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  1. 76 FR 80430 - Rio Tinto plc and Rio Tinto Limited; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-23

    ...Summary of Application: Rio Tinto plc (``RTP'') and Rio Tinto Limited (``RTL'', together with RTP, ``Rio Tinto'' or the ``Group'') seek an order under section 3(b)(2) of the Act declaring Rio Tinto to be primarily engaged in a business other than that of investing, reinvesting, owning, holding or trading in securities. Rio Tinto is a leading international mining group. Applicants also seek an......

  2. Toward a Cultural Advancement of Tinto's Theory

    ERIC Educational Resources Information Center

    Guiffrida, Douglas A.

    2006-01-01

    Despite the broad appeal of Tinto's (1993) theory, it is not well supported by empirical research, especially when applied to minority students. While prior critiques of the theory indicate the need to modify Tinto's concept of "breaking away" when applying the theory to diverse students, research suggests a need for additional refinements. In…

  3. Tinto's Model and Successful College Transitions.

    ERIC Educational Resources Information Center

    Tucker, John E.

    1999-01-01

    Compares the themes of academic and social integration in Tinto's model of college student attrition with the themes of "vision" and "sense of community" as described in a recent ethnographic study. It is argued that vision and sense of community are more useful theoretical considerations in helping address college student retention than is…

  4. Mars Analog Rio Tinto Experiment (MARTE): 2003 Drilling Campaign to Search for a Subsurface Biosphere at Rio Tinto Spain

    NASA Technical Reports Server (NTRS)

    Stoker, Carol; Dunagan, Stephen; Stevens, Todd; Amils, Ricardo; Gomez-Elvira, Javier; Fernandez, David; Hall, James; Lynch, Kennda; Cannon, Howard; Zavaleta, Jhony

    2004-01-01

    The MARTE (Mars Astrobiology Research and Technology Experiment) project, an ASTEP field experiment, is exploring for a hypothesized subsurface anaerobic chemoautotrophic biosphere in the region of the Tinto River- or Rio Tinto- in southwestern Spain. It is also demonstrating technology needed to search for a subsurface biosphere on Mars. The project has three primary objectives: (1) search for and characterize subsurface life at Rio Tinto along with the physical and chemical properties and sustaining energy sources of its environment, (2) perform a high fidelity simulation of a robotic Mars drilling mission to search for life, and (3) demonstrate the drilling, sample handling, and instrument technologies relevant to searching for life on Mars. The simulation of the robotic drilling mission is guided by the results of the aseptic drilling campaign to search for life at Rio Tinto. This paper describes results of the first phase of the aseptic drilling campaign.

  5. Extreme environments as Mars terrestrial analogs: The Rio Tinto case

    NASA Astrophysics Data System (ADS)

    Amils, Ricardo; González-Toril, Elena; Fernández-Remolar, David; Gómez, Felipe; Aguilera, Ángeles; Rodríguez, Nuria; Malki, Mustafá; García-Moyano, Antonio; Fairén, Alberto G.; de la Fuente, Vicenta; Luis Sanz, José

    2007-02-01

    The geomicrobiological characterization of the Río Tinto (Iberian Pyritic Belt) has recently proven the importance of the iron cycle, not only in the generation of the extreme conditions of the habitat (low pH, high concentration of heavy metals), but also in the maintenance of a high level of microbial diversity. The presence of vast deposits of sulfates and iron oxides on Mars, the main products of the bioleaching of iron containing sulfides found in Río Tinto, and the physico-chemical properties of iron as a source of energy, protection from radiation and oxidative stress as well as pH control, make Río Tinto an interesting Mars terrestrial analog.

  6. Mars Analog Rio Tinto Experiment (MARTE): 2003 Drilling Campaign to Search for a Subsurface Biosphere at Rio Tinto Spain

    NASA Astrophysics Data System (ADS)

    Stoker, C.; Dunagan, S.; Stevens, T.; Amils, R.; Gómez-Elvira, J.; Fernández, D.; Hall, J.; Lynch, K.; Cannon, H.; Zavaleta, J.; Glass, B.; Lemke, L.

    2004-03-01

    The results of an drilling experiment to search for a subsurface biosphere in a pyritic mineral deposit at Rio Tinto, Spain, are described. The experiment provides ground truth for a simulation of a Mars drilling mission to search for subsurface life.

  7. Lessons learned from thirty years of geomicrobiological studies of Río Tinto.

    PubMed

    Amils, Ricardo

    2016-09-01

    Río Tinto (SW Spain) is an extreme acidic environment with a remarkable concentration of toxic heavy metals. The geomicrobiological characterization of the Tinto basin, carried out over the last thirty years, has proven the importance of the iron cycle in not only generating the river's extreme conditions, but also in maintaining the high level of microbial diversity. This work also shows that the extreme conditions found in the Tinto basin are not, as previously thought, the product of mining activities, but are, in fact, the result of the active subsurface bioreactor that obtains energy from the high concentration of massive sulfide minerals present in the Iberian Pyrite Belt. PMID:27349346

  8. Iron world and its astrobiological implications: The Tinto River case

    NASA Astrophysics Data System (ADS)

    Gomez, F.; Amils, A.

    2007-08-01

    Extreme ecosystems have recently attracted considerable interest, not only because they prove that life is robust and adaptable, but also because their existence increases the probability of finding life elsewhere in the universe. Most of the best characterized extreme habitats on Earth correspond to geophysical constraints to which opportunistic microorganisms have adapted. However, some extreme acidic environments are unique in that they are the product of biological activity (chemolithotrophy). The Tinto River (Huelva, Southwestern Spain) is an unusual acidic ecosystem (100 km long, mean pH of 2.3) containing a high concentration of heavy metals and an unexpected level of microbial diversity (1,2). In the past, the extreme conditions of the river were considered the result of intense mining activity. The geomicrobiological analysis of the Tinto ecosystem strongly suggests that these conditions are the result of the metabolic activity of chemolithotrophic prokaryotes, mainly iron-oxidizers (3). The system seems to be controlled by iron, which is not only used as an electron donor, but also as an electron acceptor, allowing a full iron cycle to operate. Furthermore, ferric iron is responsible for the maintenance of the constant pH of the ecosystem and can protect the different organisms thriving in its waters from radiation. Laminar, iron-rich stromatolitic formations are generated by the precipitation of different iron minerals on the surface of the biofilms that cover most of the rocks in the river and the riverbed. These structures are similar to ancient massive bioinduced laminated iron bioformations formed long before the first mining activities started in the area 5000 years ago. The existence of these ancient iron-rich deposits formed prior to any known mining activity, under hydrochemical conditions similar to modern deposits, is considered a strong argument in favor of a natural origin of the river (4,5). Recently, the source area of the Tinto ecosystem

  9. An Empirical Test of Tinto's Integration Framework for Community Colleges Using Structural Equation Modeling

    ERIC Educational Resources Information Center

    Santos-George, Arlene A.

    2012-01-01

    This dissertation empirically tested Tinto's student integration theory through structural equation modeling using a national sample of 2,847 first-time entering community college students. Tinto theorized that the more academically and socially integrated a student is to the college environment, the more likely the student will persist…

  10. Searching for Organics During the Robotic Mars Analog Rio Tinto Drilling Experiment: Ground Truth and Contamination Issues

    NASA Astrophysics Data System (ADS)

    Bonaccorsi, R.; Stoker, C. R.; Marte Project Science Team

    2007-03-01

    The Mars Analog Rio Tinto Experiment (MARTE) performed a simulation of a Mars drilling experiment at the Rio Tinto (Spain). Ground-truth and contamination issues during the distribution of bulk organics and their CN isotopic composition in hematite and go

  11. Scale-integrated spectral characterisation of mineralogical analogues to Mars at Rio Tinto

    NASA Astrophysics Data System (ADS)

    Gleeson, D.; Fernandez Remolar, D.; Martin, P.; Moissl, R.; Ruiz, V.

    2012-09-01

    Iron-sulfur and phyllosilicate assemblages within the Rio Tinto basin of Huelva province in Spain show mineralogical similarities to sites on the surface of Mars as determined by orbital and lander datasets. Exploration of Mars surface environments is intermittent and resolution-limited, and additional layers of information available for terrestrial analogue sites may extend incomplete planetary datasets. Characterising mineralogy in satellite, field and laboratory reflectance spectra of Rio Tinto sites can determine how accurately Mars-relevant mineralogies are represented in orbital data. Comparisons with Mars datasets, such as OMEGA and CRISM, will provide insights into planetary surface conditions.

  12. Geomorphic and Aqueous Chemistry of a Portion of the Upper Rio Tinto System, Spain

    NASA Technical Reports Server (NTRS)

    Osburn, M. R.; Fernandez-Remolar, D. C.; Arvidson, R. E.; Morris, R. V.; Ming, D.; Prieto-Ballesteros, O.; Amils, R.; Stein, T. C.; Heil-Chapdelaine, V.; Friedlander, L. R.; Herndon, B.; Marlow, J.; Rosenberg, S.; Scherpker, K.; Steiner, A.

    2007-01-01

    Observations from the two Mars rovers, Spirit and Opportunity, combined with discoveries of extensive hydrated sulfate deposits from OMEGA and CRISM show that aqueous deposition and alteration involving acidic systems and sulfate deposition has been a key contributor to the martian geologic record. Rio Tinto, Spain, provides a process model for formation of sulfates on Mars by evaporation of acidic waters within shallow fluvial pools, particularly during dry seasons. We present results from a detailed investigation of an upper portion of the Rio Tinto, focusing on geomorphology, clastic sediment transport, and acidic aqueous processes. We also lay out lessons-learned for under-standing sulfate formation and alteration on Mars.

  13. Río Tinto: A Geochemical and Mineralogical Terrestrial Analogue of Mars

    PubMed Central

    Amils, Ricardo; Fernández-Remolar, David

    2014-01-01

    The geomicrobiological characterization of the water column and sediments of Río Tinto (Huelva, Southwestern Spain) have proven the importance of the iron and the sulfur cycles, not only in generating the extreme conditions of the habitat (low pH, high concentration of toxic heavy metals), but also in maintaining the high level of microbial diversity detected in the basin. It has been proven that the extreme acidic conditions of Río Tinto basin are not the product of 5000 years of mining activity in the area, but the consequence of an active underground bioreactor that obtains its energy from the massive sulfidic minerals existing in the Iberian Pyrite Belt. Two drilling projects, MARTE (Mars Astrobiology Research and Technology Experiment) (2003–2006) and IPBSL (Iberian Pyrite Belt Subsurface Life Detection) (2011–2015), were developed and carried out to provide evidence of subsurface microbial activity and the potential resources that support these activities. The reduced substrates and the oxidants that drive the system appear to come from the rock matrix. These resources need only groundwater to launch diverse microbial metabolisms. The similarities between the vast sulfate and iron oxide deposits on Mars and the main sulfide bioleaching products found in the Tinto basin have given Río Tinto the status of a geochemical and mineralogical Mars terrestrial analogue. PMID:25370383

  14. Río Tinto: A Geochemical and Mineralogical Terrestrial Analogue of Mars

    NASA Astrophysics Data System (ADS)

    Amils, Ricardo; Fernández-Remolar, David

    2014-09-01

    The geomicrobiological characterization of the water column and sediments of Río Tinto (Huelva, Southwestern Spain) have proven the importance of the iron and the sulfur cycles, not only in generating the extreme conditions of the habitat (low pH, high concentration of toxic heavy metals), but also in maintaining the high level of microbial diversity detected in the basin. It has been proven that the extreme acidic conditions of Río Tinto basin are not the product of 5000 years of mining activity in the area, but the consequence of an active underground bioreactor that obtains its energy from the massive sulfidic minerals existing in the Iberian Pyrite Belt. Two drilling projects, MARTE (Mars Astrobiology Research and Technology Experiment) (2003-2006) and IPBSL (Iberian Pyrite Belt Subsurface Life Detection) (2011-2015), were developed and carried out to provide evidence of subsurface microbial activity and the potential resources that support these activities. The reduced substrates and the oxidants that drive the system appear to come from the rock matrix. These resources need only groundwater to launch diverse microbial metabolisms. The similarities between the vast sulfate and iron oxide deposits on Mars and the main sulfide bioleaching products found in the Tinto basin have given Río Tinto the status of a geochemical and mineralogical Mars terrestrial analogue.

  15. Río tinto: a geochemical and mineralogical terrestrial analogue of Mars.

    PubMed

    Amils, Ricardo; Fernández-Remolar, David; The Ipbsl Team

    2014-01-01

    The geomicrobiological characterization of the water column and sediments of Río Tinto (Huelva, Southwestern Spain) have proven the importance of the iron and the sulfur cycles, not only in generating the extreme conditions of the habitat (low pH, high concentration of toxic heavy metals), but also in maintaining the high level of microbial diversity detected in the basin. It has been proven that the extreme acidic conditions of Río Tinto basin are not the product of 5000 years of mining activity in the area, but the consequence of an active underground bioreactor that obtains its energy from the massive sulfidic minerals existing in the Iberian Pyrite Belt. Two drilling projects, MARTE (Mars Astrobiology Research and Technology Experiment) (2003-2006) and IPBSL (Iberian Pyrite Belt Subsurface Life Detection) (2011-2015), were developed and carried out to provide evidence of subsurface microbial activity and the potential resources that support these activities. The reduced substrates and the oxidants that drive the system appear to come from the rock matrix. These resources need only groundwater to launch diverse microbial metabolisms. The similarities between the vast sulfate and iron oxide deposits on Mars and the main sulfide bioleaching products found in the Tinto basin have given Río Tinto the status of a geochemical and mineralogical Mars terrestrial analogue. PMID:25370383

  16. Reassessing Tinto's Concepts of Social and Academic Integration in Student Retention

    ERIC Educational Resources Information Center

    Davidson, Cody; Wilson, Kristin

    2013-01-01

    The purpose of this article is to trace the development of the Tinto framework for student integration and to critically analyze the application of the framework with nontraditional student populations. Specifically, the terms "academic" and "social integration" have become synonymous with student retention and, by extension,…

  17. Hydrogeochemical characteristics of the Tinto and Odiel Rivers (SW Spain). Factors controlling metal contents.

    PubMed

    Cánovas, C R; Olías, M; Nieto, J M; Sarmiento, A M; Cerón, J C

    2007-02-01

    The Tinto and Odiel Rivers are strongly affected by acid mine drainage (AMD) due to the intense sulphide mining developed in their basins over the past 5000 years. In this study the results obtained from a weekly sampling in both rivers, before their mouth in the Ría of Huelva, over three and a half years of control are analysed. In the Tinto River, the concentrations of sulphates, Al, Cd, Co, Li and Zn are double to those of the Odiel as a consequence of lower dilution. However, the concentration of Fe in the Odiel River is 20 times lower, since the precipitation of Fe oxyhydroxysulphates caused by neutralisation processes is more intense. Lower As, Cr, Cu and Pb concentrations are also found in the Odiel River as, to a greater or lesser extent, they are sorbed and/or coprecipitated with Fe. Other elements such as Be, Mn, Ni and Mg show similar values in both systems, which is ascribed to lithological factors. The seasonal evolution of contaminants is typical of rivers affected by AMD, reaching a maximum in autumn due to the dissolution of evaporitic salts precipitated during the summer. Nevertheless, in the Tinto River, Ca, Na and Sr show a strong increase during the summer, probably due to a greater water interaction with marly materials, through which the last reach of the river flows. Barium has a different behaviour from the rest of the metals and its concentration seems to be controlled by the solubility of barite. Iron, As and Pb show different behaviours in both rivers, those for Fe and As possibly linked to the prevalence of different dissolved species of Fe. The different Pb pattern is probably due to the control of Pb solubility by anglesite or other minerals rich in Pb in the Tinto River. PMID:17207846

  18. Screening of anaerobic activities in sediments of an acidic environment: Tinto River.

    PubMed

    Sánchez-Andrea, Irene; Rojas-Ojeda, Patricia; Amils, Ricardo; Sanz, José Luis

    2012-11-01

    The Tinto River (Huelva, Spain) is a natural acidic rock drainage environment produced by the bio-oxidation of metallic sulfides from the Iberian Pyritic Belt. A geomicrobiological model of the different microbial cycles operating in the sediments was recently developed through molecular biological methods, suggesting the presence of iron reducers, methanogens, nitrate reducers and hydrogen producers. In this study, we used a combination of molecular biological methods and targeted enrichment incubations to validate this model and prove the existence of those potential anaerobic activities in the acidic sediments of Tinto River. Methanogenic, sulfate-reducing, denitrifying and hydrogen-producing enrichments were all positive at pH between 5 and 7. Methanogenic enrichments revealed the presence of methanogenic archaea belonging to the genera Methanosarcina and Methanobrevibacter. Enrichments for sulfate-reducing microorganisms were dominated by Desulfotomaculum spp. Denitrifying enrichments showed a broad diversity of bacteria belonging to the genera Paenibacillus, Bacillus, Sedimentibacter, Lysinibacillus, Delftia, Alcaligenes, Clostridium and Desulfitobacterium. Hydrogen-producing enrichments were dominated by Clostridium spp. These enrichments confirm the presence of anaerobic activities in the acidic sediments of the Tinto River that are normally assumed to take place exclusively at neutral pH. PMID:22956355

  19. Scale-integrated spectral characterisation of mineralogical analogues to Mars at Rio Tinto

    NASA Astrophysics Data System (ADS)

    Gleeson, Damhnait; Fernandez-Remolar, David; Martin, Patrick; Moissl, Richard; Ruiz, Vicente

    2013-04-01

    Iron-sulfur assemblages within the Rio Tinto basin of Huelva province in Spain show mineralogical similarities to sites on the surface of Mars as determined by orbital and lander datasets. Exploration of Mars surface environments is intermittent and resolution-limited, and additional layers of information available for terrestrial analogue sites may extend incomplete planetary datasets. Characterising mineralogy in satellite, field and laboratory reflectance spectra of Rio Tinto sites can determine how accurately Mars-relevant mineralogies are represented in orbital data. Comparisons with Mars datasets, such as OMEGA and CRISM, can provide insights into planetary surface conditions. Interaction between materials in field mixtures can lead to potential interferences between endmembers and/or offsets in spectral features, which can obscure or hinder the identification of certain minerals. Such interactions can be difficult to predict on the basis of library spectra collected using pure materials. Determination of which diagnostic spectral features can be identified in field mixtures is an advantage of collecting data in real world environments, and can be used to aid interpretation of planetary datasets. This study utilizes the dynamic sulfur and iron deposits of Rio Tinto as an analogue of Mars sites such as Meridiani Planum, using the many scales of observation available for the terrestrial sites as a means of extending our view of Mars surface conditions from the orbital view to which we are frequently limited.

  20. Fossilization potential of iron-bearing minerals in acidic environments of Rio Tinto, Spain: Implications for Mars exploration

    NASA Astrophysics Data System (ADS)

    Fernández-Remolar, David C.; Knoll, Andrew H.

    2008-03-01

    Acidic waters of the Rio Tinto, southwestern Spain, evaporate seasonally, precipitating a variety of iron sulfide and oxide minerals. Schwertmannite and nanophase goethite form thin laminae on biological and detrital grain surfaces, replicating, among other things, the morphologies of insect cuticle, plant tissues, fungi, algae, and bacteria. Intergrain cements also incorporate bacterial cells and filaments. Other sulfate minerals precipitated in Rio Tinto environments are transient and contribute little to short-term preservation. Because the Rio Tinto has been cutting its current valley for several million years, terrace deposits provide a window on longer term fossil preservation. Early and later diagenesis are recorded in terrace deposits formed about one thousand and two million years ago, respectively. The sedimentary structures and mineralogies of these deposits suggest that they formed under physical and chemical conditions comparable to those of modern Rio Tinto sediments. The terrace deposits show quantitative loss of sulfate minerals, increasing crystallinity of goethite and, in the older terrace, replacement of goethite by hematite. Fossils formed originally by schwertmannite and nanophase goethite replication persist through diagenesis, preserving a long term record of local biological diversity. Fossil preservation by iron oxides in the acidic environment of Rio Tinto suggests that if life was present when sedimentary rocks formed at Meridiani Planum, Mars, precipitated minerals could record their presence.

  1. Geological record of an acidic environment driven by iron hydrochemistry: The Tinto River system

    NASA Astrophysics Data System (ADS)

    Fernández-Remolar, David C.; Rodriguez, Nuria; Gómez, Felipe; Amils, Ricardo

    2003-07-01

    The existence of possible hematitic strata on the surface of Mars demands a search for terrestrial analogues formed in unusual environments. This will help us to recognize and interpret environmental and, perhaps, biological signatures preserved in Mars' hematites. Such an analogue would allow us to establish valid reference systems based on geomicrobial and biogeochemical signatures. Two different aspects place the Tinto River inside the boundaries of a natural extreme system: its high level of biological diversity and the presence of fluvial rocks formed in the same acidic conditions as in the modern system, which could predate the Tertiary. Study of both the modern system and the ancient system is necessary to understand the formation of biosignatures. A chemolithotrophic community that biooxidizes the Iberian Pyritic Belt, acidifying water (pH between 0.9 and 3.0) and favoring high concentrations of ferric iron in solution (up to 20 g.L-1), maintains this iron-driven system. In spite of these extreme conditions, high microbial diversity was found. Its acidic bacteria, archaea, and eukarya constitute a complex community supported by algal biomass in highly stable hydrochemical conditions, which are achieved through iron buffering. The pH is maintained at constant low levels even at very high water dilution. In these conditions, iron minerals as oxyhydroxides, hydroxides, and sulfates are formed. The modern and recent parageneses contrast with the ancient Tinto River terrace mineral associations, which show dehydrated and desulfated iron oxides. If this dehydration process is considered, these Tinto River ironstones may be a key for knowing some aquatic habitats, which may have hosted a part of the early Mars biosphere.

  2. Identification of Hydrated Sulfates Collected in the Northern Rio Tinto Valley by Reflectance and Raman Spectroscopy

    NASA Technical Reports Server (NTRS)

    Chemtob, S. M.; Arvidson, R. E.; Fernandez-Remolar, D. C.; Amils, R.; Morris, R. V.; Ming, D. W.; Prieto-Ballesteros, O.; Mustard, J. F.; Hutchinson, L.; Stein, T. C.; Donovan, C. E.; Fairchild, G. M.; Friedlander, L. R.; Karas, N. M.; Klasen, N.; Mendenhall, M. P.; Robinson, E. M.; Steinhardt, S. E.; Weber, L. R.

    2006-01-01

    OMEGA recently identified spectral signatures of kieserite, gypsum, and other polyhydrated sulfates at multiple locations on the surface of Mars [1,2]. The presence of sulfates was confirmed through in situ spectroscopy by MER Opportunity [3]. An approach to validate these interpretations is to collect corresponding spectral data from sulfate-rich terrestrial analog sites. The northern Rio Tinto Valley near Nerva, Spain, is a good Martian analog locale because it features extensive seasonal sulfate mineralization driven by highly acidic waters [4]. We report on mineralogical compositions identified by field VNIR spectroscopy and laboratory Raman spectroscopy.

  3. Heavy metal anomalies in the Tinto and Odiel River and estuary system, Spain

    USGS Publications Warehouse

    Nelson, C.H.; Lamothe, P.J.

    1993-01-01

    The Tinto and Odiel rivers drain 100 km from the Rio Tinto sulphide mining district, and join at a 20-km long estuary entering the Atlantic Ocean. A reconnaissance study of heavy metal anomalies in channel sand and overbank mud of the river and estuary by semi-quantitative emission dc-arc spectrographic analysis shows the following upstream to downstream ranges in ppm (??g g-1): As 3,000 to <200, Cd 30 to <0.1, Cu 1,500 to 10, Pb 2,000 to <10, Sb 3000 to <150, and Zn 3,000 to <200. Organic-rich (1.3-2.6% total organic carbon, TOC), sandysilty overbank clay has been analyzed to represent suspended load materials. The high content of heavy metals in the overbank clay throughout the river and estuary systems indicates the importance of suspended sediment transport for dispersing heavy metals from natural erosion and anthropogenic mining activities of the sulfide deposit. The organic-poor (0.21-0.37% TOC) river bed sand has been analyzed to represent bedload transport of naturally-occurring sulfide minerals. The sand has high concentrations of metals upstream but these decrease an order of magnitude in the lower estuary. Although heavy metal contamination of estuary mouth beach sand has been diluted to background levels estuary mud exhibits increased contamination apparently related to finer grain size, higher organic carbon content, precipitation of river-borne dissolved solids, and input of anthropogenic heavy metals from industrial sources. The contaminated estuary mud disperses to the inner shelf mud belt and offshore suspended sediment, which exhibit metal anomalies from natural erosion and mining of upstream Rio Tinto sulphide lode sources (Pb, Cu, Zn) and industrial activities within the estuary (Fe, Cr, Ti). Because heavy metal contamination of Tinto-Odiel river sediment reaches or exceeds the highest levels encountered in other river sediments of Spain and Europe, a detailed analysis of metals in water and suspended sediment throughout the system, and

  4. The magnetic properties of Rio Tinto Basin sediments (Spain): a step towards Martian enviromagnetics

    NASA Astrophysics Data System (ADS)

    McIntosh, G.; Hernandez, F. M.; Remolar, D. F.; de La Presa, P.; Marin, P.; Marcos, V. V.

    2008-12-01

    Exploration by the NASA rover Opportunity revealed sulphate-and haematite-rich sedimentary rocks exposed in surface features of Meridiani Planum, Mars. Sediments of the Rio Tinto Basin, Spain, provide at least a partial analog of Meridiani rocks, thereby facilitating an understanding of mineral precipitation and diagenesis on the Martian surface. Here we present the results of a mineral magnetic study of river terrace deposits of the Rio Tinto system, the deposits ranging from Modern to Plio-Pleistocene in age. A broad range of temperature- and field-dependent measurements have been made which have identified the presence of goethite, haematite and sulphides. Seasonally driven processes are thought to lead to the precipitation of nano-phase goethite which increases in crystallinity with age, eventually being replaced by haematite. Diverse micro-organism populations inhabit the acidic and seasonally dry environments, although organic matter does not persist in the sediments. However, biosignatures are left as casts and molds in the iron oxide minerals. The potential for recognizing their characteristic magnetic signatures, and their extrapolation to Martian environments, will be discussed.

  5. Characterization of a Subsurface Biosphere in a Massive Sulfide Deposit At Rio Tinto, Spain: Implications For Extant Life On Mars

    NASA Technical Reports Server (NTRS)

    Stoker, C. R.; Stevens, T.; Amils, R.; Gomez-Elvira, J.; Rodriguez, N.; Gomez, F.; Gonzalez-Toril, E.; Aguilera, A.; Fernandez-Remolar, D.; Dunagan, S.

    2005-01-01

    The recent discovery of abundant sulfate minerals, particularly Jarosite by the Opportunity Rover at Sinus Merdiani on Mars has been interpreted as evidence for an acidic lake or sea on ancient Mars [1,2], since the mineral Jarosite is soluble in liquid water at pH above 4. The most likely mechanism to produce sufficient protons to acidify a large body of liquid water is near surface oxidation of pyrite rich deposits [3]. The acidic waters of the Rio Tinto, and the associated deposits of Hematite, Goethite, and Jarosite have been recognized as an important chemical analog to the Sinus Merdiani site on Mars [4]. The Rio Tinto is a river in southern Spain that flows 100 km from its source in the Iberian pyrite belt, one of the Earth's largest Volcanically Hosted Massive Sulfide (VHMS) provinces, into the Atlantic ocean. The river originates in artesian springs emanating from ground water that is acidified by the interaction with subsurface pyrite ore deposits. The Mars Analog Rio Tinto Experiment (MARTE) has been investigating the hypothesis that a subsurface biosphere exists at Rio Tinto living within the VHMS deposit living on chemical energy derived from sulfur and iron minerals. Reduced iron and sulfur might provide electron donors for microbial metabolism while in situ oxidized iron or oxidants entrained in recharge water might provide electron acceptors.

  6. Characterization of a Subsurface Biosphere in a Massive Sulfide Deposits at Rio Tinto, Spain: Implications for Extant Life on Mars

    NASA Technical Reports Server (NTRS)

    Stoker, C. R.; Stevens, T.; Amils, R.; Gomez-Elvira, J.; Rodriquez, N.; Gomez, F.; Gonzalez-Toril, E.; Aguilera, A.; Fernandez-Remolar, D.; Dunagan, S.

    2005-01-01

    The recent discovery of abundant sulfate minerals, particularly Jarosite by the Opportunity Rover at Sinus Merdiani on Mars has been interpreted as evidence for an acidic lake or sea on ancient Mars [1,2], since the mineral Jarosite is soluble in liquid water at pH above 4. The most likely mechanism to produce sufficient protons to acidify a large body of liquid water is near surface oxidation of pyrite rich deposits [3]. The acidic waters of the Rio Tinto, and the associated deposits of Hematite, Goethite, and Jarosite have been recognized as an important chemical analog to the Sinus Merdiani site on Mars [4]. The Rio Tinto is a river in southern Spain that flows 100 km from its source in the Iberian pyrite belt, one of the Earth s largest Volcanically Hosted Massive Sulfide (VHMS) provinces, into the Atlantic ocean. The river originates in artesian springs emanating from ground water that is acidified by the interaction with subsurface pyrite ore deposits. The Mars Analog Rio Tinto Experiment (MARTE) has been investigating the hypothesis that a subsurface biosphere exists at Rio Tinto living within the VHMS deposit living on chemical energy derived from sulfur and iron minerals. Reduced iron and sulfur might provide electron donors for microbial metabolism while in situ oxidized iron or oxidants entrained in recharge water might provide electron acceptors.

  7. The Influence of Active Learning on the College Student Departure Process: Toward a Revision of Tinto's Theory.

    ERIC Educational Resources Information Center

    Braxton, John M.; Milem, Jeffrey F.; Sullivan, Anna Shaw

    2000-01-01

    Examined the influence of faculty active-learning practices on student departure decisions in the context of Tinto's Theory of College Student Departure. Path analysis results of three surveys of 718 first-time, full-time, first-year students at a highly selective private research university found that active learning exerts statistically reliable…

  8. Fast-Turnoff Transient Electromagnetic (TEM) Field Study at the Mars Analog Site of Rio Tinto, Spain

    NASA Astrophysics Data System (ADS)

    Jernsletten, J. A.

    2005-03-01

    This report describes a Fast-Turnoff Transient Electromagnetic (TEM) study at the Peña de Hierro ("Berg of Iron") field area of the Mars Analog Research and Technology Experiment (MARTE), near the towns Rio Tinto and Nerva, Andalucia region, Spain.

  9. Influence of releases from a fresh water reservoir on the hydrochemistry of the Tinto River (SW Spain).

    PubMed

    Cánovas, Carlos Ruiz; Olias, Manuel; Vazquez-Suñé, Enric; Ayora, Carlos; Miguel Nieto, Jose

    2012-02-01

    The Tinto River is an extreme case of pollution by acid mine drainage (AMD), with pH values below 3 and high sulphate, metal and metalloid concentrations along its main course. This study evaluates the impact of releases from a freshwater reservoir on the Tinto River, identifying the metal transport mechanisms. This information is needed to understand the water quality evolution in the long term, and involves the comprehension of interactions between AMD sources, freshwaters, particulate matter and sediments. This work proposes a methodology for quantifying the proportions in which the different sources are contributing. The method is based on the mass balance of solutes and accounts for the uncertainty of end-members. The impact of the releases from the Corumbel Reservoir on the hydrochemistry of the Tinto River was significant, accounting up to a 92% of river discharge. These releases provoked a sharp decrease in dissolved metal concentrations, especially for Fe (approximately 1000 fold) due to dilution and precipitation. Cadmium, Zn, Cu, Co, Ni and Al suffered a dilution to a 12-16 fold decrease while Ca, Sr, Na, Pb and Si were less affected (2-4 folds decrease). However, these releases also gave rise to an increase in particulate transport, mainly Fe, As, Cr, Ba, Pb and Ti, due to sediment remobilisation and Fe precipitation. Aluminium, Li, K, Si, Al, Ni and Sr, together with Cu were present in the particulate phase during the discharge peak. The proposed 2-component mixing model revealed the existence of non-conservative behaviour for Al, Ca, Li, Mn, Ni and Si as a consequence of the interactions between the acidic Tinto waters and the clay-rich reservoir sediments during the bottom outlet opening. These results were improved by a 3-component mixing model, introducing a new end-member to account the chemical dissolution of clay-rich sediments by acidic Tinto waters. PMID:22221869

  10. Identification of the subsurface sulfide bodies responsible for acidity in Río Tinto source water, Spain

    NASA Astrophysics Data System (ADS)

    Gómez-Ortiz, David; Fernández-Remolar, David C.; Granda, Ángel; Quesada, Cecilio; Granda, Teresa; Prieto-Ballesteros, Olga; Molina, Antonio; Amils, Ricardo

    2014-04-01

    The acidic waters of the Río Tinto rise from several acidic springs that emerge in the area surrounding Peña de Hierro (Fernández-Remolar et al., 2005). These springs are located above minor normal faults that act as natural conduits for the water from the underlying deep aquifer. Although it has been suggested that the acidity of the river originates from the biooxidation of massive and stockwork sulfides (Fernández-Remolar et al., 2008a), the location of the source for these acidic solutions has not previously been established. This lack of evidence has been used to suggest that the acidity of the Río Tinto may be the product of the most conspicuous of the possible source, the extensive mining of the area over approximately the last 5000 years (Davis et al., 2000). In this paper, we report resistivity and time-domain electromagnetic sounding data from the Río Tinto aquifer to a depth of ∼600 m, revealing the locations for the acidic sources. Both types of data support the presence of two distinct geological units that we interpret as thrust sheets emplaced onto each other during the Variscan orogeny of the Carboniferous. These units, both of which contain massive and stockwork sulfides, act as the aquifer for the acidic waters of the Río Tinto. Under this scenario, which is in agreement with the geological record of the Río Tinto fluvial system for the past 6 Ma (Moreno et al., 2003), our results imply that mining activity had little influence on the generation of the acidic river waters.

  11. Multidisciplinary integrated field campaign to an acidic Martian Earth analogue with astrobiological interest: Rio Tinto

    NASA Astrophysics Data System (ADS)

    Gómez, F.; Walter, N.; Amils, R.; Rull, F.; Klingelhöfer, A. K.; Kviderova, J.; Sarrazin, P.; Foing, B.; Behar, A.; Fleischer, I.; Parro, V.; Garcia-Villadangos, M.; Blake, D.; Martin Ramos, J. D.; Direito, S.; Mahapatra, P.; Stam, C.; Venkateswaran, K.; Voytek, M.

    2011-07-01

    Recently reported results from latest Mars Orbiters and Rovers missions are transforming our opinion about the red planet. That dry and inhospitable planet reported in the past is becoming a wetter planet with high probabilities of water existence in the past. Nowadays, some results seem to indicate the presence of water beneath the Mars surface. But also mineralogy studies by NASA Opportunity Rover report iron oxides and hydroxides precipitates on Endurance Crater. Sedimentary deposits have been identified at Meridiani Planum. These deposits must have generated in a dune aqueous acidic and oxidizing environment. Similarities appear when we study Rio Tinto, and acidic river under the control of iron. The discovery of extremophiles on Earth widened the window of possibilities for life to develop in the Universe, and as a consequence on Mars and other planetary bodies with astrobiological interest. The compilation of data produced by the ongoing missions offers an interested view for life possibilities to exist: signs of an early wet Mars and rather recent volcanic activity as well as ground morphological characteristics that seem to be promoted by liquid water. The discovery of important accumulations of sulfates and the existence of iron minerals such as jarosite in rocks of sedimentary origin has allowed specific terrestrial models to come into focus. Río Tinto (Southwestern Spain, Iberian Pyritic Belt) is an extreme acidic environment, product of the chemolithotrophic activity of micro-organisms that thrive in the massive pyrite-rich deposits of the Iberian Pyritic Belt. Some particular protective environments should house the organic molecules and bacterial life forms in harsh environments such as Mars surface supporting microniches inside precipitated minerals or inside rocks. Terrestrial analogues could help us to afford the comprehension of habitability (on other planetary bodies). We are reporting here the multidisciplinary study of some endolithic niches

  12. Subsurface geomicrobiology in a Mars terrestrial analogue, Río Tinto (SW, Spain)

    NASA Astrophysics Data System (ADS)

    Amils, R.; Fernández-Remolar, D.; Gómez, F.; González-Toril, E.; Rodríguez, N.; Prieto-Ballesteros, O.; Sanz, J. L.; Díaz, E.; Stoker, C.

    2008-09-01

    Since its discovery, only few years ago, subsurface geomicrobiology is a matter of growing interest [1]. From a fundamental point of view, it seeks to determine whether life can be sustained in the absence of radiation. From an astrobiological point of view, it is an interesting model for life in other planetary bodies, e.g., Mars, as well as early life on Earth. Río Tinto is an unusual extreme acidic environment due to its size (around 100 km), constant acidic pH (mean pH 2.3), high concentrations of heavy metals and high level of microbial diversity [2]. Río Tinto rises in the core of the Iberian Pyritic Belt, one of the biggest sulfidic ore deposits in the world [3]. Today it is well stablished that the extreme characteristics of Río Tinto are not due to acid mine drainage from mining activity, as has been suggested in the past. To explore the hypothesis that a continuous underground reactor of chemolithotrophic microorganisms thriving in the rich sulfidic minerals of the Iberian Pyritic Belt is responsible for the extreme conditions found in the system, a drilling project has been developed to detect evidence of subsurface microbial activity and potential resources to support these microbial communities in situ (MARTE project) [4]. Here we report a search for subsurface life in volcanically hosted massive sulfidic deposits from the Iberian Pyritic Belt. Aseptic core samples were obtained within and down-gradient from the massive sulfide deposits and formation water was sampled within the resulting bore holes. Microbial activity was detected in un-contaminated samples by culture-dependent and culture-independent methods. Aerobic iron- and sulfide- oxidizing bacteria, and anaerobic denitrifying thiosulfate-oxidizing bacteria, sulfate reducing bacteria and methanogenic archaea have been identified. Potential energy fluxes detected in the system include oxidation of reduced iron and sulfur, or hydrogen gas coupled to nitrite, sulfate, ferric iron, inorganic

  13. Microbial sulphur isotope fractionation in a Mars analogue environment at Rio Tinto, SW Spain

    NASA Astrophysics Data System (ADS)

    Velasco, Esther; Mason, Paul; Gonzalez-Toril, Elena; Zegers, Tanja; Davies, Gareth; Amils, Ricardo

    2010-05-01

    The development of geochemical proxies for possible early life on Mars is important in preparation for future space missions, especially those that will return samples to Earth. Sulfur isotopes are likely to be a key future tool for this purpose since abundant sulphate minerals on the surface of Mars [1], such as jarosite (KFe3+3(SO4)2(OH)6), may record the activity of sulphur metabolizing microorganisms. Little is currently known about the sulphur isotope effects associated with sulphate reduction in the acidic environments where jarosite and other minerals are likely to have precipitated. Here we investigate the relationship between sulphate reducing activity and sulphur isotope fractionation in a modern hyper-acidic subareal environment at Rio Tinto, SW Spain [2,3,4]. The geochemical characteristics of Rio Tinto are the consequence of modern weathering of pyrite-rich ores in the Iberian Pyritic Belt, and the metabolism of iron and sulphur compounds by chemolithotrophic microorganisms. This results in a high concentration of ferric iron that is soluble under the acidic conditions generated by the biological activity. These conditions cause the precipitation of ferric-bearing minerals, including amorphous phases and hydronium jarosite. Sulphate reducing bacteria have recently been isolated from Rio Tinto sediments despite the fact that high concentrations of ferrous iron can inhibit microbial sulphate reduction. Flow-through reactor experiments were performed using sediment samples from Río Tinto, in localities where the potential for sulphate-reducing activity was previously identified. Sediments were taken both in the upper part of the river and in the estuary where tidal effects have created a dynamic environment, with mixing between hyperacidic and marine conditions. Sediments were incubated in the laboratory at 30oC, using an artificial input solution with sulphate in excess using techniques developed by Stam et al. [5]. Two sets of experiments were done at

  14. Application of a systemic approach to the study of pollution of the Tinto and Odiel rivers (Spain).

    PubMed

    Sainz, A; Grande, J A; De La Torre, M L

    2005-03-01

    The province of Huelva in the SW of Spain presents high environmental contrasts: together with the great abundance of natural spaces, it shows the impacts of historical natural resources exploitation processes. In the Ria of Huelva, the effluents of the chemical industries must be added to the contaminating inputs of the Tinto and Odiel rivers, coming from the acid drainage of the mines located in the Iberian Pyrite Belt. This forced the Environmental Agency (AMA) to elaborate in 1987 an Effluent Remediation Plan in order to negate unacceptable environmental impacts. The application of a "grey box" systemic analysis to the AMD pollution, undergone by the Tinto and Odiel rivers has allowed to set a conclusive explanation of the sampling results observed for a period of 11 years, thus making available an overall view of the polluting process and, above all, an explanation of its partial aspects. PMID:15869201

  15. Exploration of a Subsurface Biosphere in a Volcanic Massive Sulfide: Results of the Mars Analog Rio Tinto Drilling Experiment

    NASA Astrophysics Data System (ADS)

    Stoker, C. R.; Stevens, T.; Amils, R.; Fernandez, D.

    2005-12-01

    Biological systems on Earth require three key ingredients-- liquid water, an energy source, and a carbon source, that are found in very few extraterrestrial environments. Previous examples of independent subsurface ecosystems have been found only in basalt aquifers. Such lithotrophic microbial ecosystems (LME) have been proposed as models for steps in the early evolution of Earth's biosphere and for potential biospheres on other planets where the surface is uninhabitable, such as Mars and Europa.. The Mars Analog Rio Tinto Experiment (MARTE) has searched in a volcanic massive sulfide deposit in Rio Tinto Spain for a subsurface biosphere capable of living without sunlight or oxygen and found a subsurface ecosystem driven by the weathering of the massive sulfide deposit (VMS) in which the rock matrix provides sufficient resources to support microbial metabolism, including the vigorous production of H2 by water-rock interactions. Microbial production of methane and sulfate occurred in the sulfide orebody and microbial production of methane and hydrogen sulfide continued in an anoxic plume downgradient from the sulfide ore. Organic carbon concentrations in the parent rock were too low to support microbes. The Rio Tinto system thus represents a new type of subsurface ecosystem with strong relevance for exobiological studies. Commercial drilling was used to reach the aquifer system at 100 m depth and conventional laboratory techniques were used to identify and characterize the biosphere. Then, the life search strategy that led to successful identification of this biosphere was applied to the development of a robotic drilling, core handling, inspection, subsampling, and life detection system built on a prototype planetary lander that was deployed in Rio Tinto Spain in September 2005 to test the capability of a robotic drilling system to search for subsurface life. A remote science team directed the simulation and analyzed the data from the MARTE robotic drill. The results

  16. The Rio Tinto Basin, Spain: Mineralogy, Sedimentary Geobiology, and Implications for Interpretation of Outcrop Rocks at Meridiani Planum, Mars

    NASA Technical Reports Server (NTRS)

    Fernandez-Remolar, David C.; Morris, Richard V.; Gruener, John E.; Amils, Ricardo; Knoll, Andrew H.

    2005-01-01

    Exploration by the NASA rover Opportunity has revealed sulfate- and hematite-rich sedimentary rocks exposed in craters and other surface features of Meridiani Planum, Mars. Modern, Holocene, and Plio-Pleistocene deposits of the Rio Tinto, southwestern Spain, provide at least a partial environmental analog to Meridiani Planum rocks, facilitating our understanding of Meridiani mineral precipitation and diagenesis, while informing considerations of martian astrobiology. Oxidation, thought to be biologically mediated, of pyritic ore bodies by groundwaters in the source area of the Rio Tinto generates headwaters enriched in sulfuric acid and ferric iron. Seasonal evaporation of river water drives precipitation of hydronium jarosite and schwertmannite, while (Mg,Al,Fe(sup 3+))-copiapite, coquimbite, gypsum, and other sulfate minerals precipitate nearby as efflorescences where locally variable source waters are brought to the surface by capillary action. During the wet season, hydrolysis of sulfate salts results in the precipitation of nanophase goethite. Holocene and Plio-Pleistocene terraces show increasing goethite crystallinity and then replacement of goethite with hematite through time. Hematite in Meridiani spherules also formed during diagenesis, although whether these replaced precursor goethite or precipitated directly from groundwaters is not known. The retention of jarosite and other soluble sulfate salts suggests that water limited the diagenesis of Meridiani rocks. Diverse prokaryotic and eukaryotic microorganisms inhabit acidic and seasonally dry Rio Tinto environments. Organic matter does not persist in Rio Tinto sediments, but biosignatures imparted to sedimentary rocks as macroscopic textures of coated microbial streamers, surface blisters formed by biogenic gas, and microfossils preserved as casts and molds in iron oxides help to shape strategies for astrobiological investigation of Meridiani outcrops.

  17. Application of cluster analysis to the geochemistry zonation of the estuary waters in the Tinto and Odiel rivers (Huelva, Spain).

    PubMed

    Grande, José Antonio; Borrego, José; de la Torre, Maria Luisa; Sáinz, A

    2003-06-01

    The combination of acid water from mines, industrial effluents and sea water plays a determining role in the evolutionary process of the chemical makeup of the water in the estuary of the Tinto and Odiel rivers. This estuary is in the southwest of the Iberian Peninsula and is one of the estuarine systems on the northwest coast of the Gulf of Cádiz. From the statistical treatment of data obtained by analyzing samples of water from this system, which is affected by industrial and mining pollution processes, we can see how the sampling points studied form two large groups depending on whether they receive tidal or fluvial influences. Fluvial input contributes acid water with high concentrations of heavy metal, whereas industrial effluents are responsible for the presence of phosphates, silica and other nutrients. The estuarine system of the Tinto and Odiel Rivers can be divided into three areas--the Tinto estuary, the Odiel estuary and the area of confluence--based on the physical--chemical characteristics of the water. PMID:12901168

  18. Raman spectroscopy of the system iron(III)-sulfuric acid-water: an approach to Tinto River's (Spain) hydrogeochemistry.

    PubMed

    Sobron, P; Rull, F; Sobron, F; Sanz, A; Medina, J; Nielsen, C J

    2007-12-15

    Acid mine drainage is formed when pyrite (FeS(2)) is exposed and reacts with air and water to form sulfuric acid and dissolved iron. Tinto River (Huelva, Spain) is an example of this phenomenon. In this study, Raman spectroscopy has been used to investigate the speciation of the system iron(III)-sulfuric acid-water as an approach to Tinto River's aqueous solutions. The molalities of sulfuric acid (0.09 mol/kg) and iron(III) (0.01-1.5 mol/kg) were chosen to mimic the concentration of the species in Tinto River waters. Raman spectra of the solutions reveal a strong iron(III)-sulfate inner-sphere interaction through the nu(1) sulfate band at 981 cm(-1) and its shoulder at 1005 cm(-1). Iron(III)-sulfate interaction may also be facilitated by hydrogen bonds and monitored in the Raman spectra through the symmetric stretching band of bisulfate at 1052 cm(-1) and a shoulder at 1040 cm(-1). Other bands in the low-frequency region of the Raman spectra are attributed to the hydrogen-bonded complexes formation as well. PMID:17869164

  19. A Crustal Scale Heat and Fluid Flow Model for the Giant Rio Tinto VMS District, Iberian Pyrite Belt

    NASA Astrophysics Data System (ADS)

    Barrie, C.; Cathles, L. M.; Erendi, A.

    2004-05-01

    Paleo - seafloor and sub-seafloor deposits of the Rio Tinto District constitute the largest accumulation of volcanic-associated massive sulfide (VMS) on Earth. The deposits are are the type examples of giant bimodal-siliciclastic VMS deposits. This study presents relatively simple, 2D finite element heat and fluid flow models that explain how such a massive hydrothermal system may have formed. Giant VMS deposits require: 1) crustal scale hydrothermal circulation; 2) deep intrusion heat sources to drive hydrothermal convection; and 3) an optimal crustal permeability that supports large scale convection cells. We consider convection to depths of 10 and 15 km in the crust, a felsic intrusion heat source, and bulk crustal permeabilities of 10-14 to 10-16 m2 (0.1-10 millidarcies). The cases have: 1) a felsic magma heat source that is kept at 900oC for 10,000 years and then allowed to cool; 2) a more permeable, crustal-scale fracture/fault and stockwork zone beneath a 2 km2 Rio Tinto District; and 3) a thermal cracking subroutine with increased permeability from 275-475oC, in keeping with fracture development due to thermal contraction where cool, downwelling seawater interacts with conductively heated rock. Results show that at the higher crustal permeabilities, multiple hydrothermal plumes develop in the subsurface, and hydrothermal venting occurs over broad areas of the paleo - seafloor. At lower crustal permeabilities of 10-16 m2, venting is confined to the Rio Tinto District. An appropriate volume of hydrothermal fluid is vented when the crustal-scale fracture is highly permeable at 10-12 m2; at lower permeabilities, the fracture does not allow enough fluids to rise. The depth to the top of the felsic sill affects venting temperatures in the Rio Tinto District, with higher temperature venting for a shallower sill. In the preferred case, the sill is at 8-10 km depth, and fluids vent at 100-220oC for a period of ~200,000 years. In the absence of tectonic or magmatic

  20. Searching for Life Underground: An Analysis of Remote Sensing Observations of a Drill Core from Rio Tinto, Spain for Mineralogical Indications of Biological Activity

    NASA Technical Reports Server (NTRS)

    Battler, M.; Stoker, C.

    2005-01-01

    Water is unstable on the surface of Mars, and therefore the Martian surface is not likely to support life. It is possible, however, that liquid water exists beneath the surface of Mars, and thus life might also be found in the subsurface. Subsurface life would most likely be microbial, anaerobic, and chemoautotrophic; these types of biospheres on Earth are rare, and not well understood. Finding water and life are high priorities for Mars exploration, and therefore it is important that we learn to explore the subsurface robotically, by drilling. The Mars Analog Rio Tinto Experiment (MARTE), has searched successfully for a subsurface biosphere at Rio Tinto, Spain [1,2,3,4]. The Rio Tinto study site was selected to search for a subsurface biosphere because the extremely low pH and high concentrations of elements such as iron and copper in the Tinto River suggest the presence of a chemoautotrophic biosphere in the subsurface beneath the river. The Rio Tinto has been recognized as an important mineralogical analog to the Sinus Meridiani site on Mars [5].

  1. The relationship among variables in Tinto's conceptual model and attrition of bachelor's degree nursing students.

    PubMed

    Benda, E J

    1991-01-01

    This study examined the relationship among the constructs in Tinto's model of college student retention in a sample of 188 freshmen, 141 sophomores, and 236 junior bachelor's degree nursing students. Data for the independent variables, labeled pre-entry, academic and social institutional, and commitment, were gathered from subjects' American College Testing (ACT) assessments and the 104-item Student Attitude Questionnaire. Data for retention were gathered during a subsequent semester. Results of the t tests and chi 2 analyses determined that there were significant differences between retained and departed students, eg, retained freshmen scored higher than departees on the ACT subscores, Mathematics and Composite, two measures of high school grades, and high school class rank. Retained freshmen were also more likely to choose a major other than nursing at the time of the ACT assessment, perceived more external control from institutional rules and regulations, and were more certain of their ability to pay for their education. Eight pre-entry, four academic, four social-institutional, and nine commitment variables differed significantly in retained and departed freshmen. Subsequently, these variables were examined across academic classes to ascertain whether there were significant differences in retained students. Twelve of the variables differed significantly in retained students, and 13 did not. PMID:2005297

  2. Impact of millennial mining activities on sediments and microfauna of the Tinto River estuary (SW Spain).

    PubMed

    Ruiz, F; Borrego, J; González-Regalado, M L; López González, N; Carro, B; Abad, M

    2008-07-01

    In this paper, we analyze two short cores collected in the Tinto estuary (SW Spain), and describe the palaeoenvironmental evolution of this area during the last two millennia, along with the influence of historical mining activities and recent industrial pollution on sediments and microfauna (foraminifera and ostracoda). Although there were no significant changes in the distribution of microorganisms, a first pollution period (0-150 AD) was recorded in high sediment pollution by Cu in the shallow palaeochannels of the middle estuary. During this period and the following 1700 years, tolerant pioneer species of both foraminifera and ostracoda were found predominantly in the inner, protected areas of the estuary, while the bottom sediments were subjected to high hydrodynamic gradients, and consequently showed lower density and diversity of organisms. In the last 150 years, acid mine drainage processes, introduction of a new mining period, and the polluted inputs derived from two industrial processes resulted in increased heavy metal contamination of the bottom sediments, and corresponding extirpation of ostracodes and restriction of foraminifers to the inner zones of the estuary. PMID:18538354

  3. Enzyme-Cascade Analysis of the Rio Tinto Subsurface Environment: A Biosensor Experiment

    NASA Technical Reports Server (NTRS)

    McKay, David S.; Lynch, Kennda; Wainwright, Norman; Child, Alice; Williams, Kendra; McKay, David; Amils, Ricardo; Gonzalez, Elena; Stoker, Carol

    2004-01-01

    The Portable Test System (PTS), designed & developed by Charles Rivers Laboratories, Inc. (Charleston, SC) is a portable instrument that was designed to perform analysis of enzymatic assays related to rapid assessment of microbial contamination (Wainwright, 2003). The enzymatic cascade of Limulus Amebocyte Lysate (LAL) is known to be one of the most sensitive techniques available for microbial detection, enabling the PTS to be evaluated as a potential life detection instrument for in situ Astrobiology missions. In the summer of 2003 the system was tested as a part of the Mars Astrobiology Research and Technology Experiment (MARTE) ground truth science campaign in the Rio Tinto Analogue environment near Nerva, Spain. The preliminary results show that the PTS analysis correlates well with the contamination control tests and the more traditional lab-based biological assays performed during the MARTE field mission. Further work will be conducted on this research during a second field campaign in 2004 and a technology demonstration of a prototype instrument that includes autonomous sample preparation will occur in 2005.

  4. Novel acid resistance genes from the metagenome of the Tinto River, an extremely acidic environment.

    PubMed

    Guazzaroni, María-Eugenia; Morgante, Verónica; Mirete, Salvador; González-Pastor, José E

    2013-04-01

    Microorganisms that thrive in acidic environments are endowed with specialized molecular mechanisms to survive under this extremely harsh condition. In this work, we performed functional screening of six metagenomic libraries from planktonic and rhizosphere microbial communities of the Tinto River, an extremely acidic environment, to identify genes involved in acid resistance. This approach has revealed 15 different genes conferring acid resistance to Escherichia coli, most of which encoding putative proteins of unknown function or previously described proteins not known to be related to acid resistance. Moreover, we were able to assign function to one unknown and three hypothetical proteins. Among the recovered genes were the ClpXP protease, the transcriptional repressor LexA and nucleic acid-binding proteins such as an RNA-binding protein, HU and Dps. Furthermore, nine of the retrieved genes were cloned and expressed in Pseudomonas putida and Bacillus subtilis and, remarkably, most of them were able to expand the capability of these bacteria to survive under severe acid stress. From this set of genes, four presented a broad-host range as they enhance the acid resistance of the three different organisms tested. These results expand our knowledge about the different strategies used by microorganisms to survive under extremely acid conditions. PMID:23145860

  5. Eukaryotic Organisms in Extreme Acidic Environments, the Río Tinto Case

    NASA Astrophysics Data System (ADS)

    Angeles Aguilera, Angeles

    2013-07-01

    A major issue in microbial ecology is to identify the limits of life for growth and survival, and to understand the molecular mechanisms that define these limits. Thus, interest in the biodiversity and ecology of extreme environments has grown in recent years for several reasons. Some are basic and revolve around the idea that extreme environments are believed to reflect early Earth conditions. Others are related to the biotechnological potential of extremophiles. In this regard, the study of extremely acidic environments has become increasingly important since environmental acidity is often caused by microbial activity. Highly acidic environments are relatively scarce worldwide and are generally associated with volcanic activity or mining operations. For most acidic environments, low pH facilitates metal solubility, and therefore acidic waters tend to have high concentrations of heavy metals. However, highly acidic environments are usually inhabited by acidophilic and acidotolerant eukaryotic microorganisms such as algae, amoebas, ciliates, heliozoan and rotifers, not to mention filamentous fungi and yeasts. Here, we review the general trends concerning the diversity and ecophysiology of eukaryotic acidophilic microorganims, as well as summarize our latest results on this topic in one of the largest extreme acidic rivers, Río Tinto (SW, Spain).

  6. Mars Sulfate Formation Sourced in Sulfide-Enriched Subsurface Fluids: The Rio Tinto Model

    NASA Technical Reports Server (NTRS)

    Fernandez-Remolar, D. C.; Prieto-Ballesteros, O.; Osburn, M. R.; Gomez-Ortiz, D.; Arvidson, R. E.; Morris, R. V.; Ming, D.; Amils, R.; Friendlander, L. R.

    2007-01-01

    The extensive evidence for sulfate deposits on Mars provided by analyses of MER and Mars Express data shows that the sulfur played an essential role in the geochemical cycles of the planet, including reservoirs in the atmosphere, hydro-sphere and geosphere. Overall the data are consistent with a fluvial/lacustrine-evaporative origin of at least some of the sulfate deposits, with mineral precipitation through oversaturation of salty acidic fluids enriched in sulfates. This scenario requires reservoirs of sulfur and associated cations, as well as an acidic and oxidizing hydrochemistry which could be provided by surface and subsurface catching of meteoric waters resulting in the presence of sulfur-bearing gases and steam photochemistry. In this work we suggest a new scenario for the extensive generation of sulfates in Mars based on the observation of seasonal changes in the redox and pH of subsurface waters enriched in sulfur that supply the acidic Mars process analog of Rio Tinto. This model considers the long-term subsurface storage of sulfur during most of Noachian and its release from the late Noachian to Hesperian time through weathering by meteoric fluids that would acidify and oxidize the sulfur bearing compounds stored in the subsurface.

  7. The retention of first-generation college students in STEM: An extension of Tinto's longitudinal model

    NASA Astrophysics Data System (ADS)

    Uche, Ada Rosemary

    In the current technologically advanced global economy, the role of human capital and education cannot be over-emphasized. Since almost all great inventions in the world have a scientific or technological foundation, having a skilled workforce is imperative for any nation's economic growth. Currently, large segments of the United States' population are underrepresented in the attainment of science, technology, engineering, and math (STEM) degrees, and in the STEM professions. Scholars, educators, policy-makers, and employers are concerned about the decline in student enrollment and graduation from STEM disciplines. This trend is especially problematic for first-generation college students. This study uses both quantitative and qualitative methods to assess the factors that predict the retention of first-generation college students in the STEM majors. It employs Tinto's longitudinal model (1993) as a conceptual framework to predict STEM retention for first-generation college students. The analysis uses the Beginning Post-secondary Students study (BPS 04/09) data and Roots of STEM qualitative data to investigate the role of first-generation status in STEM major retention. Results indicate that upper levels of achievement in high school math have a significant effect on first-generation status in STEM outcomes.

  8. Field rates for natural attenuation of arsenic in Tinto Santa Rosa acid mine drainage (SW Spain).

    PubMed

    Asta, Maria P; Ayora, Carlos; Acero, Patricia; Cama, Jordi

    2010-05-15

    Reactive transport modelling of the main processes related to the arsenic natural attenuation observed in the acid mine drainage (AMD) impacted stream of Tinto Santa Rosa (SW Spain) was performed. Despite the simplicity of the kinetic expressions used to deal with arsenic attenuation processes, the model reproduced successfully the major chemical trends observed along the acid discharge. Results indicated that the rate of ferrous iron oxidation was similar to the one obtained in earlier field studies in which microbial catalysis is reported to occur. With regard to the scaled arsenic oxidation rate, it is one order of magnitude faster than the values obtained under laboratory conditions suggesting the existence of a catalytic agent in the natural system. Schwertmannite precipitation rate, which was represented by a simple kinetic expression relying on Fe(III) and pH, was in the range calculated for other AMD impacted sites. Finally, the obtained distribution coefficients used for representing arsenic sorption onto Fe(III) precipitates were lower than those deduced from reported laboratory data. This discrepancy is attributed to a decrease in the schwertmannite arsenate sorption capacity as sulphate increases in the solution. PMID:20153577

  9. Metal uptake and distribution in cultured seedlings of Nerium oleander L. (Apocynaceae) from the Río Tinto (Huelva, Spain).

    PubMed

    Franco, Alejandro; Rufo, Lourdes; Zuluaga, Javier; de la Fuente, Vicenta

    2013-10-01

    Nerium oleander L. (Apocynaceae) is a micro-nano phanerophyte that grows in the riverbanks of the Río Tinto basin (Southwest Iberian Peninsula). The waters and soils of the Río Tinto area are highly acidic and have high concentrations of heavy metals. In this environment, N. oleander naturally grows in both extreme acidic (EA) and less extreme acidic (LEA) water courses, excluding, and bioindicating certain metals. In this work, we compared and evaluated the accumulation preferences and capacities, the distribution and processes of biomineralization of metals (Fe, Cu, Zn, Mn, Mg, Ca) in the first stages of growth of EA and LEA oleanders by means of inductively coupled plasma-mass spectrometry, scanning electron microscopy, and energy dispersive X-ray analyzer analysis. Seeds from both environments were grown and treated with a self-made solution simulating the most extreme red waters from the Río Tinto. LEA plants drastically reduces the metal uptake at the beginning, but later reactivates the uptake reaching concentration values in the same range as the EA plants. The results showed high Mn, Zn and Mg concentrations, accumulation of Fe and Cu in plants from both environments, differing from the metal concentrations of field-grown oleanders. Iron bioformations with traces of other metals were present inside and over epidermal cells and inside vascular cells of stems and roots. They were absent of leaves. The accumulation properties of N. oleander in its early stages of development make it a species to take in consideration in phytoremediation processes but optimized conditions are needed to ensure enough biomass production. PMID:23892697

  10. Underground Habitats in the Río Tinto Basin: A Model for Subsurface Life Habitats on Mars

    NASA Astrophysics Data System (ADS)

    Fernández-Remolar, David C.; Prieto-Ballesteros, Olga; Rodríguez, Nuria; Gómez, Felipe; Amils, Ricardo; Gómez-Elvira, Javier; Stoker, Carol R.

    2008-10-01

    A search for evidence of cryptic life in the subsurface region of a fractured Paleozoic volcanosedimentary deposit near the source waters of the Río Tinto River (Iberian pyrite belt, southwest Spain) was carried out by Mars Astrobiology Research and Technology Experiment (MARTE) project investigators in 2003 and 2004. This conventional deep-drilling experiment is referred to as the MARTE ground truth drilling project. Boreholes were drilled at three sites, and samples from extracted cores were analyzed with light microscopy, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy. Core leachates were analyzed with ion chromatography, and borehole fluids were analyzed with ion and gas chromatography. Key variables of the groundwater system (e.g. , pO2, pH, and salinity) exhibit huge ranges probably due to surficial oxygenation of overall reducing waters, physical mixing of waters, and biologically mediated water-rock interactions. Mineral distribution is mainly driven by the pH of subsurface solutions, which range from highly acidic to neutral. Borehole fluids contain dissolved gases such as CO2, CH4, and H2. SEM-EDS analyses of core samples revealed evidence of microbes attacking pyrite. The Río Tinto alteration mechanisms may be similar to subsurface weathering of the martian crust and provide insights into the possible (bio)geochemical cycles that may have accompanied underground habitats in extensive early Mars volcanic regions and associated sulfide ores.

  11. Scientific results and lessons learned from an integrated crewed Mars exploration simulation at the Rio Tinto Mars analogue site

    NASA Astrophysics Data System (ADS)

    Orgel, Csilla; Kereszturi, Ákos; Váczi, Tamás; Groemer, Gernot; Sattler, Birgit

    2014-02-01

    Between 15 and 25 April 2011 in the framework of the PolAres programme of the Austrian Space Forum, a five-day field test of the Aouda.X spacesuit simulator was conducted at the Rio Tinto Mars-analogue site in southern Spain. The field crew was supported by a full-scale Mission Control Center (MCC) in Innsbruck, Austria. The field telemetry data were relayed to the MCC, enabling a Remote Science Support (RSS) team to study field data in near-real-time and adjust the flight planning in a flexible manner. We report on the experiences in the field of robotics, geophysics (Ground Penetrating Radar) and geology as well as life sciences in a simulated spaceflight operational environment. Extravehicular Activity (EVA) maps had been prepared using Google Earth and aerial images. The Rio Tinto mining area offers an excellent location for Mars analogue simulations. It is recognised as a terrestrial Mars analogue site because of the presence of jarosite and related sulphates, which have been identified by the NASA Mars Exploration Rover "Opportunity" in the El Capitan region of Meridiani Planum on Mars. The acidic, high ferric-sulphate content water of Rio Tinto is also considered as a possible analogue in astrobiology regarding the analysis of ferric sulphate related biochemical pathways and produced biomarkers. During our Mars simulation, 18 different types of soil and rock samples were collected by the spacesuit tester. The Raman results confirm the presence of minerals expected, such as jarosite, different Fe oxides and oxi-hydroxides, pyrite and complex Mg and Ca sulphates. Eight science experiments were conducted in the field. In this contribution first we list the important findings during the management and realisation of tests, and also a first summary of the scientific results. Based on these experiences suggestions for future analogue work are also summarised. We finish with recommendations for future field missions, including the preparation of the experiments

  12. A Search for Life in the Subsurface At Rio Tinto Spain, An Analog To Searching For Life On Mars.

    NASA Astrophysics Data System (ADS)

    Stoker, C. R.

    2003-12-01

    Most familiar life forms on Earth live in the surface biosphere where liquid water, sunlight, and the essential chemical elements for life are abundant. However, such environments are not found on Mars or anywhere else in the solar system. On Mars, the surface environmental conditions of pressure and temperature prevent formation of liquid water. Furthermore, conditions at the Martian surface are unfavorable to life due to intense ultraviolet radiation and strong oxidizing compounds that destroy organic compounds. However, subsurface liquid water on Mars has been predicted on theoretical grounds. The recent discovery of near surface ground ice by the Mars Odyssey mission, and the abundant evidence for recent Gully features observed by the Mars Global Surveyor mission strengthen the case for subsurface liquid water on Mars. Thus, the strategy for searching for life on Mars points to drilling to the depth of liquid water, bringing samples to the surface and analyzing them with instrumentation to detect in situ organisms and biomarker compounds. The MARTE (Mars Astrobiology Research and Technology Experiment) project is a field experiment focused on searching for a hypothesized subsurface anaerobic chemoautotrophic biosphere in the region of the Rio Tinto, a river in southwestern Spain while also demonstrating technology relevant to searching for a subsurface biosphere on Mars. The Tinto river is located in the Iberian Pyrite belt, one of the largest deposits of sulfide minerals in the world. The surface (river) system is an acidic extreme environment produced and maintained by microbes that metabolize sulfide minerals and produce sulfuric acid as a byproduct. Evidence suggests that the river is a surface manifestation of an underground biochemical reactor. Organisms found in the river are capable of chemoautotrophic metabolism using sulfide and ferric iron mineral substrates, suggesting these organisms could thrive in groundwater which is the source of the Rio Tinto

  13. Orbital Evidence for Clay and Acidic Sulfate Assemblages on Mars and Mineralogical Analogs from Rio Tinto, Spain

    NASA Astrophysics Data System (ADS)

    Kaplan, H. H.; Milliken, R.; Fernandez-Remolar, D. C.; Amils, R.; Robertson, K.; Knoll, A. H.

    2015-12-01

    A suite of enigmatic near-infrared reflectance spectra with a 'doublet' absorption between 2.2 and 2.3 µm is observed in CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) hyperspectral images over Ius and Melas Chasma on Mars. The doublet-bearing deposits are found alongside other hydrated minerals including clays, sulfates, and silica, but the mineral(s) responsible for the spectral signature has yet to be identified. Reflectance spectra of rocks and sediments at Rio Tinto, Spain exhibit similar absorptions at airborne, field, and lab spatial scales. Coupled X-ray diffraction and reflectance spectra of these terrestrial examples indicate the absorption arises from a mixture of jarosite, a ferric sulfate, and Al-phyllosilicates (illite/muscovite). Detailed analysis of CRISM data over Ius and Melas Chasma suggests that these deposits also contain mixtures of jarosite and Al-phyllosilicate, where the latter may include halloysite, kaolinite and/or montmorillonite in addition to illite/muscovite. This interpretation is supported because (1) the two absorptions in the doublet feature vary independently, implying the presence of two or more phases, (2) the position of the absorptions is consistent with Al-OH and Fe-OH vibrations in both the Rio Tinto and CRISM spectra and (3) Al-phyllosilicates and jarosite are identified separately in nearby regions. Multiple formation mechanisms are proposed based on stratigraphy in Ius Chasma, where the strength of absorptions varies within a single stratigraphic unit as well as between different units. Mechanisms include authigenic formation of jarosite, which would indicate locally acidic and oxidizing conditions, mixed with detrial Al-phyllosilicates, or authigenic formation of Al-phyllosilicates and jarosite. Each implies different conditions in terms of aqueous geochemistry, redox, and sediment transport. Results from the field, lab, and CRISM analysis will be presented to discuss how placing these spectral

  14. Río Tinto sedimentary mineral assemblages: A terrestrial perspective that suggests some formation pathways of phyllosilicates on Mars

    NASA Astrophysics Data System (ADS)

    Fernández-Remolar, D. C.; Prieto-Ballesteros, O.; Gómez-Ortíz, D.; Fernández-Sampedro, M.; Sarrazin, P.; Gailhanou, M.; Amils, R.

    2011-01-01

    The presence of extensive phyllosilicate deposits from the early Noachian of Mars are often interpreted as having formed from neutral to subalkaline solutions. In this paper we examine the Río Tinto fluvial basin, an early Mars analog, that hosts clay production and sedimentation along the entire course of the river. At Río Tinto, phyllosilicate minerals including clays and micas are sourced by volcanosedimentary bedrock of rhyolitic and andesitic composition affected by Carboniferous hydrothermal alteration. Pleistocene to modern acidic weathering of those materials chemically altered the volcanic and sedimentary materials to K/Na-clay-(montmorillonite/smectites)-kaolinite assemblages in paleosoils and fractures while physical weathering degrades phyllosilicates more resistant to acidic attack. During the wet season, phyllosilicates are eroded, transported and deposited from both acidic headwaters and neutral tributaries. During the dry season, sulfates and nanophase oxyhydroxides co-precipitate. Late summer storms that cause fast flooding events mix illite, quartz, feldspars, iron oxides and other minerals in fluvial deposits where these minerals are stabilized and aggrade until the following wet season. As a result, chemical precipitates, primary phyllosilicates and secondary clays form mineral admixtures that explain the compositional diversity of the fluvial deposits. These deposits reveal the persistence of smectites, whose occurrence is explained given that the reaction kinetics under acidic conditions of degradation is lowered by seasonal discharges of the river. The longevity of phyllosilicate minerals within fluvial deposits depends on climatic and geochemical conditions and processes which are in turn are correlated to temperature, persistence of water, hydrological cycling, hydrogeochemistry and composition of the source materials in the basement. These parameters are universal and have to be characterized in order to understand the distribution of

  15. Mars Analog Research and Technology Experiment (MARTE): A Simulated Mars Drilling Mission to Search for Subsurface Life at the Rio Tinto, Spain

    NASA Technical Reports Server (NTRS)

    Stoker, Carol; Lemke, Larry; Mandell, Humboldt; McKay, David; George, Jeffrey; Gomez-Alvera, Javier; Amils, Ricardo; Stevens, Todd; Miller, David

    2003-01-01

    The MARTE (Mars Astrobiology Research and Technology Experiment) project was selected by the new NASA ASTEP program, which supports field experiments having an equal emphasis on Astrobiology science and technology development relevant to future Astrobiology missions. MARTE will search for a hypothesized subsurface anaerobic chemoautotrophic biosphere in the region of the Tinto River in southwestern Spain while also demonstrating technology needed to search for a subsurface biosphere on Mars. The experiment is informed by the strategy for searching for life on Mars.

