the FAB through boninite sequence suggests that melting pressures and temperatures decreased through time, mantle became more depleted though time, and spreading rates waned during boninite genesis. Subduction zone fluids involved in boninite genesis appear to have been derived from progressively higher temperatures and pressures over time as the subducting slab thermally matured.

Elastic Properties of Orthoenstatite at Simultaneous High Pressure-Temperature Conditions and the Implication for the Origin of Low VP/VS Zones in the Mantle Wedge

NASA Astrophysics Data System (ADS)

Qian, W.; Wang, W.; Zou, F.; Wu, Z.

2017-12-01

The compositions of the Earth's interiors are critical in understanding the origin and evolution of the Earth and its geodynamics. Orthopyroxene is an important component for the upper mantle both in pyrolite model and in piclogite model. Furthermore, many evidences suggest the local enrichment of opx in the upper mantle. Therefore, its thermodynamic and elastic properties are fundamental for understanding of chemical compositions and dynamics of the upper mantle. We obtain the elastic properties of orthoenstatite (MgSiO3), Mg end-member orthopyroxene with space group Pbca, up to 20 GPa and 2000 K using first principles calculations with local density approximation (LDA). The calculated results are in good agreement with previous available experimental measurements and theoretical results. Both bulk and shear modulus show noticeable nonlinear pressure dependence, and the softening of shear wave velocities is prominent at high pressure. Meanwhile, orthoenstatite exhibits a negative temperature derivate of VP/VS ratios. This is different from other upper mantle minerals, such as olivine, ringwoodite and garnet, whose VP/VS increase with the increasing of the temperature. Compared to other major minerals in the upper mantle, orthoenstatite shows the lowest compressional velocities, shear velocities, and VP/VS (<1.7) ratio up to the depth of 200 km. Recently, many seismic studies have observed unusual low VP/VS (below 1.72) zones in subduction mantle wedge and orthopyroxene has been proposed to be a possible interpretation of this unusual observed. However, this explanation is still under debate because no experimental or calculated elastic data at the conditions of the upper mantle are available before. Our calculations show that VS and VP/VS ratio of orthoenstatite under the mantle wedge conditions (2-3 GPa and 1073-1723 K) are consistent of the unusual seismic observations of VP/VS in subduction mantle wedge. Therefore, the enrichment of orthopyroxene may potentially account for the observed low VP/VS in the mantle wedge.

High δ56Fe values in Samoan basalts

NASA Astrophysics Data System (ADS)

Konter, J. G.; Pietruszka, A. J.; Hanan, B. B.; Finlayson, V.

2014-12-01

Fe isotope fractionation spans ~0-0.4 permil in igneous systems, which cannot all be attributed to variable source compositions since peridotites barely overlap these compositions. Other processes may fractionate Fe isotopes such as variations in the degree of partial melting, magmatic differentiation, fluid addition related to the final stages of melt evolution, and kinetic fractionation related to diffusion. An important observation in igneous systems is the trend of increasing Fe isotope values against an index of magmatic fractionation (e.g. SiO2; [1]). The data strongly curve from δ56Fe >0.3 permil for SiO2 >70 wt% down to values around 0.09 permil from ~65 wt% down to 40 wt% SiO2 of basalts. However, ocean island basalts (OIBs) have a slightly larger δ56Fe variability than mid ocean ridge basalts (MORBs; [e.g. 2]). We present Fe isotope data on samples from the Samoan Islands (OIB) that have unusually high δ56Fe values for their SiO2 content. We rule out alteration by using fresh samples, and further test for the effects of magmatic processes on the δ56Fe values. In order to model the largest possible fractionation, unusually small degrees of melting with extreme fractionation factors are modeled with fractional crystallization of olivine alone, but such processing fails to fractionate the Fe isotopes to the observed values. Moreover, Samoan lavas likely also fractionated clinopyroxene, and its lower fractionation factor would limit the final δ56Fe value of the melt. We therefore suggest the mantle source of Samoan lavas must have had unusually high δ56Fe. However, there is no clear correlation with the highly radiogenic isotope signatures that reflect the unique source compositions of Samoa. Instead, increasing melt extraction correlates with lower δ56Fe values in peridotites assumed to be driven by the preference for the melt phase by heavy Fe3+, while high values may be related to metasomatism [3]. The latter would be in line with metasomatized xenoliths from Samoa [4]. [1] Heimann et al., 2008, doi:10.1016/j.gca.2008.06.009 [2] Teng et al., 2013, doi:10.1016/j.gca.2012.12.027 [3] Williams et al., 2004, doi: 10.1126/science.1095679 [4] Hauri et al., 1993, doi: 10.1038/365221a0

The Fatty Acid Profile Analysis of Cyperus laxus Used for Phytoremediation of Soils from Aged Oil Spill-Impacted Sites Revealed That This Is a C18:3 Plant Species.

PubMed

Rivera Casado, Noemí Araceli; Montes Horcasitas, María del Carmen; Rodríguez Vázquez, Refugio; Esparza García, Fernando José; Pérez Vargas, Josefina; Ariza Castolo, Armando; Ferrera-Cerrato, Ronald; Gómez Guzmán, Octavio; Calva Calva, Graciano

2015-01-01

The effect of recalcitrant hydrocarbons on the fatty acid profile from leaf, basal corm, and roots of Cyperus laxus plants cultivated in greenhouse phytoremediation systems of soils from aged oil spill-impacted sites containing from 16 to 340 g/Kg total hydrocarbons (THC) was assessed to investigate if this is a C18:3 species and if the hydrocarbon removal during the phytoremediation process has a relationship with the fatty acid profile of this plant. The fatty acid profile was specific to each vegetative organ and was strongly affected by the hydrocarbons level in the impacted sites. Leaf extracts of plants from uncontaminated soil produced palmitic acid (C16), octadecanoic acid (C18:0), unsaturated oleic acids (C18:1-C18:3), and unsaturated eichosanoic (C20:2-C20:3) acids with a noticeable absence of the unsaturated hexadecatrienoic acid (C16:3); this finding demonstrates, for the first time, that C. laxus is a C18:3 plant. In plants from the phytoremediation systems, the total fatty acid contents in the leaf and the corm were negatively affected by the hydrocarbons presence; however, the effect was positive in root. Interestingly, under contaminated conditions, unusual fatty acids such as odd numbered carbons (C15, C17, C21, and C23) and uncommon unsaturated chains (C20:3n6 and C20:4) were produced together with a remarkable quantity of C22:2 and C24:0 chains in the corm and the leaf. These results demonstrate that weathered hydrocarbons may drastically affect the lipidic composition of C. laxus at the fatty acid level, suggesting that this species adjusts the cover lipid composition in its vegetative organs, mainly in roots, in response to the weathered hydrocarbon presence and uptake during the phytoremediation process.

The Fatty Acid Profile Analysis of Cyperus laxus Used for Phytoremediation of Soils from Aged Oil Spill-Impacted Sites Revealed That This Is a C18:3 Plant Species

PubMed Central

Montes Horcasitas, María del Carmen; Rodríguez Vázquez, Refugio; Esparza García, Fernando José; Pérez Vargas, Josefina; Ariza Castolo, Armando; Ferrera-Cerrato, Ronald; Gómez Guzmán, Octavio

2015-01-01

The effect of recalcitrant hydrocarbons on the fatty acid profile from leaf, basal corm, and roots of Cyperus laxus plants cultivated in greenhouse phytoremediation systems of soils from aged oil spill-impacted sites containing from 16 to 340 g/Kg total hydrocarbons (THC) was assessed to investigate if this is a C18:3 species and if the hydrocarbon removal during the phytoremediation process has a relationship with the fatty acid profile of this plant. The fatty acid profile was specific to each vegetative organ and was strongly affected by the hydrocarbons level in the impacted sites. Leaf extracts of plants from uncontaminated soil produced palmitic acid (C16), octadecanoic acid (C18:0), unsaturated oleic acids (C18:1-C18:3), and unsaturated eichosanoic (C20:2-C20:3) acids with a noticeable absence of the unsaturated hexadecatrienoic acid (C16:3); this finding demonstrates, for the first time, that C. laxus is a C18:3 plant. In plants from the phytoremediation systems, the total fatty acid contents in the leaf and the corm were negatively affected by the hydrocarbons presence; however, the effect was positive in root. Interestingly, under contaminated conditions, unusual fatty acids such as odd numbered carbons (C15, C17, C21, and C23) and uncommon unsaturated chains (C20:3n6 and C20:4) were produced together with a remarkable quantity of C22:2 and C24:0 chains in the corm and the leaf. These results demonstrate that weathered hydrocarbons may drastically affect the lipidic composition of C. laxus at the fatty acid level, suggesting that this species adjusts the cover lipid composition in its vegetative organs, mainly in roots, in response to the weathered hydrocarbon presence and uptake during the phytoremediation process. PMID:26473488

Climatic and physiological controls on the stable isotope composition of modern and ancient Cupressaceae

NASA Astrophysics Data System (ADS)

Zinniker, D.; Tipple, B.; Pagani, M.

2007-12-01

Unique and abundant secondary metabolites found in waxes and resins of the Callitroid, Cupressoid, and Taxodioid clades of the Cupressaceae family can be identified and quantified in complex mixtures of sedimentary organic compounds. This unusual feature makes it possible to study relatively simple (taxon-specific) isotope systems back in time across the broad array of environments in which these conifers are found. Work on these systems can potentially provide both robust paleoenvironmental proxies (i.e. for source water δD and growing season relative humidity) and quantitative probes into the ecophysiology of these plants in modern and ancient environments. Our research focuses on three genera representing environmental end-members of Cupressaceae - Juniperus, Thuja, and Chamaecyparis - (1) across geographic and environmental gradients in the field, and (2) in specific Holocene and late Pleistocene environmental records. The latter research focuses on peat cores from New England and Oregon and fossil packrat middens from the southwestern United States. Modern transects highlight the sensitivity of Cupressaceae to climatic variables. These include both variables during growth (relative humidity, soil moisture, etc.) and variables affecting seasonal and diurnal growth rates (temperature, winter precipitation, insolation, microhabitat, etc.). Work on ancient records has demonstrated the sensitivity of these unique taxon-specific archives to both subtle and dramatic climate shifts during the Pleistocene and Holocene. This work will result in an improved understanding of climatic and physiological controls on the stable isotopic composition of modern and ancient Cupressaceae - and by extension, other arborescent gymnosperms and C3 plants - providing a framework for understanding more complexly sourced organic inputs to sediments, coals, and petroleum prior to the advent of C4 plants. This research also has direct implications for stratigraphic stable isotope studies of gymnosperm markers across the last millenium, the Pleistocene, and important climatic events in the Mesozoic and Tertiary.

Constraining Lipid Biomarker Paleoclimate Proxies in a Small Arctic Watershed

NASA Astrophysics Data System (ADS)

Dion-Kirschner, H.; McFarlin, J. M.; Axford, Y.; Osburn, M. R.

2017-12-01

Arctic amplification of climate change renders high-latitude environments unusually sensitive to changes in climatic conditions (Serreze and Barry, 2011). Lipid biomarkers, and their hydrogen and carbon isotopic compositions, can yield valuable paleoclimatic and paleoecological information. However, many variables affect the production and preservation of lipids and their constituent isotopes, including precipitation, plant growth conditions, biosynthesis mechanisms, and sediment depositional processes (Sachse et al., 2012). These variables are particularly poorly constrained for high-latitude environments, where trees are sparse or not present, and plants grow under continuous summer light and cool temperatures during a short growing season. Here we present a source-to-sink study of a single watershed from the Kangerlussuaq region of southwest Greenland. Our analytes from in and around `Little Sugarloaf Lake' (LSL) include terrestrial and aquatic plants, plankton, modern lake water, surface sediments, and a sediment core. This diverse sample set allows us to fulfill three goals: 1) We evaluate the production of lipids and isotopic signatures in the modern watershed in comparison to modern climate. Our data exhibit genus-level trends in leaf wax production and isotopic composition, and help clarify the difference between terrestrial and aquatic signals. 2) We evaluate the surface sediment of LSL to determine how lipid biomarkers from the watershed are incorporated into sediments. We constrain the relative contributions of terrestrial plants, aquatic plants, and other aquatic organisms to the sediment in this watershed. 3) We apply this modern source-to-sink calibration to the analysis of a 65 cm sediment core record. Our core is organic-rich, and relatively high deposition rates allow us to reconstruct paleoenvironmental changes with high resolution. Our work will help determine the veracity of these common paleoclimate proxies, specifically for research in southwest Greenland, and will enable an accurate, high-resolution watershed-level reconstruction of Holocene conditions. Serreze, M. and Barry, R. (2011). Global and Planetary Change, 77, 85-96. Sachse, D., et al. (2012). Annual Review of Earth and Planetary Sciences, 40, 221-249.

Pressure Sore at an Unusual Site- the Bilateral Popliteal Fossa: A Case report

PubMed Central

Kataria, Kamal; Sagar, Sushma; Singhal, Manish; Yadav, Rajni

2012-01-01

Pressure sore is tissue ulceration due to unrelieved pressure, altered sensory perception, and exposure to moisture. Geriatric patients with organic problems and patients with spinal cord injuries are the high-risk groups. Soft tissues over bony prominences are the common sites for ulcer development. About 95% of pressure ulcers occur in the lower part of the body. Ischial tuberosity, greater trochanter, sacrum and heel are common sites. In addition to these, pressure sores at unusual sites like nasal alae, malar eminences, cervical region and medial side of knee have also been described. Only 1.6% of the patients present with sores in areas outside the pelvis and lower extremity. In a paraplegic patient, pressure sores are usually over extensor surface of knee and heel but pressure ulcer over popliteal fossa are extremely rare. We herein report a case of a 36-years-old diabetic and paraplegic male, who presented with multiple bed sores involving the sacral area, heels and bilateral popliteal fossa. Popliteal fossa is an unusual site for pressure sores. Only one similar case has been previously reported in the literature. PMID:29181131

The hidden cost of organ sale.

PubMed

Rothman, S M; Rothman, D J

2006-07-01

The idea of establishing a market for organs is now the subject of unusual controversy. Proponents emphasize the concept of autonomy; opponents invoke fairness and justice. The controversy, however, has given sparse attention to what it would mean to society and medicine to establish a market in organs and to the intended and unintended consequences of such a practice. This article addresses these issues by exploring the tensions between 'extrinsic' and 'intrinsic' incentives, suggesting that donation might well decline were financial incentives introduced. It also contends that social relationship and social welfare policy would be transformed in negative ways and that a regulated market in organs would be extraordinarily difficult to achieve. Finally, it argues that organ sale would have a highly detrimental affect on medicine as a profession.

Distribution and enantiomeric composition of amino acids in the Murchison meteorite

NASA Technical Reports Server (NTRS)

Engel, M. H.; Nagy, B.

1982-01-01

Studies of the amino acid contents and enantiomeric compositions of a single stone from the Murchison meteorite are reported. Water-extracted and 6M HCl-extracted samples from the meteorite interior of meteorite fragments were analyzed by gas chromatography and combined gas chromatography-chemical ionization mass spectrometry. Examination of the D/L ratios of glutamic acid, aspartic acid, proline, leucine and alanine reveals those amino acids extractable by water to be partially racemized, whereas the acid-extracted amino acids were less racemized. The amino acid composition of the stone is similar to those previously reported, including the absence of serine, threonine, tyrosine phenylalanine and methionine and the presence of unusual amino acids including such as isovaline, alpha-aminoisobutyric acid and pseudoleucine. It is concluded that the most likely mechanism accounting for the occurrence of nonracemic amino acid mixtures in the Murchison meteorite is by extraterrestrial stereoselective synthesis or decomposition reactions.

Nacre-like calcium carbonate controlled by ionic liquid/graphene oxide composite template.

PubMed

Yao, Chengli; Xie, Anjian; Shen, Yuhua; Zhu, Jinmiao; Li, Hongying

2015-06-01

Nacre-like calcium carbonate nanostructures have been mediated by an ionic liquid (IL)-graphene oxide (GO) composite template. The resultant crystals were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and X-ray powder diffractometry (XRD). The results showed that either 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) or graphene oxide can act as a soft template for calcium carbonate formation with unusual morphologies. Based on the time-dependent morphology changes of calcium carbonate particles, it is concluded that nacre-like calcium carbonate nanostructures can be formed gradually utilizing [BMIM]BF4/GO composite template. During the process of calcium carbonate formation, [BMIM]BF4 acted not only as solvents but also as morphology templates for the fabrication of calcium carbonate materials with nacre-like morphology. Based on the observations, the possible mechanisms were also discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

The Shaw chondrite. I - The case of the missing metal

NASA Technical Reports Server (NTRS)

Rambaldi, E. R.; Larimer, J. W.

1976-01-01

The mineralogy as well as the elemental and isotopic composition of the Shaw meteorite indicate that it is a highly metamorphosed L-group chondrite which has lost a portion of its metal and sulfide. The metal which remains has an unusual composition relative to that in other L-group chondrites. It is enriched in Ga, Ge, Ir, Mo, Os, Pt, Re, and Ru but depleted in As, Au, Cu, and Sb. A comparison of the relative enrichments and depletions in Shaw with those observed in San Cristobal, the extreme end-member of group IAB iron meteorites, shows that the metal phases in these two meteorites have complementary compositions. This implies that the metal in Shaw represents the residual solid of a partial melting process while the missing metal, which drained away, may have gone to form an iron meteorite, like San Cristobal.

Phase stability and dynamics of entangled polymer-nanoparticle composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mangal, Rahul; Srivastava, Samanvaya; Archer, Lynden A.

Nanoparticle–polymer composites, or polymer–nanoparticle composites (PNCs), exhibit unusual mechanical and dynamical features when the particle size approaches the random coil dimensions of the host polymer. Here, we harness favourable enthalpic interactions between particle-tethered and free, host polymer chains to create model PNCs, in which spherical nanoparticles are uniformly dispersed in high molecular weight entangled polymers. Investigation of the mechanical properties of these model PNCs reveals that the nanoparticles have profound effects on the host polymer motions on all timescales. On short timescales, nanoparticles slow-down local dynamics of the host polymer segments and lower the glass transition temperature. On intermediate timescales,more » where polymer chain motion is typically constrained by entanglements with surrounding molecules, nanoparticles provide additional constraints, which lead to an early onset of entangled polymer dynamics. Finally, on long timescales, nanoparticles produce an apparent speeding up of relaxation of their polymer host.« less

Polyolefin-Based Aerogels

NASA Technical Reports Server (NTRS)

Lee, Je Kyun; Gould, George

2012-01-01

An organic polybutadiene (PB) rubberbased aerogel insulation material was developed that will provide superior thermal insulation and inherent radiation protection, exhibiting the flexibility, resiliency, toughness, and durability typical of the parent polymer, yet with the low density and superior insulation properties associated with the aerogels. The rubbery behaviors of the PB rubber-based aerogels are able to overcome the weak and brittle nature of conventional inorganic and organic aerogel insulation materials. Additionally, with higher content of hydrogen in their structure, the PB rubber aerogels will also provide inherently better radiation protection than those of inorganic and carbon aerogels. Since PB rubber aerogels also exhibit good hydrophobicity due to their hydrocarbon molecular structure, they will provide better performance reliability and durability as well as simpler, more economic, and environmentally friendly production over the conventional silica or other inorganic-based aerogels, which require chemical treatment to make them hydrophobic. Inorganic aerogels such as silica aerogels demonstrate many unusual and useful properties. There are several strategies to overcoming the drawbacks associated with the weakness and brittleness of silica aerogels. Development of the flexible fiber-reinforced silica aerogel composite blanket has proven one promising approach, providing a conveniently fielded form factor that is relatively robust toward handling in industrial environments compared to silica aerogel monoliths. However, the flexible silica aerogel composites still have a brittle, dusty character that may be undesirable, or even intolerable, in certain applications. Although the cross-linked organic aerogels such as resorcinol-formaldehyde (RF), polyisocyanurate, and cellulose aerogels show very high impact strength, they are also very brittle with little elongation (i.e., less rubbery). Also, silica and carbon aerogels are less efficient radiation shielding materials due to their lower content of hydrogen element. The present invention relates to maleinized polybutadiene (or polybutadiene adducted with maleic anhydride)- based aerogel monoliths and composites, and the methods for preparation. Hereafter, they are collectively referred to as polybutadiene aerogels. Specifically, the polybutadiene aerogels of the present invention are prepared by mixing a maleinized polybutadiene resin, a hardener containing a maleic anhydride reactive group, and a catalyst in a suitable solvent, and maintaining the mixture in a quiescent state for a sufficient period of time to form a polymeric gel. After aging at elevated temperatures for a period of time to provide uniformly stronger wet gels, the micro porous maleinized polybutadiene- based aerogel is then obtained by removing interstitial solvent by supercritical drying. The mesoporous maleinized polybutadiene-based aerogels contain an open-pore structure, which provides inherently hydrophobic, flexible, nearly unbreakable, less dusty aerogels with excellent thermal and physical properties. The materials can be used as thermal and acoustic insulation, radiation shielding, and vibration-damping materials. The organic PB-based rubber aerogels are very flexible, no-dust, and hydrophobic organics that demonstrated the following ranges of typical properties: densities of 0.08 to 0.255 grams per cubic centimeters, shrinkage factor (raerogel/rtarget) = 1.2 to 2.84, and thermal conductivity values of 20.0 to 35.0 mW/m-K.

Erysipelothrix rhusiopathiae endocarditis and presumed osteomyelitis

PubMed Central

Romney, Marc; Cheung, Stephen; Montessori, Valentina

2001-01-01

Erysipelothrix rhusiopathiae is known to cause infections in humans following exposure to decaying organic matter or animals colonized with the organism, such as swine and fish. Invasive infections with this organism are unusual and are manifested primarily as infective endocarditis. The present report is believed to be the first to report a case of E rhusiopathiae endocarditis and presumptive osteomyelitis. E rhusiopathiae appears to have intrinsic resistance to vancomycin. Because vancomycin is often used empirically for the treatment of endocarditis, rapid differentiation of E rhusiopathiae from other Gram-positive organisms is critical. In patients with endocarditis caused by a Gram-positive bacillus and epidemiological risk factors for E rhusiopathiae exposure, empirical treatment with vancomycin should be reconsidered. PMID:18159347

Erysipelothrix rhusiopathiae endocarditis and presumed osteomyelitis.

PubMed

Romney, M; Cheung, S; Montessori, V

2001-07-01

Erysipelothrix rhusiopathiae is known to cause infections in humans following exposure to decaying organic matter or animals colonized with the organism, such as swine and fish. Invasive infections with this organism are unusual and are manifested primarily as infective endocarditis. The present report is believed to be the first to report a case of E rhusiopathiae endocarditis and presumptive osteomyelitis. E rhusiopathiae appears to have intrinsic resistance to vancomycin. Because vancomycin is often used empirically for the treatment of endocarditis, rapid differentiation of E rhusiopathiae from other Gram-positive organisms is critical. In patients with endocarditis caused by a Gram-positive bacillus and epidemiological risk factors for E rhusiopathiae exposure, empirical treatment with vancomycin should be reconsidered.

Organic matter and the geotechnical properties of submarine sediments

NASA Astrophysics Data System (ADS)

Keller, George H.

1982-09-01

Continental slope deposits off Peru and Oregon where coastal upwelling is a pronounced oceanographic process possess significant concentrations of organic carbon. Geotechnical properties are altered to varying degrees by the organic matter. Organic matter absorbs water and causes clay-size particles to aggregate forming an open fabric. This causes unusually high water contents and plasticity and exceptionally low wet bulk densities. Some of these deposits show notable increases in shear strength, sensitivity and degree of apparent overconsolidation. Owing to the unique geotechnical properties, sediment stability characteristics are considered to be poor in situations of excess pore pressures. Failure appears to take the form of a fluidized flow somewhat similar to the quick clays of Scandinavia.

75 FR 61802 - Self-Regulatory Organizations; NASDAQ OMX PHLX LLC; Notice of Filing and Immediate Effectiveness...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-06

... replacing existing paragraph (a)(2)(C)(iv) of Rule 3312, entitled ``Numerical Guidelines Applicable to... Exchange to deviate from the Numerical Guidelines contained in paragraph (a)(2)(C)(i) when deciding which... Numerical Guidelines or Reference Prices in various ``Unusual Circumstances.'' The Exchange proposes to...

75 FR 36749 - Self-Regulatory Organizations; NYSE Amex LLC; Notice of Filing of Proposed Rule Change Amending...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-28

..., entitled ``Numerical Guidelines Applicable to Volatile Market Opens'' with a new paragraph, entitled... (g) of Rule 128 to eliminate the ability of the Exchange to deviate from the Numerical Guidelines... flexibility to the Exchange to use different Numerical Guidelines or Reference Prices in various ``Unusual...

Restoring native riparian vegetation

Treesearch

Debbie Hughes

1996-01-01

In the lower Pecos Basin, an unusual coalition of conservationists, agriculture producers, business owners, and state agencies have joined together to save what is left of the once-naturally diverse Pecos River ecosystem. This organization is going to show a state-of-the-art, economical, effective, efficient, and environmentally safe method to control salt cedar and...

Dream on: Visionary Educators and Their Big Ideas

ERIC Educational Resources Information Center

Waters, John K.

2010-01-01

It takes more than a vision to be called a visionary. One also needs the organization, determination, and spirit to see it through. Four educators are being chosen to be spotlighted as visionaries conceived, developed, and guided technology-driven initiatives perhaps initially thought to be impractical. But their unusual foresight allowed each of…

Unusual reversal of enantioselectivity in the proline-mediated alpha-amination of aldehydes induced by tertiary amine additives.

PubMed

Blackmond, Donna G; Moran, Antonio; Hughes, Matthew; Armstrong, Alan

2010-06-09

An intriguing reversal in product enantioselectivity accompanied by a change in the kinetic profile is observed in the alpha-amination of aldehydes catalyzed by proline in the presence of organic bases. Implications for the prevailing stereochemical models for proline and related aminocatalytic transformations are discussed.

Two Polymorphs of an Organic-Zincophosphate Incorporating a Terephthalate Bridging Ligand in an Unusual Bonding Mode.

PubMed

Wang, Chih-Min; Pan, Ming-Feng; Chen, Yen-Chieh; Lin, Hsiu-Mei; Chung, Mei-Ying; Wen, Yuh-Sheng; Lii, Kwang-Hwa

2017-07-17

Two new polymorphs of a zinc phosphate incorporating the terephthalate organic ligand 1,4-benzenedicarboxylate (BDC), (H 2 DA)Zn 2 (cis-BDC)(HPO 4 ) 2 (1) and (H 2 DA)Zn 2 (trans-BDC)(HPO 4 ) 2 (2), where DA = 1,7-diaminoheptane, were synthesized via a hydro(solvo)thermal method at different reaction temperatures and structurally characterized by single-crystal X-ray diffraction. Interestingly, the BDC ligands, which adopt the bis-monodentate coordination model with a unusual cis type for compound 1 and with a trans linkage for compound 2, bridge the Zn atoms of the inorganic layers in the generation of two polymorphs with structural diversities (one kind of arrangement of the layered zincophosphate layer in 1; the flat and zigzag sheets of inorganic networks in 2). A simple method for tuning the optical luminescence of the title compound from blue, red, green, yellow, and pink to white emission by stirring powdered samples in lanthanide-cation-containing aqueous ethanol solutions at room temperature for 1-2 h is also presented.

The Effect of Training in Visual Composition on Organization in Written Composition in Grade III.

ERIC Educational Resources Information Center

Tuttle, Frederick B., Jr.

The purpose of this investigation was to explore the possibility that one technique for improvement of organization in written composition might be instruction in the organizational process of another medium, such as sequencing photographs meaningfully. Two methods of improving organization in written composition were compared. The first was a…

Submarine seep of carbon dioxide in Norton Sound, Alaska

USGS Publications Warehouse

Kvenvolden, K.A.; Weliky, K.; Nelson, H.; Des Marais, D.J.

1979-01-01

Earlier workers have described a submarine gas seep in Norton Sound having an unusual mixture of petroleum-like, low-molecular-weight hydrocarbons. Actually, only about 0.04 percent of the seeping gas is hydrocarbons and 98 percent is carbon dioxide. The isotopic compositions of carbon dioxide (??13CPDB = -2.7 per mil) and methane (??13CPDB = -36 per mil, where PDB is the Peedee belemnite standard) indicate that geothermal processes are active here. Copyright ?? 1979 AAAS.

Degenerative minimalism in the genome of a psyllid endosymbiont.

PubMed

Clark, M A; Baumann, L; Thao, M L; Moran, N A; Baumann, P

2001-03-01

Psyllids, like aphids, feed on plant phloem sap and are obligately associated with prokaryotic endosymbionts acquired through vertical transmission from an ancestral infection. We have sequenced 37 kb of DNA of the genome of Carsonella ruddii, the endosymbiont of psyllids, and found that it has a number of unusual properties revealing a more extreme case of degeneration than was previously reported from studies of eubacterial genomes, including that of the aphid endosymbiont Buchnera aphidicola. Among the unusual properties are an exceptionally low guanine-plus-cytosine content (19.9%), almost complete absence of intergenic spaces, operon fusion, and lack of the usual promoter sequences upstream of 16S rDNA. These features suggest the synthesis of long mRNAs and translational coupling. The most extreme instances of base compositional bias occur in the genes encoding proteins that have less highly conserved amino acid sequences; the guanine-plus-cytosine content of some protein-coding sequences is as low as 10%. The shift in base composition has a large effect on proteins: in polypeptides of C. ruddii, half of the residues consist of five amino acids with codons low in guanine plus cytosine. Furthermore, the proteins of C. ruddii are reduced in size, with an average of about 9% fewer amino acids than in homologous proteins of related bacteria. These observations suggest that the C. ruddii genome is not subject to constraints that limit the evolution of other known eubacteria.

Isomers of hexadecenoic and hexadecadienoic acids in Androsace septentrionalis (Primulaceae) seed oil.

PubMed

Tsevegsuren, N; Aitzetmuller, K; Vosmann, K

2003-11-01

Seeds of Androsace septentrionalis of the genus Androsace (tribus Primuleae) from the plant family Primulaceae were studied for their oil content and FA composition. The seed oil of A. septentrionalis was found to contain two unusual FA rarely occurring in plants: 11-cis-hexadecenoic acid (16:1delta11c or 16:1n-5) and 9-cis,12-cis-hexadecadienoic acid (16:2delta9c,12c or 16:2n-4). It also contained an unusually high amount (21.4%) of 9-cis-hexadecenoic acid (palmitoleic acid; 16:1delta9c or 16:1n-7), i.e., at a level higher than that of oleic acid, in addition to common FA. Compared with most plant seed oils, at 3.8% the level of 18:1delta11c (or 18:1n-7) also was elevated. The nonidentity of the Androsace 16:2-acid with the 16:2-acid, which is very typical for Ranunculus spp., as well as its identity with the 16:2-acid typically found in Asclepiadaceae was established by co-chromatography. The structure and composition of the constituent FA of A. septentrionalis were also determined by various chromatographic methods (TLC, Ag+-TLC, capillary GLC) and spectroscopic methods (IR, GC-MS). The significant deviation of the Androsace FA pattern from that of other Primuleae, indicating a separate phylogenetic position of Androsace, is discussed.

