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Sample records for mineralized bacterial remnants

  1. Minerals in soil select distinct bacterial communities in their microhabitats.

    Science.gov (United States)

    Carson, Jennifer K; Campbell, Louise; Rooney, Deirdre; Clipson, Nicholas; Gleeson, Deirdre B

    2009-03-01

    We tested the hypothesis that different minerals in soil select distinct bacterial communities in their microhabitats. Mica (M), basalt (B) and rock phosphate (RP) were incubated separately in soil planted with Trifolium subterraneum, Lolium rigidum or left unplanted. After 70 days, the mineral and soil fractions were separated by sieving. Automated ribosomal intergenic spacer analysis was used to determine whether the bacterial community structure was affected by the mineral, fraction and plant treatments. Principal coordinate plots showed clustering of bacterial communities from different fraction and mineral treatments, but not from different plant treatments. Permutational multivariate anova (permanova) showed that the microhabitats of M, B and RP selected bacterial communities different from each other in unplanted and L. rigidum, and in T. subterraneum, bacterial communities from M and B differed (Ppermanova also showed that each mineral fraction selected bacterial communities different from the surrounding soil fraction (P<0.05). This study shows that the structure of bacterial communities in soil is influenced by the mineral substrates in their microhabitat and that minerals in soil play a greater role in bacterial ecology than simply providing an inert matrix for bacterial growth. This study suggests that mineral heterogeneity in soil contributes to the spatial variation in bacterial communities.

  2. Molecular Characterization of Bacterial Respiration on Minerals

    Energy Technology Data Exchange (ETDEWEB)

    Blake, Robert C.

    2013-04-26

    anomalous dispersion (MAD) phasing; 4. An acid-stable red cytochrome with a novel absorbance peak at 579 nm was purified from cell-free extracts of L. ferriphilum. Functional studies demonstrated that this cytochrome was an important component of the aerobic iron respiratory chain in this organism; 5. The specific adhesion of At. ferrooxidans to pyrite is mediated by an extracellular protein that was identified as aporusticyanin. The adhesion of At. ferrooxidans to minerals was characterized by high affinity binding that exhibited a high specificity for pyrite over other sulfide minerals. The principal biopolymer involved in this high-affinity adhesion to pyrite was isolated by mineral affinity chromatography and identified as aporusticyanin. The adhesion of purified aporusticyanin to minerals was observed to adhere to different mineral with a pattern of reactivity identical to that observed with the intact bacterium. Further, preincubation of pyrite with excess exogenous aporusticyanin served to inhibit the adherence of intact cells to the surface of the mineral, indicating that the protein and the cells adhered to the pyrite in a mutually exclusive manner. Taken together, these observations support a model where aporusticyanin located on the surface of the bacterial cell acts as a mineral-specific receptor for the initial adherence of At. ferrooxidans to solid pyrite; 6. The specific adhesion of L. ferriphilum to pyrite was mediated by a different acid-stable extracellular protein than aporusticyanin; and 7. A prototype integrating cavity absorption meter (ICAM) was assembled to determine whether this novel spectrophotometer could be used to study cellular respiration in situ.

  3. Mineral phosphate solubilizing bacterial community in agro-ecosystem

    African Journals Online (AJOL)

    Mineral phosphate solubilizing bacterial community in agro-ecosystem. N Saha, S Biswas. Abstract. The present communication deals with the assessment of phosphate solubilizing bacterial community structure across artificially created fertility gradient with regards to N, P and K status of soil in the experimental site.

  4. Culture -independent Pathogenic Bacterial Communities in Bottled Mineral Water

    Directory of Open Access Journals (Sweden)

    Hamdy A. Hassan

    2015-08-01

    Full Text Available Bottled mineral water (BMW is an alternative to mains water and consider it to be better and safer. Access to safe BMW from the bacteria involving potential health hazard is essential to health. Cultivation-independent technique PCR-based single-strand conformation polymorphism (SSCP for genetic profiling of PCR-amplified 16S rRNA genes was performed using Com primer set targeting the 16S rRNA genes for detection of pathogenic bacteria in bottled mineral water from the final product of six factories for bottled mineral drinking water in Wadi El-natron region- Egypt. These factories use often ozone technology to treat large quantities of water because of its effectiveness in purifying and conditioning water. A total of 27 single products were isolated from the profiles by PCR re-amplification and cloning. Sequence analysis of 27 SSCP bands revealed that the 16S rRNA sequences were clustered into seven operational taxonomic units (OTUs and the compositions of the communities of the six samples were all common. The results showed that most communities from phyla Alphaproteobacteria and certainly in the Sphingomonas sp. Culture-independent approaches produced complementary information, thus generating a more accurate view for the bacterial community in the BMW, particularly in the disinfection step, as it constitutes the final barrier before BMW distribution to the consumer

  5. Remnant lipoproteins

    DEFF Research Database (Denmark)

    Varbo, Anette; Nordestgaard, Børge G.

    2017-01-01

    Purpose of review: To review recent advances in the field of remnant lipoproteins and remnant cholesterol with a focus on cardiovascular disease risk. Recent findings: In line with previous years' research, current observational, genetic, and mechanistic studies find remnant lipoproteins (defined...... of cardiovascular disease risk reduction through remnant lipoprotein lowering are under way....

  6. Surface characterization of bacterial cells relevant to the mineral industry

    NARCIS (Netherlands)

    Sharma, PK; Rao, KH

    Bacteria belonging to the Acidithiobacilli group are widely used in the mineral processing industry in bioleaching and biobeneficiation operations. Paenibacillus polymyxa has also found application in biobeneficiation studies. Microbial adhesion to mineral surface is an essential step,for both

  7. Clay mineral type effect on bacterial enteropathogen survival in soil.

    Science.gov (United States)

    Brennan, Fiona P; Moynihan, Emma; Griffiths, Bryan S; Hillier, Stephen; Owen, Jason; Pendlowski, Helen; Avery, Lisa M

    2014-01-15

    Enteropathogens released into the environment can represent a serious risk to public health. Soil clay content has long been known to have an important effect on enteropathogen survival in soil, generally enhancing survival. However, clay mineral composition in soils varies, and different clay minerals have specific physiochemical properties that would be expected to impact differentially on survival. This work investigated the effect of clay materials, with a predominance of a particular mineral type (montmorillonite, kaolinite, or illite), on the survival in soil microcosms over 96 days of Listeria monocytogenes, Salmonella Dublin, and Escherichia coli O157. Clay mineral addition was found to alter a number of physicochemical parameters in soil, including cation exchange capacity and surface area, and this was specific to the mineral type. Clay mineral addition enhanced enteropathogen survival in soil. The type of clay mineral was found to differentially affect enteropathogen survival and the effect was enteropathogen-specific. © 2013.

  8. The Mineralosphere Concept: Mineralogical Control of the Distribution and Function of Mineral-associated Bacterial Communities.

    Science.gov (United States)

    Uroz, Stephane; Kelly, Laura Catherine; Turpault, Marie-Pierre; Lepleux, Cendrella; Frey-Klett, Pascale

    2015-12-01

    Soil is composed of a mosaic of different rocks and minerals, usually considered as an inert substrata for microbial colonization. However, recent findings suggest that minerals, in soils and elsewhere, favour the development of specific microbial communities according to their mineralogy, nutritive content, and weatherability. Based upon recent studies, we highlight how bacterial communities are distributed on the surface of, and in close proximity to, minerals. We also consider the potential role of the mineral-associated bacterial communities in mineral weathering and nutrient cycling in soils, with a specific focus on nutrient-poor and acidic forest ecosystems. We propose to define this microbial habitat as the mineralosphere, where key drivers of the microbial communities are the physicochemical properties of the minerals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Mineralization of linear alkylbenzene sulfonate by a four-member aerobic bacterial consortium

    International Nuclear Information System (INIS)

    Jimenez, L.; Breen, A.; Thomas, N.; Sayler, G.S.; Federle, T.W.

    1991-01-01

    A bacterial consortium capable of linear alkylbenzene sulfonate (LAS) mineralization under aerobic conditions was isolated from a chemostat inoculated with activated sludge. The consortium, designated KJB, consisted of four members, all of which were gram-negative, rod-shaped bacteria that grew in pairs and short chains. Three isolates had biochemical properties characteristic of Pseudomonas spp.; the fourth showed characteristics of the Aeromonas spp. Cell suspensions were grown together in minimal medium with [ 14 C]LAS as the only carbon source. After 13 days of incubation, more than 25% of the [ 14 C]LAS was mineralized to 14 CO 2 by the consortium. Pure bacterial cultures and combinations lacking any one member of the KJB bacterial consortium did not mineralize LAS. Three isolates carried out primary biodegradation of the surfactant, and one did not. This study shows that the four bacteria complemented each other and synergistically mineralized LAS, indicating catabolic cooperation among the four consortium members

  10. Remnant lipoproteins.

    Science.gov (United States)

    Varbo, Anette; Nordestgaard, Børge G

    2017-08-01

    To review recent advances in the field of remnant lipoproteins and remnant cholesterol with a focus on cardiovascular disease risk. In line with previous years' research, current observational, genetic, and mechanistic studies find remnant lipoproteins (defined in different ways) to be involved in atherosclerosis development and cardiovascular disease risk. High concentrations of remnant cholesterol could explain some of the residual risk of cardiovascular disease seen after LDL cholesterol lowering. This will be increasingly important as populations worldwide become more obese and more have diabetes, both of which elevate remnant cholesterol concentrations. Many smaller scale studies and post hoc analyses show that remnant cholesterol can be lowered by different types of drugs; however, results from large scale studies with the primary aim of reducing cardiovascular disease risk through lowering of remnant cholesterol in individuals with elevated concentrations are still missing, although some are under way. Remnant cholesterol is a risk factor for cardiovascular disease, and can be lowered by different types of drugs; however, large scale studies of cardiovascular disease risk reduction through remnant lipoprotein lowering are under way.

  11. Investigation of In vitro Mineral Forming Bacterial Isolates from ...

    African Journals Online (AJOL)

    Aim: Although it is known that bacterial mechanisms are involved in dental calculus formation, which is a predisposing factor in periodontal diseases, there have been few studies of such associations, and therefore, information available is limited. The purpose of this study was to isolate and identify aerobic bacteria ...

  12. Bacterial production, protozoan grazing, and mineralization in stratified Lake Vechten

    NARCIS (Netherlands)

    Bloem, J.

    1989-01-01

    The role of heterotrophic nanoflagellates (HNAN, size 2-20 μm) in grazing on bacteria and mineralization of organic matter in stratified Lake Vechten was studied.

    Quantitative effects of manipulation and fixation on HNAN were checked. Considerable losses were caused by

  13. Relationship among Phosphorus Circulation Activity, Bacterial Biomass, pH, and Mineral Concentration in Agricultural Soil

    Directory of Open Access Journals (Sweden)

    Dinesh Adhikari

    2017-12-01

    Full Text Available Improvement of phosphorus circulation in the soil is necessary to enhance phosphorus availability to plants. Phosphorus circulation activity is an index of soil’s ability to supply soluble phosphorus from organic phosphorus in the soil solution. To understand the relationship among phosphorus circulation activity; bacterial biomass; pH; and Fe, Al, and Ca concentrations (described as mineral concentration in this paper in agricultural soil, 232 soil samples from various agricultural fields were collected and analyzed. A weak relationship between phosphorus circulation activity and bacterial biomass was observed in all soil samples (R2 = 0.25, and this relationship became significantly stronger at near-neutral pH (6.0–7.3; R2 = 0.67. No relationship between phosphorus circulation activity and bacterial biomass was observed at acidic (pH < 6.0 or alkaline (pH > 7.3 pH. A negative correlation between Fe and Al concentrations and phosphorus circulation activity was observed at acidic pH (R2 = 0.72 and 0.73, respectively, as well as for Ca at alkaline pH (R2 = 0.64. Therefore, bacterial biomass, pH, and mineral concentration should be considered together for activation of phosphorus circulation activity in the soil. A relationship model was proposed based on the effects of bacterial biomass and mineral concentration on phosphorus circulation activity. The suitable conditions of bacterial biomass, pH, and mineral concentration for phosphorus circulation activity could be estimated from the relationship model.

  14. Bacterial and iron oxide aggregates mediate secondary iron mineral formation: green rust versus magnetite.

    Science.gov (United States)

    Zegeye, A; Mustin, C; Jorand, F

    2010-06-01

    In the presence of methanoate as electron donor, Shewanella putrefaciens, a Gram-negative, facultative anaerobe, is able to transform lepidocrocite (gamma-FeOOH) to secondary Fe (II-III) minerals such as carbonated green rust (GR1) and magnetite. When bacterial cells were added to a gamma-FeOOH suspension, aggregates were produced consisting of both bacteria and gamma-FeOOH particles. Recently, we showed that the production of secondary minerals (GR1 vs. magnetite) was dependent on bacterial cell density and not only on iron reduction rates. Thus, gamma-FeOOH and S. putrefaciens aggregation pattern was suggested as the main mechanism driving mineralization. In this study, lepidocrocite bioreduction experiments, in the presence of anthraquinone disulfonate, were conducted by varying the [cell]/[lepidocrocite] ratio in order to determine whether different types of aggregate are formed, which may facilitate precipitation of GR1 as opposed to magnetite. Confocal laser scanning microscopy was used to analyze the relative cell surface area and lepidocrocite concentration within the aggregates and captured images were characterized by statistical methods for spatial data (i.e. variograms). These results suggest that the [cell]/[lepidocrocite] ratio influenced both the aggregate structure and the nature of the secondary iron mineral formed. Subsequently, a [cell]/[lepidocrocite] ratio above 1 x 10(7) cells mmol(-1) leads to densely packed aggregates and to the formation of GR1. Below this ratio, looser aggregates are formed and magnetite was systematically produced. The data presented in this study bring us closer to a more comprehensive understanding of the parameters governing the formation of minerals in dense bacterial suspensions and suggest that screening mineral-bacteria aggregate structure is critical to understanding (bio)mineralization pathways.

  15. 2,4,6-Trinitrotoluene mineralization and bacterial production rates of natural microbial assemblages from coastal sediments

    Energy Technology Data Exchange (ETDEWEB)

    Montgomery, Michael T., E-mail: michael.montgomery@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Coffin, Richard B., E-mail: richard.coffin@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Boyd, Thomas J., E-mail: thomas.boyd@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Smith, Joseph P., E-mail: joseph.smith@nrl.navy.mil [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Walker, Shelby E., E-mail: Shelby.Walker@noaa.gov [Naval Research Laboratory, Marine Biogeochemistry Section, Code 6114, 4555 Overlook Avenue, Washington, DC 20375 (United States); Osburn, Christopher L., E-mail: chris_osburn@ncsu.edu [Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695 (United States)

    2011-12-15

    The nitrogenous energetic constituent, 2,4,6-Trinitrotoluene (TNT), is widely reported to be resistant to bacterial mineralization (conversion to CO{sub 2}); however, these studies primarily involve bacterial isolates from freshwater where bacterial production is typically limited by phosphorus. This study involved six surveys of coastal waters adjacent to three biome types: temperate broadleaf, northern coniferous, and tropical. Capacity to catabolize and mineralize TNT ring carbon to CO{sub 2} was a common feature of natural sediment assemblages from these coastal environments (ranging to 270+/-38 {mu}g C kg{sup -1} d{sup -1}). More importantly, these mineralization rates comprised a significant proportion of total heterotrophic production. The finding that most natural assemblages surveyed from these ecosystems can mineralize TNT ring carbon to CO{sub 2} is consistent with recent reports that assemblage components can incorporate TNT ring carbon into bacterial biomass. These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - Highlights: > TNT mineralization is a common feature of natural bacterial assemblages in coastal sediments. > TNT mineralization rates comprised a significant proportion of total heterotrophic production. > These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - The capacity to mineralize TNT ring carbon to CO{sub 2} is a common feature of natural bacterial assemblages in coastal sediment.

  16. 2,4,6-Trinitrotoluene mineralization and bacterial production rates of natural microbial assemblages from coastal sediments

    International Nuclear Information System (INIS)

    Montgomery, Michael T.; Coffin, Richard B.; Boyd, Thomas J.; Smith, Joseph P.; Walker, Shelby E.; Osburn, Christopher L.

    2011-01-01

    The nitrogenous energetic constituent, 2,4,6-Trinitrotoluene (TNT), is widely reported to be resistant to bacterial mineralization (conversion to CO 2 ); however, these studies primarily involve bacterial isolates from freshwater where bacterial production is typically limited by phosphorus. This study involved six surveys of coastal waters adjacent to three biome types: temperate broadleaf, northern coniferous, and tropical. Capacity to catabolize and mineralize TNT ring carbon to CO 2 was a common feature of natural sediment assemblages from these coastal environments (ranging to 270+/-38 μg C kg -1 d -1 ). More importantly, these mineralization rates comprised a significant proportion of total heterotrophic production. The finding that most natural assemblages surveyed from these ecosystems can mineralize TNT ring carbon to CO 2 is consistent with recent reports that assemblage components can incorporate TNT ring carbon into bacterial biomass. These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - Highlights: → TNT mineralization is a common feature of natural bacterial assemblages in coastal sediments. → TNT mineralization rates comprised a significant proportion of total heterotrophic production. → These data counter the widely held contention that TNT is recalcitrant to bacterial catabolism of the ring carbon in natural environments. - The capacity to mineralize TNT ring carbon to CO 2 is a common feature of natural bacterial assemblages in coastal sediment.

  17. Bacterial entombment by intratubular mineralization following orthograde mineral trioxide aggregate obturation:a scanning electron microscopy study

    Institute of Scientific and Technical Information of China (English)

    Jun Sang Yoo; Qiang Zhu; Kee-Yeon Kum; Seok-Woo Chang; So Ram Oh; Hiran Perinpanayagam; Sang-Min Lim; Yeon-Jee Yoo; Yeo-Rok Oh; Sang-Bin Woo; Seung-Hyun Han

    2014-01-01

    The time domain entombment of bacteria by intratubular mineralization following orthograde canal obturation with mineral trioxide aggregate (MTA) was studied by scanning electron microscopy (SEM). Single-rooted human premolars (n560) were instrumented to an apical size #50/0.06 using ProFile and treated as follows:Group 1 (n510) was filled with phosphate buffered saline (PBS);Group 2 (n510) was incubated with Enterococcus faecalis for 3 weeks, and then filled with PBS;Group 3 (n520) was obturated orthograde with a paste of OrthoMTA (BioMTA, Seoul, Korea) and PBS;and Group 4 (n520) was incubated with E. faecalis for 3 weeks and then obturated with OrthoMTA–PBS paste. Following their treatments, the coronal openings were sealed with PBS-soaked cotton and intermediate restorative material (IRM), and the roots were then stored in PBS for 1, 2, 4, 8 or 16 weeks. After each incubation period, the roots were split and their dentin/MTA interfaces examined in both longitudinal and horizontal directions by SEM. There appeared to be an increase in intratubular mineralization over time in the OrthoMTA-filled roots (Groups 3 and 4). Furthermore, there was a gradual entombment of bacteria within the dentinal tubules in the E. faecalis inoculated MTA-filled roots (Group 4). Therefore, the orthograde obturation of root canals with OrthoMTA mixed with PBS may create a favorable environment for bacterial entombment by intratubular mineralization.

  18. Influence of substrate mineralogy on bacterial mineralization of calcium carbonate: implications for stone conservation.

    Science.gov (United States)

    Rodriguez-Navarro, Carlos; Jroundi, Fadwa; Schiro, Mara; Ruiz-Agudo, Encarnación; González-Muñoz, María Teresa

    2012-06-01

    The influence of mineral substrate composition and structure on bacterial calcium carbonate productivity and polymorph selection was studied. Bacterial calcium carbonate precipitation occurred on calcitic (Iceland spar single crystals, marble, and porous limestone) and silicate (glass coverslips, porous sintered glass, and quartz sandstone) substrates following culturing in liquid medium (M-3P) inoculated with different types of bacteria (Myxococcus xanthus, Brevundimonas diminuta, and a carbonatogenic bacterial community isolated from porous calcarenite stone in a historical building) and direct application of sterile M-3P medium to limestone and sandstone with their own bacterial communities. Field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD), and 2-dimensional XRD (2D-XRD) analyses revealed that abundant highly oriented calcite crystals formed homoepitaxially on the calcitic substrates, irrespective of the bacterial type. Conversely, scattered spheroidal vaterite entombing bacterial cells formed on the silicate substrates. These results show that carbonate phase selection is not strain specific and that under equal culture conditions, the substrate type is the overruling factor for calcium carbonate polymorph selection. Furthermore, carbonate productivity is strongly dependent on the mineralogy of the substrate. Calcitic substrates offer a higher affinity for bacterial attachment than silicate substrates, thereby fostering bacterial growth and metabolic activity, resulting in higher production of calcium carbonate cement. Bacterial calcite grows coherently over the calcitic substrate and is therefore more chemically and mechanically stable than metastable vaterite, which formed incoherently on the silicate substrates. The implications of these results for technological applications of bacterial carbonatogenesis, including building stone conservation, are discussed.

  19. Extremophiles in Mineral Sulphide Heaps: Some Bacterial Responses to Variable Temperature, Acidity and Solution Composition

    Directory of Open Access Journals (Sweden)

    Helen R. Watling

    2015-07-01

    Full Text Available In heap bioleaching, acidophilic extremophiles contribute to enhanced metal extraction from mineral sulphides through the oxidation of Fe(II and/or reduced inorganic sulphur compounds (RISC, such as elemental sulphur or mineral sulphides, or the degradation of organic compounds derived from the ore, biota or reagents used during mineral processing. The impacts of variable solution acidity and composition, as well as temperature on the three microbiological functions have been examined for up to four bacterial species found in mineral sulphide heaps. The results indicate that bacteria adapt to sufficiently high metal concentrations (Cu, Ni, Co, Zn, As to allow them to function in mineral sulphide heaps and, by engaging alternative metabolic pathways, to extend the solution pH range over which growth is sustained. Fluctuating temperatures during start up in sulphide heaps pose the greatest threat to efficient bacterial colonisation. The large masses of ores in bioleaching heaps mean that high temperatures arising from sulphide oxidation are hard to control initially, when the sulphide content of the ore is greatest. During that period, mesophilic and moderately thermophilic bacteria are markedly reduced in both numbers and activity.

  20. Investigation of In vitro Mineral forming bacterial isolates from supragingival calculus.

    Science.gov (United States)

    Baris, O; Demir, T; Gulluce, M

    2017-12-01

    Although it is known that bacterial mechanisms are involved in dental calculus formation, which is a predisposing factor in periodontal diseases, there have been few studies of such associations, and therefore, information available is limited. The purpose of this study was to isolate and identify aerobic bacteria responsible for direct calcification from supragingival calculus samples. The study was conducted using supragingival calculus samples from patients with periodontal disease, which was required as part of conventional treatment. Isolations were performed by sampling the supragingival calculus with buffer and inoculating the samples on media on which crystallization could be observed. The 16S recombinant DNA of the obtained pure cultures was then amplified and sequenced. A few bacterial species that have not previously been associated with mineralization or identified on bacterial plaque or calculus were detected. The bacteria that caused mineralization an aerobic environment are identified as Neisseria flava, Aggregatibacter segnis, Streptococcus tigurinus, and Morococcus cerebrosus. These findings proved that bacteria potentially play a role in the etiopathology of supragingival calculus. The association between the effects of the identified bacteria on periodontal diseases and calculus formation requires further studies.

  1. The effects of supplementation of a novel bacterial 6-phytase on mineral digestibility and plasma minerals in lactating sows.

    Science.gov (United States)

    Nasir, Z; Broz, J; Zijlstra, R T

    2012-12-01

    Pigs digest P in plant feedstuffs poorly because pigs do not produce sufficient endogenous phytase to hydrolyze P from phytate (inositol hexaphosphate). Supplementation of phytase to diets of piglets and grower-finisher pigs increased digestibility of minerals including P and Ca; however, data on phytase efficacy in lactating sows are scarce. Therefore, effects of adding a bacterial 6-phytase expressed in a strain of Aspergillus oryzae (Ronozyme HiPhos; DSM Nutritional Products, Basel, Switzerland) on apparent total tract digestibility (ATTD) of P and Ca was assessed in 45 lactating sows. Three diets were prepared: (i) positive control (PC; 0.52% available P), a regular sow diet containing inorganic P, (ii) negative control (NC; 0.20% available P) without inorganic P, and (iii) NC + 500 units of phytase/kg diet. Each diet was fed randomly to 15 sows for 21 d (from 5 d prior to farrowing to 15 d after farrowing). At day 15 after farrowing, ATTD of P did not differ between PC and NC. Phytase supplementation to NC increased (P 0.05) ATTD of CP and Ca. On day 1 after farrowing, plasma P was 0.66 mmol/L lower (P Phytase supplementation to NC increased (P phytase supplementation increased P bioavailability in lactating sows.

  2. Endogeic earthworms shape bacterial functional communities and affect organic matter mineralization in a tropical soil

    Science.gov (United States)

    Bernard, Laetitia; Chapuis-Lardy, Lydie; Razafimbelo, Tantely; Razafindrakoto, Malalatiana; Pablo, Anne-Laure; Legname, Elvire; Poulain, Julie; Brüls, Thomas; O'Donohue, Michael; Brauman, Alain; Chotte, Jean-Luc; Blanchart, Eric

    2012-01-01

    Priming effect (PE) is defined as a stimulation of the mineralization of soil organic matter (SOM) following a supply of fresh organic matter. This process can have important consequences on the fate of SOM and on the management of residues in agricultural soils, especially in tropical regions where soil fertility is essentially based on the management of organic matter. Earthworms are ecosystem engineers known to affect the dynamics of SOM. Endogeic earthworms ingest large amounts of soil and assimilate a part of organic matter it contains. During gut transit, microorganisms are transported to new substrates and their activity is stimulated by (i) the production of readily assimilable organic matter (mucus) and (ii) the possible presence of fresh organic residues in the ingested soil. The objective of our study was to see (i) whether earthworms impact the PE intensity when a fresh residue is added to a tropical soil and (ii) whether this impact is linked to a stimulation/inhibition of bacterial taxa, and which taxa are affected. A tropical soil from Madagascar was incubated in the laboratory, with a 13C wheat straw residue, in the presence or absence of a peregrine endogeic tropical earthworm, Pontoscolex corethrurus. Emissions of 12CO2 and 13CO2 were followed during 16 days. The coupling between DNA-SIP (stable isotope probing) and pyrosequencing showed that stimulation of both the mineralization of wheat residues and the PE can be linked to the stimulation of several groups especially belonging to the Bacteroidetes phylum. PMID:21753801

  3. Minerals

    Science.gov (United States)

    Minerals are important for your body to stay healthy. Your body uses minerals for many different jobs, including keeping your bones, muscles, heart, and brain working properly. Minerals are also important for making enzymes and hormones. ...

  4. Effects of inoculation with organic-phosphorus-mineralizing bacteria on soybean (Glycine max) growth and indigenous bacterial community diversity.

    Science.gov (United States)

    Sun, Wei; Qian, Xun; Gu, Jie; Wang, Xiao-Juan; Li, Yang; Duan, Man-Li

    2017-05-01

    Three different organic-phosphorus-mineralizing bacteria (OPMB) strains were inoculated to soil planted with soybean (Glycine max), and their effects on soybean growth and indigenous bacterial community diversity were investigated. Inoculation with Pseudomonas fluorescens Z4-1 and Brevibacillus agri L7-1 increased organic phosphorus degradation by 22% and 30%, respectively, compared with the control at the mature stage. Strains P. fluorescens Z4-1 and B. agri L7-1 significantly improved the soil alkaline phosphatase activity, average well color development, and the soybean root activity. Terminal restriction fragment length polymorphism analysis demonstrated that P. fluorescens Z4-1 and B. agri L7-1 could persist in the soil at relative abundances of 2.0%-6.4% throughout soybean growth. Thus, P. fluorescens Z4-1 and B. agri L7-1 could potentially be used in organic-phosphorus-mineralizing biofertilizers. OPMB inoculation altered the genetic structure of the soil bacterial communities but had no apparent influence on the carbon source utilization profiles of the soil bacterial communities. Principal components analysis showed that the changes in the carbon source utilization profiles of bacterial community depended mainly on the plant growth stages rather than inoculation with OPMB. The results help to understand the evolution of the soil bacterial community after OPMB inoculation.

  5. Degradation and mineralization of high-molecular-weight polycyclic aromatic hydrocarbons by defined fungal-bacterial cocultures

    International Nuclear Information System (INIS)

    Boonchan, S.; Britz, M.L.; Stanley, G.A.

    2000-01-01

    This study investigated the biodegradation of high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) in liquid media and soil by bacteria (Stenotrophomonas maltophilia VUN 10,010 and bacterial consortium VUN 10,009) and a fungus (Penicillium janthinellum VUO 10,201) that were isolated from separate creosote- and manufactured-gas plant-contaminated soils. The bacteria could use pyrene as their sole carbon and energy source in a basal salts medium (BSM) and mineralized significant amounts of benzo[a]pyrene cometabolically when pyrene was also present in BSM. P. janthinellum VUO 10,201 could not utilize any high-molecular-weight PAH as sole carbon and energy source but could partially degrade these if cultured in a nutrient broth. Although small amounts of chrysene, benz[a]pyrene, and dibenz[a,h]anthracene were degraded by axenic cultures of these isolates in BSM containing a single PAH, such conditions did not support significant microbial growth or PAH mineralization. However, significant degradation of, and microbial growth on, pyrene, chrysene, benz[a]anthracene, benzo[a]pyrene, and dibenz[a,h]anthracene, each as a single PAH in BSM, occurred when P. janthinellum VUO 10,201 and either bacterial consortium VUN 10,009 or S. maltophilia VUN 10,010 were combined in the one culture, i.e., fungal-bacterial cocultures: 25% of the benzo[a]pyrene was mineralized to CO 2 by these cocultures over 49 days, accompanied by transient accumulation and disappearance of intermediates detected by high-pressure liquid chromatography. Inoculation of fungal-bacterial cocultures into PAH-contaminated soil resulted in significantly improved degradation of high-molecular-weight PAHs, benzo[a]pyrene mineralization, and reduction in the mutagenicity of organic soil extracts, compared with the indigenous microbes and soil amended with only axenic inocula

  6. Minerals

    Science.gov (United States)

    ... Aren't minerals something you find in the earth, like iron and quartz? Well, yes, but small ... canned salmon and sardines with bones leafy green vegetables, such as broccoli calcium-fortified foods — from orange ...

  7. Remnant lipoproteins and atherosclerosis

    NARCIS (Netherlands)

    Twickler, Th. B.; Dallinga-Thie, G. M.; Chapman, M. J.; Cohn, J. S.

    2005-01-01

    A recently developed assay for quantification of remnant-like particle cholesterol has provided considerable evidence that reinforces the concept that elevated levels of plasma remnants are associated with increased cardiovascular disease in different populations and distinct patient groups. In this

  8. Salt-enhanced chemical weathering of building materials and bacterial mineralization of calcium carbonate as a treatment

    Science.gov (United States)

    Schiro, M.; Ruiz-Agudo, E.; Jroundi, F.; Gonzalez-Muñoz, M. T.; Rodriguez-Navarro, C.

    2012-04-01

    Salt weathering is an important mechanism contributing to the degradation and loss of stone building materials. In addition to the physical weathering resulting from crystallization pressure, the presence of salts in solution greatly enhances the chemical weathering potential of pore waters. Flow through experiments quantify the dissolution rates of calcite and quartz grains (63-125 micrometer diameter) when subjected to 1.0 ionic strength solutions of MgSO4, MgCl, Na2SO4 or NaCl. Results indicate that the identity of the cation is the primary control over the dissolution rate of both calcite and quartz substrates, with salt-enhanced dissolution occurring most rapidly in Mg2+ bearing solutions. It has been observed that weathering rates of rocks in nature, as well as building stones, are slowed down by naturally occurring or artificially produced patinas. These tend to be bacterially produced, durable mineralized coatings that lend some degree of protection to the underlying stone surface [1]. Our research shows that bacterially produced carbonate coatings can be quite effective at reducing chemical weathering of stone by soluble salts. The calcite-producing-bacteria used in this study were isolated from stone monuments in Granada, Spain [2] and cultivated in an organic-rich culture medium on a variety of artificial and natural substrates (including limestone, marble, sandstone, quartz, calcite single crystals, glass cover-slips, and sintered porous glass). Scanning electron microscopy (FESEM) was used to image bacterial calcite growth and biofilm formation. In-situ atomic force microscopy (AFM) enabled calculation of dissolution rates of untreated and bacterially treated surfaces. 2D-XRD showed the mineralogy and crystallographic orientation of bacterial calcium carbonate. Results indicate that bacterially produced calcite crystals form a coherent, mechanically resistant surface layer in perfect crystallographic continuity with the calcite substrate (self

  9. A Combination of Biochar-Mineral Complexes and Compost Improves Soil Bacterial Processes, Soil Quality, and Plant Properties.

    Science.gov (United States)

    Ye, Jun; Zhang, Rui; Nielsen, Shaun; Joseph, Stephen D; Huang, Danfeng; Thomas, Torsten

    2016-01-01

    Organic farming avoids the use of synthetic fertilizers and promises food production with minimal environmental impact, however this farming practice does not often result in the same productivity as conventional farming. In recent years, biochar has received increasing attention as an agricultural amendment and by coating it with minerals to form biochar-mineral complex (BMC) carbon retention and nutrient availability can be improved. However, little is known about the potential of BMC in improving organic farming. We therefore investigated here how soil, bacterial and plant properties respond to a combined treatment of BMC and an organic fertilizer, i.e., a compost based on poultry manure. In a pakchoi pot trial, BMC and compost showed synergistic effects on soil properties, and specifically by increasing nitrate content. Soil nitrate has been previously observed to increase leaf size and we correspondingly saw an increase in the surface area of pakchoi leaves under the combined treatment of BMC and composted chicken manure. The increase in soil nitrate was also correlated with an enrichment of bacterial nitrifiers due to BMC. Additionally, we observed that the bacteria present in the compost treatment had a high turnover, which likely facilitated organic matter degradation and a reduction of potential pathogens derived from the manure. Overall our results demonstrate that a combination of BMC and compost can stimulate microbial process in organic farming that result in better vegetable production and improved soil properties for sustainable farming.

  10. A combination of biochar-mineral complexes and compost improves soil bacterial processes, soil quality and plant properties

    Directory of Open Access Journals (Sweden)

    JUN eYE

    2016-04-01

    Full Text Available Organic farming avoids the use of synthetic fertilizers and promises food production with minimal environmental impact, however this farming practice does not often result in the same productivity as conventional farming. In recent years, biochar has received increasing attention as an agricultural amendment and by coating it with minerals to form biochar-mineral complex (BMC carbon retention and nutrient availability can be improved. However, little is known about the potential of BMC in improving organic farming. We therefore investigated here how soil, bacterial and plant properties respond to a combined treatment of BMC and an organic fertilizer, i.e. a compost based on poultry manure. In a pakchoi pot trial, BMC and compost showed synergistic effects on soil properties, and specifically by increasing nitrate content. Soil nitrate has been previously observed to increase leaf size and we correspondingly saw an increase in the surface area of pakchoi leaves under the combined treatment of BMC and chicken manure. The increase in soil nitrate was also correlated with an enrichment of bacterial nitrifiers due to BMC. Additionally, we observed that the bacteria present in the compost treatment had a high turnover, which likely facilitated organic matter degradation and a reduction of potential pathogens derived from the manure. Overall our results demonstrate that a combination of BMC and compost can stimulate microbial process in organic farming that result in better vegetable production and improved soil properties for sustainable farming.

  11. Minerals

    Directory of Open Access Journals (Sweden)

    Vaquero, M. P.

    1998-08-01

    Full Text Available The possible changes in the mineral composition of food during frying could be the consequence of losses by leaching, or changes in concentrations caused by exchanges between the food and culinary fat of other compounds. The net result depends on the type of food, the frying fat used and the frying process. Moreover, the modifications that frying produces in other nutrients could indirectly affect the availability of dietary minerals. The most outstanding ones are those that can take place in the fat or in the protein. With respect to the interactions between frying oils and minerals, we have recent knowledge concerning the effects of consuming vegetable oils used in repeated fryings of potatoes without turnover, on the nutritive utilization of dietary minerals. The experiments have been carried out in pregnant and growing rats, which consumed diets containing, as a sole source of fat, the testing frying oils or unused oils. It seems that the consumption of various frying oils, with a polar compound content lower or close to the maximum limit of 25% accepted for human consumption, does not alter the absorption and metabolism of calcium, phosphorous, iron or copper. Magnesium absorption from diets containing frying oils tends to increase but the urinary excretion of this element increases, resulting imperceptible the variations in the magnesium balance. The urinary excretion of Zn also increased although its balance remained unchanged. Different studies referring to the effects of consuming fried fatty fish on mineral bioavailability will also be presented. On one hand, frying can cause structural changes in fish protein, which are associated with an increase in iron absorption and a decrease in body zinc retention. The nutritive utilization of other elements such as magnesium, calcium and copper seems to be unaffected. On the other hand; it has been described that an excess of fish fatty acids in the diet produces iron depletion, but when fatty

  12. Cervical Chondrocutaneous Branchial Remnants.

    Science.gov (United States)

    Klockars, Tuomas; Kajosaari, Lauri

    2017-03-01

      Cervical chondrocutaneous branchial remnants are rare malformations usually found in the lower neck. As high as 76% of patients have been reported to have associated anomalies. We review the literature and report a case series of seven patients with cervical cartilaginous remnants.   A retrospective case series of seven patients identified from the electronic hospital records.   Seven patients with cervical chondrocutaneous branchial remnants were identified (six boys and one girl). Only one of the patients had associated anomalies.   A review of the literature revealed no evidence for sinuses or cysts related to cervical chondrocutaneous branchial remnants. Operative treatment can be postponed to a suitable and safe age. There is marked variation in the reported prevalence of associated anomalies, ranging from 11% to 76%.

  13. Influence of soil properties on the toxicity of TiO₂ nanoparticles on carbon mineralization and bacterial abundance.

    Science.gov (United States)

    Simonin, Marie; Guyonnet, Julien P; Martins, Jean M F; Ginot, Morgane; Richaume, Agnès

    2015-01-01

    Information regarding the impact of low concentration of engineered nanoparticles on soil microbial communities is currently limited and the importance of soil characteristics is often neglected in ecological risk assessment. To evaluate the impact of TiO2 nanoparticles (NPs) on soil microbial communities (measured on bacterial abundance and carbon mineralization activity), 6 agricultural soils exhibiting contrasted textures and organic matter contents were exposed for 90 days to a low environmentally relevant concentration or to an accidental spiking of TiO2-NPs (1 and 500mgkg(-1) dry soil, respectively) in microcosms. In most soils, TiO2-NPs did not impact the activity and abundance of microbial communities, except in the silty-clay soil (high OM) where C-mineralization was significantly lowered, even with the low NPs concentration. Our results suggest that TiO2-NPs toxicity does not depend on soil texture but likely on pH and OM content. We characterized TiO2-NPs aggregation and zeta potential in soil solutions, in order to explain the difference of TiO2-NPs effects on soil C-mineralization. Zeta potential and aggregation of TiO2-NPs in the silty-clay (high OM) soil solution lead to a lower stability of TiO2-NP-aggregates than in the other soils. Further experiments would be necessary to evaluate the relationship between TiO2-NPs stability and toxicity in the soil. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Survey on Heterotrophic Bacterial Contamination in Bottled Mineral Water by Culture Method

    Directory of Open Access Journals (Sweden)

    Essmaeel Ghorbanalinezhad

    2014-12-01

    Full Text Available Background and Aim: This project focuses on the level of heterotrophic baceria in bottled mineral water which could be a health concern for the elderly, infants, pregnant women and immuno-compromised patients. Materials and Methods: Different brands of bottled water samples were selected randomly and evaluated for their bacteriological quality, using different specific culture media and biochemical tests. Water samples were analyzed within 24 hours of their purchase/collection. Samples were filtered with 0.45 micron and filters were plated in different media. Then media were incubated at 37˚C for 24-48 hours. Results: Morphological study and biochemical tests revealed a number of bacteria in different   brands of  bottled water. Heterotrophic bacteria(Gram positive cocci, Spore forming gram positive bacilli, non spore forming gram positive bacilli, gram negative bacilli, and gram negative coccobacilli; Pseudomonas and Stenotrophomonas counted in 70% of bottled water samples. There were no cases of fecal contamination or the presence of E.coli. Conclusions: Bottled water is not sterile and contains trace amounts of bacteria naturally present or introduced during processing. Testing drinking water for all possible pathogens is complex, time-consuming, and expensive. If only total coliform bacteria are detected in drinking water, the source is probably environmental. Since the significance of non-pathogenic heterotrophic bacteria in relation to health and diseases is not understood, there is an urgent need to establish a maximum limit for the heterotrophic count in the bottled mineral water. Growth conditions play a critical role in the recovery of heterotrophic bacteria in bottled drinking water.

  15. Evolution of Supernova Remnants

    Science.gov (United States)

    Arbutina, B.

    2017-12-01

    This book, both a monograph and a graduate textbook, is based on my original research and partly on the materials prepared earlier for the 2007 and 2008 IARS Astrophysics Summer School in Istanbul, AstroMundus course 'Supernovae and Their Remnants' that was held for the first time in 2011 at the Department of Astronomy, Faculty of Mathematics, University of Belgrade, and a graduate course 'Evolution of Supernova Remnants' that I teach at the aforementioned university. The first part Supernovae (introduction, thermonuclear supernovae, core-collapse supernovae) provides introductory information and explains the classification and physics of supernova explosions, while the second part Supernova remnants (introduction, shock waves, cosmic rays and particle acceleration, magnetic fields, synchrotron radiation, hydrodynamic and radio evolution of supernova remnants), which is the field I work in, is more detailed in scope i.e. technical/mathematical. Special attention is paid to details of mathematical derivations that often cannot be found in original works or available literature. Therefore, I believe it can be useful to both, graduate students and researchers interested in the field.

  16. Effects of Bacterial Siderophore and Biofilm Synthesis on Silicate Mineral Dissolution Kinetics: Results from Experiments with Targeted Mutants

    Science.gov (United States)

    Van Den Berghe, M. D.; West, A. J.; Nealson, K. H.

    2018-05-01

    This project aims to characterize and quantify the specific microbial mechanisms and metabolic pathways responsible for silicate mineral dissolution and micronutrient acquisition directly from mineral phases.

  17. Degradation of potassium rock by earthworms and responses of bacterial communities in its gut and surrounding substrates after being fed with mineral.

    Science.gov (United States)

    Liu, Dianfeng; Lian, Bin; Wang, Bin; Jiang, Guofang

    2011-01-01

    Earthworms are an ecosystem's engineers, contributing to a wide range of nutrient cycling and geochemical processes in the ecosystem. Their activities can increase rates of silicate mineral weathering. Their intestinal microbes usually are thought to be one of the key drivers of mineral degradation mediated by earthworms,but the diversities of the intestinal microorganisms which were relevant with mineral weathering are unclear. In this report, we show earthworms' effect on silicate mineral weathering and the responses of bacterial communities in their gut and surrounding substrates after being fed with potassium-bearing rock powder (PBRP). Determination of water-soluble and HNO(3)-extractable elements indicated some elements such as Al, Fe and Ca were significantly released from mineral upon the digestion of earthworms. The microbial communities in earthworms' gut and the surrounding substrates were investigated by amplified ribosomal DNA restriction analysis (ARDRA) and the results showed a higher bacterial diversity in the guts of the earthworms fed with PBRP and the PBRP after being fed to earthworms. UPGMA dendrogram with unweighted UniFrac analysis, considering only taxa that are present, revealed that earthworms' gut and their surrounding substrate shared similar microbiota. UPGMA dendrogram with weighted UniFrac, considering the relative abundance of microbial lineages, showed the two samples from surrounding substrate and the two samples from earthworms' gut had similarity in microbial community, respectively. Our results indicated earthworms can accelerate degradation of silicate mineral. Earthworms play an important role in ecosystem processe since they not only have some positive effects on soil structure, but also promote nutrient cycling of ecosystem by enhancing the weathering of minerals.

  18. Degradation of potassium rock by earthworms and responses of bacterial communities in its gut and surrounding substrates after being fed with mineral.

    Directory of Open Access Journals (Sweden)

    Dianfeng Liu

    Full Text Available BACKGROUND: Earthworms are an ecosystem's engineers, contributing to a wide range of nutrient cycling and geochemical processes in the ecosystem. Their activities can increase rates of silicate mineral weathering. Their intestinal microbes usually are thought to be one of the key drivers of mineral degradation mediated by earthworms,but the diversities of the intestinal microorganisms which were relevant with mineral weathering are unclear. METHODOLOGY/PRINCIPAL FINDINGS: In this report, we show earthworms' effect on silicate mineral weathering and the responses of bacterial communities in their gut and surrounding substrates after being fed with potassium-bearing rock powder (PBRP. Determination of water-soluble and HNO(3-extractable elements indicated some elements such as Al, Fe and Ca were significantly released from mineral upon the digestion of earthworms. The microbial communities in earthworms' gut and the surrounding substrates were investigated by amplified ribosomal DNA restriction analysis (ARDRA and the results showed a higher bacterial diversity in the guts of the earthworms fed with PBRP and the PBRP after being fed to earthworms. UPGMA dendrogram with unweighted UniFrac analysis, considering only taxa that are present, revealed that earthworms' gut and their surrounding substrate shared similar microbiota. UPGMA dendrogram with weighted UniFrac, considering the relative abundance of microbial lineages, showed the two samples from surrounding substrate and the two samples from earthworms' gut had similarity in microbial community, respectively. CONCLUSIONS/SIGNIFICANCE: Our results indicated earthworms can accelerate degradation of silicate mineral. Earthworms play an important role in ecosystem processe since they not only have some positive effects on soil structure, but also promote nutrient cycling of ecosystem by enhancing the weathering of minerals.

  19. PROGENITORS OF RECOMBINING SUPERNOVA REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Moriya, Takashi J., E-mail: takashi.moriya@ipmu.jp [Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8583 (Japan)

    2012-05-01

    Usual supernova remnants have either ionizing plasma or plasma in collisional ionization equilibrium, i.e., the ionization temperature is lower than or equal to the electron temperature. However, the existence of recombining supernova remnants, i.e., supernova remnants with ionization temperature higher than the electron temperature, has been recently confirmed. One suggested way to have recombining plasma in a supernova remnant is to have a dense circumstellar medium at the time of the supernova explosion. If the circumstellar medium is dense enough, collisional ionization equilibrium can be established in the early stage of the evolution of the supernova remnant and subsequent adiabatic cooling, which occurs after the shock wave gets out of the dense circumstellar medium, makes the electron temperature lower than the ionization temperature. We study the circumstellar medium around several supernova progenitors and show which supernova progenitors can have a circumstellar medium dense enough to establish collisional ionization equilibrium soon after the explosion. We find that the circumstellar medium around red supergiants (especially massive ones) and the circumstellar medium dense enough to make Type IIn supernovae can establish collisional ionization equilibrium soon after the explosion and can evolve to become recombining supernova remnants. Wolf-Rayet stars and white dwarfs have the possibility to be recombining supernova remnants but the fraction is expected to be very small. As the occurrence rate of the explosions of red supergiants is much higher than that of Type IIn supernovae, the major progenitors of recombining supernova remnants are likely to be red supergiants.

  20. Remnants of Lost Geology

    Science.gov (United States)

    2003-01-01

    [figure removed for brevity, see original site] In eastern Arabia Terra, remnants of a once vast layered terrain are evident as isolated buttes, mesas, and deeply-filled craters. The origin of the presumed sediments that created the layers is unknown, but those same sediments, now eroded, may be the source of the thick mantle of dust that covers much of Arabia Terra today.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.Image information: VIS instrument. Latitude 20.5, Longitude 50 East (310 West). 19 meter/pixel resolution.

  1. Rapid bacterial mineralization of organic carbon produced during a phytoplankton bloom induced by natural iron fertilization in the Southern Ocean

    Science.gov (United States)

    Obernosterer, Ingrid; Christaki, Urania; Lefèvre, Dominique; Catala, Philippe; Van Wambeke, France; Lebaron, Philippe

    2008-03-01

    The response of heterotrophic bacteria ( Bacteria and Archaea) to the spring phytoplankton bloom that occurs annually above the Kerguelen Plateau (Southern Ocean) due to natural iron fertilization was investigated during the KErguelen Ocean and Plateau compared Study (KEOPS) cruise in January-February 2005. In surface waters (upper 100 m) in the core of the phytoplankton bloom, heterotrophic bacteria were, on an average, 3-fold more abundant and revealed rates of production ([ 3H] leucine incorporation) and respiration (bacterial metabolic activities were attributable to high-nucleic-acid-containing cells that dominated (≈80% of total cell abundance) the heterotrophic bacterial community associated with the phytoplankton bloom. Bacterial growth efficiencies varied between 14% and 20% inside the bloom and were bacterial activity, due to the stimulation by phytoplankton-derived dissolved organic matter. Within the Kerguelen bloom, bacterial carbon demand accounted for roughly 45% of gross community production. These results indicate that heterotrophic bacteria processed a significant portion of primary production, with most of it being rapidly respired.

  2. Postprandial Hyperlipidemia and Remnant Lipoproteins.

    Science.gov (United States)

    Masuda, Daisaku; Yamashita, Shizuya

    2017-02-01

    Fasting hypertriglyceridemia is positively associated with the morbidity of coronary heart disease (CHD), and postprandial (non-fasting) hypertriglyceridemia is also correlated with the risk status for CHD, which is related to the increase in chylomicron (CM) remnant lipoproteins produced from the intestine. CM remnant particles, as well as oxidized low density lipoprotein (LDL) or very low density lipoprotein (VLDL) remnants, are highly atherogenic and act by enhancing systemic inflammation, platelet activation, coagulation, thrombus formation, and macrophage foam cell formation. The cholesterol levels of remnant lipoproteins significantly correlate with small, dense LDL; impaired glucose tolerance (IGT) and CHD prevalence. We have developed an assay of apolipoprotein (apo)B-48 levels to evaluate the accumulation of CM remnants. Fasting apoB-48 levels correlate with the morbidity of postprandial hypertriglyceridemia, obesity, type III hyperlipoproteinemia, the metabolic syndrome, hypothyroidism, chronic kidney disease, and IGT. Fasting apoB-48 levels also correlate with carotid intima-media thickening and CHD prevalence, and a high apoB-48 level is a significant predictor of CHD risk, independent of the fasting TG level. Diet interventions, such as dietary fibers, polyphenols, medium-chain fatty acids, diacylglycerol, and long-chain n-3 polyunsaturated fatty acids (PUFA), ameliorate postprandial hypertriglyceridemia, moreover, drugs for dyslipidemia (n-3 PUFA, statins, fibrates or ezetimibe) and diabetes concerning incretins (dipeptidyl-peptidase IV inhibitor or glucagon like peptide-1 analogue) may improve postprandial hypertriglyceridemia. Since the accumulation of CM remnants correlates to impaired lipid and glucose metabolism and atherosclerotic cardiovascular events, further studies are required to investigate the characteristics, physiological activities, and functions of CM remnants for the development of new interventions to reduce atherogenicity.

  3. Differential impacts of willow and mineral fertilizer on bacterial communities and biodegradation in diesel fuel oil-contaminated soil

    Directory of Open Access Journals (Sweden)

    Mary-Cathrine C.E. Leewis

    2016-06-01

    Full Text Available Despite decades of research there is limited understanding of how vegetation impacts the ability of microbial communities to process organic contaminants in soil. Using a combination of traditional and molecular assays, we examined how phytoremediation with willow and/or fertilization affected the microbial community present and active in the transformation of diesel contaminants. In a pot study, willow had a significant role in structuring the total bacterial community and resulted in significant decreases in diesel range organics (DRO. However, stable isotope probing (SIP indicated that fertilizer drove the differences seen in community structure and function. Finally, analysis of the total variance in both pot and SIP experiments indicated an interactive effect between willow and fertilizer on the bacterial communities. This study clearly demonstrates that a willow native to Alaska accelerates DRO degradation, and together with fertilizer, increased aromatic degradation by shifting microbial community structure and the identity of active naphthalene degraders.

  4. Bacterial diversity in the active stage of a bioremediation system for mineral oil hydrocarbon-contaminated soils.

    Science.gov (United States)

    Popp, Nicole; Schlömann, Michael; Mau, Margit

    2006-11-01

    Soils contaminated with mineral oil hydrocarbons are often cleaned in off-site bioremediation systems. In order to find out which bacteria are active during the degradation phase in such systems, the diversity of the active microflora in a degrading soil remediation system was investigated by small-subunit (SSU) rRNA analysis. Two sequential RNA extracts from one soil sample were generated by a procedure incorporating bead beating. Both extracts were analysed separately by generating individual SSU rDNA clone libraries from cDNA of the two extracts. The sequencing results showed moderate diversity. The two clone libraries were dominated by Gammaproteobacteria, especially Pseudomonas spp. Alphaproteobacteria and Betaproteobacteria were two other large groups in the clone libraries. Actinobacteria, Firmicutes, Bacteroidetes and Epsilonproteobacteria were detected in lower numbers. The obtained sequences were predominantly related to genera for which cultivated representatives have been described, but were often clustered together in the phylogenetic tree, and the sequences that were most similar were originally obtained from soils and not from pure cultures. Most of the dominant genera in the clone libraries, e.g. Pseudomonas, Acinetobacter, Sphingomonas, Acidovorax and Thiobacillus, had already been detected in (mineral oil hydrocarbon) contaminated environmental samples. The occurrence of the genera Zymomonas and Rhodoferax was novel in mineral oil hydrocarbon-contaminated soil.

  5. Detection and differentiation of bacterial spores in a mineral matrix by Fourier transform infrared spectroscopy (FTIR and chemometrical data treatment

    Directory of Open Access Journals (Sweden)

    Brandes Ammann Andrea

    2011-07-01

    Full Text Available Abstract Background Fourier transform infrared spectroscopy (FTIR has been used as analytical tool in chemistry for many years. In addition, FTIR can also be applied as a rapid and non-invasive method to detect and identify microorganisms. The specific and fingerprint-like spectra allow - under optimal conditions - discrimination down to the species level. The aim of this study was to develop a fast and reproducible non-molecular method to differentiate pure samples of Bacillus spores originating from different species as well as to identify spores in a simple matrix, such as the clay mineral, bentonite. Results We investigated spores from pure cultures of seven different Bacillus species by FTIR in reflection or transmission mode followed by chemometrical data treatment. All species investigated (B. atrophaeus, B. brevis, B. circulans, B. lentus, B. megaterium, B. subtilis, B. thuringiensis are typical aerobic soil-borne spore formers. Additionally, a solid matrix (bentonite and mixtures of benonite with spores of B. megaterium at various wt/wt ratios were included in the study. Both hierarchical cluster analysis and principal component analysis of the spectra along with multidimensional scaling allowed the discrimination of different species and spore-matrix-mixtures. Conclusions Our results show that FTIR spectroscopy is a fast method for species-level discrimination of Bacillus spores. Spores were still detectable in the presence of the clay mineral bentonite. Even a tenfold excess of bentonite (corresponding to 2.1 × 1010 colony forming units per gram of mineral matrix still resulted in an unambiguous identification of B. megaterium spores.

  6. Mn(II,III) oxidation and MnO2 mineralization by an expressed bacterial multicopper oxidase

    Science.gov (United States)

    Butterfield, Cristina N.; Soldatova, Alexandra V.; Lee, Sung-Woo; Spiro, Thomas G.; Tebo, Bradley M.

    2013-01-01

    Reactive Mn(IV) oxide minerals are ubiquitous in the environment and control the bioavailability and distribution of many toxic and essential elements and organic compounds. Their formation is thought to be dependent on microbial enzymes, because spontaneous Mn(II) to Mn(IV) oxidation is slow. Several species of marine Bacillus spores oxidize Mn(II) on their exosporium, the outermost layer of the spore, encrusting them with Mn(IV) oxides. Molecular studies have identified the mnx (Mn oxidation) genes, including mnxG, encoding a putative multicopper oxidase (MCO), as responsible for this two-electron oxidation, a surprising finding because MCOs only catalyze single-electron transfer reactions. Characterization of the enzymatic mechanism has been hindered by the lack of purified protein. By purifying active protein from the mnxDEFG expression construct, we found that the resulting enzyme is a blue (absorption maximum 590 nm) complex containing MnxE, MnxF, and MnxG proteins. Further, by analyzing the Mn(II)- and (III)-oxidizing activity in the presence of a Mn(III) chelator, pyrophosphate, we found that the complex facilitates both electron transfers from Mn(II) to Mn(III) and from Mn(III) to Mn(IV). X-ray absorption spectroscopy of the Mn mineral product confirmed its similarity to Mn(IV) oxides generated by whole spores. Our results demonstrate that Mn oxidation from soluble Mn(II) to Mn(IV) oxides is a two-step reaction catalyzed by an MCO-containing complex. With the purification of active Mn oxidase, we will be able to uncover its mechanism, broadening our understanding of Mn mineral formation and the bioinorganic capabilities of MCOs. PMID:23818588

  7. Iron-Coupled Anaerobic Oxidation of Methane Performed by a Mixed Bacterial-Archaeal Community Based on Poorly Reactive Minerals.

    Science.gov (United States)

    Bar-Or, Itay; Elvert, Marcus; Eckert, Werner; Kushmaro, Ariel; Vigderovich, Hanni; Zhu, Qingzeng; Ben-Dov, Eitan; Sivan, Orit

    2017-11-07

    Anaerobic oxidation of methane (AOM) was shown to reduce methane emissions by over 50% in freshwater systems, its main natural contributor to the atmosphere. In these environments iron oxides can become main agents for AOM, but the underlying mechanism for this process has remained enigmatic. By conducting anoxic slurry incubations with lake sediments amended with 13 C-labeled methane and naturally abundant iron oxides the process was evidenced by significant 13 C-enrichment of the dissolved inorganic carbon pool and most pronounced when poorly reactive iron minerals such as magnetite and hematite were applied. Methane incorporation into biomass was apparent by strong uptake of 13 C into fatty acids indicative of methanotrophic bacteria, associated with increasing copy numbers of the functional methane monooxygenase pmoA gene. Archaea were not directly involved in full methane oxidation, but their crucial participation, likely being mediators in electron transfer, was indicated by specific inhibition of their activity that fully stopped iron-coupled AOM. By contrast, inhibition of sulfur cycling increased 13 C-methane turnover, pointing to sulfur species involvement in a competing process. Our findings suggest that the mechanism of iron-coupled AOM is accomplished by a complex microbe-mineral reaction network, being likely representative of many similar but hidden interactions sustaining life under highly reducing low energy conditions.

  8. Einstein Observations of Galactic supernova remnants

    Science.gov (United States)

    Seward, Frederick D.

    1990-01-01

    This paper summarizes the observations of Galactic supernova remnants with the imaging detectors of the Einstein Observatory. X-ray surface brightness contours of 47 remnants are shown together with gray-scale pictures. Count rates for these remnants have been derived and are listed for the HRI, IPC, and MPC detectors.

  9. HI Absorption in Merger Remnants

    Science.gov (United States)

    Teng, Stacy H.; Veileux, Sylvain; Baker, Andrew J.

    2012-01-01

    It has been proposed that ultraluminous infrared galaxies (ULIRGs) pass through a luminous starburst phase, followed by a dust-enshrouded AGN phase, and finally evolve into optically bright "naked" quasars once they shed their gas/dust reservoirs through powerful wind events. We present the results of our recent 21- cm HI survey of 21 merger remnants with the Green Bank Telescope. These remnants were selected from the QUEST (Quasar/ULIRG Evolution Study) sample of ULIRGs and PG quasars; our targets are all bolometrically dominated by AGN and sample all phases of the proposed ULIRG -> IR-excess quasar -> optical quasar sequence. We explore whether there is an evolutionary connection between ULIRGs and quasars by looking for the occurrence of HI absorption tracing neutral gas outflows; our results will allow us to identify where along the sequence the majority of a merger's gas reservoir is expelled.

  10. Molecular clouds near supernova remnants

    International Nuclear Information System (INIS)

    Wootten, H.A.

    1978-01-01

    The physical properties of molecular clouds near supernova remnants were investigated. Various properties of the structure and kinematics of these clouds are used to establish their physical association with well-known remmnants. An infrared survey of the most massive clouds revealed embedded objects, probably stars whose formation was induced by the supernova blast wave. In order to understand the relationship between these and other molecular clouds, a control group of clouds was also observed. Excitation models for dense regions of all the clouds are constructed to evaluate molecular abundances in these regions. Those clouds that have embedded stars have lower molecular abundances than the clouds that do not. A cloud near the W28 supernova remnant also has low abundances. Molecular abundances are used to measure an important parameter, the electron density, which is not directly observable. In some clouds extensive deuterium fractionation is observed which confirms electron density measurements in those clouds. Where large deuterium fractionation is observed, the ionization rate in the cloud interior can also be measured. The electron density and ionization rate in the cloud near W28 are higher than in most clouds. The molecular abundances and electron densities are functions of the chemical and dynamical state of evolution of the cloud. Those clouds with lowest abundances are probably the youngest clouds. As low-abundance clouds, some clouds near supernova remnants may have been recently swept from the local interstellar material. Supernova remnants provide sites for star formation in ambient clouds by compressing them, and they sweep new clouds from more diffuse local matter

  11. Contamination of tooth-colored mineral trioxide aggregate used as a root-end filling material: a bacterial leakage study.

    Science.gov (United States)

    Montellano, Angela M; Schwartz, Scott A; Beeson, Thomas J

    2006-05-01

    This experiment investigated the ability of tooth-colored mineral trioxide aggregate (MTA) to maintain an apical seal in the presence of bacteria when contaminated with blood, saline or saliva. Ninety extracted human teeth with single canals were randomly placed into six groups of 15. Canals were prepared to size 50. The apical 3 mm of each root was removed and 3 mm root-end preparations were made with a #329 bur. Root-end preparations in groups 1 through 3 were filled with MTA after contamination with blood, saline, or saliva, respectively. In group 4, uncontaminated root-end preparations were filled with MTA. Groups 5 and 6 served as negative and positive controls. A tube/tooth assembly was utilized to suspend each root end in Trypticase Soy Broth (TSB). The access chambers were filled with Staphylococcus epidermidis. Positive growth over thirty days was demonstrated by turbidity of the TSB. Vitek analysis was used to confirm the presence of S. epidermidis in the positive samples. Data evaluation consisted of a chi(2) analysis (p < 0.05). Although all experimental groups demonstrated leakage, tooth-colored MTA contaminated with saliva (group 3) leaked significantly more than the uncontaminated tooth-colored MTA (group 4) (p = 0.028).

  12. Role of a Bacillus subtilis Direct-Fed Microbial on Digesta Viscosity, Bacterial Translocation, and Bone Mineralization in Turkey Poults Fed with a Rye-Based Diet.

    Science.gov (United States)

    Latorre, Juan D; Hernandez-Velasco, Xochitl; Kogut, Michael H; Vicente, Jose L; Wolfenden, Ross; Wolfenden, Amanda; Hargis, Billy M; Kuttappan, Vivek A; Tellez, Guillermo

    2014-01-01

    Rye contains high concentrations of non-starch polysaccharides (NSPs), leading to reduced digestibility. Since poultry have little or no endogenous enzymes capable of hydrolyzing these NSP, exogenous carbohydrases as feed additives are used in an attempt to reduce the anti-nutritional effects of these polysaccharides. Previously, an in vitro study conducted in our laboratory showed that inclusion of certain Bacillus direct-fed microbial (DFM) candidates that produce exogenous phytase, lipase, protease, cellulase, and xylanase in high-NSP diets significantly reduced both digesta viscosity and Clostridium perfringens proliferation. In the present study, rye-based turkey starter diets with or without Bacillus-DFM were administered ad libitum to day-of-hatch turkey poults in two independent experiments. In both experiments, day-of-hatch turkey poults were randomly assigned to either a control diet (CON) or a DFM treated diet (n = 25 birds/group). At 10 days-of-age, all turkey poults from experiments 1 and 2 were weighted and 12 turkey poults/group were randomly selected and humanely killed. Liver samples were aseptically collected to evaluate bacterial translocation, and intestinal digesta samples were individually collected to evaluate viscosity. Additionally, in experiment 2 both tibias were removed for assessment of bone parameters. In both experiments, the treated group showed a reduction in the total number of coliforms in the liver and a reduced digesta viscosity when compared to the CON group (P content, calcium content, and phosphorus content when compared with CON turkey poults. In summary, turkey poults fed with a rye-based diet without DFM showed an increase in bacterial translocation and digesta viscosity, accompanied by a reduction in bone mineralization; however, these adverse effects can be prevented by the inclusion of selected a Bacillus-DFM candidate in high-NSP diets.

  13. Remnant cholesterol and ischemic heart disease

    DEFF Research Database (Denmark)

    Varbo, Anette; Nordestgaard, Børge G

    2014-01-01

    PURPOSE OF REVIEW: To review recent advances in the field of remnant cholesterol as a contributor to the development of ischemic heart disease (IHD). RECENT FINDINGS: Epidemiologic, mechanistic, and genetic studies all support a role for elevated remnant cholesterol (=cholesterol in triglyceride......-rich lipoproteins) as a contributor to the development of atherosclerosis and IHD. Observational studies show association between elevated remnant cholesterol and IHD, and mechanistic studies show remnant cholesterol accumulation in the arterial wall like LDL-cholesterol (LDL-C) accumulation. Furthermore, large...... genetic studies show evidence of remnant cholesterol as a causal risk factor for IHD independent of HDL-cholesterol levels. Genetic studies also show that elevated remnant cholesterol is associated with low-grade inflammation, whereas elevated LDL-C is not. There are several pharmacologic ways of lowering...

  14. Neutron Stars in Supernova Remnants and Beyond

    Science.gov (United States)

    Gvaramadze, V. V.

    We discuss a concept of off-centred cavity supernova explosion as applied to neutron star/supernova remnant associations and show how this concept could be used to preclude the anti-humane decapitating the Duck (G5.4-1.2 + G5.27-0.9) and dismembering the Swan (Cygnus Loop), as well as to search for a stellar remnant associated with the supernova remnant RCW86.

  15. Neutron Stars in Supernova Remnants and Beyond

    OpenAIRE

    Gvaramadze, V. V.