  16. RIO Tinto Faulted Volcanosedimentary Deposits as Analog Habitats for Extant Subsurface Biospheres on Mars: A Synthesis of the MARTE Drilling Project Geobiology Results

    NASA Technical Reports Server (NTRS)

    Fernandez-Remolar, D. C.; Prieto-Ballesteros, O.; Rodriquez, N.; Davila, F.; Stevens, T.; Amils, R.; Gomez-Elvira, J.; Stoker, C.

    2005-01-01

    Geochemistry and mineralogy on Mars surface characterized by the MER Opportunity Rover suggest that early Mars hosted acidic environments in the Meridiani Planum region [1, 2]. Such extreme paleoenvironments have been suggested to be a regional expression of the global Mars geological cycle that induced acidic conditions by sulfur complexation and iron buffering of aqueous solutions [3]. Under these assumptions, underground reservoirs of acidic brines and, thereby, putative acidic cryptobiospheres, may be expected. The MARTE project [4, 5] has performed a drilling campaign to search for acidic and anaerobic biospheres in R o Tinto basement [6] that may be analogs of these hypothetical communities occurring in cryptic habitats of Mars. This Rio Tinto geological region is characterized by the occurrence of huge metallic deposits of iron sulfides [7]. Late intensive diagenesis of rocks driven by a compressive regimen [8] largely reduced the porosity of rocks and induced a cortical thickening through thrusting and inverse faulting and folding. Such structures play an essential role in transporting and storing water underground as any other aquifers do in the Earth. Once the underground water reservoirs of the Ro Tinto basement contact the hydrothermal pyrite deposits, acidic brines are produced by the release of sulfates and iron through the oxidation of sulfides [9].

  17. Mineralogical In-situ Investigation of Acid-Sulfate Samples from the Rio Tinto River, Spain, with a Portable XRD/XRF Instrument

    NASA Technical Reports Server (NTRS)

    Sarrazin, P.; Ming, D. W.; Morris, R. V.; Fernandez-Remolar, D.; Amils, R.; Arvidson, R. E.; Blake, D.; Bish, D. L.

    2007-01-01

    A field campaign was organized in September 2006 by Centro de Astobiologica (Spain) and Washington University (St Louis, USA) for the geological study of the Rio Tinto river bed sediments using a suite of in-situ instruments comprising an ASD reflectance spectrometer, an emission spectrometer, panoramic and close-up color imaging cameras, a life detection system and NASA's CheMin 4 XRD/XRF prototype. The primary objectives of the field campaign were to study the geology of the site and test the potential of the instrument suite in an astrobiological investigation context for future Mars surface robotic missions. The results of the overall campaign will be presented elsewhere. This paper focuses on the results of the XRD/XRF instrument deployment. The specific objectives of the CheMin 4 prototype in Rio Tinto were to 1) characterize the mineralogy of efflorescent salts in their native environments; 2) analyze the mineralogy of salts and oxides from the modern environment to terraces formed earlier as part of the Rio Tinto evaporative system; and 3) map the transition from hematite-dominated terraces to the mixed goethite/salt-bearing terraces where biosignatures are best preserved.

  18. The preservation and degradation of filamentous bacteria and biomolecules within iron oxide deposits at Rio Tinto, Spain.

    PubMed

    Preston, L J; Shuster, J; Fernández-Remolar, D; Banerjee, N R; Osinski, G R; Southam, G

    2011-05-01

    One of the keys to understanding and identifying life on other planets is to study the preservation of organic compounds and their precursor micro-organisms on Earth. Rio Tinto in southwestern Spain is a well documented site of microbial preservation within iron sulphates and iron oxides over a period of 2.1 Ma. This study has investigated the preservation of filamentous iron oxidising bacteria and organics through optical microscopy, scanning electron microscopy (SEM) and Fourier transform infra-red (FTIR) spectroscopy, from laboratory cultures of natural samples to contemporary natural materials to million-year old river terraces. Up to 40% elemental carbon and >7% nitrogen has been identified within microbial filaments and cell clusters in all samples through SEM EDS analyses. FTIR spectroscopy identified C-H(x) absorption bands between 2960 and 2800 cm(-1), Amide I and II absorption bands at 1656 and 1535 cm(-1), respectively and functional group vibrations from within nucleic acids at 917, 1016 and 1124 cm(-1). Absorption bands tracing the diagenetic transformation of jarosite to goethite to hematite through the samples are also identified. This combination of mineralogy, microbial morphology and biomolecular evidence allows us to further understand how organic fossils are created and preserved in iron-rich environments, and ultimately will aid in the search for the earliest life on Earth and potential organics on Mars. PMID:21443552

  19. Microbial Diversity in Anaerobic Sediments at Río Tinto, a Naturally Acidic Environment with a High Heavy Metal Content▿†

    PubMed Central

    Sánchez-Andrea, Irene; Rodríguez, Nuria; Amils, Ricardo; Sanz, José Luis

    2011-01-01

    The Tinto River is an extreme environment located at the core of the Iberian Pyritic Belt (IPB). It is an unusual ecosystem due to its size (100 km long), constant acidic pH (mean pH, 2.3), and high concentration of heavy metals, iron, and sulfate in its waters, characteristics that make the Tinto River Basin comparable to acidic mine drainage (AMD) systems. In this paper we present an extensive survey of the Tinto River sediment microbiota using two culture-independent approaches: denaturing gradient gel electrophoresis and cloning of 16S rRNA genes. The taxonomic affiliation of the Bacteria showed a high degree of biodiversity, falling into 5 different phyla: Proteobacteria, Firmicutes, Bacteroidetes, Acidobacteria, and Actinobacteria; meanwhile, all the Archaea were affiliated with the order Thermoplasmatales. Microorganisms involved in the iron (Acidithiobacillus ferrooxidans, Sulfobacillus spp., Ferroplasma spp., etc.), sulfur (Desulfurella spp., Desulfosporosinus spp., Thermodesulfobium spp., etc.), and carbon (Acidiphilium spp., Bacillus spp., Clostridium spp., Acidobacterium spp., etc.) cycles were identified, and their distribution was correlated with physicochemical parameters of the sediments. Ferric iron was the main electron acceptor for the oxidation of organic matter in the most acid and oxidizing layers, so acidophilic facultative Fe(III)-reducing bacteria appeared widely in the clone libraries. With increasing pH, the solubility of iron decreases and sulfate-reducing bacteria become dominant, with the ecological role of methanogens being insignificant. Considering the identified microorganisms—which, according to the rarefaction curves and Good's coverage values, cover almost all of the diversity—and their corresponding metabolism, we suggest a model of the iron, sulfur, and organic matter cycles in AMD-related sediments. PMID:21724883

  20. Classification of Modern and Old Río Tinto Sedimentary Deposits Through the Biomolecular Record Using a Life Marker Biochip: Implications for Detecting Life on Mars

    NASA Astrophysics Data System (ADS)

    Parro, Victor; Fernández-Remolar, David; Rodríguez-Manfredi, José A.; Cruz-Gil, Patricia; Rivas, Luis A.; Ruiz-Bermejo, Marta; Moreno-Paz, Mercedes; García-Villadangos, Miriam; Gómez-Ortiz, David; Blanco-López, Yolanda; Menor-Salván, César; Prieto-Ballesteros, Olga; Gómez-Elvira, Javier

    2011-01-01

    The particular mineralogy formed in the acidic conditions of the Río Tinto has proven to be a first-order analogue for the acid-sulfate aqueous environments of Mars. Therefore, studies about the formation and preservation of biosignatures in the Río Tinto will provide insights into equivalent processes on Mars. We characterized the biomolecular patterns recorded in samples of modern and old fluvial sediments along a segment of the river by means of an antibody microarray containing more than 200 antibodies (LDCHIP200, for Life Detector Chip) against whole microorganisms, universal biomolecules, or environmental extracts. Samples containing 0.3-0.5g of solid material were automatically analyzed in situ by the Signs Of LIfe Detector instrument (SOLID2), and the results were corroborated by extensive analysis in the laboratory. Positive antigen-antibody reactions indicated the presence of microbial strains or high-molecular-weight biopolymers that originated from them. The LDCHIP200 results were quantified and subjected to a multivariate analysis for immunoprofiling. We associated similar immunopatterns, and biomolecular markers, to samples with similar sedimentary age. Phyllosilicate-rich samples from modern fluvial sediments gave strong positive reactions with antibodies against bacteria of the genus Acidithiobacillus and against biochemical extracts from Río Tinto sediments and biofilms. These samples contained high amounts of sugars (mostly polysaccharides) with monosaccharides like glucose, rhamnose, fucose, and so on. By contrast, the older deposits, which are a mix of clastic sands and evaporites, showed only a few positives with LDCHIP200, consistent with lower protein and sugar content. We conclude that LDCHIP200 results can establish a correlation between microenvironments, diagenetic stages, and age with the biomarker profile associated with a sample. Our results would help in the search for putative martian biomarkers in acidic deposits with similar

  1. Eukaryotic Community Distribution and Its Relationship to Water Physicochemical Parameters in an Extreme Acidic Environment, Río Tinto (Southwestern Spain)†

    PubMed Central

    Aguilera, Angeles; Manrubia, Susanna C.; Gómez, Felipe; Rodríguez, Nuria; Amils, Ricardo

    2006-01-01

    The correlation between water physicochemical parameters and eukaryotic benthic composition was examined in Río Tinto. Principal component analysis showed a high inverse relationship between pH and most of the heavy metals analyzed as well as Dunaliella sp., while Chlamydomonas sp. abundance was positively related. Zn, Cu, and Ni clustered together and showed a strong inverse correlation with the diversity coefficient and most of the species analyzed. These eukaryotic communities seem to be more influenced by the presence of heavy metals than by the pH. PMID:16885283

  2. Orbital evidence for clay and acidic sulfate assemblages on Mars based on mineralogical analogs from Rio Tinto, Spain

    NASA Astrophysics Data System (ADS)

    Kaplan, Hannah H.; Milliken, Ralph E.; Fernández-Remolar, David; Amils, Ricardo; Robertson, Kevin; Knoll, Andrew H.

    2016-09-01

    Outcrops of hydrated minerals are widespread across the surface of Mars, with clay minerals and sulfates being commonly identified phases. Orbitally-based reflectance spectra are often used to classify these hydrated components in terms of a single mineralogy, although most surfaces likely contain multiple minerals that have the potential to record local geochemical conditions and processes. Reflectance spectra for previously identified deposits in Ius and Melas Chasma within the Valles Marineris, Mars, exhibit an enigmatic feature with two distinct absorptions between 2.2 and 2.3 μm. This spectral 'doublet' feature is proposed to result from a mixture of hydrated minerals, although the identity of the minerals has remained ambiguous. Here we demonstrate that similar spectral doublet features are observed in airborne, field, and laboratory reflectance spectra of rock and sediment samples from Rio Tinto, Spain. Combined visible-near infrared reflectance spectra and X-ray diffraction measurements of these samples reveal that the doublet feature arises from a mixture of Al-phyllosilicate (illite or muscovite) and jarosite. Analyses of orbital data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) shows that the martian spectral equivalents are also consistent with mixtures of Al-phyllosilicates and jarosite, where the Al-phyllosilicate may also include kaolinite and/or halloysite. A case study for a region within Ius Chasma demonstrates that the relative proportions of the Al-phyllosilicate(s) and jarosite vary within one stratigraphic unit as well as between stratigraphic units. The former observation suggests that the jarosite may be a diagenetic (authigenic) product and thus indicative of local pH and redox conditions, whereas the latter observation may be consistent with variations in sediment flux and/or fluid chemistry during sediment deposition.

  3. Acid-sulfate mixtures from Río Tinto, Spain: Spectral masking relationships and implications for Mars

    NASA Astrophysics Data System (ADS)

    Cull-Hearth, Selby; van Venrooy, Alexis; Caroline Clark, M.; Cvitkovic, Adriana

    2016-06-01

    Most sulfate minerals form only in specific pH conditions, making them useful markers of past environmental conditions on Mars. However, interpreting past environments requires a full understanding of the suite of minerals present, a task which is complicated by the fact that some minerals can spectrally mask others in the visible- to near-infrared (VNIR, 0.4-2.5 μm). Here, we report VNIR spectra of two-phase mineral combinations obtained from the Río Tinto acid mine drainage system of southern Spain. Our results show that in VNIR reflectance spectroscopy: (1) copiapite masks rhomboclase and partially masks melanterite; (2) coquimbite masks copiapite, jarosite, and rhomboclase; (3) at wavelengths <1.2 μm, gypsum is consistently masked by copiapite, jarosite, and melanterite, though at wavelengths >1.2 μm, gypsum masks these minerals; (4) unlike copiapite, jarosite, or melanterite, halotrichite masks gypsum completely; (5) in two-phase mixtures of copiapite and jarosite, both phases are evident. No consistent VNIR relationship is observed in two-phase mixtures of melanterite and halotrichite, suggesting that microtextures are likely more important than optical properties in determining VNIR reflectance. We also show that the shorter wavelengths are more sensitive to the presence of both phases: even in mixtures where one phase is masking another, both phases usually impact absorptions in the 0.75-0.95 μm region. This region may therefore be useful in remotely identifying mineral mixtures on Mars. These results have implications for several regions on Mars: most notably, they imply that the jarosite exposures reported at Mawrth Vallis may be jarosite-copiapite mixtures.

  4. How eukaryotic algae can adapt to the Spain's Rio Tinto: a neo-Darwinian proposal for rapid adaptation to an extremely hostile ecosystem.

    PubMed

    Costas, Eduardo; Flores-Moya, Antonio; Perdigones, Nieves; Maneiro, Emilia; Blanco, José Luis; García, Marta Eulalia; López-Rodas, Victoria

    2007-01-01

    Microalgae contributed 60% of the total biomass in the extremely hostile (pH 2 and metal-rich waters) environment of Rio Tinto (which is used as a model for the astrobiology of Mars). These algae are closely related to nonextreme lineages, suggesting that adaptation to Rio Tinto water (RTW) must occur rapidly. Fitness from both the microalga Dictyosphaerium chlorelloides and the cyanobacterium Microcystis aeruginosa was inhibited when they were cultured in RTW. After further incubation for several weeks, D. chlorelloides survived, as a result of the growth of a variant that was resistant to RTW, but RTW-resistant cells did not appear in M. aeruginosa. A Luria-Delbrück fluctuation test revealed that D. chlorelloides RTW-resistant cells arose randomly by rare spontaneous mutations before the RTW exposure (1.38 x 10(-6) mutants per cell division). The mutants with a diminished fitness are maintained in nonextreme waters as the result of a balance between new RTW-resistant cells arising by mutation and RTW-resistant mutants eliminated by natural selection (equilibrium at c. 15 RTW-resistant per 10(7) wild-type cells). Rapid adaptation of eukaryotic algae to RTW could be the result of selection of RTW-resistant mutants occurring spontaneously in nonextreme populations that arrived fortuitously at the river in the past, or in the present continuously. PMID:17587381

  5. Mobility of Po and U-isotopes under acid mine drainage conditions: an experimental approach with samples from Río Tinto area (SW Spain).

    PubMed

    Barbero, L; Gázquez, M J; Bolívar, J P; Casas-Ruiz, M; Hierro, A; Baskaran, M; Ketterer, M E

    2014-12-01

    Under acid mine drainage (AMD) conditions, the solubilities and mobilities of many elements are vastly different from conditions prevailing in most natural waters. Studies are underway in the Río Tinto area (Iberian Pyrite Belt), in order to understand the behavior and mobility of long-lived U-series radionuclides under AMD conditions. A set of leaching experiments utilizing typical country rocks from the Tinto River basin, waste rock pile composite materials, iron-rich riverbed sediments and gossan (weathered naturally rock) were performed towards this purpose. Initial leaching experiments using distilled water kept in contact with solid material for 300, 100, 50 and 1 h resulted in very low concentrations of U with (234)U/(238)U activity ratios close to equilibrium and activity concentrations of (210)Po < 0.03 mBq/g. Leaching experiments performed with sulfuric acid media (0.1 and 0.01 M), and contact times between the solid and solution for 24 h were conducted to quantify the amount of U-isotopes and (210)Po leached, and the radioactive disequilibria generated between the radionuclides in the leachate. These experiments show that Po mobility in acidic conditions (pH around 1-2) is very low, with (210)Po activity in the leachate to be 6% in average for the solid sample. By contrast, mobility of U-isotopes is higher than that of Po, around 1.2%. PMID:24308958

  6. Comparative microbial ecology of the water column of an extreme acidic pit lake, Nuestra Señora del Carmen, and the Río Tinto basin (Iberian Pyrite Belt).

    PubMed

    González-Toril, Elena; Santofimia, Esther; López-Pamo, Enrique; García-Moyano, Antonio; Aguilera, Ángeles; Amils, Ricardo

    2014-12-01

    The Iberian Pyrite Belt, located in Southwestern Spain, represents one of the world's largest accumulations of mine wastes and acid mine drainages. This study reports the comparative microbial ecology of the water column of Nuestra Señora del Carmen acid pit lake with the extreme acidic Río Tinto basin. The canonical correspondence analysis identified members of the Leptospirillum, Acidiphilium, Metallibacterium, Acidithiobacillus, Ferrimicrobium and Acidisphaera genera as the most representative microorganisms of both ecosystems. The presence of archaeal members is scarce in both systems. Only sequences clustering with the Thermoplasmata have been retrieved in the bottom layer of Nuestra Señora del Carmen and one station of Río Tinto. Although the photosynthetically active radiation values measured in this lake upper layer were low, they were sufficient to activate photosynthesis in acidophilic microorganisms. All identified photosynthetic microorganisms in Nuestra Señora del Carmen (members of the Chlamydomonas, Zygnemopsis and Klebsormidium genera) are major members of the photosynthetic eukaryotic community characterized in Río Tinto basin. This study demonstrates a close relationship between the microbial diversity of Nuestra Señora del Carmen pit lake and the diversity detected in the Río Tinto basin, which underlain the influence of the shared mineral substrates in the microbial ecology of these ecosystems. PMID:26421738

  7. Science results from a Mars drilling simulation (Río Tinto, Spain) and ground truth for remote science observations.

    PubMed

    Bonaccorsi, Rosalba; Stoker, Carol R

    2008-10-01

    Science results from a field-simulated lander payload and post-mission laboratory investigations provided "ground truth" to interpret remote science observations made as part of the 2005 Mars Astrobiology Research and Technology Experiment (MARTE) drilling mission simulation. The experiment was successful in detecting evidence for life, habitability, and preservation potential of organics in a relevant astrobiological analogue of Mars. SCIENCE RESULTS: Borehole 7 was drilled near the Río Tinto headwaters at Peña de Hierro (Spain) in the upper oxidized remnant of an acid rock drainage system. Analysis of 29 cores (215 cm of core was recovered from 606 cm penetrated depth) revealed a matrix of goethite- (42-94%) and hematite-rich (47-87%) rocks with pockets of phyllosilicates (47-74%) and fine- to coarse-grained loose material. Post-mission X-ray diffraction (XRD) analysis confirmed the range of hematite:goethite mixtures that were visually recognizable (approximately 1:1, approximately 1:2, and approximately 1:3 mixtures displayed a yellowish-red color whereas 3:1 mixtures displayed a dark reddish-brown color). Organic carbon was poorly preserved in hematite/goethite-rich materials (C(org) <0.05 wt %) beneath the biologically active organic-rich soil horizon (C(org) approximately 3-11 wt %) in contrast to the phyllosilicate-rich zones (C(org) approximately 0.23 wt %). GROUND TRUTH VS. REMOTE SCIENCE ANALYSIS: Laboratory-based analytical results were compared to the analyses obtained by a Remote Science Team (RST) using a blind protocol. Ferric iron phases, lithostratigraphy, and inferred geologic history were correctly identified by the RST with the exception of phyllosilicate-rich materials that were misinterpreted as weathered igneous rock. Adenosine 5'-triphosphate (ATP) luminometry, a tool available to the RST, revealed ATP amounts above background noise, i.e., 278-876 Relative Luminosity Units (RLUs) in only 6 cores, whereas organic carbon was detected in all

  8. Science Results from a Mars Drilling Simulation (Río Tinto, Spain) and Ground Truth for Remote Science Observations

    NASA Astrophysics Data System (ADS)

    Bonaccorsi, Rosalba; Stoker, Carol R.

    2008-10-01

    Science results from a field-simulated lander payload and post-mission laboratory investigations provided "ground truth" to interpret remote science observations made as part of the 2005 Mars Astrobiology Research and Technology Experiment (MARTE) drilling mission simulation. The experiment was successful in detecting evidence for life, habitability, and preservation potential of organics in a relevant astrobiological analogue of Mars. Science results. Borehole 7 was drilled near the Río Tinto headwaters at Peña de Hierro (Spain) in the upper oxidized remnant of an acid rock drainage system. Analysis of 29 cores (215 cm of core was recovered from 606 cm penetrated depth) revealed a matrix of goethite- (42-94%) and hematite-rich (47-87%) rocks with pockets of phyllosilicates (47-74%) and fine- to coarse-grained loose material. Post-mission X-ray diffraction (XRD) analysis confirmed the range of hematite:goethite mixtures that were visually recognizable (˜1:1, ˜1:2, and ˜1:3 mixtures displayed a yellowish-red color whereas 3:1 mixtures displayed a dark reddish-brown color). Organic carbon was poorly preserved in hematite/goethite-rich materials (Corg <0.05 wt %) beneath the biologically active organic-rich soil horizon (Corg ˜3-11 wt %) in contrast to the phyllosilicate-rich zones (Corg ˜0.23 wt %). Ground truth vs. remote science analysis. Laboratory-based analytical results were compared to the analyses obtained by a Remote Science Team (RST) using a blind protocol. Ferric iron phases, lithostratigraphy, and inferred geologic history were correctly identified by the RST with the exception of phyllosilicate-rich materials that were misinterpreted as weathered igneous rock. Adenosine 5‧-triphosphate (ATP) luminometry, a tool available to the RST, revealed ATP amounts above background noise, i.e., 278-876 Relative Luminosity Units (RLUs) in only 6 cores, whereas organic carbon was detected in all cores. Our manned vs. remote observations based on automated

  9. A description of how metal pollution occurs in the Tinto-Odiel rias (Huelva-Spain) through the application of cluster analysis.

    PubMed

    Grande, J A; Borrego, J; Morales, J A; de la Torre, M L

    2003-04-01

    In the last few decades, the study of space-time distribution and variations of heavy metals in estuaries has been extensively studied as an environmental indicator. In the case described here, the combination of acid water from mines, industrial effluents and sea water plays a determining role in the evolutionary process of the chemical makeup of the water in the estuary of the Tinto and Odiel Rivers, located in the southwest of the Iberian Peninsula. Based on the statistical treatment of the data from the analysis of the water samples from this system, which has been affected by processes of industrial and mining pollution, the 16 variables analyzed can be grouped into two large families. Each family presents high, positive Pearson r values that suggest common origins (fluvial or sea) for the pollutants present in the water analyzed and allow their subsequent contrast through cluster analysis. PMID:12705921

  10. Some Ecological Mechanisms to Generate Habitability in Planetary Subsurface Areas by Chemolithotrophic Communities: The Ro Tinto Subsurface Ecosystem as a Model System

    NASA Astrophysics Data System (ADS)

    Fernández-Remolar, David C.; Gómez, Felipe; Prieto-Ballesteros, Olga; Schelble, Rachel T.; Rodríguez, Nuria; Amiols, Ricardo

    2008-02-01

    Chemolithotrophic communities that colonize subsurface habitats have great relevance for the astrobiological exploration of our Solar System. We hypothesize that the chemical and thermal stabilization of an environment through microbial activity could make a given planetary region habitable. The MARTE project ground-truth drilling campaigns that sampled cryptic subsurface microbial communities in the basement of the Ro Tinto headwaters have shown that acidic surficial habitats are the result of the microbial oxidation of pyritic ores. The oxidation process is exothermic and releases heat under both aerobic and anaerobic conditions. These microbial communities can maintain the subsurface habitat temperature through storage heat if the subsurface temperature does not exceed their maximum growth temperature. In the acidic solutions of the Ro Tinto, ferric iron acts as an effective buffer for controlling water pH. Under anaerobic conditions, ferric iron is the oxidant used by microbes to decompose pyrite through the production of sulfate, ferrous iron, and protons. The integration between the physical and chemical processes mediated by microorganisms with those driven by the local geology and hydrology have led us to hypothesize that thermal and chemical regulation mechanisms exist in this environment and that these homeostatic mechanisms could play an essential role in creating habitable areas for other types of microorganisms. Therefore, searching for the physicochemical expression of extinct and extant homeostatic mechanisms through physical and chemical anomalies in the Mars crust (i.e., local thermal gradient or high concentration of unusual products such as ferric sulfates precipitated out from acidic solutions produced by hypothetical microbial communities) could be a first step in the search for biological traces of a putative extant or extinct Mars biosphere.

  11. Some ecological mechanisms to generate habitability in planetary subsurface areas by chemolithotrophic communities: the Río Tinto subsurface ecosystem as a model system.

    PubMed

    Fernández-Remolar, David C; Gómez, Felipe; Prieto-Ballesteros, Olga; Schelble, Rachel T; Rodríguez, Nuria; Amils, Ricardo

    2008-02-01

    Chemolithotrophic communities that colonize subsurface habitats have great relevance for the astrobiological exploration of our Solar System. We hypothesize that the chemical and thermal stabilization of an environment through microbial activity could make a given planetary region habitable. The MARTE project ground-truth drilling campaigns that sampled cryptic subsurface microbial communities in the basement of the Río Tinto headwaters have shown that acidic surficial habitats are the result of the microbial oxidation of pyritic ores. The oxidation process is exothermic and releases heat under both aerobic and anaerobic conditions. These microbial communities can maintain the subsurface habitat temperature through storage heat if the subsurface temperature does not exceed their maximum growth temperature. In the acidic solutions of the Río Tinto, ferric iron acts as an effective buffer for controlling water pH. Under anaerobic conditions, ferric iron is the oxidant used by microbes to decompose pyrite through the production of sulfate, ferrous iron, and protons. The integration between the physical and chemical processes mediated by microorganisms with those driven by the local geology and hydrology have led us to hypothesize that thermal and chemical regulation mechanisms exist in this environment and that these homeostatic mechanisms could play an essential role in creating habitable areas for other types of microorganisms. Therefore, searching for the physicochemical expression of extinct and extant homeostatic mechanisms through physical and chemical anomalies in the Mars crust (i.e., local thermal gradient or high concentration of unusual products such as ferric sulfates precipitated out from acidic solutions produced by hypothetical microbial communities) could be a first step in the search for biological traces of a putative extant or extinct Mars biosphere. PMID:18237256

  12. Organic and Inorganic Carbon in the Rio Tinto (Spain) Deep Subsurface System: a Possible Model for Subsurface Carbon and Lithoautotrophs on Mars.

    NASA Astrophysics Data System (ADS)

    Bonaccorsi, R.; Stoker, C. R.; MARTE Science Team

    2007-12-01

    The subsurface is the key environment for searching for life on planets lacking surface life. Subsurface ecosystems are of great relevance to astrobiology including the search for past/present life on Mars. Conditions on the Martian surface do not support biological activity but the subsurface might preserve organics and host subsurface life [1]. A key requirement for the analysis of subsurface samples on Mars is the ability to characterize organic vs. inorganic carbon pools. This information is needed to determine if the sample contains organic material of biological origin and/ or to establish if pools of inorganic carbon can support subsurface biospheres. The Mars Analog Rio Tinto Experiment (MARTE) performed deep drilling of cores i.e., down to 165-m depth, in a volcanically-hosted-massive-sulfide deposit at Rio Tinto, Spain, which is considered an important analog of the Sinus Meridiani site on Mars. Results from MARTE suggest the existence of a relatively complex subsurface life including aerobic and anaerobic chemoautotrophs, and strict anaerobic methanogens sustained by Fe and S minerals in anoxic conditions, which is an ideal model analog for a deep subsurface Martian environment. We report here on the distribution of organic (C-org: 0.01-0.3Wt% and inorganic carbon (IC = 0.01-7.0 Wt%) in a subsurface rock system including weathered/oxidized i.e., gossan, and unaltered pyrite stockwork. Cores were analyzed from 3 boreholes (BH-4, BH-7, and BH-8) that penetrated down to a depth of ~165 m into massive sulfide. Nearsurface phyllosilicate rich-pockets contain the highest amounts of organics (0.3Wt%) [2], while the deeper rocks contain the highest amount of carbonates. Assessing the amount of C pools available throughout the RT subsurface brings key insight on the type of trophic system sustaining its microbial ecosystem (i.e., heterotrophs vs. autotrophs) and the biogeochemical relationships that characterize a new type of subsurface biosphere at RT. This

  13. Influence of the very polluted inputs of the Tinto-Odiel system on the adjacent littoral sediments of southwestern Spain: a statistical approach.

    PubMed

    Sainz, A; Ruiz, F

    2006-03-01

    A spatial and temporal analysis (period 1990-2003) of 15 sampling points distributed along the southwestern Spanish coast permits to delimitate the influence area of the extremely polluted discharges coming from the Tinto-Odiel system in the bottom sediments of the adjacent littoral area. As, Cu, Pb and Zn are the main heavy metals transported by the freshwater runoffs toward the shallow shelf and present very high negative (r < -0.7) and significant (p < 0.001) correlations with the distance to the estuarine mouth. The statistical analysis (index of geoaccumulation, Pearson correlation matrix, cluster analysis) of their concentrations in the littoral sediments located between the Guadiana and Guadalquivir mouths delimitates three zones: (a) Zone 1 (from the estuarine mouth to 6 km to the east), characterized by moderate to strongly polluted bottom sediments and main responsible of the mean annual variations of the former heavy metals in the area studied; (b) Zone 2 (from 21.2 km to the west to 29 km to the east), characterized by moderate pollution levels; and (c) Zone 3, located near the Guadiana and Guadalquivir mouths, with very low As-Cu-Pb contents and unpolluted to moderately levels of Zn due to urban sewages or the presence of local low mobility areas for this element. PMID:16122777

  14. The Subsurface Geology of Río Tinto: Material Examined During a Simulated Mars Drilling Mission for the Mars Astrobiology Research and Technology Experiment (MARTE)

    NASA Astrophysics Data System (ADS)

    Prieto-Ballesteros, Olga; Martínez-Frías, Jesús; Schutt, John; Sutter, Brad; Heldmann, Jennifer L.; Bell Johnson, Mary Sue; Battler, Melissa; Cannon, Howard; Gómez-Elvira, Javier; Stoker, Carol R.

    2008-10-01

    The 2005 Mars Astrobiology Research and Technology Experiment (MARTE) project conducted a simulated 1-month Mars drilling mission in the Río Tinto district, Spain. Dry robotic drilling, core sampling, and biological and geological analytical technologies were collectively tested for the first time for potential use on Mars. Drilling and subsurface sampling and analytical technologies are being explored for Mars because the subsurface is the most likely place to find life on Mars. The objectives of this work are to describe drilling, sampling, and analytical procedures; present the geological analysis of core and borehole material; and examine lessons learned from the drilling simulation. Drilling occurred at an undis closed location, causing the science team to rely only on mission data for geological and biological interpretations. Core and borehole imaging was used for micromorphological analysis of rock, targeting rock for biological analysis, and making decisions regarding the next day's drilling operations. Drilling reached 606 cm depth into poorly consolidated gossan that allowed only 35% of core recovery and contributed to borehole wall failure during drilling. Core material containing any indication of biology was sampled and analyzed in more detail for its confirmation. Despite the poorly consolidated nature of the subsurface gossan, dry drilling was able to retrieve useful core material for geological and biological analysis. Lessons learned from this drilling simulation can guide the development of dry drilling and subsurface geological and biological analytical technologies for future Mars drilling missions.

  15. The 2005 MARTE Robotic Drilling Experiment in Río Tinto, Spain: Objectives, Approach, and Results of a Simulated Mission to Search for Life in the Martian Subsurface

    NASA Astrophysics Data System (ADS)

    Stoker, Carol R.; Cannon, Howard N.; Dunagan, Stephen E.; Lemke, Lawrence G.; Glass, Brian J.; Miller, David; Gomez-Elvira, Javier; Davis, Kiel; Zavaleta, Jhony; Winterholler, Alois; Roman, Matt; Rodriguez-Manfredi, Jose Antonio; Bonaccorsi, Rosalba; Bell, Mary Sue; Brown, Adrian; Battler, Melissa; Chen, Bin; Cooper, George; Davidson, Mark; Fernández-Remolar, David; Gonzales-Pastor, Eduardo; Heldmann, Jennifer L.; Martínez-Frías, Jesus; Parro, Victor; Prieto-Ballesteros, Olga; Sutter, Brad; Schuerger, Andrew C.; Schutt, John; Rull, Fernando

    2008-10-01

    The Mars Astrobiology Research and Technology Experiment (MARTE) simulated a robotic drilling mission to search for subsurface life on Mars. The drill site was on Peña de Hierro near the headwaters of the Río Tinto river (southwest Spain), on a deposit that includes massive sulfides and their gossanized remains that resemble some iron and sulfur minerals found on Mars. The mission used a fluidless, 10-axis, autonomous coring drill mounted on a simulated lander. Cores were faced; then instruments collected color wide-angle context images, color microscopic images, visible near infrared point spectra, and (lower resolution) visible-near infrared hyperspectral images. Cores were then stored for further processing or ejected. A borehole inspection system collected panoramic imaging and Raman spectra of borehole walls. Life detection was performed on full cores with an adenosine triphosphate luciferin-luciferase bioluminescence assay and on crushed core sections with SOLID2, an antibody array-based instrument. Two remotely located science teams analyzed the remote sensing data and chose subsample locations. In 30 days of operation, the drill penetrated to 6 m and collected 21 cores. Biosignatures were detected in 12 of 15 samples analyzed by SOLID2. Science teams correctly interpreted the nature of the deposits drilled as compared to the ground truth. This experiment shows that drilling to search for subsurface life on Mars is technically feasible and scientifically rewarding.

  16. The subsurface geology of Río Tinto: material examined during a simulated Mars drilling mission for the Mars Astrobiology Research and Technology Experiment (MARTE).

    PubMed

    Prieto-Ballesteros, Olga; Martínez-Frías, Jesús; Schutt, John; Sutter, Brad; Heldmann, Jennifer L; Bell, Mary Sue; Battler, Melissa; Cannon, Howard; Gómez-Elvira, Javier; Stoker, Carol R

    2008-10-01

    The 2005 Mars Astrobiology Research and Technology Experiment (MARTE) project conducted a simulated 1-month Mars drilling mission in the Río Tinto district, Spain. Dry robotic drilling, core sampling, and biological and geological analytical technologies were collectively tested for the first time for potential use on Mars. Drilling and subsurface sampling and analytical technologies are being explored for Mars because the subsurface is the most likely place to find life on Mars. The objectives of this work are to describe drilling, sampling, and analytical procedures; present the geological analysis of core and borehole material; and examine lessons learned from the drilling simulation. Drilling occurred at an undisclosed location, causing the science team to rely only on mission data for geological and biological interpretations. Core and borehole imaging was used for micromorphological analysis of rock, targeting rock for biological analysis, and making decisions regarding the next day's drilling operations. Drilling reached 606 cm depth into poorly consolidated gossan that allowed only 35% of core recovery and contributed to borehole wall failure during drilling. Core material containing any indication of biology was sampled and analyzed in more detail for its confirmation. Despite the poorly consolidated nature of the subsurface gossan, dry drilling was able to retrieve useful core material for geological and biological analysis. Lessons learned from this drilling simulation can guide the development of dry drilling and subsurface geological and biological analytical technologies for future Mars drilling missions. PMID:19105757

  17. The 2005 MARTE Robotic Drilling Experiment in Río Tinto, Spain: objectives, approach, and results of a simulated mission to search for life in the Martian subsurface.

    PubMed

    Stoker, Carol R; Cannon, Howard N; Dunagan, Stephen E; Lemke, Lawrence G; Glass, Brian J; Miller, David; Gomez-Elvira, Javier; Davis, Kiel; Zavaleta, Jhony; Winterholler, Alois; Roman, Matt; Rodriguez-Manfredi, Jose Antonio; Bonaccorsi, Rosalba; Bell, Mary Sue; Brown, Adrian; Battler, Melissa; Chen, Bin; Cooper, George; Davidson, Mark; Fernández-Remolar, David; Gonzales-Pastor, Eduardo; Heldmann, Jennifer L; Martínez-Frías, Jesus; Parro, Victor; Prieto-Ballesteros, Olga; Sutter, Brad; Schuerger, Andrew C; Schutt, John; Rull, Fernando

    2008-10-01

    The Mars Astrobiology Research and Technology Experiment (MARTE) simulated a robotic drilling mission to search for subsurface life on Mars. The drill site was on Peña de Hierro near the headwaters of the Río Tinto river (southwest Spain), on a deposit that includes massive sulfides and their gossanized remains that resemble some iron and sulfur minerals found on Mars. The mission used a fluidless, 10-axis, autonomous coring drill mounted on a simulated lander. Cores were faced; then instruments collected color wide-angle context images, color microscopic images, visible-near infrared point spectra, and (lower resolution) visible-near infrared hyperspectral images. Cores were then stored for further processing or ejected. A borehole inspection system collected panoramic imaging and Raman spectra of borehole walls. Life detection was performed on full cores with an adenosine triphosphate luciferin-luciferase bioluminescence assay and on crushed core sections with SOLID2, an antibody array-based instrument. Two remotely located science teams analyzed the remote sensing data and chose subsample locations. In 30 days of operation, the drill penetrated to 6 m and collected 21 cores. Biosignatures were detected in 12 of 15 samples analyzed by SOLID2. Science teams correctly interpreted the nature of the deposits drilled as compared to the ground truth. This experiment shows that drilling to search for subsurface life on Mars is technically feasible and scientifically rewarding. PMID:19032053

  18. Chemical and Isotopic Characterization of Waters in Rio Tinto, Spain, Shows Possible Origin of the Blueberry Haematite Nodules in Meridiani Planum, Mars

    NASA Astrophysics Data System (ADS)

    Coleman, M. L.; Hubbard, C. G.; Mielke, R. E.; Black, S.

    2005-12-01

    Meridiani Planum sediments formed in an acid environment and include jarosite and other evaporitic sulfate minerals. Nodular spheroidal concretions appear to have grown in situ and are predominantly hematite. The source of the Rio Tinto, S. Spain, drains an area of extensive sulfide mineralization and is dominated by acid mine drainage processes. The system is not a Mars analog but potentially similar processes of sulfide oxidation produce sulfate rich waters which feed into the river and precipitate a large range of evaporitic sulfates including jarosite. Iron oxide minerals associated with the evaporites are either dispersed or bedded but not nodular. The water compositions appear to be mixtures of a few discreet end-members: the two most significant occur in undiluted form as inputs to the river and are relevant to many such systems. They both have all sulfur totally oxidized as sulfate. The first is a bright red water, pH ~1.5, Fe/S 0.5 and 23 g/L iron which is greater than 95% Fe3+. Its sulfate oxygen isotope composition is +2‰SMOW and about +7‰, relative to the water O isotope composition. These data indicate pyrite oxidation by Fe3+ with O in sulfate coming mainly from water. The second end-member is a pale green water, pH ~0.7, Fe/S 0.7, 50 g/L iron present mainly as Fe2+ and O isotope composition of sulfate about +6‰SMOW , about +12.5‰ relative to the water O value. Oxygen in sulfate comes mainly from atmospheric oxygen resulting from pyrite oxidation by molecular oxygen dissolved in water. Although the Rio Tinto system reactions probably are microbiologically mediated (relevant genera have been identified there) similar processes could occur abiotically but more slowly. Meridiani Planum sediments and nodules can be described by a plausible set of similar end-member processes. The primary source of sulfate is oxidation of sulfides present in basalt (pyrite, FeS2 or pyrrhotite, FeS) and weathering would have produced oxidized sulfate rich solutions

  19. Quantification of Tinto River Sediment Microbial Communities: Importance of Sulfate-Reducing Bacteria and Their Role in Attenuating Acid Mine Drainage

    PubMed Central

    Sánchez-Andrea, Irene; Knittel, Katrin; Amann, Rudolf; Amils, Ricardo

    2012-01-01

    Tinto River (Huelva, Spain) is a natural acidic rock drainage (ARD) environment produced by the bio-oxidation of metallic sulfides from the Iberian Pyritic Belt. This study quantified the abundance of diverse microbial populations inhabiting ARD-related sediments from two physicochemically contrasting sampling sites (SN and JL dams). Depth profiles of total cell numbers differed greatly between the two sites yet were consistent in decreasing sharply at greater depths. Although catalyzed reporter deposition fluorescence in situ hybridization with domain-specific probes showed that Bacteria (>98%) dominated over Archaea (<2%) at both sites, important differences were detected at the class and genus levels, reflecting differences in pH, redox potential, and heavy metal concentrations. At SN, where the pH and redox potential are similar to that of the water column (pH 2.5 and +400 mV), the most abundant organisms were identified as iron-reducing bacteria: Acidithiobacillus spp. and Acidiphilium spp., probably related to the higher iron solubility at low pH. At the JL dam, characterized by a banded sediment with higher pH (4.2 to 6.2), more reducing redox potential (−210 mV to 50 mV), and a lower solubility of iron, members of sulfate-reducing genera Syntrophobacter, Desulfosporosinus, and Desulfurella were dominant. The latter was quantified with a newly designed CARD-FISH probe. In layers where sulfate-reducing bacteria were abundant, pH was higher and redox potential and levels of dissolved metals and iron were lower. These results suggest that the attenuation of ARD characteristics is biologically driven by sulfate reducers and the consequent precipitation of metals and iron as sulfides. PMID:22544246

  20. Aseptically Sampled Organics in Subsurface Rocks From the Mars Analog Rio Tinto Experiment: An Analog For The Search for Deep Subsurface Life on Mars.}

    NASA Astrophysics Data System (ADS)

    Bonaccorsi, R.; Stoker, C. R.

    2005-12-01

    The subsurface is the key environment for searching for life on planets lacking surface life. Subsurface ecosystems are of great relevance to astrobiology including the search for past/present life on Mars. The surface of Mars has conditions preventing current life but the subsurface might preserve organics and even host some life [1]. The Mars-Analog-Rio-Tinto-Experiment (MARTE) is performing a simulation of a Mars drilling experiment. This comprises conventional and robotic drilling of cores in a volcanically-hosted-massive-pyrite deposit [2] from the Iberian Pyritic Belt (IBP) and life detection experiments applying anti-contamination protocols (e.g., ATP Luminometry assay). The RT is considered an important analog of the Sinus Meridiani site on Mars and an ideal model analog for a deep subsurface Martian environment. Former results from MARTE suggest the existence of a relatively complex subsurface life including aerobic and anaerobic chemoautotrophs and strict anaerobic methanogens sustained by Fe and S minerals in anoxic conditions. A key requirement for the analysis of a subsurface sample on Mars is a set of simple tests that can help determine if the sample contains organic material of biological origin, and its potential for retaining definitive biosignatures. We report here on the presence of bulk organic matter Corg (0.03-0.05 Wt%), and Ntot (0.01-0.04 Wt%) and amount of measured ATP (Lightning MVP, Biocontrol) in weathered rocks (tuffs, gossan, pyrite stockwork from Borehole #8; >166m). This provides key insight on the type of trophic system sustaining the subsurface biosphere (i.e., heterotrophs vs. autotrophs) at RT. ATP data (Relative-Luminosity-Units, RLU) provide information on possible contamination and distribution of viable biomass with core depth (BH#8, and BH#7, ~3m). Avg. 153 RLU, i.e., surface vs. center of core, suggest that cleaness/sterility can be maintained when using a simple sterile protocol under field conditions. Results from this

  1. Organics-bearing Clays from the Rio Tinto (spain): A Novel Analog for the Phyllosilicates Outcrops Seen By Omega-mex

    NASA Astrophysics Data System (ADS)

    Bonaccorsi, Rosalba

    2007-12-01

    The Rio Tinto (RT) is considered an important analog of Sinus Meridiani on Mars and an ideal model analog for a subsurface Martian setting [1]. The RT system comprises the upper sequence of an acid rock drainage system where weathered iron -rich rocks, overlain a massive-pyrite deposit. The RT analog site is ideal for testing on the preservation of organics in hematite-rich vs. phyllosilicates-rich environments [3]. It is suggested here that RT near-surface rocks, which embed pockets of Clays, represent also a potential new model analog for the phyllosilicates-rich outcrops seen by OMEGA-MEx on the surface of Mars [5]. Results from the analysis of cores drilled under the 2005 Robotic experiment of the MARTE project (Borehole#7 Site 607cm) [2-3] are presented in this paper. Primary mineral assemblages include hematite, goethite, and Phyllosilicates e.g.,smectite, kaolinite, as quantified by X-ray diffraction [4]. Organic carbon is at low concentration (<0.05%) beneath the soil horizon in most cores dominated by iron minerals but is considerably higher in Phyllosilicate-rich levels i.e., 0.2-0.3Wt% at 385 -550 cm-depth [2-3]. Phyllosilicate-rich terrains have been identified OMEGA/MEx in the Nili Fossae, Mawrth Valles and Candor Chasma regions [e.g., 5]. These outcrops are surrounded by hematite-rich deposits, which are potentially barren in organics [6]. The potential of phyllosilicates to preserve higher amounts of organics/ biosignatures is well known for several Earth environments as well as the RT near subsurface. This potential brings a relevant element for the selection of candidate sites for the MSL mission [e.g., 1]. References: [1]Fernandez-Remolar et al.,2005 EPSL, 240,149-167; [2]Stoker et al., 2007; [3] Bonaccorsi et al., 2007; [4] Sutter et al., 2007 in Astrobiology,MARTE Spec. Issue; [5] Bibring et al., 2006, Science 312, 400-404; [6] Sumner, 2004, JGR 109. Anknowlegments: NASA-Postdoctoral-Program/C.Stoker, B.Sutter, A.F Davila and the MARTE team for

  2. Visible-Near Infrared Point Spectrometry of Drill Core Samples from Río Tinto, Spain: Results from the 2005 Mars Astrobiology Research and Technology Experiment (MARTE) Drilling Exercise

    NASA Astrophysics Data System (ADS)

    Sutter, Brad; Brown, Adrian J.; Stoker, Carol R.

    2008-10-01

    Sampling of subsurface rock may be required to detect evidence of past biological activity on Mars. The Mars Astrobiology Research and Technology Experiment (MARTE) utilized the Río Tinto region, Spain, as a Mars analog site to test dry drilling technologies specific to Mars that retrieve subsurface rock for biological analysis. This work examines the usefulness of visible-near infrared (VNIR) (450-1000 nm) point spectrometry to characterize ferric iron minerals in core material retrieved during a simulated Mars drilling mission. VNIR spectrometry can indicate the presence of aqueously precipitated ferric iron minerals and, thus, determine whether biological analysis of retrieved rock is warranted. Core spectra obtained during the mission with T1 (893-897 nm) and T2 (644-652 nm) features indicate goethite-dominated samples, while relatively lower wavelength T1 (832-880 nm) features indicate hematite. Hematite/goethite molar ratios varied from 0 to 1.4, and within the 880-898 nm range, T1 features were used to estimate hematite/goethite molar ratios. Post-mission X-ray analysis detected phyllosilicates, which indicates that examining beyond the VNIR (e.g., shortwave infrared, 1000-2500 nm) will enhance the detection of other minerals formed by aqueous processes. Despite the limited spectral range of VNIR point spectrometry utilized in the MARTE Mars drilling simulation project, ferric iron minerals could be identified in retrieved core material, and their distribution served to direct core subsampling for biological analysis.

  3. Visible-near infrared point spectrometry of drill core samples from Río Tinto, Spain: results from the 2005 Mars Astrobiology Research and Technology Experiment (MARTE) drilling exercise.

    PubMed

    Sutter, Brad; Brown, Adrian J; Stoker, Carol R

    2008-10-01

    Sampling of subsurface rock may be required to detect evidence of past biological activity on Mars. The Mars Astrobiology Research and Technology Experiment (MARTE) utilized the Río Tinto region, Spain, as a Mars analog site to test dry drilling technologies specific to Mars that retrieve subsurface rock for biological analysis. This work examines the usefulness of visible-near infrared (VNIR) (450-1000 nm) point spectrometry to characterize ferric iron minerals in core material retrieved during a simulated Mars drilling mission. VNIR spectrometry can indicate the presence of aqueously precipitated ferric iron minerals and, thus, determine whether biological analysis of retrieved rock is warranted. Core spectra obtained during the mission with T1 (893-897 nm) and T2 (644-652 nm) features indicate goethite-dominated samples, while relatively lower wavelength T1 (832-880 nm) features indicate hematite. Hematite/goethite molar ratios varied from 0 to 1.4, and within the 880-898 nm range, T1 features were used to estimate hematite/goethite molar ratios. Post-mission X-ray analysis detected phyllosilicates, which indicates that examining beyond the VNIR (e.g., shortwave infrared, 1000-2500 nm) will enhance the detection of other minerals formed by aqueous processes. Despite the limited spectral range of VNIR point spectrometry utilized in the MARTE Mars drilling simulation project, ferric iron minerals could be identified in retrieved core material, and their distribution served to direct core subsampling for biological analysis. PMID:19105759

  4. Tiempo para un cambio

    NASA Astrophysics Data System (ADS)

    Woltjer, L.

    1987-06-01

    En la reunion celebrada en diciembre dei ano pasado informe al Consejo de mi deseo de terminar mi contrato como Director General de la ESO una vez que fuera aprobado el proyecto dei VLT, que se espera sucedera hacia fines de este aAo. Cuando fue renovada mi designacion hace tres aAos, el Consejo conocia mi intencion de no completar los cinco aAos dei contrato debido a mi deseo de disponer de mas tiempo para otras actividades. Ahora, una vez terminada la fase preparatoria para el VLT, Y habiendose presentado el proyecto formalmente al Consejo el dia 31 de marzo, y esperando su muy probable aprobacion antes dei termino de este ano, me parece que el 10 de enero de 1988 presenta una excelente fecha para que se produzca un cambio en la administracion de la ESO.

  5. Separating para and ortho water.

    PubMed

    Horke, Daniel A; Chang, Yuan-Pin; Długołęcki, Karol; Küpper, Jochen

    2014-10-27

    Water exists as two nuclear-spin isomers, para and ortho, determined by the overall spin of its two hydrogen nuclei. For isolated water molecules, the conversion between these isomers is forbidden and they act as different molecular species. Yet, these species are not readily separated, and no pure para sample has been produced. Accordingly, little is known about their specific physical and chemical properties, conversion mechanisms, or interactions. The production of isolated samples of both spin isomers is demonstrated in pure beams of para and ortho water in their respective absolute ground state. These single-quantum-state samples are ideal targets for unraveling spin-conversion mechanisms, for precision spectroscopy and fundamental symmetry-breaking studies, and for spin-enhanced applications, for example laboratory astrophysics and astrochemistry or hypersensitized NMR experiments. PMID:25196938

  6. Mensaje para alumnos y padres

    NASA Video Gallery

    El astronauta de la NASA José Hernández alienta a los estudiantes a que sigan sus sueños. Hernández también habla acerca del papel que juegan los padres para ayudar a que sus hijos hagan realidad s...

  7. Functional Expression of Drosophila para Sodium Channels

    PubMed Central

    Warmke, Jeffrey W.; Reenan, Robert A.G.; Wang, Peiyi; Qian, Su; Arena, Joseph P.; Wang, Jixin; Wunderler, Denise; Liu, Ken; Kaczorowski, Gregory J.; Ploeg, Lex H.T. Van der; Ganetzky, Barry; Cohen, Charles J.

    1997-01-01

    The Drosophila para sodium channel α subunit was expressed in Xenopus oocytes alone and in combination with tipE, a putative Drosophila sodium channel accessory subunit. Coexpression of tipE with para results in elevated levels of sodium currents and accelerated current decay. Para/TipE sodium channels have biophysical and pharmacological properties similar to those of native channels. However, the pharmacology of these channels differs from that of vertebrate sodium channels: (a) toxin II from Anemonia sulcata, which slows inactivation, binds to Para and some mammalian sodium channels with similar affinity (Kd ≅ 10 nM), but this toxin causes a 100-fold greater decrease in the rate of inactivation of Para/TipE than of mammalian channels; (b) Para sodium channels are >10-fold more sensitive to block by tetrodotoxin; and (c) modification by the pyrethroid insecticide permethrin is >100-fold more potent for Para than for rat brain type IIA sodium channels. Our results suggest that the selective toxicity of pyrethroid insecticides is due at least in part to the greater affinity of pyrethroids for insect sodium channels than for mammalian sodium channels. PMID:9236205

  8. Laparoscopic extraperitoneal para-aortic lymphadenectomy

    PubMed Central

    Iserte, Pablo Padilla; Minig, Lucas; Zorrero, Cristina

    2015-01-01

    Lymph nodes are the main pathway in the spread of gynaecological malignancies, being a well-known prognostic factor. Lymph node dissection is a complex surgical procedure and requires surgical expertise to perform the procedure, thereby minimising complications. In addition, lymphadenectomy has value in the diagnosis, prognosis, and treatment of patients with gynaecologic cancer. Therefore, a video focused on the para-aortic retroperitoneal anatomy and the surgical technique of the extraperitoneal para-aortic lymphadenectomy is presented. PMID:26435746

  9. Process for para-ethyltoluene dehydrogenation

    SciTech Connect

    Chu, C.C.

    1986-06-03

    A process is described of dehydrogenating para-ethyltoluene to selectively form para-methylstyrene comprising contacting to para-ethyltoluene under dehydrogenation reaction conditions with a catalyst composition comprising: (a) from about 30% to 60% by weight of iron oxide, calculated as ferric oxide; (b) from about 13% to 48% by weight of a potassium compound, calculated as potassium oxide; and (c) from about 0% to 5% by weight of a chromium compound, calculated as chromic oxide. The improvement is described comprising dehydrogenating the para-ethyltoluene with a catalyst composition comprising, in addition to the components (a), (b) and (c), a modifying component (d) capable of rendering the para-methylstyrene-containing dehydrogenation reaction effluent especially resistant to the subsequent formation of popcorn polymers when the dehydrogenation of para-ethyltoluene is conducted over the modified catalyst, the modifying component (d) being a bismuth compound present to the extent of from about 1% to 20% by weight of the catalyst composition, calculated as bismuth trioxide.

  10. The ParaScope parallel programming environment

    NASA Technical Reports Server (NTRS)

    Cooper, Keith D.; Hall, Mary W.; Hood, Robert T.; Kennedy, Ken; Mckinley, Kathryn S.; Mellor-Crummey, John M.; Torczon, Linda; Warren, Scott K.

    1993-01-01

    The ParaScope parallel programming environment, developed to support scientific programming of shared-memory multiprocessors, includes a collection of tools that use global program analysis to help users develop and debug parallel programs. This paper focuses on ParaScope's compilation system, its parallel program editor, and its parallel debugging system. The compilation system extends the traditional single-procedure compiler by providing a mechanism for managing the compilation of complete programs. Thus, ParaScope can support both traditional single-procedure optimization and optimization across procedure boundaries. The ParaScope editor brings both compiler analysis and user expertise to bear on program parallelization. It assists the knowledgeable user by displaying and managing analysis and by providing a variety of interactive program transformations that are effective in exposing parallelism. The debugging system detects and reports timing-dependent errors, called data races, in execution of parallel programs. The system combines static analysis, program instrumentation, and run-time reporting to provide a mechanical system for isolating errors in parallel program executions. Finally, we describe a new project to extend ParaScope to support programming in FORTRAN D, a machine-independent parallel programming language intended for use with both distributed-memory and shared-memory parallel computers.

  11. Oxidative para-triflation of acetanilides.

    PubMed

    Pialat, Amélie; Liégault, Benoît; Taillefer, Marc

    2013-04-01

    Direct triflation of acetanilide derivatives with silver triflate has been accomplished under mild iodine(III)-mediated oxidative conditions. The reaction shows excellent regioselectivity for the para position and tolerates a range of ortho and meta substituents on the aromatic ring. This method is also compatible with the preparation of arylnonaflates in synthetically useful yields. PMID:23534500

  12. FDA aprueba la primera inmunoterapia para linfoma

    Cancer.gov

    La FDA ha aprobado nivolumab (Opdivo®) para el tratamiento de pacientes con el linfoma clásico de Hodgkin que ha recaído o empeorado después de recibir un trasplante autólogo hematopoyético seguido de brentuximab vedotin (Adcetris®)

  13. Centro para la Salud Mundial (CGH) del NCI

    Cancer.gov

    El Centro para la Salud Mundial (CGH) del NCI coordina actividades de investigación y trabaja con socios nacionales e internacionales para comprender y enfrentar la carga que representa el cáncer a nivel mundial.

  14. Para-hydrogen perspectives in hyperpolarized NMR.

    PubMed

    Glöggler, Stefan; Colell, Johannes; Appelt, Stephan

    2013-10-01

    The first instance of para-hydrogen induced polarization (PHIP) in an NMR experiment was serendipitously observed in the 1980s while investigating a hydrogenation reaction (Seldler et al., 1983; Bowers and Weitekamp, 1986, 1987; Eisenschmid et al., 1987) [1-4]. Remarkably a theoretical investigation of the applicability of para-hydrogen as a hyperpolarization agent was being performed in the 1980's thereby quickly providing a theoretical basis for the PHIP-effect (Bowers and Weitekamp, 1986) [2]. The discovery of signal amplification by a non-hydrogenating interaction with para-hydrogen has recently extended the interest to exploit the PHIP effect, as it enables investigation of compounds without structural alteration while retaining the advantages of spectroscopy with hyperpolarized compounds [5]. In this article we will place more emphasis of the future applications of the method while only briefly discussing the efforts that have been made in the understanding of the phenomenon and the development of the method so far. PMID:23932399

  15. Allergic contact dermatitis to para-phenylenediamine.

    PubMed

    Jenkins, David; Chow, Elizabeth T

    2015-02-01

    Exposure to hair dye is the most frequent route of sensitisation to para-phenylenediamine (PPD), a common contact allergen. International studies have examined the profile of PPD, but Australian-sourced information is lacking. Patients are often dissatisfied with advice to stop dyeing their hair. This study examines patients' characteristics, patch test results and outcomes of PPD allergy from a single Australian centre, through a retrospective analysis of patch test data from 2006 to 2013 at the Liverpool Hospital Dermatology Department. It reviews the science of hair dye allergy, examines alternative hair dyes and investigates strategies for hair dyeing. Of 584 patients, 11 were allergic to PPD. Our PPD allergy prevalence rate of 2% is at the lower end of international reported rates. About half these patients also react to para-toluenediamine (PTD). Affected patients experience a significant lifestyle disturbance. In all, 78% tried alternative hair dyes after the patch test diagnosis and more than half continued to dye their hair. Alternative non-PPD hair dyes are available but the marketplace can be confusing. Although some patients are able to tolerate alternative hair dyes, caution is needed as the risk of developing an allergy to other hair dye ingredients, especially PTD, is high. PMID:25302475

  16. On Lightlike Geometry of Para-Sasakian Manifolds

    PubMed Central

    Acet, Bilal Eftal; Kılıç, Erol

    2014-01-01

    We study lightlike hypersurfaces of para-Sasakian manifolds tangent to the characteristic vector field. In particular, we define invariant lightlike hypersurfaces and screen semi-invariant lightlike hypersurfaces, respectively, and give examples. Integrability conditions for the distributions on a screen semi-invariant lightlike hypersurface of para-Sasakian manifolds are investigated. We obtain a para-Sasakian structure on the leaves of an integrable distribution of a screen semi-invariant lightlike hypersurface. PMID:24892072

  17. El Libro de la Escritura por Pinguino Tinto (The Writing Book, by Inky Penguin).

    ERIC Educational Resources Information Center

    Padgett, Ron

    Presented completely in Spanish and intended for elementary level students, this book offers 12 writing ideas and several suggestions on how students can make a book using their writing. Each writing idea is presented with a brief description (addressed to the student), several examples of student writing, and a blank page on which to write.…

  18. Searching for an Acidic Aquifer in the Rio Tinto Basin: First Geobiology Results of MARTE Project

    NASA Technical Reports Server (NTRS)

    Fernandez-Remolar, D. C.; Prieto-Ballesteros, O.; Stoker, C.

    2004-01-01

    Among the conceivable modern habitats to be explored for searching life on Mars are those potentially developed underground. Subsurface habitats are currently environments that, under certain physicochemical circumstances, have high thermal and hydrochemical stability [1, 2]. In planets like Mars lacking an atmospheric shield, such systems are obviously protected against radiation, which strongly alters the structure of biological macromolecules. Low porosity but fractured aquifers currently emplaced inside ancient volcano/sedimentary and hydrothermal systems act as excellent habitats [3] due to its thermal and geochemical properties. In these aquifers the temperature is controlled by a thermal balance between conduction and advection processes, which are driven by the rock composition, geological structure, water turnover of aquifers and heat generation from geothermal processes or chemical reactions [4]. Moreover, microbial communities based on chemolithotrophy can obtain energy by the oxidation of metallic ores that are currently associated to these environments. Such a community core may sustain a trophic web composed of non-autotrophic forms like heterotrophic bacteria, fungi and protozoa.

  19. Dipolar induced para-hydrogen-induced polarization.

    PubMed

    Buntkowsky, Gerd; Gutmann, Torsten; Petrova, Marina V; Ivanov, Konstantin L; Bommerich, Ute; Plaumann, Markus; Bernarding, Johannes

    2014-01-01

    Analytical expressions for the signal enhancement in solid-state PHIP NMR spectroscopy mediated by homonuclear dipolar interactions and single pulse or spin-echo excitation are developed and simulated numerically. It is shown that an efficient enhancement of the proton NMR signal in solid-state NMR studies of chemisorbed hydrogen on surfaces is possible. Employing typical reaction efficacy, enhancement-factors of ca. 30-40 can be expected both under ALTADENA and under PASADENA conditions. This result has important consequences for the practical application of the method, since it potentially allows the design of an in-situ flow setup, where the para-hydrogen is adsorbed and desorbed from catalyst surfaces inside the NMR magnet. PMID:25218522

  20. Cooling by Para-to-Ortho-Hydrogen Conversion

    NASA Technical Reports Server (NTRS)

    Sherman, A.; Nast, T.

    1983-01-01

    Catalyst speeds conversion, increasing capacity of solid hydrogen cooling system. In radial-flow catalytic converter, para-hydrogen is converted to equilibrium mixture of para-hydrogen and ortho-hydrogen as it passes through porous cylinder of catalyst. Addition of catalyst increases capacity of hydrogen sublimation cooling systems for radiation detectors.

  1. Requisitos para utilizar el enlace | Smokefree Español

    Cancer.gov

    Espanol.smokefree.gov ofrece apoyo y recursos para norteamericanos que hablan español y quieren dejar de fumar. Este sitio en la red fue creada por la División de Investigación para el Control del Tabaco del Instituto Nacional del Cáncer.

  2. Construction of a Para-Ortho Hydrogen Test Cryostat

    NASA Astrophysics Data System (ADS)

    Essler, J.; Haberstroh, Ch.

    2010-04-01

    In a prospective hydrogen economy it is necessary to verify the para concentration of the employed hydrogen. In case of a short storage time of about a few days only it has been shown that a partial conversion into para-hydrogen gives an optimized overall efficiency. Hence, an easy and reliable method of measuring the para-hydrogen concentration is needed. In this paper, the concept and construction of a small test cryostat are described and first results are presented. The measuring principle is based on a catalytic induced adiabatic ortho-para conversion of a hydrogen gas flow starting from a known temperature. The operation of the system only requires a certain amount of liquid nitrogen as coolant. To determine the concentration of para-hydrogen it is only necessary to measure the temperature of the gas before and after the adiabatic catalyst cell. The measuring cryostat is used for further investigation of the spontaneous para-ortho conversion in the supercritical state. In addition, the design of the cryostat allows the investigation of different catalyst materials regarding the catalytic activity and possible degradation by using a known para concentration for the measurement.

  3. a New Equation of State for Solid para-HYDROGEN

    NASA Astrophysics Data System (ADS)

    Wang, Lecheng; Le Roy, Robert J.; Roy, Pierre-Nicholas

    2015-06-01

    Solid para-H_2 is a popular accommodating host for impurity spectroscopy due to its unique softness and the spherical symmetry of para-H_2 in its J}=0 rotational level. To simulate the properties of impurity-doped solid para-H_2, a reliable model for the `soft' pure solid para-H_2 at different pressures is highly desirable. While a couple of experimental and theoretical studies aimed at elucidating the equation of state (EOS) of solid para-H_2 have been reported, the calculated EOS was shown to be heavily dependent on the potential energy surface (PES) between two para-H_2 that was used in the simulations. The current study also demonstrates that different choices of the parameters governing the Quantum Monte Carlo simulation could produce different EOS curves. To obtain a reliable model for pure solid para-H_2, we used a new 1-D para-H_2 PES reported by Faruk et al. that was obtained by averaging over Hinde's highly accurate 6-D H_2--H_2 PES. The EOS of pure solid para-H_2 was calculated using the PIMC algorithm with periodic boundary conditions (PBC). To precisely determine the equilibrium density of solid para-H_2, both the value of the PIMC time step (τ) and the number of particles in the PBC cell were extrapolated to convergence. The resulting EOS agreed well with experimental observations, and the hcp structured solid para-H_2 was found to be more stable than the fcc one at 4.2K, in agreement with experiment. The vibrational frequency shift of para-H_2 as a function of the density of the pure solid was also calculated, and the value of the shift at the equilibrium density is found to agree well with experiment. T. Momose, H. Honshina, M. Fushitani and H. Katsuki, Vib. Spectrosc. 34, 95(2004). M. E. Fajardo, J. Phys. Chem. A 117, 13504 (2013). I. F. Silvera, Rev. Mod. Phys. 52, 393(1980). F. Operetto and F. Pederiva, Phys. Rev. B 73, 184124(2006). T. Omiyinka and M. Boninsegni, Phys. Rev. B 88, 024112(2013). N. Faruk, M. Schmidt, H. Li, R. J. Le Roy, and P

  4. ParaDiS-FEM dislocation dynamics simulation code primer

    SciTech Connect

    Tang, M; Hommes, G; Aubry, S; Arsenlis, A

    2011-09-27

    The ParaDiS code is developed to study bulk systems with periodic boundary conditions. When we try to perform discrete dislocation dynamics simulations for finite systems such as thin films or cylinders, the ParaDiS code must be extended. First, dislocations need to be contained inside the finite simulation box; Second, dislocations inside the finite box experience image stresses due to the free surfaces. We have developed in-house FEM subroutines to couple with the ParaDiS code to deal with free surface related issues in the dislocation dynamics simulations. This primer explains how the coupled code was developed, the main changes from the ParaDiS code, and the functions of the new FEM subroutines.

  5. Cooling by conversion of para to ortho-hydrogen

    NASA Technical Reports Server (NTRS)

    Sherman, A. (Inventor)

    1983-01-01

    The cooling capacity of a solid hydrogen cooling system is significantly increased by exposing vapor created during evaporation of a solid hydrogen mass to a catalyst and thereby accelerating the endothermic para-to-ortho transition of the vapor to equilibrium hydrogen. Catalyst such as nickel, copper, iron or metal hydride gels of films in a low pressure drop catalytic reactor are suitable for accelerating the endothermic para-to-ortho conversion.

  6. Para hydrogen equilibration in the atmospheres of the outer planets

    NASA Technical Reports Server (NTRS)

    Conrath, Barney J.

    1986-01-01

    The thermodynamic behavior of the atmospheres of the Jovian planets is strongly dependent on the extent to which local thermal equilibration of the ortho and para states of molecular hydrogen is achieved. Voyager IRIS data from Jupiter imply substantial departures of the para hydrogen fraction from equilibrium in the upper troposphere at low latitudes, but with values approaching equilibrium at higher latitudes. Data from Saturn are less sensitive to the orth-para ratio, but suggest para hydrogen fractions near the equilibrium value. Above approximately the 200 K temperature level, para hydrogen conversion can enhance the efficiency of convection, resulting in a substantial increase in overturning times on all of the outer planets. Currently available data cannot definitively establish the ortho-para ratios in the atmospheres of Uranus and Neptune, but suggest values closer to local equilibrium than to the 3.1 normal ratio. Modeling of sub-millimeter wavelength measurements of these planets suggest thermal structures with frozen equilibrium lapse rates in their convective regions.

  7. A Comparative Usage-Based Approach to the Reduction of the Spanish and Portuguese Preposition "Para"

    ERIC Educational Resources Information Center

    Gradoville, Michael Stephen

    2013-01-01

    This study examines the frequency effect of two-word collocations involving "para" "to," "for" (e.g. "fui para," "para que") on the reduction of "para" to "pa" (in Spanish) and "pra" (in Portuguese). Collocation frequency effects demonstrate that language speakers…

  8. ParaText : scalable text modeling and analysis.

    SciTech Connect

    Dunlavy, Daniel M.; Stanton, Eric T.; Shead, Timothy M.

    2010-06-01

    Automated processing, modeling, and analysis of unstructured text (news documents, web content, journal articles, etc.) is a key task in many data analysis and decision making applications. As data sizes grow, scalability is essential for deep analysis. In many cases, documents are modeled as term or feature vectors and latent semantic analysis (LSA) is used to model latent, or hidden, relationships between documents and terms appearing in those documents. LSA supplies conceptual organization and analysis of document collections by modeling high-dimension feature vectors in many fewer dimensions. While past work on the scalability of LSA modeling has focused on the SVD, the goal of our work is to investigate the use of distributed memory architectures for the entire text analysis process, from data ingestion to semantic modeling and analysis. ParaText is a set of software components for distributed processing, modeling, and analysis of unstructured text. The ParaText source code is available under a BSD license, as an integral part of the Titan toolkit. ParaText components are chained-together into data-parallel pipelines that are replicated across processes on distributed-memory architectures. Individual components can be replaced or rewired to explore different computational strategies and implement new functionality. ParaText functionality can be embedded in applications on any platform using the native C++ API, Python, or Java. The ParaText MPI Process provides a 'generic' text analysis pipeline in a command-line executable that can be used for many serial and parallel analysis tasks. ParaText can also be deployed as a web service accessible via a RESTful (HTTP) API. In the web service configuration, any client can access the functionality provided by ParaText using commodity protocols ... from standard web browsers to custom clients written in any language.

  9. Una técnica para filtrar patrones de fringing

    NASA Astrophysics Data System (ADS)

    Ostrov, P. G.

    Se presenta una nueva técnica para filtrar los patrones de fringing producidos en los CCDs tipo RCA. El método consiste en construir un mapa con los ángulos de inclinación de las franjas en cada punto de la imagen. Este mapa es ulteriormente utilizado para alinear con el patrón de interferencia una ventana estrecha, sobre la que se aplica un filtro de mediana. Este procedimiento permite eliminar la mayor parte del ruido del patrón de fringing sin destruirlo.

  10. Analyzing and Visualizing Cosmological Simulations with ParaView

    SciTech Connect

    Woodring, Jonathan; Heitmann, Katrin; Ahrens, James P; Fasel, Patricia; Hsu, Chung-Hsing; Habib, Salman; Pope, Adrian

    2011-01-01

    The advent of large cosmological sky surveys - ushering in the era of precision cosmology - has been accompanied by ever larger cosmological simulations. The analysis of these simulations, which currently encompass tens of billions of particles and up to a trillion particles in the near future, is often as daunting as carrying out the simulations in the first place. Therefore, the development of very efficient analysis tools combining qualitative and quantitative capabilities is a matter of some urgency. In this paper, we introduce new analysis features implemented within ParaView, a fully parallel, open-source visualization toolkit, to analyze large N-body simulations. A major aspect of ParaView is that it can live and operate on the same machines and utilize the same parallel power as the simulation codes themselves. In addition, data movement is in a serious bottleneck now and will become even more of an issue in the future; an interactive visualization and analysis tool that can handle data in situ is fast becoming essential. The new features in ParaView include particle readers and a very efficient halo finder that identifies friends-of-friends halos and determines common halo properties, including spherical overdensity properties. In combination with many other functionalities already existing within ParaView, such as histogram routines or interfaces to programming languages like Python, this enhanced version enables fast, interactive, and convenient analyses of large cosmological simulations. In addition, development paths are available for future extensions.