H/L chondrite LaPaz Icefield 031047 - A feather of Icarus?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wittmann, Axel; Friedrich, Jon M; Troiano, Julianne

2011-10-28

Antarctic meteorite LAP 031047 is an ordinary chondrite composed of loosely consolidated chondritic fragments. Its petrography, oxygen isotopic composition and geochemical inventory are ambiguous and indicate an intermediate character between H and L chondrites. Petrographic indicators suggest LAP 031047 suffered a shock metamorphic overprint below ~10 GPa, which did not destroy its unusually high porosity of ~27 vol%. Metallographic textures in LAP 031047 indicate heating above ~700 °C and subsequent cooling, which caused massive transformation of taenite to kamacite. The depletion of thermally labile trace elements, the crystallization of chondritic glass to microcrystalline plagioclase of unusual composition, and the occurrencemore » of coarsely crystallized chondrule fragments is further evidence for post-metamorphic heating to ~700-750 °C. However, this heating event had a transient character because olivine and low-Ca pyroxene did not equilibrate. Nearly complete degassing up to very high temperatures is indicated by the thorough resetting of LAP 031047's Ar-Ar reservoir ~100 ± 55 Ma ago. A noble gas cosmic-ray exposure age indicates it was reduced to a meter-size fragment at <0.5 Ma. In light of the fact that shock heating cannot account for the thermal history of LAP 031047 in its entirety, we test the hypothesis that this meteorite belonged to the near-surface of an Aten or Apollo asteroid that underwent heating during orbital passages close to the Sun.« less

Watson: A new link in the IIE iron chain

NASA Technical Reports Server (NTRS)

Olsen, Edward; Davis, Andrew; Clarke, Roy S., Jr.; Schultz, Ludolf; Weber, Hartwig W.; Clayton, Robert; Mayeda, Toshiko; Jarosewich, Eugene; Sylvester, Paul; Grossman, Lawrence

1994-01-01

Watson, which was found in 1972 in South Australia, contains the largest single silicate rock mass seen in any known iron meteorite. A comprehensive study has been completed on this unusual meteorite: petrography, metallography, analyses of the silicate inclusion (whole rock chemical analysis, INAA, RNAA, noble gases, and oxygen isotope analysis) and mineral compositions (by electron microprobe and ion microprobe). The whole rock has a composition of an H-chondrite minus the normal H-group metal and troilite content. The oxygen isotope composition is that of the silicates in the IIE iron meteorites and lies along an oxygen isotope fractionation line with the H-group chondrites. Trace elements in the metal confirm Watson is a new IIE iron. Whole rock Watson silicate shows an enrichment in K and P (each approximately 2X H-chondrites). The silicate inclusion has a highly equilibrated igneous (peridotite-like) texture with olivine largely poikilitic within low-Ca pyroxene: olivine (Fa20), opx (Fs17Wo3), capx (Fs9Wo14)(with very fine exsolution lamellae), antiperthite feldspar (An1-3Or5) with less than 1 micron exsolution lamellae (An1-3Or greater than 40), shocked feldspar with altered stoichiometry, minor whitlockite (also a poorly characterized interstitial phosphate-rich phase) and chromite, and only traces of metal and troilite. The individual silicate minerals have normal chondritic REE patterns, but whitlockite has a remarkable REE pattern. It is very enriched in light REE (La is 720X C1, and Lu is 90X C1, as opposed to usual chonditic values of approximately 300X and 100-150X, respectively) with a negative Eu anomaly. The enrichment of whole rock K is expressed both in an unusually high mean modal Or content of the feldspar, Or13, and in the presence of antiperthite.

The ultrastructural basis of steroid production in the Y-organ and the mandibular organ of the crabs Hemigrapsus nudus (Dana) and Carcinus maenas L.

PubMed

Buchholz, C; Adelung, D

1980-01-01

The ultrastructure of the steroid producing Y-organ and the mandibular organ of the crustaceans Hemigrapsus nudus and Carcinus maenas has been studied with reference to the well investigated steroid secreting cells (SSC) of mammals. In accordance with the most important characteristic of mammalian SSC, abundant SER could be shown in the Y-organ, where it is unevenly distributed. The amount of SER seems to vary in correlation with the secretion of moulting hormone during the moult cycle. Most Y-organ cells contain a great number of mitochondria of the tubular type, another important characteristic of mammalian SSC. The ultrastructure of the mandibular organ of C. maenas differs considerably from that of the Y-organ. Some SER was found, mitochondria of unusual shape and size were conspicuous. No definite conclusion as to the function of the mandibular organ is yet to be drawn.

Mercury dilution by autochthonous organic matter in a fertilized mangrove wetland.

PubMed

Machado, Wilson; Sanders, Christian J; Santos, Isaac R; Sanders, Luciana M; Silva-Filho, Emmanoel V; Luiz-Silva, Wanilson

2016-06-01

A dated sediment core from a highly-fertilized mangrove wetland located in Cubatão (SE Brazil) presented a negative correlation between mercury (Hg) and organic carbon contents. This is an unusual result for a metal with well-known affinity to organic matter. A dilution of Hg concentrations by autochthonous organic matter explained this observation, as revealed by carbon stable isotopes signatures (δ(13)C). Mercury dilution by the predominant mangrove-derived organic matter counterbalanced the positive influences of algal-derived organic matter and clay contents on Hg levels, suggesting that deleterious effects of Hg may be attenuated. Considering the current paradigm on the positive effect of organic matter on Hg concentrations in coastal sediments and the expected increase in mangrove organic matter burial due to natural and anthropogenic stimulations of primary production, predictions on the influences of organic matter on Hg accumulation in mangrove wetlands deserve caution. Copyright © 2016 Elsevier Ltd. All rights reserved.

Organic containment separator

DOEpatents

Del Mar, Peter

1995-01-01

A process of sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium by (a) passing an initial aqueous medium including a minor amount of the organic contaminant through a composite tube including a polymeric base material selected from the group of polyolefins and polyfluorocarbons and particles of a carbon allotrope material adfixed to the inner wall of the polymeric base material, the composite tube having an internal diameter of from about 0.1 to about 2.0 millimeters and being of sufficient length to permit the organic contaminant to adhere to the composite tube, (b) passing a solvent through the composite tube, said solvent capable of separating the adhered organic contaminant from the composite tube. Further, an extraction apparatus for sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium, said apparatus including a composite tube including a polymeric base material selected from the group of polyolefins and polyfluorocarbons and particles of a carbon allotrope material adfixed to the inner wall of the polymeric base material, the composite tube having an internal diameter of from about 0.1 to about 2.0 millimeters and being of sufficient length to permit an organic contaminant contained within an aqueous medium passed therethrough to adhere to the composite tube is disclosed.

Organic contaminant separator

DOEpatents

Mar, Peter D.

1994-01-01

A process of sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium by (a) passing an initial aqueous medium including a minor amount of the organic contaminant through a composite tube including a polymeric base material selected from the group of polyolefins and polyfluorocarbons and particles of a carbon allotrope material adfixed to the inner wall of the polymeric base material, the composite tube having an internal diameter of from about 0.1 to about 2.0 millimeters and being of sufficient length to permit the organic contaminant to adhere to the composite tube, (b) passing a solvent through the composite tube, said solvent capable of separating the adhered organic contaminant from the composite tube. Further, an extraction apparatus for sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium, said apparatus including a composite tube including a polymeric base material selected from the group of polyolefins and polyfluorocarbons and particles of a carbon allotrope material adfixed to the inner wall of the polymeric base material, the composite tube having an internal diameter of from about 0.1 to about 2.0 millimeters and being of sufficient length to permit an organic contaminant contained within an aqueous medium passed therethrough to adhere to the composite tube is disclosed.

Neutron-rich nuclei in cosmic rays and Wolf-Rayet stars

NASA Technical Reports Server (NTRS)

Prantzos, N.; Arnould, M.; Arcoragi, J. P.; Casse, M.

1985-01-01

Wolf-Rayet stars figure prominently in astrophysical research. As a bonus, they seem to offer, in the recent past, an interesting connection between classical astronomy and high energy astrophysics due to their unusual composition and their huge mechanical power. The material flowing from WC stars (carbon-rich WR stars) contains gas which has been processed through core-helium burning, i.e., considerably enriched into 12C,16O, 22Ne, and 25,26Mg. This composition is reminiscent of the cosmic ray source anomalies. Encouraging agreement is obtained with observation in the mass range 12 A 26 assuming acceleration of wind particles at the shock that delineates the WR cavity, and adequate dilution with normal cosmic rays, but silicon poses.

Neutron-rich nuclei in cosmic rays and Wolf-Rayet stars

NASA Astrophysics Data System (ADS)

Prantzos, N.; Arcoragi, J. P.; Arnould, M.; Casse, M.

1985-08-01

Wolf-Rayet stars figure prominently in astrophysical research. As a bonus, they seem to offer, in the recent past, an interesting connection between classical astronomy and high energy astrophysics due to their unusual composition and their huge mechanical power. The material flowing from WC stars (carbon-rich WR stars) contains gas which has been processed through core-helium burning, i.e., considerably enriched into 12C,16O, 22Ne, and 25,26Mg. This composition is reminiscent of the cosmic ray source anomalies. Encouraging agreement is obtained with observation in the mass range 12 A 26 assuming acceleration of wind particles at the shock that delineates the WR cavity, and adequate dilution with normal cosmic rays, but silicon poses.

Magnetic domains and defects in ferromagnetic liquid crystal colloids realized with optical patterning

NASA Astrophysics Data System (ADS)

Hess, Andrew; Liu, Qingkun; Smalyukh, Ivan

A promising approach in designing composite materials with unusual physical behavior combines solid nanostructures and orientationally ordered soft matter at the mesoscale. Such composites not only inherit properties of their constituents but also can exhibit emergent behavior, such as ferromagnetic ordering of colloidal metal nanoparticles forming mesoscopic magnetization domains when dispersed in a nematic liquid crystal. Here we demonstrate the optical patterning of domain structures and topological defects in such ferromagnetic liquid crystal colloids which allows for altering their response to magnetic fields. Our findings reveal the nature of the defects in this soft matter system which is different as compared to non-polar nematic and ferromagnetic systems alike. This research was supported by the NSF Grant DMR-1420736.

Carbohydrate Metabolism in Archaea: Current Insights into Unusual Enzymes and Pathways and Their Regulation

PubMed Central

Esser, Dominik; Rauch, Bernadette

2014-01-01

SUMMARY The metabolism of Archaea, the third domain of life, resembles in its complexity those of Bacteria and lower Eukarya. However, this metabolic complexity in Archaea is accompanied by the absence of many “classical” pathways, particularly in central carbohydrate metabolism. Instead, Archaea are characterized by the presence of unique, modified variants of classical pathways such as the Embden-Meyerhof-Parnas (EMP) pathway and the Entner-Doudoroff (ED) pathway. The pentose phosphate pathway is only partly present (if at all), and pentose degradation also significantly differs from that known for bacterial model organisms. These modifications are accompanied by the invention of “new,” unusual enzymes which cause fundamental consequences for the underlying regulatory principles, and classical allosteric regulation sites well established in Bacteria and Eukarya are lost. The aim of this review is to present the current understanding of central carbohydrate metabolic pathways and their regulation in Archaea. In order to give an overview of their complexity, pathway modifications are discussed with respect to unusual archaeal biocatalysts, their structural and mechanistic characteristics, and their regulatory properties in comparison to their classic counterparts from Bacteria and Eukarya. Furthermore, an overview focusing on hexose metabolic, i.e., glycolytic as well as gluconeogenic, pathways identified in archaeal model organisms is given. Their energy gain is discussed, and new insights into different levels of regulation that have been observed so far, including the transcript and protein levels (e.g., gene regulation, known transcription regulators, and posttranslational modification via reversible protein phosphorylation), are presented. PMID:24600042

Following the Interstellar History of Carbon: From the Interiors of Stars to the Surfaces of Planets.

PubMed

Ziurys, L M; Halfen, D T; Geppert, W; Aikawa, Y

2016-12-01

The chemical history of carbon is traced from its origin in stellar nucleosynthesis to its delivery to planet surfaces. The molecular carriers of this element are examined at each stage in the cycling of interstellar organic material and their eventual incorporation into solar system bodies. The connection between the various interstellar carbon reservoirs is also examined. Carbon has two stellar sources: supernova explosions and mass loss from evolved stars. In the latter case, the carbon is dredged up from the interior and then ejected into a circumstellar envelope, where a rich and unusual C-based chemistry occurs. This molecular material is eventually released into the general interstellar medium through planetary nebulae. It is first incorporated into diffuse clouds, where carbon is found in polyatomic molecules such as H 2 CO, HCN, HNC, c-C 3 H 2 , and even C 60 + . These objects then collapse into dense clouds, the sites of star and planet formation. Such clouds foster an active organic chemistry, producing compounds with a wide range of functional groups with both gas-phase and surface mechanisms. As stars and planets form, the chemical composition is altered by increasing stellar radiation, as well as possibly by reactions in the presolar nebula. Some molecular, carbon-rich material remains pristine, however, encapsulated in comets, meteorites, and interplanetary dust particles, and is delivered to planet surfaces. Key Words: Carbon isotopes-Prebiotic evolution-Interstellar molecules-Comets-Meteorites. Astrobiology 16, 997-1012.

Fischer carbene mediated covalent grafting of a peptide nucleic acid on gold surfaces and IR optical detection of DNA hybridization with a transition metalcarbonyl label

NASA Astrophysics Data System (ADS)

Srivastava, Pratima; Ghasemi, Mahsa; Ray, Namrata; Sarkar, Amitabha; Kocabova, Jana; Lachmanova, Stepanka; Hromadova, Magdalena; Boujday, Souhir; Cauteruccio, Silvia; Thakare, Pramod; Licandro, Emanuela; Fosse, Céline; Salmain, Michèle

2016-11-01

Amine-reactive surfaces comprising N-hydroxysuccinimide ester groups as well as much more unusual Fischer alkoxymetallocarbene groups were generated on gold-coated surfaces via self-assembled monolayers of carboxy- and azido-terminated thiolates, respectively. These functions were further used to immobilize homothymine peptide nucleic acid (PNA) decamer in a covalent fashion involving the primary amine located at its N-terminus. These stepwise processes were monitored by polarization modulation reflection - absorption infrared spectroscopy (PM-RAIRS) that gave useful information on the molecular composition of the organic layers. PNA grafting and hybridization with complementary DNA strand were successfully transduced by quartz crystal microbalance (QCM) measurements. Unfortunately, attempts to transduce the hybridization optically by IR in a label-free fashion were inconclusive. Therefore we undertook to introduce an IR reporter group, namely a transition metalcarbonyl (TMC) entity at the 5‧ terminus of complementary DNA. Evidence for the formation of PNA-DNA heteroduplex was brought by the presence of ν(Ctbnd O) bands in the 2000 cm-1 region of the IR spectrum of the gold surface owing to the metalcarbonyl label.

Mushroom speleothems: Stromatolites that formed in the absence of phototrophs

NASA Astrophysics Data System (ADS)

Bontognali, Tomaso; D'Angeli, Ilenia; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano; Gonzales, Esteban; DeWaele, Jo

2016-04-01

Unusual speleothems resembling giant mushrooms occur in Santa Catalina Cave, Cuba. Although these mineral buildups are considered a natural heritage, their composition and formation mechanism remain poorly understood. Here we characterize their morphology and mineralogy and present a model for their genesis. We propose that the mushrooms, which are mainly comprised of calcite and aragonite, formed during four different phases within an evolving cave environment. The stipe of the mushroom is an assemblage of three well-known speleothems: a stalagmite surrounded by calcite rafts that were subsequently encrusted by cave clouds (mammilaries). More peculiar is the cap of the mushroom, which is morphologically similar to cerebroid stromatolites and thrombolites of microbial origin occurring in marine environments. Scanning electron microscopy investigations of this last unit revealed the presence of fossilized extracellular polymeric substances (EPS) - the constituents of biofilms and microbial mats. These organic microstructures are mineralized with Ca-carbonate, suggesting that the mushroom cap formed through a microbially-influenced mineralization process. The existence of cerebroid Ca-carbonate buildups forming in dark caves (i.e., in the absence of phototrophs) has interesting implications for the study of fossil microbialites preserved in ancient rocks, which are today considered as one of the earliest evidence for life on Earth.

The Arabidopsis DESPERADO/AtWBC11 Transporter Is Required for Cutin and Wax Secretion1[C][W

PubMed Central

Panikashvili, David; Savaldi-Goldstein, Sigal; Mandel, Tali; Yifhar, Tamar; Franke, Rochus B.; Höfer, René; Schreiber, Lukas; Chory, Joanne; Aharoni, Asaph

2007-01-01

The cuticle fulfills multiple roles in the plant life cycle, including protection from environmental stresses and the regulation of organ fusion. It is largely composed of cutin, which consists of C16-18 fatty acids. While cutin composition and biosynthesis have been studied, the export of cutin monomers out of the epidermis has remained elusive. Here, we show that DESPERADO (AtWBC11) (abbreviated DSO), encoding a plasma membrane-localized ATP-binding cassette transporter, is required for cutin transport to the extracellular matrix. The dso mutant exhibits an array of surface defects suggesting an abnormally functioning cuticle. This was accompanied by dramatic alterations in the levels of cutin monomers. Moreover, electron microscopy revealed unusual lipidic cytoplasmatic inclusions in epidermal cells, disappearance of the cuticle in postgenital fusion areas, and altered morphology of trichomes and pavement cells. We also found that DSO is induced by salt, abscisic acid, and wounding stresses and its loss of function results in plants that are highly susceptible to salt and display reduced root branching. Thus, DSO is not only essential for developmental plasticity but also plays a vital role in stress responses. PMID:17951461

The Arabidopsis DESPERADO/AtWBC11 transporter is required for cutin and wax secretion.

PubMed

Panikashvili, David; Savaldi-Goldstein, Sigal; Mandel, Tali; Yifhar, Tamar; Franke, Rochus B; Höfer, René; Schreiber, Lukas; Chory, Joanne; Aharoni, Asaph

2007-12-01

The cuticle fulfills multiple roles in the plant life cycle, including protection from environmental stresses and the regulation of organ fusion. It is largely composed of cutin, which consists of C(16-18) fatty acids. While cutin composition and biosynthesis have been studied, the export of cutin monomers out of the epidermis has remained elusive. Here, we show that DESPERADO (AtWBC11) (abbreviated DSO), encoding a plasma membrane-localized ATP-binding cassette transporter, is required for cutin transport to the extracellular matrix. The dso mutant exhibits an array of surface defects suggesting an abnormally functioning cuticle. This was accompanied by dramatic alterations in the levels of cutin monomers. Moreover, electron microscopy revealed unusual lipidic cytoplasmatic inclusions in epidermal cells, disappearance of the cuticle in postgenital fusion areas, and altered morphology of trichomes and pavement cells. We also found that DSO is induced by salt, abscisic acid, and wounding stresses and its loss of function results in plants that are highly susceptible to salt and display reduced root branching. Thus, DSO is not only essential for developmental plasticity but also plays a vital role in stress responses.

Homez, a homeobox leucine zipper gene specific to the vertebrate lineage.

PubMed

Bayarsaihan, Dashzeveg; Enkhmandakh, Badam; Makeyev, Aleksandr; Greally, John M; Leckman, James F; Ruddle, Frank H

2003-09-02

This work describes a vertebrate homeobox gene, designated Homez (homeodomain leucine zipper-encoding gene), that encodes a protein with an unusual structural organization. There are several regions within Homez, including three atypical homeodomains, two leucine zipper-like motifs, and an acidic domain. The gene is ubiquitously expressed in human and murine tissues, although the expression pattern is more restricted during mouse development. Genomic analysis revealed that human and mouse genes are located at 14q11.2 and 14C, respectively, and are composed of two exons. The zebrafish and pufferfish homologs share high similarity to mammalian sequences, particularly within the homeodomain sequences. Based on homology of homeodomains and on the similarity in overall protein structure, we delineate Homez and members of ZHX family of zinc finger homeodomain factors as a subset within the superfamily of homeobox-containing proteins. The type and composition of homeodomains in the Homez subfamily are vertebrate-specific. Phylogenetic analysis indicates that Homez lineage was separated from related genes >400 million years ago before separation of ray- and lobe-finned fishes. We apply a duplication-degeneration-complementation model to explain how this family of genes has evolved.

Controls on porphyrin concentrations of Pennsylvanian organic-rich shales, Western U.S.A.

USGS Publications Warehouse

Clayton, J.L.; Michael, G.E.

1990-01-01

Organic-rich black shales of Middle Pennsylvanian (Desmoinesian) age occur over much of the central U.S. and as far west as the northern Denver and southeastern Powder River basins. Total organic carbon contents (Corg) are commonly greater than 10 wt %. Porphyrin concentrations (vanadyl + nickel) are as high as 40000 ppm relative to extractable bitumen. In bulk, the organic matter contained in the shales is mostly type II and III (Rock-Eval hydrogen indexes 200-400 mg of hydrocarbons/g of Corg). The finding of high porphyrin concentrations in type III organic matter is unusual but can be explained by a depositional model wherein high preservation of primary organic production (water column photosynthesis) is combined with substantial input of allochthonous organic matter. The allochthonous organic matter (low porphyrin concentration) may come from erosion during advance of the sea across the area or from fluvial transport from shore.

Fluid inclusions in quartz crystals from South-West Africa

USGS Publications Warehouse

Kvenvolden, K.A.; Roedder, E.

1971-01-01

Quartz crystals from calcite veins of unknown age in Precambrian metasedimentary rocks at Geiaus No. 6 and Aukam farms in South-West Africa contain both primary and secondary inclusions filled with one or a variable combination of: organic liquid, moderately saline aqueous liquid, dark-colored solid, and vapor. Analysis of these materials by microscopy and by gas chromatography and mass spectrometry shows the presence of constituents of both low and high molecular weights. The former include CH4, C2H6, C3H8 and possibly C4H10 as well as CO, CO2, H2O, N2 and H2. High molecular weight components are dominantly n-alkanes and isoprenoid hydrocarbons. The n-alkanes range from at least n-C10 to n-C33. Concentrations of n-alkanes larger than n-C17 decrease regularly with increasing carbon number. An homologous series of isoprenoid hydrocarbons ranging from at least C14 to C20 is present in unusually high concentrations. Pristane (C19) is most abundant, and C17 isoprenoid is least abundant. The molecular composition and distribution of hydrocarbons suggest biological precursors for these components. Consideration of data provided by freezing, crushing and heating experiments suggests that the pressures at the time these in part supercritical fluids were trapped probably exceeded 30-40 atm, and the minimum trapping temperature was about 120-160??C. Both primary and secondary inclusions apparently containing only organic materials were trapped by the growth of the host quartz from aqueous solution. The data obtained neither prove nor preclude Precambrian, Paleozoic or younger sources for the organic materials. ?? 1971.

Occurrence and forms of Kranz anatomy in photosynthetic organs and characterization of NAD-ME subtype C4 photosynthesis in Blepharis ciliaris (L.) B. L. Burtt (Acanthaceae).

PubMed

Akhani, Hossein; Ghasemkhani, Maraym; Chuong, Simon D X; Edwards, Gerald E

2008-01-01

Blepharis (Acanthaceae) is an Afroasiatic genus comprising 129 species which occur in arid and semi-arid habitats. This is the only genus in the family which is reported to have some C(4) species. Blepharis ciliaris (L.) B. L. Burtt. is a semi-desert species with distribution in Iran, Oman, and Pakistan. Its form of photosynthesis was investigated by studying different organs. C(4)-type carbon isotope composition, the presence of atriplicoid type Kranz anatomy, and compartmentation of starch all indicate performance of C(4) photosynthesis in cotyledons, leaves, and the lamina part of bracts. A continuous layer of distinctive bundle sheath cells (Kranz cells) encircle the vascular bundles in cotyledons and the lateral vascular bundles in leaves. In older leaves, there is extensive development of ground tissue in the midrib and the Kranz tissue becomes interrupted on the abaxial side, and then becomes completely absent in the mature leaf base. Cotyledons have 5-6 layers, and leaves 2-3 layers, of spongy chlorenchyma beneath the veins near the adaxial side of the leaf, indicating bifacial organization of chlorenchyma. As the plant matures, bracts and spines develop and contribute to carbon assimilation through an unusual arrangement of Kranz anatomy which depends on morphology and exposure to light. Stems do not contribute to carbon assimilation, as they lack chlorenchyma tissue and Kranz anatomy. Analysis of C(4) acid decarboxylases by western blot indicates B. ciliaris is an NAD-malic enzyme type C(4) species, which is consistent with the Kranz cells having chloroplasts with well-developed grana and abundant mitochondria.

Self-assembled hierarchically structured organic-inorganic composite systems.

PubMed

Tritschler, Ulrich; Cölfen, Helmut

2016-05-13

Designing bio-inspired, multifunctional organic-inorganic composite materials is one of the most popular current research objectives. Due to the high complexity of biocomposite structures found in nacre and bone, for example, a one-pot scalable and versatile synthesis approach addressing structural key features of biominerals and affording bio-inspired, multifunctional organic-inorganic composites with advanced physical properties is highly challenging. This article reviews recent progress in synthesizing organic-inorganic composite materials via various self-assembly techniques and in this context highlights a recently developed bio-inspired synthesis concept for the fabrication of hierarchically structured, organic-inorganic composite materials. This one-step self-organization concept based on simultaneous liquid crystal formation of anisotropic inorganic nanoparticles and a functional liquid crystalline polymer turned out to be simple, fast, scalable and versatile, leading to various (multi-)functional composite materials, which exhibit hierarchical structuring over several length scales. Consequently, this synthesis approach is relevant for further progress and scientific breakthrough in the research field of bio-inspired and biomimetic materials.

The Nature and Origin of Aromatic Organic Matter in the Tagish Lake Meteorite

NASA Technical Reports Server (NTRS)

Clemett, S. J.; Keller, L. P.; Nakamura, K.; McKay, D. S.

2004-01-01

The Tagish Lake meteorite is an unusual carbonaceous chondrite that does not fit well within existing chondrite taxonomy. Bulk analyses suggest approx. 5 wt.% C of which approx. 1 wt.% is in the form of organic matter and the remainder is present as inorganic carbonate. The exact nature and form of this organic component is, as is the case with the other ordinary and carbonaceous chondrites, still poorly understood. Yet its significance has far reaching implications, from contributing to the abiotic evolution of the early Earth and Mars, to providing geothermal constraints in the evolution of the Solar nebula.

Studying brain organization via spontaneous fMRI signal

PubMed Central

Power, Jonathan D; Schlaggar, Bradley L; Petersen, Steven E

2014-01-01

In recent years, some substantial advances in understanding human (and non-human) brain organization have emerged from a relatively unusual approach: the observation of spontaneous activity, and correlated patterns in spontaneous activity, in the “resting” brain. Most commonly, spontaneous neural activity is measured indirectly via fMRI signal in subjects who are lying quietly in the scanner, the so-called “resting state”. This Primer introduces the fMRI-based study of spontaneous brain activity, some of the methodological issues active in the field, and some ways in which resting state fMRI has been used to delineate aspects of area-level and supra-areal brain organization. PMID:25459408

Signs of Life on Venus

NASA Astrophysics Data System (ADS)

Ksanfomality, L.

2012-04-01

The search for "habitable zones" in extrasolar planetary systems is based on the premise of "normal" physical conditions in a habitable zone, i.e. pressure, temperature range, and atmospheric composition similar to those on the Earth. However, one should not exclude completely the possibility of the existence of life at relatively high temperatures, despite the fact that at the first glance it seems impossible. The planet Venus with its dense, hot (735 K), oxigenless CO2 - atmosphere and high 92 bar-pressure at the surface could be the natural laboratory for the studies of this type. Amid exoplanets, celestial bodies with the physical conditions similar to the Venusian can be met. The only existing data of actual close-in observations of Venus' surface are the results of a series of missions of the soviet VENERA landers which took place the 1970's and 80's in the atmosphere and on the surface of Venus. For 36 and 29 years since these missions, respectively, I repeatedly returned to the obtained images of the Venus' surface in order to reveal on them any unusual objects observed in the real conditions of Venus. The new analysis of the Venus' panoramas was based on the search of unusual elements in two ways. Since the efficiency of the VENERA landers maintained for a long time they produced a large number of primary television panoramas during the lander's work. Thus, one can try to detect: (a) any differences in successive images (appearance or disappearance of parts of the image or change of their shape), and understand what these changes are related to (e.g., wind), and whether they are related to hypothetical habitability of a planet. Another sign (b) of the wanted object is their morphological peculiarities which distinguishes them from the ordinary surface details. The results of VENERA-9 (1975) and VENERA -13 (1982) are of the main interest. A few relatively large objects ranging from a decimeter to half meter and with unusual morphology were observed in some images, but were absent in the other or altered their shape. What sources of energy, in principle, could be used by life in the high temperature oxigenless atmosphere? The objects found are large enough, they are not micro-organisms. It is most natural to assume that, like on Earth, Venusian fauna is heterotrophic, and the source of its life is hypothetical autotrophic flora. There is enough light for flora's photosynthesis. Since the critical temperature of water on Venus is about 320°C and the temperature at the surface is about 460°C, the metabolism of organisms on Venus (if any) should be built without water, on the basis of some other liquid medium. Based on data analyzed it has been suggested that because of the limited energy capacity of the Venusian fauna, the temporal characteristics of their physical actions can be much longer than that of the Earth.

Unusual Presentation of Hydatidosis - Neck Lump Causing Costo-Vertebral Erosion.

PubMed

Alam, Mehtab; Hasan, Syed-Abrar; Hashmi, Shahab-Farkhund

2016-09-01

Hydatid disease caused by larval stage of Echinococcus has been recognized endemically in many countries. Liver and lungs are the most commonly affected organs. Involvement of the head and neck region is rare and bony erosion due to hydatidosis is even rarer. We report a case of a 17-year-old girl from a poor socio-economic background who presented with a right sided supraclavicular lump, which after surgical excision and histopathological examination was diagnosed as hydatid cyst of neck. Because of its rarity in the neck region, primary diagnosis of hydatid cyst is overlooked and usually not included in the differential diagnosis of cystic neck swellings. A high index of suspicion is necessary to diagnose hydatid disease in an unusual location even in endemic areas.

Unusual Presentation of Hydatidosis - Neck Lump Causing Costo-Vertebral Erosion

PubMed Central

Alam, Mehtab; Hasan, Syed-Abrar; Hashmi, Shahab-Farkhund

2016-01-01

Introduction: Hydatid disease caused by larval stage of Echinococcus has been recognized endemically in many countries. Liver and lungs are the most commonly affected organs. Involvement of the head and neck region is rare and bony erosion due to hydatidosis is even rarer. Case Report: We report a case of a 17-year-old girl from a poor socio-economic background who presented with a right sided supraclavicular lump, which after surgical excision and histopathological examination was diagnosed as hydatid cyst of neck. Conclusion: Because of its rarity in the neck region, primary diagnosis of hydatid cyst is overlooked and usually not included in the differential diagnosis of cystic neck swellings. A high index of suspicion is necessary to diagnose hydatid disease in an unusual location even in endemic areas. PMID:27738614

Identification of the infectious source of an unusual outbreak of histoplasmosis, in a hotel in Acapulco, state of Guerrero, Mexico.

PubMed

Taylor, Maria Lucia; Ruíz-Palacios, Guillermo M; del Rocío Reyes-Montes, María; Rodríguez-Arellanes, Gabriela; Carreto-Binaghi, Laura E; Duarte-Escalante, Esperanza; Hernández-Ramírez, Aurora; Pérez, Armando; Suárez-Alvarez, Roberto O; Roldán-Aragón, Yuri A; Romero-Martínez, Rafael; Sahaza-Cardona, Jorge H; Sifuentes-Osornio, José; Soto-Ramírez, Luis E; Peña-Sandoval, Gabriela R

2005-09-01

Three isolates of Histoplasma capsulatum were identified from mice lung, liver, and spleen inoculated with soil samples of the X hotel's ornamental potted plants that had been fertilized with organic material known as compost. The presence of H. capsulatum in the original compost was detected using the dot-enzyme-linked immunosorbent assay. Nested-PCR, using a specific protein Hcp100 coding gene sequence, confirmed the fungal identification associated with an unusual histoplasmosis outbreak in Acapulco. Although, diversity between the H. capsulatum isolate from the hotel and some clinical isolates from Guerrero (positive controls) was observed using random amplification of polymorphic DNA based-PCR, sequence analyses of H-anti and ole fragment genes revealed a high homology (92-99%) between them.

Photopolarimetric observations of the minor planet Flora.

NASA Technical Reports Server (NTRS)

Veverka, J.

