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  1. Chicano Students: Applying Tinto's and Astin's Theories.

    ERIC Educational Resources Information Center

    von Destinon, Mark

    Chicano student dropout and persistence is discussed in terms of the theories of Tinto and Astin on student integration and involvement. An overview of each theory is presented with references to Chicano student retention, and a review of the literature on Chicano students is provided. The studies reviewed here identified Chicano student…

  2. Student Retention: An Interview with Vincent Tinto.

    ERIC Educational Resources Information Center

    Spann, Nancy G.

    1990-01-01

    Educator and researcher specializing in student retention, Tinto discusses own experience leaving doctoral program to join Peace Corps, reviews internal and external causes of attrition, characteristics of successful retention programs, and role of teaching in retention. Favors establishing a sense of community on campuses to enhance students'…

  3. 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.

  4. Testing Tinto's Model of Attrition on the Church-Related Campus. AIR 1985 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Cash, R. William; Bissel, H. LeVerne

    The applicability of Tinto's model of retention for first-year students attending church-related colleges and universities is examined. Data collected from entering freshmen at two Midwestern Seventh-day Adventist colleges were used to replicate studies of Tinto's model done in other settings. Based on Tinto's model, indicators of academic and…

  5. 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.

  6. A Path Analytic Validation of Tinto's Theory of College Student Attrition.

    ERIC Educational Resources Information Center

    Terenzini, Patrick T.; And Others

    An earlier path analytic study of the predictive validity of Tinto's theory of college student attrition was replicated using an independent sample of students from another university. Tinto conceived of the attrition/retention process as a series of sociopsychological interactions between the characteristics students bring with them to college…

  7. Student Drop-Out in Distance Education: An Application of Tinto's Model.

    ERIC Educational Resources Information Center

    Sweet, Robert

    1986-01-01

    Describes a survey of 356 adult students enrolled in university-level courses at the Open Learning Institute which was conducted to assess the predictive validity of Tinto's theoretical model of student dropout. It was found that, overall, the Tinto model appears to be a useful framework for such investigations. (Author/LRW)

  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 has been used like an environmental scenario for new technology validation for astrobiology space missions. M.A.R.T.E. (Mars Analog Research Technology Experiment) was a multidisciplinary project for technology development in the NAI framework. REFERENCES 1.- López-Archilla, A.I., Marín, I., Amils, R. (2001) Microbial Ecol., 41: 20-35. 2.- Amaral-Zettler, L.A., Gómez, F., Zettler, E., Keenan, B.G., Amils, R., Sogin, M. (2002) Nature, 417: 137. 3.- González-Toril, E., Gómez, F., Rodríguez, N., Fernández-Remolar, D., Zuluaga, J., Marín, I., Amils, R., (2002) Hydrometall., in press. 4.- Amils, R., González-Toril, E., Gómez, F., Fernández-Remolar, D., Rodríguez, N. (2000) Spring Meeting American Geophysical Society, Abstract B22B-05. 5.- Fernández-Remolar, D.C., Rodríguez, N., Gómez, F., Amils, R. (2003) J. Geophys. Res., 108, No.E7 doi. 10.1029/2002JE001918

  9. Eukaryotic organisms in extreme acidic environments, the río tinto case.

    PubMed

    Aguilera, Angeles

    2013-01-01

    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). PMID:25369810

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

    PubMed Central

    Aguilera, Angeles

    2013-01-01

    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). PMID:25369810

  11. 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).

  12. 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

  13. 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…

  14. 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.

  15. Iberian Pyrite Belt Subsurface Life (IPBSL): searching for life in the Rio Tinto subsurface

    NASA Astrophysics Data System (ADS)

    Amils, R.; Gómez, F.; Prieto-Ballesteros, O.; Fernández-Remolar, D.; Parro, V.; Rodríguez-Manfredi, J. A.; Tornos-Arroyo, F.; Timmis, K.; Oggerin, M.; Sánchez-Román, M.; López, F. J.; Fernández, J. P.; Omoregie, E.; Puente-Sánchez, F.; García, M.; Rodríguez, N.

    2013-09-01

    The geomicrobiologica l characterization of Río Tinto (Iberian Pyrite Belt), has proven the importance of the iron and sulfur cycles in generating the extreme conditions of acidity and high concentration of heavy metals of the habitat. It has been hypothesized that the extreme conditions found in the Tinto basin are the product of the subsurface chemolithotrophic metabolism of microorganisms thriving on the high concentrat ion of metal sulfides of the IPB. To test this hypothesis, a drilling project (IPBSL) is currently under development to provide evidence of subsurface microbial activities and the potential resources to support them.

  16. 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.

  17. A Methodological Critique of Tinto's Student Retention Theory. AIR 2002 Forum Paper.

    ERIC Educational Resources Information Center

    Liu, Richard

    College student retention has become the area of research that has done the most to integrate various administrative factors and academic disciplinary concerns in the research agenda of higher education. V. Tintos model has long been cited as the major theory in explaining dropout behavior. As his theory is so intertwined with path analysis,…

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. Macrofilamentous microbial communities in the metal-rich and acidic River Tinto, Spain.

    PubMed

    López-Archilla, Ana I; Gérard, Emmanuelle; Moreira, David; López-García, Purificación

    2004-06-15

    A novel type of macroscopic microbial community consisting of large dendritic filaments (up to 1.5 m) in a pH 2.0 dam of the River Tinto (South-western Spain) is described. The combined use of 16S rRNA-gene surveys and fluorescent in situ hybridisation (FISH) suggested that gamma-proteobacteria and a relative large diversity of alpha-proteobacteria dominated these structures. beta-Proteobacteria, Actinobacteria and Firmicutes were also detected. Whereas acidophilic bacteria of the genera Acidithiobacillus, Leptospirillum and Acidiphilium, and archaea belonging to the Thermoplasmatales dominate mine acid drainage waters and streamers (riverbed filamentous biofilms), none of the lineages identified in this study affiliate to typical acid mine drainage acidophilic bacteria. Bacteria of the Tinto macrofilaments might be heterotrophic, and could be feeding on the organic matter entrapped in the filamentous structure. PMID:15183867

  4. From Río Tinto to Mars: the terrestrial and extraterrestrial ecology of acidophiles.

    PubMed

    Amils, R; González-Toril, E; Aguilera, A; Rodríguez, N; Fernández-Remolar, D; Gómez, F; García-Moyano, A; Malki, M; Oggerin, M; Sánchez-Andrea, I; Sanz, J L

    2011-01-01

    The recent geomicrobiological characterization of Río Tinto, Iberian Pyrite Belt (IPB), has proven the importance of the iron cycle, 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, both prokaryotic and eukaryotic, detected in the water column and the sediments. The extreme conditions of the Tinto basin are not the product of industrial contamination but the consequence of the presence of an underground bioreactor that obtains its energy from the massive sulfide minerals of the IPB. To test this hypothesis, a drilling project was carried out to intersect ground waters that interact with the mineral ore in order to provide evidence of subsurface microbial activities and the potential resources to support these activities. The oxidants that drive the system appear to come from the rock matrix, contradicting conventional acid mine drainage models. These resources need only groundwater to launch microbial metabolism. There are several similarities between the vast deposits of sulfates and iron oxides on Mars and the main sulfide-containing iron bioleaching products found in the Tinto. Firstly, the short-lived methane detected both in Mars' atmosphere and in the sediments and subsurface of the IPB and secondly, the abundance of iron, common to both. The physicochemical properties of iron make it a source of energy, a shield against radiation and oxidative stress as well as a natural pH controller. These similarities have led to Río Tinto's status as a Mars terrestrial analogue. PMID:22050821

  5. The Rio Tinto Mars Analogue site: An extremophilic Raman spectroscopic study

    NASA Astrophysics Data System (ADS)

    Edwards, Howell G. M.; Vandenabeele, Peter; Jorge-Villar, Susana E.; Carter, Elizabeth A.; Perez, Fernando Rull; Hargreaves, Michael D.

    2007-12-01

    The Rio Tinto site is recognised as a terrestrial Mars analogue because of the presence of jarosite and related sulfates which have recently been identified by the NASA Mars Exploration Rover "Opportunity" in the El Capitan region of Meridiani Planum on Mars. It has long been known that acidophilic microbial action is responsible for the deep blood-red colour of the water in Rio Tinto, where the pH varies from about 1.5 to 3.0 and the water is rich in iron and sulfur. Following recent Raman spectroscopic characterisation of the mineral phases of the Rio Tinto system, we report here a study of the biological components found in several specimens of deposited minerals and near the waterside that were collected during a GeoRaman VI Conference organized field trip in 2006. Key biosignatures were found for carotenoids, scytonemin and mycosporine-like amino acids, which are indicative of the biological colonisation of exposed mineral substrates; information from this study will be useful for targeting Martian sites using a miniaturized Raman instrument where the biosignatures of relict or extant life could remain in the geological record.

  6. The Rio Tinto Mars analogue site: an extremophilic Raman spectroscopic study.

    PubMed

    Edwards, Howell G M; Vandenabeele, Peter; Jorge-Villar, Susana E; Carter, Elizabeth A; Perez, Fernando Rull; Hargreaves, Michael D

    2007-12-15

    The Rio Tinto site is recognised as a terrestrial Mars analogue because of the presence of jarosite and related sulfates which have recently been identified by the NASA Mars Exploration Rover "Opportunity" in the El Capitan region of Meridiani Planum on Mars. It has long been known that acidophilic microbial action is responsible for the deep blood-red colour of the water in Rio Tinto, where the pH varies from about 1.5 to 3.0 and the water is rich in iron and sulfur. Following recent Raman spectroscopic characterisation of the mineral phases of the Rio Tinto system, we report here a study of the biological components found in several specimens of deposited minerals and near the waterside that were collected during a GeoRaman VI Conference organized field trip in 2006. Key biosignatures were found for carotenoids, scytonemin and mycosporine-like amino acids, which are indicative of the biological colonisation of exposed mineral substrates; information from this study will be useful for targeting Martian sites using a miniaturized Raman instrument where the biosignatures of relict or extant life could remain in the geological record. PMID:17600759

  7. 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.

  8. 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.

  9. 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.

  10. 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 epidemiological analysis of heavy metal effects in humans is appropriate. ?? 1993 Estuarine Research Federation.

  11. 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.

  12. Underground habitats in the Río Tinto basin: a model for subsurface life habitats on Mars.

    PubMed

    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., pO(2), 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 CO(2), CH(4), and H(2). 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. PMID:19105758

  13. 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.

  14. 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.

  15. 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.

  16. 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 carbon or transient oxygen. These results suggest that multiple energy sources are available from sulfide-mineral weathering to support microbial metabolism, even in the absence of atmospheric oxygen. [1] Stevens, T.O and McKinley, J.P. (1995) Scienc,, 270, 450-454. [2] Amis, R. et al. (2007) Planet Space Sci, 55, 370- 381. [3] Fernández-Remolar, D. et al. (2005) Earth Planet Sci Lett, 240, 149-167. [4] Amils, R. et al. (2008) Microbiology of Extreme Soils, 205-223.

  17. Interaction between sedimentary processes, historical pollution and microfauna in the Tinto Estuary (SW Spain)

    NASA Astrophysics Data System (ADS)

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

    2009-08-01

    The analysis of a short core collected in the Tinto Estuary (SW Spain) permits to delimitate the influence of historical mining activities on sediments and microfauna (Foraminifera and Ostracoda). In very shallow palaeochannels of the middle estuary, a first mining period (~3,600 cal years BP) caused high sediment pollution by Cu, with a significant diminution of the palaeontological record due to continuous acid mining drainage processes. In this core, the polluted levels derived from both Roman extractions (2,000-1,900 years BP) and the extensive mining activities between 1870 and 1935 have been eroded. The 1,800-200 years BP period is characterized by a limited mining activity and an important improvement of this ecosystem. In addition, the effects of recent industrial wastes have been limited in this area.

  18. 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 pH 7 and pH 3 with electron donors provided by the natural substrate. Duplicate reactors were incubated for a total of 10 weeks. Initial data indicate moderate potential sulfate reduction rates of between 5 and 45 nM cm-3 h-1 at both pH 7 and pH 3. Isotope effects will be determined by measuring differences in ?34S between the sulphate in the inflow and outflow solutions. We expect our results to further help in the targeting of sampling sites in the search for traces of life on Mars. References: [1] Van Zuilen, M. (2008). Space Science Reviews 135(1-4): 221-232 [2] Amils, R., et al. (2007), Planetary and Space Science 55, 370-381. [3] Fernández-Remolar, D., et al., (2005), Earth and Planetary Science Letters 240 (2005) 149-167. [4] Mumma, M. J., et al., (2009), Science, Vol 323, pag 1041-1045. [5] Stam, M.C., et al., (2008). Geochim. Cosmochim. Acta 72: A891.

  19. Detection of peptidic sequences in the ancient acidic sediments of Río Tinto, Spain.

    PubMed

    Colín-García, María; Kanawati, Basem; Harir, Mourad; Schmitt-Kopplin, Phillippe; Amils, Ricardo; Parro, Victor; García, Miriam; Fernández-Remolar, David

    2011-12-01

    Biomarkers are molecules that are produced by or can be associated with biological activities. They can be used as tracers that give us an idea of the ancient biological communities that produced them, the paleoenvironmental conditions where they lived, or the mechanism involved in their transformation and preservation. As a consequence, the preservation potential of molecules over time depends largely on their nature, but also on the conditions of the environment, which controls the decomposition kinetics. In this context, proteins and nucleic acids, which are biomolecules bearing biological information, are among the most labile molecules. In this research, we report the presence of short-chained peptides obtained from extracts of ferruginous sedimentary deposits that have been produced under the acidic and oxidizing solutions of Río Tinto, Spain. These preliminary results go against the paradigmatic idea that considers the acidic and oxidizing environments inappropriate for the preservation of molecular information. PMID:22139519

  20. 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 of this experiment have important implications for the strategy for searching for life on Mars.

  1. 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.

  2. Acid mine drainage in the Iberian Pyrite Belt: 1. Hydrochemical characteristics and pollutant load of the Tinto and Odiel rivers.

    PubMed

    Nieto, Jose M; Sarmiento, Aguasanta M; Canovas, Carlos R; Olias, Manuel; Ayora, Carlos

    2013-11-01

    Acid mine drainage in the Iberian Pyrite Belt is probably the worst case in the world of surface water pollution associated with mining of sulphide mineral deposits. The Iberian Pyrite Belt is located in SW Iberian Peninsula, and it has been mined during the last 4,500 years. The central and eastern part of the Iberian Pyrite Belt is drained by the Tinto and Odiel rivers, which receive most of the acidic leachates from the mining areas. As a result, the main channels of the Tinto and Odiel rivers are very rich in metals and highly acidic until reaching the Atlantic Ocean. A significant amount of the pollutant load transported by these two rivers is delivered during the rainy season, as is usual in rivers of Mediterranean climate regions. Therefore, in order to have an accurate estimation of the pollutant loads transported by the Tinto and Odiel rivers, a systematic sampling on a weekly basis and a high temporal resolution sampling of floods events were both performed. Results obtained show that metal fluxes are strongly dependent on the study period, highlighting the importance of inter-annual studies involving dry and wet years. PMID:23589239

  3. 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

  4. 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].

  5. 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.

  6. 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.

  7. Contrasting Microbial Community Assembly Hypotheses: A Reconciling Tale from the Río Tinto

    PubMed Central

    Palacios, Carmen; Zettler, Erik; Amils, Ricardo; Amaral-Zettler, Linda

    2008-01-01

    Background The Río Tinto (RT) is distinguished from other acid mine drainage systems by its natural and ancient origins. Microbial life from all three domains flourishes in this ecosystem, but bacteria dominate metabolic processes that perpetuate environmental extremes. While the patchy geochemistry of the RT likely influences the dynamics of bacterial populations, demonstrating which environmental variables shape microbial diversity and unveiling the mechanisms underlying observed patterns, remain major challenges in microbial ecology whose answers rely upon detailed assessments of community structures coupled with fine-scale measurements of physico-chemical parameters. Methodology/Principal Findings By using high-throughput environmental tag sequencing we achieved saturation of richness estimators for the first time in the RT. We found that environmental factors dictate the distribution of the most abundant taxa in this system, but stochastic niche differentiation processes, such as mutation and dispersal, also contribute to observed diversity patterns. Conclusions/Significance We predict that studies providing clues to the evolutionary and ecological processes underlying microbial distributions will reconcile the ongoing debate between the Baas Becking vs. Hubbell community assembly hypotheses. PMID:19052647

  8. 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

  9. 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.