    2002-01-01

    We discuss a concept of off-centred cavity supernova explosion as applied to neutron star/supernova remnant associations and show how this concept could be used to preclude the anti-humane decapitating the Duck (G5.4-1.2 + G5.27-0.9) and dismembering the Swan (Cygnus Loop), as well as to search for a stellar remnant associated with the supernova remnant RCW86.

  16. Impact of clay mineral, wood sawdust or root organic matter on the bacterial and fungal community structures in two aged PAH-contaminated soils.

    Science.gov (United States)

    Cébron, Aurélie; Beguiristain, Thierry; Bongoua-Devisme, Jeanne; Denonfoux, Jérémie; Faure, Pierre; Lorgeoux, Catherine; Ouvrard, Stéphanie; Parisot, Nicolas; Peyret, Pierre; Leyval, Corinne

    2015-09-01

    The high organic pollutant concentration of aged polycyclic aromatic hydrocarbon (PAH)-contaminated wasteland soils is highly recalcitrant to biodegradation due to its very low bioavailability. In such soils, the microbial community is well adapted to the pollution, but the microbial activity is limited by nutrient availability. Management strategies could be applied to modify the soil microbial functioning as well as the PAH contamination through various amendment types. The impact of amendment with clay minerals (montmorillonite), wood sawdust and organic matter plant roots on microbial community structure was investigated on two aged PAH-contaminated soils both in laboratory and 1-year on-site pot experiments. Total PAH content (sum of 16 PAHs of the US-EPA list) and polar polycyclic aromatic compounds (pPAC) were monitored as well as the available PAH fraction using the Tenax method. The bacterial and fungal community structures were monitored using fingerprinting thermal gradient gel electrophoresis (TTGE) method. The abundance of bacteria (16S rRNA genes), fungi (18S rRNA genes) and PAH degraders (PAH-ring hydroxylating dioxygenase and catechol dioxygenase genes) was followed through qPCR assays. Although the treatments did not modify the total and available PAH content, the microbial community density, structure and the PAH degradation potential changed when fresh organic matter was provided as sawdust and under rhizosphere influence, while the clay mineral only increased the percentage of catechol-1,2-dioxygenase genes. The abundance of bacteria and fungi and the percentage of fungi relative to bacteria were enhanced in soil samples supplemented with wood sawdust and in the plant rhizospheric soils. Two distinct fungal populations developed in the two soils supplemented with sawdust, i.e. fungi related to Chaetomium and Neurospora genera and Brachyconidiellopsis and Pseudallescheria genera, in H and NM soils respectively. Wood sawdust amendment favoured the

  17. Dynamical study of merger remnants

    International Nuclear Information System (INIS)

    Lake, G.; Dressler, A.; ATandT Bell Labs., Murray Hill, NJ; Mount Wilson and Las Campanas Observatories, Pasadena, CA; Carnegie Institution of Washington, Washington, DC)

    1986-01-01

    The velocity dispersion of objects from the Arp and the Arp-Madore atlases that have characteristics of recently merged galaxies is measured. These data are used to test the hypothesis that the remnants become normal elliptical galaxies after the fireworks of recent star formation subside. Accurate velocity dispersions of objects dominated by Balmer lines in the blue were measured using the uncontaminated Ca triplet feature in the extreme red (8400-8700 A). No deviation from the velocity dispersion expected for elliptical galaxies of comparable luminosity, is found, e.g., these systems follow the usual L-sigma relation with no zero-point shift. For a few galaxies without Balmer contamination, stellar rotation velocities are determined. One slow, one moderate, and one fast rotator are found. 54 references

  18. Progenitor's Signatures in Type Ia Supernova Remnants

    NARCIS (Netherlands)

    Chiotellis, A.; Kosenko, D.; Schure, K.M.; Vink, J.

    2013-01-01

    The remnants of Type Ia supernovae (SNe Ia) can provide important clues about their progenitor histories. We discuss two well-observed supernova remnants (SNRs) that are believed to have resulted from SNe Ia, and use various tools to shed light on the possible progenitor histories. We find that

  19. Hydrodynamic evolution of neutron star merger remnants

    Science.gov (United States)

    Liu, Men-Quan; Zhang, Jie

    2017-11-01

    Based on the special relativistic hydrodynamic equations and updated cooling function, we investigate the long-term evolution of neutron stars merger (NSM) remnants by a one-dimensional hydrodynamic code. Three NSM models from one soft equation of state, SFHo, and two stiff equations of state, DD2 and TM1, are used to compare their influences on the hydrodynamic evolution of remnants. We present the luminosity, mass and radius of remnants, as well as the velocity, temperature and density of shocks. For a typical interstellar medium (ISM) density with solar metallicity, we find that the NSM remnant from the SFHo model makes much more changes to ISM in terms of velocity, density and temperature distributions, compared with the case of DD2 and TM1 models. The maximal luminosity of the NSM remnant from the SFHo model is 3.4 × 1038 erg s-1, which is several times larger than that from DD2 and TM1 models. The NSM remnant from the SFHo model can maintain high luminosity (>1038 erg s-1) for 2.29 × 104 yr. Furthermore, the density and temperature of remnants at the maximal luminosity are not sensitive to the power of the original remnant. For the ISM with the solar metallicity and nH = 1 cm- 3, the density of the first shock ∼10-23 g cm-3 and the temperature ∼3 × 105 K in the maximal luminosity phase; The temperature of the first shock decreases and there is a thin 'dense' shell with density ∼10-21 g cm-3 after the maximal luminosity. These characteristics may be helpful for future observations of NSM remnants.

  20. Density and energy of supernova remnants

    Energy Technology Data Exchange (ETDEWEB)

    Canto, J [Manchester Univ. (UK). Dept. of Astronomy

    1977-12-01

    The effects of an interstellar magnetic field on the gas flow behind a strong shock front are considered. The ambient density and energy of supernova remnants are estimated from the intensity ratio of sulphur lines I(6717)/I(6731). It is found that, on average, the ambient density around galactic supernova remnants is 4 cm/sup -3/. The total energy appears to be the same for all supernova remnants (to within a factor = approximately 5). A mean value of 4 10/sup 51/ erg is found.

  1. Remnants of strong tidal interactions

    International Nuclear Information System (INIS)

    Mcglynn, T.A.

    1990-01-01

    This paper examines the properties of stellar systems that have recently undergone a strong tidal shock, i.e., a shock which removes a significant fraction of the particles in the system, and where the shocked system has a much smaller mass than the producer of the tidal field. N-body calculations of King models shocked in a variety of ways are performed, and the consequences of the shocks are investigated. The results confirm the prediction of Jaffe for shocked systems. Several models are also run where the tidal forces on the system are constant, simulating a circular orbit around a primary, and the development of tidal radii under these static conditions appears to be a mild process which does not dramatically affect material that is not stripped. The tidal radii are about twice as large as classical formulas would predict. Remnant density profiles are compared with a sample of elliptical galaxies, and the implications of the results for the development of stellar populations and galaxies are considered. 38 refs

  2. A Model of the Vela Supernova Remnant

    Science.gov (United States)

    Gvaramadze, Vasilii

    2000-10-01

    A model of the Vela supernova remnant (SNR) based on a cavity explosion of a supernova (SN) star is proposed. It is suggested that the general structure of the remnant is determined by the interaction of the SN blast wave with a massive shell created by the SN progenitor (15-20 M_solar) star. A possible origin of the nebula of hard X-ray emission detected around the Vela pulsar is discussed.

  3. Evolution of supernova remnants. III. Thermal waves

    International Nuclear Information System (INIS)

    Chevalier, R.A.

    1975-01-01

    The effect of heat conduction on the evolution of supernova remnants is investigated. A thermal wave, or electron conduction front, can travel more rapidly than a shock wave during the first thousand years of the remnant's evolution. A self-similar solution describing this phase has been found by Barenblatt. Numerical computations verify the solution and give the evolution past the thermal wave phase. While shell formation is not impeded, the interior density and temperature profiles are smoothed by the action of conduction

  4. Supernova Remnant in 3-D

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Click on the image for the movie For the first time, a multiwavelength three-dimensional reconstruction of a supernova remnant has been created. This stunning visualization of Cassiopeia A, or Cas A, the result of an explosion approximately 330 years ago, uses data from several telescopes: X-ray data from NASA's Chandra X-ray Observatory, infrared data from NASA's Spitzer Space Telescope and optical data from the National Optical Astronomy Observatory 4-meter telescope at Kitt Peak, Ariz., and the Michigan-Dartmouth-MIT 2.4-meter telescope, also at Kitt Peak. In this visualization, the green region is mostly iron observed in X-rays. The yellow region is a combination of argon and silicon seen in X-rays, optical, and infrared including jets of silicon plus outer debris seen in the optical. The red region is cold debris seen in the infrared. Finally, the blue reveals the outer blast wave, most prominently detected in X-rays. Most of the material shown in this visualization is debris from the explosion that has been heated by a shock moving inwards. The red material interior to the yellow/orange ring has not yet encountered the inward moving shock and so has not yet been heated. These unshocked debris were known to exist because they absorb background radio light, but they were only recently discovered in infrared emission with Spitzer. The blue region is composed of gas surrounding the explosion that was heated when it was struck by the outgoing blast wave, as clearly seen in Chandra images. To create this visualization, scientists took advantage of both a previously known phenomenon the Doppler effect and a new technology that bridges astronomy and medicine. When elements created inside a supernova, such as iron, silicon and argon, are heated they emit light at certain wavelengths. Material moving towards the observer will have shorter wavelengths and material moving away will have longer wavelengths. Since the amount

  5. Radioiodine Remnant Ablation: A Critical Review

    International Nuclear Information System (INIS)

    Bal, Chandra Sekhar; Padhy, Ajit Kumar

    2015-01-01

    Radioiodine remnant ablation (RRA) is considered a safe and effective method for eliminating residual thyroid tissue, as well as microscopic disease if at all present in thyroid bed following thyroidectomy. The rationale of RRA is that in the absence of thyroid tissue, serum thyroglobulin (Tg) measurement can be used as an excellent tumor marker. Other considerations are like the presence of significant remnant thyroid tissue makes detection and treatment of nodal or distant metastases difficult. Rarely, microscopic disease in the thyroid bed if not ablated, in the future, could be a source of anaplastic transformation. On the other hand, microscopic tumor emboli in distant sites could be the cause of distant metastasis too. The ablation of remnant tissue would in all probability eliminate these theoretical risks. It may be noted that all these are unproven contentious issues except postablation serum Tg estimation that could be a good tumor marker for detecting early biochemical recurrence in long-term follow-up strategy. Radioactive iodine is administered as a form of “adjuvant therapy” for remnant ablation. There have been several reports with regard to the administered dose for remnant ablation. The first report of a prospective randomized clinical trial was published from India by a prospective randomized study conducted at the All India Institute of Medical Sciences, New Delhi in the year 1996. The study reported that increasing the empirical 131 I initial dose to more than 50 mCi results in plateauing of the dose-response curve and thus, conventional high-dose remnant ablation needs critical evaluation. Recently, two important studies were published: One from French group and the other from UK on a similar line. Interestingly, all three studies conducted in three different geographical regions of the world showed exactly similar conclusion. The new era of low-dose remnant ablation has taken a firm scientific footing across the continents

  6. Modelling the interaction of thermonuclear supernova remnants with circumstellar structures: the case of Tycho's supernova remnant

    NARCIS (Netherlands)

    Chiotellis, A.; Kosenko, D.; Schure, K.M.; Vink, J.; Kaastra, J.S.

    2013-01-01

    The well-established Type Ia remnant of Tycho's supernova (SN 1572) reveals discrepant ambient medium-density estimates based on either the measured dynamics or the X-ray emission properties. This discrepancy can potentially be solved by assuming that the supernova remnant (SNR) shock initially

  7. Autopsy of the Supernova Remnant Cassiopeia A

    Science.gov (United States)

    Milisavljevic, Dan; Fesen, Robert A.

    2014-01-01

    Three-dimensional kinematic reconstructions of optically emitting ejecta in the young Galactic supernova remnant Cassiopeia A (Cas A) are discussed. The reconstructions encompass the remnant's faint outlying ejecta knots, including the exceptionally high-velocity NE and SW streams of debris often referred to as `jets'. The bulk of Cas A's ejecta are arranged in several circular rings with diameters between approximately 30'' (0.5 pc) and 2' (2 pc). We suggest that similar large-scale ejecta rings may be a common phenomenon of young core-collapse remnants and may explain lumpy emission line profile substructure sometimes observed in spectra of extragalactic core-collapse supernovae years after explosion. A likely origin for these large ejecta rings is post-explosion input of energy from plumes of radioactive 56Ni-rich ejecta that rise, expand, and compress non-radioactive material to form bubble-like structures.

  8. Cosmic Ray Acceleration in Supernova Remnants

    International Nuclear Information System (INIS)

    O'C Drury, Luke

    2005-01-01

    This paper describes some recent developments in our understanding of cosmic ray acceleration in supernova remnant shocks. It is pointed out that while good agreement now exists as to steady nonlinear modifications to the shock structure, there is also growing evidence that the mesoscopic scales may not in fact be steady and that significant instabilities associated with magnetic field amplification may be a feature of strong collisionless plasma shocks. There is strong observational evidence for such magnetic field amplification, and it appears to solve a number of long-standing issues concerned with acceleration of cosmic rays in supernova remnants

  9. X-ray haloes around supernova remnants

    International Nuclear Information System (INIS)

    Morfill, G.E.; Aschenbach, B.

    1984-01-01

    Recent observations of the Cas-A supernova remnant have shown X-ray emissions not only from the interior, but also from a fainter 'halo' extending beyond what is normally regarded as the outer boundary, or shock front. The authors suggest that this may be due to the diffusion of energetic, charged particles out of the remnant giving rise to precursor structure of the type predicted by the theory of diffusive shock acceleration. If this is the case we are seeing thermal emission from ambient gas heated by compression and wave dissipation. (author)

  10. X-ray haloes around supernova remnants

    Energy Technology Data Exchange (ETDEWEB)

    Morfill, G.E.; Aschenbach, B. (Max-Planck-Institut fuer Physik und Astrophysik, Garching (Germany, F.R.). Inst. fuer Extraterrestrische Physik); Drury, L.O' C. (Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany, F.R.))

    1984-09-27

    Recent observations of the Cas-A supernova remnant have shown X-ray emissions not only from the interior, but also from a fainter 'halo' extending beyond what is normally regarded as the outer boundary, or shock front. The authors suggest that this may be due to the diffusion of energetic charged particles out of the remnant giving rise to precursor structure of the type predicted by the theory of diffusive shock acceleration. If this is the case we are seeing thermal emission from ambient gas heated by compression and wave dissipation.

  11. The interface interaction behavior between E. coli and two kinds of fibrous minerals.

    Science.gov (United States)

    Dai, Qunwei; Han, Linbao; Deng, Jianjun; Zhao, Yulian; Dang, Zheng; Tan, Daoyong; Dong, Faqin

    2017-11-09

    In the present, studies of interaction between human normal flora and fibrous mineral are still lacking. Batch experiments were performed to deal with the interaction of Escherichia coli and two fibrous minerals (brucite and palygorskite), and the interface and liquid phase characteristics in the short-term interaction processes were discussed. The bacterial concentrations, the remnant glucose (GLU), pyruvic acid, and the activity of β-galactosidase and six elements were measured, and the results show that the promoting effect of brucite on the growth of E. coli was more significant than that of palygorskite. FTIR and XRD analysis results also confirmed E. coli has obviously dissolved on brucite and damage effect on palygorskite silicon structure. SEM results show that the interfacial contact degree between E. coli cells and brucite fibers was higher than that of palygorskite. These may be due to the zeta potential difference between E. coli and palygorskite was 14.57-22.37 mV, while it of brucite was 44.04-64.24 mV. The elements dissolving of two fibrous minerals not only increased regularly to liquid EC but also had a good buffer effect to the decrease of liquid pH. Studies of short-term interaction between E. coli and brucite and palygorskite can help to understand the effect of fibrous minerals on microeubiosis of human normal flora and the contribution of microbial behaviors on the fibrous minerals weathering in the natural environment.

  12. Effects of probiotics, prebiotics, and synbiotics on mineral metabolism in ovariectomized rats — impact of bacterial mass, intestinal absorptive area and reduction of bone turn-over

    Directory of Open Access Journals (Sweden)

    Katharina E. Scholz-Ahrens

    2016-08-01

    Conclusion: SYN exerted a synergistic effect on bone mineralization, presumably due to changes in gut microbiota and ecology associated with large bowel digesta weight (most likely reflecting microbial mass and with large bowel weight (reflecting absorptive area, while bone turnover tended to be reduced as indicated by BAP.

  13. Particle acceleration and nonthermal radiation in supernova remnants

    International Nuclear Information System (INIS)

    Zirakashvili, Vladimir

    2013-01-01

    Cosmic ray acceleration and magnetic amplification in shell-type supernova remnants is shortly reviewed. The results on the modeling of broadband electromagnetic emission from supernova remnants are presented and compared with observations.

  14. GALACTIC AND EXTRAGALACTIC SUPERNOVA REMNANTS AS SITES OF PARTICLE ACCELERATION

    Directory of Open Access Journals (Sweden)

    Manami Sasaki

    2013-12-01

    Full Text Available Supernova remnants, owing to their strong shock waves, are likely sources of Galactic cosmic rays. Studies of supernova remnants in X-rays and gamma rays provide us with new insights into the acceleration of particles to high energies. This paper reviews the basic physics of supernova remnant shocks and associated particle acceleration and radiation processes. In addition, the study of supernova remnant populations in nearby galaxies and the implications for Galactic cosmic ray distribution are discussed.

  15. Neutron Star/supernova Remnant Associations

    Science.gov (United States)

    Gvaramadze, V. V.

    We propose a new approach for studying the neutron star/supernova remnant associations, based on the idea that the (diffuse) supernova remnants (SNRs) can be products of an off-centred supernova (SN) explosion in a preexisting bubble created by the wind of a moving massive star. A cavity SN explosion of a moving star results in a considerable offset of the neutron star (NS) birth-place from the geometrical centre of the SNR. Therefore: a) the high transverse velocities inferred for a number of NSs (e.g. PSR B 1610-50, PSR B 1757-24, SGR 0525-66) through their association with SNRs can be reduced; b) the proper motion vector of a NS should not necessarily point away from the geometrical centre of the associated SNR. Taking into account of these two facts allow us to enlarge the circle of possible NS/SNR associations, and could significantly affect the results of previous studies of NS/SNR associations. The possibilities of our approach are illustrated with the example of the association between PSR B 1706-44 and SNR G 343.1-2.3. We show that this association could be real if both objects are the remnants of a SN exploded within a mushroom-like cavity (created by the SN progenitor wind breaking out of the parent molecular cloud and expanding into an intercloud medium of a much less density). We also show that the SN explosion sites in some middle-aged (shell-like) SNRs could be marked by (compact) nebulae of thermal X-ray emission. The possible detection of such nebulae within middle-aged SNRs could be used for the re-estimation of implied transverse velocities of known NSs or for the search of new stellar remnants possibly associated with these SNRs.

  16. Supernova remnants in the GC region

    Science.gov (United States)

    Asvarov, Abdul

    2016-07-01

    Along with the central Black hole the processes of active star formation play very important role in the energetics of the Galactic center region. The SNe and their remnants (SNRs) are the main ingredients of the processes of star formation. SNRs are also the sources of electromagnetic radiation of all wavelengths from the optical to hard gamma rays. In the presented work we consider the physics of supernova remnants evolving in extreme environmental conditions which are typical for the region of the Galactic center. Because of the high density and strong inhomogeneity of the surrounding medium these objects remain practically invisible at almost all wavelengths. We model evolution of SNR taking into account the pressure of the surrounding medium and the gravitational field of the matter (stars, compact clouds, dark matter) inside the remnant. As it is well established, considerable portion of the kinetic energy of the SNR can be converted into the cosmic ray particles by diffusive shock acceleration mechanism. Therefore the effect of particle acceleration is also included in the model (with the effectiveness of acceleration as a free parameter). Using the observed radiation fluxes at different wavelengths we attempt to obtain limits on the parameters of the model of the Galactic Center, namely, the frequency of star birth, the average density of the matter and radiation field, etc.

  17. THE FIRST FERMI LAT SUPERNOVA REMNANT CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Acero, F.; Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Université Paris Diderot, Service d’Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Ackermann, M.; Buehler, R. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Ajello, M. [Department of Physics and Astronomy, Clemson University, Kinard Lab of Physics, Clemson, SC 29634-0978 (United States); Baldini, L. [Università di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa I-56127 Pisa (Italy); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D.; Buson, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bellazzini, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bissaldi, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, I-70126 Bari (Italy); Blandford, R. D.; Bloom, E. D.; Bottacini, E.; Caliandro, G. A.; Cameron, R. A. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Bonino, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Torino, I-10125 Torino (Italy); Brandt, T. J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Bregeon, J. [Laboratoire Univers et Particules de Montpellier, Université Montpellier, CNRS/IN2P3, Montpellier (France); Bruel, P., E-mail: francesco.depalma@ba.infn.it, E-mail: t.j.brandt@nasa.gov, E-mail: john.w.hewitt@unf.edu [Laboratoire Leprince-Ringuet, École polytechnique, CNRS/IN2P3, Palaiseau (France); and others

    2016-05-01

    To uniformly determine the properties of supernova remnants (SNRs) at high energies, we have developed the first systematic survey at energies from 1 to 100 GeV using data from the Fermi Large Area Telescope (LAT). Based on the spatial overlap of sources detected at GeV energies with SNRs known from radio surveys, we classify 30 sources as likely GeV SNRs. We also report 14 marginal associations and 245 flux upper limits. A mock catalog in which the positions of known remnants are scrambled in Galactic longitude allows us to determine an upper limit of 22% on the number of GeV candidates falsely identified as SNRs. We have also developed a method to estimate spectral and spatial systematic errors arising from the diffuse interstellar emission model, a key component of all Galactic Fermi LAT analyses. By studying remnants uniformly in aggregate, we measure the GeV properties common to these objects and provide a crucial context for the detailed modeling of individual SNRs. Combining our GeV results with multiwavelength (MW) data, including radio, X-ray, and TeV, we demonstrate the need for improvements to previously sufficient, simple models describing the GeV and radio emission from these objects. We model the GeV and MW emission from SNRs in aggregate to constrain their maximal contribution to observed Galactic cosmic rays.

  18. Radio evolution of young supernova remnants

    International Nuclear Information System (INIS)

    Shirkey, R.C. Jr.

    1976-01-01

    A one dimensional spherically symmetric magnetohydrodynamic code was developed to describe the evolution of the dynamical and radio properties of young supernova remnants. The code contains subroutines which treat the development of Rayleigh-Taylor instabilities wherever they arise in the remnant. Under the assumption of quasi-stationary equilibrium (dynamical changes considered slow in comparison to the time it takes the instability to achieve equilibrium) determined that the velocity of the instability is W approximately (a lambda)/sup 1 / 2 /, where a is the Rayleigh-Taylor acceleration and lambda is the wavelength of the instability. Subsequent processing of the kinetic energy of expansion, through turbulence, resulted in an increase in temperature and magnetic field strength. The model was used to analyze instability effects of density inhomogeneities in the interstellar medium on magnetic field amplification. A model was constructed for Cassiopeia A which gave good agreement with the measured dynamics, radio structure, and secular flux density decrease for the remnant. In order to compare observation with theory a computer routine was written that convolves the surface brightness at the source. The resultant convolved surface brightness graph is in good agreement with Rosenberg's observed ''model profile;'' differences between the graphs can be attributed to the asymmetric expansion of Cassiopeia A

  19. The interplay of dietary nutrient specification and varying calcium to total phosphorus ratio on efficacy of a bacterial phytase: 1. Growth performance and tibia mineralization.

    Science.gov (United States)

    Olukosi, O A; Fru-Nji, F

    2014-12-01

    A 14-d experiment was conducted to study the effects of 2 dietary variables on efficacy of a 6-phytase from Citrobacter braakii on broiler growth performance and tibia mineralization. Diets were formulated with or without nutrient matrix values for phytase as negative or positive control (NC or PC, respectively) and with 2 Ca:total P (tP; 2:1 or 2.5:1). The diets were supplemented with 0, 1,000, or 2,000 phytase units (FYT)/kg, thus producing a 2 × 2 × 3 factorial arrangement. Birds and feed were weighed on d 7 and 21, and tibia bones were collected from all the birds on d 21. The main effects of nutrient matrix, Ca:tP, and phytase supplementation were significant (P phytase and matrix × phytase interactions were significant (P phytase increased weight gain (P phytase increased (P Phytase supplementation of diets with 2:1 Ca:tP increased (P phytase supplementation increased (P phytase supplementation (1,000 FYT/kg) was in NC diets with narrow Ca:tP, whereas the best response to higher level of phytase supplementation (2,000 FYT/kg) was achieved in diets in PC diets with wide Ca:tP. ©2014 Poultry Science Association Inc.

  20. Supernova Remnants with Fermi Large Area Telescope

    Directory of Open Access Journals (Sweden)

    Caragiulo M.

    2017-01-01

    Full Text Available The Large Area Telescope (LAT, on-board the Fermi satellite, proved to be, after 8 years of data taking, an excellent instrument to detect and observe Supernova Remnants (SNRs in a range of energies running from few hundred MeV up to few hundred GeV. It provides essential information on physical processes that occur at the source, involving both accelerated leptons and hadrons, in order to understand the mechanisms responsible for the primary Cosmic Ray (CR acceleration. We show the latest results in the observation of Galactic SNRs by Fermi-LAT.

  1. Runaway companions of supernova remnants with Gaia

    Science.gov (United States)

    Boubert, Douglas; Fraser, Morgan; Evans, N. Wyn

    2018-04-01

    It is expected that most massive stars have companions and thus that some core-collapse supernovae should have a runaway companion. The precise astrometry and photometry provided by Gaia allows for the systematic discovery of these runaway companions. We combine a prior on the properties of runaway stars from binary evolution with data from TGAS and APASS to search for runaway stars within ten nearby supernova remnants. We strongly confirm the existing candidate HD 37424 in S147, propose the Be star BD+50 3188 to be associated with HB 21, and suggest tentative candidates for the Cygnus and Monoceros Loops.

  2. VHE Gamma-ray Supernova Remnants

    Energy Technology Data Exchange (ETDEWEB)

    Funk, Stefan; /KIPAC, Menlo Park

    2007-01-22

    Increasing observational evidence gathered especially in X-rays and {gamma}-rays during the course of the last few years support the notion that Supernova remnants (SNRs) are Galactic particle accelerators up to energies close to the ''knee'' in the energy spectrum of Cosmic rays. This review summarizes the current status of {gamma}-ray observations of SNRs. Shell-type as well as plerionic type SNRs are addressed and prospect for observations of these two source classes with the upcoming GLAST satellite in the energy regime above 100 MeV are given.

  3. On neutron star/supernova remnant associations

    OpenAIRE

    Gvaramadze, V. V.

    2000-01-01

    It is pointed out that a cavity supernova (SN) explosion of a moving massive star could result in a significant offset of the neutron star (NS) birth-place from the geometrical centre of the supernova remnant (SNR). Therefore: a) the high implied transverse velocities of a number of NSs (e.g. PSR B1610-50, PSR B1757-24, SGR0525-66) could be reduced; b) the proper motion vector of a NS should not necessarily point away from the geometrical centre of the associated SNR; c) the circle of possibl...

  4. Remnant cholesterol as a cause of ischemic heart disease

    DEFF Research Database (Denmark)

    Varbo, Anette; Benn, Marianne; Nordestgaard, Børge G

    2014-01-01

    This review focuses on remnant cholesterol as a causal risk factor for ischemic heart disease (IHD), on its definition, measurement, atherogenicity, and levels in high risk patient groups; in addition, present and future pharmacological approaches to lowering remnant cholesterol levels...... are considered. Observational studies show association between elevated levels of remnant cholesterol and increased risk of cardiovascular disease, even when remnant cholesterol levels are defined, measured, or calculated in different ways. In-vitro and animal studies also support the contention that elevated...... levels of remnant cholesterol may cause atherosclerosis same way as elevated levels of low-density lipoprotein (LDL) cholesterol, by cholesterol accumulation in the arterial wall. Genetic studies of variants associated with elevated remnant cholesterol levels show that an increment of 1mmol/L (39mg...

  5. Are crab-type supernova remnants (plerions) short-lived

    International Nuclear Information System (INIS)

    Weiler, K.W.; Panagia, N.

    1978-01-01

    Arguments are given for a possible picture of the origin, maintenance, and lifetimes of the so-called Crab-like supernova remnants. It is suggested that these objects imply the existence of at least two distinct types of supernova events. A possible connection of the remnant types with the optically defined supernovae of Type I and Type II is discussed. Accepting that a pulsar is formed in at least some supernova events, the proposal is made that a rapidly rotating, rapidly slowing pulsar is necessary to create and maintain a Crab-like supernova remnant. Finally, arguments are presented that such a supernova remnant will be relatively short lived with respect to the more common shell-type of supernova remnant, perhaps surviving only 10000-20000 yr before fading into the Galactic background. The name of plerion is proposed for these filled-center supernova remnants and observational possiblities for confirming their nature are suggested. (orig.) [de

  6. Oligotyping reveals stronger relationship of organic soil bacterial community structure with N-amendments and soil chemistry in comparison to that of mineral soil at Harvard Forest, MA, USA.

    Science.gov (United States)

    Turlapati, Swathi A; Minocha, Rakesh; Long, Stephanie; Ramsdell, Jordan; Minocha, Subhash C

    2015-01-01

    The impact of chronic nitrogen amendments on bacterial communities was evaluated at Harvard Forest, Petersham, MA, USA. Thirty soil samples (3 treatments × 2 soil horizons × 5 subplots) were collected in 2009 from untreated (control), low nitrogen-amended (LN; 50 kg NH4NO3 ha(-1) yr(-1)) and high nitrogen-amended (HN; 150 kg NH4NO3 ha(-1) yr(-1)) plots. PCR-amplified partial 16S rRNA gene sequences made from soil DNA were subjected to pyrosequencing (Turlapati et al., 2013) and analyses using oligotyping. The parameters M (the minimum count of the most abundant unique sequence in an oligotype) and s (the minimum number of samples in which an oligotype is expected to be present) had to be optimized for forest soils because of high diversity and the presence of rare organisms. Comparative analyses of the pyrosequencing data by oligotyping and operational taxonomic unit clustering tools indicated that the former yields more refined units of taxonomy with sequence similarity of ≥99.5%. Sequences affiliated with four new phyla and 73 genera were identified in the present study as compared to 27 genera reported earlier from the same data (Turlapati et al., 2013). Significant rearrangements in the bacterial community structure were observed with N-amendments revealing the presence of additional genera in N-amended plots with the absence of some that were present in the control plots. Permutational MANOVA analyses indicated significant variation associated with soil horizon and N treatment for a majority of the phyla. In most cases soil horizon partitioned more variation relative to treatment and treatment effects were more evident for the organic (Org) horizon. Mantel test results for Org soil showed significant positive correlations between bacterial communities and most soil parameters including NH4 and NO3. In mineral soil, correlations were seen only with pH, NH4, and NO3. Regardless of the pipeline used, a major hindrance for such a study remains to be the lack

  7. Oligotyping reveals stronger relationship of organic soil bacterial community structure with N-amendments and soil chemistry in comparison to that of mineral soil at Harvard Forest, MA, USA

    Directory of Open Access Journals (Sweden)

    Swathi Anuradha Turlapati

    2015-02-01

    Full Text Available The impact of chronic nitrogen amendments on bacterial communities was evaluated at Harvard Forest, Petersham MA. Thirty soil samples (3 treatments x 2 soil horizons x 5 subplots were collected in 2009 from untreated (control, low nitrogen-amended (LN; 50 kg NH4NO3 ha-1 yr-1 and high nitrogen-amended (HN; 150 kg NH4NO3 ha-1 yr-1 plots. PCR-amplified partial 16S rDNA sequences made from soil DNA were subjected to pyrosequencing (Turlapati et al., 2013 and analyses using oligotyping. The parameters M (the minimum count of the most abundant unique sequence in an oligotype and s (minimum number of samples in which an oligotype is expected to be present had to be optimized for forest soils because of high diversity and the presence of rare organisms. Comparative analyses of the pyrosequencing data by oligotyping and OTU (Operational Taxonomic Unit clustering tools indicated that the former yields more refined units of taxonomy with sequence similarity of ≥99.5%. Sequences affiliated with 4 new phyla and 73 genera were identified in the present study as compared to 27 genera reported earlier from the same data (Turlapati et al., 2013. Significant rearrangements in the bacterial community structure were observed with N-amendments revealing the presence of additional genera in N-amended plots with the absence of some that were present in the control plots. Permutational MANOVA analyses indicated significant variation associated with soil horizon and N treatment for a majority of the phyla. In most cases soil horizon partitioned more variation relative to treatment and treatment effects were more evident for the organic horizon. Mantel test results for organic soil showed significant positive correlations between bacterial communities and most soil parameters including NH4 and NO3. In mineral soil, correlations were seen only with pH, NH4 and NO3. Regardless of the pipeline used, a major hindrance for such a study remains to be the lack of reference

  8. Biodegradability of bacterial surfactants.

    Science.gov (United States)

    Lima, Tânia M S; Procópio, Lorena C; Brandão, Felipe D; Carvalho, André M X; Tótola, Marcos R; Borges, Arnaldo C

    2011-06-01

    This work aimed at evaluating the biodegradability of different bacterial surfactants in liquid medium and in soil microcosms. The biodegradability of biosurfactants by pure and mixed bacterial cultures was evaluated through CO(2) evolution. Three bacterial strains, Acinetobacter baumanni LBBMA ES11, Acinetobacter haemolyticus LBBMA 53 and Pseudomonas sp. LBBMA 101B, used the biosurfactants produced by Bacillus sp. LBBMA 111A (mixed lipopeptide), Bacillus subtilis LBBMA 155 (lipopeptide), Flavobacterium sp. LBBMA 168 (mixture of flavolipids), Dietzia Maris LBBMA 191(glycolipid) and Arthrobacter oxydans LBBMA 201(lipopeptide) as carbon sources in minimal medium. The synthetic surfactant sodium dodecyl sulfate (SDS) was also mineralized by these microorganisms, but at a lower rate. CO(2) emitted by a mixed bacterial culture in soil microcosms with biosurfactants was higher than in the microcosm containing SDS. Biosurfactant mineralization in soil was confirmed by the increase in surface tension of the soil aqueous extracts after incubation with the mixed bacterial culture. It can be concluded that, in terms of biodegradability and environmental security, these compounds are more suitable for applications in remediation technologies in comparison to synthetic surfactants. However, more information is needed on structure of biosurfactants, their interaction with soil and contaminants and scale up and cost for biosurfactant production.

  9. Urachal remnant carcinoma - a rare entity

    Directory of Open Access Journals (Sweden)

    Vanesha Naidu

    2013-06-01

    Full Text Available Primary malignancy of the urachal remnant is a rare neoplasm that accounts for less than 0.01% of all adult cancers, with an estimated annual incidence of 1:5 million. The tumour carries a grave prognosis that attests to its highly aggressive nature. Owing to its extra-peritoneal location, the tumour runs a relatively silent clinical course until late presentation, when most patients display extensive local invasion and metastatic spread. In this report, we highlight a case of primary malignancy of the urachus that on initial clinical evaluation masqueraded as a Sister Mary Joseph’s nodule. Characteristic imaging features, however, proved decisive in establishing the diagnosis of a urachal carcinoma.

  10. A Python Calculator for Supernova Remnant Evolution

    Science.gov (United States)

    Leahy, D. A.; Williams, J. E.

    2017-05-01

    A freely available Python code for modeling supernova remnant (SNR) evolution has been created. This software is intended for two purposes: to understand SNR evolution and to use in modeling observations of SNR for obtaining good estimates of SNR properties. It includes all phases for the standard path of evolution for spherically symmetric SNRs. In addition, alternate evolutionary models are available, including evolution in a cloudy ISM, the fractional energy-loss model, and evolution in a hot low-density ISM. The graphical interface takes in various parameters and produces outputs such as shock radius and velocity versus time, as well as SNR surface brightness profile and spectrum. Some interesting properties of SNR evolution are demonstrated using the program.

  11. THE DRESSMAKER, REMNANTS OF A LIFE

    DEFF Research Database (Denmark)

    Carpe Pérez, Inmaculada Concepción

    2015-01-01

    The Dressmaker, remnants of a life, is a visual representation of our research in animation ,at the Animated Learning Lab, as a means of reflection on the construction of the self and memories. Through the artistic production of motion pictures, an introspection is done in the author’s personal...... knowledge, which help us to reflect upon thoughts, feelings and actions (personal or external). Such experiences shape our personalities and whose emotional balance our happiness depends on. Memories are the left over product out of experiences, constituents of a reality. This is seen and created...... the psychology of the self. Animation, for it’s metaphorical power and playfulness: mix of reality and fantasy, results a very attractive and effective tool to explore different points of view and work the neuroplasticity, facilitator of the physical changes of our brain and our behavior, area of study...

  12. Exosat observations of the Kepler supernova remnant

    International Nuclear Information System (INIS)

    Smith, A.; Peacock, A.; Arnaud, M.; Ballet, J.; Rothenflug, R.

    1989-01-01

    The medium-energy experiment on board Exosat was used to measure the X-ray spectrum of the Kepler supernova remnant over the range 1.5-10 keV. An Fe emission line was clearly resolved with an energy of about 6.5 keV and equivalent width of about 1.8 keV. This was superposed on a continuum with a temperature of 5.0(+3.8, -1.9) keV. The medium-energy spectrum is shown to be consistent with a model in which the Kepler SNR is presently in a Sedov phase of evolution, the 5 keV continuum arises from the shocked interstellar/circumstellar medium, and thermal (but not ionization) equilibrium exists between electrons and ions behind the primary shock front. However, in this case, an overabundance of iron by more than 6 times cosmic is required. 28 refs

  13. On Neutron Star/Supernova Remnant Association

    Science.gov (United States)

    Gvaramadze, V. V.

    It is pointed out that a cavity supernova (SN) explosion of a moving massive star could result in a significant offset of the neutron star (NS) birth-place from the geometrical centre of the supernova remnant (SNR). Therefore: a) the high implied transverse velocities of a number of NSs (e.g. PSR B1610-50, PSR B1706-44, PSR B1757-24, SGR 0526-66) could be reduced; b) the proper motion vector of a NS should not necessarily point away from the geometrical centre of the associated SNR; c) the circle of possible NS/SNR associations could be enlarged. An observational test is discussed, which could provide a determination of the true birth-places of NSs associated with middle-aged SNRs, and thereby provide more reliable estimates of their transverse velocities.

  14. Remnants of occipital vertebrae: proatlas segmentation abnormalities.

    Science.gov (United States)

    Menezes, Arnold H; Fenoy, Kathleen A

    2009-05-01

    Developmental remnants around the foramen magnum, or proatlas segmentation abnormalities, have been recorded in postmortem studies but very rarely in a clinical setting. Because of their rarity, the pathological anatomy has been misunderstood, and treatment has been fraught with failures. The objectives of this prospective study were to understand the correlative anatomy, pathology, and embryology and to recognize the clinical presentation and gain insights on the treatment and management. Our craniovertebral junction (CVJ) database started in 1977 and comprises 5200 cases. This prospective study has retrieval capabilities. Neurodiagnostic studies changed with the evolution of imaging. Seventy-two patients were recognized as having symptomatic proatlas segmentation abnormalities. Ventral bony masses from the clivus or medial occipital condyle occurred in 66% (44/72), lateral or anterolateral compressive masses in 37% (27 of 72 patients), and dorsal bony compression in 17% (12 of 72 patients). Hindbrain herniation was associated in 33%. The age at presentation was 3 to 23 years. Motor symptoms occurred in 72% (52 of 72 patients); palsies in Cranial Nerves IX, X, and XII in 33% (24 of 72 patients); and vertebrobasilar symptoms in 25% (18 of 72 patients). Trauma precipitated symptoms in 55% (40 of 72 patients). The best definition of the abnormality was demonstrated by 3-dimensional computed tomography combined with magnetic resonance imaging. Treatment was aimed at decompression of the pathology and stabilization. Remnants of the occipital vertebrae around the foramen magnum were recognized in 72 of 5200 CVJ cases (7.2%). Magnetic resonance imaging with 3-dimensional computed tomography of the CVJ provides the best definition and understanding of the lesions. Brainstem myelopathy and lower cranial nerve deficits are common clinical presentations in the first and second decades of life. Treatment is aimed at decompression of the pathology and CVJ stabilization.

  15. Benner's remnants: culture, tradition and everyday understanding.

    Science.gov (United States)

    Paley, John

    2002-06-01

    Benner's account of meaning and embodiment in nursing depends on a theory which she has never fully articulated, although she makes numerous allusions to it. Behind the background of shared meanings hovers something called 'culture', which provides each individual with meaning, determines what counts as real for her, and actively hands down interpretation-laden practices. This view is based, Benner claims, on the Heideggerian assumption that the meaning and organization of a culture precedes individual meaning-giving activity. I explore Benner's implicit view of culture, drawing on her published work over 15 years, and offer an appraisal of it. In doing so, I attempt to make sense of some rather strange remarks Benner has recently made about 'remnants' of Cartesian and Kantian thinking being found in the everyday understandings of people with asthma. The concept of culture is developed with reference to both Benner's own work and that of the anthropologist, Clifford Geertz, whose work she frequently cites. Having identified the principal tenets of what we might conveniently call the Benner-Geertz theory, I proceed to interrogate the theory, using the recent anthropological literature -- and, in particular, materialist attacks on the idea of culture as a system of meanings -- in order to cast doubt on it. I also review, very briefly, an alternative way of understanding 'culture', which is not vulnerable to the same criticisms. Benner's implicit theory of culture is revealed, somewhat ironically, as an inverted form of Cartesian dualism. Its intellectual provenance is not Heidegger, who appears to reject it, but the sort of American sociology associated with Talcott Parsons. As a corollary, it is suggested that Benner's 'remnants' analogy cannot be justified, and that the idea of Cartesian and Kantian concepts permeating Western culture, infecting both the providers and receivers of health care, is a myth.

  16. Supernova remnants and the origin of cosmic rays

    NARCIS (Netherlands)

    Vink, J.

    2014-01-01

    Supernova remnants have long been considered to be the dominant sources of Galactic cosmic rays. For a long time the prime evidence consisted of radio synchrotron radiation from supernova remnants, indicating the presence of electrons with energies of several GeV. However, in order to explain the

  17. Supernova Remnants as the Sources of Galactic Cosmic Rays

    NARCIS (Netherlands)

    Vink, J.

    2013-01-01

    The origin of cosmic rays holds still manymysteries hundred years after they were first discovered. Supernova remnants have for long been the most likely sources of Galactic cosmic rays. I discuss here some recent evidence that suggests that supernova remnants can indeed efficiently accelerate

  18. Relating Eye Activity Measures to Human Controller Remnant Characteristics

    NARCIS (Netherlands)

    Popovici, A; Zaal, P.M.T.; Pool, D.M.; Mulder, M.; Sawaragi, T

    2016-01-01

    This study attempts to partially explain the characteristics of the human perceptual remnant, following Levison’s representation of the remnant as an equivalent observation noise. Eye activity parameters are recorded using an eye tracker in two compensatory tracking tasks in which the visual

  19. [Recurrent neck abscess due to a branchial cleft remnant].

    Science.gov (United States)

    Kruijff, Schelto; Mastboom, Walter J; Vriens, Menno R; Sidhu, Stan B; Delbridge, Leigh W

    2013-01-01

    Abscesses arising from a third or fourth branchial cleft remnant are uncommon clinical entities and are often not recognised in a timely manner. In a 33-year-old female patient with a recurrent abscess in the left side of her neck, the cause turned out to be a fistula in the third branchial cleft remnant. She was treated initially with antibiotics and prednisone without adequate results. When the abscess was finally surgically drained, she became very ill and was admitted to the ICU with sepsis and multiple organ failure. She was discharged from hospital after six weeks. Four months later, a third-branchial cleft remnant was found during pharyngoscopy, immediately after which the cleft remnant fistula was excised and an ipsilateral hemi-thyroidectomy was performed. In young patients with recurring peri-thyroidal abscesses, a branchial cleft remnant should be considered a causative factor; this could avoid high morbidity and a delay in the appropriate treatment.

  20. Miners' welfare

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, C

    1984-06-13

    The Miners' Welfare Committee (MWC) was formed in Britain in 1921 and initiated building programmes to provide welfare amenities for miners and families, using architecture to improve the quality of a miner's working and leisure time. The article reviews the MWC's work, and assesses the design and architecture at the Selby Coalfield. (7 refs.)

  1. Remnant Cholesterol Elicits Arterial Wall Inflammation and a Multilevel Cellular Immune Response in Humans

    NARCIS (Netherlands)

    Bernelot Moens, Sophie J.; Verweij, Simone L.; Schnitzler, Johan G.; Stiekema, Lotte C. A.; Bos, Merijn; Langsted, Anne; Kuijk, Carlijn; Bekkering, Siroon; Voermans, Carlijn; Verberne, Hein J.; Nordestgaard, Børge G.; Stroes, Erik S. G.; Kroon, Jeffrey

    2017-01-01

    Mendelian randomization studies revealed a causal role for remnant cholesterol in cardiovascular disease. Remnant particles accumulate in the arterial wall, potentially propagating local and systemic inflammation. We evaluated the impact of remnant cholesterol on arterial wall inflammation,

  2. Bacterial meningitis

    NARCIS (Netherlands)

    Roos, Karen L.; van de Beek, Diederik

    2010-01-01

    Bacterial meningitis is a neurological emergency. Empiric antimicrobial and adjunctive therapy should be initiated as soon as a single set of blood cultures has been obtained. Clinical signs suggestive of bacterial meningitis include fever, headache, meningismus, vomiting, photophobia, and an

  3. Generation of Cosmic rays in Historical Supernova Remnants

    Directory of Open Access Journals (Sweden)

    Sinitsyna V.Y.

    2013-06-01

    Full Text Available We present the results of observations of two types of Galactic supernova remnants with the SHALON mirror Cherenkov telescope of Tien-Shan high-mountain Observatory: the shell-type supernova remnants Tycho, Cas A and IC 443; plerions Crab Nebula, 3c58(SN1181 and Geminga (probably plerion. The experimental data have confirmed the prediction of the theory about the hadronic generation mechanism of very high energy (800 GeV - 100 TeV gamma-rays in Tycho's supernova remnant. The data obtainedsuggest that the very high energy gamma-ray emission in the objects being discussedis different in origin.

  4. Revised Distances to 21 Supernova Remnants

    Science.gov (United States)

    Ranasinghe, S.; Leahy, D. A.

    2018-05-01

    We carry out a comprehensive study of H I 21 cm line observations and 13CO line observations of 21 supernova remnants (SNRs). The aim of the study is to search for H I absorption features to obtain kinematic distances in a consistent manner. The 21 SNRs are in the region of sky covered by the Very Large Array Galactic Plane Survey (H I 21 cm observations) and Galactic Ring Survey (13CO line observations). We obtain revised distances for 10 SNRs based on new evidence in the H I and 13CO observations. We revise distances for the other 11 SNRs based on an updated rotation curve and new error analysis. The mean change in distance for the 21 SNRs is ≃25%, i.e., a change of 1.5 kpc compared to a mean distance for the sample of 6.4 kpc. This has a significant impact on interpretation of the physical state of these SNRs. For example, using a Sedov model, age and explosion energy scale as the square of distance, and inferred ISM density scales as distance.

  5. Quantum remnants in the classical limit

    International Nuclear Information System (INIS)

    Kowalski, A.M.; Plastino, A.

    2016-01-01

    We analyze here the common features of two dynamical regimes: a quantum and a classical one. We deal with a well known semi-classic system in its route towards the classical limit, together with its purely classic counterpart. We wish to ascertain i) whether some quantum remnants can be found in the classical limit and ii) the details of the quantum-classic transition. The so-called mutual information is the appropriate quantifier for this task. Additionally, we study the Bandt–Pompe's symbolic patterns that characterize dynamical time series (representative of the semi-classical system under scrutiny) in their evolution towards the classical limit. - Highlights: • We investigate the classical limit (CL) of a well known semi classical model. • The study is made by reference to the Bandt Pompe symbolic approach. • The number and type of associated symbols changes as one proceeds towards the CL. • We ascertain which symbols pertaining to the quantum zone remain in the CL.

  6. Nonthermal Radiation from Supernova Remnant Shocks

    Directory of Open Access Journals (Sweden)

    Hyesung Kang

    2013-09-01

    Full Text Available Most of high energy cosmic rays (CRs are thought to be produced by diffusive shock acceleration (DSA at supernova remnants (SNRs within the Galaxy. Fortunately, nonthermal emissions from CR protons and electrons can provide direct observational evidence for such a model and place strong constraints on the complex nonlinear plasma processes in DSA theory. In this study we calculate the energy spectra of CR protons and electrons in Type Ia SNRs, using time-dependent DSA simulations that incorporate phenomenological models for some wave-particle interactions. We demonstrate that the timedependent evolution of the self-amplified magnetic fields, Alfvénic drift, and escape of the highest energy particles affect the energy spectra of accelerated protons and electrons, and so resulting nonthermal radiation spectrum. Especially, the spectral cutoffs in X-ray and γ-ray emission spectra are regulated by the evolution of the highest energy particles, which are injected at the early phase of SNRs. Thus detailed understandings of nonlinear wave-particle interactions and time-dependent DSA simulations of SNRs are crucial in testing the SNR hypothesis for the origin of Galactic cosmic rays.

  7. Radio emission from embryonic superluminous supernova remnants

    Science.gov (United States)

    Omand, Conor M. B.; Kashiyama, Kazumi; Murase, Kohta

    2018-02-01

    It has been widely argued that Type-I superluminous supernovae (SLSNe-I) are driven by powerful central engines with a long-lasting energy injection after the core-collapse of massive progenitors. One of the popular hypotheses is that the hidden engines are fast-rotating pulsars with a magnetic field of B ˜ 1013-1015 G. Murase, Kashiyama & Mészáros proposed that quasi-steady radio/submm emission from non-thermal electron-positron pairs in nascent pulsar wind nebulae can be used as a relevant counterpart of such pulsar-driven supernovae (SNe). In this work, focusing on the nascent SLSN-I remnants, we examine constraints that can be placed by radio emission. We show that the Atacama Large Millimeter/submillimetre Array can detect the radio nebula from SNe at DL ˜ 1 Gpc in a few years after the explosion, while the Jansky Very Large Array can also detect the counterpart in a few decades. The proposed radio follow-up observation could solve the parameter degeneracy in the pulsar-driven SN model for optical/UV light curves, and could also give us clues to young neutron star scenarios for SLSNe-I and fast radio bursts.

  8. Quantum remnants in the classical limit

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, A.M., E-mail: kowalski@fisica.unlp.edu.ar [Instituto de Física (IFLP-CCT-Conicet), Universidad Nacional de La Plata, C.C. 727, 1900 La Plata (Argentina); Comision de Investigaciones Científicas (CIC) (Argentina); Plastino, A., E-mail: plastino@fisica.unlp.edu.ar [Instituto de Física (IFLP-CCT-Conicet), Universidad Nacional de La Plata, C.C. 727, 1900 La Plata (Argentina); Argentina' s National Research Council (CONICET) (Argentina); SThAR, EPFL Innovation Park, Lausanne (Switzerland)

    2016-09-16

    We analyze here the common features of two dynamical regimes: a quantum and a classical one. We deal with a well known semi-classic system in its route towards the classical limit, together with its purely classic counterpart. We wish to ascertain i) whether some quantum remnants can be found in the classical limit and ii) the details of the quantum-classic transition. The so-called mutual information is the appropriate quantifier for this task. Additionally, we study the Bandt–Pompe's symbolic patterns that characterize dynamical time series (representative of the semi-classical system under scrutiny) in their evolution towards the classical limit. - Highlights: • We investigate the classical limit (CL) of a well known semi classical model. • The study is made by reference to the Bandt Pompe symbolic approach. • The number and type of associated symbols changes as one proceeds towards the CL. • We ascertain which symbols pertaining to the quantum zone remain in the CL.

  9. Predicting gravitational lensing by stellar remnants

    Science.gov (United States)

    Harding, Alexander J.; Stefano, R. Di; Lépine, S.; Urama, J.; Pham, D.; Baker, C.

    2018-03-01

    Gravitational lensing provides a means to measure mass that does not rely on detecting and analysing light from the lens itself. Compact objects are ideal gravitational lenses, because they have relatively large masses and are dim. In this paper, we describe the prospects for predicting lensing events generated by the local population of compact objects, consisting of 250 neutron stars, five black holes, and ≈35 000 white dwarfs. By focusing on a population of nearby compact objects with measured proper motions and known distances from us, we can measure their masses by studying the characteristics of any lensing event they generate. Here, we concentrate on shifts in the position of a background source due to lensing by a foreground compact object. With Hubble Space Telescope, JWST, and Gaia, measurable centroid shifts caused by lensing are relatively frequent occurrences. We find that 30-50 detectable events per decade are expected for white dwarfs. Because relatively few neutron stars and black holes have measured distances and proper motions, it is more difficult to compute realistic rates for them. However, we show that at least one isolated neutron star has likely produced detectable events during the past several decades. This work is particularly relevant to the upcoming data releases by the Gaia mission and also to data that will be collected by JWST. Monitoring predicted microlensing events will not only help to determine the masses of compact objects, but will also potentially discover dim companions to these stellar remnants, including orbiting exoplanets.

  10. Cystic duct remnant mucocele in a liver transplant recipient

    Energy Technology Data Exchange (ETDEWEB)

    Ahlawat, Sushil K. [Georgetown University Hospital, Department of Medicine, Division of Gastroenterology, Washington, DC (United States); University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ (United States); Fishbien, Thomas M. [Georgetown University Hospital, Department of Medicine, Division of Gastroenterology, Washington, DC (United States); Haddad, Nadim G. [Georgetown University Hospital, Department of Surgery, Division of Transplant Surgery, Washington, DC (United States)

    2008-08-15

    Cystic duct remnant mucocele is an extremely rare complication of liver transplantation in children. Surgical correction is usually required for cystic duct remnant mucocele when it causes biliary obstruction. We describe a 14-month-old liver transplant recipient who presented with biliary obstruction 1 month after orthotopic liver transplantation with an end-to-end choledochocholedocal biliary anastomosis for hepatoblastoma. US, CT and cholangiography findings were consistent with mucocele of the allograft cystic duct remnant. Surgery was not needed in our patient because the mucocele and biliary obstruction had resolved on repeat imaging most likely due to guidewire manipulation during cholangiography, resulting in opening of the cystic duct remnant orifice and drainage into the common duct. (orig.)

  11. Cystic duct remnant mucocele in a liver transplant recipient

    International Nuclear Information System (INIS)

    Ahlawat, Sushil K.; Fishbien, Thomas M.; Haddad, Nadim G.

    2008-01-01

    Cystic duct remnant mucocele is an extremely rare complication of liver transplantation in children. Surgical correction is usually required for cystic duct remnant mucocele when it causes biliary obstruction. We describe a 14-month-old liver transplant recipient who presented with biliary obstruction 1 month after orthotopic liver transplantation with an end-to-end choledochocholedocal biliary anastomosis for hepatoblastoma. US, CT and cholangiography findings were consistent with mucocele of the allograft cystic duct remnant. Surgery was not needed in our patient because the mucocele and biliary obstruction had resolved on repeat imaging most likely due to guidewire manipulation during cholangiography, resulting in opening of the cystic duct remnant orifice and drainage into the common duct. (orig.)

  12. Hydrodynamic Simulations of Kepler's Supernova Remnant

    Science.gov (United States)

    Sullivan, Jessica; Blondin, John; Borkowski, Kazik; Reynolds, Stephen

    2018-01-01

    Kepler’s supernova remnant contains unusual features that strongly suggest an origin in a single-degenerate Type Ia explosion, including anisotropic circumstellar medium (CSM), a strong brightness gradient, and spatially varying expansion proper motions. We present 3Dhydrodynamic simulations to test a picture in which Kepler's progenitor binary emitted a strong asymmetric wind, densest in the orbital plane, while the system moved at high velocity through the ISM. We simulate the creation of the presupernova environment as well as the supernova blast wave, using the VH-1 grid-based hydrodynamics code. We first modeled an anisotropic wind to create an asymmetric bowshock around the progenitor, then the blast wave from thesupernova. The final simulation places both previous model pieces onto a single grid and allows the blast wave to expand into the bowshock. Models were completed on a Yin-Yang grids with matching angular resolutions. By manipulating parameters that control the asymmetry of the system, we attempted to find conditions that recreated the current state of Kepler. We analyzed these models by comparing images of Kepler from the Chandra X-ray Observatory to line-of-sight projections from the model results. We also present comparisons of simulated expansion velocities with recent observations of X-ray proper motions from Chandra images. We were able to produce models that contained similar features to those seen in Kepler. We find the greatest resemblance to Kepler images with a presupernova wind with an equator-to-pole density contrast of 3 and a moderately disk-like CSM at a 5° angle between equatorial plane and system motion.

  13. Supernova Remnant Observations with Micro-X

    Science.gov (United States)

    Figueroa, Enectali

    Micro-X is a sounding rocket payload that combines an X-ray microcalorimeter with an imaging mirror to offer breakthrough science from high spectral resolution observations of extended X-ray sources. This payload has been in design and development for the last five years and is now completely built and undergoing integration; its first flight will be in November, 2012, as part of our current NASA award. This four-year follow-on proposal seeks funding for: (1) analysis of the first flight data, (2) the second flight and its data analysis, (3) development of payload upgrades and launch of the third flight, and (4) third flight data analysis. The scientific payload consists of a Transition Edge Sensor (TES) microcalorimeter array at the focus of a flight-proven conical imaging mirror. Micro-X capitalizes on three decades of NASA investment in the development of microcalorimeters and X-ray imaging optics. Micro-X offers a unique combination of bandpass, collecting area, and spectral and angular resolution. The spectral resolution goal across the 0.2 - 3.0 keV band is 2 - 4 eV Full-Width at Half Maximum (FWHM). The measured angular resolution of the mirror is 2.4 arcminute Half-Power Diameter (HPD). The effective area of the mirror, 300 square centimeters at 1 keV, is sufficient to provide observations of unprecedented quality of several astrophysical X-ray sources, even in a brief sounding rocket exposure of 300 sec. Our scientific program for this proposal will focus on supernova remnants (SNRs), whose spatial extent has made high-energy resolution observations with grating instruments extremely challenging. X-ray observations of SNRs with microcalorimeters will enable the study of the detailed atomic physics of the plasma; the determination of temperature, turbulence, and elemental abundances; and in conjunction with historical data, full three dimensional mapping of the kinematics of the remnant. These capabilities will open new avenues towards understanding the

  14. SUPERNOVA REMNANT PROGENITOR MASSES IN M31

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, Zachary G.; Williams, Benjamin F.; Dalcanton, Julianne J.; Gilbert, Karoline M.; Fouesneau, Morgan; Weisz, Daniel R. [Department of Astronomy, University of Washington Seattle, Box 351580, WA 98195 (United States); Murphy, Jeremiah W. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Dolphin, Andrew E., E-mail: zachjenn@uw.edu, E-mail: adolphin@raytheon.com [Raytheon, 1151 East Hermans Road, Tucson, AZ 85706 (United States)

    2012-12-10

    Using Hubble Space Telescope photometry, we age-date 59 supernova remnants (SNRs) in the spiral galaxy M31 and use these ages to estimate zero-age main-sequence masses (M{sub ZAMS}) for their progenitors. To accomplish this, we create color-magnitude diagrams (CMDs) and employ CMD fitting to measure the recent star formation history of the regions surrounding cataloged SNR sites. We identify any young coeval population that likely produced the progenitor star, then assign an age and uncertainty to that population. Application of stellar evolution models allows us to infer the M{sub ZAMS} from this age. Because our technique is not contingent on identification or precise location of the progenitor star, it can be applied to the location of any known SNRs. We identify significant young star formation around 53 of the 59 SNRs and assign progenitor masses to these, representing a factor of {approx}2 increase over currently measured progenitor masses. We consider the remaining six SNRs as either probable Type Ia candidates or the result of core-collapse progenitors that have escaped their birth sites. In general, the distribution of recovered progenitor masses is bottom-heavy, showing a paucity of the most massive stars. If we assume a single power-law distribution, dN/dM{proportional_to}M{sup {alpha}}, then we find a distribution that is steeper than a Salpeter initial mass function (IMF) ({alpha} = -2.35). In particular, we find values of {alpha} outside the range -2.7 {>=} {alpha} {>=} -4.4 to be inconsistent with our measured distribution at 95% confidence. If instead we assume a distribution that follows a Salpeter IMF up to some maximum mass, then we find that values of M{sub Max} > 26 are inconsistent with the measured distribution at 95% confidence. In either scenario, the data suggest that some fraction of massive stars may not explode. The result is preliminary and requires more SNRs and further analysis. In addition, we use our distribution to estimate a

  15. Paleoenvironmental analyses of an organic deposit from an erosional landscape remnant, Arctic Coastal Plain of Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Eisner, W R; Bockheim, J G; Hinkel, K M; Brown, T A; Nelson, F E; Peterson, K M; Jones, B M

    2005-01-02

    The dominant landscape process on the Arctic Coastal Plain of northern Alaska is the formation and drainage of thaw lakes. Lakes and drained thaw lake basins account for approximately 75% of the modern surface expression of the Barrow Peninsula. The thaw lake cycle usually obliterates lacustrine or peat sediments from previous cycles which could otherwise be used for paleoecological reconstruction of long-term landscape and vegetation changes. Several possible erosional remnants of a former topographic surface that predates the formation of the thaw lakes have been tentatively identified. These remnants are characterized by a higher elevation, a thick organic layer with very high ground ice content in the upper permafrost, and a plant community somewhat atypical of the region. Ten soil cores were collected from one site, and one core was intensively sampled for soil organic carbon content, pollen analysis, and {sup 14}C dating. The lowest level of the organic sediments represents the earliest phase of plant growth and dates to ca. 9000 cal BP. Palynological evidence indicates the presence of mesic shrub tundra (including sedge, birch, willow, and heath vegetation); and microfossil indicators point to wetter eutrophic conditions during this period. Carbon accumulation was rapid due to high net primary productivity in a relatively nutrient-rich environment. These results are interpreted as the local response to ameliorating climate during the early Holocene. The middle Holocene portion of the record contains an unconformity, indicating that between 8200 and 4200 cal BP sediments were eroded from the site, presumably in response to wind activity during a drier period centered around 4500 cal BP. The modern vegetation community of the erosional remnant was established after 4200 cal BP, and peat growth resumed. During the late Holocene, carbon accumulation rates were greatly reduced in response to the combined effects of declining productivity associated with climatic

  16. Complex structure of the supernova remnant HB 3

    Science.gov (United States)

    Leahy, D. A.; Venkatesan, D.; Long, K. S.; Naranan, S.

    1985-01-01

    HB 3 is an old, large (84 pc diameter) supernova remnant associated with the W3 H II region/molecular cloud complex. Observations of the imaging proportional counter (IPC) onboard the Einstein X-ray astronomy satellite have been reprocessed to yield a contour map of X-ray brightness and spectra of various regions of this remnant. The measured IPC flux is 2.4 x 10 to the -11th ergs per sq cm per s, giving a 0.2-4 keV luminosity of 1.6 x 10 to the 35th ergs/s for a column densityof 6 x 10 to the 21st per sq cm. The measured X-ray temperatures reveal a decrease from center to limb of the remnant of 1-0.3 keV. HB 3 is in the late adiabatic blast-wave phase of evolution, 30,000 to 50,000 yr old and with an initial blast energy of 3 x 10 to the 50th ergs. The X-ray map is compared with available radio and optical images. In X-rays, HB 3 has two components - a diffuse emission inside the 84 pc radio remnant and a ring of emission at the center of 30 pc in diameter. The diffuse emission is similar to that from other supernova remnants which are moderately obscured (column density, nH approximately 10 to the 22nd per sq cm). Three possibilities for the origin of the ring are explored: (1) a second supernova remnant, (2) a shocked shell in the interstellar medium surrounding HB 3, and (3) reverse-shock heated ejecta. There is no hot neutron star within the remnant.

  17. Black hole remnants and the information loss paradox

    Energy Technology Data Exchange (ETDEWEB)

    Chen, P., E-mail: pisinchen@phys.ntu.edu.tw [Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China); Graduate Institute of Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China); Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford University, CA 94305 (United States); Ong, Y.C., E-mail: yenchin.ong@nordita.org [Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden); Yeom, D.-H., E-mail: innocent.yeom@gmail.com [Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China)

    2015-11-22

    Forty years after the discovery of Hawking radiation, its exact nature remains elusive. If Hawking radiation does not carry any information out from the ever shrinking black hole, it seems that unitarity is violated once the black hole completely evaporates. On the other hand, attempts to recover information via quantum entanglement lead to the firewall controversy. Amid the confusions, the possibility that black hole evaporation stops with a “remnant” has remained unpopular and is often dismissed due to some “undesired properties” of such an object. Nevertheless, as in any scientific debate, the pros and cons of any proposal must be carefully scrutinized. We fill in the void of the literature by providing a timely review of various types of black hole remnants, and provide some new thoughts regarding the challenges that black hole remnants face in the context of the information loss paradox and its latest incarnation, namely the firewall controversy. The importance of understanding the role of curvature singularity is also emphasized, after all there remains a possibility that the singularity cannot be cured even by quantum gravity. In this context a black hole remnant conveniently serves as a cosmic censor. We conclude that a remnant remains a possible end state of Hawking evaporation, and if it contains large interior geometry, may help to ameliorate the information loss paradox and the firewall controversy. We hope that this will raise some interests in the community to investigate remnants more critically but also more thoroughly.

  18. Black hole remnants and the information loss paradox

    International Nuclear Information System (INIS)

    Chen, P.; Ong, Y.C.; Yeom, D.-H.