1971-01-01

Review of the rotation period, phase coefficients, and polarization curve of the unusual asteroid Flora. It is an almost spherical asteroid whose period of rotation is probably 13.6 h, but may be only one half of this. Its surface layer consists of a dark material resembling lunar surface soil, but since the polarization curves of Flora and the moon, though generally similar, are not identical the surface of Flora must differ somewhat either in composition or in texture from that of the moon.

Neutrino Background from Population III Stars

NASA Astrophysics Data System (ADS)

Iocco, Fabio

2011-12-01

Population III Stars (PopIII) are the first generation of stars formed from the collapse of the very first structures in the Universe. Their peculiar chemical composition (metal-free, resembling the Primordial Nucleosynthesis yields) affects their formation and evolution and makes them unusually big and hot stars. They are good candidates for the engines of Reionization of the Universe although their direct observation is extremely difficult. Here we summarize a study of their expected diffuse low-energy neutrino background flux at Earth.

Trace Element Abundances in an Unusual Hibonite-Perovskite Refractory Inclusion from Allende

NASA Technical Reports Server (NTRS)

Mane, Prajkta; Wadhwa, M.; Keller, L. P.

2013-01-01

Calcium-aluminum-rich refractory inclusions (CAIs) are thought to be the first-formed solids in the Solar protoplanetary disk and can provide information about the earliest Solar System processes (e.g., [1]). A hibonite-perovskitebearing CAI from the Allende CV3 chondrite (SHAL, [2]) contains a single of 500 micrometers hibonite grain and coarse-grained perovskite. The mineralogy and oxygen isotopic composition of this CAI shows similarities with FUN inclusions, especially HAL [2]. Here we present trace element abundances in SHAL.

The Crystal Structure of Thorium and Zirconium Dihydrides by X-ray and Neutron Diffraction

DOE R&D Accomplishments Database

Rundle, R.E.; Shull, C.G.; Wollan, E.O.

1951-04-20

Thorium forms a tetragonal lower hydride of composition ThH{sub 2}. The hydrides ThH{sub 2}, ThD{sub 2}, and ZrD{sub 2} have been studied by neutron diffraction in order that hydrogen positions could be determined. The hydrides are isomorphous, and have a deformed fluorite structure. Metal-hydrogen distances in thorium hydride are unusually large, as in UH{sub 3}. Thorium and zirconium scattering amplitudes and a revised scattering amplitude for deuterium are reported.

Growth of textured thin Au coatings on iron oxide nanoparticles with near infrared absorbance

PubMed Central

Ma, L L; Borwankar, A U; Willsey, B W; Yoon, K Y; Tam, J O; Sokolov, K V; Feldman, M D; Milner, T E; Johnston, K P

2013-01-01

A homologous series of Au-coated iron oxide nanoparticles, with hydrodynamic diameters smaller than 60 nm was synthesized with very low Auto-iron mass ratios as low as 0.15. The hydrodynamic diameter was determined by dynamic light scattering and the composition by atomic absorption spectroscopy and energy dispersive x-ray spectroscopy (EDS). Unusually low Au precursor supersaturation levels were utilized to nucleate and grow Au coatings on iron oxide relative to formation of pure Au nanoparticles. This approach produced unusually thin coatings, by lowering autocatalytic growth of Au on Au, as shown by transmission electron microscopy (TEM). Nearly all of the nanoparticles were attracted by a magnet indicating a minimal amount of pure Au particles The coatings were sufficiently thin to shift the surface plasmon resonance (SPR) to the near infrared (NIR), with large extinction coefficients., despite the small particle hydrodynamic diameters, observed from dynamic light scattering to be less than 60 nm. PMID:23238021

Mineralogy and petrography of HAL, an isotopically-unusual Allende inclusion

NASA Technical Reports Server (NTRS)

Allen, J. M.; Grossman, L.; Lee, T.; Wasserburg, G. J.

1980-01-01

Results of a detailed mineralogical and textural study of the HAL (Hibonite ALlende) inclusion of the Allende meteorite, which has been found to exhibit no Mg-26 excesses despite very high Al-27/Mg-24 ratios and large fractionation effects with small nuclear effects in its Ca, are reported. The inclusion is found to consist of three up to 1-mm diameter hibonite crystals partially surrounded by a black rim resembling a devitrified glass and containing an anisotropic Al-Fe oxide, which is in turn surrounded by a 2-mm thick friable rim sequence consisting of five layers distinguishable by mineral composition. From the available evidence, it is concluded that each of the layers of the friable rim formed by the accretion of an assemblage of condensate grains rather than by the complete reaction of a HAL precursor with a nebular gas, thus explaining its unusual isotopic characteristics and supporting the conclusion that the solar nebular contained isotopically-distinct reservoirs.

The biosynthesis of nitrogen-, sulfur-, and high-carbon chain-containing sugars.

PubMed

Lin, Chia-I; McCarty, Reid M; Liu, Hung-wen

2013-05-21

Carbohydrates serve many structural and functional roles in biology. While the majority of monosaccharides are characterized by the chemical composition (CH2O)n, modifications including deoxygenation, C-alkylation, amination, O- and N-methylation, which are characteristic of many sugar appendages of secondary metabolites, are not uncommon. Interestingly, some sugar molecules are formed via modifications including amine oxidation, sulfur incorporation, and "high-carbon" chain attachment. Most of these unusual sugars have been identified over the past several decades as components of microbially produced natural products, although a few high-carbon sugars are also found in the lipooligosaccharides of the outer cell walls of Gram-negative bacteria. Despite their broad distribution in nature, these sugars are considered "rare" due to their relative scarcity. The biosynthetic steps that underlie their formation continue to perplex researchers to this day and many questions regarding key transformations remain unanswered. This review will focus on our current understanding of the biosynthesis of unusual sugars bearing oxidized amine substituents, thio-functional groups, and high-carbon chains.

Review of sn-2 palmitate oil implications for infant health.

PubMed

Bar-Yoseph, Fabiana; Lifshitz, Yael; Cohen, Tzafra

2013-09-01

Human milk provides the optimal balanced nutrition for the growing infant in the first months after birth. The human mammary gland has evolved with unusual pathways, resulting in a specific positioning of fatty acids at the outer sn-1 and sn-3, and center sn-2 of the triacylglyceride, which is different from the triglycerides in other human tissues and plasma. The development of structured triglycerides enables mimicking the composition as well as structure of human milk fat in infant formulas. Studies conducted two decades ago, together with very recent studies, have provided increasing evidence that this unusual positioning of 16:0 in human milk triglycerides has a significant role for infant health in different directions, such as fat and calcium absorption, bone health, intestinal flora and infant comfort. This review aims to unravel the relevance of human milk triglyceride sn-2 16:0 for intestinal health and inflammatory pathways and for other post-absorption effects. Copyright © 2013 Elsevier Ltd. All rights reserved.

75 FR 36752 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing of a Proposed Rule Change...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-28

... Securities.'' Second, the Exchange is replacing existing paragraph (C)(4) of Rule 11890, entitled ``Numerical... the ability of the Exchange to deviate from the Numerical Guidelines contained in paragraph (C)(1... flexibility to the Exchange to use different Numerical Guidelines or Reference Prices in various ``Unusual...

Yersinia enterocolitica Outbreak Associated with Ready-to-Eat Salad Mix, Norway, 2011

PubMed Central

Heier, Berit Tafjord; Nygård, Karin; Stalheim, Torunn; Cudjoe, Kofitsyo S.; Skjerdal, Taran; Wester, Astrid Louise; Lindstedt, Bjørn-Arne; Stavnes, Trine-Lise; Vold, Line

2012-01-01

In 2011, an outbreak of illness caused by Yersinia enterocolitica O:9 in Norway was linked to ready-to-eat salad mix, an unusual vehicle for this pathogen. The outbreak illustrates the need to characterize isolates of this organism, and reinforces the need for international traceback mechanisms for fresh produce. PMID:22932318

Ingressive Speech Errors: A Service Evaluation of Speech-Sound Therapy in a Child Aged 4;6

ERIC Educational Resources Information Center

Hrastelj, Laura; Knight, Rachael-Anne

2017-01-01

Background: A pattern of ingressive substitutions for word-final sibilants can be identified in a small number of cases in child speech disorder, with growing evidence suggesting it is a phonological difficulty, despite the unusual surface form. Phonological difficulty implies a problem with the cognitive process of organizing speech into sound…

Oral purpura as the first manifestation of primary systemic amyloidosis.

PubMed

McCormick, Robert Stuart; Sloan, Philip; Farr, David; Carrozzo, Marco

2016-07-01

Oral blood blisters and purpura are rare features of primary systemic amyloidosis (amyloid light-chain (AL) amyloidosis). We report a case in which these unusual presentations led to a diagnosis of amyloidosis, which enabled effective treatment before organ failure. Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Effects of short-range order on electronic properties of Zr-Ni glasses as seen from low-temperature specific heat

NASA Astrophysics Data System (ADS)

Kroeger, D. M.; Koch, C. C.; Scarbrough, J. O.; McKamey, C. G.

1984-02-01

Measurements of the low-temperature specific heat Cp of liquid-quenched Zr-Ni glasses for a large number of compositions in the range from 55 to 74 at.% Zr revealed an unusual composition dependence of the density of states at the Fermi level, N(EF). Furthermore, for some compositions the variation of Cp near the superconducting transition temperature Tc indicated the presence of two superconducting phases, i.e., two superconducting transitions were detected. Comparison of the individual Tc's in phase-separated samples to the composition dependence of Tc for all of the samples suggests that amorphous phases with compositions near 60 and 66.7 at.% Zr occur. We discuss these results in terms of an "association model" for liquid alloys (due to Sommer), in which associations of unlike atoms with definite stoichiometries are assumed to exist in equilibrium with unassociated atoms. We conclude that in the composition range studied, associate clusters with the compositions Zr3Ni2 and Zr2Ni occur. In only a few cases are the clusters sufficiently large, compared with the superconducting coherence length, for separate superconducting transitions to be observed. The variation of N(EF) with composition is discussed, as well as the effects of this chemical short-range ordering on the crystallization behavior and glass-forming tendency.

Improved lifetime of new fibrous carbon/ceramic composites

NASA Astrophysics Data System (ADS)

Gumula, Teresa

2018-03-01

New carbon/ceramic composites have been synthesized from low-cost phenol-formaldehyde resin and polysiloxane preceram. A reference carbon composite reinforced with carbon fibre (CC composite) is obtained in first place from a carbon fibre roving impregnated with a solution of phenol-formaldehyde resin in isopropyl alcohol. To obtain fibrous carbon/ceramic composites the CC perform is impregnated with polymethylphenylsiloxane polymer and then a thermal treatment in an inert atmosphere is applied. Depending on the temperature of this process, the resulting ceramics can be silicon carbide (SiC) or silicon oxycarbide (SiCO). Three representative samples, named CC/SiCO( a) (obtained at 1000 °C), CC/SiCO( b) (1500 °C) and CC/SiC (1700 °C), have been tested for fatigue behaviour and oxidation resistance. The value of the Young's modulus remains constant in fatigue tests done in flexion mode for the three new composites during a high number of cycles until sudden degradation begins. This is an unusual and advantageous characteristic for this type of materials and results in the absence of delamination during the measurements. In contrast, the CC reference composite shows a progressive degradation of the Young's modulus accompanied by delamination. SEM micrographs revealed that the formation of filaments of submicrometer diameter during the heat treatment can be responsible for the improved behaviour of these composites. The CC/SiC composite shows the best oxidation resistance among the three types of composites, with a 44% mass loss after 100 h of oxidation.

Chlorine-resistant composite membranes with high organic rejection

DOEpatents

McCray, Scott B.; Friesen, Dwayne T.; Barss, Robert P.; Nelson, Leslie D.

1996-01-01

A method for making a chlorine-resistant composite polyamide membrane having high organic rejection, the essential step of which comprises treating a conventional composite membrane with an acyl halide. The novel membrane is especially suitable for the treatment of water containing chlorine or lower molecular weight organic compounds.

Extra-adrenal pheochromocytoma: an unusual cause of deep vein thrombosis.

PubMed

Stevenson, Susan; Ramani, Vijay; Nasim, Akhtar

2005-09-01

We report a case of extra-adrenal pheochromocytoma within the organ of Zuckerkandl that presented initially with a left iliofemoral deep venous thrombosis (DVT). At the time of presentation, the DVT was thought to be idiopathic as no underlying cause was detected. Subsequently, because of a series of medical events, the patient was further investigated. This led to a diagnosis of extra-adrenal pheochromocytoma. We discuss the management of patients presenting with DVT, the nature of pheochromocytoma within the organ of Zuckerkandl, and problems relating to its diagnosis.

Group B streptococcal metastatic endophthalmitis.

PubMed

Nagelberg, H P; Petashnick, D E; To, K W; Woodcome, H A

1994-04-15

Reports of invasive Group B Streptococcus infection in adults with underlying medical conditions have been increasing. Ocular infection with this organism is unusual. Metastatic endophthalmitis in adults caused by this organism has been reported rarely and has only been associated with endocarditis. We encountered two cases of Group B streptococcal metastatic endophthalmitis in adults who did not have endocarditis. These cases reflect the increasing incidence of invasive Group B Streptococcus infection with its varying manifestations. Additionally, they emphasize the importance of considering this pathogen as a cause of metastatic endophthalmitis in adults with predisposing illnesses.

Self-organized minimum-energy structures for dielectric elastomer actuators

NASA Astrophysics Data System (ADS)

Kofod, G.; Paajanen, M.; Bauer, S.

2006-11-01

When a stretched elastomer is laminated to a flat plastic frame, a complex shape is formed, which is termed a minimum-energy structure. It is shown how self-organized structures can be applied in the development of actuators with complex, out-of-plane actuationmodes. This unusual concept is then demonstrated in the case of dielectric elastomer actuators. Among advantages of this approach are the simplicity in manufacturing, the potential complexity and sophistication of the manufactured structures, and the general benefits of the concept when applied to other electro-mechanically active materials.

Thiophene-based covalent organic frameworks

PubMed Central

Bertrand, Guillaume H. V.; Michaelis, Vladimir K.; Ong, Ta-Chung; Griffin, Robert G.; Dincă, Mircea

2013-01-01

We report the synthesis and characterization of covalent organic frameworks (COFs) incorporating thiophene-based building blocks. We show that these are amenable to reticular synthesis, and that bent ditopic monomers, such as 2,5-thiophenediboronic acid, are defect-prone building blocks that are susceptible to synthetic variations during COF synthesis. The synthesis and characterization of an unusual charge transfer complex between thieno[3,2-b]thiophene-2,5-diboronic acid and tetracyanoquinodimethane enabled by the unique COF architecture is also presented. Together, these results delineate important synthetic advances toward the implementation of COFs in electronic devices. PMID:23479656

Examining Archean methanotrophy

NASA Astrophysics Data System (ADS)

Slotznick, Sarah P.; Fischer, Woodward W.

2016-05-01

The carbon isotope ratios preserved in sedimentary rocks can be used to fingerprint ancient metabolisms. Organic carbon in Late Archean samples stands out from that of other intervals with unusually low δ13C values (∼-45 to -60‰). It was hypothesized that these light compositions record ecosystem-wide methane cycling and methanotrophy, either of the aerobic or anaerobic variety. To test this idea, we studied the petrography and carbon and oxygen isotope systematics of well-known and spectacular occurrences of shallow water stromatolites from the 2.72 Ga Tumbiana Formation of Western Australia. We examined the carbonate cements and kerogen produced within the stromatolites, because methanotrophy is expected to leave an isotopic fingerprint in these carbon reservoirs. Mathematical modeling of Archean carbonate chemistry further reveals that methanotrophy should still have a discernible signature preserved in the isotopic record, somewhat diminished from those observed in Phanerozoic sedimentary basins due to higher dissolved inorganic carbon concentrations. These stromatolites contain kerogen with δ13Corg values of ∼ - 50 ‰. By microsampling different regions and textures within the stromatolites, we determined that the isotopic compositions of the authigenic calcite cements show a low degree of variation and are nearly identical to values estimated for seawater at this time; the lack of low and variable δ13Ccarb values implies that methanotrophy does not explain the low δ13Corg seen in the coeval kerogen. These observations do not support a methanotrophy hypothesis, but instead hint that the Late Archean may constitute an interval wherein autotrophs employed markedly different biochemical processes of energy conservation and carbon fixation.

Minor Elements in Nakhlite Pyroxenes: Cr in MIL00346

NASA Technical Reports Server (NTRS)

McKay, G. A.; Schwandt, C.; Le, L.; Makishima, J.; Kurihara, T.

2006-01-01

Nakhlites are olivine-bearing clinopyroxene cumulates. Based on petrographic characteristics, they may be divided into groups that cooled at different rates and may have been formed at different depths in a single flow. The order of cooling rate from slowest to fastest is NWA998

A Haloalkane Dehalogenase from a Marine Microbial Consortium Possessing Exceptionally Broad Substrate Specificity.

PubMed

Buryska, Tomas; Babkova, Petra; Vavra, Ondrej; Damborsky, Jiri; Prokop, Zbynek

2018-01-15

The haloalkane dehalogenase enzyme DmmA was identified by marine metagenomic screening. Determination of its crystal structure revealed an unusually large active site compared to those of previously characterized haloalkane dehalogenases. Here we present a biochemical characterization of this interesting enzyme with emphasis on its structure-function relationships. DmmA exhibited an exceptionally broad substrate specificity and degraded several halogenated environmental pollutants that are resistant to other members of this enzyme family. In addition to having this unique substrate specificity, the enzyme was highly tolerant to organic cosolvents such as dimethyl sulfoxide, methanol, and acetone. Its broad substrate specificity, high overexpression yield (200 mg of protein per liter of cultivation medium; 50% of total protein), good tolerance to organic cosolvents, and a broad pH range make DmmA an attractive biocatalyst for various biotechnological applications. IMPORTANCE We present a thorough biochemical characterization of the haloalkane dehalogenase DmmA from a marine metagenome. This enzyme with an unusually large active site shows remarkably broad substrate specificity, high overexpression, significant tolerance to organic cosolvents, and activity under a broad range of pH conditions. DmmA is an attractive catalyst for sustainable biotechnology applications, e.g., biocatalysis, biosensing, and biodegradation of halogenated pollutants. We also report its ability to convert multiple halogenated compounds to corresponding polyalcohols. Copyright © 2018 American Society for Microbiology.

Hip adductor pyomyositis from Streptococcus mitis in a four-year-old child.

PubMed

Buldu, Metin Tolga; Raman, Raghu

2016-01-01

The unique aspect of this case study is the unusual history, presentation, ultrasonography, MRI and blood culture results, which lead to the diagnosis and treatment of adductor pyomyositis with a rare organism in a temperate country. The patient presented with a one-day history of malaise, fever, left groin pain and inability to weight bear on the left leg. There was no history of any trauma, predisposing infections or recent travel. Plain radiograph and ultrasound of the hip was normal with no effusion. Two consecutive blood cultures suggested Streptococcus mitis bacteraemia and MRI scan confirmed pyomyositis of the left hip adductors that was too small to drain. S. mitis is a normal commensal organism however it can lead to opportunistic infections particularly endocarditis. Echocardiogram revealed no cardiac complications, in particular no endocarditic vegetation. Patient was treated with intravenous benzylpenicillin for a week followed by oral phenoxymethylpenicillin for a week. Adductor pyomyositis must be considered as a differential diagnosis in a child with unusual presentation of hip pain. When an ultrasound is normal, MRI scan is warranted to confirm diagnosis. Septic screen should include blood cultures. The commonest causative organisms are the Staphylococcus family. However if S. mitis is isolated, cardiac sources of infection resulting in septic emboli must be investigated. Repeated MRI scans are required particularly if the patient does not respond to medical management. IV.

Unusual seasonal patterns and inferred processes of nitrogen retention in forested headwater catchments of the Upper Susquehanna basin

NASA Astrophysics Data System (ADS)

Goodale, C. L.; Thomas, S. A.; Fredriksen, G.; Elliott, E. M.; Flinn, K. M.; Butler, T. J.

2008-12-01

The Susquehanna River provides two-thirds of the annual nitrogen (N) load to the Chesapeake Bay, and atmospheric deposition is a major contributor to the basin's N inputs. Yet, there are few measurements of the retention of atmospheric N in the Upper Susquehanna's forested headwaters. We characterized the amount, form (nitrate, ammonium, and dissolved organic nitrogen), isotopic composition (del18O- and del15N-nitrate), and seasonality of stream N over two years from 8-15 small forested headwater catchments of the Susquehanna Basin. We expected high rates of N retention and seasonal nitrate patterns typical of other seasonally snow-covered catchments: dormant season peaks and growing season minima. Annual nitrate exports were approximately 0.1-0.7 kg N ha-1 y-1, and correlated positively with the percent of catchment free from historical agriculture. DON export averaged 0.6 +/- 0.1 kg N ha-1 y-1. All catchments had high rates of N retention but with atypical seasonal nitrate patterns, consisting of summer peaks, fall crashes, and modest rebounds during the dormant season. The fall nitrate crash coincided with carbon inputs at leaffall, indicating in-stream heterotrophic uptake. Stream del18O-nitrate values indicated microbial nitrification as the dominant source of stream nitrate, with modest contributions directly from precipitation in early stages of snowmelt. Three hypothesized sources of summer nitrate peaks include: delayed release of nitrate flushed to groundwater at snowmelt, weathering of geologic N, and increased net nitrate production. Measurements of shale del15N as well as soil, well-, and springwater nitrate within one catchment point toward a summer increase in net nitrification in surface soils. Rather than plant demand, processes governing the production, retention, and hydrologic transport of nitrate in surface mineral soils may drive the unusual nitrate seasonality in this and other systems, and provide insights on N retention in general.

Solid polymer electrolyte compositions

DOEpatents

Garbe, James E.; Atanasoski, Radoslav; Hamrock, Steven J.; Le, Dinh Ba

2001-01-01

An electrolyte composition is featured that includes a solid, ionically conductive polymer, organically modified oxide particles that include organic groups covalently bonded to the oxide particles, and an alkali metal salt. The electrolyte composition is free of lithiated zeolite. The invention also features cells that incorporate the electrolyte composition.

Chemical Characterization and Reactivity of Fuel-Oxidizer Reaction Product

NASA Technical Reports Server (NTRS)

David, Dennis D.; Dee, Louis A.; Beeson, Harold D.

1997-01-01

Fuel-oxidizer reaction product (FORP), the product of incomplete reaction of monomethylhydrazine and nitrogen tetroxide propellants prepared under laboratory conditions and from firings of Shuttle Reaction Control System thrusters, has been characterized by chemical and thermal analysis. The composition of FORP is variable but falls within a limited range of compositions that depend on three factors: the fuel-oxidizer ratio at the time of formation; whether the composition of the post-formation atmosphere is reducing or oxidizing; and the reaction or post-reaction temperature. A typical composition contains methylhydrazinium nitrate, ammonium nitrate, methylammonium nitrate, and trace amounts of hydrazinium nitrate and 1,1-dimethylhydrazinium nitrate. Thermal decomposition reactions of the FORP compositions used in this study were unremarkable. Neither the various compositions of FORP, the pure major components of FORP, nor mixtures of FORP with propellant system corrosion products showed any unusual thermal activity when decomposed under laboratory conditions. Off-limit thruster operations were simulated by rapid mixing of liquid monomethylhydrazine and liquid nitrogen tetroxide in a confined space. These tests demonstrated that monomethylhydrazine, methylhydrazinium nitrate, ammonium nitrate, or Inconel corrosion products can induce a mixture of monomethylhydrazine and nitrogen tetroxide to produce component-damaging energies. Damaging events required FORP or metal salts to be present at the initial mixing of monomethylhydrazine and nitrogen tetroxide.

Marine netpen farming leads to infections with some unusual parasites.

PubMed

Kent, M L

2000-03-01

Marine netpen farming of salmonid fishes is a rapidly growing industry in several countries. With this relatively recent industry, new or unusual infections by parasitic pathogens have been observed. This is due to different hosts being reared in new geographic areas, or by indigenous species being reared in a different environmental condition, i.e. the marine netpen. Examples of the former include Kudoa thyrsites (Myxozoa) and Hemobaphes disphaerocephalus (Copepoda) infections in Atlantic salmon (Salmo salar) reared in the Pacific Northwest, Ceratothoa gaudichaudii (Isopoda) infections in Atlantic salmon reared in Chile, Neoparamoeba (=Paramoeba) sp. (Sacromastigophora) from salmonids reared in Tasmania, and Stephanostomum tenue (Digenea) infections in rainbow trout (Oncorhynchus mykiss) reared in Atlantic Canada. Chinook salmon (Oncorhynchus tshawytscha) reared in its native region, the Pacific Northwest, provides some examples of unusual or more severe infections than those normally seen in wild or freshwater reared chinook salmon. These include infections by Loma salmonae (Microsporidia), Gilguina squali (Cestoda) and the rosette agent, an undescribed fungus-like organism related to choanoflagellates. As the industry continues to expand, it is certain that more novel host-parasite relationships will be observed, providing challenges for fish farmers and parasitologists.

Fungal community composition in soils subjected to long-term chemical fertilization is most influenced by the type of organic matter.

PubMed

Sun, Ruibo; Dsouza, Melissa; Gilbert, Jack A; Guo, Xisheng; Wang, Daozhong; Guo, Zhibin; Ni, Yingying; Chu, Haiyan

2016-12-01

Organic matter application is a widely used practice to increase soil carbon content and maintain soil fertility. However, little is known about the effect of different types of organic matter, or the input of exogenous species from these materials, on soil fungal communities. In this study, fungal community composition was characterized from soils amended with three types of organic matter over a 30-year fertilization experiment. Chemical fertilization significantly changed soil fungal community composition and structure, which was exacerbated by the addition of organic matter, with the direction of change influenced by the type of organic matter used. The addition of organic matter significantly increased soil fungal richness, with the greatest richness achieved in soils amended with pig manure. Importantly, following addition of cow and pig manure, fungal taxa associated with these materials could be found in the soil, suggesting that these exogenous species can augment soil fungal composition. Moreover, the addition of organic matter decreased the relative abundance of potential pathogenic fungi. Overall, these results indicate that organic matter addition influences the composition and structure of soil fungal communities in predictable ways. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Irradiation of nitrogen-rich ices by swift heavy ions. Clues for the formation of ultracarbonaceous micrometeorites

NASA Astrophysics Data System (ADS)

Augé, B.; Dartois, E.; Engrand, C.; Duprat, J.; Godard, M.; Delauche, L.; Bardin, N.; Mejía, C.; Martinez, R.; Muniz, G.; Domaracka, A.; Boduch, P.; Rothard, H.

2016-08-01

Context. Extraterrestrial materials, such as meteorites and interplanetary dust particles, provide constraints on the formation and evolution of organic matter in the young solar system. Micrometeorites represent the dominant source of extraterrestrial matter at the Earth's surface, some of them originating from large heliocentric distances. Recent analyses of ultracarbonaceous micrometeorites recovered from Antarctica (UCAMMs) reveal an unusually nitrogen-rich organic matter. Such nitrogen-rich carbonaceous material could be formed in a N2-rich environment, at very low temperature, triggered by energetic processes. Aims: Several formation scenarios have been proposed for the formation of the N-rich organic matter observed in UCAMMs. We experimentally evaluate the scenario involving high energy irradiation of icy bodies subsurface orbiting at large heliocentric distances. Methods: The effect of Galactic cosmic ray (GCR) irradiation of ices containing N2 and CH4 was studied in the laboratory. The N2-CH4 (90:10 and 98:2) ice mixtures were irradiated at 14 K by 44 MeV Ni11+ and 160 MeV Ar15+ swift heavy ion beams. The evolution of the samples was monitored using in-situ Fourier transform infrared spectroscopy. The evolution of the initial ice molecules and new species formed were followed as a function of projectile fluence. After irradiation, the target was annealed to room temperature. The solid residue of the whole process left after ice sublimation was characterized in-situ by infrared spectroscopy, and the elemental composition was measured ex-situ. Results: The infrared bands that appear during irradiation allow us to identify molecules and radicals (HCN, CN-, NH3, ...). The infrared spectra of the solid residues measured at room temperature show similarities with that of UCAMMs. The results point towards the efficient production of a poly-HCN-like residue from the irradiation of N2-CH4 rich surfaces of icy bodies. The room temperature residue provides a viable precursor for the N-rich organic matter found in UCAMMs.

Meteoritic Stardust and the Presolar History of the Solar Neighborhood

NASA Astrophysics Data System (ADS)

Nittler, Larry R.

Presolar stardust is present at low levels in meteorites and cometary dust and identified as ancient stellar matter by unusual isotopic compositions reflecting nuclear processes in stellar interiors and galactic chemical evolution. Most grains originated in winds from asymptotic giant branch (AGB) stars and supernova and their isotopic compositions provide important constraints on models of evolution and nucleosynthesis in these environments. The presolar grains from AGB stars appear to have formed in a lower-mass population of stars than predicted by GCE models. A merger of the Milky Way with a dwarf galaxy some 1 Gyr before the birth of the Solar System may explain this and other grain observations and the data thus can provide a unique window into the presolar history of the solar neighborhood.

Development of partially fluorinated resin apex seals

NASA Technical Reports Server (NTRS)

Green, H. E.; Chang, G. E. C.; Powell, S. H.; Yates, K.

1984-01-01

Partially fluorinated polyimides were prepared and molded in the form of discs and pins for test as potential apex seal materials for advanced rotary combustion engines. The polyimides were formulated from the diamine 2,2-bis 4-(4-aminophenoxy)phenyl hexafluoropropane (4-BDAF) and the dianhydrides of pyromellitic acid (PMDA) and benzophenonetetracarboxylic acid (BTDA). Tribological testing was performed at sliding speeds of 0.31 to 11.6 m/s and at temperatures of from 298K to 573K. It is shown that the carbon fiber filled polyimides, particularly the 80/20 compositions, have an excellent balance of wear/friction at 573K. The unfilled, 80/20 and 60/40 compositions indicate an unusual combination of high friction and low wear which may be advantageous in such applications as brakes and traction drives.

Inorganic, Radioisotopic, and Organic Analysis of 241-AP-101 Tank Waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fiskum, S.K.; Bredt, P.R.; Campbell, J.A.

2000-10-17

Battelle received five samples from Hanford waste tank 241-AP-101, taken at five different depths within the tank. No visible solids or organic layer were observed in the individual samples. Individual sample densities were measured, then the five samples were mixed together to provide a single composite. The composite was homogenized and representative sub-samples taken for inorganic, radioisotopic, and organic analysis. All analyses were performed on triplicate sub-samples of the composite material. The sample composite did not contain visible solids or an organic layer. A subsample held at 10 C for seven days formed no visible solids.