  10. 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

  11. 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

  12. Hydrochemical variations and contaminant load in the Río Tinto (Spain) during flood events

    NASA Astrophysics Data System (ADS)

    Cánovas, C. R.; Hubbard, C. G.; Olías, M.; Nieto, J. M.; Black, S.; Coleman, M. L.

    2008-02-01

    SummaryThe aim of this work is to study the hydrochemical variations during flood events in the Río Tinto, SW Spain. Three separate rainfall/flood events were monitored in October 2004 following the dry season. In general, concentrations markedly increased following the first event (Fe from 99 to 1130 mg/L; Qmax = 0.78 m 3/s) while dissolved loads peaked in the second event (Fe = 7.5 kg/s, Cu = 0.83 kg/s, Zn = 0.82 kg/s; Qmax = 77 m 3/s) and discharge in the third event ( Qmax = 127 m 3/s). This pattern reflects a progressive depletion of metals and sulphate stored in the dry summer as soluble evaporitic salt minerals and concentrated pore fluids, with dilution by freshwater becoming increasingly dominant as the month progressed. Variations in relative concentrations were attributed to oxyhydroxysulphate Fe precipitation, to relative changes in the sources of acid mine drainage (e.g. salt minerals, mine tunnels, spoil heaps etc.) and to differences in the rainfall distributions along the catchment. The contaminant load carried by the river during October 2004 was enormous, totalling some 770 t of Fe, 420 t of Al, 100 t of Cu, 100 t of Zn and 71 t of Mn. This represents the largest recorded example of this flush-out process in an acid mine drainage setting. Approximately 1000 times more water and 140-8200 times more dissolved elements were carried by the river during October 2004 than during the dry, low-flow conditions of September 2004, highlighting the key role of flood events in the annual pollutant transport budget of semi-arid and arid systems and the need to monitor these events in detail in order to accurately quantify pollutant transport.

  13. Microbial community structure across the tree of life in the extreme Río Tinto.

    PubMed

    Amaral-Zettler, Linda A; Zettler, Erik R; Theroux, Susanna M; Palacios, Carmen; Aguilera, Angeles; Amils, Ricardo

    2011-01-01

    Understanding biotic versus abiotic forces that shape community structure is a fundamental aim of microbial ecology. The acidic and heavy metal extreme Río Tinto (RT) in southwestern Spain provides a rare opportunity to conduct an ecosystem-wide biodiversity inventory at the level of all three domains of life, because diversity there is low and almost exclusively microbial. Despite improvements in high-throughput DNA sequencing, environmental biodiversity studies that use molecular metrics and consider entire ecosystems are rare. These studies can be prohibitively expensive if domains are considered separately, and differences in copy number of eukaryotic ribosomal RNA genes can bias estimates of relative abundances of phylotypes recovered. In this study we have overcome these barriers (1) by targeting all three domains in a single polymerase chain reaction amplification and (2) by using a replicated sampling design that allows for incidence-based methods to extract measures of richness and carry out downstream analyses that address community structuring effects. Our work showed that combined bacterial and archaeal richness is an order of magnitude higher than eukaryotic richness. We also found that eukaryotic richness was highest at the most extreme sites, whereas combined bacterial and archaeal richness was highest at less extreme sites. Quantitative community phylogenetics showed abiotic forces to be primarily responsible for shaping the RT community structure. Canonical correspondence analysis revealed co-occurrence of obligate symbionts and their putative hosts that may contribute to biotic forces shaping community structure and may further provide a possible mechanism for persistence of certain low-abundance bacteria encountered in the RT. PMID:20631808

  14. Microbial community structure across the tree of life in the extreme Río Tinto

    PubMed Central

    Amaral-Zettler, Linda A; Zettler, Erik R; Theroux, Susanna M; Palacios, Carmen; Aguilera, Angeles; Amils, Ricardo

    2011-01-01

    Understanding biotic versus abiotic forces that shape community structure is a fundamental aim of microbial ecology. The acidic and heavy metal extreme Río Tinto (RT) in southwestern Spain provides a rare opportunity to conduct an ecosystem-wide biodiversity inventory at the level of all three domains of life, because diversity there is low and almost exclusively microbial. Despite improvements in high-throughput DNA sequencing, environmental biodiversity studies that use molecular metrics and consider entire ecosystems are rare. These studies can be prohibitively expensive if domains are considered separately, and differences in copy number of eukaryotic ribosomal RNA genes can bias estimates of relative abundances of phylotypes recovered. In this study we have overcome these barriers (1) by targeting all three domains in a single polymerase chain reaction amplification and (2) by using a replicated sampling design that allows for incidence-based methods to extract measures of richness and carry out downstream analyses that address community structuring effects. Our work showed that combined bacterial and archaeal richness is an order of magnitude higher than eukaryotic richness. We also found that eukaryotic richness was highest at the most extreme sites, whereas combined bacterial and archaeal richness was highest at less extreme sites. Quantitative community phylogenetics showed abiotic forces to be primarily responsible for shaping the RT community structure. Canonical correspondence analysis revealed co-occurrence of obligate symbionts and their putative hosts that may contribute to biotic forces shaping community structure and may further provide a possible mechanism for persistence of certain low-abundance bacteria encountered in the RT. PMID:20631808

  15. Assessing The Value of Hydrological Ensemble Predictions for Rio Tinto Alcan's Hydropower System in Eastern Canada

    NASA Astrophysics Data System (ADS)

    Latraverse1, M.; Cote, P.; Larouche1, B.

    2012-04-01

    Rio Tinto Alcan (RTA) is a multinational aluminium producer with smelters in Quebec, Canada. RTA also owns and operates power houses on Péribonka and Saguenay Rivers. The system, which is run by RTA's Quebec Power Operations Division, consists of 6 generating stations and 3 major reservoirs, for an installed capacity of 2900 MW. One of the significant issues that had to be resolved for effective operation of this system was to determine the volume of water release per week for all generating stations. Several challenges had to be dealt with before a suitable solution could be found. Last year, RTA started a five year R&D project for improving the management of the hydropower system. This project includes data monitoring, hydrological ensemble prediction (HEP) and stochastic optimization methods. A concomitant presentation (submitted to HS5.7 by Cote et al.) describes the stochastic optimization project that aims to assess the value of using a stochastic solver instead of a deterministic one. Cote et al. evaluated two different stochastic optimization approaches: lag-1 Stochastic Dynamic Programming (SDP) and Sampling Stochastic Dynamic Programming (SSDP) algorithms. Both stochastic optimization methods use Hydrological Ensemble Prediction (HEP) to capture the spatio-temporal variability of the inflows. This presentation investigates the value of using different HEP procedures in the operation of RTA's hydropower system with stochastic optimization methods. More precisely, the value of using biased or unbiased HEP, the value of using HEP with a good representation or a misrepresentation of the predictive uncertainties were assessed using a test bench study that mimics real-world RTA's operations. The results indicate that in real world operations, biased HEP or under-dispersed HEP can void the gain obtained by stochastic optimization methods.

  16. 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

    2014-09-01

    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 [Int Microbiol 2014; 17(4):225-233]. PMID:26421738

  17. Assessing Stochastic Optimization for Rio Tinto Alcan's Hydropower System in Eastern Canada

    NASA Astrophysics Data System (ADS)

    Cote, P.; Latraverse, M.; Leconte, R.; Larouche, B.

    2012-04-01

    Rio Tinto Alcan (RTA) is a multinational aluminium producer with smelters in Quebec, Canada. RTA also owns and operates power houses on Péribonka and Saguenay Rivers. The system, which is run by RTA's Quebec Power Operations Division, consists of 6 generating stations and 3 major reservoirs, for an installed capacity of 2900 MW. One of the significant issues that had to be resolved for effective operation of this system was to determine the volume of water release per week for all generating stations. Several challenges had to be dealt with before a suitable solution could be found. Last year, RTA started a five year R&D project for improving the management of the hydropower system. This project includes data monitoring, Hydrological Ensemble Prediction (HEP) and stochastic optimization (SO) methods. Development of SO methods is particularly interesting for RTA since, until now, the decision making process has been based on a deterministic solver even if it is impossible to predict naturally contributed volumes with any accuracy beyond a few days. Moreover, the production at the generating stations follows a non-linear, non-convex function of turbine flow rates and water head. Both of these factors have the effect of requiring that the decision should be based upon solving a non-linear and non-convex stochastic optimization problem. The following presentation describes the first part of the SO project and aims to assess the value of using a stochastic solver instead of a deterministic solver. Two different SO approaches were evaluated: lag-1 Stochastic Dynamic Programming (SDP) and Sampling Stochastic Dynamic Programming (SSDP) algorithms. HEP are used to capture the spatio-temporal variability of the inflows. Scenarios are generated using a hydrological model (HM) by initialising the HM with the same initial conditions (hydrologic state variables). These hydrologic variables are estimated using real-time observations available for the catchment area. Inter-scenario variability is provided by using different sequences of meteorological observations entered into the HM. The scenarios are used to estimate the parameters of the auto-regressive model utilized by SDP and the hydrologic state variables are used to estimate the probability transition between scenarios required by the SSDP algorithm. The optimization methods were implemented in RTA's system and the results compared with the actual deterministic decision procedure. Methods were compared using a test bench into which were incorporated the characteristics of the facilities and the HEP database.

  18. 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, communication and data transfer - as an aid to the planning of future simulations.

  19. 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. The MARTE project will simulate the search for subsurface life on Mars using a drilling system developed for future Mars flight to accomplish subsurface access. Augmenting the drill are robotic systems for extracting the cores from the drill head and performing analysis using a suite of instruments to understand the composition, mineralogy, presence of organics, and to search for life signatures in subsurface samples. A robotic bore-hole inspection system will characterize borehole properties in situ. A Mars drilling mission simulation including remote operation of the drilling, sample handling, and instruments and interpretation of results by a remote science team will be performed. This simulated mission will be augmented by manual methods of drilling, sample handling, and sample analysis to fully document the subsurface, prevent surface microbial contamination, identify subsurface biota, and compare what can be learned with robotically-operated instruments. The first drilling campaign in the MARTE project takes place in September 2003 and is focused on characterizing the microbiology of the subsurface at Rio Tinto using conventional drilling, sample handling and laboratory analysis techniques. Lessons learned from this "ground truth" drilling campaign will guide the development of robotic systems and instruments needed for searching for life underground on Mars.

  20. Impact of abandoned mine waste on atmospheric respirable particulate matter in the historic mining district of Rio Tinto (Iberian Pyrite Belt).

    PubMed

    Sánchez de la Campa, Ana M; de la Rosa, Jesús D; Fernández-Caliani, Juan C; González-Castanedo, Yolanda

    2011-11-01

    This work documents for the first time the levels and composition of atmospheric particulate matter in the historic mining district of Rio Tinto (Spain) to estimate the contribution and impact of resuspended particles from hazardous mine waste on air quality. The resuspended mine waste dust contributes notably (32%) to the total concentrations of toxic trace metals (Bi, As, Cu, Pb, Cd, Zn and Sb) into the atmosphere, with the consequent impact on public health. PMID:21802077

  1. 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.

  2. 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].

  3. 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.

  4. Trace metal partitioning over a tidal cycle in an estuary affected by acid mine drainage (Tinto estuary, SW Spain).

    PubMed

    Hierro, A; Olías, M; Cánovas, C R; Martín, J E; Bolivar, J P

    2014-11-01

    The Tinto River estuary is highly polluted with the acid lixiviates from old sulphide mines. In this work the behaviour of dissolved and particulate trace metals under strong chemical gradients during a tidal cycle is studied. The pH values range from 4.4 with low tide to 6.9 with high tide. Precipitation of Fe and Al is intense during rising tides and As and Pb are almost exclusively found in the particulate matter (PM). Sorption processes are very important in controlling the mobility (and hence bioavailability) of some metals and particularly affect Cu below pH 6. Above pH~6 Cu is desorbed, probably by the formation of Cu(I)-chloride complexes. Although less pronounced than Cu, also Zn desorption above pH 6.5 seems to occur. Mn and Co are affected by sorption processes at pH higher than ca. 6. Cd behaves conservatively and Ni is slightly affected by sorption processes. PMID:25112821

  5. 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

  6. Classification of modern and old Río Tinto sedimentary deposits through the biomolecular record using a life marker biochip: implications for detecting life on Mars.

    PubMed

    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 0.3-0.5 g 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 diagenetic maturity. Our LDCHIP200 and SOLID-like instruments may be excellent tools for the search for molecular biomarkers on Mars or other planets. PMID:21294642

  7. 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 diagenetic maturity. Our LDCHIP200 and SOLID-like instruments may be excellent tools for the search for molecular biomarkers on Mars or other planets.

  8. 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

  9. 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

  10. 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 acquisitions during the project provide insights for the preparation of future astrobiology-driven Mars missions.

  11. 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 cores. Our manned vs. remote observations based on automated acquisitions during the project provide insights for the preparation of future astrobiology-driven Mars missions. PMID:19105754

  12. 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

  13. 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.

  14. 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 potentially novel biosphere on Earth could be used as a model to test for extant and extinct life on Mars. Furthermore, having found carbonates in an hyperacidic system (pH ~2.3) brings new insights on the possible occurrence of deep carbonates deposits under low-pH condition on Mars. [1] Boston, P.J., et al., 1992. Icarus 95,300-308; Bonaccorsi, Stoker and Sutter, 2007 Accepted with review in Astrobiology.

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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 at low pH. Ground water migration could produce evaporitic ponds where various bedded sulfate mineral sediments could form. The intergranular pore-spaces would be water filled. Most terrestrial spheroidal nodular concretions form by radial diffusion in pore-water of a chemical component of a very different oxidation state from that of the surrounding water. A nodular concretion is most usually formed by the reaction of the diffusive component with others in the pore-water. There are two main possible reaction sets for formation of the Blueberries that are consistent with all current data. 1. Local concentrations of organic matter (pre-biotic or biotic) formed reduction spots in which a small amount of Fe3+ either in solution or from evaporite mineral salts, was reduced to Fe2+ and then diffused radially to form an iron oxide nodule by reaction with inwardly diffusing dissolved oxygen. 2. Similar local concentrations of organic matter could also have engendered sulfate reduction and consequent outward diffusion of dissolved sulfide reacted with iron in solution to produce an iron sulfide nodule, subsequently oxidized in situ to hematite (maybe via goethite). Our current work is successfully identifying chemical and stable isotopic characteristics for both microbial and abiotic modes of all relevant reactions.

  2. 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

  3. Quantification of Tinto River sediment microbial communities: importance of sulfate-reducing bacteria and their role in attenuating acid mine drainage.

    PubMed

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

    2012-07-01

    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

  4. 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 valuable suggestions.

  5. 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 research will support future drilling mission planned on Mars. [1] Boston, P.J., et al., 1992. Icarus 95,300-308; [2] Leistel et al., 1998.

  6. 76 FR 80430 - Rio Tinto plc and Rio Tinto Limited; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-23

    ... international mining group. Applicants also seek an order under section 45(a) of the Act granting confidential... business involved in each stage of metal and mineral production including finding, developing, mining and processing natural resources such as aluminium, copper, coal, iron ore, uranium, gold and industrial...

  7. Problemas para dormir

    Cancer.gov

    Dormir bien es importante para su salud física y mental. Un buen sueño en la noche no solo le ayuda a pensar claramente, también le baja su presión arterial, ayuda su apetito y fortalece su sistema inmunitario.

  8. 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.

  9. Tomografía computarizada (TC) y exploraciones para cáncer

    Cancer.gov

    Hoja informativa que describe el procedimiento y la tecnología de exploraciones con tomografía computarizada así como sus usos para el diagnóstico, para exámenes de detección y para tratamiento del cáncer.

  10. 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.

  11. 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.…

  12. 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.

  13. 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.…

  14. Generalized deformed para-Bose oscillator and its coherent states

    SciTech Connect

    Bang, Ha Huy

    1996-04-01

    Generalized deformed commutation relations for a single-mode para-Bose oscillator are constructed. The connection of generalized deformed para-Bose oscillators with para-Bose oscillators is determined. From these, the energy spectrum of generalized deformed para-Bose oscillators and the coherent states of the annihilation operators are discussed.