    2015-01-01

    Forty years after the discovery of Hawking radiation, its exact nature remains elusive. If Hawking radiation does not carry any information out from the ever shrinking black hole, it seems that unitarity is violated once the black hole completely evaporates. On the other hand, attempts to recover information via quantum entanglement lead to the firewall controversy. Amid the confusions, the possibility that black hole evaporation stops with a “remnant” has remained unpopular and is often dismissed due to some “undesired properties” of such an object. Nevertheless, as in any scientific debate, the pros and cons of any proposal must be carefully scrutinized. We fill in the void of the literature by providing a timely review of various types of black hole remnants, and provide some new thoughts regarding the challenges that black hole remnants face in the context of the information loss paradox and its latest incarnation, namely the firewall controversy. The importance of understanding the role of curvature singularity is also emphasized, after all there remains a possibility that the singularity cannot be cured even by quantum gravity. In this context a black hole remnant conveniently serves as a cosmic censor. We conclude that a remnant remains a possible end state of Hawking evaporation, and if it contains large interior geometry, may help to ameliorate the information loss paradox and the firewall controversy. We hope that this will raise some interests in the community to investigate remnants more critically but also more thoroughly.

  19. Aggregate and Mineral Resources - Minerals

    Data.gov (United States)

    NSGIC State | GIS Inventory — This point occurrence data set represents the current mineral and selected energy resources of Utah. The data set coordinates were derived from USGS topographic maps...

  20. Planck intermediate results XXXI. Microwave survey of Galactic supernova remnants

    DEFF Research Database (Denmark)

    Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.

    2016-01-01

    The all-sky Planck survey in 9 frequency bands was used to search for emission from all 274 known Galactic supernova remnants. Of these, 16 were detected in at least two Planck frequencies. The radio-through-microwave spectral energy distributions were compiled to determine the mechanism for micr......The all-sky Planck survey in 9 frequency bands was used to search for emission from all 274 known Galactic supernova remnants. Of these, 16 were detected in at least two Planck frequencies. The radio-through-microwave spectral energy distributions were compiled to determine the mechanism...... for microwave emission. In only one case, IC 443, is there high-frequency emission clearly from dust associated with the supernova remnant. In all cases, the low-frequency emission is from synchrotron radiation. As predicted for a population of relativistic particles with energy distribution that extends...

  1. Bacterial prostatitis.

    Science.gov (United States)

    Gill, Bradley C; Shoskes, Daniel A

    2016-02-01

    The review provides the infectious disease community with a urologic perspective on bacterial prostatitis. Specifically, the article briefly reviews the categorization of prostatitis by type and provides a distillation of new findings published on bacterial prostatitis over the past year. It also highlights key points from the established literature. Cross-sectional prostate imaging is becoming more common and may lead to more incidental diagnoses of acute bacterial prostatitis. As drug resistance remains problematic in this condition, the reemergence of older antibiotics such as fosfomycin, has proven beneficial. With regard to chronic bacterial prostatitis, no clear clinical risk factors emerged in a large epidemiological study. However, bacterial biofilm formation has been associated with more severe cases. Surgery has a limited role in bacterial prostatitis and should be reserved for draining of a prostatic abscess or the removal of infected prostatic stones. Prostatitis remains a common and bothersome clinical condition. Antibiotic therapy remains the basis of treatment for both acute and chronic bacterial prostatitis. Further research into improving prostatitis treatment is indicated.

  2. Case report of bilateral cervical chondrocutaneous branchial remnants.

    Science.gov (United States)

    Braun, Hannes; Hofmann, Thiemo; Wolfgruber, Herwig; Anderhuber, Wolfgang; Beham, Alfred; Stammberger, Heinz

    2003-01-01

    Cervical chondrocutaneous branchial remnants are rare and not well known lesions. Histologically the lesion per definition presents as a Choristoma. Choristoma is the pathohistological term for a developmental tumor-like anomaly consisting of tissues foreign to the site at which it is located. Treatment is complete surgical removal as promptly as possible in order to get an exact histopathological diagnosis. A case of a 4-month-old boy with cervical chondrocutaneous branchial remnants anterior to the sternocleidomastoid muscles on both sides is presented. According to literature search this appears to be the second case published on such a bilateral lesion.

  3. The acceleration of cosmic rays in supernova remnants

    International Nuclear Information System (INIS)

    Bhat, C.L.; Issa, M.R.

    1986-01-01

    The idea that the bulk of cosmic rays below 10 GeV are accelerated in supernova remnants suggests that cosmic rays should also exhibit intensity variations on a scale comparable with the linear size of a representative remnant. Following the general spirit of shock-wave acceleration models, here Monte Carlo simulations are carried out to predict what this scale should be and then corroborative evidence is presented from an autocorrelation analysis of the COS B and SAS II γ-ray data for the latitude range |b|=10-20 0 ('near Galaxy') and |b| 0 ('far Galaxy'). (author)

  4. Fumarolic minerals

    DEFF Research Database (Denmark)

    Balic Zunic, Tonci; Garavelli, Anna; Jakobsson, Sveinn Peter

    2016-01-01

    The fumarolic mineralogy of the Icelandic active volcanoes, the Tyrrhenian volcanic belt (Italy) and the Aegean active arc (Greece) is investigated, and literature data surveyed in order to define the characteristics of the European fumarolic systems. They show broad diversity of mineral...... associations, with Vesuvius and Vulcano being also among the world localities richest in mineral species. Volcanic systems, which show recession over a longer period, show fumarolic development from the hightemperature alkaline halide/sulphate, calcic sulphate or sulphidic parageneses, synchronous...... with or immediately following the eruptions, through mediumtemperature ammonium minerals, metal chlorides, or fluoride associations to the late low-temperature paragenesis dominated by sulphur, gypsum, alunogen, and other hydrous sulphates. The situation can be different in the systems that are not recessing but show...

  5. Mineral sands

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    This paper presents an outlook of the Australian mineral sand industry and covers the major operators. It is shown that conscious of an environmentally minded public, the Australian miners have led the way in the rehabilitation of mined areas. Moreover the advanced ceramic industry is generating exciting new perspectives for zircon producers and there is a noticeable growth in the electronic market for rare earths, but in long term the success may depend as much on environmental management and communication skills as on mining and processing skills

  6. Bacterial Vaginosis

    Science.gov (United States)

    ... Archive STDs Home Page Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ( ... of getting other STDs, such as chlamydia and gonorrhea . These bacteria can sometimes cause pelvic inflammatory disease ( ...

  7. Nucleated regeneration of semiarid sclerophyllous forests close to remnant vegetation

    NARCIS (Netherlands)

    Fuentes-Castillo, T.; Miranda, A.; Rivera-Hutinel, A.; Smith-Ramirez, C.; Holmgren, M.

    2012-01-01

    Natural regeneration of mediterranean plant communities has proved difficult in all continents. In this paper we assess whether regeneration of sclerophyllous forests shows nucleated patterns indicative of a positive effect of vegetation remnants at the landscape level and compare the regeneration

  8. X-Ray Emission Properties of Supernova Remnants

    NARCIS (Netherlands)

    Vink, J.; Alsabti, A.W.; Murdin, P.

    2016-01-01

    X-ray emission from supernova remnants can be broadly divided into thermal X-ray emission from the shock-heated plasmas and in nonthermal (synchrotron) emission caused by very high-energy (10–100 TeV) electrons moving in the magnetic fields of the hot plasmas. The thermal X-ray emission of young

  9. Supernova remnants, pulsar wind nebulae and their interaction

    NARCIS (Netherlands)

    Swaluw, E. van der

    2001-01-01

    A supernova explosion marks the end of the evolution of a massive star. What remains of the exploded star is a high density neutron star or a black hole. The material which has been ejected by the supernova explosion will manifest itself as a supernova remnant: a hot bubble of gas expanding in the

  10. The origin of radio recombination lines seen toward supernova remnants

    International Nuclear Information System (INIS)

    Pankonin, V.; Downes, D.

    1976-01-01

    New observations have been made of the 166 α spectrum in the direction of the supernova remnants G-0.6 - 0.1, 3 C 391 and W 49 B. The variation of the intensity of the hydrogen recombination lines with frequency indicates that the lines arise in extended, low-density H II regions and not in cold clouds. (orig.) [de

  11. Efficacy of different I-131 doses for thyroid remnant ablation

    International Nuclear Information System (INIS)

    Nguyen, X.C.; Thiep, T.V.; Hung, N.C.

    2007-01-01

    Full text: Radioactive iodine 131 I has been widely used as a treatment modality of differentiated thyroid carcinoma. The need for high dose radioiodine ablation of thyroid remnant is still in question. The aim of this prospective study was to assess the efficacy of 131 I different single and fractionated doses in ablation of post-operative thyroid remnant. Patients and methods: One hundred-twelve patients were included in this study. Sixty-one patients with TSH≥30 μU/ml were treated 30 mCi in group 1 (36 patients) or 100 mCi in group 2 (25 patients). Fifty one patients with TSH 131 I high dose of 100 mCi and no severe adverse effect in the other groups. Conclusion: Single high dose (100 mCi) may be more efficient than single low dose (30 mCi) for post-operative remnant ablation with serum TSH≥30 μU/ml and the efficacy of low fractionated doses (30+30 mCi) was comparable with high-fractionated dose (30+100 mCi) for post-operative remnant ablation with low serum TSH in differentiated thyroid carcinoma. (author)

  12. CASE REPORT Urachal remnant carcinoma - a rare entity

    African Journals Online (AJOL)

    Magnetic resonance imaging (MRI) was not undertaken as it was thought to confer little benefit in the setting of advanced disease. Following histological confirmation of moderately differentiated invasive adenocarcinoma of the urachal remnant, and administration of chemotherapy, the patient developed cerebral metastasis ...

  13. Bat use of remnant old-growth redwood stands

    Science.gov (United States)

    William J. Zielinski; Steven T. Gellman

    1999-01-01

    Most of the old-growth redwood (Sequoia sempervirens) in Calfornia has been cut; regenerating forests will probably never resemble those that were harvested, and what old growth remains on private land occurs in small, isolated remnant patches. The landscapes in which these stands occur differ so markedly from their original condition that their...

  14. Constraining the number of compact remnants near Sgr A*

    Science.gov (United States)

    Deegan, Patrick; Nayakshin, Sergei

    2007-05-01

    Due to dynamical friction stellar mass black holes and neutron stars are expected to form high-density cusps in the inner parsec of our Galaxy. These compact remnants, expected to number around 20000, may be accreting cold dense gas present there, and give rise to potentially observable X-ray emission. Here we build a simple but detailed time-dependent model of such emission. The possibility that these accretion flows are radiatively inefficient is taken into account and brings in some uncertainty in the conclusions. Despite this uncertainty, we find that at least several X-ray sources of this nature should be detectable with Chandra at any one time. Turning this issue around, we also ask a question of what current observational constraints might be telling us about the total number of compact remnants. In our `best guess' model, a cusp of ~40000 remnants overpredicts the number of discrete sources and the total X-ray luminosity of the inner parsec, and is hence ruled out. In the most radiatively inefficient scenario that we consider, the radiative efficiency is set to be as small as ɛ = 10-5. In this rather unlikely scenario, a cusp of ~40000 black holes would be allowed by the data, but several individual sources should still be visible. Future observations of the distribution and orbits of the cold ionized gas in the inner parsec of our Galaxy will put tighter constraints on the cusp of compact remnants.

  15. On The Origin Of Two-Shell Supernova Remnants

    Science.gov (United States)

    Gvaramadze, Vasilii

    2007-07-01

    The proper motion of massive stars could cause them to explode far from the geometric centers of their wind-driven bubbles and thereby could affect the symmetry of the resulting diffuse supernova remnants (SNRs). We use this fact to explain the origin of SNRs consisting of two partially overlapping shells (e.g. Cygnus Loop, 3C 400.2, etc.).

  16. A Recurrent Nova Super-Remnant in the Andromeda Galaxy

    DEFF Research Database (Denmark)

    Darnley, M. J.; Hounsell, R.; O'Brien, T. J.

    2017-01-01

    Here we report that the most rapidly recurring nova, M31N 2008-12a, which erupts annually, is surrounded by a "nova super-remnant" which demonstrates that M31N 2008-12a has erupted with high frequency for millions of years....

  17. Cervical chondrocutaneous branchial remnants--report of 17 cases.

    Science.gov (United States)

    Begovic, Ninoslav; Simic, Radoje; Vlahovic, Aleksandar; Kravljanac, Djordje; Djuricic, Slavisa; Mijovic, Tanja

    2014-11-01

    Cervical chondrocutaneous branchial remnants are congenital, benign and rare neck masses. These anomalies are limited in the literature, reported mostly as case reports. Cervical chondrocutaneous branchial remnant is always present at birth, and the lesion is usually unilateral. Understanding and treatment of cervical chondrocutaneous branchial remnants requires knowledge of the related embryology. From January 2005 to December 2008, 17 patients with mean age of 32 months (range from 2 months to 15 years) with CCBRs were treated at the Division of Pediatric Surgery, Department of Plastic and Reconstructive Surgery and Burns at the Institute for Mother and Child Health Care, Belgrade, Serbia. The following objections were recorded: sex, lesion side, surgical data, associated malformations and pathohistology findings. There were 7 females and 10 males, 4 with bilateral presences. Five children had associated anomalies, as follows: vesicoureteral reflux, atrial and ventricular septal defect, ventricular septal defect, branchiootorenal syndrome and preauricular sinus. There was a positive family history in one patient. Fifteen patients (88%) were treated with complete surgical excision and no connections with deep underlying structures of the neck were found. There were no complications at surgery. No recurrence was found during follow-up. Histopathology analysis revealed both, hyaline and elastic cartilage. Cervical chondrocutaneous branchial remnants are rare anomalies arising from branchial arch, probably originally from remnants of first or second arch. Surgical excision is the treatment of choice. From our experience, we suggest surgical treatment early in childhood because of esthetic reason, simplicity of the intervention and low complication rate. Also, the abdominal ultrasound and cardiac examination is recommended because of associated anomalies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  18. Hot interstellar tunnels. I. Simulation of interacting supernova remnants

    International Nuclear Information System (INIS)

    Smith, B.W.

    1977-01-01

    Reexamining a suggestion of Cox and Smith, we find that intersecting supernova remnants can indeed generate and maintain hot interstellar regions with napproximately-less-than10 -2 cm -3 and Tapprox.10 6 K. These regions are likely to occupy at least 30% of the volume of a spiral arm near the midplane of the gaseous disk if the local supernova rate there is greater than 1.5 x 10 -7 Myr -1 pc -3 . Their presence in the interstellar medium is supported by observations of the soft X-ray background. The theory required to build a numerical simulation of interacting supernova remnants is developed. The hot cavities within a population of remnants will become connected for a variety of assumed conditions in the outer shells of old remnants. Extensive hot cavity regions or tunnels are built and enlarged by supernovae occurring in relatively dense gas which produce connections, but tunnels are kept hot primarily by supernovae occurring within the tunnels. The latter supernovae initiate fast shock waves which apparently reheat tunnels faster than they are destroyed by thermal conduction in a galactic magnetic field or by radiative cooling. However, the dispersal of these rejuvenating shocks over a wide volume is inhibited by motions of cooler interstellar gas in the interval between shocks. These motions disrupt the contiguity of the component cavities of a tunnel and may cause its death.The Monte Carlo simulations indicate that a quasi-equilibrium is reached within 10 7 years of the first supernova in a spiral arm. This equilibrium is characterized by a constant average filling fraction for cavities in the interstellar volume. Aspects of the equilibrium are discussed for a range of supernova rates. Two predictions of Cox and Smith are not confirmed within this range: critical growth of hot regions to encompass the entire medium, and the efficient quenching of a remnant's expansion by interaction with other cavities

  19. X-ray surface brightness of Kepler's supernova remnant

    International Nuclear Information System (INIS)

    White, R.L.; Long, K.S.

    1983-01-01

    We have observed Kepler's supernova remnant (SNR) with the imaging instruments on board the Einstein Observatory. The 0.15-4.5 keV flux incident on the Earth is 1.2 x 10 - 10 ergs cm - 2 s - 1 ; the flux corrected for interstellar absorption is 3.4 x 10 - 10 ergs cm - 2 s - 1 (L/sub x/ = 1.0 x 10 36 ergs s - 1 at D = 5 kpc) if the absorbing column density is N/sub H/ = 2.8 x 10 21 cm - 2 . The remnant is circular and shows a strong shell which is at least 5 times brighter in the north than in the south. The X-ray observations do not unambiguously determine whether the remnant is in the adiabatic or the free expansion phase. If the remnant is in the adiabatic phase, the density of the interstellar medium (ISM) ( 2 /sub e/>/sup 1/2/) surrounding Kepler's SNR must be about 5 cm - 3 . If the remnant is in the free expansion phase, where most of the emission arises from shock-heated ejecta, the ISM density must still be relatively high, n/sub i/> or approx. =0.1 cm - 3 . Even if the ISM is very inhomogeneous, with very many small, dense clouds, we show that the mean density of the ISM must be greater than approx.0.1 cm - 3 . In any case, the density of the x-ray emitting gas must be high ( 2 /sub e/>/sup 1/2/ > or approx. =10 cm - 3 ), and the temperature must be fairly low (T/sub e/ 7 K). The relatively high ISM density which is required is surprising in view of Kepler's distance above the galactic plane, approx.600 pc. Possibly the ISM around Kepler's SNR and around other type i SNRs is dominated by the mass lost from the presupernova star

  20. Oligotyping reveals stronger relationship of organic soil bacterial community structure with N-amendments and soil chemistry in comparison to that of mineral soil at Harvard Forest, MA, USA

    Science.gov (United States)

    Swathi A. Turlapati; Rakesh Minocha; Stephanie Long; Jordan Ramsdell; Subhash C. Minocha

    2015-01-01

    The impact of chronic nitrogen amendments on bacterial communities was evaluated at Harvard Forest, Petersham, MA, USA. Thirty soil samples (3 treatments × 2 soil horizons × 5 subplots) were collected in 2009 from untreated (control), low nitrogen-amended (LN; 50 kg NH4NO3ha-1yr

  1. Hydrothermal minerals

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.

    flux. Circulation of seawater through the oceanic crust and upper mantle gives rise to a complex series of physical and chemical reactions that lead to the 1) formation of seafloor mineral deposits; 2) alteration of oceanic crust; 3) control... temperature in the high-temperature reaction zone near the heat source. Important parameters in determining the high- temperature fluid composition are • pressure, • temperature, • water/rock ratio, • rock composition, • recharge fluid...

  2. BACTERIAL CONSORTIUM

    Directory of Open Access Journals (Sweden)

    Payel Sarkar

    2013-01-01

    Full Text Available Petroleum aromatic hydrocarbons like benzen e, toluene, ethyl benzene and xylene, together known as BTEX, has almost the same chemical structure. These aromatic hydrocarbons are released as pollutants in th e environment. This work was taken up to develop a solvent tolerant bacterial cons ortium that could degrade BTEX compounds as they all share a common chemical structure. We have isolated almost 60 different types of bacterial strains from different petroleum contaminated sites. Of these 60 bacterial strains almost 20 microorganisms were screene d on the basis of capability to tolerate high concentration of BTEX. Ten differe nt consortia were prepared and the compatibility of the bacterial strains within the consortia was checked by gram staining and BTEX tolerance level. Four successful mi crobial consortia were selected in which all the bacterial strains concomitantly grew in presence of high concentration of BTEX (10% of toluene, 10% of benzene 5% ethyl benzene and 1% xylene. Consortium #2 showed the highest growth rate in pr esence of BTEX. Degradation of BTEX by consortium #2 was monitored for 5 days by gradual decrease in the volume of the solvents. The maximum reduction observed wa s 85% in 5 days. Gas chromatography results also reveal that could completely degrade benzene and ethyl benzene within 48 hours. Almost 90% degradation of toluene and xylene in 48 hours was exhibited by consortium #2. It could also tolerate and degrade many industrial solvents such as chloroform, DMSO, acetonitrile having a wide range of log P values (0.03–3.1. Degradation of aromatic hydrocarbon like BTEX by a solvent tolerant bacterial consortium is greatly significant as it could degrade high concentration of pollutants compared to a bacterium and also reduces the time span of degradation.

  3. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    , which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to significantly...... tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion...... is the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental parameters...

  4. Bacterial meningitis

    NARCIS (Netherlands)

    Heckenberg, Sebastiaan G. B.; Brouwer, Matthijs C.; van de Beek, Diederik

    2014-01-01

    Bacterial meningitis is a neurologic emergency. Vaccination against common pathogens has decreased the burden of disease. Early diagnosis and rapid initiation of empiric antimicrobial and adjunctive therapy are vital. Therapy should be initiated as soon as blood cultures have been obtained,

  5. Bacterial lipases

    NARCIS (Netherlands)

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation,

  6. Bacterial stress

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Bacterial stress. Physicochemical and chemical parameters: temperature, pressure, pH, salt concentration, oxygen, irradiation. Nutritional depravation: nutrient starvation, water shortage. Toxic compounds: Antibiotics, heavy metals, toxins, mutagens. Interactions with other cells: ...

  7. Contribution of infrared observations to the study of supernovae remnants

    International Nuclear Information System (INIS)

    Douvion, Thomas

    2000-01-01

    This research thesis addresses the study of dust in young supernovae remnants observed in middle infrared, mainly by means of the ISOCAM instrument installed on the ISO satellite. The author first presents the supernovae physics and the studied young remnants, describes dusts and the main sites of formation and destruction, and outlines the difficulties and benefits of observations performed in the middle infrared. Then, the author reports acquired evidences related to the formation of dusts in supernovae, and the search for a millimetre emission by cold dust contained in regions which are not yet excited by the shock, in order to better assess the overall quantities created by supernovae. He reports the use of observations of dust and neon in Cassiopeia A to perform a diagnosis on the mixture of elements during the supernovae explosion [fr

  8. The population of supernova remnants in the Magellanic Clouds

    CERN Document Server

    Dennefeld, M

    1978-01-01

    The detection of SNRs in the Magellanic Clouds is reviewed with emphasis on its limits. A sample of SNRs is then used to derive the mean interval between SN explosions, tau . After the maximum constraints have been put on all the other parameters, the distribution of diameters of remnants with diameter less than 30 pc in the LMC is shown to agree well with theoretical predictions. In adopting a mean value of E/sub 0//n/sub 0/ (energy at explosion over surrounding density) of 5*10/sup 51/ ergs cm/sup 3/, the best value of tau is 300+or-100 years in good agreement with predictions from statistics of supernovae in external galaxies. The small number of remnants in the SMC prevents a similar approach being used with any statistical significance. (20 refs).

  9. Dynamics of supernova remnants in the Galactic centre.

    Science.gov (United States)

    Bortolas, E.; Mapelli, M.; Spera, M.

    The Galactic centre (GC) is a unique place to study the extreme dynamical processes occurring near a super-massive black hole (SMBH). Here we simulate a large set of binaries orbiting the SMBH while the primary member undergoes a supernova (SN) explosion, in order to study the impact of SN kicks on the orbits of stars and dark remnants in the GC. We find that SN explosions are efficient in scattering neutron stars and other light stars on new (mostly eccentric) orbits, while black holes (BHs) tend to retain memory of the orbit of their progenitor star. SN kicks are thus unable to eject BHs from the GC: a cusp of dark remnants may be lurking in the central parsec of our Galaxy.

  10. Intestinal obstruction caused by omphalomesenteric duct remnant: usefulness of laparoscopy.

    Science.gov (United States)

    Bueno Lledó, J; Serralta Serra, A; Planeéis Roig, M; Dobón Giménez, F; Ibáñez Palacín, F; Rodero Rodero, R

    2003-10-01

    The anomalies related to omphalomesenteric duct remnant constitute an uncommon cause of intestinal obstruction, of which Meckel"s diverticulum and its variants represent the most important clinical presentation. In most cases they are asymptomatic and usually affect young patients. When symptomatic, they usually present episodes of gastrointestinal bleeding or acute abdomen syndromes caused by strangulation of intestinal loops as a result of fibrous intraabdominal remnants or inflammation produced by the diverticulum. In most cases, the unexpected presence of these alterations makes intraoperative diagnosis necessary. Treatment is surgical and consists in exeresis of the diverticulum or the fibrous band causing the clinical picture. We report two cases of persistence of the vitelline duct resolved by laparoscopic approach.

  11. Confinement of the crab pulsar's wind by its supernova remnant

    International Nuclear Information System (INIS)

    Kennel, C.F.; Coroniti, F.V.

    1984-01-01

    We construct a steady state, spherically symmetric, magnetohydrodynamic model of the Crab nebual. A highly relativistic, positronic pulsar wind is terminated by a strong MHD shock that decelerates the flow and increases its pressure to match boundary conditions imposed by the recently discovered supernova remnant that surrounds the nebula. If the magnetic luminosity of the pulsar wind upsteam of the shock is about 0.3% of its particle luminosity, the pressure and velocity boundary conditions imposed by the remnant place the shock where we infer it to be; near the outer boundary of an underluminous region observed to surround the pulsar. It is necessary to include the weak magnetization of the wind to satisfy the boundary conditions and to calculate the nebular synchrotron radiation self-consistently

  12. The optical emission from the supernova remnant HB 3

    Science.gov (United States)

    Fesen, R. A.; Gull, T. R.

    1983-01-01

    The supernova remnant HB 3 was first detected as a radio source by Brown and Hazard (1953). On the basis of subsequent radio studies, it was concluded that the object was a supernova remnant (SNR). HB 3 is located at the far western edge of the H II region/molecular cloud complex W3-W4-W5 (IC 1795-1805-1848). However, a physical association of HB 3 with this complex is uncertain. In the present investigation, attention is called to the probability that HB 3 exhibits a more extensive optical emission structure than previously realized, and one which agrees well with both the position and morphology of the radio emission. It is found that narrow-passband optical images strongly suggest an almost complete optical emission shell for HB 3. Spectroscopic observations are, however, required to confirm that this emission is characteristic of a SNR.

  13. Chandra Observations of Tycho's Supernova Remnant U. Hwang , R ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    runaway thermal instabilities in a white dwarf. It was observed for 50 ks with the superb 0.5 resolution mirror on the Chandra X-ray .... emission that comes from ejecta that have propagated to the forward shock. Such a spectrum, taken from a portion of the west rim of the remnant, is shown in the right panel of Fig. 2. The fitted ...

  14. Cosmic Ray and Tev Gamma Ray Generation by Quasar Remnants

    Science.gov (United States)

    Boldt, Elihu; Loewenstein, Michael; White, Nicholas E. (Technical Monitor)

    2000-01-01

    Results from new broadband (radio to X-ray) high-resolution imaging studies of the dormant quasar remnant cores of nearby giant elliptical galaxies are now shown to permit the harboring of compact dynamos capable of generating the highest energy cosmic ray particles and associated curvature radiation of TeV photons. Confirmation would imply a global inflow of interstellar gas all the way to the accretion powered supermassive black hole at the center of the host galaxy.

  15. Study of the photon remnant in resolved photoproduction at HERA

    International Nuclear Information System (INIS)

    Derrick, M.; Krakauer, D.; Magill, S.

    1995-01-01

    Photoproduction at HERA is studied in ep collisions, with the ZEUS detector, for γp centre-of-mass energies ranging from 130-270 GeV. A sample of events with two high-p T jets (p T >6 GeV, η T with respect to the beam axis is measured to be 2.1±0.2 GeV, which demonstrates substantial mean transverse momenta for the photon remnant. (orig.)

  16. Time evolution of gamma rays from supernova remnants

    Science.gov (United States)

    Gaggero, Daniele; Zandanel, Fabio; Cristofari, Pierre; Gabici, Stefano

    2018-04-01

    We present a systematic phenomenological study focused on the time evolution of the non-thermal radiation - from radio waves to gamma rays - emitted by typical supernova remnants via hadronic and leptonic mechanisms, for two classes of progenitors: thermonuclear and core-collapse. To this aim, we develop a numerical tool designed to model the evolution of the cosmic ray spectrum inside a supernova remnant, and compute the associated multi-wavelength emission. We demonstrate the potential of this tool in the context of future population studies based on large collection of high-energy gamma-ray data. We discuss and explore the relevant parameter space involved in the problem, and focus in particular on their impact on the maximum energy of accelerated particles, in order to study the effectiveness and duration of the PeVatron phase. We outline the crucial role of the ambient medium through which the shock propagates during the remnant evolution. In particular, we point out the role of dense clumps in creating a significant hardening in the hadronic gamma-ray spectrum.

  17. Search for Nonthermal X-Rays from Supernova Remnant Shells

    Science.gov (United States)

    Petre, R.; Keohane, J.; Hwang, U.; Allen, G.; Gotthelf, E.

    The demonstration by ASCA that the nonthermal X-ray emission from the rim of SN1006 is synchrotron emission from TeV electrons, produced in the same environment responsible for cosmic ray protons and nuclei (Koyama et al. 1995, Nature 378, 255), has stimulated a search for nonthermal X-rays from other remnants. Nonthermal emission has subsequently been found to arise in the shells of at least two other remnants, Cas A and IC 443. In Cas A, a hard tail is detected using ASCA, XTE, and OSSE to energies exceeding 100 keV; the shape of the spectrum rules out all mechanisms except synchrotron radiation. In IC 443, the previously known hard emission has been shown using ASCA to be isolated to a small region along the rim of the remnant, where the shock is interacting most strongly with a molecular cloud. Nonthermal X-ray emission is thought to arise here by enhanced cosmic ray production associated with the shock/cloud interaction (Keohane et al. 1997, ApJ in press). We describe the properties of the nonthermal emission in SN1006, Cas A, and IC 443, and discuss the status of our search for nonthermal emission associated with the shocks of other Galactic and LMC SNR's.

  18. CORRELATION OF SUPERNOVA REMNANT MASERS AND GAMMA-RAY SOURCES

    International Nuclear Information System (INIS)

    Hewitt, John W.; Yusef-Zadeh, Farhad; Wardle, Mark

    2009-01-01

    Supernova remnants (SNRs) interacting with molecular clouds are potentially exciting systems in which to detect evidence of cosmic ray acceleration. Prominent γ-ray emission is produced via the decay of neutral pions when cosmic rays encounter nearby dense clouds. In many of the SNRs coincident with γ-ray sources, the presence of OH (1720 MHz) masers is used to identify interaction with dense gas and to provide a kinematic distance to the system. In this Letter we use statistical tests to demonstrate that there is a correlation between these masers and a class of GeV- to TeV-energy γ-ray sources coincident with interacting remnants. For pion decay the γ-ray luminosity provides a direct estimate of the local cosmic ray density. We find the cosmic ray density is enhanced by one to two orders of magnitude over the local solar value, comparable to X-ray-induced ionization in these remnants. The inferred ionization rates are sufficient to explain non-equilibrium chemistry in the post-shock gas, where high columns of hydroxyl are observed.

  19. Current status in remnant gastric cancer after distal gastrectomy

    Science.gov (United States)

    Ohira, Masaichi; Toyokawa, Takahiro; Sakurai, Katsunobu; Kubo, Naoshi; Tanaka, Hiroaki; Muguruma, Kazuya; Yashiro, Masakazu; Onoda, Naoyoshi; Hirakawa, Kosei

    2016-01-01

    Remnant gastric cancer (RGC) and gastric stump cancer after distal gastrectomy (DG) are recognized as the same clinical entity. In this review, the current knowledges as well as the non-settled issues of RGC are presented. Duodenogastric reflux and denervation of the gastric mucosa are considered as the two main factors responsible for the development of RGC after benign disease. On the other hand, some precancerous circumstances which already have existed at the time of initial surgery, such as atrophic gastritis and intestinal metaplasia, are the main factors associated with RGC after gastric cancer. Although eradication of Helicobacter pylori (H. pylori) in remnant stomach is promising, it is still uncertain whether it can reduce the risk of carcinogenesis. Periodic endoscopic surveillance after DG was reported useful in detecting RGC at an early stage, which offers a chance to undergo minimally invasive endoscopic treatment or laparoscopic surgery and leads to an improved prognosis in RGC patients. Future challenges may be expected to elucidate the benefit of eradication of H. pylori in the remnant stomach if it could reduce the risk for RGC, to build an optimal endoscopic surveillance strategy after DG by stratifying the risk for development of RGC, and to develop a specific staging system for RGC for the standardization of the treatment by prospecting the prognosis. PMID:26937131

  20. Are young supernova remnants interacting with circumstellar gas

    International Nuclear Information System (INIS)

    Chevalier, R.A.

    1982-01-01

    The young remnants of galactic Type I supernovae (SN 1006, SN 1572, and SN 1604) appear to be interacting with moderately dense gas (n/sub O/> or =0.1 cm -3 ). If the gas in the ambient interstellar medium, the observations suggest that gas of this density is fairly pervasive. If the gas is circumstellar, there are important implications for the progenitors of Type I supernovae. A plausible density distribution for circumstellar gas is rhoinfinityr -2 . The expansion of a supernova into such a medium is examined and is compared with expansion into a uniform medium. The two cases can be distinguished on the basis of their density profiles and their rates of expansion. Currently available data factor the hypothesis of expansion in a uniform medium for all three Type I remnants; the evidence is the strongest for SN 1572 and the weakest for SN 1604. Further X-ray and radio observations of the galactic remnants and of extragalactic Type I supernovae should serve to test this hypothesis

  1. Modelling neutrino and gamma-ray fluxes in supernova remnants

    International Nuclear Information System (INIS)

    Ballet, J; Cassam-Chenai, G; Maurin, G; Naumann, C

    2008-01-01

    Supernova remnants (SNRs) are believed to accelerate charged particles by diffusive shock acceleration (DSA) and to produce the majority of galactic cosmic rays, at least up to the 'knee' at 3-10 15 electron volts. In the framework of a hydrodynamic self-similar simulation of the evolution of young supernova remnants, its interaction with the ambient matter as well as the microwave and infrared background is studied. The photon spectra resulting from synchrotron and inverse Compton emission as well as from hadronic processes are calculated, as are the accompanying neutrino fluxes. Applying this method to the particular case of the SNR RXJ-1713, 7-3946, we find that its TeV emission can in principle be explained by pion decay if the ambient density is assumed to grow with increasing distance from the centre. The neutrino flux associated with this hadronic model is of a magnitude that may be detectable by a cubic-kilometre sized deep-sea neutrino telescope in the northern hemisphere. In this poster, a description of the supernova remnant simulation is given together with the results concerning RXJ-1713.

  2. [Bacterial vaginosis].

    Science.gov (United States)

    Romero Herrero, Daniel; Andreu Domingo, Antonia

    2016-07-01

    Bacterial vaginosis (BV) is the main cause of vaginal dysbacteriosis in the women during the reproductive age. It is an entity in which many studies have focused for years and which is still open for discussion topics. This is due to the diversity of microorganisms that cause it and therefore, its difficult treatment. Bacterial vaginosis is probably the result of vaginal colonization by complex bacterial communities, many of them non-cultivable and with interdependent metabolism where anaerobic populations most likely play an important role in its pathogenesis. The main symptoms are an increase of vaginal discharge and the unpleasant smell of it. It can lead to serious consequences for women, such as an increased risk of contracting sexually transmitted infections including human immunodeficiency virus and upper genital tract and pregnancy complications. Gram stain is the gold standard for microbiological diagnosis of BV, but can also be diagnosed using the Amsel clinical criteria. It should not be considered a sexually transmitted disease but it is highly related to sex. Recurrence is the main problem of medical treatment. Apart from BV, there are other dysbacteriosis less characterized like aerobic vaginitis of which further studies are coming slowly but are achieving more attention and consensus among specialists. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  3. Bacterial mitosis

    DEFF Research Database (Denmark)

    Møller-Jensen, Jakob; Borch, Jonas; Dam, Mette

    2003-01-01

    Bacterial DNA segregation takes place in an active and ordered fashion. In the case of Escherichia coli plasmid R1, the partitioning system (par) separates paired plasmid copies and moves them to opposite cell poles. Here we address the mechanism by which the three components of the R1 par system...... act together to generate the force required for plasmid movement during segregation. ParR protein binds cooperatively to the centromeric parC DNA region, thereby forming a complex that interacts with the filament-forming actin-like ParM protein in an ATP-dependent manner, suggesting that plasmid...

  4. OXYGEN-RICH SUPERNOVA REMNANT IN THE LARGE MAGELLANIC CLOUD

    Science.gov (United States)

    2002-01-01

    This is a NASA Hubble Space Telescope image of the tattered debris of a star that exploded 3,000 years ago as a supernova. This supernova remnant, called N132D, lies 169,000 light-years away in the satellite galaxy, the Large Magellanic Cloud. A Hubble Wide Field Planetary Camera 2 image of the inner regions of the supernova remnant shows the complex collisions that take place as fast moving ejecta slam into cool, dense interstellar clouds. This level of detail in the expanding filaments could only be seen previously in much closer supernova remnants. Now, Hubble's capabilities extend the detailed study of supernovae out to the distance of a neighboring galaxy. Material thrown out from the interior of the exploded star at velocities of more than four million miles per hour (2,000 kilometers per second) plows into neighboring clouds to create luminescent shock fronts. The blue-green filaments in the image correspond to oxygen-rich gas ejected from the core of the star. The oxygen-rich filaments glow as they pass through a network of shock fronts reflected off dense interstellar clouds that surrounded the exploded star. These dense clouds, which appear as reddish filaments, also glow as the shock wave from the supernova crushes and heats the clouds. Supernova remnants provide a rare opportunity to observe directly the interiors of stars far more massive than our Sun. The precursor star to this remnant, which was located slightly below and left of center in the image, is estimated to have been 25 times the mass of our Sun. These stars 'cook' heavier elements through nuclear fusion, including oxygen, nitrogen, carbon, iron etc., and the titanic supernova explosions scatter this material back into space where it is used to create new generations of stars. This is the mechanism by which the gas and dust that formed our solar system became enriched with the elements that sustain life on this planet. Hubble spectroscopic observations will be used to determine the exact

  5. Ten years of experience with third and fourth branchial remnants.

    Science.gov (United States)

    Liberman, Moishe; Kay, Saundra; Emil, Sherif; Flageole, Hélène; Nguyen, Luong T; Tewfik, Ted L; Oudjhane, Kamal; Laberge, Jean-Martin

    2002-05-01

    Third and fourth branchial remnants may result in cysts and abscesses that are in close contact with the thyroid gland. These anomalies are rare and often present diagnostic and therapeutic challenges. The charts of patients diagnosed with a branchial anomaly between July 1991 and July 2001 at the Montreal Children's Hospital were reviewed. All cases of third and fourth branchial remnants or pyriform sinus fistulae were identified. Clinical presentation, imaging, treatment, and outcome were recorded. Eight patients with a third or fourth branchial anomaly were identified and ranged in age from birth to 13 years. All anomalies were left sided. Presenting symptoms consisted of an asymptomatic cervical mass (n = 1), an infected mass (n = 5), neonatal respiratory distress (n = 1), and 1 incidental cyst found on magnetic resonance imaging. Ultrasonography was useful in suggesting the diagnosis in 7 cases. Barium swallow was performed in 3 patients with 2 positive results. Pharyngoscopy results showed the internal opening in 2 of 7 patients. A portion of the thyroid gland was resected in 6 patients. One patient has not yet undergone a definitive procedure. There was 1 recurrence in a patient whose pathology did not confirm a branchial remnant. The diagnosis and management of pyriform sinus anomalies are challenging. Ultrasound scan, computed tomography scan, barium swallow, and pharyngoscopy are all useful. The portion of thyroid involved in the fistula must be excised en bloc with the inflammatory mass, and the tract should be ligated at the level of the pharynx to minimize recurrence. Copyright 2002, Elsevier Science (USA). All rights reserved.

  6. Remarks on Remnants by Fermions’ Tunnelling from Black Strings

    Directory of Open Access Journals (Sweden)

    Deyou Chen

    2014-01-01

    Full Text Available Hawking’s calculation is unable to predict the final stage of the black hole evaporation. When effects of quantum gravity are taken into account, there is a minimal observable length. In this paper, we investigate fermions’ tunnelling from the charged and rotating black strings. With the influence of the generalized uncertainty principle, the Hawking temperatures are not only determined by the rings, but also affected by the quantum numbers of the emitted fermions. Quantum gravity corrections slow down the increases of the temperatures, which naturally leads to remnants left in the evaporation.

  7. Radio and X-ray emission from newly born remnants

    International Nuclear Information System (INIS)

    Salvati, M.

    1983-01-01

    Radio and X-ray observations of SN 1979c and SN 1980k offer a unique opportunity of monitoring the transition from supernovae to remnants. By means of the two-frequency radio light curves, the hypothesis that these objects are surrounded by circumstellar matter, originated in a presupernova wind, is tested, and the relevant parameters are derived. Then the absorption-corrected light curves are used to test the various proposed models. SN 1980k appears to be powered by a canonical shock, while SN 1979c is a good plerion candidate. An optical pulsar could still be detected at its location. (Auth.)

  8. Radio and X-ray emission from supernova remnants

    International Nuclear Information System (INIS)

    Asvarova, A.I.; Novruzova, H.I.; Ahmedova, S.I.

    2010-01-01

    In this paper it was studied the statistical correlation between radio and X-ray emissions from shell-type supernova remnants (SNR). The primary aim of this study is to test the model of radio emission of shell-type SNRs presented by one of the authors. Based on this model of radio emission, by using the Monte Carlo techniques we have simulated statistical relations radio - X-ray luminosities (not surface brightnesses) which then were compared with the observations. X-ray emission is assumed to be thermal. To have a uniform statistical material it was used observational data on the SNRs in Magellanic Clouds

  9. A 3D View of a Supernova Remnant

    Science.gov (United States)

    Kohler, Susanna

    2017-06-01

    The outlined regions mark the 57 knots in Tycho selected by the authors for velocity measurements. Magenta regions have redshifted line-of-sight velocities (moving away from us); cyan regions have blueshifted light-of-sight velocities (moving toward us). [Williams et al. 2017]The Tycho supernova remnant was first observed in the year 1572. Nearly 450 years later, astronomers have now used X-ray observations of Tycho to build the first-ever 3D map of a Type Ia supernova remnant.Signs of ExplosionsSupernova remnants are spectacular structures formed by the ejecta of stellar explosions as they expand outwards into the surrounding interstellar medium.One peculiarity of these remnants is that they often exhibit asymmetries in their appearance and motion. Is this because the ejecta are expanding into a nonuniform interstellar medium? Or was the explosion itself asymmetric? The best way we can explore this question is with detailed observations of the remnants.Histograms of the velocity in distribution of the knots in the X (green), Y (blue) and Z (red) directions (+Z is away from the observer). They show no evidence for asymmetric expansion of the knots. [Williams et al. 2017]Enter TychoTo this end, a team of scientists led by Brian Williams (Space Telescope Science Institute and NASA Goddard SFC) has worked to map out the 3D velocities of the ejecta in the Tycho supernova remnant. Tycho is a Type Ia supernova thought to be caused by the thermonuclear explosion of a white dwarf in a binary system that was destabilized by mass transfer from its companion.After 450 years of expansion, the remnant now has the morphological appearance of a roughly circular cloud of clumpy ejecta. The forward shock wave from the supernova, however, is known to have twice the velocity on one side of the shell as on the other.To better understand this asymmetry, Williams and collaborators selected a total of 57 knots in Tychos ejecta, spread out around the remnant. They then used 12 years of

  10. Minerals Yearbook, volume I, Metals and Minerals

    Science.gov (United States)

    ,

    2018-01-01

    The U.S. Geological Survey (USGS) Minerals Yearbook discusses the performance of the worldwide minerals and materials industries and provides background information to assist in interpreting that performance. Content of the individual Minerals Yearbook volumes follows:Volume I, Metals and Minerals, contains chapters about virtually all metallic and industrial mineral commodities important to the U.S. economy. Chapters on survey methods, summary statistics for domestic nonfuel minerals, and trends in mining and quarrying in the metals and industrial mineral industries in the United States are also included.Volume II, Area Reports: Domestic, contains a chapter on the mineral industry of each of the 50 States and Puerto Rico and the Administered Islands. This volume also has chapters on survey methods and summary statistics of domestic nonfuel minerals.Volume III, Area Reports: International, is published as four separate reports. These regional reports contain the latest available minerals data on more than 180 foreign countries and discuss the importance of minerals to the economies of these nations and the United States. Each report begins with an overview of the region’s mineral industries during the year. It continues with individual country chapters that examine the mining, refining, processing, and use of minerals in each country of the region and how each country’s mineral industry relates to U.S. industry. Most chapters include production tables and industry structure tables, information about Government policies and programs that affect the country’s mineral industry, and an outlook section.The USGS continually strives to improve the value of its publications to users. Constructive comments and suggestions by readers of the Minerals Yearbook are welcomed.

  11. Remnant trees affect species composition but not structure of tropical second-growth forest.

    Science.gov (United States)

    Sandor, Manette E; Chazdon, Robin L

    2014-01-01

    Remnant trees, spared from cutting when tropical forests are cleared for agriculture or grazing, act as nuclei of forest regeneration following field abandonment. Previous studies on remnant trees were primarily conducted in active pasture or old fields abandoned in the previous 2-3 years, and focused on structure and species richness of regenerating forest, but not species composition. Our study is among the first to investigate the effects of remnant trees on neighborhood forest structure, biodiversity, and species composition 20 years post-abandonment. We compared the woody vegetation around individual remnant trees to nearby plots without remnant trees in the same second-growth forests ("control plots"). Forest structure beneath remnant trees did not differ significantly from control plots. Species richness and species diversity were significantly higher around remnant trees. The species composition around remnant trees differed significantly from control plots and more closely resembled the species composition of nearby old-growth forest. The proportion of old-growth specialists and generalists around remnant trees was significantly greater than in control plots. Although previous studies show that remnant trees may initially accelerate secondary forest growth, we found no evidence that they locally affect stem density, basal area, and seedling density at later stages of regrowth. Remnant trees do, however, have a clear effect on the species diversity, composition, and ecological groups of the surrounding woody vegetation, even after 20 years of forest regeneration. To accelerate the return of diversity and old-growth forest species into regrowing forest on abandoned land, landowners should be encouraged to retain remnant trees in agricultural or pastoral fields.

  12. Laboratory of minerals purification

    International Nuclear Information System (INIS)

    2002-01-01

    The laboratory of minerals purification was organized in 1962 where with application of modern physical and chemical methods were investigated the mechanism of flotation reagents interaction with minerals' surface, was elaborated technologies on rising complexity of using of republic's minerals

  13. A modified theoretical Σ − D relation for supernova remnants: I. The case of constant temperature within the supernova remnant

    Directory of Open Access Journals (Sweden)

    Urošević Dejan V.

    2003-01-01

    Full Text Available We present a modification of the theoretical Σ − D relation for supernova remnants (SNRs in the adiabatic expansion phase. This modification is based on the convolution of the relation first derived by Shklovsky with the Σ − D relation derived in this paper for thermal bremsstrahlung radiation from the ionized gas cloud. We adopt McKee & Ostriker’s model for the components of the interstellar medium as part of our derivation. The modified Shklovsky theory agrees well with empirical results. Kesteven’s modified theoretical relation gives the best agreement with the updated Galactic empirical Σ − D relation.

  14. Improved optical spectrophotometry of supernova remnants in M33

    Science.gov (United States)

    Blair, W. P.; Kirshner, R. P.

    1985-01-01

    Optical spectra of SNRs in M33 have been used to investigate abundance gradients and SNR evolution in this galaxy. Abundances of O, N, and S are derived from the spectra using new shock models by Dopita et al. (1984). The results for N and S show abundance gradients similar to those in NGC 300 and the Galaxy. The O abundances may be affected by possible contamination from H II regions and low-velocity shocks. Electron densities derived from the forbidden S II 6717 A/6731 A line ratio are used with a pressure equilibrium argument to estimate the initial explosion energy for each SNR. Evolutionary models for the remnants are investigated, and the distribution of the number of remnants with diameter is found to be consistent with free expansion of the SNRs to diameters of about 26 pc. The results may also be consistent with Sedov evolution if the ranges of initial supernova energies and surrounding interstellar medium densities are large enough.

  15. DESTRUCTION OF INTERSTELLAR DUST IN EVOLVING SUPERNOVA REMNANT SHOCK WAVES

    International Nuclear Information System (INIS)

    Slavin, Jonathan D.; Dwek, Eli; Jones, Anthony P.

    2015-01-01

    Supernova generated shock waves are responsible for most of the destruction of dust grains in the interstellar medium (ISM). Calculations of the dust destruction timescale have so far been carried out using plane parallel steady shocks, however, that approximation breaks down when the destruction timescale becomes longer than that for the evolution of the supernova remnant (SNR) shock. In this paper we present new calculations of grain destruction in evolving, radiative SNRs. To facilitate comparison with the previous study by Jones et al., we adopt the same dust properties as in that paper. We find that the efficiencies of grain destruction are most divergent from those for a steady shock when the thermal history of a shocked gas parcel in the SNR differs significantly from that behind a steady shock. This occurs in shocks with velocities ≳200 km s −1 for which the remnant is just beginning to go radiative. Assuming SNRs evolve in a warm phase dominated ISM, we find dust destruction timescales are increased by a factor of ∼2 compared to those of Jones et al., who assumed a hot gas dominated ISM. Recent estimates of supernova rates and ISM mass lead to another factor of ∼3 increase in the destruction timescales, resulting in a silicate grain destruction timescale of ∼2–3 Gyr. These increases, while not able to resolve the problem of the discrepant timescales for silicate grain destruction and creation, are an important step toward understanding the origin and evolution of dust in the ISM

  16. RADIO POLARIMETRY SIGNATURES OF STRONG MAGNETIC TURBULENCE IN SUPERNOVA REMNANTS

    International Nuclear Information System (INIS)

    Stroman, Wendy; Pohl, Martin

    2009-01-01

    We discuss the emission and transport of polarized radio-band synchrotron radiation near the forward shocks of young shell-type supernova remnants, for which X-ray data indicate a strong amplification of turbulent magnetic field. Modeling the magnetic turbulence through the superposition of waves, we calculate the degree of polarization and the magnetic polarization direction which is at 90 deg. to the conventional electric polarization direction. We find that isotropic strong turbulence will produce weakly polarized radio emission even in the absence of internal Faraday rotation. If anisotropy is imposed on the magnetic-field structure, the degree of polarization can be significantly increased, provided internal Faraday rotation is inefficient. Both for shock compression and a mixture with a homogeneous field, the increase in polarization degree goes along with a fairly precise alignment of the magnetic-polarization angle with the direction of the dominant magnetic-field component, implying tangential magnetic polarization at the rims in the case of shock compression. We compare our model with high-resolution radio polarimetry data of Tycho's remnant. Using the absence of internal Faraday rotation we find a soft limit for the amplitude of magnetic turbulence, δB ∼ 0 . An alternative viable scenario involves anisotropic turbulence with stronger amplitudes in the radial direction, as was observed in recent Magnetohydrodynamics simulations of shocks propagating through a medium with significant density fluctuations.

  17. [Management of urachal remnants in children: Is surgical excision mandatory?].

    Science.gov (United States)

    Heuga, B; Mouttalib, S; Bouali, O; Juricic, M; Galinier, P; Abbo, O

    2015-09-01

    The classical management of urachal remants consists in surgical resection, in order to prevent infections and long term malignancies. However, some reports have recently spread a wait and see management. The aim of our study was to report the results of the surgical management in our center. We conducted a retrospective, monocentric review of all patients managed for urachal remnants from January 2005 to December 2014. Thirty-five patients have been operated during the study period (18 girls and 17 boys). Mean age at surgery was 4,9±4,4 years old. Twenty-seven patients were referred due to symptoms whereas 8 were discovered incidentally (4 by ultrasound scan and 4 during laparoscopy). Among them, 10 were urachal cysts, 15 were urachus sinusa and 10 were patent urachus. Thirty were operated using an open approach and 5 using a laparoscopic approach. Mean length of stay was 3,8±1,7days (1-10) with a mean duration of bladder drainage of 2,5±1 days. No major complications occurred. No abnormal tissue was discovered at the histological analysis. Presentation of urachal remnants is variable but surgical outcomes remain excellent in our experience. When symptoms occur, the surgical decision is easy, but when the diagnosis is incidental, the decision is much more complicated. Official guidelines could ease the decision process and the management of urachal anomalies. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  18. FERMI LARGE AREA TELESCOPE OBSERVATION OF SUPERNOVA REMNANT S147

    Energy Technology Data Exchange (ETDEWEB)

    Katsuta, J.; Uchiyama, Y.; Tanaka, T.; Tajima, H.; Bechtol, K.; Funk, S.; Lande, J. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d' Astrophysique, CEA Saclay, 91191 Gif sur Yvette (France); Hanabata, Y. [Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Lemoine-Goumard, M. [Universite Bordeaux 1, CNRS/IN2p3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, 33175 Gradignan (France); Takahashi, T., E-mail: katsuta@slac.stanford.edu, E-mail: uchiyama@slac.stanford.edu [Institute of Space and Astronautical Science, Japanese Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)

    2012-06-20

    We present an analysis of gamma-ray data obtained with the Large Area Telescope on board the Fermi Gamma-ray Space Telescope in the region around supernova remnant (SNR) S147 (G180.0-1.7). A spatially extended gamma-ray source detected in an energy range of 0.2-10 GeV is found to coincide with SNR S147. We confirm its spatial extension at >5{sigma} confidence level. The gamma-ray flux is (3.8 {+-} 0.6) Multiplication-Sign 10{sup -8} photons cm{sup -2} s{sup -1}, corresponding to a luminosity of 1.3 Multiplication-Sign 10{sup 34} (d/1.3 kpc){sup 2} erg s{sup -1} in this energy range. The gamma-ray emission exhibits a possible spatial correlation with the prominent H{alpha} filaments of SNR S147. There is no indication that the gamma-ray emission comes from the associated pulsar PSR J0538+2817. The gamma-ray spectrum integrated over the remnant is likely dominated by the decay of neutral {pi} mesons produced through the proton-proton collisions in the filaments. The reacceleration of the pre-existing cosmic rays and subsequent adiabatic compression in the filaments is sufficient to provide the energy density required of high-energy protons.

  19. Population III Stars and Remnants in High-redshift Galaxies

    Science.gov (United States)

    Xu, Hao; Wise, John H.; Norman, Michael L.

    2013-08-01

    Recent simulations of Population III star formation have suggested that some fraction form in binary systems, in addition to having a characteristic mass of tens of solar masses. The deaths of metal-free stars result in the initial chemical enrichment of the universe and the production of the first stellar-mass black holes. Here we present a cosmological adaptive mesh refinement simulation of an overdense region that forms a few 109 M ⊙ dark matter halos and over 13,000 Population III stars by redshift 15. We find that most halos do not form Population III stars until they reach M vir ~ 107 M ⊙ because this biased region is quickly enriched from both Population III and galaxies, which also produce high levels of ultraviolet radiation that suppress H2 formation. Nevertheless, Population III stars continue to form, albeit in more massive halos, at a rate of ~10-4 M ⊙ yr-1 Mpc-3 at redshift 15. The most massive starless halo has a mass of 7 × 107 M ⊙, which could host massive black hole formation through the direct gaseous collapse scenario. We show that the multiplicity of the Population III remnants grows with halo mass above 108 M ⊙, culminating in 50 remnants located in 109 M ⊙ halos on average. This has implications that high-mass X-ray binaries and intermediate-mass black holes that originate from metal-free stars may be abundant in high-redshift galaxies.

  20. Dust in Supernovae and Supernova Remnants II: Processing and Survival

    Science.gov (United States)

    Micelotta, E. R.; Matsuura, M.; Sarangi, A.

    2018-03-01

    Observations have recently shown that supernovae are efficient dust factories, as predicted for a long time by theoretical models. The rapid evolution of their stellar progenitors combined with their efficiency in precipitating refractory elements from the gas phase into dust grains make supernovae the major potential suppliers of dust in the early Universe, where more conventional sources like Asymptotic Giant Branch (AGB) stars did not have time to evolve. However, dust yields inferred from observations of young supernovae or derived from models do not reflect the net amount of supernova-condensed dust able to be expelled from the remnants and reach the interstellar medium. The cavity where the dust is formed and initially resides is crossed by the high velocity reverse shock which is generated by the pressure of the circumstellar material shocked by the expanding supernova blast wave. Depending on grain composition and initial size, processing by the reverse shock may lead to substantial dust erosion and even complete destruction. The goal of this review is to present the state of the art about processing and survival of dust inside supernova remnants, in terms of theoretical modelling and comparison to observations.

  1. South Africa's mineral industry

    International Nuclear Information System (INIS)

    1985-06-01

    The main aim of the Minerals Bureau in presenting this annual review is to provide an up-to-date reference document on the current state of the mineral industry in South Africa. This includes a brief look at the production, trade, economy, resources and deposits of precious metals and minerals, energy minerals, metallic minerals, and non-metallic minerals. One article discusses the production, trade, export, deposits and economy of uranium

  2. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    compounds these must first be undergo extracellular hydrolysis. Bacteria have a great diversity with respect to types of metabolism that far exceeds the metabolic repertoire of eukaryotic organisms. Bacteria play a fundamental role in the biosphere and certain key processes such as, for example......, the production and oxidation of methane, nitrate reduction and fixation of atmospheric nitrogen are exclusively carried out by different groups of bacteria. Some bacterial species – ‘extremophiles’ – thrive in extreme environments in which no eukaryotic organisms can survive with respect to temperature, salinity...... biogeochemical processes are carried exclusively by bacteria. * Bacteria play an important role in all types of habitats including some that cannot support eukaryotic life....

  3. A blowout numerical model for the supernova remnant G352.7-0.1

    OpenAIRE

    Toledo Roy, J. C.; Velazquez, P. F.; Esquivel, A.; Giacani, Elsa Beatriz

    2017-01-01

    We present 3D hydrodynamical simulations of the Galactic supernova remnant G352.7−0.1. This remnant is peculiar for having a shell-like inner ring structure and an outer arc in radio observations. In our model, the supernova explosion producing the remnant occurs inside and near the border of a spherical cloud with a density higher than that of the surrounding interstellar medium. A blowout is produced when the remnant reaches the border of the cloud. We have then used the results of our hydr...

  4. Pancreatic Cancer Arising From the Remnant Pancreas: Is It a Local Recurrence or New Primary Lesion?

    Science.gov (United States)

    Hashimoto, Daisuke; Chikamoto, Akira; Masuda, Toshiro; Nakagawa, Shigeki; Imai, Katsunori; Yamashita, Yo-Ichi; Reber, Howard A; Baba, Hideo

    2017-10-01

    Local recurrence of pancreatic cancer (PC) can occur in the pancreatic remnant. In addition, new primary PC can develop in the remnant. There are limited data available regarding this so-called remnant PC. The aim of this review was to describe the characteristics and therapeutic strategy regarding remnant PC. A literature search was performed using Medline published in English according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The incidence of remnant PC has been reported to be 3% to 5%. It is difficult to distinguish local recurrence from new primary PC. Genetic diagnosis such as Kirsten rat sarcoma viral oncogene homolog mutation may resolve this problem. For patients with remnant PC, repeated pancreatectomy can be performed. Residual total pancreatectomy is the most common procedure. Recent studies have described the safety of the operation because of recent surgical progress and perioperative care. The patients with remnant PC without distant metastasis have shown good long-term outcomes, especially those who underwent repeated pancreatectomy. Adjuvant chemotherapy may contribute to longer survival. In conclusion, this review found that both local recurrence and new primary PC can develop in the pancreatic remnant. Repeated pancreatectomy for the remnant PC is a feasible procedure and can prolong patient survival.

  5. Bacterial Actins.

    Science.gov (United States)

    Izoré, Thierry; van den Ent, Fusinita

    2017-01-01

    A diverse set of protein polymers, structurally related to actin filaments contributes to the organization of bacterial cells as cytomotive or cytoskeletal filaments. This chapter describes actin homologs encoded by bacterial chromosomes. MamK filaments, unique to magnetotactic bacteria, help establishing magnetic biological compasses by interacting with magnetosomes. Magnetosomes are intracellular membrane invaginations containing biomineralized crystals of iron oxide that are positioned by MamK along the long-axis of the cell. FtsA is widespread across bacteria and it is one of the earliest components of the divisome to arrive at midcell, where it anchors the cell division machinery to the membrane. FtsA binds directly to FtsZ filaments and to the membrane through its C-terminus. FtsA shows altered domain architecture when compared to the canonical actin fold. FtsA's subdomain 1C replaces subdomain 1B of other members of the actin family and is located on the opposite side of the molecule. Nevertheless, when FtsA assembles into protofilaments, the protofilament structure is preserved, as subdomain 1C replaces subdomain IB of the following subunit in a canonical actin filament. MreB has an essential role in shape-maintenance of most rod-shaped bacteria. Unusually, MreB filaments assemble from two protofilaments in a flat and antiparallel arrangement. This non-polar architecture implies that both MreB filament ends are structurally identical. MreB filaments bind directly to membranes where they interact with both cytosolic and membrane proteins, thereby forming a key component of the elongasome. MreB filaments in cells are short and dynamic, moving around the long axis of rod-shaped cells, sensing curvature of the membrane and being implicated in peptidoglycan synthesis.

  6. Miscellaneous Industrial Mineral Operations

    Data.gov (United States)

    Department of Homeland Security — This map layer includes miscellaneous industrial minerals operations in the United States. The data represent commodities covered by the Minerals Information Team...

  7. Minerals from Macedonia: XV. Sivec mineral assemble

    International Nuclear Information System (INIS)

    Boev, Blazho; Jovanovski, Gligor; Makreski, Petre; Bermanec, Vladimir

    2005-01-01

    The paper presents investigations carried out on the collected minerals from the Sivec deposit. It is situated in the vicinity of the town of Prilep, representing a rare occurrence of sugary white dolomite marbles. The application of suitable methods of exploitation of decorative-dimension stones makes possible to obtain large amounts of commercial blocks well known in the world. Despite the existence of dolomite marbles, a series of exotic minerals are typical in Sivec mineralization. Among them, the most significant are: calcite, fluorite, rutile, phlogopite, corundum, diaspore, almandine, kosmatite (clintonite or margarite), clinochlore, muscovite, quartz, pyrite, tourmaline and zoisite. An attempt to identify ten collected minerals using the FT IR spectroscopy is performed. The identification of the minerals was based on the comparison of the infrared spectra of our specimens with the corresponding literature data for the mineral species originating all over the world. The coloured pictures of all studied silicate minerals are presented as well. (Author)

  8. NUMERICAL STUDY OF THE VISHNIAC INSTABILITY IN SUPERNOVA REMNANTS

    International Nuclear Information System (INIS)

    Michaut, C.; Cavet, C.; Bouquet, S. E.; Roy, F.; Nguyen, H. C.

    2012-01-01

    The Vishniac instability is thought to explain the complex structure of radiative supernova remnants in their Pressure-Driven Thin Shell (PDTS) phase after a blast wave (BW) has propagated from a central explosion. In this paper, the propagation of the BW and the evolution of the PDTS stage are studied numerically with the two-dimensional (2D) code HYDRO-MUSCL for a finite-thickness shell expanding in the interstellar medium (ISM). Special attention is paid to the adiabatic index, γ, and three distinct values are taken for the cavity (γ 1 ), the shell (γ 2 ), and the ISM (γ 3 ) with the condition γ 2 1 , γ 3 . This low value of γ 2 accounts for the high density in the shell achieved by a strong radiative cooling. Once the spherical background flow is obtained, the evolution of a 2D-axisymmetric perturbation is computed from the linear to the nonlinear regime. The overstable mechanism, previously demonstrated theoretically by E. T. Vishniac in 1983, is recovered numerically in the linear stage and is expected to produce and enhance anisotropies and clumps on the shock front, leading to the disruption of the shell in the nonlinear phase. The period of the increasing oscillations and the growth rate of the instability are derived from several points of view (the position of the perturbed shock front, mass fluxes along the shell, and density maps), and the most unstable mode differing from the value given by Vishniac is computed. In addition, the influence of several parameters (the Mach number, amplitude and wavelength of the perturbation, and adiabatic index) is examined and for wavelengths that are large enough compared to the shell thickness, the same conclusion arises: in the late stage of the evolution of the radiative supernova remnant, the instability is dampened and the angular initial deformation of the shock front is smoothed while the mass density becomes uniform with the angle. As a result, our model shows that the supernova remnant returns to a

  9. A novel mineral flotation process using Thiobacillus ferrooxidans.

    Science.gov (United States)

    Nagaoka, T; Ohmura, N; Saiki, H

    1999-08-01

    Oxidative leaching of metals by Thiobacillus ferrooxidans has proven useful in mineral processing. Here, we report on a new use for T. ferrooxidans, in which bacterial adhesion is used to remove pyrite from mixtures of sulfide minerals during flotation. Under control conditions, the floatabilities of five sulfide minerals tested (pyrite, chalcocite, molybdenite, millerite, and galena) ranged from 90 to 99%. Upon addition of T. ferrooxidans, the floatability of pyrite was significantly suppressed to less than 20%. In contrast, addition of the bacterium had little effect on the floatabilities of the other minerals, even when they were present in relatively large quantities: their floatabilities remained in the range of 81 to 98%. T. ferrooxidans thus appears to selectively suppress pyrite floatability. As a consequence, 77 to 95% of pyrite was removed from mineral mixtures while 72 to 100% of nonpyrite sulfide minerals was recovered. The suppression of pyrite floatability was caused by bacterial adhesion to pyrite surfaces. When normalized to the mineral surface area, the number of cells adhering to pyrite was significantly larger than the number adhering to other minerals. These results suggest that flotation with T. ferrooxidans may provide a novel approach to mineral processing in which the biological functions involved in cell adhesion play a key role in the separation of minerals.

  10. Detection of explosive remnants of war by neutron thermalisation

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, F.D., E-mail: frank.brooks@uct.ac.za [Department of Physics, University of Cape Town, Rondebosch 7701 (South Africa); Drosg, M. [Faculty of Physics, University of Vienna, Wien A-1090 (Austria); Smit, F.D.; Wikner, C. [iThemba Laboratory for Accelerator-Based Sciences, Somerset West 7129 (South Africa)

    2012-01-15

    The HYDAD-D landmine detector () has been modified and field-tested for 17 months in a variety of soil conditions. Test objects containing about the same mass of hydrogen (20 g) as small explosive remnants of war, such as antipersonnel landmines, were detected with efficiency 100% when buried at cover depths up to 10 cm. The false alarm rate under the same conditions was 9%. Plots of detection efficiency versus false alarm rate are presented. - Highlights: Black-Right-Pointing-Pointer A new version of the HYDAD-D antipersonnel landmine detector is described. Black-Right-Pointing-Pointer Field tests were carried out for 17 months under different conditions. Black-Right-Pointing-Pointer Dummy antipersonnel mines were detected with 100% efficiency at cover depths up to 10 cm. Black-Right-Pointing-Pointer Results are presented as plots of landmine detection efficiency versus false alarm rate.