  11. Cabozantinib y lenvatinib para cáncer renal

    Cancer.gov

    Artículo del blog del NCI sobre la aprobación reciente de la FDA de cabozantinib (Cabometyx®) y de lenvatinib (Lenvima®) para el tratamiento de pacientes cuyo cáncer avanzado de riñón ha evolucionado después de tratamiento con terapias antiangiogénicas.

  12. Leucemia—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento de la leucemia, así como referencias a estudios clínicos, investigación, estadísticas y otros temas relacionados con este tipo de cáncer.

  13. ACUTE TOXICITY OF PARA-NONYLPHENOL TO SALTWATER ANIMALS

    EPA Science Inventory

    ?para-Nonylphenol (PNP), a mixture of alkylphenols used in producing nonionic surfactants, is distributed widely in surface waters and aquatic sediments, where it can affect saltwater species. This article describes a database for acute toxicity of PNP derived for calculating a n...

  14. Hacer frente - Para la familia y los amigos

    Cancer.gov

    Si usted ayuda a su familiar o amigo durante el tratamiento del cáncer, usted es quien le cuida. Estar al cuidado de una persona con cáncer puede incluir muchas tensiones. Sugerencias para que se cuide usted cuando cuida a otros.

  15. Tumores cerebrales—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento de los tumores cerebrales, así como referencias a estudios clínicos, estadísticas y otros temas relacionados con estos tipos de cáncer.

  16. Linfoma—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del linfoma, así como referencias a estudios clínicos, investigación, estadísticas y otros temas relacionados con este tipo de cáncer.

  17. Fatiga (PDQ®)—Versión para pacientes

    Cancer.gov

    Resumen de información revisada por expertos acerca de la fatiga, una afección caracterizada por extremo cansancio e incapacidad para funcionar por la falta de energía, que a menudo se observa como una complicación del cáncer y su tratamiento.

  18. Delirio (PDQ®)—Versión para pacientes

    Cancer.gov

    Resumen de información revisada por expertos acerca del delirio como una complicación del cáncer o su tratamiento. Se tratan enfoques de los cuidados médicos de apoyo y los abordajes farmacológicos para el manejo del delirio.

  19. Mesotelioma maligno—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento y las causas del mesotelioma maligno, así como referencias a estudios clínicos y otros temas relacionados con este tipo de cáncer.

  20. Retinoblastoma—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del retinoblastoma, así como referencias a estudios clínicos, estadísticas y otros temas relacionados con este tipo de cáncer.

  1. Analyzing and Visualizing Cosmological Simulations with ParaView

    NASA Astrophysics Data System (ADS)

    Woodring, Jonathan; Heitmann, Katrin; Ahrens, James; Fasel, Patricia; Hsu, Chung-Hsing; Habib, Salman; Pope, Adrian

    2011-07-01

    The advent of large cosmological sky surveys—ushering in the era of precision cosmology—has been accompanied by ever larger cosmological simulations. The analysis of these simulations, which currently encompass tens of billions of particles and up to a trillion particles in the near future, is often as daunting as carrying out the simulations in the first place. Therefore, the development of very efficient analysis tools combining qualitative and quantitative capabilities is a matter of some urgency. In this paper, we introduce new analysis features implemented within ParaView, a fully parallel, open-source visualization toolkit, to analyze large N-body simulations. A major aspect of ParaView is that it can live and operate on the same machines and utilize the same parallel power as the simulation codes themselves. In addition, data movement is in a serious bottleneck now and will become even more of an issue in the future; an interactive visualization and analysis tool that can handle data in situ is fast becoming essential. The new features in ParaView include particle readers and a very efficient halo finder that identifies friends-of-friends halos and determines common halo properties, including spherical overdensity properties. In combination with many other functionalities already existing within ParaView, such as histogram routines or interfaces to programming languages like Python, this enhanced version enables fast, interactive, and convenient analyses of large cosmological simulations. In addition, development paths are available for future extensions.

  2. Neuroblastoma—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento y los exámenes de detección del neuroblastoma, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  3. Sistemas Correctores de Campo Para EL Telescopio Cassegrain IAC80

    NASA Astrophysics Data System (ADS)

    Galan, M. J.; Cobos, F. J.

    1987-05-01

    El proyecto de instrumentación de mayor importancia que ha tenido el Instituto de Astrofisica de Canarias en los últimos afios ha sido el diseflo y construcción del te1escopio IAC8O. Este requería del esfuerzo con junto en mec´nica, óptica y electrónica, lo que facilitó la estructuración y el crecimiento de los respectivos grupos de trabajo, que posteriormente se integraron en departamentos En su origen (1977), el telescopio IAC80 fue concebido como un sistema clásico tipo Cassegrain, con una razón focal F/i 1.3 para el sistema Casse grain y una razón focal F/20 para el sistema Coudé. Posteriormente, aunque se mantuvo la filosofia de que el sistema básico fuera el F/11.3, se consideró conveniente el diseño de secundarios para razones focales F/16 y F/32, y se eliminó el de F/20. Sin embargo, dada la importancia relativa que un foco estrictamente fotográfico tiene en un telescopio moderno, diseñado básicamente para fotometría fotoeléctrica y con un campo util mínimamente de 40 minutos de arco, se decídió Ilevar a cabo el diseño de un secundario F/8 con un sistema corrector de campo, pero que estuviera formado únicamente por lentes con superficies esféricas para que asl su construcción fuera posible en España ó en México. La creciente utilización de detectores bidimensionales para fines de investigación astron6mica y la viabilidad de que en un futuro cercano éstos tengan un área sensible cada vez mayor, hicieron atractiva la idea de tener diseñado un sistema corrector de campo para el foco primario (F/3), con un campo útil mínimo de un grado, y también con la limitante de que sus componentes tuvieron sólamente supérficies esféricas. Ambos diseños de los sis-temas correctores de campo se llevaron a cabo, en gran medida, como parte de un proyecto de colaboración e intercambio en el área de diseño y evaluación de sistemas ópticos.

  4. [Ricerca storica sul contributo di Cristina Trivulzio di Belgiojoso all'assistenza infermieristica].

    PubMed

    Bertozzi, Simona; Di Mauro, Stefania; Manzoni, Edoardo

    2016-01-01

    The aim of this historical research project is to examine the contribution of Cristina Trivulzio Princess of Belgiojoso to the development of the nursing organisation in Italy. Specifically, the analysis focuses on the period of the Roman Republic, as in 1849 Cristina Trivulzio (Princess of Belgiojoso) was one of the person in charge of the service of caring and rescuing of the injured. For this reason, nineteen volumes were analysed out of the one hundred twenty-nine volumes found in five Italian historical archives. All documentary sources were evaluated accordingly to the Chabod historical research method (1999), while for their critical interpretation a scheme of analysis was created. As a result, five topics clearly emerged from the data collected: organisation, health politics, training, research and nursing. To sum up, this research reveals that the contributions of Cristina Trivulzio are so relevant that she may be counted among the founders of the italian nursing organisation. PMID:27191519

  5. La Cometa 67P Churyumov-Gerasimenko el il contributo degli astrofili italiani alla missione ROSETTA

    NASA Astrophysics Data System (ADS)

    Milani, Giannantonio

    2004-08-01

    Comet 67P Churyumov-Gerasimenko, the new target of the ROSETTA spacecraft, was oberved during the 2002/2003 apparition, displacing an unusual tail. The tail was compatible with a neck-line structure and this implies a high nuclear activity far before perihelion. Images and data from the current and previous apparitions show that the comet reaches the maximum brightening after the perihelion passage (Af[rho] = 200-250 cm).

  6. DESIGN NOTE: A compact catalytic converter for the production of para-hydrogen

    NASA Astrophysics Data System (ADS)

    Juarez, A. M.; Cubric, D.; King, G. C.

    2002-05-01

    The design and operation of a compact converter to produce a constant flow of para-hydrogen from normal hydrogen is described. The converter features a paramagnetic compound (nickel sulfate) that catalyses the conversion of ortho- to para-hydrogen at temperatures of 14-21 K. The converter has been tested by measuring rotationally resolved photoelectron spectra in the para-hydrogen produced. The percentage of the para-hydrogen species in the converted gas was determined to be >97%.

  7. Control del dolor: Apoyo para las personas con cáncer

    Cancer.gov

    Contiene información sobre las medicinas contra el dolor para pacientes con cáncer, los planes para controlarlo, cómo hablar con su equipo de atención médica sobre el dolor que usted siente y qué hacer para controlar los efectos físicos y emocionales del

  8. ParA resolvase catalyzes site-specific excision of DNA from the Arabidopsis genome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The small serine resolvase ParA from bacterial plasmids RK2 and RP4 catalyzes the recombination of two identical 133 bp recombination sites known as MRS. Previously, we reported that ParA is active in the fission yeast Schizosaccharomyces pombe. In this work, the parA recombinase gene was placed un...

  9. The Regulation of para-Nitrophenol Degradation in Pseudomonas putida DLL-E4

    PubMed Central

    Chen, Qiongzhen; Tu, Hui; Luo, Xue; Zhang, Biying; Huang, Fei; Li, Zhoukun; Wang, Jue; Shen, Wenjing; Wu, Jiale; Cui, Zhongli

    2016-01-01

    Pseudomonas putida DLL-E4 can efficiently degrade para-nitrophenol and its intermediate metabolite hydroquinone. The regulation of para-nitrophenol degradation was studied, and PNP induced a global change in the transcriptome of P. putida DLL-E4. When grown on PNP, the wild-type strain exhibited significant downregulation of 2912 genes and upregulation of 845 genes, whereas 2927 genes were downregulated and 891 genes upregulated in a pnpR-deleted strain. Genes related to two non-coding RNAs (ins1 and ins2), para-nitrophenol metabolism, the tricarboxylic acid cycle, the outer membrane porin OprB, glucose dehydrogenase Gcd, and carbon catabolite repression were significantly upregulated when cells were grown on para-nitrophenol plus glucose. pnpA, pnpR, pnpC1C2DECX1X2, and pnpR1 are key genes in para-nitrophenol degradation, whereas pnpAb and pnpC1bC2bDbEbCbX1bX2b have lost the ability to degrade para-nitrophenol. Multiple components including transcriptional regulators and other unknown factors regulate para-nitrophenol degradation, and the transcriptional regulation of para-nitrophenol degradation is complex. Glucose utilization was enhanced at early stages of para-nitrophenol supplementation. However, it was inhibited after the total consumption of para-nitrophenol. The addition of glucose led to a significant enhancement in para-nitrophenol degradation and up-regulation in the expression of genes involved in para-nitrophenol degradation and carbon catabolite repression (CCR). It seemed that para-nitrophenol degradation can be regulated by CCR, and relief of CCR might contribute to enhanced para-nitrophenol degradation. In brief, the regulation of para-nitrophenol degradation seems to be controlled by multiple factors and requires further study. PMID:27191401

  10. Para rubber seed oil: new promising unconventional oil for cosmetics.

    PubMed

    Lourith, Nattaya; Kanlayavattanakul, Mayuree; Sucontphunt, Apirada; Ondee, Thunnicha

    2014-01-01

    Para rubber seed was macerated in petroleum ether and n-hexane, individually, for 30 min. The extraction was additionally performed by reflux and soxhlet for 6 h with the same solvent and proportion. Soxhlet extraction by petroleum ether afforded the greatest extractive yield (22.90 ± 0.92%). Although antioxidant activity by means of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay was insignificantly differed in soxhleted (8.90 ± 1.15%) and refluxed (9.02 ± 0.71%) by n-hexane, soxhlet extraction by n-hexane was significantly (p < 0.05) potent scavenged 2,2'-azino-bis(3-ethylbenzothaiazoline)-6-sulfonic acid) or ABTS radical with trolox equivalent antioxidant capacity (TEAC) of 66.54 ± 6.88 mg/100 g oil. This extract was non cytotoxic towards normal human fibroblast cells. In addition, oleic acid and palmitic acid were determined at a greater content than in the seed of para rubber cultivated in Malaysia, although linoleic and stearic acid contents were not differed. This bright yellow extract was further evaluated on other physicochemical characters. The determined specific gravity, refractive index, iodine value, peroxide value and saponification value were in the range of commercialized vegetable oils used as cosmetic raw material. Therefore, Para rubber seed oil is highlighted as the promising ecological ingredient appraisal for cosmetics. Transforming of the seed that is by-product of the important industrial crop of Thailand into cosmetics is encouraged accordingly. PMID:24976614

  11. TELEMEDICINA: UN DESAFÍO PARA AMÉRICA LATINA

    PubMed Central

    Litewka, Sergio

    2011-01-01

    La telemedicina es una tendencia creciente en la prestación de los servicios médicos. Aunque la eficacia de esta práctica no ha estado bien establecida, es probable que los países en desarrollo compartirán este nuevo paradigma con los desarrollados. Los defensores de la telemedicina en América Latina sostienen que será una herramienta útil para reducir las disparidades y mejorar la accesibilidad de atención de salud. Aunque América Latina quizá se convierta en un lugar para la investigación e investigación de estos procedimientos, no está claro cómo la telemedicina podría contribuir a mejorar la accesibilidad para las poblaciones desfavorecidas, o coexistir con sistemas de atención de salud públicos crónicamente enfermos. Telemedicine is a growing trend in the provision of medical services. Although the effectiveness of this practice has not been well established, it is likely that developing countries will share this new paradigm with developed ones. Supporters of telemedicine in Latin America maintain that it will be a useful tool for reducing disparities and improving health care accessibility. Although Latin America might become a place for research and investigation of these procedures, it is not clear how telemedicine could contribute to improving accessibility for disadvantaged populations, or coexist with chronically ill-funded public healthcare systems. PMID:21625326

  12. ORTHO-PARA SELECTION RULES IN THE GAS-PHASE CHEMISTRY OF INTERSTELLAR AMMONIA

    SciTech Connect

    Faure, A.; Hily-Blant, P.; Le Gal, R.; Rist, C.

    2013-06-10

    The ortho-para chemistry of ammonia in the cold interstellar medium is investigated using a gas-phase chemical network. Branching ratios for the primary reaction chain involved in the formation and destruction of ortho- and para-NH{sub 3} were derived using angular momentum rules based on the conservation of the nuclear spin. We show that the 'anomalous' ortho-to-para ratio of ammonia ({approx}0.7) observed in various interstellar regions is in fact consistent with nuclear spin selection rules in a para-enriched H{sub 2} gas. This ratio is found to be independent of temperature in the range 5-30 K. We also predict an ortho-to-para ratio of {approx}2.3 for NH{sub 2}. We conclude that a low ortho-to-para ratio of H{sub 2} naturally drives the ortho-to-para ratios of nitrogen hydrides below the statistical values.

  13. ParA resolvase catalyzes site-specific excision of DNA from the Arabidopsis genome.

    PubMed

    Thomson, James G; Yau, Yuan-Yeu; Blanvillain, Robert; Nunes, Wylla M; Chiniquy, Dawn; Thilmony, Roger; Ow, David W

    2009-04-01

    The small serine resolvase ParA from bacterial plasmids RK2 and RP4 catalyzes the recombination of two identical 133 bp recombination sites known as MRS. Previously, we reported that ParA is active in the fission yeast Schizosaccharomyces pombe. In this work, the parA recombinase gene was placed under the control of the Arabidopsis OXS3 promoter and introduced into Arabidopsis lines harboring a chromosomally integrated MRS-flanked target. The ParA recombinase excised the MRS-flanked DNA and the excision event was detected in subsequent generations in the absence of ParA, indicating germinal transmission of the excision event. The precise site-specific deletion by the ParA recombination system in planta demonstrates that the ParA recombinase can be used to remove transgenic DNA, such as selectable markers or other introduced transgenes that are no longer desired in the final product. PMID:18704739

  14. Laparoscopic para-aortic lymph node dissection for patients with primary colorectal cancer and clinically suspected para-aortic lymph nodes

    PubMed Central

    Song, Sung Ho; Park, Soo Yeun; Park, Jun Seok; Kim, Hye Jin; Yang, Chun-Seok

    2016-01-01

    Purpose Treatment of patients with para-aortic lymph node metastasis from colorectal cancer is controversial. The goal of this study was to investigate the technical feasibility of laparoscopic intrarenal para-aortic lymph node dissection in patients with colorectal cancer and clinically suspected para-aortic lymph node dissection. Methods The inclusion criteria for the laparoscopic approach were patients with infrarenal para-aortic lymph node metastasis from colorectal cancer. Patients who had any other distant metastatic lesion or metachronous para-aortic lymph node metastasis were excluded from this study. Perioperative outcomes and survival outcomes were analyzed. Results Between November 2004 and October 2013, 40 patients underwent laparoscopic para-aortic lymph node dissection. The mean operating time was 192.3 ± 68.8 minutes (range, 100-400 minutes) and the mean estimated blood loss was 65.6 ± 52.6 mL (range, 20-210 mL). No patient required open conversion. The postoperative complication rate was 15.0%. Sixteen patients (40.0%) had pathologically positive lymph nodes. In patients with metastatic para-aortic lymph nodes, the 3-year overall survival rate and disease-free survival rate were 65.7% and 40.2%, respectively. Conclusion The results of our study suggest that a laparoscopic approach for patients with colorectal cancer with metastatic para-aortic lymph nodes can be a reasonable option for selected patients. PMID:26793690

  15. Centro para la Salud Mundial del NCI anuncia becas de investigación para tecnologías portátiles

    Cancer.gov

    El Centro para la Salud Mundial del NCI (CGH) anunció el otorgamiento de subvenciones que apoyarán el desarrollo y la validación de tecnologías portátiles y de bajo costo para mejorar la detección temprana, el diagnóstico y el tratamiento del cáncer.

  16. TELEMEDICINA: UN DESAFÍO PARA AMÉRICA LATINA.

    PubMed

    Litewka, Sergio

    2005-01-01

    La telemedicina es una tendencia creciente en la prestación de los servicios médicos. Aunque la eficacia de esta práctica no ha estado bien establecida, es probable que los países en desarrollo compartirán este nuevo paradigma con los desarrollados. Los defensores de la telemedicina en América Latina sostienen que será una herramienta útil para reducir las disparidades y mejorar la accesibilidad de atención de salud. Aunque América Latina quizá se convierta en un lugar para la investigación e investigación de estos procedimientos, no está claro cómo la telemedicina podría contribuir a mejorar la accesibilidad para las poblaciones desfavorecidas, o coexistir con sistemas de atención de salud públicos crónicamente enfermos.Telemedicine is a growing trend in the provision of medical services. Although the effectiveness of this practice has not been well established, it is likely that developing countries will share this new paradigm with developed ones. Supporters of telemedicine in Latin America maintain that it will be a useful tool for reducing disparities and improving health care accessibility. Although Latin America might become a place for research and investigation of these procedures, it is not clear how telemedicine could contribute to improving accessibility for disadvantaged populations, or coexist with chronically ill-funded public healthcare systems. PMID:21625326

  17. Amazon Land Wars in the South of Para

    NASA Technical Reports Server (NTRS)

    Simmons, Cynthia S.; Walker, Robert T.; Arima, Eugenio Y.; Aldrich, Stephen P.; Caldas, Marcellus M.

    2007-01-01

    The South of Para, located in the heart of the Brazilian Amazon, has become notorious for violent land struggle. Although land conflict has a long history in Brazil, and today impacts many parts of the country, violence is most severe and persistent here. The purpose of this article is to examine why. Specifically, we consider how a particular Amazonian place, the so-called South of Para has come to be known as Brazil's most dangerous badland. We begin by considering the predominant literature, which attributes land conflict to the frontier expansion process with intensified struggle emerging in the face of rising property values and demand for private property associated with capitalist development. From this discussion, we distill a concept of the frontier, based on notions of property rights evolution and locational rents. We then empirically test the persistence of place-based violence in the region, and assess the frontier movement through an analysis of transportation costs. The findings from the analyses indicate that the prevalent theorization of frontier violence in Amazonia does little to explain its persistent and pervasive nature in the South of Para. To fill this gap in understanding, we develop an explanation based the geographic conception of place, and we use contentious politics theory heuristically to elucidate the ways in which general processes interact with place specific history to engender a landscape of violence. In so doing, we focus on environmental, cognitive, and relational mechanisms (and implicated structures), and attempt to deploy them in an explanatory framework that allows direct observation of the accumulating layers of the region's tragic history. We end by placing our discussion within a political ecological context, and consider the implications of the Amazon Land War for the environment.

  18. American Indian/Alaskan Native Undergraduate Retention at Predominantly White Institutions: An Elaboration of Tinto's Theory of College Student Departure

    ERIC Educational Resources Information Center

    Lee, Junghee; Donlan, William; Brown, Eddie F.

    2011-01-01

    This article reports findings from a major public university sponsored study undertaken with the intention of (a) improving university understanding of factors affecting American Indian/Alaskan Native (AI/AN) undergraduates' persistence at this institution, and (b) identifying in what areas, and in what manner, this institution could improve…

  19. The Search for Subsurface Life on Mars: Results from the MARTE Analog Drill Experiment in Rio Tinto, Spain

    NASA Astrophysics Data System (ADS)

    Stoker, C. R.; Lemke, L. G.; Cannon, H.; Glass, B.; Dunagan, S.; Zavaleta, J.; Miller, D.; Gomez-Elvira, J.

    2006-03-01

    The Mars Analog Research and Technology (MARTE) experiment has developed an automated drilling system on a simulated Mars lander platform including drilling, sample handling, core analysis and down-hole instruments relevant to searching for life in the Martian subsurface.

  20. Mars Analog Rio Tinto Experiment (MARTE): An Experimental Demonstration of Key Technologies for Searching for Life on Mars

    NASA Technical Reports Server (NTRS)

    Stoker, Carol

    2004-01-01

    The discovery of near surface ground ice by the Mars Odyssey mission and the abundant evidence for recent Gulley features observed by the Mars Global Surveyor mission support longstanding theoretical arguments for subsurface liquid water on Mars. Thus, implementing the Mars program goal to search for life points to drilling on Mars to reach liquid water, collecting samples and analyzing them with instrumentation to detect in situ organisms and biomarker compounds. Searching for life in the subsurface of Mars will require drilling, sample extraction and handling, and new technologies to find and identify biomarker compounds and search for living organisms.

  1. RVA: A Plugin for ParaView 3.14

    SciTech Connect

    2015-09-04

    RVA is a plugin developed for the 64-bit Windows version of the ParaView 3.14 visualization package. RVA is designed to provide support in the visualization and analysis of complex reservoirs being managed using multi-fluid EOR techniques. RVA, for Reservoir Visualization and Analysis, was developed at the University of Illinois at Urbana-Champaign, with contributions from the Illinois State Geological Survey, Department of Computer Science and National Center for Supercomputing Applications. RVA was designed to utilize and enhance the state-of-the-art visualization capabilities within ParaView, readily allowing joint visualization of geologic framework and reservoir fluid simulation model results. Particular emphasis was placed on enabling visualization and analysis of simulation results highlighting multiple fluid phases, multiple properties for each fluid phase (including flow lines), multiple geologic models and multiple time steps. Additional advanced functionality was provided through the development of custom code to implement data mining capabilities. The built-in functionality of ParaView provides the capacity to process and visualize data sets ranging from small models on local desktop systems to extremely large models created and stored on remote supercomputers. The RVA plugin that we developed and the associated User Manual provide improved functionality through new software tools, and instruction in the use of ParaView-RVA, targeted to petroleum engineers and geologists in industry and research. The RVA web site (http://rva.cs.illinois.edu) provides an overview of functions, and the development web site (https://github.com/shaffer1/RVA) provides ready access to the source code, compiled binaries, user manual, and a suite of demonstration data sets. Key functionality has been included to support a range of reservoirs visualization and analysis needs, including: sophisticated connectivity analysis, cross sections through simulation results between

  2. Spectroscopy of Single Dibenzoterrylene Molecules in para-Dichlorobenzene.

    PubMed

    Verhart, Nico R; Müller, Mathias; Orrit, Michel

    2016-05-18

    We study single dibenzoterrylene (DBT) molecules embedded in 1,4-dichlorobenzene (para-dichlorobenzene, pDCB) at 1.2 K. Due to the relatively low melting point of pDCB (53 °C), this host-guest system can be easily prepared from the molten phase. Narrow linewidths, stable molecular lines and high saturation count rates of single DBT molecules were observed. For this reason, we consider this host-guest system a promising candidate for the study of interactions of single molecules with other small objects such as waveguides or nanoparticles. PMID:26840901

  3. RVA: A Plugin for ParaView 3.14

    Energy Science and Technology Software Center (ESTSC)

    2015-09-04

    RVA is a plugin developed for the 64-bit Windows version of the ParaView 3.14 visualization package. RVA is designed to provide support in the visualization and analysis of complex reservoirs being managed using multi-fluid EOR techniques. RVA, for Reservoir Visualization and Analysis, was developed at the University of Illinois at Urbana-Champaign, with contributions from the Illinois State Geological Survey, Department of Computer Science and National Center for Supercomputing Applications. RVA was designed to utilize andmore » enhance the state-of-the-art visualization capabilities within ParaView, readily allowing joint visualization of geologic framework and reservoir fluid simulation model results. Particular emphasis was placed on enabling visualization and analysis of simulation results highlighting multiple fluid phases, multiple properties for each fluid phase (including flow lines), multiple geologic models and multiple time steps. Additional advanced functionality was provided through the development of custom code to implement data mining capabilities. The built-in functionality of ParaView provides the capacity to process and visualize data sets ranging from small models on local desktop systems to extremely large models created and stored on remote supercomputers. The RVA plugin that we developed and the associated User Manual provide improved functionality through new software tools, and instruction in the use of ParaView-RVA, targeted to petroleum engineers and geologists in industry and research. The RVA web site (http://rva.cs.illinois.edu) provides an overview of functions, and the development web site (https://github.com/shaffer1/RVA) provides ready access to the source code, compiled binaries, user manual, and a suite of demonstration data sets. Key functionality has been included to support a range of reservoirs visualization and analysis needs, including: sophisticated connectivity analysis, cross sections through simulation results

  4. Biodegradation of Para Amino Acetanilide by Halomonas sp. TBZ3

    PubMed Central

    Hajizadeh, Nader; Sefidi Heris, Youssof; Zununi Vahed, Sepideh; Vallipour, Javad; Hejazi, Mohammad Amin; Golabi, Sayyed Mahdi; Asadpour-Zeynali, Karim; Hejazi, Mohammad Saeid

    2015-01-01

    Background: Aromatic compounds are known as a group of highly persistent environmental pollutants. Halomonas sp. TBZ3 was isolated from the highly salty Urmia Lake of Iran. In this study, characterization of a new Halomonas isolate called Halomonas sp. TBZ3 and its employment for biodegradation of para-amino acetanilide (PAA), as an aromatic environmental pollutant, is described. Objectives: This study aimed to characterize the TBZ3 isolate and to elucidate its ability as a biodegradative agent that decomposes PAA. Materials and Methods: Primarily, DNA-DNA hybridization between TBZ3, Halomonas denitrificans DSM18045T and Halomonas saccharevitans LMG 23976T was carried out. Para-amino acetanilide biodegradation was assessed using spectrophotometry and confirmed by gas chromatography-mass spectroscopy (GC-MS). Parameters effective on biodegradation of PAA were optimized by the Response Surface Methodology (RSM). Results: The DNA-DNA hybridization experiments between isolate TBZ3, H. denitrificans and H. saccharevitans revealed relatedness levels of 57% and 65%, respectively. According to GC-MS results, TBZ3 degrades PAA to benzene, hexyl butanoate, 3-methyl-1-heptanol and hexyl hexanoate. Temperature 32.92°C, pH 6.76, and salinity 14% are the optimum conditions for biodegradation with a confidence level of 95% (at level α = 0.05). Conclusions: According to our results, Halomonas sp. TBZ3 could be considered as a biological agent for bioremediation of PAA and possibly other similar aromatic compounds. PMID:26495103

  5. CYP96T1 of Narcissus sp. aff. pseudonarcissus Catalyzes Formation of the Para-Para' C-C Phenol Couple in the Amaryllidaceae Alkaloids

    PubMed Central

    Kilgore, Matthew B.; Augustin, Megan M.; May, Gregory D.; Crow, John A.; Kutchan, Toni M.

    2016-01-01

    The Amaryllidaceae alkaloids are a family of amino acid derived alkaloids with many biological activities; examples include haemanthamine, haemanthidine, galanthamine, lycorine, and maritidine. Central to the biosynthesis of the majority of these alkaloids is a C-C phenol-coupling reaction that can have para-para', para-ortho', or ortho-para' regiospecificity. Through comparative transcriptomics of Narcissus sp. aff. pseudonarcissus, Galanthus sp., and Galanthus elwesii we have identified a para-para' C-C phenol coupling cytochrome P450, CYP96T1, capable of forming the products (10bR,4aS)-noroxomaritidine and (10bS,4aR)-noroxomaritidine from 4′-O-methylnorbelladine. CYP96T1 was also shown to catalyzed formation of the para-ortho' phenol coupled product, N-demethylnarwedine, as less than 1% of the total product. CYP96T1 co-expresses with the previously characterized norbelladine 4′-O-methyltransferase. The discovery of CYP96T1 is of special interest because it catalyzes the first major branch in Amaryllidaceae alkaloid biosynthesis. CYP96T1 is also the first phenol-coupling enzyme characterized from a monocot. PMID:26941773

  6. Ortho-para mixing hyperfine interaction in the H2O+ ion and nuclear spin equilibration.

    PubMed

    Tanaka, Keiichi; Harada, Kensuke; Oka, Takeshi

    2013-10-01

    The ortho to para conversion of water ion, H2O(+), due to the interaction between the magnetic moments of the unpaired electron and protons has been theoretically studied to calculate the spontaneous emission lifetime between the ortho- and para-levels. The electron spin-nuclear spin interaction term, Tab(SaΔIb + SbΔIa) mixes ortho (I = 1) and para (I = 0) levels to cause the "forbidden" ortho to para |ΔI| = 1 transition. The mixing term with Tab = 72.0 MHz is 4 orders of magnitude higher for H2O(+) than for its neutral counterpart H2O where the magnetic field interacting with proton spins is by molecular rotation rather than the free electron. The resultant 10(8) increase of ortho to para conversion rate possibly makes the effect of conversion in H2O(+) measurable in laboratories and possibly explains the anomalous ortho to para ratio recently reported by Herschel heterodyne instrument for the far-infrared (HIFI) observation. Results of our calculations show that the ortho ↔ para mixings involving near-degenerate ortho and para levels are high (∼10(-3)), but they tend to occur at high energy levels, ∼300 K. Because of the rapid spontaneous emission, such high levels are not populated in diffuse clouds unless the radiative temperature of the environment is very high. The low-lying 101 (para) and 111 (ortho) levels of H2O(+) are mixed by ∼10(-4) making the spontaneous emission lifetime for the para 101 → ortho 000 transition 520 years and 5200 years depending on the F value of the hyperfine structure. Thus the ortho ↔ para conversion due to the unpaired electron is not likely to seriously affect thermalization of interstellar H2O(+) unless either the radiative temperature is very high or number density of the cloud is very low. PMID:23530629

  7. ParaText : scalable text analysis and visualization.

    SciTech Connect

    Dunlavy, Daniel M.; Stanton, Eric T.; Shead, Timothy M.

    2010-07-01

    Automated analysis of unstructured text documents (e.g., web pages, newswire articles, research publications, business reports) is a key capability for solving important problems in areas including decision making, risk assessment, social network analysis, intelligence analysis, scholarly research and others. However, as data sizes continue to grow in these areas, scalable processing, modeling, and semantic analysis of text collections becomes essential. In this paper, we present the ParaText text analysis engine, a distributed memory software framework for processing, modeling, and analyzing collections of unstructured text documents. Results on several document collections using hundreds of processors are presented to illustrate the exibility, extensibility, and scalability of the the entire process of text modeling from raw data ingestion to application analysis.

  8. Pneumatic protection applied to an airbag for para-gliders

    NASA Astrophysics Data System (ADS)

    Raievski, V.; Valladas, G.

    1998-02-01

    We present a theory of pneumatic protection based on the laws of thermodynamics, elasticity and fluid mechanics. A general pneumatic protection system is made up of several communicating compartments, the differences in pressure of the compartments generating a transfer of mass and energy between them. The transfer offers interesting possibilities to improve the performance of the system. An example of this type of protection in aerial sport is the airbag for para-gliders, it is used in this paper to illustrate the theory. As the pressure in the airbag depends uniquely on its volume, the geometric model in the theory can be simplified. Experiments carried out with crash-test dummies equipped with sensors have confirmed the theoretical predictions.

  9. Spectroscopy of Defects in Epitaxially Grown Para-sexiphenyl Nanostructures

    NASA Astrophysics Data System (ADS)

    Kadashchuk, A.; Schols, S.; Skryshevski, Yu.; Beynik, I.; Teichert, C.; Hernandez-Sosa, G.; Sitter, H.; Andreev, A.; Frank, P.; Winkler, A.

    We present a study of steady-state- and time-resolved photoluminescence of para-sexiphenyl (PSP) films on KCl grown by organic molecular beam epitaxy (OMBE). Using different OMBE growth conditions has enabled us to vary greatly the morphology of the PSP crystallites but keeping virtually untouched their chemical structure. By this comparative study we prove that the broad red-shifted emission band has a structure-related origin rather than being due to monomolecular oxidative defects. The relative intensity of the defect emission band observed in the delayed spectra was found to be drastically suppressed in the OMBE-grown films dominated by growth mounds composed of upright standing molecules as opposed to the films consisting of crystallites formed by molecules lying parallel to the substrate.

  10. Para-Hydrogen-Enhanced Gas-Phase Magnetic Resonance Imaging

    SciTech Connect

    Bouchard, Louis-S.; Kovtunov, Kirill V.; Burt, Scott R.; Anwar,M. Sabieh; Koptyug, Igor V.; Sagdeev, Renad Z.; Pines, Alexander

    2007-02-23

    Herein, we demonstrate magnetic resonance imaging (MRI) inthe gas phase using para-hydrogen (p-H2)-induced polarization. A reactantmixture of H2 enriched in the paraspin state and propylene gas is flowedthrough a reactor cell containing a heterogenized catalyst, Wilkinson'scatalyst immobilized on modified silica gel. The hydrogenation product,propane gas, is transferred to the NMR magnet and is spin-polarized as aresult of the ALTADENA (adiabatic longitudinal transport and dissociationengenders net alignment) effect. A polarization enhancement factor of 300relative to thermally polarized gas was observed in 1D1H NMR spectra.Enhancement was also evident in the magnetic resonance images. This isthe first demonstration of imaging a hyperpolarized gaseous productformed in a hydrogenation reaction catalyzed by a supported catalyst.This result may lead to several important applications, includingflow-through porous materials, gas-phase reaction kinetics and adsorptionstudies, and MRI in low fields, all using catalyst-free polarizedfluids.

  11. Nuevos sistemas de frecuencia intermedia para el IAR

    NASA Astrophysics Data System (ADS)

    Olalde, J. C.; Perilli, D.; Larrarte, J. J.

    Se presenta el diagrama en bloques de los nuevos sistemas de Frecuencia Intermedia para los dos radiómetros instalados en el IAR. Entre las características más importantes del sistema podemos mencionar la posibilidad de conectar cualquiera de las dos antenas a los ``backend" disponibles: analizador espectral de alta resolución (META II) de 0,05 Hz, autocorrelador de 1008 canales y contínuo. Se incorporan al sistema nuevos sintetizadores de frecuencia implementados con PLL y la moderna técnica de síntesis digital directa. Por último, el conjunto del sistema es susceptible de ser configurado por las computadoras de adquisición de datos, supervisadas por otra, que entrega el estado de funcionamiento actual y evita la selección de configuraciones incorrectas por parte del usuario.

  12. Wave intensity analysis of para-aortic counterpulsation.

    PubMed

    Lu, Pong-Jeu; Yang, Chi-Fu Jeffrey; Wu, Meng-Yu; Hung, Chun-Hao; Chan, Ming-Yao; Hsu, Tzu-Cheng

    2012-04-01

    Wave intensity analysis (WIA) was used to delineate and maximize the efficacy of a newly developed para-aortic blood pump (PABP). The intra-aortic balloon pump (IABP) was employed as the comparison benchmark. Acute porcine experiments using eight pigs, randomly divided into IABP (n = 4) and PABP (n = 4) groups, were conducted to compare the characteristics of intra- and para-aortic counterpulsation. We measured pressure and velocity with probes installed in the left anterior descending coronary artery and aorta, during and without PABP assistance. Wave intensity for aortic and left coronary waves were derived from pressure and flow measurements with synchronization correction applied. To achieve maximized support efficacy, deflation timings ranging from 25 ms ahead of to 35 ms after the R-wave were tested. Similar to those associated with IABP counterpulsation, the PABP-generated backward-traveling waves predominantly drove aortic and coronary blood flows. However, in contrast with IABP counterpulsation, the nonocclusive nature of the PABP allowed systolic unloading to be delayed into early systole, which resulted in near elimination of coronary blood steal without diminution of systolic left ventricular ejection wave intensities. WIA can elucidate subtleties among different counterpulsatile support means with high sensitivity. Total accelerating wave intensity (TAWI), which was defined as the sum of the time integration of accelerated parts of the positive and negative wave intensities, was used to quantify counterpulsation efficacy. In general, the larger the TAWI gain, the better the counter-pulsatile support efficacy. However, when PABP deflation timings were delayed to after the R-wave, the TAWI was found to be inversely correlated with coronary perfusion. In this delayed deflation timing setting, greater wave cancellation occurred, which led to decreased TAWI but increased coronary perfusion attributed to blood regurgitation reduction. PMID:22227124

  13. The Clearance of Creatinine, Inulin, Para-aminohippurate and Phenosulphothalein in the Cat

    PubMed Central

    Osbaldiston, G. W.; Fuhrman, W.

    1970-01-01

    Endogenous creatinine, inulin, para-amino-hippurate and phenolsulphothalein clearances for healthy cats are presented. The values for inulin and para-aminohippurate clearances (ml/kg/min) are similar to those for the dog. Creatinine clearance was less than inulin clearance values. Pnenolsulphothalein clearance may be a better index of glomerular rather than tubular function in the cat. PMID:4246836

  14. Chiral phosphoric acid catalyzed asymmetric addition of naphthols to para-quinone methides.

    PubMed

    Wong, Yuk Fai; Wang, Zhaobin; Sun, Jianwei

    2016-06-28

    An asymmetric addition of naphthols to in situ generated para-quinone methides catalyzed by a chiral phosphoric acid is described. A range of useful triarylmethanes can be generated from stable general para-hydroxybenzyl alcohols with good efficiency and enantioselectivity. PMID:26932597

  15. Para-meatal urethral cyst with bladder calculi: A case report and review of the literature.

    PubMed

    Patil, Siddangouda B; Patil, Nikhil Ashok; Kundargi, Vinay S; Biradar, Ashok N

    2015-01-01

    Para-meatal urethral cyst or median raphe cyst of the glans penis is a benign cystic lesion uncommonly encountered in prepubertal age group. Approximately, about 50 cases have been reported till date in the world literature. Herein we report a case of para-meatal urethral cyst concurrent with urinary bladder calculi. PMID:26539378

  16. The parA resolvase performs site-specific genomic excision in Arabidopsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have designed a site-specific excision detection system in Arabidopsis to study the in planta activity of the small serine recombinase ParA. Using a transient expression assay as well as stable transgenic plant lines, we show that the ParA recombinase is catalytically active and capable of perfo...

  17. Para-meatal urethral cyst with bladder calculi: A case report and review of the literature

    PubMed Central

    Patil, Siddangouda B.; Patil, Nikhil Ashok; Kundargi, Vinay S.; Biradar, Ashok N.

    2015-01-01

    Para-meatal urethral cyst or median raphe cyst of the glans penis is a benign cystic lesion uncommonly encountered in prepubertal age group. Approximately, about 50 cases have been reported till date in the world literature. Herein we report a case of para-meatal urethral cyst concurrent with urinary bladder calculi. PMID:26539378

  18. Under the skin: Biotransformation of para-aminophenol and para-phenylenediamine in reconstructed human epidermis and human hepatocytes.

    PubMed

    Nohynek, Gerhard J; Duche, Daniel; Garrigues, Alexia; Meunier, Pierre-Alain; Toutain, Herve; Leclaire, Jacques

    2005-09-15

    We investigated the biotransformation of the oxidative arylamine (AA) hair dye ingredients [14C]-para-aminophenol (PAP) and [14C]-para-phenylenediamine (PPD) in reconstructed human epidermis and human hepatocytes. Human epidermis quantitatively transformed PAP to its N-acetylated derivative (APAP), whereas hepatocytes transformed PAP to sulfate or glucuronic acid conjugates of APAP or PAP as well as free APAP. Epidermis and hepatocytes converted PPD to N-mono- (MAPPD) and N,N'-di-acetylated (DAPPD) derivatives. At higher concentrations of PPD (250-1000 microM), epidermis or hepatocytes produced more of the MAPPD, whereas concentrations below 250 microM and lower favoured formation of the DAPPD metabolite. When compared with epidermis, human hepatocytes had a three-fold or eight-fold greater capacity for generation of MAPPD or DAPPD, respectively. No evidence of transformation of PAP or PPD to N-hydroxylated derivatives was found in epidermis or hepatocytes. Our results suggest that (i) after dermal absorption of PAP or PPD, humans are systemically exposed to acetylated derivatives; (ii) current in vitro skin absorption studies may be inadapated for determination of human systemic exposure to AAs due to reduced or absent metabolic capacity of non-viable skin; (iii) due to qualitative differences between dermal and hepatic metabolism, oral toxicity studies may be unsuited for the hazard assessment of dermal exposure to AAs; and (iv) use of induced rodent liver S9 metabolic activation systems for in vitro genotoxicity studies may produce misleading results on the hazard of human dermal exposure to AAs. In conclusion, our data support the growing evidence that AAs are transformed in human skin and suggest that current practices of safety assessment of AAs should take these findings into account. PMID:15890478

  19. Contextual Factors that Foster or Inhibit Para-Teacher Professional Development: The Case of an Indian, Non-Governmental Organization

    ERIC Educational Resources Information Center

    Raval, Harini; McKenney, Susan; Pieters, Jules

    2012-01-01

    The appointment of para-professionals to overcome skill shortages and/or make efficient use of expensive resources is well established in both developing and developed countries. The present research concerns para-teachers in India. The literature on para-teachers is dominated by training for special needs settings, largely in developed societies.…

  20. Females prefer carotenoid colored males as mates in the pentamorphic livebearing fish, Poecilia parae.

    PubMed

    Bourne, Godfrey R; Breden, Felix; Allen, Teresa C

    2003-09-01

    The first results of female preference and chosen male mating success in a new model organism, the pentamorphic livebearing fish, Poecilia parae, are presented. Poecilia parae is a relative of the guppy, P. reticulata, and is assumed to have similar reproductive behavior. We tested the hypothesis that P. parae females, like female guppies, prefer carotenoid colored males as mates. Here we show that the time a female spent with males was significantly greater for carotenoid coloration in red and yellow melanzona, but time with these two morphs did not differ. The preferred red and yellow males mated significantly more often with their choosing females than did the non-preferred blue and parae males. The few blue melanzona and parae males that mated did so without performing courtship displays. Some females mated with all phenotypes including immaculata males during open group trials. Female P. parae clearly preferred males with carotenoid coloration, thereby corroborating the hypothesis. Alternative male mating tactics by blue melanzona, parae, and immaculata morphs and promiscuous mating by females also resembled features of reproductive behaviors exhibited by guppies. PMID:14504782

  1. Quantum fluctuations increase the self-diffusive motion of para-hydrogen in narrow carbon nanotubes.

    PubMed

    Kowalczyk, Piotr; Gauden, Piotr A; Terzyk, Artur P; Furmaniak, Sylwester

    2011-05-28

    Quantum fluctuations significantly increase the self-diffusive motion of para-hydrogen adsorbed in narrow carbon nanotubes at 30 K comparing to its classical counterpart. Rigorous Feynman's path integral calculations reveal that self-diffusive motion of para-hydrogen in a narrow (6,6) carbon nanotube at 30 K and pore densities below ∼29 mmol cm(-3) is one order of magnitude faster than the classical counterpart. We find that the zero-point energy and tunneling significantly smoothed out the free energy landscape of para-hydrogen molecules adsorbed in a narrow (6,6) carbon nanotube. This promotes a delocalization of the confined para-hydrogen at 30 K (i.e., population of unclassical paths due to quantum effects). Contrary the self-diffusive motion of classical para-hydrogen molecules in a narrow (6,6) carbon nanotube at 30 K is very slow. This is because classical para-hydrogen molecules undergo highly correlated movement when their collision diameter approached the carbon nanotube size (i.e., anomalous diffusion in quasi-one dimensional pores). On the basis of current results we predict that narrow single-walled carbon nanotubes are promising nanoporous molecular sieves being able to separate para-hydrogen molecules from mixtures of classical particles at cryogenic temperatures. PMID:21503294

  2. Para-nitrobenzyl esterases with enhanced activity in aqueous and nonaqueous media

    DOEpatents

    Arnold, F.H.; Moore, J.C.

    1999-05-25

    A method is disclosed for isolating and identifying modified para-nitrobenzyl esterases which exhibit improved stability and/or esterase hydrolysis activity toward selected substrates and under selected reaction conditions relative to the unmodified para-nitrobenzyl esterase. The method involves preparing a library of modified para-nitrobenzyl esterase nucleic acid segments (genes) which have nucleotide sequences that differ from the nucleic acid segment which encodes for unmodified para-nitrobenzyl esterase. The library of modified para-nitrobenzyl nucleic acid segments is expressed to provide a plurality of modified enzymes. The clones expressing modified enzymes are then screened to identify which enzymes have improved esterase activity by measuring the ability of the enzymes to hydrolyze the selected substrate under the selected reaction conditions. Specific modified para-nitrobenzyl esterases are disclosed which have improved stability and/or ester hydrolysis activity in aqueous or aqueous-organic media relative to the stability and/or ester hydrolysis activity of unmodified naturally occurring para-nitrobenzyl esterase. 43 figs.

  3. Para-nitrobenzyl esterases with enhanced activity in aqueous and nonaqueous media

    DOEpatents

    Arnold, Frances H.; Moore, Jeffrey C.

    1999-01-01

    A method for isolating and identifying modified para-nitrobenzyl esterases which exhibit improved stability and/or esterase hydrolysis activity toward selected substrates and under selected reaction conditions relative to the unmodified para-nitrobenzyl esterase. The method involves preparing a library of modified para-nitrobenzyl esterase nucleic acid segments (genes) which have nucleotide sequences that differ from the nucleic acid segment which encodes for unmodified para-nitrobenzyl esterase. The library of modified para-nitrobenzyl nucleic acid segments is expressed to provide a plurality of modified enzymes. The clones expressing modified enzymes are then screened to identify which enzymes have improved esterase activity by measuring the ability of the enzymes to hydrolyze the selected substrate under the selected reaction conditions. Specific modified para-nitrobenzyl esterases are disclosed which have improved stability and/or ester hydrolysis activity in aqueous or aqueous-organic media relative to the stability and/or ester hydrolysis activity of unmodified naturally occurring para-nitrobenzyl esterase.

  4. Para-nitrobenzyl esterases with enhanced activity in aqueous and nonaqueous media

    DOEpatents

    Arnold, Frances H.; Moore, Jeffrey C.

    1998-01-01

    A method for isolating and identifying modified para-nitrobenzyl esterases which exhibit improved stability and/or esterase hydrolysis activity toward selected substrates and under selected reaction conditions relative to the unmodified para-nitrobenzyl esterase. The method involves preparing a library of modified para-nitrobenzyl esterase nucleic acid segments (genes) which have nucleotide sequences that differ from the nucleic acid segment which encodes for unmodified para-nitrobenzyl esterase. The library of modified para-nitrobenzyl nucleic acid segments is expressed to provide a plurality of modified enzymes. The clones expressing modified enzymes are then screened to identify which enzymes have improved esterase activity by measuring the ability of the enzymes to hydrolyze the selected substrate under the selected reaction conditions. Specific modified para-nitrobenzyl esterases are disclosed which have improved stability and/or ester hydrolysis activity in aqueous or aqueous-organic media relative to the stability and/or ester hydrolysis activity of unmodified naturally occurring para-nitrobenzyl esterase.

  5. Para-nitrobenzyl esterases with enhanced activity in aqueous and nonaqueous media

    DOEpatents

    Arnold, F.H.; Moore, J.C.

    1998-04-21

    A method is disclosed for isolating and identifying modified para-nitrobenzyl esterases. These enzymes exhibit improved stability and/or esterase hydrolysis activity toward selected substrates and under selected reaction conditions relative to the unmodified para-nitrobenzyl esterase. The method involves preparing a library of modified para-nitrobenzyl esterase nucleic acid segments (genes) which have nucleotide sequences that differ from the nucleic acid segment which encodes for unmodified para-nitrobenzyl esterase. The library of modified para-nitrobenzyl nucleic acid segments is expressed to provide a plurality of modified enzymes. The clones expressing modified enzymes are then screened to identify which enzymes have improved esterase activity by measuring the ability of the enzymes to hydrolyze the selected substrate under the selected reaction conditions. Specific modified para-nitrobenzyl esterases are disclosed which have improved stability and/or ester hydrolysis activity in aqueous or aqueous-organic media relative to the stability and/or ester hydrolysis activity of unmodified naturally occurring para-nitrobenzyl esterase. 43 figs.

  6. Para-hydrogen induced polarization in heterogeneous hydrogenationreactions

    SciTech Connect

    Koptyug, Igor V.; Kovtunov, Kirill; Burt, Scott R.; Anwar, M.Sabieh; Hilty, Christian; Han, Song-I; Pines, Alexander; Sagdeev, Renad Z.

    2007-01-31

    We demonstrate the creation and observation ofpara-hydrogen-induced polarization in heterogeneous hydrogenationreactions. Wilkinson's catalyst, RhCl(PPh3)3, supported on eithermodified silica gel or a polymer, is shown to hydrogenate styrene intoethylbenzene and to produce enhanced spin polarizations, observed throughNMR, when the reaction was performed with H2 gas enriched in the paraspinisomer. Furthermore, gaseous phase para-hydrogenation of propylene topropane with two catalysts, the Wilkinson's catalyst supported onmodified silica gel and Rh(cod)(sulfos) (cod = cycloocta-1,5-diene;sulfos) - O3S(C6H4)CH2C(CH2PPh2)3) supported on silica gel, demonstratesheterogeneous catalytic conversion resulting in large spin polarizations.These experiments serve as a direct verification of the mechanism ofheterogeneous hydrogenation reactions involving immobilized metalcomplexes and can be potentially developed into a practical tool forproducing catalyst-free fluids with highly polarized nuclear spins for abroad range of hyperpolarized NMR and MRI applications.

  7. DYNA3D/ParaDyn Regression Test Suite Inventory

    SciTech Connect

    Lin, J I

    2011-01-25

    The following table constitutes an initial assessment of feature coverage across the regression test suite used for DYNA3D and ParaDyn. It documents the regression test suite at the time of production release 10.1 in September 2010. The columns of the table represent groupings of functionalities, e.g., material models. Each problem in the test suite is represented by a row in the table. All features exercised by the problem are denoted by a check mark in the corresponding column. The definition of ''feature'' has not been subdivided to its smallest unit of user input, e.g., algorithmic parameters specific to a particular type of contact surface. This represents a judgment to provide code developers and users a reasonable impression of feature coverage without expanding the width of the table by several multiples. All regression testing is run in parallel, typically with eight processors. Many are strictly regression tests acting as a check that the codes continue to produce adequately repeatable results as development unfolds, compilers change and platforms are replaced. A subset of the tests represents true verification problems that have been checked against analytical or other benchmark solutions. Users are welcomed to submit documented problems for inclusion in the test suite, especially if they are heavily exercising, and dependent upon, features that are currently underrepresented.

  8. Anise oil as para-methoxyamphetamine (PMA) precursor.

    PubMed

    Waumans, Dieter; Bruneel, Noël; Tytgat, Jan

    2003-04-23

    These days, MDMA is one of the most popular drugs of abuse. Due to its illegality, MDMA and its chemical precursors are watched by governmental organizations in many countries. To avoid conflicts with legal instances, underground chemists have tried to market several new unregulated amphetamine analogues, such as 4-MTA. Para-methoxyamphetamine (PMA), on the other hand, is regulated by law but its precursors are easily obtained since they are cheap and unwatched. This article presents such a case, namely the large scale synthesis of PMA using anethole, a main constituent of anise oil, as precursor. Anethole has been converted to its phenyl acetone analogue via peracid oxidation, while PMA itself has been synthesized using this ketone as precursor in the Leuckart synthesis. The synthesis of PMA using anethole as starting product has been investigated applying GC/MS and GC-HSPME/MS techniques, hereby discovering new specific (4-methoxyphenol) and already identified synthesis impurities (4-methyl-5-(4-methoxyphenyl)pyrimidine, N-(beta-4-methoxyphenylisopropyl)-4-methoxybenzyl methyl ketimine, 1-(4-methoxyphenyl)-N-(2-(4-methoxyphenyl)-1-methylethyl-2-propanamine, 1-(4-methoxyphenyl)-N-methyl-N-(2-(4-methoxyphenyl)-1-methylethyl-2-propanamine, N-(beta-4-methoxyphenylisopropyl)-4-methoxybenzaldimine). The new impurity 4-methoxyphenol is specific for the application of a peracid oxidation method where anethole is used as precursor. PMID:12742705

  9. Metabolism of para-aminophenol by rat hepatocytes.

    PubMed

    Yan, Z; Nikelly, J G; Killmer, L; Tarloff, J B

    2000-08-01

    Autoxidation of para-aminophenol (PAP) has been proposed to account for the selective nephrotoxicity of this compound. However, other studies suggest that hepatic metabolites of PAP rather than the parent compound may be responsible for renal damage. These studies were designed to investigate PAP metabolism in isolated hepatocytes. We synthesized several proposed metabolites for analysis by HPLC/mass spectrometry and compared those results with HPLC/mass spectrometric analyses of metabolites found after incubating hepatocytes with PAP. Hepatocytes prepared from male Sprague-Dawley rats were incubated in Krebs-Henseleit buffer at 37 degrees C for 5 h with 2.3 mM PAP under an atmosphere of 5% CO2/95% O2. Aliquots were withdrawn at 0.1 h of incubation and then hourly through 5 h of incubation. Reactions were terminated by the addition of acetonitrile. Hepatocyte viability was unaltered with PAP present in the incubation medium. We found that hepatocytes converted PAP to two major metabolites (PAP-GSH conjugates and PAP-N-acetylcysteine conjugates) and several minor metabolites [PAP-O-glucuronide, acetaminophen (APAP), APAP-O-glucuronide, APAP-GSH conjugates, and 4-hydroxyformanilide]. Preincubating hepatoyctes with 1-aminobenzotriazole, an inhibitor of cytochromes P450, did not alter the pattern of PAP metabolism. In conclusion, we found that PAP was metabolized in hepatocytes predominantly to PAP-GSH conjugates and PAP-N-acetylcysteine conjugates in sufficient quantities to account for the nephrotoxicity of PAP. PMID:10901695

  10. Conformation of ionizable poly Para phenylene ethynylene in dilute solutions

    DOE PAGESBeta

    Wijesinghe, Sidath; Maskey, Sabina; Perahia, Dvora; Grest, Gary S.

    2015-11-03

    The conformation of dinonyl poly para phenylene ethynylenes (PPEs) with carboxylate side chains, equilibrated in solvents of different quality is studied using molecular dynamics simulations. PPEs are of interest because of their tunable electro-optical properties, chemical diversity, and functionality which are essential in wide range of applications. The polymer conformation determines the conjugation length and their assembly mode and affects electro-optical properties which are critical in their current and potential uses. The current study investigates the effect of carboxylate fraction on PPEs side chains on the conformation of chains in the dilute limit, in solvents of different quality. The dinonylmore » PPE chains are modeled atomistically, where the solvents are modeled both implicitly and explicitly. Dinonyl PPEs maintained a stretched out conformation up to a carboxylate fraction f of 0.7 in all solvents studied. The nonyl side chains are extended and oriented away from the PPE backbone in toluene and in implicit good solvent whereas in water and implicit poor solvent, the nonyl side chains are collapsed towards the PPE backbone. Thus, rotation around the aromatic ring is fast and no long range correlations are seen within the backbone.« less

  11. Evidence for para dechlorination of polychlorobiphenyls by methanogenic bacteria

    SciTech Connect

    Ye, D.; Quensen, J.F.; Tiedje, J.M.

    1995-06-01

    When microorganisms eluted from upper Hudson River sediment were cultured without any substrate except polychlorobiphenyl (PCB)-free Hudson River sediment, methane formation was the terminal step of the anaerobic food chain. In sediments containing Aroclor 1242, addition of eubacterium-inhibiting antibiotics, which should have directly inhibited fermentative bacteria and thereby should have indirectly inhibited methanogens, resulted in no dechlorination activity or methane production. However, when substrates for methanogenic bacteria were provided along with the antibiotics (to free the methanogens from dependence on eubacteria), concomitant methane production and dechlorination of PCBs were observed. The dechlorination of Aroclor 1242 was from the para positions, a pattern distinctly different from, and more limited than, the pattern observed with untreated or pasteurized inocula. Both methane production and dechlorination in cultures amended with antibiotics plus methanogenic substrates were inhibited by 2-bromoethanesulfonic acid. These results suggest that the methanogenic bacteria are among the physiological groups capable of anaerobic dechlorination of PCBs, but that the dechlorination observed with methanogenic bacteria is less extensive than the dechlorination observed with more complex anaerobic consortia. 27 refs., 5 figs., 1 tab.

  12. Uninfected Para-Anastomotic Aneurysms after Infrarenal Aortic Grafting

    PubMed Central

    Nano, Giovanni; Cusmai, Francesco; Ramponi, Fabio; Stegher, Silvia; Dell'Aglio, Daniela; Malacrida, Giovanni; Tealdi, Domenico G.

    2009-01-01

    Purpose This single-institution retrospective review examines the management of uninfected para-anastomotic aneurysms of the abdominal aorta (PAAA), developed after infrarenal grafting. Materials and Methods From October 1979 to November 2005, 31 PAAA were observed in our Department. Twenty-six uninfected PAAA of degenerative etiology, including 24 false and 2 true aneurysms, were candidates for intervention and retrospectively included in our database for management and outcome evaluation. Six (23%) patients were treated as emergencies. Surgery included tube graft interposition (n = 12), new reconstruction (n = 8), and graft removal with extra-anatomic bypass (n = 3). Endovascular management (n = 3) consisted of free-flow tube endografts. Results The mortality rate among the elective and emergency cases was 5% and 66.6%, respectively (p = 0.005). The morbidity rate in elective cases was 57.8%, whereas 75% in emergency cases (p = 0.99). The survival rate during the follow-up was significantly higher for elective cases than for emergency cases. Conclusion Uninfected PAAA is a late complication of aortic grafting, tends to evolve silently and is difficult to diagnose. The prevalence is underestimated and increases with time since surgery. The mortality rate is higher among patients treated as an emergency than among patients who undergo elective surgery, therefore, elective treatment and aggressive management in the case of pseudoaneurysm are the keys to obtain a good outcome. Endovascular treatment could reduce mortality. Patients who undergo infrarenal aortic grafting require life-long surveillance after surgery. PMID:19430556

  13. Para-Tyrosine Supplementation Improves Insulin- and Liraglutide- Induced Vasorelaxation in Cholesterol-Fed Rats.

    PubMed

    Sélley, Eszter; Kun, Szilárd; Kürthy, Mária; Kovács, Tibor; Wittmann, István; Molnár, Gergo A

    2015-01-01

    Former data of our workgroup indicated that the accumulation of oxidized amino acids (meta- and ortho-tyrosine) due to oxidative stress may play an important role in the impaired insulininduced vasoactive properties of different arterial segments. There are evidences, that incorporation of these amino acids into cellular proteins leads to certain hormonal resistances, which might be restored by supplementation with the physiologic isoform, para-tyrosine. Rats in the control group were kept on a regular diet, rats in the cholesterol-fed group received high-fat diet, while the third group of rats received high-fat diet with para-tyrosine supplementation for 16 weeks. Plasma cholesterol level was significantly higher in the cholesterol-fed group, while the level of cholesterol in the cholesterol+para-tyrosine group did not differ significantly from that of the controls. Plasma level of insulin after glucose stimulation was decreased in the cholesterol-fed group, while that in the para-tyrosine supplemented group did not differ significantly from the controls. Vascular para-, meta- and ortho-tyrosine content was measured with HPLC. Elevated vascular meta-tyrosine/para-tyrosine ratio of cholesterol fed rats could be avoided by para-tyrosine supplementation. Vascular response of the thoracic aorta to insulin and liraglutide was assessed by a DMT multi-myograph. Cholesterol feeding resulted in vascular insulin-and liraglutide resistance, which was restored by para-tyrosine supplementation. Incorporation of the oxidative stress induced pathological tyrosine isoforms leads to vascular-hormone-resistances. We show that the physiological amino acid para-tyrosine is capable of restoring hypercholesterolemia-induced increased meta-tyrosine content of the vascular wall, thus attenuating functional vascular damage. PMID:26202368

  14. Endovascular Treatment of a Ruptured Para-Anastomotic Aneurysm of the Abdominal Aorta

    SciTech Connect

    Sfyroeras, Giorgos S.; Lioupis, Christos Bessias, Nikolaos; Maras, Dimitris; Pomoni, Maria; Andrikopoulos, Vassilios

    2008-07-15

    We report a case of a ruptured para-anastomotic aortic aneurysm treated with implantation of a bifurcated stent-graft. A 72-year-old patient, who had undergone aortobifemoral bypass for aortoiliac occlusive disease 16 years ago, presented with a ruptured para-anastomotic aortic aneurysm. A bifurcated stent-graft was successfully deployed into the old bifurcated graft. This is the first report of a bifurcated stent-graft being placed through an 'end-to-side' anastomosed old aortobifemoral graft. Endovascular treatment of ruptured para-anastomotic aortic aneurysms can be accomplished successfully, avoiding open surgery which is associated with increased mortality and morbidity.

  15. Measurement of the formaldehyde ortho to para ratio in three molecular clouds

    NASA Technical Reports Server (NTRS)

    Kahane, C.; Lucas, R.; Frerking, M. A.; Langer, W. D.; Encrenaz, P.

    1984-01-01

    Observations of ortho and para H2CO in two types of clouds, a warm cloud (Orion A) and two cold clouds (L183 and TMC1), are presented. The ortho to para ratio in Orion deduced from the H2(C-13)O data is about three, while that for TMC1 is about one and that for L183 is 1-2. The former value is in agreement with the value calculated from chemical models of ortho and para H2CO production. The values for the cold clouds are consistent with thermal equilibrium at a temperature slightly smaller than 10 K.

  16. Management of large para-esophageal hiatal hernias.

    PubMed

    Collet, D; Luc, G; Chiche, L

    2013-12-01

    Para-esophageal hernias are relatively rare and typically occur in elderly patients. The various presenting symptoms are non-specific and often occur in combination. These include symptoms of gastro-esophageal reflux (GERD) in 26 to 70% of cases, microcytic anemia in 17 to 47%, and respiratory symptoms in 9 to 59%. Respiratory symptoms are not completely resolved by surgical intervention. Acute complications such as gastric volvulus with incarceration or strangulation are rare (estimated incidence of 1.2% per patient per year) but gastric ischemia leading to perforation is the main cause of mortality. Only patients with symptomatic hernias should undergo surgery. Prophylactic repair to prevent acute incarceration should only be undertaken in patients younger than 75 in good condition; surgical indications must be discussed individually beyond this age. The laparoscopic approach is now generally accepted. Resection of the hernia sac is associated with a lower incidence of recurrence. Repair of the hiatus can be reinforced with prosthetic material (either synthetic or biologic), but the benefit of prosthetic repair has not been clearly shown. Results of prosthetic reinforcement vary in different studies; it has been variably associated with four times fewer recurrences or with no measurable difference. A Collis type gastroplasty may be useful to lengthen a foreshortened esophagus, but no objective criteria have been defined to support this approach. The anatomic recurrence rate can be as high as 60% at 12years. But most recurrences are asymptomatic and do not affect the quality of life index. It therefore seems more appropriate to evaluate functional results and quality of life measures rather than to gauge success by a strict evaluation of anatomic hernia reduction. PMID:24060742

  17. Successful Mnemonics for "por"/"para" and Affirmative Commands with Pronouns.

    ERIC Educational Resources Information Center

    Mason, Keith

    1992-01-01

    Two mnemonic devices, "4A Rule" and "PERFECT," are described to simplify the learning of two grammar points: the placement of object pronouns with respect to commands and the distinction between "por" and "para." (five references) (LB)

  18. Tumores carcinoides gastrointestinales—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del tumor carcinoide gastrointestinal, así como referencias a estudios clínicos y otros temas relacionados.

  19. Carcinoma de tumor primario desconocido—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del carcinoma de tumor primario desconocido, así como referencias a estudios clínicos y otros temas relacionados.

  20. Efficient ortho-para conversion of H2 on interstellar grain surfaces

    NASA Astrophysics Data System (ADS)

    Bron, Emeric; Le Petit, Franck; Le Bourlot, Jacques

    2016-04-01

    Context. Fast surface conversion between ortho- and para-H2 has been observed in laboratory studies, and it has been proposed that this mechanism plays a role in the control of the ortho-para ratio in the interstellar medium. Observations of rotational lines of H2 in photo-dissociation regions (PDRs) have indeed found significantly lower ortho-para ratios than expected at equilibrium. The mechanisms controlling the balance of the ortho-para ratio in the interstellar medium thus remain incompletely understood, while this ratio can affect the thermodynamical properties of the gas (equation of state, cooling function). Aims: We aim to build an accurate model of ortho-para conversion on dust surfaces based on the most recent experimental and theoretical results, and to validate it by comparison to observations of H2 rotational lines in PDRs. Methods: We propose a statistical model of ortho-para conversion on dust grains with fluctuating dust temperatures. It is based on a master equation approach. This computation is then coupled to full PDR models and compared to PDR observations. Results: We show that the observations of rotational H2 lines indicate a high conversion efficiency on dust grains and that this high efficiency can be accounted for if taking dust temperature fluctuations into account with our statistical model of surface conversion. Simpler models that neglect the dust temperature fluctuations do not reach the high efficiency deduced from the observations. Moreover, this high efficiency induced by dust temperature fluctuations is very insensitive to the values of the model's microphysical parameters. Conclusions: Ortho-para conversion on grains is thus an efficient mechanism in most astrophysical conditions and can play a significant role in controlling the ortho-para ratio.

  1. A comparison of extraperitoneal versus transperitoneal laparoscopic para-aortic lymphadenectomy for staging of endometrial carcinoma

    PubMed Central

    Pakish, Janelle; Soliman, Pamela T.; Frumovitz, Michael; Westin, Shannon N.; Schmeler, Kathleen M.; dos Reis, Ricardo; Munsell, Mark F.; Ramirez, Pedro T.

    2014-01-01

    Objective The objective of our study was to compare the surgical outcomes of extraperitoneal laparoscopic, transperitoneal laparoscopic, and robotic transperitoneal para-aortic lymphadenectomy in endometrial cancer staging. Methods A retrospective review was performed from January 2007 to November 2012. Three groups were compared: extraperitoneal laparoscopic para-aortic lymphadenectomy and robotic hysterectomy and pelvic lymphadenectomy (“extraperitoneal group”; N=34); laparoscopic hysterectomy and transperitoneal pelvic and para-aortic lymphadenectomy (“transperitoneal laparoscopic group”; N=108); and robotic hysterectomy and transperitoneal pelvic and para-aortic lymphadenectomy (“transperitoneal robotic group”; N=52). Fisher’s exact test and Kruskal-Wallis test were used for statistical analysis, and statistical significance was defined as P< 0.05. Results Median number of para-aortic lymph nodes obtained was higher in the extraperitoneal group than in the transperitoneal laparoscopic and robotic groups (10, 5, and 4.5 nodes, respectively; P<0.001). Among patients with BMI <35 kg/m2, the median number of para-aortic nodes harvested was higher in the extraperitoneal group than in the transperitoneal laparoscopic and robotic groups (9, 4, and 5 nodes, respectively; P<0.01). The same pattern was observed among patients with BMI ≥35 kg/m2 (10, 6, and 3 nodes, respectively) (P=0.001). There was no significant difference in median estimated blood loss between the extraperitoneal group and either the transperitoneal laparoscopic group (100 vs. 112.5 mL; P=0.06) or the transperitoneal robotic group (100 vs. 67.5 mL; P=0.23). Conclusion Extraperitoneal laparoscopic para-aortic lymphadenectomy resulted in a higher number of para-aortic lymph nodes removed than transperitoneal laparoscopic or robotic lymphadenectomy. The extraperitoneal approach should be considered for endometrial cancer staging. PMID:24361579

  2. Ortho-Para Mixing Interaction in the Vinyl Radical Detected by Millimeter-Wave Spectroscopy and Prediction of Fast Ortho-Para Conversion Rate

    NASA Astrophysics Data System (ADS)

    Tanaka, Keiichi; Hayashi, Masato; Ohtsuki, Mitsuhiko; Harada, Kensuke; Tanaka, Takehiko

    2010-06-01

    Ortho-para mixing interaction due to the coupling of nuclear and electron spins was detected for the first time by millimeter-wave spectroscopy of deuterated vinyl radicals, H_2CCD and D_2CCD, of which the ground states are split by the tunneling motion of the α deuteron into two components 0^+ and 0^-, whose separations have been determined to be Δ E_0 = 1186.644(16) and 771.978(18) MHz, respectively. The observed tunneling-rotation spectra are significantly perturbed by the othro-para mixing interaction expressed by < 0^± |H'|0^mprangle = (δ aF(β)/2) S \\cdot(I_β 1-I_β 2), where I_β 1 and I_β 2 are spins of the two hydrogen nuclei in the β position and S is the electron spin, which connects rotational levels in the 0^+ and 0^- states, one being an ortho level and the other a para level. The δ aF(β) constants for H_2CCD and D_2CCD have been determined to be 68.06(53) and 10.63(94) MHz, respectively, consistent each other within the isotopic mass relation. The othro and para states are mixed by about 0.097% and 0.0123% due to this interaction. The δ aF constant for H_2CCH should be similar to that for H_2CCD because of the same probability density of the unpaired electron at the β protons, but could not be determined independently in our previous study. It is because the mixing of para- and ortho-levels of about 0.00044% is much smaller than that for H_2CCD due to the large tunneling splitting of Δ E_0=16271.8429(59) MHz. The rate constant of para to ortho (I_β = 0 → 1) conversion is predicted as 1.2× 10^5 s-1 torr-1 for H_2CCD, suggesting extremely rapid mutual conversion between ortho and para nuclear spin isomers of H_2CCD, which is more than 106 times faster compared with that in closed shell molecules such as H_2CO and H_2CCH_2. K. Tanaka, M. Hayashi, M. Ohtsuki, K. Harada, T. Tanaka, J. Chem. Phys., 131, 111101 (2009). K. Tanaka, M. Toshimitsu, K. Harada, T. Tanaka, J. Chem. Phys., 120, 3604 (2004).

  3. para-Sulphonato-calix[n]arenes as selective activators for the passage of molecules across the Caco-2 model intestinal membrane.

    PubMed

    Roka, Eszter; Vecsernyes, Miklos; Bacskay, Ildiko; Félix, Caroline; Rhimi, Moez; Coleman, Anthony W; Perret, Florent

    2015-06-01

    The passage of Lucifer Yellow across the Caco-2 intestinal model membrane has been studied for the para-sulphonato-calix[n]arenes, the results show that para-sulphonato-calix[4]arene and para-sulphonato-calix[8]arene activate membrane passage when used simultaneously with a transport probe, Lucifer Yellow, whereas para-sulphonato-calix[6]arene has no effect. PMID:25958962

  4. Il contributo di G. Braga alla Sociologia del linguaggio (The Contributions of G. Braga to the Sociology of Language).