  15. 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

  16. Efficient Ortho Hydrogen to Para Hydrogen Conversion

    NASA Astrophysics Data System (ADS)

    Zhou, D.; Sullivan, N. S.

    2004-03-01

    One of the most important considerations in the production and storage of liquid hydrogen is the need for efficient cost-effective means of conversion from ortho- to para-hydrogen.(See Ref.1.) At 300 K, the equilibrium concentration is 75% ortho, while at the boiling point (20.3 K), the equilibrium ortho concentration is 0.21%. Because of the large heat of ortho-para conversion (670 J/g), incomplete conversion during liquefaction results in severe losses due to boil-off during storage and transport. Most manufacturers use a two-stage catalytic converter, at 77 K, and at 20.3 K in the liquefying process. The conversion at 77 K can produce 50% para-H2, and the remaining conversion at 20.3 K consumes a significant fraction ( ˜ 50%) of liquid hydrogen. We propose a high efficient ortho-para hydrogen converter, using Cr2O3 powder as the active element contained in a continuous heat exchanger that allows the heat of conversion to be removed by the hydrogen gas flow. Ref. 1. N. S. Sullivan, D. Zhou and C. M. Edwards, Cryogenics 30, 734 (1990) # Supported by NASA Contract NAG3-2750

  17. Para-methylstyrene from toluene and acetaldehyde

    SciTech Connect

    Innes, R.A.; Occelli, M.L.

    1984-08-01

    High yields of para-methylstyrene (PMS) were obtained in this study by coupling toluene and acetaldehyde then cracking the resultant 1,1-ditolylethane (DTE) to give equimolar amounts of PMS and toluene. In the first step, a total DTE and ''trimer'' yield of 98% on toluene and 93% on acetaldehyde was obtained using 98% sulfuric acid as catalyst at 5-10/sup 0/C. In the second step, a choline chloride-offretite cracked DTE with 84.0% conversion and 91% selectivity to PMS and toluene. Additional PMS can be obtained by cracking the by-product ''trimer'' formed by coupling DTE and toluene with acetaldehyde. Zeolite Rho was as active but yielded less PMS (86%) and produced more para-ethyltoluene (PET), an undesirable by-product.

  18. Sensitization to methylenedianiline and para-structures.

    PubMed

    Van Joost, T; Heule, F; de Boer, J

    1987-05-01

    A toxic-allergic skin reaction of the face, neck and arms due to accidental contact with methylenedianiline (syn: 4-4'-diaminodiphenylmethane) is reported in a cleaner at a chemical plant. Patch tests revealed sensitization to chemicals of the para-group. Earlier exposure to it was unlikely. Previous sensitization to related chemicals and possible cross-sensitization was considered to be the primary cause of the allergy and the clinical manifestations. PMID:3621924

  19. 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)

  20. Dotar de precisión a exámenes de detección para cáncer

    Cancer.gov

    Una conferencia reciente patrocinada por el NCI reunió a investigadores importantes de exámenes de detección y de control de cáncer para tratar la situación de la ciencia de exámenes de detección de precisión para cinco cánceres.

  1. 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.

  2. The para radiation effects current simulator

    NASA Astrophysics Data System (ADS)

    Bhuva, Bharat; Kerns, Sherra

    1992-01-01

    The Parametric Analysis of Radiation effects software development is given the general title PARA. This report describes the development of algorithms and source codes for the simulation of radiation effects on CMOS ICs. The project concentrated on the simulation of total dose effects and the ways to establish/predict the operational lifetime and radiation tolerance of ICs. The switch level simulator incorporates the capability to assign bias dependent post-irradiation drive parameters to transistors within a microcircuit and to calculate propagation delays based on those parameters. This permits test vectors to be assigned based on worst case post-irradiation propagation delays.

  3. 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

  4. 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.

  5. On q-DEFORMED Para Oscillators and PARA-q Oscillators

    NASA Astrophysics Data System (ADS)

    Kumari, M. Krishna; Shanta, P.; Chaturvedi, S.; Srinivasan, V.

    Three generalized commutation relations for a single mode of the harmonic oscillator which contains para-bose and q oscillator commutation relations are constructed. These are shown to be inequivalent. The coherent states of the annihilation operator for these three cases are also constructed.

  6. New strategies maximize para-xylene production

    SciTech Connect

    Jeanneret, J.J.; Low, C.D.; Zukauskas, V. )

    1994-06-01

    Strong consumption growth and the shutdown of some capacity in 1992 have completely eliminated the surplus of para-xylene (p-xylene) capacity, which existed from 1990 to 1993. p-Xylene supplies are becoming tight and market prices have risen dramatically over the last several months, sparking considerable interest in new p-xylene production capacity. However, adding new capacity does not necessarily mean building new grassroots facilities. Additional capacity can be found'' by creative use of existing BTX (benzene, toluene and xylenes) resources. Options include: debottleneck existing units, reload with new catalysts, convert idle units to new services and diversify into new feedstocks. By making the most of existing facilities, producers can capitalize on the current upswing of the p-xylene market cycle. The paper describes this high demand chemical and how it is integrated with BTX complexes, then discusses short-, medium-, and long-term strategies for increased production.

  7. Time domain para hydrogen induced polarization.

    PubMed

    Ratajczyk, Tomasz; Gutmann, Torsten; Dillenberger, Sonja; Abdulhussaein, Safaa; Frydel, Jaroslaw; Breitzke, Hergen; Bommerich, Ute; Trantzschel, Thomas; Bernarding, Johannes; Magusin, Pieter C M M; Buntkowsky, Gerd

    2012-01-01

    Para hydrogen induced polarization (PHIP) is a powerful hyperpolarization technique, which increases the NMR sensitivity by several orders of magnitude. However the hyperpolarized signal is created as an anti-phase signal, which necessitates high magnetic field homogeneity and spectral resolution in the conventional PHIP schemes. This hampers the application of PHIP enhancement in many fields, as for example in food science, materials science or MRI, where low B(0)-fields or low B(0)-homogeneity do decrease spectral resolution, leading to potential extinction if in-phase and anti-phase hyperpolarization signals cannot be resolved. Herein, we demonstrate that the echo sequence (45°-?-180°-?) enables the acquisition of low resolution PHIP enhanced liquid state NMR signals of phenylpropiolic acid derivatives and phenylacetylene at a low cost low-resolution 0.54 T spectrometer. As low field TD-spectrometers are commonly used in industry or biomedicine for the relaxometry of oil-water mixtures, food, nano-particles, or other systems, we compare two variants of para-hydrogen induced polarization with data-evaluation in the time domain (TD-PHIP). In both TD-ALTADENA and the TD-PASADENA strong spin echoes could be detected under conditions when usually no anti-phase signals can be measured due to the lack of resolution. The results suggest that the time-domain detection of PHIP-enhanced signals opens up new application areas for low-field PHIP-hyperpolarization, such as non-invasive compound detection or new contrast agents and biomarkers in low-field Magnetic Resonance Imaging (MRI). Finally, solid-state NMR calculations are presented, which show that the solid echo (90y-?-90x-?) version of the TD-ALTADENA experiment is able to convert up to 10% of the PHIP signal into visible magnetization. PMID:22365288

  8. On Lightlike Geometry of Para-Sasakian Manifolds

    PubMed Central

    Acet, Bilal Eftal; K?l?ç, 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

  9. Spirocyclopropanation Reaction of para-Quinone Methides with Sulfonium Salts: The Synthesis of Spirocyclopropanyl para-Dienones.

    PubMed

    Zhang, Xiang-Zhi; Du, Ji-Yuan; Deng, Yu-Hua; Chu, Wen-Dao; Yan, Xu; Yu, Ke-Yin; Fan, Chun-An

    2016-03-18

    A novel DBU-mediated stereoselective spirocyclopropanation of para-quinone methides with sulfonium salts has been developed on the basis of the mode involving a 1,6-conjugate addition/intramolecular dearomatizing cyclization cascade. This reaction provides a mild and effective method for the assembly of synthetically and structurally interesting spirocyclopropanyl para-dienones. The feasibility for the enantioselective access to such functionalized para-dienones has also been explored by using the axially chiral sulfonium salt. Importantly, the regioselective ring openings of the related spirocyclopropanyl para-dienones have been achieved divergently. PMID:26892163

  10. Towards a double field theory on para-Hermitian manifolds

    SciTech Connect

    Vaisman, Izu

    2013-12-15

    In a previous paper, we have shown that the geometry of double field theory has a natural interpretation on flat para-Kähler manifolds. In this paper, we show that the same geometric constructions can be made on any para-Hermitian manifold. The field is interpreted as a compatible (pseudo-)Riemannian metric. The tangent bundle of the manifold has a natural, metric-compatible bracket that extends the C-bracket of double field theory. In the para-Kähler case, this bracket is equal to the sum of the Courant brackets of the two Lagrangian foliations of the manifold. Then, we define a canonical connection and an action of the field that correspond to similar objects of double field theory. Another section is devoted to the Marsden-Weinstein reduction in double field theory on para-Hermitian manifolds. Finally, we give examples of fields on some well-known para-Hermitian manifolds.

  11. 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.

  12. 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.

  13. Navigating Mainstream Higher Education: Examining the Experiences of Native Students Using Tinto's Interactionalist's Model

    ERIC Educational Resources Information Center

    Harrington, Billie Jo Graham

    2012-01-01

    Postsecondary degree attainment for American Indian college students at predominantly White institutions has consistently been the lowest among any ethnic and/or racial group for the past three decades. A plethora of studies have been conducted to examine the experiences of Native students at mainstream institutions within the conceptual framework…

  14. 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…

  15. 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…

  16. 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.

  17. Electrically charged selectivity of poly-para-xylylene deposition.

    PubMed

    Wu, Chih-Yu; Sun, Ho-Yi; Liang, Wei-Chieh; Hsu, Hung-Lun; Ho, Hsin-Ying; Chen, Yu-Ming; Chen, Hsien-Yeh

    2016-02-18

    The bottom-up patterning approach provides intrinsic advantages associated with unlimited resolution but is limited by the materials available for selection. A general and simple approach towards the selective deposition of poly-para-xylylenes is introduced in this communication. The chemical vapour deposition (CVD) of poly-para-xylylenes is inhibited on the high-energy surfaces of electrically charged conducting substrates. This technology provides an approach to selectively deposit poly-para-xylylenes irrespective of the substituted functionality and to pattern these polymer thin films from the bottom up. PMID:26788557

  18. 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 (?) 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.-N. Roy, J. Chem. Phys. 141, 014310(2014). R. J. Hinde, J. Chem. Phys. 128, 154308(2008).

  19. Vibronic spectroscopy of a nitrile/isonitrile isoelectronic pair: para-diisocyanobenzene and para-isocyanobenzonitrile.

    PubMed

    Mehta-Hurt, Deepali N; Korn, Joseph A; Gutberlet, Anna K; Zwier, Timothy S

    2015-03-26

    The ultraviolet spectroscopy of isoelectronic pair para-diisocyanobenzene (pDIB) and para-isocyanobenzonitrile (pIBN) has been studied under gas-phase, jet-cooled conditions. These molecules complete a sequence of mono and disubstituted nitrile/isonitrile benzene derivatives, enabling a comparison of the electronic effects of such substitution. Utilizing laser-induced fluorescence (LIF) and resonant two-photon ionization (R2PI) spectroscopy, the S0-S1 electronic origins of pDIB and pIBN have been identified at 35,566 and 35,443 cm(-1), respectively. In pDIB, the S0-S1 origin is very weak, with b(3g) fundamentals induced by vibronic coupling to the S2 state dominating the spectrum at 501 cm(-1) (?17, isocyano bend) and 650 cm(-1) (?16, ring distortion). The spectrum extends over 5000 cm(-1), remaining sharp and relatively uncongested over much of this range. Dispersed fluorescence (DFL) spectra confirm the dominating role played by vibronic coupling and identify Franck-Condon active ring modes built off the vibronically-induced bands. In pDIB, the S2 state has been tentatively observed at about 6100 cm(-1) above the S0-S1 origin. In pIBN, the S0-S1 origin is considerably stronger, but vibronic coupling still plays an important role, involving fundamentals of b2 symmetry. The bending mode of the nitrile group dominates the vibronically-induced activity. Calculations carried out at the TD-DFT B3LYP/6-31+G(d) level of theory account for the extremely weak S0-S1 oscillator strength of pDIB and the larger intensity of the S0-S1 origins of pIBN and pDCB (para-dicyanobenzene) as nitrile groups are substituted for isonitrile groups. In pDIB, a nearly perfect cancellation of transition dipoles occurs due to two one-electron transitions that contribute nearly equally to the S0-S1 transition. The spectra of both molecules show no clear evidence of charge-transfer interactions that play such an important role in some cyanobenzene derivatives. PMID:25699407

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

    Cancer.gov

    Libro sobre el control del dolor en pacientes con cáncer. Cubre los métodos y medicinas, así como los efectos físicos y emocionales del dolor. Es una adaptación cultural para el público de habla hispana del libro en inglés Pain Control.

  1. Consejos para cuando le duelan la boca o la garganta

    Cancer.gov

    Información para personas que están recibiendo radioterapia y consejos sobre cómo controlar las molestias en la boca y garganta, sentirse mejor durante el tratamiento y comunicarse con su doctor o enfermera.

  2. Terapias adyuvantes y neoadyuvantes para el cáncer de seno

    Cancer.gov

    Hoja informativa que explica las terapias adyuvantes (tratamiento que se administra además de la terapia primaria para aumentar la posibilidad de supervivencia a largo plazo) y las neoadyuvantes (terapia que se administra antes de la terapia principal).

  3. 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.

  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. Ortho- and para-hydrogen in neutron thermalization

    SciTech Connect

    Daemen, L. L.; Brun, T. O.

    1998-01-01

    The large difference in neutron scattering cross-section at low neutron energies between ortho- and para-hydrogen was recognized early on. In view of this difference (more than an order of magnitude), one might legitimately ask whether the ortho/para ratio has a significant effect on the neutron thermalization properties of a cold hydrogen moderator. Several experiments performed in the 60`s and early 70`s with a variety of source and (liquid hydrogen) moderator configurations attempted to investigate this. The results tend to show that the ortho/para ratio does indeed have an effect on the energy spectrum of the neutron beam produced. Unfortunately, the results are not always consistent with each other and much unknown territory remains to be explored. The problem has been approached from a computational standpoint, but these isolated efforts are far from having examined the ortho/para-hydrogen problem in neutron moderation in all its complexity. Because of space limitations, the authors cannot cover, even briefly, all the aspects of the ortho/para question here. This paper will summarize experiments meant to investigate the effect of the ortho/para ratio on the neutron energy spectrum produced by liquid hydrogen moderators.

  7. 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.

  8. 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.

  9. 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 público em questão.

  10. "Espanol para ti": A Video Program That Works.

    ERIC Educational Resources Information Center

    Steele, Elena; Johnson, Holly

    2000-01-01

    Describes the development of "Espanol para ti," a video program for teaching Spanish at the elementary school level. The program was designed for use in Clark County, Nevada elementary schools and is taught by a certified Spanish teacher via video twice a week, utilizing comprehensible input through visuals, games, and songs that are conducive to…

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Mensaje para alumnos y padres - Duration: 3 minutes, 1 second.

    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...

  16. 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.

  17. 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.

  18. "Espanol para ti": A Video Program That Works.

    ERIC Educational Resources Information Center

    Steele, Elena; Johnson, Holly

    2000-01-01

    Describes the development of "Espanol para ti," a video program for teaching Spanish at the elementary school level. The program was designed for use in Clark County, Nevada elementary schools and is taught by a certified Spanish teacher via video twice a week, utilizing comprehensible input through visuals, games, and songs that are conducive to…

  19. 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.

  20. 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.

  1. 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.

  2. 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...

  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. 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.

  5. On Linear Differential Equations Involving a Para-Grassmann Variable

    NASA Astrophysics Data System (ADS)

    Mansour, Toufik; Schork, Matthias

    2009-07-01

    As a first step towards a theory of differential equations involving para-Grassmann variables the linear equations with constant coefficients are discussed and solutions for equations of low order are given explicitly. A connection to n-generalized Fibonacci numbers is established. Several other classes of differential equations (systems of first order, equations with variable coefficients, nonlinear equations) are also considered and the analogies or differences to the usual (''bosonic'') differential equations discussed.