  11. Compact binary merger and kilonova: outflows from remnant disc

    Science.gov (United States)

    Yi, Tuan; Gu, Wei-Min; Liu, Tong; Kumar, Rajiv; Mu, Hui-Jun; Song, Cui-Ying

    2018-05-01

    Outflows launched from a remnant disc of compact binary merger may have essential contribution to the kilonova emission. Numerical calculations are conducted in this work to study the structure of accretion flows and outflows. By the incorporation of limited-energy advection in the hyper-accretion discs, outflows occur naturally from accretion flows due to imbalance between the viscous heating and the sum of the advective and radiative cooling. Following this spirit, we revisit the properties of the merger outflow ejecta. Our results show that around 10-3 ˜ 10-1 M⊙ of the disc mass can be launched as powerful outflows. The amount of unbound mass varies with the disc mass and the viscosity. The outflow-contributed peak luminosity is around 1040 ˜ 1041 erg s-1. Such a scenario can account for the observed kilonovae associated with short gamma-ray bursts, including the recent event AT2017gfo (GW170817).

  12. Shocked molecular hydrogen in the supernova remnant IC 443

    International Nuclear Information System (INIS)

    Burton, M.G.; Brand, P.W.J.L.; Webster, A.S.

    1988-01-01

    Emission from the υ = 1-0 S(1) line of molecular hydrogen has been mapped over a section of the supernova remnant IC 443. The emission originates in a sinuous ridge where the expanding shell of the SNR is interacting with a molecular cloud. The relative intensities of the 1-0 S(1), 1-0 S(0) and 2-1 S(1) lines at 2.1-2.2 μm were measured and found to be characteristic of shock-excitation of the gas. The ridge shows bright spots which are possibly density enhancements in the molecular cloud. The total luminosity of the molecular hydrogen lines in the mapped region is estimated to be about 1000 times the solar luminosity, making IC 443 one of the most luminous galactic molecular hydrogen sources yet detected. (author)

  13. New selection effect of statistical investigations of supernova remnants

    International Nuclear Information System (INIS)

    Allakhverdiev, A.O.; Gusejnov, O.Kh.; Kasumov, F.K.

    1986-01-01

    The influence of H2 regions on the parameters of Supernova remnants (SNR) is investigated. It has been shown that the projection of such regions on the SNRs leads to local changes of morphological structure of young shell-type SNRs and considerable distortions of integral parameters of evolved shell-type SNRs (with D > 10 pc) and plerions, up to their complete undetectability on the background of classical and gigantic H2 regions. A new selection effect, in fact, arises from these factors connected with additional limitations made by the real structure of the interstellar medium on the statistical investigations of SNRs. The influence of this effect on the statistical completeness of objects has been estimated

  14. New selection effect in statistical investigations of supernova remnants

    Science.gov (United States)

    Allakhverdiev, A. O.; Guseinov, O. Kh.; Kasumov, F. K.

    1986-01-01

    The influence of H II regions on the parameters of supernova remnants (SNR) is investigated. It has been shown that the projection of such regions on the SNRs leads to: a) local changes of morphological structure of young shell-type SNRs and b) considerable distortions of integral parameters of evolved shell-type SNRs (with D > 10 pc) and plerions, up to their complete undetectability on the background of classical and gigantic H II regions. A new selection effect, in fact, arises from these factors connected with additional limitations made by the real structure of the interstellar medium on the statistical investigations of SNRs. The influence of this effect on the statistical completeness of objects has been estimated.

  15. Grain Destruction in a Supernova Remnant Shock Wave

    Science.gov (United States)

    Raymond, John C.; Ghavamian, Parviz; Williams, Brian J.; Blair, William P.; Borkowski, Kazimierz J.; Gaetz, Terrance J.; Sankrit, Ravi

    2014-01-01

    Dust grains are sputtered away in the hot gas behind shock fronts in supernova remnants, gradually enriching the gas phase with refractory elements. We have measured emission in C IV (lambda)1550 from C atoms sputtered from dust in the gas behind a non-radiative shock wave in the northern Cygnus Loop. Overall, the intensity observed behind the shock agrees approximately with predictions from model calculations that match the Spitzer 24 micron and the X-ray intensity profiles. Thus these observations confirm the overall picture of dust destruction in SNR shocks and the sputtering rates used in models. However, there is a discrepancy in that the CIV intensity 10'' behind the shock is too high compared to the intensities at the shock and 25'' behind it. Variations in the density, hydrogen neutral fraction and the dust properties over parsec scales in the pre- shock medium limit our ability to test dust destruction models in detail.

  16. Approximate supernova remnant dynamics with cosmic ray production

    International Nuclear Information System (INIS)

    Voelk, H.J.; Drury, L.O.; Dorfi, E.A.

    1985-01-01

    Supernova explosions are the most violent and energetic events in the galaxy and have long been considered probable sources of cosmic rays. Recent shock acceleration models treating the cosmic rays (CR's) as test particles nb a prescribed supernova remnant (SNR) evolution, indeed indicate an approximate power law momentum distribution f sub source (p) approximation p(-a) for the particles ultimately injected into the interstellar medium (ISM). This spectrum extends almost to the momentum p = 1 million GeV/c, where the break in the observed spectrum occurs. The calculated power law index approximately less than 4.2 agrees with that inferred for the galactic CR sources. The absolute CR intensity can however not be well determined in such a test particle approximation

  17. Approximate supernova remnant dynamics with cosmic ray production

    Science.gov (United States)

    Voelk, H. J.; Drury, L. O.; Dorfi, E. A.

    1985-01-01

    Supernova explosions are the most violent and energetic events in the galaxy and have long been considered probably sources of Cosmic Rays. Recent shock acceleration models treating the Cosmic Rays (CR's) as test particles nb a prescribed Supernova Remnant (SNR) evolution, indeed indicate an approximate power law momentum distribution f sub source (p) approximation p(-a) for the particles ultimately injected into the Interstellar Medium (ISM). This spectrum extends almost to the momentum p = 1 million GeV/c, where the break in the observed spectrum occurs. The calculated power law index approximately less than 4.2 agrees with that inferred for the galactic CR sources. The absolute CR intensity can however not be well determined in such a test particle approximation.

  18. Diffuse remnants of supernova explosions of moving massive stars

    Science.gov (United States)

    Gvaramadze, V. V.

    The modification of the ambient interstellar medium by the wind of massive stars (the progenitors of most of supernovae) results in that the structure and evolution of diffuse supernova remnants (SNRs) significantly deviate from those derived from standard models of SNRs based of the Sedov-Taylor solution. The stellar proper motion and the regular interstellar magnetic field affect the symmetry of the processed medium and cause the SNR to be non-spherically-symmetric. We show that taking into account these effects allows us to explain the diverse morphologies of the known SNRs (the particular attention is paid to the elongated axisymmetric SNRs and the SNRs consisting of two partially overlapping shells) and to infer the ``true" supernova explosion sites in some peculiar SNRs (therefore to search for new neutron stars associated with them).

  19. Remnants of black rings from gravity’s rainbow

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Ahmed Farag [Center for Fundamental Physics, Zewail City of Science and Technology,6th of October City, Giza 12588 (Egypt); Department of Physics, Faculty of Science, Benha University,Benha 13518 (Egypt); Faizal, Mir [Department of Physics and Astronomy, University of Waterloo,Waterloo, Ontario, N2L 3G1 (Canada); Khalil, Mohammed M. [Department of Electrical Engineering, Alexandria University,El-Horreya Rd., Alexandria 12544 (Egypt)

    2014-12-29

    In this paper, we investigate a spinning black ring and a charged black ring in the context of gravity’s rainbow. By incorporating rainbow functions proposed by Amelino-Camelia, et al. in http://dx.doi.org/10.1142/S0217751X97000566 http://dx.doi.org/10.12942/lrr-2013-5 in the metric of the black rings, a considerable modification happens to their thermodynamical properties. We calculate corrections to the temperature, entropy and heat capacity of the black rings. These calculations demonstrate that the behavior of Hawking radiation changes considerably near the Planck scale in gravity’s rainbow, where it is shown that black rings do not evaporate completely and a remnant is left as the black rings evaporate down to Planck scale.

  20. Assessment of industrial minerals and rocks in the controlled area

    International Nuclear Information System (INIS)

    Castor, S.B.; Lock, D.E.

    1996-01-01

    Yucca Mountain in Nye County, Nevada, is a potential site for a permanent repository for high-level nuclear waste in Miocene ash flow tuff. The Yucca Mountain controlled area occupies approximately 98 km 2 that includes the potential repository site. The Yucca Mountain controlled area is located within the southwestern Nevada volcanic field, a large area of Miocene volcanism that includes at least four major calderas or cauldrons. It is sited on a remnant of a Neogene volcanic plateau that was centered around the Timber Mountain caldera complex. The Yucca Mountain region contains many occurrences of valuable or potentially valuable industrial minerals, including deposits with past or current production of construction aggregate, borate minerals, clay, building stone, fluorspar, silicate, and zeolites. The existence of these deposits in the region and the occurrence of certain mineral materials at Yucca Mountain, indicate that the controlled area may have potential for industrial mineral and rock deposits. Consideration of the industrial mineral potential within the Yucca Mountain controlled area is mainly based on petrographic and lithologic studies of samples from drill holes in Yucca Mountain. Clay minerals, zeolites, fluorite, and barite, as minerals that are produced economically in Nevada, have been identified in samples from drill holes in Yucca Mountain

  1. Assessment of industrial minerals and rocks in the controlled area

    Energy Technology Data Exchange (ETDEWEB)

    Castor, S.B. [Nevada Bureau of Mines and Geology, Reno, NV (United States); Lock, D.E. [Mackay School of Mines, Reno, NV (United States)

    1996-08-01

    Yucca Mountain in Nye County, Nevada, is a potential site for a permanent repository for high-level nuclear waste in Miocene ash flow tuff. The Yucca Mountain controlled area occupies approximately 98 km{sup 2} that includes the potential repository site. The Yucca Mountain controlled area is located within the southwestern Nevada volcanic field, a large area of Miocene volcanism that includes at least four major calderas or cauldrons. It is sited on a remnant of a Neogene volcanic plateau that was centered around the Timber Mountain caldera complex. The Yucca Mountain region contains many occurrences of valuable or potentially valuable industrial minerals, including deposits with past or current production of construction aggregate, borate minerals, clay, building stone, fluorspar, silicate, and zeolites. The existence of these deposits in the region and the occurrence of certain mineral materials at Yucca Mountain, indicate that the controlled area may have potential for industrial mineral and rock deposits. Consideration of the industrial mineral potential within the Yucca Mountain controlled area is mainly based on petrographic and lithologic studies of samples from drill holes in Yucca Mountain. Clay minerals, zeolites, fluorite, and barite, as minerals that are produced economically in Nevada, have been identified in samples from drill holes in Yucca Mountain.

  2. Supernova models with slow energy pumping and galactic supernova remnants

    International Nuclear Information System (INIS)

    Utrobin, V.P.

    1978-01-01

    The study of supernova (SN) models with slow energy pumping is continued. At maximum luminosity the main characteristics of a SN are shown to be independent of the initial structure of the model. However, they depend on the mass Msub(e) of the envelope, and on the intensity of energy pumping Lsub(epsilon), with an increase of Msub(e) leading qualitatively to the same changes in the SN parameters as a decrease in Lsub(epsilon). A simple relationship connecting the important SN parameters is obtained. From the inflection of the color index B-V curve, the possibility of deriving the characteristic time of energy pumping with intensity Lsub(epsilon) approximately 10 44 erg s -1 is pointed out. The comparison of the extragalactic type I SN observations with the results of calculations leads to the estimate of Msub(e) approximately 0.3-0.7 solar masses. An investigation of the galactic type I SN remnants is carried out. The estimate of Msub(e) approximately 0.2-0.3 solar masses is obtained for the remnants of supernovae SN 1006, SN 1572, and SN 1604. It completely fits the results for the extragalactic type I SNs. The total initial mass of SN 1604 presupernova was shown to be at least about 7 solar masses. It was established that the Crab nebula resulted from the outburst of a peculiar SN. The unique properties of such SNs, including SN 1054, are due to the low intensity of energy pumping (Lsub(epsilon) approximately 10 42 erg s -1 ). The mass of the envelope of the Crab nebula is evaluated to be Msub(e) approximately 0.7 solar masses. (Auth.)

  3. Supernova remnant W49B and its environment

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, H.; Tian, W. W.; Zuo, P., E-mail: zhuhui@bao.ac.cn, E-mail: tww@bao.ac.cn [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2014-10-01

    We study gamma-ray supernova remnant (SNR) W49B and its environment using recent radio and infrared data. Spitzer Infrared Spectrograph low resolution data of W49B shows shocked excitation lines of H{sub 2} (0,0) S(0)-S(7) from the SNR-molecular cloud interaction. The H{sub 2} gas is composed of two components with temperatures of ∼260 K and ∼1060 K, respectively. Various spectral lines from atomic and ionic particles are detected toward W49B. We suggest that the ionic phase has an electron density of ∼500 cm{sup –3} and a temperature of ∼10{sup 4} K by the spectral line diagnoses. The mid- and far-infrared data from MSX, Spitzer, and Herschel reveal a 151 ± 20 K hot dust component with a mass of 7.5 ± 6.6 × 10{sup –4} M {sub ☉} and a 45 ± 4 K warm dust component with a mass of 6.4 ± 3.2 M {sub ☉}. The hot dust is likely from materials swept up by the shock of W49B. The warm dust may possibly originate from the evaporation of clouds interacting with W49B. We build the H I absorption spectra of W49B and four nearby H II regions (W49A, G42.90+0.58, G42.43-0.26, and G43.19-0.53) and study the relation between W49B and the surrounding molecular clouds by employing the 2.12 μm infrared and CO data. We therefore obtain a kinematic distance of ∼10 kpc for W49B and suggest that the remnant is likely associated with the CO cloud at about 40 km s{sup –1}.

  4. Functional and morphological changes in pancreatic remnant after pancreaticoduodenectomy.

    Science.gov (United States)

    Fang, Wen-Liang; Su, Cheng-Hsi; Shyr, Yi-Ming; Chen, Tien-Hua; Lee, Rheun-Chuan; Tai, Ling-Chen; Wu, Chew-Wun; Lui, Wing-Yiu

    2007-11-01

    Pancreatic exocrine insufficiency has been reported to be more common in pancreaticogastrostomy (PG) than in pancreaticojejunostomy (PJ) after pancreaticoduodenectomy (PD). This study aimed to evaluate the long-term outcome after PD between these 2 groups. We evaluated the long-term functional status of 42 surviving patients diagnosed with periampullary lesions who underwent PJ or PG after PD and followed up for more than 1 year. Among these, 23 patients underwent PJ and 19 patients underwent PG. To compare the 2 groups, we analyzed the (1) pancreatic exocrine insufficiency by questioning the presence or absence of steatorrhea, (2) pancreatic endocrine function by measuring glycohemoglobin A1c, fasting blood glucose, and history of new-onset diabetes, (3) nutritional status by measuring serum total protein, albumin, cholesterol, and triglyceride, (4) gastric emptying time, (5) panendoscopic findings, (6) changes of pancreatic duct diameter by computed tomography, and (7) relaparotomy rate. The mean follow-up time for PG and PJ were 37 +/- 23 and 103 +/- 52 months, respectively (P pancreatic exocrine insufficiency, and 11.9% had new-onset diabetes. There was no significant difference between PJ and PG groups. A significantly improved postoperative nutritional state regarding serum total protein and albumin were noticed in both groups. There was no significant difference in terms of gastric emptying time, positive panendoscopic findings, and changes in pancreatic duct diameter. The pancreatic remnant-related relaparotomy rate was higher in the PJ group as compared with the PG group (17.4% vs 0%; P = 0.056). There is no significant difference in pancreatic exocrine or endocrine insufficiency, gastric emptying time, and positive panendoscopic findings between PJ and PG. Pancreaticojejunostomy was associated with a higher pancreatic remnant-related relaparotomy rate; however, because of a shorter follow-up in the PG group, a continuous long-term follow-up is still

  5. Hubble Space Telescope Image, Supernova Remnant Cassiopeia A

    Science.gov (United States)

    2000-01-01

    The colorful streamers that float across the sky in this photo taken by NASA's Hubble Space Telescope (HST) were created by the universe's biggest firecracker, the titanic supernova explosion of a massive star. The light from the exploding star reached Earth 320 years ago, nearly a century before the United States celebrated its birth with a bang. The dead star's shredded remains are called Cassiopeia A, or 'Cas A' for short. Cas A is the youngest known supernova remnant in our Milky Way Galaxy and resides 10,000 light-years away in the constellation Cassiopeia, so the star actually blew up 10,000 years before the light reached Earth in the late 1600s. This HST image of Cas A shows for the first time that the debris is arranged into thousands of small, cooling knots of gas. This material eventually will be recycled into building new generations of stars and planets. Our own Sun and planets are constructed from the debris of supernovae that exploded billions of years ago. This photo shows the upper rim of the super nova remnant's expanding shell. Near the top of the image are dozens of tiny clumps of matter. Each small clump, originally just a small fragment of the star, is tens of times larger than the diameter of our solar system. The colors highlight parts of the debris where chemical elements are glowing. The dark blue fragments, for example, are richest in oxygen; the red material is rich in sulfur. The images were taken with the Wide Field and Planetary Camera 2 in January 2000 and January 2002. Image Credit: NASA and HST team (Stoics/AURA). Acknowledgment: R. Fesen (Darmouth) and J. Morse ( Univ. of Colorado).

  6. POPULATION III STARS AND REMNANTS IN HIGH-REDSHIFT GALAXIES

    International Nuclear Information System (INIS)

    Xu Hao; Norman, Michael L.; Wise, John H.

    2013-01-01

    Recent simulations of Population III star formation have suggested that some fraction form in binary systems, in addition to having a characteristic mass of tens of solar masses. The deaths of metal-free stars result in the initial chemical enrichment of the universe and the production of the first stellar-mass black holes. Here we present a cosmological adaptive mesh refinement simulation of an overdense region that forms a few 10 9 M ☉ dark matter halos and over 13,000 Population III stars by redshift 15. We find that most halos do not form Population III stars until they reach M vir ∼ 10 7 M ☉ because this biased region is quickly enriched from both Population III and galaxies, which also produce high levels of ultraviolet radiation that suppress H 2 formation. Nevertheless, Population III stars continue to form, albeit in more massive halos, at a rate of ∼10 –4 M ☉ yr –1 Mpc –3 at redshift 15. The most massive starless halo has a mass of 7 × 10 7 M ☉ , which could host massive black hole formation through the direct gaseous collapse scenario. We show that the multiplicity of the Population III remnants grows with halo mass above 10 8 M ☉ , culminating in 50 remnants located in 10 9 M ☉ halos on average. This has implications that high-mass X-ray binaries and intermediate-mass black holes that originate from metal-free stars may be abundant in high-redshift galaxies

  7. Search and modelling of remnant radio galaxies in the LOFAR Lockman Hole field

    NARCIS (Netherlands)

    Brienza, M.; Godfrey, L.; Morganti, R.; Prandoni, I.; Harwood, J.; Mahony, E. K.; Hardcastle, M. J.; Murgia, M.; Röttgering, H. J. A.; Shimwell, T. W.; Shulevski, A.

    2017-01-01

    Context. The phase of radio galaxy evolution after the jets have switched off, often referred to as the remnant phase, is poorly understood and very few sources in this phase are known. Aims: In this work we present an extensive search for remnant radio galaxies in the Lockman Hole, a well-studied

  8. Effect of Hashimoto thyroiditis on low-dose radioactive-iodine remnant ablation.

    Science.gov (United States)

    Kwon, Hyungju; Choi, June Young; Moon, Jae Hoon; Park, Hyo Jin; Lee, Won Woo; Lee, Kyu Eun

    2016-04-01

    Radioactive-iodine remnant ablation is an integral part of the papillary thyroid carcinoma (PTC) treatment. Although a minimum dose is usually recommended, there is controversy as to whether the low-dose (1100 MBq) radioactive-iodine remnant ablation is adequate for selected patients. A retrospective cohort study was conducted on 691 patients. Patients with no remnant thyroid on the follow-up whole body scan and low stimulated thyroglobulin (sTg) level (Hashimoto thyroiditis based on histopathology diagnosis (odds ratio [OR] = 3.23; p Hashimoto thyroiditis and elevated sTg are negative predictive factors for successful low-dose radioactive-iodine remnant ablation treatment. An appropriate risk-adjusted approach may improve the efficacy of radioactive-iodine remnant ablation treatment. © 2015 Wiley Periodicals, Inc. Head Neck 38: E730-E735, 2016. © 2015 Wiley Periodicals, Inc.

  9. Remnant Cholesterol Elicits Arterial Wall Inflammation and a Multilevel Cellular Immune Response in Humans

    DEFF Research Database (Denmark)

    Bernelot Moens, Sophie J; Verweij, Simone L; Schnitzler, Johan G

    2017-01-01

    cholesterol accumulates in human hematopoietic stem and progenitor cells coinciding with myeloid skewing. CONCLUSIONS: Patients with FD have increased arterial wall and cellular inflammation. These findings imply an important inflammatory component to the atherogenicity of remnant cholesterol, contributing......OBJECTIVE: Mendelian randomization studies revealed a causal role for remnant cholesterol in cardiovascular disease. Remnant particles accumulate in the arterial wall, potentially propagating local and systemic inflammation. We evaluated the impact of remnant cholesterol on arterial wall...... inflammation, circulating monocytes, and bone marrow in patients with familial dysbetalipoproteinemia (FD). APPROACH AND RESULTS: Arterial wall inflammation and bone marrow activity were measured using 18F-FDG PET/CT. Monocyte phenotype was assessed with flow cytometry. The correlation between remnant levels...

  10. Mineral transformations during the dissolution of uranium ore minerals by dissimilatory metal-reducing bacteria

    Science.gov (United States)

    Glasauer, S.; Weidler, P.; Fakra, S.; Tyliszczak, T.; Shuh, D.

    2011-12-01

    Carnotite minerals [X2(UO2)2(VO4)2]; X = K, Ca, Ba, Mn, Na, Cu or Pb] form the major ore of uranium in the Colorado Plateau. These deposits are highly oxidized and contain U(VI) and V(IV). The biotransformation of U(VI) bound in carnotite by bacteria during dissimilatory metal reduction presents a complex puzzle in mineral chemistry. Both U(VI) and V(V) can be respired by metal reducing bacteria, and the mineral structure can change depending on the associated counterion. We incubated anaerobic cultures of S. putrefaciens CN32 with natural carnotite minerals from southeastern Utah in a nutrient-limited defined medium. Strain CN32 is a gram negative bacterium and a terrestrial isolate from New Mexico. The mineral and metal transformations were compared to a system that contained similar concentrations of soluble U(VI) and V(V). Electron (SEM, TEM) microscopies and x-ray spectromicroscopy (STXM) were used in conjunction with XRD to track mineral changes, and bacterial survival was monitored throughout the incubations. Slow rates of metal reduction over 10 months for the treatment with carnotite minerals revealed distinct biotic and abiotic processes, providing insight on mineral transformation and bacteria-metal interactions. The bacteria existed as small flocs or individual cells attached to the mineral phase, but did not adsorb soluble U or V, and accumulated very little of the biominerals. Reduction of mineral V(V) necessarily led to a dismantling of the carnotite structure. Bioreduction of V(V) by CN32 contributed small but profound changes to the mineral system, resulting in new minerals. Abiotic cation exchange within the carnotite group minerals induced the rearrangement of the mineral structures, leading to further mineral transformation. In contrast, bacteria survival was poor for treatments with soluble U(VI) and V(V), although both metals were reduced completely and formed solid UO2 and VO2; we also detected V(III). For these treatments, the bacteria

  11. Bioprocessing of coal - 10 - an application of microbial flotation to mineral processing

    Energy Technology Data Exchange (ETDEWEB)

    Nagaoka, T. [and others] [CRIEPI, Abiko-shi (Japan). Abiko Research Lab.

    1996-09-01

    Microbial flotation for coal desulfurization is being developed. Pyrite in coal is removed by bacterial adhesion by changing the surface property of pyrite. The bacterial adhesion of Thiobacillus ferrooxidans to sulfide minerals (pyrite, galena, molybdenite, chalcocite and millerite), and pyrite removal from the mixture of these sulfide minerals by microbial flotation was investigated. To compare the adhesion of T. ferrooxidans to pyrite with that to the other four minerals mentioned, the surface areas of the minerals, where the bacterium could adhere, was measured. It was observed that the roughness on the mineral surfaces was much smaller than the size of the bacterial cells. Hence, it was suggested that the roughness did not affect the bacterial adhesion to mineral surfaces. Bacterial adhesion to pyrite was compared with that to the other minerals. The amount of adhering bacterium was estimated on the basis of the adherable surface area measured with microscopic method. The amount of adhering cells to pyrite was 421.6 x 10{sup 8} cells/cm{sup 2}. On the other hand, the amounts of adhering cells to the minerals, except for pyrite were in a range of 77.1 to 160.8 x 10{sup 8} cells/cm{sup 2}. The bacterium adheres more to pyrite than to the other minerals, and only adheres to pyrite even if the pyrite is mixed with other minerals. Hence, T. ferrooxidans could adhere selectively to pyrite. Pyrite removal from the mineral mixtures was investigated with microbial flotation. Pyrite removal was in a range of 83.7% to 95.1% and mineral recovery was 72.9% to 100%. The grade of recovered minerals was in a range of 79.2 to 86.0% and that of rejected pyrite was in a range of 78.7 to 90.0%. These results suggest that microbial flotation can be a novel technology for mineral processing.

  12. Importance of riparian remnants for frog species diversity in a highly fragmented rainforest.

    Science.gov (United States)

    Rodríguez-Mendoza, Clara; Pineda, Eduardo

    2010-12-23

    Tropical forests undergo continuous transformation to other land uses, resulting in landscapes typified by forest fragments surrounded by anthropogenic habitats. Small forest fragments, specifically strip-shaped remnants flanking streams (referred to as riparian remnants), can be particularly important for the maintenance and conservation of biodiversity within highly fragmented forests. We compared frog species diversity between riparian remnants, other forest fragments and cattle pastures in a tropical landscape in Los Tuxtlas, Mexico. We found similar species richness in the three habitats studied and a similar assemblage structure between riparian remnants and forest fragments, although species composition differed by 50 per cent. Frog abundance was halved in riparian remnants compared with forest fragments, but was twice that found in pastures. Our results suggest that riparian remnants play an important role in maintaining a portion of frog species diversity in a highly fragmented forest, particularly during environmentally stressful (hot and dry) periods. In this regard, however, the role of riparian remnants is complementary, rather than substitutive, with respect to the function of other forest fragments within the fragmented forest.

  13. Remnant Cholesterol Elicits Arterial Wall Inflammation and a Multilevel Cellular Immune Response in Humans.

    Science.gov (United States)

    Bernelot Moens, Sophie J; Verweij, Simone L; Schnitzler, Johan G; Stiekema, Lotte C A; Bos, Merijn; Langsted, Anne; Kuijk, Carlijn; Bekkering, Siroon; Voermans, Carlijn; Verberne, Hein J; Nordestgaard, Børge G; Stroes, Erik S G; Kroon, Jeffrey

    2017-05-01

    Mendelian randomization studies revealed a causal role for remnant cholesterol in cardiovascular disease. Remnant particles accumulate in the arterial wall, potentially propagating local and systemic inflammation. We evaluated the impact of remnant cholesterol on arterial wall inflammation, circulating monocytes, and bone marrow in patients with familial dysbetalipoproteinemia (FD). Arterial wall inflammation and bone marrow activity were measured using 18 F-FDG PET/CT. Monocyte phenotype was assessed with flow cytometry. The correlation between remnant levels and hematopoietic activity was validated in the CGPS (Copenhagen General Population Study). We found a 1.2-fold increase of 18 F-FDG uptake in the arterial wall in patients with FD (n=17, age 60±8 years, remnant cholesterol: 3.26 [2.07-5.71]) compared with controls (n=17, age 61±8 years, remnant cholesterol 0.29 [0.27-0.40]; P wall and cellular inflammation. These findings imply an important inflammatory component to the atherogenicity of remnant cholesterol, contributing to the increased cardiovascular disease risk in patients with FD. © 2017 American Heart Association, Inc.

  14. Cholesterol remnants and triglycerides are associated with decreased myocardial function in patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Jørgensen, Peter Godsk; Jensen, Magnus Thorsten; Biering-Sørensen, Tor

    2016-01-01

    BACKGROUND: Recently, genetic studies have suggested a causal relationship between cholesterol remnants and ischemic heart disease. We aimed to determine whether cholesterol remnants and its marker, triglyceride levels, are associated with cardiac function as determined by sensitive echocardiogra......BACKGROUND: Recently, genetic studies have suggested a causal relationship between cholesterol remnants and ischemic heart disease. We aimed to determine whether cholesterol remnants and its marker, triglyceride levels, are associated with cardiac function as determined by sensitive...... secondary care centers. RESULTS: In multivariable analyses, triglycerides and cholesterol remnants were not associated with left ventricular ejection fraction, but with subtle measures of systolic function, including global longitudinal strain by speckle tracking and longitudinal displacement by tissue...... Doppler echocardiography: global longitudinal strain [0.33 % (0.14), p = 0.02 per doubling in cholesterol remnants and 0.28 % (0.13), p = 0.03 per doubling in triglyceride levels] and with longitudinal displacement [-0.25 mm (0.10), p = 0.01 per doubling in cholesterol remnants and -0.25 mm (0.09), p = 0...

  15. Influence of the Roof Movement Control Method on the Stability of Remnant

    Science.gov (United States)

    Adach-Pawelus, Karolina

    2017-12-01

    In the underground mines, there are geological and mining situations that necessitate leaving behind remnants in the mining field. Remnants, in the form of small, irregular parcels, are usually separated in the case of: significant problems with maintaining roof stability, high rockburst hazard, the occurrence of complex geological conditions and for random reasons (ore remnants), as well as for economic reasons (undisturbed rock remnants). Remnants left in the mining field become sites of high stress values concentration and may affect the rock in their vicinity. The values of stress inside the remnant and its vicinity, as well as the stability of the remnant, largely depend on the roof movement control method used in the mining field. The article presents the results of the numerical analysis of the influence of roof movement control method on remnant stability and the geomechanical situation in the mining field. The numerical analysis was conducted for the geological and mining conditions characteristic of Polish underground copper mines owned by KGHM Polska Miedz S.A. Numerical simulations were performed in a plane strain state by means of Phase 2 v. 8.0 software, based on the finite element method. The behaviour of remnant and rock mass in its vicinity was simulated in the subsequent steps of the room and pillar mining system for three types of roof movement control method: roof deflection, dry backfill and hydraulic backfill. The parameters of the rock mass accepted for numerical modelling were calculated by means of RocLab software on the basis of the Hoek-Brown classification. The Mohr-Coulomb strength criterion was applied.

  16. CHARACTERISTICS OF EPIRETINAL MEMBRANE REMNANT EDGE BY OPTICAL COHERENCE TOMOGRAPHY AFTER PARS PLANA VITRECTOMY.

    Science.gov (United States)

    Gaber, Raouf; You, Qi Sheng; Muftuoglu, Ilkay Kilic; Alam, Mostafa; Tsai, Frank F; Mendoza, Nadia; Freeman, William R

    2017-11-01

    To evaluate the incidence, characteristics, and the progression of epiretinal membrane (ERM) remnant edge seen by optical coherence tomography after ERM peeling. A retrospective chart review was conducted for 86 eyes of 85 consecutive patients who were diagnosed with ERM and underwent pars plana vitrectomy for epiretinal membrane peeling between 2013 and 2014. Data collected and analyzed included age, gender, preoperative and postoperative visual acuity, use of indocyanine green dye to stain internal limiting membrane, tamponade used after vitrectomy, ERM edge boundaries, presence of cystoid macular edema, and central foveal thickness. An ERM remnant edge was detected in 33/86 study eyes (38.4%) at the first postoperative optical coherence tomography scan. Compared with those without an ERM remnant, patients with an ERM remnant after surgery were significantly older at baseline and had a higher incidence of ERM recurrence at their last visit. They were not significantly different in terms of gender, preoperative and postoperative visual acuity, reduction of central foveal thickness from baseline, proportion of eyes with preoperative ERM elevation on optical coherence tomography, presence of macular edema before surgery, intraoperative use of indocyanine green staining for ILM peeling, or tamponade used. Based on the edge morphology, we classified the ERM remnant into three types: Type 1 was flat and blended with the retina (14/33 eyes, 42.4%), Type 2 was flat but stepped (17/33 eyes, 51.5%), and Type 3 was elevated (2/33 eyes, 6.0%). A significantly higher risk of ERM recurrence was seen in Type 2 and Type 3 ERM remnants (75% and 100%, respectively) than Type 1 ERM remnants (10%). An ERM remnant edge was detected by optical coherence tomography after ERM peeling in 38.4% of eyes. The presence of a postoperative ERM edge was associated with a higher risk of ERM recurrence, particularly in Type 2 and Type 3 ERM remnants.

  17. Construction Minerals Operations

    Data.gov (United States)

    Department of Homeland Security — This map layer includes construction minerals operations in the United States. The data represent commodities covered by the Minerals Information Team (MIT) of the...

  18. Agricultural Minerals Operations

    Data.gov (United States)

    Department of Homeland Security — This map layer includes agricultural minerals operations in the United States. The data represent commodities covered by the Minerals Information Team (MIT) of the...

  19. Mineral commodity summaries 2015

    Science.gov (United States)

    ,

    2015-01-01

    Each chapter of the 2015 edition of the U.S. Geological Survey (USGS) Mineral Commodity Summaries (MCS) includes information on events, trends, and issues for each mineral commodity as well as discussions and tabular presentations on domestic industry structure, Government programs, tariffs, 5-year salient statistics, and world production and resources. The MCS is the earliest comprehensive source of 2014 mineral production data for the world. More than 90 individual minerals and materials are covered by two-page synopses.

  20. DEM L241, A SUPERNOVA REMNANT CONTAINING A HIGH-MASS X-RAY BINARY

    International Nuclear Information System (INIS)

    Seward, F. D.; Charles, P. A.; Foster, D. L.; Dickel, J. R.; Romero, P. S.; Edwards, Z. I.; Perry, M.; Williams, R. M.

    2012-01-01

    A Chandra observation of the Large Magellanic Cloud supernova remnant DEM L241 reveals an interior unresolved source which is probably an accretion-powered binary. The optical counterpart is an O5III(f) star making this a high-mass X-ray binary with an orbital period likely to be of the order of tens of days. Emission from the remnant interior is thermal and spectral information is used to derive density and mass of the hot material. Elongation of the remnant is unusual and possible causes of this are discussed. The precursor star probably had mass >25 M ☉

  1. DEM L241, A SUPERNOVA REMNANT CONTAINING A HIGH-MASS X-RAY BINARY

    Energy Technology Data Exchange (ETDEWEB)

    Seward, F. D. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Charles, P. A. [School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Foster, D. L. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935, Cape Town (South Africa); Dickel, J. R.; Romero, P. S. [Department of Physics and Astronomy, University of New Mexico, 1919 Lomas Boulevard NE, Albuquerque, NM 87131 (United States); Edwards, Z. I.; Perry, M.; Williams, R. M. [Department of Earth and Space Sciences, Columbus State University, Coca Cola Space Science Center, 701 Front Avenue, Columbus, GA 31901 (United States)

    2012-11-10

    A Chandra observation of the Large Magellanic Cloud supernova remnant DEM L241 reveals an interior unresolved source which is probably an accretion-powered binary. The optical counterpart is an O5III(f) star making this a high-mass X-ray binary with an orbital period likely to be of the order of tens of days. Emission from the remnant interior is thermal and spectral information is used to derive density and mass of the hot material. Elongation of the remnant is unusual and possible causes of this are discussed. The precursor star probably had mass >25 M {sub Sun}.

  2. Mucocele of the cystic duct remnant after orthotopic liver transplant: a problem revisited.

    Science.gov (United States)

    Chatterjee, Suvadip; Das, Debasish; Hudson, Mark; Bassendine, Margaret Fiona; Scott, John; Oppong, Kofi Ernest; Sen, Gourab; French, Jeremy J

    2011-06-01

    Mucocele of the cystic duct remnant is an uncommon hepatobiliary complication of a liver transplant. Current practice usually involves either excising the cystic duct, or incorporating the distal end of the transected cystic duct into the suture line of the biliary anastomosis to ensure drainage. We report a patient who developed cystic duct remnant mucocele after the latter approach was adopted. We believe that this is likely related to delayed anastomotic stricturing, which prevented draining from the remnant cystic duct. We also discuss the incidence, pathology, investigations, and treatment of this condition.

  3. Numerical code for fitting radial emission profile of a shell supernova remnant: Application

    Directory of Open Access Journals (Sweden)

    Opsenica Slobodan

    2011-01-01

    Full Text Available We present IDL (Interactive Data Language codes for fitting a theoretical emission profile of a shell supernova remnant (SNR to the mean profile of an SNR obtained from radio observations. Two considered theoretical models are: 1 a shell with constant emissivity and 2 a synchrotron shell with radially aligned magnetic field. The codes were applied to several observed supernova remnants. Good results are obtained in five considered cases, which justify the use of our code for remnants that are bright (so that observational errors are not large and spherically symmetric enough.

  4. Supernova remnant S147 and its associated neutron star(s)

    OpenAIRE

    Gvaramadze, V. V.

    2005-01-01

    The supernova remnant S147 harbors the pulsar PSR J0538+2817 whose characteristic age is more than an order of magnitude greater than the kinematic age of the system (inferred from the angular offset of the pulsar from the geometric center of the supernova remnant and the pulsar proper motion). To reconcile this discrepancy we propose that PSR J0538+2817 could be the stellar remnant of the first supernova explosion in a massive binary system and therefore could be as old as its characteristic...

  5. Putative nanobacteria represent physiological remnants and culture by-products of normal calcium homeostasis.

    Directory of Open Access Journals (Sweden)

    John D Young

    Full Text Available Putative living entities called nanobacteria (NB are unusual for their small sizes (50-500 nm, pleomorphic nature, and accumulation of hydroxyapatite (HAP, and have been implicated in numerous diseases involving extraskeletal calcification. By adding precipitating ions to cell culture medium containing serum, mineral nanoparticles are generated that are morphologically and chemically identical to the so-called NB. These nanoparticles are shown here to be formed of amorphous mineral complexes containing calcium as well as other ions like carbonate, which then rapidly acquire phosphate, forming HAP. The main constituent proteins of serum-derived NB are albumin, fetuin-A, and apolipoprotein A1, but their involvement appears circumstantial since so-called NB from different body fluids harbor other proteins. Accordingly, by passage through various culture media, the protein composition of these particles can be modulated. Immunoblotting experiments reveal that antibodies deemed specific for NB react in fact with either albumin, fetuin-A, or both, indicating that previous studies using these reagents may have detected these serum proteins from the same as well as different species, with human tissue nanoparticles presumably absorbing bovine serum antigens from the culture medium. Both fetal bovine serum and human serum, used earlier by other investigators as sources of NB, paradoxically inhibit the formation of these entities, and this inhibition is trypsin-sensitive, indicating a role for proteins in this inhibitory process. Fetuin-A, and to a lesser degree albumin, inhibit nanoparticle formation, an inhibition that is overcome with time, ending with formation of the so-called NB. Together, these data demonstrate that NB are most likely formed by calcium or apatite crystallization inhibitors that are somehow overwhelmed by excess calcium or calcium phosphate found in culture medium or in body fluids, thereby becoming seeds for calcification. The

  6. Pervasive Defaunation of Forest Remnants in a Tropical Biodiversity Hotspot

    Science.gov (United States)

    Canale, Gustavo R.; Peres, Carlos A.; Guidorizzi, Carlos E.; Gatto, Cassiano A. Ferreira; Kierulff, Maria Cecília M.

    2012-01-01

    Tropical deforestation and forest fragmentation are among the most important biodiversity conservation issues worldwide, yet local extinctions of millions of animal and plant populations stranded in unprotected forest remnants remain poorly explained. Here, we report unprecedented rates of local extinctions of medium to large-bodied mammals in one of the world's most important tropical biodiversity hotspots. We scrutinized 8,846 person-years of local knowledge to derive patch occupancy data for 18 mammal species within 196 forest patches across a 252,669-km2 study region of the Brazilian Atlantic Forest. We uncovered a staggering rate of local extinctions in the mammal fauna, with only 767 from a possible 3,528 populations still persisting. On average, forest patches retained 3.9 out of 18 potential species occupancies, and geographic ranges had contracted to 0–14.4% of their former distributions, including five large-bodied species that had been extirpated at a regional scale. Forest fragments were highly accessible to hunters and exposed to edge effects and fires, thereby severely diminishing the predictive power of species-area relationships, with the power model explaining only ∼9% of the variation in species richness per patch. Hence, conventional species-area curves provided over-optimistic estimates of species persistence in that most forest fragments had lost species at a much faster rate than predicted by habitat loss alone. PMID:22905103

  7. Pervasive defaunation of forest remnants in a tropical biodiversity hotspot.

    Directory of Open Access Journals (Sweden)

    Gustavo R Canale

    Full Text Available Tropical deforestation and forest fragmentation are among the most important biodiversity conservation issues worldwide, yet local extinctions of millions of animal and plant populations stranded in unprotected forest remnants remain poorly explained. Here, we report unprecedented rates of local extinctions of medium to large-bodied mammals in one of the world's most important tropical biodiversity hotspots. We scrutinized 8,846 person-years of local knowledge to derive patch occupancy data for 18 mammal species within 196 forest patches across a 252,669-km(2 study region of the Brazilian Atlantic Forest. We uncovered a staggering rate of local extinctions in the mammal fauna, with only 767 from a possible 3,528 populations still persisting. On average, forest patches retained 3.9 out of 18 potential species occupancies, and geographic ranges had contracted to 0-14.4% of their former distributions, including five large-bodied species that had been extirpated at a regional scale. Forest fragments were highly accessible to hunters and exposed to edge effects and fires, thereby severely diminishing the predictive power of species-area relationships, with the power model explaining only ~9% of the variation in species richness per patch. Hence, conventional species-area curves provided over-optimistic estimates of species persistence in that most forest fragments had lost species at a much faster rate than predicted by habitat loss alone.

  8. Cold H I clouds near the supernova remnant W44

    International Nuclear Information System (INIS)

    Sato, F.

    1986-01-01

    The cold H I clouds near the supernova remnant W44 are investigated by the use of the Maryland-Green Bank Survey (Westerhout 1973). Several clouds with a mean diameter of about 20 pc are distributed in the region. They do not seem to make a shell around W44, contrary to the suggestion by Knapp and Kerr (1974) based on the low-resolution data at coarse grids. Some of them form a chain, about 100 pc in length, extending approximately along the galactic equator. It resembles the cold H I cloud near W3 and W4. The major constituent of the clouds is probably the hydrogen molecule, and the total mass of the entire complex amounts to 25,000 81,000 solar masses. The estimated Jeans mass indicates that they will contract to dense molecular clouds. Therefore, it may safely be concluded that the cold H1 cloud complex near W44 is a giant molecular cloud at an early evolutionary stage. 14 references

  9. Comparing Neutron Star Kicks to Supernova Remnant Asymmetries

    Energy Technology Data Exchange (ETDEWEB)

    Holland-Ashford, Tyler; Lopez, Laura A. [The Ohio State University Department of Astronomy, 140 W 18th Avenue, Columbus, OH 43201 (United States); Auchettl, Katie [The Ohio State University Center for Cosmology and Astro-particle Physics, 191 West Woodruff Avenue, Columbus, OH 43210 (United States); Temim, Tea [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Ramirez-Ruiz, Enrico, E-mail: holland-ashford.1@osu.edu [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

    2017-07-20

    Supernova explosions are inherently asymmetric and can accelerate new-born neutron stars (NSs) to hundreds of km s{sup −1}. Two prevailing theories to explain NS kicks are ejecta asymmetries (e.g., conservation of momentum between NS and ejecta) and anisotropic neutrino emission. Observations of supernova remnants (SNRs) can give us insights into the mechanism that generates these NS kicks. In this paper, we investigate the relationship between NS kick velocities and the X-ray morphologies of 18 SNRs observed with the Chandra X-ray Observatory and the Röntgen Satellite ( ROSAT ). We measure SNR asymmetries using the power-ratio method (a multipole expansion technique), focusing on the dipole, quadrupole, and octupole power ratios. Our results show no correlation between the magnitude of the power ratios and NS kick velocities, but we find that for Cas A and G292.0+1.8, whose emission traces the ejecta distribution, their NSs are preferentially moving opposite to the bulk of the X-ray emission. In addition, we find a similar result for PKS 1209–51, CTB 109, and Puppis A; however, their emission is dominated by circumstellar/interstellar material, so their asymmetries may not reflect their ejecta distributions. Our results are consistent with the theory that NS kicks are a consequence of ejecta asymmetries as opposed to anisotropic neutrino emission. In the future, additional observations to measure NS proper motions within ejecta-dominated SNRs are necessary to robustly constrain the NS kick mechanism.

  10. Search for surviving companions in type Ia supernova remnants

    International Nuclear Information System (INIS)

    Pan, Kuo-Chuan; Ricker, Paul M.; Taam, Ronald E.

    2014-01-01

    The nature of the progenitor systems of type Ia supernovae (SNe Ia) is still unclear. One way to distinguish between the single-degenerate scenario and double-degenerate scenario for their progenitors is to search for the surviving companions (SCs). Using a technique that couples the results from multi-dimensional hydrodynamics simulations with calculations of the structure and evolution of main-sequence- (MS-) and helium-rich SCs, the color and magnitude of MS- and helium-rich SCs are predicted as functions of time. The SC candidates in Galactic type Ia supernova remnants (Ia SNR) and nearby extragalactic Ia SNRs are discussed. We find that the maximum detectable distance of MS SCs (helium-rich SCs) is 0.6-4 Mpc (0.4-16 Mpc), if the apparent magnitude limit is 27 in the absence of extinction, suggesting that the Large and Small Magellanic Clouds and the Andromeda Galaxy are excellent environments in which to search for SCs. However, only five Ia SNRs have been searched for SCs, showing little support for the standard channels in the singe-degenerate scenario. To better understand the progenitors of SNe Ia, we encourage the search for SCs in other nearby Ia SNRs.

  11. Fermi-LAT Observation of Supernova Remnant S147

    Energy Technology Data Exchange (ETDEWEB)

    Katsuta, J.; Uchiyama, Y.; Tanaka, T.; /SLAC /KIPAC, Menlo Park; Tajima, H.; /SLAC /KIPAC, Menlo Park /Nagoya U., Solar-Terrestrial Environ. Lab.; Bechtol, K.; Funk, S.; Lande, J.; /SLAC /KIPAC, Menlo Park; Ballet, J.; /AIM, Saclay; Hanabata, Y.; /Hiroshima U.; Lemoine-Goumard, M.; /CENBG, Gradignan; Takahashi, T.; /JAXA, Sagamihara

    2012-08-17

    We present an analysis of gamma-ray data obtained with the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope in the region around SNR S147 (G180.0-1.7). A spatially extended gamma-ray source detected in an energy range of 0.2-10 GeV is found to coincide with SNR S147. We confirm its spatial extension at >5{sigma} confidence level. The gamma-ray flux is (3.8 {+-} 0.6) x 10{sup -8} photons cm{sup -2} s{sup -1}, corresponding to a luminosity of 1.3 x 10{sup 34} (d/1.3 kpc){sup 2} erg s{sup -1} in this energy range. The gamma-ray emission exhibits a possible spatial correlation with prominent H{alpha} filaments of S147. There is no indication that the gamma-ray emission comes from the associated pulsar PSR J0538+2817. The gamma-ray spectrum integrated over the remnant is likely dominated by the decay of neutral {pi} mesons produced through the proton-proton collisions in the filaments. Reacceleration of pre-existing CRs and subsequent adiabatic compression in the filaments is sufficient to provide the required energy density of high-energy protons.

  12. Evolution of Supernova Remnants Near the Galactic Center

    Energy Technology Data Exchange (ETDEWEB)

    Yalinewich, A.; Piran, T.; Sari, R. [Racah Institute of Physics, the Hebrew University, 91904, Jerusalem (Israel)

    2017-03-20

    Supernovae near the Galactic center (GC) evolve differently from regular Galactic supernovae. This is mainly due to the environment into which the supernova remnants (SNRs) propagate. SNRs near the GC propagate into a wind swept environment with a velocity directed away from the GC, and a graded density profile. This causes these SNRs to be non-spherical, and to evolve faster than their Galactic counterparts. We develop an analytic theory for the evolution of explosions within a stellar wind, and verify it using a hydrodynamic code. We show that such explosions can evolve in one of three possible morphologies. Using these results we discuss the association between the two SNRs (SGR East and SGR A’s bipolar radio/X-ray lobes) and the two neutron stars (the Cannonball and SGR J1745-2900) near the GC. We show that, given the morphologies of the SNR and positions of the neutron stars, the only possible association is between SGR A’s bipolar radio/X-ray lobes and SGR J1745-2900. If a compact object was created in the explosion of SGR East, it remains undetected, and the SNR of the supernova that created the Cannonball has already disappeared.

  13. Superdiffusion of relativistic electrons at supernova remnant shocks

    Science.gov (United States)

    Perri, Silvia

    2018-01-01

    Anomalous transport has been observed in various systems as nonlinear systems, numerical simulations of plasma turbulence, in laboratory plasmas, and recently in the propagation of energetic particles in the interplanetary space. Thanks to in situ observations it has been possible to deduce transport properties directly from spacecraft data. This technique has further found applicability to remote observations of relativistic electrons accelerated at supernova remnants (SNRs) shocks, pointing out that far upstream of the blast waves, the x-ray synchrotron emission, as captured by the Chandra spacecraft, is consistent with models of superdiffusive transport (i.e., transport faster than normal diffusive). Here we present and summarize evidences of superdiffusion both in the interplanetary space and upstream of SNRs shock fronts, in particular by analyzing, for the first time in the framework of superdiffusion, the transport properties of electrons accelerated at the young G1.9+0.3 SNR. We also briefly describe how this new model can be used to interpret radio emissions from electrons accelerated at shocks forming during galaxy cluster mergers.

  14. EXPECTATION ON OBSERVATION OF SUPERNOVA REMNANTS WITH THE LHAASO PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ye; Huang, Xingtao [School of Physics and Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Jinan 250100 (China); Cao, Zhen; Chen, Songzhan; He, Huihai; Ma, Xinhua [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Chen, Yang; Zhang, Xiao [Department of Astronomy, Nanjing University, Nanjing 210093 (China); Cui, Shuwang [The College of Physics Science and Information Engineering, Hebei Normal University, Shijiazhuang, 050016 (China); Yuan, Qiang, E-mail: huangxt@sdu.edu.cn, E-mail: maxh@ihep.ac.cn [Department of Astronomy, University of Massachusetts, 710 North Pleasant St., Amherst, MA 01003 (United States); Collaboration: On behalf of the LHAASO Collaboration

    2016-07-20

    Supernova remnants (SNRs) are believed to be the most important acceleration sites for cosmic rays (CRs) below ∼10{sup 15} eV in the Galaxy. High-energy photons, either directly from the shocks of the SNRs or indirectly from the interaction between SNRs and the nearby clouds, are crucial probes for the CR acceleration. Big progresses on observations of SNRs have been achieved by space- and ground-based γ -ray facilities. However, whether γ -rays come from accelerated hadrons or not, as well as their connection with the CRs observed at Earth, remains in debate. Large High Altitude Air Shower Observatory (LHAASO), a next-generation experiment, is designed to survey the northern part of the very high energy γ -ray sky from ∼0.3 TeV to PeV with the sensitivity of ≲1% of the Crab Nebula flux. In this paper, we indicate that LHAASO will be dedicated to enlarging the γ -ray SNR samples and improving the spectral and morphological measurements. These measurements, especially at energies above 30 TeV, will be important for us to finally understand the CR acceleration in SNRs.

  15. THE FATE OF THE COMPACT REMNANT IN NEUTRON STAR MERGERS

    Energy Technology Data Exchange (ETDEWEB)

    Fryer, Chris L. [Department of Physics, The University of Arizona, Tucson, AZ 85721 (United States); Belczynski, Krzysztoff [Astronomical Observatory, University of Warsaw, Al Ujazdowskie 4, 00-478 Warsaw (Poland); Ramirez-Ruiz, Enrico [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Rosswog, Stephan [The Oskar klein Center, Department of Astronomy, AlbaNova, Stockholm University, SE-106 91 Stockholm (Sweden); Shen, Gang [Institute for Nuclear Theory, University of Washington, Seattle, WA 98195 (United States); Steiner, Andrew W. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States)

    2015-10-10

    Neutron star (binary neutron star and neutron star–black hole) mergers are believed to produce short-duration gamma-ray bursts (GRBs). They are also believed to be the dominant source of gravitational waves to be detected by the advanced LIGO and advanced VIRGO and the dominant source of the heavy r-process elements in the universe. Whether or not these mergers produce short-duration GRBs depends sensitively on the fate of the core of the remnant (whether, and how quickly, it forms a black hole). In this paper, we combine the results of Newtonian merger calculations and equation of state studies to determine the fate of the cores of neutron star mergers. Using population studies, we can determine the distribution of these fates to compare to observations. We find that black hole cores form quickly only for equations of state that predict maximum non-rotating neutron star masses below 2.3–2.4 solar masses. If quick black hole formation is essential in producing GRBs, LIGO/Virgo observed rates compared to GRB rates could be used to constrain the equation of state for dense nuclear matter.

  16. The Population of Supernova Remnants in M51

    Science.gov (United States)

    Long, Knox S.; Blair, William P.; Kuntz, K. D.; Winkler, P. Frank

    2017-08-01

    The nearby, actively star-forming, nearly face-on spiral galaxy, M51 (NGC 5194/5), has been the site of four supernovae since 1941. As a result it should have a rich population of young supernova remnants (SNRs). Here we describe a search for optical SNRs in M51 among the 298 X-ray sources discovered inside the D25 contour in deep Chandra observations. The search uses interference filter images obtained with the WFC3 on Hubble Space Telescope and more recent images from GMOS on Gemini North. Of 80 emission nebulae identified in the HST images as SNR candidates based on elevated [SII]: Ha ratios compared to HII regions, 40 have X-ray counterparts. The diameters of the SNRs and SNR candidates detected with HST are systematically smaller than seen in SNR populations of other galaxies at comparable distances. However, this is most likely an instrumental effect, which our ongoing analysis of the new GMOS images will correct. At that point, we will be able to make of fair multi-wavelength comparison of the SNR population in M51 with other nearby, actively star-forming spiral galaxies, such as M83 and NGC6946.

  17. Acceleration of cosmic rays in supernova-remnants

    Science.gov (United States)

    Dorfi, E. A.; Drury, L. O.

    1985-01-01

    It is commonly accepted that supernova-explosions are the dominant source of cosmic rays up to an energy of 10 to the 14th power eV/nucleon. Moreover, these high energy particles provide a major contribution to the energy density of the interstellar medium (ISM) and should therefore be included in calculations of interstellar dynamic phenomena. For the following the first order Fermi mechanism in shock waves are considered to be the main acceleration mechanism. The influence of this process is twofold; first, if the process is efficient (and in fact this is the cas) it will modify the dynamics and evolution of a supernova-remnant (SNR), and secondly, the existence of a significant high energy component changes the overall picture of the ISM. The complexity of the underlying physics prevented detailed investigations of the full non-linear selfconsistent problem. For example, in the context of the energy balance of the ISM it has not been investigated how much energy of a SN-explosion can be transfered to cosmic rays in a time-dependent selfconsistent model. Nevertheless, a lot of progress was made on many aspects of the acceleration mechanism.

  18. Acceleration of cosmic rays in supernova-remnants

    International Nuclear Information System (INIS)

    Dorfi, E.A.; Drury, L.O.

    1985-01-01

    It is commonly accepted that supernova-explosions are the dominant source of cosmic rays up to an energy of 10 to the 14th power eV/nucleon. Moreover, these high energy particles provide a major contribution to the energy density of the interstellar medium (ISM) and should therefore be included in calcuations of interstellar dynamic phenomena. For the following the first order Fermi mechanism in shock waves are considered to be the main acceleration mechanism. The influence of this process is twofold; first, if the process is efficient (and in fact this is the case) it will modify the dynamics and evolution of a supernova-remnant (SNR), and secondly, the existence of a significant high energy component changes the overall picture of the ISM. The complexity of the underlying physics prevented detailed investigations of the full non-linear selfconsistent problem. For example, in the context of the energy balance of the ISM it has not been investigated how much energy of a SN-explosion can be transfered to cosmic rays in a time-dependent selfconsistent model. Nevertheless, a lot of progress was made on many aspects of the acceleration mechnism

  19. The high energy X-ray spectra of supernova remnants

    Science.gov (United States)

    Pravdo, S. H.; Nugent, J. J.

    The results of fitting an ionization-nonequilibrium (INE) model to the high-energy (above 5-keV) X-ray spectra of the young supernova remnants Cas A and Tycho are presented. As an additional constraint, the models must simultaneously fit lower-energy, higher-resolution data. For Cas A, a single INE component cannot adequately reproduce the features for the entire X-ray spectrum because the ionization structure of iron ions responsible for the K emission is inconsistent with that of the ions responsible for the lower-energy lines, and the flux of the highest-energy X-rays is underestimated. The iron K line and the high-energy continuum could arise from the same INE component, but the identification of this component with either the blast wave or the ejecta in the standard model is difficult. In Tycho, the high-energy data rule out a class of models for the lower-energy data which have too large a continuum contribution.

  20. Soil Microbes and soil microbial proteins: interactions with clay minerals

    International Nuclear Information System (INIS)

    Spence, A.; Kelleher, B. P.

    2009-01-01

    Bacterial enumeration in soil environments estimates that the population may reach approximately 10 1 0 g - 1 of soil and comprise up to 90% of the total soil microbial biomass. Bacteria are present in soils as single cells or multicell colonies and often strongly adsorb onto mineral surfaces such as sand and clay. The interactions of microbes and microbial biomolecules with these minerals have profound impacts on the physical, chemical and biological properties of soils. (Author)

  1. The majority of lipoprotein lipase in plasma is bound to remnant lipoproteins: A new definition of remnant lipoproteins.

    Science.gov (United States)

    Sato, Koichi; Okajima, Fumikazu; Miyashita, Kazuya; Imamura, Shigeyuki; Kobayashi, Junji; Stanhope, Kimber L; Havel, Peter J; Machida, Tetsuo; Sumino, Hiroyuki; Murakami, Masami; Schaefer, Ernst; Nakajima, Katsuyuki

    2016-10-01

    Lipoprotein lipase (LPL) is a multifunctional protein and a key enzyme involved in the regulation of lipoprotein metabolism. We determined the lipoproteins to which LPL is bound in the pre-heparin and post-heparin plasma. Tetrahydrolipstatin (THL), a potent inhibitor of serine lipases, was used to block the lipolytic activity of LPL, thereby preventing changes in the plasma lipoproteins due to ex vivo lipolysis. Gel filtration was performed to obtain the LPL elution profiles in plasma and the isolated remnant lipoproteins (RLP). When ex vivo lipolytic activity was inhibited by THL in the post-heparin plasma, majority of the LPL was found in the VLDL elution range, specifically in the RLP as inactive dimers. However, in the absence of THL, most of the LPL was found in the HDL elution range as active dimers. Furthermore, majority of the LPL in the pre-heparin plasma was found in the RLP as inactive form, with broadly diffused lipoprotein profiles in the presence and absence of THL. It is suggested that during lipolysis in vivo, the endothelial bound LPL dimers generates RLP, forming circulating RLP-LPL complexes in an inactive form that subsequently binds and initiates receptor-mediated catabolism. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. A concise review of nanoscopic aspects of bioleaching bacteria-mineral interactions.

    Science.gov (United States)

    Diao, Mengxue; Taran, Elena; Mahler, Stephen; Nguyen, Anh V

    2014-10-01

    Bioleaching is a technology for the recovery of metals from minerals by means of microorganisms, which accelerate the oxidative dissolution of the mineral by regenerating ferric ions. Bioleaching processes take place at the interface of bacteria, sulfide mineral and leaching solution. The fundamental forces between a bioleaching bacterium and mineral surface are central to understanding the intricacies of interfacial phenomena, such as bacterial adhesion or detachment from minerals and the mineral dissolution. This review focuses on the current state of knowledge in the colloidal aspect of bacteria-mineral interactions, particularly for bioleaching bacteria. Special consideration is given to the microscopic structure of bacterial cells and the atomic force microscopy technique used in the quantification of fundamental interaction forces at nanoscale. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Fissure minerals, literature review

    International Nuclear Information System (INIS)

    Larsson, S.Aa.

    1980-01-01

    This paper is a review of methods used for direct and indirect dating of tectonic events. Isotope geochemistry including stable isotopes as well as fission track- dating, fluid inclusion and thermoluminescens techniques have been considered. It has been concluded that an investigation of tectonic (and thermal) events should start with a detailed study of the mineral phases grown in seald fissures as well as minerals from fissure walls. This study should include phase identification, textures as well as mineral chemistry. The information from this study is fundamental for the decision of further investigations. Mineral chemistry including isotopes and fluid inclusion studies will give an essential knowledge about crystallization conditions for fissure minerals concerned. Direct dating using fission tracks as well as radioactive isotopes could be useful for some minerals. Application of thermoluminescens dating on fissure minerals is doubtful. (Auth.)

  4. Analyzing Data Remnant Remains on User Devices to Determine Probative Artifacts in Cloud Environment.

    Science.gov (United States)

    Ahmed, Abdulghani Ali; Xue Li, Chua

    2018-01-01

    Cloud storage service allows users to store their data online, so that they can remotely access, maintain, manage, and back up data from anywhere via the Internet. Although helpful, this storage creates a challenge to digital forensic investigators and practitioners in collecting, identifying, acquiring, and preserving evidential data. This study proposes an investigation scheme for analyzing data remnants and determining probative artifacts in a cloud environment. Using pCloud as a case study, this research collected the data remnants available on end-user device storage following the storing, uploading, and accessing of data in the cloud storage. Data remnants are collected from several sources, including client software files, directory listing, prefetch, registry, network PCAP, browser, and memory and link files. Results demonstrate that the collected remnants data are beneficial in determining a sufficient number of artifacts about the investigated cybercrime. © 2017 American Academy of Forensic Sciences.

  5. Remnant pancreatic parenchymal volume predicts postoperative pancreatic exocrine insufficiency after pancreatectomy.

    Science.gov (United States)

    Okano, Keisuke; Murakami, Yoshiaki; Nakagawa, Naoya; Uemura, Kenichiro; Sudo, Takeshi; Hashimoto, Yasushi; Kondo, Naru; Takahashi, Shinya; Sueda, Taijiro

    2016-03-01

    Pancreatectomy, including pancreatoduodenectomy and distal pancreatectomy, often causes postoperative pancreatic exocrine insufficiency (PEI). Our aim was to clarify a relationship between remnant pancreatic volume and postoperative PEI. A total of 227 patients who underwent pancreatoduodenectomy or distal pancreatectomy were enrolled in this study. All patients underwent a (13)C-labeled mixed triglyceride breath test to assess pancreatic exocrine function and abdominal dynamic computed tomography for assessing remnant pancreatic volume after pancreatectomy at a median of 7 months postoperatively. The percent (13)CO2 cumulative dose at 7 hours (% dose (13)C cum 7 h) pancreatectomy were performed in 174 (76.7%) and 53 (23.3%) patients, respectively. Of the 227 patients, 128 (56.3%) developed postoperative PEI. Postoperative % dose (13)C cum 7 h was strongly correlated with remnant pancreatic volume (r = .509, P pancreatectomy (P pancreatectomy. Remnant pancreatic volume may predict postoperative PEI in patients who undergo pancreatectomy. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Remnant for all black objects due to gravity's rainbow

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Ahmed Farag, E-mail: afarag@zewailcity.edu.eg [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Center for Fundamental Physics, Zewail City of Science and Technology, Giza 12588 (Egypt); Department of Physics, Faculty of Science, Benha University, Benha 13518 (Egypt); Faizal, Mir, E-mail: f2mir@uwaterloo.ca [Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Khalil, Mohammed M., E-mail: moh.m.khalil@gmail.com [Department of Electrical Engineering, Alexandria University, Alexandria 12544 (Egypt)

    2015-05-15

    We argue that a remnant is formed for all black objects in gravity's rainbow. This will be based on the observation that a remnant depends critically on the structure of the rainbow functions, and this dependence is a model independent phenomena. We thus propose general relations for the modified temperature and entropy of all black objects in gravity's rainbow. We explicitly check this to be the case for Kerr, Kerr–Newman-dS, charged-AdS, and higher dimensional Kerr–AdS black holes. We also try to argue that a remnant should form for black saturn in gravity's rainbow. This work extends our previous results on remnants of Schwarzschild black holes and black rings.

  7. Bioleaching of serpentine group mineral by fungus Talaromyces flavus: application for mineral carbonation

    Science.gov (United States)

    Li, Z.; Lianwen, L.; Zhao, L.; Teng, H.

    2011-12-01

    Many studies of serpentine group mineral dissolution for mineral carbonation have been published in recent years. However, most of them focus mainly on either physical and chemical processes or on bacterial function, rather than fungal involvement in the bioleaching of serpentine group mineral. Due to the excessive costs of the magnesium dissolution process, finding a lower energy consumption method will be meaningful. A fungal strain Talaromyces flavus was isolated from serpentinic rock of Donghai (China). No study of its bioleaching ability is currently available. It is thus of great significance to explore the impact of T. flavus on the dissolution of serpentine group mineral. Serpentine rock-inhabiting fungi belonging to Acremonium, Alternaria, Aspergillus, Botryotinia, Cladosporium, Clavicipitaceae, Cosmospora, Fusarium, Monascus, Paecilomyces, Penicillium, Talaromyces, Trichoderma were isolated. These strains were chosen on the basis of resistance to magnesium and nickel characterized in terms of minimum inhibiting concentration (MIC). Specifically, the strain Talaromyces flavus has a high tolerance to both magnesium (1 mol/L) and nickel (10 mM/L), and we examine its bioleaching ability on serpentine group mineral. Contact and separation experiments (cut-off 8 000-14 000 Da), as well as three control experiments, were set up for 30 days. At least three repeated tests were performed for each individual experiment. The results of our experiments demonstrate that the bioleaching ability of T. flavus towards serpentine group mineral is evident. 39.39 wt% of magnesium was extracted from lizardite during the bioleaching period in the contact experiment, which showed a dissolution rate at about a constant 0.126 mM/d before reaching equilibrium in 13 days. The amount of solubilized Mg from chrysotile and antigorite were respectively 37.79 wt% and 29.78 wt% in the contact experiment. These results make clear the influence of mineral structure on mineral bioleaching

  8. Remnant cholesterol as a causal risk factor for ischemic heart disease

    DEFF Research Database (Denmark)

    Varbo, Anette; Benn, Marianne; Tybjærg-Hansen, Anne

    2013-01-01

    The aim of this study was to test the hypothesis that elevated nonfasting remnant cholesterol is a causal risk factor for ischemic heart disease independent of reduced high-density lipoprotein (HDL) cholesterol.......The aim of this study was to test the hypothesis that elevated nonfasting remnant cholesterol is a causal risk factor for ischemic heart disease independent of reduced high-density lipoprotein (HDL) cholesterol....