Degenerative Minimalism in the Genome of a Psyllid Endosymbiont

PubMed Central

Clark, Marta A.; Baumann, Linda; Thao, MyLo Ly; Moran, Nancy A.; Baumann, Paul

2001-01-01

Psyllids, like aphids, feed on plant phloem sap and are obligately associated with prokaryotic endosymbionts acquired through vertical transmission from an ancestral infection. We have sequenced 37 kb of DNA of the genome of Carsonella ruddii, the endosymbiont of psyllids, and found that it has a number of unusual properties revealing a more extreme case of degeneration than was previously reported from studies of eubacterial genomes, including that of the aphid endosymbiont Buchnera aphidicola. Among the unusual properties are an exceptionally low guanine-plus-cytosine content (19.9%), almost complete absence of intergenic spaces, operon fusion, and lack of the usual promoter sequences upstream of 16S rDNA. These features suggest the synthesis of long mRNAs and translational coupling. The most extreme instances of base compositional bias occur in the genes encoding proteins that have less highly conserved amino acid sequences; the guanine-plus-cytosine content of some protein-coding sequences is as low as 10%. The shift in base composition has a large effect on proteins: in polypeptides of C. ruddii, half of the residues consist of five amino acids with codons low in guanine plus cytosine. Furthermore, the proteins of C. ruddii are reduced in size, with an average of about 9% fewer amino acids than in homologous proteins of related bacteria. These observations suggest that the C. ruddii genome is not subject to constraints that limit the evolution of other known eubacteria. PMID:11222582

Evidence for Reduced, Carbon-rich Regions in the Solar Nebula from an Unusual Cometary Dust Particle

NASA Astrophysics Data System (ADS)

De Gregorio, Bradley T.; Stroud, Rhonda M.; Nittler, Larry R.; Kilcoyne, A. L. David

2017-10-01

Geochemical indicators in meteorites imply that most formed under relatively oxidizing conditions. However, some planetary materials, such as the enstatite chondrites, aubrite achondrites, and Mercury, were produced in reduced nebular environments. Because of large-scale radial nebular mixing, comets and other Kuiper Belt objects likely contain some primitive material related to these reduced planetary bodies. Here, we describe an unusual assemblage in a dust particle from comet 81P/Wild 2 captured in silica aerogel by the NASA Stardust spacecraft. The bulk of this ˜20 μm particle is comprised of an aggregate of nanoparticulate Cr-rich magnetite, containing opaque sub-domains composed of poorly graphitized carbon (PGC). The PGC forms conformal shells around tiny 5-15 nm core grains of Fe carbide. The C, N, and O isotopic compositions of these components are identical within errors to terrestrial standards, indicating a formation inside the solar system. Magnetite compositions are consistent with oxidation of reduced metal, similar to that seen in enstatite chondrites. Similarly, the core-shell structure of the carbide + PGC inclusions suggests a formation via FTT reactions on the surface of metal or carbide grains in warm, reduced regions of the solar nebula. Together, the nanoscale assemblage in the cometary particle is most consistent with the alteration of primary solids condensed from a C-rich, reduced nebular gas. The nanoparticulate components in the cometary particle provide the first direct evidence from comets of reduced, carbon-rich regions that were present in the solar nebula.

Cave speleothems as repositories of microbial biosignatures

NASA Astrophysics Data System (ADS)

Miller, Ana Z.; Jurado, Valme; Pereira, Manuel F. C.; Fernández, Octavio; Calaforra, José M.; Dionísio, Amélia; Saiz-Jimenez, Cesareo

2015-04-01

The need to better understand the biodiversity, origins of life on Earth and on other planets, and the wide applications of the microbe-mineral interactions have led to a rapid expansion of interest in subsurface environments. Recently reported results indicated signs of an early wet Mars and rather recent volcanic activity which suggest that Mars's subsurface can house organic molecules or traces of microbial life, making the search for microbial life on Earth's subsurface even more compelling. Caves on Earth are windows into the subsurface that harbor a wide variety of mineral-utilizing microorganisms, which may contribute to the formation of biominerals and unusual microstructures recognized as biosignatures. These environments contain a wide variety of redox interfaces and stable physicochemical conditions, which enhance secondary mineral precipitation and microbial growth under limited organic nutrient inputs. Enigmatic microorganisms and unusual mineral features have been found associated with secondary mineral deposits or speleothems in limestone caves and lava tubes. In this study, Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray spectroscopy (EDS) analyses were conducted on cave speleothem samples to assess microbe-mineral interactions, evaluate biogenicity, as well as to describe unusual mineral formations and microbial features. Microbial mats, extracellular polymeric substances, tubular empty sheaths, mineralized cells, filamentous fabrics, as well as "cell-sized" etch pits or microborings produced by bacterial cells were observed on minerals. These features evidence microbe-mineral interactions and may represent mineralogical signatures of life. We can thus consider that caves on Earth are plausible repositories of terrestrial biosignatures where we can look for microbial signatures. Acknowledgments: AZM acknowledges the support from the Marie Curie Intra-European Fellowship within the 7th European Community Framework Programme (PIEF-GA-2012-328689- DECAVE). The authors acknowledge the Spanish Ministry of Economy and Competitiveness (project CGL2013-41674-P) for financial support.

Characterization of PM2.5 and identification of transported secondary and biomass burning contribution in Seoul, Korea.

PubMed

Kim, Yumi; Seo, Jihoon; Kim, Jin Young; Lee, Ji Yi; Kim, Hwajin; Kim, Bong Mann

2018-02-01

The chemical and seasonal characteristics of fine particulates in Seoul, Korea, were investigated based on 24-h integrated PM 2.5 measurements made over four 1-month periods in each season between October 2012 and September 2013. The four-season average concentration of PM 2.5 was 37 μg m -3 , and the major chemical components were secondary inorganic aerosol (SIA) species of sulfate, nitrate, and ammonium (49%), followed by organic matter (34%). The mass concentration and most of the chemical components of PM 2.5 showed clear seasonal variation, with a winter-high and summer-low pattern. The winter-to-summer sulfate ratio and the winter organic carbon (OC)-to-elemental carbon (EC) ratio were unusually high compared with those in previous studies. Strong correlations of both the sulfate level and the sulfur oxidation ratio with relative humidity, and between water-soluble OC (WSOC) and SIA in winter, suggest the importance of aqueous phase chemistry for secondary aerosols. A strong correlation between non-sea salt sulfate and Na + levels, a high Cl - /Na + ratio, and an unusual positive correlation between the nitrogen oxidation ratio and temperature during the winter indicate the influence of transported secondary emission sources from upwind urban areas and from China across the Yellow Sea. Despite the absence of local forest fires and the regulation of wood burning, a high levoglucosan concentration and its correlations with OC and WSOC indicate that Seoul was affected by biomass burning sources in the winter. The unusually high water-insoluble OC (WIOC)-to-EC ratio in winter implies additional transported combustion sources of WIOC. The strong correlation between WIOC and levoglucosan suggests the likely influence of transported biomass burning sources on the high WIOC/EC ratio during the winter.

Dehydration-induced luminescence in clay minerals

NASA Technical Reports Server (NTRS)

Coyne, L. M.; Lahav, N.; Lawless, J. G.

1981-01-01

Reports of triboluminescent phenomena in organic crystalline materials prompted a search for related processes in clay minerals. The reported extensive mechanical distortion produced on freezing and drying of montmorillonite was particularly interesting because of studies of condensation reactions in a wet/dry cycled reaction sequence. The discovery of an unusual luminescent process in several clay minerals is reported and its characteristics are described.

Moraxella septic arthritis of the knee joint: a case report.

PubMed

Schonholtz, G J; Scott, W O

1986-01-01

Moraxella osloensis pyarthrosis of the knee joint is an unusual infection. The diagnosis can be quite difficult since the organism is fastidious in its growth characteristics. This case report presents an adult with M. osloensis sepsis of the knee, which could only be diagnosed by arthroscopic synovial biopsy and culture. Moreover, arthroscopy played a critical role in the definitive therapy.

Aerophagia and belching after herpes simplex encephalitis.

PubMed

Scheid, Rainer; Teich, Niels; Schroeter, Matthias L

2008-03-01

The etiology of abnormal belching is not known. Currently, it is being subsumed under "functional gastroduodenal disorders." Here, we report the unusual case history of a patient who developed aerophagia and consecutive excessive belching in association with herpes simplex encephalitis. The case report adds to the limited information about potential organic geneses of belching. Implications for possible medical therapies are discussed.

Munchausen syndrome: Playing sick or sick player

PubMed Central

Prakash, Jyoti; Das, R. C.; Srivastava, K.; Patra, P.; Khan, S. A.; Shashikumar, R.

2014-01-01

Munchausen syndrome is rare factitious disorder which entails frequent hospitalization, pathological lying and intentional production of symptoms for sick role. Management requires collateral history taking, sound clinical approach, exclusion of organicity and addressing psychological issues. A case which presented with unusual symptoms of similar dimension is discussed here. The case brings out finer nuances in evaluation and management of this entity. PMID:25535450

Emerging Infections and Bioterrorism

DTIC Science & Technology

2001-09-01

bioterrorism. Some examples of unusual outbreaks that could have been mistaken for bioterrorism are given below: Event/ Disease Location Year Legionnaires ...Geminiviruses) 1 237 Table 2. Viral Hemorrhagic Fevers Family and/or genus Disease ( s ) Arenaviridae Lassa fever, Bolivian HF (Machupo virus), Argentine HF (Junin...bioterrorist agents: these are the organisms or toxins that cause the diseases anthrax, botulism, brucellosis, plague, Q fever, smallpox, staphylococcal

The performance and capabilities of terrestrial organisms in extreme and unusual gaseous and liquid environments. Performance of fungi in exotic and harsh environments

NASA Technical Reports Server (NTRS)

Siegel, S. M.

1975-01-01

The growth of Penicillium in saline and low temperature conditions during a 15 month incubation period was studied. Data are also given on the potential 1f fungu for modification of the surface geochemistry of the earth and the capacity of these fungi to solubilize and concentrate metals.

Lipid composition and chemotaxonomy of Pseudomonas putrefaciens (Alteromonas putrefaciens).

PubMed

Wilkinson, S G; Caudwell, P F

1980-06-01

The major polar lipids in cells of Pseudomonas putrefaciens NCIB 10472 grown on nutrient agar were phosphatidylethanolamine, phoisphatidylglycerol, a glucosyldiacylglycerol, a glucuronosyldiacylglycerol and an ornithine amide lipid. An additional phospholipid, tentatively identified as acyl phosphatidylglycerol or bis-phosphatidic acid, was a trace component of the wall lipids from broth cultures, which lacked the glycolipids and the ornithine amide lipid. The wall lipids from broth cultures of three further strains of P. putrefaciens (NCIB 10471, NCIB 11156 and NCTC 10737) contained all of the above lipids, and in two cases (strains NCIB 10471 and NCIB 11156) had an unusually high content of free fatty acid. Fatty acid compositions of the extractable lipids were qualitatively similar for all four strains: the major components were iso-pentadecanoic acid, pentadecanoic acid, a cis-heptadecenoic acid and a cis-hexadecenoic acid. Anteiso fatty acids were minor components in strain NCIB 10472. Lipid mixtures in which the ornithine amide lipid was present also contained small amounts of beta-hydroxy fatty acids: in strain NCIB 10472 the major ones were the straight-chain and iso-branched C16 acids. Lipopolysaccharides from all four strains had similar, complex fatty acid compositions. The major non-hydroxy acids were the straight-chain and iso-branched C13 acids. beta-Hydroxy acids common to all strains included the straight-chain C11, C12, C13, C14 and C15 acids, together with branched-chain C13 and C15 acids probably belonging to the iso series. The lipopolysaccharide from strains NCIB 10472 also contained C12 and C14 hydroxy acids of the same series, and small amounts of C13 and C15 beta-hydroxy acids probably belonging to the anteiso series. The close resemblance in both polar lipid and fatty acid compositions between strains of P. putrefaciens and Pseudomonas rubescens is further evidence that these species are synonymous. Significant differences between the lipids and fatty acids of P. putrefaciens and those reported for a strain of Alteromonas haloplanktis do not harmonize with a proposal to transfer the former organism to the genus Alteromonas.

Tailored Engineering of an Unusual (C4 H9 NH3 )2 (CH3 NH3 )2 Pb3 Br10 Two-Dimensional Multilayered Perovskite Ferroelectric for a High-Performance Photodetector.

PubMed

Li, Lina; Sun, Zhihua; Wang, Peng; Hu, Weida; Wang, Sasa; Ji, Chengmin; Hong, Maochun; Luo, Junhua

2017-09-25

Two-dimensional (2D) layered hybrid perovskites have shown great potential in optoelectronics, owing to their unique physical attributes. However, 2D hybrid perovskite ferroelectrics remain rare. The first hybrid ferroelectric with unusual 2D multilayered perovskite framework, (C 4 H 9 NH 3 ) 2 (CH 3 NH 3 ) 2 Pb 3 Br 10 (1), has been constructed by tailored alloying of the mixed organic cations into 3D prototype of CH 3 NH 3 PbBr 3 . Ferroelectricity is created through molecular reorientation and synergic ordering of organic moieties, which are unprecedented for the known 2D multilayered hybrid perovskites. Single-crystal photodetectors of 1 exhibit fascinating performances, including extremely low dark currents (ca. 10 -12  A), large on/off current ratios (ca. 2.5×10 3 ), and very fast response rate (ca. 150 μs). These merits are superior to integrated detectors of other 2D perovskites, and compete with the most active CH 3 NH 3 PbI 3 . © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Designing nacre-like materials for simultaneous stiffness, strength and toughness: Optimum materials, composition, microstructure and size

NASA Astrophysics Data System (ADS)

Barthelat, Francois

2014-12-01

Nacre, bone and spider silk are staggered composites where inclusions of high aspect ratio reinforce a softer matrix. Such staggered composites have emerged through natural selection as the best configuration to produce stiffness, strength and toughness simultaneously. As a result, these remarkable materials are increasingly serving as model for synthetic composites with unusual and attractive performance. While several models have been developed to predict basic properties for biological and bio-inspired staggered composites, the designer is still left to struggle with finding optimum parameters. Unresolved issues include choosing optimum properties for inclusions and matrix, and resolving the contradictory effects of certain design variables. Here we overcome these difficulties with a multi-objective optimization for simultaneous high stiffness, strength and energy absorption in staggered composites. Our optimization scheme includes material properties for inclusions and matrix as design variables. This process reveals new guidelines, for example the staggered microstructure is only advantageous if the tablets are at least five times stronger than the interfaces, and only if high volume concentrations of tablets are used. We finally compile the results into a step-by-step optimization procedure which can be applied for the design of any type of high-performance staggered composite and at any length scale. The procedure produces optimum designs which are consistent with the materials and microstructure of natural nacre, confirming that this natural material is indeed optimized for mechanical performance.

Thermoelectric Transport Signatures of Dirac Composite Fermions in the Half-Filled Landau Level

NASA Astrophysics Data System (ADS)

Potter, Andrew C.; Serbyn, Maksym; Vishwanath, Ashvin

2016-07-01

The half-filled Landau level is expected to be approximately particle-hole symmetric, which requires an extension of the Halperin-Lee-Read (HLR) theory of the compressible state observed at this filling. Recent work indicates that, when particle-hole symmetry is preserved, the composite fermions experience a quantized π -Berry phase upon winding around the composite Fermi surface, analogous to Dirac fermions at the surface of a 3D topological insulator. In contrast, the effective low-energy theory of the composite fermion liquid originally proposed by HLR lacks particle-hole symmetry and has vanishing Berry phase. In this paper, we explain how thermoelectric transport measurements can be used to test the Dirac nature of the composite fermions by quantitatively extracting this Berry phase. First, we point out that longitudinal thermopower (Seebeck effect) is nonvanishing because of the unusual nature of particle-hole symmetry in this context and is not sensitive to the Berry phase. In contrast, we find that off-diagonal thermopower (Nernst effect) is directly related to the topological structure of the composite Fermi surface, vanishing for zero Berry phase and taking its maximal value for π Berry phase. In contrast, in purely electrical transport signatures, the Berry phase contributions appear as small corrections to a large background signal, making the Nernst effect a promising diagnostic of the Dirac nature of composite fermions.

Studying brain organization via spontaneous fMRI signal.

PubMed

Power, Jonathan D; Schlaggar, Bradley L; Petersen, Steven E

2014-11-19

In recent years, some substantial advances in understanding human (and nonhuman) brain organization have emerged from a relatively unusual approach: the observation of spontaneous activity, and correlated patterns in spontaneous activity, in the "resting" brain. Most commonly, spontaneous neural activity is measured indirectly via fMRI signal in subjects who are lying quietly in the scanner, the so-called "resting state." This Primer introduces the fMRI-based study of spontaneous brain activity, some of the methodological issues active in the field, and some ways in which resting-state fMRI has been used to delineate aspects of area-level and supra-areal brain organization. Copyright © 2014 Elsevier Inc. All rights reserved.

The Future of Cell Biology: Emerging Model Organisms.

PubMed

Goldstein, Bob; King, Nicole

2016-11-01

Most current research in cell biology uses just a handful of model systems including yeast, Arabidopsis, Drosophila, Caenorhabditis elegans, zebrafish, mouse, and cultured mammalian cells. And for good reason - for many biological questions, the best system for the question is likely to be found among these models. However, in some cases, and particularly as the questions that engage scientists broaden, the best system for a question may be a little-studied organism. Modern research tools are facilitating a renaissance for unusual and interesting organisms as emerging model systems. As a result, we predict that an ever-expanding breadth of model systems may be a hallmark of future cell biology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Compositions comprising a polypeptide having cellulolytic enhancing activity and an organic compound and uses thereof

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quinlan, Jason; Xu, Feng; Sweeney, Matthew

The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and an organic compound. The present invention also relates to methods of using the compositions.

Structural Characterization of the Histone Variant macroH2A

PubMed Central

Chakravarthy, Srinivas; Gundimella, Sampath Kumar Y.; Caron, Cecile; Perche, Pierre-Yves; Pehrson, John R.; Khochbin, Saadi; Luger, Karolin

2005-01-01

macroH2A is an H2A variant with a highly unusual structural organization. It has a C-terminal domain connected to the N-terminal histone domain by a linker. Crystallographic and biochemical studies show that changes in the L1 loop in the histone fold region of macroH2A impact the structure and potentially the function of nucleosomes. The 1.6-Å X-ray structure of the nonhistone region reveals an α/β fold which has previously been found in a functionally diverse group of proteins. This region associates with histone deacetylases and affects the acetylation status of nucleosomes containing macroH2A. Thus, the unusual domain structure of macroH2A integrates independent functions that are instrumental in establishing a structurally and functionally unique chromatin domain. PMID:16107708

Migration & Extra-solar Terrestrial Planets: Watering the Planets

NASA Astrophysics Data System (ADS)

Carter-Bond, Jade C.; O'Brien, David P.; Raymond, Sean N.

2014-04-01

A diverse range of terrestrial planet compositions is believed to exist within known extrasolar planetary systems, ranging from those that are relatively Earth-like to those that are highly unusual, dominated by species such as refractory elements (Al and Ca) or C (as pure C, TiC and SiC)(Bond et al. 2010b). However, all prior simulations have ignored the impact that giant planet migration during planetary accretion may have on the final terrestrial planetary composition. Here, we combined chemical equilibrium models of the disk around five known planetary host stars (Solar, HD4203, HD19994, HD213240 and Gl777) with dynamical models of terrestrial planet formation incorporating various degrees of giant planet migration. Giant planet migration is found to drastically impact terrestrial planet composition by 1) increasing the amount of Mg-silicate species present in the final body; and 2) dramatically increasing the efficiency and amount of water delivered to the terrestrial bodies during their formation process.

Succession in a microbial mat community: A gaian perspective

NASA Astrophysics Data System (ADS)

Stolz, J. F.

The Gaia hypothesis originally proposed by James E. Lovelock states that the composition, oxidation-reduction state and temperature of the troposphere are actively regulated by the activities of the biota. The gaian concept has been extrapolated to include the composition of surface sediments through the process of biomineralization. The stratified microbial community dominated by the cyanobacterium Microcoleus chthonoplastes is actively involved in the deposition of laminated sediments at Laguna Figueroa, Baja California, Mexico. Unusually heavy rains in the winters of 1979 and 1980 flooded the evaporite flat with up to 3 meters of meteoric water and deposited 5 - 10 cm of allocthonous sediment. The composition of the microbial community changed as a succession of dominating microbial species ensued, ultimately leading to the recolonization of the surface sediment by the original Microcoleus-dominated community. The resiliency of bacterial communities is suggested to be an important mechanism of gaian control systems. Present address: Control and Energy Conversion Division, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, U.S.A.

A Case of a Composite Adrenal Medullary Tumor of Pheochromocytoma and Ganglioneuroma Masquerading as Acute Pancreatitis

PubMed Central

Choi, Eun-Kyoung; Kim, Wan-Ho

2006-01-01

Composite adrenal medullary tumors, composed of both pheochromocytoma and ganglioneuroma, are extremely rare, as are pheochromocytomas masquerading as acute relapsing pancreatitis. We recently experienced a case of a 48-year-old male with both these phenomena. The patient complained of an acute onset of intense abdominal discomfort. At the same time, pancreatic enzymes were increased in concentration. An abdominal computed tomographic scan revealed an enlarged pancreas and a 3-cm left adrenal incidentaloma. Biochemical and 131I-MIBG scintigraphic findings were compatible with a pheochromocytoma. Yet, he had no clinical manifestations suggesting pheochromocytoma. An adrenalectomy was performed and a composite adrenal medullary tumor of pheochromocytoma and ganglioneuroma was confirmed during a pathologic examination. This case illustrates two points: 1) acute abdominal intense discomfort and hyperamylasemia may be unusual presentations of pheochromocytomas; and 2) the possibility of the pheochromocytoma, albeit rare, should be considered when a relapsing pancreatitis of uncertain etiology develops. PMID:16913447

Solidification and crystal growth of solid solution semiconducting alloys

NASA Technical Reports Server (NTRS)

Lehoczky, S. L.; Szofran, F. R.

1984-01-01

Problems associated with the solidification and crytal growth of solid-solution semiconducting alloy crystals in a terrestrial environment are described. A detailed description is given of the results for the growth of mercury cadmium telluride (HgCdTe) alloy crystals by directional solidification, because of their considerable technological importance. A series of HgCdTe alloy crystals are grown from pseudobinary melts by a vertical Bridgman method using a wide range of growth rates and thermal conditions. Precision measurements are performed to establish compositional profiles for the crystals. The compositional variations are related to compositional variations in the melts that can result from two-dimensional diffusion or density gradient driven flow effects ahead of the growth interface. These effects are discussed in terms of the alloy phase equilibrium properties, the recent high temperature thermophysical data for the alloys and the highly unusual heat transfer characteristics of the alloy/ampule/furnace system that may readily lead to double diffusive convective flows in a gravitational environment.

Diamond and moissanite in ophiolitic mantle rocks and podiform chromitites: A deep carbon source?

NASA Astrophysics Data System (ADS)

Yang, J.; Xu, X.; Wiedenbeck, M.; Trumbull, R. B.; Robinson, P. T.

2010-12-01

Diamonds are known from a variety of occurreces, mainly from mantle-derived kimberlites, meteorite impact craters, and continental deep subduction and collision zones. Recently, an unusual mineral group was discovered in the Luobusa ophiolitic chromitites from the Yarlung Zangbu suture, Tibet, which probably originated from a depth of over 300 km in the mantle. Minerals of deep origin include coesite apparently pseudomorphing stishovite, and diamond as individual grains or inclusions in OsIr alloy. To determine if such UHP and unusual minerals occur elsewhere, we collected about 1.5 t of chromitite from two orebodies in an ultramafic body in the Polar Urals. Thus far, more than 60 different mineral species have been separated from these ores. The most exciting discovery is the common occurrence of diamond, a typical UHP mineral in the Luobusa chromitites. These minerals are very similar in composition and structure to those reported from the Luobusa chromitites. So far diamond and/or moissanite have been discovered from many different ophiolitic ultramafic rocks, including in-situ grains in polished chromitite fragments. These discoveries demonstrate that the Luobusa ophiolite is not a unique diamond-bearing massif. Secondary ion mass spectrometric (SIMS) analysis shows that the ophiolite-hosted diamond has a distinctive 13C-depleted isotopic composition (δ13C from -18 to -28‰, n=70), compatible to the ophiolite-hosted moissanite (δ13C from -18 to -35‰, n=36), both are much lighter than the main carbon reservoir in the upper mantle (δ13C near -5‰). The compiled data from moissanite from kimberlites and other mantle settings share the characteristic of strongly 13C-depleted isotopic composition. This suggests that diamond and moissanite originates from a separate carbon reservoir in the mantle or that its formation involved strong isotopic fractionation. Subduction of biogenic carbonaceous material could potentially satisfy both the unusual isotopic and redox constraints on diamond and moissanite formation, but this material would need to stay chemically isolated from the upper mantle until it reached the high-T stability field of diamond and moissanite. The origin of diamond and moissanite in the mantle is still unsolved, but all evidence from the upper mantle indicates that they cannot have formed there, except under special and local redox conditions. We suggest, alternatively, that diamond and moissanite may have formed in the lower mantle, where the existence of 13C-depleted carbon is strongly suspected.

Relative Amino Acid Composition Signatures of Organisms and Environments

PubMed Central

Moura, Alexandra; Savageau, Michael A.; Alves, Rui

2013-01-01

Background Identifying organism-environment interactions at the molecular level is crucial to understanding how organisms adapt to and change the chemical and molecular landscape of their habitats. In this work we investigated whether relative amino acid compositions could be used as a molecular signature of an environment and whether such a signature could also be observed at the level of the cellular amino acid composition of the microorganisms that inhabit that environment. Methodologies/Principal Findings To address these questions we collected and analyzed environmental amino acid determinations from the literature, and estimated from complete genomic sequences the global relative amino acid abundances of organisms that are cognate to the different types of environment. Environmental relative amino acid abundances clustered into broad groups (ocean waters, host-associated environments, grass land environments, sandy soils and sediments, and forest soils), indicating the presence of amino acid signatures specific for each environment. These signatures correlate to those found in organisms. Nevertheless, relative amino acid abundance of organisms was more influenced by GC content than habitat or phylogeny. Conclusions Our results suggest that relative amino acid composition can be used as a signature of an environment. In addition, we observed that the relative amino acid composition of organisms is not highly determined by environment, reinforcing previous studies that find GC content to be the major factor correlating to amino acid composition in living organisms. PMID:24204807

Relative amino acid composition signatures of organisms and environments.

PubMed

Moura, Alexandra; Savageau, Michael A; Alves, Rui

2013-01-01

Identifying organism-environment interactions at the molecular level is crucial to understanding how organisms adapt to and change the chemical and molecular landscape of their habitats. In this work we investigated whether relative amino acid compositions could be used as a molecular signature of an environment and whether such a signature could also be observed at the level of the cellular amino acid composition of the microorganisms that inhabit that environment. To address these questions we collected and analyzed environmental amino acid determinations from the literature, and estimated from complete genomic sequences the global relative amino acid abundances of organisms that are cognate to the different types of environment. Environmental relative amino acid abundances clustered into broad groups (ocean waters, host-associated environments, grass land environments, sandy soils and sediments, and forest soils), indicating the presence of amino acid signatures specific for each environment. These signatures correlate to those found in organisms. Nevertheless, relative amino acid abundance of organisms was more influenced by GC content than habitat or phylogeny. Our results suggest that relative amino acid composition can be used as a signature of an environment. In addition, we observed that the relative amino acid composition of organisms is not highly determined by environment, reinforcing previous studies that find GC content to be the major factor correlating to amino acid composition in living organisms.

Petrological and experimental evidence for differentiation of water-rich magmas beneath St. Kitts, Lesser Antilles

NASA Astrophysics Data System (ADS)

Melekhova, Elena; Blundy, Jon; Martin, Rita; Arculus, Richard; Pichavant, Michel

2017-12-01

St. Kitts lies in the northern Lesser Antilles, a subduction-related intraoceanic volcanic arc known for its magmatic diversity and unusually abundant cognate xenoliths. We combine the geochemistry of xenoliths, melt inclusions and lavas with high pressure-temperature experiments to explore magma differentiation processes beneath St. Kitts. Lavas range from basalt to rhyolite, with predominant andesites and basaltic andesites. Xenoliths, dominated by calcic plagioclase and amphibole, typically in reaction relationship with pyroxenes and olivine, can be divided into plutonic and cumulate varieties based on mineral textures and compositions. Cumulate varieties, formed primarily by the accumulation of liquidus phases, comprise ensembles that represent instantaneous solid compositions from one or more magma batches; plutonic varieties have mineralogy and textures consistent with protracted solidification of magmatic mush. Mineral chemistry in lavas and xenoliths is subtly different. For example, plagioclase with unusually high anorthite content (An≤100) occurs in some plutonic xenoliths, whereas the most calcic plagioclase in cumulate xenoliths and lavas are An97 and An95, respectively. Fluid-saturated, equilibrium crystallisation experiments were performed on a St. Kitts basaltic andesite, with three different fluid compositions ( XH2O = 1.0, 0.66 and 0.33) at 2.4 kbar, 950-1025 °C, and fO2 = NNO - 0.6 to NNO + 1.2 log units. Experiments reproduce lava liquid lines of descent and many xenolith assemblages, but fail to match xenolith and lava phenocryst mineral compositions, notably the very An-rich plagioclase. The strong positive correlation between experimentally determined plagioclase-melt KdCa-Na and dissolved H2O in the melt, together with the occurrence of Al-rich mafic lavas, suggests that parental magmas were water-rich (> 9 wt% H2O) basaltic andesites that crystallised over a wide pressure range (1.5-6 kbar). Comparison of experimental and natural (lava, xenolith) mafic mineral composition reveals that whereas olivine in lavas is predominantly primocrysts precipitated at low-pressure, pyroxenes and spinel are predominantly xenocrysts formed by disaggregation of plutonic mushes. Overall, St. Kitts xenoliths and lavas testify to mid-crustal differentiation of low-MgO basalt and basaltic andesite magmas within a trans-crustal, magmatic mush system. Lower crustal ultramafic cumulates that relate parental low-MgO basalts to primary, mantle -derived melts are absent on St. Kitts.

Testing a measure of organizational learning capacity and readiness for transformational change in human services.

PubMed

Bess, Kimberly D; Perkins, Douglas D; McCown, Diana L

2011-01-01

Transformative organizational change requires organizational learning capacity, which we define in terms of (1) internal and (2) external organizational systems alignment, and promoting a culture of learning, including (3) an emphasis on exploration and information, (4) open communication, (5) staff empowerment, and (6) support for professional development. We shortened and adapted Watkins and Marsick's Dimensions of Learning Organizations Questionnaire into a new 16-item Organizational Learning Capacity Scale (OLCS) geared more toward nonprofit organizations. The OLCS and its subscales measuring each of the above 6 dimensions are unusually reliable for their brevity. ANOVAs for the OLCS and subscales clearly and consistently confirmed extensive participant observations and other qualitative data from four nonprofit human service organizations and one local human service funding organization.

Petrology and geochemistry of the unbrecciated achondrite Northwest Africa 1240 (NWA 1240): an HED parent body impact melt

NASA Astrophysics Data System (ADS)

Barrat, J. A.; Jambon, A.; Bohn, M.; Blichert-Toft, J.; Sautter, V.; Göpel, C.; Gillet, Ph.; Boudouma, O.; Keller, F.

2003-10-01

NWA 1240 is an unusual eucrite recently recovered in Morocco as a single stone of 98 g. It is an unbrecciated greenish-brown rock nearly devoid of fusion crust. It displays porphyritic texture consisting of skeletal hollow low-Ca pyroxene phenocrysts set in a variolitic (fan-spherulitic) mesostasis of fine elongate pyroxene and plagioclase crystals. Minor phases are skeletal chromite, iron, silica, troilite, ilmenite and minute amounts of phosphate and fayalite. Pyroxenes are unequilibrated and show one of the widest ranges of composition so far described for a eucrite, from En 76.0Wo 1.9Fs 22.1 to compositions nearly devoid of Mg (unusual ferrosilite and Fe-augite symplectites and possibly pyroxferroite). Plagioclase crystals contain significant amounts of Fe and Mg, which are possibly controlled by the Ca(Mg,Fe 2+)Si 3O 8 plagioclase component. To discuss the potential effects of hot-desert weathering on NWA 1240, we have analyzed a series of Saharan eucrites (Agoult, Aoufous, Igdi, Smara, NWA 047 and NWA 049) and large aliquots (0.39 to 2.8 g) of eucrite falls (Bereba, Bouvante, Jonzac, Juvinas and Serra de Magé). These results indicate that among the elements we have determined, Pb, Ba and Sr are the most sensitive indicators of Saharan weathering. The bulk composition of NWA 1240 has been determined for 45 elements by ICP-AES and ICP-MS. The data show that the meteorite is not significantly weathered: its Pb concentration is very low; Ba and Sr concentrations are not anomalously high; the Th/U and Hf/Sm ratios are chondritic (Th/U = 3.65, Hf/Sm = 0.74). NWA 1240 is rich in MgO (10.4 wt%) and Cr 2O 3 (0.71 wt%), and displays striking similarities with cumulate eucrites, such as having similar incompatible trace element patterns and a significant positive Eu anomaly (Eu/Eu* = 1.37). The combination of fast cooling and cumulate eucrite-dominated composition suggests that NWA 1240 is not an igneous rock but rather an impact melt.