  6. ParaGlide: interactive parameter space partitioning for computer simulations.

    PubMed

    Bergner, Steven; Sedlmair, Michael; Möller, Torsten; Abdolyousefi, Sareh Nabi; Saad, Ahmed

    2013-09-01

    In this paper, we introduce ParaGlide, a visualization system designed for interactive exploration of parameter spaces of multidimensional simulation models. To get the right parameter configuration, model developers frequently have to go back and forth between setting input parameters and qualitatively judging the outcomes of their model. Current state-of-the-art tools and practices, however, fail to provide a systematic way of exploring these parameter spaces, making informed decisions about parameter configurations a tedious and workload-intensive task. ParaGlide endeavors to overcome this shortcoming by guiding data generation using a region-based user interface for parameter sampling and then dividing the model's input parameter space into partitions that represent distinct output behavior. In particular, we found that parameter space partitioning can help model developers to better understand qualitative differences among possibly high-dimensional model outputs. Further, it provides information on parameter sensitivity and facilitates comparison of models. We developed ParaGlide in close collaboration with experts from three different domains, who all were involved in developing new models for their domain. We first analyzed current practices of six domain experts and derived a set of tasks and design requirements, then engaged in a user-centered design process, and finally conducted three longitudinal in-depth case studies underlining the usefulness of our approach. PMID:23846095

  7. 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.

  8. 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

  9. Creating and managing lookmarks in ParaView.

    SciTech Connect

    Kegelmeyer, W. Philip, Jr.; Stanton, Eric T.

    2004-06-01

    This paper describes the integration of lookmarks into the ParaView visualization tool. Lookmarks are pointers to views of specific parts of a dataset. They were so named because lookmarks are to a visualization tool and dataset as bookmarks are to a browser and the World Wide Web. A lookmark can be saved and organized among other lookmarks within the context of ParaView. Then at a later time, either in the same ParaView session or in a different one, it can be regenerated, displaying the exact view of the data that had previously been saved. This allows the user to pick up where they left off, to continue to adjust the view or otherwise manipulate the data. Lookmarks facilitate collaboration between users who wish to share views of a dataset. They enable more effective data comparison because they can be applied to other datasets. They also serve as a way of organizing a user's data. Ultimately, a lookmark is a time-saving tool that automates the recreation of a complex view of the data.

  10. Electronic structure of the para-benzoquinone radical anion revisited.

    PubMed

    Kunitsa, Alexander A; Bravaya, Ksenia B

    2016-01-27

    Photoinduced dynamics of the para-benzoquinone anion features a subtle interplay between autodetachment and non-adiabatic transitions involving a dense manifold of resonances. We report the results of a multistate multireference perturbation theory study of the electronic structure of the para-benzoquinone anion in the ground, several low-lying excited electronic states, and in the lowest electron-detached state (the ground state of the neutral molecule). The electronic structure calculations revealed non-planar equilibrium geometry of the (2)Au excited state of the anion, but the effects of non-planarity on the shape of the absorption spectrum are found to be minor. Despite the large differences in the vertical excitation energies for the two lowest bright excited states, (2)Au (2.55 eV) and (2)B3u (2.93 eV), the simulated absorption spectra significantly overlap for the photon energies below 2.7 eV. Relevant minimum energy crossing points have been located using the CASSCF method. Excited-state deactivation channels are discussed in the context of accurate energetics and recent spectroscopic studies of the para-benzoquinone anion. PMID:26750380

  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. Un vistazo al auge de la cirugía robótica para el cáncer de próstata

    Cancer.gov

    El uso de la cirugía robótica para el cáncer de próstata ha aumentado en forma acelerada. Lo que esta tendencia significa para los pacientes y el sistema de salud todavía sigue siendo objeto de estudio y debate.

  13. Laparoscopy-assisted gastrectomy with para-aortic lymphadenectomy after palliative chemotherapy for advanced gastric cancer with isolated para-aortic lymph node metastasis

    PubMed Central

    Son, Sang-Yong; Lee, Chang Min; Lee, Ju-Hee; Ahn, Sang-Hoon; Kim, Jin Won; Lee, Kuhn-Uk; Park, Do Joong

    2013-01-01

    Prophylactic para-aortic lymphadenectomy is not recommended in curable advanced gastric cancer. However, there are few reports on therapeutic para-aortic lymphadenectomy after palliative chemotherapy in far advanced gastric cancer. We report three cases of laparoscopy-assisted gastrectomy with para-aortic lymphadenectomy after palliative chemotherapy for the first time in Korea. Three gastric cancer patients with isolated para-aortic lymph node (PAN) metastasis showed partial response to capecitabine-based chemotherapy, and laparoscopy-assisted gastrectomy with para-aortic lymphadenectomy was performed with curative intent. The mean total operation time was 365 minutes (range, 310 to 415 minutes), and the mean estimated blood loss was 158 mL (range, 125 to 200 mL). The mean number of retrieved PAN was 9 (range, 8 to 11), and all pathologic results showed no metastasis of para-aortic region. All patients recovered and were discharged without any significant complications. PMID:23646317

  14. 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

  15. 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...

  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. Ortho-to-para ratio of interstellar heavy water

    NASA Astrophysics Data System (ADS)

    Vastel, C.; Ceccarelli, C.; Caux, E.; Coutens, A.; Cernicharo, J.; Bottinelli, S.; Demyk, K.; Faure, A.; Wiesenfeld, L.; Scribano, Y.; Bacmann, A.; Hily-Blant, P.; Maret, S.; Walters, A.; Bergin, E. A.; Blake, G. A.; Castets, A.; Crimier, N.; Dominik, C.; Encrenaz, P.; Gérin, M.; Hennebelle, P.; Kahane, C.; Klotz, A.; Melnick, G.; Pagani, L.; Parise, B.; Schilke, P.; Wakelam, V.; Baudry, A.; Bell, T.; Benedettini, M.; Boogert, A.; Cabrit, S.; Caselli, P.; Codella, C.; Comito, C.; Falgarone, E.; Fuente, A.; Goldsmith, P. F.; Helmich, F.; Henning, T.; Herbst, E.; Jacq, T.; Kama, M.; Langer, W.; Lefloch, B.; Lis, D.; Lord, S.; Lorenzani, A.; Neufeld, D.; Nisini, B.; Pacheco, S.; Pearson, J.; Phillips, T.; Salez, M.; Saraceno, P.; Schuster, K.; Tielens, X.; van der Tak, F.; van der Wiel, M. H. D.; Viti, S.; Wyrowski, F.; Yorke, H.; Cais, P.; Krieg, J. M.; Olberg, M.; Ravera, L.

    2010-10-01

    Context. Despite the low elemental deuterium abundance in the Galaxy, enhanced molecular D/H ratios have been found in the environments of low-mass star-forming regions, and in particular the Class 0 protostar IRAS 16293-2422. Aims: The CHESS (Chemical HErschel Surveys of Star forming regions) key program aims to study the molecular complexity of the interstellar medium. The high sensitivity and spectral resolution of the Herschel/HIFI instrument provide a unique opportunity to observe the fundamental 11,1-00,0 transition of the ortho-D2O molecule, which is inaccessible from the ground, and determine the ortho-to-para D2O ratio. Methods: We detected the fundamental transition of the ortho-D2O molecule at 607.35 GHz towards IRAS 16293-2422. The line is seen in absorption with a line opacity of 0.62 ± 0.11 (1σ). From the previous ground-based observations of the fundamental 11,0-10,1 transition of para-D2O seen in absorption at 316.80 GHz, we estimate a line opacity of 0.26 ± 0.05 (1σ). Results: We show that the observed absorption is caused by the cold gas in the envelope of the protostar. Using these new observations, we estimate for the first time the ortho-to-para D2O ratio to be lower than 2.6 at a 3σ level of uncertainty, which should be compared with the thermal equilibrium value of 2:1. Herschel is an ESA space observatory with science instruments provided by European-led principal Investigator consortia and with important participation from NASA.

  19. 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 between selected wells, simplified volumetric calculations, global vertical exaggeration adjustments, ingestion of UTChem simulation results, ingestion of Isatis geostatistical framework models, interrogation of joint geologic and reservoir modeling results, joint visualization and analysis of well history files, location-targeted visualization, advanced correlation analysis, visualization of flow paths, and creation of static images and animations highlighting targeted reservoir features.« less

  20. 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 selected wells, simplified volumetric calculations, global vertical exaggeration adjustments, ingestion of UTChem simulation results, ingestion of Isatis geostatistical framework models, interrogation of joint geologic and reservoir modeling results, joint visualization and analysis of well history files, location-targeted visualization, advanced correlation analysis, visualization of flow paths, and creation of static images and animations highlighting targeted reservoir features.

  1. Ortho-Para Selection Rules in the Gas-phase Chemistry of Interstellar Ammonia

    NASA Astrophysics Data System (ADS)

    Faure, A.; Hily-Blant, P.; Le Gal, R.; Rist, C.; Pineau des Forêts, G.

    2013-06-01

    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-NH3 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 (~0.7) observed in various interstellar regions is in fact consistent with nuclear spin selection rules in a para-enriched H2 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 ~2.3 for NH2. We conclude that a low ortho-to-para ratio of H2 naturally drives the ortho-to-para ratios of nitrogen hydrides below the statistical values.

  2. 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.

  3. 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

  4. The infrared dielectric function of solid para-hydrogen

    NASA Astrophysics Data System (ADS)

    Kettwich, Sharon C.; Anderson, David T.; Walker, Mark A.; Tuntsov, Artem V.

    2015-06-01

    We report laboratory measurements of the absorption coefficient of solid para-H2, within the wavelength range from 1 to 16.7 ?m, at high spectral resolution. In addition to the narrow rovibrational lines of H2 which are familiar from gas-phase spectroscopy, the data manifest double transitions and broad phonon branches that are characteristic specifically of hydrogen in the solid phase. These transitions are of interest because they provide a spectral signature which is independent of the impurity content of the matrix. We have used our data, in combination with a model of the ultraviolet absorptions of the H2 molecule, to construct the dielectric function of solid para-H2 over a broad range of frequencies. Our results will be useful in determining the electromagnetic response of small particles of solid hydrogen. The dielectric function makes it clear that pure H2 dust would contribute to infrared (IR) extinction predominantly by scattering starlight, rather than absorbing it, and the characteristic IR absorption spectrum of the hydrogen matrix itself will be difficult to observe.

  5. Sensitivity to para-phenylenediamine and intolerance to hydrochlorothiazide.

    PubMed

    Jacob, Sharon E; Zapolanski, Tamar; Chayavichitsilp, Pamela

    2008-01-01

    para-Phenylenediamine (PPD) is a contact allergen that cross-reacts with a variety of medications, including thiazide diuretics and sulfonamides. We present the case of a 52-year-old African American atopic woman who came for evaluation of a severe eyelid dermatitis and recurrent outbreaks of acneiform (follicular-based) pruritic papules on her face, chest, and back. These symptoms presented after the patient was started on hydrochlorothiazide for hypertension. The patient also reported a history of eyelid dermatitis associated with "black hair dye." Patch testing revealed a positive reaction to para-phenylenediamine (1+) and Disperse Blue 106 (1+). It was suspected that the patient might be demonstrating cross-reactivity to hydrochlorothiazide and a flare-up reaction of the eyelid dermatitis. After her cardiologist changed her blood pressure medication, the patient's eyelid dermatitis and eruption cleared. This case highlights the impact of PPD sensitization on the medical care of a patient with hypertension and the importance of choosing safer PPD-free alternatives and minimizing PPD exposures. PMID:19134428

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. "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…

  17. 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…

  18. 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…

  19. 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…

  20. Features of the ancestral bilaterian inferred from Platynereis dumerilii ParaHox genes

    PubMed Central

    Hui, Jerome HL; Raible, Florian; Korchagina, Natalia; Dray, Nicolas; Samain, Sylvie; Magdelenat, Ghislaine; Jubin, Claire; Segurens, Béatrice; Balavoine, Guillaume; Arendt, Detlev; Ferrier, David EK

    2009-01-01

    Background The ParaHox gene cluster is the evolutionary sister to the Hox cluster. Whilst the role of the Hox cluster in patterning the anterior-posterior axis of bilaterian animals is well established, and the organisation of vertebrate Hox clusters is intimately linked to gene regulation, much less is known about the more recently discovered ParaHox cluster. ParaHox gene clustering, and its relationship to expression, has only been described in deuterostomes. Conventional protostome models (Drosophila melanogaster and Caenorhabditis elegans) are secondarily derived with respect to ParaHox genes, suffering gene loss and cluster break-up. Results We provide the first evidence for ParaHox gene clustering from a less-derived protostome animal, the annelid Platynereis dumerilii. Clustering of these genes is thus not a sole preserve of the deuterostome lineage within Bilateria. This protostome ParaHox cluster is not entirely intact however, with Pdu-Cdx being on the opposite end of the same chromosome arm from Pdu-Gsx and Pdu-Xlox. From the genomic sequence around the P. dumerilii ParaHox genes the neighbouring genes are identified, compared with other taxa, and the ancestral arrangement deduced. Conclusion We relate the organisation of the ParaHox genes to their expression, and from comparisons with other taxa hypothesise that a relatively complex pattern of ParaHox gene expression existed in the protostome-deuterostome ancestor, which was secondarily simplified along several invertebrate lineages. Detailed comparisons of the gene content around the ParaHox genes enables the reconstruction of the genome surrounding the ParaHox cluster of the protostome-deuterostome ancestor, which existed over 550 million years ago. PMID:19627570

  1. 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.

  2. 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.

  3. Acute toxicity and primary irritation of para-tertiary butylphenol.

    PubMed

    Klonne, D R; Myers, R C; Nachreiner, D J; Homan, E R

    1988-01-01

    Para-tertiary butylphenol [(PTBP); the Union Carbide Corporation trademark for this chemical is UCAR Butylphenol 4-T Flake] has applications as a raw material in the manufacture of resins and also as an industrial intermediate. Acute peroral LD50 values (95% confidence limits) of 5.4 (3.6-7.9) g/kg and 3.6 (3.0-4.4) g/kg were obtained for male and female albino rats, respectively. Occluded cutaneous applications of moistened PTBP at 16 g/kg for 24 hr produced no mortalities in male or female rabbits, but signs of local toxicity and irritation were apparent at the site of application. A 6 hr exposure to a substantially saturated vapor under static conditions produced no mortality, while a 4 hr exposure to a dynamically generated respirable dust aerosol at a concentration of 5.6 mg/L produced 20% mortality. Occluded dermal contact (4 hr) with 0.5 g moistened PTBP produced a range of effects from no reaction to necrosis. PTBP placed in the conjunctival sac of rabbits produced severe ocular injury which generally persisted for 21 days after exposure. The major hazard associated with acute exposure to PTBP appears to be the irritation produced by dermal or ocular contact. PMID:3378509

  4. 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.

  5. Evidence for para dechlorination of polychlorobiphenyls by methanogenic bacteria.

    PubMed

    Ye, D; Quensen, J I; Tiedje, J M; Boyd, S A

    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. PMID:16535042

  6. 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

  7. The ortho to para transition in muonic molecular hydrogen

    NASA Astrophysics Data System (ADS)

    Clark, Jessica Higgins Deseret

    A precise measurement of the induced weak pseudoscalar coupling constant of the proton, gp, is of interest as a basic test of chiral symmetry breaking. This is the least well-known weak form factor of the nucleon. Muon capture experiments [Jonkmans et al., Phys. Rev. Lett. 77(1996)4512] have been used to measure gp. However, the interpretation of these muon capture experiments requires knowledge of the relative population of the muonic atomic and molecular states for muons in liquid hydrogen. In particular, lambda op, the transition rate between the ortho- and para-molecular states of the pmup molecule, needs to be known with precision. The only previous measurement [Bardin et al., Phys. Lett. 104B(1981)320.] of lambda op yielded a value of (4.1 +/- 1.4) x 10 4 s-1, significantly different than the theoretical prediction [Bakalov et al., Nucl. Phys. A384(1982)302.] of 7.1 x 104 s-1. A measurement of lambdaop using the time distribution of neutrons from muon capture was performed at TRIUMF during June--July 1999 and November 1999. The lambdaop measured in this experiment is (13.8 +/- 1.6) x 104 s-1 . The uncertainty is dominated by the statistical precision of the fit and the background due to the deuterium contamination in the protium target. The implications of this result for gp are discussed.