    ERIC Educational Resources Information Center

    Tessarolo, Marisella

    1989-01-01

    Discusses Braga's contribution to the study of the sociology of language. Braga developed a dynamic interdisciplinary model of verbal communication based on theories of sociology and linguistics and stressed the importance of language in the acculturation of an individual and in the determination of that individual's status in society. (CFM)

  5. Vesicular erythema multiforme-like reaction to para-phenylenediamine in a henna tattoo.

    PubMed

    Sidwell, Rachel U; Francis, Nick D; Basarab, Tamara; Morar, Nilesh

    2008-01-01

    Allergic contact dermatitis reaction to topical "black henna" tattoo is usually described secondary to the organic dye para-phenylenediamine, a derivative of analine. Allergic contact dermatitis reactions to para-phenylenediamine are well recognized and most commonly involve an eczematous reaction that may become generalized and an acute angio-edema. Only four previous instances have been reported of an erythema multiforme-like reaction to para-phenylenediamine and its derivatives, including only one mild reaction to a tattoo. A vesicular erythema multiforme-like reaction has not been reported. An erythema multiforme-like reaction to contact allergens is usually caused by potent allergens including plant quinolones in Compositae and sesquiterpene lactones in exotic woods, and it is also reported to topical drugs, epoxy resin, metals (particularly nickel), and various chemicals. A generalized vesicular erythema multiforme-like reaction is unusual, and rarely reported. We describe a 6-year-old boy who developed a localized, eczematous and severe generalized vesicular erythema multiforme-like contact allergy to para-phenylenediamine secondary to a henna tattoo. As henna tattoos are becoming increasingly popular, one should be aware of the possibility of such a reaction. This presentation also highlights the call to ban the use of para-phenylenediamine and its derivatives in dyes. PMID:18429780

  6. Sistemas Correctores de Campo Para EL Telescopio Ritchey-Chretien UNAM212

    NASA Astrophysics Data System (ADS)

    Cobos, F. J.; Galan, M. J.

    1987-05-01

    El telescopio UNAM2l2 fue inaugurado hace siete años y concebido para trabajar en las razones focales: f/7.5, F/13.5, F/27 y F/98. El diseño Ritchey-Chretién corresponde a la razón focal F/7.5 y el foco primario (F/2.286) no se consideró como utilizable para fotografía directa. En el Instituto de Astronomía de la UNAM, se diseñó y construyó un sistema corrector de campo para la razón focal F/7.5, que actualmente está en funcionamiento. Dentro de un programa de colaboración en diseflo y evaluación de sistemas ópticos, entre el Instituto de Astrofísica de Canarias y el Instituto de Astronomía de la UNAM, decidimos intentar el diseño de una correctora de campo para el foco primario del tȩlescopio UNAM212 bajo la consideración de que no son insalvables los problemas que implicaría su instalación y de que es muy posible que, en un futuro relativamente cercano, podamom tener un detector bidimenmional tipo Mepsicrón cuya área sensible haga tentadora la idea de construir la cámara directa para foco primario

  7. On the Ortho:Para Ratio of H+ 3 in Diffuse Molecular Clouds

    NASA Astrophysics Data System (ADS)

    Crabtree, Kyle N.; Indriolo, Nick; Kreckel, Holger; Tom, Brian A.; McCall, Benjamin J.

    2011-03-01

    The excitation temperature T 01 derived from the relative intensities of the J = 0 (para) and J = 1 (ortho) rotational levels of H2 has been assumed to be an accurate measure of the kinetic temperature in interstellar environments. In diffuse molecular clouds, the average value of T 01 is ~70 K. However, the excitation temperature T(H+ 3) derived from the (J, K) = (1, 1) (para) and (1, 0) (ortho) rotational levels of H+ 3 has been observed to be ~30 K in the same types of environments. In this work, we present observations of H+ 3 in three additional diffuse cloud sight lines for which H2 measurements are available, showing that in four of five cases T 01 and T(H+ 3) are discrepant. We then examine the thermalization mechanisms for the ortho:para ratios of H+ 3 and H2, concluding that indeed T 01 is an accurate measure of the cloud kinetic temperature, while the ortho:para ratio of H+ 3 need not be thermal. By constructing a steady-state chemical model taking into account the nuclear spin dependence of reactions involving H+ 3, we show that the ortho:para ratio of H+ 3 in diffuse molecular clouds is likely governed by a competition between dissociative recombination with electrons and thermalization via reactive collisions with H2. Based in part on observations made with ESO Telescopes at the La Silla or Paranal Observatories under program ID 384.C-0618.

  8. The formaldehyde ortho/para ratio as a probe of dark cloud chemistry and evolution

    NASA Technical Reports Server (NTRS)

    Dickens, J. E.; Irvine, W. M.

    1999-01-01

    We present measurements of the H2CO ortho/para ratio toward four star-forming cores, L723, L1228, L1527, and L43, and one quiescent core, L1498. Combining these data with earlier results by Minh et al., three quiescent cores are found to have ortho/para ratios near 3, the ratio of statistical weights expected for gas-phase formation processes. In contrast, ortho/para ratios are 1.5-2.1 in five star-forming cores, suggesting thermalization at a kinetic temperature of 10 K. We attribute modification of the ortho/para ratio in the latter cores to formation and/or equilibration of H2CO on grains with sub-sequent release back into the gas phase due to the increased energy inputs from the forming star and outflow. We see accompanying enhancements in the H2CO abundance relative to H, to support this idea. The results suggest that the formaldehyde ortho/para ratio can differentiate between quiescent cores and those in which low-mass star formation has occurred.

  9. Terahertz absorption spectrum of para and ortho water vapors at different humidities at room temperature

    NASA Astrophysics Data System (ADS)

    Xin, X.; Altan, H.; Saint, A.; Matten, D.; Alfano, R. R.

    2006-11-01

    Terahertz time-domain spectroscopy has been used to measure the absorption of water vapor in 0.2-2.4THz range from low to high humidity at room temperature. The observed absorption lines are due to the water molecular rotations in the ground vibrational state. We find that the absorption strength of para transitions increases as humidity increases, while the absorption strength of ortho transitions increases and then decreases in intensity with increasing humidity. We explain this difference based on the nuclear spin statistics based ratio of ortho to para water monomer populations at room temperature. The preferential adsorption on the solid surfaces of para water leads to an ortho dominated vapor cloud whose monomer rotational absorption intensity decreases due to the effects of dimerization, molecular collisions, clustering, and interactions with liquid droplets at high concentrations.

  10. Production and characterization of para-hydrogen gas for matrix isolation infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Sundararajan, K.; Sankaran, K.; Ramanathan, N.; Gopi, R.

    2016-08-01

    Normal hydrogen (n-H2) has 3:1 ortho/para ratio and the production of enriched para-hydrogen (p-H2) from normal hydrogen is useful for many applications including matrix isolation experiments. In this paper, we describe the design, development and fabrication of the ortho-para converter that is capable of producing enriched p-H2. The p-H2 thus produced was probed using infrared and Raman techniques. Using infrared measurement, the thickness and the purity of the p-H2 matrix were determined. The purity of p-H2 was determined to be >99%. Matrix isolation infrared spectra of trimethylphosphate (TMP) and acetylene (C2H2) were studied in p-H2 and n-H2 matrices and the results were compared with the conventional inert matrices.

  11. Electrical detection of ortho-para conversion in fullerene-encapsulated water

    NASA Astrophysics Data System (ADS)

    Meier, Benno; Mamone, Salvatore; Concistrè, Maria; Alonso-Valdesueiro, Javier; Krachmalnicoff, Andrea; Whitby, Richard J.; Levitt, Malcolm H.

    2015-08-01

    Water exists in two spin isomers, ortho and para, that have different nuclear spin states. In bulk water, rapid proton exchange and hindered molecular rotation obscure the direct observation of two spin isomers. The supramolecular endofullerene H2O@C60 provides freely rotating, isolated water molecules even at cryogenic temperatures. Here we show that the bulk dielectric constant of this substance depends on the ortho/para ratio, and changes slowly in time after a sudden temperature jump, due to nuclear spin conversion. The attribution of the effect to ortho-para conversion is validated by comparison with nuclear magnetic resonance and quantum theory. The change in dielectric constant is consistent with an electric dipole moment of 0.51+/-0.05 Debye for an encapsulated water molecule, indicating the partial shielding of the water dipole by the encapsulating cage. The dependence of bulk dielectric constant on nuclear spin isomer composition appears to be a previously unreported physical phenomenon.

  12. Quantitative structure–activity relationship analysis of the pharmacology of para-substituted methcathinone analogues

    PubMed Central

    Bonano, J S; Banks, M L; Kolanos, R; Sakloth, F; Barnier, M L; Glennon, R A; Cozzi, N V; Partilla, J S; Baumann, M H; Negus, S S

    2015-01-01

    Background and Purpose Methcathinone (MCAT) is a potent monoamine releaser and parent compound to emerging drugs of abuse including mephedrone (4-CH3 MCAT), the para-methyl analogue of MCAT. This study examined quantitative structure–activity relationships (QSAR) for MCAT and six para-substituted MCAT analogues on (a) in vitro potency to promote monoamine release via dopamine and serotonin transporters (DAT and SERT, respectively), and (b) in vivo modulation of intracranial self-stimulation (ICSS), a behavioural procedure used to evaluate abuse potential. Neurochemical and behavioural effects were correlated with steric (Es), electronic (σp) and lipophilic (πp) parameters of the para substituents. Experimental Approach For neurochemical studies, drug effects on monoamine release through DAT and SERT were evaluated in rat brain synaptosomes. For behavioural studies, drug effects were tested in male Sprague-Dawley rats implanted with electrodes targeting the medial forebrain bundle and trained to lever-press for electrical brain stimulation. Key Results MCAT and all six para-substituted analogues increased monoamine release via DAT and SERT and dose- and time-dependently modulated ICSS. In vitro selectivity for DAT versus SERT correlated with in vivo efficacy to produce abuse-related ICSS facilitation. In addition, the Es values of the para substituents correlated with both selectivity for DAT versus SERT and magnitude of ICSS facilitation. Conclusions and Implications Selectivity for DAT versus SERT in vitro is a key determinant of abuse-related ICSS facilitation by these MCAT analogues, and steric aspects of the para substituent of the MCAT scaffold (indicated by Es) are key determinants of this selectivity. PMID:25438806

  13. Experiments at Scale with In-Situ Visualization Using ParaView/Catalyst in RAGE

    SciTech Connect

    Kares, Robert John

    2014-10-31

    In this paper I describe some numerical experiments performed using the ParaView/Catalyst in-situ visualization infrastructure deployed in the Los Alamos RAGE radiation-hydrodynamics code to produce images from a running large scale 3D ICF simulation on the Cielo supercomputer at Los Alamos. The detailed procedures for the creation of the visualizations using ParaView/Catalyst are discussed and several images sequences from the ICF simulation problem produced with the in-situ method are presented. My impressions and conclusions concerning the use of the in-situ visualization method in RAGE are discussed.

  14. Simulation Studies of the Vibrational Dynamics of para-HYDROGEN Clusters

    NASA Astrophysics Data System (ADS)

    Faruk, Nabil F.; Yang, Jing; Le Roy, Robert J.; Roy, Pierre-Nicholas

    2011-06-01

    This paper discusses the construction and application of reduced-dimensional potential energy surfaces for use in performing simulation of para-hydrogen clusters. Simple spherical averaging and `adiabatic-hindered-rotor' averaging treatments of the angular degrees of freedom are considered and compared. The resulting one-dimensional surface is used in quantum Monte Carlo simulations of para-hydrogen clusters of varying sizes. Energetic, and structural properties are computed and compared to previously published results, and vibrational frequency shifts are predicted and compared to available experimental measurements. H. Li, P.N. Roy and R.J. Le Roy, J. Chem. Phys. 133, 104305 (2010).

  15. Le lipome para testiculaire: à propos d'un cas rare

    PubMed Central

    Lasri, Abdelouahed; Lamchahab, Hamza; Lahyani, Mounir; Karmouni, Tarik; Elkhader, Khalid; Koutani, Abdellatif; Andaloussi, Ahmed Ibn Attya

    2015-01-01

    Les tumeurs para testiculaires sont des tumeurs rares et complexes qui ont une symptomatologie insidieuse et pauvre. Les formes bénignes représentent 70%. Le lipome para testiculaire étant le type le plus fréquent. L'examen clinique est peu spécifique. L'examen échographique est la pierre angulaire pour assoir le diagnostic. Le traitement chirurgical s'impose en cas de tumeur symptomatique, l'histologie étant habituellement typique permet la confirmation diagnostique. Le pronostic est bon malgré d’éventuelles récidives. PMID:26175802

  16. Quantum rotation of ortho and para-water encapsulated in a fullerene cage

    PubMed Central

    Beduz, Carlo; Carravetta, Marina; Chen, Judy Y.-C.; Concistrè, Maria; Denning, Mark; Frunzi, Michael; Horsewill, Anthony J.; Johannessen, Ole G.; Lawler, Ronald; Lei, Xuegong; Levitt, Malcolm H.; Li, Yongjun; Mamone, Salvatore; Murata, Yasujiro; Nagel, Urmas; Nishida, Tomoko; Ollivier, Jacques; Rols, Stéphane; Rõõm, Toomas; Sarkar, Riddhiman; Turro, Nicholas J.; Yang, Yifeng

    2012-01-01

    Inelastic neutron scattering, far-infrared spectroscopy, and cryogenic nuclear magnetic resonance are used to investigate the quantized rotation and ortho–para conversion of single water molecules trapped inside closed fullerene cages. The existence of metastable ortho-water molecules is demonstrated, and the interconversion of ortho-and para-water spin isomers is tracked in real time. Our investigation reveals that the ground state of encapsulated ortho water has a lifted degeneracy, associated with symmetry-breaking of the water environment. PMID:22837402

  17. [PDS cord fixation of sternoclavicular dislocation and para-articular clavicular fractures].

    PubMed

    Friedl, W; Fritz, T

    1994-05-01

    Sternoclavicular joint dislocation and para-articular fractures of the clavicle are rare injuries. Because severe complications of dorsal dislocations have often been seen and because functional impairment has often followed ventral dislocations, we treat most patients with such injuries operatively. Internal fixation with K-wires frequently leads to severe complications. We present our operation techniques with a resorbable 2 mm polydioxanon cord. This pack up technique can be used in both dislocations and para-articular fractures with no risk of implant dislocation. PMID:8052863

  18. In para totale...una cosa da panico...sulla lingua dei giovani in Italia (In para totale...una cosa da panico...The Language of Young People in Italy).

    ERIC Educational Resources Information Center

    Marcato, Carla

    1997-01-01

    Describes and analyzes the language of young people in Italy today. Particular focus is on the expressions using "para" (e.g., "in para totale" = to be very bored or worried) and the phrase "una cosa da panico" (something terrible or its opposite something wonderful). (CFM)

  19. EVALUATION OF PARA-DICHLOROBENZENE EMISSIONS FROM SOLID MOTH REPELLANT AS A SOURCE OF INDOOR AIR POLLUTION

    EPA Science Inventory

    The paper reports results of dynamic and static chamber tests to evaluate para-dichlorobenzene emission rates from mothcakes. he data were analyzed by a model that assumes that the para-dichlorobenzene emission from mothcakes is a temperature-sensitive sublimation process. ull-sc...

  20. EVALUATION OF PARA-DICHLOROBENZENE EMISSIONS FROM SOLID MOTH REPELLANT AS A SOURCE OF INDOOR AIR POLLUTION

    EPA Science Inventory

    Mothcakes made of para-dichlorobenzene have been widely available for the general population to be used as a moth repellant to protect garments from insect damage. Usually, a mothcake is expected to last for weeks or even months during which the para-dichlorobenzene emits slowly ...

  1. Experimental and theoretical investigation of para-aminophenol ionization in corona discharge

    NASA Astrophysics Data System (ADS)

    Bahrami, H.; Salehabadi, H.

    2015-03-01

    Ionization of para-aminophenol was investigated using an ion mobility spectrometer equipped with a corona discharge as ionization source. The experimental results were confirmed with the use of theoretical method, based on density functional theory. Two peaks were observed in the ion mobility spectrum in the positive ion mode which was corresponded to the protonated isomers of para-aminophenol. It was observed that the relative intensities of the peaks depend on the sample concentration and the nature of the reactant ions. The relative energies of ions derived from protonation of para-aminophenol and its topical proton affinities were determined for different sites in the gas phase. The peak with the lower drift time was assigned to the oxygen protonated isomer and the other peak was ascribed to the nitrogen protonated isomer of para-aminophenol. The calculated dipole moment and localized charge of each isomer were used to verify the ion mobility peak separation. It was shown that combination of theoretical and experimental tools leads to reliable prediction of reactive protonation sites of chemicals in a corona discharge.

  2. Synthesis and properties of para-substituted NCN-pincer palladium and platinum complexes.

    PubMed

    Slagt, Martijn Q; Rodríguez, Gema; Grutters, Michiel M P; Klein Gebbink, Robertus J M; Klopper, Wim; Jenneskens, Leonardus W; Lutz, Martin; Spek, Anthony L; van Koten, Gerard

    2004-03-19

    A variety of para-substituted NCN-pincer palladium(II) and platinum(II) complexes [MX(NCN-Z)] (M=Pd(II), Pt(II); X=Cl, Br, I; NCN-Z=[2,6-(CH(2)NMe(2))(2)C(6)H(2)-4-Z](-); Z=NO(2), COOH, SO(3)H, PO(OEt)(2), PO(OH)(OEt), PO(OH)(2), CH(2)OH, SMe, NH(2)) were synthesised by routes involving substitution reactions, either prior to or, notably, after metalation of the ligand. The solubility of the pincer complexes is dominated by the nature of the para substituent Z, which renders several complexes water-soluble. The influence of the para substituent on the electronic properties of the metal centre was studied by (195)Pt NMR spectroscopy and DFT calculations. Both the (195)Pt chemical shift and the calculated natural population charge on platinum correlate linearly with the sigma(p) Hammett substituent constants, and thus the electronic properties of predesigned pincer complexes can be predicted. The sigma(p) value for the para-PtI group itself was determined to be -1.18 in methanol and -0.72 in water/methanol (1/1). Complexes substituted with protic functional groups (CH(2)OH, COOH) exist as dimers in the solid state due to intermolecular hydrogen-bonding interactions. PMID:15034878

  3. Cáncer de páncreas—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de páncreas, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  4. Cáncer de vagina—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de vagina, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  5. An Analysis of Interlanguage Development Over Time: Part 1, "por" and "para".

    ERIC Educational Resources Information Center

    Guntermann, Gail

    1992-01-01

    The first part of a larger planned investigation, this study examines the use of "por" and "para" by nine Peace Corps volunteers in oral interviews at the end of training and roughly one year later, to trace their acquisition over time, in two learning contexts. (24 references) (LB)

  6. The Acquisition of Lexical Meaning in a Study Abroad Context: The Spanish Prepositions "por" and "para."

    ERIC Educational Resources Information Center

    Lafford, Barbara A.; Ryan, John M.

    1995-01-01

    Examination of the development of form/function relations of the prepositions "por" and "para" at different levels of proficiency in the interlanguage of study-abroad students in Granada, Spain, revealed "noncanonical" as well as "canonical" uses of these prepositions. The most common noncanonical uses were as substitutions for other prepositions…

  7. Preguntas para hacerle al doctor acerca del cáncer

    Cancer.gov

    Serie de preguntas, organizadas por tema, que los pacientes con cáncer pueden hacer al médico o a otros miembros de su equipo de atención médica para conocer más acerca de su tipo de cáncer y lo que pueden esperar.

  8. Terapia hormonal para la menopausia y el cáncer

    Cancer.gov

    Hoja informativa acerca de los resultados de los estudios sobre el uso de la terapia hormonal para la menopausia. Incluye información sobre el efecto de esta terapia en el cuerpo y explica los riesgos y beneficios del uso de hormonas.

  9. Resultados de estudio para cáncer de pulmón indica

    Cancer.gov

    El Instituto Nacional del Cáncer (NCI) da a conocer hoy resultados iniciales de un estudio de gran envergadura sobre métodos de detección para reducir el número de muertes por cáncer de pulmón al detectar cánceres en estadios relativamente iniciales.

  10. Factor Structure of the "Escala de Autoeficacia para la Depresion en Adolescentes" (EADA)

    ERIC Educational Resources Information Center

    Diaz-Santos, Mirella; Cumba-Aviles, Eduardo; Bernal, Guillermo; Rivera-Medina, Carmen

    2011-01-01

    The current concept and measures of self-efficacy for depression in adolescents do not consider developmental and cultural aspects essential to understand and assess this construct in Latino youth. We examined the factor structure of the "Escala de Autoeficacia para la Depresion en Adolescentes" (EADA), a Spanish instrument designed to assess this…

  11. Sarcoma de tejido blando—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del sarcoma de tejido blando, así como referencias a estudios clínicos, investigación, estadísticas y otros temas relacionados con este tipo de cáncer.

  12. Cannabis y canabinoides (PDQ®)—Versión para profesionales de salud

    Cancer.gov

    Resumen de información revisada por expertos sobre el uso del Cannabis y canabinoides para el tratamiento de los efectos secundarios relacionados con el tratamiento del cáncer, como la náusea y el vómito.

  13. Cannabis y canabinoides (PDQ®)—Versión para pacientes

    Cancer.gov

    Resumen de información revisada por expertos sobre el uso del Cannabis y canabinoides para el tratamiento de los efectos secundarios relacionados con el tratamiento del cáncer como la náusea y el vómito.

  14. Cáncer de intestino delgado—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de intestino delgado, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  15. Interrupting Commemoration: Thinking with Art, Thinking through the Strictures of Argentina's "Espacio para la memoria"

    ERIC Educational Resources Information Center

    Paolantonio, Mario Di

    2011-01-01

    Recently, a few buildings within the "Espacio para la memoria" in Buenos Aires have been designated as a UNESCO Centre where, amongst other educational activities, evidentiary materials of the past repression are to be stored and displayed. Another building in the complex houses a Community Centre operated by the Mothers of the Plaza de Mayo,…

  16. Cáncer colorrectal—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento, la prevención, las causas y los exámenes de detección del cáncer de colon y recto, así como referencias a estudios clínicos, estadísticas y otros temas.

  17. Estudios ALCHEMIST para el cáncer de pulmón en estadio inicial

    Cancer.gov

    ALCHEMIST comprende tres estudios clínicos integrados de medicina de precisión diseñados para identificar a personas con cáncer de pulmón en estadio inicial cuyos tumores tienen ciertos cambios genéticos poco comunes.

  18. Can para-aryl-dithiols cross-link two plasmonic noble nanoparticles as monolayer dithiolate spacers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Para-aryl-dithiols (PADTs, HS-(C6H4)n-SH, n = 1, 2, and 3) have been used extensively in molecular electronics, surface-enhanced Raman spectroscopy (SERS), and quantum electron tunneling between two gold or silver nanoparticles (AuNPs and AgNPs). One popular belief is that these dithiols cross-link ...

  19. Cáncer de la corteza suprarrenal—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del carcinoma de corteza suprarrenal, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  20. Tumores de hipófisis—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del tumor de hipófisis, así como referencias a estudios clínicos, investigación y otros temas relacionados.

  1. Cáncer de útero—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento, la prevención, las causas y los exámenes de detección del cáncer uterino, así como referencias a estudios clínicos, investigación, estadísticas y otros temas.

  2. Tumores extracraneales de células germinativas—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del tumor extracraneal de células germinativas en los niños, así como referencias a estudios clínicos y otros temas relacionados.

  3. Cáncer de ano—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de ano, así como referencias a estudios clínicos y otros temas relacionados con este tipo de cáncer.

  4. Cáncer de tiroides—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de tiroides, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  5. Cáncer de pene—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de pene, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  6. Cáncer de testículo—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento, las causas y los exámenes de detección del cáncer de testículo, así como referencias a estudios clínicos, investigación y otros temas.

  7. Cáncer de vejiga—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento, las causas y los exámenes de detección del cáncer de vejiga, así como referencias a estudios clínicos, investigación, estadísticas y otros temas.

  8. Cáncer de vulva—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de vulva, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  9. Cáncer de paratiroides—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de paratiroides, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  10. Cáncer de uretra—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de uretra, así como referencias a estudios clínicos y otros temas relacionados con este tipo de cáncer.

  11. Antimicrobial effect of para-alkoxyphenylcarbamic acid esters containing substituted N-phenylpiperazine moiety

    PubMed Central

    Malík, Ivan; Bukovský, Marián; Andriamainty, Fils; Gališinová, Jana

    2013-01-01

    In current research, nine basic esters of para-alkoxyphenylcarbamic acid with incorporated 4-(4-fluoro-/3-trifluoromethylphenyl)piperazin-1-yl fragment, 6i–6m and 8f–8i, were screened for their in vitro antimicrobial activity against Candida albicans, Staphylococcus aureus and Escherichia coli, respectively. Taking into account the minimum inhibitory concentration assay (MIC), as the most active against given yeast was evaluated 8i (MIC = 0.20 mg/mL), the most lipophilic structure containing para-butoxy and trifluoromethyl substituents. Investigating the efficiency of the compounds bearing only a single atom of fluorine and appropriate para-alkoxy side chain against Candida albicans, the cut-off effect was observed. From evaluated homological series, the maximum of the effectiveness was noticed for the stucture 6 k (MIC = 0.39 mg/mL), containing para-propoxy group attached to phenylcarbamoyloxy fragment, beyond which the compounds ceased to be active. On the contrary, all the tested molecules were against Staphylococcus aureus and Escherichia coli (MICs > 1.00 mg/mL) practically inactive. PMID:24294237

  12. Delirio (PDQ®)—Versión para profesionales de salud

    Cancer.gov

    Resumen de información revisada por expertos acerca del delirio como una complicación a causa del cáncer o su tratamiento. Se discuten los enfoques de los cuidados médicos de apoyo, asi como farmacológicos para el manejo del delirio.

  13. Irradiation of para-aortic lymph node metastases from carcinoma of the cervix or endometrium

    SciTech Connect

    Komaki, R.; Mattingly, R.F.; Hoffman, R.G.; Barber, S.W.; Satre, R.; Greenberg, M.

    1983-04-01

    Twenty-two patients with biopsy-proved para-aortic lymph node metastases from carcinoma of the cervix (15 patients) or endometrium (7 patients) received a median dose of 5,000 rad/25 fractions. Para-aortic nodal metastases were controlled in 77% of cases. Control was significantly lower following radical retroperitoneal lymph node dissection than less extensive sampling procedures. Obstruction of the small bowel developed in 3 patients with tumor recurrence in the para-aortic region. Eight of the 10 patients who were disease-free at 2 years received >5,000 rad. Three patients were still alive without disease at 129, 63, and 60 months, respectively. The 5-year disease-free survival rate was 40% for cervical cancer and 60% for endometrial cancer: in the former group, it was significantly different depending on whether the para-aortic nodes were irradiated (40%) or not (0%). The authors suggest that 5,000-5,500 rad in 5-5.5 weeks is well tolerated and can control aortic nodal metastases in cervical and possibly endometrial cancer.

  14. Antimicrobial effect of para-alkoxyphenylcarbamic acid esters containing substituted N-phenylpiperazine moiety.

    PubMed

    Malík, Ivan; Bukovský, Marián; Andriamainty, Fils; Gališinová, Jana

    2013-01-01

    In current research, nine basic esters of para-alkoxyphenylcarbamic acid with incorporated 4-(4-fluoro-/3-trifluoromethylphenyl)piperazin-1-yl fragment, 6i-6m and 8f-8i, were screened for their in vitro antimicrobial activity against Candida albicans, Staphylococcus aureus and Escherichia coli, respectively. Taking into account the minimum inhibitory concentration assay (MIC), as the most active against given yeast was evaluated 8i (MIC = 0.20 mg/mL), the most lipophilic structure containing para-butoxy and trifluoromethyl substituents. Investigating the efficiency of the compounds bearing only a single atom of fluorine and appropriate para-alkoxy side chain against Candida albicans, the cut-off effect was observed. From evaluated homological series, the maximum of the effectiveness was noticed for the stucture 6 k (MIC = 0.39 mg/mL), containing para-propoxy group attached to phenylcarbamoyloxy fragment, beyond which the compounds ceased to be active. On the contrary, all the tested molecules were against Staphylococcus aureus and Escherichia coli (MICs > 1.00 mg/mL) practically inactive. PMID:24294237

  15. Up from Apathy: Para-Professional Training for the Socially Disadvantaged

    ERIC Educational Resources Information Center

    Jones, Mark J.; Wright, Bobbye S.

    1970-01-01

    Describes a program of training for young men to fill a para-professional position in the growing field of social services. The program provides training in human relations, basic skills, and on-the-job techniques. Training Technology is a quarterly supplement to Educational Technology Magazine. (GR)

  16. Ortho-para conversion of endohedral water in the fullerene C60 at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Shugai, Anna; Nagel, U.; Rõõm, T.; Mamone, S.; Concistrè, M.; Meier, B.; Krachmalnicoff, A.; Whitby, R. J.; Levitt, M. H.; Lei, Xuegong; Li, Yongjun; Turro, N. J.

    2015-03-01

    Water displays the phenomenon of spin isomerism in which the two proton spins either couple to form a triplet (ortho water, I = 1) or a singlet nuclear spin state (para water, I = 0). Here we study the interconversion of para and ortho water. The exact mechanism of this process is still not fully understood. In order to minimize interactions between molecules we use a sample where a single H2O is trapped in the C60 molecular cage (H2O@C60)andH2O@C60iscrystallized.H2O@C60 has long-lived ortho state and ortho-para conversion kinetics is non-exponential at LHeT. We studied mixtures of H2O@C60, D2O@C60 and C60 using IR absorption, NMR and dielectric measurements. We saw the speeding up of the interconversion with the growth of H2O@C60 concentration in C60 or when D2O@C60 was added. At some temperatures the kinetics is exponential. Models are discussed in order to explain the T and concentration dependence of ortho-para interconversion kinetics. This work was supported by institutional research funding IUT23-3 of the Estonian Ministry of Education and Research.

  17. Construction of erythrinane skeleton via Pd(0)-catalyzed intramolecular dearomatization of para-aminophenols.

    PubMed

    Xu, Ren-Qi; Gu, Qing; Wu, Wen-Ting; Zhao, Zhuo-An; You, Shu-Li

    2014-11-01

    A novel Pd(0)-catalyzed intramolecular arylative dearomatization of para-aminophenol derivatives is described. In the presence of 1.25 mol % [Pd(C3H5)Cl]2 and 3.75 mol % RuPhos, the arylative dearomatization reaction proceeds smoothly for a broad range of substrates, offering an efficient synthetic route to erythrinane derivatives in excellent yields. PMID:25308898

  18. Fabrication of multipotent poly-para-xylylene particles in controlled nanoscopic dimensions.

    PubMed

    Yuan, Ruei-Hung; Li, Yi-Jye; Sun, Ho-Yi; Wu, Chih-Yu; Guan, Zhen-Yu; Ho, Hsin-Ying; Fang, Cheng-Yuan; Chen, Hsien-Yeh

    2016-03-01

    In this study, poly-para-xylylene-based multifunctional nanoparticles (PPX-NPs) were fabricated. Based on the solubility characteristics determined for asymmetrically substituted poly-para-xylylenes in polar solvents, well-dispersed nanocolloids with a controllable size ranging from 50 to 800nm were produced in solution by the displacement of the solvent (water). These size ranges were found to have acceptable cellular compatibility through examinations of cultured 3T3 fibroblasts and adipose-derived stem cells treated with the PPX-NPs. In addition, these nanoscale PPX-NPs exhibited versatile bioconjugation properties in that a variety of available functional groups can be adopted from their counterpart, thin-film poly-para-xylylenes, during the production of these nanoparticles. For instance, bifunctional PPX-NPs with maleimide and benzoyl moieties were produced to enable immobilization via a maleimide-thiol reaction concurrent with a photochemical reaction. A cleavable PPX-NP was also produced with a thiol-exchangeable surface property. Additionally, by performing electrohydrodynamic jetting of parallel polymer solutions of selected poly-para-xylylenes, Janus-type or multicompartment PPX-NPs were created. The PPX-NPs can potentially be used for various biomedical applications such as combined diagnostics and drug delivery, multiplexing of detection, multiple-drug loading, and the targeted delivery of biomolecules or drugs. PMID:26724467

  19. Energia Renovable para Centros de Salud Rurales (Renewable Energy for Rural Health Clinics)

    SciTech Connect

    Jimenez, T.; Olson, K.

    1999-07-28

    Esta es la primera de una serie de guias de aplicaciones que el Programa de Energia de Villas de NREL esta comisionando para acoplar sistemas comerciales renovables con aplicaciones rurales, incluyendo agua, escuelas rurales y micro empresas. La guia esta complementada por las actividades de desarrollo del Programa de Energia de Villas de NREL, proyectos pilotos internacionales y programas de visitas profesionales.

  20. Autoguía para el telescopio 2,15 mts de CASLEO

    NASA Astrophysics Data System (ADS)

    Aballay, J. A.; Casagrande, A. R.; Pereyra, P. F.; Marún, A. H.

    Se está desarrollando un sistema de autoguía para el telescopio de 2,15 mts. El mismo se realizará aprovechando el Offset Guider. Al ocular móvil de éste se vinculará alguna cámara digital (ST4-ST7-CH250) para lograr la visión del objeto. El funcionamiento del equipo será el siguiente: primero, dadas las coordenadas del objeto a observar, se tomarán las coordenadas del telescopio para que, a través de una base de datos, se determine un campo de objetos que sirvan para la cámara de visión, luego, la PC obtendrá el offset entre la estrella de observación y la estrella seleccionada como guía, este valor será trasladado a los motores que posicionarán en forma automática el ocular. Una vez que la estrella es visualizada en la cámara (monitor de PC ) se correrá el programa que guiará el telescopio automáticamente.

  1. Fatiga (PDQ®)—Versión para profesionales de salud

    Cancer.gov

    Resumen de información revisada por expertos acerca de la fatiga, una afección caracterizada por extremo cansancio e incapacidad para funcionar por la falta de energía, que a menudo se observa como una complicación del cáncer y su tratamiento.

  2. Cáncer de hueso—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de hueso (óseo), así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  3. Vínculos observacionais para o processo-S em estrelas gigantes de Bário

    NASA Astrophysics Data System (ADS)

    Smiljanic, R. H. S.; Porto de Mello, G. F.; da Silva, L.

    2003-08-01

    Estrelas de bário são gigantes vermelhas de tipo GK que apresentam excessos atmosféricos dos elementos do processo-s. Tais excessos são esperados em estrelas na fase de pulsos térmicos do AGB (TP-AGB). As estrelas de bário são, no entanto, menos massivas e menos luminosas que as estrelas do AGB, assim, não poderiam ter se auto-enriquecido. Seu enriquecimento teria origem em uma estrela companheira, inicialmente mais massiva, que evolui pelo TP-AGB, se auto-enriquece com os elementos do processo-s e transfere material contaminado para a atmosfera da atual estrela de bário. A companheira evolui então para anã branca deixando de ser observada diretamente. As estrelas de bário são, portanto, úteis como testes observacionais para teorias de nucleossíntese pelo processo-s, convecção e perda de massa. Análises detalhadas de abundância com dados de alta qualidade para estes objetos são ainda escassas na literatura. Neste trabalho construímos modelos de atmosferas e, procedendo a uma análise diferencial, determinamos parâmetros atmosféricos e evolutivos de uma amostra de dez gigantes de bário e quatro normais. Determinamos seus padrões de abundância para Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Eu e Gd, concluindo que algumas estrelas classificadas na literatura como gigantes de bário são na verdade gigantes normais. Comparamos dois padrões médios de abundância, para estrelas com grandes excessos e estrelas com excessos moderados, com modelos teóricos de enriquecimento pelo processo-s. Os dois grupos de estrelas são ajustados pelos mesmos parâmetros de exposição de nêutrons. Tal resultado sugere que a ocorrência do fenômeno de bário com diferentes intensidades não se deve a diferentes exposições de nêutrons. Discutimos ainda efeitos nucleossintéticos, ligados ao processo-s, sugeridos na literatura para os elementos Cu, Mn, V e Sc.

  4. Hox and ParaHox gene expression in early body plan patterning of polyplacophoran mollusks

    PubMed Central

    Fritsch, Martin; Wollesen, Tim

    2016-01-01

    ABSTRACT Molecular developmental studies of various bilaterians have shown that the identity of the anteroposterior body axis is controlled by Hox and ParaHox genes. Detailed Hox and ParaHox gene expression data are available for conchiferan mollusks, such as gastropods (snails and slugs) and cephalopods (squids and octopuses), whereas information on the putative conchiferan sister group, Aculifera, is still scarce (but see Fritsch et al., 2015 on Hox gene expression in the polyplacophoran Acanthochitona crinita). In contrast to gastropods and cephalopods, the Hox genes in polyplacophorans are expressed in an anteroposterior sequence similar to the condition in annelids and other bilaterians. Here, we present the expression patterns of the Hox genes Lox5, Lox4, and Lox2, together with the ParaHox gene caudal (Cdx) in the polyplacophoran A. crinita. To localize Hox and ParaHox gene transcription products, we also investigated the expression patterns of the genes FMRF and Elav, and the development of the nervous system. Similar to the other Hox genes, all three Acr‐Lox genes are expressed in an anteroposterior sequence. Transcripts of Acr‐Cdx are seemingly present in the forming hindgut at the posterior end. The expression patterns of both the central class Acr‐Lox genes and the Acr‐Cdx gene are strikingly similar to those in annelids and nemerteans. In Polyplacophora, the expression patterns of the Hox and ParaHox genes seem to be evolutionarily highly conserved, while in conchiferan mollusks these genes are co‐opted into novel functions that might have led to evolutionary novelties, at least in gastropods and cephalopods. PMID:27098677

  5. Rotational excitation of HCN by para- and ortho-H{sub 2}

    SciTech Connect

    Vera, Mario Hernández; Kalugina, Yulia; Denis-Alpizar, Otoniel; Stoecklin, Thierry; Lique, François

    2014-06-14

    Rotational excitation of the hydrogen cyanide (HCN) molecule by collisions with para-H{sub 2}( j = 0, 2) and ortho-H{sub 2}( j = 1) is investigated at low temperatures using a quantum time independent approach. Both molecules are treated as rigid rotors. The scattering calculations are based on a highly correlated ab initio 4-dimensional (4D) potential energy surface recently published. Rotationally inelastic cross sections among the 13 first rotational levels of HCN were obtained using a pure quantum close coupling approach for total energies up to 1200 cm{sup −1}. The corresponding thermal rate coefficients were computed for temperatures ranging from 5 to 100 K. The HCN rate coefficients are strongly dependent on the rotational level of the H{sub 2} molecule. In particular, the rate coefficients for collisions with para-H{sub 2}( j = 0) are significantly lower than those for collisions with ortho-H{sub 2}( j = 1) and para-H{sub 2}( j = 2). Propensity rules in favor of even Δj transitions were found for HCN in collisions with para-H{sub 2}( j = 0) whereas propensity rules in favor of odd Δj transitions were found for HCN in collisions with H{sub 2}( j ⩾ 1). The new rate coefficients were compared with previously published HCN-para-H{sub 2}( j = 0) rate coefficients. Significant differences were found due the inclusion of the H{sub 2} rotational structure in the scattering calculations. These new rate coefficients will be crucial to improve the estimation of the HCN abundance in the interstellar medium.

  6. Hox and ParaHox gene expression in early body plan patterning of polyplacophoran mollusks.

    PubMed

    Fritsch, Martin; Wollesen, Tim; Wanninger, Andreas

    2016-03-01

    Molecular developmental studies of various bilaterians have shown that the identity of the anteroposterior body axis is controlled by Hox and ParaHox genes. Detailed Hox and ParaHox gene expression data are available for conchiferan mollusks, such as gastropods (snails and slugs) and cephalopods (squids and octopuses), whereas information on the putative conchiferan sister group, Aculifera, is still scarce (but see Fritsch et al., 2015 on Hox gene expression in the polyplacophoran Acanthochitona crinita). In contrast to gastropods and cephalopods, the Hox genes in polyplacophorans are expressed in an anteroposterior sequence similar to the condition in annelids and other bilaterians. Here, we present the expression patterns of the Hox genes Lox5, Lox4, and Lox2, together with the ParaHox gene caudal (Cdx) in the polyplacophoran A. crinita. To localize Hox and ParaHox gene transcription products, we also investigated the expression patterns of the genes FMRF and Elav, and the development of the nervous system. Similar to the other Hox genes, all three Acr-Lox genes are expressed in an anteroposterior sequence. Transcripts of Acr-Cdx are seemingly present in the forming hindgut at the posterior end. The expression patterns of both the central class Acr-Lox genes and the Acr-Cdx gene are strikingly similar to those in annelids and nemerteans. In Polyplacophora, the expression patterns of the Hox and ParaHox genes seem to be evolutionarily highly conserved, while in conchiferan mollusks these genes are co-opted into novel functions that might have led to evolutionary novelties, at least in gastropods and cephalopods. PMID:27098677

  7. Ancient origins of axial patterning genes: Hox genes and ParaHox genes in the Cnidaria.

    PubMed

    Finnerty, J R; Martindale, M Q

    1999-01-01

    Among the bilaterally symmetrical, triploblastic animals (the Bilateria), a conserved set of developmental regulatory genes are known to function in patterning the anterior-posterior (AP) axis. This set includes the well-studied Hox cluster genes, and the recently described genes of the ParaHox cluster, which is believed to be the evolutionary sister of the Hox cluster (Brooke et al. 1998). The conserved role of these axial patterning genes in animals as diverse as frogs and flies is believed to reflect an underlying homology (i.e., all bilaterians derive from a common ancestor which possessed an AP axis and the developmental mechanisms responsible for patterning the axis). However, the origin and early evolution of Hox genes and ParaHox genes remain obscure. Repeated attempts have been made to reconstruct the early evolution of Hox genes by analyzing data from the triphoblastic animals, the Bilateria (Schubert et al. 1993; Zhang and Nei 1996). A more precise dating of Hox origins has been elusive due to a lack of sufficient information from outgroup taxa such as the phylum Cnidaria (corals, hydras, jellyfishes, and sea anemones). In combination with outgroup taxa, another potential source of information about Hox origins is outgroup genes (e.g., the genes of the ParaHox cluster). In this article, we present cDNA sequences of two Hox-like genes (anthox2 and anthox6) from the sea anemone, Nematostella vectensis. Phylogenetic analysis indicates that anthox2 (= Cnox2) is homologous to the GSX class of ParaHox genes, and anthox6 is homologous to the anterior class of Hox genes. Therefore, the origin of Hox genes and ParaHox genes occurred prior to the evolutionary split between the Cnidaria and the Bilateria and predated the evolution of the anterior-posterior axis of bilaterian animals. Our analysis also suggests that the central Hox class was invented in the bilaterian lineage, subsequent to their split from the Cnidaria. PMID:11324016

  8. Saturn’s Tropospheric Temperatures and Para-Hydrogen Distribution from Ten Years of Cassini Observations

    NASA Astrophysics Data System (ADS)

    Fletcher, Leigh N.; Irwin, Patrick G.; Sinclair, James; Giles, Rohini; Barstow, Joanna; Achterberg, Richard K.; Orton, Glenn S.

    2014-11-01

    Cassini/CIRS observations of Saturn’s 10-1400 cm-1 spectrum have been inverted to construct a global record of tropospheric temperature and para-hydrogen variability over the ten-year span of the Cassini mission. The data record the slow reversal of seasonal asymmetries in tropospheric conditions from northern winter (2004, Ls=293), through northern spring equinox (2009, Ls=0) to the present day (2014, Ls=60). Mid-latitude tropospheric temperatures have cooled by approximately 4-6 K in the south and warmed by 2-4 K in the north, with the seasonal contrast decreasing with depth. CIRS detected the north polar minimum 100-mbar temperatures 6-8 years after winter solstice, whereas the south polar maximum occurred 1-2 years after summer solstice, consistent with the lag times predicted by radiative equilibrium models. Warm polar cyclones and the northern hexagon persist throughout the mission, suggesting that they are permanent features of Saturn’s tropospheric circulation. The 200-mbar thermal enhancement (“knee”) that was strongest in the summer but weak or absent in winter in 2004-2006 (Fletcher et al., 2007, Icarus 189, p.457-478) has now shifted northward and is present globally in 2014, suggestive of radiative heating in Saturn’s tropospheric haze layer. Saturn’s para-H2 fraction, which serves as a tracer of both tropospheric mixing and the efficiency of re-equilibration between the ortho- and para-hydrogen states, is slowly altering: super-equilibrium conditions (para-H2 fraction exceeding equilibrium expectations and suggestive of subsiding airmasses) that dominated the southern summer hemisphere are now weakening, whereas the sub-equilibrium conditions (suggestive of uplift) of the northern winter are being replaced by equilibrium or super-equilibrium conditions in spring. The thermal ‘knee’ and the para-H2 distribution are tracking both the increased spring illumination and the increasing tropospheric haze opacity of the springtime hemisphere

  9. Anatomic Distribution of Fluorodeoxyglucose-Avid Para-aortic Lymph Nodes in Patients With Cervical Cancer

    SciTech Connect

    Takiar, Vinita; Fontanilla, Hiral P.; Eifel, Patricia J.; Jhingran, Anuja; Kelly, Patrick; Iyer, Revathy B.; Levenback, Charles F.; Zhang, Yongbin; Dong, Lei; Klopp, Ann

    2013-03-15

    Purpose: Conformal treatment of para-aortic lymph nodes (PAN) in cervical cancer allows dose escalation and reduces normal tissue toxicity. Currently, data documenting the precise location of involved PAN are lacking. We define the spatial distribution of this high-risk nodal volume by analyzing fluorodeoxyglucose (FDG)-avid lymph nodes (LNs) on positron emission tomography/computed tomography (PET/CT) scans in patients with cervical cancer. Methods and Materials: We identified 72 PANs on pretreatment PET/CT of 30 patients with newly diagnosed stage IB-IVA cervical cancer treated with definitive chemoradiation. LNs were classified as left-lateral para-aortic (LPA), aortocaval (AC), or right paracaval (RPC). Distances from the LN center to the closest vessel and adjacent vertebral body were calculated. Using deformable image registration, nodes were mapped to a template computed tomogram to provide a visual impression of nodal frequencies and anatomic distribution. Results: We identified 72 PET-positive para-aortic lymph nodes (37 LPA, 32 AC, 3 RPC). All RPC lymph nodes were in the inferior third of the para-aortic region. The mean distance from aorta for all lymph nodes was 8.3 mm (range, 3-17 mm), and from the inferior vena cava was 5.6 mm (range, 2-10 mm). Of the 72 lymph nodes, 60% were in the inferior third, 36% were in the middle third, and 4% were in the upper third of the para-aortic region. In all, 29 of 30 patients also had FDG-avid pelvic lymph nodes. Conclusions: A total of 96% of PET positive nodes were adjacent to the aorta; PET positive nodes to the right of the IVC were rare and were all located distally, within 3 cm of the aortic bifurcation. Our findings suggest that circumferential margins around the vessels do not accurately define the nodal region at risk. Instead, the anatomical extent of the nodal basin should be contoured on each axial image to provide optimal coverage of the para-aortic nodal compartment.

  10. Astronomia para/com crianças carentes em Limeira

    NASA Astrophysics Data System (ADS)

    Bretones, P. S.; Oliveira, V. C.

    2003-08-01

    Em 2001, o Instituto Superior de Ciências Aplicadas (ISCA Faculdades de Limeira) iniciou um projeto pelo qual o Observatório do Morro Azul empreendeu uma parceria com o Centro de Promoção Social Municipal (CEPROSOM), instituição mantida pela Prefeitura Municipal de Limeira para atender crianças e adolescentes carentes. O CEPROSOM contava com dois projetos: Projeto Centro de Convivência Infantil (CCI) e Programa Criança e Adolescente (PCA), que atendiam crianças e adolescentes em Centros Comunitários de diversas áreas da cidade. Esses projetos têm como prioridades estabelecer atividades prazerosas para as crianças no sentido de retirá-las das ruas. Assim sendo, as crianças passaram a ter mais um tipo de atividade - as visitas ao observatório. Este painel descreve as várias fases do projeto, que envolveu: reuniões de planejamento, curso de Astronomia para as orientadoras dos CCIs e PCAs, atividades relacionadas a visitas das crianças ao Observatório, proposta de construção de gnômons e relógios de Sol nos diversos Centros Comunitários de Limeira e divulgação do projeto na imprensa. O painel inclui discussões sobre a aprendizagem de crianças carentes, relatos que mostram a postura das orientadoras sobre a pertinência do ensino de Astronomia, relatos do monitor que fez o atendimento no Observatório e o que o número de crianças atendidas representou para as atividades da instituição desde o início de suas atividades e, em particular, em 2001. Os resultados são baseados na análise de relatos das orientadoras e do monitor do Observatório, registros de visitas e matérias da imprensa local. Conclui com uma avaliação do que tal projeto representou para as Instituições participantes. Para o Observatório, em particular, foi feita uma análise com relação às outras modalidades de atendimentos que envolvem alunos de escolas e público em geral. Também é abordada a questão do compromisso social do Observatório na educação do

  11. Differential regulation of ParaHox genes by retinoic acid in the invertebrate chordate amphioxus (Branchiostoma floridae).

    PubMed

    Osborne, Peter W; Benoit, Gérard; Laudet, Vincent; Schubert, Michael; Ferrier, David E K

    2009-03-01

    The ParaHox cluster is the evolutionary sister to the Hox cluster. Like the Hox cluster, the ParaHox cluster displays spatial and temporal regulation of the component genes along the anterior/posterior axis in a manner that correlates with the gene positions within the cluster (a feature called collinearity). The ParaHox cluster is however a simpler system to study because it is composed of only three genes. We provide a detailed analysis of the amphioxus ParaHox cluster and, for the first time in a single species, examine the regulation of the cluster in response to a single developmental signalling molecule, retinoic acid (RA). Embryos treated with either RA or RA antagonist display altered ParaHox gene expression: AmphiGsx expression shifts in the neural tube, and the endodermal boundary between AmphiXlox and AmphiCdx shifts its anterior/posterior position. We identified several putative retinoic acid response elements and in vitro assays suggest some may participate in RA regulation of the ParaHox genes. By comparison to vertebrate ParaHox gene regulation we explore the evolutionary implications. This work highlights how insights into the regulation and evolution of more complex vertebrate arrangements can be obtained through studies of a simpler, unduplicated amphioxus gene cluster. PMID:19103191

  12. ParA and ParB coordinate chromosome segregation with cell elongation and division during Streptomyces sporulation.

    PubMed

    Donczew, Magdalena; Mackiewicz, Paweł; Wróbel, Agnieszka; Flärdh, Klas; Zakrzewska-Czerwińska, Jolanta; Jakimowicz, Dagmara

    2016-04-01

    In unicellular bacteria, the ParA and ParB proteins segregate chromosomes and coordinate this process with cell division and chromosome replication. During sporulation of mycelial Streptomyces, ParA and ParB uniformly distribute multiple chromosomes along the filamentous sporogenic hyphal compartment, which then differentiates into a chain of unigenomic spores. However, chromosome segregation must be coordinated with cell elongation and multiple divisions. Here, we addressed the question of whether ParA and ParB are involved in the synchronization of cell-cycle processes during sporulation in Streptomyces To answer this question, we used time-lapse microscopy, which allows the monitoring of growth and division of single sporogenic hyphae. We showed that sporogenic hyphae stop extending at the time of ParA accumulation and Z-ring formation. We demonstrated that both ParA and ParB affect the rate of hyphal extension. Additionally, we showed that ParA promotes the formation of massive nucleoprotein complexes by ParB. We also showed that FtsZ ring assembly is affected by the ParB protein and/or unsegregated DNA. Our results indicate the existence of a checkpoint between the extension and septation of sporogenic hyphae that involves the ParA and ParB proteins. PMID:27248800

  13. ParA and ParB coordinate chromosome segregation with cell elongation and division during Streptomyces sporulation

    PubMed Central

    Donczew, Magdalena; Mackiewicz, Paweł; Wróbel, Agnieszka; Flärdh, Klas; Zakrzewska-Czerwińska, Jolanta

    2016-01-01

    In unicellular bacteria, the ParA and ParB proteins segregate chromosomes and coordinate this process with cell division and chromosome replication. During sporulation of mycelial Streptomyces, ParA and ParB uniformly distribute multiple chromosomes along the filamentous sporogenic hyphal compartment, which then differentiates into a chain of unigenomic spores. However, chromosome segregation must be coordinated with cell elongation and multiple divisions. Here, we addressed the question of whether ParA and ParB are involved in the synchronization of cell-cycle processes during sporulation in Streptomyces. To answer this question, we used time-lapse microscopy, which allows the monitoring of growth and division of single sporogenic hyphae. We showed that sporogenic hyphae stop extending at the time of ParA accumulation and Z-ring formation. We demonstrated that both ParA and ParB affect the rate of hyphal extension. Additionally, we showed that ParA promotes the formation of massive nucleoprotein complexes by ParB. We also showed that FtsZ ring assembly is affected by the ParB protein and/or unsegregated DNA. Our results indicate the existence of a checkpoint between the extension and septation of sporogenic hyphae that involves the ParA and ParB proteins. PMID:27248800

  14. Aplicación del Teorema de Nekhorochev para tiempos de estabilidad en Mecánica Celeste

    NASA Astrophysics Data System (ADS)

    Miloni, O.; Núñez, J.; Brunini, A.

    En Mecánica Celeste, uno de los problemas centrales consiste en la determinación de los tiempos de estabilidad. El teorema de Nekhorochev proporciona un método para dicho estudio, para un sistema determinado por un hamiltoniano descripto en las variables acción-ángulo. El trabajo consiste en la acotación tanto del potencial perturbador y de la matriz hessiana del hamiltoniano integrable para determinar luego el tiempo de estabilidad de dicho sistema, donde por estabilidad se entiende la separación en norma infinito en el espacio de las acciones.

  15. Una propuesta para el desarrollo de un arreglo de síntesis de apertura

    NASA Astrophysics Data System (ADS)

    Arnal, E. M.

    Los estudios llevados a cabo en la transición del hidrógeno neutro a λ~21-cm han contribuído a incrementar nuestro conocimiento acerca de las propiedades globales del medio interestelar, sea este galáctico o extragaláctico. Avances en este campo han sido provocados, a menudo, por la puesta en servicio de radiotelescopios que poseen una mayor resolución angular. Aquí se presenta una propuesta para desarrollar un nuevo instrumento, un interferómetro, que permitirá abrir nuevas líneas de investigación. Este instrumento combinará la técnica de síntesis de apertura con la de espectroscopía de correlación digital, para alcanzar una resolución angular de 1' y un campo de visión de ~1o.7.

  16. Charge-transfer-directed radical substitution enables para-selective C-H functionalization.

    PubMed

    Boursalian, Gregory B; Ham, Won Seok; Mazzotti, Anthony R; Ritter, Tobias

    2016-08-01

    Efficient C-H functionalization requires selectivity for specific C-H bonds. Progress has been made for directed aromatic substitution reactions to achieve ortho and meta selectivity, but a general strategy for para-selective C-H functionalization has remained elusive. Herein we introduce a previously unappreciated concept that enables nearly complete para selectivity. We propose that radicals with high electron affinity elicit arene-to-radical charge transfer in the transition state of radical addition, which is the factor primarily responsible for high positional selectivity. We demonstrate with a simple theoretical tool that the selectivity is predictable and show the utility of the concept through a direct synthesis of aryl piperazines. Our results contradict the notion, widely held by organic chemists, that radical aromatic substitution reactions are inherently unselective. The concept of radical substitution directed by charge transfer could serve as the basis for the development of new, highly selective C-H functionalization reactions. PMID:27442288

  17. Molecular Characterization of Neurally Expressing Genes in the Para Sodium Channel Gene Cluster of Drosophila

    PubMed Central

    Hong, C. S.; Ganetzky, B.

    1996-01-01

    To elucidate the mechanisms regulating expression of para, which encodes the major class of sodium channels in the Drosophila nervous system, we have tried to locate upstream cis-acting regulatory elements by mapping the transcriptional start site and analyzing the region immediately upstream of para in region 14D of the polytene chromosomes. From these studies, we have discovered that the region contains a cluster of neurally expressing genes. Here we report the molecular characterization of the genomic organization of the 14D region and the genes within this region, which are: calnexin (Cnx), actin related protein 14D (Arp14D), calcineurin A 14D (CnnA14D), and chromosome associated protein (Cap). The tight clustering of these genes, their neuronal expression patterns, and their potential functions related to expression, modulation, or regulation of sodium channels raise the possibility that these genes represent a functionally related group sharing some coordinate regulatory mechanism. PMID:8849894

  18. Control of Photoluminescence of Carbon Nanodots via Surface Functionalization using Para-substituted Anilines

    PubMed Central

    Kwon, Woosung; Do, Sungan; Kim, Ji-Hee; Seok Jeong, Mun; Rhee, Shi-Woo

    2015-01-01

    Carbon nanodots (C-dots) are a kind of fluorescent carbon nanomaterials, composed of polyaromatic carbon domains surrounded by amorphous carbon frames, and have attracted a great deal of attention because of their interesting properties. There are still, however, challenges ahead such as blue-biased photoluminescence, spectral broadness, undefined energy gaps and etc. In this report, we chemically modify the surface of C-dots with a series of para-substituted anilines to control their photoluminescence. Our surface functionalization endows our C-dots with new energy levels, exhibiting long-wavelength (up to 650 nm) photoluminescence of very narrow spectral widths. The roles of para-substituted anilines and their substituents in developing such energy levels are thoroughly studied by using transient absorption spectroscopy. We finally demonstrate light-emitting devices exploiting our C-dots as a phosphor, converting UV light to a variety of colors with internal quantum yields of ca. 20%. PMID:26218869

  19. Sludge reduction by uncoupling metabolism: SBR tests with para-nitrophenol and a commercial uncoupler.

    PubMed

    Zuriaga-Agustí, E; Mendoza-Roca, J A; Bes-Piá, A; Alonso-Molina, J L; Amorós-Muñoz, I

    2016-11-01

    Nowadays cost reduction is a very important issue in wastewater treatment plants. One way, is to minimize the sludge production. Microorganisms break down the organic matter into inorganic compounds through catabolism. Uncoupling metabolism is a method which promote catabolism reactions instead of anabolism ones, where adenosine triphosphate synthesis is inhibited. In this work, the influence of the addition of para-nitrophenol and a commercial reagent to a sequencing batch reactor (SBR) on sludge production and process performance has been analyzed. Three laboratory SBRs were operated in parallel to compare the effect of the addition of both reagents with a control reactor. SBRs were fed with synthetic wastewater and were operated with the same conditions. Results showed that sludge production was slightly reduced for the tested para-nitrophenol concentrations (20 and 25 mg/L) and for a LODOred dose of 1 mL/day. Biological process performance was not influenced and high COD removals were achieved. PMID:27505165

  20. ROTATIONAL SPECTROSCOPY OF THE CO-PARA-H{sub 2} MOLECULAR COMPLEX

    SciTech Connect

    Potapov, A. V.; Surin, L. A.; Giesen, T. F.; Schlemmer, S.; Panfilov, V. A.; Dumesh, B. S.; Raston, P. L.; Jaeger, W.

    2009-10-01

    The rotational spectrum of the CO-para-H{sub 2} van der Waals complex, produced using a molecular jet expansion, was observed with two different techniques: OROTRON intracavity millimeter-wave spectroscopy and pulsed Fourier transform microwave spectroscopy. Thirteen transitions in the frequency range from 80 to 130 GHz and two transitions in the 14 GHz region were measured and assigned, allowing for a precise determination of the corresponding energy level positions of CO-para-H{sub 2}. The data obtained enable further radio astronomical searches for this molecular complex and provide a sensitive test of the currently best available intermolecular potential energy surface for the CO-H{sub 2} system.

  1. Development of an integrated remote monitoring technique and its application to para-stressing bridge system

    NASA Astrophysics Data System (ADS)

    Miyamoto, Ayaho; Motoshita, Minoru; Casas, Joan R.

    2013-12-01

    Bridge monitoring system via information technology is capable of providing more accurate knowledge of bridge performance characteristics than traditional strategies. This paper describes not only an integrated Internet monitoring system that consists of a stand-alone monitoring system (SMS) and a Web-based Internet monitoring system (IMS) for bridge maintenance but also its application to para-stressing bridge system as an intelligent structure. IMS, as a Web-based system, is capable of addressing the remote monitoring by introducing measuring information derived from SMS into the system through Internet or intranet connected by either PHS or LAN. Moreover, the key functions of IMS such as data management system, condition assessment, and decision making with the proposed system are also introduced in this paper. Another goal of this study is to establish the framework of a para-stressing bridge system which is an intelligent bridge by integrating the bridge monitoring information into the system to control the bridge performance automatically.

  2. Regioselective Enzymatic β-Carboxylation of para-Hydroxy- styrene Derivatives Catalyzed by Phenolic Acid Decarboxylases

    PubMed Central

    Wuensch, Christiane; Pavkov-Keller, Tea; Steinkellner, Georg; Gross, Johannes; Fuchs, Michael; Hromic, Altijana; Lyskowski, Andrzej; Fauland, Kerstin; Gruber, Karl; Glueck, Silvia M; Faber, Kurt

    2015-01-01

    We report on a ‘green’ method for the utilization of carbon dioxide as C1 unit for the regioselective synthesis of (E)-cinnamic acids via regioselective enzymatic carboxylation of para-hydroxystyrenes. Phenolic acid decarboxylases from bacterial sources catalyzed the β-carboxylation of para-hydroxystyrene derivatives with excellent regio- and (E/Z)-stereoselectivity by exclusively acting at the β-carbon atom of the C=C side chain to furnish the corresponding (E)-cinnamic acid derivatives in up to 40% conversion at the expense of bicarbonate as carbon dioxide source. Studies on the substrate scope of this strategy are presented and a catalytic mechanism is proposed based on molecular modelling studies supported by mutagenesis of amino acid residues in the active site. PMID:26190963

  3. Charge-transfer-directed radical substitution enables para-selective C–H functionalization

    NASA Astrophysics Data System (ADS)

    Boursalian, Gregory B.; Ham, Won Seok; Mazzotti, Anthony R.; Ritter, Tobias

    2016-08-01

    Efficient C–H functionalization requires selectivity for specific C–H bonds. Progress has been made for directed aromatic substitution reactions to achieve ortho and meta selectivity, but a general strategy for para-selective C–H functionalization has remained elusive. Herein we introduce a previously unappreciated concept that enables nearly complete para selectivity. We propose that radicals with high electron affinity elicit arene-to-radical charge transfer in the transition state of radical addition, which is the factor primarily responsible for high positional selectivity. We demonstrate with a simple theoretical tool that the selectivity is predictable and show the utility of the concept through a direct synthesis of aryl piperazines. Our results contradict the notion, widely held by organic chemists, that radical aromatic substitution reactions are inherently unselective. The concept of radical substitution directed by charge transfer could serve as the basis for the development of new, highly selective C–H functionalization reactions.

  4. Repeated Topical Application of para-Phenylenediamine Induces Renal Histopathological Changes in Rats.

    PubMed

    Bharali, Manuj Kr; Basumatary, Rajeev; Rahman, Taibur; Dutta, Karabi

    2012-05-01

    Hemolytic anemia and rhabdomyolysis have been often reported to be an adverse effect of drug- and chemical-induced toxicity both in experimental and real-life scenario. para-Phenylenediamine (PPD) is a derivative of para-nitroaniline and has been found as an ingredient of almost all hair dye formulations in varying concentrations from 2% to 4% w/v. Earlier studies have reported that the accidental oral ingestion of PPD in humans can lead to acute renal failure because of rhabdomyolysis. In the present investigation, we have tested the chronic topical application of PPD and its effect on the renal histology of Sprague-Dawley rats. The experiment provides clear evidence that topically applied PPD induces hemolytic anemia as evident from the decrease in the total RBC count, packed cell volume, and hemoglobin content apart from rhabdomyolysis which subsequently causes acute renal failure in rats. PMID:22778510

  5. Modelizacion, control e implementacion de un procesador energetico paralelo para aplicacion en sistemas multisalida

    NASA Astrophysics Data System (ADS)

    Ferreres Sabater, Agustin

    Cualquier sistema electronico que incluya un procesado o tratamiento de la senal, y ademas, algun tipo de actuador mecanico generalmente necesita, como minimo, dos tensiones diferentes de alimentacion. Excluyendo los sistemas de alimentacion distribuida, la solucion tecnica mas utilizada para proporcionar dos o mas tensiones consiste en las fuentes de alimentacion multisalida. En una fuente de alimentacion multisalida los diferentes circuitos que conforman cada salida comparten un mismo transformador de potencia optimizando coste, masa, y volumen. Las ventajas obtenidas con este procedimiento tienen en su contra el efecto que sobre cada salida individual provocan las demas en su conjunto debido, principalmente, a los efectos de los elementos parasitos de los componentes. Un cambio de carga en una de las salidas produce un transitorio que es visto por todas las demas como un efecto de impedancia cruzada, y al final del transitorio, la tension de cada salida es diferente respecto a la que tenian antes del transitorio. Este ultimo resultado se conoce como regulacion cruzada. La disminucion de los efectos de la regulacion cruzada ha sido objeto de estudio durante los ultimos anos. El objetivo ha sido el desarrollo de distintas estrategias que permiten, desde disminuir los efectos de la regulacion cruzada hasta los niveles deseables, a eliminarla completamente. El resultado final suele suponer una penalizacion sobre el diseno del sistema directamente proporcional al grado de regulacion a conseguir en las distintas salidas. Entre las soluciones propuestas para eliminar la regulacion cruzada las tecnicas de post-regulacion se han consolidado como la opcion mas aceptada ya que, pueden aplicarse a cualquier convertidor y no suponen ninguna complejidad adicional a la hora de plantear el diseno. En esta Tesis Doctoral se abordara el estudio de la tecnica conocida como postregulacion mediante transformador controlado, que si bien se ha empleado en convertidores resonantes, su

  6. Polar Effects Control the Gas-phase Reactivity of Charged para-Benzyne Analogs

    PubMed Central

    Wittrig, Ashley M.; Archibold, Enada F.; Sheng, Huaming; Nash, John J.; Kenttämaa, Hilkka I.

    2014-01-01

    The gas-phase reactivity of charged para-benzynes is entirely unexplored as they and/or their precursors tend to undergo ring-opening upon their generation. We report here a gas-phase reactivity study of two such benzynes, the 2,5-didehydropyridinium and 5,8-didehydroisoquinolinium cations, generated in a modified dual-linear quadrupole ion trap (DLQIT) mass spectrometer. Both biradicals were found to form diagnostic products with organic molecules, indicating the presence of two radical sites. As opposed to earlier predictions that the singlet-triplet (S-T) splitting controls the radical reactivity of such species, the 2,5-didehydropyridinium cation reacts much faster in spite of its larger S-T splitting. Calculated vertical electron affinities of the radical sites of the para-benzynes, a parameter related to the polarity of the transition states of their reactions, appears to be the most important reactivity controlling factor. PMID:25838787

  7. The Impact of Family Support on the Success of Black Men at an Historically Black University: Affirming the Revision of Tinto's Theory

    ERIC Educational Resources Information Center

    Palmer, Robert T.; Davis, Ryan J.; Maramba, Dina C.

    2011-01-01

    This qualitative study of 11 Black male students who entered a public historically Black college and university (HBCU) as academically under-prepared and persisted to graduation, provides insight into the ways in which family promotes academic success for Black male students at a public HBCU. The study's findings encourage practitioners at HBCUs…

  8. Mars Analog Research and Technology Experiment (MARTE): A Simulated Mars Drilling Mission to Search for Subsurface Life at the Rio Tinto, Spain

    NASA Astrophysics Data System (ADS)

    Stoker, C. R.; Lemke, L. G.; Mandell, H.; McKay, D.; George, J.; Gomez-Elvira, J.; Amils, R.; Stevens, T.; Miller, D.

    2003-03-01

    MARTE is a Mars analog drilling experiment to search for subsurface life on Mars while also characterizing a sulfide-based subsurface biosphere. MARTE is among the first set of field experiments supported by the ASTEP program.

  9. Río Tinto Faulted Volcanosedimentary Deposits as Analog Habitats for Extant Subsurface Biospheres on Mars: A Synthesis of the MARTE Drilling Project Geobiology Results

    NASA Astrophysics Data System (ADS)

    Fernández-Remolar, D. C.; Prieto-Ballesteros, O.; Rodríguez, N.; Dávila, F.; Stevens, T.; Amils, R.; Gómez-Elvira, J.; Stoker, C. R.

    2005-03-01

    Reconstruction of the probable habitats hosting the detected microbial communities through the integration of the geobiological data obtained from the MARTE drilling campaigns, TEM sounding and field surface geological survey

  10. Summer Bridge Programs: A Quantitative Study of the Relationship between Participation and Institutional Integration Using Tinto's Student Integration Model at a Mid-Sized, Public University in Massachusetts

    ERIC Educational Resources Information Center

    Arena, Meaghan L.

    2013-01-01

    With six-year degree completion rates for undergraduate students at a dismal 50% nationally (Weddle-West & Bingham, 2010), many institutions of higher education strive to develop programming to increase student retention rates. Summer bridge programs, an example of commonly used retention programs, seek to increase retention rates by…

  11. "How Much Economic Value Does My Credential Have?": Reformulating Tinto's Model to Study Students' Persistence in Community Colleges

    ERIC Educational Resources Information Center

    Stuart, G. Rob; Rios-Aguilar, Cecilia; Deil-Amen, Regina

    2014-01-01

    Community colleges play a key role in educating the large number of non-traditional, low-income, and under-prepared students who have entered higher education in the past several decades. Despite increased access, community colleges are struggling to graduate students. Most, if not all, strategies provided by scholars to improve college completion…

  12. Iodine(III)-Mediated para-Selective Direct Imidation of Anilides.

    PubMed

    Pialat, Amélie; Bergès, Julien; Sabourin, Axel; Vinck, Robin; Liégault, Benoît; Taillefer, Marc

    2015-07-01

    The direct, nucleophilic imidation of acetanilide derivatives has been performed under mild, iodine(III)-mediated or -catalyzed conditions, employing lithium triflimide as the nitrogen source. The reaction exhibits exclusive regioselectivity for the para position and shows a good tolerance for varied functional groups at both the ortho or meta positions. Preliminary mechanistic data suggest that the LiNTf2 reagent plays a key role in the reactivity. PMID:26095155

  13. Synthesis of icariin from kaempferol through regioselective methylation and para-Claisen-Cope rearrangement.

    PubMed

    Mei, Qinggang; Wang, Chun; Zhao, Zhigang; Yuan, Weicheng; Zhang, Guolin

    2015-01-01

    The hemisynthesis of the naturally occurring bioactive flavonoid glycoside icariin (1) has been accomplished in eleven steps with 7% overall yield from kaempferol. The 4'-OH methylation of kaempferol, the 8-prenylation of 3-O-methoxymethyl-4'-O-methyl-5-O-prenyl-7-O-benzylkaempferol (8) via para-Claisen-Cope rearrangement catalyzed by Eu(fod)3 in the presence of NaHCO3, and the glycosylation of icaritin (3) are the key steps. PMID:26425179

  14. Conformerism, enantiomorphism and double catemer motifs in para-substituted nostoclide analogues

    NASA Astrophysics Data System (ADS)

    Teixeira, Róbson Ricardo; Barbosa, Luiz Claudio Almeida; Valero Antolinez, Isabel; de Souza Corrêa, Rodrigo; Martins, Felipe Terra; Doriguetto, Antônio Carlos

    2016-02-01

    We have here elucidated the crystal structures of five nostoclide analogues. A common feature in all compounds is a substituent at the para-position of the benzylidene group. Compounds with either bromine (3) or hydroxyl (4) as para-substituent crystallizes with Z' = 2 as result of conformerism. It was also observed that Z' > 1 in the compound with a para-dimethylamino substituent (1). However, its four crystallographically independent molecules are conformationally similar. They are not related by crystallographic symmetry due to the offset packing of their C-H … Odbnd C nonclassical hydrogen bonded double chains. This compound (1) has also crystallized in a chiral space group (P21) despite the lack of a stereocenter. Such enantiomorphism phenomenon is related to the presence of only one of the two mirror benzyl conformations with phenyl ring at the equatorial position opposite the lactone oxygen atom. The molecular mean plane of nostoclide analogues has been featured by high level of planarity, except in the brominated compound where two twisted conformations occurred due to rotations on the single bond axis into benzylidene group. The benzyl conformation has been the greatest difference between the two crystallographically independent molecules of the para-hydroxylated compound (4). The crystal packing of the compounds is marked by double catemer motif assembled through C-H … Odbnd C non-classical hydrogen bonds, although C-H … π interactions do play an important role in stabilizing the crystal packing of some compounds of the series.