Desensitization of metastable intermolecular composites

DOEpatents

Busse, James R [South Fork, CO; Dye, Robert C [Los Alamos, NM; Foley, Timothy J [Los Alamos, NM; Higa, Kelvin T [Ridgecrest, CA; Jorgensen, Betty S [Jemez Springs, NM; Sanders, Victor E [White Rock, NM; Son, Steven F [Los Alamos, NM

2011-04-26

A method to substantially desensitize a metastable intermolecular composite material to electrostatic discharge and friction comprising mixing the composite material with an organic diluent and removing enough organic diluent from the mixture to form a mixture with a substantially putty-like consistency, as well as a concomitant method of recovering the metastable intermolecular composite material.

Desensitization and recovery of metastable intermolecular composites

DOEpatents

Busse, James R [South Fork, CO; Dye, Robert C [Los Alamos, NM; Foley, Timothy J [Los Alamos, NM; Higa, Kelvin T [Ridgecrest, CA; Jorgensen, Betty S [Jemez Springs, NM; Sanders, Victor E [White Rock, NM; Son, Steven F [Los Alamos, NM

2010-09-07

A method to substantially desensitize a metastable intermolecular composite material to electrostatic discharge and friction comprising mixing the composite material with an organic diluent and removing enough organic diluent from the mixture to form a mixture with a substantially putty-like consistency, as well as a concomitant method of recovering the metastable intermolecular composite material.

76 FR 78216 - Organ Procurement and Transplantation Network

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-16

... composite tissue allograft; however, for the purposes of rulemaking, the Health Resources and Services..., Hand transplantation and vascularized composite tissue allografts in orthopaedics and traumatology... vascularized composite allografts, described below, within the definition of organs covered by the rules...

Mesoporous Fluorinated Metal-Organic Frameworks with Exceptional Adsorption of Fluorocarbons and CFCs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Teng-Hao; Popov, Ilya; Kaveevivitchai, Watchareeya

2016-02-08

Two mesoporous fluorinated metal–organic frameworks (MOFs) were synthesized from extensively fluorinated tritopic carboxylate- and tetrazolate-based ligands. The tetrazolate-based framework MOFF-5 has an accessible surface area of 2445 m 2g -1, the highest among fluorinated MOFs. Crystals of MOFF-5 adsorb hydrocarbons, fluorocarbons, and chlorofluorocarbons (CFCs)—the latter two being ozone-depleting substances and potent greenhouse species—with weight capacities of up to 225%. The material exhibits an apparent preference for the adsorption of non-spherical molecules, binding unusually low amounts of both tetrafluoromethane and sulfur hexafluoride.

Shape memory alloys: Properties and biomedical applications

NASA Astrophysics Data System (ADS)

Mantovani, Diego

2000-10-01

Shape memory alloys provide new insights for the design of biomaterials in bioengineering for the design of artificial organs and advanced surgical instruments, since they have specific characteristics and unusual properties. This article will examine (a) the four properties of shape memory alloys, (b) medical applications with high potential for improving the present and future quality of life, and (c) concerns regarding the biocom-patibility properties of nickel-titanium alloys. In particular, the long-term challenges of using shape memory alloys will be discussed, regarding corrosion and potential leakage of elements and ions that could be toxic to cells, tissues and organs.

No-Oven, No-Autoclave Composite Processing

NASA Technical Reports Server (NTRS)

Rauscher, Michael D.

2015-01-01

Very large composite structures, such as those used in NASA's Space Launch System, push the boundaries imposed by current autoclaves. New technology is needed to maintain composite performance and free manufacturing engineers from the restraints of curing equipment size limitations. Recent efforts on a Phase II project by Cornerstone Research Group, Inc. (CRG), have advanced the technology and manufacturing readiness levels of a unique two-part epoxy resin system. Designed for room-temperature infusion of a dry carbon preform, the system includes a no-heat-added cure that delivers 350 F composite performance in a matter of hours. This no-oven, no-autoclave (NONA) composite processing eliminates part-size constraints imposed by infrastructure and lowers costs by increasing throughput and reducing capital-specific, process-flow bottlenecks. As a result of the Phase II activity, NONA materials and processes were used to make high-temperature composite tooling suitable for further production of carbon-epoxy laminates and honeycomb/ sandwich-structure composites with an aluminum core. The technology platform involves tooling design, resin infusion processing, composite part design, and resin chemistry. The various technology elements are combined to achieve a fully cured part. The individual elements are not unusual, but they are combined in such a way that enables proper management of the heat generated by the epoxy resin during cure. The result is a self-cured carbon/ epoxy composite part that is mechanically and chemically stable at temperatures up to 350 F. As a result of the successful SBIR effort, CRG has launched NONA Composites as a spinoff subsidiary. The company sells resin to end users, fabricates finished goods for customers, and sells composite tooling made with NONA materials and processes to composite manufacturers.

Third wave of African swine fever infection in Armenia: Virus demonstrates the reduction of pathogenicity

PubMed Central

Sargsyan, M. A.; Voskanyan, H. E.; Karalova, E. M.; Hakobyan, L. H.; Karalyan, Z. A.

2018-01-01

Aim: First cases of clinically uncommon African swine fever (ASF), caused by virus genotype II are described in this article. These cases occurred in Armenia, Tavush region, Dilijan municipality in 2011. The aim of this study was to identify and describe the new pathogenic forms of ASF in Armenia. Materials and Methods: The isolation and identification of ASF virus (ASFV) were carried out using conventional techniques. Clinical signs of infection were recorded daily. Gross anatomical pathology characteristics were observed during routine postmortem examinations. Blood and serum were obtained by puncture of the jugular vein using a vacutainer system. Results: The presence of ASFV DNA in the spleens was confirmed by polymerase chain reaction. Sequenced sections of p72 showed phylogenetic identity to genotype 2. The pathology exhibits unusual manifestations of the main disease. The unusual form of ASF demonstrates characteristics of a subacute form of the disease, with the possibility of conversion to a chronic form. Decreased lethality, low level of hemorrhages, and absence of severe pancytopenia in smears from spleen, lymph nodes, and blood are common features of the new form of ASF. Unlike severe thrombocytopenia in the typical ASF, the unusual form exhibited moderate or minor decrease of this feature. Despite a moderate decrease in hemadsorption titers, the unusual pattern of the disease was characterized by viremia and the presence of the virus in the visceral organs, including the brain. Conclusion: Our data allow assuming that new nosological form of ASF (genotype II) may present as a transitional form of the disease with the possibility of chronization. PMID:29479149

Multiple squamous hyperplastic-fibrous inflammatory polyps of the oesophagus: a new feature of eosinophilic oesophagitis?

PubMed

Mulder, D J; Gander, S; Hurlbut, D J; Soboleski, D A; Smith, R G; Justinich, C J

2009-09-01

This report describes the unusual case of a 12-year-old boy with multiple polyps in the oesophagus and concurrent eosinophilic oesophagitis (EoE). Polyps were of a fibrous-inflammatory composition featuring eosinophils, mast cells, hyperplastic epithelium and fibrosis, which are all features described with EoE. EoE is an increasingly recognised clinicopathological disorder characterised by large numbers of eosinophils infiltrating the oesophageal mucosa. Polyps in the oesophagus are rare, have not previously been associated with EoE, and may represent a new feature of the disease.

ABC Triblock Copolymer Vesicles with Mesh-like Morphology

NASA Astrophysics Data System (ADS)

Zhao, Wei; Russell, Thomas; Grason, Gregory

2010-03-01

Polymer vesicles can be made from poly(isoprene-b-styrene-b-2-vinylpyridene) (PI-b-PS-b-P2VP) triblock copolymer under the confinement of anodic aluminum oxide (AAO) membrane. It was found that these vesicles have well-defined, nanoscopic size and a microphase-separated hydrophobic core, comprised of PS and PI blocks. Vesicle formation was tracked using both transmission and scanning electron microscopy. A mesh-like morphology formed in the core at a well-defined composition of three blocks. Confinement played an important role in generating these vesicles with such an unusual morphology.

Carbon nanotubes as vaccine scaffolds

PubMed Central

Scheinberg, David A.; McDevitt, Michael R.; Dao, Tao; Mulvey, Justin J.; Feinberg, Evan; Alidori, Simone

2013-01-01

Carbon nanotubes display characteristics that are potentially useful in their development as scaffolds for vaccine compositions. These features include stability in vivo, lack of intrinsic immunogenicity, low toxicity, and the ability to be appended with multiple copies of antigens. In addition, the particulate nature of carbon nanotubes and their unusual properties of rapid entry into antigen-presenting cells, such as dendritic cells, make them especially useful as carriers of antigens. Early attempts demonstrating carbon nanotube-based vaccines can be used in both infectious disease settings and cancer are promising. PMID:23899863

Soft mechanical metamaterials with unusual swelling behavior and tunable stress-strain curves

PubMed Central

Guo, Xiaogang; Wu, Jun

2018-01-01

Soft adaptable materials that change their shapes, volumes, and properties in response to changes under ambient conditions have important applications in tissue engineering, soft robotics, biosensing, and flexible displays. Upon water absorption, most existing soft materials, such as hydrogels, show a positive volume change, corresponding to a positive swelling. By contrast, the negative swelling represents a relatively unusual phenomenon that does not exist in most natural materials. The development of material systems capable of large or anisotropic negative swelling remains a challenge. We combine analytic modeling, finite element analyses, and experiments to design a type of soft mechanical metamaterials that can achieve large effective negative swelling ratios and tunable stress-strain curves, with desired isotropic/anisotropic features. This material system exploits horseshoe-shaped composite microstructures of hydrogel and passive materials as the building blocks, which extend into a periodic network, following the lattice constructions. The building block structure leverages a sandwiched configuration to convert the hydraulic swelling deformations of hydrogel into bending deformations, thereby resulting in an effective shrinkage (up to around −47% linear strain) of the entire network. By introducing spatially heterogeneous designs, we demonstrated a range of unusual, anisotropic swelling responses, including those with expansion in one direction and, simultaneously, shrinkage along the perpendicular direction. The design approach, as validated by experiments, allows the determination of tailored microstructure geometries to yield desired length/area changes. These design concepts expand the capabilities of existing soft materials and hold promising potential for applications in a diverse range of areas.

Ecological and evolutionary significance of genomic GC content diversity in monocots

PubMed Central

Šmarda, Petr; Bureš, Petr; Horová, Lucie; Leitch, Ilia J.; Mucina, Ladislav; Pacini, Ettore; Tichý, Lubomír; Grulich, Vít; Rotreklová, Olga

2014-01-01

Genomic DNA base composition (GC content) is predicted to significantly affect genome functioning and species ecology. Although several hypotheses have been put forward to address the biological impact of GC content variation in microbial and vertebrate organisms, the biological significance of GC content diversity in plants remains unclear because of a lack of sufficiently robust genomic data. Using flow cytometry, we report genomic GC contents for 239 species representing 70 of 78 monocot families and compare them with genomic characters, a suite of life history traits and climatic niche data using phylogeny-based statistics. GC content of monocots varied between 33.6% and 48.9%, with several groups exceeding the GC content known for any other vascular plant group, highlighting their unusual genome architecture and organization. GC content showed a quadratic relationship with genome size, with the decreases in GC content in larger genomes possibly being a consequence of the higher biochemical costs of GC base synthesis. Dramatic decreases in GC content were observed in species with holocentric chromosomes, whereas increased GC content was documented in species able to grow in seasonally cold and/or dry climates, possibly indicating an advantage of GC-rich DNA during cell freezing and desiccation. We also show that genomic adaptations associated with changing GC content might have played a significant role in the evolution of the Earth’s contemporary biota, such as the rise of grass-dominated biomes during the mid-Tertiary. One of the major selective advantages of GC-rich DNA is hypothesized to be facilitating more complex gene regulation. PMID:25225383

Timing is the elusive connector of dreams

NASA Astrophysics Data System (ADS)

Lones, Joe J.; Lones, Lance

2014-12-01

Establishing San Diego as the venue for SPIE annual meetings was an activity loaded with unusual efforts and imagination on the part Joe Yaver, his wife, Anita, and some southern California members. Of interest is the origin (and retention) of SPIE as a name for the organization. Few know the associated logo has real technical meaning. Then there was moving SPIE headquarters to Bellingham, Washington, to complicate things.

Hemangiopericytoma: an unusual cause of peritoneal carcinomatosis

PubMed Central

Prakash, Mahesh; Sodhi, Kushaljeet S.; Kapoor, R.; Khandelwal, Niranjan

2009-01-01

Abstract Hemangiopericytoma, a rare mesenchymal tumour, is believed to originate from the pericyte of Zimmermann. It may affect every organ in the body. Recurrences after treatment and metastasis are well known. However, presentation of hemangiopericytoma with peritoneal carcinomatosis is not documented in literature. To the best our knowledge, we report the imaging findings of the first histologically proven case of hemangiopericytoma with peritoneal carcinomatosis. PMID:19602469

Synthetic Chemicals with Potential for Natural Attenuation (Postprint)

DTIC Science & Technology

2012-07-01

The purpose of this paper is to describe examples of other synthetic organic compounds that are known to be biodegradable ...chlorophenols are unusual among the synthetic compounds discussed here in that they can be very toxic to microorganisms . They are often used as biocides...widely distributed. In contract, bacteria able to grow at the expense of chlorinated aliphatic compounds are less common and the

Sustaining the Light-Heavy Brigade

DTIC Science & Technology

1991-06-07

of the combined arms concept. In the twentieth century technology made a significant impact on how units were organized and fought. One of these...34Support personnel must use innovation , suspend normal procedures when necessary, take advantage of unusual sources of supply and transportation and take...designed to be broken out to individual task forces. Therefore, support planners must be innovative in developing a solution that best supports the

"This Must Have Been a Grand Sight": George Bent and the Battle of Platte Bridge

ERIC Educational Resources Information Center

Haack, Steven C.

2010-01-01

The Battle of Platte Bridge, July 26, 1865, is a noteworthy event in the annals of the American Indian Wars. An alliance of Cheyenne, Sioux, and Arapahoe, numbering in excess of 2,000 warriors, traveled three days to a specific military objective, an undertaking unusual both in terms of its magnitude and its level of organization. The battle,…

Solid-state radioluminescent compositions

DOEpatents

Clough, Roger L.; Gill, John T.; Hawkins, Daniel B.; Renschler, Clifford L.; Shepodd, Timothy J.; Smith, Henry M.

1991-01-01

A solid state radioluminescent composition for light source comprises an optically clear polymer organic matrix containing tritiated organic materials and dyes capable of "red" shifting primary scintillation emissions from the polymer matrix. The tritiated organic materials are made by reducing, with tritium, an unsaturated organic compound that prior to reduction contains olefinic or alkynylic bonds.

Looking inside and out: the impact of employee and community demographic composition on organizational diversity climate.

PubMed

Pugh, S Douglas; Dietz, Joerg; Brief, Arthur P; Wiley, Jack W

2008-11-01

An organization's diversity climate refers to employees' shared perceptions of the policies and practices that communicate the extent to which fostering diversity and eliminating discrimination is a priority in the organization. The authors propose a salient element of the organizational context, the racial composition of the community where the organization is located, serves an important signaling function that shapes the formation of climate perceptions. In a study of 142 retail bank units in the United States, evidence is found for a relationship between the racial composition of an organization's workforce and diversity climate that is moderated by the racial composition of the community where the organization is located. The results suggest that when few racial minorities live in the community in which an organization is embedded, workforce diversity has an impact on employees' diversity climate perceptions. As racial minority popular share increases, workforce diversity tends to lose this signaling value.

Compositions for enhancing hydroysis of cellulosic material by cellulolytic enzyme compositions

DOEpatents

Quinlan, Jason; Xu, Feng; Sweeney, Matthew; Johansen, Katja Salomon

2014-09-30

The present invention relates to compositions comprising a GH61 polypeptide having cellulolytic enhancing activity and an organic compound comprising a carboxylic acid moiety, a lactone moiety, a phenolic moiety, a flavonoid moiety, or a combination thereof, wherein the combination of the GH61 polypeptide having cellulolytic enhancing activity and the organic compound enhances hydrolysis of a cellulosic material by a cellulolytic enzyme compared to the GH61 polypeptide alone or the organic compound alone. The present invention also relates to methods of using the compositions.

Stable isotope compositions and water contents of boninite series volcanic rocks from Chichi-jima, Bonin Islands, Japan

USGS Publications Warehouse

Dobson, P.F.; O'Neil, J.R.

1987-01-01

Measurements of stable isotope compositions and water contents of boninite series volcanic rocks from the island of Chichi-jima, Bonin Islands, Japan, confirm that a large amount (1.6-2.4 wt.%) of primary water was present in these unusual magmas. An enrichment of 0.6??? in 18O during differentiation is explained by crystallization of 18O-depleted mafic phases. Silicic glasses have elevated ??18O values and relatively low ??D values indicating that they were modified by low-temperature alteration and hydration processes. Mafic glasses, on the other hand, have for the most part retained their primary isotopic signatures since Eocene time. Primary ??D values of -53 for boninite glasses are higher than those of MORB and suggest that the water was derived from subducted oceanic lithosphere. ?? 1987.

Unusual large-pitch banding in poly(L-lactic acid): Effects of composition and geometry confinement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woo, Eamor M.; Lugito, Graecia; Hsieh, Ya-Ting

2014-02-24

Lamellar patterns and orientations in blends of two crystalline polymers: poly(ethylene oxide) (PEO) and low-molecular-weight poly(L-lactic acid) (PLLA) were investigated using polarizing light optical microscopy (POM), and atomic and scanning electron microscopy (AFM, SEM). Specific etching off of PEO was used to reveal the complex earlier-grown PLLA lamellae patterns with various PEO content in blends. Banding of extremely long pitch (50 μm) in crystallized PLLA spherulites was induced by two kinetic factors: geometry confinement by top cover and introduction of diluent such as PEO. The mechanisms and correlation among the lamellar assembly, ring bands, and cracks are exemplified. Lamellar patternsmore » and ring-band types in blends were found to vary with respect to not only blend compositions, but also confinement of top-cover.« less

Nitriding kinetics of Si-SiC powder mixtures as simulations of reaction bonded Si3N4-SiC composites

NASA Technical Reports Server (NTRS)

Lightfoot, A.; Sheldon, B. W.; Flint, J. H.; Haggerty, J. S.

1989-01-01

The nitriding kinetics of Si and Si plus SiC powder mixtures were studied to simulate the fabrication of RBSN-SiC ceramic matrix composites. Very clean, assynthesized, and solvent-exposed powders were studied; C-rich and Si-rich SiC 0.04-0.05 micron diameter powders were mixed in varying concentrations with SiH4-derived 0.2-0.3 micron diameter Si powder. Complete nitridation is achieved with C-rich SiC powders in 140 min at 1250 C, and in the centers of Si-rich SiC powders in 15 min. The effects on the incubation periods, fast reaction periods, and slow reaction periods that characterize these nitriding processes were studied to explain unusual reverse reaction gradients and other effects of contamination.

The use of Stable Isotopes to Assess Climatic Controls on Groundwater Recharge in the Southern Sacramento Mountains, New Mexico

NASA Astrophysics Data System (ADS)

Newton, B. T.; Timmons, S. S.; Rawling, G. C.; Kludt, T.; Eastoe, C. J.

2008-12-01

We used the stable isotopes of hydrogen and oxygen to relate the temporal variability of groundwater recharge to climatic conditions in the southern Sacramento Mountains as a part of a larger regional hydrogeologic study. The southern Sacramento Mountains are the primary recharge source not only to local aquifers, but also to the Lower Pecos River Basin, the Roswell Artesian aquifer and aquifers in the Salt Basin. Aquifers in the study area mainly consist of fractured limestone. In years prior to 2006, groundwater levels within the study area showed a steady decline. We observed a significant increase in regional groundwater levels and spring discharge during and shortly after the unusually wet 2006 monsoon season. We developed a local meteoric water line (LMWL) in δ18O vs. δD space based on precipitation samples collected from several different elevations over a period of two years. The stable isotopic compositions of streams during base flow conditions define an evaporation line with a slope of 5.5 that intersects the LMWL in the region that represents winter precipitation. Spring and well samples collected in 2003 and spring samples collected in 2008 exhibit isotopic compositions that plot near the evaporation line, indicating that groundwater recharge is largely snow melt that has subsequently undergone evaporation in local streams. After the unusually wet 2006 monsoon season, the isotopic compositions of springs sampled in fall of 2006 and wells sampled in spring of 2007 deviated from the evaporation line, plotting closer to the LMWL. This observed isotopic trend is thought to represent a large input of 2006 monsoon precipitation to the groundwater system via relatively short fracture-dominated flow paths. Stable isotope results indicate that while snow melt is probably the main source of groundwater recharge in the southern Sacramento Mountains, as exhibited by the 2003 and 2008 samples, above average summer precipitation events, such as in 2006, can also contribute to significant groundwater recharge.

Pushing the Limits: 3D Layer-by-Layer-Assembled Composites for Cathodes with 160 C Discharge Rates.

PubMed

Mo, Runwei; Tung, Siu On; Lei, Zhengyu; Zhao, Guangyu; Sun, Kening; Kotov, Nicholas A

2015-05-26

Deficiencies of cathode materials severely limit cycling performance and discharge rates of Li batteries. The key problem is that cathode materials must combine multiple properties: high lithium ion intercalation capacity, electrical/ionic conductivity, porosity, and mechanical toughness. Some materials revealed promising characteristics in a subset of these properties, but attaining the entire set of often contrarian characteristics requires new methods of materials engineering. In this paper, we report high surface area 3D composite from reduced graphene oxide loaded with LiFePO4 (LFP) nanoparticles made by layer-by-layer assembly (LBL). High electrical conductivity of the LBL composite is combined with high ionic conductivity, toughness, and low impedance. As a result of such materials properties, reversible lithium storage capacity and Coulombic efficiency were as high as 148 mA h g(-1) and 99%, respectively, after 100 cycles at 1 C. Moreover, these composites enabled unusually high reversible charge-discharge rates up to 160 C with a storage capacity of 56 mA h g(-1), exceeding those of known LFP-based cathodes, some of them by several times while retaining high content of active cathode material. The study demonstrates that LBL-assembled composites enable resolution of difficult materials engineering tasks.

Multiple-component covalent organic frameworks

PubMed Central

Huang, Ning; Zhai, Lipeng; Coupry, Damien E.; Addicoat, Matthew A.; Okushita, Keiko; Nishimura, Katsuyuki; Heine, Thomas; Jiang, Donglin

2016-01-01

Covalent organic frameworks are a class of crystalline porous polymers that integrate molecular building blocks into periodic structures and are usually synthesized using two-component [1+1] condensation systems comprised of one knot and one linker. Here we report a general strategy based on multiple-component [1+2] and [1+3] condensation systems that enable the use of one knot and two or three linker units for the synthesis of hexagonal and tetragonal multiple-component covalent organic frameworks. Unlike two-component systems, multiple-component covalent organic frameworks feature asymmetric tiling of organic units into anisotropic skeletons and unusually shaped pores. This strategy not only expands the structural complexity of skeletons and pores but also greatly enhances their structural diversity. This synthetic platform is also widely applicable to multiple-component electron donor–acceptor systems, which lead to electronic properties that are not simply linear summations of those of the conventional [1+1] counterparts. PMID:27460607

Multiple-component covalent organic frameworks

NASA Astrophysics Data System (ADS)

Huang, Ning; Zhai, Lipeng; Coupry, Damien E.; Addicoat, Matthew A.; Okushita, Keiko; Nishimura, Katsuyuki; Heine, Thomas; Jiang, Donglin

2016-07-01

Covalent organic frameworks are a class of crystalline porous polymers that integrate molecular building blocks into periodic structures and are usually synthesized using two-component [1+1] condensation systems comprised of one knot and one linker. Here we report a general strategy based on multiple-component [1+2] and [1+3] condensation systems that enable the use of one knot and two or three linker units for the synthesis of hexagonal and tetragonal multiple-component covalent organic frameworks. Unlike two-component systems, multiple-component covalent organic frameworks feature asymmetric tiling of organic units into anisotropic skeletons and unusually shaped pores. This strategy not only expands the structural complexity of skeletons and pores but also greatly enhances their structural diversity. This synthetic platform is also widely applicable to multiple-component electron donor-acceptor systems, which lead to electronic properties that are not simply linear summations of those of the conventional [1+1] counterparts.

On the enrichment of hydrophobic organic compounds in fog droplets

NASA Astrophysics Data System (ADS)

Valsaraj, K. T.; Thoma, G. J.; Reible, D. D.; Thibodeaux, L. J.

The unusual degree of enrichment of hydrophobic organics in fogwater droplets reported by several investigators can be interpreted as a result of (a) the effects of temperature correction on the reported enrichment factors, (b) the effects of colloidal organic matter (both filterable and non-filterable) in fog water and (c) the effects of the large air-water interfacial adsorption of neutral hydrophobic organics on the tiny fog droplets. The enrichment factor was directly correlated to the hydrophobicity (or the activity coefficient in water) of the compounds, as indicated by their octanol-water partition constants. Compounds with large octanol-water partition coefficients (high activity coefficients in water) showed the largest enrichment. Available experimental data on the adsorption of hydrophobic compounds at the air-water interface and on colloidal organic carbon were used to show that the large specific air-water interfacial areas of fog droplets contribute significantly to the enrichment factor.

Temperature response of litter and soil organic matter decomposition is determined by chemical composition of organic material.

PubMed

Erhagen, Björn; Öquist, Mats; Sparrman, Tobias; Haei, Mahsa; Ilstedt, Ulrik; Hedenström, Mattias; Schleucher, Jürgen; Nilsson, Mats B

2013-12-01

The global soil carbon pool is approximately three times larger than the contemporary atmospheric pool, therefore even minor changes to its integrity may have major implications for atmospheric CO2 concentrations. While theory predicts that the chemical composition of organic matter should constitute a master control on the temperature response of its decomposition, this relationship has not yet been fully demonstrated. We used laboratory incubations of forest soil organic matter (SOM) and fresh litter material together with NMR spectroscopy to make this connection between organic chemical composition and temperature sensitivity of decomposition. Temperature response of decomposition in both fresh litter and SOM was directly related to the chemical composition of the constituent organic matter, explaining 90% and 70% of the variance in Q10 in litter and SOM, respectively. The Q10 of litter decreased with increasing proportions of aromatic and O-aromatic compounds, and increased with increased contents of alkyl- and O-alkyl carbons. In contrast, in SOM, decomposition was affected only by carbonyl compounds. To reveal why a certain group of organic chemical compounds affected the temperature sensitivity of organic matter decomposition in litter and SOM, a more detailed characterization of the (13) C aromatic region using Heteronuclear Single Quantum Coherence (HSQC) was conducted. The results revealed considerable differences in the aromatic region between litter and SOM. This suggests that the correlation between chemical composition of organic matter and the temperature response of decomposition differed between litter and SOM. The temperature response of soil decomposition processes can thus be described by the chemical composition of its constituent organic matter, this paves the way for improved ecosystem modeling of biosphere feedbacks under a changing climate. © 2013 John Wiley & Sons Ltd.

The Role of Physical and Human Landscape Properties on Carbon Composition of Organic Matter in Tropical Rivers

NASA Astrophysics Data System (ADS)

Ballester, M. R.; Krusche, A. V.; Victoria, R. L.; Richey, J. E.; Deegan, L.; Neill, C.

2011-12-01

To evaluate physical and human controls organic matter carbon composition in tropical rivers, we applied an integrated analysis of landscape properties and riverine isotopic composition. Our goal was to establish the relationships between basin attributes and forms and composition of dissolved and particulate organic matter in rivers. A GIS template was developed as tool to support the understanding of the biogeochemistry of the surface waters of the Ji-Paraná (Western Amazonia) and the Piracicaba (southeastern of Brazil)rivers. Each basin was divided into drainage units, organized according to river network morphology and degree of land-use impact. The delineated drainage areas were individually characterized in terms of topography, soils and land use using data sets compiled as layers in ArcGis and ERDAS-IMAGINE software. DOM and POM carbon stable isotopic composition were determined at several sites along the main tributaries and small streams. The effects of these drivers on the fluvial carbon was quantified by a multiple linear regression analysis, relating basin characteristics and river isotopic composition. The results showed that relatively recent land cover changes have already had an impact on the composition of the riverine DOM and POM, indicating that, as in natural ecosystems, the vegetation plays a key role in the composition of the riverine organic matter in agricultural systems.

Morphology and formation mechanism in precipitation of calcite induced by Curvibacter lanceolatus strain HJ-1

NASA Astrophysics Data System (ADS)

Zhang, Chonghong; Li, Fuchun; Lv, Jiejie

2017-11-01

Precipitation of calcium carbobate induced by microbial activities is common occurrence in controlled solution, but the formation mechanism and morphology in precipitation of calcite in solution systems is unclear, and the role of microbes is disputed. Here, culture experiment was performed for 50 days using the Curvibacter lanceolatus strain HJ-1 in a M2 culture medium, and the phase composition and morphology of the precipitates were characterized by the X-ray diffraction (XRD), Fourier transform infrared (FT-IR), and scanning electron microscopy (SEM) techniques. We show that the precipitation processes in our experiment lead to unusual morphologies of crystals corresponding to different growth stages, and the morphologies of the precipitated crystal aggregates ranging from the main rod-, cross-, star-, cauliflower-like morphologies to spherulitic structure. The complex and unusual morphologies of the precipitated calcite by strain HJ-1 may provide a reference point for better understanding the biomineralization mechanism of calcite, moreover, morphological transition of minerals revealed that the multi-ply crystals-aggregation mechanism for calcite growth in crystallisation media.

Stabilization of nucleic acids by unusual polyamines produced by an extreme thermophile, Thermus thermophilus

PubMed Central

2005-01-01

Extreme thermophiles produce two types of unusual polyamine: long linear polyamines such as caldopentamine and caldohexamine, and branched polyamines such as quaternary ammonium compounds [e.g. tetrakis(3-aminopropyl)ammonium]. To clarify the physiological roles of long linear and branched polyamines in thermophiles, we synthesized them chemically and tested their effects on the stability of ds (double-stranded) and ss (single-stranded) DNAs and tRNA in response to thermal denaturation, as measured by differential scanning calorimetry. Linear polyamines stabilized dsDNA in proportion to the number of amino nitrogen atoms within their molecular structure. We used the empirical results to derive formulae that estimate the melting temperature of dsDNA in the presence of polyamines of a particular molecular composition. ssDNA and tRNA were stabilized more effectively by tetrakis(3-aminopropyl)ammonium than any of the other polyamines tested. We propose that long linear polyamines are effective to stabilize DNA, and tetrakis(3-aminopropyl)ammonium plays important roles in stabilizing RNAs in thermophile cells. PMID:15673283

The Biosynthesis of Nitrogen-, Sulfur-, and High-carbon Chain-containing Sugars†

PubMed Central

Lin, Chia-I; McCarty, Reid M.; Liu, Hung-wen

2013-01-01

Carbohydrates serve many structural and functional roles in biology. While the majority of monosaccharides are characterized by the chemical composition: (CH2O)n, modifications including deoxygenation, C-alkylation, amination, O- and N-methylation, which are characteristic of many sugar appendages of secondary metabolites, are not uncommon. Interestingly, some sugar molecules are formed via modifications including amine oxidation, sulfur incorporation, and “high-carbon” chain attachment. Most of these unusual sugars have been identified over the past several decades as components of microbially produced natural products, although a few high-carbon sugars are also found in the lipooligosaccharides of the outer cell walls of Gram-negative bacteria. Despite their broad distribution in nature, these sugars are considered “rare” due to their relative scarcity. The biosynthetic steps that underlie their formation continue to perplex researchers to this day and many questions regarding key transformations remain unanswered. This review will focus on our current understanding of the biosynthesis of unusual sugars bearing oxidized amine substituents, thio-functional groups, and high-carbon chains. PMID:23348524

Excited-state proton transfer dynamics of firefly's chromophore D-luciferin in DMSO-water binary mixture.