  8. Publicación de Propuesta Presupuestaria del NCI para el Año Fiscal 2017

    Cancer.gov

    Ayer, tuve el honor de presentar al Presidente Barack Obama el Plan Anual del NCI y Propuesta Presupuestaria para el Año Fiscal 2017. Creo que la “Propuesta Presupuestaria”, como se conoce ahora, es especialmente importante este año para la investigación oncológica por dos razones.

  9. Primer registro para Peru del genero Nielsonia Young, 1977 (Hemiptera: Cicadellidae: Cicadellinae: Cicadellini)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    En este articulo se reporta por primera vez para el Peru una especies del genero Nielsonia Young, 1977, de material procedente del Departamento de Tumbes. El genero ha sido reportada anteriormente de Ecuador, como unico registro para Sudamerica, y America Central. El unico especimen hembra encontra...

  10. 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...

  11. [The place of para-aortic lymphadenectomy in gynaecological malignancies. An old debate].

    PubMed

    Philippe, Anne-Cécile; Dauplat, Jacques; Martinez, Alejandra; Canis, Michel; Bourdel, Nicolas; Ferron, Gwenaël; Pomel, Christophe

    2014-04-01

    There is a lack of prospective randomized trial and scientific evidence for the use of para-aortic lymphadenectomy in gynaecological malignancies. This results in variations between countries for its utility. Based on the recommandations of the French Institute of Cancer (INCa), we open the debate of the place of para-aortic lymphadenectomy. PMID:24793624

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Diffusion Monte Carlo Study of Para-Diiodobenzene Polymorphism Revisited.

    PubMed

    Hongo, Kenta; Watson, Mark A; Iitaka, Toshiaki; Aspuru-Guzik, Alán; Maezono, Ryo

    2015-03-10

    We revisit our investigation of the diffusion Monte Carlo (DMC) simulation of para-diiodobenzene (p-DIB) molecular crystal polymorphism. [See J. Phys. Chem. Lett. 2010, 1, 1789-1794.] We perform, for the first time, a rigorous study of finite-size effects and choice of nodal surface on the prediction of polymorph stability in molecular crystals using fixed-node DMC. Our calculations are the largest that are currently feasible using the resources of the K-computer and provide insights into the formidable challenge of predicting such properties from first principles. In particular, we show that finite-size effects can influence the trial nodal surface of a small (1 × 1 × 1) simulation cell considerably. Therefore, we repeated our DMC simulations with a 1 × 3 × 3 simulation cell, which is the largest such calculation to date. We used a density functional theory (DFT) nodal surface generated with the PBE functional, and we accumulated statistical samples with ∼6.4 × 10(5) core hours for each polymorph. Our final results predict a polymorph stability that is consistent with experiment, but they also indicate that the results in our previous paper were somewhat fortuitous. We analyze the finite-size errors using model periodic Coulomb (MPC) interactions and kinetic energy corrections, according to the CCMH scheme of Chiesa, Ceperley, Martin, and Holzmann. We investigate the dependence of the finite-size errors on different aspect ratios of the simulation cell (k-mesh convergence) in order to understand how to choose an appropriate ratio for the DMC calculations. Even in the most expensive simulations currently possible, we show that the finite size errors in the DMC total energies are much larger than the energy difference between the two polymorphs, although error cancellation means that the polymorph prediction is accurate. Finally, we found that the T-move scheme is essential for these massive DMC simulations in order to circumvent population explosions and large time-step biases. PMID:26579744

  17. 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

  18. 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)

  19. Descripción de la zona de alta difusión en un modelo bidimensional para hojas de corriente

    NASA Astrophysics Data System (ADS)

    Montero, M. F.; Paola, C. A.; Platzeck, A. M.

    Los modelos bidimensionales para describir hojas de corriente de alta simetría no suministran una descripción detallada de las regiones donde la difusión es considerablemente importante. Tal es el caso de los modelos desarrollados en la década del '60 por Sweet, Parker, Petschek y Sonnerup. En esta comunicación presentamos una solución de las ecuaciones MHD en el entorno del origen, construyendo series bidimensionales para todas las magnitudes físicas involucradas. Valiéndonos de la alta simetría y de las características del problema, logramos reducir el número de coeficientes a calcular. Utilizamos un programa autoconsistente para extender el cálculo a regiones vecinas con difusión moderada o despreciable.

  20. In vitro dehalogenation of para-substituted aromatic halides in rat liver preparations.

    PubMed

    Scott, M T; Sinsheimer, J E

    1984-08-01

    The in vitro dehalogenation of a series of para-substituted halobenzenes was studied using HPLC separation followed by scintillation counting or neutron-activation analysis. Microsomal and cytosolic deiodination were established for iodobenzene substrates whose para-substituents were CO2H, CHO, NO2, OH, and C6H5 but not for para-iodobenzonitrile. A nonglutathione cytosolic deiodinase was only indicated with 4-iodobiphenyl as the substrate. In vitro dehalogenation could not be established for 4-bromobiphenyl using neutron-activation analysis. PMID:6387082

  1. 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.

  2. All the three ParaHox genes are present in Nuttallochiton mirandus (Mollusca: polyplacophora): evolutionary considerations.

    PubMed

    Barucca, Marco; Biscotti, Maria A; Olmo, Ettore; Canapa, Adriana

    2006-03-15

    The ParaHox gene cluster contains three homeobox genes, Gsx, Xlox and Cdx and has been demonstrated to be an evolutionary sister of the Hox gene cluster. Among deuterostomes the three genes are found in the majority of taxa, whereas among protostomes they have so far been isolated only in the phylum Sipuncula. We report the partial sequences of all three ParaHox genes in the polyplacophoran Nuttallochiton mirandus, the first species of the phylum Mollusca where all ParaHox genes have been isolated. This finding has phylogenetic implications for the phylum Mollusca and for its relationships with the other lophotrochozoan taxa. PMID:16331637

  3. Use of UV ParaLens adapter for detection of acid-fast organisms.

    PubMed

    Patterson, K V; McDonald, C L; Miller, B F; Chapin, K C

    1995-01-01

    Auramine-stained mycobacterial smears from 136 clinical specimens were interpreted by using the UV ParaLens adapter (Beckton Dickinson), and results were compared with smear interpretations using a traditional fluorescent microscope and culture. The sensitivity and specificity of the ParaLens were 84 and 93%, respectively. Smears yielding discrepant results were overstained by the Kinyoun method. Overall, the sensitivity of auramine-stained smears interpreted with the UV ParaLens was comparable to that of Kinyoun-stained smears. PMID:7535314

  4. 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.

  5. 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.

  6. Pd-on-Si catalysts prepared via galvanic displacement for the selective hydrogenation of para-chloronitrobenzene.

    PubMed

    Wei, Qian; Shi, Yu-Sheng; Sun, Ke-Qiang; Xu, Bo-Qing

    2016-02-01

    The direct redox reaction (galvanic displacement) between Pd(2+) and substrate Si was used to deposit Pd on Si, and the Pd-Si catalysts enabled a chemoselective hydrogenation of para-chloronitrobenzene with the selectivity for para-chloroaniline higher than 99.9% at complete conversion of para-chloronitrobenzene. PMID:26788556

  7. 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.

  8. Lo que usted debe saber antes de dar sus tejidos para investigación médica

    Cancer.gov

    Contiene información sobre las cosas que usted debe saber y tener en cuenta al tomar una decisión de donar sus tejidos para investigación. El tejido puede incluir materiales de su cuerpo tales como piel, cabello, uñas, sangre y orina.

  9. Infografía: beneficios y perjuicios de la prueba del PSA para la detección del cáncer de próstata

    Cancer.gov

    Infografía que muestra los beneficios y perjuicios de la prueba del PSA para la detección del cáncer de próstata, según estimaciones de dos estudios sobre exámenes de detección del cáncer de próstata.

  10. 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.

  11. Genomic organisation of the seven ParaHox genes of coelacanths

    PubMed Central

    Mulley, John F; Holland, Peter WH

    2014-01-01

    Human and mouse genomes contain six ParaHox genes implicated in gut and neural patterning. In coelacanths and cartilaginous fish, an additional ParaHox gene exists—Pdx2—that dates back to the genome duplications in early vertebrate evolution. Here we examine the genomic arrangement and flanking genes of all ParaHox genes in coelacanths, to determine the full complement of these genes. We find that coelacanths have seven ParaHox genes in total, in four chromosomal locations, revealing that five gene losses occurred soon after vertebrate genome duplication. Comparison of intergenic sequences reveals that some Pdx1 regulatory regions associated with development of pancreatic islets are older than tetrapods, that Pdx1 and Pdx2 share few if any conserved non-coding elements, and that there is very high sequence conservation between coelacanth species. PMID:23775937

  12. Para-Selective Halogenation of Nitrosoarenes with Copper(II) Halides.

    PubMed

    van der Werf, Angela; Selander, Nicklas

    2015-12-18

    The para-selective direct bromination and chlorination of nitrosoarenes with copper(II) bromide and chloride is reported. Under mild reaction conditions, a range of halogenated arylnitroso compounds are obtained in moderate to good yields with high regioselectivity. Additionally, the versatility of the method is demonstrated by the development of a one-pot procedure to obtain the corresponding para-halogenated aniline- and nitrobenzene derivatives. PMID:26606695

  13. 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.

  14. Two anaerobic polychlorinated biphenyl-dehalogenating enrichments that exhibit different para-dechlorination specificities.

    PubMed Central

    Wu, Q; Wiegel, J

    1997-01-01

    Two anaerobic polychlorinated biphenyl (PCB)-dechlorinating enrichments with distinct substrate specificities were obtained: a 2,3,4,6-tetrachlorobiphenyl (2346-CB) para-dechlorinating enrichment derived from Aroclor 1260-contaminated Woods Pond (Lenox, Mass.) sediment and a 2,4,6-trichlorobiphenyl (246-CB) unflanked para-dechlorinating enrichment derived from PCB-free Sandy Creek Nature Center (Athens, Ga.) sediment. The enrichments have been successfully transferred to autoclaved soil slurries over 20 times by using 300 to 350 microM 2346-CB or 246-CB. Both enrichments required soil for successful transfer of dechlorination activity. The 2346-CB enrichment para dehalogenated, in the absence or presence of 2346-CB, only 4 of 25 tested para halogen-containing congeners: 234-CB, 2345-CB, 2346-CB, and 2,4,6-tribromobiphenyl (246-BrB). In the presence of 246-CB, the 246-CB enrichment para dehalogenated 23 of the 25 tested congeners. However, only three congeners (34-CB, 2346-CB, and 246-BrB) were dehalogenated in the absence of 246-CB, indicating that these specific congeners initiate dehalogenation in this enrichment culture. The addition of the 2346-CB (para)-dechlorinating enrichment did not further stimulate the 2346-CB-primed dechlorination of the Aroclor 1260 residue in Woods Pond sediment samples. Compared to the addition of the primer 246-CB or the 246-CB unflanked para-dechlorinating enrichment alone, the addition of both 246-CB (300 microM) and the 246-CB enrichment stimulated the unflanked para dechlorination of the Aroclor 1260 residue in Woods Pond sediments. These results indicate that the two enrichments contain different PCB-dechlorinating organisms, each with high substrate specificities. Furthermore, bioaugmentation with the enrichment alone did not stimulate the desired dechlorination in PCB-contaminated Woods Pond sediment. PMID:9406402

  15. A Diagnostic Assessment for the Teaching of Astronomy. (Spanish Title: Una Evaluación Diagnóstica Para la Enseñanza de la Astronomia.) Uma Avaliação Diagnóstica Para o Ensino da Astronomia

    NASA Astrophysics Data System (ADS)

    Pacifico Ribeiro de Assis Silveira, Felipa; Soares Gomes de Sousa, Célia Maria; Moreira, Antonio

    2011-07-01

    This article aims to present the results of a diagnostic evaluation, used as a tool for collecting data on prior knowledge of scientific concepts needed to understand the topic "Earth and Universe", from a group comprised of 47 students of 6th grade. The educational method of diagnosing the student's prior knowledge before teaching them is founded on the Meaningful Learning theory, proposed by David Ausubel. The diagnostic evaluation consisted of 25 questions; the answers were analyzed and categorized, making possible their interpretation, which allows us to understand the meanings assigned by the student to these concepts. It follows from the diagnostic evaluation, that the majority of students surveyed had difficulties in exposing scientific concepts on the topic "Earth and Universe" when starting the 6th grade. However, we identified relevant ideas and representations that contributed to the re-signification of scientific concepts proposed for the teaching of the subject in this grade. The results of diagnostic evaluation served as reference to the organization of the syllabus, making possible the learning process by matching the sequence of teaching to the students" characteristics and context of the classroom. It is expected that other researchers in this topic can also use the instrument presented in this paper. Este artículo tiene como objetivo presentar los resultados de una evaluación diagnóstica, utilizada como una herramienta para recoger datos sobre el conocimiento previo de los conceptos científicos necesarios para comprender el tema "Tierra y Universo", de un grupo compuesto por 47 alumnos de 6º grado de la escuela primaria. La acción pedagógica del diagnóstico de los conocimientos previos del estudiante antes de enseñarles está justificada por la teoría del Aprendizaje Significativo, propuesta por David Ausubel. La evaluación de diagnóstico consistió en 25 preguntas, las respuestas fueron analizadas y clasificadas objetivando-se su interpretación, lo que nos permite comprender los significados asignados por el estudiante a estos conceptos. Se desprende de la evaluación diagnóstica que la mayoría de los encuestados ha tenido dificultades para exponer los conceptos científicos sobre el Universo y la Tierra, para iniciar el 6 º grado. Sin embargo, se identificaron ideas relevantes y las representaciones que contribuyeron a la re-significación de los conceptos científicos propuestos para la enseñanza del tema en esta serie. Los resultados de la evaluación diagnóstica han servido como referencia para la organización del Programa, facilitando el proceso de aprendizaje, haciendo coincidir la secuencia didáctica a las características de los estudiantes y el contexto del aula. Se espera que el instrumento presentado en este documento también pueda ser utilizado por otros investigadores en investigaciones relacionadas con el tema. Este artigo tem como objetivo apresentar os resultados de uma avaliação diagnóstica, utilizada como instrumento para a coleta de dados sobre o conhecimento prévio de conceitos científicos, necessários à compreensão do tema Terra e Universo, de um grupo composto por 47 estudantes, da 6ª série do Ensino Fundamental. A ação pedagógica de diagnosticar os conhecimentos prévios, do estudante, antes de ensiná-los, tem fundamento na teoria da Aprendizagem Significativa, proposta por David Ausubel. Essa avaliação diagnóstica foi composta por 25 questões, cujas respostas foram analisadas e categorizadas visando sua interpretação, o que permitiu compreender os significados atribuídos pelo estudante a esses conceitos. Conclui-se, a partir da avaliação diagnóstica, que a maioria dos estudantes pesquisados apresentou dificuldades em expor conceitos científicos sobre o tema Terra e Universo ao iniciar a 6ª série. Entretanto, foram identificadas ideias e representações relevantes que contribuíram para a (re)significação dos conceitos científicos propostos para o ensino do tema nessa série. Os resultados da avaliação diagnóstica serviram como referência para a organização do plano de ensino, viabilizando o processo de aprendizagem, por adequar a sequência didática às características dos estudantes e ao contexto da sala de aula. É esperado que o instrumento apresentado nesse artigo possa ser utilizado também por outros pesquisadores em investigações relacionadas ao tema.