  15. Highly regioselective para-methylthiolation/bridging methylenation of arylamines promoted by NH4I.

    PubMed

    Xu, Yinfeng; Cong, Tiantian; Liu, Ping; Sun, Peipei

    2015-10-14

    Aryl methyl thioethers and methylene-bridged arylamines were synthesized via highly regioselective para-methylthiolation/bridging methylenation of arylamines using DMSO as the methylthio or methylene source in the presence of NH4I under metal-free conditions. For the substrates with both electron-donating and electron-withdrawing substituents, the reaction proceeded smoothly and gave moderate to good yields. PMID:26337143

  16. Stimulated rotational Raman scattering in CO2-pumped para-H2

    SciTech Connect

    Carlsten, J.L.; Wenzel, R.G.

    1983-09-01

    Stimulated rotational Raman scattering in a 300 K multipass cell filled with para-H2 with a single-mode CO2 pump laser was studied using a single-mode OPO as a probe laser at the Stokes frequency for the So(0) transition. Amplification and pump depletion are examined as a function of incident pump energy. For an incident CO2 pump laser energy of 1.5 J, a photon conversion efficiency of 47 percent is observed.

  17. ParaDiS on Blue Gene/L: stepping up to the challenge

    SciTech Connect

    Hommes, G; Arsenlis, A; Bulatov, V; Cai, W; Cook, R; Hiratani, M; Oppestrup, T; Rhee, M; Tang, M

    2006-06-09

    This paper reports on the efforts to enable fully scalable simulations of Dislocation Line Dynamics (DLD) for direct calculations of strength of crystalline materials. DLD simulations are challenging and do not lend themselves naturally to parallel computing. Through a combinations of novel physical approaches, mathematical algorithms and computational science developments, a new DLD code ParaDiS is shown to take meaningful advantage of BG/L and, by doing so, to enable discovery class science by computation.

  18. Cáncer de cuello uterino—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento, la prevención, las causas y los exámenes de detección del cáncer de cuello uterino, así como referencias a estudios clínicos, investigación, estadísticas y otros temas relacionados.

  19. Cáncer de pulmón—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento, la prevención, las causas y los exámenes de detección del cáncer de pulmón, así como referencias a estudios clínicos, investigación, estadísticas y otros temas

  20. ParaDiS on BlueGene/L: scalable line dynamics

    SciTech Connect

    Bulatov, V; Cai, W; Fier, J; Hiratani, M; Pierce, T; Tang, M; Rhee, M; Yates, R K; Arsenlis, A

    2004-04-29

    We describe an innovative highly parallel application program, ParaDiS, which computes the plastic strength of materials by tracing the evolution of dislocation lines over time. We discuss the issues of scaling the code to tens of thousands of processors, and present early scaling results of the code run on a prototype of the BlueGene/L supercomputer being developed by IBM in partnership with the US DOE's ASC program.

  1. Stable self-trapping and ring formation in polydiacetylene para-toluene sulfonate

    NASA Astrophysics Data System (ADS)

    Wright, Ewan M.; Lawrence, Brian L.; Torruellas, William; Stegeman, George

    1995-12-01

    Numerical simulations of two-dimensional beam propagation in polydiacetylene para-toluene sulfonate measured values for n2>0 and n3<0 , where Delta n=n2I+n 3I2 , predict stable self-trapping and a new phenomenon in which a spatial ring evolves from a Gaussian input beam. We interpret the numerical results theoretically, using the variational model of nonlinear Gaussian beam propagation.

  2. Towards physical interpretation of substituent effects: the case of meta- and para-substituted anilines.

    PubMed

    Szatylowicz, Halina; Siodla, Tomasz; Stasyuk, Olga A; Krygowski, Tadeusz M

    2016-04-28

    Quantum chemical modeling was used to investigate the electron-donating properties of the amino group in a series of meta- and para-X-substituted anilines (X = NMe2, NH2, OH, OMe, CH3, H, F, Cl, CF3, CN, CHO, COMe, CONH2, COOH, NO2, and NO). Different methods (HF, B3LYP, and M06-2X) and basis sets (6-31+G(d,p), 6-311++G(d,p), and aug-cc-pVDZ) were applied and compared with the MP2 approach. The B3LYP/6-311++G(d,p) method was chosen as the most appropriate one. The substituent properties were described by σ, cSAR(X) and SESE descriptors; the amino group was characterized by structural (dCN, dNH and ΣNH2) and electronic [δ(N) and cSAR(NH2)] parameters; whereas the transmitting moiety was characterized by aromaticity indices HOMA and NICS, as well as by QTAIM characteristics at the ring critical point. All the used parameters were found to be mutually interrelated with much better correlations for the para-derivatives than the meta-derivatives. It was numerically confirmed that sensitivity of the amino group to the substituent effect was greater by over three times when the substituent was located in the para-position. In the case of the meta-derivatives, variability of characteristics for both the reaction center and the substituent was small. The reverse substituent effect was clearly shown by comparison of the cSAR(X) characteristics for monosubstituted benzenes, and meta- and para-substituted anilines. PMID:26725941

  3. Parallel Visualization and Analysis with ParaView on a Cray XT4

    SciTech Connect

    Patchett, John; Ahrens, James; Ahern, Sean; Pugmire, Dave

    2009-01-01

    Scienti c data sets produced by modern supercomputers like ORNL s Cray XT 4, Jaguar, can be extremely large, making visualization and analysis more di cult as moving large resultant data to dedicated analysis systems can be pro- hibitively expensive. We share our continuing work of integrating a parallel visu- alization system, ParaView, on ORNL s Jaguar system and our e orts to enable extreme scale interactive data visualization and analysis. We will discuss porting challenges and present performance numbers.

  4. Atlas de aves: Un metodo para documentar distribucion y seguir poblaciones

    USGS Publications Warehouse

    Robbins, C.S.; Dowell, B.A.; Dawson, D.K.

    1988-01-01

    Los Atlas de Aves son proyectos nacionales o regionalies para trazar en mapas la distribucion en reproduccion de cada especie de ave. Ese procedimiento se esta usando en Europa, Australia, Nueva Zelanda, Norteamerica, y partes de Africa. El tama?o de los cuadrados varia de medio grado de latitud y Iongitud hasta 5 x 5 km. El trabajo de campo de cada proyecto exige aproxlmadamente cinco a?os, pero los aficionados pueden llevar a cabo la mayor parte del trabajo. Es posible almacenar los resultados en un computador personal. Hay muchos beneficios: (I) se presenta la distribucion corriente de las aves de la nacion, del estado, o de la Iocalidad; (2) se desarrolla nueva informacion especialmente sobre especies raras o en peligro; (3) se descubren areas que tienen una avlfauna sobresaliente o habitats raros y ayuda a su proteccion, (4) se documentan cambios de dlstribucion; (5) se pueden usar para documentar cambios de poblacion, especialmente en los tropicos donde otros metodos son mas dificiles de usar porque hay muchas especies y no hay muchos observadores calificados en la identificacion de sonidos de las aves; (6) son proyectos buenos de investigacion para estudiantes graduados; (7) los turistas y los jefes de excursiones de historia natural pueden contribuir con muchas informaciones

  5. Consistent assignment of the vibrations of symmetric and asymmetric para-disubstituted benzene molecules

    NASA Astrophysics Data System (ADS)

    Andrejeva, Anna; Gardner, Adrian M.; Tuttle, William D.; Wright, Timothy G.

    2016-03-01

    We give a description of the phenyl-ring-localized vibrational modes of the ground states of the para-disubstituted benzene molecules including both symmetric and asymmetric cases. In line with others, we quickly conclude that the use of Wilson mode labels is misleading and ambiguous; we conclude the same regarding the related ones of Varsányi. Instead we label the modes consistently based upon the Mulliken (Herzberg) method for the modes of para-difluorobenzene (pDFB). Since we wish the labelling scheme to cover both symmetrically- and asymmetrically-substituted molecules, we apply the Mulliken labelling under C2v symmetry. By studying the variation of the vibrational wavenumbers with mass of the substituent, we are able to identify the corresponding modes across a wide range of molecules and hence provide consistent assignments. Particularly interesting are pairs of vibrations that evolve from in- and out-of-phase motions in pDFB to more localized modes in asymmetric molecules. We consider the para isomers of the following: the symmetric dihalobenzenes, xylene, hydroquinone, the asymmetric dihalobenzenes, halotoluenes, halophenols and cresol.

  6. The ortho:para-H_2 ratio in C- and J-type shocks

    NASA Astrophysics Data System (ADS)

    Wilgenbus, D.; Cabrit, S.; Pineau des Forêts, G.; Flower, D. R.

    2000-04-01

    We have computed extensive grids of models of both C- and J-type planar shock waves, propagating in dark, cold molecular clouds, in order to study systematically the behaviour of the ortho:para-H_2 ratio. Careful attention was paid to both macroscopic (dynamical) and microscopic (chemical reactions and collisional population transfer in H_2) aspects. We relate the predictions of the models to observational determinations of the ortho:para-H_2 ratio using both pure rotational lines and rovibrational lines. As an illustration, we consider ISO and ground-based H_2 observations of HH 54. Neither planar C-type nor planar J-type shocks appear able to account fully for these observations. Given the additional constraints provided by the observed ortho:para H_2 ratios, a C-type bowshock, or a C-type precursor followed by a J-type shock, remain as plausible models. Tables~2a-f and 4a-f are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

  7. Theoretical study of the design of a catalyst for para to ortho hydrogen conversion

    NASA Technical Reports Server (NTRS)

    Coffman, Robert E.

    1992-01-01

    The theory of Petzinger and Scalapino (1973) was thoroughly reviewed, and all of the basic equations for paramagnetic para to ortho hydrogen catalysis re-derived. There are only a few minor phase errors and errors of omission in the description of the theory. Three models (described by Petzinger and Scalapino) for the rate of para to ortho H2 catalysis were worked out, and uniform agreement obtained to within a constant factor of 2 pi. The analytical methods developed in the course of this study were then extended to two new models, which more adequately describe the process of surface catalysis including transfer of hydrogen molecules onto and off of the surface. All five equations for the para to ortho catalytic rate of conversion are described. The two new equations describe the catalytic rate for these models: H2 on the surface is a 2-D gas with lifetime tau; and H2 on the surface is a 2-D liquid undergoing Brownian motion (diffusion) with surface lifetime tau.

  8. The ortho:para ratio of H{sub 3}{sup +} in laboratory and astrophysical plasmas

    SciTech Connect

    Crabtree, Kyle N.; Indriolo, Nick; Kreckel, Holger; McCall, Benjamin J.

    2015-01-22

    The discovery of H{sub 3}{sup +} in the diffuse interstellar medium has dramatically changed our view of the cosmic-ray ionization rate in diffuse molecular clouds. However, another surprise has been that the ortho:para ratio of H{sub 3}{sup +} in these clouds is inconsistent with the temperature derived from the excitation of H{sub 2}, the dominant species in these clouds. In an effort to understand this discrepancy, we have embarked on an experimental program to measure the nuclear spin dependence of the dissociative electron recombination rate of H{sub 3}{sup +} using the CRYRING and TSR ion storage rings. We have also performed the first measurements of the reaction H{sub 3}{sup +}+H{sub 2}→H{sub 2}+H{sub 3}{sup +} below room temperature. This reaction is likely the most common bimolecular reaction in the universe, and plays an important role in interconverting ortho- and para-H{sub 3}{sup +}. Finally, we have constructed a steady-state chemical model for diffuse clouds, which takes into account the spin-dependence of the formation of H{sub 3}{sup +}, its electron recombination, and its reaction with H{sub 2}. We find that the ortho:para ratio of H{sub 3}{sup +} in diffuse clouds is likely governed by a competition between dissociative recombination and thermalization by reactive collisions.

  9. ParaGard gets mixed reviews at one-year anniversary.

    PubMed

    1989-07-01

    IUDs fill a need for reliable convenient contraceptives in multiparous, monogamous women who have no history of ectopic pregnancy, pelvic inflammatory disease, or sexually transmitted disease, and who are primarily interested in birth spacing or who have completed their family and do not opt for sterilization. The only IUDs currently available in the US are Progestasert, a progestin-releasing device that must be replaced after 1 year, and ParaGard, a copper-bearing device manufactured by GynoPharma, that can be left in place for up to 4 years. IUD use has declined in the US because of adverse publicity and lawsuits. Both IUDs have problems with insertion. There is an incidence of 1.8 cervical lacerations for every 100 insertions, and the ParaGard inserter is likely to drop to the floor if the clinician fails to use the thumb ring, which is designed to keep it from doing so. ParaGard is accompanied by a 5-page consent form to protect the manufacturer, which deters many women. Prophylactic administration of antibiotics before insertion is recommended, and some clinicians recommend ibuprofen to prevent inflammation. Both IUDs cost about $80. PMID:12282179

  10. Quantum chemical and experimental study of 1,2,4-trihydroxy-para-menthane

    NASA Astrophysics Data System (ADS)

    Rottmannová, Lenka; Lukeš, Vladimír; Ilčin, Michal; Fodran, Peter; Herich, Peter; Kožíšek, Jozef; Liptaj, Tibor; Klein, Erik

    2013-10-01

    The conformational analysis of the para-menthane (PM) and 1,2,4-trihydroxy-para-menthane (TPM) is performed using the quantum chemical density functional theory (DFT) and ab initio Møller-Plesset perturbation theory up to the second order (MP2). In TPM, three hydroxyl groups generate eight stereoisomers comparing to the four para-menthane stereoisomers. From the thermodynamics point of view, the most preferred conformations show the chair-shaped configuration of the cyclohexane ring. The obtained energy barriers for the isopropyl group rotation in the chair-shaped stereoisomers are between 35 and 45 kJ mol-1. The crystal structure as well as the solvated TPM stereoisomer isolated from the Tea tree oil, Melaleuca alternifolia (Maiden & Betche) Cheel, were investigated experimentally. Isolated stereoisomer corresponds to the most energetically preferred conformation and the calculated structural data agree very well with the results from the X-ray and nuclear magnetic resonance measurements. Finally, the influence of the conformation and the presence of the intramolecular hydrogen bonds on the homolytic Osbnd H bond dissociation enthalpies and proton affinities were also discussed with respect to the simple alcohols (methanol, iso-propanol, iso-pentanol, tert-butanol, cyclohexanol) and phenol.

  11. El diseño final del espectrógrafo de banco (EBASIM) para CASLEO

    NASA Astrophysics Data System (ADS)

    Simmons, J.; Levato, H.

    Utilizando el código de óptica ACCOS V se ha finalizado el diseño del espectrógrafo de banco para CASLEO. En una comunicación anterior habíamos indicado que utilizaríamos un colimador de 150 mm de diámetro con un radio de curvatura de 1540 mm. Para el espejo cámara, que tiene un diámetro de 200 mm, el radio de curvatura es de 1200 mm, ambos radios con una tolerancia no mayor a los 3 mm. En la presente, se informa sobre los detalles finales del cálculo del espectrógrafo que incluye el cómputo para 5 longitudes de onda diferentes y alrededor de 100 rayos. En todos los casos el 75 % de energía está dentro de un diámetro de 13 micrones. El diseño ha sido probado entre 3500 Å hasta 9000 Å con resultados satisfactorios.

  12. Base de linhas moleculares para síntese espectral estelar

    NASA Astrophysics Data System (ADS)

    Milone, A.; Sanzovo, G.

    2003-08-01

    A análise das abundâncias quí micas fotosféricas em estrelas do tipo solar ou tardia, através do cálculo teórico de seus espectros, emprega a espectroscopia de alta resolução e necessita de uma base representativa de linhas atômicas e moleculares com suas respectivas constantes bem determinadas. Nesse trabalho, utilizamos como ponto de partida as extensas listas de linhas espectrais de sistemas eletrônicos de algumas moléculas diatômicas compiladas por Kurucz para a construção de uma base de linhas moleculares para a sí ntese espectral estelar. Revisamos as determinações dos fatores rotacionais de Honl-London das forças de oscilador das linhas moleculares, para cada banda vibracional de alguns sistemas eletrônicos, seguindo a regra usual de normalização. Usamos as forças de oscilador eletrônicas da literatura. Os fatores vibracionais de Franck-Condon de cada banda foram especialmente recalculados empregando-se novas constantes moleculares. Reproduzimos, com êxito, as absorções espectrais de determinadas bandas eletrônicas-vibracionais das espécies moleculares C12C12, C12N14 e Mg24H em espectros de estrelas de referência como o Sol e Arcturus.

  13. Effects of para-substituents of styrene derivatives on their chemical reactivity on platinum nanoparticle surfaces.

    PubMed

    Hu, Peiguang; Chen, Limei; Deming, Christopher P; Lu, Jia-En; Bonny, Lewis W; Chen, Shaowei

    2016-06-01

    Stable platinum nanoparticles were successfully prepared by the self-assembly of para-substituted styrene derivatives onto the platinum surfaces as a result of platinum-catalyzed dehydrogenation and transformation of the vinyl groups to the acetylene ones, forming platinum-vinylidene/-acetylide interfacial bonds. Transmission electron microscopic measurements showed that the nanoparticles were well dispersed without apparent aggregation, suggesting sufficient protection of the nanoparticles by the organic capping ligands, and the average core diameter was estimated to be 2.0 ± 0.3 nm, 1.3 ± 0.2 nm, and 1.1 ± 0.2 nm for the nanoparticles capped with 4-tert-butylstyrene, 4-methoxystyrene, and 4-(trifluoromethyl)styrene, respectively, as a result of the decreasing rate of dehydrogenation with the increasing Taft (polar) constant of the para-substituents. Importantly, the resulting nanoparticles exhibited unique photoluminescence, where an increase of the Hammett constant of the para-substituents corresponded to a blue-shift of the photoluminescence emission, suggesting an enlargement of the HOMO-LUMO band gap of the nanoparticle-bound acetylene moieties. Furthermore, the resulting nanoparticles exhibited apparent electrocatalytic activity towards oxygen reduction in acidic media, with the best performance among the series of samples observed with the 4-tert-butylstyrene-capped nanoparticles due to an optimal combination of the nanoparticle core size and ligand effects on the bonding interactions between platinum and oxygen species. PMID:27242019

  14. The "drinking-buddy" scale as a measure of para-social behavior.

    PubMed

    Powell, Larry; Richmond, Virginia P; Cantrell-Williams, Glenda

    2012-06-01

    Para-social behavior is a form of quasi-interpersonal behavior that results when audience members develop bonds with media personalities that can resemble interpersonal social interaction, but is not usually applied to political communication. This study tested whether the "Drinking-Buddy" Scale, a simple question frequently used in political communication, could be interpreted as a single-item measure of para-social behavior with respect to political candidates in terms of image judgments related to interpersonal attraction and perceived similarity to self. The participants were college students who had voted in the 2008 election. They rated the candidates, Obama or McCain, as drinking buddies and then rated the candidates' perceived similarity to themselves in attitude and background, and also the social and task attraction to the candidate. If the drinking-buddy rating serves as a proxy measure for para-social behavior, then it was expected that participants' ratings for all four kinds of similarity to and attraction toward a candidate would be higher for the candidate they chose as a drinking buddy. The directional hypotheses were supported for interpersonal attraction, but not for perceived similarity. These results indicate that the drinking-buddy scale predicts ratings of interpersonal attraction, while voters may view perceived similarity as an important but not essential factor in their candidate preference. PMID:22897105

  15. Single crystalline nature of para-sexiphenyl crystallites grown on KCl(100).

    PubMed

    Haber, T; Oehzelt, M; Resel, R; Andreev, A; Thierry, A; Sitter, H; Smilgies, D M; Schaffer, B; Grogger, W; Resel, R

    2006-03-01

    This work focuses on studies of the single crystal nature of para-sexiphenyl structures grown on freshly cleaved KCl(100) surfaces. Two different kinds of morphologies, namely terrace like structures and needle like structures, are found by atomic force microscopy as well as by electron microscopy. Regardless of the morphology the individual crystallites show highly regular shapes. The crystalline alignment and the degree of order of the crystallites on the surface are determined by X-ray diffraction. Several epitaxial alignments of para-sexiphenyl on KCl(100) are observed and all of them are perfectly aligned on the surface. The rocking curve widths of the organic crystallites do not exceed 800" which is approximately only the four fold of the substrates' ones. The single crystalline nature of para-sexiphenyl crystallites is proven by transmission electron microscopy, diffraction patterns, dark field imaging and high resolution techniques. Single crystalline terraced mounds reach diameters of several microns and heights of 50 nm. Single crystal needles show heights and breadths of more than 100 nm and lengths of several microns. PMID:16573123

  16. Neoplasias mieloproliferativas y síndromes mielodisplásicos—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento de las neoplasias mieloproliferativas, así como referencias a estudios clínicos y otros temas relacionados.

  17. Melhoramentos no código Wilson-Devinney para binárias eclipsantes

    NASA Astrophysics Data System (ADS)

    Vieira, L. A.; Vaz, L. P. R.

    2003-08-01

    A análise de curvas de luz e velocidades radiais de sistemas binários eclipsantes pode ser feita por meio de vários modelos. Um desses é o Modelo Wilson-Devinney (WD). Ao longo dos anos, esse modelo sofreu várias alterações em seus códigos principais, com a finalidade de torná-lo mais consistente tanto fíisica como numericamente. O Modelo WD tem sido melhorado de várias maneiras em seus dois códigos: um para a predição das curvas de luz teórica e de velocidade radiais e outra para as soluções destas curvas. Teoricamente, na física do modelo, nós introduzimos a possibilidade de levar em conta os efeitos do movimento apsidal. Numericamente, nós introduzimos a possibilidade de usar o Método SIMPLEX no procedimento da solução, como uma alternativa para o já implementado Método de Mínimos Quadrados (Least Squares Method). Estas modificações, juntamente com outras já introduzidas pelo nosso grupo anteriormente, tornam o código mais eficiente na solução das curvas de luz e de velocidade radiais de binárias eclipsantes. Como o modelo tem sido usado para analisar sistemas com componentes pré-sequência principal (TY CrA, Casey et al. 1998, Vaz et al. 1998), SM 790, Stassun et al. 2003), este melhoramento beneficiará estes casos também. Apresentamos os resultados obtidos com a modificação do código WD por meio do uso de dados da estrela GL Carinae, comprovando, (1) que os parâmetros orbitais calculados por nós são coerentes com os obtidos anteriormente na literatura (Giménez & Clausen, 1986) e com os obtidos por Faria (1987), e (2) que a implementação do Método SIMPLEX torna o código mais lento mas completamente consistente internamente e evita os problemas gerados pelo uso do Método de Mínimos Quadrados, tais como imprecisão no cálculo das derivadas parciais e convergência para mínimos locais.

  18. Quantum Monte Carlo Simulation of Vibrational Frequency Shifts of CO in Solid para-HYDROGEN

    NASA Astrophysics Data System (ADS)

    Wang, Lecheng; Le Roy, Robert; Roy, Pierre-Nicholas

    2014-06-01

    Stimulated by Fajardo's remarkable study of the rovibrational spectra of CO isotopologues trapped in solid para-hydrogen, we have performed quantum Monte Carlo simulations to predict his observed vibrational frequency shifts and inertial rotational constants using 2-body potentials based on the best available models for the pH_2-pH_2 and CO-pH_2, potential energy functions. We started by fitting an analytic `Morse/Long-Range' (MLR) function to the 1D ``adiabaic hindered rotor" version of Hinde's 5D pH_2-pH_2 potential developed by Faruk et al. We then modified it to take account of many-body effects by scaling it until it yielded the correct equilibrium lattice parameters for the fcc and hcp structures of pure solid para-hydrogen. A CO molecule was then placed at different interstitial or substitution sites in large equilibrated fcc or hcp para-hydrogen lattices, and the structural and dynamical behaviors of the micro-solvation environment around CO were simulated with a PIMC algorithm using a 2D effective pH_2-CO potential based on the 5D H_2--CO potential energy surface recently reported by Li et al., with a lattice sum of values of the 2D CO vibrational difference potential being use to predict the vibrational frequency shift. The effective rotational constants Beff for CO in different solid para-hydrogen structures were also calculated and compared with the experimental observations and with predicted Beff values for CO in large-sized para-hydrogen--CO clusters. M. E. Fajardo, J. Phys. Chem. A 117, 13504 (2013). R. Hinde, J. Chem. Phys., 128, 154308 (2008). H. Li, X-L. Zhang, R.J. Le Roy, and P.-N. Roy, J. Chem. Phys. 139, 164315 (2013). R.J. Le Roy, C.C. Haugen, J. Tao and Hui Li, Mol. Phys., 109, 435 (2011) N. Faruk, R.J. Le Roy, and P.-N. Roy, J. Chem. Phys. (submitted December 2013). Y. Mizumoto and Y. Ohtsuki, Chem. Phys. Lett. 501, 304 (2011).

  19. Implementação de um algoritmo para a limpeza de mapas da RCFM

    NASA Astrophysics Data System (ADS)

    Souza, C. L.; Wuensche, C. A.

    2003-08-01

    A Radiação Cósmica de Fundo em Microondas (RCFM), descoberta por Penzias e Wilson em 1965, é uma das ferramentas mais poderosas para o estudo da cosmologia. Com a descoberta de flutuações de temperatura na RCFM, da ordem de uma parte em 105, pelo COBE (1992), uma nova era teve início. Nos últimos onze anos, diversos instrumentos fizeram novas medidas de alta precisão, refinando os resultados apresentados pelo COBE, culminando com os resultados recentes do satélite WMAP. A análise de dados da RCFM, especialmente no caso de experimentos com pequena cobertura do céu, apresenta uma série de dificuldades devido a emissões de contaminantes externos, tais como a emissão da Galáxia e de fontes pontuais, e de ruídos intrínsecos tanto ao sistema de detecção quanto à estratégia de observação do céu. Uma das soluções típicas para a filtragem de dados brutos de um experimento para medir flutuações de temperatura é aplicar um gabarito (template) e um filtro passa alta ao produzir mapas simplificados (sem considerar matrizes de correlação ou covariância). No caso de experimentos que utilizam detectores HEMT, essa combinação de filtros remove, satisfatoriamente, ruídos do tipo 1/f gerados pela instabilidade no ganho do detector acoplado ao movimento do instrumento, definido pela estratégia de observação. Entretanto, o sinal resultante medido, tanto em simulações quanto em séries temporais reais, sugere que parte do sinal cosmológico pode estar sendo removido junto com o ruído dos detectores. Este trabalho descreve as etapas para a produção de um mapa típico (simulado) e os testes preliminares de um algoritmo para remover ruídos do tipo 1/f introduzidos pela estratégia de observação sem prejudicar a qualidade do sinal cosmológico presente no mapa.

  20. ParaDyn Implementation in the US Navy's DYSMAS Simulation System: FY08 Progress Report

    SciTech Connect

    Ferencz, R M; DeGroot, A J; Lin, J I; Zywicz, E; Durrenberger, J K; Sherwood, R J; Corey, I R

    2008-07-29

    The goal of this project is to increase the computational efficiency and capacity of the Navy's DYSMAS simulation system for full ship shock response to underwater explosion. Specifically, this project initiates migration to a parallel processing capability for the structural portion of the overall fluid-structure interaction model. The capstone objective for the first phase is to demonstrate operation of the DYSMAS simulation engine with a production model on a Naval Surface Warfare Center (IHD) parallel platform using the ParaDyn code for parallel processing of the structural dynamics. This year saw a successful launch to integrate ParaDyn, the high-parallel structural dynamics code from Lawrence Livermore National Laboratory (LLNL), into the DYSMAS system for simulating the response of ship structures to underwater explosion (UNDEX). The current LLNL version of DYNA3D, representing ten years of general development beyond the source branch used to initiate DYNA-N customization for DYSMAS, was first connected to the GEMINI flow code through DYSMAS Standard Coupler Interface (SCI). This permitted an early 'sanity check' by Naval Surface Warfare Center, Indian Head Division (NSWC-IHD) personnel that equivalent results were generated for their standard UNDEX test problems, thus ensuring the Verification & Validation pedigree they have developed remains intact. The ParaDyn code was then joined to the SCI in a manner requiring no changes to GEMINI. Three NSWC-IHD engineers were twice hosted at LLNL to become familiar with LLNL computer systems, the execution of the prototype software system, and to begin assessment of its accuracy and performance. Scaling data for the flow solver GEMINI was attained up to a one billion cell, 1000 processor run. The NSWC-IHD engineers were granted privileges to continue their evaluations through remote connections to LLNL's Open Computing Facility. Finally, the prototype changes were integrated into the mainline ParaDyn source

  1. El uso de la neuromodulación para el tratamiento del temblor

    PubMed Central

    Bendersky, Damián; Ajler, Pablo; Yampolsky, Claudio

    2014-01-01

    Introducción: El temblor puede ser un desorden incapacitante y el tratamiento de primera línea para estos pacientes es farmacológico. Sin embargo, este tratamiento puede llevar a una reducción satisfactoria del temblor en sólo el 50% de los pacientes con temblor esencial. La talamotomía era el tratamiento de elección para el temblor refractario al tratamiento médico hasta que comenzó a utilizarse la estimulación cerebral profunda (ECP) del núcleo ventral intermedio (Vim) del tálamo. En la actualidad, raramente se realiza la talamotomía. Métodos: Este artículo es una revisión no sistemática de las indicaciones, resultados, parámetros de programación y técnica quirúrgica de la ECP del Vim para el tratamiento del temblor. Resultados: Aunque los resultados clínicos son similares usando la talamotomía o la ECP del Vim, la primera causa más efectos adversos que la última. Además, la ECP puede ser usada bilateralmente, mientras que la talamotomía tiene un alto riesgo de causar disartria cuando se realiza de ambos lados. La ECP del Vim logró una adecuada mejoría del temblor en varias series de pacientes con temblor causado por temblor esencial, enfermedad de Parkinson o esclerosis múltiple. Además del Vim, hay otros blancos que están siendo usados por varios autores, tales como la zona incerta y las radiaciones prelemniscales. Conclusión: La ECP del Vim es un tratamiento útil para el temblor incapacitante refractario al tratamiento médico. Es esencial realizar una precisa selección de pacientes, así como utilizar una técnica quirúrgica correcta. Aún se desconoce el mejor blanco estereotáctico para el temblor, aunque el Vim es el más usado. PMID:25165613

  2. Charge-transfer complexation and photoreduction of viologen derivatives bearing the para-substituted benzophenone group in dimethyl sulfoxide

    SciTech Connect

    Tanaka, Chiho; Nambu, Yoko; Endo, Takeshi

    1992-08-20

    New viologen derivatives having the various para-substituted benzophenone groups connected with a -(CH{sub 2}){sub 3}-linkage were effectively photoreduced by dimethyl sulfoxide by the intramolecular charge transfer complex formation between the viologen and benzophenone groups through effective stacking. The photoreduction was enhanced by the introduction of electron-donating para-substituents on the benzophenone units which were favorable for the intramolecular charge transfer complexation. 6 refs., 5 figs.

  3. Conformational isomerism in the solid-state structures of tetracaine and tamoxifen with para-sulphonato-calix[4]arene

    NASA Astrophysics Data System (ADS)

    Danylyuk, Oksana; Monachino, Melany; Lazar, Adina N.; Suwinska, Kinga; Coleman, Anthony W.

    2010-02-01

    The solid-state complexes between para-sulphonato-calix[4]arene and the drugs tamoxifen and tetracaine show an unusual 4:1 guest-host stoichiometry with formation of hydrophobic layer of drug molecules held between bilayers of para-sulphonato-calix[4]arene. In both structures each of the four independent drug molecules adopts different conformation due to the different mode of interaction with the anionic host, the neighbouring drug cations and water molecules.

  4. Identification and Characterization of Catabolic para-Nitrophenol 4-Monooxygenase and para-Benzoquinone Reductase from Pseudomonas sp. Strain WBC-3▿

    PubMed Central

    Zhang, Jun-Jie; Liu, Hong; Xiao, Yi; Zhang, Xian-En; Zhou, Ning-Yi

    2009-01-01

    Pseudomonas sp. strain WBC-3 utilizes para-nitrophenol (PNP) as a sole source of carbon, nitrogen, and energy. In order to identify the genes involved in this utilization, we cloned and sequenced a 12.7-kb fragment containing a conserved region of NAD(P)H:quinone oxidoreductase genes. Of the products of the 13 open reading frames deduced from this fragment, PnpA shares 24% identity to the large component of a 3-hydroxyphenylacetate hydroxylase from Pseudomonas putida U and PnpB is 58% identical to an NAD(P)H:quinone oxidoreductase from Escherichia coli. Both PnpA and PnpB were purified to homogeneity as His-tagged proteins, and they were considered to be a monomer and a dimer, respectively, as determined by gel filtration. PnpA is a flavin adenine dinucleotide-dependent single-component PNP 4-monooxygenase that converts PNP to para-benzoquinone in the presence of NADPH. PnpB is a flavin mononucleotide-and NADPH-dependent p-benzoquinone reductase that catalyzes the reduction of p-benzoquinone to hydroquinone. PnpB could enhance PnpA activity, and genetic analyses indicated that both pnpA and pnpB play essential roles in PNP mineralization in strain WBC-3. Furthermore, the pnpCDEF gene cluster next to pnpAB shares significant similarities with and has the same organization as a gene cluster responsible for hydroquinone degradation (hapCDEF) in Pseudomonas fluorescens ACB (M. J. Moonen, N. M. Kamerbeek, A. H. Westphal, S. A. Boeren, D. B. Janssen, M. W. Fraaije, and W. J. van Berkel, J. Bacteriol. 190:5190-5198, 2008), suggesting that the genes involved in PNP degradation are physically linked. PMID:19218392

  5. Effects of para-substituents of styrene derivatives on their chemical reactivity on platinum nanoparticle surfaces

    NASA Astrophysics Data System (ADS)

    Hu, Peiguang; Chen, Limei; Deming, Christopher P.; Lu, Jia-En; Bonny, Lewis W.; Chen, Shaowei

    2016-06-01

    Stable platinum nanoparticles were successfully prepared by the self-assembly of para-substituted styrene derivatives onto the platinum surfaces as a result of platinum-catalyzed dehydrogenation and transformation of the vinyl groups to the acetylene ones, forming platinum-vinylidene/-acetylide interfacial bonds. Transmission electron microscopic measurements showed that the nanoparticles were well dispersed without apparent aggregation, suggesting sufficient protection of the nanoparticles by the organic capping ligands, and the average core diameter was estimated to be 2.0 +/- 0.3 nm, 1.3 +/- 0.2 nm, and 1.1 +/- 0.2 nm for the nanoparticles capped with 4-tert-butylstyrene, 4-methoxystyrene, and 4-(trifluoromethyl)styrene, respectively, as a result of the decreasing rate of dehydrogenation with the increasing Taft (polar) constant of the para-substituents. Importantly, the resulting nanoparticles exhibited unique photoluminescence, where an increase of the Hammett constant of the para-substituents corresponded to a blue-shift of the photoluminescence emission, suggesting an enlargement of the HOMO-LUMO band gap of the nanoparticle-bound acetylene moieties. Furthermore, the resulting nanoparticles exhibited apparent electrocatalytic activity towards oxygen reduction in acidic media, with the best performance among the series of samples observed with the 4-tert-butylstyrene-capped nanoparticles due to an optimal combination of the nanoparticle core size and ligand effects on the bonding interactions between platinum and oxygen species.Stable platinum nanoparticles were successfully prepared by the self-assembly of para-substituted styrene derivatives onto the platinum surfaces as a result of platinum-catalyzed dehydrogenation and transformation of the vinyl groups to the acetylene ones, forming platinum-vinylidene/-acetylide interfacial bonds. Transmission electron microscopic measurements showed that the nanoparticles were well dispersed without apparent

  6. Madres para la Salud: Design of a Theory-based Intervention for Postpartum Latinas

    PubMed Central

    Keller, Colleen; Records, Kathie; Ainsworth, Barbara; Belyea, Michael; Permana, Paska; Coonrod, Dean; Vega-López, Sonia; Nagle-Williams, Allison

    2011-01-01

    Background Weight gain in young women suggests that childbearing may be an important contributor to the development of obesity in women. Depressive symptoms can interfere with resumption of normal activity levels following childbirth or with the initiation of or adherence to physical activity programs essential for losing pregnancy weight. Depression symptoms may function directly to promote weight gain through a physiologic mechanism. Obesity and its related insulin resistance may contribute to depressed mood physiologically. Although physical activity has well-established beneficial effects on weight management and depression, women tend to under participate in physical activity during childbearing years. Further, the mechanisms underpinning the interplay of overweight, obesity, physical activity, depression, and inflammatory processes are not clearly explained. Objectives This report describes the theoretical rationale, design considerations, and cultural relevance for “Madres para la Salud” [Mothers for Health]. Design and Methods Madres para la Salud is a 12 month prospective, randomized controlled trial exploring the effectiveness of a culturally specific intervention using “bouts” of physical activity to effect changes in body fat, systemic and fat tissue inflammation, and postpartum depression symptoms in sedentary postpartum Latinas. Summary The significance and innovation of Madres para la Salud includes use of a theory-driven approach to intervention, specification and cultural relevance of a social support intervention, use of a Promotora model to incorporate cultural approaches, use of objective measures of physical activity in post partum Latinas women, and the examination of biomarkers indicative of cardiovascular risk related to physical activity behaviors in postpartum Latinas. PMID:21238614

  7. Supported transition metal catalysts for para- to ortho-hydrogen conversion

    NASA Technical Reports Server (NTRS)

    Brooks, Christopher J.; Wang, Wei; Eyman, Darrell P.

    1994-01-01

    The main goal of this study was to develop and improve on existing catalysts for the conversion of ortho- to para-hydrogen. Starting with a commercially available Air Products nickel silicate, which had a beta value of 20, we were trying to synthesize catalysts that would be an improvement to AP. This was accomplished by preparing silicates with various metals as well as different preparation methods. We also prepared supported ruthenium catalysts by various techniques using several metal precursors to improve present technology. What was also found was that the activation conditions prior to catalytic testing was highly important for both the silicates and the supported ruthenium catalysts. While not the initial focus of the research, we made some interesting observations into the adsorption of H2 on ruthenium. This helped us to get a better understanding of how ortho- to para-H2 conversion takes place, and what features in a catalyst are important to optimize activity. Reactor design was the final area in which some interesting conclusions were drawn. As discussed earlier, the reactor catalyst bed must be constructed using straight 1/8 feet OD stainless steel tubing. It was determined that the use of 1/4 feet OD tubing caused two problems. First, the radius from the center of the bed to the wall was too great for thermal equilibrium. Since the reaction of ortho- to para-H2 is exothermic, the catalyst bed center was warmer than the edges. Second, the catalyst bed was too shallow using a 1/4 feet tube. This caused reactant blow-by which was thought to decrease the measured activity when the flow rate was increased. The 1/8 feet tube corrected both of these concerns.

  8. Molecular basis for H blood group deficiency in Bombay (Oh) and para-Bombay individuals.

    PubMed Central

    Kelly, R J; Ernst, L K; Larsen, R D; Bryant, J G; Robinson, J S; Lowe, J B

    1994-01-01

    The penultimate step in the biosynthesis of the human ABO blood group oligosaccharide antigens is catalyzed by alpha-(1,2)-fucosyltransferase(s) (GDP-L-fucose: beta-D-galactoside 2-alpha-L-fucosyltransferase, EC 2.4.1.69), whose expression is determined by the H and Secretor (SE) blood group loci (also known as FUT1 and FUT2, respectively). These enzymes construct Fuc alpha 1-->2Gal beta-linkages, known as H determinants, which are essential precursors to the A and B antigens. Erythrocytes from individuals with the rare Bombay and para-Bombay blood group phenotypes are deficient in H determinants, and thus A and B determinants, as a consequence of apparent homozygosity for null alleles at the H locus. We report a molecular analysis of a human alpha-(1,2)-fucosyltransferase gene, thought to correspond to the H blood group locus, in a Bombay pedigree and a para-Bombay pedigree. We find inactivating point mutations in the coding regions of both alleles of this gene in each H-deficient individual. These results define the molecular basis for H blood group antigen deficiency in Bombay and para-Bombay phenotypes, provide compelling evidence that this gene represents the human H blood group locus, and strongly support a hypothesis that the H and SE loci represent distinct alpha-(1,2)-fucosyltransferase genes. Candidate sequences for the human SE locus are identified by low-stringency Southern blot hybridization analyses, using a probe derived from the H alpha-(1,2)-fucosyltransferase gene. Images PMID:7912436

  9. Improvement of DNA minicircle production by optimization of the secondary structure of the 5'-UTR of ParA resolvase.

    PubMed

    Šimčíková, Michaela; Alves, Cláudia P A; Brito, Liliana; Prather, Kristala L J; Prazeres, Duarte M F; Monteiro, Gabriel A

    2016-08-01

    The use of minicircles in gene therapy applications is dependent on the availability of high-producer cell systems. In order to improve the performance of minicircle production in Escherichia coli by ParA resolvase-mediated in vivo recombination, we focus on the 5' untranslated region (5'-UTR) of parA messenger RNA (mRNA). The arabinose-inducible PBAD/araC promoter controls ParA expression and strains with improved arabinose uptake are used. The 27-nucleotide-long 5'-UTR of parA mRNA was optimized using a predictive thermodynamic model. An analysis of original and optimized mRNA subsequences predicted a decrease of 8.6-14.9 kcal/mol in the change in Gibbs free energy upon assembly of the 30S ribosome complex with the mRNA subsequences, indicating a more stable mRNA-rRNA complex and enabling a higher (48-817-fold) translation initiation rate. No effect of the 5'-UTR was detected when ParA was expressed from a low-copy number plasmid (∼14 copies/cell), with full recombination obtained within 2 h. However, when the parA gene was inserted in the bacterial chromosome, a faster and more effective recombination was obtained with the optimized 5'-UTR. Interestingly, the amount of this transcript was 2.6-3-fold higher when compared with the transcript generated from the original sequence, highlighting that 5'-UTR affects the level of the transcript. A Western blot analysis confirmed that E. coli synthesized higher amounts of ParA with the new 5'-UTR (∼1.8 ± 0.7-fold). Overall, these results show that the improvements made in the 5'-UTR can lead to a more efficient translation and hence to faster and more efficient minicircle generation. PMID:27147534

  10. Where does the electron go? The nature of ortho/para and meta group directing in electrophilic aromatic substitution

    SciTech Connect

    Liu, Shubin

    2014-11-21

    Electrophilic aromatic substitution as one of the most fundamental chemical processes is affected by atoms or groups already attached to the aromatic ring. The groups that promote substitution at the ortho/para or meta positions are, respectively, called ortho/para and meta directing groups, which are often characterized by their capability to donate electrons to or withdraw electrons from the ring. Though resonance and inductive effects have been employed in textbooks to explain this phenomenon, no satisfactory quantitative interpretation is available in the literature. Here, based on the theoretical framework we recently established in density functional reactivity theory (DFRT), where electrophilicity and nucleophilicity are simultaneously quantified by the Hirshfeld charge, the nature of ortho/para and meta group directing is systematically investigated for a total of 85 systems. We find that regioselectivity of electrophilic attacks is determined by the Hirshfeld charge distribution on the aromatic ring. Ortho/para directing groups have most negative charges on the ortho/para positions, while meta directing groups often possess the largest negative charge on the meta position. Our results do not support that ortho/para directing groups are electron donors and meta directing groups are electron acceptors. Most neutral species we studied here are electron withdrawal in nature. Anionic systems are always electron donors. There are also electron donors serving as meta directing groups. We predicted ortho/para and meta group directing behaviors for a list of groups whose regioselectivity is previously unknown. In addition, strong linear correlations between the Hirshfeld charge and the highest occupied molecular orbital have been observed, providing the first link between the frontier molecular orbital theory and DFRT.

  11. A centroid molecular dynamics study of liquid para-hydrogen and ortho-deuterium.

    PubMed

    Hone, Tyler D; Voth, Gregory A

    2004-10-01

    Centroid molecular dynamics (CMD) is applied to the study of collective and single-particle dynamics in liquid para-hydrogen at two state points and liquid ortho-deuterium at one state point. The CMD results are compared with the results of classical molecular dynamics, quantum mode coupling theory, a maximum entropy analytic continuation approach, pair-product forward- backward semiclassical dynamics, and available experimental results. The self-diffusion constants are in excellent agreement with the experimental measurements for all systems studied. Furthermore, it is shown that the method is able to adequately describe both the single-particle and collective dynamics of quantum liquids. PMID:15446940

  12. Various Spectrum of MRI Findings in Articular and Para-articular Tuberculosis: Pictorial Assay.

    PubMed

    Panchal, Hiten; Chiripal, Priyanka

    2015-12-01

    Tuberculosis continues to be a health-related issue in India. Musculoskeletal tuberculosis is noted to occur dramatically as isolates, primarily accounting for large numbers of extra-pulmonary tuberculosis since early diagnosis is always a priority; with good prognosis, it is a curable disease. Delayed treatment is associated with severe morbidity. Musculoskeletal tuberculosis accounts for a large number of extra-pulmonary tuberculosis. In this article, we describe various articular and para-articular MRI spectrum findings that are seen in patients with tuberculosis. MRI is the perfect modality to study the extent of involvement and its related complications. PMID:26730089

  13. Unprecedented new nonadecyl para-hydroperoxycinnamate isolated from Erythrina excelsa and its cytotoxic activity.

    PubMed

    Kwamou, Guy M N; Sandjo, Louis P; Kuete, Victor; Wandja, Anaelle A K; Tankeo, Simplice B; Efferth, Thomas; Nkengfack, Augustin E

    2015-01-01

    A new unprecedented cinnamate derivative (1) was obtained from Erythrina excelsa (Leguminosae) and identified as nonadecyl para-hydroperoxycinnamate. This compound was isolated together with three known compounds, namely lupeol (2), mixture of sitosterol and stigmasterol (3), and isoneorautenol (4). Their structures were established on the basis of NMR and mass spectroscopic data in conjunction with those reported in the literature. Compound 1 was evaluated for its capability of inhibiting cancer cell lines and growth of a panel of microbial strains. It turned out that 1 is moderately to significantly cytotoxic against six cancer cell lines and shows weak to no antimicrobial activity. PMID:25220189

  14. Stimulated rotational Raman scattering in CO/sub 2/ - pumped para - H/sub 2/

    SciTech Connect

    Carlsten, J.L.; Wenzel, R.

    1983-09-01

    Stimulated rotational Raman scattering in a 300 K multipass cell filled with para-H/sub 2/ with a single-mode CO/sub 2/ pump laser was studied using a single-mode OPO as a probe laser at the Stokes frequency for the S/sub 0/ (0) transition. Amplification and pump depletion are examined as a function of incident pump energy. For an incident CO/sub 2/ pump laser energy of 1.5 J, a photon conversion efficiency of 47 percent is observed.

  15. ortho-, meta-, and para-dihydroindenofluorene derivatives as host materials for phosphorescent OLEDs.

    PubMed

    Romain, Maxime; Thiery, Sébastien; Shirinskaya, Anna; Declairieux, Céline; Tondelier, Denis; Geffroy, Bernard; Jeannin, Olivier; Rault-Berthelot, Joëlle; Métivier, Rémi; Poriel, Cyril

    2015-01-19

    This work reports the first structure-properties relationship study of ortho [2,1-c]-, meta [1,2-a]-, and para [1,2-b]dihydroindenofluorenes, highlighting the influence of bridge rigidification on the electronic properties. This study has made it possible to devise an extended π-conjugated molecule with both a high triplet state energy level and excellent thermal and morphological stability. As a proof of concept, dihydroindenofluorenes were used as the host in sky-blue phosphorescent organic light-emitting diodes (PhOLEDs) with high performance. PMID:25469476

  16. Three-dimensional treatment planning for para-aortic node irradiation in patients with cervical cancer

    SciTech Connect

    Munzenrider, J.E.; Doppke, K.P.; Brown, A.P.; Burman, C.; Cheng, E.; Chu, J.; Chui, C.; Drzymala, R.E.; Goitein, M.; Manolis, J.M. )

    1991-05-15

    Three-dimensional treatment planning has been used by four cooperating centers to prepare and analyze multiple treatment plans on two cervix cancer patients. One patient had biopsy-proven and CT-demonstrable metastasis to the para-aortic nodes, while the other was at high risk for metastatic involvement of para-aortic nodes. Volume dose distributions were analyzed, and an attempt was made to define the role of 3-D treatment planning to the para-aortic region, where moderate to high doses (50-66 Gy) are required to sterilize microscopic and gross metastasis. Plans were prepared using the 3-D capabilities for tailoring fields to the target volumes, but using standard field arrangements (3-D standard), and with full utilization of the 3-D capabilities (3-D unconstrained). In some but not all 3-D unconstrained plans, higher doses were delivered to the large nodal volume and to the volume containing gross nodal disease than in plans analyzed but not prepared with full 3-D capability (3-D standard). The small bowel was the major dose limiting organ. Its tolerance would have been exceeded in all plans which prescribed 66 Gy to the gross nodal mass, although some reduction in small bowel near-maximum dose was achieved in the 3-D unconstrained plans. All plans were able to limit doses to other normal organs to tolerance levels or less, with significant reductions seen in doses to spinal cord, kidneys, and large bowel in the 3-D unconstrained plans, as compared to the 3-D standard plans. A high probability of small bowel injury was detected in one of four 3-D standard plans prescribed to receive 50 Gy to the large para-aortic nodal volume; the small bowel dose was reduced to an acceptable level in the corresponding 3-D unconstrained plan. An optimum beam energy for treating this site was not identified, with plans using 4, 6, 10, 15, 18, and 25 MV photons all being equally acceptable. (Abstract Truncated)

  17. Instrumentation for Astronomy Teaching: Projecting the Sun Image. (Spanish Title: Instrumentación Para la Enseñanza de Astronomía: Proyectando la Imagen del Sol.) Instrumentação Para O Ensino de Astronomia: Projetando a Imagem do Sol

    NASA Astrophysics Data System (ADS)

    Catelli, Francisco; Giovan, Odilon; Balen, Osvaldo; Siqueira da Silva, Fernando

    2009-07-01

    In this work we describe a simple optical device to project the Sun image which is useful for solar eclipses observing and for sunspots' size estimating.

    Se describe un dispositivo óptico simple para proyectar la imagen del Sol, lo cual es apropiado para las observaciones de eclipses solares y para estimar las dimensiones de las manchas solares.

    É descrito um dispositivo ótico simples para projetar a imagem do Sol, adequado para observações de eclipses solares e à estimativa do tamanho das manchas solares.

  18. ParaHox gene expression in larval and postlarval development of the polychaete Nereis virens (Annelida, Lophotrochozoa)

    PubMed Central

    Kulakova, Milana A; Cook, Charles E; Andreeva, Tatiana F

    2008-01-01

    Background Transcription factors that encode ANTP-class homeobox genes play crucial roles in determining the body plan organization and specification of different organs and tissues in bilaterian animals. The three-gene ParaHox family descends from an ancestral gene cluster that existed before the evolution of the Bilateria. All three ParaHox genes are reported from deuterostomes and lophotrochozoans, but not to date from any ecdysozoan taxa, and there is evidence that the ParaHox genes, like the related Hox genes, were ancestrally a single chromosomal cluster. However, unlike the Hox genes, there is as yet no strong evidence that the ParaHox genes are expressed in spatial and temporal order during embryogenesis. Results We isolated fragments of the three Nereis virens ParaHox genes, then used these as probes for whole-mount in situ hybridization in larval and postlarval worms. In Nereis virens the ParaHox genes participate in antero-posterior patterning of ectodermal and endodermal regions of the digestive tract and are expressed in some cells in the segment ganglia. The expression of these genes occurs in larval development in accordance with the position of these cells along the main body axis and in postlarval development in accordance with the position of cells in ganglia along the antero-posterior axis of each segment. In none of these tissues does expression of the three ParaHox genes follow the rule of temporal collinearity. Conclusion In Nereis virens the ParaHox genes are expressed during antero-posterior patterning of the digestive system (ectodermal foregut and hindgut, and endodermal midgut) of Nereis virens. These genes are also expressed during axial specification of ventral neuroectodermal cell domains, where the expression domains of each gene are re-iterated in each neuromere except for the first parapodial segment. These expression domains are probably predetermined and may be directed on the antero-posterior axis by the Hox genes, whose

  19. Um enfoque antropológico para o ensino de astronomia no nível médio

    NASA Astrophysics Data System (ADS)

    Costa, G. B.; Jafelice, L. C.

    2003-08-01

    Há uma enorme carência de materiais didático-pedagógicos em astronomia para professores do ensino médio, sobretudo materiais que explorem também aspectos humanísticos. A origem do Universo é um bom exemplo desta constatação central. Embora tal origem teve explicações culturais diversas, os professores não têm informações sobre isso e muito menos material que trabalhe diferentes visões de mundo e treinamento que os capacite a abordá-las devidamente. Conseqüentemente o ensino de astronomia costuma ser tecnicista e dissociado do aspecto humano que alimenta o grande interesse e curiosidade que esses temas despertam. Aqui apresentamos propostas visando contribuir para reverter esse quadro e trabalhamos distintas visões de Universo: espontâneas, autóctones e científicas. Desenvolvemos práticas, materiais instrucionais e textos para viabilizar a adoção de um enfoque antropológico para o ensino de astronomia no nível médio, no qual as culturas humanística e científica sejam integradas de uma maneira contextualizada e eficaz para aquele ensino. Estas propostas foram aplicadas em um curso de treinamento para professores da rede pública de diferentes disciplinas. A receptividade dos professores à abordagem proposta e os resultados alcançados foram muito estimulantes. Destes, destacamos: produção de roteiros de atividades; desenvolvimento de práticas didático-pedagógicas específicas (e.g., encenação de mitos; dança primordial guarani; "criação" de constelações e interpretações pluriculturais; etc.); e sugestões concretas para a efetiva realização de um ensino interdisciplinar contextualizado, onde questões cosmogônicas servem de mote para iniciar tal ensino. Discutimos estes resultados e como o enfoque adotado pode instrumentalizar os professores para leituras de mundo que incluem naturalmente aspectos culturais, sociais e históricos associados aos temas estudados. (PPGECNM/UFRN; PRONEX/FINEP; NUPA/USP; Temáticos/FAPESP)

  20. Ordered expression pattern of Hox and ParaHox genes along the alimentary canal in the ascidian juvenile.

    PubMed

    Nakayama, Satoshi; Satou, Kunihiro; Orito, Wataru; Ogasawara, Michio

    2016-07-01

    The Hox and ParaHox genes of bilateria share a similar expression pattern along the body axis and are known to be associated with anterior-posterior patterning. In vertebrates, the Hox genes are also expressed in presomitic mesoderm and gut endoderm and the ParaHox genes show a restricted expression pattern in the gut-related derivatives. Regional expression patterns in the embryonic central nervous system of the basal chordates amphioxus and ascidian have been reported; however, little is known about their endodermal expression in the alimentary canal. We focus on the Hox and ParaHox genes in the ascidian Ciona intestinalis and investigate the gene expression patterns in the juvenile, which shows morphological regionality in the alimentary canal. Gene expression analyses by using whole-mount in situ hybridization reveal that all Hox genes have a regional expression pattern along the alimentary canal. Expression of Hox1 to Hox4 is restricted to the posterior region of pharyngeal derivatives. Hox5 to Hox13 show an ordered expression pattern correlated with each Hox gene number along the postpharyngeal digestive tract. This expression pattern along the anterior-posterior axis has also been observed in Ciona ParaHox genes. Our observations suggest that ascidian Hox and ParaHox clusters are dispersed; however, the ordered expression patterns along the alimentary canal appear to be conserved among chordates. PMID:26837224

  1. Determination of the ortho to para ratio of H2Cl+ and H2O+ from submillimeter observations.

    PubMed

    Gerin, Maryvonne; de Luca, Massimo; Lis, Dariusz C; Kramer, Carsten; Navarro, Santiago; Neufeld, David; Indriolo, Nick; Godard, Benjamin; Le Petit, Franck; Peng, Ruisheng; Phillips, Thomas G; Roueff, Evelyne

    2013-10-01

    The opening of the submillimeter sky with the Herschel Space Observatory has led to the detection of new interstellar molecular ions, H2O(+), H2Cl(+), and HCl(+), which are important intermediates in the synthesis of water vapor and hydrogen chloride. In this paper, we report new observations of H2O(+) and H2Cl(+) performed with both Herschel and ground-based telescopes, to determine the abundances of their ortho and para forms separately and derive the ortho-to-para ratio. At the achieved signal-to-noise ratio, the observations are consistent with an ortho-to-para ratios of 3 for both H2O(+) and H2Cl(+), in all velocity components detected along the lines-of-sight to the massive star-forming regions W31C and W49N. We discuss the mechanisms that contribute to establishing the observed ortho-to-para ratio and point to the need for a better understanding of chemical reactions, which are important for establishing the H2O(+) and H2Cl(+) ortho-to-para ratios. PMID:23869910

  2. In-Situ Visualization Experiments with ParaView Cinema in RAGE

    SciTech Connect

    Kares, Robert John

    2015-10-15

    A previous paper described some numerical experiments performed using the ParaView/Catalyst in-situ visualization infrastructure deployed in the Los Alamos RAGE radiation-hydrodynamics code to produce images from a running large scale 3D ICF simulation. One challenge of the in-situ approach apparent in these experiments was the difficulty of choosing parameters likes isosurface values for the visualizations to be produced from the running simulation without the benefit of prior knowledge of the simulation results and the resultant cost of recomputing in-situ generated images when parameters are chosen suboptimally. A proposed method of addressing this difficulty is to simply render multiple images at runtime with a range of possible parameter values to produce a large database of images and to provide the user with a tool for managing the resulting database of imagery. Recently, ParaView/Catalyst has been extended to include such a capability via the so-called Cinema framework. Here I describe some initial experiments with the first delivery of Cinema and make some recommendations for future extensions of Cinema’s capabilities.

  3. Semantics-based distributed I/O with the ParaMEDIC framework.

    SciTech Connect

    Balaji, P.; Feng, W.; Lin, H.; Mathematics and Computer Science; Virginia Tech; North Carolina State Univ.

    2008-01-01

    Many large-scale applications simultaneously rely on multiple resources for efficient execution. For example, such applications may require both large compute and storage resources; however, very few supercomputing centers can provide large quantities of both. Thus, data generated at the compute site oftentimes has to be moved to a remote storage site for either storage or visualization and analysis. Clearly, this is not an efficient model, especially when the two sites are distributed over a wide-area network. Thus, we present a framework called 'ParaMEDIC: Parallel Metadata Environment for Distributed I/O and Computing' which uses application-specific semantic information to convert the generated data to orders-of-magnitude smaller metadata at the compute site, transfer the metadata to the storage site, and re-process the metadata at the storage site to regenerate the output. Specifically, ParaMEDIC trades a small amount of additional computation (in the form of data post-processing) for a potentially significant reduction in data that needs to be transferred in distributed environments.

  4. Ortho-to-para ratio in interstellar water on the sightline toward Sagittarius B2(N).

    PubMed

    Lis, Dariusz C; Bergin, Edwin A; Schilke, Peter; van Dishoeck, Ewine F

    2013-10-01

    The determination of the water ortho-to-para ratio (OPR) is of great interest for studies of the formation and thermal history of water ices in the interstellar medium and protoplanetary disk environments. We present new Herschel observations of the fundamental rotational transitions of ortho- and para-water on the sightline toward Sagittarius B2(N), which allow improved estimates of the measurement uncertainties due to instrumental effects and assumptions about the excitation of water molecules. These new measurements, suggesting a spin temperature of 24-32 K, confirm the earlier findings of an OPR below the high-temperature value on the nearby sightline toward Sagittarius B2(M). The exact implications of the low OPR in the galactic center molecular gas remain unclear and will greatly benefit from future laboratory measurements involving water freeze-out and evaporation processes under low-temperature conditions, similar to those present in the galactic interstellar medium. Given the specific conditions in the central region of the Milky Way, akin to those encountered in active Galactic nuclei, gas-phase processes under the influence of strong X-ray and cosmic ray ionization also have to be carefully considered. We summarize some of the latest laboratory measurements and their implications here. PMID:23656468

  5. Rotational relaxation of CS by collision with ortho- and para-H{sub 2} molecules

    SciTech Connect

    Denis-Alpizar, Otoniel; Stoecklin, Thierry Halvick, Philippe; Dubernet, Marie-Lise

    2013-11-28

    Quantum mechanical investigation of the rotationally inelastic collisions of CS with ortho- and para-H{sub 2} molecules is reported. The new global four-dimensional potential energy surface presented in our recent work is used. Close coupling scattering calculations are performed in the rigid rotor approximation for ortho- and para-H{sub 2} colliding with CS in the j = 0–15 rotational levels and for collision energies ranging from 10{sup −2} to 10{sup 3} cm{sup −1}. The cross sections and rate coefficients for selected rotational transitions of CS are compared with the ones previously reported for the collision of CS with He. The largest discrepancies are observed at low collision energy, below 1 cm{sup −1}. Above 10 cm{sup −1}, the approximation using the square root of the relative mass of the colliders to calculate the cross sections between a molecule and H{sub 2} from the data available with {sup 4}He is found to be a good qualitative approximation. The rate coefficients calculated with the electron gas model for the He-CS system show more discrepancy with our accurate results. However, scaling up these rates by a factor of 2 gives a qualitative agreement.

  6. Infrapatellar Fat Pad Para-Articular Osteochondroma: A Ten-Year Follow-up and Review

    PubMed Central

    Bombaci, Hasan; Bilgin, Emre

    2015-01-01

    Introduction: Para-articular masses are not clear enough in terms of their etiology and nomenclature. Although surgical removal of the mass is the preferred treatment, long term follow-up after surgical treatment has not been reported yet. The current study presents a patient with the osteo-cartilaginous mass of infrapatellar region, diagnosed after a trauma. This case has the longest follow-up period in the literature. Case Presentation: A 52-year-old female patient referred after falling down on her right knee. Lateral radiographs of the knee revealed a mass in the infrapatellar area. The case was treated surgically by total excision of the mass. The mass was extra-capsular with lobular and irregular shape. After mass removal the clinical course was uneventful and at the 10-year follow-up, no signs of recurrence were evident clinically or radiologically. Conclusions: Tumor-like lesions within the infrapatellar fat pad should remind the para-articular osteochondroma. Although its etiology has not yet been elicited, operative removal of the mass is the preferred treatment of choice and also curative in long-term follow-up. PMID:26566510

  7. A non-equilibrium ortho-to-para ratio of water in the Orion PDR

    NASA Astrophysics Data System (ADS)

    Choi, Y.; van der Tak, F. F. S.; Bergin, E. A.; Plume, R.

    2014-12-01

    Context. The ortho-to-para ratio (OPR) of H2O is thought to be sensitive to the temperature of water formation. The OPR of H2O is thus useful for studying the formation mechanism of water. Aims: We investigate the OPR of water in the Orion PDR (photon-dominated region), at the Orion Bar and Orion S positions, using data from Herschel/HIFI. Methods: We detect the ground-state lines of ortho- and para-H218O in the Orion Bar and Orion S and estimate the column densities using local thermodynamical equilibrium (LTE) and non-LTE methods. Results: Based on our calculations, the OPR in the Orion Bar is 0.1-0.5, which is unexpectedly low given the gas temperature of ~85 K, and also lower than the values measured for other interstellar clouds and protoplanetary disks. Toward Orion S, our OPR estimate is below 2. Conclusions: This low OPR at 2 positions in the Orion PDR is inconsistent with gas phase formation and with thermal evaporation from dust grains, but it may be explained by photodesorption. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendices are available in electronic form at http://www.aanda.org

  8. O-Methylation of Chlorinated para-Hydroquinones by Rhodococcus chlorophenolicus

    PubMed Central

    Häggblom, Max M.; Apajalahti, Juha H. A.; Salkinoja-Salonen, Mirja S.

    1988-01-01

    Rhodococcus chlorophenolicus PCP-I, a degrader of polychlorinated phenols, guaiacols (2-methoxyphenols), and syringols (2,6-dimethoxyphenols), was shown to O-methylate the degradation intermediate, a chlorinated para-hydroquinone, into 4-methoxyphenol. O-methylation was constitutively expressed, whereas the degradation of chlorophenols and chlorohydroquinones was inducible in R. chlorophenolicus. The O-methylating reaction required two hydroxyl groups in positions para to each other. R. chlorophenolicus selectively methylated the hydroxyl group flanked by two chlorine substituents. Tetrachlorohydroquinone, trichlorohydroquinone, and 2,6-dichlorohydroquinone were methylated into tetrachloro-4-methoxyphenol, 2,3,5-trichloro-4-methoxyphenol, and 3,5-dichloro-4-methoxyphenol, respectively. Chlorohydroquinones with only one chlorine adjacent to a hydroxyl group were methylated only in trace amounts, and no metabolite was formed from hydroquinone. The degradation intermediates formed in hydroxylation of tetrachloroguaiacol and trichlorosyringol by R. chlorophenolicus were O-methylated into two isomeric trichlorodimethoxyphenols and two isomeric dichlorotrimethoxyphenols, respectively. R. chlorophenolicus also degraded the polychlorinated methylation products (tetrachlorinated and trichlorinated 4-methoxyphenols), but not mono- and dichlorinated 4-methoxyphenols. PMID:16347691

  9. Comparing the Well-Being of Para and Olympic Sport Athletes: A Systematic Review.

    PubMed

    Macdougall, Hannah; O'Halloran, Paul; Shields, Nora; Sherry, Emma

    2015-07-01

    This systematic review included 12 studies that compared the well-being of Para and Olympic sport athletes. Meta-analyses revealed that Para athletes, compared with Olympic sport athletes, had lower levels of self-acceptance, indicated by athletic identity, d = 0.47, 95% confidence interval (CI) [0.77, 0.16], and body-image perceptions, d = 0.33, 95% CI [0.59, 0.07], and differed from Olympic sport athletes in terms of their motivation, indicated by a greater mastery-oriented climate, d = 0.74, 95% CI [0.46, 1.03]. Given an inability to pool the remaining data for meta-analysis, individual standardized mean differences were calculated for other dimensions of psychological and subjective well-being. The results have implications for professionals and coaches aiming to facilitate the well-being needs of athletes under their care. Future research would benefit from incorporating established models of well-being based on theoretical rationale combined with rigorous study designs. PMID:26113553

  10. Resonances in the reaction ortho- and para- D2 + H at temperatures below 10 K

    NASA Astrophysics Data System (ADS)

    Simbotin, I.; Côté, R.

    2016-05-01

    In a previous study we reported cross sections for the reaction H2 + D in the temperature regime 10-6 < T < 10 K, and found pronounced shape resonances, especially in the p and d partial waves. We found that the resonant structures were sensitive to the initial rovibrational state of H2; in particular, we showed that the effect of the nuclear-spin symmetry was very important, since ortho- and para- H2 gave significantly different results. We now investigate the reaction D2 + H for vibrationally excited ortho- and para- D2, and compare and contrast these results with those for H2 + D. We remark that this benchmark system is a prototypical example of reactions with a strong barrier, which have very small cross sections in the cold and ultracold regimes. However, shape resonances can enhance the reaction cross sections by orders of magnitude for temperatures around and below T = 1 K. Moreover, resonant features would provide stringent tests for quantum chemistry calculations of potential energy surfaces. Partial support from the US Army Research Office (Grant No. W911NF-13-1-0213).

  11. Effects of acoustic feedback training in elite-standard Para-Rowing.

    PubMed

    Schaffert, Nina; Mattes, Klaus

    2015-01-01

    Assessment and feedback devices have been regularly used in technique training in high-performance sports. Biomechanical analysis is mainly visually based and so can exclude athletes with visual impairments. The aim of this study was to examine the effects of auditory feedback on mean boat speed during on-water training of visually impaired athletes. The German National Para-Rowing team (six athletes, mean ± s, age 34.8 ± 10.6 years, body mass 76.5 ± 13.5 kg, stature 179.3 ± 8.6 cm) participated in the study. Kinematics included boat acceleration and distance travelled, collected with Sofirow at two intensities of training. The boat acceleration-time traces were converted online into acoustic feedback and presented via speakers during rowing (sections with and without alternately). Repeated-measures within-participant factorial ANOVA showed greater boat speed with acoustic feedback than baseline (0.08 ± 0.01 m·s(-1)). The time structure of rowing cycles was improved (extended time of positive acceleration). Questioning of athletes showed acoustic feedback to be a supportive training aid as it provided important functional information about the boat motion independent of vision. It gave access for visually impaired athletes to biomechanical analysis via auditory information. The concept for adaptive athletes has been successfully integrated into the preparation for the Para-Rowing World Championships and Paralympics. PMID:25105858

  12. Genetic evidence that the degradation of para-cresol by Geobacter metallireducens is catalyzed by the periplasmic para-cresol methylhydroxylase.

    PubMed

    Chaurasia, Akhilesh Kumar; Tremblay, Pier-Luc; Holmes, Dawn E; Zhang, Tian

    2015-10-01

    Two pathways for para-cresol (p-cresol) degradation by anaerobic bacteria have been elucidated; one involves fumarate addition at the methyl group of p-cresol by a hydroxylbenzylsuccinate synthase protein while the other utilizes a methylhydroxylase protein (PCMH) to catalyze hydroxylation of the methyl group of p-cresol. In Geobacter metallireducens, in vitro enzymatic assays showed that p-cresol is degraded via the methylhydroxylation pathway. However, prior to this study these results had not been confirmed by genetic analyses. In this work, the gene coding for benzylsuccinate-CoA dehydrogenase (bbsG), an enzyme required for toluene degradation by G. metallireducens that is homologous to the p-hydroxybenzylsuccinyl-CoA dehydrogenase involved in p-cresol degradation by Desulfobacula toluolica Tol2 via fumarate addition, and the gene encoding the alpha prime subunit of PCMH (pcmI), were deleted to investigate the possibility of co-existing p-cresol degradation pathways in G. metallireducens. The absence of a functional PcmI protein completely inhibited p-cresol degradation, while deletion of the bbsG gene had little impact. These results further support the observation that G. metallireducens utilizes a PCMH-initiated pathway for p-cresol degradation. PMID:26316547

  13. 75 FR 34156 - United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-16

    ... Terrace, London, W2 6LG, United Kingdom, and Alcan Corporation, 8770 West Bryn Mawr Avenue, Chicago, IL...''), Rio Tinto plc (``Rio Tinto''), and Alcan Corporation to enjoin Amcor's proposed acquisition from Rio... sales totaled approximately $44 billion. Rio Tinto acquired Alcan Corporation in 2007. 6....

  14. Computational studies of the regioselectivities of COMT-catalyzed meta-/para-O methylations of luteolin and quercetin.