PubMed

Kuchlyan, Jagannath; Banik, Debasis; Roy, Arpita; Kundu, Niloy; Sarkar, Nilmoni

2014-12-04

In this article we have investigated intermolecular excited-state proton transfer (ESPT) of firefly's chromophore D-luciferin in DMSO-water binary mixtures using steady-state and time-resolved fluorescence spectroscopy. The unusual behavior of DMSO-water binary mixture as reported by Bagchi et al. (J. Phys. Chem. B 2010, 114, 12875-12882) was also found using D-luciferin as intermolecular ESPT probe. The binary mixture has given evidence of its anomalous nature at low mole fractions of DMSO (below XD = 0.4) in our systematic investigation. Upon excitation of neutral D-luciferin molecule, dual fluorescence emissions (protonated and deprotonated form) are observed in DMSO-water binary mixture. A clear isoemissive point in the time-resolved area normalized emission spectra further indicates two emissive species in the excited state of D-luciferin in DMSO-water binary mixture. DMSO-water binary mixtures of different compositions are fascinating hydrogen bonding systems. Therefore, we have observed unusual changes in the fluorescence emission intensity, fluorescence quantum yield, and fluorescence lifetime of more hydrogen bonding sensitive anionic form of D-luciferin in low DMSO content of DMSO-water binary mixture.

The origin of the 'FUN' anomalies and the high temperature inclusions in the Allende meteorite. [Fractionation and Unknown Nuclear processes

NASA Technical Reports Server (NTRS)

Consolmagno, G. J.; Cameron, A. G. W.

1980-01-01

The discovery of isotopic anomalies in white inclusions of the meteorite Allende has led to fundamental questions concerning the origin of these anomalies and of the white inclusions themselves. An analysis of the 'FUN' anomalies in the inclusions C1 and EK1-4-1 demonstrates that these isotopic anomalies may be decomposed into individual nucleosynthetic components, which have been subjected to separate mass and component fractionations. There is no evidence that any freshly-synthesized material injected into the primitive solar nebula was of abnormal isotopic composition, or that the FUN anomalies were due to an injection of unusual material. Rather, they show the effects of large mass fractionations and an unusual mixture of normal nucleosynthetic material, likely to be in the form of interstellar grains whose size or chemistry served as a memory for the nucleosynthetic origins of their constituent atoms. Giant gaseous protoplanets, as described for the early solar nebula by Cameron (1978), are a potential site for achieving both mass and component fractionations, and for producing white inclusions in general.

Nano Titanium Monoxide Crystals and Unusual Superconductivity at 11 K.

PubMed

Xu, Jijian; Wang, Dong; Yao, Heliang; Bu, Kejun; Pan, Jie; He, Jianqiao; Xu, Fangfang; Hong, Zhanglian; Chen, Xiaobo; Huang, Fuqiang

2018-03-01

Nano TiO 2 is investigated intensely due to extraordinary photoelectric performances in photocatalysis, new-type solar cells, etc., but only very few synthesis and physical properties have been reported on nanostructured TiO or other low valent titanium-containing oxides. Here, a core-shell nanoparticle made of TiO core covered with a ≈5 nm shell of amorphous TiO 1+ x is newly constructed via a controllable reduction method to synthesize nano TiO core and subsequent soft oxidation to form the shell (TiO 1+ x ). The physical properties measurements of electrical transport and magnetism indicate these TiO@TiO 1+ x nanocrystals are a type-ІІ superconductor of a recorded T c onset = 11 K in the binary Ti-O system. This unusual superconductivity could be attributed to the interfacial effect due to the nearly linear gradient of O/Ti ratio across the outer amorphous layer. This novel synthetic method and enhanced superconductivity could open up possibilities in interface superconductivity of nanostructured composites with well-controlled interfaces. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An Unusual Strong Visible-Light Absorption Band in Red Anatase TiO2 Photocatalyst Induced by Atomic Hydrogen-Occupied Oxygen Vacancies.

PubMed

Yang, Yongqiang; Yin, Li-Chang; Gong, Yue; Niu, Ping; Wang, Jian-Qiang; Gu, Lin; Chen, Xingqiu; Liu, Gang; Wang, Lianzhou; Cheng, Hui-Ming

2018-02-01

Increasing visible light absorption of classic wide-bandgap photocatalysts like TiO 2 has long been pursued in order to promote solar energy conversion. Modulating the composition and/or stoichiometry of these photocatalysts is essential to narrow their bandgap for a strong visible-light absorption band. However, the bands obtained so far normally suffer from a low absorbance and/or narrow range. Herein, in contrast to the common tail-like absorption band in hydrogen-free oxygen-deficient TiO 2 , an unusual strong absorption band spanning the full spectrum of visible light is achieved in anatase TiO 2 by intentionally introducing atomic hydrogen-mediated oxygen vacancies. Combining experimental characterizations with theoretical calculations reveals the excitation of a new subvalence band associated with atomic hydrogen filled oxygen vacancies as the origin of such band, which subsequently leads to active photo-electrochemical water oxidation under visible light. These findings could provide a powerful way of tailoring wide-bandgap semiconductors to fully capture solar light. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Shell thickness-dependent microwave absorption of core-shell Fe3O4@C composites.

PubMed

Du, Yunchen; Liu, Wenwen; Qiang, Rong; Wang, Ying; Han, Xijiang; Ma, Jun; Xu, Ping

2014-08-13

Core-shell composites, Fe3O4@C, with 500 nm Fe3O4 microspheres as cores have been successfully prepared through in situ polymerization of phenolic resin on the Fe3O4 surface and subsequent high-temperature carbonization. The thickness of carbon shell, from 20 to 70 nm, can be well controlled by modulating the weight ratio of resorcinol and Fe3O4 microspheres. Carbothermic reduction has not been triggered at present conditions, thus the crystalline phase and magnetic property of Fe3O4 micropsheres can be well preserved during the carbonization process. Although carbon shells display amorphous nature, Raman spectra reveal that the presence of Fe3O4 micropsheres can promote their graphitization degree to a certain extent. Coating Fe3O4 microspheres with carbon shells will not only increase the complex permittivity but also improve characteristic impedance, leading to multiple relaxation processes in these composites, thus the microwave absorption properties of these composites are greatly enhanced. Very interestingly, a critical thickness of carbon shells leads to an unusual dielectric behavior of the core-shell structure, which endows these composites with strong reflection loss, especially in the high frequency range. By considering good chemical homogeneity and microwave absorption, we believe the as-fabricated Fe3O4@C composites can be promising candidates as highly effective microwave absorbers.

Hemophagocytic syndrome as one of the main primary manifestations in acute systemic lupus erythematosus--case report and literature review.

PubMed

Carvalheiras, G; Anjo, D; Mendonça, T; Vasconcelos, C; Farinha, F

2010-05-01

Hemophagocytic syndrome is an unusual but fatal disorder characterized by pancytopenia and activation of macrophages. We describe one case of acute systemic lupus erythematosus with an unusual presentation of hemophagocytic syndrome not related to infection. The patient presented with pancytopenia related to increasing hemophagocytic activity of histiocytes in the bone marrow. Concomitant class IV World Health Organization lupus nephritis, serositis, high titer of antinuclear factor and positive test for anti-DNA antibody fitted the diagnostic criteria of systemic lupus erythematosus. She also presented with alveolar hemorrhage and lupus myocarditis. She underwent immunosuppressive therapy with recovery from the hemophagocytic syndrome. Therefore, diagnosis of acute lupus hemophagocytic syndrome was made. The clinical presentation, laboratory diagnosis, and management of the patient are discussed and the literature was reviewed and presented, with emphasis on a possible distinct lupus subset, which includes a more aggressive systemic disease with heart involvement.

Unusual intraosseous fossilized soft tissues from the Middle Triassic Nothosaurus bone

NASA Astrophysics Data System (ADS)

Surmik, Dawid; Rothschild, Bruce M.; Pawlicki, Roman

2017-04-01

Fossilized soft tissues, occasionally found together with skeletal remains, provide insights to the physiology and functional morphology of extinct organisms. Herein, we present unusual fossilized structures from the cortical region of bone identified in isolated skeletal remains of Middle Triassic nothosaurs from Upper Silesia, Poland. The ribbed or annuli-shaped structures have been found in a sample of partially demineralized coracoid and are interpreted as either giant red blood cells or as blood vessel walls. The most probable function is reinforcing the blood vessels from changes of nitrogen pressure in air-breathing diving reptiles. These structures seem to have been built of extensible muscle layers which prevent the vessel damage during rapid ascent. Such suspected function presented here is parsimonious with results of previous studies, which indicate rarity of the pathological modification of bones associated with decompression syndrome in Middle Triassic nothosaurs.

A novel porous framework as variable chemo-sensor: from response of specific carcinogenic alkyl-aromatic to selective detection of explosive nitro-aromatics.

PubMed

Chen, Qihui

2018-06-07

Selective probing one molecule from one class similar molecules is highly challenging due to their similar chemical and physical properties. Here, a novel metal-organic framework FJI-H15 with flexible porous cages has been designed and synthesized, which can specifically recognize ethyl-benzene with ultrahigh enhancement efficiency from series of alkyl-aromatics, in which an unusual size-dependent interaction has been found and proved. While it also can selectively detect phenolic-nitroaromatics among series of nitro-aromatics based on energy transferring and electrostatic interaction. Such unusual specificity and variable mechanisms responding to different type molecules has not been reported, which will provide a new strategy for developing more effective chemo-sensor based on MOFs for probing small structural differences in molecules. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bacteroides (Parabacteroides) distasonis splenic abscess in a sickle cell patient.

PubMed

Al-Tawfiq, Jaffar A

2008-01-01

Splenic abscess is not an uncommon complication of patients with sickle-cell disease. Here we describe an 18 year-old boy with sickle cell disease and left upper quadrant abdominal pain. Computerized axial tomography revealed left sided free flowing pleural effusion and splenomegaly with liquefaction and possible gas formation. The splenic fluid grew an unusual organism known as Bacteroides distasonis. The patient received antimicrobial therapy and underwent a splenectomy with full recovery. The spleen was cystically infarcted and measured 22 x 16 x 5 cm. The capsule was thickened and covered by fibrinous exudate. Histopathologic examination of the spleen showed complete necrosis with reparative fibrosis. This case presents an unusual cause of splenic abscess due to Bacteroides distasonis with a subacute to chronic course. The presence of fever and left sided pleuritic chest pain in patients with sickle cell disease should raise the suspicion of splenic abscess.

Polymer-Attached Functional Inorganic-Organic Hybrid Nano-Composite Aerogels

DTIC Science & Technology

2003-01-01

drugs. The chemistry to synthesize polyamino- siloxane based aerogel composite was discussed. In addition, two approaches to synthesize PHEMA aerogel... Composite Aerogels DISTRIBUTION: Approved for public release, distribution unlimited This paper is part of the following report: TITLE: Materials...Proc. Vol. 740 © 2003 Materials Research Society 112.24 Polymer-Attached Functional Inorganic-Organic Hybrid Nano- composite Aerogels Xipeng Liu, Mingzhe

The mitochondrial genome of the ethanol-metabolizing, wine cellar mold Zasmidium cellare is the smallest for a filamentous ascomycete.

PubMed

Goodwin, Stephen B; McCorison, Cassandra B; Cavaletto, Jessica R; Culley, David E; LaButti, Kurt; Baker, Scott E; Grigoriev, Igor V

2016-08-01

Fungi in the class Dothideomycetes often live in extreme environments or have unusual physiology. One of these, the wine cellar mold Zasmidium cellare, produces thick curtains of mycelia in cellars with high humidity, and its ability to metabolize volatile organic compounds is thought to improve air quality. Whether these abilities have affected its mitochondrial genome is not known. To fill this gap, the circular-mapping mitochondrial genome of Z. cellare was sequenced and, at only 23 743 bp, is the smallest reported for a filamentous fungus. Genes were encoded on both strands with a single change of direction, different from most other fungi but consistent with the Dothideomycetes. Other than its small size, the only unusual feature of the Z. cellare mitochondrial genome was two copies of a 110-bp sequence that were duplicated, inverted and separated by approximately 1 kb. This inverted-repeat sequence confused the assembly program but appears to have no functional significance. The small size of the Z. cellare mitochondrial genome was due to slightly smaller genes, lack of introns and non-essential genes, reduced intergenic spacers and very few ORFs relative to other fungi rather than a loss of essential genes. Whether this reduction facilitates its unusual biology remains unknown. Published by Elsevier Ltd.

Nanoporous poly(3-hexylthiophene) thin film structures from self-organization of a tunable molecular bottlebrush scaffold

DOE PAGES

Ahn, Suk-kyun; Carrillo, Jan-Michael Y.; Keum, Jong K.; ...

2017-04-07

The ability to widely tune the design of macromolecular bottlebrushes provides access to self-assembled nanostructures formed by microphase segregation in melt, thin film and solution that depart from structures adopted by simple linear copolymers. A series of random bottlebrush copolymers containing poly(3-hexylthiophene) (P3HT) and poly(D,L-lactide) (PLA) side chains grafted on a poly(norbornene) backbone were synthesized via ring-opening metathesis polymerization (ROMP) using the grafting through approach. P3HT side chains induce a physical aggregation of the bottlebrush copolymers upon solvent removal by vacuum drying, primarily driven by attractive π–π interactions; however, the amount of aggregation can be controlled by adjusting side chainmore » composition or by adding linear P3HT chains to the bottlebrush copolymers. Coarse-grained molecular dynamics simulations reveal that linear P3HT chains preferentially associate with P3HT side chains of bottlebrush copolymers, which tends to reduce the aggregation. The nanoscale morphology of microphase segregated thin films created by casting P3HT–PLA random bottlebrush copolymers is highly dependent on the composition of P3HT and PLA side chains, while domain spacing of nanostructures is mainly determined by the length of the side chains. The selective removal of PLA side chains under alkaline conditions generates nanoporous P3HT structures that can be tuned by manipulating molecular design of the bottlebrush scaffold, which is affected by molecular weight and grafting density of the side chains, and their sequence. Furthermore, the ability to exploit the unusual architecture of bottlebrushes to fabricate tunable nanoporous P3HT thin film structures may be a useful way to design templates for optoelectronic applications or membranes for separations.« less

Nanoporous poly(3-hexylthiophene) thin film structures from self-organization of a tunable molecular bottlebrush scaffold

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahn, Suk-kyun; Carrillo, Jan-Michael Y.; Keum, Jong K.

The ability to widely tune the design of macromolecular bottlebrushes provides access to self-assembled nanostructures formed by microphase segregation in melt, thin film and solution that depart from structures adopted by simple linear copolymers. A series of random bottlebrush copolymers containing poly(3-hexylthiophene) (P3HT) and poly(D,L-lactide) (PLA) side chains grafted on a poly(norbornene) backbone were synthesized via ring-opening metathesis polymerization (ROMP) using the grafting through approach. P3HT side chains induce a physical aggregation of the bottlebrush copolymers upon solvent removal by vacuum drying, primarily driven by attractive π–π interactions; however, the amount of aggregation can be controlled by adjusting side chainmore » composition or by adding linear P3HT chains to the bottlebrush copolymers. Coarse-grained molecular dynamics simulations reveal that linear P3HT chains preferentially associate with P3HT side chains of bottlebrush copolymers, which tends to reduce the aggregation. The nanoscale morphology of microphase segregated thin films created by casting P3HT–PLA random bottlebrush copolymers is highly dependent on the composition of P3HT and PLA side chains, while domain spacing of nanostructures is mainly determined by the length of the side chains. The selective removal of PLA side chains under alkaline conditions generates nanoporous P3HT structures that can be tuned by manipulating molecular design of the bottlebrush scaffold, which is affected by molecular weight and grafting density of the side chains, and their sequence. Furthermore, the ability to exploit the unusual architecture of bottlebrushes to fabricate tunable nanoporous P3HT thin film structures may be a useful way to design templates for optoelectronic applications or membranes for separations.« less

Graphene Quantum Dot-Aerogel: From Nanoscopic to Macroscopic Fluorescent Materials. Sensing Polyaromatic Compounds in Water.

PubMed

Martín-Pacheco, Ana; Del Río Castillo, Antonio Esaú; Martín, Cristina; Herrero, María Antonia; Merino, Sonia; García Fierro, José Luis; Díez-Barra, Enrique; Vázquez, Ester

2018-05-30

Fluorescence based on quantum confinement is a property restricted to the nanoscopic range. The incorporation of nanoparticles in a three-dimensional polymeric network could afford macroscopic scaffolds that show nanoscopic properties. Moreover, if these scaffolds are based on strong bonds, the stability of the resulting materials can be preserved, thus enhancing their final applications. We report for the first time the preparation of a graphene quantum dot (GQD) composite based on a cationic covalent network. This new material has unusual features: (i) the final composite remains stable after several swelling-deswelling cycles, thus demonstrating strong interactions between GQDs and the polymeric material, and therefore it could be used as a portable system. (ii) Fluorescence emission in the composite and in solution is quasi-independent to the excitation wavelength. (iii) However, and in contrast to the behavior observed in GQD solutions, the fluorescence of the composite remains unaltered over a wide pH range and in the presence of different ions commonly found in tap water. (iv) Fluorescence quenching is only observed as a consequence of molecules that bear aromatic systems, and this could be applied to the preparation of in situ water sensors.

Evaporation in the young solar nebula as the origin of 'just-right' melting of chondrules

PubMed

Cohen; Hewins; Yu

2000-08-10

Chondrules are millimetre-sized, solidified melt spherules formed in the solar nebula by an early widespread heating event of uncertain nature. They were accreted into chondritic asteroids, which formed about 4.56 billion years ago and have not experienced melting or differentiation since that time. Chondrules have diverse chemical compositions, corresponding to liquidus temperatures in the range 1,350-1,800 degrees C. Most chondrules, however, show porphyritic textures (consisting of large crystals in a distinctly finer grained or glassy matrix), indicative of melting within the narrow range 0-50 degrees C below the liquidus. This suggests an unusual heating mechanism for chondrule precursors, which would raise each individual chondrule to just the right temperature (particular to individual bulk composition) in order to form porphyritic textures. Here we report the results of isothermal melting of a chondritic composition at nebular pressures. Our results suggest that evaporation stabilizes porphyritic textures over a wider range of temperatures below the liquidus (about 200 degrees C) than previously believed, thus removing the need for individual chondrule temperature buffering. In addition, we show that evaporation explains many chondrule bulk and mineral compositions that have hitherto been difficult to understand.

17 CFR 1.64 - Composition of various self-regulatory organization governing boards and major disciplinary...

Code of Federal Regulations, 2014 CFR

2014-04-01

... ACT Miscellaneous § 1.64 Composition of various self-regulatory organization governing boards and... organization means “self-regulatory organization” as defined in § 1.3(ee), not including a “clearing... authorized by a self-regulatory organization to conduct disciplinary hearings, to settle disciplinary charges...

17 CFR 1.64 - Composition of various self-regulatory organization governing boards and major disciplinary...

Code of Federal Regulations, 2010 CFR

2010-04-01

... ACT Miscellaneous § 1.64 Composition of various self-regulatory organization governing boards and... organization means “self-regulatory organization” as defined in § 1.3(ee), not including a “clearing... authorized by a self-regulatory organization to conduct disciplinary hearings, to settle disciplinary charges...

17 CFR 1.64 - Composition of various self-regulatory organization governing boards and major disciplinary...

Code of Federal Regulations, 2012 CFR

2012-04-01

... ACT Miscellaneous § 1.64 Composition of various self-regulatory organization governing boards and... organization means “self-regulatory organization” as defined in § 1.3(ee), not including a “clearing... authorized by a self-regulatory organization to conduct disciplinary hearings, to settle disciplinary charges...

17 CFR 1.64 - Composition of various self-regulatory organization governing boards and major disciplinary...

Code of Federal Regulations, 2013 CFR

2013-04-01

... ACT Miscellaneous § 1.64 Composition of various self-regulatory organization governing boards and... organization means “self-regulatory organization” as defined in § 1.3(ee), not including a “clearing... authorized by a self-regulatory organization to conduct disciplinary hearings, to settle disciplinary charges...

17 CFR 1.64 - Composition of various self-regulatory organization governing boards and major disciplinary...

Code of Federal Regulations, 2011 CFR

2011-04-01

... ACT Miscellaneous § 1.64 Composition of various self-regulatory organization governing boards and... organization means “self-regulatory organization” as defined in § 1.3(ee), not including a “clearing... authorized by a self-regulatory organization to conduct disciplinary hearings, to settle disciplinary charges...

A LEAFY co-regulator encoded by UNUSUAL FLORAL ORGANS.

PubMed

Lee, I; Wolfe, D S; Nilsson, O; Weigel, D

1997-02-01

. Development of petals and stamens in Arabidopsis flowers requires the function of the organ-identity gene APETALA3 (AP3), whose RNA is expressed specifically in petal and stamen primordia. AP3 expression is positively regulated by the meristem-identity gene LEAFY (LFY), which is expressed ubiquitously in young flowers. It is unknown how the transition from ubiquitous expression of LFY to region-specific expression of AP3 is made. It has previously been proposed for Antirrhinum that another gene, FIMBRIATA (FIM), mediates between the LFY and AP3 orthologs, with the three genes acting in a simple regulatory hierarchy. FIM is activated later than the LFY ortholog, and its expression is more restricted than that of the LFY ortholog. . We have tested whether the model proposed for Antirrhinum applies to Arabidopsis, by creating transgenic plants in which the FIM ortholog UNUSUAL FLORAL ORGANS (UFO) was expressed constitutively from the promoter of the cauliflower mosaic virus 35S gene. In 35S::UFO flowers, AP3 was expressed precociously and ectopically, confirming that UFO is an upstream regulator of AP3. However, 35S::UFO could not restore petal and stamen development in lfy mutants, indicating that UFO can only function in the presence of LFY activity. The failure of 35S::UFO to rescue lfy mutants is consistent with our observation that UFO expression levels are not markedly changed in lfy mutants. . We conclude that UFO is not a simple mediator between meristem- and organ-identity genes, but is likely to be a partially dispensable co-regulator that acts together with LFY. The interplay between LFY and UFO provides a paradigm for how a global regulator such as LFY activates selected target genes only in restricted regions within its expression domain.

Diatoms in sediments of perennially ice-covered Lake Hoare, and implications for interpreting lake history in the McMurdo Dry Valleys of Antarctica

USGS Publications Warehouse

Spaulding, S.A.; McKnight, Diane M.; Stoermer, E.F.; Doran, P.T.

1997-01-01

Diatom assemblages in surficial sediments, sediment cores, sediment traps, and inflowing streams of perennially ice-covered Lake Hore, South Victorialand, Antarctica were examined to determine the distribution of diatom taxa, and to ascertain if diatom species composition has changed over time. Lake Hoare is a closed-basin lake with an area of 1.8 km2, maximum depth of 34 m, and mean depth of 14 m, although lake level has been rising at a rate of 0.09 m yr-1 in recent decades. The lake has an unusual regime of sediment deposition: coarse grained sediments accumulate on the ice surface and are deposited episodically on the lake bottom. Benthic microbial mats are covered in situ by the coarse episodic deposits, and the new surfaces are recolonized. Ice cover prevents wind-induced mixing, creating the unique depositional environment in which sediment cores record the history of a particular site, rather than a lake=wide integration. Shallow-water (<1 m) diatom assemblages (Stauroneis anceps, Navicula molesta, Diadesmis contenta var. parallela, Navicula peraustralis) were distinct from mid-depth (4-16 m) assemblages (Diadesmis contenta, Luticola muticopsis fo. reducta, Stauroneis anceps, Diadesmis contenta var. parallela, Luticola murrayi) and deep-water (2-31 m) assemblages (Luticola murrayi, Luticola muticopsis fo. reducta, Navicula molesta. Analysis of a sediment core (30 cm long, from 11 m water depth) from Lake Hoare revealed two abrupt changes in diatom assemblages. The upper section of the sediment core contained the greatest biomass of benthic microbial mat, as well as the greatest total abundance and diversity of diatoms. Relative abundances of diatoms in this section are similar to the surficial samples from mid-depths. An intermediate zone contained less organic material and lower densities of diatoms. The bottom section of core contained the least amount of microbial mat and organic material, and the lowest density of diatoms. The dominant process influencing species composition and abundance of diatom assemblages in the benthic microbial mats is episodic deposition of coarse sediment from the ice surface.

Size-Resolved Composition of Organic Aerosol on the California Central Coast

NASA Astrophysics Data System (ADS)

Babila, J. E.; Depew, C. J.; Heinrich, S. E.; Zoerb, M.

2016-12-01

Organic compounds represent a significant mass fraction of submicrometer aerosol and can influence properties such as radiative forcing and cloud formation. Despite their broad importance, a complete description of particle sources and composition is lacking. Here we present measurements of solvent-extracted organic compounds in ambient aerosol in San Luis Obispo, CA. Ambient particles were sampled and size segregated with a micro-orifice uniform deposit impactor (MOUDI). Water and methanol soluble organic carbon was characterized with electrospray ionization mass spectrometry (ESI-MS) and UV/Vis spectroscopy. Particle composition and influences from local and regional sources on the organic fraction will be discussed.

Tunable organic transistors that use microfluidic source and drain electrodes

NASA Astrophysics Data System (ADS)

Maltezos, George; Nortrup, Robert; Jeon, Seokwoo; Zaumseil, Jana; Rogers, John A.

2003-09-01

This letter describes a type of transistor that uses conducting fluidic source and drain electrodes of mercury which flow on top of a thin film of the organic semiconductor pentacene. Pumping the mercury through suitably designed microchannels changes the width of the transistor channel and, therefore, the electrical characteristics of the device. Measurements on transistors with a range of channel lengths reveal low contact resistances between mercury and pentacene. Data collected before, during, and after pumping the mercury through the microchannels demonstrate reversible and systematic tuning of the devices. This unusual type of organic transistor has the potential to be useful in plastic microfluidic devices that require active elements for pumps, sensors, or other components. It also represents a noninvasive way to build transistor test structures that incorporate certain classes of chemically and mechanically fragile organic semiconductors.

The mineralogy, petrology, and composition of anomalous eucrite Emmaville

NASA Astrophysics Data System (ADS)

Barrett, T. J.; Mittlefehldt, D. W.; Greenwood, R. C.; Charlier, B. L. A.; Hammond, S. J.; Ross, D. K.; Anand, M.; Franchi, I. A.; Abernethy, F. A. J.; Grady, M. M.

2017-04-01

The Emmaville eucrite is a relatively poorly studied basaltic achondrite with an anomalous oxygen isotope signature. In this study, we report comprehensive mineralogical, petrographic, and geochemical data from Emmaville in order to understand its petrogenesis and relationship with the basaltic eucrites. Emmaville is an unusually fine-grained, hornfelsic-textured metabasalt with pervasive impact melt veins and mineral compositions similar to those of typical basaltic eucrites. The major and trace element bulk composition of Emmaville is also typical of a basaltic eucrite. Three separated individual lithologies were also analyzed for O isotopes; a dark gray fraction (E1), a shocked lithology (E2), and a lighter gray portion (E3). Fractions E1 and E2 shared similar O isotope compositions to the bulk sample (E-B), whereas the lighter gray portion (E3) is slightly elevated in Δ17O and significantly elevated in δ18O compared to bulk. No evidence for any exogenous material is observed in the thin sections, coupled with the striking compositional similarity to typical basaltic eucrites, appears to preclude a simple impact-mixing hypothesis. The O-isotopes of Emmaville are similar to those of Bunburra Rockhole, A-881394, and EET 92023, and thus distinct from the majority of the HEDs, despite having similarities in petrology, mineral, and bulk compositions. It would, therefore, seem plausible that all four of these samples are derived from a single HED-like parent body that is isotopically distinct from that of the HEDs (Vesta) but similar in composition.

Purification and characterization of creatine kinase isozymes from the nurse shark Ginglymostoma cirratum.

PubMed

Gray, K A; Grossman, S H; Summers, D D

1986-01-01

Creatine kinase from nurse shark brain and muscle has been purified to apparent homogeneity. In contrast to creatine kinases from most other vertebrate species, the muscle isozyme and the brain isozyme from nurse shark migrate closely in electrophoresis and, unusually, the muscle isozyme is anodal to the brain isozyme. The isoelectric points are 5.3 and 6.2 for the muscle and brain isozymes, respectively. The purified brain preparation also contains a second active protein with pI 6.0. The amino acid content of the muscle isozyme is compared with other isozymes of creatine kinase using the Metzger Difference Index as an estimation of compositional relatedness. All comparisons show a high degree of compositional similarity including arginine kinase from lobster muscle. The muscle isozyme is marginally more resistant to temperature inactivation than the brain isozyme; the muscle protein does not exhibit unusual stability towards high concentrations of urea. Kinetic analysis of the muscle isozyme reveals Michaelis constants of 1.6 mM MgATP, 12 mM creatine, 1.2 mM MgADP and 50 mM creatine phosphate. Dissociation constants for the same substrate from the binary and ternary enzyme-substrate complex do not differ significantly, indicating limited cooperatively in substrate binding. Enzyme activity is inhibited by small planar anions, most severely by nitrate. Shark muscle creatine kinase hybridizes in vitro with rabbit muscle or monkey brain creatine kinase; shark brain isozyme hybridizes with monkey brain or rabbit brain creatine kinase. Shark muscle and shark brain isozymes, under a wide range of conditions, failed to produce a detectable hybrid.

Temperature and Oxygen Fugacity Constraints on CK and R Chondrites and Implications for Water and Oxidation in the Early Solar System

NASA Technical Reports Server (NTRS)

Righter, K.; Neff, K. E.

2007-01-01

Recent chondritic meteorite finds in Antarctica have included CB, CH, CK and R chondrites, the latter two of which are among the most oxidized materials found in meteorite collections. In this study we present petrographic and mineralogic data for a suite of CK and R chondrites, and compare to previous studies of CK and R, as well as some CV chondrites. In particular we focus on the opaque minerals magnetite, chromite, sulfides, and metal as well as unusual silicates hornblende, biotite, and plagioclase. Several mineral thermometers and oxy-barometers are utilized to calculate temperatures and oxygen fugacities for these unusual meteorites compared to other more common chondrite groups. R and CK chondrites show lower equilibrium temperatures than ordinary chondrites, even though they are at similar petrologic grades (e.g., thermal type 6). Oxygen fugacity calculated for CV and R chondrites ranges from values near the iron-wustite (IW) oxygen buffer to near the fayalite-magnetite-quartz (FMQ) buffer. In comparison, the fO2 recorded by ilmenite-magnetite pairs from CK chondrites are much higher, from FMQ+3.1 to FMQ+5.2. The latter values are the highest recorded for materials in meteorites, and place some constraints on the formation conditions of these magnetite-bearing chondrites. Differences between mineralogic and O isotopic compositions of CK and R chondrites suggest two different oxidation mechanisms, which may be due to high and low water: rock ratios during metamorphism, or to different fluid compositions, or both.

Discovery of modern (post-1850 CE) lavas in south-central British Columbia, Canada: Origin from coal fires or intraplate volcanism?