  16. Competing ParA Structures Space Bacterial Plasmids Equally over the Nucleoid

    PubMed Central

    Gerdes, Kenn; Howard, Martin

    2014-01-01

    Low copy number plasmids in bacteria require segregation for stable inheritance through cell division. This is often achieved by a parABC locus, comprising an ATPase ParA, DNA-binding protein ParB and a parC region, encoding ParB-binding sites. These minimal components space plasmids equally over the nucleoid, yet the underlying mechanism is not understood. Here we investigate a model where ParA-ATP can dynamically associate to the nucleoid and is hydrolyzed by plasmid-associated ParB, thereby creating nucleoid-bound, self-organizing ParA concentration gradients. We show mathematically that differences between competing ParA concentrations on either side of a plasmid can specify regular plasmid positioning. Such positioning can be achieved regardless of the exact mechanism of plasmid movement, including plasmid diffusion with ParA-mediated immobilization or directed plasmid motion induced by ParB/parC-stimulated ParA structure disassembly. However, we find experimentally that parABC from Escherichia coli plasmid pB171 increases plasmid mobility, inconsistent with diffusion/immobilization. Instead our observations favor directed plasmid motion. Our model predicts less oscillatory ParA dynamics than previously believed, a prediction we verify experimentally. We also show that ParA localization and plasmid positioning depend on the underlying nucleoid morphology, indicating that the chromosomal architecture constrains ParA structure formation. Our directed motion model unifies previously contradictory models for plasmid segregation and provides a robust mechanistic basis for self-organized plasmid spacing that may be widely applicable. PMID:25521716

  17. Spontaneous Emission Between - and Para-Levels of Water-Ion H_2O^+

    NASA Astrophysics Data System (ADS)

    Tanaka, Keiichi; Harada, Kensuke; Nanbu, Shinkoh; Oka, Takeshi

    2012-06-01

    Nuclear spin conversion interaction of water ion, H_2O^+, has been studied to derive spontaneous emission lifetime between ortho- and para-levels. H_2O^+ is a radical ion with the ^2B_1 electronic ground state. Its off-diagonal electron spin-nuclear spin interaction term, Tab(S_a? I_b + S_b? I_a), connects para and ortho levels, because ? I = I_1 - I_2 has nonvanishing matrix elements between I = 0 and 1. The mixing by this term with Tab = 72 MHz predicted by ab initio theory in the MRD-CI/Bk level, is many orders of magnitude larger than for closed shell molecules because of the large magnetic interaction due to the un-paired electron. Using the molecular constants reported by Mürtz et al. by FIR-LMR, we searched for ortho and para coupling channels below 1000 cm-1 with accidental near degeneracy between para and ortho levels. For example, hyperfine components of the 42,2(ortho) and 33,0(para) levels mix by 1.2 × 10-3 due to their near degeneracy (? E = 0.417 cm-1), and give the ortho-para spontaneous emission lifetime of about 0.63 year. The most significant low lying 10,1(para) and 11,1(ortho) levels, on the contrary, mix only by 8.7 × 10-5 because of their large separation (? E = 16.267 cm-1) and give the spontaneous emission lifetime from 10,1(para) to 00,0(ortho) of about 100 year.These results qualitatively help to understand the observed high ortho- to para- H_2O^+ ratio of 4.8 ± 0.5 toward Sgr B2 but they are too slow to compete with the conversion by collision unless the number density of the region is very low (n ˜1 cm-3) or radiative temperature is very high (T_r > 100 K). M. Staikova, B. Engels, M. Peric, and S.D. Peyerimhoff, Mol. Phys. 80, 1485 (1993) P. Mürtz, L.R. Zink, K.M. Evenson, and J.M. Brown J. Chem. Phys. 109, 9744 (1998). LP. Schilke, et al., A&A 521, L11 (2010).

  18. 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.

  19. 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 t?lescopio 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

  20. 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.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26299447

  2. 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.

  3. Superfluid Effects in PARA-H_2 Clusters Probed by CO_2 Rotation-Vibration Transitions

    NASA Astrophysics Data System (ADS)

    Li, Hui; Le Roy, Robert J.; Roy, Pierre-Nicholas; McKellar, A. R. W.

    2010-06-01

    The prospect of directly observing superfluidity in para-H_2 is a tantalizing but elusive goal. Like ^4He, para-H_2 is a light zero-spin boson. However, H_2-H_2 intermolecular interactions, though weak, are stronger than He-He interactions, and hydrogen is a solid below about 14 K. This makes detection of superfluidity in bulk hydrogen problematical, to say the least. But there are still possibilities for para-H_2 in the form of clusters or in nano-confined environments, and superfluid transition temperatures as high as ˜6 K have been predicted. Spectroscopic observations of (para-H_2)_N-CO_2 clusters were at first very difficult to interpret for N > 5. However, with the help of path integral Monte Carlo simulations and an accurate new H_2-CO_2 intermolecular potential surface which explicitly incorporates dependence on the CO_2 ?b{3} asymmetric stretch, it is now possible to achieve a remarkably consistent picture of (para-H_2)_N-CO_2 clusters in the size range N = 1 ˜ 20. By combining the experimental spectroscopic measurements and theoretical simulations, we determine the size evolution of the superfluid response of the CO_2-doped para-H_2 clusters, which peaks for the "magic" number N = 12. V. L. Ginzburg and A. A. Sobyanin, JETP Lett. 15, 343 (1972). A. R. W. McKellar, Paper WH04, 63rd OSU International Symposium on Molecular Spectroscopy, June 16-20, 2008. H. Li, P.-N. Roy, and R. J. Le Roy, J. Chem. Phys., submitted.

  4. Low temperature HD+ortho-/para-H2 inelastic scattering of astrophysical interest

    NASA Astrophysics Data System (ADS)

    Sultanov, Renat A.; Guster, Dennis; Adhikari, S. K.

    2016-01-01

    State-selected total cross sections and thermal rate coefficients are computed for the HD + ortho-/para-H2 rotational energy transfer collision at low temperatures: 2 K ? T ? 300 K. A modified H2-H2 potential energy surface (PES) devised by Hinde is used for this pure quantum-mechanical dynamical computation. A comparison of the new results for the HD + ortho-/para-H2 scattering problem and previous calculations computed with the use of other older PESs is presented and discussed.

  5. 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

  6. Organocatalyzed Asymmetric 1,6-Conjugate Addition of para-Quinone Methides with Dicyanoolefins.

    PubMed

    Li, Xuanyi; Xu, Xiuyan; Wei, Weiwei; Lin, Aijun; Yao, Hequan

    2016-02-01

    A chiral thiourea catalyzed asymmetric 1,6-conjugate addition of para-quinone methides with dicyanoolefins has been developed. The reaction provided an efficient approach to the synthesis of chiral diarylmethine skeletons in good yields (up to 99% yield) with high diastereo- and enantioselectivity (>20:1 dr and up to 99.5:0.5 er), also on a gram scale. The preliminary mechanistic study showed that the remote stereocontrol was achieved through intermolecular hydrogen-bond interaction between the chiral thiourea catalyst and the para-quinone methides directly for the first time. PMID:26760214

  7. 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

  8. Large scale visualization on the Cray XT3 using ParaView.

    SciTech Connect

    Rogers, David; Geveci, Berk; Eschenbert, Kent; Neundorf, Alexander; Marion, Patrick; Moreland, Kenneth D.; Greenfield, John

    2008-05-01

    Post-processing and visualization are key components to understanding any simulation. Porting ParaView, a scalable visualization tool, to the Cray XT3 allows our analysts to leverage the same supercomputer they use for simulation to perform post-processing. Visualization tools traditionally rely on a variety of rendering, scripting, and networking resources; the challenge of running ParaView on the Lightweight Kernel is to provide and use the visualization and post-processing features in the absence of many OS resources. We have successfully accomplished this at Sandia National Laboratories and the Pittsburgh Supercomputing Center.

  9. Evaluation of an immobilized cell bioreactor for degradation of meta- and para-nitrobenzoate

    NASA Astrophysics Data System (ADS)

    Peretti, Steven W.; Thomas, Stuart M.

    1994-01-01

    Meta- and para-nitrobenzoic acid are pollutants found in waste streams from metal-stripping processes using cyanide-free solvents. The Kelly AFB industrial Waste Treatment Plant (IWTP) is currently incapable of removing these compounds from its wastewaters because of the presence of significant quantities of ethylenediamine, a preferred substrate and upper limit of 4-5 hours on the hydraulic residence time in the IWTP. This report describes the enrichment and preliminary characterization of a microbial consortium capable of utilizing both Meta- and Para-Nitrobenzoate as sole carbon sources.

  10. 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 ?~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.

  11. 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.

  12. 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…

  13. 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.

  14. Evaluation of Modified Formalin-Ether Concentration Method Using Para Tube in Clinical Settings

    PubMed Central

    Won, Eun Jeong; Kim, Jin

    2015-01-01

    Conventional formalin-ether concentration method is a gold standard for the diagnosis of parasite infection. However, it may be time-consuming and laborious. We aimed to reveal the clinical usefulness of a modified formalin-ether concentration method using the Para Tube (KS Corporation, Korea) compared with the conventional method. A total of 117 fresh, unpreserved fecal samples composed to 90 negative controls and 27 positive controls with ova of Diphyllobothrium latum/D. nihonkaiense, ova of Clonorchis sinensis and cysts of Giardia lamblia were used in this study. Both methods showed comparable correct identification rate (87.2% for the Para Tube vs. 86.3% for the conventional method).When five samples were examined at once, the Para Tube method reduced the procedure time compared with the conventional method (19 min 58 sec vs. 23 min 18 sec, P=0.0286). We concluded that the modified formalin-ether concentration method using the Para Tube is a rapid, simple, and reliable fecal concentration method for clinical use. PMID:26131417

  15. Evaluation of Modified Formalin-Ether Concentration Method Using Para Tube in Clinical Settings.

    PubMed

    Won, Eun Jeong; Kim, Jin; Ryang, Dong Wook

    2015-07-01

    Conventional formalin-ether concentration method is a gold standard for the diagnosis of parasite infection. However, it may be time-consuming and laborious. We aimed to reveal the clinical usefulness of a modified formalin-ether concentration method using the Para Tube (KS Corporation, Korea) compared with the conventional method. A total of 117 fresh, unpreserved fecal samples composed to 90 negative controls and 27 positive controls with ova of Diphyllobothrium latum/D. nihonkaiense, ova of Clonorchis sinensis and cysts of Giardia lamblia were used in this study. Both methods showed comparable correct identification rate (87.2% for the Para Tube vs. 86.3% for the conventional method).When five samples were examined at once, the Para Tube method reduced the procedure time compared with the conventional method (19 min 58 sec vs. 23 min 18 sec, P=0.0286). We concluded that the modified formalin-ether concentration method using the Para Tube is a rapid, simple, and reliable fecal concentration method for clinical use. PMID:26131417

  16. 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.

  17. 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.

  18. 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.

  19. 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,…

  20. Para-Professionals in Further Education: Changing Roles in Vocational Delivery

    ERIC Educational Resources Information Center

    Scott, Gill

    2005-01-01

    Roles and structures within further education colleges seem to be in constant change and development; roles are becoming blurred, and lecturers are taking on more management tasks. Alongside this has been the development of para-professional roles, using non-lecturers to undertake teaching tasks. This can allow for the greater involvement of…

  1. 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.

  2. 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.

  3. 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

  4. 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…

  5. 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.

  6. 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 ...

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Performance characteristics of magnesium/para-nitrophenol cells in 2:1 magnesium electrolytes

    SciTech Connect

    Kumar, G.; Sivashanugam, A.; Sridharan, R. )

    1993-11-01

    1 V/1 Ah magnesium/para-nitrophenol (PNP) reserve cells were fabricated and their performance was evaluated in different electrolytes [2M aqueous solutions of Mg(C1O[sub 4])[sub 2], MgCl[sub 2], and MgBr[sub 2

  17. 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.

  18. 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.

  19. 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.

  20. Cáncer de riñón—Versión para profesionales de salud

    Cancer.gov

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

  1. 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.

  2. 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.

  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 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Cáncer de piel—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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Intact cluster and chordate-like expression of ParaHox genes in a sea star

    PubMed Central

    2013-01-01

    Background The ParaHox genes are thought to be major players in patterning the gut of several bilaterian taxa. Though this is a fundamental role that these transcription factors play, their activities are not limited to the endoderm and extend to both ectodermal and mesodermal tissues. Three genes compose the ParaHox group: Gsx, Xlox and Cdx. In some taxa (mostly chordates but to some degree also in protostomes) the three genes are arranged into a genomic cluster, in a similar fashion to what has been shown for the better-known Hox genes. Sea urchins possess the full complement of ParaHox genes but they are all dispersed throughout the genome, an arrangement that, perhaps, represented the primitive condition for all echinoderms. In order to understand the evolutionary history of this group of genes we cloned and characterized all ParaHox genes, studied their expression patterns and identified their genomic loci in a member of an earlier branching group of echinoderms, the asteroid Patiria miniata. Results We identified the three ParaHox orthologs in the genome of P. miniata. While one of them, PmGsx is provided as maternal message, with no zygotic activation afterwards, the other two, PmLox and PmCdx are expressed during embryogenesis, within restricted domains of both endoderm and ectoderm. Screening of a Patiria bacterial artificial chromosome (BAC) library led to the identification of a clone containing the three genes. The transcriptional directions of PmGsx and PmLox are opposed to that of the PmCdx gene within the cluster. Conclusions The identification of P. miniata ParaHox genes has revealed the fact that these genes are clustered in the genome, in contrast to what has been reported for echinoids. Since the presence of an intact cluster, or at least a partial cluster, has been reported in chordates and polychaetes respectively, it becomes clear that within echinoderms, sea urchins have modified the original bilaterian arrangement. Moreover, the sea star ParaHox domains of expression show chordate-like features not found in the sea urchin, confirming that the dynamics of gene expression for the respective genes and their putative regulatory interactions have clearly changed over evolutionary time within the echinoid lineage. PMID:23803323

  16. 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

  17. 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.

  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. Relación masa-radio para estrellas enanas blancas y la interpretación de recientes mediciones hechas por Hipparcos

    NASA Astrophysics Data System (ADS)

    Panei, J. A.; Althaus, L. G.; Benvenuto, O. G.

    Recientes mediciones de la masa y el radio hechas por Hipparcos de las estrellas enanas blancas 40 Eri B y Procyon B (Shipman, H. & Provencal, J. - ApJ. 1998, 494, 759), sugieren un núcleo compuesto de hierro para dichas estrellas, en lugar de carbono y oxígeno como predice la teoría standard de evolución estelar. Para interpretar estas observaciones, presentamos aquí, relaciones masa-radio para configuraciones degeneradas a temperatura finita para distintas composiciones químicas centrales. Para tal fin hemos calculado secuencias evolutivas de enanas blancas utilizando el código de evolución estelar, desarrollado en el Observatorio de La Plata. Dicho código resuelve las ecuaciones de estructura y evolución estelar mediante la técnica de relajación de Henyey, y esta basado en una descripción física muy detallada y actualizada.

  2. 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 observed via colour changes in visible light, suggesting a close connection between the tropospheric temperatures, para-H2 and haze characteristics.

  3. 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.

  4. A Density Functional Approach to Para-hydrogen at Zero Temperature

    NASA Astrophysics Data System (ADS)

    Ancilotto, Francesco; Barranco, Manuel; Navarro, Jesús; Pi, Marti

    2016-01-01

    We have developed a density functional (DF) which reproduces by constructing either the metastable liquid or the solid equation of state of bulk para-hydrogen, as derived from quantum Monte Carlo zero temperature calculations. As an application, we have used it to study the structure and energetics of small para-hydrogen clusters made of up to N=40 molecules. We compare our results for liquid clusters with diffusion Monte Carlo (DMC) calculations and find a fair agreement between them. In particular, the transition found within DMC between hollow-core structures for small N values and center-filled structures at higher N values is reproduced. The present DF approach yields results for (pH_2 )_N clusters indicating that for small N values a liquid-like character of the clusters prevails, while solid-like clusters are instead energetically favored for N ≥ 15.

  5. Molecular characterization of neurally expressing genes in the para sodium channel gene cluster of Drosophila

    SciTech Connect

    Hong, Chang-Sook; Ganetzky, B.

    1996-03-01

    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. 76 refs., 11 figs.

  6. Copolymers containing meta-pyridylvinylene and para-arylenevinylene fragments: synthesis, quaternization reaction, and photophysical properties

    NASA Astrophysics Data System (ADS)

    Barashkov, Nikolay N.; Olivos, Hernando J.; Ferraris, John P.