    PubMed

    Cao, Yang; Chen, Zhong-Jian; Jiang, Hui-Di; Chen, Jian-Zhong

    2014-01-16

    Catechol-O-methyltransferase (COMT, EC 2.1.1.6) plays a central role in the inactivation of neurotransmitters sharing a catecholic motif by transferring a methyl group from AdoMet. Methylation of the meta-hydroxyl is much more common than that of the para-hydroxyl in many COMT substrates, such as dopamine and norepinephrine. Our experimental data showed that quercetin preferred meta-methylation but luteolin favored a para-methylation. To elucidate the mechanism for different preferences of methylations of quercetin and luteolin, we performed a theoretical investigation on the different regioseletivities of COMT-catalyzed methylations for quercetin and luteolin by a combined approach of MD simulations, ab initio calculations, and QM/MM computations. The ab initio calculation results showed that both quercetin and luteolin have more negative charge distributions on the meta-O atom than the para-O atom, which indicated that meta-O preferred SN2 reaction for their methylation. Our QM/MM computations also confirmed that these two flavonoids have lower reaction energetic barriers for COMT-catalyzed meta-O-methylation than para-O-methylation. On the other hand, our binding free energy computation results indicated that quercetin has a more stable binding mode for meta-O-methylation than para-O-methylation but luteolin has a more stable binding mode for para-O-methylation than meta-O-methylation. We gave a comprehensive explanation considering both thermodynamics and reaction kinetics aspects and discussed the protein-inhibitor interactions as well as the O-methylation mechanism in our present work. PMID:24354565

  15. Evolution of Antp-class genes and differential expression of Hydra Hox/paraHox genes in anterior patterning

    PubMed Central

    Gauchat, Dominique; Mazet, Françoise; Berney, Cédric; Schummer, Michèl; Kreger, Sylvia; Pawlowski, Jan; Galliot, Brigitte

    2000-01-01

    The conservation of developmental functions exerted by Antp-class homeoproteins in protostomes and deuterostomes suggested that homologs with related functions are present in diploblastic animals. Our phylogenetic analyses showed that Antp-class homeodomains belong either to non-Hox or to Hox/paraHox families. Among the 13 non-Hox families, 9 have diploblastic homologs, Msx, Emx, Barx, Evx, Tlx, NK-2, and Prh/Hex, Not, and Dlx, reported here. Among the Hox/paraHox, poriferan sequences were not found, and the cnidarian sequences formed at least five distinct cnox families. Two are significantly related to the paraHox Gsx (cnox-2) and the mox (cnox-5) sequences, whereas three display some relatedness to the Hox paralog groups 1 (cnox-1), 9/10 (cnox-3) and the paraHox cdx (cnox-4). Intermediate Hox/paraHox genes (PG 3 to 8 and lox) did not have clear cnidarian counterparts. In Hydra, cnox-1, cnox-2, and cnox-3 were not found chromosomally linked within a 150-kb range and displayed specific expression patterns in the adult head. During regeneration, cnox-1 was expressed as an early gene whatever the polarity, whereas cnox-2 was up-regulated later during head but not foot regeneration. Finally, cnox-3 expression was reestablished in the adult head once it was fully formed. These results suggest that the Hydra genes related to anterior Hox/paraHox genes are involved at different stages of apical differentiation. However, the positional information defining the oral/aboral axis in Hydra cannot be correlated strictly to that characterizing the anterior–posterior axis in vertebrates or arthropods. PMID:10781050

  16. Uma grade de perfis teóricos para estrelas massivas em transição

    NASA Astrophysics Data System (ADS)

    Nascimento, C. M. P.; Machado, M. A.

    2003-08-01

    Na XXVIII Reunião Anual da Sociedade Astronômica Brasileira (2002) apresentamos uma grade de perfis calculados de acordo com os pontos da trajetória evolutiva de metalicidade solar, Z = 0.02 e taxa de perda de massa () padrão, para estrelas com massa inicial de 25, 40, 60, 85 e 120 massas solares. Estes perfis foram calculados com o auxílio de um código numérico adequado para descrever os ventos de objetos massivos, supondo simetria esférica, estacionaridade e homogeneidade. No presente trabalho, apresentamos a complementação da grade com os perfis teóricos relativos às trajetórias de Z = 0.02 com taxa de perda de massa dobrada em relação a padrão (2´), e de metalicidade Z = 0.008. Para cada ponto das três trajetórias obtemos os perfis teóricos de Ha, Hb, Hg e Hd, e como esperado eles se apresentam em pura emissão, pura absorção ou em P-Cygni. Para valores de taxa de perda de massa muito baixos (~10-7) não há formação de linhas, o que é visto nos primeiros pontos em todas as trajetórias. Em geral, para um mesmo ponto a componente de emissão diminui e a absorção aumenta de Ha para Hd. É verificado que as trajetórias com Z = 0.02 e padrão possuem menos circuitos (loops) do que as com metalicidade Z = 0.02 e 2´ padrão, e seus perfis são, em geral, menos intensos. Em relação a trajetória de Z = 0.008, verifica-se menos circuitos e maior variação em luminosidade, e seus perfis mostram-se em, algumas trajetórias, mais intensos. Verificamos também que, pontos distintos em uma mesma trajetória, apresentam perfis diferentes para valores similares de luminosidade e temperatura efetiva. Sendo assim, uma grade de perfis teóricos parece ser útil para fornecer uma informação preliminar sobre o estágio evolutivo de uma estrela massiva.

  17. Evaluation of para-dichlorobenzene emissions from solid moth repellant as a source of indoor air pollution

    SciTech Connect

    Chang, J.C.S.; Krebs, K.A.

    1992-01-01

    The paper reports results of dynamic and static chamber tests to evaluate para-dichlorobenzene emission rates from mothcakes. The data were analyzed by a model that assumes that the emission rate is controlled by gas-phase mass transfer. Results indicate that the para-dichlorobenzene emission from mothcakes is a temperature-sensitive sublimation process. Full-scale house tests were also conducted to measure mass transfer coefficients based on the model developed. The values of the mass transfer coefficient obtained are very comparable to those estimated by theoretical heat transfer studies.

  18. Practical in-situ determination of ortho-para hydrogen ratios via fiber-optic based Raman spectroscopy

    SciTech Connect

    Sutherland, Liese -Marie; Knudson, James N.; Mocko, Michal; Renneke, Richard M.

    2015-12-17

    An experiment was designed and developed to prototype a fiber-optic-based laser system, which measures the ratio of ortho-hydrogen to para-hydrogen in an operating neutron moderator system at the Los Alamos Neutron Science Center (LANSCE) spallation neutron source. Preliminary measurements resulted in an ortho to para ratio of 3.06:1, which is within acceptable agreement with the previously published ratio. As a result, the successful demonstration of Raman Spectroscopy for this measurement is expected to lead to a practical method that can be applied for similar in-situ measurements at operating neutron spallation sources.

  19. Experimental verification of equilibrium para-hydrogen levels in hydrogen moderators irradiated by spallation neutrons at J-PARC

    NASA Astrophysics Data System (ADS)

    Teshigawara, M.; Harada, M.; Tatsumoto, H.; Aso, T.; Ohtsu, K.; Takada, H.; Futakawa, M.; Ikeda, Y.

    2016-02-01

    By sampling gaseous hydrogen from a circulating liquid hydrogen loop for Laser Raman spectroscopy, we measured the para-/ortho-hydrogen fractions in liquid hydrogen under neutron irradiation for the first time to identify whether irradiated hydrogen has an elevated ortho-hydrogen fraction. This measurement indicates that para-hydrogen equilibrium persists at 300 kW proton power in the presence of an iron(III) oxide hydroxide [Fe(OH)3] catalyst. The measurements will be repeated as the power at the Japan Proton Accelerator Research Complex (J-PARC) increases to the MW level.

  20. Practical in-situ determination of ortho-para hydrogen ratios via fiber-optic based Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Sutherland, Liese-Marie; Knudson, James N.; Mocko, Michal; Renneke, Richard M.

    2016-02-01

    An experiment was designed and developed to prototype a fiber-optic-based laser system, which measures the ratio of ortho-hydrogen to para-hydrogen in an operating neutron moderator system at the Los Alamos Neutron Science Center (LANSCE) spallation neutron source. Preliminary measurements resulted in an ortho to para ratio of 3.06:1, which is within acceptable agreement with the previously published ratio. The successful demonstration of Raman Spectroscopy for this measurement is expected to lead to a practical method that can be applied for similar in-situ measurements at operating neutron spallation sources.

  1. Metabolism of Doubly para-Substituted Hydroxychlorobiphenyls by Bacterial Biphenyl Dioxygenases

    PubMed Central

    Pham, Thi Thanh My; Sondossi, Mohammad

    2015-01-01

    In this work, we examined the profile of metabolites produced from the doubly para-substituted biphenyl analogs 4,4′-dihydroxybiphenyl, 4-hydroxy-4′-chlorobiphenyl, 3-hydroxy-4,4′-dichlorobiphenyl, and 3,3′-dihydroxy-4,4′-chlorobiphenyl by biphenyl-induced Pandoraea pnomenusa B356 and by its biphenyl dioxygenase (BPDO). 4-Hydroxy-4′-chlorobiphenyl was hydroxylated principally through a 2,3-dioxygenation of the hydroxylated ring to generate 2,3-dihydro-2,3,4-trihydroxy-4′-chlorobiphenyl and 3,4-dihydroxy-4′-chlorobiphenyl after the removal of water. The former was further oxidized by the biphenyl dioxygenase to produce ultimately 3,4,5-trihydroxy-4′-chlorobiphenyl, a dead-end metabolite. 3-Hydroxy-4,4′-dichlorobiphenyl was oxygenated on both rings. Hydroxylation of the nonhydroxylated ring generated 2,3,3′-trihydroxy-4′-chlorobiphenyl with concomitant dechlorination, and 2,3,3′-trihydroxy-4′-chlorobiphenyl was ultimately metabolized to 2-hydroxy-4-chlorobenzoate, but hydroxylation of the hydroxylated ring generated dead-end metabolites. 3,3′-Dihydroxy-4,4′-dichlorobiphenyl was principally metabolized through a 2,3-dioxygenation to generate 2,3-dihydro-2,3,3′-trihydroxy-4,4′-dichlorobiphenyl, which was ultimately converted to 3-hydroxy-4-chlorobenzoate. Similar metabolites were produced when the biphenyl dioxygenase of Burkholderia xenovorans LB400 was used to catalyze the reactions, except that for the three substrates used, the BPDO of LB400 was less efficient than that of B356, and unlike that of B356, it was unable to further oxidize the initial reaction products. Together the data show that BPDO oxidation of doubly para-substituted hydroxychlorobiphenyls may generate nonnegligible amounts of dead-end metabolites. Therefore, biphenyl dioxygenase could produce metabolites other than those expected, corresponding to dihydrodihydroxy metabolites from initial doubly para-substituted substrates. This finding shows that a clear

  2. Metabolism of Doubly para-Substituted Hydroxychlorobiphenyls by Bacterial Biphenyl Dioxygenases.

    PubMed

    Pham, Thi Thanh My; Sondossi, Mohammad; Sylvestre, Michel

    2015-07-01

    In this work, we examined the profile of metabolites produced from the doubly para-substituted biphenyl analogs 4,4'-dihydroxybiphenyl, 4-hydroxy-4'-chlorobiphenyl, 3-hydroxy-4,4'-dichlorobiphenyl, and 3,3'-dihydroxy-4,4'-chlorobiphenyl by biphenyl-induced Pandoraea pnomenusa B356 and by its biphenyl dioxygenase (BPDO). 4-Hydroxy-4'-chlorobiphenyl was hydroxylated principally through a 2,3-dioxygenation of the hydroxylated ring to generate 2,3-dihydro-2,3,4-trihydroxy-4'-chlorobiphenyl and 3,4-dihydroxy-4'-chlorobiphenyl after the removal of water. The former was further oxidized by the biphenyl dioxygenase to produce ultimately 3,4,5-trihydroxy-4'-chlorobiphenyl, a dead-end metabolite. 3-Hydroxy-4,4'-dichlorobiphenyl was oxygenated on both rings. Hydroxylation of the nonhydroxylated ring generated 2,3,3'-trihydroxy-4'-chlorobiphenyl with concomitant dechlorination, and 2,3,3'-trihydroxy-4'-chlorobiphenyl was ultimately metabolized to 2-hydroxy-4-chlorobenzoate, but hydroxylation of the hydroxylated ring generated dead-end metabolites. 3,3'-Dihydroxy-4,4'-dichlorobiphenyl was principally metabolized through a 2,3-dioxygenation to generate 2,3-dihydro-2,3,3'-trihydroxy-4,4'-dichlorobiphenyl, which was ultimately converted to 3-hydroxy-4-chlorobenzoate. Similar metabolites were produced when the biphenyl dioxygenase of Burkholderia xenovorans LB400 was used to catalyze the reactions, except that for the three substrates used, the BPDO of LB400 was less efficient than that of B356, and unlike that of B356, it was unable to further oxidize the initial reaction products. Together the data show that BPDO oxidation of doubly para-substituted hydroxychlorobiphenyls may generate nonnegligible amounts of dead-end metabolites. Therefore, biphenyl dioxygenase could produce metabolites other than those expected, corresponding to dihydrodihydroxy metabolites from initial doubly para-substituted substrates. This finding shows that a clear picture of the fate of polychlorinated

  3. ORTHO-TO-PARA ABUNDANCE RATIO OF WATER ION IN COMET C/2001 Q4 (NEAT): IMPLICATION FOR ORTHO-TO-PARA ABUNDANCE RATIO OF WATER

    SciTech Connect

    Shinnaka, Yoshiharu; Kawakita, Hideyo; Kobayashi, Hitomi; Boice, Daniel C.; Martinez, Susan E.

    2012-04-20

    The ortho-to-para abundance ratio (OPR) of cometary molecules is considered to be one of the primordial characteristics of cometary ices, and contains information concerning their formation. Water is the most abundant species in cometary ices, and OPRs of water in comets have been determined from infrared spectroscopic observations of H{sub 2}O rovibrational transitions so far. In this paper, we present a new method to derive OPR of water in comets from the high-dispersion spectrum of the rovibronic emission of H{sub 2}O{sup +} in the optical wavelength region. The rovibronic emission lines of H{sub 2}O{sup +} are sometimes contaminated by other molecular emission lines but they are not affected seriously by telluric absorption compared with near-infrared observations. Since H{sub 2}O{sup +} ions are mainly produced from H{sub 2}O by photoionization in the coma, the OPR of H{sub 2}O{sup +} is considered to be equal to that of water based on the nuclear spin conservation through the reaction. We have developed a fluorescence excitation model of H{sub 2}O{sup +} and applied it to the spectrum of comet C/2001 Q4 (NEAT). The derived OPR of water is 2.54{sup +0.32}{sub -0.25}, which corresponds to a nuclear spin temperature (T{sub spin}) of 30{sup +10}{sub -4} K. This is consistent with the previous value determined in the near-infrared for the same comet (OPR = 2.6 {+-} 0.3, T{sub spin} = 31{sup +11}{sub -5} K).

  4. Statistical ortho-to-para ratio of water desorbed from ice at 10 kelvin

    NASA Astrophysics Data System (ADS)

    Hama, Tetsuya; Kouchi, Akira; Watanabe, Naoki

    2016-01-01

    The anomalously low ortho-to-para ratios (OPRs) exhibited by gaseous water in space have been used to determine the formation temperature (<50 kelvin) of ice on cold interstellar dust. This approach assumes that the OPR of water desorbed from ice is related to the ice formation temperature on the dust. However, we report that water desorbed from ice at 10 kelvin shows a statistical high-temperature OPR of 3, even when the ice is produced in situ by hydrogenation of O2, a known formation process of interstellar water. This invalidates the assumed relation between OPR and temperature. The necessary reinterpretation of the low OPRs will help elucidate the chemical history of interstellar water from molecular clouds and processes in the early solar system, including comet formation.

  5. Parallel Grand Canonical Monte Carlo (ParaGrandMC) Simulation Code

    NASA Technical Reports Server (NTRS)

    Yamakov, Vesselin I.

    2016-01-01

    This report provides an overview of the Parallel Grand Canonical Monte Carlo (ParaGrandMC) simulation code. This is a highly scalable parallel FORTRAN code for simulating the thermodynamic evolution of metal alloy systems at the atomic level, and predicting the thermodynamic state, phase diagram, chemical composition and mechanical properties. The code is designed to simulate multi-component alloy systems, predict solid-state phase transformations such as austenite-martensite transformations, precipitate formation, recrystallization, capillary effects at interfaces, surface absorption, etc., which can aid the design of novel metallic alloys. While the software is mainly tailored for modeling metal alloys, it can also be used for other types of solid-state systems, and to some degree for liquid or gaseous systems, including multiphase systems forming solid-liquid-gas interfaces.

  6. Searching for Auxetics with DYNA3D and ParaDyn

    SciTech Connect

    Hoover, W G; Hoover, C G

    2004-09-11

    We sought to simulate auxetic behavior by carrying out dynamic analyses of mesoscopic model structures. We began by generating nearly periodic cellular structures. Four-node 'Shell' elements and eight-node 'Brick' elements are the basic building blocks for each cell. The shells and bricks obey standard elastic-plastic continuum mechanics. The dynamical response of the structures was next determined for a three-stage loading process: (1) homogeneous compression; (2) viscous relaxation; (3) uniaxial compression. The simulations were carried out with both serial and parallel computer codes--DYNA3D and ParaDyn--which describe the deformation of the shells and bricks with a robust contact algorithm. We summarize the results found here.

  7. Theoretical and Experimental Studies on the Nonlinear Optical Chromophore para Bromoacetanilide

    NASA Astrophysics Data System (ADS)

    Jothy, V. Bena; Vijayakumar, T.; Jayakumar, V. S.; Udayalekshmi, K.; Ramamurthy, K.; Joe, I. Hubert

    2008-11-01

    Vibrational spectral analysis of the hydrogen bonded non-linear optical (NLO) material para Bromo Acetanilide (PBA) is carried out using NIR FT-Raman and FT-IR spectroscopy. Ab initio molecular orbital computations have been performed at HF/6-31G(d) level to derive equilibrium geometry, vibrational wavenumbers, intensities and first hyperpolarizability. The lowering of the imino stretching wavenumbers suggests the existence of strong intermolecular N-H⋯O hydrogen bonding substantiated by the natural bond orbital (NBO) analysis. Blue shifting CH stretching wavenumbers, simultaneous activation of carbonyl stretching mode and the strong activation of low wavenumber H-bond stretching vibrations shows the presence of intramolecular charge transfer in the molecule.

  8. Surface treatment of para-aramid fiber by argon dielectric barrier discharge plasma at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Gu, Ruxi; Yu, Junrong; Hu, Chengcheng; Chen, Lei; Zhu, Jing; Hu, Zuming

    2012-10-01

    This paper is focused on influence of argon dielectric barrier discharge (DBD) plasma on the adhesive performance and wettability of para-aramid fibers and three parameters including treated power, exposure time and argon flux were detected. The interfacial shear strength (IFSS) was greatly increased by 28% with 300 W, 60 s, 2 L min-1 argon flux plasma treatment. The content of oxygen atom and oxygen-containing polar functional groups were enhanced after the argon plasma treated, so as the surface roughness, which contributed to the improvement of surface wettability and the decrease of contact angle with water. However, long-time exposure, exorbitant power or overlarge argon flux could partly destroy the prior effects of the treatment and damage the mechanical properties of fibers to some degree.

  9. Food for Life / Comida para la Vida: creating a food festival to raise diabetes awareness.

    PubMed

    Lancaster, Kristie; Walker, Willie; Vance, Thomas; Kaskel, Phyllis; Arniella, Guedy; Horowitz, Carol

    2009-01-01

    African and Latino Americans have higher rates of diabetes and its complications than White Americans. Identifying people with undiagnosed diabetes and helping them obtain care can help to prevent complications and mortality. To kick off a screening initiative, our community-academic partnership created the "Food for Life Festival," or "Festival Comida para la Vida." This article will describe the community's perspective on the Festival, which was designed to screen residents, and demonstrate that eating healthy can be fun, tasty, and affordable in a community-centered, culturally consonant setting. More than 1,000 residents attended the event; 382 adults were screened for diabetes, and 181 scored as high risk. Fifteen restaurants distributed free samples of healthy versions of their popular dishes. Community residents, restaurateurs, and clinicians commented that the event transformed many of their preconceived ideas about healthy foods and patient care. PMID:20097997

  10. Analysis of the thermal reaction products of para polyphenylene by combined gas chromatography-mass spectrometry

    NASA Technical Reports Server (NTRS)

    Fewell, L. L.

    1976-01-01

    Analysis of the volatiles and sublimate produced when para-polyphenylene is pyrolyzed to constant weight under vacuum in the temperature range from 380 to 1000 C indicates that the polymer undergoes thermal degradation in two stages. The first stage involved dehydrohalogenation, which is essentially a curing reaction that produces crosslinking between polyphenylene chains resulting from the loss of chlorine from the polymer in the form of hydrogen chloride. The second stage of the thermal degradation is dehydrogenation because hydrogen is the major volatile species. Increasing amounts of polycyclic aromatic hydrocarbons (phenanthrene and 9, 10 benzphenanthrene) in the sublimate, concomitant with increasing C/H ratios of the polymeric residue with pyrolysis temperature, is consistent with the buildup of polynuclear structures in the polymer matrix.

  11. Study and manufacture of a para-/ortho-hydrogen catalytic converter for a space cryostat

    NASA Astrophysics Data System (ADS)

    Baston, A. H.; Bradshaw, T. W.; Butler, G.; Clark, N. S.; Chadwick, A. T.; Harris, D. H. C.; Leach, F.; Norris, J. O. W.; Price, D.

    1986-01-01

    The design and optimization of a para-/ortho-hydrogen converter to increase the efficiency and lifetime of the hydrogen cryogenic system of the ISO project are described. Catalyst technology and associated heat transfer technology is evaluated. Four catalyst systems were characterized. Their catalytic activity under the orbital conditions anticipated for the three radiation shields of ISO are reported. Results from experiments on in situ deactivation and reactivation are given, indicating that this is a key parameter. Iron oxide gel is the most promising catalyst system. A full scale prototype converter was designed to ESTEC specifications, and three converters were manufactured and tested. Performance, except for two small details, meets or exceeds specification. Plans for the development and testing of flight unit converters are proposed.

  12. Beard dermatitis due to para-phenylenediamine use in Arabic men.

    PubMed

    Hsu, T S; Davis, M D; el-Azhary, R; Corbett, J F; Gibson, L E

    2001-05-01

    The most common active ingredient in hair coloring is para-phenylenediamine (PPDA), which can produce contact dermatitis, particularly in persons who dye their scalp hair and in hairdressers. We have identified another group of patients also at risk, namely men from Arab countries, who commonly grow beards and dye them. We searched the computerized patient database at the Mayo Clinic for patients with beard dermatitis associated with dye use. Eight Arabic men presented to the Mayo Clinic between 1994 and 1999 with beard dermatitis and a positive patch test to PPDA. The lesions were described as pruritic, erythematous, papular eruptions that developed in the jaw area after each application of beard dye. The symptoms subsided after the patients discontinued use of the PPDA-containing dye and received treatment with topical corticosteroids. Allergic contact dermatitis in the beard area due to PPDA occurs in Arabic men as a result of their propensity to dye their beards. PMID:11312440

  13. Perspectivas Futuras para o Observatório do Pico dos Dias

    NASA Astrophysics Data System (ADS)

    Bruch, Albert

    2004-02-01

    Com o Observatório Gemini plenamente operacional e o telescópio SOAR iniciando suas operações em breve, a astronomia observacional brasileira encontra-se no auge de uma transformação profunda que terá um impacto grave no Observatório do Pico dos Dias - OPD. Refletimos aqui sobre a natureza desse impacto e estratégias para manter a competitividade do OPD. Não queremos apresentar receitas prontas, mas idéias que poderão servir como base de discussão sobre o uso inteligente dos telescópios do OPD como parte do conjunto de instrumentos disponíveis à comunidade astronômica brasileira.

  14. Applicability of the ParaDNA(®) Screening System to Seminal Samples.

    PubMed

    Tribble, Nicholas D; Miller, Jamie A D; Dawnay, Nick; Duxbury, Nicola J

    2015-05-01

    Seminal fluid represents a common biological material recovered from sexual assault crime scenes. Such samples can be prescreened using different techniques to determine cell type and relative amount before submitting for full STR profiling. The ParaDNA(®) Screening System is a novel forensic test which identifies the presence of DNA through amplification and detection of two common STR loci (D16S539 and TH01) and the Amelogenin marker. The detection of the Y allele in samples could provide a useful tool in the triage and submission of sexual assault samples by enforcement authorities. Male template material was detected on a range of common sexual assault evidence items including cotton pillow cases, condoms, swab heads and glass surfaces and shows a detection limit of 1 in 1000 dilution of neat semen. These data indicate this technology has the potential to be a useful tool for the detection of male donor DNA in sexual assault casework. PMID:25739746

  15. Transient effects and pump depletion in stimulated Raman scattering. [Para-hydrogen

    SciTech Connect

    Carlsten, J.L.; Wenzel, R.G.; Druehl, K.

    1983-01-01

    Stimulated rotational Raman scattering in a 300-K multipass cell filled with para-H/sub 2/ with a single-mode CO/sub 2/-pumped laser is studied using a frequency-narrowed optical parametric oscillator (OPO) as a probe laser at the Stokes frequency for the S/sub 0/(O) transition. Amplification and pump depletion are examined as a function of incident pump energy. The pump depletion shows clear evidence of transient behavior. A theoretical treatment of transient stimulated Raman scattering, including effects of both pump depletion and medium saturation is presented. In a first approximation, diffraction effects are neglected, and only plane-wave interactions are considered. The theoretical results are compared to the experimental pulse shapes.

  16. A Very Rare Cause of a Relapsing Para-Oesophageal Abscess

    PubMed Central

    Wespi, Simon Peter; Frei, Remus; Sulz, Michael Christian

    2016-01-01

    Oesophageal involvement in Crohn's disease (CD) is uncommon and most often accompanied by involvement of more distal parts. Its presentation is mostly non-specific, and therefore a diagnosis, especially in isolated oesophageal disease, is difficult. We present the case of a 42-year-old male patient who was referred to our gastroenterology department because of a para-oesophageal abscess. Under antibiotic treatment the abscess healed, but despite great diagnostic efforts, its aetiology remained unclear. Three years later the patient was hospitalized again because of an abscess at the same site. Endoscopy showed disseminated ulcerations of the lower oesophagus, raising suspicion of CD. After excluding other possible causes, we made the diagnosis of isolated CD of the oesophagus. We review the available literature on this topic and discuss the clinical presentation, symptoms, endoscopic findings, and histology as well as treatment of oesophageal CD. PMID:27403115

  17. Proyecto para la medición sistemática de seeing en CASLEO

    NASA Astrophysics Data System (ADS)

    Fernández Lajus, E.; Forte, J. C.

    La calidad del seeing astronómico es ciertamente uno de los parámetros mas importantes que caracterizan el sitio de un observatorio. Por tanto se desea determinar si el alto valor de seeing observado con el telescopio de 2.15 m se debe a efectos internos y/o del entorno a la cupula o si se debe simplemente al seeing propio del lugar. El actual mecanismo de refrigeración del espejo primario del 2.15, parece haber mejorado notablemente la calidad del seeing. Sin embargo se hace necesario saber hasta que punto el valor del seeing puede ser mejorado. La primera etapa del proyecto consistió en la puesta a punto del telescopio emplazado para este propósito y la adquisición de las primeras medidas tentativas de seeing.

  18. Ortho/para ratio of H2O+ toward Sagittarius B2(M) revisited.

    PubMed

    Schilke, Peter; Lis, Dariusz C; Bergin, Edwin A; Higgins, Ronan; Comito, Claudia

    2013-10-01

    The HIFI instrument aboard the Herschel satellite has allowed the observation and characterization of light hydrides, the building blocks of interstellar chemistry. In this article, we revisit the ortho/para ratio for H2O(+) toward the Sgr B2(M) cloud core. The line of sight toward this star forming region passes through several spiral arms and the gas in the Bar potential in the inner Galaxy. In contrast to earlier findings, which used fewer lines to constrain the ratio, we find a ratio of 3, which is uniformly consistent with high-temperature formation of the species. In view of the reactivity of this ion, this matches the expectations. PMID:23713712

  19. Conformational study of a single molecule of poly para phenylene ethynylenes in dilute solutions

    NASA Astrophysics Data System (ADS)

    Maskey, Sabina; Pierce, Flint; Perahia, Dvora; Grest, Gary S.

    2011-06-01

    The conformation of single molecules of dialkyl poly para phenylene ethynylenes (PPEs), electro-active polymers, is studied in solutions using molecular dynamics simulations. The conformation of conjugated polymers affects their electro-optical properties and therefore is critical to their current and potential uses, though only limited theoretical knowledge is available regarding the factors that control their configuration. The present study investigates the affects of molecular parameters including molecular weight of the polymer and chemical structure of the side chains of PPEs in different solvents on the conformation of the polymers. The PPEs are modeled atomistically where the solvents are modeled both implicitly and explicitly. The study finds that PPEs assume extended configuration which is affected by the length of the polymer backbone and the nature and length of substituting side chains. While the polymer remains extended, local dynamics is retained and no long range correlations are observed within the backbone. The results are compared with scattering experiments.

  20. Single strand dna breaks in human lymphocytes exposed to para-phenylenediamine and its derivatives.

    PubMed

    Chye, Soi Mei; Hseu, You Cheng; Liang, Shih-Hsiung; Chen, Chin-Hui; Chen, Ssu Ching

    2008-01-01

    Para-Phenylenediamine (PPD), the main aromatic amines used in the hair dye formation, and its four derivatives (2-chloro-p-phenylenediamine, 4-chloro-o-phenylenediamine, 2-nitro-p-phenylenediamine, and 4-nitro-o-phenylenediamine) were examined for their potential to produce single strand DNA breaks in human lymphocytes using the alkaline comet assay. Results revealed that all the tested chemicals within the range of doses from 100 microM to 500 microM showed the genotoxicity in a dose-dependent manner after the incubation of lymphocytes with these chemicals for 2 h. In this study, we first reported that PPD and its four derivatives can elicit the type of single strand breaks in human lymphocytes. PMID:18058049

  1. Properties of single crystal para-terphenyl as medium for high resolution TOF detector

    NASA Astrophysics Data System (ADS)

    De Gerone, M.; Biasotti, M.; Ceriale, V.; Corsini, D.; Gatti, F.; Orlando, A.; Pizzigoni, G.

    2016-07-01

    In the last years organic scintillators have been largely investigated in order to achieve high light yield together with good time response. Pure organic compound with high quality crystalline structure can achieve both this goals. Among a large type of organic compound, para-terphenyl (C18H14) have proven to have practical applications as detector medium for particle physics. In this work, the characterization of different sizes high quality mono-crystal p-terphenyl samples is presented. The optical and scintillation properties (emission spectrum, light yield, attenuation length, and decay time) are investigated. Coupling a Silicon PhotoMultiplier-based readout system to the crystal, a small prototype for a high resolution TOF detector was built; the preliminary results, obtained on a 20×30×3 mm3 sample, with dual-side read-out (Hamamatsu S10931-050P SiPMs) and irradiated with 90Sr source, show a time resolution of 35 ps.

  2. Coordination nano-space as stage of hydrogen ortho–para conversion

    PubMed Central

    Kosone, Takashi; Hori, Akihiro; Nishibori, Eiji; Kubota, Yoshiki; Mishima, Akio; Ohba, Masaaki; Tanaka, Hiroshi; Kato, Kenichi; Kim, Jungeun; Real, José Antonio; Kitagawa, Susumu; Takata, Masaki

    2015-01-01

    The ability to design and control properties of nano-sized space in porous coordination polymers (PCPs) would provide us with an ideal stage for fascinating physical and chemical phenomena. We found an interconversion of nuclear-spin isomers for hydrogen molecule H2 adsorbed in a Hofmann-type PCP, {Fe(pz)[Pd(CN)4]} (pz=pyrazine), by the temperature dependence of Raman spectra. The ortho (o)–para (p) conversion process of H2 is forbidden for an isolated molecule. The charge density study using synchrotron radiation X-ray diffraction reveals the electric field generated in coordination nano-space. The present results corroborate similar findings observed on different systems and confirm that o–p conversion can occur on non-magnetic solids and that electric field can induce the catalytic hydrogen o–p conversion. PMID:26587262

  3. Cholecystocutaneous fistula: an unusual complication of a para-umbilical hernia repair

    PubMed Central

    Dixon, Steven; Sharma, Mitesh; Holtham, Stephen

    2014-01-01

    This case describes a 94-year-old woman who presented 2 years postsutured para-umbilical hernia repair with a painful black lump protruding through her scar with blood stained discharge. This was initially thought to be either ischaemic bowel secondary to strangulated incisional hernia or a large organised haematoma. An urgent CT scan was performed following which the patient passed two large calculi and bile-stained fluid spontaneously through the wound, making the diagnosis somewhat clearer. The scan revealed an incisional hernia containing the gallbladder and two large calculi at the skin surface and an incidental large caecal cancer with surrounding lymphadenopathy. Frail health and the incidental finding of a colon cancer rendered invasive surgical management inappropriate. Therefore, she was managed conservatively with antibiotics. A catheter was inserted into the fistula tract to allow free drainage and alleviate pressure-related symptoms. The patient was discharged following a multidisciplinary team discussion. PMID:24862413

  4. Development of a para-orthohydrogen catalytic converter for a solid hydrogen cooler

    NASA Technical Reports Server (NTRS)

    Nast, T. C.; Hsu, I. C.

    1984-01-01

    Design features of a tested catalytic converter for altering vented cryogenic parahydrogen used as a coolant on spacecraft into a para-ortho equilibrium for channeling to other cooling functions are described. The hydrogen is expected to be stored in either liquid or solid form. A high surface area Ni-on-Si catalyst was selected for tests at an operating pressure of 2 torr at a ratio of 1000 gr catalyst for a gr/sec hydrogen flow. Cylindrical and radial flow geometries were tried and measurements centered on the converter efficiencies at different operating temperatures when the converter was placed in the vent line of the H2 cooler. Efficiencies ranging from 10-100 percent were obtained for varying flow rates. Further testing is necessary to characterize the converter performance under a wider range of operating temperatures and environments.

  5. El Proyecto Sismico "LARSE" - Trabajando Hacia un Futuro con Mas Seguridad para Los Angeles

    USGS Publications Warehouse

    Henyey, Thomas L.; Fuis, Gary S.; Benthien, Mark L.; Burdette, Thomas R.; Christofferson, Shari A.; Clayton, Robert W.; Criley, Edward E.; Davis, Paul M.; Hendley, James W., II; Kohler, Monica D.; Lutter, William J.; McRaney, John K.; Murphy, Janice M.; Okaya, David A.; Ryberg, Trond; Simila, Gerald W.; Stauffer, Peter H.

    1999-01-01

    La region de Los Angeles contiene una red de fallas activas, incluyendo muchas fallas por empuje que son profundas y no rompen la superficie de la tierra. Estas fallas ocultas incluyen la falla anteriormente desconocida que fue responsable por la devastacion que ocurrio durante el terremoto de Northridge en enero de 1994, el terremoto mas costoso en la historia de los Estados Unidos. El Experimento Sismico en la Region de Los Angeles (Los Angeles Region Seismic Experiment, LARSE), esta localizando los peligros ocultos de los terremotos debajo de la region de Los Angeles para mejorar la construccion de las estructuras que pueden apoyar terremotos que son inevitables en el futuro, y que ayudaran a los cientificos determinar donde occurira el sacudimento mas fuerte y poderoso.

  6. Surface Temperature Dependence of Hydrogen Ortho-Para Conversion on Amorphous Solid Water

    NASA Astrophysics Data System (ADS)

    Ueta, Hirokazu; Watanabe, Naoki; Hama, Tetsuya; Kouchi, Akira

    2016-06-01

    The surface temperature dependence of the ortho-to-para conversion of H2 on amorphous solid water is first reported. A combination of photostimulated desorption and resonance-enhanced multiphoton ionization techniques allowed us to sensitively probe the conversion on the surface of amorphous solid water at temperatures of 9.2-16 K. Within a narrow temperature window of 8 K, the conversion time steeply varied from ˜4.1 ×103 to ˜6.4 ×102 s . The observed temperature dependence is discussed in the context of previously suggested models and the energy dissipation process. The two-phonon process most likely dominates the conversion rate at low temperatures.

  7. Surface Temperature Dependence of Hydrogen Ortho-Para Conversion on Amorphous Solid Water.

    PubMed

    Ueta, Hirokazu; Watanabe, Naoki; Hama, Tetsuya; Kouchi, Akira

    2016-06-24

    The surface temperature dependence of the ortho-to-para conversion of H_{2} on amorphous solid water is first reported. A combination of photostimulated desorption and resonance-enhanced multiphoton ionization techniques allowed us to sensitively probe the conversion on the surface of amorphous solid water at temperatures of 9.2-16 K. Within a narrow temperature window of 8 K, the conversion time steeply varied from ∼4.1×10^{3} to ∼6.4×10^{2}  s. The observed temperature dependence is discussed in the context of previously suggested models and the energy dissipation process. The two-phonon process most likely dominates the conversion rate at low temperatures. PMID:27391719

  8. ACT-asthma control y tratamiento para niños: a progress report.

    PubMed

    Lewis, M A; de la Sota, A; Rachelefsky, G; Lewis, C E; Quinones, H; Richards, W

    1987-01-01

    A randomized clinical trial is in progress to evaluate an asthma educational program for Latino children and their parents. The intervention, "ACT-Asma Control y Tratamiento Para Niños," was adapted from ACT for Kids, an asthma self-management program for English-speaking families. Results of a pilot study indicated that socioeconomic status was a critical variable to be considered in the design of such programs. Latino children and parents encounter significant barriers to access and continuity of medical care. Therefore, the intervention was redesigned to include "linkages" using a nurse to reduce barriers and to coordinate care. The lesson plans emphasize concrete, experimental learning experiences, with repetition of key points in each session. PMID:3654235

  9. Coordination nano-space as stage of hydrogen ortho-para conversion.

    PubMed

    Kosone, Takashi; Hori, Akihiro; Nishibori, Eiji; Kubota, Yoshiki; Mishima, Akio; Ohba, Masaaki; Tanaka, Hiroshi; Kato, Kenichi; Kim, Jungeun; Real, José Antonio; Kitagawa, Susumu; Takata, Masaki

    2015-07-01

    The ability to design and control properties of nano-sized space in porous coordination polymers (PCPs) would provide us with an ideal stage for fascinating physical and chemical phenomena. We found an interconversion of nuclear-spin isomers for hydrogen molecule H2 adsorbed in a Hofmann-type PCP, {Fe(pz)[Pd(CN)4]} (pz=pyrazine), by the temperature dependence of Raman spectra. The ortho (o)-para (p) conversion process of H2 is forbidden for an isolated molecule. The charge density study using synchrotron radiation X-ray diffraction reveals the electric field generated in coordination nano-space. The present results corroborate similar findings observed on different systems and confirm that o-p conversion can occur on non-magnetic solids and that electric field can induce the catalytic hydrogen o-p conversion. PMID:26587262

  10. Food for Life/Comida para la Vida: Creating a Food Festival to Raise Diabetes Awareness

    PubMed Central

    Lancaster, Kristie; Walker, Willie; Vance, Thomas; Kaskel, Phyllis; Arniella, Guedy; Horowitz, Carol

    2012-01-01

    African and Latino Americans have higher rates of diabetes and its complications than White Americans. Identifying people with undiagnosed diabetes and helping them obtain care can help to prevent complications and mortality. To kick off a screening initiative, our community-academic partnership created the “Food for Life Festival,” or “Festival Comida para la Vida.” This article will describe the community’s perspective on the Festival, which was designed to screen residents, and demonstrate that eating healthy can be fun, tasty, and affordable in a community-centered, culturally consonant setting. More than 1,000 residents attended the event; 382 adults were screened for diabetes, and 181 scored as high risk. Fifteen restaurants distributed free samples of healthy versions of their popular dishes. Community residents, restaurateurs, and clinicians commented that the event transformed many of their preconceived ideas about healthy foods and patient care. PMID:20097997

  11. A method to obtain a well-defined fraction of respirable para-aramid fibers.

    PubMed

    Schins, R P; Gaudichet, A; Jaurand, M C

    1993-10-01

    We developed a preparation method to obtain respirable-sized fractions of para-aramid fibers. The procedure, based on floatability, consists of stirring and subsequent settling of p-aramid pulp in distilled water. Two distinct phases are obtained, with small fibers in the upper part of the suspension, which represents about 33% of the total volume. Optimal results were obtained when 2.0 g pulp was stirred for 15 hr in 800 ml distilled water containing 0.125% ethanol and settled for 5 hr. The mass yield ranged between 0.4 and 0.6%, more than 90% of the particles had an aspect ratio > or = 3:1. The mean fiber length was about 6 microns, and the mean fiber diameter was about 0.4 microns as determined by transmission and scanning electron microscopy. The number of fibers obtained was 4 x 10(6) fibers/micrograms under our standard conditions. PMID:8119251

  12. Constraining the ortho-to-para ratio of H2 with anomalous H_2CO absorption

    NASA Astrophysics Data System (ADS)

    Troscompt, N.; Faure, A.; Maret, S.; Ceccarelli, C.; Hily-Blant, P.; Wiesenfeld, L.

    2009-11-01

    Context: The ortho-to-para ratio (OPR) of molecular hydrogen is a fundamental parameter in understanding the physics and chemistry of molecular clouds. In dark and cold regions, however, H2 is not directly observable and the OPR of H2 in these sources has so far remained elusive. Aims: We show that the 6 cm absorption line of ortho-formaldehyde (H2CO) can be employed to constrain both the density and the OPR of H2 in dark clouds. Methods: Green Bank Telescope (GBT) observations of ortho-H2CO toward the molecular cloud Barnard 68 (B68) are reported. Non-LTE radiative transfer calculations combined with the well-constrained structure of B68 are then employed to derive the physical conditions in the absorption region. Results: We provide the first firm confirmation of the Townes & Cheung mechanism: propensity rules for the collisions of H2CO with H2 molecules are responsible for the sub-2.7 K cooling of the 6 cm doublet. Non-LTE calculations show that in the absorption region of B68, the kinetic temperature is ˜ 10 K, the ortho-H2CO column density amounts to ˜ 2.2× 1013 cm-2, the H2 density is in the range 1.4{-}2.4× 10 4 cm-3, and the OPR of H2 is close to zero. Our observations thus provide fresh evidence that H2 is mostly in its para form in the cold gas, as expected from theoretical considerations. Our results also suggest that formaldehyde absorption originates in the edge of B68, at visual extinctions A_V⪉ 0.5 mag. This work has been inspired by our colleague and friend Pierre Valiron, who passed away in August 2008. This paper is dedicated to his memory.

  13. Cost-effectiveness of para-aortic lymphadenectomy before chemoradiotherapy in locally advanced cervical cancer

    PubMed Central

    Lee, Jung-Yun; Kim, Younhee; Lee, Tae-Jin; Jeon, Yong Woo; Kim, Kidong; Chung, Hyun Hoon; Park, Sang Min; Kim, Jae-Weon

    2015-01-01

    Objective To evaluate the cost-effectiveness of nodal staging surgery before chemoradiotherapy (CRT) for locally advanced cervical cancer in the era of positron emission tomography/computed tomography (PET/CT). Methods A modified Markov model was constructed to evaluate the cost-effectiveness of para-aortic staging surgery before definite CRT when no uptake is recorded in the para-aortic lymph nodes (PALN) on PET/CT. Survival and complication rates were estimated based on the published literature. Cost data were obtained from the Korean Health Insurance Review and Assessment Service. Strategies were compared using an incremental cost-effectiveness ratio (ICER). Sensitivity analyses were performed, including estimates for the performance of PET/CT, postoperative complication rate, and varying survival rates according to the radiation field. Results We compared two strategies: strategy 1, pelvic CRT for all patients; and strategy 2, nodal staging surgery followed by extended-field CRT when PALN metastasis was found and pelvic CRT otherwise. The ICER for strategy 2 compared to strategy 1 was $19,505 per quality-adjusted life year (QALY). Under deterministic sensitivity analyses, the model was relatively sensitive to survival reduction in patients who undergo pelvic CRT alone despite having occult PALN metastasis. A probabilistic sensitivity analysis demonstrated the robustness of the case results, with a 91% probability of cost-effectiveness at the willingness-to-pay thresholds of $60,000/QALY. Conclusion Nodal staging surgery before definite CRT may be cost-effective when PET/CT imaging shows no evidence of PALN metastasis. Prospective trials are warranted to transfer these results to guidelines. PMID:25925292

  14. The analysis of para-cresol production and tolerance in Clostridium difficile 027 and 012 strains

    PubMed Central

    2011-01-01

    Background Clostridium difficile is the major cause of antibiotic associated diarrhoea and in recent years its increased prevalence has been linked to the emergence of hypervirulent clones such as the PCR-ribotype 027. Characteristically, C. difficile infection (CDI) occurs after treatment with broad-spectrum antibiotics, which disrupt the normal gut microflora and allow C. difficile to flourish. One of the relatively unique features of C. difficile is its ability to ferment tyrosine to para-cresol via the intermediate para-hydroxyphenylacetate (p-HPA). P-cresol is a phenolic compound with bacteriostatic properties which C. difficile can tolerate and may provide the organism with a competitive advantage over other gut microflora, enabling it to proliferate and cause CDI. It has been proposed that the hpdBCA operon, rarely found in other gut microflora, encodes the enzymes responsible for the conversion of p-HPA to p-cresol. Results We show that the PCR-ribotype 027 strain R20291 quantitatively produced more p-cresol in-vitro and was significantly more tolerant to p-cresol than the sequenced strain 630 (PCR-ribotype 012). Tyrosine conversion to p-HPA was only observed under certain conditions. We constructed gene inactivation mutants in the hpdBCA operon in strains R20291 and 630Δerm which curtails their ability to produce p-cresol, confirming the role of these genes in p-cresol production. The mutants were equally able to tolerate p-cresol compared to the respective parent strains, suggesting that tolerance to p-cresol is not linked to its production. Conclusions C. difficile converts tyrosine to p-cresol, utilising the hpdBCA operon in C. difficile strains 630 and R20291. The hypervirulent strain R20291 exhibits increased production of and tolerance to p-cresol, which may be a contributory factor to the virulence of this strain and other hypervirulent PCR-ribotype 027 strains. PMID:21527013

  15. Self-assembled catalytic DNA nanostructures for synthesis of para-directed polyaniline.

    PubMed

    Wang, Zhen-Gang; Zhan, Pengfei; Ding, Baoquan

    2013-02-26

    Templated synthesis has been considered as an efficient approach to produce polyaniline (PANI) nanostructures. The features of DNA molecules enable a DNA template to be an intriguing template for fabrication of emeraldine PANI. In this work, we assembled HRP-mimicking DNAzyme with different artificial DNA nanostructures, aiming to manipulate the molecular structures and morphologies of PANI nanostructures through the controlled DNA self-assembly. UV-vis absorption spectra were used to investigate the molecular structures of PANI and monitor kinetic growth of PANI. It was found that PANI was well-doped at neutral pH and the redox behaviors of the resultant PANI were dependent on the charge density of the template, which was controlled by the template configurations. CD spectra indicated that the PANI threaded tightly around the helical DNA backbone, resulting in the right handedness of PANI. These reveal the formation of the emeraldine form of PANI that was doped by the DNA. The morphologies of the resultant PANI were studied by AFM and SEM. It was concluded from the imaging and spectroscopic kinetic results that PANI grew preferably from the DNAzyme sites and then expanded over the template to form 1D PANI nanostructures. The strategy of the DNAzyme-DNA template assembly brings several advantages in the synthesis of para-coupling PANI, including the region-selective growth of PANI, facilitating the formation of a para-coupling structure and facile regulation. We believe this study contributes significantly to the fabrication of doped PANI nanopatterns with controlled complexity, and the development of DNA nanotechnology. PMID:23272944

  16. On Ensino de Astronomia: Desafios para Implantação

    NASA Astrophysics Data System (ADS)

    Faria, R. Z.; Voelzke, M. R.

    2008-09-01

    Em 2002 o ensino de Astronomia foi proposto como um dos temas estruturadores pelos Parâmetros Curriculares Nacionais e sugerido como facilitador para que o aluno compreendesse a Física como construção humana e parte do seu mundo vivencial, mas raramente seus conceitos foram ensinados. A presente pesquisa discute dois aspectos relacionados à abordagem de Astronomia. O primeiro aspecto é se ela está sendo abordada pelos professores do Ensino Médio e o segundo, aborda a maneira como ela está sendo ensinada. Optou-se pela aplicação de um questionário a partir do 2° semestre de 2006 e durante o ano de 2007 com professores que ministram a disciplina de Física, os quais trabalham em escolas estaduais em Rio Grande da Serra, Ribeirão Pires e Mauá no estado São Paulo. Dos 66,2% dos professores que responderam ao questionário nos municípios de Rio Grande da Serra, Ribeirão Pires e Mauá, 57,4% não aplicaram nenhum tópico de astronomia, 70,2% não utilizaram laboratório, 89,4% não utilizaram qualquer tipo de programa computacional, 83,0% nunca fizeram visitas com alunos a museus e planetários e 38,3% não indicaram qualquer tipo de livro ou revista referente à astronomia aos seus alunos. Mesmo considerando a Astronomia um conteúdo potencialmente significativo, esta não fez parte dos planejamentos escolares. Portanto são necessárias propostas que visem estratégias para a educação continuada dos professores como, por exemplo, cursos específicos sobre o ensino em Astronomia.

  17. Controlling electronic product branching at conical intersections in the UV photolysis of para-substituted thiophenols.

    PubMed

    Oliver, Thomas A A; King, Graeme A; Tew, David P; Dixon, Richard N; Ashfold, Michael N R

    2012-12-27

    H (Rydberg) atom photofragment translation spectroscopy and high-level ab initio electronic structure calculations are used to explore the photodissociation dynamics of three para-substituted thiophenols (p-YPhSH; Y = CH(3), F, and MeO). UV excitation in the wavelength range 305 > λ(phot) > 240 nm results in S-H bond fission and formation of p-YPhS radicals in their ground (X̃(2)B(1)) and first excited (Ã(2)B(2)) electronic states; the X̃/Ã state product branching ratio, Γ, varies with para-Y substituent and excitation wavelength. Excitation at λ(phot) < 265 nm results in direct population of the dissociative 1(1)πσ* potential energy surface (PES). Γ falls across the series p-CH(3)PhSH > p-FPhSH > p-MeOPhSH. Branching is ultimately determined at the conical intersection (CI) formed by the 1(1)πσ* and ground (S(0)) PESs at extended R(S-H) bond length but is sensitively dependent on the orientation of the S-H bond (relative to the ring plane) in the S(0) molecules prior to photoexcitation. Excitation at λ(phot) > 265 nm populates quasi-bound levels of the respective 1(1)ππ* states, which predissociate rapidly by tunneling under the lower diabats of the 1(1)ππ*/1(1)πσ* CI at short R(S-H). Less extreme X̃/Ã product branching ratios are measured, implicating intramolecular vibrational redistribution within the photoexcited 1(1)ππ* molecules prior to their sampling the region of the 1(1)πσ*/S(0) CI. PMID:23110379

  18. Prevalence of oral trauma in Para-Pan American Games athletes.

    PubMed

    Andrade, Rafaela Amarante; Modesto, Adriana; Evans, Patricia Louise Scabell; Almeida, Anne Louise Scabell; da Silva, Juliana de Jesus Rodrigues; Guedes, Aurelino Machado Lima; Guedes, Fábio Ribeiro; Ranalli, Dennis N; Tinoco, Eduardo Muniz Barretto

    2013-08-01

    The aim of this cross-sectional epidemiological survey was to assess the prevalence of oral trauma in athletes representing 25 countries competing at the most recent Para-Pan American Games (III PARAPAN) held in Rio de Janeiro, Brazil. The study was approved by the appropriate institutional review board. The examiners participated in standardization and calibration training sessions before the field phase began. Invitations were sent to >1200 participating athletes competing in eight sports and to the Medical Committee of the Para-Pan American Sports Organization before and during the III PARAPAN. A convenience sample of 120 athletes was recruited. After signing an informed consent, all athletes answered a questionnaire. Data were collected at the clinical examination and recorded in a specific trauma form. The mean age of the athletes was 32.5 years. Males comprised 79.2% of the sample; females 20.8%. The prevalence of oral trauma among the athletes was 47.5% (N = 57). However, only 15 athletes reported that these traumatic injuries were sports-related. The sport with the highest prevalence of oral trauma was judo (75%); the least was volleyball with no reported traumatic injuries. The most common traumatic injury was enamel fracture (27.4%). The teeth most affected were the maxillary permanent central incisors (N = 19), followed by the maxillary premolars (N = 8). On the basis of the results of this study of oral trauma among athletes examined at the III PARAPAN, a recommendation for enhanced educational efforts and the use of properly fitted mouthguards to prevent traumatic injuries among high-performance athletes with disabilities seems warranted. PMID:22882839

  19. Uso de exámenes de detección como oportunidad para ayudar a fumadores a dejar el tabaco

    Cancer.gov

    El NCI ha publicado un anuncio de financiamiento para ayudar a estimular la investigación sobre métodos óptimos para dejar de fumar cigarrillos que se entreguen junto con los exámenes de detección.

  20. Enfermedad trofoblástica de la gestación—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento de la enfermedad trofoblástica de la gestación, así como referencias a estudios clínicos y otros temas relacionados.

  1. Pruebas sin beneficio comprobado se usan aún para viiglar cáncer de ovario

    Cancer.gov

    Artículo del blog Temas y Relatos del NCI sobre un estudio que indica que los medicos clínicos siguen usando análisis de CA-125 y exploraciones con TC para vigilar de rutina las recurrencias aunque no se ha comprobado el beneficio de estas pruebas.

  2. ParaStream: A parallel streaming Delaunay triangulation algorithm for LiDAR points on multicore architectures

    NASA Astrophysics Data System (ADS)

    Wu, Huayi; Guan, Xuefeng; Gong, Jianya

    2011-09-01

    This paper presents a robust parallel Delaunay triangulation algorithm called ParaStream for processing billions of points from nonoverlapped block LiDAR files. The algorithm targets ubiquitous multicore architectures. ParaStream integrates streaming computation with a traditional divide-and-conquer scheme, in which additional erase steps are implemented to reduce the runtime memory footprint. Furthermore, a kd-tree-based dynamic schedule strategy is also proposed to distribute triangulation and merging work onto the processor cores for improved load balance. ParaStream exploits most of the computing power of multicore platforms through parallel computing, demonstrating qualities of high data throughput as well as a low memory footprint. Experiments on a 2-Way-Quad-Core Intel Xeon platform show that ParaStream can triangulate approximately one billion LiDAR points (16.4 GB) in about 16 min with only 600 MB physical memory. The total speedup (including I/O time) is about 6.62 with 8 concurrent threads.

  3. Factor Analysis of the Spanish Version of the WAIS: The Escala de Inteligencia Wechsler para Adultos (EIWA).

    ERIC Educational Resources Information Center

    Gomez, Francisco C., Jr.; And Others

    1992-01-01

    The standardization of the Escala de Inteligencia Wechsler para Adultos (EIWA) and the original Wechsler Adult Intelligence Scale (WAIS) were subjected to principal components analysis to examine their comparability for 616 EIWA subjects and 800 WAIS subjects. Similarity of factor structures of both scales is supported. (SLD)

  4. The Role Of Women In Popular Education In Bolivia: A Case Study Of The "Oficina Juridica Para La Mujer"

    ERIC Educational Resources Information Center

    Kollins, Judith M.; Hansman, Catherine A.

    2005-01-01

    This study examines how the Education Office of the "Oficina Juridica Para la Mujer" [Women's Legal Office] , a community-based popular education organization in Cochabamba, Bolivia, works with women to address personal, legal, and policy issues through local leadership training and popular education methodology. We investigate the marginalization…

  5. PLASMA CLEARANCE OF VITELLOGENIN IN SHEEPSHEAD MINNOWS AFTER CESSATION OF EXPOSURE TO 17BETA-ESTRADIOL AND PARA-NONYLPHENOL

    EPA Science Inventory

    Two experiments were performed to determine the rate of vitellogenin plasma accumulation and clearance in male sheepshead minnows (Cyprinodon variegatus) during and after exposure to either 17b-estradiol (E2) or para-nonylphenol (p-NP). Adult fish were continuously exposed to aqu...

  6. A Conceptual Model for Supporting Para-Teacher Learning in an Indian Non-Governmental Organization (NGO)

    ERIC Educational Resources Information Center

    Raval, Harini; McKenney, Susan; Pieters, Jules

    2010-01-01

    Non-governmental organizations (NGOs) are being recognized globally for their influential role in realizing the UN Millennium Development Goal of education for all in developing countries. NGOs mostly employ untrained para-educators for grassroots activities. The professional development of these teachers is critical for NGO effectiveness, yet…

  7. Familiares a cargo de pacientes de cáncer (PDQ®)—Versión para pacientes

    Cancer.gov

    Sumario informativo revisado por expertos acerca de los desafíos que enfrentan los familiares a cargo de los pacientes con cáncer. Este resumen se centra en las funciones típicas y las inquietudes de las personas a cargo del paciente y en las intervenciones útiles para esas personas.

  8. Cáncer de piel (incluye el melanoma)—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento, la prevención, las causas y los exámenes de detección del cáncer de piel, así como referencias a estudios clínicos, investigación y otros temas.

  9. Cáncer de vesícula biliar—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de vesícula biliar, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  10. Violencia de Pareja en Mujeres Hispanas: Implicaciones para la Investigación y la Práctica

    PubMed Central

    Gonzalez-Guarda, Rosa Maria; Becerra, Maria Mercedes

    2012-01-01

    Las investigaciones sobre la violencia entre parejas sugieren que las mujeres hispanas están siendo afectadas desproporcionadamente por la ocurrencia y consecuencias de este problema de salud pública. El objetivo del presente artículo es dar a conocer el estado del arte en relación a la epidemiologia, consecuencias y factores de riesgo para VP entre mujeres Hispanas, discutiendo las implicaciones para la investigación y la práctica. Investigaciones han demostrado una fuerte asociación del status socioeconómico, abuso de droga y el alcohol, la salud mental, aculturación, inmigración, comportamientos sexuales riesgosos e historia de abuso con la violencia entre parejas. Sin embargo, más estudios se deben llevar a cabo para identificar otros factores de riesgos y de protección a poblaciones hispanas no clínicas. Mientras que el conocimiento sobre la etiología de la VP entre mujeres Hispanas se expanda, enfermeras y otros profesionales de la salud deben desarrollar, implementar y evaluar estrategias culturalmente adecuadas para la prevención primaria y secundaria de la violencia entre pareja. PMID:26166938

  11. Cáncer de hígado y de conducto biliar—Versión para profesionales de salud

    Cancer.gov

    Información del NCI para profesionales de salud sobre el tratamiento, la prevención y los exámenes de detección del cáncer de hígado y de conducto biliar, así como referencias a estudios clínicos, investigación y otros temas.

  12. Intensity-Modulated Radiation Therapy for the Treatment of Squamous Cell Anal Cancer With Para-aortic Nodal Involvement

    SciTech Connect

    Hodges, Joseph C.; Das, Prajnan; Eng, Cathy; Reish, Andrew G.; Beddar, A. Sam; Delclos, Marc E.; Krishnan, Sunil; Crane, Christopher H.

    2009-11-01

    Purpose: To determine the rates of toxicity, locoregional control, distant control, and survival in anal cancer patients with para-aortic nodal involvement, treated with intensity-modulated radiotherapy (IMRT) and concurrent chemotherapy at a single institution. Methods and Materials: Between 2001 and 2007, 6 patients with squamous cell anal cancer and para-aortic nodal involvement were treated with IMRT and concurrent infusional 5-fluorouracil and cisplatin. The primary tumor was treated with a median dose of 57.5 Gy (range, 54-60 Gy), involved para-aortic, pelvic, and inguinal lymph nodes were treated with a median dose of 55 Gy (range, 50.5-55 Gy), and noninvolved nodal regions were treated with a median dose of 45 Gy (range, 43.5-45 Gy). Results: After a median follow-up of 25 months, none of the patients had a recurrence at the primary tumor, pelvic/inguinal nodes, or para-aortic nodes, whereas 2 patients developed distant metastases to the liver. Four of the 6 patients are alive. The 3-year actuarial locoregional control, distant control, and overall survival rates were 100%, 56%, and 63%, respectively. Four of the 6 patients developed Grade 3 acute gastrointestinal toxicity during chemoradiation. Conclusions: Intensity-modulated radiotherapy and concurrent chemotherapy could potentially serve as definitive therapy in anal cancer patients with para-aortic nodal involvement. Adjuvant chemotherapy may be indicated in these patients, as demonstrated by the distant failure rates. These patients need to be followed carefully because of the potential for treatment-related toxicities.

  13. Long-term results of para-aortic irradiation for patients with stage I seminoma of the testis

    SciTech Connect

    Niazi, Tamim M.; Souhami, Luis . E-mail: luis.souhami@muhc.mcgill.ca; Sultanem, Khalil; Duclos, Marie; Shenouda, George; Freeman, Carolyn

    2005-03-01

    Purpose: Adjuvant postoperative para-aortic lymph nodal irradiation is an acceptable alternative to para-aortic and ipsilateral pelvic irradiation postorchiectomy for patients with Stage I seminoma of the testis. In this article, we report the long-term results of our prospective evaluation of para-aortic irradiation only for such patients. Methods and materials: Between March 1991 and September 2000, 71 patients with Stage I seminoma were treated with adjuvant irradiation to the para-aortic region only after radical inguinal orchiectomy. Radiotherapy was delivered using parallel-opposed fields extending from T11 to L5. A total dose of 25 Gy in 15 fractions was prescribed to midpoint. Follow-up was performed every 3 months for the first year, every 4 months for the second and third years, every 6 months for the fourth and fifth years, and annually thereafter. Chest X-ray, tumor markers, and computed tomography scan of the pelvis were performed routinely as part of the follow-up investigation. Results: At a median follow-up of 75 months, 68 of 71 patients are alive and free of relapse. Only 1 patient (1.4%) experienced failure in the ipsilateral inguinal nodal region. Two patients (2.8%) died of unrelated causes. The actuarial 10-year relapse free survival is 98.5% and the actuarial 10-year overall survival is 92%. No late toxicity has been encountered. Conclusion: Patients with Stage I seminoma of the testis may be safely treated with para-aortic radiotherapy only. Risk of pelvic failure is very low and treatment toxicity minimal.

  14. The Ortho-to-Para Ratio and the Chemical Properties of C3 H2 in Dark Cloud Cores

    NASA Astrophysics Data System (ADS)

    Takakuwa, Shigehisa; Kawaguchi, Kentarou; Mikami, Hitomi; Saito, Masao

    2001-04-01

    We have observed cyclic C3H2 (JKaKc = 212-101, 202 - 111, 312 - 303) lines at the 3 mm wavelength region toward the starless TMC-1C cloud and the protostellar core of L 1527 with the 45 m telescope at Nobeyama Radio Observatory. In both clouds, the 212-101 and 202 - 111 lines are strongly detected, while the 312 - 303 line is only detected toward the center of the protostellar core L 1527. From our statistical equilibrium analyses of the ortho-C3H2(212-101) and the para-C3H2(202-111)lines, the ortho-to-para ratios of C3H2 are determined to be 2.4 +/- 0.1 and 2.5 +/- 0.5 in TMC-1C and L 1527, respectively. These values are lower than the statistical value of 3, although the error of the ratio in L 1527 is large. Since thermal equilibrium with a dust temperature of 10 K still gives a ratio of 3 in c-C3H2, this result should suggest the lower ortho-to-para ratio of the precursor molecule, c-C3H+3, which is thought to be mainly produced by C3H++H2. Thus, we conclude that the lower ortho-to-para ratio of c-C3H2 is due to a lower ortho-to-para ratio of H2 than the statistical value.

  15. PFI-ZEKE (Pulsed Field Ionization-Zero Electron Kinetic Energy) para el estudio de iones

    NASA Astrophysics Data System (ADS)

    Castaño, F.; Fernández, J. A.; Basterretxea, A. Longarte. F.; Sánchez Rayo, M. N.; Martínez, R.

    Entre las áreas hacia donde ha evolucionado la Química en los últimos años están los estudios de sistemas con especies reactivas de alta energía y los dominados por fuerzas intermoleculares débiles, con energías de unas pocas kcal/mol. En efecto, el estudio de las propiedades de los iones, comenzando por su relación con la molécula neutra de la que procede, la energía de ionización, los estados vibracionales y rotacionales, energías de enlace de Van der Waals entre el ión y una amplia variedad de otras moléculas, sus confórmeros o isómeros y sus reacciones o semi-reacciones químicas están en la raíz de la necesidad de la espectroscopía conocida como PFI-ZEKE, Pulsed Field Ionization-Zero Electron Kinetic Energy. Entre las aplicaciones que requieren estos conocimientos se encuentran la generación de plasmas para la fabricación de semiconductores, memorias magnéticas, etc, así como los sistemas astrofísicos, la ionosfera terrestre, etc. La espectroscopía ZEKE es una evolución de las de fluorescencia inducida por láser, LIF, ionización multifotónica acrecentada por resonancia, REMPI, con uno y dos colores y acoplada a un sistema de tiempo de vuelo, REMPI-TOF-MS, y las espectroscopías de doble resonancia IR-UV y UV-UV. Sus espectros y la ayuda de cálculos ab inicio permite determinar las energías de enlace de complejos de van der Waals en estados fundamental y excitados, identificar confórmeros e isómeros, obtener energías de ionización experimentales aproximadas (100 cm-1) y otras variables de interés. Al igual que con LIF, REMPI y dobles resonancias, es posible utilizar muestras gaseosas, pero los espectros están muy saturados de bandas y su interpretación es difícil o imposible. Se evitan estas dificultades estudiando las moléculas o complejos en expansiones supersónicas, donde la T de los grados de libertad solo alcanzan unos pocos K. Para realizar experimentos de ZEKE hay que utilizar una propiedad recientemente

  16. A remarkably stable TipE gene cluster: evolution of insect Para sodium channel auxiliary subunits

    PubMed Central

    2011-01-01

    Background First identified in fruit flies with temperature-sensitive paralysis phenotypes, the Drosophila melanogaster TipE locus encodes four voltage-gated sodium (NaV) channel auxiliary subunits. This cluster of TipE-like genes on chromosome 3L, and a fifth family member on chromosome 3R, are important for the optional expression and functionality of the Para NaV channel but appear quite distinct from auxiliary subunits in vertebrates. Here, we exploited available arthropod genomic resources to trace the origin of TipE-like genes by mapping their evolutionary histories and examining their genomic architectures. Results We identified a remarkably conserved synteny block of TipE-like orthologues with well-maintained local gene arrangements from 21 insect species. Homologues in the water flea, Daphnia pulex, suggest an ancestral pancrustacean repertoire of four TipE-like genes; a subsequent gene duplication may have generated functional redundancy allowing gene losses in the silk moth and mosquitoes. Intronic nesting of the insect TipE gene cluster probably occurred following the divergence from crustaceans, but in the flour beetle and silk moth genomes the clusters apparently escaped from nesting. Across Pancrustacea, TipE gene family members have experienced intronic nesting, escape from nesting, retrotransposition, translocation, and gene loss events while generally maintaining their local gene neighbourhoods. D. melanogaster TipE-like genes exhibit coordinated spatial and temporal regulation of expression distinct from their host gene but well-correlated with their regulatory target, the Para NaV channel, suggesting that functional constraints may preserve the TipE gene cluster. We identified homology between TipE-like NaV channel regulators and vertebrate Slo-beta auxiliary subunits of big-conductance calcium-activated potassium (BKCa) channels, which suggests that ion channel regulatory partners have evolved distinct lineage-specific characteristics

  17. Cosmoeducação: uma proposta para o ensino de astronomia

    NASA Astrophysics Data System (ADS)

    Medeiros, L. A. L.; Jafelice, L. C.

    2003-08-01

    Entende-se por cosmoeducação o desenvolvimento vivencial da unidade homem-cosmo. Este conceito é norteado pela psicologia transpessoal, que estuda o ser humano em sua totalidade, onde suas relações ecológicas e cósmicas são de grande importância. Constata-se uma necessidade latente no ser humano moderno em resgatar uma relação holística com o Universo. Neste trabalho exploramos meios de cultivar a consciência de que o ser humano constitui parte integrante do cosmo e se relaciona com este com o objetivo de promover em si uma percepção ambiental mais ampla. Nossa hipótese de trabalho inicial foi que o ensino de conteúdos básicos em astronomia realizado através de uma abordagem holística, que incorpore práticas vivenciais correlacionadas àqueles conteúdos, pode despertar no indivíduo sua identidade cósmica. O método que utilizamos é o fenomenológico e o universo desta pesquisa é um grupo de estudantes da disciplina de Astronomia (Curso de Licenciatura em Geografia/UFRN), onde realizamos observação participante, entrevistas, depoimentos e as práticas vivenciais mencionadas. Neste caso estamos desenvolvendo e adaptando exercícios de algumas técnicas terapêuticas de psicologia transpessoal, que um de nós (LALM) tem aplicado no contexto clínico, para trabalhar aspectos cognitivos envolvidos naquele processo de conscientização cósmica. Resultados parciais claramente referendam a hipótese inicial. Um resultado a destacar é fruto de uma dinâmica de representação corporal interiorizada do eclipse lunar, envolvendo um pequeno grupo daqueles estudantes, na qual conteúdos míticos afloraram de maneira espontânea e contundente para todos, sugerindo ressonância, ou pelo menos isomorfismo, entre o macro e o microcosmo. Este e outros resultados são discutidos em detalhe neste trabalho. (PPGECNM/UFRN; PRONEX/FINEP; NUPA/USP; Temáticos/FAPESP).

  18. Community Preferences for the Allocation &Donation of Organs - The PAraDOx Study

    PubMed Central

    2011-01-01

    Background Transplantation is the treatment of choice for people with severe organ failure. However, demand substantially exceeds supply of suitable organs; consequently many people wait months, or years to receive an organ. Reasons for the chronic shortage of deceased organ donations are unclear; there appears to be no lack of 'in principle' public support for organ donation. Methods/Design The PAraDOx Study examines community preferences for organ donation policy in Australia. The aims are to 1) determine which factors influence decisions by individuals to offer their organs for donation and 2) determine the criteria by which the community deems the allocation of donor organs to be fair and equitable. Qualitative and quantitative methods will be used to assess community preferences for organ donation and allocation. Focus group participants from the general community, aged between 18-80, will be purposively sampled to ensure a variety of cultural backgrounds and views on organ donation. Each focus group will include a ranking exercise using a modified nominal group technique. Focus groups of organ recipients, their families, and individuals on a transplant waiting list will also be conducted. Using the qualitative work, a discrete choice study will be designed to quantitatively assess community preferences. Discrete choice methods are based on the premise that goods and services can be described in terms of a number of separate attributes. Respondents are presented with a series of choices where levels of attributes are varied, and a mathematical function is estimated to describe numerically the value respondents attach to different options. Two community surveys will be conducted in approximately 1000 respondents each to assess community preferences for organ donation and allocation. A mixed logit model will be used; model results will be expressed as parameter estimates (β) and the odds of choosing one option over an alternative. Trade-offs between attributes

  19. PREVENCION DE VIH PARA MUJERES HISPANAS DE 50 AÑOS Y MÁS

    PubMed Central

    Villegas, N.; Cianelli, R.; Ferrer, L.; Kaelber, L.; Peragallo, N.; Yaya, Alexandra O.