NASA Astrophysics Data System (ADS)

Canil, Dante; Mihalynuk, Mitch; Lacourse, Terri

2018-01-01

We describe three unusual lavas in the Northern Cordillera in south-central British Columbia, Canada, occurring as spatter, scoria and blocks over small 400 m2 areas. The lavas coat and weld cobbles and pebbles in glacial till and are vesicular and glassy with microlites of clinopyroxene and plagioclase, and xenocrysts of quartz, feldspar or clinopyroxene. Chemically the lavas are basaltic trachyandesite (55-61 wt% SiO2) with trace element patterns similar to average British Columbia upper crust, except for having higher V and lower Zr, Hf, Nb, Th and U. Melting experiments and plagioclase-melt thermometry on the glasses, and phase equilibrium in simple systems, require liquidus temperatures of 1150-1300 °C. Interaction of the liquids with carbonaceous matter at low pressure formed Fe metal spherules and SiC. Radiocarbon ages of charcoal and dendrochronology show the lavas are modern, emplaced in the last 120 years. The similar bulk composition of these lavas to several other Quaternary-aged volcanic centers in the North American Cordillera, some of which show recent seismic activity, could suggest a possible tectonic origin, but the deposits are unusually small and show no central vent for emplacement. Conversely, the balance of evidence would suggest an origin from coal fires or hot gas venting, but is less consistent with the observed calc- and per-alkaline lava compositions, and the lack of known local coal-bearing strata as a heat source. Other anthropogenic origins for the lavas are considered less plausible.

PAH Emission From ULIRGs: Evidence For Unusual Grain Properties?

NASA Astrophysics Data System (ADS)

Marshall, Jason A.; Armus, L.; Spoon, H. W. W.

2007-12-01

The tremendous power emerging from ultraluminous infrared galaxies (ULIRGs) is driven both by high levels of star-formation activity and AGN-related accretion. Observations of star-forming regions in the Milky Way and external star-forming galaxies provide evidence that the first of these energy generation mechanisms often also gives rise to emission from PAH molecules in the form of characteristic mid-IR features. Given the composite nature of ULIRGs, it is not surprising that many also exhibit significant emission from PAHs. Perhaps more surprising, however, is that some ULIRGs believed to be powered primarily by AGNs also show emission from PAHs, although typically at lower levels relative to their total dust output. To investigate the nature of the PAH emission from galaxies powered either by star-formation or AGN accretion alone, as well as emission from composite systems such as ULIRGs powered by both mechanisms, we present a detailed study of the PAH emission spectra from galaxies of each type. We use the CAFE spectral energy distribution decomposition software we have developed to derive and extinction correct the spectra of PAH emission from a sample of 100 galaxies with Spitzer/IRS observations, and use the results of this analysis to calculate the ratios of the various mid-IR PAH feature luminosities. In particular, we investigate to what extent these relative feature strengths vary as a function of the optical classification of galaxies, and we inquire into whether or not the derived feature strength ratios provide evidence for unusual grain properties in the extreme conditions within ULIRGs.

Evidence for Reduced, Carbon-rich Regions in the Solar Nebula from an Unusual Cometary Dust Particle

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Gregorio, Bradley T.; Stroud, Rhonda M.; Nittler, Larry R.

Geochemical indicators in meteorites imply that most formed under relatively oxidizing conditions. However, some planetary materials, such as the enstatite chondrites, aubrite achondrites, and Mercury, were produced in reduced nebular environments. Because of large-scale radial nebular mixing, comets and other Kuiper Belt objects likely contain some primitive material related to these reduced planetary bodies. Here, we describe an unusual assemblage in a dust particle from comet 81P/Wild 2 captured in silica aerogel by the NASA Stardust spacecraft. The bulk of this ∼20 μ m particle is comprised of an aggregate of nanoparticulate Cr-rich magnetite, containing opaque sub-domains composed of poorlymore » graphitized carbon (PGC). The PGC forms conformal shells around tiny 5–15 nm core grains of Fe carbide. The C, N, and O isotopic compositions of these components are identical within errors to terrestrial standards, indicating a formation inside the solar system. Magnetite compositions are consistent with oxidation of reduced metal, similar to that seen in enstatite chondrites. Similarly, the core–shell structure of the carbide + PGC inclusions suggests a formation via FTT reactions on the surface of metal or carbide grains in warm, reduced regions of the solar nebula. Together, the nanoscale assemblage in the cometary particle is most consistent with the alteration of primary solids condensed from a C-rich, reduced nebular gas. The nanoparticulate components in the cometary particle provide the first direct evidence from comets of reduced, carbon-rich regions that were present in the solar nebula.« less

Impacts of Fertilization Regimes on Arbuscular Mycorrhizal Fungal (AMF) Community Composition Were Correlated with Organic Matter Composition in Maize Rhizosphere Soil

PubMed Central

Zhu, Chen; Ling, Ning; Guo, Junjie; Wang, Min; Guo, Shiwei; Shen, Qirong

2016-01-01

The understanding of the response of arbuscular mycorrhizal fungi (AMF) community composition to fertilization is of great significance in sustainable agriculture. However, how fertilization influences AMF diversity and composition is not well-established yet. A field experiment located in northeast China in typical black soil (Chernozem) was conducted and high-throughput sequencing approach was used to investigate the effects of different fertilizations on the variation of AMF community in the rhizosphere soil of maize crop. The results showed that AMF diversity in the maize rhizosphere was significantly altered by different fertilization regimes. As revealed by redundancy analysis, the application of organic manure was the most important factor impacting AMF community composition between samples with and without organic manure, followed by N fertilizer and P fertilizer inputs. Moreover, the organic matter composition in the rhizosphere, determined by GC–MS, was significantly altered by the organic manure amendment. Many of the chemical components displayed significant relationships with the AMF community composition according to the Mantel test, among those, 2-ethylnaphthalene explained the highest percentage (54.2%) of the variation. The relative contents of 2-ethylnaphthalene and 2, 6, 10-trimethyltetradecane had a negative correlation with Glomus relative abundance, while the relative content of 3-methylbiphenyl displayed a positive correlation with Rhizophagus. The co-occurrence patterns in treatments with and without organic manure amendment were analyzed, and more hubs were detected in the network of soils with organic manure amendment. Additionally, three operational taxonomic units (OTUs) belonging to Glomerales were identified as hubs in all treatments, indicating these OTUs likely occupied broad ecological niches and were always active for mediating AMF species interaction in the maize rhizosphere. Taken together, impacts of fertilization regimes on AMF community composition were correlated with organic matter composition in maize rhizosphere soil and the application of manure could activate more AMF species to interact with other species in the maize rhizosphere. This knowledge can be valuable in regulating the symbiotic system of plants and AMF, maintaining the health and high yields of crops and providing a primary basis for rational fertilization. PMID:27899920

Advanced organic composite materials for aircraft structures: Future program

NASA Technical Reports Server (NTRS)

1987-01-01

Revolutionary advances in structural materials have been responsible for revolutionary changes in all fields of engineering. These advances have had and are still having a significant impact on aircraft design and performance. Composites are engineered materials. Their properties are tailored through the use of a mix or blend of different constituents to maximize selected properties of strength and/or stiffness at reduced weights. More than 20 years have passed since the potentials of filamentary composite materials were identified. During the 1970s much lower cost carbon filaments became a reality and gradually designers turned from boron to carbon composites. Despite progress in this field, filamentary composites still have significant unfulfilled potential for increasing aircraft productivity; the rendering of advanced organic composite materials into production aircraft structures was disappointingly slow. Why this is and research and technology development actions that will assist in accelerating the application of advanced organic composites to production aircraft is discussed.

Organic-inorganic composites designed for biomedical applications.

PubMed

Miyazaki, Toshiki; Ishikawa, Kunio; Shirosaki, Yuki; Ohtsuki, Chikara

2013-01-01

Several varieties of ceramics, such as Bioglass-type glasses, sintered hydroxyapatite and glass-ceramic A-W, exhibit specific biological affinity, i.e., direct bonding to surrounding bone, when implanted in bony defects. These bone-bonding ceramics are called bioactive ceramics and are utilized as important bone substitutes in the medical field. However, there is a limitation to their clinical applications because of their inappropriate mechanical properties. Natural bone takes a kind of organic-inorganic composite, where apatite nanocrystals are precipitated on collagen fibers. Therefore, problems with the bioactive ceramics can be solved by material design based on the composites. In this paper, current research topics on the development of bioactive organic-inorganic composites inspired by actual bone microstructure have been reviewed in correlation with preparation methods and various properties. Several kinds of inorganic components have been found to exhibit bioactivity in the body environment. Combination of the inorganic components with various organic polymers enables the development of bioactive organic-inorganic composites. In addition, novel biomedical applications of the composites to drug delivery systems, scaffolds for tissue regeneration and injectable biomaterials are available by combining drugs or biological molecules with appropriate control of its microstructure.

Preparation of Ag deposited TiO2 (Ag/TiO2) composites and investigation on visible-light photocatalytic degradation activity in magnetic field

NASA Astrophysics Data System (ADS)

Zhang, L.; Ma, C. H.; Wang, J.; Li, S. G.; Li, Y.

2014-12-01

In this study, Ag deposited TiO2 (Ag/TiO2) composites were prepared by three different methods (Ultraviolet Irradiation Deposition (UID), Vitamin C Reduction (VCR) and Sodium Borohydride Reduction (SBR)) for the visible-light photocatalytic degradation of organic dyes in magnetic field. And then the prepared Ag deposited TiO2 (Ag/TiO2) composites were characterized physically by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The visible-light photocatalytic activities of these three kinds of Ag deposited TiO2 (Ag/TiO2) composites were examined and compared through the degradation of several organic dyes under visible-light irradiation in magnetic field. In addition, some influence factors such as visible-light irradiation time, organic dye concentration, revolution speed, magnetic field intensity and organic dye kind on the visible-light photocatalytic activity of Ag deposited TiO2 (Ag/TiO2) composite were reviewed. The research results showed that the presence of magnetic field significantly enhanced the visible-light photocatalytic activity of Ag deposited TiO2 (Ag/TiO2) composites and then contributed to the degradation of organic dyes.

Nonlinear optics in organic cavity polaritons (Conference Presentation)

NASA Astrophysics Data System (ADS)

Singer, Kenneth D.; Liu, Bin; Crescimanno, Michael; Twieg, Robert J.

2017-02-01

Coupling between excitons belonging to organic dyes and photons in a microcavities forming cavity polaritons have been receiving attention for their fundamental interest as well as potential applications in coherent light sources. Organic materials are of particular interest as the coupling is particularly strong due to the large oscillator strength of conjugated organic molecules. The resulting coupling in organic materials is routinely in the strong regime. Ultrastrong coupling between photons and excitons in microcavities containing organic dyes and semiconductors has been recently observed in room temperature. We have studied the coupling between cavity pairs in the ultrastrong regime and found that the high order terms in the modified Jaynes-Cummings model result in broken degeneracy between the symmetric and antisymmetric modes. The unusually strong coupling between cavity photons and organic excitons dovetail with the robust nonlinear optical responses of the same materials. This provides a new and promising hybrid material for photonics. We report on measurements of photorefraction in organic cavities containing a derivative of the photorefractive organic glass based on 2-dicyanomethylene-3-cyano-2,5-dihydrofuran (DCDHF).

Contributions of Organic Sources to Atmospheric Aerosol Particle Concentrations and Growth

NASA Astrophysics Data System (ADS)

Russell, L. M.

2017-12-01

Organic molecules are important contributors to aerosol particle mass and number concentrations through primary emissions as well as secondary growth in the atmosphere. New techniques for measuring organic aerosol components in atmospheric particles have improved measurements of this contribution in the last 20 years, including Scanning Transmission X-ray Microscopy Near Edge X-ray Absorption Fine Structure (STXM-NEXAFS), Fourier Transform Infrared spectroscopy (FTIR), and High-Resolution Aerosol Mass Spectrometry (AMS). STXM-NEXAFS individual aerosol particle composition illustrated the variety of morphology of organic components in marine aerosols, the inherent relationships between organic composition and shape, and the links between atmospheric aerosol composition and particles produced in smog chambers. This type of single particle microscopy has also added to size distribution measurements by providing evidence of how surface-controlled and bulk-controlled processes contribute to the growth of particles in the atmosphere. FTIR analysis of organic functional groups are sufficient to distinguish combustion, marine, and terrestrial organic particle sources and to show that each of those types of sources has a surprisingly similar organic functional group composition over four different oceans and four different continents. Augmenting the limited sampling of these off-line techniques with side-by-side inter-comparisons to online AMS provides complementary composition information and consistent quantitative attribution to sources (despite some clear method differences). Single-particle AMS techniques using light scattering and event trigger modes have now also characterized the types of particles found in urban, marine, and ship emission aerosols. Most recently, by combining with off-line techniques, single particle composition measurements have separated and quantified the contributions of organic, sulfate and salt components from ocean biogenic and sea spray emissions to particles, addressing the persistent question of the sources of cloud condensation nuclei in clean marine conditions.

Aspiration of an interesting foreign body: Myiasis.

PubMed

İnce, Emine; Oğuzkurt, Pelin; Gezer, Hasan Özkan; Alışkan, Hikmet Eda; Hiçsönmez, Akgün

2015-01-01

Myiasis is a rare condition caused by the invasion of tissues by the larvae of flies. Many cases of myiasis involving various human organs have been reported. Tracheopulmonary or intratracheal myiasis is a very unusual and aberrant form of the disease in humans. We present a case of respiratory myiasis after aspiration of larvae by a healthy 8-month-old girl, which cannot be found in the English literature.

[ULTRASTRUCTURE OF PARENCHYMA IN THE SYNCYTIAL DIGESTIVE SYSTEM IN TURBELLARIA Convoluta convoluta (Acoela].

PubMed

Gazizova, G R; Zabotin, Ya I; Golubev, A I

2015-01-01

The paper presents data on the ultrastructure of parenchyma that is involved in the digestion in turbellaria Convoluta convoluta (n = 15). Unusual connections between the nuclear envelope, endoplasmic reticulum and plasma membrane of parenchymal cells were found for the first time, which may indicate the origin of these cell structures. The double trophic role of zooxanthellae in the organism of Convoluta is described.

A case report: mixed thrombus formation in a previously sutured right atrium.

PubMed

Yunfei, Ling; Dongxu, Li; Shuhua, Luo; Yabo, Wang; San, Deep; Changping, Gan; Ke, Lin; Qi, An

2014-08-01

We describe the case of a 19-year-old Chinese woman who nine months prior underwent repair of an atrial septal defect and came to our hospital with a right atrial mass attached to the anterior wall of the right atrium on transthoracic echocardiography. Pathologic examination revealed the mass was a mixed-type thrombosis with some unusual organization, which previously was not described in literature.

Spatial orientation in weightlessness and readaptation to earth's gravity

NASA Technical Reports Server (NTRS)

Young, L. R.; Oman, C. M.; Lichtenberg, B. K.; Watt, D. G. D.; Money, K. E.

1984-01-01

Unusual vestibular responses to head movements in weightlessness may produce spatial orientation illusions and symptoms of space motion sickness. An integrated set of experiments was performed during Spacelab 1, as well as before and after the flight, to evaluate responses mediated by the otolith organs and semicircular canals. A variety of measurements were used, including eye movements, postural control, perception of orientation, and susceptibility to space sickness.

76 FR 41086 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Volatile Organic Compound...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-13

... Promulgation of Air Quality Implementation Plans; Ohio; Volatile Organic Compound Reinforced Plastic Composites... compound (VOC) emissions from reinforced plastic composites production operations. This rule applies to any facility that has reinforced plastic composites production operations. This rule is approvable because it...

Functional Body Composition and Related Aspects in Research on Obesity and Cachexia

PubMed Central

Müller, M.J.; Baracos, V.; Bosy-Westphal, A.; Dulloo, A.; Eckel, J.; Fearon, K.C.H.; Hall, K.D.; Pietrobelli, A.; Sørensen, T.I.A.; Speakman, J.; Trayhurn, P.; Visser, M.; Heymsfield, S.B.

2014-01-01

The 12th Stock Conference addressed body composition and related functions in two extreme situations, obesity and cancer cachexia. The concept of “functional body composition” integrates body components into regulatory systems relating the mass of organs and tissues to corresponding in vivo functions and metabolic processes. This concept adds to an understanding of organ/tissue mass and function in the context of metabolic adaptations to weight change and disease. During weight gain and loss there are associated changes in individual body components while the relationships between organ and tissue mass are fixed. Thus, an understanding of weight regulation involves an examination of organ-tissue regulation rather than of individual organ mass. The between organ/tissue mass relationships are associated with and explained by cross-talk between organs and tissues mediated by cytokines, hormones, and metabolites that are coupled with changes in body weight, composition, and function as observed in obesity and cancer cachexia. In addition to established roles in intermediary metabolism, cell function and inflammation, organ-tissue cross-talk mediators are determinants of body composition and its’ change with weight gain and loss. The 12th Stock Conference supported Michael Stocks’ concept of gaining new insights by integrating research ideas from obesity and cancer cachexia. The conference presentations provide an in-depth understanding of body composition and metabolism. PMID:24835453

Evidence of thermal transport anisotropy in stable glasses of vapor deposited organic molecules

NASA Astrophysics Data System (ADS)

Ràfols-Ribé, Joan; Dettori, Riccardo; Ferrando-Villalba, Pablo; Gonzalez-Silveira, Marta; Abad, Llibertat; Lopeandía, Aitor F.; Colombo, Luciano; Rodríguez-Viejo, Javier

2018-03-01

Vapor deposited organic glasses are currently in use in many optoelectronic devices. Their operation temperature is limited by the glass transition temperature of the organic layers and thermal management strategies become increasingly important to improve the lifetime of the device. Here we report the unusual finding that molecular orientation heavily influences heat flow propagation in glassy films of small molecule organic semiconductors. The thermal conductivity of vapor deposited thin-film semiconductor glasses is anisotropic and controlled by the deposition temperature. We compare our data with extensive molecular dynamics simulations to disentangle the role of density and molecular orientation on heat propagation. Simulations do support the view that thermal transport along the backbone of the organic molecule is strongly preferred with respect to the perpendicular direction. This is due to the anisotropy of the molecular interaction strength that limits the transport of atomic vibrations. This approach could be used in future developments to implement small molecule glassy films in thermoelectric or other organic electronic devices.

Fibrillar Organic Phases And Their Roles In Rigid Biological Composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arey, Bruce W.; Park, John J.; Mayer, George

2015-06-01

This study focused on determining the presence of organic phases in the siliceous components of rigid marine composites ("glass" sponge spicules), and thereby to clarify how those composites dissipate significant mechanical energy. Through the use of imaging by helium ion microscopy in the examination of the spicules, the organic phase that is present between the layers of hydrated silica was also detected within the silica cylinders of the composite, indicating the existence therein of a network, scaffolding, or other pattern that has not yet been determined. It was concluded that the presence of an interpenetrating network of some kind, andmore » tenacious fibrillar interfaces are responsible for the large energy dissipation in these siliceous composites by viscoelastic processes. This discovery means that future mechanics analyses of such composites, extending to large deformations must consider such interpenetrating phases.« less

Aqueous Processing of Atmospheric Organic Particles in Cloud Water Collected via Aircraft Sampling.

PubMed

Boone, Eric J; Laskin, Alexander; Laskin, Julia; Wirth, Christopher; Shepson, Paul B; Stirm, Brian H; Pratt, Kerri A

2015-07-21

Cloudwater and below-cloud atmospheric particle samples were collected onboard a research aircraft during the Southern Oxidant and Aerosol Study (SOAS) over a forested region of Alabama in June 2013. The organic molecular composition of the samples was studied to gain insights into the aqueous-phase processing of organic compounds within cloud droplets. High resolution mass spectrometry (HRMS) with nanospray desorption electrospray ionization (nano-DESI) and direct infusion electrospray ionization (ESI) were utilized to compare the organic composition of the particle and cloudwater samples, respectively. Isoprene and monoterpene-derived organosulfates and oligomers were identified in both the particles and cloudwater, showing the significant influence of biogenic volatile organic compound oxidation above the forested region. While the average O:C ratios of the organic compounds were similar between the atmospheric particle and cloudwater samples, the chemical composition of these samples was quite different. Specifically, hydrolysis of organosulfates and formation of nitrogen-containing compounds were observed for the cloudwater when compared to the atmospheric particle samples, demonstrating that cloud processing changes the composition of organic aerosol.

Aqueous Processing of Atmospheric Organic Particles in Cloud Water Collected via Aircraft Sampling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boone, Eric J.; Laskin, Alexander; Laskin, Julia

2015-07-21

Cloud water and below-cloud atmospheric particle samples were collected onboard a research aircraft during the Southern Oxidant and Aerosol Study (SOAS) over a forested region of Alabama in June 2013. The organic molecular composition of the samples was studied to gain insights into the aqueous-phase processing of organic compounds within cloud droplets. High resolution mass spectrometry with nanospray desorption electrospray ionization and direct infusion electrospray ionization were utilized to compare the organic composition of the particle and cloud water samples, respectively. Isoprene and monoterpene-derived organosulfates and oligomers were identified in both the particles and cloud water, showing the significant influencemore » of biogenic volatile organic compound oxidation above the forested region. While the average O:C ratios of the organic compounds were similar between the atmospheric particle and cloud water samples, the chemical composition of these samples was quite different. Specifically, hydrolysis of organosulfates and formation of nitrogen-containing compounds were observed for the cloud water when compared to the atmospheric particle samples, demonstrating that cloud processing changes the composition of organic aerosol.« less

Discharge-related trends in the composition of particulate organic matter exported by small mountainous rivers: results from Oregon and California (Invited)

NASA Astrophysics Data System (ADS)

Goni, M. A.; Hatten, J. A.; Wheatcroft, R. A.; Borgeld, J.; Williamson, A.; Padgett, J.; Pasternack, G. B.; Gray, A.; Watson, E. B.

2009-12-01

Small mountainous rivers display highly variable discharges on both seasonal and event scales. Previous work has shown marked differences in the composition of the particulate load of rivers collected at different stages of the hydrograph, but fewer studies have specifically investigated how the biogeochemical compositions of particulate organic matter change as a function of discharge and how this variation affects the characteristics of the materials reaching the ocean. We explore these issues using data from three rivers along the west coast of the U.S. (Umpqua, Eel and Salinas) with similar watershed size but contrasting climate, vegetation and land use. Coarse and fine particulate organic matter samples collected at different discharges, including several flood events, were analyzed for carbon and nitrogen content, stable carbon and nitrogen isotopic compositions, radiocarbon compositions and yields of different organic biomarkers (e.g. lignin phenols, cutin acids, amino acid products). This presentation will focus on comparing and contrasting the provenance, age, and biochemical make-up of materials transported by each of the rivers as a function of discharge. Seasonal and event-scale differences in organic matter concentrations and compositions will be the subject of an accompanying poster. We will discuss both the processes responsible for these contrasts and the impacts they have on the delivery and fate of terrigenous organic matter in the coastal ocean.

A case with unexplained bleeding from multiple sites: munchausen syndrome by proxy.

PubMed

Tüfekçi, Özlem; Gözmen, Salih; Yılmaz, Şebnem; Hilkay Karapınar, Tuba; Çetin, Benhur; Burak Dursun, Onur; Emiroğlu, Neslihan; Ören, Hale; Irken, Gülersu

2011-08-01

Munchausen syndrome by proxy (MBP) is an extreme form of child abuse where children were unnecessarily treated or investigated for medical conditions that were falsified by their caregivers. Here the authors report a 16-year-old female with the complaints of bleeding from multiple and unusual sites, including hemoptysis, hematuria, bloody tears, and bloody nipple discharge, all of which are only witnessed by her mother. Extensive investigation revealed no organic etiologies for bleeding. The diagnosis of MBP was put by a multidisciplinary team. The diagnosis of MBP must be kept in mind in conditions where there is no underlying organic pathology in a bleeding patient.

Surfactant-thermal method to prepare two new cobalt metal-organic frameworks

NASA Astrophysics Data System (ADS)

Yu, Xianglin; Toh, Yong Siang; Zhao, Jun; Nie, Lina; Ye, Kaiqi; Wang, Yue; Li, Dongsheng; Zhang, Qichun

2015-12-01

Employing surfactants as reaction media, two new metal-organic frameworks (MOFs):(HTEA)3[Co3(BTC)3] (NTU-Z33) and (HTEA)[Co3(HBTC)2(BTC)] (NTU-Z34) (H3BTC=1,3,5-benzenetricarboxylic acid, TEA=trimethylamine, and NTU=Nanyang Technological University), have been successfully synthesized and fully characterized. Note that NTU-Z33 has an unusual trimeric [Co3(COO)9] secondary building unit (SBU). Magnetic characterization suggests that both compounds have weak antiferromagnetic behaviors. Our success in preparing new crystalline Co-BTC based MOFs under different surfactant media could provide a new road to prepare new diverse MOFs through various combinations of surfactants.

Red, green and blue reflections enabled in an optically tunable self-organized 3D cubic nanostructured thin film.

PubMed

Lin, Tsung-Hsien; Li, Yannian; Wang, Chun-Ta; Jau, Hung-Chang; Chen, Chun-Wei; Li, Cheng-Chung; Bisoyi, Hari Krishna; Bunning, Timothy J; Li, Quan

2013-09-25

A new light-driven chiral molecular switch doped in a stable blue phase (BP) liquid crystal allows wide optical tunability of three-dimensional cubic nanostructures with a selective reflection wavelength that is reversibly tuned through the visible region. Moreover, unprecedented reversible light-directed red, green, and blue reflections of the self-organized three-dimensional cubic nanostructure in a single film are demonstrated for the first time. Additionally, unusual isothermal photo-stimulated less ordered BP II to more ordered BP I phase transition was observed in the system. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Off-Resonant Two-Photon Absorption Cross-Section Enhancement of an Organic Chromophore on Gold Nanorods

PubMed Central

Sivapalan, Sean T.; Vella, Jarrett H.; Yang, Timothy K.; Dalton, Matthew J.; Haley, Joy E.; Cooper, Thomas M.; Urbas, Augustine M.; Tan, Loon-Seng; Murphy, Catherine J.

2013-01-01

Surface-plasmon-initiated interference effects of polyelectrolyte-coated gold nanorods on the two-photon absorption of an organic chromophore were investigated. With polyelectrolyte bearing gold nanorods of 2,4,6 and 8 layers, the role of the plasmonic fields as function of distance on such effects was examined. An unusual distance dependence was found: enhancements in the two-photon cross-section were at a minimum at an intermediate distance, then rose again at a further distance. The observed values of enhancement were compared to theoretical predictions using finite element analysis and showed good agreementdue to constructive and destructive interference effects. PMID:23687561

A multipartite mitochondrial genome in the potato cyst nematode Globodera pallida.

PubMed

Armstrong, M R; Blok, V C; Phillips, M S

2000-01-01

The mitochondrial genome (mtDNA) of the plant parasitic nematode Globodera pallida exists as a population of small, circular DNAs that, taken individually, are of insufficient length to encode the typical metazoan mitochondrial gene complement. As far as we are aware, this unusual structural organization is unique among higher metazoans, although interesting comparisons can be made with the multipartite mitochondrial genome organizations of plants and fungi. The variation in frequency between populations displayed by some components of the mtDNA is likely to have major implications for the way in which mtDNA can be used in population and evolutionary genetic studies of G. pallida.

PM2.5 ORGANIC COMPOSITION FROM SEVERAL SITES IN THE UNITED STATES

EPA Science Inventory

Organic constituents make up an important component of fine particulate matter (PM2.5) in ambient environments. While part of the composition of organic aerosol results from emissions of primary sources, an additional component appears to come from gas-to-particle conversion o...

Nanoparticles of noble metals in the supergene zone

NASA Astrophysics Data System (ADS)

Zhmodik, S. M.; Kalinin, Yu. A.; Roslyakov, N. A.; Mironov, A. G.; Mikhlin, Yu. L.; Belyanin, D. K.; Nemirovskaya, N. A.; Spiridonov, A. M.; Nesterenko, G. V.; Airiyants, E. V.; Moroz, T. N.; Bul'bak, T. A.

2012-04-01

Formation of noble metal nanoparticles is related to various geological processes in the supergene zone. Dispersed mineral phases appear during weathering of rocks with active participation of microorganisms, formation of soil, in aqueous medium and atmosphere. Invisible gold and other noble metals are incorporated into oxides, hydroxides, and sulfides, as well as in dispersed organic and inorganic carbonic matter. Sulfide minerals that occur in bedrocks and ores unaltered by exogenic processes and in cementation zone are among the main concentrators of noble metal nanoparticles. The ability of gold particles to disaggregate is well-known and creates problems in technological and analytical practice. When Au and PGE nanoparticles and clusters occur, these problems are augmented because of their unusual reactions and physicochemical properties. The studied gold, magnetite, titanomagnetite and pyrite microspherules from cementation zone and clay minerals of laterites in Republic of Guinea widen the knowledge of their abundance and inferred formation conditions, in particular, in the contemporary supergene zone. Morphology and composition of micrometer-sized Au mineral spherules were studied with SEM and laser microprobe. The newly formed segregations of secondary gold on the surface of its residual grains were also an object of investigation. The character of such overgrowths is the most indicative for nanoparticles. The newly formed Au particles provide evidence for redistribution of ultradispersed gold during weathering. There are serious prerequisites to state that microorganisms substantially control unusual nano-sized microspherical morphology of gold particles in the supergene zone. This is supported by experiments indicating active absorption of gold by microorganisms and direct evidence for participation of Ralstonia metallidurans bacteria in the formation of peculiar corroded bacteriomorphic surface of gold grains. In addition, the areas enriched in carbon and nitrogen have been detected with SEM on the surface of gold spherules from Guinea. Such organic compounds as serine, alanine, and glycine are identified on their surface with Raman spectroscopy. The experiments have been carried out and new data have been obtained indicating the role of micromycetes in concentration and distribution of noble metals in ferromanganese nodules of the World Ocean. Au and Pt were detected in the system with radioisotopes. It has been established that two forms of gold distribution develop within pseudomorphs of fungi colonies: (1) as pseudomorphic concentrates and (2) dispersed form unrelated to the colony structure. Inhomogeneities in distribution of dispersed platinum are manifested in the form of linear anomalies with elevated concentrations at the margins of the colonies.

Where and What Is Pristine Marine Aerosol?

NASA Astrophysics Data System (ADS)

Russell, L. M.; Frossard, A. A.; Long, M. S.; Burrows, S. M.; Elliott, S.; Bates, T. S.; Quinn, P.

2014-12-01

The sources and composition of atmospheric marine aerosol particles have been measured by functional group composition (from Fourier transform infrared spectroscopy) to identify the organic composition of the pristine primary marine (ocean-derived) particles as 65% hydroxyl, 21% alkane, 6% amine, and 7% carboxylic acid functional groups [Frossard et al., 2014a,b]. Pristine but non-primary components from photochemical reactions (likely from biogenic marine vapor emissions) add carboxylic acid groups. Non-pristine contributions include shipping effluent in seawater and ship emissions, which add additional alkane groups (up to 70%), and coastal or continental emissions mix in alkane and carboxylic acid groups. The pristine primary marine (ocean-derived) organic aerosol composition is nearly identical to model generated primary marine aerosol particles from bubbled seawater, indicating that its overall functional group composition is the direct consequence of the organic constituents of the seawater source. While the seawater organic functional group composition was nearly invariant across all three ocean regions studied and the ratio of organic carbon to sodium (OC/Na+) in the generated primary marine aerosol particles remained nearly constant over a broad range of chlorophyll-a concentrations, the generated primary marine aerosol particle alkane group fraction increased with chlorophyll-a concentrations. In addition, the generated primary marine aerosol particles have a hydroxyl group absorption peak location characteristic of monosaccharides and disaccharides, where the seawater hydroxyl group peak location is closer to that of polysaccharides. References Cited Frossard, Amanda A., Lynn M. Russell, Paola Massoli, Timothy S. Bates, and Patricia K. Quinn, "Side-by-Side Comparison of Four Techniques Explains the Apparent Differences in the Organic Composition of Generated and Ambient Marine Aerosol Particles," Aerosol Science and Technology - Aerosol Research Letter, 48:v-x, doi10.1080/02786826.2013.879979, 2014a. Frossard, A.A., L.M. Russell, M.S. Long, S.M. Burrows, S.M. Elliot, T.S. Bates, and P.K. Quinn, "Sources and Composition of Submicron Organic Mass in Marine Aerosol Particles," Journal of Geophysical Research - Atmospheres, submitted 2014b.