    1997-12-01

    We report the Wittig reaction of the diphosphonium salt of 2,6-bis(chloromethyl)pyridine with terephthaldehyde, 2.5- dioctyloxyterephthaldehyde, or 9,10-anthracenedicarbaldehyde to form conjugated copolymers with fragments of 2,6 - pyridylene and para-arylenevinylene. The protonation reaction of poly(para-arylenevinylene)-co-(meta- pyridylvinylene) with hydrochloric acid and the quaternization reaction of poly(2,5-dioctyloxy-1,4- phenylenevinylene)-co-(2,6-pyridylvinylene) with methyl triflate have been investigated by spectrophotometric and fluorescent methods. The absorption, excitation and fluorescence spectra of these copolymers as well as their corresponding model compounds were studied and compared. The photophysical properties of the investigated polymers suggest that these materials could be good candidates for the fabrication of efficient blue and green light-emitting diodes.

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

    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%.

  8. Chirality driven crystallization behavior of ortho, meta, and para-cyanophenyl glycerol ethers

    NASA Astrophysics Data System (ADS)

    Bredikhin, Alexander A.; Litvinov, Igor A.; Krivolapov, Dmitry B.; Fattahov, Bulat R.; Gubaidullin, Aidar T.; Akhatova, Flyura S.; Bredikhina, Zemfira A.

    2010-09-01

    Enantiopure and racemic samples of ortho, meta, and para CN-substituted phenyl glycerol ethers 1- 3 were investigated by differential scanning calorimetry and single-crystal X-ray analysis. The absolute configuration for ( S)- 1 was established through Flack parameter method. Whereas ortho-derivative 1 demonstrates spontaneous resolution upon crystallization, homochiral lattice for scalemic meta-derivative 2 is exceeded in stability by heterochiral lattice of racemic compound. This tendency becomes all the more evident for the para-derivative 3, in which case the difference in Gibbs free energy between rac and scal lattices amounts Δ G0 = -4.48 kJ mol -1. Most of these phenomena could be understood by reference to crystal packing details.

  9. Kyste géant para-urétral feminine

    PubMed Central

    Kassogué, Amadou; Coulibaly, Mamadou; Ouattara, Zanafon; Diarra, Alkadri; Tembely, Aly; Ouattara, Kalilou; Farih, My Hassan

    2014-01-01

    Le kyste géant para-urétral féminin infecté est rarement rapporté dans la littérature. Ce kyste est différent du diverticule sous urétral sur le plan clinique, diagnostique et thérapeutique. Sa pathogénie se confond avec celle des diverticules sous urétraux. Son traitement n'est pas bien codifié, vu sa rareté. Nous rapportons un cas atypique de kyste géant para urétral infecté chez une jeune femme de 26 ans. Le kyste était symptomatique et la patiente a eu un traitement chirurgical. Nous discutons les aspects cliniques, diagnostiques et thérapeutiques de cette entité rare à travers une revue de la littérature.

  10. 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.

  11. 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

  12. Action spectra for ultraviolet photosensitized killing of mammalian cells by misonidazole and para-nitroacetophenone

    SciTech Connect

    Fisher, G.J.; Sutherland, B.M.; Sutherland, J.C.

    1983-05-01

    Chinese hamster fibroblasts in monolayer culture were exposed to ulraviolet radiation at 313, 334, 365, 380, and 405 nm in the presence of either misonidazole or para-nitroacetophenone, drugs which act as both photosensitizers and radiosensitizers of cell killing. Survival was measured by a colony-forming assay. The resulting action spectra for cell death photosensitized by the drugs (the reciprocals of the exposures required at each wavelength to reduce cell survival to a given level) closely match their absorption spectra over a range of three orders of magnitude. These results demonstrate that cells can be killed upon excitation of misonidazole or para-nitroacetophenone in the absence of any other types of energy deposition or biomolecular damage.

  13. 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

  14. 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

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

    PubMed Central

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

    2012-01-01

    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

  16. Complexation and determination of palladium (II) ion with para-Cl-phenylazo-R-acid spectrophotometrically.

    PubMed

    Hanna, W G

    1999-11-15

    The complexation of para-Cl-phenylazo-R-acid azo dye with Pd(II) has been studied spectrophotometrically. Protonation constant (pK(a)) of the ligand has been calculated and the stability conditional constants of para-Cl-phenylazo-R-acid ligand with palladium ion has been determined at a constant temperature (25.0 degrees C), where the molar ratio of this complex is 1:1 (metal:ligand) with logbeta(1)=3.75, and 1:2 with logbeta(2)=8.55. Solid complex of para-Cl-phenylazo-R-acid has been prepared and characterized on the basis of elemental analysis and FTIR spectral data. A procedure for the spectrophotometric determination of Pd(II) using para-Cl-phenylazo-R-acid as a new azo chromophore is proposed where it is rapid, sensitive and highly specific. Beer's law was obeyed in the range 0.50-10.00 ppm at pH 5.0-6.0 to form a violet-red complex (epsilon=7.7 x 10(4) l(-1) mol(-1) cm(-1) at lambda(max)=560 nm). Metal ions such as Cu(II), Cr(III), La(III), Yb(III), Y(III), and Rh(III) interfere with the complex. Ammonium salt of trimellitic acid is used to precipitate some of the interfering ions and a scheme for separation of Pd(II) from a synthetic mixture similar in composition to platinum ore or deposit was made. PMID:18967771

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

    PubMed Central

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

    2015-01-01

    Summary 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

  19. 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

  20. 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.

  1. [A case of para-cerebral abscess as a complication of middle ear purulent inflammation].

    PubMed

    Ko?ody?ski, Piotr; Ja?wiec, Przemys?aw; Barna?, Szczepan; Wilczy?ski, Krzysztof; Ca?ka, Karol; Kedzierski, Bart?omiej; Bojarski, Boles?aw; Chudzik, Maciej

    2002-01-01

    We reported the case of para-cerebral abscess in the left temporal region, being a complication of exacerbation of chronic middle ear inflammation with cholesteatoma. Computed tomography was performed, which helped in the diagnosis. The patient was treated conservatively by aimed antibiotic therapy. We performed surgery of the middle ear, with abscess removal through trepan apertura attaining good results. We have presented principles of diagnostic and therapeutic procedures which help in prevention of intracranial complications in ear diseases. PMID:12418291

  2. 4-Amino-12-methyl­sulfon­yloxy-[2.2]para­cyclo­phane

    PubMed Central

    Meng, Xiangchao; Duan, Wenzeng; Han, Yinfeng

    2014-01-01

    The title compound, C17H19NO3S, was synthesized from 4-benzhydryl­idene­amino-12-hy­droxy-[2.2]para­cyclo­phane and methane­sulfonyl chloride. In the mol­ecule, the distance between the centroids of two aromatic rings is 2.960?(5)?Å. In the crystal, weak N—H?O and C—H?O hydrogen bonds link the mol­ecules into layers parallel to the ac plane. PMID:24526969

  3. Nickel-catalysed para-CH activation of pyridine with switchable regioselective hydroheteroarylation of allylarenes.

    PubMed

    Lee, Wei-Chih; Chen, Chien-Hung; Liu, Cheng-Yuan; Yu, Ming-Shiuan; Lin, Yung-Huei; Ong, Tiow-Gan

    2015-12-14

    para-CH activation of pyridine with allylbenzene is described by Ni/Al cooperative catalysis in combination with a bulkier NHC ligand and a Lewis acid, leading to linear hydroheteroarylation products. Interestingly, the branch selectivity can be achieved by using the combination of a less sterically hindered amino-NHC ligand and AlMe3 through tandem reaction of facile alkene isomerization followed by a slow CH bond activation process. PMID:26451893

  4. 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.

  5. An Unusual Case of Bilateral Maxillary and Mandibular Para Premolar: A Case Report

    PubMed Central

    Chanagay, Sunil Kumar Vishwanath; Singh, Vikram; Bantwal, Sunil Rao; Muniyappa, Manjunatha

    2013-01-01

    The presence of supernumerary teeth is not uncommon in the general population. They occur more frequently in patients with a family history of such teeth. It is rare to find multiple supernumeraries in individuals with no other associated disease or syndrome. There have been very few documented cases of bilateral maxillary and mandibular supernumeraries in the premolar region. An unusual case of a 35-year-old man with six para premolars and complete dentition is presented. PMID:24396358

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. Fragrance material review on 1-(para-menthen-6-yl)-1-propanone.

    PubMed

    Scognamiglio, J; Letizia, C S; Api, A M

    2013-12-01

    A toxicologic and dermatologic review of 1-(para-Menthen-6-yl)-1-propanone when used as a fragrance ingredient is presented. 1-(para-Menthen-6-yl)-1-propanone is a member of the fragrance structural group Alkyl Cyclic Ketones. These fragrances can be described as being composed of an alkyl, R1, and various substituted and bicyclic saturated or unsaturated cyclic hydrocarbons, R2, in which one of the rings may include up to 12 carbons. Alternatively, R2 may be a carbon bridge of C2-C4 carbon chain length between the ketone and cyclic hydrocarbon. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 1-(para-Menthen-6-yl)-1-propanone were evaluated then summarized and includes physical properties, acute toxicity, skin irritation, and skin sensitization, data. A safety assessment of the entire Alkyl Cyclic Ketones will be published simultaneously with this document; please refer to Belsito et al. (2013) [Belsito, D., Bickers, D., Bruze, M., Calow, P., Dagli, M., Fryer, A.D., Greim, H., Miyachi, Y., Saurat, J.H., Sipes, I.G., 2013 A Toxicologic and Dermatologic Assessment of Alkyl Cyclic Ketones When Used as Fragrance Ingredients. Submitted with this manuscript.] for an overall assessment of the safe use of this material and all Alkyl Cyclic Ketones in fragrances. PMID:24246181

  11. Para-GMRF: parallel algorithm for anomaly detection of hyperspectral image

    NASA Astrophysics Data System (ADS)

    Dong, Chao; Zhao, Huijie; Li, Na; Wang, Wei

    2007-12-01

    The hyperspectral imager is capable of collecting hundreds of images corresponding to different wavelength channels for the observed area simultaneously, which make it possible to discriminate man-made objects from natural background. However, the price paid for the wealthy information is the enormous amounts of data, usually hundreds of Gigabytes per day. Turning the huge volume data into useful information and knowledge in real time is critical for geoscientists. In this paper, the proposed parallel Gaussian-Markov random field (Para-GMRF) anomaly detection algorithm is an attempt of applying parallel computing technology to solve the problem. Based on the locality of GMRF algorithm, we partition the 3-D hyperspectral image cube in spatial domain and distribute data blocks to multiple computers for concurrent detection. Meanwhile, to achieve load balance, a work pool scheduler is designed for task assignment. The Para-GMRF algorithm is organized in master-slave architecture, coded in C programming language using message passing interface (MPI) library and tested on a Beowulf cluster. Experimental results show that Para-GMRF algorithm successfully conquers the challenge and can be used in time sensitive areas, such as environmental monitoring and battlefield reconnaissance.

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

    NASA Astrophysics Data System (ADS)

    Rottmannová, Lenka; Lukeš, Vladimír; Il?in, 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.

  13. 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

  14. 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

  15. Otimização de procedimento de manobra para indução de reentrada de um satélite retornável

    NASA Astrophysics Data System (ADS)

    Schulz, W.; Suarez, M.

    2003-08-01

    Veículos espaciais que retornam à Terra passam por regimes de velocidade e condições de vôo distintos. Estas diferenças dificultam sua concepção aerodinâmica e o planejamento de seu retorno. A partir de uma proposta de um veículo orbital retornável (satélite SARA, em desenvolvimento no IAE/CTA) para realização de experimentos científicos e tecnológicos em ambiente de baixa gravidade, surge a necessidade de realizarem-se estudos considerando-se os aspectos relativos à sua aerodinâmica. Após o lançamento, o veículo deve permanecer em órbita pelo tempo necessário para a condução de experimentos, sendo depois direcionado à Terra e recuperado em solo. A concepção aerodinâmica é de importância para o vôo em suas diversas fases e deve considerar aspectos relativos à estabilização Aerodinâmica e ao arrasto atmosférico, sendo este último de importância crucial na análise do aquecimento a ser enfrentado. A manobra de retorno inclui considerações sobre as condições atmosféricas e dinâmica de reentrada, devendo ser calculada de forma mais precisa possível. O trabalho proposto avalia estudos da dinâmica de vôo de um satélite recuperável considerando aspectos relativos à determinação orbital com GPS, técnica utilizada com sucesso na CONAE, e seu comportamento aerodinâmico em vôo balístico de retorno, com ênfase em sua fase de reentrada atmosférica. Busca-se otimizar a manobra de reentrada de tal forma que a utilização do sistema GPS garanta minimizar a área de impacto com o solo.

  16. Comparação de modelos para o cálculo de perturbações orbitais devidas à maré terrestre

    NASA Astrophysics Data System (ADS)

    Vieira Pinto, J.; Vilhena de Moraes, R.

    2003-08-01

    Aplicações recentes de satélites artificiais com finalidades geodinâmicas requerem órbitas determinadas com bastante precisão. Em particular marés terrestres influenciam o potencial terrestre causando perturbações adicionais no movimento de satélites artificiais, as quais tem sido medidas por diversos processos. A atração exercida pela lua e pelo sol sobre a terra produz deslocamentos elásticos em seu interior e uma protuberância em sua superfície. O resultado é uma pequena variação na distribuição da massa na terra, consequentemente no geopotencial. As perturbações nos elementos orbitais de satélites artificiais terrestres devidas a maré terrestre podem ser estudadas a partir das equações de Lagrange, considerando-se um conveniente potencial. Por outro lado, como tem sido feito pelo IERS, as mudanças induzidas pela maré terrestre no geopotencial podem ser convenientemente modeladas como variações nos coeficientes Cnm e Snm do geopotencial. As duas teorias ainda não foram comparados para um mesmo satélite. Neste trabalho são apresentadas e comparadas as variações de longo período e seculares nas perturbações orbitais devidas à maré terrestre, calculadas por um modelo simples, o de Kozai, e pelo modelo do IERS. Resultados preliminares mostram, para os satélites SCD2 e CBERS1, e para a Lua em movimento elíptico e precessionando, as perturbações seculares no argumento do perigeu e na longitude do nodo ascendente.

  17. 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

  18. 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.

  19. Enhanced mitigation of para-chlorophenol using stratified activated carbon adsorption columns.

    PubMed

    Sze, Michael Fan Fu; McKay, Gordon

    2012-03-01

    The adsorptive removal of toxic para-chlorophenol using activated carbon adsorption columns is a proven effective engineering process. This paper examined the possibility to stratify an adsorbent bed into layers, in order to enhance the adsorption process performance in terms of increased column service time and adsorbent bed saturation. Four different types of fixed-bed adsorption columns are used and compared under the same operating conditions, but with the variation of column geometry and activated carbon particle size stratification. The Type 3 column - a cylindrical column with particle stratification packing, is found to be the most efficient choice, as the extent of column service time and adsorbent bed saturation are the largest. This could eventually decrease the frequency of adsorbent replacement/regeneration and hence reduce the operating cost of the fixed-bed adsorption process. The Homogeneous Surface Diffusion Model (HSDM) was applied successfully to describe the dynamic adsorption of para-chlorophenol onto Filtrasorb 400 (F400) activated carbon in different types of columns. The Redlich-Peterson isotherm model equation, an experimentally derived external mass transfer correlation and a constant surface diffusivity are used in the HSDM. The optimised surface diffusivity of para-chlorophenol is found to be 1.20E-8 cm(2)/s, which is in good agreement with other phenolics/F400 carbon diffusing systems in literature. PMID:22154109

  20. 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

  1. A sensitive and selective enzyme-linked immunosorbent assay for the analysis of Para red in foods.

    PubMed

    Wang, Jia; Wei, Keyi; Li, Hao; Li, Qing X; Li, Ji; Xu, Ting

    2012-05-01

    Para red is a synthetic dye and a potential genotoxic carcinogen. A hapten mimicking Para red structure was synthesized by introducing a carboxyl to the naphthol part of Para red and coupled to carrier protein to form an immunogen for the production of specific antibodies. A sensitive and selective enzyme-linked immunosorbent assay (ELISA) was developed for the detection of Para red in food samples. The limit of detection and inhibition half-maximum concentrations of Para red in phosphate buffered saline with 10% methanol were 0.06 and 2.2 ng mL(-1), respectively. Cross-reactivity values of the ELISA with the tested compounds including Sudan red I, II, III, IV, and G, sunset yellow, 2-naphthol, and 4-nitroaniline were ?0.2%. This assay was used to determine Para red in tomato sauce, chilli sauce, chilli powder and sausage samples after ultrasonic extraction, cleanup and concentration steps. The average recoveries, repeatability (intraday extractions and analysis), and intra-laboratory reproducibility (interday extractions and analysis) were in the range 90-108%, 4-12% and 8-17%, respectively. This assay was compared to a high-performance liquid chromatographic method for 28 samples, displaying a good correlation (R(2) = 0.95). Para red residues in 53 real world samples determined by ELISA were below the limit of detection. PMID:22439137

  2. Identification of an intact ParaHox cluster with temporal colinearity but altered spatial colinearity in the hemichordate Ptychodera flava

    PubMed Central

    2013-01-01

    Background ParaHox and Hox genes are thought to have evolved from a common ancestral ProtoHox cluster or from tandem duplication prior to the divergence of cnidarians and bilaterians. Similar to Hox clusters, chordate ParaHox genes including Gsx, Xlox, and Cdx, are clustered and their expression exhibits temporal and spatial colinearity. In non-chordate animals, however, studies on the genomic organization of ParaHox genes are limited to only a few animal taxa. Hemichordates, such as the Enteropneust acorn worms, have been used to gain insights into the origins of chordate characters. In this study, we investigated the genomic organization and expression of ParaHox genes in the indirect developing hemichordate acorn worm Ptychodera flava. Results We found that P. flava contains an intact ParaHox cluster with a similar arrangement to that of chordates. The temporal expression order of the P. flava ParaHox genes is the same as that of the chordate ParaHox genes. During embryogenesis, the spatial expression pattern of PfCdx in the posterior endoderm represents a conserved feature similar to the expression of its orthologs in other animals. On the other hand, PfXlox and PfGsx show a novel expression pattern in the blastopore. Nevertheless, during metamorphosis, PfXlox and PfCdx are expressed in the endoderm in a spatially staggered pattern similar to the situation in chordates. Conclusions Our study shows that P. flava ParaHox genes, despite forming an intact cluster, exhibit temporal colinearity but lose spatial colinearity during embryogenesis. During metamorphosis, partial spatial colinearity is retained in the transforming larva. These results strongly suggest that intact ParaHox gene clustering was retained in the deuterostome ancestor and is correlated with temporal colinearity. PMID:23802544

  3. 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.