    2012-01-01

    Introducción Las mujeres Hispanas de 50 años y más (MHC) son una minoría en Estados Unidos que está a elevado riesgo de adquirir VIH y son el grupo menos estudiado en lo que respecta a salud, características sociales y de comportamiento sexual. Objetivo Investigar los factores que incrementan el riesgo de VIH en las MHC con el propósito de desarrollar o adaptar una intervención apropiada para la “edad y la cultura "de este grupo de mujeres. Metodología Estudio descriptivo de corte transversal con una muestra de 50 MHC, sexualmente activas y que residían en Miami, Florida, Estados Unidos. Se utilizó un cuestionario estructurado administrado por entrevistadores entrenados y bilingües (inglés/español). Las participantes fueron reclutadas en diferentes lugares en el Sur de Florida. Para el análisis de los datos se utilizó estadística descriptiva, tanto medidas de tendencia central como medidas de dispersión. Resultados La edad promedio de las MHC fue de 55,7 ± 6 años (rango 50–76 años). Todas las MHC estaban en la menopausia. Prevención del VIH Las MHC reportaron niveles medios de conocimientos sobre VIH y comunicación con la pareja. En la muestra se reportó la presencia de síntomas depresivos, violencia en la pareja, actitudes negativas hacia las personas viviendo con VIH y baja percepción de riesgo de adquirir VIH. Las MHC mencionaron necesidades de aprendizaje en tópicos relacionados con prevención de VIH y cambios de la edad. Conclusión Las MHC están a riesgo de adquirir VIH y tienen necesidades especiales en términos de educación sobre prevención de VIH. PMID:25242862

  20. Desarrollo curricular, conciencia ambiental y tecnologia para estudiantes de intermedia: Una investigacion en accion

    NASA Astrophysics Data System (ADS)

    Rodriguez Ramos, Teresita

    Se llevó a cabo una investigación en acción con los propósitos de 1) documentar las relaciones de las tecnologías de la información y la comunicación en las clases de ciencias de escuela intermedia como elemento de apoyo cuando se aborda el tema ambiental y sus conceptos pertinentes, a partir de las observaciones de la investigadora, así como las entrevistas y diarios reflexivos de los estudiantes de una escuela intermedia en la zona metropolitana, y luego 2) diseñar una unidad instruccional sobre el tema ambiental que integre actividades tecnologías para el curso de ciencias de la escuela intermedia según el modelo PROCIC y las observaciones que hayan iniciado los estudiantes participantes. Finalmente, se plantearon las implicaciones educativas para el currículo del Programa de Ciencias al instrumentar este modelo de unidad mediante PROCIC, e integrado la tecnología y el tema ambiental. Los hallazgos se analizaron y se categorizaron de acuerdo con las preguntas de investigación. El hallazgo principal de la investigación aborda las cuatro relaciones centrales en las que se articula la utilización de las tecnologías y sus aplicaciones en la clase de ciencias. Estas cuatro relaciones que recogen la posición de los estudiantes son: 1) Perspectiva de los estudiantes hacia la tecnología. 2) Participación de los estudiantes en los aspectos docentes. 3) Aprendizaje estudiantil sobre el ambiente, y 4) Conciencia ambiental en relación con la vida diaria. Estas relaciones ponen de manifiesto,cómo se plantea en las implicaciones, la necesidad de más investigación en acción en la sala de clases, la importancia—como tema transversal—de la conciencia ambiental mediante la tecnología al construir conocimientos significativos dentro y fuera de la escuela, asó como, valorar la investigación y la dialogicidad en la sala de clases como actividades que obligan al reexamen de la práctica didáctica en su formas curriculares de objetivos, recursos

  1. Positive Pacing Strategies Are Utilized by Elite Male and Female Para-cyclists in Short Time Trials in the Velodrome

    PubMed Central

    Wright, Rachel L.

    2016-01-01

    In para-cycling, competitors are classed based on functional impairment resulting in cyclists with neurological and locomotor impairments competing against each other. In Paralympic competition, classes are combined by using a factoring adjustment to race times to produce the overall medallists. Pacing in short-duration track cycling events is proposed to utilize an “all-out” strategy in able-bodied competition. However, pacing in para-cycling may vary depending on the level of impairment. Analysis of the pacing strategies employed by different classification groups may offer scope for optimal performance; therefore, this study investigated the pacing strategy adopted during the 1-km time trial (TT) and 500-m TT in elite C1 to C3 para-cyclists and able-bodied cyclists. Total times and intermediate split times (125-m intervals; measured to 0.001 s) were obtained from the C1-C3 men's 1-km TT (n = 28) and women's 500-m TT (n = 9) from the 2012 Paralympic Games and the men's 1-km TT (n = 19) and women's 500-m TT (n = 12) from the 2013 UCI World Track Championships from publically available video. Split times were expressed as actual time, factored time (for the para-cyclists) and as a percentage of total time. A two-way analysis of variance was used to investigate differences in split times between the different classifications and the able-bodied cyclists in the men's 1-km TT and between the para-cyclists and able-bodied cyclists in the women's 500-m TT. The importance of position at the first split was investigated with Kendall's Tau-b correlation. The first 125-m split time was the slowest for all cyclists, representing the acceleration phase from a standing start. C2 cyclists were slowest at this 125-m split, probably due to a combination of remaining seated in this acceleration phase and a high proportion of cyclists in this group being trans-femoral amputees. Not all cyclists used aero-bars, preferring to use drop, flat or bullhorn handlebars. Split times

  2. Usina de ciências: um espaço pedagógico para aprendizagens múltiplas

    NASA Astrophysics Data System (ADS)

    Martin, V. A. F.; Poppe, P. C. R.; Orrico, A. C. P.; Pereira, M. G.

    2003-08-01

    Entendemos que o Ensino de Astronomia é especialmente apropriado para motivar os alunos e aprofundar conteúdos em diversas áreas do conhecimento, pois envolve temas ligados à Física, Matemática, Química, Computação, Tratamento de Imagens e Instrumentação de Alta Precisão, além daqueles pertinentes as áreas de Geografia, História e Antropologia. Contudo, apesar do caráter interdisciplinar que esta ciência possui, a realidade atual é que a maioria dos professores em sala de aula não foram devidamente capacitados, durante o período de formação acadêmica, para ministrar conteúdos de Astronomia nos atuais Ensinos Fundamental e Médio. Neste trabalho, discutiremos de maneira ampla, num primeiro momento, a realidade do atual ensino de ciências praticado no Estado da Bahia, apontando por dependência administrativa, o crescimento e a redução do número de escolas, da taxa de analfabetismo por faixa etária, da escolarização, do atendimento, da aprovação, reprovação e abandono, de equipamentos e laboratórios e o grau de formação dos nossos atuais professores em pleno exercício de atividade docente. Num segundo momento, discutiremos o papel do Observatório Astronômico Antares/UEFS dentro desse contexto, ou seja, suas ações implementadas ao longo dos últimos anos e em particular, o recente projeto de extensão Ensino e Difusão de Astronomia, financiado pela Fundação Vitae, que procura traduzir no lúdico, no brincar de ciências, um espaço pedagógico para aprendizagens múltiplas. Neste, o papel do professor multiplicador associado ao laboratório de kits didáticos, de fácil construção e manipulação (alguns dos quais serão mostrados), perfazem os principais veículos para o desenvolvimento de conhecimentos, atitudes, habilidades e valores que preparam os nossos alunos para a carreira técnico-científica e para sua participação crítica e criativa na Sociedade.

  3. Positive Pacing Strategies Are Utilized by Elite Male and Female Para-cyclists in Short Time Trials in the Velodrome.

    PubMed

    Wright, Rachel L

    2015-01-01

    In para-cycling, competitors are classed based on functional impairment resulting in cyclists with neurological and locomotor impairments competing against each other. In Paralympic competition, classes are combined by using a factoring adjustment to race times to produce the overall medallists. Pacing in short-duration track cycling events is proposed to utilize an "all-out" strategy in able-bodied competition. However, pacing in para-cycling may vary depending on the level of impairment. Analysis of the pacing strategies employed by different classification groups may offer scope for optimal performance; therefore, this study investigated the pacing strategy adopted during the 1-km time trial (TT) and 500-m TT in elite C1 to C3 para-cyclists and able-bodied cyclists. Total times and intermediate split times (125-m intervals; measured to 0.001 s) were obtained from the C1-C3 men's 1-km TT (n = 28) and women's 500-m TT (n = 9) from the 2012 Paralympic Games and the men's 1-km TT (n = 19) and women's 500-m TT (n = 12) from the 2013 UCI World Track Championships from publically available video. Split times were expressed as actual time, factored time (for the para-cyclists) and as a percentage of total time. A two-way analysis of variance was used to investigate differences in split times between the different classifications and the able-bodied cyclists in the men's 1-km TT and between the para-cyclists and able-bodied cyclists in the women's 500-m TT. The importance of position at the first split was investigated with Kendall's Tau-b correlation. The first 125-m split time was the slowest for all cyclists, representing the acceleration phase from a standing start. C2 cyclists were slowest at this 125-m split, probably due to a combination of remaining seated in this acceleration phase and a high proportion of cyclists in this group being trans-femoral amputees. Not all cyclists used aero-bars, preferring to use drop, flat or bullhorn handlebars. Split times

  4. Adapting a Common Photographic Camera to Take Pictures of the Sky. (Spanish Title: Adaptando Una Camara Fotografica Comun Para Obtener Fotografias del Cielo.) Adaptando Uma Câmera Fotográfica Manual Simples Para Fotografar o Céu

    NASA Astrophysics Data System (ADS)

    Danhoni Neves, Marcos Cesar; Pereira, Ricardo Francisco

    2007-12-01

    In this paper will be introduced a method of astrophotography using a non-reflex photographic camera (a low-cost method). It will be revised some photographic processes commonly used nowadays for comparison with the aims of this paper. En este trabajo será introducido un método de astrofotografia que utiliza una cámara fotográfica non-reflex (un método de bajo costo). Serán revisados algunos procesos fotográficos comúnmente utilizados actualmente para comparación con los objetivos de este trabajo. O presente artigo procura introduzir um método de astrofotografia utilizando uma câmera fotográfica não reflex, de baixo custo. É feita uma revisão do processo fotográfico comumente empregado para fins de comparação com os objetivos pretendidos no presente trabalho.

  5. Para-toluenesulfonamide induces tongue squamous cell carcinoma cell death through disturbing lysosomal stability.

    PubMed

    Liu, Zhe; Liang, Chenyuan; Zhang, Zhuoyuan; Pan, Jian; Xia, Hui; Zhong, Nanshan; Li, Longjiang

    2015-11-01

    Para-toluenesulfonamide (PTS) has been implicated with anticancer effects against a variety of tumors. In the present study, we investigated the inhibitory effects of PTS on tongue squamous cell carcinoma (Tca-8113) and explored the lysosomal and mitochondrial changes after PTS treatment in vitro. High-performance liquid chromatography showed that PTS selectively accumulated in Tca-8113 cells with a relatively low concentration in normal fibroblasts. Next, the effects of PTS on cell viability, invasion, and cell death were determined. PTS significantly inhibited Tca-8113 cells' viability and invasive ability with increased cancer cell death. Flow cytometric analysis and the lactate dehydrogenase release assay showed that PTS induced cancer cell death by activating apoptosis and necrosis simultaneously. Morphological changes, such as cellular shrinkage, nuclear condensation as well as formation of apoptotic body and secondary lysosomes, were observed, indicating that PTS might induce cell death through disturbing lysosomal stability. Lysosomal integrity assay and western blot showed that PTS increased lysosomal membrane permeabilization associated with activation of lysosomal cathepsin B. Finally, PTS was shown to inhibit ATP biosynthesis and induce the release of mitochondrial cytochrome c. Therefore, our findings provide a novel insight into the use of PTS in cancer therapy. PMID:26302210

  6. Para-dichlorobenzene toxicity – a review of potential neurotoxic manifestations

    PubMed Central

    Dubey, Divyanshu; Sharma, Vibhash D.; Pass, Steven E.; Sawhney, Anshudha

    2014-01-01

    Background: Para-dichlorobenzene (PDCB) is an active ingredient of mothballs, deodorizers and fumigants. Due to the easy availability of this chemical, there is a considerable risk for accidental or intentional toxic exposure. Recently, multiple cases of PDCB toxicity due to mothball ingestion were reported. PDCB toxicity can affect multiple organ systems including liver, kidneys, skin, lung and the central nervous system (CNS). CNS toxicity often results in leukoencephalopathy and heterogeneous neurological manifestations. Objectives: The objective of this study was to illustrate the clinical presentation, imaging findings, diagnosis and management of PDCB toxicity. Methods: We carried out a literature review of the pharmacological and toxicological properties of PDCB. Conclusions: PDCB and other aromatic hydrocarbons are capable of CNS tissue damage and in promoting functional neurological decline. While very little is currently known about prevalence of PDCB addiction, it cannot be ruled out that its illicit use among young people is under-recognized. The number of cases of PDCB toxicity might also rise due to the increasing industrial and domestic use of this chemical. PMID:24790648

  7. Para-Phenylenediamine Induces Apoptotic Death of Melanoma Cells and Reduces Melanoma Tumour Growth in Mice.

    PubMed

    Bhowmick, Debajit; Bhar, Kaushik; Mallick, Sanjaya K; Das, Subhadip; Chatterjee, Nabanita; Sarkar, Tuhin Subhra; Chakrabarti, Rajarshi; Das Saha, Krishna; Siddhanta, Anirban

    2016-01-01

    Melanoma is one of the most aggressive forms of cancer, usually resistant to standard chemotherapeutics. Despite a huge number of clinical trials, any success to find a chemotherapeutic agent that can effectively destroy melanoma is yet to be achieved. Para-phenylenediamine (p-PD) in the hair dyes is reported to purely serve as an external dyeing agent. Very little is known about whether p-PD has any effect on the melanin producing cells. We have demonstrated p-PD mediated apoptotic death of both human and mouse melanoma cells in vitro. Mouse melanoma tumour growth was also arrested by the apoptotic activity of intraperitoneal administration of p-PD with almost no side effects. This apoptosis is shown to occur primarily via loss of mitochondrial membrane potential (MMP), generation of reactive oxygen species (ROS), and caspase 8 activation. p-PD mediated apoptosis was also confirmed by the increase in sub-G0/G1 cell number. Thus, our experimental observation suggests that p-PD can be a potential less expensive candidate to be developed as a chemotherapeutic agent for melanoma. PMID:27293892

  8. Long-Range Ruthenium-Amine Electronic Communication through the para-Oligophenylene Wire

    PubMed Central

    Shen, Jun-Jian; Zhong, Yu-Wu

    2015-01-01

    The studies of long-range electronic communication are hampered by solubility and potential-splitting issues. A “hybridized redox-asymmetry” method using a combination of organic and inorganic redox species is proposed and exemplified to overcome these two issues. Complexes 1(PF6)–6(PF6) (from short to long in length) with the organic redox-active amine and inorganic cyclometalated ruthenium termini bridged by the para-oligophenylene wire have been prepared. Complex 6 has the longest Ru-amine geometrical distance of 27.85 Å. Complexes 3(PF6) and 4(PF6) show lamellar crystal packing on the basis of a head-to-tail anti-parallelly aligned dimeric structure. Two redox waves are observed for all complexes in the potential region between +0.2 and +0.9 V vs Ag/AgCl. The electrochemical potential splitting is 410, 220, 143, 112, 107, and 105 mV for 1(PF6) through 6(PF6), respectively. Ruthenium (+2) to aminium (N•+) charge transfer transitions have been identified for the odd-electron compounds 12+–62+ by spectroelectrochemical measurements. The electronic communication between amine and ruthenium decreases exponentially with a decay slope of −0.137 Å−1. DFT calculations have been performed to complement these experimental results. PMID:26344929

  9. Ab initio study of vibrational anharmonic coupling effects in oligo(para-phenylenes)

    NASA Astrophysics Data System (ADS)

    Heimel, G.; Somitsch, D.; Knoll, P.; Zojer, E.

    2002-06-01

    In this work, we clarify the nature of a previously not precisely identified Fermi dyad in the frequency range around 1600 cm-1 in oligo( para-phenylenes). To this end, we deploy a novel method to calculate third order anharmonic coupling effects in molecules. This Fermi dyad is shown to yield important information on the structural properties of the investigated materials. The nature of all vibrations contributing to this quantum mechanical resonance phenomenon is explained on the basis of a detailed normal coordinate analysis. The anharmonic coupling is then closely investigated by applying our theoretical model. In particular, we discuss the intensity redistribution among the two components of the Fermi doublet as well as their energetic separation. Subsequently, we establish a relation between these features and the structural conformation of the molecules. We show, how oligomer length and planarity of these systems can be determined from experimental Raman spectra by extracting the positions and relative intensities of the two components of the Fermi doublet. Furthermore, this Fermi resonance is shown to be sensitive to chemical modification on the molecules such as deuteration or substitution. Finally, we extend our model to electronically excited states in this class of molecules, as well as to charged species.

  10. Foco Nasmyth para el telescopio 2,15mts. de CASLEO

    NASA Astrophysics Data System (ADS)

    Casagrande, A. R.

    En principio, este proyecto intenta lograr el mayor aprovechamiento posible del instrumental que se dispone, buscando la manera de optimizar y hacer más eficiente el servicio que brinda el CASLEO a la comunidad astronómica. El mismo consiste en utilizar dispositivos ya existentes en el telescopio, y darle una utilidad. Tal es el caso del camino óptico destinado al foco Coude. Si tenemos en cuenta que disponemos de un tercer espejo Coude, con todos sus mecanismos automatizados, (actualmente sin uso), una distancia apropiada del plano focal, el espacio y el lugar físico necesario para instalar un periférico, es posible la habilitación de un foco Nasmyth en el telescopio 2,15mts. El hecho de contar con este nuevo foco, redundará en importantes beneficios. En primer lugar, posibilitará la observación, casi simultánea, con dos instrumentos. Otro aspecto a tener en cuenta, es que disminuirá el frecuente cambio del instrumental periférico, motivo este que degrada su ideal puesta a punto. Por último, también de interés, es de destacar su escaso costo de ejecución.

  11. Health promotion programs related to the Athens 2004 Olympic and Para Olympic games

    PubMed Central

    Soteriades, Elpidoforos S; Hadjichristodoulou, Christos; Kremastinou, Jeni; Chelvatzoglou, Fotini C; Minogiannis, Panagiotis S; Falagas, Matthew E

    2006-01-01

    Background The Olympic Games constitute a first-class opportunity to promote athleticism and health messages. Little is known, however on the impact of Olympic Games on the development of health-promotion programs for the general population. Our objective was to identify and describe the population-based health-promotion programs implemented in relation to the Athens 2004 Olympic and Para Olympic Games. Methods A cross-sectional survey of all stakeholders of the Games, including the Athens 2004 Organizing Committee, all ministries of the Greek government, the National School of Public Health, all municipalities hosting Olympic events and all official private sponsors of the Games, was conducted after the conclusion of the Games. Results A total of 44 agencies were surveyed, 40 responded (91%), and ten (10) health-promotion programs were identified. Two programs were implemented by the Athens 2004 Organizing Committee, 2 from the Greek ministries, 2 from the National School of Public Health, 1 from municipalities, and 3 from official private sponsors of the Games. The total cost of the programs was estimated at 943,000 Euros; a relatively small fraction (0.08%) of the overall cost of the Games. Conclusion Greece has made a small, however, significant step forward, on health promotion, in the context of the Olympic Games. The International Olympic Committee and the future hosting countries, including China, are encouraged to elaborate on this idea and offer the world a promising future for public health. PMID:16504120

  12. ParaText : scalable solutions for processing and searching very large document collections : final LDRD report.

    SciTech Connect

    Crossno, Patricia Joyce; Dunlavy, Daniel M.; Stanton, Eric T.; Shead, Timothy M.

    2010-09-01

    This report is a summary of the accomplishments of the 'Scalable Solutions for Processing and Searching Very Large Document Collections' LDRD, which ran from FY08 through FY10. Our goal was to investigate scalable text analysis; specifically, methods for information retrieval and visualization that could scale to extremely large document collections. Towards that end, we designed, implemented, and demonstrated a scalable framework for text analysis - ParaText - as a major project deliverable. Further, we demonstrated the benefits of using visual analysis in text analysis algorithm development, improved performance of heterogeneous ensemble models in data classification problems, and the advantages of information theoretic methods in user analysis and interpretation in cross language information retrieval. The project involved 5 members of the technical staff and 3 summer interns (including one who worked two summers). It resulted in a total of 14 publications, 3 new software libraries (2 open source and 1 internal to Sandia), several new end-user software applications, and over 20 presentations. Several follow-on projects have already begun or will start in FY11, with additional projects currently in proposal.

  13. Development and Validation of the Escala de Actitudes Emprendedoras para Estudiantes (EAEE).

    PubMed

    Oliver, Amparo; Galiana, Laura

    2015-01-01

    During the last few years, entrepreneurship has gained an important role in many economic and social policies, with the consequent growth of entrepreneurial research in many social areas. However, in the Spanish psychometric context, there is not an updated scale including recent contributions to entrepreneurship attitudes literature. The aim of this study is to present and validate a new scale named Escala de Actitudes Emprendedoras para Estudiantes-EAEE, (Entrepreneurial Attitudes Scale for Students, EASS), in two samples of high school and university Spanish students. Data comes from a cross-sectional survey of 524 high school and undergraduate students, from Valencia (Spain). Two confirmatory factor analyses (CFAs) were estimated, together with reliability and validity evidence of the scale. Results offered evidence of the adequate psychometric properties of the EASS. The CFAs showed overall and analytical adequate fit indexes (χ 2 (120) = 163.19 (p < .01), GFI = .906, CFI = .959, SRMR = .044, RMSEA = .040 [CI .022-.054]); reliability indices of the entrepreneurial attitudes were appropriate for most of the entrepreneurial attitudes (α were between .63 and .87 for the different dimensions); and external evidence relating entrepreneurial dimensions to personality traits was similar to in previous studies. The scale could be a useful instrument both for previous diagnosis and effectiveness assessment of programs on entrepreneurship promotion. PMID:26055696

  14. Analysis of passive motion of para- and retropharyngeal structures during swallowing using dynamic magnetic resonance imaging.

    PubMed

    Chitose, Shun-ichi; Haraguchi, Masahiro; Nagata, Shuji; Katayama, Reiji; Sato, Kiminori; Fukahori, Mioko; Sueyoshi, Shintaro; Kurita, Takashi; Abe, Toshi; Nakashima, Tadashi

    2014-06-01

    The purpose of this study was to analyze passive motion of the para- and retropharyngeal space (PRS) during swallowing using dynamic magnetic resonance imaging (MRI). We conducted a preliminary study involving 30 healthy volunteers who underwent dynamic MRI. Consecutive MRI axial images were obtained by examining the plane parallel to the hard palate at the level of the anterior inferior corner of C2. Anterior displacement of the posterior pharyngeal wall (PPW) was measured as a motion index of pharyngeal contraction. The displacement and internal angle of the bilateral external and internal carotid arteries (ECA and ICA) and the bilateral centroids of the PRS area, as well as the increase in PRS area, were calculated at rest and at maximum pharyngeal contraction. In most participants, the bilateral ECA, ICA, and centroids were anterointernally displaced by pharyngeal contraction. The normalized ECA displacement (r = 0.64, r (2) = 0.41), normalized ICA displacement (r = 0.60, r (2) = 0.37), and normalized centroid displacement (r = 0.43, r (2) = 0.19) were more than moderately positively correlated with the normalized PPW displacement. The normalized PRS area increase (r = 0.35, r (2) = 0.12) was weakly positively correlated with the normalized PPW displacement. These results revealed that PRS area increased as the ECA and ICA were drawn anterointernally via its passive motion by pharyngeal contraction. PMID:24859486

  15. Polycrystalline para-terphenyl scintillator adopted in a β- detecting probe for radio-guided surgery

    NASA Astrophysics Data System (ADS)

    Solfaroli Camillocci, E.; Bellini, F.; Bocci, V.; Collamati, F.; De Lucia, E.; Faccini, R.; Marafini, M.; Mattei, I.; Morganti, S.; Paramatti, R.; Patera, V.; Pinci, D.; Recchia, L.; Russomando, A.; Sarti, A.; Sciubba, A.; Senzacqua, M.; Voena, C.

    2015-06-01

    A radio-guided surgery technique exploiting β- emitters is under development. It aims at a higher target-to-background activity ratio implying both a smaller radiopharmaceutical activity and the possibility of extending the technique to cases with a large uptake of surrounding healthy organs. Such technique requires a dedicated intraoperative probe detecting β- radiation. A first prototype has been developed relying on the low density and high light yield of the diphenylbutadiene doped para-therphenyl organic scintillator. The scintillation light produced in a cylindrical crystal, 5 mm in diameter and 3 mm in height, is guided to a photo-multiplier tube by optical fibres. The custom readout electronics is designed to optimize its usage in terms of feedback to the surgeon, portability and remote monitoring of the signal. Tests show that with a radiotracer activity comparable to those administered for diagnostic purposes the developed probe can detect a 0.1 ml cancerous residual of meningioma in a few seconds.

  16. Crystal structures of supramolecular assemblies based on a para-dicyclohexanocucurbit[6]uil with metal ions

    NASA Astrophysics Data System (ADS)

    Qin, Xiao; Chen, Wen-Jian; Zhang, Yun-Qian; Zhu, Qian-Jiang; Xue, Sai-Feng; Tao, Zhu

    2011-06-01

    Five crystals based on para-dicyclohexanocucurbit[6]uil (DCyHQ[6]) were synthesized and structurally characterized by single-crystal X-ray diffractions. They are {Dioxane@DCyHQ[6]}·18H 2O ( 1), {[Cu(HO)6]2DCyHQ[6]}·2SO42-·10HO ( 2), {[Zn(HO)6]2DCyHQ[6]}·2SO42-·10HO ( 3), {[Sr(HO)5]2DCyHQ[6]}·5Cl·(HO)+·8HO ( 4), {[Na(HO)4]2DCyHQ[6]}·4Br·2(HO)+·14HO ( 5). The compound 1 which is a dioxane @DCyHQ[6] inclusion host-guest complex; the other three crystal structures of the compounds 2, 3 and 4 show supramolecular assemblies comprising of DCyHQ[6] and metal ions or their aqueous complexes through hydrogen bonding; while the crystal structure of the compound 5 shows a one-dimensional supramolecular polymer through direct coordination of sodium cations to the portal carbonyl oxygen atoms of the DCyHQ[6].

  17. Mycobacterium tuberculosis Folate Metabolism and the Mechanistic Basis for para-Aminosalicylic Acid Susceptibility and Resistance

    PubMed Central

    Minato, Yusuke; Thiede, Joshua M.; Kordus, Shannon Lynn; McKlveen, Edward J.; Turman, Breanna J.

    2015-01-01

    para-Aminosalicylic acid (PAS) entered clinical use in 1946 as the second exclusive drug for the treatment of tuberculosis (TB). While PAS was initially a first-line TB drug, the introduction of more potent antitubercular agents relegated PAS to the second-line tier of agents used for the treatment of drug-resistant Mycobacterium tuberculosis infections. Despite the long history of PAS usage, an understanding of the molecular and biochemical mechanisms governing the susceptibility and resistance of M. tuberculosis to this drug has lagged behind that of most other TB drugs. Herein, we discuss previous studies that demonstrate PAS-mediated disruption of iron acquisition, as well as recent genetic, biochemical, and metabolomic studies that have revealed that PAS is a prodrug that ultimately corrupts one-carbon metabolism through inhibition of the formation of reduced folate species. We also discuss findings from laboratory and clinical isolates that link alterations in folate metabolism to PAS resistance. These advancements in our understanding of the basis of the susceptibility and resistance of M. tuberculosis to PAS will enable the development of novel strategies to revitalize this and other antimicrobial agents for use in the global effort to eradicate TB. PMID:26033719

  18. LabVIEW-based control software for para-hydrogen induced polarization instrumentation

    SciTech Connect

    Agraz, Jose Grunfeld, Alexander; Li, Debiao; Cunningham, Karl; Willey, Cindy; Pozos, Robert; Wagner, Shawn

    2014-04-15

    The elucidation of cell metabolic mechanisms is the modern underpinning of the diagnosis, treatment, and in some cases the prevention of disease. Para-Hydrogen induced polarization (PHIP) enhances magnetic resonance imaging (MRI) signals over 10 000 fold, allowing for the MRI of cell metabolic mechanisms. This signal enhancement is the result of hyperpolarizing endogenous substances used as contrast agents during imaging. PHIP instrumentation hyperpolarizes Carbon-13 ({sup 13}C) based substances using a process requiring control of a number of factors: chemical reaction timing, gas flow, monitoring of a static magnetic field (B{sub o}), radio frequency (RF) irradiation timing, reaction temperature, and gas pressures. Current PHIP instruments manually control the hyperpolarization process resulting in the lack of the precise control of factors listed above, resulting in non-reproducible results. We discuss the design and implementation of a LabVIEW based computer program that automatically and precisely controls the delivery and manipulation of gases and samples, monitoring gas pressures, environmental temperature, and RF sample irradiation. We show that the automated control over the hyperpolarization process results in the hyperpolarization of hydroxyethylpropionate. The implementation of this software provides the fast prototyping of PHIP instrumentation for the evaluation of a myriad of {sup 13}C based endogenous contrast agents used in molecular imaging.

  19. Porous poly(para-phenylene) scaffolds for load-bearing orthopedic applications.

    PubMed

    DiRienzo, Amy L; Yakacki, Christopher M; Frensemeier, Mareike; Schneider, Andreas S; Safranski, David L; Hoyt, Anthony J; Frick, Carl P

    2014-02-01

    The focus of this study was to fabricate and investigate the mechanical behavior of porous poly(para-phenylene) (PPP) for potential use as a load-bearing orthopedic biomaterial. PPPs are known to have exceptional mechanical properties due to their aromatic backbone; however, the manufacturing and properties of PPP porous structures have not been previously investigated. Tailored porous structures with either small (150-250µm) or large (420-500µm) pore sizes were manufactured using a powder-sintering/salt-leaching technique. Porosities were systematically varied using 50 to 90vol%. Micro-computed tomography (µCT) and scanning electron microscopy (SEM) were used to verify an open-cell structure and investigate pore morphology of the scaffolds. Uniaxial mechanical behavior of solid and porous PPP samples was characterized through tensile and compressive testing. Both modulus and strength decreased with increasing porosity and matched well with foam theory. Porous scaffolds showed a significant decrease in strain-to-failure (<4%) under tensile loading and experienced linear elasticity, plastic deformation, and densification under compressive loading. Over the size ranges tested, pore size did not significantly influence the mechanical behavior of the scaffolds on a consistent basis. These results are discussed in regards to use of porous PPP for orthopedic applications and a prototype porous interbody fusion cage is presented. PMID:24374261

  20. Theoretical study of para-nitro-aniline adsorption on the Au(111) surface

    NASA Astrophysics Data System (ADS)

    Li, Cui; Monti, Susanna; Li, Xin; Rinkevicius, Zilvinas; Ågren, Hans; Carravetta, Vincenzo

    2016-07-01

    The electronic structure, bonding properties and dynamics of para-nitro-aniline (PNA) adsorbed on the Au(111) surface for a sub-monolayer coverge have been investigated by density-functional theory (DFT) static calculations and quantum molecular dynamics simulations. Four main adsorption geometries have been identified by DFT energy optimization with the gradient corrected PBE functional and accounting for the role of the van del Waals (vdW) interaction. Quantum dynamics calculations starting from the four different structures have been performed at room temperature to estimate the relative stability of the adsorbates and the presence of barriers for their interconversion. Quantum simulations suggest that the most stable adsorption geometry at room temperature is that of PNA with a slightly distorted molecular plane almost parallel to the Au(111) surface. In a second less populated configuration the PNA molecule interacts with the substrate by its NO2 group while the molecular plane is orthogonal to the surface. The N 1s electron photoemission spectrum has been simulated for the identified adsorbate geometries and a measurable variation of the absolute and relative chemical shift for the two nitrogen atoms in comparison with the known values for PNA in gas phase is predicted.

  1. Performance of three different anodes in electrochemical degradation of 4-para-nitrophenol.

    PubMed

    Murugaesan, Pramila; Aravind, Priyadharshini; Muniyandi, Neelavannan Guruswamy; Kandasamy, Subramanian

    2015-01-01

    In recent years, removal of pollutants from wastewater by electrochemical oxidation has become an attractive method. The present investigation deals with the degradation of 4-para-nitrophenol (4-PNP) by electrochemical oxidation using three different anodes, namely TiO2-RuO2-IrO2/Ti (titanium substrate insoluble anode - TSIA)), IrO2-PbO2/Ti and graphite. Electrochemical oxidation of 4-PNP was carried out employing sodium chloride as the supporting electrolyte, at pH 7 with a current density of 15 mA/cm(2). The degradation of 4-PNP by electro-oxidation was characterized by ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy and high-performance liquid chromatography. The performance efficiency and current efficiency of the three anodic materials in this study were evaluated by chemical oxygen demand (COD). Comparisons of energy consumption for the three anodes employed were also calculated. Among electrodes investigated, the IrO2-PbO2/Ti electrode resulted in 98% of COD removal in 30 min comparatively at a less energy consumption of 1 × 10(-2) kWh m(-3), depicting its higher performance efficiency in 4-PNP degradation. PMID:25885262

  2. Origin of the low-energy emission band in epitaxially grown para-sexiphenyl nanocrystallites

    NASA Astrophysics Data System (ADS)

    Kadashchuk, A.; Schols, S.; Heremans, P.; Skryshevski, Yu.; Piryatinski, Yu.; Beinik, I.; Teichert, C.; Hernandez-Sosa, G.; Sitter, H.; Andreev, A.; Frank, P.; Winkler, A.

    2009-02-01

    A comparative study of steady-state and time-resolved photoluminescence of para-sexiphenyl (PSP) films grown by organic molecular beam epitaxy (OMBE) and hot wall epitaxy (HWE) under comparable conditions is presented. Using different template substrates [mica(001) and KCl(001) surfaces] as well as different OMBE growth conditions has enabled us to vary greatly the morphology of the PSP crystallites while keeping their chemical structure virtually untouched. We prove that the broad redshifted emission band has a structure-related origin rather than being due to monomolecular oxidative defects. We conclude that the growth conditions and type of template substrate impacts substantially on the film morphology (measured by atomic force microscopy) and emission properties of the PSP films. The relative intensity of the defect emission band observed in the delayed spectra was found to correlate with the structural quality of PSP crystallites. In particular, the defect emission has been found to be drastically suppressed when (i) a KCl template substrate was used instead of mica in HWE-grown films, and (ii) in the OMBE-grown films dominated by growth mounds composed of upright standing molecules as opposed to the films consisting of crystallites formed by molecules lying parallel to the substrate.

  3. LabVIEW-based control software for para-hydrogen induced polarization instrumentation

    NASA Astrophysics Data System (ADS)

    Agraz, Jose; Grunfeld, Alexander; Li, Debiao; Cunningham, Karl; Willey, Cindy; Pozos, Robert; Wagner, Shawn

    2014-04-01

    The elucidation of cell metabolic mechanisms is the modern underpinning of the diagnosis, treatment, and in some cases the prevention of disease. Para-Hydrogen induced polarization (PHIP) enhances magnetic resonance imaging (MRI) signals over 10 000 fold, allowing for the MRI of cell metabolic mechanisms. This signal enhancement is the result of hyperpolarizing endogenous substances used as contrast agents during imaging. PHIP instrumentation hyperpolarizes Carbon-13 (13C) based substances using a process requiring control of a number of factors: chemical reaction timing, gas flow, monitoring of a static magnetic field (Bo), radio frequency (RF) irradiation timing, reaction temperature, and gas pressures. Current PHIP instruments manually control the hyperpolarization process resulting in the lack of the precise control of factors listed above, resulting in non-reproducible results. We discuss the design and implementation of a LabVIEW based computer program that automatically and precisely controls the delivery and manipulation of gases and samples, monitoring gas pressures, environmental temperature, and RF sample irradiation. We show that the automated control over the hyperpolarization process results in the hyperpolarization of hydroxyethylpropionate. The implementation of this software provides the fast prototyping of PHIP instrumentation for the evaluation of a myriad of 13C based endogenous contrast agents used in molecular imaging.

  4. The Protonation Site of para-Dimethylaminobenzoic Acid Using Atmospheric Pressure Ionization Methods

    NASA Astrophysics Data System (ADS)

    Chai, Yunfeng; Weng, Guofeng; Shen, Shanshan; Sun, Cuirong; Pan, Yuanjiang

    2015-04-01

    The protonation site of para-dimethylaminobenzoic acid ( p-DMABA) was investigated using atmospheric pressure ionization methods (ESI and APCI) coupled with collision-induced dissociation (CID), nuclear magnetic resonance (NMR), and computational chemistry. Theoretical calculations and NMR experiments indicate that the dimethyl amino group is the preferred site of protonation both in the gas phase and aqueous solution. Protonation of p-DMABA occurs at the nitrogen atom by ESI independent of the solvents and other operation conditions under typical thermodynamic control. However, APCI produces a mixture of the nitrogen- and carbonyl oxygen-protonated p-DMABA when aprotic organic solvents (acetonitrile, acetone, and tetrahydrofuran) are used, exhibiting evident kinetic characteristics of protonation. But using protic organic solvents (methanol, ethanol, and isopropanol) in APCI still leads to the formation of thermodynamically stable N-protonated p-DMABA. These structural assignments were based on the different CID behavior of the N- and O-protonated p-DMABA. The losses of methyl radical and water are the diagnostic fragmentations of the N- and O-protonated p-DMABA, respectively. In addition, the N-protonated p-DMABA is more stable than the O-protonated p-DMABA in CID revealed by energy resolved experiments and theoretical calculations.

  5. Conformational Analysis of R-(+)-3-METHYLCYCLOPENTANONE by IR Spectroscopy in Para-Hydrogen Crystal

    NASA Astrophysics Data System (ADS)

    Al-Basheer, Watheq; Toh, Shin Yi; Miyazaki, Jun; Momose, Takamasa

    2014-06-01

    Para-hydrogen (pH_2) soft quantum crystal is an ideal isolation matrix due to its impressive intrinsic properties, i.e. its significant lattice constant, large zero-point vibration as well as its ability to repair itself of crystal defects. To investigate molecular conformation of a chiral ketone, IR spectra of R-(+)-3-methylcyclopentanone (R3MCP), hosted in pH_2 crystal, were recorded as a function of sample concentration and host pH_2 crystal temperature over the low deposition range {3.5-6.0K}. IR spectra of R3MCP in pH_2 crystal will be presented and compared against corresponding spectra in Ar matrix as well as IR spectra of the neat crystalline R3MCP at low deposition temperatures. Furthermore, density functional theory calculations of simulated IR spectra for the optimized geometries of R3MCP, equatorial-methyl and axial-methyl conformers are compared against experimental spectra for the purpose of investigating molecular conformation. Upon comparison between theoretical and experimental IR spectra, vibrational modes arising from equatorial and axial conformers have been successfully assigned and related to the individual conformer's structure.

  6. Long-Range Ruthenium-Amine Electronic Communication through the para-Oligophenylene Wire

    NASA Astrophysics Data System (ADS)

    Shen, Jun-Jian; Zhong, Yu-Wu

    2015-09-01

    The studies of long-range electronic communication are hampered by solubility and potential-splitting issues. A “hybridized redox-asymmetry” method using a combination of organic and inorganic redox species is proposed and exemplified to overcome these two issues. Complexes 1(PF6)-6(PF6) (from short to long in length) with the organic redox-active amine and inorganic cyclometalated ruthenium termini bridged by the para-oligophenylene wire have been prepared. Complex 6 has the longest Ru-amine geometrical distance of 27.85 Å. Complexes 3(PF6) and 4(PF6) show lamellar crystal packing on the basis of a head-to-tail anti-parallelly aligned dimeric structure. Two redox waves are observed for all complexes in the potential region between +0.2 and +0.9 V vs Ag/AgCl. The electrochemical potential splitting is 410, 220, 143, 112, 107, and 105 mV for 1(PF6) through 6(PF6), respectively. Ruthenium (+2) to aminium (N•+) charge transfer transitions have been identified for the odd-electron compounds 12+-62+ by spectroelectrochemical measurements. The electronic communication between amine and ruthenium decreases exponentially with a decay slope of -0.137 Å-1. DFT calculations have been performed to complement these experimental results.

  7. Long-Range Ruthenium-Amine Electronic Communication through the para-Oligophenylene Wire.

    PubMed

    Shen, Jun-Jian; Zhong, Yu-Wu

    2015-01-01

    The studies of long-range electronic communication are hampered by solubility and potential-splitting issues. A "hybridized redox-asymmetry" method using a combination of organic and inorganic redox species is proposed and exemplified to overcome these two issues. Complexes 1(PF6)-6(PF6) (from short to long in length) with the organic redox-active amine and inorganic cyclometalated ruthenium termini bridged by the para-oligophenylene wire have been prepared. Complex 6 has the longest Ru-amine geometrical distance of 27.85 Å. Complexes 3(PF6) and 4(PF6) show lamellar crystal packing on the basis of a head-to-tail anti-parallelly aligned dimeric structure. Two redox waves are observed for all complexes in the potential region between +0.2 and +0.9 V vs Ag/AgCl. The electrochemical potential splitting is 410, 220, 143, 112, 107, and 105 mV for 1(PF6) through 6(PF6), respectively. Ruthenium (+2) to aminium (N(•+)) charge transfer transitions have been identified for the odd-electron compounds 1(2+)-6(2+) by spectroelectrochemical measurements. The electronic communication between amine and ruthenium decreases exponentially with a decay slope of -0.137 Å(-1). DFT calculations have been performed to complement these experimental results. PMID:26344929

  8. High performance hybrid supercapacitors by using para-Benzoquinone ionic liquid redox electrolyte

    NASA Astrophysics Data System (ADS)

    Navalpotro, Paula; Palma, Jesús; Anderson, Marc; Marcilla, Rebeca

    2016-02-01

    A solution of 0.4M para-Benzoquinone (p-BQ) in the ionic liquid N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (PYR14TFSI) was used as a redox electrolyte in hybrid supercapacitors. Two carbons with very different textural properties, Pica carbon and Vulcan carbon, were used as electrode material. Electrochemical performance of these energy storage systems was investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge (CD). Unlike SCs with pure IL electrolyte, new battery-like features appeared in the CV curves and CD profiles. This electrochemical performance, associated with the faradaic contribution of the redox electrolyte, results in a significant improvement of the electrochemical performance of the hybrid system. For Vulcan carbon with low specific surface area (SBET = 240 m2 g-1), specific capacitance (Cs) and specific real energy (Ereal) values as high as 70 Fg-1 and 10.3 WhKg-1 were obtained at 5 mAcm-2 with hybrid SC operating at 3 V. This represents an increment of 300% in Cs and Ereal with respect to the SC based on pure PYR14TFSI. For high surface area carbon such as Pica (SBET = 2410 m2g-1), the addition of the redox quinone molecule resulted in a moderate enhancement reaching values of 156 Fg-1 and 30 WhKg-1 under the same experimental conditions (36% and 10% increment, respectively).

  9. Uso de Sustancias en Mujeres con Desventaja Social: Riesgo para el Contagio de VIH/SIDA

    PubMed Central

    Cianelli, R.; Ferrer, L; Bernales, M.; Miner, S.; Irarrázabal, L.; Molina, Y.

    2009-01-01

    Antecedentes La caracterización epidemiológica en Chile apunta a feminización, pauperización y heterosexualización de la epidemia del VIH, lo que implica un mayor riesgo para las mujeres en desventaja social. Si a esto se suma la utilización de sustancias, la vulnerabilidad de este grupo frente al VIH/SIDA aumenta. Objetivo Describir el uso de sustancias en mujeres con desventaja social e identificar factores de riesgo de contagio de VIH, asociados a este consumo. Material y Método 52 mujeres fueron entrevistadas como parte del proyecto “Testeando una intervención en prevención de VIH/SIDA en mujeres chilenas” GRANT # RO1 TW 006977. Se describen variables sociodemográficas y de consumo de sustancias a través de estadísticas descriptivas y se analiza la relación entre variables a través de pruebas de correlación. Resultados Los resultados indican un perfil sociodemográfico que sitúa a las mujeres en situación de vulnerabilidad frente al contagio de VIH/SIDA, con alto índice de uso de sustancias que acentúa el riesgo. Conclusiones Los hallazgos apuntan a la necesidad de considerar intervenciones que se enfoquen en la prevención de VIH en mujeres, abordando los riesgos asociados al consumo de sustancias. PMID:21197380

  10. Para-cresyl sulfate acutely impairs vascular reactivity and induces vascular remodeling.

    PubMed

    Gross, Priscilla; Massy, Ziad A; Henaut, Lucie; Boudot, Cédric; Cagnard, Joanna; March, Cécilia; Kamel, Saïd; Drueke, Tilman B; Six, Isabelle

    2015-12-01

    Chronic kidney disease (CKD) is characterized by vascular remodeling and the retention of uremic toxins, several of which are independently associated with the high cardiovascular mortality rate in CKD patients. Whether the association between these uremic toxins and cardiovascular mortality is due to induction of vascular dysfunction and resulting vascular remodeling remains to be determined. This study evaluates the effects of para-cresyl sulfate (PCS), a newly identified uremic toxin, on vascular function and remodeling. PCS acutely induced oxidative stress in both endothelial and vascular smooth muscle cells, with a maximal effect at 0.15 mM, corresponding to the mean "uremic" concentration found in dialysis patients. PCS significantly increased within 30 min phenylephrine-induced contraction of mouse thoracic aorta, through direct activation of rho-kinase, independently of oxidative stress induction, as demonstrated by the capacity of rho-kinase inhibitor Y-27632 to abolish this effect. After exposure of the aorta to PCS for 48 h, we observed inward eutrophic remodeling, a hallmark of uremic vasculopathy characterized by a reduction of the area of both lumen and media, with unchanged media/lumen ratio. In conclusion, elevated PCS concentrations such as those observed in CKD patients, by promoting both vascular dysfunction and vascular remodeling, may contribute to the development of hypertension and to cardiovascular mortality in CKD. PMID:25899466

  11. Conformation of ionizable poly Para phenylene ethynylene in dilute solutions

    SciTech Connect

    Wijesinghe, Sidath; Maskey, Sabina; Perahia, Dvora; Grest, Gary S.

    2015-11-03

    The conformation of dinonyl poly para phenylene ethynylenes (PPEs) with carboxylate side chains, equilibrated in solvents of different quality is studied using molecular dynamics simulations. PPEs are of interest because of their tunable electro-optical properties, chemical diversity, and functionality which are essential in wide range of applications. The polymer conformation determines the conjugation length and their assembly mode and affects electro-optical properties which are critical in their current and potential uses. The current study investigates the effect of carboxylate fraction on PPEs side chains on the conformation of chains in the dilute limit, in solvents of different quality. The dinonyl PPE chains are modeled atomistically, where the solvents are modeled both implicitly and explicitly. Dinonyl PPEs maintained a stretched out conformation up to a carboxylate fraction f of 0.7 in all solvents studied. The nonyl side chains are extended and oriented away from the PPE backbone in toluene and in implicit good solvent whereas in water and implicit poor solvent, the nonyl side chains are collapsed towards the PPE backbone. Thus, rotation around the aromatic ring is fast and no long range correlations are seen within the backbone.

  12. Testicular toxicity of para-phenylenediamine after subchronic topical application in rat.

    PubMed

    Bharali, Manuj Kr; Dutta, Karabi

    2012-01-01

    Para-phenylenediamine (PPD) is a most widely used chemical in almost all hair dye formulations. The present experiment was conducted in order to assess the reproductive toxicity of PPD in male rats. After sub-chronic topical application of different doses (0, 1, 2 and 3 mg/kg/day) of PPD, the male albino rats exhibited significant decrease in the total sperm count (p<0.05, 0.01) with consistent decrease in the testicular weight (p<0.05), increase in the germ cell apoptosis indicated by cellular morphology as well as loss of germinal layer, sloughing of testicular cellular layers. Elevation of lipid peroxidation product in the testicular tissue indicated the potential oxidative stress that may be crucial in the induction of the apoptosis and further tissue injury in the PPD-treated rats. The study was designed to examine the testicular effect of 1% to 3% PPD which mimic the actual dosage available in most of the hair dying formulation. The possibilities of impaired testicular function after sub-chronic topical exposure to PPD on male rats have demonstrated. PMID:22149045

  13. Hematopathology in Sprague-Dawley rats following sub-chronic topical application of para-phenylenediamine.

    PubMed

    Bharali, Manuj Kr; Dutta, Karabi

    2012-10-01

    The aim of the present study was to analyze the hematological profile of male SD rats treated topically with aqueous solution of para-phenylenediamine (PPD), a component of almost all hair dye formulations. The rats were painted with different concentration of PPD (0, 1, 2 and 3 mg Kg(-1) Day(-1)) for 90 days and then sacrificed. The hematological profile indicated severe anemia characterized by significant (p < 0.05, 0.001) reduction of total RBC count (59%), packed cell volume (PCV, 50%) and haemoglobin level (70%) in the peripheral blood of PPD treated animals when compared to control group. The leucocytes profile exhibited an overall elevation of around twofold as compared to the control group with significant lymphocytosis (44.4%) and a higher percentage of blast cells (8.5%) as well as smudge (10.3%) and hairy cells (6.2%) in the peripheral blood of treated animals. Histopathological examination of spleen from treated rat's exhibit red pulp congestion, expansion of the germinal centre, hyperplasia of the membrane capsule and extensive accumulation of hemosidderin pigments in the red pulp of the spleen. Overall this study indicated an abnormal pathophysiological condition indicating adverse effect of PPD in the treated animal groups. The risk assessment of hair dye formulation needs to be reviewed in view of widespread usage of paraphenylenediamine in almost all hair dye formulation. PMID:22886424

  14. From clusters to fibers: Parameters for discontinuous para-hexaphenylene thin film growth

    SciTech Connect

    Kankate, Laxman; Balzer, Frank; Niehus, Horst; Rubahn, Horst-Guenter

    2008-02-28

    All relevant steps of discontinuous thin film growth of para-hexaphenylene on muscovite mica (0 0 1) from wetting layer over small and large clusters to nanofibers are observed and investigated in detail by a combined polarized fluorescence and atomic force microscopy study. From a variation of film thickness and surface temperature, we determine effective activation energies for cluster growth of 0.17 eV, for nanofiber length growth of 0.46 eV, for width growth of 0.19 eV, and for height growth of 0.07 eV. The corresponding exponential prefactors for the nanofiber growth are 1x10{sup 9}, 6x10{sup 4}, and 3x10{sup 2} nm. Polarized fluorescence studies reveal that nanofibers grow along the grooves of the mica surface and that they do not change direction if they cross an even number of mica surface steps, while they change direction by 120 deg. for an odd number of steps. These results are taken as an input for a model of the unidirectional growth process on mica. Absolute parameters allowing one to grow nanofibers of predetermined morphology via organic molecular beam epitaxy are also given.

  15. Origin of the low-energy emission band in epitaxially grown para-sexiphenyl nanocrystallites

    SciTech Connect

    Kadashchuk, A.; Schols, S.; Heremans, P.; Skryshevski, Yu.; Piryatinski, Yu.; Beinik, I.; Teichert, C.; Hernandez-Sosa, G.; Sitter, H.; Andreev, A.; Frank, P.; Winkler, A.

    2009-02-28

    A comparative study of steady-state and time-resolved photoluminescence of para-sexiphenyl (PSP) films grown by organic molecular beam epitaxy (OMBE) and hot wall epitaxy (HWE) under comparable conditions is presented. Using different template substrates [mica(001) and KCl(001) surfaces] as well as different OMBE growth conditions has enabled us to vary greatly the morphology of the PSP crystallites while keeping their chemical structure virtually untouched. We prove that the broad redshifted emission band has a structure-related origin rather than being due to monomolecular oxidative defects. We conclude that the growth conditions and type of template substrate impacts substantially on the film morphology (measured by atomic force microscopy) and emission properties of the PSP films. The relative intensity of the defect emission band observed in the delayed spectra was found to correlate with the structural quality of PSP crystallites. In particular, the defect emission has been found to be drastically suppressed when (i) a KCl template substrate was used instead of mica in HWE-grown films, and (ii) in the OMBE-grown films dominated by growth mounds composed of upright standing molecules as opposed to the films consisting of crystallites formed by molecules lying parallel to the substrate.

  16. Robotic Transperitoneal Infrarenal Para-Aortic Lymphadenectomy With Double Docking: Technique, Learning Curve, and Perioperative Outcomes.

    PubMed

    Ponce, Jordi; Barahona, Marc; Pla, Maria Jesus; Rovira, Jordi; Garcia-Tejedor, Amparo; Gil-Ibanez, Blanca; Gaspar, Hugo Manuel; Sabria, Enric; Bartolomé, Carlos; Marti, Lola

    2016-01-01

    Para-aortic lymphadenectomy (PAL) is a challenging procedure performed by minimally invasive surgery in very few centers, owing to its intrinsic technical complexity. We describe and assess the feasibility and learning curve of robotic double-docking transperitoneal infrarenal PAL combined with oncological pelvic surgery. Fifty patients who underwent this procedure using the Da Vinci S surgical system between March 2010 and May 2013 were included. The mean operating time for PAL surgery was 76 minutes (range, 32-150 minutes), and the mean number of lymph nodes per patient was 11.8 (range, 1-44). There were no conversions to laparotomy or laparoscopy. The mean length of hospital stay was 2 days (range, 1-25 days). Statistically significant decreases were noted for mean table rotation time (17 ± 6.8 minutes vs 13 ± 3.6 minutes; p = .02) and mean PAL operating time (85.4 ± 25.8 minutes vs 69.8 ± 24.6 minutes; p = .04) when comparing the first 20 patients and the last 30 patients. The number of nodes was similar in the first 20 patients and last 30 patients. The double-docking transperitoneal infrarenal PAL technique combined with oncological pelvic surgery is feasible, with minimal morbidity and a short learning curve. PMID:26898894

  17. Clinical and experimental aspects of allergic contact dermatitis to para-phenylenediamine.

    PubMed

    McFadden, John P; Yeo, Lyndsey; White, Jonathan L

    2011-01-01

    The allergenicity of para-phenylenediamine (PPD) is related to oxidative processes on and in the skin. Patients with stronger reactions to PPD are significantly more likely to have a clear history of reacting to normal consumer hair dye. Those with stronger reactions are much less likely to be still dyeing their hair. Individuals allergic to PPD have a significant frequency of simultaneous sensitivity to chemically related clothing dyes. A 24-hour test application of hair dye, which has been proposed as a self-screen, does not reliably predict all individuals allergic to PPD. Duration studies have proven that exposures of 5 to 30 minutes, the period used for hair dyeing, are sufficient to elicit reactions. A significant rise in the frequency of PPD allergy was observed over 7 years among our patch test population. Active sensitization from standard PPD patch testing is not common. Immunologic findings relating to PPD can correctly predict that if hair dyes are commonly used there will be a significant prevalence of allergy to PPD among the normal adult population and that some clinical reactions will be severe. To protect the public from allergy to chemicals in consumer products, immunologic and epidemiologic data should both be used by regulatory authorities. PMID:21496741

  18. Selective para hydroxylation of phenol and aniline by singlet molecular oxygen.

    PubMed

    Briviba, K; Devasagayam, T P; Sies, H; Steenken, S

    1993-01-01

    Phenol reacts with singlet oxygen (1O2) generated in aqueous solution (H2O or D2O) by (a) the exposure of methylene blue to light or (b) the thermal dissociation of the endoperoxide of 3,3'-(1,4-naphthylidene)dipropionate to lead selectively to hydroquinone as the primary product. The other isomers of phenol hydroxylation, catechol and resorcinol, were not observed. In agreement with the involvement of 1O2 as the reactive species in the hydroxylation, in D2O the yield of hydroquinone is 7 times that in H2O, and the 1O2 quenchers azide and the thiols, glutathione and dithiothreitol, suppress the production of hydroquinone. In contrast, the hydroxyl radical scavengers, tert-butyl alcohol, propanol, or sodium formate, are without effect. In a follow-up reaction, hydroquinone is converted into benzoquinone. Reaction of 1O2 with aniline leads to the selective formation of 4-hydroxyaniline as the initial product. This is further converted to hydroquinone with formation of ammonia (deamination), and then to benzoquinone. On the basis of these results, the selective para hydroxylation of phenol or aniline may be used as an indicator for the involvement of singlet oxygen as compared to .OH radical- or cytochrome P450-mediated reactions. PMID:8374055

  19. Hyperfine excitation of CN by para- and ortho-H2

    NASA Astrophysics Data System (ADS)

    Kalugina, Yulia; Lique, François

    2015-01-01

    Among the interstellar molecules, the CN radical is of particular interest since it is a good probe of cold dark molecular clouds, and especially prestellar cores. Modelling of CN emission spectra from these dense molecular clouds requires the calculation of rate coefficients for excitation by collisions with the most abundant species. We calculate fine- and hyperfine-structure-resolved excitation rate coefficients of CN(X2Σ+) by para- and ortho-H2. The calculations are based on a new potential energy surface obtained recently from highly correlated ab initio calculations. State-to-state rate coefficients between fine and hyperfine levels of CN were calculated for low temperatures ranging from 5 to 100 K. The new results are compared to available CN rate coefficients. Significant differences are found between the different sets of rate coefficients. This comparison shows that the new CN-H2 rate coefficients have to be used for observations interpretations. We expect that their use will help significantly to have a new insight into the physical conditions of prestellar cores.

  20. Geochemical and isotopic constraints on the tectonic setting of Serra dos Carajas belt, eastern Para, Brazil

    NASA Technical Reports Server (NTRS)

    Olszewski, W. J., Jr.; Gibbs, A. K.; Wirth, K. R.

    1986-01-01

    The lower part of the Serra dos Carajas belt is the metavolcanic and metasedimentary Grao para Group (GPG). The GPG is thought to unconformably overlie the older (but undated) Xingu Complex, composed of medium and high-grade gneisses and amphibolite and greenstone belts. The geochemical data indicate that the GPG has many features in common with ancient and modern volcanic suites erupted through continental crust. The mafic rocks clearly differ from those of most Archean greenstone belts, and modern MORB, IAB, and hot-spot basalts. The geological, geochemical, and isotopic data are all consistent with deposition on continental crust, presumably in a marine basin formed by crustal extension. The isotopic data also suggest the existence of depleted mantle as a source for the parent magmas of the GPG. The overall results suggest a tectonic environment, igneous sources, and petrogenesis similar to many modern continental extensional basins, in contrast to most Archean greenstone belts. The Hammersley basin in Australia and the circum-Superior belts in Canada may be suitable Archean and Proterozoic analogues, respectively.

  1. Epidemiology of snakebite accidents in the municipalities of the state of Paraíba, Brazil.

    PubMed

    Leite, Renner de Souza; Targino, Isabely Tamarys Gomes; Lopes, Ysabel Arianne Cordeiro Ferreira; Barros, Rafaella Moreno; Vieira, Alecxandro Alves

    2013-05-01

    Accidents involving venomous animals represent an important, albeit neglected, public health issue worldwide. A descriptive study was made of snakebite cases attended and recorded between 2007 and 2010 in the health units of the municipalities of Cariri, State of Paraíba, northeastern Brazil. Data was collected from the Injury Notification Information System data banks of the Health Ministry and a total of 351 records of snakebite victims were reviewed. Victims were predominantly male farm workers over 50. The highest incidence of snakebites occurred in rural areas, between April and June of 2007 and 2010. Snakes of the genus Bothrops were responsible for most cases, and victims were mostly bitten on the feet. The majority of the victims received medical assistance within 1 to 3 hours after being bitten. The most common clinical manifestations were pain, edema and ecchymosis, which were mainly classified as mild or moderate. Two deaths were reported. It was concluded that there is a significant impact of seasonality in snakebites, the prevalence of attacks caused by Bothrops, affecting the lower limbs of adult male farmers in rural areas. The findings of this study may contribute to identify the conditions that increase the risk of snake attacks in the northeastern region. PMID:23670475

  2. Epidemiology of bee stings in Campina Grande, Paraíba state, Northeastern Brazil

    PubMed Central

    2014-01-01

    Background The present study aims to investigate the clinical-epidemiological characteristics of bee sting cases recorded between 2007 and 2012 in the city of Campina Grande, Paraíba state, Brazil. Data were collected from the database of the Injury Notification Information System of the Brazilian Ministry of Health. Results A total of 459 bee sting cases were retrospectively analyzed. The average annual incidence was 19 cases per 100,000 inhabitants. Cases were distributed in all months of the year, with higher prevalence in September and February. Most victims were men aged between 20 and 29 years. The highest incidence of cases was recorded in urban areas. Victims were stung mainly on the head and torso and received medical assistance predominantly 1 to 3 hours after being stung. The most frequent clinical manifestations were pain, edema and itching. Most cases were classified as mild, and three deaths were reported. Conclusions The high incidence of envenomations provoked by bees in Campina Grande suggests that it may be an important risk area for accidents. Since several medical records lacked information, clinical-epidemiological profile of bee sting cases in the studied region could not be accurately determined. The current study provides relevant data for the development of strategies to promote control and prevention of bee stings in this area. Further training for health professionals seems to be necessary to improve their skills in recording clinical-epidemiological information as well as in treating bee sting victims. PMID:24694193

  3. RNA editing of the Drosophila para Na(+) channel transcript. Evolutionary conservation and developmental regulation.

    PubMed Central

    Hanrahan, C J; Palladino, M J; Ganetzky, B; Reenan, R A

    2000-01-01

    Post-transcriptional editing of pre-mRNAs through the action of dsRNA adenosine deaminases results in the modification of particular adenosine (A) residues to inosine (I), which can alter the coding potential of the modified transcripts. We describe here three sites in the para transcript, which encodes the major voltage-activated Na(+) channel polypeptide in Drosophila, where RNA editing occurs. The occurrence of RNA editing at the three sites was found to be developmentally regulated. Editing at two of these sites was also conserved across species between the D. melanogaster and D. virilis. In each case, a highly conserved region was found in the intron downstream of the editing site and this region was shown to be complementary to the region of the exonic editing site. Thus, editing at these sites would appear to involve a mechanism whereby the edited exon forms a base-paired secondary structure with the distant conserved noncoding sequences located in adjacent downstream introns, similar to the mechanism shown for A-to-I RNA editing of mammalian glutamate receptor subunits (GluRs). For the third site, neither RNA editing nor the predicted RNA secondary structures were evolutionarily conserved. Transcripts from transgenic Drosophila expressing a minimal editing site construct for this site were shown to faithfully undergo RNA editing. These results demonstrate that Na(+) channel diversity in Drosophila is increased by RNA editing via a mechanism analogous to that described for transcripts encoding mammalian GluRs. PMID:10880477

  4. Role of pelvic and para-aortic lymphadenectomy in endometrial cancer: Current evidence

    PubMed Central

    Bogani, Giorgio; Dowdy, Sean C.; Cliby, William A.; Ghezzi, Fabio; Rossetti, Diego; Mariani, Andrea

    2015-01-01

    The aim of the present review is to summarize the current evidence on the role of pelvic and para-aortic lymphadenectomy in endometrial cancer. In 1988, the International Federation of Obstetrics and Gynecology recommended surgical staging for endometrial cancer patients. However, 25 years later, the role of lymph node dissection remains controversial. Although the findings of two large independent randomized trials suggested that pelvic lymphadenectomy provides only adjunctive morbidity with no clear influence on survival outcomes, the studies have many pitfalls that limit interpretation of the results. Theoretically, lymphadenectomy may help identify patients with metastatic dissemination, who may benefit from adjuvant therapy, thus reducing radiation-related morbidity. Also, lymphadenectomy may eradicate metastatic disease. Because lymphatic spread is relatively uncommon, our main effort should be directed at identifying patients who may potentially benefit from lymph node dissection, thus reducing the rate of unnecessary treatment and associated morbidity. This review will discuss the role of lymphadenectomy in endometrial cancer, focusing on patient selection, extension of the surgical procedure, postoperative outcomes, quality of life and costs. The need for new surgical studies and efficacious systemic drugs is recommended. PMID:24472047

  5. Critical point of a para-ferrimagnetic phase transition of the ANNNI model in a field

    NASA Astrophysics Data System (ADS)

    Sznajd, J.

    2012-10-01

    The finite field para-ferrimagnetic phase transition in the axial next-nearest-neighbor Ising (ANNNI) model is studied by using the linear perturbation real space renormalization group transformation. The method is examined in systems of ferromagnetic and antiferromagnetic Ising chains coupled by ferromagnetic interactions in the longitudinal field. As one would expect, the external field in the first case destroys the continuous phase transition and in the second shifts the critical point toward a lower temperature according to the square law. For the ferromagnetic chains coupled by the competing interchain nearest-neighbor J1 < 0 and next-nearest-neighbor J2 < 0 interactions, the external field changes the character of the phase transition from continuous to discontinuous. However, it has been found that for the ratio J2/J1 around 0.5 there is a critical value of the field for which an isolated critical point exists. The temperature dependences of the specific heat for several values of J2/J1 and the external field are presented.

  6. A method to obtain a well-defined fraction of respirable para-aramid fibers.

    PubMed Central

    Schins, R P; Gaudichet, A; Jaurand, M C

    1993-01-01

    We developed a preparation method to obtain respirable-sized fractions of para-aramid fibers. The procedure, based on floatability, consists of stirring and subsequent settling of p-aramid pulp in distilled water. Two distinct phases are obtained, with small fibers in the upper part of the suspension, which represents about 33% of the total volume. Optimal results were obtained when 2.0 g pulp was stirred for 15 hr in 800 ml distilled water containing 0.125% ethanol and settled for 5 hr. The mass yield ranged between 0.4 and 0.6%, more than 90% of the particles had an aspect ratio > or = 3:1. The mean fiber length was about 6 microns, and the mean fiber diameter was about 0.4 microns as determined by transmission and scanning electron microscopy. The number of fibers obtained was 4 x 10(6) fibers/micrograms under our standard conditions. Images p414-a Figure 1. Figure 2. Figure 3. PMID:8119251

  7. Selective plasmon-driven catalysis for para-nitroaniline in aqueous environments

    NASA Astrophysics Data System (ADS)

    Cui, Lin; Wang, Peijie; Li, Yuanzuo; Sun, Mengtao

    2016-02-01

    The plasmon-driven oxidation of amine (-NH2) groups and the reduction of nitro (-NO2) groups on a nanostructured metal surface in an aqueous environment have been reported experimentally and theoretically. The question of which process occurs first in the aqueous environment is an interesting question in the field of plasmon-related photochemistry. Para-nitroaniline (PNA), with both nitro (-NO2) and amine (-NH2) groups, is the best candidate for studying the priority of the plasmon-driven oxidation and the reduction reactions in an aqueous environment. Using surface-enhanced Raman scattering (SERS) spectroscopy, our experimental results and theoretical simulations reveal that PNA is selectively catalyzed to 4,4‧-diaminoazobenzene (DAAB) through the plasmon-assisted dimerization of the nitro (-NO2) group into an azo group in an aqueous environment. This indicates that the plasmon-driven reduction of the nitro (-NO2) group clearly occurs before the oxidation of the amine (-NH2) group in an aqueous environment. The plasmon-driven reduction of PNA to DAAB is a selective surface catalytic reduced reaction in aqueous environment.

  8. Para-Phenylenediamine Induces Apoptotic Death of Melanoma Cells and Reduces Melanoma Tumour Growth in Mice

    PubMed Central

    Bhowmick, Debajit; Bhar, Kaushik; Mallick, Sanjaya K.; Das, Subhadip; Chatterjee, Nabanita; Sarkar, Tuhin Subhra; Chakrabarti, Rajarshi; Das Saha, Krishna; Siddhanta, Anirban

    2016-01-01

    Melanoma is one of the most aggressive forms of cancer, usually resistant to standard chemotherapeutics. Despite a huge number of clinical trials, any success to find a chemotherapeutic agent that can effectively destroy melanoma is yet to be achieved. Para-phenylenediamine (p-PD) in the hair dyes is reported to purely serve as an external dyeing agent. Very little is known about whether p-PD has any effect on the melanin producing cells. We have demonstrated p-PD mediated apoptotic death of both human and mouse melanoma cells in vitro. Mouse melanoma tumour growth was also arrested by the apoptotic activity of intraperitoneal administration of p-PD with almost no side effects. This apoptosis is shown to occur primarily via loss of mitochondrial membrane potential (MMP), generation of reactive oxygen species (ROS), and caspase 8 activation. p-PD mediated apoptosis was also confirmed by the increase in sub-G0/G1 cell number. Thus, our experimental observation suggests that p-PD can be a potential less expensive candidate to be developed as a chemotherapeutic agent for melanoma. PMID:27293892

  9. X-ray photoelectron spectroscopy study of para-substituted benzoic acids chemisorbed to aluminum oxide thin films

    SciTech Connect

    Kreil, Justin; Ellingsworth, Edward; Szulczewski, Greg

    2013-11-15

    A series of para-substituted, halogenated (F, Cl, Br, and I) benzoic acid monolayers were prepared on the native oxide of aluminum surfaces by solution self-assembly and spin-coating techniques. The monolayers were characterized by x-ray photoelectron spectroscopy (XPS) and water contact angles. Several general trends are apparent. First, the polarity of the solvent is critical to monolayer formation. Protic polar solvents produced low coverage monolayers; in contrast, nonpolar solvents produced higher coverage monolayers. Second, solution deposition yields a higher surface coverage than spin coating. Third, the thickness of the monolayers determined from XPS suggests the plane of the aromatic ring is perpendicular to the surface with the carboxylate functional group most likely binding in a bidentate chelating geometry. Fourth, the saturation coverage (∼2.7 × 10{sup 14} molecules cm{sup −2}) is independent of the para-substituent.

  10. Breaking the Barrier to Slow Water Exchange Rates for Optimal Magnetic Resonance Detection of paraCEST Agents.

    PubMed

    Fernando, W Shirangi; Martins, André F; Zhao, Piyu; Wu, Yunkou; Kiefer, Garry E; Platas-Iglesias, Carlos; Sherry, A Dean

    2016-03-21

    EuDOTA-tetraamide complexes as paraCEST agents offer an attractive platform for designing biological sensors and responsive agents. The early versions of these agents showed low sensitivity at temperature and power levels suitable for in vivo applications partly due to non-optimal water exchange rates. Here we report two new EuDOTA derivatives having glutamyl-phosphonate side arms that display the slowest water exchange rates of any other paraCEST agent reported so far. The advantages of such systems are demonstrated experimentally both in vitro and in vivo and DFT calculations were performed to help understand the physical-chemical reasons for this interesting behavior. PMID:26937683

  11. The total neutron cross-section of an ortho-para mixture of gaseous hydrogen at 75K

    NASA Astrophysics Data System (ADS)

    Corradi, G.; Celli, M.; Rhodes, N.; Soper, A. K.; Zoppi, M.

    2004-07-01

    From the data of a transmission experiment we have extracted the total neutron cross-section of a sample of gaseous hydrogen (T=75.03K, p=84.8bar, n=8.42nm-3) with a thermodynamic equilibrium ortho-para content (48% ortho, 52% para). The experiment was carried out on the PEARL instrument operating at the ISIS pulsed neutron source. After an accurate data reduction, the neutron spectra have been analyzed in the framework of the Modified Young and Koppel (MYK) theory, which is a successful extension to interacting fluids of the original Young and Koppel model valid for a dilute gas of hydrogen molecules. The total cross-section calculated with MYK theory, whose unique unknown parameter-the mean kinetic energy of the molecular centre of mass-was obtained through an independent path integral Monte Carlo simulation, shows a satisfactory agreement with the experimental results.

  12. Significado de los cambios en el cuello uterino: Guía para la salud de la mujer

    Cancer.gov

    Explica qué es la infección por el VPH; los exámenes de detección del cáncer de cuello uterino, entre ellos la prueba de Pap, la prueba del VPH y la prueba conjunta de Pap y del VPH; las pautas para los exámenes de detección; los posibles resultados de la

  13. Vanadium-catalyzed oxidative Strecker reaction: α-C–H cyanation of para-methoxyphenyl (PMP)-protected primary amines

    PubMed Central

    Zhu, Chen; Xia, Ji-Bao; Chen, Chuo

    2013-01-01

    We describe an oxidative Strecker reaction that allows for direct cyanation of para-methoxyphenyl (PMP)-protected primary amines. A vanadium(V) complex was used as the catalyst and TBHP as the oxidant. The cyanation occurs at the α-C position bearing either an alkyl or an aromatic group. This method provides a direct access to α-aminonitrile from amines with one-carbon extension. PMID:24415804

  14. Luminescent properties of europium(III) and terbium(III) complexes with para- and ortho-ethoxybenzoic acids

    NASA Astrophysics Data System (ADS)

    Panyushkin, V. T.; Mutuzova, M. Kh.; Shamsutdinova, M. Kh.