  9. STAR FORMATION ASSOCIATED WITH THE SUPERNOVA REMNANT IC443

    International Nuclear Information System (INIS)

    Xu Jinlong; Wang Junjie; Miller, Martin

    2011-01-01

    We have performed submillimeter and millimeter observations in CO lines toward supernova remnant (SNR) IC443. The CO molecular shell coincides well with the partial shell of the SNR detected in radio continuum observations. Broad emission lines and three 1720 MHz OH masers were detected in the CO molecular shell. The present observations have provided further evidence in support of the interaction between the SNR and the adjoining molecular clouds (MCs). The total mass of the MCs is 9.26 x 10 3 M sun . The integrated CO line intensity ratio (R I CO(3-2) /I CO(2-1) ) for the whole MC is between 0.79 and 3.40. The average value is 1.58, which is much higher than previous measurements of individual Galactic MCs. Higher line ratios imply that shocks have driven into the MCs. We conclude that high R I CO(3-2) /I CO(2-1) is identified as a good signature of the SNR-MC interacting system. Based on the IRAS Point Source Catalog and the Two Micron All Sky Survey near-infrared database, 12 protostellar object and 1666 young stellar object (YSO) candidates (including 154 classical T Tauri stars and 419 Herbig Ae/Be stars) are selected. In the interacting regions, the significant enhancement of the number of protostellar objects and YSOs indicates the presence of some recently formed stars. After comparing the characteristic timescales of star formation with the age of IC443, we conclude that the protostellar objects and YSO candidates are not triggered by IC443. For the age of the stellar winds shell, we have performed our calculation on the basis of a stellar wind shell expansion model. The results and analysis suggest that the formation of these stars may be triggered by the stellar winds of the IC443 progenitor.

  10. Interstellar and ejecta dust in the cas a supernova remnant

    Energy Technology Data Exchange (ETDEWEB)

    Arendt, Richard G. [CRESST, University of Maryland, Baltimore County, Baltimore, MD 21250 (United States); Dwek, Eli; Kober, Gladys [NASA Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Rho, Jeonghee [SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043 (United States); Hwang, Una, E-mail: Richard.G.Arendt@nasa.gov [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)

    2014-05-01

    Infrared continuum observations provide a means of investigating the physical composition of the dust in the ejecta and swept up medium of the Cas A supernova remnant (SNR). Using low-resolution Spitzer IRS spectra (5-35 μm), and broad-band Herschel PACS imaging (70, 100, and 160 μm), we identify characteristic dust spectra, associated with ejecta layers that underwent distinct nuclear burning histories. The most luminous spectrum exhibits strong emission features at ∼9 and 21 μm and is closely associated with ejecta knots with strong Ar emission lines. The dust features can be reproduced by magnesium silicate grains with relatively low Mg to Si ratios. Another dust spectrum is associated with ejecta having strong Ne emission lines. It has no indication of any silicate features and is best fit by Al{sub 2}O{sub 3} dust. A third characteristic dust spectrum shows features that are best matched by magnesium silicates with a relatively high Mg to Si ratio. This dust is primarily associated with the X-ray-emitting shocked ejecta, but it is also evident in regions where shocked interstellar or circumstellar material is expected. However, the identification of dust composition is not unique, and each spectrum includes an additional featureless dust component of unknown composition. Colder dust of indeterminate composition is associated with emission from the interior of the SNR, where the reverse shock has not yet swept up and heated the ejecta. Most of the dust mass in Cas A is associated with this unidentified cold component, which is ≲ 0.1 M {sub ☉}. The mass of warmer dust is only ∼0.04 M {sub ☉}.

  11. Investigation of In vitro Mineral Forming Bacterial Isolates from ...

    African Journals Online (AJOL)

    2018-01-30

    Jan 30, 2018 ... Keywords: Bacteria, biomineralization, supragingival dental calculus. Investigation of In vitro ... of damage that is associated with plaque‑forming ... Materials and Methods ... Amplification reaction mixture was prepared in a 30 μL .... gingiva, palatine tonsils, and throat), skin (right and .... Neisseria mucosa.

  12. Mineral phosphate solubilizing bacterial community in agro-ecosystem

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-15

    Dec 15, 2009 ... patterns. Four insoluble phosphate sources; purulia rock phosphate (PRP), mussourie rock phosphate. (MRP) ... community composition analysis (Garland, 1996a) and ..... the threshold level that enabled only a few species to.

  13. Remnant radio-loud AGN in the Herschel-ATLAS field

    Science.gov (United States)

    Mahatma, V. H.; Hardcastle, M. J.; Williams, W. L.; Brienza, M.; Brüggen, M.; Croston, J. H.; Gurkan, G.; Harwood, J. J.; Kunert-Bajraszewska, M.; Morganti, R.; Röttgering, H. J. A.; Shimwell, T. W.; Tasse, C.

    2018-04-01

    Only a small fraction of observed active galactic nuclei (AGN) display large-scale radio emission associated with jets, yet these radio-loud AGN have become increasingly important in models of galaxy evolution. In determining the dynamics and energetics of the radio sources over cosmic time, a key question concerns what happens when their jets switch off. The resulting `remnant' radio-loud AGN have been surprisingly evasive in past radio surveys, and therefore statistical information on the population of radio-loud AGN in their dying phase is limited. In this paper, with the recent developments of Low-Frequency Array (LOFAR) and the Very Large Array, we are able to provide a systematically selected sample of remnant radio-loud AGN in the Herschel-ATLAS field. Using a simple core-detection method, we constrain the upper limit on the fraction of remnants in our radio-loud AGN sample to 9 per cent, implying that the extended lobe emission fades rapidly once the core/jets turn off. We also find that our remnant sample has a wide range of spectral indices (-1.5≤slant α ^{1400}_{150}≤slant -0.5), confirming that the lobes of some remnants may possess flat spectra at low frequencies just as active sources do. We suggest that, even with the unprecedented sensitivity of LOFAR, our sample may still only contain the youngest of the remnant population.

  14. Grouping Minerals by Their Formulas

    Science.gov (United States)

    Mulvey, Bridget

    2018-01-01

    Minerals are commonly taught in ways that emphasize mineral identification for its own sake or maybe to help identify rocks. But how do minerals fit in with other science content taught? The author uses mineral formulas to help Earth science students wonder about the connection between elements, compounds, mixtures, minerals, and mineral formulas.…

  15. 43 CFR 19.8 - Prospecting, mineral locations, mineral patents, and mineral leasing within National Forest...

    Science.gov (United States)

    2010-10-01

    ... patents, and mineral leasing within National Forest Wilderness. 19.8 Section 19.8 Public Lands: Interior... § 19.8 Prospecting, mineral locations, mineral patents, and mineral leasing within National Forest... locations, mineral patents, and mineral leasing within National Forest Wilderness are contained in parts...

  16. Radioactive mineral deposits

    Energy Technology Data Exchange (ETDEWEB)

    1948-01-01

    This publication was designed as a guide for uranium and thorium prospectors in Australia. Physical properties, such as color, streak, luster, hardness, fracture, and specific gravity of the uranium and thorium-bearing minerals are summarized and the various methods suitable for detecting radioactivity in minerals are described. Two colored plates show samples of pitchblende (uraninite), autunite, carnotite, monazite, and others of the most important minerals sources of uranium and thorium.

  17. Brazilian minerals annual report

    International Nuclear Information System (INIS)

    1977-01-01

    Statistics of Brazilian mineral resources and production in 1977 are presented. Data included refer also to economic aspects, market, taxes, government incentives, manpower, exportation, importation, etc [pt

  18. Minerals industry survey, 1984

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    This is the seventh edition of the statistical survey commissioned by the Australian Mining Industry Council. It represents the most comprehensive review of the financial position of the Australian minerals industry and provides timely financial data on the minerals industry. The tables of this survey have been prepared for AMIC by Coopers and Lybrand, Chartered Accountants, based on information supplied to them in confidence by the respondent companies. For the purpose of the survey, the minerals industry has been defined as including exploration for, and extraction and primary processing of, minerals in Australia. The oil and gas industry is not included.

  19. Reagan issues mineral policy

    Science.gov (United States)

    The National Materials and Minerals Program plan and report that President Reagan sent to Congress on April 5 aims to ‘decrease America's minerals vulnerability’ while reducing future dependence on potentially unstable foreign sources of minerals. These goals would be accomplished by taking inventory of federal lands to determine mineral potential; by meeting the stockpile goals set by the Strategic and Critical Material Stockpiling Act; and by establishing a business and political climate that would encourage private-sector research and development on minerals.Now that the Administration has issued its plan, the Subcommittee on Mines and Mining of the House Committee on Interior and Insular Affairs will consider the National Minerals Security Act (NMSA), which was introduced 1 year ago by subcommittee chairman Jim Santini (D-Nev.) [Eos, May 19, 1981, p. 497]. The bill calls for establishing a three-member White-House-level council to coordinate the development of a national minerals policy; amending tax laws to assist the mining industry to make capital investments to locate and produce strategic materials; and creating a revolving fund for the sale and purchase of strategic minerals. In addition, the NMSA bill would allow the secretary of the interior to make previously withdrawn public lands available for mineral development. The subcommittee will hold a hearing on the Administration's plan on May 11. Interior Secretary James Watt has been invited to testify.

  20. International mineral economics

    International Nuclear Information System (INIS)

    Gocht, W.R.; Eggert, R.G.

    1988-01-01

    International Mineral Economics provides an integrated overview of the important concepts. The treatment is interdisciplinary, drawing on the fields of economics, geology, business, and mining engineering. Part I examines the technical concepts important for understanding the geology of ore deposits, the methods of exploration and deposit evaluation, and the activities of mining and mineral processing. Part II focuses on the economic and related concepts important for understanding mineral development, the evaluation of exploration and mining projects, and mineral markets and market models. Finally, Part III reviews and traces the historical development of the policies of international organizations, the industrialized countries, and the developing countries. (orig.)

  1. Mineral statistics yearbook 1994

    International Nuclear Information System (INIS)

    1994-01-01

    A summary of mineral production in Saskatchewan was compiled and presented as a reference manual. Statistical information on fuel minerals such as crude oil, natural gas, liquefied petroleum gas and coal, and of industrial and metallic minerals, such as potash, sodium sulphate, salt and uranium, was provided in all conceivable variety of tables. Production statistics, disposition and value of sales of industrial and metallic minerals were also made available. Statistical data on drilling of oil and gas reservoirs and crown land disposition were also included. figs., tabs

  2. Marine Mineral Exploration

    DEFF Research Database (Denmark)

    in EEZ areas are fairly unknown; many areas need detailed mapping and mineral exploration, and the majority of coastal or island states with large EEZ areas have little experience in exploration for marine hard minerals. This book describes the systematic steps in marine mineral exploration....... Such exploration requires knowledge of mineral deposits and models of their formation, of geophysical and geochemical exploration methods, and of data evaluation and interpretation methods. These topics are described in detail by an international group of authors. A short description is also given of marine...

  3. SUPERNOVA 1987A: A TEMPLATE TO LINK SUPERNOVAE TO THEIR REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Orlando, S.; Miceli, M.; Pumo, M. L.; Bocchino, F., E-mail: orlando@astropa.inaf.it [INAF—Osservatorio Astronomico di Palermo “G.S. Vaiana”, Piazza del Parlamento 1, I-90134 Palermo (Italy)

    2015-09-10

    The emission of supernova remnants (SNRs) reflects the properties of both the progenitor supernovae (SNe) and the surrounding environment. The complex morphology of the remnants, however, hampers the disentanglement of the two contributions. Here, we aim at identifying the imprint of SN 1987A on the X-ray emission of its remnant and at constraining the structure of the environment surrounding the SN. We performed high-resolution hydrodynamic simulations describing SN 1987A soon after the core-collapse and the following three-dimensional expansion of its remnant between days 1 and 15,000 after the SN. We demonstrated that the physical model reproducing the main observables of SN 1987A during the first 250 days of evolution also reproduces the X-ray emission of the subsequent expanding remnant, thus bridging the gap between SNe and SNRs. By comparing model results with observations, we constrained the explosion energy in the range 1.2–1.4 × 10{sup 51} erg and the envelope mass in the range 15–17 M{sub ⊙}. We found that the shape of X-ray lightcurves and spectra at early epochs (<15 years) reflects the structure of outer ejecta: our model reproduces the observations if the outermost ejecta have a post-explosion radial profile of density approximated by a power law with index α = −8. At later epochs, the shapes of X-ray lightcurves and spectra reflect the density structure of the nebula around SN 1987A. This enabled us to ascertain the origin of the multi-thermal X-ray emission, disentangle the imprint of the SN on the remnant emission from the effects of the remnant interaction with the environment, and constrain the pre-supernova structure of the nebula.

  4. Bacterial flora of soil after application of oily waste

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, V

    1975-01-01

    The influence of mineral oils and oily waste on the bacterial flora of soil was studied both in the field and in model experiments by plate counts followed by examination of the composition of the bacterial flora developing on the plates and by enrichment cultures followed by isolation of pure cultures. A strong increase in bacterial numbers after oil application was observed both in field and model experiments, and this increase occurred within all groups of bacteria, except spore formers and streptomycetes. The most important species of oil decomposing bacteria belonged to the genera Arthrobacter and Pseudomonas.

  5. The presence of dysplastic nevus remnants in malignant melanomas. A population-based study of 551 malignant melanomas.

    Science.gov (United States)

    Hastrup, N; Osterlind, A; Drzewiecki, K T; Hou-Jensen, K

    1991-08-01

    We examined 512 malignant melanomas, representing all newly diagnosed cutaneous malignant melanomas, excluding lentigo maligna melanomas, from the period October 1, 1982 to March 31, 1985 occurring in the region of eastern Denmark in patients aged 20-79 years for the presence of dysplastic nevus remnants. Criteria for the diagnosis of a dysplastic nevus remnant include all the following changes (a) lentiginous or epithelioid melanocyte hyperplasia, (b) cytologic melanocyte atypia, (c) eosinophilic fibroplasia, (d) lamellar fibroplasia, and (e) lymphocytic infiltration in the dermis. Dysplastic nevus remnants were found in association with 34 (7%) of the evaluable 512 malignant melanomas. Fourteen (41%) of the remnants were of compound nevus type. In nine (27%) of the remnants, atypia was pronounced. Most (62%) dysplastic nevus remnants were contiguous to thin superficial spreading melanomas. We conclude from this population-based study that about 7% of malignant melanomas arise in prior dysplastic nevi.

  6. Mineral oil industry

    NARCIS (Netherlands)

    Brasser, L.J.; Suess, M.J.; Grefen, K.; Reinisch, D.W.

    1985-01-01

    In this chapter a general picture is presented of the air pollution aspects in the mineral oil industry. The complete field is covered, starting from drilling operations and the well head up to the delivery of the products to the consumer. A large field of activities as is given by the mineral oil

  7. Vitamins, Minerals, and Mood

    Science.gov (United States)

    Kaplan, Bonnie J.; Crawford, Susan G.; Field, Catherine J.; Simpson, J. Steven A.

    2007-01-01

    In this article, the authors explore the breadth and depth of published research linking dietary vitamins and minerals (micronutrients) to mood. Since the 1920s, there have been many studies on individual vitamins (especially B vitamins and Vitamins C, D, and E), minerals (calcium, chromium, iron, magnesium, zinc, and selenium), and vitamin-like…

  8. Mineral commodity summaries 2018

    Science.gov (United States)

    Ober, Joyce A.

    2018-01-31

    This report is the earliest Government publication to furnish estimates covering 2017 nonfuel mineral industry data. Data sheets contain information on the domestic industry structure, Government programs, tariffs, and 5-year salient statistics for more than 90 individual minerals and materials.

  9. Indochina area mineral prospects

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-05

    Prospects for commercial mining of various minerals are considered for Kampuchea (Cambodia), Laos, Vietnam, Myanmar (Burma) and Thailand. Mineral production is much below its geologic potential for economic and political reasons. Resource potential is limited to tin, tungsten, lead and zinc, barytes and gemstones, and coal. 1 fig.

  10. [ARTHROSCOPIC STUDY OF REMNANT-PRESERVED RECONSTRUCTION OF ANTERIOR CRUCIATE LIGAMENT].

    Science.gov (United States)

    Lu, Daifeng; Xiao, Mochao; Zhang, Yunpeng; Yan, Shi; Dong, Feng; Lian, Yongyun

    2015-08-01

    To investigate the value of ligament remnant preservation during anterior cruciate ligament (ACL) reconstruction by observing the integrity, the tension, the synovial membrane covering, and the color of the reconstructed ligament under arthroscopy. Between January 2011 and December 2013, 122 patients who underwent ACL reconstruction and arthroscopic internal fixation removal at 1 year after reconstruction were included in this study. Of these cases, 61 cases underwent ACL reconstruction using the remnant-preserved technique (preservation group); the other 61 cases underwent ACL reconstruction using non remnant-preserved technique (non preservation group). There was no significant difference in gender, age, injury side, body mass index, type of injury, the time from injury to reconstruction, and the result of KT-2000 examination between 2 groups (P > 0.05). The reconstructed ACL were observed under arthroscopy when internal fixation was removed, and the effectiveness was evaluated according to the criteria of AO Yingfang. In preservation group, the results were excellent in 34 cases, good in 22 cases, fair in 4 cases, and poor in 1 case; and in non preservation group, the results were excellent in 29 cases, good in 20 cases, fair in 10 cases, and poor in 2 cases; and there was no significant difference between 2 groups (Z= -1.320, P=0.187). In ACL reconstruction, the remnant-preserved technique is not obviously better than non remnant-preserved technique in the integrity, tension, membrane covering, and color.

  11. THE ABSENCE OF EX-COMPANIONS IN TYPE Ia SUPERNOVA REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Di Stefano, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kilic, Mukremin, E-mail: rd@cfa.harvard.edu, E-mail: kilic@ou.edu [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 West Brooks Street, Norman, OK 73019 (United States)

    2012-11-01

    Type Ia supernovae (SNe Ia) play important roles in our study of the expansion and acceleration of the universe, but because we do not know the exact nature or natures of the progenitors, there is a systematic uncertainty that must be resolved if SNe Ia are to become more precise cosmic probes. No progenitor system has ever been identified either in the pre- or post-explosion images of a Ia event. There have been recent claims for and against the detection of ex-companion stars in several SNe Ia remnants. These studies, however, usually ignore the angular momentum gain of the progenitor white dwarf (WD), which leads to a spin-up phase and a subsequent spin-down phase before explosion. For spin-down timescales greater than 10{sup 5} years, the donor star could be too dim to detect by the time of explosion. Here we revisit the current limits on ex-companion stars to SNR 0509-67.5, a 400-year-old remnant in the Large Magellanic Cloud. If the effects of possible angular momentum gain on the WD are included, a wide range of single-degenerate progenitor models are allowed for this remnant. We demonstrate that the current absence of evidence for ex-companion stars in this remnant, as well as other SNe Ia remnants, does not necessarily provide the evidence of absence for ex-companions. We discuss potential ways to identify such ex-companion stars through deep imaging observations.

  12. THE ABSENCE OF EX-COMPANIONS IN TYPE Ia SUPERNOVA REMNANTS

    International Nuclear Information System (INIS)

    Di Stefano, R.; Kilic, Mukremin

    2012-01-01

    Type Ia supernovae (SNe Ia) play important roles in our study of the expansion and acceleration of the universe, but because we do not know the exact nature or natures of the progenitors, there is a systematic uncertainty that must be resolved if SNe Ia are to become more precise cosmic probes. No progenitor system has ever been identified either in the pre- or post-explosion images of a Ia event. There have been recent claims for and against the detection of ex-companion stars in several SNe Ia remnants. These studies, however, usually ignore the angular momentum gain of the progenitor white dwarf (WD), which leads to a spin-up phase and a subsequent spin-down phase before explosion. For spin-down timescales greater than 10 5 years, the donor star could be too dim to detect by the time of explosion. Here we revisit the current limits on ex-companion stars to SNR 0509-67.5, a 400-year-old remnant in the Large Magellanic Cloud. If the effects of possible angular momentum gain on the WD are included, a wide range of single-degenerate progenitor models are allowed for this remnant. We demonstrate that the current absence of evidence for ex-companion stars in this remnant, as well as other SNe Ia remnants, does not necessarily provide the evidence of absence for ex-companions. We discuss potential ways to identify such ex-companion stars through deep imaging observations.

  13. Hot gas in the interstellar medium, from supernova remnants to the diffuse coronal phase

    International Nuclear Information System (INIS)

    Ballet, Jean

    1988-01-01

    This research thesis addresses the study of the hot interstellar medium and of its main component, supernovae remnants. The author studied the hypothesis according to which ions observed in the interstellar medium are produced during the evaporation of cold clouds in the coronal phase. He shows that effects of ionisation delay are important and modify by a factor 10 the total quantity of ions predicted by the model. The study of the influence on ionisation of hot electrons penetrating cold layers revealed that this effect is rather weak. Then, based on the observation of the Kepler supernovae remnants by means of EXOSAT, and on the use of a hydrodynamics code coupled with a step-by-step calculation of ionisation of elements, the author studied the evolution of young supernovae remnants: propagation of the main shock in the interstellar medium, and of the backlash in the matter ejected by the star. The author also studied the X emission of an older supernovae remnant (the Cygnus Loop) by analysing three EXOSAT observations of this remnant. Results of Fabry-Perot spectrophotometry have been used to study optic lines [fr

  14. The role of small woodland remnants on ground dwelling insect conservation in Chaco Serrano, Central Argentina.

    Science.gov (United States)

    Moreno, María Laura; Fernández, María Guadalupe; Molina, Silvia Itati; Valladares, Graciela

    2013-01-01

    Many terrestrial ecosystems are changing due to extensive land use and habitat fragmentation, posing a major threat to biodiversity. In this study, the effects of patch size, isolation, and edge/interior localization on the ground dwelling insect communities in the Chaco Serrano woodland remnants in central Argentina were examined. Sampling was carried out in December 2003 and March 2004 in nine remnants (0.57 to 1000 hectares) using pitfall traps. In total, 7071 individuals representing 12 orders and 79 families were recorded. The taxonomic composition of these communities was linked to remnant size. Insect abundance increased (as did their richness, albeit marginally) as remnant area decreased, with no significant effects of isolation or edge/interior localization on abundance, richness, or diversity. No differential area effects were observed when abundance and richness of predators, scavengers, and herbivores were compared. Thus, ground insect communities in fragmented Chaco Serrano seem to respond mainly to patch level, rather than to within-patch (edge effects) or landscape (isolation) level variables. These results suggest that small Chaco Serrano remnants, by supporting larger ground-dwelling insect assemblages, may play an important role from a conservation viewpoint.

  15. Taxation of unmined minerals

    International Nuclear Information System (INIS)

    Bremberg, B.P.

    1989-01-01

    This paper reports on the Kentucky Revenue Cabinet which began implementing its controversial unmined minerals tax program. The Revenue Cabinet should complete its first annual assessment under this program in December, 1989. The Revenue Cabinet's initial efforts to collect basic data concerning the Commonwealth's coal bearing lands has yielded data coverage for 5 million of Kentucky's 10 million acres of coal lands. Approximately 1000 detailed information returns have been filed. The returns will be used to help create an undeveloped mineral reserves inventory, determine mineral ownership, and value mineral reserves. This new program is run by the Revenue Cabinet's Mineral Valuation Section, under the Division of Technical Support, Department of Property Taxation. It has been in business since September of 1988

  16. Mineral industry in Australia

    International Nuclear Information System (INIS)

    Parbo, S.A.

    1982-01-01

    The paper reviews the history and growth of the mineral industry in Australia and its significance to the nation's economic growth and overseas trade, particularly over the last twenty years during which time production of coal, iron ore, manganese and mineral sands has increased greatly and new discoveries of petroleum, bauxite and nickel have given rise to major new industries. Australia ranks fourteenths in the value of world trade and is among the world's largest exporters of alumina, iron ore, mineral sands, coal, lead, zinc and nickel. Some details of production, processing and exports of the major minerals are given. Comment is made on the policies and roles of the six State Governments and the Federal Government in respect of ownership and control of the mining, processing and exporting of both energy and non-energy minerals. (orig.) [de

  17. Entirely Laparoscopic Gastrectomy and Colectomy for Remnant Gastric Cancer with Gastric Outlet Obstruction and Transverse Colon Invasion

    OpenAIRE

    Kim, Hyun Il; Kim, Min Gyu

    2015-01-01

    It is well known that gastrectomy with curative intent is the best way to improve outcomes of patients with remnant gastric cancer. Recently,several investigators reported their experiences with laparoscopic gastrectomy of remnant gastric cancer. We report the case of an 83-year-old female patient who was diagnosed with remnant gastric cancer with obstruction. She underwent an entirely laparoscopic distal gastrectomy with colectomy because of direct invasion of the transverse colon. The opera...

  18. Bacterial lung abscess

    International Nuclear Information System (INIS)

    Groskin, S.A.; Panicek, D.M.; Ewing, D.K.; Rivera, F.; Math, K.; Teixeira, J.; Heitzman, E.R.

    1987-01-01

    A retrospective review of patients with bacterial lung abscess was carried out. Demographic, clinical, and radiographical features of this patient group are compared with similar data from patients with empyema and/or cavitated lung carcinoma; differential diagnostic points are stressed. The entity of radiographically occult lung abscess is discussed. Complications associated with bacterial lung abscess are discussed. Current therapeutic options and treatment philosophy for patients with bacterial lung abscess are noted

  19. Peritonitis - spontaneous bacterial

    Science.gov (United States)

    Spontaneous bacterial peritonitis (SBP); Ascites - peritonitis; Cirrhosis - peritonitis ... who are on peritoneal dialysis for kidney failure. Peritonitis may have other causes . These include infection from ...

  20. Biodegradation of bacterial polysaccharides adsorbed on montmorillonite

    International Nuclear Information System (INIS)

    Guckert, A.; Tok, H.H.; Jacquin, F.

    1977-01-01

    In this research, by means of a model, a study was made of the biodegradation of microbial organic compounds adsorbed on clays, with a parallel experiment on Fontainebleau sand serving as the control. During incubation the three classes of organic matter ( 14 C-labelled glucose, 14 C-labelled polysaccharides and 14 C-labelled microbial cells) mineralize more actively in the presence of sand than in the presence of clay, since the latter provides protection against biodegradation. Mineralization of the adsorbed organic compounds, however, is marked by clear-cut differences after three weeks - glucose (55%)>polysaccharides (43%)>microbial organisms (7.3%). After incubation, chemical extraction of the organo-mineral complexes by alkaline solvents shows only water-soluble and alkali-soluble products in the case of sand; conversely, in that of montmorillonite the bulk of the 14 C was found in the non-extractable fraction or humin (18.1% of the initial 14 C for glucose, 27.3% for the polysaccharides, and 67.6% for the microbial organisms). A second incubation carried out after a phase in which there was drying and remoistening of the organo-mineral complexes, brings to light the important part played by climatic alternations during the biodegradation process. A new mineralization phase is observed, affecting more the bacterial organisms (14.1%) than the polysaccharides (6.3%), with the glucose-base complexes occupying an intermediate position (11.2%). The chemical fractioning of the organo-mineral complexes following re-incubation shows the stability of 14 C in humin very clearly, especially in the case of polysaccharides, where the mineralization phase relates primarily to the products extractable with alkalis. (author)

  1. Olive oil increases the magnitude of postprandial chylomicron remnants compared to milk fat and safflower oil.

    Science.gov (United States)

    Higashi, K; Ishikawa, T; Shige, H; Tomiyasu, K; Yoshida, H; Ito, T; Nakajima, K; Yonemura, A; Sawada, S; Nakamura, H

    1997-10-01

    The acute effects of olive oil, milk fat and safflower oil on postprandial lipemia and remnant lipoprotein metabolism were investigated. Eight Healthy male volunteers randomly underwent three types of oral fat-vitamin A loading tests. The test drink was a mixture of retinyl palmitate (RP)(50,000 IU of aqueous vitamin A/m2 body surface area) and one of the three types of oils (40 g of fat/m2 body surface area): olive oil (70.7% oleic acid of total fatty acids); milk fat (69.3% saturated fatty acid); safflower oil (74.2% linoleic acid). Olive oil significantly increased plasma triacylglycerol and RP concentrations 4 hours after fat loading, as compared to other fats. Increases of remnant like particle concentrations were higher after olive oil than after the other two fats. These results show that olive oil increases the magnitude of postprandial chylomicrons and chylomicron remnants compared to milk fat and safflower oil.

  2. Three cases of laparoscopic total gastrectomy with intracorporeal esophagojejunostomy for gastric cancer in remnant stomach.

    Science.gov (United States)

    Pan, Yu; Mou, Yi-Ping; Chen, Ke; Xu, Xiao-Wu; Cai, Jia-Qin; Wu, Di; Zhou, Yu-Cheng

    2014-11-13

    Gastric cancer in remnant stomach is a rare tumor but with poor prognosis. Compared with conventional open surgery, laparoscopic gastrectomy has potential benefits for these patients due to advantages resulting from its minimally invasive approach. Herein, we report on three patients with gastric cancer in remnant stomach who underwent laparoscopic total gastrectomy with intracorporeal esophagojejunostomy successfully. The operative time was 280, 250 and 225 minutes, the estimated blood loss was 100, 80 and 50 ml and the length of postoperative hospital stay was seven, eight and nine days respectively. Our experience has suggested that laparoscopic total gastrectomy with intracorporeal esophagojejunostomy can be a safe, feasible and promising option for patients with gastric cancer in remnant stomach.

  3. Optical pulsations in the Large Magellanic Cloud remnant 0540-69.3

    International Nuclear Information System (INIS)

    Middleditch, J.; Pennypacker, C.

    1985-01-01

    The X-ray pulsar PSR0540-693 was discovered in the Large Magellanic Cloud (LMC) supernova remnant, 0540-69.3, as a pulse, with repetition period approx. 50 ms, in Einstein Observatory data. Previous workers had noted that this remnant resembles the Crab Nebula because of the X-ray power law spectrum and suggested that the nebular emission was synchrotron radiation powered by a central pulsar. After the announcement of X-ray pulsed emission, other workers measured the broad optical band properties of the nebula and found evidence for synchrotron emission; and reported that the 4.5-arc s continuum emission remnant has only a tenth of the luminosity of the Crab Nebula. The authors have now detected pulsed optical emission for the X-ray pulsar, having a time-averaged magnitude of approx. 22.7. (author)

  4. Gravitational waves from remnant massive neutron stars of binary neutron star merger: Viscous hydrodynamics effects

    Science.gov (United States)

    Shibata, Masaru; Kiuchi, Kenta

    2017-06-01

    Employing a simplified version of the Israel-Stewart formalism of general-relativistic shear-viscous hydrodynamics, we explore the evolution of a remnant massive neutron star of binary neutron star merger and pay special attention to the resulting gravitational waveforms. We find that for the plausible values of the so-called viscous alpha parameter of the order 10-2 the degree of the differential rotation in the remnant massive neutron star is significantly reduced in the viscous time scale, ≲5 ms . Associated with this, the degree of nonaxisymmetric deformation is also reduced quickly, and as a consequence, the amplitude of quasiperiodic gravitational waves emitted also decays in the viscous time scale. Our results indicate that for modeling the evolution of the merger remnants of binary neutron stars we would have to take into account magnetohydrodynamics effects, which in nature could provide the viscous effects.

  5. Soft X-ray observations of the supernova remnants HB 3 and 3C 58

    Science.gov (United States)

    Galas, C. M. F.; Tuohy, I. R.; Garmire, G. P.

    1980-01-01

    The HEAO 1 A-2 low energy detectors have discovered soft X-ray emission from a source positionally coincident with the supernova remnant HB 3. The flux in the energy range 0.3-2.2 keV is about 6 x 10 to the -11th ergs per sq cm s. The spectral data are fitted to a hydrogen thermal bremsstrahlung model, and the physical parameters of the supernova remnant are estimated. The age derived is about 21,000 years, and the initial blast energy is about 3.1 x 10 to the 50th ergs. Upper limits to the soft X-ray flux and the luminosity of the supernova remnant 3 C 58 are also derived.

  6. Protocol for thyroid remnant ablation after recombinant TSH in thyroid carcinoma

    International Nuclear Information System (INIS)

    Pitoia, F.; Salvai, M.E.; Niepomniszcze, H.; Tamer, E. El

    2009-01-01

    In some countries, in order to perform rhTSH-aided thyroid remnant ablation (TRA) after surgery, it is generally necessary to confirm that thyroidectomy has been almost complete. Otherwise, the nuclear medicine specialist will not administer a high radioiodine dose because it might be hazardous due to the possibility of thyroid remnant actinic thyroiditis. Considering this, it would be necessary to use two rhTSH kits (one for diagnostic purposes and the other one to administer the 131 I dose). In this study, we used an alternative protocol for TRA with the use of one kit of rhTSH in twenty patients diagnosed with low risk papillary thyroid carcinoma. All patients had negative titers of anti-thyroglobulin antibodies. Successful thyroid remnant ablation was confirmed with an undetectable rhTSH stimulated thyroglobulin level ( [es

  7. Microbial ecology of bacterially mediated PCB biodegradation

    International Nuclear Information System (INIS)

    Pettigrew, C.A. Jr.

    1989-01-01

    The roles of plasmid mediated and consortia mediated polychlorinated biphenyl (PCB) biodegradation by bacterial populations isolated from PCB contaminated freshwater sediments were investigated. PCB degrading bacteria were isolated by DNA:DNA colony hybridization, batch enrichments, and chemostat enrichment. Analysis of substrate removal and metabolite production were done using chlorinated biphenyl spray plates, reverse phase high pressure liquid chromatography, Cl - detection, and 14 C-labeled substrate mineralization methods. A bacterial consortium, designated LPS10, involved in a concerted metabolic attack on chlorinated biphenyls, was shown to mineralize 4-chlorobiphenyl (4CB) and 4,4'-dichlorobiphenyl (4,4' CB). The LPS10 consortium was isolated by both batch and chemostat enrichment using 4CB and biphenyl (BP) as sole carbon source and was found to have tree bacterial isolates that predominated; these included: Pseudomonas, testosteroni LPS10A which mediated the breakdown of 4CB and 4,4' CB to the putative meta-cleavage product and subsequently to 4-chlorobenzoic acid (4CBA), an isolate tentatively identified as an Arthrobacter sp. LPS10B which mediated 4CBA degradation, and Pseudomonas putida by A LPS10C whose role in the consortium has not been determined

  8. Mineral facilities of Europe

    Science.gov (United States)

    Almanzar, Francisco; Baker, Michael S.; Elias, Nurudeen; Guzman, Eric

    2010-01-01

    This map displays over 1,700 records of mineral facilities within the countries of Europe and western Eurasia. Each record represents one commodity and one facility type at a single geographic location. Facility types include mines, oil and gas fields, and plants, such as refineries, smelters, and mills. Common commodities of interest include aluminum, cement, coal, copper, gold, iron and steel, lead, nickel, petroleum, salt, silver, and zinc. Records include attributes, such as commodity, country, location, company name, facility type and capacity (if applicable), and latitude and longitude geographical coordinates (in both degrees-minutes-seconds and decimal degrees). The data shown on this map and in table 1 were compiled from multiple sources, including (1) the most recently available data from the U.S. Geological Survey (USGS) Minerals Yearbook (Europe and Central Eurasia volume), (2) mineral statistics and information from the USGS Minerals Information Web site (http://minerals.usgs.gov/minerals/pubs/country/europe.html), and (3) data collected by the USGS minerals information country specialists from sources, such as statistical publications of individual countries, annual reports and press releases of operating companies, and trade journals. Data reflect the most recently published table of industry structure for each country at the time of this publication. Additional information is available from the country specialists listed in table 2.

  9. Agricultural intensification exacerbates spillover effects on soil biogeochemistry in adjacent forest remnants.

    Directory of Open Access Journals (Sweden)

    Raphael K Didham

    Full Text Available Land-use intensification is a central element in proposed strategies to address global food security. One rationale for accepting the negative consequences of land-use intensification for farmland biodiversity is that it could 'spare' further expansion of agriculture into remaining natural habitats. However, in many regions of the world the only natural habitats that can be spared are fragments within landscapes dominated by agriculture. Therefore, land-sparing arguments hinge on land-use intensification having low spillover effects into adjacent protected areas, otherwise net conservation gains will diminish with increasing intensification. We test, for the first time, whether the degree of spillover from farmland into adjacent natural habitats scales in magnitude with increasing land-use intensity. We identified a continuous land-use intensity gradient across pastoral farming systems in New Zealand (based on 13 components of farmer input and soil biogeochemistry variables, and measured cumulative off-site spillover effects of fertilisers and livestock on soil biogeochemistry in 21 adjacent forest remnants. Ten of 11 measured soil properties differed significantly between remnants and intact-forest reference sites, for both fenced and unfenced remnants, at both edge and interior. For seven variables, the magnitude of effects scaled significantly with magnitude of surrounding land-use intensity, through complex interactions with fencing and edge effects. In particular, total C, total N, δ15N, total P and heavy-metal contaminants of phosphate fertilizers (Cd and U increased significantly within remnants in response to increasing land-use intensity, and these effects were exacerbated in unfenced relative to fenced remnants. This suggests movement of livestock into surrounding natural habitats is a significant component of agricultural spillover, but pervasive changes in soil biogeochemistry still occur through nutrient spillover channels alone

  10. The influence of massive black hole binaries on the morphology of merger remnants

    Science.gov (United States)

    Bortolas, E.; Gualandris, A.; Dotti, M.; Read, J. I.

    2018-06-01

    Massive black hole (MBH) binaries, formed as a result of galaxy mergers, are expected to harden by dynamical friction and three-body stellar scatterings, until emission of gravitational waves (GWs) leads to their final coalescence. According to recent simulations, MBH binaries can efficiently harden via stellar encounters only when the host geometry is triaxial, even if only modestly, as angular momentum diffusion allows an efficient repopulation of the binary loss cone. In this paper, we carry out a suite of N-body simulations of equal-mass galaxy collisions, varying the initial orbits and density profiles for the merging galaxies and running simulations both with and without central MBHs. We find that the presence of an MBH binary in the remnant makes the system nearly oblate, aligned with the galaxy merger plane, within a radius enclosing 100 MBH masses. We never find binary hosts to be prolate on any scale. The decaying MBHs slightly enhance the tangential anisotropy in the centre of the remnant due to angular momentum injection and the slingshot ejection of stars on nearly radial orbits. This latter effect results in about 1 per cent of the remnant stars being expelled from the galactic nucleus. Finally, we do not find any strong connection between the remnant morphology and the binary hardening rate, which depends only on the inner density slope of the remnant galaxy. Our results suggest that MBH binaries are able to coalesce within a few Gyr, even if the binary is found to partially erase the merger-induced triaxiality from the remnant.

  11. Mergers in galaxy groups. I. Structure and properties of elliptical remnants

    International Nuclear Information System (INIS)

    Taranu, Dan S.; Dubinski, John; Yee, H. K. C.

    2013-01-01

    We present collisionless simulations of dry mergers in groups of 3 to 25 galaxies to test the hypothesis that elliptical galaxies form at the centers of such groups. Mock observations of the central remnants confirm their similarity to ellipticals, despite having no dissipational component. We vary the profile of the original spiral's bulge and find that ellipticals formed from spirals with exponential bulges have too low Sersic indices. Mergers of spirals with de Vaucouleurs (classical) bulges produce remnants with larger Sersic indices correlated with luminosity, as with Sloan Digital Sky Survey ellipticals. Exponential bulge mergers are better fits to faint ellipticals, whereas classical bulge mergers better match luminous ellipticals. Similarly, luminous ellipticals are better reproduced by remnants undergoing many (>5) mergers, and fainter ellipticals by those with fewer mergers. The remnants follow tight size-luminosity and velocity dispersion-luminosity (Faber-Jackson) relations (<0.12 dex scatter), demonstrating that stochastic merging can produce tight scaling relations if the merging galaxies also follow tight scaling relations. The slopes of the size-luminosity and Faber-Jackson relations are close to observations but slightly shallower in the former case. Both relations' intercepts are offset—remnants are too large but have too low dispersions at fixed luminosity. Some remnants show substantial (v/σ > 0.1) rotational support, although most are slow rotators and few are very fast rotators (v/σ > 0.5). These findings contrast with previous studies concluding that dissipation is necessary to produce ellipticals from binary mergers of spirals. Multiple, mostly minor and dry mergers can produce bright ellipticals, whereas significant dissipation could be required to produce faint, rapidly rotating ellipticals.

  12. X-ray emission of the hot gas and of accelerated particles in supernova remnants

    International Nuclear Information System (INIS)

    Acero, F.

    2008-09-01

    The current observations seem to support the theory that the shock wave of supernova remnants accelerate electrons (representing about 1% of cosmic rays) of the interstellar medium up to energies of about 10 15 eV. However there is still no solid evidence that supernova remnants also accelerate protons (major component of cosmic rays). The X-ray observations of those supernova remnants with the satellite XMM-Newton can provide crucial information on the acceleration mechanisms and on this population of accelerated particles. This thesis presents the X-ray analysis of the supernova remnants RX J1713.7-3946 and SN 1006 for which it has been shown that they accelerate electrons efficiently. As a result, these objects are very good targets to compare the theoretical models of acceleration to the observation. For the first object, I constructed through new XMM-Newton observations, the first high-angular resolution mosaic of the entire supernova remnant. I then compared the X- and gamma-ray emission of this object in order to understand the nature of the gamma-ray emission. This spectral and morphological comparison allowed me to discuss the two possible origins of the gamma-ray radiation (issued by electrons or by protons). For SN 1006, I studied the density of the ambient medium in which the shock wave propagates. This density is a key parameter for the hydrodynamical evolution of the remnant and for studying a future gamma-ray emission. The study of X-ray emission of the gas heated by the shock wave allowed me to better estimate of the value of the density so far poorly constrained for this object. (author)

  13. Definitions of Health Terms: Minerals

    Science.gov (United States)

    ... gov/definitions/mineralsdefinitions.html Definitions of Health Terms : Minerals To use the sharing features on this page, ... National Institutes of Health, Office of Dietary Supplements Minerals Minerals are those elements on the earth and ...

  14. Iron oxyhydroxide mineralization on microbial extracellular polysaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Clara S.; Fakra, Sirine C.; Edwards, David C.; Emerson, David; Banfield, Jillian F.

    2010-06-22

    Iron biominerals can form in neutral pH microaerophilic environments where microbes both catalyze iron oxidation and create polymers that localize mineral precipitation. In order to classify the microbial polymers that influence FeOOH mineralogy, we studied the organic and mineral components of biominerals using scanning transmission X-ray microscopy (STXM), micro X-ray fluorescence ({mu}XRF) microscopy, and high-resolution transmission electron microscopy (HRTEM). We focused on iron microbial mat samples from a creek and abandoned mine; these samples are dominated by iron oxyhydroxide-coated structures with sheath, stalk, and filament morphologies. In addition, we characterized the mineralized products of an iron-oxidizing, stalk-forming bacterial culture isolated from the mine. In both natural and cultured samples, microbial polymers were found to be acidic polysaccharides with carboxyl functional groups, strongly spatially correlated with iron oxyhydroxide distribution patterns. Organic fibrils collect FeOOH and control its recrystallization, in some cases resulting in oriented crystals with high aspect ratios. The impact of polymers is particularly pronounced as the materials age. Synthesis experiments designed to mimic the biomineralization processes show that the polysaccharide carboxyl groups bind dissolved iron strongly but release it as mineralization proceeds. Our results suggest that carboxyl groups of acidic polysaccharides are produced by different microorganisms to create a wide range of iron oxyhydroxide biomineral structures. The intimate and potentially long-term association controls the crystal growth, phase, and reactivity of iron oxyhydroxide nanoparticles in natural systems.

  15. Minerals industry survey 1987

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

    This is the eleventh Minerals Industry Survey produced by the Australian Mining Industry Council. It represents an invaluable time series on the minerals industry's financial performance, as well as an up to date description of the industry for the latest financial year. The survey has been conceived as a supplement to and expansion of the various Australian Bureau of Statistics and Bureau of Mineral Resources, Geology and Geophysics publications which describe the exploration, mining and smelting and refining industries in Australia. The tables in this survey have been prepared by Coopers and Lybrand, Chartered Accountants, based on information supplied to them in confidence by the respondent companies.

  16. Characterization of clay minerals

    International Nuclear Information System (INIS)

    Diaz N, C.; Olguin, M.T.; Solache R, M.; Alarcon H, T.; Aguilar E, A.

    2002-01-01

    The natural clays are the more abundant minerals on the crust. They are used for making diverse industrial products. Due to the adsorption and ion exchange properties of these, a great interest for developing research directed toward the use of natural clays for the waste water treatment has been aroused. As part of such researches it is very important to carry out previously the characterization of the interest materials. In this work the results of the mineral and elemental chemical composition are presented as well as the morphological characteristics of clay minerals from different regions of the Mexican Republic. (Author)

  17. Geonic black holes and remnants in Eddington-inspired Born-Infeld gravity.

    Science.gov (United States)

    Olmo, Gonzalo J; Rubiera-Garcia, D; Sanchis-Alepuz, Helios

    We show that electrically charged solutions within the Eddington-inspired Born-Infeld theory of gravity replace the central singularity by a wormhole supported by the electric field. As a result, the total energy associated with the electric field is finite and similar to that found in the Born-Infeld electromagnetic theory. When a certain charge-to-mass ratio is satisfied, in the lowest part of the mass and charge spectrum the event horizon disappears, yielding stable remnants. We argue that quantum effects in the matter sector can lower the mass of these remnants from the Planck scale down to the TeV scale.

  18. Onion-shell model for cosmic ray electrons and radio synchrotron emission in supernova remnants

    International Nuclear Information System (INIS)

    Beck, R.; Drury, L.O.; Voelk, H.J.; Bogdan, T.J.

    1985-01-01

    The spectrum of cosmic ray electrons, accelerated in the shock front of a supernova remnant (SNR), is calculated in the test-particle approximation using an onion-shell model. Particle diffusion within the evolving remnant is explicity taken into account. The particle spectrum becomes steeper with increasing radius as well as SNR age. Simple models of the magnetic field distribution allow a prediction of the intensity and spectrum of radio synchrotron emission and their radial variation. The agreement with existing observations is satisfactory in several SNR's but fails in other cases. Radiative cooling may be an important effect, especially in SNR's exploding in a dense interstellar medium

  19. Onion-shell model for cosmic ray electrons and radio synchrotron emission in supernova remnants

    Science.gov (United States)

    Beck, R.; Drury, L. O.; Voelk, H. J.; Bogdan, T. J.

    1985-01-01

    The spectrum of cosmic ray electrons, accelerated in the shock front of a supernova remnant (SNR), is calculated in the test-particle approximation using an onion-shell model. Particle diffusion within the evolving remnant is explicity taken into account. The particle spectrum becomes steeper with increasing radius as well as SNR age. Simple models of the magnetic field distribution allow a prediction of the intensity and spectrum of radio synchrotron emission and their radial variation. The agreement with existing observations is satisfactory in several SNR's but fails in other cases. Radiative cooling may be an important effect, especially in SNR's exploding in a dense interstellar medium.

  20. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    . As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will become...

  1. Law of radioactive minerals

    International Nuclear Information System (INIS)

    1980-01-01

    Legal device done in order to standardize and promote the exploration and explotation of radioactive minerals by peruvian and foreign investors. This device include the whole process, since the prospection until the development, after previous auction given by IPEN

  2. Mineral Commodity Summaries 2009

    Science.gov (United States)

    ,

    2009-01-01

    Each chapter of the 2009 edition of the U.S. Geological Survey (USGS) Mineral Commodity Summaries (MCS) includes information on events, trends, and issues for each mineral commodity as well as discussions and tabular presentations on domestic industry structure, Government programs, tariffs, 5-year salient statistics, and world production and resources. The MCS is the earliest comprehensive source of 2008 mineral production data for the world. More than 90 individual minerals and materials are covered by two-page synopses. For mineral commodities for which there is a Government stockpile, detailed information concerning the stockpile status is included in the two-page synopsis. Because specific information concerning committed inventory was no longer available from the Defense Logistics Agency, National Defense Stockpile Center, that information, which was included in earlier Mineral Commodity Summaries publications, has been deleted from Mineral Commodity Summaries 2009. National reserves and reserve base information for most mineral commodities found in this report, including those for the United States, are derived from a variety of sources. The ideal source of such information would be comprehensive evaluations that apply the same criteria to deposits in different geographic areas and report the results by country. In the absence of such evaluations, national reserves and reserve base estimates compiled by countries for selected mineral commodities are a primary source of national reserves and reserve base information. Lacking national assessment information by governments, sources such as academic articles, company reports, common business practice, presentations by company representatives, and trade journal articles, or a combination of these, serve as the basis for national reserves and reserve base information reported in the mineral commodity sections of this publication. A national estimate may be assembled from the following: historically reported

  3. sequenceMiner algorithm

    Data.gov (United States)

    National Aeronautics and Space Administration — Detecting and describing anomalies in large repositories of discrete symbol sequences. sequenceMiner has been open-sourced! Download the file below to try it out....

  4. Mineral industry statistics 1975

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    Production, consumption and marketing statistics are given for solid fuels (coal, peat), liquid fuels and gases (oil, natural gas), iron ore, bauxite and other minerals quarried in France, in 1975. Also accident statistics are included. Production statistics are presented of the Overseas Departments and territories (French Guiana, New Caledonia, New Hebrides). An account of modifications in the mining field in 1975 is given. Concessions, exploitation permits, and permits solely for prospecting for mineral products are discussed. (In French)

  5. Coastal placer minerals

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.; Gujar, A.R.

    to be processed and purified to extract the metal either by sulphate or chloride route. The economical aspects of placer mining would involve the cost to benefit ratio, which would encompass the money Selective sorting has resulted in two distinct sediments... or mineral at the national and international levels. Interestingly, though gold is the most sought metal and the prices per gram keep rising, there are others that are much more costly such as diamond and rare earth metals. Uses of Heavy Minerals...

  6. [Pneumoconiosis in bauxite miners].

    Science.gov (United States)

    Molinini, R; Pesola, M; Digennaro, M A; Carino, M; Nuzzaco, A; Coviello, F

    1985-01-01

    The authors examined a group of 40 miners who were being working at an Apulian bauxite mine, presently inactive. Radiographic findings of pulmonary micronodulation without significant reduction of lung functions were showed in 15 miners. Mineralogical analysis of mine dust samples excluded any presence of more than 1% free silica. As a result of this study hypotheses have been formulated about pathogenesis of this moderated and non-invasive pneumoconiosis, showed in long exposed subjects to low silica content dusts.

  7. Mineral commodity summaries 2013

    Science.gov (United States)

    ,

    2013-01-01

    Each chapter of the 2013 edition of the U.S. Geological Survey (USGS) Mineral Commodity Summaries (MCS) includes information on events, trends, and issues for each mineral commodity as well as discussions and tabular presentations on domestic industry structure, Government programs, tariffs, 5-year salient statistics, and world production and resources. The MCS is the earliest comprehensive source of 2012 mineral production data for the world. More than 90 individual minerals and materials are covered by two-page synopses. For mineral commodities for which there is a Government stockpile, detailed information concerning the stockpile status is included in the two-page synopsis. Abbreviations and units of measure, and definitions of selected terms used in the report, are in Appendix A and Appendix B, respectively. “Appendix C—Reserves and Resources” includes “Part A—Resource/Reserve Classification for Minerals” and “Part B—Sources of Reserves Data.” A directory of USGS minerals information country specialists and their responsibilities is Appendix D. The USGS continually strives to improve the value of its publications to users. Constructive comments and suggestions by readers of the MCS 2013 are welcomed.

  8. Mineral commodity summaries 2014

    Science.gov (United States)

    ,

    2014-01-01

    Each chapter of the 2014 edition of the U.S. Geological Survey (USGS) Mineral Commodity Summaries (MCS) includes information on events, trends, and issues for each mineral commodity as well as discussions and tabular presentations on domestic industry structure, Government programs, tariffs, 5-year salient statistics, and world production and resources. The MCS is the earliest comprehensive source of 2013 mineral production data for the world. More than 90 individual minerals and materials are covered by two-page synopses. For mineral commodities for which there is a Government stockpile, detailed information concerning the stockpile status is included in the two-page synopsis. Abbreviations and units of measure, and definitions of selected terms used in the report, are in Appendix A and Appendix B, respectively. “Appendix C—Reserves and Resources” includes “Part A—Resource/Reserve Classification for Minerals” and “Part B—Sources of Reserves Data.” A directory of USGS minerals information country specialists and their responsibilities is Appendix D. The USGS continually strives to improve the value of its publications to users. Constructive comments and suggestions by readers of the MCS 2014 are welcomed.

  9. EXOTIC PLANTS IN THE CIBODAS BOTANIC GARDENS REMNANT FOREST: INVENTORY AND CLUSTER ANALYSIS OF SEVERAL ENVIRONMENTAL FACTORS

    Directory of Open Access Journals (Sweden)

    Decky Indrawan Junaedi

    2014-01-01

    Full Text Available Due to potential impact of invasive alien (exotic species to the natural ecosystems, inventory of exotic species in the Cibodas Botanic Gardens (CBG remnant forest area is an urgent need for CBG. Inventory of exotic species can assist gardens manager to set priorities and plan better responses for possible or existed invasive plants in the CBG remnants forest. The objectives of this study are to do inventory of the exotic species in the CBG remnant forest and to determine whether several environmental variables play role to the existence of exotic species in the CBG remnant forests. There are 26 exotic plant species (23 genera, 14 families found and recorded from all four remnant forests in CBG. Cluster analysis of four environmental variables shows that clustering of environmental factors of exotic species correlates with the abundances of those exotic species. The relation between environmental factor clusters and the abundance of those exotics signify the role of environmental variables on the existence of exotic plant species. The information of exotic plant species in the remnants forest is the base information for gardens manager to manage exotic species in CBG remnants forest. The relation of several environmental factors with exotic species abundance could assist gardens manager to understand better the supportive and or suppressor factors of exotics in the CBG remnants forest. Further study on these species is needed to set priorities to decide which species should be treated first in order to minimize the impact of exotic plant species to native ecosystem of CBG.

  10. EXOTIC PLANTS IN THE CIBODAS BOTANIC GARDENS REMNANT FOREST: INVENTORY AND CLUSTER ANALYSIS OF SEVERAL ENVIRONMENTAL FACTORS

    Directory of Open Access Journals (Sweden)

    Decky Indrawan Junaedi

    2014-01-01

    Full Text Available Due to potential impact of invasive alien (exotic species to the natural ecosystems, inventory of exotic species in the Cibodas Botanic Gardens (CBG remnant forest area is an urgent need for CBG. Inventory of exotic species can assist gardens manager to set priorities and plan better responses for possible or existed invasive plants in the CBG remnants forest. The objectives of this study are to do inventory of the exotic species in the CBG remnant forest and to determine whether several environmental variables play role to the existence of exotic species in the CBG remnant forests. There are 26 exotic plant species  (23 genera, 14 families found and recorded from all four remnant forests in CBG. Cluster analysis of four environmental variables shows that clustering of environmental factors of exotic species correlates with the abundances of those exotic species. The relation between environmental factor clusters and the abundance of those exotics signify the role of environmental variables on the existence of exotic plant species. The information of exotic plant species in the remnants forest is the base information for gardens manager to manage exotic species in CBG remnants forest. The relation of several environmental factors with exotic species abundance could assist gardens manager to understand better the supportive and or suppressor factors of exotics in the CBG remnants forest. Further study on these species is needed to set priorities to decide which species should be treated first in order to minimize the impact of exotic plant species to native ecosystem of CBG.

  11. Modeling supernova remnants: effects of diffusive cosmic-ray acceleration on the evolution and application to observations

    NARCIS (Netherlands)

    Kosenko, D.; Blinnikov, S.; Vink, J.

    2011-01-01

    We present numerical models for supernova remnant evolution, using a new version of the hydrodynamical code SUPREMNA. We added a cosmic-ray diffusion equation to the code scheme, employing a two-fluid approximation. We investigate the dynamics of the simulated supernova remnants with different

  12. Effects of mineral and vitamin supplementation to pasteurized whole milk diets on growth and health of preruminant Holstein bull calves

    Science.gov (United States)

    Our objective was to determine whether supplementation of vitamins and trace minerals (VTM), formulated to meet or exceed NRC requirements when added to pasteurized whole milk (PWM), increases challenge resolution and prevents intestinal macromolecular permeability after injection with bacterial lip...

  13. Clinical relevance of non-fasting and postprandial hypertriglyceridemia and remnant cholesterol

    DEFF Research Database (Denmark)

    Nordestgaard, Børge G; Freiberg, Jacob J

    2011-01-01

    Non-fasting triglycerides are measured at any time within up to 8 h (14 h) after any normal meal, while postprandial triglycerides are measured at a fixed time point within up to 8 h (14 h) of a standardised fat tolerance test. The simplest possible way of evaluating remnant cholesterol is non......-fasting/postprandial total cholesterol minus low-density lipoprotein (LDL) cholesterol minus high-density lipoprotein (HDL) cholesterol. Elevated levels of non-fasting/postprandial triglycerides directly correlate with elevated remnant cholesterol. In the general population, 38% of men have non......-fasting/postprandial triglycerides > 2mmol/L (>176 mg/dL) while 45% of men have non-fasting/postprandial triglyceride levels of 1-2 mmol/L (89-176 mg/dL); corresponding fractions in women are 20% and 47%. Also, 31% of men have remnant cholesterol levels > 1mmol/L (>39 mg/dL) while 46% of men have remnant cholesterol levels of 0...

  14. AN X-RAY INVESTIGATION OF THREE SUPERNOVA REMNANTS IN THE LARGE MAGELLANIC CLOUD

    International Nuclear Information System (INIS)

    Klimek, Matthew D.; Points, S. D.; Smith, R. C.; Shelton, R. L.; Williams, R.

    2010-01-01

    We have investigated three supernova remnants (SNRs) in the LMC using multi-wavelength data. These SNRs are generally fainter than the known sample (see Section 4) and may represent a previously missed population. One of our SNRs is the second LMC remnant analyzed which is larger than any Galactic remnant for which a definite size has been established. The analysis of such a large remnant contributes to the understanding of the population of highly evolved SNRs. We have obtained X-ray images and spectra of three of these recently identified SNRs using the XMM-Newton observatory. These data, in conjunction with pre-existing optical emission-line images and spectra, were used to determine the physical conditions of the optical- and X-ray-emitting gas in the SNRs. We have compared the morphologies of the SNRs in the different wavebands. The physical properties of the warm ionized shell were determined from the Hα surface brightness and the SNR expansion velocity. The X-ray spectra were fit with a thermal plasma model and the physical conditions of the hot gas were derived from the model fits. Finally, we have compared our observations with simulations of SNR evolution.

  15. Vocal cord paralysis following I-131 ablation of a postthyroidectomy remnant

    International Nuclear Information System (INIS)

    Lee, T.C.; Harbert, J.C.; Dejter, S.W.; Mariner, D.R.; VanDam, J.

    1985-01-01

    Vocal cord paralysis has been reported following I-131 therapy of thyrotoxicosis and following ablation of the whole thryoid. However, this rare complication has not previously been described following I-131 ablation of a postthyroidectomy remnant. The authors report a patient who required tracheostomy for bilateral vocal cord paralysis following I-131 ablation after near-total thyroidectomy for papillary thyroid carcinoma

  16. Case Report: CT diagnosis of thymic remnant cyst/thymopharyngeal duct cyst

    International Nuclear Information System (INIS)

    Daga, Bipin V; Chaudhary, VA; Dhamangaokar, VB

    2009-01-01

    A 4-year-old boy presented with history of left anterolateral neck swelling since birth. He was clinically diagnosed to have a branchial cleft cyst. A CT scan revealed findings suggestive of a thymic remnant cyst. The lesion was excised and the diagnosis was confirmed by histopathology

  17. Gamma-ray bursts from stellar remnants - Probing the universe at high redshift

    NARCIS (Netherlands)

    Wijers, R.A.M.J.; Bloom, J.S.; Bagla, J.S.; Natarajan, P.

    1998-01-01

    A gamma-ray burst (GRB) releases an amount of energy similar to that of a supernova explosion, which combined with its rapid variability suggests an origin related to neutron stars or black holes. Since these compact stellar remnants form from the most massive stars not long after their birth, GRBs

  18. HIGH RESOLUTION 36 GHz IMAGING OF THE SUPERNOVA REMNANT OF SN 1987A

    International Nuclear Information System (INIS)

    Potter, T. M.; Staveley-Smith, L.; Zanardo, G.; Ng, C.-Y.; Gaensler, B. M.; Ball, Lewis; Kesteven, M. J.; Manchester, R. N.; Tzioumis, A. K.

    2009-01-01

    The aftermath of supernova (SN) 1987A continues to provide spectacular insights into the interaction between an SN blastwave and its circumstellar environment. We here present 36 GHz observations from the Australia Telescope Compact Array of the radio remnant of SN 1987A. These new images, taken in 2008 April and 2008 October, substantially extend the frequency range of an ongoing monitoring and imaging program conducted between 1.4 and 20 GHz. Our 36.2 GHz images have a diffraction-limited angular resolution of 0.''3-0.''4, which covers the gap between high resolution, low dynamic range VLBI images of the remnant and low resolution, high dynamic range images at frequencies between 1 and 20 GHz. The radio morphology of the remnant at 36 GHz is an elliptical ring with enhanced emission on the eastern and western sides, similar to that seen previously at lower frequencies. Model fits to the data in the Fourier domain show that the emitting region is consistent with a thick inclined torus of mean radius 0.''85, and a 2008 October flux density of 27 ± 6 mJy at 36.2 GHz. The spectral index for the remnant at this epoch, determined between 1.4 GHz and 36.2 GHz, is α = -0.83. There is tentative evidence for an unresolved central source with flatter spectral index.

  19. Numerical Simulations of Supernova Remnant Evolution in a Cloudy Interstellar Medium

    Energy Technology Data Exchange (ETDEWEB)

    Slavin, Jonathan D.; Smith, Randall K.; Foster, Adam; Winter, Henry D.; Raymond, John C.; Slane, Patrick O. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Yamaguchi, Hiroya, E-mail: jslavin@cfa.harvard.edu [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)

    2017-09-01

    The mixed morphology class of supernova remnants has centrally peaked X-ray emission along with a shell-like morphology in radio emission. White and Long proposed that these remnants are evolving in a cloudy medium wherein the clouds are evaporated via thermal conduction once being overrun by the expanding shock. Their analytical model made detailed predictions regarding temperature, density, and emission profiles as well as shock evolution. We present numerical hydrodynamical models in 2D and 3D including thermal conduction, testing the White and Long model and presenting results for the evolution and emission from remnants evolving in a cloudy medium. We find that, while certain general results of the White and Long model hold, such as the way the remnants expand and the flattening of the X-ray surface brightness distribution, in detail there are substantial differences. In particular we find that the X-ray luminosity is dominated by emission from shocked cloud gas early on, leading to a bright peak, which then declines and flattens as evaporation becomes more important. In addition, the effects of thermal conduction on the intercloud gas, which is not included in the White and Long model, are important and lead to further flattening of the X-ray brightness profile as well as lower X-ray emission temperatures.

  20. X-ray emission from reverse-shocked ejecta in supernova remnants

    Science.gov (United States)

    Cioffi, Denis F.; Mckee, Christopher F.

    1990-01-01

    A simple physical model of the dynamics of a young supernova remnant is used to derive a straightforward kinematical description of the reverse shock. With suitable approximations, formulae can then be developed to give the X-ray emission of the reverse-shocked ejecta. The results are found to agree favorably with observations of SN1006.

  1. Use of radionuclide techniques for assessment of splenic function and detection of splenic remnants

    International Nuclear Information System (INIS)

    Ganguly, S.; Sinha, S.; Sarkar, B.R.; Basu, S.; Ghosh, S.

    1998-01-01

    Full text: The spleen is often involved in hematological malignancies; it is also the site of RBC destruction in thalassemia and ITP. In latter cases, splenectomy is often performed and postoperatively, detection of functioning splenic remnants affect the prognosis adversely. In this study, we assessed the usefulness of radionuclide techniques in : a) assessment of splenic function in primarily non-splenic diseases (benign or malignant), and b) detection of splenic remnant after splenectomy. 12 patients of splenomegaly and 5 patients after splenectomy underwent splenic imaging; imaging was performed using both 99m Tc-sulphur colloid (with first pass) and 99m Tc labelled heat denatured RBCs as tracers. Thus splenic perfusion, morphology and RBC trapping functions were all assessed. The colloid images usually matched the RBC images except in 2 cases where photogenic areas (presumably infarcts) were visualized on RBC scans that were missed on colloid scans. Three of the post splenectomy cases revealed functioning splenic remnants, which was also better visualized on RBC scans. It is concluded that radionuclide imaging could be used regularly for assessing function of spleen, or detecting splenic remnants

  2. Clinical outcomes of endoscopic submucosal dissection for early gastric cancer in remnant stomach or gastric tube.

    Science.gov (United States)

    Nishide, N; Ono, H; Kakushima, N; Takizawa, K; Tanaka, M; Matsubayashi, H; Yamaguchi, Y

    2012-06-01

    Little information exists regarding the optimal treatment of early gastric cancer (EGC) in a remnant stomach or gastric tube. The aim of this study was to assess the feasibility and clinical outcomes of endoscopic submucosal dissection (ESD) for EGC in a remnant stomach and gastric tube. Between September 2002 and December 2009, ESD was performed in 62 lesions in 59 patients with EGC in a remnant stomach (48 lesions) or gastric tube (14 lesions). Clinicopathological data were retrieved retrospectively to assess the en bloc resection rate, complications, and outcomes. Treatment results were assessed according to the indications for endoscopic resection, and were compared with those of ESD performed in a whole stomach during the same study period. The en bloc resection rates for lesions within the standard and expanded indication were 100 % and 93 %, respectively. Postoperative bleeding occurred in five patients (8 %). The perforation rate was significantly higher (18 %, 11 /62) than that of ESD in a whole stomach (5 %, 69 /1479). Among the perforation cases, eight lesions involved the anastomotic site or stump line, and ulcerative changes were observed in five lesions. The 3-year overall survival rate was 85 %, with eight deaths due to other causes and no deaths from gastric cancer. A high en bloc resection rate was achieved by ESD for EGC in a remnant stomach or gastric tube; however, this procedure is still technically demanding due to the high complication rate of perforation. © Georg Thieme Verlag KG Stuttgart · New York.