Tennantite-tetrahedrite series from the Madan Pb-Zn deposits, Central Rhodopes, Bulgaria

NASA Astrophysics Data System (ADS)

Vassileva, Rossitsa D.; Atanassova, Radostina; Kouzmanov, Kalin

2014-08-01

Minerals from the tennantite-tetrahedrite series (fahlores) are found as single euhedral crystals and crustiform aggregates in hydrothermal veins of the Gradishte and Petrovitsa Pb-Zn deposits of the Madan ore field, southern Bulgaria. Unusually large compositional variations and fine oscillatory crystal zoning were investigated with electron microprobe analysis. The Gradishte samples correspond dominantly to tennantite, while Petrovitsa crystals have exclusively tetrahedrite composition. Fahlore compositions at Madan correspond to zincian varieties (1.6-1.95 apfu), with low Fe-content (<0.45 apfu). Minor silver is characteristic only for the Petrovitsa samples, reaching a maximum of 0.30 apfu. The (Cu+Ag) content of the Petrovitsa tennantites and the Cu content of the Gradishte tetrahedrites systematically exceed 10 apfu resulting in compensation of the excess Cu in the structure by Fe3+. Textural characteristics, mineral relationships and available fluid inclusion and stable isotope data suggest that fahlores precipitated in the late stages of mineralization at Madan, at temperature interval of 300-200 °C from oxidizing fluids with mixed (magmatic-meteoric) signatures.

Shaping Nanoparticles with Hydrophilic Compositions and Hydrophobic Properties as Nanocarriers for Antibiotic Delivery

PubMed Central

2015-01-01

Inspired by the lotus effect in nature, surface roughness engineering has led to novel materials and applications in many fields. Despite the rapid progress in superhydrophobic and superoleophobic materials, this concept of Mother Nature’s choice is yet to be applied in the design of advanced nanocarriers for drug delivery. Pioneering work has emerged in the development of nanoparticles with rough surfaces for gene delivery; however, the preparation of nanoparticles with hydrophilic compositions but with enhanced hydrophobic property at the nanoscale level employing surface topology engineering remains a challenge. Herein we report for the first time the unique properties of mesoporous hollow silica (MHS) nanospheres with controlled surface roughness. Compared to MHS with a smooth surface, rough mesoporous hollow silica (RMHS) nanoparticles with the same hydrophilic composition show unusual hydrophobicity, leading to higher adsorption of a range of hydrophobic molecules and controlled release of hydrophilic molecules. RMHS loaded with vancomycin exhibits an enhanced antibacterial effect. Our strategy provides a new pathway in the design of novel nanocarriers for diverse bioapplications. PMID:27162988

Design and numerical investigations of a counter-rotating axial compressor for a geothermal power plant application

NASA Astrophysics Data System (ADS)

Qualman, Thomas, II

Geothermal provides a steady source of energy unlike other renewable sources, however, there are non-condensable gases (NCG's) that need to be removed before the steam enters the turbine/generator or the efficiency suffers. By utilizing a multistage counter-rotating axial compressor with integrated composite wound impellers the process of removing NCG's could be significantly improved. The novel composite impeller design provides a high level of corrosion resistance, a good strength to weight ratio, reduced size, and reduced manufacturing and maintenance costs. This thesis focuses on the design of the first 3 stages of a multistage counter-rotating axial compressor with integrated composite wound impellers for NCG removal. Because of the novel technique, an unusual set of constraints required a simplified 1 and 2D design methodology to be developed and investigated through CFD. The results indicate that by utilizing constant thickness blades with constant shroud radius (to ease manufacturing difficulties) a total pressure ratio of 1.37 with a total polytropic efficiency of 89.81% could be achieved.

High-Strength Composite Fabric Tested at Structural Benchmark Test Facility

NASA Technical Reports Server (NTRS)

Krause, David L.

2002-01-01

Large sheets of ultrahigh strength fabric were put to the test at NASA Glenn Research Center's Structural Benchmark Test Facility. The material was stretched like a snare drum head until the last ounce of strength was reached, when it burst with a cacophonous release of tension. Along the way, the 3-ft square samples were also pulled, warped, tweaked, pinched, and yanked to predict the material's physical reactions to the many loads that it will experience during its proposed use. The material tested was a unique multi-ply composite fabric, reinforced with fibers that had a tensile strength eight times that of common carbon steel. The fiber plies were oriented at 0 and 90 to provide great membrane stiffness, as well as oriented at 45 to provide an unusually high resistance to shear distortion. The fabric's heritage is in astronaut space suits and other NASA programs.

Unusual olivine and pyroxene composition in interplanetary dust and unequilibrated ordinary chondrites

NASA Technical Reports Server (NTRS)

Klock, W.; Mckay, D. S.; Thomas, K. L.; Palme, H.

1989-01-01

The presence, in both a number of interplanetary dust particles (IDPs) and in meteorite matrices, of olivine and orthopyroxene grains, low in FeO but containing up to 5 wt pct MnO, is reported. The majority of olivines and pyroxenes in meteorites contain less than 0.5 wt pct MnO. The presence of these low-iron, manganese-enriched (LIME) olivines and pyroxenes in IDPs and meteorites may indicate a link between the origin and history of IDPs and the matrix material of primitive meteorites. The origin of the LIME silicates could be explained by condensation from a gas of solar composition. Forsterite is the first major silicate phase to condense from a solar nebula gas, and Mn, which is not stable as a metal under solar nebula conditions, would condense at about 1100 K as Mn2SiO4 in solid solution with forsterite.

Flooding and forest succession in a modified stretch along the Upper Mississippi River

USGS Publications Warehouse

Yin, Yao

1998-01-01

This research examines the effect of a rare flood on floodplain forest regeneration in a 102-km stretch of the Mississippi River beginning 21 km above the mouth of the Ohio River. The river has been restricted by levees and navigation structures and subjected to sediment dredging to maintain a stable navigation channel. Because the bank erosion–accretion process has been slowed or eliminated, cottonwood (Populus spp.) and willow (Salix spp.) communities regenerate poorly in the modified river environment. An unusually large flood in 1993 destroyed the entire ground vegetation layer, killing 77.2% of the saplings and 32.2% of the trees. The flood created an alternative mechanism for cottonwood and willow to regenerate under canopy openings, enabling the community type composition of the present-day forest to be sustained for the next 50 years. Over time, however, the forest will likely exhibit considerable compositional fluctuation. 

Explosive Welding in the 1990's

NASA Technical Reports Server (NTRS)

Lalwaney, N. S.; Linse, V. D.

1985-01-01

Explosive bonding is a unique joining process with the serious potential to produce composite materials capable of fulfilling many of the high performance materials capable of fulfilling many of the high performance materials needs of the 1990's. The process has the technological versatility to provide a true high quality metallurgical compatible and incompatible systems. Metals routinely explosively bonded include a wide variety of combinations of reactive and refractory metals, low and high density metals and their alloys, corrosion resistant and high strength alloys, and common steels. The major advantage of the process is its ability to custom design and engineer composites with physical and/or mechanical properties that meet a specific or unusual performance requirement. Explosive bonding offers the designer unique opportunities in materials selection with unique combinations of properties and high integrity bonds that cannot be achieved by any other metal joining process. The process and some applications are discussed.

Topological model of composite fermions in the cyclotron band generator picture: New insights

NASA Astrophysics Data System (ADS)

Staśkiewicz, Beata

2018-03-01

A combinatorial group theory in the braid groups is correlated with the unusual "anyon" statistic of particles in 2D Hall system in the fractional quantum regime well. On this background has been derived cyclotron band generator as a modification and generalization band generator, first established to solve the word and conjugacy problems in the braid group terms. Topological commensurability condition has been embraced by canonical factors - like, based on the concept of parallel descending cycles. Owing to this we can mathematically capture the general hierarchy of correlated states in the lowest Landau level, describing the fractional quantum Hall effect hierarchy, in terms of cyclotron band generators, especially for those being beyond conventional composite fermions model. It has been also shown that cyclotron braid subgroups, developed for interpretation of Laughlin correlations, are a special case of the right-angled Artin groups.

The maternal-effect, selfish genetic element Medea is associated with a composite Tc1 transposon.

PubMed

Lorenzen, Marcé D; Gnirke, Andreas; Margolis, Jonathan; Garnes, Jeffrey; Campbell, Margie; Stuart, Jeffrey J; Aggarwal, Rajat; Richards, Stephen; Park, Yoonseong; Beeman, Richard W

2008-07-22

Maternal-Effect Dominant Embryonic Arrest ("Medea") factors are selfish nuclear elements that combine maternal-lethal and zygotic-rescue activities to gain a postzygotic survival advantage. We show that Medea(1) activity in Tribolium castaneum is associated with a composite Tc1 transposon inserted just downstream of the neurotransmitter reuptake symporter bloated tubules (blot), whose Drosophila ortholog has both maternal and zygotic functions. The 21.5-kb insertion contains defective copies of elongation initiation factor-3, ATP synthase subunit C, and an RNaseD-related gene, as well as a potentially intact copy of a prokaryotic DUF1703 gene. Sequence comparisons suggest that the current distribution of Medea(1) reflects global emanation after a single transpositional event in recent evolutionary time. The Medea system in Tribolium represents an unusual type of intragenomic conflict and could provide a useful vehicle for driving desirable genes into populations.

The maternal-effect, selfish genetic element Medea is associated with a composite Tc1 transposon

PubMed Central

Lorenzen, Marcé D.; Gnirke, Andreas; Margolis, Jonathan; Garnes, Jeffrey; Campbell, Margie; Stuart, Jeffrey J.; Aggarwal, Rajat; Richards, Stephen; Park, Yoonseong; Beeman, Richard W.

2008-01-01

Maternal-Effect Dominant Embryonic Arrest (“Medea”) factors are selfish nuclear elements that combine maternal-lethal and zygotic-rescue activities to gain a postzygotic survival advantage. We show that Medea1 activity in Tribolium castaneum is associated with a composite Tc1 transposon inserted just downstream of the neurotransmitter reuptake symporter bloated tubules (blot), whose Drosophila ortholog has both maternal and zygotic functions. The 21.5-kb insertion contains defective copies of elongation initiation factor-3, ATP synthase subunit C, and an RNaseD-related gene, as well as a potentially intact copy of a prokaryotic DUF1703 gene. Sequence comparisons suggest that the current distribution of Medea1 reflects global emanation after a single transpositional event in recent evolutionary time. The Medea system in Tribolium represents an unusual type of intragenomic conflict and could provide a useful vehicle for driving desirable genes into populations. PMID:18621706

Facile synthesis of polyaniline-modified CuS with enhanced adsorbtion and photocatalytic activity

NASA Astrophysics Data System (ADS)

Wang, Xiufang; Chen, Shaohua; Shuai, Ying

2016-10-01

Novel hierarchical polyaniline-modified CuS (PANI-CuS) has been synthesized by simple assembling PANI on the surface of flower-like CuS spheres. The PANI modification enhances the adsorption properties of flower-like CuS. The prepared PANI-CuS composites exhibit higher visible-light-driven photocatalytic activities in degradation of rhodamine B (RhB) than that of neat CuS. The unusual photocatalytic activity could be attributed to the great adsorptivity of dyes, the extended photoresponse range, and the high migration efficiency of photoinduced electrons, which may effectively suppress the charge recombination. This work not only provides a simple strategy for fabricating highly efficient and stable CuS-based composites, but also proves that these unique structures are excellent platforms for significantly improving their visible- light-driven photoactivities, holding great promise for their applications in the field of purifying polluted water resources.

Patterns of cell division, DNA base compositions, and fine structures of some radiation-resistant vegetative bacteria found in food

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanders, S.W.; Maxcy, R.B.

1979-01-01

Representative highly radiation-resistant Moraxella-Acinetobacter (M-A), Pseudomonas radiora, Micrococcus radiodurans, and Micrococcus radiophilus exhibited a wide variety of division systems and cell wall characteristics. However, the more resistant M-A possessed unusually thick cell walls, indicating a possible role of the cell wall in radiation resistance in the M-A. Thick septation was present in most of the bacteria studied, but was absent in P. radiora, thus excluding this as a necessity for high resistance. Reliable determination of the number of division planes of the M-A for use as a taxonomic criterion was achieved by the direct observation of dividing cells. The highlymore » resistant M-A were found to divide in multiple planes and had base compositions of 54.0 to 57.5%, unlike typical Moraxella and/or Acinetobacter species. The taxonomic position of most highly resistant bacteria remains unclear.« less

Thermally controllable reflective characteristics from rupture and self-assembly of hydrogen bonds in cholesteric liquid crystals.

PubMed

Hu, Wang; Cao, Hui; Song, Li; Zhao, Haiyan; Li, Sijin; Yang, Zhou; Yang, Huai

2009-10-22

A cholesteric liquid crystal (Ch-LC) composite, made of a series of cholesteryl esters, a nematic LC, and a hydrogen bond (H-bond) chiral dopant (HCD), was prepared and filled into a planar treated cell. When the cell was heated, the selective reflection of the cell exhibited an unusual blue shift. One of the reasonable mechanisms was that the helical twisting power (HTP) value of cholesteryl esters increased with an increasing temperature. The other one was that the H-bonds of HCD were ruptured when the temperature was above 60.0 degrees C and HCD was split into two kinds of new chiral dopants, which made the HTP value of the chiral dopants change a lot, thus changing the pitch length of the composite greatly. On the basis of this mechanism, a novel thermally controllable reflective color paper could be achieved.

A MATLAB toolbox and Excel workbook for calculating the densities, seismic wave speeds, and major element composition of minerals and rocks at pressure and temperature

NASA Astrophysics Data System (ADS)

Abers, Geoffrey A.; Hacker, Bradley R.

2016-02-01

To interpret seismic images, rock seismic velocities need to be calculated at elevated pressure and temperature for arbitrary compositions. This technical report describes an algorithm, software, and data to make such calculations from the physical properties of minerals. It updates a previous compilation and Excel® spreadsheet and includes new MATLAB® tools for the calculations. The database of 60 mineral end-members includes all parameters needed to estimate density and elastic moduli for many crustal and mantle rocks at conditions relevant to the upper few hundreds of kilometers of Earth. The behavior of α and β quartz is treated as a special case, owing to its unusual Poisson's ratio and thermal expansion that vary rapidly near the α-β transition. The MATLAB tools allow integration of these calculations into a variety of modeling and data analysis projects.

Zoned Cr, Fe-spinel from the La Perouse layered gabbro, Fairweather Range, Alaska

USGS Publications Warehouse

Czamanske, G.K.; Himmelberg, G.R.; Goff, F.E.

1976-01-01

Zoned spinel of unusual composition and morphology has been found in massive pyrrhotite-chalcopyrite-pent-landite ore from the La Perouse layered gabbro intrusion in the Fairweather Range, southeastern Alaska. The spinel grains show continuous zoning from cores with up to 53 wt.% Cr2O3 to rims with less than 11 wt.% Cr2O3. Their composition is exceptional because they contain less than 0.32 wt.% MgO and less than 0.10 wt.% Al2O3 and TiO2. Also notable are the concentrations of MnO and V2O3, which reach 4.73 and 4.50 wt.%, respectively, in the cores. The spinel is thought to have crystallized at low oxygen fugacity and at temperatures above 900??C, directly from a sulfide melt that separated by immiscibility from the gabbroic parental magma. ?? 1976.

Advanced Modeling Strategies for the Analysis of Tile-Reinforced Composite Armor

NASA Technical Reports Server (NTRS)

Davila, Carlos G.; Chen, Tzi-Kang

1999-01-01

A detailed investigation of the deformation mechanisms in tile-reinforced armored components was conducted to develop the most efficient modeling strategies for the structural analysis of large components of the Composite Armored Vehicle. The limitations of conventional finite elements with respect to the analysis of tile-reinforced structures were examined, and two complementary optimal modeling strategies were developed. These strategies are element layering and the use of a tile-adhesive superelement. Element layering is a technique that uses stacks of shear deformable shell elements to obtain the proper transverse shear distributions through the thickness of the laminate. The tile-adhesive superelement consists of a statically condensed substructure model designed to take advantage of periodicity in tile placement patterns to eliminate numerical redundancies in the analysis. Both approaches can be used simultaneously to create unusually efficient models that accurately predict the global response by incorporating the correct local deformation mechanisms.

Unusual seismogenic soft-sediment deformation structures in Cambrian epicratonic carbonate deposits, western Colorado, U.S.A

NASA Astrophysics Data System (ADS)

Myrow, P.; Chen, J.

2013-12-01

A wide variety of unusual penecontemporaneous deformation structures exist in grainstone and flat-pebble conglomerate beds of the Upper Cambrian strata, western Colorado, including slide scarps, thrusted beds, irregular blocks and internally deformed beds. Slide scarps are characterized by concave-up, sharp surfaces that truncate one or more underlying beds. Thrusted beds record movement of a part of a bed onto itself along a moderate to steeply inclined (generally 25°-40°) ramp. The hanging wall lenses in cases show fault-bend geometries, with either intact or mildly deformed bedding. Irregular bedded to internally deformed blocks isolated on generally flat upper bedding surfaces are similar in composition to the underlying beds. These features represent parts of beds that were detached, moved up onto, and some distances across, the laterally adjacent undisturbed bed surfaces. The blocks moved either at the sediment-water interface or intrastratally at shallow depths within overlying muddy deposits. Finally, internally deformed beds have large blocks, fitted fabrics of highly irregular fragments, and contorted lamination, which represent heterogeneous deformation, such as brecciation and liquefaction. The various deformation structures were most probably triggered by earthquakes, considering the nature of deformation (regional distribution of liquefaction structures, and the brittle segmentation and subsequent transportation of semi-consolidated beds) and the reactivation of Mesoproterozoic, crustal-scale shear zones in the central Rockies during the Late Cambrian. Features produced by initial brittle deformation are unusual relative to most reported seismites, and may represent poorly recognized to unrecognized seismogenic structures in the rock record.

Characterization of organic composition in snow and surface waters in the Athabasca Oil Sands Region, using ultrahigh resolution Fourier transform mass spectrometry.

PubMed

Yi, Y; Birks, S J; Cho, S; Gibson, J J

2015-06-15

This study was conducted to characterize the composition of dissolved organic compounds present in snow and surface waters in the Athabasca Oil Sands Region (AOSR) with the goal of identifying whether atmospherically-derived organic compounds present in snow are a significant contributor to the compounds detected in surface waters (i.e., rivers and lakes). We used electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR MS) to characterize the dissolved organic compound compositions of snow and surface water samples. The organic profiles obtained for the snow samples show compositional differences between samples from near-field sites (<5 km from oil sands activities) and those from more distant locations (i.e., far-field sites). There are also significant compositional differences between samples collected in near-field sites and surface water samples in the AOSR. The composition of dissolved organic compounds at the upstream Athabasca River site (i.e., Athabasca River at Athabasca) is found to be different from samples obtained from downstream sites in the vicinity of oil sands operations (i.e., Athabasca River at Fort McMurray and Athabasca River at Firebag confluence). The upstream Athabasca River sites tended to share some compositional similarities with far-field snow deposition, while the downstream Athabasca River sites are more similar to local lakes and tributaries. This contrast likely indicates the relative role of regional snowmelt contributions to the Athabasca River vs inputs from local catchments in the reach downstream of Fort McMurray. Copyright © 2015 Elsevier B.V. All rights reserved.

HST-STIS spectra and the redness of Saturn's rings

NASA Astrophysics Data System (ADS)

Cuzzi, Jeffrey N.; French, Richard G.; Hendrix, Amanda R.; Olson, Daniel M.; Roush, Ted; Vahidinia, Sanaz

2018-07-01

We have observed the main rings of Saturn with the Space Telescope Imaging Spectrometer (STIS) on the Hubble Space Telescope (HST), covering the spectral region from 180-570 nm (including for the first time the critical near-UV range 190-340 nm) with very good signal to noise ratio and a radial resolution of approximately 160-330 km. After correcting for an unexpected grating scatter problem associated with the bright, red, extended planet-ring target, we obtained complete I/F spectra for each major ring region. We have interpreted the spectra in terms of the ring particle material composition using a combination of traditional "Hapke" theory and a new correction for shadowing on the rough, re-entrant ring particle surfaces, along with a correction for the nonclassical scattering of the ring layer itself. We tested a variety of UV absorbers: iron (including nano-iron) grains, hematite, "planetary silicates", organic carbon-ring tholins of varying aromaticity, and amorphous carbon. The A and B rings can contain no more NH3 than about 10-4 by volume. We conclude that the best spectral fit for the well-known, unusually red color of the A and B rings is provided by a sub-percent mass fraction of organic tholins. It appears that the most likely regolith configuration for the A and B Rings is a heterogeneous "intimate mixture", dominated by relatively pure water ice, with some 2-40% of the grains containing roughly 5-10% tholin by volume (the amount depending on whether silicates are present), but it is hard to allow much amorphous carbon to be present in the B Ring material at least. These predictions of compositional heterogeneity can be tested by Cassini direct compositional measurements. There is some suggestion that the tholin properties differ slightly between the A and B rings. We show that tholins of this type, in the abundance we predict, would be difficult to detect at near-IR wavelengths. The C Ring particles have lower albedos, and the best fit models require a significantly higher abundance of silicates and (more importantly) "neutral" absorber which we model as amorphous carbon, plausibly representing meteoritic infall. Because of our new treatment of shadowing, our estimates of the abundance of amorphous carbon in the C Ring particles are lower (1-5% in the particle regoliths) than previously obtained. The relative abundance of silicate and carbonaceous materials in the C Ring remains uncertain due to uncertainties in how to model the C ring particle phase function.

Results Of Initial Analyses Of The Salt (Macro) Batch 9 Tank 21H Qualification Samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, T.

2015-10-08

Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Interim Salt Disposition Project (ISDP) Salt (Macro) Batch 9 for processing through the Actinide Removal Process (ARP) and the Modular Caustic-Side Solvent Extraction Unit (MCU). This document reports the initial results of the analyses of samples of Tank 21H. Analysis of the Tank 21H Salt (Macro) Batch 9 composite sample indicates that the material does not display any unusual characteristics. Further results on the chemistry and other tests will be issued in the future.

Making a nutritional assessment.

PubMed Central

Pencharz, P. B.

1982-01-01

The assessment of nutritional deficiencies depends on both clinical and laboratory diagnosis. The standard physical examination should be supplemented by nutritional anthropometry, consisting of accurate growth and skinfold measurements. A careful dietary history, preferably taken by a dietitian, is necessary to construct a record of past nutrient intake. Since biochemical abnormalities often appear before clinical signs of nutritional deficiency a battery of biochemical tests is sometimes needed. In unusual cases newer techniques of assessing body composition or immunologic or physiologic function may be required. In all cases the patient's physical state, nutritional intake and biochemical status must be related to age and sex standards. PMID:7139499

Preliminary Examination of Sahara 99555: Mineralogy and Experimental Studies of a New Angrite

NASA Technical Reports Server (NTRS)

Mikouchi, T.; McKay, G.; Le, L.; Mittlefehldt, D. W.

2000-01-01

A 2710 g meteorite, Sahara 99555 (Sah99), was recently recovered from the Sahara and reported to be the 5th angrite. It is the largest angrite ever found and may offer useful information to better understand the unusual petrogeneses of this rare achondrite group. It may also allow us to examine the chronological record of igneous activity in the very early solar system. We obtained a 2.6 g chip of Sah99 and here present a preliminary report of its petrology and mineralogy in conjunction with a crystallization experiment on an analogue composition.

Mineralogical studies of sulfide samples and volatile concentrations of basalt glasses from the southern Juan de Fuca Ridge.

USGS Publications Warehouse

Brett, R.; Evans, H.T.; Gibson, E.K.; Hedenquist, J.W.; Wandless, M.-V.; Sommer, M.A.

1987-01-01

Specifically considers unusual minerals and geothermometric relations not previously covered. Equilibrium, if attained at all, during deposition of most sulfides was a transient event over a few tens of micrometers at most and was perturbed by rapid temperature and compositional changes of the circulating fluid. Two new minerals were found: one, a hydrated Zn, Fe hydroxy-chlorosulfate, and the other, a (Mn, Mg, Fe) hydroxide or hydroxy-hydrate. Both were formed at relatively low temperatures. Lizardite, starkeyite, and anatase were found for the first time in such an environment.-from Authors

An unconventional depiction of viewpoint in rock art.

PubMed

Pettigrew, Jack; Scott-Virtue, Lee

2015-01-01

Rock art in Africa sometimes takes advantage of three-dimensional features of the rock wall, such as fissures or protuberances, that can be incorporated into the artistic composition (Lewis-Williams, 2002). More commonly, rock artists choose uniform walls on which two-dimensional depictions may represent three-dimensional figures or objects. In this report we present such a two-dimensional depiction in rock art that we think reveals an intention by the artist to represent an unusual three-dimensional viewpoint, namely, with the two human figures facing into the rock wall, instead of the accustomed Western viewpoint facing out!

Photovoltaic cells with a graded active region achieved using stamp transfer printing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forrest, Stephen R.; Lee, Jun Yeob; Cho, Yong Joo

Disclosed herein are processes for fabricating organic photosensitive optoelectronic devices with a vertical compositionally graded organic active layer. The processes use either a single-stamp or double-stamp printing technique to transfer the vertical compositionally graded organic active layer from a starting substrate to a device layer.

On Organic Material in E Ring Ice Grains

NASA Astrophysics Data System (ADS)

Postberg, F.; Khawaja, N.; Reviol, R.; Nölle, L.; Klenner, F.; Hsu, H. W.; Horanyi, M.

2015-12-01

Pure water ice dominates the composition of the micron and sub-micron sized dust particles in Saturn's E-ring, a ring constantly replenished by active ice jets of the moon Enceladus [1]. Details about the composition of this tenuous, optically thin ring can only be constrained by in situ measurements. The Cosmic Dust Analyzer (CDA) onboard Cassini investigates the composition of these grains by cationic time-of-flight mass spectra of individual ice grains hitting the instruments target surface. From these spectra three compositional types of E ring ice grains have been identified previously [2,3]: Type-1: Almost pure water, Type-2: Enriched in organics, and Type-3: Enriched in salt. Unlike Type-1 and 3, organic-enriched Type-2 spectra have not yet been investigated in depth. Here we report the first detailed compositional analysis of this type. The spectra analysis is supported by a large-scale laboratory ground campaign yielding a library of analogue spectra for organic material embedded in a water ice matrix. In contrast to Type 1 and 3, Type-2 spectra display a great compositional diversity, which indicates varying contributions of several organic species. So far we have identified characteristic fragment patterns of at least three classes of organic compounds: aromatic species, amines, and carbonyl group species. Work is in progress to quantify concentrations of the identified species and to assign yet un-specified organic mass lines in Type 2 spectra. Due to the dynamical evolution of the orbital elements of E ring grains a large fraction collides with the icy moons embedded in the E ring. Therefore, the organic components identified by CDA can accumulate on the surfaces of these bodies over time. Ref: :[1]Kempf et al., Icarus-206, 2010. [2]Postberg et al., Nature-459, 2009. [3]Postberg et al., Icarus-193, 2008.

Multiple organ dysfunction syndrome, an unusual complication of heroin intoxication: a case report and review of literature.

PubMed

Feng, Gang; Luo, Qiancheng; Guo, Enwei; Yao, Yulan; Yang, Feng; Zhang, Bingyu; Li, Longxuan

2015-01-01

Multiple organ dysfunction syndrome (MODS) has rarely been described in patients with heroin intoxication. Here, we report a rare case of MODS involving six organs, due to heroin intoxication. The patient was a 32-year-old Chinese man with severe heroin intoxication complicated by acute pulmonary edema and respiratory insufficiency, shock, myocardial damage and cardiac insufficiency, rhabdomyolysis and acute renal insufficiency, acute liver injury and hepatic insufficiency, toxic leukoencephalopathy, and hypoglycemia. He managed to survive and was discharged after 10 weeks of intensive care. The possible pathogenesis and therapeutic measures of MODS induced by heroin intoxication and some suggestions for preventing and treating severe complications of heroin intoxication, based on clinical evidence and the pertinent literature, are discussed in this report.

Molecular Imaging of Ultrathin Pentacene Films: Evidence for Homoepitaxy

NASA Astrophysics Data System (ADS)

Wu, Yanfei; Haugstad, Greg; Frisbie, C. Daniel

2013-03-01

Ultrathin polycrystalline films of organic semiconductors have received intensive investigations due to the critical role they play in governing the performance of organic thin film transistors. In this work, a variety of scanning probe microscopy (SPM) techniques have been employed to investigate ultrathin polycrystalline films (1-3 nm) of the benchmark organic semiconductor pentacene. By using spatially resolved Friction Force Microscopy (FFM), Kelvin Probe Force Microscopy (KFM) and Electrostatic Force Microscopy (EFM), an interesting multi-domain structure is revealed within the second layer of the films, characterized as two distinct friction and surface potential domains correlating with each other. The existence of multiple homoepitaxial modes within the films is thus proposed and examined. By employing lattice-revolved imaging using contact mode SPM, direct molecular evidence for the unusual homoepitaxy is obtained.

A traveling opera troupe.

PubMed

Gao, M

1995-08-01

In China, Mr. Chang Junjie, a retired middle school principal has personally organized and financed the "Family Planning Retired Cadre's Troupe," which travels around the countryside performing newly written costume operas. In the six years since he first began to organize the troupe, Chang's players have performed more than 1700 times for more than a million people. The operas draw their material from the real life situations faced by farmers and emphasize the importance of family planning by setting good examples. Chang's operas have been well received, and it is not unusual for his audiences to be moved to laughter and tears. Despite his widespread success, Chang is not content with what he has accomplished and is currently organizing a children's opera troupe and seeking ways to make a greater impact on the promotion of family planning.

New 3 D Tubular Porous Structure of an Organic-Zincophosphite Framework with Interesting Gas Adsorption and Luminescence Properties.

PubMed

Wang, Chih-Min; Lee, Li-Wei; Chang, Tsung-Yuan; Fan, Bing-Lun; Wang, Chih-Ling; Lin, Hsiu-Mei; Lu, Kuang-Lieh

2016-11-02

A new 3D tubular zinc phosphite, Zn 2 (C 22 H 22 N 8 ) 0.5 (HPO 3 ) 2 ⋅H 2 O (1), incorporating a tetradentate organic ligand was synthesized under hydro(solvo)thermal conditions and structurally characterized by single-crystal X-ray diffraction. Compound 1 is the first example of inorganic zincophosphite chains being interlinked through 1,2,4,5-tetrakis(imidazol-1-ylmethyl)benzene to form a tubular porous framework with unusual organic-inorganic hybrid channels. The thermal and chemical stabilities, high capacity for CO 2 adsorption compared to that for N 2 adsorption, and interesting optical properties of LED devices fabricated using this compound were also studied. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Conducting Layered Organic-inorganic Halides Containing <110>-Oriented Perovskite Sheets.

PubMed

Mitzi, D B; Wang, S; Feild, C A; Chess, C A; Guloy, A M

1995-03-10

Single crystals of the layered organic-inorganic perovskites, [NH(2)C(I=NH(2)](2)(CH(3)NH(3))m SnmI3m+2, were prepared by an aqueous solution growth technique. In contrast to the recently discovered family, (C(4)H(9)NH(3))(2)(CH(3)NH(3))n-1SnnI3n+1, which consists of (100)-terminated perovskite layers, structure determination reveals an unusual structural class with sets of m <110>-oriented CH(3)NH(3)SnI(3) perovskite sheets separated by iodoformamidinium cations. Whereas the m = 2 compound is semiconducting with a band gap of 0.33 +/- 0.05 electron volt, increasing m leads to more metallic character. The ability to control perovskite sheet orientation through the choice of organic cation demonstrates the flexibility provided by organic-inorganic perovskites and adds an important handle for tailoring and understanding lower dimensional transport in layered perovskites.