    2016-02-01

    The luminescent properties of europium(III) and terbium(III) complexes with para- and ortho-ethoxybenzoic acids are studied. The excitation energies of the triplet states of ligands are determined, a hypothesis is made about the efficient luminescence of europium(III) and terbium(III) complexes, the geometry of the coordination polyhedron of a europium complex is established, and the luminescence quantum yields of the complexes in solution are determined.

  15. The vitamin-like dietary supplement para-aminobenzoic acid enhances the antitumor activity of ionizing radiation

    SciTech Connect

    Xavier, Sandhya; MacDonald, Shannon; Roth, Jennifer; Caunt, Maresa; Akalu, Abebe; Morais, Danielle; Buckley, Michael T.; Liebes, Leonard; Formenti, Silvia C.; Brooks, Peter C. . E-mail: peter.brooks@med.nyu.edu

    2006-06-01

    Purpose: To determine whether para-aminobenzoic acid (PABA) alters the sensitivity of tumor cells to ionizing radiation in vitro and in vivo. Methods and Materials: Cellular proliferation was assessed by WST-1 assays. The effects of PABA and radiation on tumor growth were examined with chick embryo and murine models. Real-time reverse transcriptase-polymerase chain reaction and Western blotting were used to quantify p21{sup CIP1} and CDC25A levels. Results: Para-aminobenzoic acid enhanced (by 50%) the growth inhibitory activity of radiation on B16F10 cells, whereas it had no effect on melanocytes. Para-aminobenzoic acid enhanced (50-80%) the antitumor activity of radiation on B16F10 and 4T1 tumors in vivo. The combination of PABA and radiation therapy increased tumor apoptosis. Treatment of tumor cells with PABA increased expression of CDC25A and decreased levels of p21{sup CIP1}. Conclusions: Our findings suggest that PABA might represent a compound capable of enhancing the antitumor activity of ionizing radiation by a mechanism involving altered expression of proteins known to regulate cell cycle arrest.

  16. Comparison of photoinduced reorientation of ortho-, meta-, and para-methyl red-doped nematic liquid crystals on rubbed polyimide.

    PubMed

    Statman, David; Statman, Ariel T; Wozniak, Kaitlin; Brennan, Christopher

    2015-08-01

    We compare the photoinduced reorientation of the easy axis on rubbed polyimide surfaces for the nematic E7 doped with three isomers of methyl red; ortho, meta, and para. Using optical techniques, the angle and the pitch of the director at the polymer surface were measured before, during, and after photoexcitation of the dye. Optical absorbances were also measured before and after photoexcitation. Extrapolation lengths, hence anchoring energies, were determined with the on/off application of a magnetic field for meta- and para-methyl red-doped nematics. Because of an elastic reorientation of the easy axis in the presence of the magnetic field, we could not determine the extrapolation length of the ortho-methyl red-doped nematic. Our results confirm that photoinduced reorientation is facilitated by desorption of all dyes from the polymer surface. While there is little evidence of weak photoinduced adsorption of meta- and para-methyl red to the surface during photoexcitation, there is strong evidence of photoinduced adsorption of ortho-methyl red, which is long lasting. PMID:26382419

  17. Comparison of photoinduced reorientation of ortho-, meta-, and para-methyl red-doped nematic liquid crystals on rubbed polyimide

    NASA Astrophysics Data System (ADS)

    Statman, David; Statman, Ariel T.; Wozniak, Kaitlin; Brennan, Christopher

    2015-08-01

    We compare the photoinduced reorientation of the easy axis on rubbed polyimide surfaces for the nematic E7 doped with three isomers of methyl red; ortho, meta, and para. Using optical techniques, the angle and the pitch of the director at the polymer surface were measured before, during, and after photoexcitation of the dye. Optical absorbances were also measured before and after photoexcitation. Extrapolation lengths, hence anchoring energies, were determined with the on/off application of a magnetic field for meta- and para-methyl red-doped nematics. Because of an elastic reorientation of the easy axis in the presence of the magnetic field, we could not determine the extrapolation length of the ortho-methyl red-doped nematic. Our results confirm that photoinduced reorientation is facilitated by desorption of all dyes from the polymer surface. While there is little evidence of weak photoinduced adsorption of meta- and para-methyl red to the surface during photoexcitation, there is strong evidence of photoinduced adsorption of ortho-methyl red, which is long lasting.

  18. Developmental validation of the ParaDNA(®) Intelligence System-A novel approach to DNA profiling.

    PubMed

    Blackman, Stephen; Dawnay, Nick; Ball, Glyn; Stafford-Allen, Beccy; Tribble, Nicholas; Rendell, Paul; Neary, Kelsey; Hanson, Erin K; Ballantyne, Jack; Kallifatidis, Beatrice; Mendel, Julian; Mills, DeEtta K; Wells, Simon

    2015-07-01

    DNA profiling through the analysis of STRs remains one of the most widely used tools in human identification across the world. Current laboratory STR analysis is slow, costly and requires expert users and interpretation which can lead to instances of delayed investigations or non-testing of evidence on budget grounds. The ParaDNA(®) Intelligence System has been designed to provide a simple, fast and robust way to profile DNA samples in a lab or field-deployable manner. The system analyses 5-STRs plus amelogenin to deliver a DNA profile that enables users to gain rapid investigative leads and intelligent prioritisation of samples in human identity testing applications. Utilising an innovative sample collector, minimal training is required to enable both DNA analysts and nonspecialist personnel to analyse biological samples directly, without prior processing, in approximately 75min. The test uses direct PCR with fluorescent HyBeacon(®) detection of STR allele lengths to provide a DNA profile. The developmental validation study described here followed the Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines and tested the sensitivity, reproducibility, accuracy, inhibitor tolerance, and performance of the ParaDNA Intelligence System on a range of mock evidence items. The data collected demonstrate that the ParaDNA Intelligence System displays useful DNA profiles when sampling a variety of evidence items including blood, saliva, semen and touch DNA items indicating the potential to benefit a number of applications in fields such as forensic, military and disaster victim identification (DVI). PMID:25980941

  19. Importance of the Anchor Group Position (Para versus Meta) in Tetraphenylmethane Tripods: Synthesis and Self-Assembly Features.

    PubMed

    Lindner, Marcin; Valášek, Michal; Homberg, Jan; Edelmann, Kevin; Gerhard, Lukas; Wulfhekel, Wulf; Fuhr, Olaf; Wächter, Tobias; Zharnikov, Michael; Kolivoška, Viliam; Pospíšil, Lubomír; Mészáros, Gábor; Hromadová, Magdaléna; Mayor, Marcel

    2016-09-01

    The efficient synthesis of tripodal platforms based on tetraphenylmethane with three acetyl-protected thiol groups in either meta or para positions relative to the central sp(3) carbon for deposition on Au (111) surfaces is reported. These platforms are intended to provide a vertical arrangement of the substituent in position 4 of the perpendicular phenyl ring and an electronic coupling to the gold substrate. The self-assembly features of both derivatives are analyzed on Au (111) surfaces by low-temperature ultra-high-vacuum STM, high-resolution X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy, and reductive voltammetric desorption studies. These experiments indicated that the meta derivative forms a well-ordered monolayer, with most of the anchoring groups bound to the surface, whereas the para derivative forms a multilayer film with physically adsorbed adlayers on the chemisorbed para monolayer. Single-molecule conductance values for both tripodal platforms are obtained through an STM break junction experiment. PMID:27505302

  20. Experimental and computational studies on the formation of three para-benzyne analogues in the gas phase.

    PubMed

    Kirkpatrick, Lindsey M; Vinueza, Nelson R; Jankiewicz, Bartłomiej J; Gallardo, Vanessa A; Archibold, Enada F; Nash, John J; Kenttämaa, Hilkka I

    2013-07-01

    Experimental and computational studies on the formation of three gaseous, positively-charged para-benzyne analogues in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer are reported. The structures of the cations were examined by isolating them and allowing them to react with various neutral reagents whose reactions with aromatic carbon-centered σ-type mono- and biradicals are well understood. Cleavage of two iodine-carbon bonds in N-deuterated 1,4-diiodoisoquinolinium cation by collision-activated dissociation (CAD) produced a long-lived cation that showed nonradical reactivity, which was unexpected for a para-benzyne. However, the reactivity closely resembles that of an isomeric enediyne, N-deuterated 2-ethynylbenzonitrilium cation. A theoretical study on possible rearrangement reactions occurring during CAD revealed that the cation formed upon the first iodine atom loss undergoes ring-opening before the second iodine atom loss to form an enediyne instead of a para-benzyne. Similar results were obtained for the 5,8-didehydroisoquinolinium cation and the 2,5-didehydropyridinium cation. The findings for the 5,8-didehydroisoquinolinium cation are in contradiction with an earlier report on this cation. The cation described in the literature was regenerated by using the literature method and demonstrated to be the isomeric 5,7-didehydro-isoquinolinium cation and not the expected 5,8-isomer. PMID:23703949

  1. Antibacterial activity of sulfamethoxazole transformation products (TPs): general relevance for sulfonamide TPs modified at the para position.

    PubMed

    Majewsky, Marius; Wagner, Danny; Delay, Markus; Bräse, Stefan; Yargeau, Viviane; Horn, Harald

    2014-10-20

    Sulfonamide antibiotics undergo transformation in the aquatic environment through biodegradation, photolysis, or hydrolysis. In this study, the residual antibacterial activity of 11 transformation products (TPs) of sulfamethoxazole (SMX) was investigated with regard to their in vitro growth and luminescence inhibition on Vibrio fischeri (30 min and 24 h exposure). Two transformation products, 4-hydroxy-SMX and N(4)-hydroxy-acetyl-SMX, were synthesized in-house and confirmed by nuclear magnetic resonance and high-resolution mass spectrometry. Results of individual compound experiments showed that TPs modified at the para amino group still exhibit clear antibacterial effects, whereas TPs resulting from breakdown of the SMX structure lost this mechanism of action. 4-NO2- and 4-OH-SMX were found to inhibit growth to a clearly greater extent than the parent compound, SMX. In contrast, the N(4)-acetyl- and N(4)-hydroxy-acetyl-derivatives retain less than 10 and 5% of the effect of SMX on growth and luminescence inhibition, respectively. The effect of a mixture of para-modified TPs was observed to be additive. Considering the homologous series of sulfa drugs widely prescribed and their common mechanism of action, the potential environmental impact must consider the total amount of sulfonamide antibiotics and their derivative TPs, which might end up in a water body. Extrapolating the results obtained here for the para TPs of SMX to other sulfa drugs and determining the persistence and occurrence of these compounds in the aquatic environment is required for improved risk assessment. PMID:25211553

  2. High-strength poly(para-phenylene) as an orthopedic biomaterial.

    PubMed

    Frick, Carl P; DiRienzo, Amy L; Hoyt, Anthony J; Safranski, David L; Saed, Mohand; Losty, Eric J; Yakacki, Christopher M

    2014-09-01

    Poly(para-phenylene) (PPP) exhibits exceptional mechanical strength, stiffness, toughness, and chemical inertness, although it is not currently used in any biomedical applications. The purpose of this study is to serve as a preliminary investigation into the potential of PPP as a biomaterial in orthopedic load-bearing applications. Nuclear magnetic resonance (NMR) analysis confirmed a polymer structure composed of an aromatic backbone and side groups. Tensile PPP specimens along with samples from several other polymers often used for orthopedic applications were elongated to failure after being soaked in phosphate buffered saline (PBS) for 1 h, 1 day, 1 week, 2 weeks, 1 month, and more than 1 year. Results showed that PBS absorption of the PPP plateaued at 1 week at values of ∼0.7 wt % and remained within one standard deviation when soaked for over 1 year. PBS absorption did not affect elastic modulus (5.0 GPa), yield strength (141 MPa), fracture strength (120 MPa) and strain-to-failure (17%) more than one standard deviation. Zero-to-tension fatigue testing established an endurance limit of approximately 35 MPa, which was relatively insensitive to frequency (1-10 Hz). Eagle's minimum essential medium (MEM) elution assay with fibroblasts confirmed that the PPP was noncytotoxic. Relative to other polymers used for load-bearing biomedical applications, PPP displays promising mechanical properties that remain stable in aqueous solution. Lastly, prototype PPP and polyetheretherketone (PEEK) bone plates were manufactured and tested, with the PPP plate showing a 38% higher maximum tensile load before failure. PMID:24123879

  3. Long-term health-enhancing physical activity in rheumatoid arthritis - the PARA 2010 study

    PubMed Central

    2012-01-01

    Background People with rheumatoid arthritis (RA) suffer increased risk of disability andpremature mortality. Health-enhancing physical activity (HEPA) could be one importantfactor to reduce this risk. Rising health care costs call for the development and evaluation ofnew modes of rehabilitation, including physical activity in settings outside the health caresystem. Methods/Design This cohort study targets 450 patients with RA that do not currently meet HEPA recommendations, recruited from six hospitals reporting to the Swedish Rheumatology Quality Registers (SRQ). We have developed a two-year real-life intervention program including a minimum of twice-weekly circuit training, moderately intense physical activity the remaining days of the week and group meetings to support behavior change every other week. Our hypothesis is that increased physical activity and exercise will improve perceived health, reduce pain and fatigue, increase muscle function and aerobic capacity, impact psychosocial factors and prevent future cardiovascular events. Research questions regard outcomes, retention rates, dose–response matters and the exploration of responder characteristics. This protocol outlines recruitment procedure, design, assessment methods and the intervention program of the study. Discussion The PARA 2010 project is designed to expand the knowledge on HEPA in RA by a progressive approach regarding population, setting, intervention, time frames and outcome measures. To our knowledge this is the first long-term HEPA program based on Social Cognitive Theory, and performed in a real life environment to demonstrate if this new setting can promote increased and maintained physical activity in people with RA. Trial registration number ISRCTN25539102 PMID:22656861

  4. A structural and spectroscopic study on para-aminohippuric acid with experimental and theoretical approaches

    NASA Astrophysics Data System (ADS)

    Karabacak, Mehmet; Cinar, Zeliha; Cinar, Mehmet

    2012-01-01

    In this work, the molecular conformation, vibrational and electronic analysis of para-aminohippuric acid (pAHA, C 9H 10N 2O 3) were presented for the ground state using experimental techniques (FT-IR, FT-Raman and UV) and density functional theory (DFT) employing B3LYP exchange correlation with the 6-311++G(d,p) basis set. FT-IR and FT-Raman spectra were recorded in the regions of 400-4000 cm -1 and 50-4000 cm -1, respectively. The UV absorption spectra of the compound that dissolved in ethanol and water solution were recorded in the range of 190-400 nm. Potential energy curve was computed by means of scanning NCC dbnd O torsion angle. The geometry optimization and the energies associated possible four conformers (C1-C4) were computed. The computational results diagnose the most stable conformer of pAHA as the C1 form. Optimized structure of compound was interpreted and compared with the earlier reported experimental values. The complete assignments of fundamental vibrations were performed on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. A study on the electronic properties, such as frontier molecular energies, absorption wavelengths and oscillator strengths, were predicted by time-dependent DFT (TD-DFT) approach, while taking solvent effects into account. To investigate non-linear optical properties: polarizability, anisotropy of polarizability and molecular first hyperpolarizability of molecule were computed. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound at different temperatures were calculated.

  5. OV-Wav: um novo pacote para análise multiescalar em astronomia

    NASA Astrophysics Data System (ADS)

    Pereira, D. N. E.; Rabaça, C. R.

    2003-08-01

    Wavelets e outras formas de análise multiescalar têm sido amplamente empregadas em diversas áreas do conhecimento, sendo reconhecidamente superiores a técnicas mais tradicionais, como as análises de Fourier e de Gabor, em certas aplicações. Embora a teoria dos wavelets tenha começado a ser elaborada há quase trinta anos, seu impacto no estudo de imagens astronômicas tem sido pequeno até bem recentemente. Apresentamos um conjunto de programas desenvolvidos ao longo dos últimos três anos no Observatório do Valongo/UFRJ que possibilitam aplicar essa poderosa ferramenta a problemas comuns em astronomia, como a remoção de ruído, a detecção hierárquica de fontes e a modelagem de objetos com perfis de brilho arbitrários em condições não ideais. Este pacote, desenvolvido para execução em plataforma IDL, teve sua primeira versão concluída recentemente e está sendo disponibilizado à comunidade científica de forma aberta. Mostramos também resultados de testes controlados ao quais submetemos os programas, com a sua aplicação a imagens artificiais, com resultados satisfatórios. Algumas aplicações astrofísicas foram estudadas com o uso do pacote, em caráter experimental, incluindo a análise da componente de luz difusa em grupos compactos de galáxias de Hickson e o estudo de subestruturas de nebulosas planetárias no espaço multiescalar.

  6. Resveratrol and para-coumarate serve as ring precursors for coenzyme Q biosynthesis[S

    PubMed Central

    Xie, Letian X.; Williams, Kevin J.; He, Cuiwen H.; Weng, Emily; Khong, San; Rose, Tristan E.; Kwon, Ohyun; Bensinger, Steven J.; Marbois, Beth N.; Clarke, Catherine F.

    2015-01-01

    Coenzyme Q (Q or ubiquinone) is a redox-active polyisoprenylated benzoquinone lipid essential for electron and proton transport in the mitochondrial respiratory chain. The aromatic ring 4-hydroxybenzoic acid (4HB) is commonly depicted as the sole aromatic ring precursor in Q biosynthesis despite the recent finding that para-aminobenzoic acid (pABA) also serves as a ring precursor in Saccharomyces cerevisiae Q biosynthesis. In this study, we employed aromatic 13C6-ring-labeled compounds including 13C6-4HB, 13C6-pABA, 13C6-resveratrol, and 13C6-coumarate to investigate the role of these small molecules as aromatic ring precursors in Q biosynthesis in Escherichia coli, S. cerevisiae, and human and mouse cells. In contrast to S. cerevisiae, neither E. coli nor the mammalian cells tested were able to form 13C6-Q when cultured in the presence of 13C6-pABA. However, E. coli cells treated with 13C6-pABA generated 13C6-ring-labeled forms of 3-octaprenyl-4-aminobenzoic acid, 2-octaprenyl-aniline, and 3-octaprenyl-2-aminophenol, suggesting UbiA, UbiD, UbiX, and UbiI are capable of using pABA or pABA-derived intermediates as substrates. E. coli, S. cerevisiae, and human and mouse cells cultured in the presence of 13C6-resveratrol or 13C6-coumarate were able to synthesize 13C6-Q. Future evaluation of the physiological and pharmacological responses to dietary polyphenols should consider their metabolism to Q. PMID:25681964

  7. Taxas de eventos para as fontes astrofísicas do detector Mario Schenberg

    NASA Astrophysics Data System (ADS)

    Castro, C. S.; Araujo, J. C. N.; Miranda, O. D.; Aguiar, O. D.

    2003-08-01

    O detector de ondas gravitacionais Mario Schenberg será sensível a sinais que cheguem à Terra com amplitude h~10-21 e dentro da faixa em frequências que varia de 3,0 a 3,4 kHz. As principais fontes astrofísicas em condições de gerar um sinal detectável pela antena Schenberg são: colapsos estelares que produzam eventos do tipo supernova; instabilidades hidrodinâmicas em estrelas de nêutrons; excitação dos modos fluído (modos f) de estrelas de nêutrons; excitação dos primeiros modos quadrupolares de buracos negros com massa ~ 3,8 M¤; coalescências de estrelas de nêutrons e buracos negros em sistemas binários e, ainda, espiralações de mini-buracos negros. Neste trabalho nós determinamos as taxas de eventos para o Schenberg associadas a dois tipos de fontes: através da de-excitação dos modos f de estrelas de nêutrons e através da coalescência de mini-buracos negros de 0,5 M¤ (que atualmente têm sido colocados como possíveis candidatos a objetos massivos do halo Galáctico). Nós mostramos que esses tipos de fontes poderão produzir sinais em ondas gravitacionais com uma taxa em torno de um evento por ano dentro da banda do Schenberg.

  8. Introduccion a la hidraulica de aguas subterraneas : un texto programado para auto-ensenanza

    USGS Publications Warehouse

    Bennett, Gordon D.

    1987-01-01

    Este ' texto programado esta diseflado para ayudarle a comprender la teoria de la hidniulica de aguas subterraneas por medio de la auto-enseflanza. La instrucci6n programada es un enfoque a una materia, un metodo de aprender;que no elimina el esfuerzo mental del proceso de aprendizaje. Algunas secciones de este programa necesitan solamente ser leidas; otras tendrian que ser elaboradas con lapiz y papel. Algunas preguntas pueden ser contestadas directamente; otras requieren calculos. A medida que se avanza en el texto, tendra que consultar frecuentemente textos o referencias sobre matematicas, mecanica de fluidos e hidrologia. En cada una de las ocho partes del texto, inicie el programa de instrucci6n leyendo la Secci6n 1. Elija una respuesta a la pregunta al final de la secci6n y dirijase a la nueva secci6n indicada al lado de la respuesta escogida. Si su respuesta fue correcta, pase a la secci6n que contiene materia nueva y otra pregunta, y proceda tal como en la Secci6n 1. Si su respuesta no fue correcta, dirijase a la secci6n que contiene explicaciones adicionales sobre el tema anterior y que le indica volver a la pregunta inicial e intentar de nuevo. En este caso, valdra Ia pena repasar el material de la secci6n anterior. Continue de esta man era en el programa hasta que llegue a Ia secci6n que indica el final de la parte. Observe que aunque las secciones estan en orden numerico en cada una de las ocho partes, por lo general, usted no procedeni en secuencia numerica (Secci6n 1 ala Secci6n 2, etc.) de principia a fin.

  9. Origin of the bimodal island size distribution in ultrathin films of para-hexaphenyl on mica

    NASA Astrophysics Data System (ADS)

    Tumbek, L.; Gleichweit, C.; Zojer, K.; Winkler, A.

    2012-08-01

    Ultrathin films of para-hexaphenyl (6P) were prepared on freshly cleaved and sputter-amorphized mica(001) by physical vapor deposition. Ex situ atomic force microscopy (AFM) revealed a bimodal island size distribution for the films on both surfaces. On freshly cleaved mica long needlelike islands exist, which are surrounded by small crystallites. On the sputter-amorphized substrates, large dendritic islands exist which are again surrounded by small, compact islands. We could prove by thermal desorption spectroscopy that the small islands are the result of adsorbate-induced subsequent nucleation, when the films were exposed to air. In case of the freshly cleaved mica, islands grow on a wetting layer in vacuum. This layer dewets and forms the small islands upon venting, due to the adsorption of water. In the case of the amorphous mica substrate an equilibrium exists between the islands and a two-dimensional gas phase in the sub-monolayer regime. Again, the latter phase nucleates after venting. In a particular coverage range, islands due to nucleation during deposition and subsequent nucleation coexist on the substrate, leading to the bimodal island size distribution. Kinetic Monte Carlo (KMC) simulations were performed to model the nucleation process after venting on the sputter-modified mica substrate. The density of the subsequently nucleated islands just depends on the initial coverage and the critical island size. A critical cluster size of i = 7 molecules was determined for 6P on amorphized mica, by comparing the KMC results with the AFM images in case of adsorbate-induced nucleation. Furthermore, the experimentally obtained island size distributions could be well reproduced by KMC simulations.

  10. Liquid chromatographic determination of para-toluenesulfonamide in edible fillet tissues from three species of fish

    USGS Publications Warehouse

    Meinertz, J.R.; Schmidt, L.J.; Stehly, G.R.; Gingerich, W.H.

    1999-01-01

    Chloramine-T (N-sodium-N-chloro-p-toluene-sulfonamide) is a candidate therapeutic drug for treating bacterial gill disease, a predominant disease of a variety of fish species. Research has been initiated to obtain the U.S. Food and Drug Administration's (FDA) approval for the use of chloramine-T on a variety of fish species. An attribute of a therapeutic aquaculture drug that must be characterized before the FDA approves its use is depletion of the drug's marker residue (the drug's parent compound or metabolite of highest concentration in an edible tissue). Para-Toluenesulfonamide (p-TSA) is the primary degradation product and marker residue for chloramine-T in rainbow trout. To conduct residue depletion studies for chloramine-T in fish, a robust analytical method sensitive and specific for p-TSA residues in edible fillet tissue from a variety of fish was required. Homogenized fillet tissues from rainbow trout (Oncorhynchus mykiss), walleye (Stizostedion vitreum), and channel catfish (Ictalurus punctatus) were fortified at nominal p-TSA concentrations of 17, 67, 200, 333, and 1000 ng/g. Samples were analyzed by isocratic reversed-phase liquid chromatography (LC) with absorbance detection at 226 nm. Mean recoveries of p-TSA ranged from 77 to 93.17%; relative standard deviations ranged from 1.5 to 14%; method quantitation limits ranged from 13 to 18 ng/g; and method detection limits ranged from 3.8 to 5.2 ng/g. The LC parameters produced p-TSA peaks without coelution of endogenous compounds and excluded chromatographic interference from at least 20 chemicals and drugs of potential use in aquaculture.

  11. Low concentrations of Bisphenol A and para-Nonylphenol affect extravillous pathway of human trophoblast cells.

    PubMed

    Spagnoletti, Antonella; Paulesu, Luana; Mannelli, Chiara; Ermini, Leonardo; Romagnoli, Roberta; Cintorino, Marcella; Ietta, Francesca

    2015-09-01

    Bisphenol A (BPA) and para-Nonylphenol (p-NP) are chemicals of industrial origin which may influence human reproductive health. The effects of these substances in the prenatal life is an important topic that is receiving greater attention in the developed countries. In this study, human trophoblast cells HTR-8/SVneo were exposed to BPA and p-NP (1 × 10(-15), 1 × 10(-13), 1 × 10(-11), 1 × 10(-9) and 1 × 10(-7) M) and incubated for 24, 48 and/or 72 h then, examined for the main physiological processes which characterize the extravillous trophoblast. Cell proliferation showed no changes while the processes of cell migration and invasion were both reduced by BPA and p-NP. For each chemical, the activity was higher at lower concentrations with a maximum activity between 1 × 10(-13) and 1 × 10(-11) M (p < 0.05 for 1 × 10(-9) and p < 0.001 for 1 × 10(-11) M). Co-culture studies with human umbilical cord endothelial cells (HUVEC) revealed that trophoblast/endothelial interaction was significantly reduced by p-NP at 1 × 10(-11) M. Moreover, both chemicals were inducing differentiation of HTR-8/SVneo toward polyploidy by the process of endoreduplication. The estrogen-receptor antagonist ICI significantly reduced p-NP action, while it had no effect on BPA treated cells. In conclusion, p-NP and BPA act on trophoblast cells altering key physiological processes in placenta development. The exact mechanism of action of the chemicals in human trophoblast still needs to be clarified. PMID:26027920

  12. Concordance study between the ParaDNA® Intelligence Test, a rapid DNA profiling assay, and a conventional STR typing kit (AmpFlSTR® SGM Plus®).

    PubMed

    Ball, G; Dawnay, N; Stafford-Allen, B; Panasiuk, M; Rendell, P; Blackman, S; Duxbury, N; Wells, S

    2015-05-01

    The ParaDNA® Intelligence Test enables STR profiling directly from human biological samples and evidence items collected from crime scene in 75min. Designed for non-expert use this system allows DNA information to be available to investigators before it would typically be available from a laboratory. The ParaDNA Intelligence Test system amplifies D3S1358, D8S119, D16S539, D18S1358 and TH01 STR loci and the gender typing locus amelogenin and detects the alleles present with HyBeacon® probes. Individual DNA samples from 381 UK Caucasian individuals were analysed using AmpFlSTR® SGM Plus® and the ParaDNA Intelligence Test with the derived STR profiles compared. Here we describe the high level of concordance demonstrated between the two systems and discuss this with reference to allele frequencies and the discriminatory power offered by the ParaDNA Intelligence Test. PMID:25528026

  13. Energy Savers: Tips for Saving Energy and Money at Home; El Ahorro de Energa: Sugerencias para ahorrar energa y dinero en el hogar

    SciTech Connect

    Jones, J.

    2000-06-01

    The Department of Energy of the United States of America works to guarantee provisions of safe energy, reliable and economically accessible to support to one developing economy and to protect the atmosphere. These suggestions and ideas to increase the energy efficiency in their house represent simple ways in which our citizens can contribute to preserve the atmosphere at world-wide level, to reduce the level of contamination of the air and to reserve our natural resources for future generations. [Spanish] El Departamento de Energa de los Estados Unidos de America trabaja para garantizar suministros de energa seguros, confiables y econmicamente accesibles para apoyar a una economa en desarrollo y proteger el medio ambiente. Estas sugerencias e ideas para aumentar la eficiencia energetica en su casa representan maneras sencillas en que nuestros ciudadanos pueden contribuir a preservar el medio ambiente a nivel mundial, a reducir el nivel de contaminacin del aire y a reservar nuestros recursos naturales para las generaciones futuras.

  14. Deposition, clearance, and shortening of Kevlar para-aramid fibrils in acute, subchronic, and chronic inhalation studies in rats.

    PubMed

    Kelly, D P; Merriman, E A; Kennedy, G L; Lee, K P

    1993-10-01

    The deposition and clearance of lung-deposited Kevlar para-aramid fibrils (subfibers) have been investigated as part of a subchronic and chronic inhalation toxicity testing program. Fibrils recovered from lung tissue in para-aramid-exposed Sprague-Dawley rats were microscopically counted and measured after exposures to airborne fibrils which were about 12 microns median length (ML) and < 0.3 micron median diameter. In each of three studies lung-recovered fibrils were progressively shorter with increasing residence time in the lungs. Twenty-eight days after a single 6-hr exposure at 400 respirable fibrils per cubic centimeter (f/cm3) the ML of recovered fibrils decreased to about 5 microns. Twenty-four months after a 3-week exposure to 25 or 400 f/cm3, fibrils reached about 2 microns ML. After 2 years of continuous exposure at 2.5, 25, or 100 f/cm3 or 1 year exposure plus 1 year recovery at 400 f/cm3, fibril ML approached 4 microns. In the 2-year study, the lung-fiber accumulation rate/exposure concentration was similar for the three highest concentrations and was about 3 x greater than that seen at 2.5 f/cm3, indicating that concentrations of about 25 f/cm3 or more may overwhelm clearance mechanisms. Time required for fibrils to be reduced to < 5 microns in the lung was markedly less at lower exposure concentration and shorter exposure time. The primary shortening mechanism is proposed to be long fibril cutting by enzymatic attack at fibril defects. However, length-selective fibril deposition and clearance may contribute to shortening in the first few days after exposure. The enzymatic cutting hypothesis is supported by measured increases in numbers of short fibers following cessation of exposures, continued shortening of the fibril length distribution up to 2 years following exposure, and in vitro fibril shortening after 3 months in a proteolytic enzyme preparation. The conclusion is that para-aramid fibrils are less durable in the lungs of rats than expected from

  15. Challenges in preparing, preserving and detecting para-water in bulk: overcoming proton exchange and other hurdles.

    PubMed

    Mammoli, Daniele; Salvi, Nicola; Milani, Jonas; Buratto, Roberto; Bornet, Aurélien; Sehgal, Akansha Ashvani; Canet, Estel; Pelupessy, Philippe; Carnevale, Diego; Jannin, Sami; Bodenhausen, Geoffrey

    2015-10-28

    Para-water is an analogue of para-hydrogen, where the two proton spins are in a quantum state that is antisymmetric under permutation, also known as singlet state. The populations of the nuclear spin states in para-water are believed to have long lifetimes just like other Long-Lived States (LLSs). This hypothesis can be verified by measuring the relaxation of an excess or a deficiency of para-water, also known as a "Triplet-Singlet Imbalance" (TSI), i.e., a difference between the average population of the three triplet states T (that are symmetric under permutation) and the population of the singlet state S. In analogy with our recent findings on ethanol and fumarate, we propose to adapt the procedure for Dissolution Dynamic Nuclear Polarization (D-DNP) to prepare such a TSI in frozen water at very low temperatures in the vicinity of 1.2 K. After rapid heating and dissolution using an aprotic solvent, the TSI should be largely preserved. To assess this hypothesis, we studied the lifetime of water as a molecular entity when diluted in various solvents. In neat liquid H2O, proton exchange rates have been characterized by spin-echo experiments on oxygen-17 in natural abundance, with and without proton decoupling. One-dimensional exchange spectroscopy (EXSY) has been used to study proton exchange rates in H2O, HDO and D2O mixtures diluted in various aprotic solvents. In the case of 50 mM H2O in dioxane-d8, the proton exchange lifetime is about 20 s. After dissolving, one can observe this TSI by monitoring intensities in oxygen-17 spectra of H2O (if necessary using isotopically enriched samples) where the AX2 system comprising a "spy" oxygen A and two protons X2 gives rise to binomial multiplets only if the TSI vanishes. Alternatively, fast chemical addition to a suitable substrate (such as an activated aldehyde or ketone) can provide AX2 systems where a carbon-13 acts as a spy nucleus. Proton signals that relax to equilibrium with two distinct time constants can be

  16. Protegiendo a su familia de los terremotos-Los siete pasos a la seguridad para prepararse en caso de un terremoto (en espa?ol y en ingles)

    USGS Publications Warehouse

    Desarrollado por American Red Cross, Asian Pacific Fund, California Earthquake Authority, Governor's Office of Emergency Services, New America Media, U.S. Department of Homeland Security Federal Emergency Management Agency, and U.S. Geological Survey

    2007-01-01

    Les escribimos esta carta para comunicarle un mensaje sumamente importante sobre las preparaciones de emergencia. Historicamente, hemos sufrido terremotos aqui en el Area de la Bahia de San Francisco que han causado graves privaciones para los residentes de la comunidad y da?os increibles a nuestras ciudades. Es probable que suframos un terremoto de gran magnitud en los proximos 30 a?os. Muchos de nosotros venimos de otros paises donde hemos pasado por terremotos y por eso creemos entenderlos. Sin embargo, la manera que nos preparamos para terremotos en nuestros paises de origen puede ser distinta a la que empleamos aca en los Estados Unidos. Muy pocas personas mueren a causa de los derrumbes de los edificios en el Area de la Bahia porque la mayoria de los edificios son construidos para resistir el sacudimiento de la tierra. Pero es muy probable que su familia no tenga atencion medica, alimentos o que esten separados del uno al otro por dias o semanas. Finalmente depende de usted mantener a su familia a salvo hasta que llegue asistencia, por eso les pedimos que nos unamos para aprender a cuidar a su familia antes, durante, y despues de un terremoto. El primer paso es leer este libro. Cada uno de su familia, ni?os y adultos, pueden aprender como prepararse para un terremoto. Haga participar e incluya sus ni?os; pueden ayudarle a prepararse. Aproveche las clases ofrecidas en su comunidad sobre las preparaciones de terremotos por la Cruz Roja Estadounidense (American Red Cross). Estos cursos de preparacion son gratis y disponibles en espa?ol para todos en la comunidad sin tomar en cuenta la historia de la familia, estado legal, genero o edad. Les recomendamos que tome ventaja de estas clases gratuitas. Para mas informacion consulte la ultima pagina de este libro. Recuerde que un terremoto puede ocurrir sin aviso y la unica manera de reducir el da?o de terremotos es estar preparados. !Preparese!

  17. Nueva opción de tratamiento para mujeres jóvenes con cáncer de seno sensible a las hormonas

    Cancer.gov

    Un fármaco usado para el tratamiento del cáncer de seno (mama), conocido como exemestano, es más eficaz que tamoxifeno, un fármaco preventivo de uso común para el cáncer de seno, en la prevención de la recidiva del cáncer de seno en mujeres jóvenes que ta

  18. Opciones de cirugía para mujeres con CDIS o con cáncer de seno- página de publicaciones

    Cancer.gov

    Contiene información sobre los tipos de cirugía de seno, como la operación para conservar el seno y la mastectomía, y ayuda a las mujeres diagnosticadas con CDIS o con cáncer de seno a decidir cuál cirugía es la más conveniente para ellas.

  19. Photoinduced Charge and Energy Transfer within meta- and para-Linked Chlorophyll a-Perylene-3,4:9,10-bis(dicarboximide) Donor-Acceptor Dyads.

    PubMed

    Huang, Guan-Jhih; Harris, Michelle A; Krzyaniak, Matthew D; Margulies, Eric A; Dyar, Scott M; Lindquist, Rebecca J; Wu, Yilei; Roznyatovskiy, Vladimir V; Wu, Yi-Lin; Young, Ryan M; Wasielewski, Michael R

    2016-02-01

    Connecting electron donors and acceptors to a benzene ring in a meta or para relationship results in quantum interference effects that can strongly influence charge separation (CS) and charge recombination (CR) processes in these systems. We report on the energy and electron transfer behavior of chlorophyll-based para- and meta-linked donor-bridge-acceptor (D-B-A) dyads, where the semisynthetic chlorophyll a derivative, zinc methyl 3-ethyl-pyrochlorophyllide a (D), is covalently attached at its 20-position to the para position of one phenyl of diphenylacetylene (B). The meta or para position of the phenyl in B distal to the donor is in turn attached to perylene-3,4:9,10-bis(dicarboximide) (PDI) (A). Photoexcitation of the D-B-A dyads produces long-lived radical ion pairs D(•+)-B-A(•-), which recombine to the ground state and to both (3*)D-B-A and D-B-(3*)A. Time-resolved optical and electron paramagnetic resonance spectroscopies were used to monitor the charge transfer and triplet energy transfer (TEnT) processes. At longer times, TEnT occurs from (3*)D-B-A to D-B-(3*)A. Surprisingly, the D-B-A molecules linked via the meta linkage exhibit faster CS, CR, and TEnT rates than do those with the para linkage in contrast to most other meta/para-linked D-B-A molecules previously examined. PMID:26731377

  20. BSSDATA - um programa otimizado para filtragem de dados em radioastronomia solar

    NASA Astrophysics Data System (ADS)

    Martinon, A. R. F.; Sawant, H. S.; Fernandes, F. C. R.; Stephany, S.; Preto, A. J.; Dobrowolski, K. M.

    2003-08-01

    A partir de 1998, entrou em operação regular no INPE, em São José dos Campos, o Brazilian Solar Spectroscope (BSS). O BSS é dedicado às observações de explosões solares decimétricas com alta resolução temporal e espectral, com a principal finalidade de investigar fenômenos associados com a liberação de energia dos "flares" solares. Entre os anos de 1999 e 2002, foram catalogadas, aproximadamente 340 explosões solares classificadas em 8 tipos distintos, de acordo com suas características morfológicas. Na análise detalhada de cada tipo, ou grupo, de explosões solares deve-se considerar a variação do fluxo do sol calmo ("background"), em função da freqüência e a variação temporal, além da complexidade das explosões e estruturas finas registradas superpostas ao fundo variável. Com o intuito de realizar tal análise foi desenvolvido o programa BSSData. Este programa, desenvolvido em linguagem C++, é constituído de várias ferramentas que auxiliam no tratamento e análise dos dados registrados pelo BSS. Neste trabalho iremos abordar as ferramentas referentes à filtragem do ruído de fundo. As rotinas do BSSData para filtragem de ruído foram testadas nos diversos grupos de explosões solares ("dots", "fibra", "lace", "patch", "spikes", "tipo III" e "zebra") alcançando um bom resultado na diminuição do ruído de fundo e obtendo, em conseqüência, dados onde o sinal torna-se mais homogêneo ressaltando as áreas onde existem explosões solares e tornando mais precisas as determinações dos parâmetros observacionais de cada explosão. Estes resultados serão apresentados e discutidos.

  1. Yeast Coq9 controls deamination of coenzyme Q intermediates that derive from para-aminobenzoic acid.

    PubMed

    He, Cuiwen H; Black, Dylan S; Nguyen, Theresa P T; Wang, Charles; Srinivasan, Chandra; Clarke, Catherine F

    2015-09-01

    Coq9 is a polypeptide subunit in a mitochondrial multi-subunit complex, termed the CoQ-synthome, required for biosynthesis of coenzyme Q (ubiquinone or Q). Deletion of COQ9 results in dissociation of the CoQ-synthome, but over-expression of Coq8 putative kinase stabilizes the CoQ-synthome in the coq9 null mutant and leads to the accumulation of two nitrogen-containing Q intermediates, imino-demethoxy-Q6 (IDMQ6) and 3-hexaprenyl-4-aminophenol (4-AP) when para-aminobenzoic acid (pABA) is provided as a ring precursor. To investigate whether Coq9 is responsible for deamination steps in Q biosynthesis, we utilized the yeast coq5-5 point mutant. The yeast coq5-5 point mutant is defective in the C-methyltransferase step of Q biosynthesis but retains normal steady-state levels of the Coq5 polypeptide. Here, we show that when high amounts of 13C6-pABA are provided, the coq5-5 mutant accumulates both 13C6-imino-demethyl-demethoxy-Q6 (13C6-IDDMQ6) and 13C6-demethyl-demethoxy-Q6 (13C6-DDMQ6). Deletion of COQ9 in the yeast coq5-5 mutant along with Coq8 over-expression and 13C6- pABA labeling leads to the absence of 13C6-DDMQ6, and the nitrogen-containing intermediates 13C6-4-AP and 13C6-IDDMQ6 persist. We describe a coq9 temperature-sensitive mutant and show that at the non-permissive temperature, steady-state polypeptide levels of Coq9-ts19 increased, while Coq4, Coq5, Coq6, and Coq7 decreased. The coq9-ts19 mutant had decreased Q6 content and increased levels of nitrogen-containing intermediates. These findings identify Coq9 as a multi-functional protein that is required for the function of Coq6 and Coq7 hydroxylases, for removal of the nitrogen substituent from pABA-derived Q intermediates, and is an essential component of the CoQ synthome. PMID:26008578

  2. Microporosity linked fluid focusing and monazite instability in greenschist facies para-conglomerates, western India

    NASA Astrophysics Data System (ADS)

    Rekha, S.; Bhattacharya, A.; Viswanath, T. A.

    2013-03-01

    In a deformed para-conglomerate (western India), monazites occur as discrete grains (50-250 μm long axis) in tonalite clasts, in the warping chlorite-biotite-calcite schist layers, and as disseminated grains (<5 μm) along with xenotime and huttonite forming veins in schist layers. The veins are absent in clasts. Chlorite and biotite defining schistosity in schist layers and in synchronously-formed extensional veins/fractures in clasts are chemically identical. δ18O (VSMOW) and δ13C (VPDB) in calcite in schistosity, in clasts, and in "beards" in pressure shadow zones around clasts are tightly bracketed, 11.4-12.2‰ and -3.1 to -3.6‰ respectively. Margins of clast-hosted monazites are partly altered to fluorapatite - huttonite ± allanite ± Y-xenotime. By contrast, monazite alteration in schist layers is extensive. In schist layers, rafts of embayed monazite occur in fluorapatite-dominated corona studded with idiomorphic huttonite, Y-xenotime ± allanite. Mass balance calculation in a well-defined alteration zone around monazite in schist layer with P conserved indicate large gain in mass fraction of lower-abundance, less soluble HREEs, Y and Th in the alteration zone was compensated by minor loss in mass fraction of higher abundance elements (LREEs, MREEs) resulting in negligible net mass change. Monazite decomposition was associated with ˜50% dilation strain. Yb, Th and U abundances in alteration zones around decomposed monazites in schist layer are computed to be manifold higher than average schists. The contemporaneous formation of pore microstructures, the chemical homogeneity among ferromagnesian minerals and C-O isotope data in calcite in different textural domains, and results of mass balance calculations are compatible with deformation-aided porosity generation, synchronous fluid-mediated advection transport of elements, and dissolution-re-precipitation of mica-calcite aggregates at upper crustal conditions, ˜500 °C, ˜4 kbar. Monazite instability

  3. Antitumor effect of para-toluenesulfonamide against lung cancer xenograft in a mouse model

    PubMed Central

    Gao, Yang; Gao, Yonghua; Guan, Weijie; Huang, Liyan; Xu, Xiaoming; Zhang, Chenting; Chen, Xiuqing; Wu, Yizhuang; Zeng, Guangqiao

    2013-01-01

    Background Conventional chemotherapy and radiation therapy against non-small cell lung cancer (NSCLC) are relatively insensitive and unsatisfactory. Para-toluenesulfonamide (PTS), a unique antitumor drug for local intratumoral injection, shows an efficacy of severely suppressing solid tumor growth with mild side effects in clinical trials. The aim of this study was to investigate the effect of PTS on lung cancer H460 cells in vivo in nude mice and its underlying mechanisms in vitro. Methods A lung cancer model for in vivo experiment was established in BALB/c nude mice using H460 cells to examine the effect of local injection of PTS on tumor suppression. We also assessed the injury to the normal tissue by subcutaneous injection of PTS. In vitro, PTS was diluted into different doses for study on its antitumor mechanisms. We evaluated the necrotic effect of PTS on H460 cells by PI and Hoechst 33342 staining. Cell viability and membrane permeability were also determined by using CCK-8 and LDH assays respectively. All these tests were conducted in comparison with traditional local injection of anhydrous ethanol. Results PTS was shown to significantly inhibit the growth of H460 tumor xenografts in nude mice by inducing necrosis of the tumor histologically. Its effect on tumor growth was significantly stronger than that of anhydrous ethanol. By contrast, the injured normal tissue by PTS injection was less than that by ethanol. In vitro, PTS still demonstrated excellent necrotizing effect on H460 cells when diluted to a lower concentration. Detailed analysis of PTS on H460 cells indicated that PTS had a better effect on attenuating the cell viability and increasing the cell membrane permeability than ethanol at the same level. Conclusions PTS exhibits excellent inhibition effect on the growth of lung cancer by necrotizing tumor in vivo and in vitro, reducing tumor cell viability and augmenting the membrane permeability in vitro, with only mild injury to normal tissue. The

  4. para-Aminobenzoic Acid Is a Precursor in Coenzyme Q6 Biosynthesis in Saccharomyces cerevisiae*

    PubMed Central

    Marbois, Beth; Xie, Letian X.; Choi, Samuel; Hirano, Kathleen; Hyman, Kyle; Clarke, Catherine F.

    2010-01-01

    Coenzyme Q (ubiquinone or Q) is a crucial mitochondrial lipid required for respiratory electron transport in eukaryotes. 4-Hydroxybenozoate (4HB) is an aromatic ring precursor that forms the benzoquinone ring of Q and is used extensively to examine Q biosynthesis. However, the direct precursor compounds and enzymatic steps for synthesis of 4HB in yeast are unknown. Here we show that para-aminobenzoic acid (pABA), a well known precursor of folate, also functions as a precursor for Q biosynthesis. A hexaprenylated form of pABA (prenyl-pABA) is normally present in wild-type yeast crude lipid extracts but is absent in yeast abz1 mutants starved for pABA. A stable 13C6-isotope of pABA (p- amino[aromatic-13C6]benzoic acid ([13C6]pABA)), is prenylated in either wild-type or abz1 mutant yeast to form prenyl-[13C6]pABA. We demonstrate by HPLC and mass spectrometry that yeast incubated with either [13C6]pABA or [13C6]4HB generate both 13C6-demethoxy-Q (DMQ), a late stage Q biosynthetic intermediate, as well as the final product 13C6-coenzyme Q. Pulse-labeling analyses show that formation of prenyl-pABA occurs within minutes and precedes the synthesis of Q. Yeast utilizing pABA as a ring precursor produce another nitrogen containing intermediate, 4-imino-DMQ6. This intermediate is produced in small quantities in wild-type yeast cultured in standard media and in abz1 mutants supplemented with pABA. We suggest a mechanism where Schiff base-mediated deimination forms DMQ6 quinone, thereby eliminating the nitrogen contributed by pABA. This scheme results in the convergence of the 4HB and pABA pathways in eukaryotic Q biosynthesis and has implications regarding the action of pABA-based antifolates. PMID:20592037

  5. An integrated management tool for rockfall evaluation along transportation corridors: the ParaChute research project

    NASA Astrophysics Data System (ADS)

    Cloutier, Catherine; Locat, Jacques; Mayers, Mélanie; Noël, François; Turmel, Dominique; Jacob, Chantal; Dorval, Pierre; Bossé, François; Gionet, Pierre; Jaboyedoff, Michel

    2016-04-01

    Rockfall is a significant hazard along linear infrastructures due to the presence of natural and man-made rock slopes. Knowing where the problematic rockfalls source areas are is of primary importance to properly manage and mitigate the risk associated to rockfall along linear infrastructures. The aim of the ParaChute research project is to integrate various technologies into a workflow for rockfall characterization for such infrastructures, using a 220 km-long railroad as the study site which is located on Québec's North Shore, Canada. The objectives of this 3-year project which started in 2014 are: (1) to optimize the use of terrestrial, mobile and airborne laser scanners data into terrain analysis, structural geology analysis and rockfall susceptibility rating, (2) to further develop the use of unmanned aerial vehicles (UAV) for photogrammetry applied to rock cliff characterization, and (3) to integrate rockfall simulation studies into a rock slope classification system similar to the Rockfall Hazard Rating System. Firstly, based on laser scanner data and aerial photographs, the morpho-structural features of the terrain (genetic material, landform, drainage, etc.) are mapped. The result can be used to assess all types of mass movements. Secondly, to guide field work and decrease uncertainty of various parameters, systematic rockfall simulations and a first structural analysis are made from point clouds acquired by mobile and airborne laser scanner. The simulation results are used to recognize the rock slopes that have potentially problematic rockfall paths, meaning they could reach the linear infrastructure. Other rock slopes are not included in the inventory. Field work is carried out to validate and complete the rock slopes characterization previously made from remote sensing technique. Because some or parts of cliffs are not visible or accessible from the railroad, we are currently developing the use of photogrammetry by UAV in order to complete the

  6. Failures of TDDFT in describing the lowest intramolecular charge-transfer excitation in para-nitroaniline

    NASA Astrophysics Data System (ADS)

    Eriksen, Janus J.; Sauer, Stephan P. A.; Mikkelsen, Kurt V.; Christiansen, Ove; Jensen, Hans Jørgen Aa.; Kongsted, Jacob

    2013-07-01

    We investigate the failure of time-dependent density functional theory (TDDFT) with the CAM-B3LYP exchange-correlation (xc) functional coupled to the polarisable embedding (PE) scheme (PE-CAM-B3LYP) in reproducing the solvatochromic shift of the lowest intense charge-transfer excitation in para-nitroaniline (pNA) in water by comparing with results obtained with the coupled cluster singles and doubles (CCSD) model also coupled to the polarisable embedding scheme (PE-CCSD). We determine the amount of charge separation in the ground and excited charge-transfer state with both methods by calculating the electric dipole moments in the gas phase and for 100 solvent configurations. We find that CAM-B3LYP overestimates the amount of charge separation inherent in the ground state and TDDFT/CAM-B3LYP drastically underestimates this amount in the excited charge-transfer state. As the errors in the solvatochromatic shift are found to be inverse proportional to the change in dipole moment upon excitation, we conclude that the flaws in the description of the solvatochromic shift of this excitation are related to TDDFT itself and how it responds to the solvent effects modelled by the PE scheme. We recommend therefore to benchmark results of TDDFT calculations with CAM-B3LYP for intramolecular charge-transfer excitations in molecular systems similar to pNA against higher level ab initio wave function methods, like, e.g. CCSD, prior to their use. Using the calculated change in dipole moment upon excitation as a measure for charge-transfer character, we furthermore confirm that the difference between excitation energies calculated with TDDFT and with the Tamm-Dancoff approximation (TDA) to TDDFT is indeed correlated with the charge-transfer character of a given electronic transition both in vacuo and in solution. This is supported by a corresponding correlation between the change in dipole moment and the size of the Λ index diagnostic for the investigated CT excitation.

  7. The change in upper tract urolithiasis composition, surgical treatments and outcomes of para and quadriplegic patients over time.

    PubMed

    Clifton, Marisa M; Gettman, Matthew T; Patterson, David E; Rangel, Laureano; Krambeck, Amy E

    2014-10-01

    Stone disease in patients with spinal cord injury is a source of morbidity and mortality. Previous studies have indicated a decrease in infection-based urolithiasis in recent decades. We aimed to identify changes in stone composition and surgical outcomes in patients with para and quadriplegia over time. A retrospective review of para and quadriplegic patients from 1986 to 2011 who underwent surgical intervention for urolithiasis was performed, identifying 95 patients. The Mantel-Haenszel Chi square test was used to compare change in stone composition over time. The mean patient age was 44.0 years (range 18-88) and treatment included percutaneous nephrolithotomy (PCNL) 40 (42.1 %), ureteroscopy 28 (29.5 %), shock wave lithotripsy (SWL) 26 (27.4 %), and nephrectomy 1 (1 %). Overall stone-free status was found in 47.4 % with 19.0 % requiring a repeat procedure. The median hospital stay for patients undergoing SWL was 2.5 days, ureteroscopy 5 days, and PCNL 6 days. Infection-based stone composition was identified in 23 patients (36.5 %). We evaluated the linear change in percent of each stone component over time and identified increasing components of calcium oxalate dihydrate (p = 0.002) and calcium carbonate (p = 0.009). However, over a period of 25 years, the incidence of infection-based stone did not change (p = 0.57). Para and quadriplegic patients with urolithiasis can be difficult to treat surgically with prolonged hospitalizations, low stone-free status, and often require additional procedures. Despite improvements in antibiotic agents and management of neurogenic bladders, infection-based calculi continue to be a significant source of morbidity to this patient population. PMID:25015593

  8. Radiosurgery for Para-IAC Meningiomas: The Effect of Radiation Dose to the Cochlea on Hearing Outcome

    SciTech Connect

    Kim, Young-Hoon; Kim, Dong Gyu; Han, Jung Ho; Chung, Hyun-Tai; Kim, In Kyung; Song, Sang Woo; Park, Jeong-Hoon; Kim, Jin Wook; Kim, Yong Hwy; Park, Chul-Kee; Kim, Chae-Yong; Paek, Sun Ha; Jung, Hee-Won

    2012-11-01

    Purpose: This study was performed to assess the radiosurgical results of meningiomas extending into the internal acoustic canal (para-IAC meningiomas), with a particular focus on the effect of radiation dose to the cochlea on hearing outcome. Methods and Materials: A total of 50 patients who underwent radiosurgery for para-IAC meningiomas between 1998 and 2009, which were followed for 2 years, were enrolled. The mean age was 55.8 years (range, 15-75). The mean tumor volume was 6.1 cm{sup 3} (range, 1.0-19.0), the mean tumor length in the IAC was 6.9 mm (range, 1.3-13.3), and the mean prescribed marginal dose was 13.1 Gy (range, 10-15) at an isodose line of 50%. The mean follow-up duration was 46 months (range, 24-122). Results: Eight (16.0%) patients had nonserviceable hearing at the time of surgery. At the last follow-up, the tumor control rate was 94%; unchanged in 17 patients, decreased in 30 patients, and increased in 3 patients. Among 42 patients with serviceable hearing at the time of radiosurgery, it was preserved in 41 (97.6%) patients at the last follow-up. The maximal and mean radiation doses to the cochleae of these 41 patients were 5.8 Gy {+-} 0.3 (range, 3.1-11.5) and 4.3 Gy {+-} 0.2 (range, 2.2-7.5), respectively. The maximal dose to the cochlea of the patient who lost hearing after radiosurgery was 4.7 Gy. Conclusions: The radiation dose to the cochlea may have the minimal toxic effect on the hearing outcome in patients who undergo radiosurgery for para-IAC meningiomas.

  9. High Resolution Infrared Spectroscopy of CH_3F-({ortho}-H_2){n} Cluster in Solid {para}-H_2

    NASA Astrophysics Data System (ADS)

    Kawasaki, Hiroyuki; Mizoguchi, Asao; Kanamori, Hideto

    2015-06-01

    The absorption spectrum of the ν3 (C-F stretching) mode of CH_3F in solid {para}-H_2 by FTIR showed a series of equal interval peaks. Their interpretation was that the {}-th peak of this series was due to CH_3F-({ortho}-H_2){n} clusters which were formed CH_3F and {n}'s {ortho}-H_2 in first nearest neighbor sites of the {para}-H_2 crystal with {hcp} structure. In order to understand this system in more detail, we have studied these peaks, especially {n} = 0 - 3 corresponding to 1037 - 1041 wn, by using high-resolution and high-sensitive infrared quantum cascade (QC) laser spectroscopy. Before now, we found many peaks around each {n}-th peak of the cluster, which we didn't know their origins. We observed photochromic phenomenon of these peaks by taking an advantage of the high brightness of the laser. In this study, we focus on satellite series consisting of six peaks which locate at the lower energy side of each main peak. All the peaks showed a common red shouldered line profile, which corresponds to partly resolved transitions of {ortho}- and {para}- CH_3F. The spectral pattern and time behavior of the peaks may suggest that these satellite series originate from a family of CH_3F clusters involving {ortho}-H_2 in second nearest neighbor sites. A model function assuming this idea is used to resolve the observed spectrum into each Lorentzian component, and then some common features of the satellite peaks are extracted and the physical meanings of them will be discussed. K. Yoshioka and D. T. Anderson, J. Chem. Phys. 119 (2003) 4731-4742 A. R. W. McKellar, A. Mizoguchi, and H. Kanamori, J. Chem. Phys. 135 (2011) 124511 A. R. W. McKellar, A. Mizoguchi, and H. Kanamori, Phys. Chem. Chem. Phys. 13 (2011) 11587-11589.

  10. The effect of partial hepatectomy on the metabolism, distribution, and nephrotoxicity of para-methylthiobenzamide in the rat.

    PubMed

    Cox, D N; Davidson, V P; Judd, C E; Stodgell, C; Traiger, G J

    1992-04-01

    Para-Methylthiobenzamide (PMTB) produces injury to the liver and kidney. Toxicity is mediated via its biotransformation to a reactive S,S-dioxide metabolite. The objective of this study was to examine the role of hepatic metabolism in the production of PMTB-induced renal toxicity. Renal injury was assessed in partially hepatectomized and sham-operated rats and the effect of this procedure on the distribution and metabolism of PMTB was examined. The in vitro oxidation of PMTB and [14C]thiobenzamide by rat kidney microsomes was also examined. Plasma urea levels and renal cortical slice uptake of organic ions were used to monitor renal function. Partial hepatectomy alone did not alter renal function nor raise blood urea nitrogen levels. Nephrotoxicity resulted when a nonnephrotoxic dose of PMTB (1.2 mmol/kg) was given to partially hepatectomized rats. An HPLC method was used for measurement of PMTB and its metabolites para-methylthiobenzamide S-oxide (PMTBSO) and para-methylbenzamide (PMBA) in plasma and kidney. Hepatectomy delayed the removal of this dose of PMTB from plasma and allowed greater concentrations of PMTB and PMTBSO to accumulate in plasma and kidney at 6 and 15 hr. The level of PMBA was similar in both groups at 6 hr, but was increased in plasma and kidney of the hepatectomized group at 15 hr. Kidney microsomes rapidly converted PMTB to PMTBSO and small amounts of PMBA. [14C]TB was oxidized by microsomes to thiobenzamide S-oxide, benzamide, and covalently bound metabolites. The results indicate that partial hepatectomy lowered the threshold for the expression of nephrotoxicity by PMTB. This procedure is associated with an increased renal accumulation of PMTB and PMTBSO, which are both sequentially transformed to the toxic metabolite. PMID:1561633

  11. Developing Continuous-Wave Raman Lasers Using Solid Para-Hydrogen and Barium Nitrate for Molecular Spectroscopy Applications

    NASA Astrophysics Data System (ADS)

    Evans, William R.; Momose, Takamasa; McCall, Benjamin J.

    2012-06-01

    Many interesting molecular targets have vibrational transitions between 5 and 10 μm. However, widely tunable continuous-wave laser sources in this region are extremely rare. One possible solution to this situation is with continuous-wave Raman lasers. We will present our recent work toward the construction of two continuous-wave Raman lasers: one using solid para-hydrogen as the Raman shifting medium, and the other using barium nitrate. Solid para-hydrogen is a promising medium for a continuous-wave Raman laser because of its high Raman gain coefficient (18 cm/MW, almost 400 times higher than any room-temperature crystal), wide spectral transmission window (transparent from ˜100 nm to ˜30 μm), its nature as a ``quantum crystal," and its large Raman shift (4150 cm-1 in the solid). We will also describe our more recent work designing and constructing a continuous-wave Raman laser in barium nitrate. Barium nitrate has the advantage of being the room-temperature crystal with the highest Raman gain coefficient, as well as being highly transparent from 350 to 1800 nm. Barium nitrate has been used as a continuous-wave Raman shifter for several years. Our recent work builds upon this foundation, combining lessons learned from our work with solid para-hydrogen. Our design is the first barium nitrate Raman laser using an actively-locked, doubly-resonant laser cavity. This holds the promise of requiring much lower threshold pump powers than previous setups. We will discuss some of the details in designing and building these lasers. Finally, we will report on the current state of our projects as well as anticipated future work.

  12. Desarrollo de la Escala sobre el Estigma Relacionado con el VIH/SIDA para Profesionales de la Salud mediante el uso de métodos mixtos123

    PubMed Central

    Varas-Díaz, Nelson; Neilands, Torsten B.; Guilamo-Ramos, Vincent; Cintrón Bou, Francheska N.

    2009-01-01

    El estigma relacionado con el VIH/SIDA continúa siendo un obstáculo para la prevención primaria y secundaria del VIH. Las consecuencias para las personas que viven con la enfermedad han sido muy documentadas y continúan siendo una gran preocupación para las personas que proveen servicios de salud y para aquellas que investigan el tema. Estas consecuencias son preocupantes cuando el estigma emana de profesionales de la salud porque se puede limitar el acceso a los servicios. Uno de los principales obstáculos para la investigación del estigma relacionado con el VIH en Puerto Rico es la falta de instrumentos cuantitativos para evaluar las manifestaciones del estigma entre profesionales de la salud. El objetivo principal de este estudio fue desarrollar y probar las propiedades psicométricas de una escala sobre el estigma relacionado con el VIH/SIDA culturalmente apropiada para personas que proveen servicios de salud puertorriqueñas y desarrollar una versión corta de la escala que pudiera usarse en escenarios clínicos con tiempo limitado. El instrumento desarrollado estuvo basado en evidencia cualitativa recopilada entre profesionales y estudiantes de profesiones de la salud puertorriqueños/as (n=80) y administrado a una muestra de 421 profesionales de la salud en adiestramiento. La escala contenía 12 dimensiones del estigma relacionado con el VIH/SIDA. El análisis cuantitativo corroboró 11 de ellas, teniendo como resultado un instrumento con validez y confiabilidad satisfactoria. Estas dimensiones, a su vez, fueron subcomponentes de un factor de estigma general superior. PMID:20333258

  13. Application of meta- and para- phenylenediamine as enhanced oxime ligation catalysts for protein labeling, PEGylation, immobilization and release

    PubMed Central

    Mahmoodi, Mohammad M.; Rashidian, Mohammad; Zhang, Yi; Distefano, Mark D.

    2015-01-01

    Meta- and para- phenylenediamines have recently been shown to catalyze oxime and hydrazone ligation reactions at rates much faster than aniline, a commonly used catalyst. Here, it is demonstrated how these new catalysts can be used in a generally applicable procedure for fluorescent labeling, PEGylation, immobilization and release of aldehyde and ketone functionalized proteins. The chemical orthogonality of phenylenediamine-catalyzed oxime ligation versus copper catalyzed click reaction has also been harnessed for simultaneous dual labeling of bifunctional proteins containing both aldehyde and alkyne groups in high yield. PMID:25640893

  14. Direct Construction of 4-Hydroxybenzils via Para-Selective C-C Bond Coupling of Phenols and Aryl Methyl Ketones.

    PubMed

    Xiang, Jia-Chen; Cheng, Yan; Wang, Miao; Wu, Yan-Dong; Wu, An-Xin

    2016-09-01

    A highly para-selective C-C bond coupling is presented between phenols C(sp(2)) and aryl methyl ketones C(sp(3)), which enables the direct construction of 4-hydroxybenzil derivatives. This practical method exhibits a broad substrate scope and large-scale applicability and represents a general gateway to the hydroxybenzil natural product family. Mechanistic investigations indicated that the combination of HI with DMSO realized the oxidative carbonylation of aryl methyl ketones, while boric acid acted as a dual-functional relay reagent to promote this transformation. PMID:27513164

  15. Optically engineered quantum interference of delocalized wave functions in a bulk solid: The example of solid para-hydrogen

    NASA Astrophysics Data System (ADS)

    Katsuki, Hiroyuki; Kayanuma, Yosuke; Ohmori, Kenji

    2013-07-01

    Local excitations of indistinguishable particles in a solid are quantum-mechanically superposed to give delocalized wave functions. Their interference is often so short-lived that it eludes observation and manipulation. Here we have actively controlled interference of delocalized vibrational wave functions in solid para-hydrogen produced by a pair of ultrashort laser pulses. The ultrafast evolution of their interference changes from almost completely constructive (amplification by a factor of ˜4) to destructive when we change the timing of those two laser pulses by only 4 fs. This active control serves as an experimental tool to investigate the spatiotemporal evolution of a wave function in a bulk solid.

  16. Selective and Efficient Generation of ortho-Brominated para-Substituted Phenols in ACS-Grade Methanol.

    PubMed

    Georgiev, David; Saes, Bartholomeus W H; Johnston, Heather J; Boys, Sarah K; Healy, Alan; Hulme, Alison N

    2016-01-01

    The mono ortho-bromination of phenolic building blocks by NBS has been achieved in short reaction times (15-20 min) using ACS-grade methanol as a solvent. The reactions can be conducted on phenol, naphthol and biphenol substrates, giving yields of >86% on gram scale. Excellent selectivity for the desired mono ortho-brominated products is achieved in the presence of 10 mol % para-TsOH, and the reaction is shown to be tolerant of a range of substituents, including CH3, F, and NHBoc. PMID:26771597

  17. Projeto do sistema anti-ressonante da fiação dos transdutores para o detector Mario Schenberg

    NASA Astrophysics Data System (ADS)

    Vieira, S. J.., Jr.; Melo, J. L.

    2003-08-01

    O detector de ondas gravitacionais Mario Schenberg está sendo projetado e construído pelo grupo Gráviton. Sua construção está ocorrendo no Laboratório de Estado Sólido e Baixas Temperaturas (LESBT) da Universidade de São Paulo, na cidade de São Paulo. Esse detector possui uma massa ressonante esférica de cobre-alumínio, com 65 cm de diâmetro, pesando aproximadamente 1150 Kg, suspensa por um sistema de isolamento vibracional, que se encontra em fase de testes preliminares. A real eficácia desse sistema, entretanto, só poderá ser comprovada quando o detector estiver aparelhado com, pelo menos, um transdutor eletromecânico de altíssima sensibilidade acoplado à massa ressonante. Neste momento, não só este sistema de isolamento vibracional será posto em teste, como o do projeto da fiação que transporta os sinais de microondas até os transdutores e destes para a pré-amplificação. Apesar dessa fiação ter sido projetada para não apresentar nenhum contato com a superfície esférica da antena, de maneira a não haver nenhuma transmissão de ruído vibracional do laboratório para esta, deve-se minimizar o ruído microfônico produzido nessa fiação por oscilações mecânicas, uma vez que ela não utiliza nenhum sistema de isolamento vibracional. Com o intuito de resolver este problema, projetamos uma estrutura, formada por pequenos cilindros conectados por barras, a qual não terá nenhuma ressonância mecânica na faixa de freqüências de interesse para detecção (3000 - 3400 Hz). Desta forma, as vibrações nessa faixa não serão amplificadas. O projeto foi feito usando iterativamente, de maneira a otimizar os resultados obtidos, o programa de elementos finitos Msc/Nastran. Através de simulações feitas neste programa, determinamos os parâmetros geométricos ideais a serem utilizados, os quais proporcionam a maior região espectral de interesse livre de ressonâncias.

  18. Microbiological Transformations. 33. Fungal Epoxide Hydrolases Applied to the Synthesis of Enantiopure Para-Substituted Styrene Oxides. A Mechanistic Approach.

    PubMed

    Pedragosa-Moreau, S.; Morisseau, C.; Zylber, J.; Archelas, A.; Baratti, J.; Furstoss, R.

    1996-10-18

    The biohydrolysis of differently para-substituted styrene oxide derivatives was studied, using whole cells of the fungi Aspergillus niger or Beauveria sulfurescens. These microorganisms proved to be equipped with epoxide hydrolases which are able to achieve these hydrolyses with high enantioselectivity. This allowed the preparation of the optically active epoxides and of the corresponding vicinal diols which were obtained with good to excellent enantiomeric purity. These two microorganisms proved to be enantiocomplementary. A mechanistic study, carried out using a crude lyophilized enzymatic extract from A.niger, indicated via Hammet coefficient plotting that this hydrolysis is very probably due to a general base-catalyzed process. PMID:11667667

  19. An inverse geometry neutron scattering spectrometer with graphite Venetian blind crystal analyser and a para-hydrogen filter

    NASA Astrophysics Data System (ADS)

    Petrillo, C.; Sacchetti, F.; Celli, M.; Zoppi, M.; Checchi, C. A.

    2000-03-01

    The design of a neutron spectrometer for inelastic scattering with inverse geometry configuration is presented. The main new characteristics of the proposed design are the use of a Venetian blind arrangement for the crystal analysers and the insertion of a para-hydrogen filter for the suppression of higher-order reflections. Based on this design, a prototype arm was built and tested at ISIS Spallation Neutron Source (UK). The results of the test measurements, showing the performances of the system, are presented and discussed.

  20. Simple ortho- and para-hydroquinones as compounds neuroprotective against oxidative stress in a manner associated with specific transcriptional activation

    SciTech Connect

    Satoh, Takumi Saitoh, Sachie; Hosaka, Manami; Kosaka, Kunio

    2009-02-06

    Electrophilic compounds protect neurons through the activation of the Keap1/Nrf2 pathway and the induction of phase-2 enzymes [T. Satoh, S.A. Lipton, Redox regulation of neuronal survival by electrophilic compounds, Trends Neurosci. 30 (2007) 38-45; T. Satoh, S. Okamoto, J. Cui, Y. Watanabe, K. Furuta, M. Suzuki, K. Tohyama, S.A. Lipton, Activation of the Keap1/Nrf2 pathway for neuroprotection by electrophilic phase II inducers. Proc. Natl. Acad. Sci. USA 103 (2006) 768-773]. Hydroquinone-type electrophilic compounds such as tert-butyl hydroquinone (TBHQ) and carnosic acid (CA) have attracted special attention, because the oxidative conversion of 'hydroquinone' to 'quinone' is essential for the transcriptional activation of the above-mentioned enzymes [T. Satoh, K. Kosaka, K. Itoh, A. Kobayashi, M. Yamamoto, Y. Shimojo, C. Kitajima, J. Cui, J. Kamins, S. Okamoto, T. Shirasawa, S.A. Lipton, Carnosic acid, a catechol-type electrophilic compound, protect neurons both in vitro and in vivo through activation of the Keap1/Nrf2 pathway via S-alkylation of specific cysteine, J. Neurochem. 104 (2008) 1161-1131; A.D. Kraft, D.A. Johnson, J.A. Johnson, Nuclear factor E2-related factor 2-dependent antioxidant response element activation by tert-butylhydroquinone and sulforaphane occurring preferentially in astrocytes conditions neurons against oxidative insult, J. Neurosci. 24 (2004) 1101-1112]. In the present study, we examined the relationship between electrophilicity and the protective effects afforded by electrophilic compounds. Electrophilicity was assessed in terms of the ability of a compound to bind to a cysteine on bovine serum albumin, by which we found that neuroprotective hydroquinones [TBHQ (para-) and CA (ortho-)] had distinctive patterns of cysteine binding compared with other electrophilic compounds. Further, we found that isomers of simple ortho- and para-hydroquinones such as 2-methylhydroquinone (para-) and 4-methyl-catechol (ortho-) [not in abstract] had