  3. The influence of thermal pressure on equilibrium models of hypermassive neutron star merger remnants

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, J. D.; Ott, C. D.; Roberts, L. [TAPIR, California Institute of Technology, Mailcode 350-17, Pasadena, CA 91125 (United States); O' Connor, E. P. [CITA, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Kiuchi, K. [Yukawa Institute for Theoretical Physics, University of Kyoto, Kyoto (Japan); Duez, M., E-mail: cott@tapir.caltech.edu [Department of Physics and Astronomy, Washington State University, Pullman, WA (United States)

    2014-07-20

    The merger of two neutron stars leaves behind a rapidly spinning hypermassive object whose survival is believed to depend on the maximum mass supported by the nuclear equation of state (EOS), angular momentum redistribution by (magneto-)rotational instabilities, and spindown by gravitational waves. The high temperatures (∼5-40 MeV) prevailing in the merger remnant may provide thermal pressure support that could increase its maximum mass and, thus, its life on a neutrino-cooling timescale. We investigate the role of thermal pressure support in hypermassive merger remnants by computing sequences of spherically symmetric and axisymmetric uniformly and differentially rotating equilibrium solutions to the general-relativistic stellar structure equations. Using a set of finite-temperature nuclear EOS, we find that hot maximum-mass critically spinning configurations generally do not support larger baryonic masses than their cold counterparts. However, subcritically spinning configurations with mean density of less than a few times nuclear saturation density yield a significantly thermally enhanced mass. Even without decreasing the maximum mass, cooling and other forms of energy loss can drive the remnant to an unstable state. We infer secular instability by identifying approximate energy turning points in equilibrium sequences of constant baryonic mass parameterized by maximum density. Energy loss carries the remnant along the direction of decreasing gravitational mass and higher density until instability triggers collapse. Since configurations with more thermal pressure support are less compact and thus begin their evolution at a lower maximum density, they remain stable for longer periods after merger.

  4. The influence of thermal pressure on equilibrium models of hypermassive neutron star merger remnants

    International Nuclear Information System (INIS)

    Kaplan, J. D.; Ott, C. D.; Roberts, L.; O'Connor, E. P.; Kiuchi, K.; Duez, M.

    2014-01-01

    The merger of two neutron stars leaves behind a rapidly spinning hypermassive object whose survival is believed to depend on the maximum mass supported by the nuclear equation of state (EOS), angular momentum redistribution by (magneto-)rotational instabilities, and spindown by gravitational waves. The high temperatures (∼5-40 MeV) prevailing in the merger remnant may provide thermal pressure support that could increase its maximum mass and, thus, its life on a neutrino-cooling timescale. We investigate the role of thermal pressure support in hypermassive merger remnants by computing sequences of spherically symmetric and axisymmetric uniformly and differentially rotating equilibrium solutions to the general-relativistic stellar structure equations. Using a set of finite-temperature nuclear EOS, we find that hot maximum-mass critically spinning configurations generally do not support larger baryonic masses than their cold counterparts. However, subcritically spinning configurations with mean density of less than a few times nuclear saturation density yield a significantly thermally enhanced mass. Even without decreasing the maximum mass, cooling and other forms of energy loss can drive the remnant to an unstable state. We infer secular instability by identifying approximate energy turning points in equilibrium sequences of constant baryonic mass parameterized by maximum density. Energy loss carries the remnant along the direction of decreasing gravitational mass and higher density until instability triggers collapse. Since configurations with more thermal pressure support are less compact and thus begin their evolution at a lower maximum density, they remain stable for longer periods after merger.

  5. Effect of statin versus fibrate on postprandial endothelial dysfunction: role of remnant-like particles

    NARCIS (Netherlands)

    Wilmink, H. W.; Twickler, M. B.; Banga, J. D.; Dallinga-Thie, G. M.; Eeltink, H.; Erkelens, D. W.; Rabelink, T. J.; Stroes, E. S.

    2001-01-01

    BACKGROUND: Postprandial lipemia is associated with endothelial dysfunction. Remnant-like particles (RLP) have been suggested to contribute to these adverse vascular effects. We investigated the effect of cerivastatin and gemfibrozil upon oral fat load induced changes in endothelial function and

  6. Bat activity at remnant oak trees in California Central Coast vineyards

    Science.gov (United States)

    William D. Tietje; Ted Weller; Christopher C. Yim

    2015-01-01

    During 1990 to 2013, the area planted with wine grapes increased nearly 4.5 times in San Luis Obispo County. Much of this development occurred on open oak savanna with scattered oak (Quercus spp.) trees. Remnant trees are retained in some vineyards, but their value to biodiversity retention has not been quantified. During April to September 2014,...

  7. Effect of adhesive remnant removal on enamel topography after bracket debonding

    Directory of Open Access Journals (Sweden)

    Larissa Adrian Meira Cardoso

    2014-12-01

    Full Text Available INTRODUCTION: At orthodontic treatment completion, knowledge about the effects of adhesive remnant removal on enamel is paramount.OBJECTIVE: This study aimed at assessing the effect of different adhesive remnant removal methods on enamel topography (ESI and surface roughness (Ra after bracket debonding and polishing.METHODS: A total of 50 human premolars were selected and divided into five groups according to the method used for adhesive remnant removal: high speed tungsten carbide bur (TCB, Sof-Lex discs (SL, adhesive removing plier (PL, ultrasound (US and Fiberglass burs (FB. Metal brackets were bonded with Transbond XT, stored at 37oC for 24 hours before debonding with adhesive removing plier. Subsequently, removal methods were carried out followed by polishing with pumice paste. Qualitative and quantitative analyses were conducted with pre-bonding, post-debonding and post-polishing analyses. Results were submitted to statistical analysis with F test (ANOVA and Tukey's (Ra as well as with Kruskal-Wallis and Bonferroni tests (ESI (P < 0.05.RESULTS: US Ra and ESI were significantly greater than TCB, SL, PL and FB. Polishing minimized Ra and ESI in the SL and FB groups.CONCLUSION: Adhesive remnant removal with SL and FB associated with polishing are recommended due to causing little damage to the enamel.

  8. Energy Dependence of Synchrotron X-Ray Rims in Tycho's Supernova Remnant

    Science.gov (United States)

    Tran, Aaron; Williams, Brian J.; Petre, Robert; Ressler, Sean M.; Reynolds, Stephen P.

    2015-01-01

    Several young supernova remnants exhibit thin X-ray bright rims of synchrotron radiation at their forward shocks. Thin rims require strong magnetic field amplification beyond simple shock compression if rim widths are only limited by electron energy losses. But, magnetic field damping behind the shock could produce similarly thin rims with less extreme field amplification. Variation of rim width with energy may thus discriminate between competing influences on rim widths. We measured rim widths around Tycho's supernova remnant in 5 energy bands using an archival 750 ks Chandra observation. Rims narrow with increasing energy and are well described by either loss-limited or damped scenarios, so X-ray rim width-energy dependence does not uniquely specify a model. But, radio counterparts to thin rims are not loss-limited and better reflect magnetic field structure. Joint radio and X-ray modeling favors magnetic damping in Tycho's SNR with damping lengths approximately 1-5% of remnant radius and magnetic field strengths approximately 50-400 micron G assuming Bohm diffusion. X-ray rim widths are approximately 1% of remnant radius, somewhat smaller than inferred damping lengths. Electron energy losses are important in all models of X-ray rims, suggesting that the distinction between loss-limited and damped models is blurred in soft X-rays. All loss-limited and damping models require magnetic fields approximately greater than 20 micron G, arming the necessity of magnetic field amplification beyond simple compression.

  9. Supernova remnant S 147 and its associated neutron star(s)

    Science.gov (United States)

    Gvaramadze, V. V.

    2006-07-01

    The supernova remnant S 147 harbors the pulsar PSR J 0538+2817 whose characteristic age is more than an order of magnitude greater than the kinematic age of the system (inferred from the angular offset of the pulsar from the geometric center of the supernova remnant and the pulsar proper motion). To reconcile this discrepancy we propose that PSR J 0538+2817 could be the stellar remnant of the first supernova explosion in a massive binary system and therefore could be as old as its characteristic age. Our proposal implies that S 147 is the diffuse remnant of the second supernova explosion (that disrupted the binary system) and that a much younger second neutron star (not necessarily manifesting itself as a radio pulsar) should be associated with S 147. We use the existing observational data on the system to suggest that the progenitor of the supernova that formed S 147 was a Wolf-Rayet star (so that the supernova explosion occurred within a wind bubble surrounded by a massive shell) and to constrain the parameters of the binary system. We also restrict the magnitude and direction of the kick velocity received by the young neutron star at birth and find that the kick vector should not strongly deviate from the orbital plane of the binary system.

  10. The Derivation of Scandinavian Object Shift and Remnant VP-Topicalisation

    DEFF Research Database (Denmark)

    Engels, Eva; Vikner, Sten

    2013-01-01

    Based on the examination of remnant VP-topicalization constructions, this chapter argues for an order preservation analysis to Scandinavian Object Shift. Reviewing Fox and Pesetsky’s (2003, 2005) cyclic linearization approach and extending the empirical data base, we show that the phenomena are b...

  11. The mineral economy of Brazil--Economia mineral do Brasil

    Science.gov (United States)

    Gurmendi, Alfredo C.; Barboza, Frederico Lopes; Thorman, Charles H.

    1999-01-01

    This study depicts the Brazilian government structure, mineral legislation and investment policy, taxation, foreign investment policies, environmental laws and regulations, and conditions in which the mineral industry operates. The report underlines Brazil's large and diversified mineral endowment. A total of 37 mineral commodities, or groups of closely related commodities, is discussed. An overview of the geologic setting of the major mineral deposits is presented. This report is presented in English and Portuguese in pdf format.

  12. Postviral Complications: Bacterial Pneumonia.

    Science.gov (United States)

    Prasso, Jason E; Deng, Jane C

    2017-03-01

    Secondary bacterial pneumonia after viral respiratory infection remains a significant source of morbidity and mortality. Susceptibility is mediated by a variety of viral and bacterial factors, and complex interactions with the host immune system. Prevention and treatment strategies are limited to influenza vaccination and antibiotics/antivirals respectively. Novel approaches to identifying the individuals with influenza who are at increased risk for secondary bacterial pneumonias are urgently needed. Given the threat of further pandemics and the heightened prevalence of these viruses, more research into the immunologic mechanisms of this disease is warranted with the hope of discovering new potential therapies. Published by Elsevier Inc.

  13. 3-D Model of Broadband Emission from Supernova Remnants Undergoing Non-linear Diffusive Shock Acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Shiu-Hang; Kamae, Tuneyoshi; Ellison, Donald C.

    2008-07-02

    We present a 3-dimensional model of supernova remnants (SNRs) where the hydrodynamical evolution of the remnant is modeled consistently with nonlinear diffusive shock acceleration occurring at the outer blast wave. The model includes particle escape and diffusion outside of the forward shock, and particle interactions with arbitrary distributions of external ambient material, such as molecular clouds. We include synchrotron emission and cooling, bremsstrahlung radiation, neutral pion production, inverse-Compton (IC), and Coulomb energy-loss. Boardband spectra have been calculated for typical parameters including dense regions of gas external to a 1000 year old SNR. In this paper, we describe the details of our model but do not attempt a detailed fit to any specific remnant. We also do not include magnetic field amplification (MFA), even though this effect may be important in some young remnants. In this first presentation of the model we don't attempt a detailed fit to any specific remnant. Our aim is to develop a flexible platform, which can be generalized to include effects such as MFA, and which can be easily adapted to various SNR environments, including Type Ia SNRs, which explode in a constant density medium, and Type II SNRs, which explode in a pre-supernova wind. When applied to a specific SNR, our model will predict cosmic-ray spectra and multi-wavelength morphology in projected images for instruments with varying spatial and spectral resolutions. We show examples of these spectra and images and emphasize the importance of measurements in the hard X-ray, GeV, and TeV gamma-ray bands for investigating key ingredients in the acceleration mechanism, and for deducing whether or not TeV emission is produced by IC from electrons or pion-decay from protons.

  14. The evolving instability of the remnant Larsen B Ice Shelf and its tributary glaciers

    Science.gov (United States)

    Khazendar, Ala; Borstad, Christopher P.; Scheuchl, Bernd; Rignot, Eric; Seroussi, Helene

    2015-06-01

    Following the 2002 disintegration of the northern and central parts of the Larsen B Ice Shelf, the tributary glaciers of the southern surviving part initially appeared relatively unchanged and hence assumed to be buttressed sufficiently by the remnant ice shelf. Here, we modify this perception with observations from IceBridge altimetry and InSAR-inferred ice flow speeds. Our analyses show that the surfaces of Leppard and Flask glaciers directly upstream from their grounding lines lowered by 15 to 20 m in the period 2002-2011. The thinning appears to be dynamic as the flow of both glaciers and the remnant ice shelf accelerated in the same period. Flask Glacier started accelerating even before the 2002 disintegration, increasing its flow speed by ∼55% between 1997 and 2012. Starbuck Glacier meanwhile did not change much. We hypothesize that the different evolutions of the three glaciers are related to their dissimilar bed topographies and degrees of grounding. We apply numerical modeling and data assimilation that show these changes to be accompanied by a reduction in the buttressing afforded by the remnant ice shelf, a weakening of the shear zones between its flow units and an increase in its fracture. The fast flowing northwestern part of the remnant ice shelf exhibits increasing fragmentation, while the stagnant southeastern part seems to be prone to the formation of large rifts, some of which we show have delimited successive calving events. A large rift only 12 km downstream from the grounding line is currently traversing the stagnant part of the ice shelf, defining the likely front of the next large calving event. We propose that the flow acceleration, ice front retreat and enhanced fracture of the remnant Larsen B Ice Shelf presage its approaching demise.

  15. HIGH-RESOLUTION RADIO OBSERVATIONS OF THE REMNANT OF SN 1987A AT HIGH FREQUENCIES

    International Nuclear Information System (INIS)

    Zanardo, Giovanna; Staveley-Smith, L.; Potter, T. M.; Ng, C.-Y.; Gaensler, B. M.; Manchester, R. N.; Tzioumis, A. K.

    2013-01-01

    We present new imaging observations of the remnant of Supernova (SN) 1987A at 44 GHz, performed in 2011 with the Australia Telescope Compact Array (ATCA). The 0.''35 × 0.''23 resolution of the diffraction-limited image is the highest achieved to date in high-dynamic range. We also present a new ATCA image at 18 GHz derived from 2011 observations, which is super-resolved to 0.''25. The flux density is 40 ± 2 mJy at 44 GHz and 81 ± 6 mJy at 18 GHz. At both frequencies, the remnant exhibits a ring-like emission with two prominent lobes, and an east-west brightness asymmetry that peaks on the eastern lobe. A central feature of fainter emission appears at 44 GHz. A comparison with previous ATCA observations at 18 and 36 GHz highlights higher expansion velocities of the remnant's eastern side. The 18-44 GHz spectral index is α = –0.80 (S ν ∝ν α ). The spectral index map suggests slightly steeper values at the brightest sites on the eastern lobe, whereas flatter values are associated with the inner regions. The remnant morphology at 44 GHz generally matches the structure seen with contemporaneous X-ray and Hα observations. Unlike the Hα emission, both the radio and X-ray emission peaks on the eastern lobe. The regions of flatter spectral index align and partially overlap with the optically visible ejecta. Simple free-free absorption models suggest that emission from a pulsar wind nebula or a compact source inside the remnant may now be detectable at high frequencies or at low frequencies if there are holes in the ionized component of the ejecta.

  16. Elevated Remnant Cholesterol Causes Both Low-Grade Inflammation and Ischemic Heart Disease, Whereas Elevated Low-Density Lipoprotein Cholesterol Causes Ischemic Heart Disease Without Inflammation

    DEFF Research Database (Denmark)

    Varbo, Anette; Benn, Marianne; Tybjærg-Hansen, Anne

    2013-01-01

    Elevated nonfasting remnant cholesterol and low-density lipoprotein (LDL) cholesterol are causally associated with ischemic heart disease (IHD), but whether elevated nonfasting remnant cholesterol and LDL cholesterol both cause low-grade inflammation is currently unknown....

  17. Bacterial vaginosis - aftercare

    Science.gov (United States)

    Bacterial vaginosis (BV) is a type of vaginal infection. The vagina normally contains both healthy bacteria and unhealthy bacteria. BV occurs when more unhealthy bacteria grow than healthy bacteria. No one knows ...

  18. Bacterial surface adaptation

    Science.gov (United States)

    Utada, Andrew

    2014-03-01

    Biofilms are structured multi-cellular communities that are fundamental to the biology and ecology of bacteria. Parasitic bacterial biofilms can cause lethal infections and biofouling, but commensal bacterial biofilms, such as those found in the gut, can break down otherwise indigestible plant polysaccharides and allow us to enjoy vegetables. The first step in biofilm formation, adaptation to life on a surface, requires a working knowledge of low Reynolds number fluid physics, and the coordination of biochemical signaling, polysaccharide production, and molecular motility motors. These crucial early stages of biofilm formation are at present poorly understood. By adapting methods from soft matter physics, we dissect bacterial social behavior at the single cell level for several prototypical bacterial species, including Pseudomonas aeruginosa and Vibrio cholerae.

  19. Bacterial intermediate filaments

    DEFF Research Database (Denmark)

    Charbon, Godefroid; Cabeen, M.; Jacobs-Wagner, C.

    2009-01-01

    Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin...

  20. Diagnosis of bacterial infection

    African Journals Online (AJOL)

    direct or indirect evidence of a compatible bacterial pathogen. Inflammation may be .... cardinal features (fever, confusion, headache and neck stiffness). .... specificity, inappropriate indications or poor sampling technique may diminish this ...

  1. Microbially mediated mineral carbonation

    Science.gov (United States)

    Power, I. M.; Wilson, S. A.; Dipple, G. M.; Southam, G.

    2010-12-01

    Mineral carbonation involves silicate dissolution and carbonate precipitation, which are both natural processes that microorganisms are able to mediate in near surface environments (Ferris et al., 1994; Eq. 1). (Ca,Mg)SiO3 + 2H2CO3 + H2O → (Ca,Mg)CO3 + H2O + H4SiO4 + O2 (1) Cyanobacteria are photoautotrophs with cell surface characteristics and metabolic processes involving inorganic carbon that can induce carbonate precipitation. This occurs partly by concentrating cations within their net-negative cell envelope and through the alkalinization of their microenvironment (Thompson & Ferris, 1990). Regions with mafic and ultramafic bedrock, such as near Atlin, British Columbia, Canada, represent the best potential sources of feedstocks for mineral carbonation. The hydromagnesite playas near Atlin are a natural biogeochemical model for the carbonation of magnesium silicate minerals (Power et al., 2009). Field-based studies at Atlin and corroborating laboratory experiments demonstrate the ability of a microbial consortium dominated by filamentous cyanobacteria to induce the precipitation of carbonate minerals. Phototrophic microbes, such as cyanobacteria, have been proposed as a means for producing biodiesel and other value added products because of their efficiency as solar collectors and low requirement for valuable, cultivable land in comparison to crops (Dismukes et al., 2008). Carbonate precipitation and biomass production could be facilitated using specifically designed ponds to collect waters rich in dissolved cations (e.g., Mg2+ and Ca2+), which would allow for evapoconcentration and provide an appropriate environment for growth of cyanobacteria. Microbially mediated carbonate precipitation does not require large quantities of energy or chemicals needed for industrial systems that have been proposed for rapid carbon capture and storage via mineral carbonation (e.g., Lackner et al., 1995). Therefore, this biogeochemical approach may represent a readily

  2. Estimation of Remnant Dentin Thickness under Proximal Caries Using Digital Bitewing Radiography: An In-Vitro Study

    Directory of Open Access Journals (Sweden)

    Masoomeh Afsa

    2015-12-01

    Full Text Available Objectives: In restorative dentistry, it is essential to estimate the amount of remnant tooth structure after caries removal to make the best treatment plan. The present study was aimed to determine whether there is a correlation between the real thickness of remnant dentin under carious lesion and the radiographical measurement from photostimulable phosphor plates (PSPs. Methods: a whole number of 68 unrestored permanent human molar and premolar teeth with 82 proximal carious surfaces were mounted in an artificial arch. Digital bitewing radiographs with PSPs were taken, carious lesions were removed and radiographic imaging was repeated. Teeth were sectioned mesiodistally in two parts and thickness of remnant tooth structure to pulp was measured. Measurements of remnant dentin under caries from radiographic images and teeth structures were compared. Result: The mean measurements of remnant dentin on primary radiographs were statistically different from the measurements on teeth structures. The mean thickness of remnant dentin on tooth structure was around 30% less than what measured on radiographic image. Conclusion: The real thickness of remnant dentin under caries is about 70% of its thickness measured on digital bitewing radiographs prepared by PSPs as image receptor.

  3. AN X-RAY AND RADIO STUDY OF THE VARYING EXPANSION VELOCITIES IN TYCHO’S SUPERNOVA REMNANT

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Brian J. [CRESST/USRA and X-ray Astrophysics Laboratory, NASA GSFC, 8800 Greenbelt Road, Greenbelt, MD, Code 662 (United States); Chomiuk, Laura [Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States); Hewitt, John W. [University of North Florida, Department of Physics, 1 UNF Drive, Jacksonville, FL 32224 (United States); Blondin, John M.; Borkowski, Kazimierz J.; Reynolds, Stephen P. [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Ghavamian, Parviz [Department of Physics, Astronomy, and Geosciences, Towson University, Towson, MD 21252 (United States); Petre, Robert, E-mail: brian.j.williams@nasa.gov [NASA GSFC, X-ray Astrophysics Laboratory, Greenbelt, MD 20771 (United States)

    2016-06-01

    We present newly obtained X-ray and radio observations of Tycho’s supernova remnant using Chandra and the Karl G. Jansky Very Large Array in 2015 and 2013/14, respectively. When combined with earlier epoch observations by these instruments, we now have time baselines for expansion measurements of the remnant of 12–15 years in the X-rays and 30 years in the radio. The remnant’s large angular size allows for proper motion measurements at many locations around the periphery of the blast wave. Consistent with earlier measurements, we find a clear gradient in the expansion velocity of the remnant, despite its round shape. The proper motions on the western and southwestern sides of the remnant are about a factor of two higher than those in the east and northeast. We showed in an earlier work that this is related to an offset of the explosion site from the geometric center of the remnant due to a density gradient in the ISM, and using our refined measurements reported here, we find that this offset is ∼23″ toward the northeast. An explosion center offset in such a circular remnant has implications for searches for progenitor companions in other remnants.

  4. Sleeve Gastrectomy: Correlation of Long-Term Results with Remnant Morphology and Eating Disorders.

    Science.gov (United States)

    Tassinari, Daniele; Berta, Rossana D; Nannipieri, Monica; Giusti, Patrizia; Di Paolo, Luca; Guarino, Daniela; Anselmino, Marco

    2017-11-01

    Remnant dimension is considered one of the crucial elements determining the success of sleeve gastrectomy (SG), and dilation of the gastric fundus is often believed to be the main cause of failure. The main outcome of this study is to find correlations between remnant morphology in the immediate post-operative stage, its dilation in years, and the long-term results. The second purpose aims to correlate preoperative eating disorders, taste alteration, hunger perception, and early satiety with post-SG results. Remnant morphology was evaluated, in the immediate post-operative stage and over the years (≥2 years), through X-ray of the oesophagus-stomach-duodenum calculating the surface in anteroposterior (AP) and right anterior oblique projection (RAO). Presurgery diagnosis of eating disorders and their evaluation through "Eating Disorder Inventory-3" (EDI3) during follow-up were performed. Change in taste perception, sense of appetite, and early satiety were evaluated. Patients were divided into two groups: "failed SGs (EWL50%). There were a total of 50 patients (37 F, 13 M), with mean age 52 years, preoperative weight 131 ± 21.8 kg, and BMI 47.4 ± 6.8 kg/m 2 . Post-operative remnant mean dimensions overlapped between the two groups. On a long-term basis, an increase of 57.2 and 48.4% was documented in the AP and RAO areas respectively. In "failed" SGs, dilation was significantly superior to "efficient" SGs (AP area 70.2 vs 46.1%; RAO area 59.3 vs 39%; body width 102% vs 41.7%). Preoperative eating disorders were more present in efficient SGs than in failed SGs with the exception of sweet eating. There were no significant changes to taste perception during follow-up. Fifty-two percent of efficient SGs vs 26% of failed SGs reported a persistent lack of sense of hunger; similarly, 92.5 vs 78% declared the persistence of a sense of early satiety. The two groups did not statistically differ as far as all the variables of the EDI3 are concerned. On a long

  5. Radioiodine remnant ablation in differentiated thyroid cancer after combined endogenous and exogenous TSH stimulation.

    Science.gov (United States)

    Vrachimis, A; Schober, O; Riemann, B

    2012-01-01

    Radioiodine remnant ablation (RRA) after (near-)total thyroidectomy (TE) is a key element in patients with differentiated thyroid cancer (DTC). The use of exogenous TSH stimulation (rhTSH) prior to RRA has shown promising results as compared to conventional thyroid hormone withdrawal (THW). As yet, the efficacy of RRA after brief THW and single rhTSH administration has not been assessed. The study sample comprised 147 patients with DTC referred to our center between May 2008 and September 2010. All patients received TE with subsequent RRA. None of these 147 patients had evidence of distant metastasis. 93 patients had endogenous TSH stimulation 4-5 weeks after surgery (group I) and twenty-six received two rhTSH injections (group II). 28 patients were treated with a single rhTSH injection after a brief THW (group III). RRA-Efficacy was assessed three months after therapy by diagnostic whole-body scan and measurement of the tumour marker thyroglobulin (Tg) under TSH stimulation. Three categories of success were defined for remnant ablation. Based on the definition of successful remnant ablation no visible uptake and a Tg ≤ 2.0 ng/ml (category 1) was seen in 62/93 patients in group I, in 17/26 patients in group II (p = n.s.) and in 12/28 patients in group III (p 2.0 ng/ml (category 3) was found in 3/93 patients in group I and 1/26 patients in group II but in no patient in group III. The third strategy of remnant ablation using a single injection of rhTSH after a brief THW period resulted in a significant higher rate of patients with residual uptake in the thyroid bed and a Tg level below 2 ng/ml three months after remnant ablation in comparison to THW. However, the overall efficacy of the third protocol was not significantly different as compared to two rhTSH injections. Under the aspect of the supply shortage of rhTSH the combined endogenous and exogenous TSH stimulation may be an attractive alternative for remnant ablation in differentiated thyroid cancer.

  6. Low temperature anaerobic bacterial diagenesis of ferrous monosulfide to pyrite

    Science.gov (United States)

    Donald, Ravin; Southam, Gordon

    1999-07-01

    In vitro enrichment cultures of dissimilatory sulfate-reducing bacteria precipitated FeS and catalyzed its transformation into FeS 2 at ambient temperature and pressure under anaerobic conditions. When compared to purely abiotic processes, the bacterially mediated transformation was shown to be more efficient in transforming FeS into FeS 2. This occurred due to the large, reactive surface area available for bacterially catalyzed diagenesis, where the biogenic FeS precursor was immobilized as a thin film (˜25 nm thick) on the μm-scale bacteria. The bacteria also contained the source(s) of sulfur for diagenesis to occur. Using a radiolabeled organic-sulfur tracer study, sulfur was released during cell autolysis and was immobilized at the bacterial cell surface forming FeS 2. The formation of FeS 2 occurred on both the inner and outer surfaces of the cell envelope and represented the first step of bacterial mineral diagenesis. Pyrite crystals, having linear dimensions of ˜1 μm, grew outward from the bacterial cell surfaces. These minerals were several orders of magnitude larger in volume than those originating abiotically.

  7. Minerals in deserts

    International Nuclear Information System (INIS)

    Smith, G.I.

    1982-01-01

    Almost any kind of mineral deposit can occur in desert areas, and the lack of vegetation and soil cover makes finding them easier. Some kinds of deposits, though, are more likely to occur in deserts than elsewhere. Some of these result from processes genetically related to the present desert climate that improved lower grade deposits of ore. One such process, termed secondary enrichment, is most effective in areas with deep water tables, and many low-grade copper, silver, and uranium deposits have been converted into mineable ore by the downward migration and redeposition of soluble metals. In a desert terrane, placer processes are effective whenever running water flowing over steep slopes erodes outcropping ore bodies and transports and concentrates the heavier ore minerals at lower levels, thus converting low-grade or hard-to-mine bedrock deposits into economically workable concentrations. Other kinds of deposits are better preserved in deserts because the lower rainfall at the surface, and the lower volume of flow and the greater depths to groundwater, result in less destruction of soluble ores; deposits of salines and phosphates are the most notable ores affected by these factors. Still other ore deposits are created as a consequence of the arid climate, mostly because the high evaporation rates operating on standing bodies of water produce brines that can lead directly to concentrations of salts and indirectly to secondary minerals, such as zeolites, that are produced by reaction of silicate minerals with saline waters

  8. Carbonizing bituminous minerals

    Energy Technology Data Exchange (ETDEWEB)

    1921-05-01

    A process for carbonizing bituminous minerals, like oil-shale, in a furnace with addition of air in the presence of heat-receiving material is characterized by the fact that to the feed such solid or liquid material (with the exception of oil) is added, which, through vaporization or heat-binding decomposition or conversion, hinders the establishment of excessive temperatures.

  9. Uruguay minerals fuels

    International Nuclear Information System (INIS)

    Goso, H.

    1967-01-01

    In this report the bases for the development of the necessary works of prospection are exposed on mineral fuels of Uruguay. We have taken the set from: coal, lutitas bituminous, uranium, petroleum and disturbs. In all the cases we have talked about to the present state of the knowledge and to the works that we considered necessary to develop in each case

  10. Discovery of recombining plasma from the faintest GeV supernova remnant HB 21 and a possible scenario for cosmic rays escaping from supernova remnant shocks

    Science.gov (United States)

    Suzuki, Hiromasa; Bamba, Aya; Nakazawa, Kazuhiro; Furuta, Yoshihiro; Sawada, Makoto; Yamazaki, Ryo; Koyama, Katsuji

    2018-06-01

    We present an X-ray study of the GeV gamma-ray supernova remnant (SNR) HB 21 with Suzaku. HB 21 is interacting with molecular clouds, and is the faintest in the GeV band among known GeV SNRs. We discovered strong radiative recombination continua of Si and S from the center of the remnant, which provide direct evidence of a recombining plasma (RP). The total emission can be explained with the RP and ionizing plasma components. The electron temperature and recombination timescale of the RP component were estimated as 0.17 (0.15-0.18) keV and 3.2 (2.0-4.8) × 1011 s cm-3, respectively. The estimated age of the RP (˜170 kyr) is the longest among known recombining GeV SNRs, because of a very low density of electrons (˜0.05 cm-3). We have examined the dependencies of GeV spectral indices on each of RP ages and SNR diameters for nine recombining GeV SNRs. Both showed possible positive correlations, indicating that both the parameters can be good indicators of properties of accelerated protons, for instance the degree of escape from SNR shocks. A possible scenario for a process of proton escape is introduced: interaction with molecular clouds makes weaker magnetic turbulence and cosmic-ray protons escape, simultaneously cooling down the thermal electrons and generating an RP.

  11. Bacterial Cell Mechanics.

    Science.gov (United States)

    Auer, George K; Weibel, Douglas B

    2017-07-25

    Cellular mechanical properties play an integral role in bacterial survival and adaptation. Historically, the bacterial cell wall and, in particular, the layer of polymeric material called the peptidoglycan were the elements to which cell mechanics could be primarily attributed. Disrupting the biochemical machinery that assembles the peptidoglycan (e.g., using the β-lactam family of antibiotics) alters the structure of this material, leads to mechanical defects, and results in cell lysis. Decades after the discovery of peptidoglycan-synthesizing enzymes, the mechanisms that underlie their positioning and regulation are still not entirely understood. In addition, recent evidence suggests a diverse group of other biochemical elements influence bacterial cell mechanics, may be regulated by new cellular mechanisms, and may be triggered in different environmental contexts to enable cell adaptation and survival. This review summarizes the contributions that different biomolecular components of the cell wall (e.g., lipopolysaccharides, wall and lipoteichoic acids, lipid bilayers, peptidoglycan, and proteins) make to Gram-negative and Gram-positive bacterial cell mechanics. We discuss the contribution of individual proteins and macromolecular complexes in cell mechanics and the tools that make it possible to quantitatively decipher the biochemical machinery that contributes to bacterial cell mechanics. Advances in this area may provide insight into new biology and influence the development of antibacterial chemotherapies.

  12. Aggregate and Mineral Resources - Industrial Mineral Mining Operations

    Data.gov (United States)

    NSGIC Education | GIS Inventory — An Industrial Mineral Mining Operation is a DEP primary facility type related to the Industrial Mineral Mining Program. The sub-facility types are listed below:Deep...

  13. Limitations of intraoperative adrenal remnant volume measurement in patients undergoing subtotal adrenalectomy.

    Science.gov (United States)

    Brauckhoff, Michael; Stock, Karsten; Stock, Susanne; Lorenz, Kerstin; Sekulla, Carsten; Brauckhoff, Katrin; Thanh, Phuong Nguyen; Gimm, Oliver; Spielmann, Rolf Peter; Dralle, Henning

    2008-05-01

    Recent studies have shown that a minimum of approximately one-third of one normal adrenal gland is required for sufficient adrenocortical stress capacity. Correlation between intraoperative measurement, determination of remnant size by computed tomography (CT), and adrenocortical stress capacity has not been examined so far. Twenty-two patients with familial pheochromocytoma (n=13), sporadic pheochromocytoma (n=3), and adrenocortical tumors (n=6) who underwent unilateral or bilateral subtotal adrenalectomy (STAE, 28 adrenal remnants) were prospectively studied. Patients were examined in a multi-slice CT to determine residual adrenal tissue and by ACTH test 4 days and 3 months postoperatively. There was a slight significant correlation between intraoperative and CT calculated volumes (r=0.77; pSTAE has limitations. CT gives larger volumes compared with intraoperative determination. For calculation of a volume-function correlation of residual adrenal tissue, in clinical practice, the determination of relative adrenal residual volume is acceptable.

  14. Probing Extreme-density Matter with Gravitational-wave Observations of Binary Neutron Star Merger Remnants

    Energy Technology Data Exchange (ETDEWEB)

    Radice, David [Institute for Advanced Study, 1 Einstein Drive, Princeton, NJ 08540 (United States); Bernuzzi, Sebastiano [Department of Mathematical, Physical and Computer Sciences, University of Parma, I-43124 Parma (Italy); Pozzo, Walter Del [Dipartimento di Fisica “Enrico Fermi,” Università di Pisa, Pisa I-56127 (Italy); Roberts, Luke F. [NSCL/FRIB and Department of Physics and Astronomy, Michigan State University, 640 S Shaw Lane, East Lansing, MI 48824 (United States); Ott, Christian D. [TAPIR, Walter Burke Institute for Theoretical Physics, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125 (United States)

    2017-06-20

    We present a proof-of-concept study, based on numerical-relativity simulations, of how gravitational waves (GWs) from neutron star merger remnants can probe the nature of matter at extreme densities. Phase transitions and extra degrees of freedom can emerge at densities beyond those reached during the inspiral, and typically result in a softening of the equation of state (EOS). We show that such physical effects change the qualitative dynamics of the remnant evolution, but they are not identifiable as a signature in the GW frequency, with the exception of possible black hole formation effects. The EOS softening is, instead, encoded in the GW luminosity and phase and is in principle detectable up to distances of the order of several megaparsecs with advanced detectors and up to hundreds of megaparsecs with third-generation detectors. Probing extreme-density matter will require going beyond the current paradigm and developing a more holistic strategy for modeling and analyzing postmerger GW signals.

  15. A newly-recognized galactic supernova remnant with shell-type and filled-center features

    International Nuclear Information System (INIS)

    Barnes, D.J.; Turtle, A.J.

    1988-01-01

    While the number of galactic supernova remnants (SNRs) now known is fairly large (>150), the subset among these that are known to resemble the Crab Nebula is still distressingly small, about 15 or so. Thus any object that can be unambiguously included in this exclusive club forms a valuable addition to knowledge of this class. The authors report observations of a newly recognized nonthermal galactic object, G18.94-1.06, having all the hallmarks of the classical shell-type SNRs, while also appearing to have a filled-centre component located inside the shell. Among the known Crab-like remnants, about one third show this dual nature. This diagnosis of G18.94-1.06 is supported mainly by the variations in spectral index across the source, as seen between the two observation frequencies, 408 MHz and 5.0 GHz

  16. Spectroscopic observations of the supernova remnant candidates 3 C 400.2 and S91

    International Nuclear Information System (INIS)

    Sabbadin, F.; D'Odorico, S.

    1976-01-01

    Spectra of 3 C 400.2 and S 91 have been used to measure the emission line rations Hα/N II region, Hα/ SII region and 6,717/6,731 of S II region in the two nebulae. By comparing the measured ratios with the mean values observed in supernova remnants, in planetary nebulae und in glactic H II regions, it is possible to conclude that the two nebulae are the result of supernova explosions. For S 91, previously catalogued as an H II region, we derive a linear diameter of 34 pc and a distance of 0.7 kpc using a relation between the diameter of supernova remnants and the average Hα/ N II region intensity ratio in their optical filaments. (orig.) [de

  17. FERMI LARGE AREA TELESCOPE DETECTION OF THE YOUNG SUPERNOVA REMNANT TYCHO

    International Nuclear Information System (INIS)

    Giordano, F.; Naumann-Godo, M.; Ballet, J.; Bechtol, K.; Funk, S.; Lande, J.; Tanaka, T.; Uchiyama, Y.; Mazziotta, M. N.; Rainò, S.; Tibolla, O.

    2012-01-01

    After almost three years of data taking in sky-survey mode, the Fermi Large Area Telescope has detected γ-ray emission toward Tycho's supernova remnant (SNR). The Tycho SNR is among the youngest remnants in the Galaxy, originating from a Type Ia Supernova in AD 1572. The γ-ray integral flux from 400 MeV up to 100 GeV has been measured to be (3.5 ± 1.1 stat ± 0.7 syst )× 10 –9 cm –2 s –1 with a photon index of 2.3 ± 0.2 stat ± 0.1 syst . A simple model consistent with TeV, X-ray, and radio data is sufficient to explain the observed emission as originating from π 0 decays as a result of cosmic-ray acceleration and interaction with the ambient medium.

  18. Probing Extreme-density Matter with Gravitational-wave Observations of Binary Neutron Star Merger Remnants

    International Nuclear Information System (INIS)

    Radice, David; Bernuzzi, Sebastiano; Pozzo, Walter Del; Roberts, Luke F.; Ott, Christian D.

    2017-01-01

    We present a proof-of-concept study, based on numerical-relativity simulations, of how gravitational waves (GWs) from neutron star merger remnants can probe the nature of matter at extreme densities. Phase transitions and extra degrees of freedom can emerge at densities beyond those reached during the inspiral, and typically result in a softening of the equation of state (EOS). We show that such physical effects change the qualitative dynamics of the remnant evolution, but they are not identifiable as a signature in the GW frequency, with the exception of possible black hole formation effects. The EOS softening is, instead, encoded in the GW luminosity and phase and is in principle detectable up to distances of the order of several megaparsecs with advanced detectors and up to hundreds of megaparsecs with third-generation detectors. Probing extreme-density matter will require going beyond the current paradigm and developing a more holistic strategy for modeling and analyzing postmerger GW signals.

  19. X-ray characteristics of the Lupus Loop and SN1006 supernova remnants

    Energy Technology Data Exchange (ETDEWEB)

    Toor, A [California Univ., Livermore (USA). Lawrence Livermore Lab.

    1980-01-01

    The spatial extent of the Lupus Loop and spectra for the Lupus Loop and SN1006 supernova remnants have been determined with a rocket-borne payload. The Lupus Loop is an extended source of soft X-rays (approx. 300' diam) that shows a correlation between its brightest X-ray and radio-emission regions. Its spectrum is characterized by a temperature of 350 eV. Thus, the Lupus Loop appears similar to Vela X and Cygnus Loop, although much weaker. Emission from SN1006 is spatially unresolved and exhibits a harder spectrum than that of the Lupus Loop. All spectral data (0.2 100 keV) from our observation and previous observations are satisfactorily fit with a power law (index = 2.15). This spectral dependence suggests the possibility that a rotating neutron star is the underlying source of the radiated energy although such an interpretation appears inconsistent with the remnant's morphology.

  20. X-ray characteristics of the Lupus Loop and SN1006 supernova remnants

    International Nuclear Information System (INIS)

    Toor, A.

    1980-01-01

    The spatial extent of the Lupus Loop and spectra for the Lupus Loop and SN1006 supernova remnants have been determined with a rocket-borne payload. The Lupus Loop is an extended source of soft X-rays (approx. 300' diam) that shows a correlation between its brightest X-ray and radio-emission regions. Its spectrum is characterized by a temperature of 350 eV. Thus, the Lupus Loop appears similar to Vela X and Cygnus Loop, although much weaker. Emission from SN1006 is spatially unresolved and exhibits a harder spectrum than that of the Lupus Loop. All spectral data (0.2 100 keV) from our observation and previous observations are satisfactorily fit with a power law (index = 2.15). This spectral dependence suggests the possibility that a rotating neutron star is the underlying source of the radiated energy although such an interpretation appears inconsistent with the remnant's morphology. (orig.)

  1. A hydrodynamical model of Kepler's supernova remnant constrained by x-ray spectra

    International Nuclear Information System (INIS)

    Ballet, J.; Arnaud, M.; Rothinfluo, R.; Chieze, J.P.; Magne, B.

    1988-01-01

    The remnant of the historical supernova observed by Kepler in 1604 was recently observed in x-rays by the EXOSAT satellite up to 10 keV. A strong Fe K emission line around 6.5 keV is readily apparent in the spectrum. From an analysis of the light curve of the SN, reconstructed from historical descriptions, a previous study proposed to classify it as type I. Standard models of SN I based on carbon deflagration of white dwarf predict the synthesis of about 0.5 M circle of iron in the ejecta. Observing the iron line is a crucial check for such models. It has been argued that the light curve of Sn II-L is very similar to that of SN I and that the original observations are compatible with either type. In view of this uncertainty the authors have run a hydrodynamics-ionization code for both SN II and SN I remnants

  2. X-ray emission from supernova remnants with particular reference to the Cygnus Loop

    International Nuclear Information System (INIS)

    Gronenschild, E.H.B.M.

    1979-01-01

    Observational or theoretical results related to the study of supernova remnants (SNRs) are described. Some background information is given by reviewing the present status of our knowledge of supernovae and supernova remnants, both from theory and observations. Also the distribution of all known radio, optical, and X-ray SNRs in the Galaxy is shown and a comparison is made. The X-ray observations of the well-known X-ray SNR the Cygnus Loop are discussed in detail and the discovery of a new X-ray emitting SNR W44 is described. Other radio sources are investigated, and the observed X-ray emission of SNRs are analysed using thermal spectra like exponential or bremsstrahlung spectra. The X-ray line spectrum that emerges from SNRs is described in detail. (Auth.)

  3. Duty-cycle and energetics of remnant radio-loud AGN

    Science.gov (United States)

    Turner, Ross J.

    2018-05-01

    Deriving the energetics of remnant and restarted active galactic nuclei (AGNs) is much more challenging than for active sources due to the complexity in accurately determining the time since the nucleus switched-off. I resolve this problem using a new approach that combines spectral ageing and dynamical models to tightly constrain the energetics and duty-cycles of dying sources. Fitting the shape of the integrated radio spectrum yields the fraction of the source age the nucleus is active; this, in addition to the flux density, source size, axis ratio, and properties of the host environment, provides a constraint on dynamical models describing the remnant radio source. This technique is used to derive the intrinsic properties of the well-studied remnant radio source B2 0924+30. This object is found to spend 50_{-12}^{+14} Myr in the active phase and a further 28_{-5}^{+6} Myr in the quiescent phase, have a jet kinetic power of 3.6_{-1.7}^{+3.0}× 10^{37} W, and a lobe magnetic field strength below equipartition at the 8σ level. The integrated spectra of restarted and intermittent radio sources are found to yield a `steep-shallow' shape when the previous outburst occurred within 100 Myr. The duty-cycle of B2 0924+30 is hence constrained to be δ < 0.15 by fitting the shortest time to the previous comparable outburst that does not appreciably modify the remnant spectrum. The time-averaged feedback energy imparted by AGNs into their host galaxy environments can in this manner be quantified.

  4. Former food products safety: microbiological quality and computer vision evaluation of packaging remnants contamination.

    Science.gov (United States)

    Tretola, M; Di Rosa, A R; Tirloni, E; Ottoboni, M; Giromini, C; Leone, F; Bernardi, C E M; Dell'Orto, V; Chiofalo, V; Pinotti, L

    2017-08-01

    The use of alternative feed ingredients in farm animal's diets can be an interesting choice from several standpoints, including safety. In this respect, this study investigated the safety features of selected former food products (FFPs) intended for animal nutrition produced in the framework of the IZS PLV 06/14 RC project by an FFP processing plant. Six FFP samples, both mash and pelleted, were analysed for the enumeration of total viable count (TVC) (ISO 4833), Enterobacteriaceae (ISO 21528-1), Escherichia coli (ISO 16649-1), coagulase-positive Staphylococci (CPS) (ISO 6888), presumptive Bacillus cereus and its spores (ISO 7932), sulphite-reducing Clostridia (ISO 7937), yeasts and moulds (ISO 21527-1), and the presence in 25 g of Salmonella spp. (ISO 6579). On the same samples, the presence of undesired ingredients, which can be identified as remnants of packaging materials, was evaluated by two different methods: stereomicroscopy according to published methods; and stereomicroscopy coupled with a computer vision system (IRIS Visual Analyzer VA400). All FFPs analysed were safe from a microbiological point of view. TVC was limited and Salmonella was always absent. When remnants of packaging materials were considered, the contamination level was below 0.08% (w/w). Of note, packaging remnants were found mainly from the 1-mm sieve mesh fractions. Finally, the innovative computer vision system demonstrated the possibility of rapid detection for the presence of packaging remnants in FFPs when combined with a stereomicroscope. In conclusion, the FFPs analysed in the present study can be considered safe, even though some improvements in FFP processing in the feeding plant can be useful in further reducing their microbial loads and impurity.

  5. The Cherenkov Telescope Array potential for the study of young supernova remnants

    Czech Academy of Sciences Publication Activity Database

    Acharya, B.S.; Aramo, C.; Babic, A.; Boháčová, Martina; Chudoba, Jiří; Ebr, Jan; Hrabovský, Miroslav; Janeček, Petr; Mandát, Dušan; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Řídký, Jan; Schovánek, Petr; Trávníček, Petr

    2015-01-01

    Roč. 62, Mar (2015), s. 152-164 ISSN 0927-6505 R&D Projects: GA MŠk(CZ) 7AMB12AR013; GA MŠk LE13012; GA MŠk LG14019 Institutional support: RVO:68378271 Keywords : acceleration of particles * gamma rays: general * ISM: supernova remnants * radiation mechanisms: non-termal Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.425, year: 2015

  6. Exploring the Diffuse X-ray Emission of Supernova Remnant Kesteven 69 with XMM-Newton

    Directory of Open Access Journals (Sweden)

    Kyoung-Ae Seo

    2013-06-01

    Full Text Available We have investigated the X-ray emission from the shock-heated plasma of the Galactic supernova remnant Kesteven 69 with XMM-Newton. Assuming the plasma is at collisional ionization equilibrium, a plasma temperature and a column absorption are found to be kT ~ 0.62 keV and NH ~ 2.85 ×1022 cm-2 respectively by imaging spectroscopy. Together with the deduced emission measure, we place constraints on its Sedov parameters.

  7. Abiotic factors drives floristic variations of fern’s metacommunity in an Atlantic Forest remnant

    OpenAIRE

    L. E. N. Costa; R. P. Farias; A. C. P. Santiago; I. A. A. Silva; I. C. L. Barros

    2018-01-01

    Abstract We analyzed floristic variations in fern’s metacommunity at the local scale and their relationship with abiotic factors in an Atlantic Forest remnant of northeastern Brazil. Floristic and environmental variations were accessed on ten plots of 10 × 20 m. We performed cluster analyses, based on Bray-Curtis dissimilarity index to establish the floristic relationship. The influence of abiotic factors: luminosity, temperature, relative air humidity and relative soil moisture was evaluated...

  8. Toward the Understanding of the Physical Origin of Recombining Plasma in the Supernova Remnant IC 443

    Science.gov (United States)

    Matsumura, Hideaki; Tanaka, Takaaki; Uchida, Hiroyuki; Okon, Hiromichi; Tsuru, Takeshi Go

    2017-12-01

    We perform a spatially resolved spectroscopic analysis of X-ray emission from the supernova remnant (SNR) IC 443 with Suzaku. All of the spectra are well reproduced by a model consisting of a collisional ionization equilibrium (CIE) and two recombining plasma (RP) components. Although previous X-ray studies found an RP in the northeastern region, this is the first report on RPs in the other parts of the remnant. The electron temperature, kT e , of the CIE component is almost uniform at ∼0.2 keV across the remnant. The CIE plasma has metal abundances consistent with solar and is concentrated toward the rim of the remnant, suggesting that it is of shocked interstellar medium origin. The two RP components have different kT e : one in the range of 0.16–0.28 keV and the other in the range of 0.48–0.67 keV. The electron temperatures of both RP components decrease toward the southeast, where the SNR shock is known to be interacting with a molecular cloud. We also find the normalization ratio of the lower-kT e RP to higher-kT e RP components increases toward the southeast. Both results suggest the X-ray emitting plasma in the southeastern region is significantly cooled by some mechanism. One of the plausible cooling mechanisms is a thermal conduction between the hot plasma and the molecular cloud. If the cooling proceeds faster than the recombination timescale of the plasma, the same mechanism can account for the recombining plasma as well.

  9. EVOLUTION OF THE RADIO REMNANT OF SUPERNOVA 1987A: MORPHOLOGICAL CHANGES FROM DAY 7000

    Energy Technology Data Exchange (ETDEWEB)

    Ng, C.-Y. [Department of Physics, The University of Hong Kong, Pokfulam Road (Hong Kong); Zanardo, G.; Potter, T. M.; Staveley-Smith, L. [International Centre for Radio Astronomy Research (ICRAR), The University of Western Australia, Crawley, WA 6009 (Australia); Gaensler, B. M. [Australian Research Council, Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia); Manchester, R. N.; Tzioumis, A. K., E-mail: ncy@bohr.physics.hku.hk [CSIRO Astronomy and Space Science, Australia Telescope National Facility, Marsfield, NSW 1710 (Australia)

    2013-11-10

    We present radio imaging observations of supernova remnant 1987A at 9 GHz, taken with the Australia Telescope Compact Array over 21 years from 1992 to 2013. By employing a Fourier modeling technique to fit the visibility data, we show that the remnant structure has evolved significantly since day 7000 (mid-2006): the emission latitude has gradually decreased such that the overall geometry has become more similar to a ring structure. Around the same time, we find a decreasing trend in the east-west asymmetry of the surface emissivity. These results could reflect the increasing interaction of the forward shock with material around the circumstellar ring, and the relative weakening of the interaction with the lower-density material at higher latitudes. The morphological evolution caused an apparent break in the remnant expansion measured with a torus model, from a velocity of 4600{sup +150}{sub -}200 km s{sup –1} between day 4000 and 7000 to 2400{sup +100}{sub -200} km s{sup –1} after day 7000. However, we emphasize that there is no conclusive evidence for a physical slowing of the shock at any given latitude in the expanding remnant, and that a change of radio morphology alone appears to dominate the evolution. This is supported by our ring-only fits which show a constant expansion of 3890 ± 50 km s{sup –1} without deceleration between days 4000 and 9000. We suggest that once the emission latitude no longer decreases, the expansion velocity obtained from the torus model should return to the same value as that measured with the ring model.

  10. Method of calculation of tanks forced ventilation from the remnants of liquid products

    Directory of Open Access Journals (Sweden)

    С. О. Пузік

    2013-07-01

    Full Text Available The advantages of gasoline compared to other petroleum products in terms of feasibility of their research. Calculations of the duration of ventilation and changes in the concentration of vapors of gasoline remains in the gas space of the vertical tank with a capacity of 1000 m3 (RUS-1000. Nomogram constructed for the quantitative forecast available liquid balances petrol A-95 and the time duration ventylyaiyi RUS-1000 from the remnants of the petrol

  11. Seed shadow of Swietenia macrophylla remnant trees in a Mexican rainforest: Implications for forest management

    OpenAIRE

    Alcalá, Raúl E.; Alonso, Roxalma L.; Gutiérrez-Granados, Gabriel

    2014-01-01

    The understanding of processes affecting the regeneration and coexistence of tree species is of high concern in tropical landscapes disturbed by anthropogenic activities. In this study, we evaluated the seed shadow of eight small remnant Swietenia macrophylla trees to determine the possible consequences of selective logging on the first stages of natural regeneration. We expected to find a restricted dispersal ability and a marked loss of seeds due to biotic interactions. To test this, seed s...

  12. Multi-dimensional simulations of the expanding supernova remnant of SN 1987A

    Energy Technology Data Exchange (ETDEWEB)

    Potter, T. M.; Staveley-Smith, L. [International center for Radio Astronomy Research (ICRAR) M468, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia); Reville, B. [Center for Plasma Physics, Queen' s University Belfast, University Road, Belfast BT7 1NN (United Kingdom); Ng, C.-Y. [Department of Physics, The University of Hong Kong, Pokfulam Road (Hong Kong); Bicknell, G. V.; Sutherland, R. S. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 0200 (Australia); Wagner, A. Y., E-mail: tobympotter@gmail.com [Center for Computational Sciences, Tsukuba University, Tsukuba, Ibaraki, 305-8577 (Japan)

    2014-10-20

    The expanding remnant from SN 1987A is an excellent laboratory for investigating the physics of supernovae explosions. There is still a large number of outstanding questions, such as the reason for the asymmetric radio morphology, the structure of the pre-supernova environment, and the efficiency of particle acceleration at the supernova shock. We explore these questions using three-dimensional simulations of the expanding remnant between days 820 and 10,000 after the supernova. We combine a hydrodynamical simulation with semi-analytic treatments of diffusive shock acceleration and magnetic field amplification to derive radio emission as part of an inverse problem. Simulations show that an asymmetric explosion, combined with magnetic field amplification at the expanding shock, is able to replicate the persistent one-sided radio morphology of the remnant. We use an asymmetric Truelove and McKee progenitor with an envelope mass of 10 M {sub ☉} and an energy of 1.5 × 10{sup 44} J. A termination shock in the progenitor's stellar wind at a distance of 0.''43-0.''51 provides a good fit to the turn on of radio emission around day 1200. For the H II region, a minimum distance of 0.''63 ± 0.''01 and maximum particle number density of (7.11 ± 1.78) × 10{sup 7} m{sup –3} produces a good fit to the evolving average radius and velocity of the expanding shocks from day 2000 to day 7000 after explosion. The model predicts a noticeable reduction, and possibly a temporary reversal, in the asymmetric radio morphology of the remnant after day 7000, when the forward shock left the eastern lobe of the equatorial ring.

  13. An unusual case of cancer of the urachal remnant following repair of bladder exstrophy.

    LENUS (Irish Health Repository)

    Fanning, D M

    2012-02-01

    INTRODUCTION: We report the first case of cancer of the urachal remnant following repair of bladder exstrophy, in a renal transplant recipient. METHOD: A retrospective review of this clinical case and the associated literature were performed. CONCLUSION: This unusual case highlights two very rare entities. Bladder exstrophy has an incidence of 1 in 50,000 newborns, whereas urachal cancer accounts for less than 1% of all bladder tumours.

  14. An unusual case of cancer of the urachal remnant following repair of bladder exstrophy.

    LENUS (Irish Health Repository)

    Fanning, D M

    2009-03-18

    INTRODUCTION: We report the first case of cancer of the urachal remnant following repair of bladder exstrophy, in a renal transplant recipient. METHOD: A retrospective review of this clinical case and the associated literature were performed. CONCLUSION: This unusual case highlights two very rare entities. Bladder exstrophy has an incidence of 1 in 50,000 newborns, whereas urachal cancer accounts for less than 1% of all bladder tumours.

  15. Bacterial meningitis in children

    International Nuclear Information System (INIS)

    Marji, S.

    2007-01-01

    To demonstrate the epidemiology, clinical manifestations and bacteriological profile of bacterial meningitis in children beyond the neonatal period in our hospital. This was a retrospective descriptive study conducted at Prince Rashid Hospital in Irbid, Jordan. The medical records of 50 children with the diagnosis of bacterial meningitis during 4 years period, were reviewed. The main cause of infection was streptococcus pneumoniae, followed by Haemophilus influenza and Niesseria meningitides. Mortality was higher in infants and meningococcal infection, while complications were more encountered in cases of streptococcus pneumoniae. Cerebrospinal fluid culture was positive in 11 cases and Latex agglutination test in 39. There is a significant reduction of the numbers of bacterial meningitis caused by Haemophilus influenza type B species. (author)

  16. Oxygen Extraction from Minerals

    Science.gov (United States)

    Muscatello, Tony

    2017-01-01

    Oxygen, whether used as part of rocket bipropellant or for astronaut life support, is a key consumable for space exploration and commercialization. In Situ Resource Utilization (ISRU) has been proposed many times as a method for making space exploration more cost effective and sustainable. On planetary and asteroid surfaces the presence of minerals in the regolith that contain oxygen is very common, making them a potential oxygen resource. The majority of research and development for oxygen extraction from minerals has been for lunar regolith although this work would generally be applicable to regolith at other locations in space. This presentation will briefly survey the major methods investigated for oxygen extraction from regolith with a focus on the current status of those methods and possible future development pathways. The major oxygen production methods are (1) extraction from lunar ilmenite (FeTiO3) with either hydrogen or carbon monoxide, (2) carbothermal reduction of iron oxides and silicates with methane, and (3) molten regolith electrolysis (MRE) of silicates. Methods (1) and (2) have also been investigated in a two-step process using CO reduction and carbon deposition followed by carbothermal reduction. All three processes have byproducts that could also be used as resources. Hydrogen or carbon monoxide reduction produce iron metal in small amounts that could potentially be used as construction material. Carbothermal reduction also makes iron metal along with silicon metal and a glass with possible applications. MRE produces iron, silicon, aluminum, titanium, and glass, with higher silicon yields than carbothermal reduction. On Mars and possibly on some moons and asteroids, water is present in the form of mineral hydrates, hydroxyl (-OH) groups on minerals, andor water adsorbed on mineral surfaces. Heating of the minerals can liberate the water which can be electrolyzed to provide a source of oxygen as well. The chemistry of these processes, some key

  17. Indústria mineral

    Directory of Open Access Journals (Sweden)

    Iran F. Machado

    1998-08-01

    Full Text Available A INDÚSTRIA mineral brasileira é analisada, de modo sucinto, face aos desafios impostos pela globalização contemporânea. As mudanças profundas ocorridas no contexto internacional na última década, abrangendo as esferas política, econômica, social e institucional, exigem uma reflexão aprofundada sobre o papel a ser desempenhado pelo Brasil no comércio internacional de bens minerais. De um lado, as oportunidades de aproveitamento de jazidas de classe internacional, principalmente na Amazônia, são bastante promissoras. Por outro, não se deve ignorar que: a explotação dessas reservas terá de obedecer a critérios de sustentabilidade, seguindo paradigmas já adotados em países desenvolvidos; o Brasil terá de garantir a sua competitividade diante dos seus principais concorrentes (Austrália, CEI, China e Índia. A questão dos minerais estratégicos é também abordada, com ênfase nas preocupações demonstradas pelo Departamento de Estado dos EUA. Finalmente, são alinhados três cenários possíveis para o desempenho futuro da mineração brasileira, instando-se o governo a dedicar maior atenção ao destino do nosso subsolo.THE MINERAL industry of Brazil is briefly analysed vis-à-vis the challenges imposed by the cruenta globalization process. The profound changes that occurred in the international framework during the last decade, encompassing the political, economic, social, and institutional structures, demand a thorough appraisal about the role to be played by Brazil in the international market of mineral commodities. On one hand, the opportunities open for world class deposits, mainly in the Amazon, are very promising. On the other hand, it is mandatory to take into account that: the exploitation of these reserves shall comply with sound sustainability criteria, following guidelines already adopted by some developed countries; Brazil will have to demonstrate its competitiveness among the major competitors (Australia

  18. Bacterial formation of phosphatic laminites off Peru.

    Science.gov (United States)

    Arning, E T; Birgel, D; Brunner, B; Peckmann, J

    2009-06-01

    Authigenic phosphatic laminites enclosed in phosphorite crusts from the shelf off Peru (10 degrees 01' S and 10 degrees 24' S) consist of carbonate fluorapatite layers, which contain abundant sulfide minerals including pyrite (FeS(2)) and sphalerite (ZnS). Low delta(34)S(pyrite) values (average -28.8 per thousand) agree with bacterial sulfate reduction and subsequent pyrite formation. Stable sulfur isotopic compositions of sulfate bound in carbonate fluorapatite are lower than that of sulfate from ambient sea water, suggesting bacterial reoxidation of sulfide by sulfide-oxidizing bacteria. The release of phosphorus and subsequent formation of the autochthonous phosphatic laminites are apparently caused by the activity of sulfate-reducing bacteria and associated sulfide-oxidizing bacteria. Following an extraction-phosphorite dissolution-extraction procedure, molecular fossils of sulfate-reducing bacteria (mono-O-alkyl glycerol ethers, di-O-alkyl glycerol ethers, as well as the short-chain branched fatty acids i/ai-C(15:0), i/ai-C(17:0) and 10MeC(16:0)) are found to be among the most abundant compounds. The fact that these molecular fossils of sulfate-reducing bacteria are distinctly more abundant after dissolution of the phosphatic laminite reveals that the lipids are tightly bound to the mineral lattice of carbonate fluorapatite. Moreover, compared with the autochthonous laminite, molecular fossils of sulfate-reducing bacteria are: (1) significantly less abundant and (2) not as tightly bound to the mineral lattice in the other, allochthonous facies of the Peruvian crusts consisting of phosphatic coated grains. These observations confirm the importance of sulfate-reducing bacteria in the formation of the phosphatic laminite. Model calculations highlight that organic matter degradation by sulfate-reducing bacteria has the potential to liberate sufficient phosphorus for phosphogenesis.

  19. Magnetic Resonance Evaluation of Müllerian Remnants in Mayer-Rokitansky-Küster-Hauser Syndrome

    International Nuclear Information System (INIS)

    Yoo, Roh-Eul; Cho, Jeong Yeon; Kim, Sang Youn; Kim, Seung Hyup

    2013-01-01

    To analyze magnetic resonance imaging (MRI) findings of Müllerian remnants in young females clinically suspected of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome in a primary amenorrhea workup. Fifteen young females underwent multiplanar T2- and transverse T1-weighted MRI at either a 1.5T or 3.0T MR imager. Two gynecologic radiologists reached consensus decisions for the evaluation of Müllerian remnants, vagina, ovaries, and associated findings. All cases had bilateral uterine buds in the pelvic cavity, with unilateral cavitation in two cases. The buds had an average long-axis diameter of 2.64 ± 0.65 cm. In all cases, bilateral buds were connected with fibrous band-like structures. In 13 cases, the band-like structures converged at the midline or a paramedian triangular soft tissue lying above the bladder dome. The lower one-third of the vagina was identified in 14 cases. Fourteen cases showed bilateral normal ovaries near the uterine buds. One unilateral pelvic kidney, one unilateral renal agenesis, one mild scoliosis, and three lumbar sacralization cases were found as associated findings. Typical Müllerian remnants in MRKH syndrome consist of bilateral uterine buds connected by the fibrous band-like structures, which converge at the midline triangular soft tissue lying above the bladder dome

  20. Practical Aspects of X-ray Imaging Polarimetry of Supernova Remnants and Other Extended Sources

    Directory of Open Access Journals (Sweden)

    Jacco Vink

    2018-04-01

    Full Text Available The new generation of X-ray polarisation detectors, the gas pixel detectors, which will be employed by the future space missions IXPE and eXTP, allows for spatially resolved X-ray polarisation studies. This will be of particular interest for X-ray synchrotron emission from extended sources like young supernova remnants and pulsar wind nebulae. Here we report on employing a polarisation statistic that can be used to makes maps in the Stokes I, Q, and U parameters, a method that we expand by correcting for the energy-dependent instrumental modulation factor, using optimal weighting of the signal. In order to explore the types of Stokes maps that can be obtained, we present a Monte Carlo simulation program called xpolim, with which different polarisation weighting schemes are explored. We illustrate its use with simulations of polarisation maps of young supernova remnants, after having described the general science case for polarisation studies of supernova remnants, and its connection to magnetic-field turbulence. We use xpolim simulations to show that in general deep, ~2 Ms observations are needed to recover polarisation signals, in particular for Cas A, for which in the polarisation fraction may be as low as 5%.

  1. Explaining the morphology of supernova remnant (SNR) 1987A with the jittering jets explosion mechanism

    Science.gov (United States)

    Bear, Ealeal; Soker, Noam

    2018-04-01

    We find that the remnant of supernova (SN) 1987A shares some morphological features with four supernova remnants (SNRs) that have signatures of shaping by jets, and from that we strengthen the claim that jets played a crucial role in the explosion of SN 1987A. Some of the morphological features appear also in planetary nebulae (PNe) where jets are observed. The clumpy ejecta bring us to support the claim that the jittering jets explosion mechanism can account for the structure of the remnant of SN 1987A, i.e., SNR 1987A. We conduct a preliminary attempt to quantify the fluctuations in the angular momentum of the mass that is accreted on to the newly born neutron star via an accretion disk or belt. The accretion disk/belt launches the jets that explode core collapse supernovae (CCSNe). The relaxation time of the accretion disk/belt is comparable to the duration of a typical jet-launching episode in the jittering jets explosion mechanism, and hence the disk/belt has no time to relax. We suggest that this might explain two unequal opposite jets that later lead to unequal sides of the elongated structures in some SNRs of CCSNe. We reiterate our earlier call for a paradigm shift from neutrino-driven explosion to a jet-driven explosion of CCSNe.

  2. Evidence for the Stochastic Acceleration of Secondary Antiprotons by Supernova Remnants

    Energy Technology Data Exchange (ETDEWEB)

    Cholis, Ilias [Johns Hopkins U.; Hooper, Dan [Chicago U., KICP; Linden, Tim [Ohio State U.

    2017-01-16

    The antiproton-to-proton ratio in the cosmic-ray spectrum is a sensitive probe of new physics. Using recent measurements of the cosmic-ray antiproton and proton fluxes in the energy range of 1-1000 GeV, we study the contribution to the $\\bar{p}/p$ ratio from secondary antiprotons that are produced and subsequently accelerated within individual supernova remnants. We consider several well-motivated models for cosmic-ray propagation in the interstellar medium and marginalize our results over the uncertainties related to the antiproton production cross section and the time-, charge-, and energy-dependent effects of solar modulation. We find that the increase in the $\\bar{p}/p$ ratio observed at rigidities above $\\sim$ 100 GV cannot be accounted for within the context of conventional cosmic-ray propagation models, but is consistent with scenarios in which cosmic-ray antiprotons are produced and subsequently accelerated by shocks within a given supernova remnant. In light of this, the acceleration of secondary cosmic rays in supernova remnants is predicted to substantially contribute to the cosmic-ray positron spectrum, accounting for a significant fraction of the observed positron excess.

  3. MULTI-WAVELENGTH ANALYSIS OF THE GALACTIC SUPERNOVA REMNANT MSH 11-61A

    Energy Technology Data Exchange (ETDEWEB)

    Auchettl, Katie; Slane, Patrick; Foster, Adam R.; Smith, Randall K. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Castro, Daniel [MIT-Kavli Center for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)

    2015-09-01

    Due to its centrally bright X-ray morphology and limb brightened radio profile, MSH 11–61A (G290.1–0.8) is classified as a mixed morphology supernova remnant (SNR). H i and CO observations determined that the SNR is interacting with molecular clouds found toward the north and southwest regions of the remnant. In this paper we report on the detection of γ-ray emission coincident with MSH 11–61A, using 70 months of data from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. To investigate the origin of this emission, we perform broadband modeling of its non-thermal emission considering both leptonic and hadronic cases and concluding that the γ-ray emission is most likely hadronic in nature. Additionally we present our analysis of a 111 ks archival Suzaku observation of this remnant. Our investigation shows that the X-ray emission from MSH 11–61A arises from shock-heated ejecta with the bulk of the X-ray emission arising from a recombining plasma, while the emission toward the east arises from an ionizing plasma.

  4. Association of intima-media thickness of carotid arteries with remnant lipoproteins in men and women.

    Science.gov (United States)

    Piťha, J; Kovář, J; Škodová, Z; Cífková, R; Stávek, P; Červenka, L; Šejda, T; Lánská, V; Poledne, R

    2015-01-01

    The subclass of triglyceride-rich lipoproteins - remnant-like particles (RLP) seems to be strong and independent risk factor for cardiovascular disease. We evaluated the role of RLP and other risk factors (RF) with sonographically measured intima-media thickness of carotid arteries (IMT CCA) in a cohort of Czech population including women defined according to the time after menopause. We investigated relation of IMT CCA to age, weight, central obesity, plasma lipids including remnant-like particles cholesterol (RLP-C) and triglycerides (RLP-TG) in 136 men and 160 women. Using multiple linear regression analysis, significant association between IMT CCA and RLP-C was found in women 1-7 years after menopause. In the whole group of women, only age and fasting blood glucose were independently associated with IMT CCA. In men only age significantly correlated with IMT CCA. Significant decrease of all plasma lipids between 1988 and 1996 in men was detected, while in women significant increase in triglycerides and no change in non-HDL cholesterol was observed. RLP-C was the strongest independent RF for atherosclerosis in postmenopausal women but its association with IMT CCA was limited to several years after menopause. In conclusion, women changing reproductive status could be more sensitive to atherogenic impact of remnant lipoproteins.

  5. Magnetic Resonance Evaluation of Müllerian Remnants in Mayer-Rokitansky-Küster-Hauser Syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Roh-Eul; Cho, Jeong Yeon; Kim, Sang Youn; Kim, Seung Hyup [Department of Radiology, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of)

    2013-07-01

    To analyze magnetic resonance imaging (MRI) findings of Müllerian remnants in young females clinically suspected of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome in a primary amenorrhea workup. Fifteen young females underwent multiplanar T2- and transverse T1-weighted MRI at either a 1.5T or 3.0T MR imager. Two gynecologic radiologists reached consensus decisions for the evaluation of Müllerian remnants, vagina, ovaries, and associated findings. All cases had bilateral uterine buds in the pelvic cavity, with unilateral cavitation in two cases. The buds had an average long-axis diameter of 2.64 ± 0.65 cm. In all cases, bilateral buds were connected with fibrous band-like structures. In 13 cases, the band-like structures converged at the midline or a paramedian triangular soft tissue lying above the bladder dome. The lower one-third of the vagina was identified in 14 cases. Fourteen cases showed bilateral normal ovaries near the uterine buds. One unilateral pelvic kidney, one unilateral renal agenesis, one mild scoliosis, and three lumbar sacralization cases were found as associated findings. Typical Müllerian remnants in MRKH syndrome consist of bilateral uterine buds connected by the fibrous band-like structures, which converge at the midline triangular soft tissue lying above the bladder dome.

  6. Incidence of metachronous gastric cancer in the remnant stomach after synchronous multiple cancer surgery.

    Science.gov (United States)

    Nozaki, Isao; Hato, Shinji; Kobatake, Takaya; Ohta, Koji; Kubo, Yoshirou; Nishimura, Rieko; Kurita, Akira

    2014-01-01

    In the preoperative evaluation for gastric cancer, high-resolution endoscopic technologies allow us to detect small accessory lesions. However, it is not known if the gastric remnant after partial gastrectomy for synchronous multiple gastric cancers has a greater risk for metachronous cancer. The purpose of this study was to determine the incidence of metachronous cancer in this patient subset compared with that after solitary cancer surgery. Data on a consecutive series of 1,281 patients gastrectomized for early gastric cancer from 1991 to 2007 were analyzed retrospectively. The 715 gastric remnants after distal gastrectomy were periodically surveyed by endoscopic examination in Shikoku Cancer Center. Among those surveyed cases, 642 patients were pathologically diagnosed with solitary lesion (SO group) and 73 patients with synchronous multiple lesions (MU group) at the time of the initial surgery. In the follow-up period, 15 patients in the SO group and 3 patients in the MU group were diagnosed as having metachronous cancer in the gastric remnant. The cumulative 4-year incidence rate was 1.9 % in the SO group and 5.5 % in the MU group. The difference did not reach the significant level by the log-rank test. The incidence of metachronous cancer is higher after multiple cancer surgery; however, the difference is not statistically significant.

  7. Optical pulsar in the Large Magellanic Cloud remnant 0540-69.3

    International Nuclear Information System (INIS)

    Middleditch, J.; Pennypacker, C.R.

    1984-01-01

    We have detected pulsed optical emission from the Large Magellanic Cloud (LMC) X-ray pulsar PSR 0540-693 (Seward et al. 1984). The pulsed emission has a time averaged magnitude of approximately 22.7. The X-ray pulsar was discovered in the LMC remnant, 0540-69.3 as a pulse repetition period of approx. 50 milliseconds (ms) in Einstein Obsrvatory data (Seward et al. 1984). Earlier, Clark et al. (1982) had noted that this remnant resembles the Crab Nebula because of the X-ray power law spectrum, and suggested that the nebular emission was synchrotron radiation powered by a central pulsar. After the announcement of X-ray pulsed emission, Chanan et al. (1984) measured the broad optical band properties of the nebula and found evidence for synchrotron emission. They reported that the 4.5 arc second continuum emission remnant has only a tenth the luminosity of the Crab Nebula. We have recorded broad-band optical time-series data at 1 ms intervals with the 4-m and 1.5-m Cerro Tololo telescopes and have found strong pulsations, employing the usual Fourier transform methods. A summary of the observations, including magnitudes, barycentric frequencies and times of arrival is given

  8. Cygnus Loop supernova remnant: new observations and a framework for understanding its structure and evolution

    International Nuclear Information System (INIS)

    Hester, J.J.

    1985-01-01

    New observational data on the Cygnus Loop supernova remnant (SNR) include: (1) a detailed high resolution comparison of x-ray and optical emission for a field in the SE; (2) a map of the [O III] electron temperature for the field previously studied by Hester, Parker, and Dufour (1983); and (3) CCD imagery of the NE limb in the light of four emission lines. A wide range of new and existing observations of the Loop are for the first time interpreted within the context of a single physical description. The Cygnus Loop is not an evaporative SNR evolving into the McKee and Ostriker (1977) ISM, nor are tiny cloudlets necessary to explain its morphology. The data show the Cygnus Loop to be evolving into a medium consisting primarily of an intercloud phase with N 0 approx. 0.1 cm -3 containing clouds with parsec dimensions and N 0 less than or equal to 10 cm -3 . The optical emission arises from extensive sheet like radiative shock fronts driven into the clouds. These fronts locally form the outer boundary of the remnant. The appearance of x-ray emission outside the optical emission on the limbs is due solely to projection effects. The distorted and bumpy shock front is shown to give rise in projection to the filamentary morphology of the remnant

  9. A deep optical imaging study of the nebular remnants of classical novae

    Science.gov (United States)

    Slavin, A. J.; O'Brien, T. J.; Dunlop, J. S.

    1995-09-01

    An optical imaging study of old nova remnants has revealed previously unobserved features in the shells of 13 classical novae - DQ Her, FH Ser, HR Del, GK Per, V1500 Cyg, T Aur, V533 Her, NQ Vul, V476 Cyg, DK Lac, LV Vul, RW UMi and V450 Cyg. These data indicate a possible correlation between nova speed class and the ellipticity of the resulting remnants - those of faster novae tend to comprise randomly distributed clumps of ejecta superposed on spherically symmetric diffuse material, whilst slower novae produce more structured ellipsoidal remnants with at least one and sometimes several rings of enhanced emission. By measuring the extent of the resolved shells and combining this information with previously published ejection speeds, we use expansion parallax to estimate distances for the 13 novae. Whilst we are able to deduce new information about every nova, it is notable that these observations include the first detections of shells around the old novae V450 Cyg and NQ Vul, and that velocity-resolved images of FH Ser and DQ Her have enabled us to estimate their orbital inclinations. Our observations of DQ Her also show that the main ellipsoidal shell is constricted by three rings and surrounded by a faint halo; this halo contains long tails extending outwards from bright knots, perhaps indicating that during or after outburst a fast inner wind has broken through the fractured principal shell.

  10. Hepatectomy Based on Future Liver Remnant Plasma Clearance Rate of Indocyanine Green

    Directory of Open Access Journals (Sweden)

    Yuichiro Uchida

    2016-01-01

    Full Text Available Background. Hepatectomy, an important treatment modality for liver malignancies, has high perioperative morbidity and mortality rates. Safe, comprehensive criteria for selecting patients for hepatectomy are needed. Since June 2011, we have used a cut-off value of ≧ 0.05 for future liver remnant plasma clearance rate of indocyanine green as a criterion for hepatectomy. The aim of this study was to verify the validity of this criterion. Methods. From June 2011 to December 2015, 212 hepatectomies were performed in Tenri Yorozu Hospital. Of these 212 patients, 107 who underwent preoperative computed tomography imaging volumetry, indocyanine green clearance test, and hepatectomy (excluding partial resection or enucleation were retrospectively analyzed. Results. There was no postoperative mortality. Posthepatectomy liver failure occurred in 59 patients (55.1% (International Study Group of Liver Surgery Grade A: 43 cases (40.2%, Grade B: 16 cases (15.0%, and Grade C: no cases. Operative morbidity greater than Clavien-Dindo Grade 3 occurred in 23 patients (21.5%. A low future liver remnant plasma clearance rate of indocyanine green was a good predictor for Grade B cases (area under curve = 0.804; 95% confidence interval, 0.712–0.895. Conclusion. Liver remnant plasma clearance rate of indocyanine green is a valid criterion for hepatectomy.

  11. Effect of cascade remnants on freely migrating defects in Cu-1% Au alloys

    Energy Technology Data Exchange (ETDEWEB)

    Iwase, A; Rehn, L E; Baldo, P M; Funk, L [Argonne National Lab., IL (United States). Materials Science Div.

    1997-03-01

    The effects of cascade remnants on Freely Migrating Defects (FMD) were studied by measuring Radiation-Induced Segregation (RIS) in Cu-1%Au at 400degC during simultaneous irradiation with 1.5-MeV He and (400-800)-keV heavy ions (Ne, Ar or Cu). The large RIS observed during 1.5-MeV He-only irradiation was dramatically suppressed under simultaneous heavy ion irradiation. For Cu simultaneous irradiation, the suppression disappeared immediately after the Cu irradiation ceased, while for simultaneous inert gas (Ne or Ar) irradiation, the suppression persisted after the ion beam was turned off. These results demonstrate that the displacement cascades created by heavy ions introduce additional annihilation sites, which reduce the steady-state FMD concentrations. As the cascade remnants produced by Cu ions are thermally unstable at 400degC, the RIS suppression occurs only during simultaneous irradiation. On the other hand, the inert gas atoms which accumulate in the specimen apparently stabilize the cascade remnants, allowing the suppression to persist. (author)

  12. Adult bacterial meningitis

    DEFF Research Database (Denmark)

    Meyer, C N; Samuelsson, I S; Galle, M

    2004-01-01

    Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin susceptibi......Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin...

  13. Internal Porosity of Mineral Coating Supports Microbial Activity in Rapid Sand Filters for Groundwater Treatment

    DEFF Research Database (Denmark)

    Gülay, Arda; Tatari, Karolina; Musovic, Sanin

    2014-01-01

    of the filter material. The volumetric NH4+ removal rate also increased with the degree of mineral coating. Consistently, bacterial 16S rRNA and amoA abundances positively correlated with increased mineral coating levels. Microbial colonization could be visualized mainly within the outer periphery (60.6 ± 35......, and abundance of microbiota. This study reveals that a mineral coating can positively affect the colonization and activity of microbial communities in rapid sand filters. To understand this effect, we investigated the abundance, spatial distribution, colonization, and diversity of all and of nitrifying...... prokaryotes in filter material with various degrees of mineral coating. We also examined the physical and chemical characteristics of the mineral coating. The amount of mineral coating correlated positively with the internal porosity, the packed bulk density, and the biologically available surface area...

  14. Outlook 96: Minerals and Energy

    International Nuclear Information System (INIS)

    1996-01-01

    Papers discussing the future of Australia's minerals and energy are presented under the following headings: Australia in the global minerals and energy markets; minerals exploration; steelmaking raw materials; aluminium and alumina; gold; nickel; base metals; titanium minerals; energy for a sustainable future; electricity; electricity in Asia; crude oil; coal trade; natural gas in Australia and uranium. Relevant papers are individually indexed/abstracted. Tabs., figs., refs

  15. International availability of energy minerals

    Energy Technology Data Exchange (ETDEWEB)

    White, N A [Norman White Associates, London (UK)

    1979-06-01

    Whereas the ultimate world supply of energy minerals - defined as fossil fuels and fissile minerals - is controlled by geological factors, the actual supply at any particular time is controlled by economic feasibility, technological innovations and/or political decisions. This paper identifies and discusses the principal uncertainties surrounding the international availability of energy minerals from now until the end of the century. A brief comparison is also made between energy and non-energy minerals.

  16. Aggregates from mineral wastes

    Directory of Open Access Journals (Sweden)

    Baic Ireneusz

    2016-01-01

    Full Text Available The problem concerning the growing demand for natural aggregates and the need to limit costs, including transportation from remote deposits, cause the increase in growth of interest in aggregates from mineral wastes as well as in technologies of their production and recovery. The paper presents the issue related to the group of aggregates other than natural. A common name is proposed for such material: “alternative aggregates”. The name seems to be fully justified due to adequacy of this term because of this raw materials origin and role, in comparison to the meaning of natural aggregates based on gravel and sand as well as crushed stones. The paper presents characteristics of the market and basic application of aggregates produced from mineral wastes, generated in the mining, power and metallurgical industries as well as material from demolished objects.

  17. The bismuth miners study

    International Nuclear Information System (INIS)

    Grosche, B.; Kreuzer, M.; Kreisheimer, M.; Schnelzer, M.; Tschense, A.; Gottschalk, K.

    2005-01-01

    The Federal Radiation Protection Office carried out a retrospective cohort study on some 60,000 former employees of the SAG/SDAG Wismut. The purpose of the study was to validate the radon-related risk of acquiring lung cancer previously calculated from 11 jointly evaluated studies among miners on the basis of an independent, homogeneous data record of comparable size. A further goal was to study the risk of acquiring extrapulmonal tumours. This paper only briefly describes the sampling, design and methods used in the study, as these were already presented during the Radon Status Talks. The first follow-up on the cohort was completed in 2003. Around this time a job exposure matrix (JEM) suitable for scientific inquiries was made available by the professional miners' association and the roof organisation of professional trade associations (HVBG). This paper is the first to report on the outcome of the risk analysis in direct comparison with the results found by BEIR

  18. Iodine mineral waters

    Directory of Open Access Journals (Sweden)

    Iluta Alexandru

    2011-11-01

    Full Text Available Iodine mineral waters are found especially in sub-Carpathian region, also in regions with Salif deposits. Waters are currently used iodine in drinking cure for chaps and Basedow. Are also indicated in balneology. Iodine water containing at least 1 mg L, there is pure iodine is usually given the nature of other types of mineral waters further: sodium chlorinated water (Bazna (50-70 mg iodine / l, Baile Govora (50 - 70 mg / l, Bălţăteşti (4-5 mg / l, salted Monteoru (30 mg / l, mine water mixed alkaline chlorination, sulphate, which are indicated for crenoterapie (hypo or isotonic to the bathrooms Olăneşti or Călimăneşti-Căciulata.

  19. Rock and mineral magnetism

    CERN Document Server

    O’Reilly, W

    1984-01-01

    The past two decades have witnessed a revolution in the earth sciences. The quantitative, instrument-based measurements and physical models of. geophysics, together with advances in technology, have radically transformed the way in which the Earth, and especially its crust, is described. The study of the magnetism of the rocks of the Earth's crust has played a major part in this transformation. Rocks, or more specifically their constituent magnetic minerals, can be regarded as a measuring instrument provided by nature, which can be employed in the service of the earth sciences. Thus magnetic minerals are a recording magnetometer; a goniometer or protractor, recording the directions of flows, fields and forces; a clock; a recording thermometer; a position recorder; astrain gauge; an instrument for geo­ logical surveying; a tracer in climatology and hydrology; a tool in petrology. No instrument is linear, or free from noise and systematic errors, and the performance of nature's instrument must be assessed and ...

  20. Combined use of radioiodine therapy and radiofrequency ablation in treating postsurgical thyroid remnant of differentiated thyroid carcinoma

    Directory of Open Access Journals (Sweden)

    Bin Long

    2015-01-01

    Conclusion: Combined use of RAI therapy and radiofrequency ablation in treating excessive postsurgical thyroid remnant of DTC can be an effective approach and avoids re-operation. Long-term efficacy monitoring would further determine its feasibility.

  1. Variation in diel activity of ground beetles (Coleoptera: Carabidae) associated with a soybean field and coal mine remnant

    Science.gov (United States)

    Willand, J.E.; McCravy, K.W.

    2006-01-01

    Diel activities of carabids (Coleoptera: Carabidae) associated with a coal mine remnant and surrounding soybean field were studied in west-central Illinois from June through October 2002. A total of 1,402 carabids, representing 29 species and 17 genera, were collected using pitfall traps. Poecilus chalcites (Say) demonstrated roughly equal diurnal and nocturnal activity in June, but greater diurnal activity thereafter. Pterostichus permundus (Say), Cyclotrachelus seximpressus (LeConte), Amara obesa (Say), and Scarites quadriceps Chaudoir showed significant nocturnal activity. Associations between habitat and diel activity were found for three species: P. chalcites associated with the remnant and edge habitats showed greater diurnal activity than those associated with the soybean field; C. seximpressus was most active diurnally in the remnant, and Harpalus pensylvanicus (DeGeer) showed the greatest nocturnal activity in the remnant and edge habitats. We found significant temporal and habitat-related variation in diel activity among carabid species inhabiting agricultural areas in west-central Illinois.

  2. Genetically elevated non-fasting triglycerides and calculated remnant cholesterol as causal risk factors for myocardial infarction

    DEFF Research Database (Denmark)

    Jørgensen, Anders Berg; Frikke-Schmidt, Ruth; West, Anders Sode

    2012-01-01

    AimsElevated non-fasting triglycerides mark elevated levels of remnant cholesterol. Using a Mendelian randomization approach, we tested whether genetically increased remnant cholesterol in hypertriglyceridaemia due to genetic variation in the apolipoprotein A5 gene (APOA5) associates with an incr......AimsElevated non-fasting triglycerides mark elevated levels of remnant cholesterol. Using a Mendelian randomization approach, we tested whether genetically increased remnant cholesterol in hypertriglyceridaemia due to genetic variation in the apolipoprotein A5 gene (APOA5) associates...... with an increased risk of myocardial infarction (MI).Methods and resultsWe resequenced the core promoter and coding regions of APOA5 in individuals with the lowest 1% (n = 95) and highest 2% (n = 190) triglyceride levels in the Copenhagen City Heart Study (CCHS, n = 10 391). Genetic variants which differed...... in frequency between the two extreme triglyceride groups (c.-1131T > C, S19W, and c.*31C > T; P-value: 0.06 to...

  3. Characterization lithium mineralized pegmatite

    International Nuclear Information System (INIS)

    Pereira, E.F.S.; Luz Ferreira, O. da; Cancado, R.Z.L.

    1986-01-01

    Lithium economic importance has increased in the last years. In Brazil its reserves, generally pegmatites bodies, are found in Itinga-Aracuai-MG. This study of characterization belongs to a global plan of lithium mineralized bodies research of 'Arqueana de Minerios e Metais Ltda', which purpose is to give subsidies for implementation of pegmatite unit, in order to make better use of them. (F.E.) [pt

  4. Are we headed towards the defaunation of the last large Atlantic Forest remnants? Poaching activities in one of the largest remnants of the Tabuleiro forests in southeastern Brazil.

    Science.gov (United States)

    Sousa, José Adelson C; Srbek-Araujo, Ana C

    2017-03-01

    Hunting is a problem to animal conservation in different parts of the world and it has caused the local extinction of several species. The aim of this study was to characterize the poaching activities in one of the main tabuleiro forest remnants of Brazil, the Linhares-Sooretama Block (LSB). Poaching records from 2010 to 2013 were gathered from the agencies responsible for monitoring and combating environmental crimes in the LSB. A total of 693 records (mean = 173 events/year) were collected involving direct (hunted animals, firearms, handmade firearms, traps, poachers, and various hunting supplies) and indirect (tree stands, baits, and poacher signs) evidences of poaching. No differences in the monthly cumulative number of records were found among years, but the distribution of records differed according to the type of evidence. A total of 40 animal seizure events were recorded involving a total of at least 15 taxa directly affected by poaching (reptiles = 2, birds = 6, mammals = 7) and 75 individuals seized (19 individuals/year). Five of the poached species are threatened. Lowland paca (Cuniculus paca) and armadillos were the most poached mammals in the region. Most of the poachers conduct such activities for fun (entertainment) and/or professionally (commercial hunting). The collected data show an approximately 32% increase in the number of poaching events in the region compared with the historical data available for LSB. It may have resulted from a gradual decrease in protection, both in terms of the number of agents deployed and the levels of effort of the teams, which began in 2009. The data demonstrate that poaching is a significant threat to the conservation of the LSB fauna, as it is in other Atlantic Forest remnants and in other regions of the world. Protection activities must be intensified to effectively combat the impacts of poaching in the LSB region, thereby contributing to the conservation of species in one of the few Atlantic Forest

  5. 76 FR 6110 - Conflict Minerals

    Science.gov (United States)

    2011-02-03

    ...-10] RIN 3235-AK84 Conflict Minerals AGENCY: Securities and Exchange Commission. ACTION: Proposed rule...'') and would require any such issuer for which conflict minerals are necessary to the functionality or... body of its annual report whether its conflict minerals originated in the Democratic Republic of the...

  6. Flotation of sulphide minerals 1990

    Energy Technology Data Exchange (ETDEWEB)

    Forssberg, K S.E. [ed.; Luleaa University of Technology, Luleaa (Sweden). Division of Mineral Processing

    1991-01-01

    A total of 27 papers presented at the workshop on flotation of sulphide minerals, reprinted from the International Journal of Mineral Processing, vol. 33, nos. 1-4, are included in this book. They cover various aspects of flotation of such minerals as chalcopyrite, pyrrhotite, galena, malachite and pyrite.

  7. Digital mineral logging system

    International Nuclear Information System (INIS)

    West, J.B.

    1980-01-01

    A digital mineral logging system acquires data from a mineral logging tool passing through a borehole and transmits the data uphole to an electronic digital signal processor. A predetermined combination of sensors, including a deviometer, is located in a logging tool for the acquisition of the desired data as the logging tool is raised from the borehole. Sensor data in analog format is converted in the logging tool to a digital format and periodically batch transmitted to the surface at a predetermined sampling rate. An identification code is provided for each mineral logging tool, and the code is transmitted to the surface along with the sensor data. The self-identifying tool code is transmitted to the digital signal processor to identify the code against a stored list of the range of numbers assigned to that type of tool. The data is transmitted up the d-c power lines of the tool by a frequency shift key transmission technique. At the surface, a frequency shift key demodulation unit transmits the decoupled data to an asynchronous receiver interfaced to the electronic digital signal processor. During a recording phase, the signals from the logging tool are read by the electronic digital signal processor and stored for later processing. During a calculating phase, the stored data is processed by the digital signal processor and the results are outputted to a printer or plotter, or both

  8. Dynamics of mineral crystallization from precipitated slab-derived fluid phase: first in situ synchrotron X-ray measurements

    Science.gov (United States)

    Malaspina, Nadia; Alvaro, Matteo; Campione, Marcello; Wilhelm, Heribert; Nestola, Fabrizio

    2015-03-01

    Remnants of the fluid phase at ultrahigh pressure (UHP) in subduction environments may be preserved as primary multiphase inclusions in UHP minerals. The mode of crystallization of daughter minerals during precipitation within the inclusion and/or the mechanism of interaction between the fluid at supercritical conditions and the host mineral are still poorly understood from a crystallographic point of view. A case study is represented by garnet-orthopyroxenites from the Maowu Ultramafic Complex (China) deriving from harzburgite precursors metasomatized at ~4 GPa, 750 °C by a silica- and incompatible trace element-rich fluid phase. This metasomatism produced poikilitic orthopyroxene and inclusion-rich garnet porphyroblasts. Solid multiphase primary inclusions in garnet display a size within a few tens of micrometres and negative crystal shapes. Infilling minerals (spinel: 10-20 vol%; amphibole, chlorite, talc, mica: 80-90 vol%) occur with constant volume proportions and derive from trapped solute-rich aqueous fluids. To constrain the possible mode of precipitation of daughter minerals, we performed for the first time a single-crystal X-ray diffraction experiment by synchrotron radiation at Diamond Light Source. In combination with electron probe microanalyses, this measurement allowed the unique identification of each mineral phase and reciprocal orientations. We demonstrated the epitaxial relationship between spinel and garnet and between some hydrous minerals. Such information is discussed in relation to the physico-chemical aspects of nucleation and growth, shedding light on the mode of mineral crystallization from a fluid phase trapped at supercritical conditions.

  9. The hard X-ray view of the young supernova remnant G1.9+0.3

    DEFF Research Database (Denmark)

    Zoglauer, Andreas; Reynolds, Stephen P.; An, Hongjun

    2015-01-01

    NuSTAR observed G1.9+0.3, the youngest known supernova remnant in the Milky Way, for 350 ks and detected emission up to ~30 keV. The remnant's X-ray morphology does not change significantly across the energy range from 3 to 20 keV. A combined fit between NuSTAR and Chandra shows that the spectrum...

  10. Environmental effects of the Big Rapids dam remnant removal, Big Rapids, Michigan, 2000-02

    Science.gov (United States)

    Healy, Denis F.; Rheaume, Stephen J.; Simpson, J. Alan

    2003-01-01

    The U.S. Geological Survey (USGS), in cooperation with the city of Big Rapids, investigated the environmental effects of removal of a dam-foundation remnant and downstream cofferdam from the Muskegon River in Big Rapids, Mich. The USGS applied a multidiscipline approach, which determined the water quality, sediment character, and stream habitat before and after dam removal. Continuous water-quality data and discrete water-quality samples were collected, the movement of suspended and bed sediment were measured, changes in stream habitat were assessed, and streambed elevations were surveyed. Analyses of water upstream and downstream from the dam showed that the dam-foundation remnant did not affect water quality. Dissolved-oxygen concentrations downstream from the dam remnant were depressed for a short period (days) during the beginning of the dam removal, in part because of that removal effort. Sediment transport from July 2000 through March 2002 was 13,800 cubic yards more at the downstream site than the upstream site. This increase in sediment represents the remobilized sediment upstream from the dam, bank erosion when the impoundment was lowered, and contributions from small tributaries between the sites. Five habitat reaches were monitored before and after dam-remnant removal. The reaches consisted of a reference reach (A), upstream from the effects of the impoundment; the impoundment (B); and three sites below the impoundment where habitat changes were expected (C, D, and E, in downstream order). Stream-habitat assessment reaches varied in their responses to the dam-remnant removal. Reference reach A was not affected. In impoundment reach B, Great Lakes and Environmental Assessment Section (GLEAS) Procedure 51 ratings went from fair to excellent. For the three downstream reaches, reach C underwent slight habitat degradation, but ratings remained good; reach D underwent slight habitat degradation with ratings changing from excellent to good; and, in an area

  11. [Bacterial biofilms and infection].

    Science.gov (United States)

    Lasa, I; Del Pozo, J L; Penadés, J R; Leiva, J

    2005-01-01

    In developed countries we tend to think of heart disease and the numerous forms of cancer as the main causes of mortality, but on a global scale infectious diseases come close, or may even be ahead: 14.9 million deaths in 2002 compared to cardiovascular diseases (16.9 million deaths) and cancer (7.1 million deaths) (WHO report 2004). The infectious agents responsible for human mortality have evolved as medical techniques and hygienic measures have changed. Modern-day acute infectious diseases caused by specialized bacterial pathogens such as diphtheria, tetanus, cholera, plague, which represented the main causes of death at the beginning of XX century, have been effectively controlled with antibiotics and vaccines. In their place, more than half of the infectious diseases that affect mildly immunocompromised patients involve bacterial species that are commensal with the human body; these can produce chronic infections, are resistant to antimicrobial agents and there is no effective vaccine against them. Examples of these infections are the otitis media, native valve endocarditis, chronic urinary infections, bacterial prostatitis, osteomyelitis and all the infections related to medical devices. Direct analysis of the surface of medical devices or of tissues that have been foci of chronic infections shows the presence of large numbers of bacteria surrounded by an exopolysaccharide matrix, which has been named the "biofilm". Inside the biofilm, bacteria grow protected from the action of the antibodies, phagocytic cells and antimicrobial treatments. In this article, we describe the role of bacterial biofilms in human persistent infections.

  12. Interfering with bacterial gossip

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    that appropriately target bacteria in their relevant habitat with the aim of mitigating their destructive impact on patients. In this review we describe molecular mechanisms involved in “bacterial gossip” (more scientifically referred to as quorum sensing (QS) and c-di-GMP signaling), virulence, biofilm formation...

  13. Bacterial fingerprints across Europe

    NARCIS (Netherlands)

    Glasner, Corinna

    2014-01-01

    Bacterial pathogens, such as Staphylococcus aureus and carbapenemase-producing Enterobacteriaceae (CPE), impose major threats to human health worldwide. Both have a ‘Jekyll & Hyde’ character, since they can be present as human commensals, but can also become harmful invasive pathogens especially

  14. Bacterial membrane proteomics.

    Science.gov (United States)

    Poetsch, Ansgar; Wolters, Dirk

    2008-10-01

    About one quarter to one third of all bacterial genes encode proteins of the inner or outer bacterial membrane. These proteins perform essential physiological functions, such as the import or export of metabolites, the homeostasis of metal ions, the extrusion of toxic substances or antibiotics, and the generation or conversion of energy. The last years have witnessed completion of a plethora of whole-genome sequences of bacteria important for biotechnology or medicine, which is the foundation for proteome and other functional genome analyses. In this review, we discuss the challenges in membrane proteome analysis, starting from sample preparation and leading to MS-data analysis and quantification. The current state of available proteomics technologies as well as their advantages and disadvantages will be described with a focus on shotgun proteomics. Then, we will briefly introduce the most abundant proteins and protein families present in bacterial membranes before bacterial membrane proteomics studies of the last years will be presented. It will be shown how these works enlarged our knowledge about the physiological adaptations that take place in bacteria during fine chemical production, bioremediation, protein overexpression, and during infections. Furthermore, several examples from literature demonstrate the suitability of membrane proteomics for the identification of antigens and different pathogenic strains, as well as the elucidation of membrane protein structure and function.

  15. [Spontaneous bacterial peritonitis].

    Science.gov (United States)

    Velkey, Bálint; Vitális, Eszter; Vitális, Zsuzsanna

    2017-01-01

    Spontaneous bacterial peritonitis occurs most commonly in cirrhotic patients with ascites. Pathogens get into the circulation by intestinal translocation and colonize in peritoneal fluid. Diagnosis of spontaneous bacterial peritonitis is based on elevated polymorphonuclear leukocyte count in the ascites (>0,25 G/L). Ascites culture is often negative but aids to get information about antibiotic sensitivity in positive cases. Treatment in stable patient can be intravenous then orally administrated ciprofloxacin or amoxicillin/clavulanic acid, while in severe cases intravenous III. generation cephalosporin. Nosocomial spontaneous bacterial peritonitis often caused by Gram-positive bacteria and multi-resistant pathogens can also be expected thus carbapenem should be the choice of the empiric treatment. Antibiotic prophylaxis should be considered. Norfloxacin is used most commonly, but changes are expected due to increase in quinolone resistance. As a primary prophylaxis, a short-term antibiotic treatment is recommended after gastrointestinal bleeding for 5 days, while long-term prophylaxis is for patients with low ascites protein, and advanced disease (400 mg/day). Secondary prophylaxis is recommended for all patients recovered from spontaneous bacterial peritonitis. Due to increasing antibiotic use of antibiotics prophylaxis is debated to some degree. Orv. Hetil., 2017, 158(2), 50-57.

  16. Microbially induced selective flotation of sphalerite from galena using mineral-adapted strains of Bacillus megaterium.

    Science.gov (United States)

    Vasanthakumar, B; Ravishankar, H; Subramanian, S

    2013-12-01

    The selective flotation of sphalerite from a sphalerite-galena mineral mixture has been achieved using cells and extracellular secretions of Bacillus megaterium after adaptation to the chosen minerals. The extracellular secretions obtained after thermolysis of bacterial cells adapted to sphalerite yield the highest flotation recovery of sphalerite with a selectivity index value of 24.5, in comparison to the other cellular and extra-cellular bio-reagents studied. The protein profile for the unadapted and mineral-adapted cells has been found to differ distinctly, attesting to variation in the yield and nature of extra-cellular polymeric substances (EPS). The changes induced in the bacterial cell wall components after adaptation to sphalerite or galena with respect to the contents of phosphate, uronic acid and acetylated sugars of B. megaterium have been quantified. The role of the dissolved metal ions from the minerals as well as that of the constituents of extracellular secretions in modulating the surface charge of the bacterial cells as well as the minerals under study has been confirmed using various enzymatic treatments of the bacterial cells. It has been demonstrated that the induction of additional molecular weight protein fractions as well as the higher amount of extracellular proteins and phosphate secreted after adaptation to sphalerite vis-à-vis galena are contributory factors for the selective separation of sphalerite from galena. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Corticosteroids for Bacterial Keratitis

    Science.gov (United States)

    Srinivasan, Muthiah; Mascarenhas, Jeena; Rajaraman, Revathi; Ravindran, Meenakshi; Lalitha, Prajna; Glidden, David V.; Ray, Kathryn J.; Hong, Kevin C.; Oldenburg, Catherine E.; Lee, Salena M.; Zegans, Michael E.; McLeod, Stephen D.; Lietman, Thomas M.; Acharya, Nisha R.

    2013-01-01

    Objective To determine whether there is a benefit in clinical outcomes with the use of topical corticosteroids as adjunctive therapy in the treatment of bacterial corneal ulcers. Methods Randomized, placebo-controlled, double-masked, multicenter clinical trial comparing prednisolone sodium phosphate, 1.0%, to placebo as adjunctive therapy for the treatment of bacterial corneal ulcers. Eligible patients had a culture-positive bacterial corneal ulcer and received topical moxifloxacin for at least 48 hours before randomization. Main Outcome Measures The primary outcome was best spectacle-corrected visual acuity (BSCVA) at 3 months from enrollment. Secondary outcomes included infiltrate/scar size, reepithelialization, and corneal perforation. Results Between September 1, 2006, and February 22, 2010, 1769 patients were screened for the trial and 500 patients were enrolled. No significant difference was observed in the 3-month BSCVA (−0.009 logarithm of the minimum angle of resolution [logMAR]; 95% CI, −0.085 to 0.068; P = .82), infiltrate/scar size (P = .40), time to reepithelialization (P = .44), or corneal perforation (P > .99). A significant effect of corticosteroids was observed in subgroups of baseline BSCVA (P = .03) and ulcer location (P = .04). At 3 months, patients with vision of counting fingers or worse at baseline had 0.17 logMAR better visual acuity with corticosteroids (95% CI, −0.31 to −0.02; P = .03) compared with placebo, and patients with ulcers that were completely central at baseline had 0.20 logMAR better visual acuity with corticosteroids (−0.37 to −0.04; P = .02). Conclusions We found no overall difference in 3-month BSCVA and no safety concerns with adjunctive corticosteroid therapy for bacterial corneal ulcers. Application to Clinical Practice Adjunctive topical corticosteroid use does not improve 3-month vision in patients with bacterial corneal ulcers. PMID:21987582

  18. Bacterial infec tions in travellers

    African Journals Online (AJOL)

    namely bacterial causes of travellers' diarrhoea and skin infections, as well as .... Vaccination: protective efficacy against typhoid may be overcome by ingesting a high bacterial load. Vaccine ..... preparation such as cream sauce. Only after ...

  19. Inducing mineral precipitation in groundwater by addition of phosphate

    Directory of Open Access Journals (Sweden)

    Hartmann Thomas

    2011-10-01

    Full Text Available Abstract Background Induced precipitation of phosphate minerals to scavenge trace elements from groundwater is a potential remediation approach for contaminated aquifers. The success of engineered precipitation schemes depends on the particular phases generated, their rates of formation, and their long term stability. The purpose of this study was to examine the precipitation of calcium phosphate minerals under conditions representative of a natural groundwater. Because microorganisms are present in groundwater, and because some proposed schemes for phosphate mineral precipitation rely on stimulation of native microbial populations, we also tested the effect of bacterial cells (initial densities of 105 and 107 mL-1 added to the precipitation medium. In addition, we tested the effect of a trace mixture of propionic, isovaleric, formic and butyric acids (total concentration 0.035 mM. Results The general progression of mineral precipitation was similar under all of the study conditions, with initial formation of amorphous calcium phosphate, and transformation to poorly crystalline hydroxylapatite (HAP within one week. The presence of the bacterial cells appeared to delay precipitation, although by the end of the experiments the overall extent of precipitation was similar for all treatments. The stoichiometry of the final precipitates as well as Rietveld structure refinement using x-ray diffraction data indicated that the presence of organic acids and bacterial cells resulted in an increasing a and decreasing c lattice parameter, with the higher concentration of cells resulting in the greatest distortion. Uptake of Sr into the solids was decreased in the treatments with cells and organic acids, compared to the control. Conclusions Our results suggest that the minerals formed initially during an engineered precipitation application for trace element sequestration may not be the ones that control long-term immobilization of the contaminants. In

  20. Stellar remnants

    CERN Document Server

    Kawaler, S D; Srinivasan, G

    1997-01-01

    This volume examines the internal structure, origin and evolution of white dwarfs, neutron stars and black holes, all objects at the final stage of stellar evolution. It covers topics such as: pulsation of white dwarfs; millisecond pulsars; and the dynamics around black holes.

  1. Magnetotactic Bacterial Cages as Safe and Smart Gene Delivery Vehicles

    KAUST Repository

    Alsaiari, Shahad K.

    2016-07-27

    In spite of the huge advances in the area of synthetic carriers, their efficiency still poorly compares to natural vectors. Herein, we report the use of unmodified magnetotactic bacteria as a guidable delivery vehicle for DNA functionalized gold nanoparticles (AuNPs). High cargo loading is established under anaerobic conditions (bacteria is alive) through endocytosis where AuNPs are employed as transmembrane proteins mimics (facilitate endocytosis) as well as imaging agents to verify and quantify loading and release. The naturally bio-mineralized magnetosomes, within the bacteria, induce heat generation inside bacteria through magnetic hyperthermia. Most importantly after exposing the system to air (bacteria is dead) the cell wall stays intact providing an efficient bacterial vessel. Upon incubation with THP-1 cells, the magnetotactic bacterial cages (MBCs) adhere to the cell wall and are directly engulfed through the phagocytic activity of these cells. Applying magnetic hyperthermia leads to the dissociation of the bacterial microcarrier and eventual release of cargo.

  2. Magnetotactic Bacterial Cages as Safe and Smart Gene Delivery Vehicles

    KAUST Repository

    Alsaiari, Shahad K.; Ezzedine, Alaa H.; Abdallah, Abdallah; Sougrat, Rachid; Khashab, Niveen M.

    2016-01-01

    In spite of the huge advances in the area of synthetic carriers, their efficiency still poorly compares to natural vectors. Herein, we report the use of unmodified magnetotactic bacteria as a guidable delivery vehicle for DNA functionalized gold nanoparticles (AuNPs). High cargo loading is established under anaerobic conditions (bacteria is alive) through endocytosis where AuNPs are employed as transmembrane proteins mimics (facilitate endocytosis) as well as imaging agents to verify and quantify loading and release. The naturally bio-mineralized magnetosomes, within the bacteria, induce heat generation inside bacteria through magnetic hyperthermia. Most importantly after exposing the system to air (bacteria is dead) the cell wall stays intact providing an efficient bacterial vessel. Upon incubation with THP-1 cells, the magnetotactic bacterial cages (MBCs) adhere to the cell wall and are directly engulfed through the phagocytic activity of these cells. Applying magnetic hyperthermia leads to the dissociation of the bacterial microcarrier and eventual release of cargo.

  3. Nuclear minerals in Pakistan

    International Nuclear Information System (INIS)

    Mansoor, M.

    2005-01-01

    Strategic importance of Nuclear Minerals was recognized during early formative years of the Pakistan Atomic Energy Commission, and prospecting for uranium was started in Dera Ghazi Khan in collaboration with the Geological Survey of Pakistan (GSP) as early as 1961. Later, the responsibility for countrywide surveys and exploration was fully entrusted with PAEC and in this respect a Directorate of Nuclear Minerals(DNM) was established in 1966 at Lahore. Later, DNM was shifted to the Atomic Energy Centre (AEC), Lahore building and renamed as Atomic Energy Minerals Centre. It has state-of-the-art Chemistry, Mineralogy, Remote Sensing and Electronics Laboratories and an Ore Processing Pilot Plant. The Centre has Prospecting, Exploration, Geophysics, Geochemistry, Geo-tectonics, Mining and Drilling Sections. Regional Offices have been established to facilitate work at Karachi, Quetta and Peshawar. Siwaliks were recognized as a favorable geological formation of prime importance. Sandstone-shale sequence of Siwaliks Formation is exposed in all provinces of Pakistan and in Azad Jammu and Kashmir (AJK), broadly categorized into Rajanpur-Dera Ghazi Khan, Bannu Basin-Kohat Plateau and Potwar-AJK zones. Baghalchur, Nangar Nai and Taunsa uranium deposits have been discovered in the Rajanpur- D.G. Khan Zone. Qabul Khel and Shanawah Uranium deposits have been discovered in the Shanawah-Kohat Plateau Zone. Prospection and exploration is in progress. The first uranium mine was opened at Baghalchur, and uranium mill was established at D.G Khan in 1977-78 all by indigenous effort. The uranium mine was the most advanced and mechanized mine of that time in the country. Later, a second uranium mine was opened at Qabul Khel in 1992, which was based on a new and advanced in situ leach technology, developed to suit local geological and ore zone parameters. Mining of Nanganai and Taunsa Deposits was started respectively in 1996 and 2002, and is also based on in situ leach technology which is

  4. Does remnant gastric cancer really differ from primary gastric cancer? A systematic review of the literature by the Task Force of Japanese Gastric Cancer Association.

    Science.gov (United States)

    Shimada, Hideaki; Fukagawa, Takeo; Haga, Yoshio; Oba, Koji

    2016-04-01

    Remnant gastric cancer, most frequently defined as cancer detected in the remnant stomach after distal gastrectomy for benign disease and those cases after surgery of gastric cancer at least 5 years after the primary surgery, is often reported as a tumor with poor prognosis. The Task Force of Japanese Gastric Cancer Association for Research Promotion evaluated the clinical impact of remnant gastric cancer by systematically reviewing publications focusing on molecular carcinogenesis, lymph node status, patient survival, and surgical complications. A systematic literature search was performed using PubMed/MEDLINE with the keywords "remnant," "stomach," and "cancer," revealing 1154 relevant reports published up to the end of December 2014. The mean interval between the initial surgery and the diagnosis of remnant gastric cancer ranged from 10 to 30 years. The incidence of lymph node metastases at the splenic hilum for remnant gastric cancer is not significantly higher than that for primary proximal gastric cancer. Lymph node involvement in the jejunal mesentery is a phenomenon peculiar to remnant gastric cancer after Billroth II reconstruction. Prognosis and postoperative morbidity and mortality rates seem to be comparable to those for primary proximal gastric cancer. The crude 5-year mortality for remnant gastric cancer was 1.08 times higher than that for primary proximal gastric cancer, but this difference was not statistically significant. In conclusion, although no prospective cohort study has yet evaluated the clinical significance of remnant gastric cancer, our literature review suggests that remnant gastric cancer does not adversely affect patient prognosis and postoperative course.

  5. Minerals and rumen function

    International Nuclear Information System (INIS)

    Smith, R.H.

    1984-01-01

    The mechanisms are discussed of some clinical disorders, characteristic only of ruminants and related to the effects of abnormal mineral intake on rumen function. With particular attention to tropical conditions, consideration is given to: (a) the possible effects of phosphorus deficiency on rumen microbial activity; (b) the depression of rumen microbial synthesis in sulphur deficiency; (c) the inhibition of magnesium absorption from the forestomachs; and (d) the involvement of the rumen microorganisms in leading to copper and vitamin B 12 deficiencies as a result of low intakes of cobalt. (author)

  6. Reducing coal miner absenteeism

    Energy Technology Data Exchange (ETDEWEB)

    Peters, R.H.; Clingan, M.R. (Bureau of Mines, PA (USA). Pittsburgh Research Center)

    1989-09-01

    High absenteeism at coal mines can seriously affect safety and hamper productivity. Several effective strategies for achieving high attendance which mine operators may not have considered are presented and a method is proposed for implementing programs for minimizing absenteeism among coal miners. The best strategies for improving attendance will vary according to the needs and circumstances of the particular mine, however, the process for establishing such a program is relatively invariant. A four-stage process is recommended; evaluate data from prior attendance records, communicate attendance goals and policy, develop and implement an attendance promotion program, and recycle. 12 refs., 5 figs.

  7. United States mineral resources

    Science.gov (United States)

    Brobst, Donald A.; Pratt, Walden P.

    1973-01-01

    The work on this volume began in January 1972, but in a broader sense its production began many years ago. The chapters were written by geologists most of whom have had many years of experience studying the geology of mineral deposits, and more particularly the commodities about which they have written here. A total of nearly 2,300 man-years of professional experience in the geology of mineral resources is represented by the authors of the volume, and about 30 man-years went directly into its preparation. Each chapter contains not only a synthesis of the state of knowledge of the geology of the commodity, but also an appraisal of the known resources, and an examination of the geologic possibilities for finding additional deposits. In January 1972, responsibility for the preparation of the volume was assigned to us as co-editors, and we were given a tentative list of commodities and authors. We provided each author with a suggested outline of general topics to be covered, and some guidelines as to scope and philosophy of approach, but beyond that we avoided any attempt to fit each chapter into a stereotype. Moreover, the types of commodities range from the major metals and industrial minerals such as copper, silver, and fluorspar, which have been the subject of geologic research for years, to other commodities that are of such varied geologic nature (such as pigments or gemstones) or of such minor present importance (such as scandium or thallium) that they cannot be treated from the same viewpoint as the major minerals. The chapters range, therefore, from comprehensive summary reports to general essays that reflect the individuality of the authors as well as the variation among commodities. Throughout the book the emphasis is on geology, but each chapter contains some summary information on uses, technology, and economics. These summaries are not meant to be exhaustive, however, and additional details are in the 1970 edition of "Mineral Facts and Problems" (Bulletin

  8. Refining mineral oils

    Energy Technology Data Exchange (ETDEWEB)

    1946-07-05

    A process is described refining raw oils such as mineral oils, shale oils, tar, their fractions and derivatives, by extraction with a selected solvent or a mixture of solvents containing water, forming a solvent more favorable for the hydrocarbons poor in hydrogen than for hydrocarbons rich in hydrogen, this process is characterized by the addition of an aiding solvent for the water which can be mixed or dissolved in the water and the solvent or in the dissolving mixture and increasing in this way the solubility of the water in the solvent or the dissolving mixture.

  9. RELATIVE TRACE MINERAL BIOAVAILABILITY

    OpenAIRE

    Rchard D. Miles; Peter R. Henry

    2006-01-01

    Para determinar a eficiência de utilização de elementos minerais dietéticos, deve-se conhecer a biodisponibilidade relativa de cada elemento de um determinado ingrediente ou de uma ração completa. Análises químicas da dieta ou de um determinado ingrediente não indicam a efetividade biológica de um nutriente. Existem muitos fatores que influenciam a biodisponibilidade dos minerais, especialmente dos minerais-traço, tais como: nível de consumo do mineral, forma química, digestibilidade da dieta...

  10. Structure of bacterial lipopolysaccharides.

    Science.gov (United States)

    Caroff, Martine; Karibian, Doris

    2003-11-14

    Bacterial lipopolysaccharides are the major components of the outer surface of Gram-negative bacteria They are often of interest in medicine for their immunomodulatory properties. In small amounts they can be beneficial, but in larger amounts they may cause endotoxic shock. Although they share a common architecture, their structural details exert a strong influence on their activity. These molecules comprise: a lipid moiety, called lipid A, which is considered to be the endotoxic component, a glycosidic part consisting of a core of approximately 10 monosaccharides and, in "smooth-type" lipopolysaccharides, a third region, named O-chain, consisting of repetitive subunits of one to eight monosaccharides responsible for much of the immunospecificity of the bacterial cell.

  11. Cooperative Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2009-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a novel optimization algorithm based on the social foraging behavior of E. coli bacteria. This paper presents a variation on the original BFO algorithm, namely, the Cooperative Bacterial Foraging Optimization (CBFO, which significantly improve the original BFO in solving complex optimization problems. This significant improvement is achieved by applying two cooperative approaches to the original BFO, namely, the serial heterogeneous cooperation on the implicit space decomposition level and the serial heterogeneous cooperation on the hybrid space decomposition level. The experiments compare the performance of two CBFO variants with the original BFO, the standard PSO and a real-coded GA on four widely used benchmark functions. The new method shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  12. Spectroscopic mapping of the physical properties of supernova remnant N 49

    Science.gov (United States)

    Pauletti, D.; Copetti, M. V. F.

    2016-10-01

    Context. Physical conditions inside a supernova remnant can vary significantly between different positions. However, typical observational data of supernova remnants are integrated data or contemplate specific portions of the remnant. Aims: We study the spatial variation in the physical properties of the N 49 supernova remnant based on a spectroscopic mapping of the whole nebula. Methods: Long-slit spectra were obtained with the slit (~4' × 1.03″) aligned along the east-west direction from 29 different positions spaced by 2″ in declination. A total of 3248 1D spectra were extracted from sections of 2″ of the 2D spectra. More than 60 emission lines in the range 3550 Å to 8920 Å were measured in these spectra. Maps of the fluxes and of intensity ratios of these emission lines were built with a spatial resolution of 2″ × 2″. Results: An electron density map has been obtained using the [S II] λ6716 /λ6731 line ratio. Values vary from ~500 cm-3 at the northeast region to more than 3500 cm-3 at the southeast border. We calculated the electron temperature using line ratio sensors for the ions S+, O++, O+, and N+. Values are about 3.6 × 104 K for the O++ sensor and about 1.1 × 104 K for other sensors. The Hα/Hβ ratio map presents a ring structure with higher values that may result from collisional excitation of hydrogen. We detected an area with high values of [N II] λ6583/Hα extending from the remnant center to its northeastern border, which may be indicating an overabundance of nitrogen in the area due to contamination by the progenitor star. We found a radial dependence in many line intensity ratio maps. We observed an increase toward the remnant borders of the intensity ratio of any two lines in which the numerator comes before in the sequence [O III] λ5007, [O III] λ4363, [Ar III] λ7136, [Ne III] λ3869, [O II] λ7325, [O II] λ3727, He II λ4686, Hβ λ4861, [N II] λ6583, He I λ6678, [S II] λ6731, [S II] λ6716, [O I] λ6300, [Ca II]

  13. Mineral supplementation for grazing ruminants

    International Nuclear Information System (INIS)

    McDowell, L.R.; Conrad, J.H.; Ellis, G.L.

    1986-01-01

    Grazing ruminants to which concentrate feeds cannot be economically fed must rely on self-feeding of mineral supplements. A number of factors affect mineral consumption of free-choice mixtures. Livestock exhibit little nutritional wisdom and will select palatable mixtures in preference to mixtures designed to meet their requirements. Palatability and appetite stimulators are often used to achieve a more uniform herd-wide consumption. It is best to formulate free-choice mixtures on the basis of analyses or other available data. However, when no information on mineral status is known, a free-choice complete mineral supplement is warranted. A 'complete' mineral mixture usually includes salt, a low fluoride P source, Ca, Co, Cu, I, Mn and Zn. Selenium, Mg, K, S, Fe or additional elements can be incorporated into a mineral supplement as new information suggests a need. The detriment to ruminant production caused by providing Ca, Se and Cu in excess can be greater than any benefit derived by providing a mineral supplement. In regions where high forage Mo predominates, three to five times the Cu content in mineral mixtures is needed to counteract Mo toxicity. Supplemental minerals are most critical during the wet season, when cattle are gaining weight rapidly and energy and protein supplies are adequate. Economic return on mineral supplementation is high. (author)

  14. Bacterial control of cyanobacteria

    CSIR Research Space (South Africa)

    Ndlela, Luyanda L

    2017-08-01

    Full Text Available of biological control appears to be direct contact. • Ndlela, L. L. et al. (2016) ‘An overview of cyanobacterial bloom occurrences and research in Africa over the last decade’, Harmful Algae, 60 • Gumbo, J.R. et al. (2010) The Isolation and identification... of Predatory Bacteria from a Microcystis algal Bloom.. African Journal of Biotechnology, 9. *Special acknowledgement goes to the National Research foundation for funding this presentation Bacterial control of cyanobacteria Luyanda...

  15. Bacterial growth kinetics

    International Nuclear Information System (INIS)

    Boonkitticharoen, V.; Ehrhardt, J.C.; Kirchner, P.T.

    1989-01-01

    Quantitative measurement of bacterial growth may be made using a radioassay technique. This method measures, by scintillation counting, the 14 CO 2 derived from the bacterial metabolism of a 14 C-labeled substrate. Mathematical growth models may serve as reliable tools for estimation of the generation rate constant (or slope of the growth curve) and provide a basis for evaluating assay performance. Two models, i.e., exponential and logistic, are proposed. Both models yielded an accurate fit to the data from radioactive measurement of bacterial growth. The exponential model yielded high precision values of the generation rate constant, with an average relative standard deviation of 1.2%. Under most conditions the assay demonstrated no changes in the slopes of growth curves when the number of bacteria per inoculation was changed. However, the radiometric assay by scintillation method had a growth-inhibiting effect on a few strains of bacteria. The source of this problem was thought to be hypersensitivity to trace amounts of toluene remaining on the detector

  16. Adaptive Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2011-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a recently developed nature-inspired optimization algorithm, which is based on the foraging behavior of E. coli bacteria. Up to now, BFO has been applied successfully to some engineering problems due to its simplicity and ease of implementation. However, BFO possesses a poor convergence behavior over complex optimization problems as compared to other nature-inspired optimization techniques. This paper first analyzes how the run-length unit parameter of BFO controls the exploration of the whole search space and the exploitation of the promising areas. Then it presents a variation on the original BFO, called the adaptive bacterial foraging optimization (ABFO, employing the adaptive foraging strategies to improve the performance of the original BFO. This improvement is achieved by enabling the bacterial foraging algorithm to adjust the run-length unit parameter dynamically during algorithm execution in order to balance the exploration/exploitation tradeoff. The experiments compare the performance of two versions of ABFO with the original BFO, the standard particle swarm optimization (PSO and a real-coded genetic algorithm (GA on four widely-used benchmark functions. The proposed ABFO shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  17. Removal of Retained Adherent Placental Remnants Using the Hysteroscopy Endo-Operative System.

    Science.gov (United States)

    Zhu, Ke-An; Huang, Huan; Xue, Min; Subedi, Jigyasa; Jamail, Grace; Zhao, Weidong; Xu, Dabao; Xiao, Songshu

    2016-01-01

    Removal of retained adherent placental remnants (RAPRs) may be challenging using traditional 5Fr or 7Fr hysteroscopic grasping forceps because they are very small. This is particularly true when the retained placental remnant is large. This video demonstrates the advantages of using the Hysteroscopy Endo-Operative System (HEOS), a specially designed operative hysteroscope with a 13Fr working channel, to remove retained placental remnants. Step-by-step explanation of the technique using videos and pictures (educative video) (Canadian Task Force Classification III). Third Xiangya Hospital of Central South University, Hunan, China. A 32-year-old woman was diagnosed with RAPRs 5 weeks after the evacuation of retained placenta after a spontaneous abortion at 16 weeks' gestation. Gynecologic examination revealed an anterior 8-week uterus and no tenderness. Serum β-human chorionic gonadotropin was 150 mIU/L. Sonography revealed an irregular intrauterine mass, 3.5 cm × 3.5 cm × 3 cm in size. Removal of RAPRs using HEOS (Sopro-comeg Company, Bordeaux, France). The operation time was only 12 minutes. The RAPRs were removed completely and quickly in 1 procedure with no complications. The serum β-human chorionic gonadotropin titer normalized 1 week after the procedure. This study was approved by the institutional review board of the Third Xiangya Hospital of Central South University. When indicated, removal of RAPRs using HEOS is safe and simple because of its large and strong cold forceps. Additionally, it avoids electrical and thermal injury to the endometrium, which is particularly important in a population that wants to preserve fertility. Copyright © 2016 AAGL. Published by Elsevier Inc. All rights reserved.

  18. Mass Ejection from the Remnant of a Binary Neutron Star Merger: Viscous-radiation Hydrodynamics Study

    Science.gov (United States)

    Fujibayashi, Sho; Kiuchi, Kenta; Nishimura, Nobuya; Sekiguchi, Yuichiro; Shibata, Masaru

    2018-06-01

    We perform long-term general relativistic neutrino radiation hydrodynamics simulations (in axisymmetry) for a massive neutron star (MNS) surrounded by a torus, which is a canonical remnant formed after the binary neutron star merger. We take into account the effects of viscosity, which is likely to arise in the merger remnant due to magnetohydrodynamical turbulence. The viscous effect plays key roles for the mass ejection from the remnant in two phases of the evolution. In the first t ≲ 10 ms, a differential rotation state of the MNS is changed to a rigidly rotating state. A shock wave caused by the variation of its quasi-equilibrium state induces significant mass ejection of mass ∼(0.5–2.0) × {10}-2 {M}ȯ for the α-viscosity parameter of 0.01–0.04. For the longer-term evolution with ∼0.1–10 s, a significant fraction of the torus material is ejected. We find that the total mass of the viscosity-driven ejecta (≳ {10}-2 {M}ȯ ) could dominate over that of the dynamical ejecta (≲ {10}-2 {M}ȯ ). The electron fraction, Y e , of the ejecta is always high enough (Y e ≳ 0.25) that this post-merger ejecta is lanthanide-poor; hence, the opacity of the ejecta is likely to be ∼10–100 times lower than that of the dynamical ejecta. This indicates that the electromagnetic signal from the ejecta would be rapidly evolving, bright, and blue if it is observed from a small viewing angle (≲45°) for which the effect of the dynamical ejecta is minor.

  19. EVOLUTION OF HIGH-ENERGY PARTICLE DISTRIBUTION IN MATURE SHELL-TYPE SUPERNOVA REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Houdun; Xin, Yuliang; Liu, Siming; Zhang, Shuinai [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Jokipii, J. R. [University of Arizona, Tucson, Arizona, 85721 (United States); Zhang, Li, E-mail: zhd@pmo.ac.cn, E-mail: liusm@pmo.ac.cn [Key Laboratory of Astroparticle Physics of Yunnan Province, Kunming, 650091 (China)

    2017-01-10

    Multi-wavelength observations of mature supernova remnants (SNRs), especially with recent advances in γ -ray astronomy, make it possible to constrain energy distribution of energetic particles within these remnants. In consideration of the SNR origin of Galactic cosmic rays and physics related to particle acceleration and radiative processes, we use a simple one-zone model to fit the nonthermal emission spectra of three shell-type SNRs located within 2° on the sky: RX J1713.7−3946, CTB 37B, and CTB 37A. Although radio images of these three sources all show a shell (or half-shell) structure, their radio, X-ray, and γ -ray spectra are quite different, offering an ideal case to explore evolution of energetic particle distribution in SNRs. Our spectral fitting shows that (1) the particle distribution becomes harder with aging of these SNRs, implying a continuous acceleration process, and the particle distributions of CTB 37A and CTB 37B in the GeV range are harder than the hardest distribution that can be produced at a shock via the linear diffusive shock particle acceleration process, so spatial transport may play a role; (2) the energy loss timescale of electrons at the high-energy cutoff due to synchrotron radiation appears to be always a bit (within a factor of a few) shorter than the age of the corresponding remnant, which also requires continuous particle acceleration; (3) double power-law distributions are needed to fit the spectra of CTB 37B and CTB 37A, which may be attributed to shock interaction with molecular clouds.

  20. Removal of foreskin remnants in circumcised adults for treatment of premature ejaculation

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Namavar

    2011-01-01

    Full Text Available Background and Aim : Premature ejaculation (PE is the most prevalent sexual dysfunction in every country. There are many types of treatment, but the main limitation of medical treatment for premature ejaculation is recurrence after withdrawal of medicine. The prepuce is a specific erogenous zone that contains a rich and complex network of nerves. Circumcision radically desensitizes the penis, but incomplete circumcision may cause premature ejaculation. We evaluate the effect of removal of foreskin remnants in adults on PE. Materials and Methods : The sensitive area of penile skin and the remaining parts of foreskin in adult men were recognized in 47 selective patients. Under local anesthesia, the remnant parts of foreskin were incised and removed. They were asked to fill the investigating questionnaire about the changes of intravaginal latency ejaculatory time (IVELT, patients and their sexual partners′ satisfaction with sexual life, control over ejaculation, and penile sensitivity, before and after treatment. Results : There were no signs of inflammation and no serious adverse reactions in all cases after operation. IVELT significantly increased from 64.25 before surgery to 731.49 sec after surgery (P<0.001. The percentage of postoperative satisfaction in both the patient and his partner significantly increased (P<0.001. After surgery, 95.7% of men had better control over their ejaculation. This surgery significantly decreased sensitivity of penis (P<0.001, but it did not change glans penis insensitivity. Conclusions : These results indicate that removal of foreskin remnants in adults is an effective modality in selective patients of PE.

  1. GW170817 and the Prospect of Forming Supramassive Remnants in Neutron Star Mergers

    Science.gov (United States)

    Ma, Peng-Xiong; Jiang, Jin-Liang; Wang, Hao; Jin, Zhi-Ping; Fan, Yi-Zhong; Wei, Da-Ming

    2018-05-01

    The gravitational wave data of GW170817 favor the equation of state (EoS) models that predict compact neutron stars (NSs), consistent with the radius constraints from X-ray observations. Motivated by such remarkable progress, we examine the fate of the remnants formed in NS mergers and focus on the roles of the angular momentum and the mass distribution of the binary NSs. In the mass-shedding limit (for which the dimensionless angular momentum equals the Keplerian value, i.e., j = j Kep), the adopted seven EoS models, except for H4 and ALF2, yield supramassive NSs in more than half of the mergers. However, for j ≲ 0.7 j Kep, the presence or absence of a non-negligible fraction of supramassive NSs formed in the mergers depends sensitively on both the EoS and the mass distribution of the binary systems. The NS mergers with a total gravitational mass ≤ 2.6 M ⊙ are found to be able to shed valuable light on both the EoS model and the angular momentum of the remnants if supramassive NSs are still absent. We have also discussed the uncertainty on estimating the maximum gravitational mass of nonrotating NSs (M max) due to the unknown j of the precollapse remnants. With the data of GW170817 and the assumption of the mass loss of 0.03 M ⊙, we have M max < (2.19, 2.32) M ⊙ (90% confidence level) for j = (1.0, 0.8) j Kep, respectively.

  2. Wind dispersal of alien plant species into remnant natural vegetation from adjacent agricultural fields

    Directory of Open Access Journals (Sweden)

    Chika Egawa

    2017-07-01

    Full Text Available Knowledge regarding the seed dispersal of alien species is crucial to manage invasion risk in fragmented natural habitats. Focusing on wind dispersal, this study assessed the spatial and quantitative extents to which a remnant natural fen receives the seeds of alien species dispersed from adjacent hay meadows in Hokkaido, northern Japan. I established a total of 80 funnel seed traps in the fen at distances of 1, 2, 5, 10, 20, 30, 50, and 100 m from the meadows. The proportion of alien species in the seed rain at each distance was quantified, and the 99th-percentile dispersal distance from the meadows was estimated for each alien species by constructing dispersal kernels. Despite the presence of a marginal ditch and an elevational difference between the fen and the meadows, five alien species, including four grasses that do not have modified seed structures for wind dispersal, dispersed their seeds into the fen. These alien species accounted for up to 65.9% of the seed rain in terms of quantity. The 99th-percentile dispersal distances of the alien species ranged from 3.8 m to 309.3 m, and these distances were longer than the values predicted on the basis of their functional traits, such as terminal velocity. The results of this study demonstrated that numerous seeds of farmland-derived alien species were transported into the remnant vegetation via wind dispersal, and that simple predictions of dispersal distance based on functional traits could underestimate the potential area that alien species can reach. Continuous management both in farmland (to reduce seed escape and in remnant vegetation (to prevent the establishment of alien species is necessary to protect native vegetation from biological invasion in agricultural landscapes.

  3. Fish remnants from the excavations of the Bronze Age barrow near Maryanskoe village (Dnepropetrovsk region, Ukraine

    Directory of Open Access Journals (Sweden)

    O. M. Kovalchuk

    2014-10-01

    Full Text Available The Bronze Age mound (2.5–2.3 kya BC is located near the Maryanskoe village (Apostolovskyi district, Dnepropetrovsk region and was excavated in 1953. The results of determination of the fish remnants, which were found during the excavation, are presented in the paper. Eleven species belonging to 9 genera, 5 families and 5 orders (Acipenseriformes, Cypriniformes, Siluriformes, Esociformes, Perciformes were identified: russian sturgeon Acipenser gueldenstaedtii Brandt et Ratzeburg, 1833, stellate sturgeon A. stellatus Pallas, 1771, common ide Idus idus (Linnaeus, 1758, common roach Rutilus rutilus (Linnaeus, 1758, pontic roach R. frisii (Nordmann, 1840, common bream Abramis brama (Linnaeus, 1758, common carp Cyprinus carpio Linnaeus, 1758, tench Tinca tinca (Linnaeus, 1758, european catfish Silurus glanis Linnaeus, 1758, northern pike Esox lucius (Linnaeus, 1758, and zander Sander lucioperca (Linnaeus, 1758. Most of them are quite common in the Dnieper river basin. It was found that carp fishes predominate in the number of species. Most of the bone remnants in the collection belong to zander, catfish and pike, while common roach, pontic roach and common bream are identified by the few bones. This may indicate a different role of these species in the diet of the local population. The ratio of skeletal elements in the collection is the evidence of the fish cutting on the site. Body length and weight was reconstructed for 64 fish specimens. It was found that they were mature and small-sized, except for catfish, pike and perch. Taking into account the characteristics of the funeral rituals of the Yamna culture population, fish bones from the mound near Maryanskoe can be remnants of the parting meal.

  4. Empagliflozin decreases remnant-like particle cholesterol in type 2 diabetes patients with insulin resistance.

    Science.gov (United States)

    Hattori, Sachiko

    2017-11-28

    Remnant lipoproteins are thought to be atherogenic. Remnant-like particle cholesterol (RLP-C), which reflects the levels of various kinds of remnant lipoproteins in the blood, has a significant correlation with insulin resistance. In the present study, we measured the effect of empagliflozin (EMPA) on the levels of RLP-C, and investigated whether EMPA-mediated change in RLP-C is associated with a change in insulin resistance in type 2 diabetes patients who have insulin resistance. Patients were allocated to receive a placebo (n = 51) or EMPA (n = 58) as an add-on treatment. Fasting blood samples were collected before and 12 weeks after this intervention. EMPA significantly decreased glycated hemoglobin, bodyweight, systolic blood pressure, plasma triglycerides, liver transaminases and estimated glomerular filtration rate, and increased high-density lipoprotein cholesterol. Furthermore, EMPA decreased RLP-C and homeostatic model assessment of insulin resistance. In the placebo group, there were no significant changes in these factors except for slight increases in liver transaminases. Multiple regression analysis showed that the change in homeostatic model assessment of insulin resistance (P = 0.0102) and the change in alanine aminotransferase (P = 0.0301) were significantly associated with the change in RLP-C in the EMPA group. The change in RLP-C significantly correlated with the change in homeostatic model assessment of insulin resistance (Pearson correlation coefficient 0.503, 95% confidence interval 0.199-0.719; P = 0.00241). EMPA decreases RLP-C levels, which is closely associated with amelioration of insulin sensitivity in diabetes patients who have insulin resistance. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

  5. Aggregate and Mineral Resources - MO 2014 Industrial Mineral Mines (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — This data set contains names, locations and additional data for active Industrial Mineral Mines permitted with the Missouri Department of Natural Resources, Division...

  6. Temporary ovarian failure in thyroid cancer patients after thyroid remnant ablation with radioactive iodine

    International Nuclear Information System (INIS)

    Raymond, J.P.; Izembart, M.; Marliac, V.; Dagousset, F.; Merceron, R.E.; Vulpillat, M.; Vallee, G.

    1989-01-01

    We studied ovarian function retrospectively in 66 women who had regular menstrual cycles before undergoing complete thyroidectomy for differentiated thyroid cancer and subsequent thyroid remnant ablation with 131 I. Eighteen women developed temporary amenorrhea accompanied by increased serum gonadotropin concentrations during the first year after 131 I therapy. No correlation was found between the radioactive iodine dose absorbed, thyroid uptake before treatment, oral contraceptive use, or thyroid autoimmunity. Only age was a determining factor, with the older women being the most affected. We conclude that radioiodine ablation therapy is followed by transient ovarian failure, especially in older women

  7. The Atomic Physics of Fe K alpha: Toward Accurate Abundance Diagnostics for Supernova Remnants

    Science.gov (United States)

    Brickhouse, Nancy

    2009-09-01

    We propose to conduct a case study of Fe XVI K alpha emission produced during the transient ionization of a supernova remnant. This study includes critical evaluation of the existing data for electron impact inner-shell ionization and fluorescence yields, including tests conducted using a variety of theoretical atomic physics methods. Standard and newly developed atomic codes will be used. Once error estimates for the atomic data are complete, we will propagate these errors using the APEC code to simulate spectra and determine the overall accuracy of iron abundances determined from X-ray spectra.

  8. Scandinavian object shift, remnant VP-topicalisation, verb particles and causatives

    DEFF Research Database (Denmark)

    Engels, Eva; Vikner, Sten

    2013-01-01

    constructions in Danish and Swedish, namely particle verb constructions and causative constructions with Danish "lade" and Swedish "låta" ‘let’. It is shown how differences in the VP-internal object position give rise to mirror image sequences concerning Object Shift in connection with verb second (Vº......On the basis of an examination of remnant VP-topicalisation constructions, this paper argues for an order preservation analysis of Scandinavian Object Shift. Extending the empirical database, we account for the phenomena in an Optimality Theoretic framework. The paper focusses on two particular...

  9. Remnants of semiclassical bistability in the few-photon regime of cavity QED.

    Science.gov (United States)

    Kerckhoff, Joseph; Armen, Michael A; Mabuchi, Hideo

    2011-11-21

    Broadband homodyne detection of the light transmitted by a Fabry-Perot cavity containing a strongly-coupled (133)Cs atom is used to probe the dynamic optical response in a regime where semiclassical theory predicts bistability but strong quantum corrections should apply. While quantum fluctuations destabilize true equilibrium bistability, our observations confirm the existence of metastable states with finite lifetimes and a hysteretic response is apparent when the optical drive is modulated on comparable timescales. Our experiment elucidates remnant semiclassical behavior in the attojoule (~10 photon) regime of single-atom cavity QED, of potential significance for ultra-low power photonic signal processing. © 2011 Optical Society of America

  10. Soft x-ray emission from the Lupus Loop and SN 1006 supernova remnants

    International Nuclear Information System (INIS)

    Winkler, P.F. Jr.; Hearn, D.R.; Richardson, J.A.; Behnken, J.M.

    1979-01-01

    X-ray maps of the Lupus region have been obtained in a raster scan observation from SAS 3. These show the Lupus Loop to be a faint, extended source of soft x-rays with a temperature about 2.5 x 10 6 K. The most prominent feature of the region is the A.D. 1006 supernova remnant, which is unexpectedly bright at 0.2--1.0 keV. One speculative interpretation of the low-energy flux from SN 1006 is as blackbody radiation from a hot neutron star

  11. Temporary ovarian failure in thyroid cancer patients after thyroid remnant ablation with radioactive iodine

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, J.P.; Izembart, M.; Marliac, V.; Dagousset, F.; Merceron, R.E.; Vulpillat, M.; Vallee, G.

    1989-07-01

    We studied ovarian function retrospectively in 66 women who had regular menstrual cycles before undergoing complete thyroidectomy for differentiated thyroid cancer and subsequent thyroid remnant ablation with /sup 131/I. Eighteen women developed temporary amenorrhea accompanied by increased serum gonadotropin concentrations during the first year after /sup 131/I therapy. No correlation was found between the radioactive iodine dose absorbed, thyroid uptake before treatment, oral contraceptive use, or thyroid autoimmunity. Only age was a determining factor, with the older women being the most affected. We conclude that radioiodine ablation therapy is followed by transient ovarian failure, especially in older women.

  12. Young supernova remnants and INTEGRAL: "4"4Ti lines and non-thermal emission

    International Nuclear Information System (INIS)

    Renaud, M.

    2006-10-01

    This thesis deals with the search for and the study of young galactic supernova remnants using the observations performed by IBIS/ISGRI, one of the two main coded-mask instruments onboard the european gamma-ray satellite INTEGRAL. This research is based on i) the study of gamma-ray lines coming from the radioactive decay of "4"4Ti, a short-lived nucleus (τ∼ 86 y) exclusively produced during the first stages of stellar explosions, and ii) the study of the nonthermal continuum mechanisms which take place inside the young supernova remnants. I separate the manuscript in four main parts. The first one presents an overview of supernovae from an observational and theoretical point of view. The second part describes the INTEGRAL satellite with its instruments, the techniques used for analyzing the data collected by IBIS/ISGRI, and my personal investigations concerning different developments such as: the spectral calibration of the IBIS/ISGRI instrument, the correction of noisy pixels on the camera, the creation of background maps, and the development of an alternative pipeline useful for dealing with a large amount of data. I also present a method for imaging extended sources with a coded-mask instrument such as IBIS/ISGRI, and its first application on the Coma Cluster. The results obtained on historical supernova remnants like Cas A, Tycho, RXJ0852-4622 (Vela Junior) are presented in the third part. The first chapter of the last part is devoted to the study of the detectability of supernovae in the optical domain with a model of the interstellar extinction. The second chapter reports on the search for missing and hidden young supernova remnants in the Milky Way with the IBIS/ISGRI galactic plane survey through the "4"4Sc gamma-ray lines as well as with a multi-wavelength approach, from the radio domain (VLA) to the new observational window at TeV energies (HESS). I also discuss the constraints on the supernova rate and the "4"4Ti production in core-collapse supernovae

  13. Synthesis of LTA zeolite for bacterial adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Belaabed, R.; Eabed, S.; Addaou, A.; Laajab, A.; Rodriguez, M.A.; Lahsini, A.

    2016-07-01

    High affinity and adhesion capacity for Gram-positive bacteria on minerals has been widely studied. In this work the adhesion of bacteria on synthesized zeolite has been studied. The Zeolite Linde Type A (LTA) has been synthesized using hydrothermal route using processing parameters to obtain low cost materials. For adhesion studies Staphylococcus aureus and Bacillus subtilis were used as Gram-positive bacteria, Escherichia coli and Pseudomonas aeruginosa are used as Gram-negative bacteria. X-ray diffraction, environmental scanning electron microscope and attenuated total reflection-Fourier transform infrared spectroscopy were used to characterize the synthesized zeolite. To evaluate the bacterial adhesion to zeolite LTA the hydrophobicity and surface properties are examined using contact angle measurement. (Author)

  14. Spectroscopic characterization of manganese minerals.

    Science.gov (United States)

    Lakshmi Reddy, S; Padma Suvarna, K; Udayabhaska Reddy, G; Endo, Tamio; Frost, R L

    2014-01-03

    Manganese minerals ardenite, alleghanyite and leucopoenicite originated from Madhya Pradesh, India, Nagano prefecture Japan, Sussex Country and Parker Shaft Franklin, Sussex Country, New Jersey respectively are used in the present work. In these minerals manganese is the major constituent and iron if present is in traces only. An EPR study of on all of the above samples confirms the presence of Mn(II) with g around 2.0. Optical absorption spectrum of the mineral alleghanyite indicates that Mn(II) is present in two different octahedral sites and in leucophoenicite Mn(II) is also in octahedral geometry. Ardenite mineral gives only a few Mn(II) bands. NIR results of the minerals ardenite, leucophoenicite and alleghanyite are due to hydroxyl and silicate anions which confirming the formulae of the minerals. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Impact of activated carbon, biochar and compost on the desorption and mineralization of phenanthrene in soil

    International Nuclear Information System (INIS)

    Marchal, Geoffrey; Smith, Kilian E.C.; Rein, Arno; Winding, Anne; Wollensen de Jonge, Lis; Trapp, Stefan; Karlson, Ulrich G.

    2013-01-01

    Sorption of PAHs to carbonaceous soil amendments reduces their dissolved concentrations, limiting toxicity but also potentially biodegradation. Therefore, the maximum abiotic desorption of freshly sorbed phenanthrene (≤5 mg kg −1 ) was measured in three soils amended with activated carbon (AC), biochar or compost. Total amounts of phenanthrene desorbed were similar between the different soils, but the amendment type had a large influence. Complete desorption was observed in the unamended and compost amended soils, but this reduced for biochar (41% desorbed) and AC (8% desorbed). Cumulative amounts mineralized were 28% for the unamended control, 19% for compost, 13% for biochar and 4% for AC. Therefore, the effects of the amendments in soil in reducing desorption were also reflected in the extents of mineralization. Modeling was used to analyze key processes, indicating that for the AC and charcoal treatments bacterial activity did not limit mineralization, but rather desorption into the dissolved phase. -- Highlights: •Phenanthrene desorption and mineralization compared in soils with activated carbon, charcoal or compost. •Only activated charcoal and biochar hindered both desorption and mineralization. •A linear relationship was found between the extents desorbed and mineralized. •Modelling indicated that bacterial activity was not limiting but that desorption was. -- Extraction into an exhaustive silicone sink measures the maximum phenanthrene desorption from soils with amendments, and this is reflected in the extent of mineralization

  16. Spatial variation of sediment mineralization supports differential CO2 emissions from a tropical hydroelectric reservoir.

    Science.gov (United States)

    Cardoso, Simone J; Vidal, Luciana O; Mendonça, Raquel F; Tranvik, Lars J; Sobek, Sebastian; Fábio, Roland

    2013-01-01

    Substantial amounts of organic matter (OM) from terrestrial ecosystems are buried as sediments in inland waters. It is still unclear to what extent this OM constitutes a sink of carbon, and how much of it is returned to the atmosphere upon mineralization to carbon dioxide (CO2). The construction of reservoirs affects the carbon cycle by increasing OM sedimentation at the regional scale. In this study we determine the OM mineralization in the sediment of three zones (river, transition, and dam) of a tropical hydroelectric reservoir in Brazil as well as identify the composition of the carbon pool available for mineralization. We measured sediment organic carbon mineralization rates and related them to the composition of the OM, bacterial abundance and pCO2 of the surface water of the reservoir. Terrestrial OM was an important substrate for the mineralization. In the river and transition zones most of the OM was allochthonous (56 and 48%, respectively) while the dam zone had the lowest allochthonous contribution (7%). The highest mineralization rates were found in the transition zone (154.80 ± 33.50 mg C m(-) (2) d(-) (1)) and the lowest in the dam (51.60 ± 26.80 mg C m(-) (2) d(-) (1)). Moreover, mineralization rates were significantly related to bacterial abundance (r (2) = 0.50, p hydroelectric reservoirs.

  17. Destructive textures around radioactive minerals

    International Nuclear Information System (INIS)

    Montel, J.M.; Seydoux-Guillaume, A.M.

    2009-01-01

    In most of the rocks, natural uranium and thorium are concentrated in some minerals which provide favourable crystallographic sites. These minerals are thus submitted to an intense auto-irradiation which may transform them. Using conventional investigation methods (petrographic or scanning electronic microscopy, electronic micro-probe) and less conventional ones (transmission electronic microscopy), the authors studied the interfaces between radioactive minerals and their host minerals. They comment the possible mechanical and structural aspects of this interaction by irradiation, and the influence of geological events

  18. Trace Mineral Losses in Sweat

    National Research Council Canada - National Science Library

    Chinevere, Troy D; McClung, James P; Cheuvront, Samuel N

    2007-01-01

    Copper, iron and zinc are nutritionally essential trace minerals that confer vital biological roles including the maintenance of cell structure and integrity, regulation of metabolism, immune function...

  19. Normalization of pH level and gastric mucosa after eradication of H. pylori in the remnant stomach.

    Science.gov (United States)

    Kato, Shunji; Matsukura, Norio; Matsuda, Noriko; Tsuchiya, Shinichi; Naito, Zenya; Tajiri, Takashi

    2008-12-01

    The Updated Sydney System (USS) is used to evaluate chronic gastritis and chronic atrophic gastritis (CAG) due to H. pylori infection. Here, we investigated USS scores and gastric juice pH levels in H. pylori infection-positive or -eradicated patients with remnant stomach after surgery. Gastric juice pH levels were measured using pH test-tape in 197 patients (112 H. pylori-positive and 85 H. pylori-negative after eradication) who had undergone distal gastrectomy and conventional H. pylori eradication therapy. In H. pylori infection-positive remnant stomach cases, gastric juice pH showed a reverse correlation with pepsinogen I/II ratio, and H. pylori infection-negative patients following eradication showed associations with the degree of atrophy and intestinal metaplasia at both the anastomosis and in the corpus. Further, pH levels in these patients were normalized time depending after the eradication in the remnant stomach. Eradication therapy for the remnant stomach contributes to the possible improvement of stomach conditions by controlling the pH level of gastric juice. This effect will be protective against the risk of secondary stomach carcinogenesis in the remnant stomach.

  20. The many sides of RCW 86: a Type Ia supernova remnant evolving in its progenitor's wind bubble

    Science.gov (United States)

    Broersen, Sjors; Chiotellis, Alexandros; Vink, Jacco; Bamba, Aya

    2014-07-01

    We present the results of a detailed investigation of the Galactic supernova remnant RCW 86 using the XMM-Newton X-ray telescope. RCW 86 is the probable remnant of SN 185 A.D., a supernova that likely exploded inside a wind-blown cavity. We use the XMM-Newton Reflection Grating Spectrometer to derive precise temperatures and ionization ages of the plasma, which are an indication of the interaction history of the remnant with the presumed cavity. We find that the spectra are well fitted by two non-equilibrium ionization models, which enables us to constrain the properties of the ejecta and interstellar matter plasma. Furthermore, we performed a principal component analysis on EPIC MOS and pn data to find regions with particular spectral properties. We present evidence that the shocked ejecta, emitting Fe K and Si line emission, are confined to a shell of approximately 2 pc width with an oblate spheroidal morphology. Using detailed hydrodynamical simulations, we show that general dynamical and emission properties at different portions of the remnant can be well reproduced by a Type Ia supernova that exploded in a non-spherically symmetric wind-blown cavity. We also show that this cavity can be created using general wind properties for a single degenerate system. Our data and simulations provide further evidence that RCW 86 is indeed the remnant of SN 185, and is the likely result of a Type Ia explosion of single degenerate origin.

  1. The effects of two soft drinks on bond strength, bracket microleakage, and adhesive remnant on intact and sealed enamel.

    Science.gov (United States)

    Navarro, Raúl; Vicente, Ascensión; Ortiz, Antonio J; Bravo, Luis A

    2011-02-01

    The purpose of this study was to evaluate the effects of Coca-Cola and Schweppes Limón on bond strength, adhesive remnant, and microleakage beneath brackets. One hundred and twenty upper central incisor brackets were bonded to bovine incisors and divided into three groups: (1) Control, (2) Coca-Cola, and (3) Schweppes Limón. The teeth were submerged in the drinks three times a day for 15 minutes over a 15 day period. Shear bond strength (SBS) was measured with a universal testing machine, and adhesive remnant evaluated using image analysis equipment. Microleakage at the enamel-adhesive and adhesive-bracket interfaces was determined using methylene blue. One hundred and eight teeth were used for scanning electron microscopy to determine the effect of the drinks on intact and sealed enamel. SBS and adhesive remnant data were analysed using the Kruskal-Wallis test (P adhesive remnant between the groups (P > 0.05). Microleakage at the enamel-adhesive interface for groups 2 and 3 was significantly greater than for group 1 (P adhesive-bracket interface, microleakage was significantly greater in group 2 than in group 1 (P enamel erosion, loss of adhesive and microleakage. Coca-Cola and Schweppes Limón did not affect the SBS of brackets or the adhesive remnant.

  2. Silicoaluminous minerals analysis

    International Nuclear Information System (INIS)

    Puglisi, Celia; Fina, J.P.

    1987-01-01

    A group of silicoaluminous minerals of known composition have been analyzed by means of an energy dispersive electron microprobe. The analysis has been performed using a standarless semiquantitative method. The concentration was calculated using the program included in the software of the on-line computer, based on the ZAF correction. It is well known that it is difficult to analyze Si, Al and Na by this method because the absortion correction in the range of 0.9 to 2.0 KeV is not very accurate and the background substraction is also questionable. The purpose of this work is to evaluate the errors involved in these measurements and the best operation conditions. (Author) [es

  3. Protein- mediated enamel mineralization

    Science.gov (United States)

    Moradian-Oldak, Janet

    2012-01-01

    Enamel is a hard nanocomposite bioceramic with significant resilience that protects the mammalian tooth from external physical and chemical damages. The remarkable mechanical properties of enamel are associated with its hierarchical structural organization and its thorough connection with underlying dentin. This dynamic mineralizing system offers scientists a wealth of information that allows the study of basic principals of organic matrix-mediated biomineralization and can potentially be utilized in the fields of material science and engineering for development and design of biomimetic materials. This chapter will provide a brief overview of enamel hierarchical structure and properties as well as the process and stages of amelogenesis. Particular emphasis is given to current knowledge of extracellular matrix protein and proteinases, and the structural chemistry of the matrix components and their putative functions. The chapter will conclude by discussing the potential of enamel for regrowth. PMID:22652761

  4. Mineral fibres and health

    International Nuclear Information System (INIS)

    Hoskins, J.A.

    2001-01-01

    The use of inorganic fibrous materials is a comparatively new phenomenon and was uncommon before the Industrial Revolution. Humans evolved in a comparatively fibre-free environment and consequently never fully developed the defence mechanisms needed to deal with the consequences of inhaling fibres. However, the urban environment now has an airborne fibre concentration of around 1 f.l -1 , which is a tenfold increase on the natural background. Any sample of ambient air collected indoors or outdoors will probably contain some mineral fibres, but there is little evidence that these pose any risk to human health. They come from asbestos used in brakes, glass and mineral wools used as insulation and fire proofing of buildings, gypsum from plaster and a variety of types from many sources. Few of these have the potential to do any harm. Asbestos is the only fibre of note but urban levels are insignificant compared to occupational exposures. When the health of cohorts occupationally exposed to the several types of asbestos is studied the problem can be put into perspective. Studies of workers in the chrysotile industry exposed to much higher dust levels than in a factory today show no excess lung cancer or mesothelioma. By comparison those living near crocidolite mines, let alone working in them, may develop asbestos-related disease. As always, dose is the critical factor. Chrysotile is cleared from the lungs very efficiently, only the amphiboles are well retained. The only real health problem comes from the earlier use of asbestos products that may now be old, friable and damaged and made from amphibole or mixed fibre. If though, these are still in good condition, they do not pose a health problem. Asbestos-related diseases are very rare in those not occupationally exposed. Where they exist exposure has nearly always been to crocidolite. (author)

  5. Of minerals and men. [Discovery of new mineral species

    Energy Technology Data Exchange (ETDEWEB)

    De Waal, S.W. (Council for Mineral Technology, Randburg (South Africa))

    1983-01-01

    The rate of discovery of new mineral species appears to be on the increase in Southern Africa and classification and nomenclature, once haphazard, are now subject to international scientific screening and rules. Earlier names entrenched in the literature provide a fascinating background to the minerals scene.

  6. Evolution Models of Helium White Dwarf–Main-sequence Star Merger Remnants

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xianfei; Bi, Shaolan [Department of Astronomy, Beijing Normal University, Beijing, 100875 (China); Hall, Philip D.; Jeffery, C. Simon, E-mail: zxf@bnu.edu.cn [Armagh Observatory, College Hill, Armagh BT61 9DG (United Kingdom)

    2017-02-01

    It is predicted that orbital decay by gravitational-wave radiation and tidal interaction will cause some close binary stars to merge within a Hubble time. The merger of a helium-core white dwarf with a main-sequence (MS) star can produce a red giant branch star that has a low-mass hydrogen envelope when helium is ignited and thus become a hot subdwarf. Because detailed calculations have not been made, we compute post-merger models with a stellar evolution code. We find the evolutionary paths available to merger remnants and find the pre-merger conditions that lead to the formation of hot subdwarfs. We find that some such mergers result in the formation of stars with intermediate helium-rich surfaces. These stars later develop helium-poor surfaces owing to diffusion. Combining our results with a model population and comparing to observed stars, we find that some observed intermediate helium-rich hot subdwarfs can be explained as the remnants of the mergers of helium-core white dwarfs with low-mass MS stars.

  7. Radio and x-ray observations of compact sources in or near supernova remnants

    International Nuclear Information System (INIS)

    Seaquist, E.R.; Gilmore, W.S.

    1982-01-01

    We present VLA multifrequency radio observations of six compact radio sources from the list of nine objects proposed by Ryle et al. [Nature 276, 571 (1978)] as a new class of radio star, possibly the stellar remnants of supernovae. We also present the results of a search for x-ray emission from four of these objects with the Einstein observatory. The radio observations provide information on spectra, polarization, time variability, angular structure, and positions for these sources. The bearing of these new data on the nature of the sources is discussed. One particularly interesting result is that the polarization and angular-size measurements are combined in an astrophysical argument to conclude that one of the sources (2013+370) is extragalactic. No x-ray emission was detected from any of the four objects observed, but an extended x-ray source was found coincident with the supernova remnant G 33.6+0.1 near 1849+005. Our measurements provide no compelling arguments to consider any of the six objects studied as radio stars

  8. Ovarian remnant syndrome in dogs and cats: 21 cases (2000-2007).

    Science.gov (United States)

    Ball, Rebecca L; Birchard, Stephen J; May, Lauren R; Threlfall, Walter R; Young, Gregory S

    2010-03-01

    To describe signalment, clinical findings, diagnostic tests, and results of treatment of dogs and cats with ovarian remnant syndrome (ORS). Retrospective case series. 19 dogs and 2 cats with ORS. Medical records for animals examined between June 2000 and October 2007 were reviewed for signalment, clinical signs, age at time of ovariohysterectomy (OHE), surgical findings during OHE, experience of the surgeon (veterinary student vs veterinarian), interval from OHE until diagnosis of ORS, results of diagnostic tests, surgical findings, and results of histologic examination of excised tissues. 21 animals (19 dogs and 2 cats) with ORS were identified. The most common clinical signs were those associated with proestrus and estrus. More dogs than cats were affected, and all residual ovarian tissues were found in the region of the ovarian pedicles. The right ovary in dogs was affected significantly more often than the left ovary. Seven animals had neoplasms of the reproductive system. These animals had a significantly longer interval between OHE and diagnosis of ORS than did the 14 animals without neoplasms. Long-term follow-up of 18 animals revealed resolution of clinical signs following exploratory laparotomy. Ovarian remnants were found in typical locations for ovaries and were not considered ectopic tissue; thus, surgical error during OHE was suspected as the cause of ORS. Anatomic differences may account for differences between species, and clinical signs may not be recognized until years after OHE. Surgical removal of residual ovarian tissue resulted in resolution of clinical signs.

  9. High Energy Observational Investigations of Supernova Remnants and their Interactions with Surroundings

    Directory of Open Access Journals (Sweden)

    Chung-Yue Hui

    2013-09-01

    Full Text Available Here we review the effort of Fermi Asian Network (FAN in exploring the supernova remnants (SNRs with state-of-art high energy observatories, including Fermi Gamma-ray Space Telescope and Chandra X-ray Observatory, in the period of 2011- 2012. Utilizing the data from Fermi LAT, we have discovered the GeV emission at the position of the Galactic SNR Kes 17 which provides evidence for the hadronic acceleration. Our study also sheds light on the propagation of cosmic rays from their acceleration site to the intersteller medium. We have also launched an identification campaign of SNR candidates in the Milky Way, in which a new SNR G308.3-1.4 have been uncovered with our Chandra observation. Apart from the remnant, we have also discovered an associated compact object at its center. The multiwavelength properties of this X-ray source suggest it can possibly be the compact binary that survived a supernova explosion.

  10. FERMI-LAT AND WMAP OBSERVATIONS OF THE PUPPIS A SUPERNOVA REMNANT

    Energy Technology Data Exchange (ETDEWEB)

    Hewitt, J. W. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Grondin, M.-H. [Max-Planck-Institut fuer Kernphysik, D-69029 Heidelberg (Germany); Lemoine-Goumard, M.; Reposeur, T. [Centre d' Etudes Nucleaires de Bordeaux-Gradignan, Universite Bordeaux 1, CNRS/IN2p3, F-33175 Gradignan (France); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d' Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Tanaka, T., E-mail: john.w.hewitt@nasa.gov, E-mail: marie-helene.grondin@mpi-hd.mpg.de, E-mail: lemoine@cenbg.in2p3.fr [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States)

    2012-11-10

    We report the detection of GeV {gamma}-ray emission from the supernova remnant (SNR) Puppis A with the Fermi Gamma-Ray Space Telescope. Puppis A is among the faintest SNRs yet detected at GeV energies, with a luminosity of only 2.7 Multiplication-Sign 10{sup 34} (D/2.2 kpc){sup 2} erg s{sup -1} between 1 and 100 GeV. The {gamma}-ray emission from the remnant is spatially extended, with a morphology matching that of the radio and X-ray emission, and is well described by a simple power law with an index of 2.1. We attempt to model the broadband spectral energy distribution (SED), from radio to {gamma}-rays, using standard nonthermal emission mechanisms. To constrain the relativistic electron population we use 7 years of Wilkinson Microwave Anisotropy Probe data to extend the radio spectrum up to 93 GHz. Both leptonic- and hadronic-dominated models can reproduce the nonthermal SED, requiring a total content of cosmic-ray electrons and protons accelerated in Puppis A of at least W {sub CR} Almost-Equal-To (1-5) Multiplication-Sign 10{sup 49} erg.

  11. Evolution Models of Helium White Dwarf–Main-sequence Star Merger Remnants

    International Nuclear Information System (INIS)

    Zhang, Xianfei; Bi, Shaolan; Hall, Philip D.; Jeffery, C. Simon

    2017-01-01

    It is predicted that orbital decay by gravitational-wave radiation and tidal interaction will cause some close binary stars to merge within a Hubble time. The merger of a helium-core white dwarf with a main-sequence (MS) star can produce a red giant branch star that has a low-mass hydrogen envelope when helium is ignited and thus become a hot subdwarf. Because detailed calculations have not been made, we compute post-merger models with a stellar evolution code. We find the evolutionary paths available to merger remnants and find the pre-merger conditions that lead to the formation of hot subdwarfs. We find that some such mergers result in the formation of stars with intermediate helium-rich surfaces. These stars later develop helium-poor surfaces owing to diffusion. Combining our results with a model population and comparing to observed stars, we find that some observed intermediate helium-rich hot subdwarfs can be explained as the remnants of the mergers of helium-core white dwarfs with low-mass MS stars.

  12. 5 Floristics and structure of a Mixed Rain Forest remnant on the Catarinense Plateau

    Directory of Open Access Journals (Sweden)

    Carine Klauberg

    2010-03-01

    Full Text Available The objective of this study was to describe the floristics and the structure of tree species in the Parque Municipal Natural of Lages, SC, a remnant of mixed rain forest located in southern Brazil. For this, we allocated four plots (40 x 40m and each plot was divided into 16 sub-plots of 10 x 10m. Trees with dbh ≥ 5cm and height ≥ 1.3m were mapped, tagged and measured. The individuals were identified and voucher material was deposited in the herbarium. A total of 46 species were sampled, distributed in 39 genera and 27 families. The richest families in number of species were Myrtaceae, Lauraceae, Salicaceae and Sapindaceae. Seven species represented more than 60% of the total of individuals. The specific diversity was H’ = 3.05 nats.ind-1 (J’ = 0.81. The similarity among plots was 32 at 44%, indicating low similarity among plots. The spatial distribution of most of the species is classified as clumped, according to the Morisita index. This forest remains with a considerable richness and diversity with some endangered tree species such as Araucaria angustifolia and Dicksonia sellowiana. Due to its ecological importance for the local flora and fauna and the fragmentation process in the region, this remnant should be considered as a priority area for conservation.

  13. Hard X-ray Emission and Efficient Particle Acceleration by Supernova Remnants

    International Nuclear Information System (INIS)

    Vink, Jacco

    2009-01-01

    I discuss the non-thermal X-ray emission from young supernova remnants. Over the last decade it has become clear from both X-ray and γ-ray observations that young supernovae accelerate particles up to 100 TeV. In soft X-rays the accelerated >10 TeV electrons produce synchrotron radiation, coming from narrow filaments located at the shock fronts. The width of these filaments shows that the magnetic fields are relatively high, thus providing evidence for magnetic field amplification.The synchrotron radiation of several remnants is known to extend into the hard X-ray regime. In particular Cas A, has a spectrum that appears as a power law up to almost 100 TeV. This is very surprising, as a steepening is expected going from the soft to the hard X-ray band. The spectrum is likely a result of many superimposed individual spectra, each steepening at different energies. This implies considerable spatial variation in hard X-rays, an obvious target for Simbol-X. The variations will be important to infer local shock acceleration properties, but also magnetic field fluctuations may cause spatial and temporal variations.Finally, I draw the attention to super bubbles and supernovae as sources of cosmic rays. As such they may be sources of hard X-ray emission. In particular, supernovae exploding inside the dense red supergiants winds of their progenitors ares promising candidates for hard X-ray emission.

  14. Hard X-ray Emission and Efficient Particle Acceleration by Supernova Remnants

    Science.gov (United States)

    Vink, Jacco

    2009-05-01

    I discuss the non-thermal X-ray emission from young supernova remnants. Over the last decade it has become clear from both X-ray and γ-ray observations that young supernovae accelerate particles up to 100 TeV. In soft X-rays the accelerated >10 TeV electrons produce synchrotron radiation, coming from narrow filaments located at the shock fronts. The width of these filaments shows that the magnetic fields are relatively high, thus providing evidence for magnetic field amplification. The synchrotron radiation of several remnants is known to extend into the hard X-ray regime. In particular Cas A, has a spectrum that appears as a power law up to almost 100 TeV. This is very surprising, as a steepening is expected going from the soft to the hard X-ray band. The spectrum is likely a result of many superimposed individual spectra, each steepening at different energies. This implies considerable spatial variation in hard X-rays, an obvious target for Simbol-X. The variations will be important to infer local shock acceleration properties, but also magnetic field fluctuations may cause spatial and temporal variations. Finally, I draw the attention to super bubbles and supernovae as sources of cosmic rays. As such they may be sources of hard X-ray emission. In particular, supernovae exploding inside the dense red supergiants winds of their progenitors ares promising candidates for hard X-ray emission.

  15. Far Ultraviolet Spectroscopic Explorer Observations of the Supernova Remnant N49 in the Large Magellanic Cloud

    CERN Document Server

    Blair, W P; Shelton, R; Sembach, K R; Moos, H W; Raymond, J C; York, D G; Feldman, P D; Chayer, P; Murphy, E M; Sahnow, D J; Wilkinson, E; Blair, William P.; Sankrit, Ravi; Shelton, Robin; Sembach, Kenneth R.; Raymond, John C.; York, Donald G.; Feldman, Paul D.; Chayer, Pierre; Murphy, Edward M.; Sahnow, David J.; Wilkinson, Erik

    2001-01-01

    We report a Far Ultraviolet Spectroscopic Explorer satellite observation of the supernova remnant N49 in the Large Magellanic Cloud, covering the 905 -- 1187 A spectral region. A 30'' square aperture was used, resulting in a velocity resolution of ~100 km/s. The purpose of the observation was to examine several bright emission lines expected from earlier work and to demonstrate diffuse source sensitivity by searching for faint lines never seen previously in extragalactic supernova remnant UV spectra. Both goals were accomplished. Strong emission lines of O VI 1031.9 A, 1037.6 A and C III 977.0 A were seen, Doppler broadened to +/- 225 km/s and with centroids red-shifted to 350 km/s, consistent with the LMC. Superimposed on the emission lines are absorptions by C III and O VI 1031.9 at +260 km/s, which are attributed to warm and hot gas (respectively) in the LMC. The O VI 1037.6 A line is more severely affected by overlying interstellar and H2 absorption from both the LMC and our galaxy. N III 989.8 A is not s...

  16. The remnant of the European rabbit (Oryctolagus cuniculus IgD gene.

    Directory of Open Access Journals (Sweden)

    Dennis K Lanning

    Full Text Available Although IgD first appeared, along with IgM, in the cartilaginous fishes and has been retained throughout subsequent vertebrate evolution, it has been lost in a diverse group of vertebrate species. We previously showed that, unlike vertebrates that express IgD, the rabbit lacks an IgD (Cδ gene within 13.5 kb downstream of the IgM gene. We report here that, by conducting BLAST searches of rabbit Ig heavy chain genomic DNA with known mammalian IgD exons, we identified the remnant of the rabbit Cδ gene approximately 21 kb downstream of the IgM gene. The remnant Cδ locus lacks the δCH1 and hinge exons, but contains truncated δCH2 and δCH3 exons, as well as largely intact, but non-functional, secretory and transmembrane exons. In addition, we report that the Cδ gene probably became non-functional in leporids at least prior to the divergence of rabbits and hares ~12 million years ago.

  17. The origin of X-ray protrusions in the VELA supernova remnant

    Science.gov (United States)

    Gvaramadze, V. V.

    We propose a possible explanation for the formation of X-ray protrusions in the Vela SNR, recently observed by the ROSAT X-ray telescope (Aschenbach, Egger & Trumper, 1995, Nature, 373, 587). We suggest that the highly asymmetric shape of the Vela SNR is the result of the interaction of the SN ejecta/shock with the pre-existing wind-driven shell blown-up in a medium with a density gradient (perpendicular to the Galactic plane). The interaction of the radiative (north-east) half of the remnant, approaching towards the Galactic plane, with dense obstacles (cloudlets or wind zones of stars) can produce X-ray "bullets" radially moving beyond the SNR boundary. These "bullets" originate due to the cooling and condensation of a gas swept-up by converging conical shocks arising behind the dense obstacles overtaken by the SN shock. The X-ray protrusions observed in the western part of the remnant might be explained by outflows of hot gas of the SNR's interior emanating through the gaps in the shell. The origin of the X-ray "jet" (Markwardt & Ogelman, 1995, Nature, 375, 40) in the central part of the Vela SNR is also discussed.

  18. Freely Expanding Knots of X-Ray-emitting Ejecta in Kepler’s Supernova Remnant

    Science.gov (United States)

    Sato, Toshiki; Hughes, John P.

    2017-08-01

    We report measurements of proper motion, radial velocity, and elemental composition for 14 compact X-ray-bright knots in Kepler’s supernova remnant (SNR) using archival Chandra data. The knots with the highest speed show both large proper motions (μ ˜ 0.″11-0.″14 yr-1) and high radial velocities (v ˜ 8700-10,020 km s-1). For these knots the estimated space velocities (9100 km s-1 ≲ v 3D ≲ 10,400 km s-1) are similar to the typical Si velocity seen in supernovae (SNe) Ia near maximum light. High-speed ejecta knots appear only in specific locations and are morphologically and kinematically distinct from the rest of the ejecta. The proper motions of five knots extrapolate back over the age of Kepler’s SNR to a consistent central position. This new kinematic center agrees well with previous determinations, but is less subject to systematic errors and denotes a location about which several prominent structures in the remnant display a high degree of symmetry. These five knots are expanding at close to the free expansion rate (expansion indices of 0.75 ≲ m ≲ 1.0), which we argue indicates either that they were formed in the explosion with a high density contrast (more than 100 times the ambient density) or that they have propagated through regions of relatively low density (n H ruled out.

  19. GAMMA-RAY EMISSION OF ACCELERATED PARTICLES ESCAPING A SUPERNOVA REMNANT IN A MOLECULAR CLOUD

    International Nuclear Information System (INIS)

    Ellison, Donald C.; Bykov, Andrei M.

    2011-01-01

    We present a model of gamma-ray emission from core-collapse supernovae (SNe) originating from the explosions of massive young stars. The fast forward shock of the supernova remnant (SNR) can accelerate particles by diffusive shock acceleration (DSA) in a cavern blown by a strong, pre-SN stellar wind. As a fundamental part of nonlinear DSA, some fraction of the accelerated particles escape the shock and interact with a surrounding massive dense shell producing hard photon emission. To calculate this emission, we have developed a new Monte Carlo technique for propagating the cosmic rays (CRs) produced by the forward shock of the SNR, into the dense, external material. This technique is incorporated in a hydrodynamic model of an evolving SNR which includes the nonlinear feedback of CRs on the SNR evolution, the production of escaping CRs along with those that remain trapped within the remnant, and the broadband emission of radiation from trapped and escaping CRs. While our combined CR-hydro-escape model is quite general and applies to both core collapse and thermonuclear SNe, the parameters we choose for our discussion here are more typical of SNRs from very massive stars whose emission spectra differ somewhat from those produced by lower mass progenitors directly interacting with a molecular cloud.

  20. Particle Acceleration, Magnetic Field Generation and Emission from Relativistic Jets and Supernova Remnants

    Science.gov (United States)

    Nishikawa, K.-I.; Hartmann, D. H.; Hardee, P.; Hededal, C.; Mizunno, Y.; Fishman, G. J.

    2006-01-01

    We performed numerical simulations of particle acceleration, magnetic field generation, and emission from shocks in order to understand the observed emission from relativistic jets and supernova remnants. The investigation involves the study of collisionless shocks, where the Weibel instability is responsible for particle acceleration as well as magnetic field generation. A 3-D relativistic particle-in-cell (RPIC) code has been used to investigate the shock processes in electron-positron plasmas. The evolution of theWeibe1 instability and its associated magnetic field generation and particle acceleration are studied with two different jet velocities (0 = 2,5 - slow, fast) corresponding to either outflows in supernova remnants or relativistic jets, such as those found in AGNs and microquasars. Slow jets have intrinsically different structures in both the generated magnetic fields and the accelerated particle spectrum. In particular, the jet head has a very weak magnetic field and the ambient electrons are strongly accelerated and dragged by the jet particles. The simulation results exhibit jitter radiation from inhomogeneous magnetic fields, generated by the Weibel instability, which has different spectral properties than standard synchrotron emission in a homogeneous magnetic field.

  1. Molecular analysis of manufactured gas plant soils for naphthalene mineralization

    International Nuclear Information System (INIS)

    Sanseverino, J.; Werner, C.; Fleming, J.; Applegate, B.M.; King, J.M.H.; Sayler, G.S.; Blackburn, J.

    1991-01-01

    New molecular tools are being developed and tested to ascertain the biodegradability of hazardous wastes by soil bacterial population. The potential for manufactured gas plant (MGP) soil bacterial populations to degrade naphthalene, as a component mixture of polynuclear aromatic hydrocarbons, was evaluated by the detection of a naphthalene biodegradative genotype by DNA probe hybridization with DNA extracts and colonies of cultured bacteria of the MGP soils. The activity of the naphthalene-degrading populations was evaluated by mineralization assays, 14 CO 2 production from 14 C-naphthalene. Direct messenger RNA (mRNA) extraction from MGP soil was evaluated as an instantaneous measure of naphthalene catabolic gene expression in MGP soil. The bioavailability of naphthalene for bacterial degradation within the MGP soils was assessed by measuring the bioluminescent response of a naphthalene-lux catabolic reporter strain Pseudomonas fluorescens HK44 (pUTK21). DNA extracted from 5 MGP soils and 1 creosote-contaminated soil and hybridized with a nahA gene probe indicated that the naphthalene degradative genes were present in all samples in the range of 0.06 to 0.95 ng/100 μl DNA extract which was calculated to represent 3.58 x 10 8 to 1.05 x 10 10 nahA positive cells/g soil. Phenanthrene, anthracene, and benzo(a)pyrene were mineralized also by some of the soils. NAH7 homologous messenger RNA transcripts were detectable in one MGP soil and in the creosote-contaminated soil

  2. Radiology of bacterial pneumonia

    International Nuclear Information System (INIS)

    Vilar, Jose; Domingo, Maria Luisa; Soto, Cristina; Cogollos, Jonathan

    2004-01-01

    Bacterial pneumonia is commonly encountered in clinical practice. Radiology plays a prominent role in the evaluation of pneumonia. Chest radiography is the most commonly used imaging tool in pneumonias due to its availability and excellent cost benefit ratio. CT should be used in unresolved cases or when complications of pneumonia are suspected. The main applications of radiology in pneumonia are oriented to detection, characterisation and follow-up, especially regarding complications. The classical classification of pneumonias into lobar and bronchial pneumonia has been abandoned for a more clinical classification. Thus, bacterial pneumonias are typified into three main groups: Community acquired pneumonia (CAD), Aspiration pneumonia and Nosocomial pneumonia (NP).The usual pattern of CAD is that of the previously called lobar pneumonia; an air-space consolidation limited to one lobe or segment. Nevertheless, the radiographic patterns of CAD may be variable and are often related to the causative agent. Aspiration pneumonia generally involves the lower lobes with bilateral multicentric opacities. Nosocomial Pneumonia (NP) occurs in hospitalised patients. The importance of NP is related to its high mortality and, thus, the need to obtain a prompt diagnosis. The role of imaging in NP is limited but decisive. The most valuable information is when the chest radiographs are negative and rule out pneumonia. The radiographic patterns of NP are very variable, most commonly showing diffuse multifocal involvement and pleural effusion. Imaging plays also an important role in the detection and evaluation of complications of bacterial pneumonias. In many of these cases, especially in hospitalised patients, chest CT must be obtained in order to better depict these associate findings

  3. Radiology of bacterial pneumonia

    Energy Technology Data Exchange (ETDEWEB)

    Vilar, Jose E-mail: vilar_jlu@gva.es; Domingo, Maria Luisa; Soto, Cristina; Cogollos, Jonathan

    2004-08-01

    Bacterial pneumonia is commonly encountered in clinical practice. Radiology plays a prominent role in the evaluation of pneumonia. Chest radiography is the most commonly used imaging tool in pneumonias due to its availability and excellent cost benefit ratio. CT should be used in unresolved cases or when complications of pneumonia are suspected. The main applications of radiology in pneumonia are oriented to detection, characterisation and follow-up, especially regarding complications. The classical classification of pneumonias into lobar and bronchial pneumonia has been abandoned for a more clinical classification. Thus, bacterial pneumonias are typified into three main groups: Community acquired pneumonia (CAD), Aspiration pneumonia and Nosocomial pneumonia (NP).The usual pattern of CAD is that of the previously called lobar pneumonia; an air-space consolidation limited to one lobe or segment. Nevertheless, the radiographic patterns of CAD may be variable and are often related to the causative agent. Aspiration pneumonia generally involves the lower lobes with bilateral multicentric opacities. Nosocomial Pneumonia (NP) occurs in hospitalised patients. The importance of NP is related to its high mortality and, thus, the need to obtain a prompt diagnosis. The role of imaging in NP is limited but decisive. The most valuable information is when the chest radiographs are negative and rule out pneumonia. The radiographic patterns of NP are very variable, most commonly showing diffuse multifocal involvement and pleural effusion. Imaging plays also an important role in the detection and evaluation of complications of bacterial pneumonias. In many of these cases, especially in hospitalised patients, chest CT must be obtained in order to better depict these associate findings.

  4. Abscess of urachal remnants presenting with acute abdomen: a case series

    Directory of Open Access Journals (Sweden)

    Tazi Fadl

    2012-07-01

    Full Text Available Abstract Introduction Urachal diseases are rare and may develop from a congenital anomaly in which a persistent or partial reopening of the fetal communication between the bladder and the umbilicus persists. The most frequently reported urachal anomalies in adults are infected urachal cyst and urachal carcinoma. The diagnosis of this entity is not always easy because of the rarity of these diseases and the atypical symptoms at presentation. Imaging techniques, such as ultrasonography and computed tomography have a significant role in recognizing the presence of urachus-derived lesions. Cases presentations Case presentation 1: A 25-year-old Arab-Berber man presented with a 10-day history of progressive lower abdominal pain accompanied by fever, vomiting, and low urinary tract symptoms to our emergency department. Laboratory data revealed leucocytosis. The diagnosis of an acute peritonitis was made initially. Abdominal ultrasonography revealed a hypoechoic tract from the umbilicus to the abdominal wall, and the diagnosis was rectified (infected urachal remnants. The patient was initially treated with intravenous antibiotics in combination with a percutaneous drainage. Afterwards an extraperitoneal excision of the urachal remnant including a cuff of bladder was performed. The histological analysis did not reveal a tumor of the urachal remnant. Follow-up examinations a few months later showed no abnormality. Case presentation 2: A 35-year-old Arab-Berber man, without prior medical history with one week of abdominal pain, nausea and vomiting, associated with fever but without lower urinary tract symptoms visited our emergency department. Laboratory data revealed leucocytosis. Abdominal ultrasonography was not conclusive. Computed tomography of the abdomen was the key to the investigation and the diagnosis of an abscess of urachal remnants was made. The patient underwent the same choice of medical-surgical treatment as previously described for case

  5. Protozoan predation in soil slurries compromises determination of contaminant mineralization potential

    International Nuclear Information System (INIS)

    Badawi, Nora; Johnsen, Anders R.; Brandt, Kristian K.; Sørensen, Jan; Aamand, Jens

    2012-01-01

    Soil suspensions (slurries) are commonly used to estimate the potential of soil microbial communities to mineralize organic contaminants. The preparation of soil slurries disrupts soil structure, however, potentially affecting both the bacterial populations and their protozoan predators. We studied the importance of this “slurry effect” on mineralization of the herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA, 14 C-labelled), focussing on the effects of protozoan predation. Mineralization of MCPA was studied in “intact” soil and soil slurries differing in soil:water ratio, both in the presence and absence of the protozoan activity inhibitor cycloheximide. Protozoan predation inhibited mineralization in dense slurry of subsoil (soil:water ratio 1:3), but only in the most dilute slurry of topsoil (soil:water ratio 1:100). Our results demonstrate that protozoan predation in soil slurries may compromise quantification of contaminant mineralization potential, especially when the initial density of degrader bacteria is low and their growth is controlled by predation during the incubation period. - Highlights: ► We studied the protozoan impact on MCPA mineralization in soil slurries. ► Cycloheximide was used as protozoan inhibitor. ► Protozoa inhibited MCPA mineralization in dilute topsoil slurry and subsoil slurry. ► Mineralization potentials may be underestimated when using soil slurries. - Protozoan predation may strongly bias the quantification of mineralization potential when performed in soil slurries, especially when the initial density of degrader bacteria is low such as in subsoil or very dilute topsoil slurries.

  6. Radio-continuum observations of small, radially polarised Supernova Remnant J0519-6902 in the large Magellanic cloud

    Directory of Open Access Journals (Sweden)

    Bozzetto L.M.

    2012-01-01

    Full Text Available We report on new Australian Telescope Compact Array (ATCA observations of SNR J0519-6902. The Supernova Remnant (SNR is small in size (~8 pc and exhibits a typical SNR spectrum with α = -0.53±0.07, with steeper spectral indices towards the northern limb of the remnant. SNR J0519-6902 contains a low level of radially orientated polarisation at wavelengths of 3 and 6 cm, which is typical of younger SNRs. A fairly strong magnetic field was estimated to ~171µG. The remnant appears to be the result of a typical Type Ia supernova, sharing many properties with another small and young Type Ia LMC SNR, J0509-6731. [Projekat Ministarstva nauke Republike Srbije, br. 176005

  7. Plant macro- and micronutrient minerals

    Science.gov (United States)

    All plants must obtain a number of inorganic mineral elements from their environment to ensure successful growth and development of both vegetative and reproductive tissues. A total of fourteen mineral nutrients are considered to be essential. Several other elements have been shown to have beneficia...

  8. Radioisotopes in plant mineral nutrition

    International Nuclear Information System (INIS)

    Singh, Bhupinder

    2016-01-01

    Extensive investigations on mineral composition of different plant species growing on various soils, helped in realizing that neither the presence nor the concentration of a mineral element in a plant can be regarded as a criterion for essentially. Plants have a limited capability for selective uptake of those mineral elements which are essential for their growth. They also take up mineral element which are not necessary for growth and may even be toxic. The mineral composition of plants growing in soils cannot, therefore, be used to establish essentially of a mineral element. Once this fact was appreciated, both water and sand culture experiments were carried out in which particular mineral elements were omitted. Von Sach and Knop are credited with reintroduction of the solution culture method using which they demonstrated the absolute requirement of ten macronutrients. As evident, these techniques made possible a more precise characterization of essentially of mineral elements and led to a better understanding of their role in plant metabolism. By the beginning of 20"t"h century importance of micronutrients like B, Mn, Cu, Mo and CI was also established

  9. Miners' strike 1984-85

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L; Salter, S [comps.

    1985-01-01

    References relating to the 1984-85 UK miners strike are listed under the following subject headings: events and analysis - a chronological record; short term effects - coal stocks and supplies, electricity supplies, financial, industrial and economic; the miners and their leadership; social aspects - civil liberties, media coverage, mining communities, picketing, policing, the future; pit closures. 240 references.

  10. Minerals From the Marine Environment

    Science.gov (United States)

    Cruickshank, Michael J.

    The current interest in minerals centering on, among other things, potential shortages, long-term needs, and deep seabed nodules, accentuates the usefulness and timeliness of this little book authored by a former chairman of the British National Environmental Research Council.In less than 100 pages, the author puts into perspective the potential for producing minerals from offshore areas of the world. After introducing the reader to the ocean environment and the extraordinary variety of the nature of the seabed, the author describes in some detail the variety of minerals found there. This is done in seven separate chapters entitled ‘Bulk and Non-Metallic Minerals From the Seas’ ‘Metals From the Shallow Seas’ ‘Metals From the Deep Oceans’ ‘Minerals From Solution’ ‘Oil and Gas from the Shallow Seas’ ‘Oil and Gas From Deep Waters’ and ‘Coal Beneath the Sea.’ The remaining chapters give a brief regional review of marine minerals distribution for eight areas of significant socioeconomic structure, and a short recapitulation of special problems of mineral recovery in the marine environment including such matters as the effect of water motion on mineral processing and of international law on investments. Glossaries of geological periods and technical terms, a short list of references, and an index complete the work.

  11. Ways to defuse miners' anger

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    The violence and riots which often occur with mining personnel are considered. The emotions and feelings which miners often experience because of their work environment are dealth with. From recognizing the pressures, the article then works to present methods to help defuse the miners' hostility and anger

  12. 77 FR 56273 - Conflict Minerals

    Science.gov (United States)

    2012-09-12

    ... auditor and to certify the audit. In addition, Section 13(p) requires the report to include a description.... Auditor Independence iii. Audit Objective 4. Recycled and Scrap Minerals a. Proposed Rules b. Comments on... Minerals Report must also identify the independent private sector auditor \\23\\ and certify the independent...

  13. Sulfide Mineral Surfaces

    International Nuclear Information System (INIS)

    Rosso, Kevin M.; Vaughan, David J.

    2006-01-01

    The past twenty years or so have seen dramatic development of the experimental and theoretical tools available to study the surfaces of solids at the molecular (?atomic resolution?) scale. On the experimental side, two areas of development well illustrate these advances. The first concerns the high intensity photon sources associated with synchrotron radiation; these have both greatly improved the surface sensitivity and spatial resolution of already established surface spectroscopic and diffraction methods, and enabled the development of new methods for studying surfaces. The second centers on the scanning probe microscopy (SPM) techniques initially developed in the 1980's with the first scanning tunneling microscope (STM) and atomic force microscope (AFM) experiments. The direct 'observation' of individual atoms at surfaces made possible with these methods has truly revolutionized surface science. On the theoretical side, the availability of high performance computers coupled with advances in computational modeling has provided powerful new tools to complement the advances in experiment. Particularly important have been the quantum mechanics based computational approaches such as density functional theory (DFT), which can now be easily used to calculate the equilibrium crystal structures of solids and surfaces from first principles, and to provide insights into their electronic structure. In this chapter, we review current knowledge of sulfide mineral surfaces, beginning with an overview of the principles relevant to the study of the surfaces of all crystalline solids. This includes the thermodynamics of surfaces, the atomic structure of surfaces (surface crystallography and structural stability, adjustments of atoms at the surface through relaxation or reconstruction, surface defects) and the electronic structure of surfaces. We then discuss examples where specific crystal surfaces have been studied, with the main sulfide minerals organized by structure type

  14. Sulfide Mineral Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Rosso, Kevin M.; Vaughan, David J.

    2006-08-01

    The past twenty years or so have seen dramatic development of the experimental and theoretical tools available to study the surfaces of solids at the molecular (?atomic resolution?) scale. On the experimental side, two areas of development well illustrate these advances. The first concerns the high intensity photon sources associated with synchrotron radiation; these have both greatly improved the surface sensitivity and spatial resolution of already established surface spectroscopic and diffraction methods, and enabled the development of new methods for studying surfaces. The second centers on the scanning probe microscopy (SPM) techniques initially developed in the 1980's with the first scanning tunneling microscope (STM) and atomic force microscope (AFM) experiments. The direct 'observation' of individual atoms at surfaces made possible with these methods has truly revolutionized surface science. On the theoretical side, the availability of high performance computers coupled with advances in computational modeling has provided powerful new tools to complement the advances in experiment. Particularly important have been the quantum mechanics based computational approaches such as density functional theory (DFT), which can now be easily used to calculate the equilibrium crystal structures of solids and surfaces from first principles, and to provide insights into their electronic structure. In this chapter, we review current knowledge of sulfide mineral surfaces, beginning with an overview of the principles relevant to the study of the surfaces of all crystalline solids. This includes the thermodynamics of surfaces, the atomic structure of surfaces (surface crystallography and structural stability, adjustments of atoms at the surface through relaxation or reconstruction, surface defects) and the electronic structure of surfaces. We then discuss examples where specific crystal surfaces have been studied, with the main sulfide minerals organized by

  15. G25.5 + 0.2: a very young supernova remnant or a galactic planetary nebula?

    International Nuclear Information System (INIS)

    White, R.L.; Becker, R.H.

    1990-01-01

    G25.5 + 0.2, a radio source suggested by previous authors to be a very young galactic supernova remnant, is more likely to be a planetary nebula. Its IRAS colours and fluxes and its radio spectrum and morphology are all consistent with the properties of planetary nebulae; its radio flux and distance imply a large mass of ionized gas, which is expected from a Type I planetary nebula lying in the galactic plane. We suggest some definitive observations which should be able to determine whether this interesting object is a planetary nebula or a supernova remnant. (author)

  16. An X-ray study of the supernova remnant G20.0-0.2 and its surroundings

    OpenAIRE

    Petriella, Alberto; Paron, Sergio; Giacani, Elsa

    2013-01-01

    Aims. We study the supernova remnant G20.0-0.2 and its surroundings in order to look for the high energy counterpart of the radio nebula and to find evidence of interaction between the shock front and the interstellar medium. Methods. We used Chandra archival observations to analyze the X-ray emission from the supernova remnant. The surrounding gas was investigated using data extracted from the Galactic Ring Survey, the VLA Galactic Plane Survey, the Galactic Legacy Infrared Midplane Survey E...

  17. Anomalous external carotid artery-internal carotid artery anastomosis in two patients with proximal internal carotid arterial remnants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang Hun [Dept. of Neurology, Stroke Center, Myongji Hospital, Goyang (Korea, Republic of); Cho, Young Dae; Kang, Hyun Seung; Kim, Jeong Eun; Han, Moon Hee [Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of); Jung, Seung Chai [Dept. of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Ahn, Jun Hyong [Dept. of Neurosurgery, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang (Korea, Republic of)

    2015-08-15

    Two angiographic instances of anomalous external carotid artery (ECA) and internal carotid artery (ICA) anastomosis are described, each occurring at the C2-3 level and bearing remnants of proximal ICA. The ICA remnant of one patient (identifiable immediately upon bifurcation of the common carotid artery) was hypoplastic, and that of the other patient was an occluded arterial stump. These features are not typical of non-bifurcating ICA. The occipital artery originated from an anomalous connection in one instance and from the main trunk of the ECA (just past the ECA-ICA connection) in the other.

  18. Chemical composition and anti-bacterial activity of essential oil from ...

    African Journals Online (AJOL)

    This work assesses the chemical compositions and in vitro anti-bacterial activities of seed essential oil from Cedrela sinesis (A. Juss.) Roem. seed. which has abundant mineral elements such as K, Ca, Fe. The fatty acid profiles of seed essential oil are characterized by considerable unsaturated fatty acids (90.39%) ...

  19. Diffusive propagation of cosmic rays from supernova remnants in the Galaxy. I: spectrum and chemical composition

    International Nuclear Information System (INIS)

    Blasi, Pasquale; Amato, Elena

    2012-01-01

    In this paper we investigate the effect of stochasticity in the spatial and temporal distribution of supernova remnants on the spectrum and chemical composition of cosmic rays observed at Earth. The calculations are carried out for different choices of the diffusion coefficient D(E) experienced by cosmic rays during propagation in the Galaxy. In particular, at high energies we assume that D(E)∝E δ , with δ = 1/3 and δ = 0.6 being the reference scenarios. The large scale distribution of supernova remnants in the Galaxy is modeled following the distribution of pulsars, with and without accounting for the spiral structure of the Galaxy. We find that the stochastic fluctuations induced by the spatial and temporal distribution of supernovae, together with the effect of spallation of nuclei, lead to mild but sensible violations of the simple, leaky-box-inspired rule that the spectrum observed at Earth is N(E)∝E −α with α = γ+δ, where γ is the slope of the cosmic ray injection spectrum at the sources. Spallation of nuclei, even with the small rates appropriate for He, may account for small differences in spectral slopes between different nuclei, possibly providing an explanation for the recent CREAM observations. For δ = 1/3 we find that the slope of the proton and helium spectra are ∼ 2.67 and ∼ 2.6 respectively (with fluctuations depending on the realization of source distribution) at energies around ∼ 1 TeV (to be compared with the measured values of 2.66±0.02 and 2.58±0.02). For δ = 0.6 the hardening of the He spectra is not observed. The stochastic effects discussed above cannot be found in ordinary propagation calculations, such as GALPROP, where these effects and the point like nature of the sources are not taken into account. We also comment on the effect of time dependence of the escape of cosmic rays from supernova remnants, and of a possible clustering of the sources in superbubbles. In a second paper we will discuss the implications of

  20. Diffusive propagation of cosmic rays from supernova remnants in the Galaxy. I: spectrum and chemical composition

    Energy Technology Data Exchange (ETDEWEB)

    Blasi, Pasquale; Amato, Elena, E-mail: blasi@arcetri.astro.it, E-mail: amato@arcetri.astro.it [INAF/Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5 — 50125 Firenze (Italy)

    2012-01-01

    In this paper we investigate the effect of stochasticity in the spatial and temporal distribution of supernova remnants on the spectrum and chemical composition of cosmic rays observed at Earth. The calculations are carried out for different choices of the diffusion coefficient D(E) experienced by cosmic rays during propagation in the Galaxy. In particular, at high energies we assume that D(E)∝E{sup δ}, with δ = 1/3 and δ = 0.6 being the reference scenarios. The large scale distribution of supernova remnants in the Galaxy is modeled following the distribution of pulsars, with and without accounting for the spiral structure of the Galaxy. We find that the stochastic fluctuations induced by the spatial and temporal distribution of supernovae, together with the effect of spallation of nuclei, lead to mild but sensible violations of the simple, leaky-box-inspired rule that the spectrum observed at Earth is N(E)∝E{sup −α} with α = γ+δ, where γ is the slope of the cosmic ray injection spectrum at the sources. Spallation of nuclei, even with the small rates appropriate for He, may account for small differences in spectral slopes between different nuclei, possibly providing an explanation for the recent CREAM observations. For δ = 1/3 we find that the slope of the proton and helium spectra are ∼ 2.67 and ∼ 2.6 respectively (with fluctuations depending on the realization of source distribution) at energies around ∼ 1 TeV (to be compared with the measured values of 2.66±0.02 and 2.58±0.02). For δ = 0.6 the hardening of the He spectra is not observed. The stochastic effects discussed above cannot be found in ordinary propagation calculations, such as GALPROP, where these effects and the point like nature of the sources are not taken into account. We also comment on the effect of time dependence of the escape of cosmic rays from supernova remnants, and of a possible clustering of the sources in superbubbles. In a second paper we will discuss the