  4. 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).

  5. 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 repository and issued as part of its Version 8.1 beta release. This source was transmitted to NSWC-IHD and in collaboration with LLNL personnel the entire ParaDyn software suite successfully installed and demonstrated on its new SGI Altix machine. The ability of even minor numbers of processors for the structural dynamics to impact overall time-to-solution for DYSMAS has been demonstrated. Assessments of combined parallel efficiencies are beginning to highlight areas for further DYSMAS optimizations.

  6. 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

  7. Dicopper(II) Metallacyclophanes with Electroswitchable Polymethyl-Substituted para-Phenylene Spacers.

    PubMed

    Ferrando-Soria, Jesús; Castellano, María; Ruiz-García, Rafael; Cano, Joan; Julve, Miguel; Lloret, Francesc; Ruiz-Pérez, Catalina; Pasán, Jorge; Cañadillas-Delgado, Laura; Armentano, Donatella; Journaux, Yves; Pardo, Emilio

    2013-09-01

    Double-stranded anionic dinuclear copper(II) metallacyclic complexes of the paracyclophane type [Cu2L2](4-) have been prepared by the Cu(II)-mediated self-assembly of different para-phenylenebis(oxamato) bridging ligands with either zero-, one-, or four-electron-donating methyl substituents (L=N,N'-para-phenylenebis(oxamate) (ppba; 1), 2-methyl- N,N'-para-phenylenebis(oxamate) (Meppba; 2), and 2,3,5,6-tetramethyl- N,N'-para-phenylenebis(oxamate) (Me4ppba; 3)). These complexes have been isolated as their tetra-n-butylammonium (1 a-3 a), lithium(I) (1 b-3 b), and tetraphenylphosphonium salts (1 c-3 c). The X-ray crystal structures of 1 a and 3 c show a parallel-displaced ?-stacked conformation with a smaller deviation from perpendicularity between the two benzene rings and the basal planes of the square planar Cu(II) ions when increasing the number of methyl substituents (average dihedral angles (?) of 58.72(7) and 73.67(5)° for 1 a and 3 c, respectively). Variable-temperature (2.0-300 K) magnetic-susceptibility measurements show an overall increase of the intramolecular antiferromagnetic coupling with the number of methyl substituents onto the para-phenylene spacers (-J=75-95, 100-124, and 128-144 cm(-1) for 1 a-c, 2 a-c, and 3 a-c, respectively; H=-JS1×S2). Cyclic voltammetry (CV) measurements show a reversible one-electron oxidation of the double polymethyl-substituted para-phenylenediamidate bridging skeleton at a relatively low formal potential that decreases with the number of methyl substituents (E1=+0.33, +0.24, and +0.15 V vs. SCE for 1-3, respectively). The monooxidized dicopper(II) ?-radical cation species 3' prepared by the chemical oxidation of 3 with bromine exhibits intense metal-to-ligand charge-transfer (MLCT) transitions in the visible and near-IR (?max=595 and 875 nm, respectively) regions together with a rhombic EPR signal with a seven-line splitting pattern due to hyperfine coupling with the nuclear spin of the two Cu(II) ions. Density functional (DF) calculations for 3' evidence a characteristic iminoquinonoid-type short-long-short alternating sequence of C-N and C-C bonds for both tetramethyl-para-phenylenediamidate bridges and a large amount of spin density of negative sign mainly delocalized along each of the four benzene C atoms directly attached to the amidate N atoms, which is in agreement with a fully delocalized ?-stacked monoradical ligand description. Hence, the spins of the two Cu(II) ions (SCu=1/2) that are antiparallel aligned in 3 (OFF state) become parallel in 3' (ON state). Further developments may be then envisaged for this new permethylated dicopper(II) paracyclophane with a redox noninnocent ligand as a prototype for molecular magnetic electroswitch. PMID:23873803

  8. IN VITRO EMBRYOTOXICITY OF A SERIES OF PARA-SUBSTITUTED PHENOLS: STRUCTURE, ACTIVITY AND CORRELATION WITH IN VIVO DATA

    EPA Science Inventory

    The embryotoxicity of phenol and twelve para-substituted congeners on mid-gestation rat embryos was evaluated in vitro. hrough application of correlative procedures and stepwise regression, equation describing the relationship between physical-chemical properties and various meas...

  9. 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.

  10. 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.

  11. 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.

  12. Contextual influence on the tilt after-effect in foveal and para-foveal vision.

    PubMed

    Chen, Cheng; Chen, Xianghui; Gao, Min; Yang, Qiong; Yan, Hongmei

    2015-06-01

    A sensory stimulus can only be properly interpreted in light of the stimuli that surround it in space and time. The tilt illusion (TI) and tilt after-effect (TAE) provide good evidence that the perception of a target depends strongly on both its spatial and temporal context. In previous studies, the TI and TAE have typically been investigated separately, so little is known about their co-effects on visual perception and information processing mechanisms. Here, we considered the influence of the spatial context and the temporal effect together and asked how center-surround context affects the TAE in foveal and para-foveal vision. Our results showed that different center-surround spatial patterns significantly affected the TAE for both foveal and para-foveal vision. In the fovea, the TAE was mainly produced by central adaptive gratings. Cross-oriented surroundings significantly inhibited the TAE, and iso-oriented surroundings slightly facilitated it; surround inhibition was much stronger than surround facilitation. In the para-fovea, the TAE was mainly decided by the surrounding patches. Likewise, a cross-oriented central patch inhibited the TAE, and an iso-oriented one facilitated it, but there was no significant difference between inhibition and facilitation. Our findings demonstrated, at the perceptual level, that our visual system adopts different mechanisms to process consistent or inconsistent central-surround orientation information and that the unequal magnitude of surround inhibition and facilitation is vitally important for the visual system to improve the detectability or discriminability of novel or incongruent stimuli. PMID:25895001

  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. Salud Para Su Carozón--a Latino promotora-led cardiovascular health education program.

    PubMed

    Spinner, Jovonni R; Alvarado, Matilde

    2012-01-01

    Salud Para Su Carozón is a culturally sensitive, community-based program to increase heart healthy knowledge and behaviors among Latinos. Promotoras were trained using a 10-session manual to teach participants from 7 communities about heart disease risk factors and skills to achieve heart healthy behaviors. In 435 participants with pre-to-post self-reported data, there were increases in physical activity outside of work (57%-78%), heart health knowledge (49%-76%), and confidence in preparing heart healthy meals (66%-81%) (all Ps < .001). Results suggest that promotoras can provide effective health education to improve heart health risk behaviors in select Latino communities. PMID:22367258

  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. Photochemical transformation of nitrate in the presence of para-halogenated phenols in frozen solutions

    NASA Astrophysics Data System (ADS)

    Abida, O.; Osthoff, H. D.; Sutherland, T. C.

    2010-12-01

    Photochemical reactions leading to the chemical transformation of trace compounds in the atmosphere do not only occur in the atmospheric gas and liquid phases, but also in the tropospheric ice phase. The photochemical reactions of trace compounds embedded in ice have important implications for the composition of the atmospheric boundary layer in ice and snow covered regions and for interpretation of concentration profiles in snow and ice in the context of the composition of the past atmosphere. One of the prominent reactions is the photolysis of nitrate. This reaction is well established in natural waters, and is of interest since formation of highly mutagenic/carcinogenic nitro-compounds is possible. In contrast, the photochemical behaviour of nitrate in ice and snow is more complex. The photolysis of nitrate embedded in ice has been shown to generate OH radical, NO2(g) and NO(g) as primary photoproducts, but little is known how this photochemistry is affected by the presence of organic impurities embedded in the ice surface. In this work, we studied the effect of the presence of para-halogenated phenols on the photo-transformation of frozen nitrate solutions by Diffuse Reflective Infrared Fourier Transform Spectroscopy (DRIFTS). Moreover, the evolution of volatile nitrogen oxides to the gas phase was monitored by a commercial chemiluminescence NO/NOy monitor, chemical ionization mass spectrometry (CIMS), and thermal-dissociation cavity ring-down spectroscopy (TD-CRDS). In addition, some of the organic intermediate products were characterized by GC/MS and HPLC/PDA. We show that DRIFTS can provide a qualitative picture of the chemical transformations that take place at the ice surface and kinetic data on the phototransformation of nitrate. The photochemistry of frozen solutions of nitrate in the presence of various para-halogenated phenols was found to be dependent on the ice temperature, pH, the light intensity, and the concentration and nature of para-halogenated phenols added. The release of NOy species to the gas-phase was dramatically accelerated by low pH values as well as the nature of para-halogen, in the order Cl>Br>F. The major species released were identified as NO2 and HONO.

  17. Salud Para Su Corazon (Health for Your Heart) Community Health Worker Model

    PubMed Central

    Balcazar, H.; Alvarado, M.; Ortiz, G.

    2012-01-01

    This article describes 6 Salud Para Su Corazon (SPSC) family of programs that have addressed cardiovascular disease risk reduction in Hispanic communities facilitated by community health workers (CHWs) or Promotores de Salud (PS). A synopsis of the programs illustrates the designs and methodological approaches that combine community-based participatory research for 2 types of settings: community and clinical. Examples are provided as to how CHWs can serve as agents of change in these settings. A description is presented of a sustainability framework for the SPSC family of programs. Finally, implications are summarized for utilizing the SPSC CHW/PS model to inform ambulatory care management and policy. PMID:21914992

  18. Rational extensions of the trigonometric Darboux-Pöschl-Teller potential based on para-Jacobi polynomials

    NASA Astrophysics Data System (ADS)

    Bagchi, B.; Grandati, Y.; Quesne, C.

    2015-06-01

    The possibility for the Jacobi equation to admit, in some cases, general solutions that are polynomials has been recently highlighted by Calogero and Yi, who termed them para-Jacobi polynomials. Such polynomials are used here to build seed functions of a Darboux-Bäcklund transformation for the trigonometric Darboux-Pöschl-Teller potential. As a result, one-step regular rational extensions of the latter depending both on an integer index n and on a continuously varying parameter ? are constructed. For each n value, the eigenstates of these extended potentials are associated with a novel family of ?-dependent polynomials, which are orthogonal on [-1,1].

  19. Effect of nuclear spin symmetry in cold and ultracold reactions: D + para/ortho-H2

    NASA Astrophysics Data System (ADS)

    Simbotin, Ionel; Côté, Robin

    2015-06-01

    We report results for reaction and vibrational quenching of the collision D with para-H2(v,j=0) and ortho-H2(v,j=1) at cold and ultracold temperatures. We investigate the effect of nuclear spin symmetry for barrier dominated processes (0?slant v?slant 4) and for one barrierless case (v = 5). We find resonant structures for energies in the range corresponding to 0.01-10 K, which depend on the nuclear spin of H2, arising from contributions of specific partial waves. We discuss the implications on the results in this benchmark system for ultracold chemistry.

  20. The Ortho:Para Ratio of H3+ in Diffuse Molecular Clouds

    NASA Astrophysics Data System (ADS)

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

    2010-11-01

    Since its first interstellar detection in the mid 1990s, H3+ has proved to be a powerful probe of astrophysical conditions. In cold molecular clouds, only the lowest two rotational energy levels of H3+ are populated: the (J,K) = (1,1) para state and the (1,0) ortho state. The relative populations of these levels can be used to calculate an excitation temperature, Tex. In dense molecular clouds, Tex agrees well with the estimated cloud kinetic temperature. However, in diffuse molecular clouds, Tex is found to be 30 K, while the kinetic temperature, as determined from the excitation temperature T01 (given by the relative populations of the J = 0 and J = 1 rotational levels of H2) is on average 60-70 K in these environments. Because the (1,1) state of H3+ is the lower-energy state, this indicates that there is more para-H3+ in diffuse molecular clouds than would be expected based on the cloud kinetic temperature. To understand the excess para-H3+ (or the lower-than-expected Tex), we have constructed a chemical model that takes into account the nuclear spin dependence of H3+ formation, proton scrambling via collisions with H2, and dissociative recombination with electrons. At the heart of this model is the reaction H3+ + H2 → H2 + H3+ , which can proceed by one of three pathways: the identity, proton hop, and hydrogen exchange. The branching fractions for the three pathways, Sid, Shop, and Sexch, influence the nature and extent of the proton scrambling. We use the microcanonical statistical model of Park and Light (J. Chem. Phys. 126, 044305, 1997) to calculate nuclear-spin-dependent rate coefficients that describe the extent of proton scrambling as a function of temperature and the aforementioned branching fractions. As a result, our model predicts, based on these parameters, what the observed Tex should be for a certain cloud kinetic temperature. Our model suggests that on its own, the H3+ + H2 reaction would effectively thermalize the ortho:para H3+ ratio (i.e., Tex = T01). However, dissociative recombination is taken into account, this thermalization is incomplete, and the resultant competition between thermalization and dissociative recombination seems to reproduce the astronomical observations for Sid ~ 0.8-0.9. However, the details of the spin-dependence of H3+ dissociative recombination are important, and at present, experimentally uncertain. More information about this process is needed to determine the validity of our modeling results.

  1. Photophysical and acid-base properties of para-substituted N,N-dimethylanilines

    NASA Astrophysics Data System (ADS)

    Szabelski, Mariusz; Bojarski, Piotr; Wieczorek, Zbigniew

    2013-05-01

    Ultraviolet absorption and fluorescence spectra were collected for para-substituted N,N-dimethylanilines in aqueous solution at various pH conditions. Two fluorescing forms were observed for all studied compounds, one protonated (ANsH+) and the second unprotonated (ANs) each of them with specific spectroscopic properties. Changing pH of solution results in the displacement of the equilibrium between two forms. It was found that protonated aniline derivatives in aqueous solutions undergo very fast excited-state proton dissociation and the pKa values obtained from absorption and fluorescence spectra are similar. The excited state pKa? values were calculated using the Förster cycle method.

  2. Ortho-to-para Ratio of Cometary Ammonia in Comet Hale-Bopp: What is Indicated by Ortho-to-para Ratio of Cometary Molecules?

    NASA Astrophysics Data System (ADS)

    Kawakita, H.; Watanabe, J.

    The ortho-to-para ratio (OPR) of cometary molecules is thought to be a primordial characteristic of comets. However, the real meaning of the OPR is not clear. A spin temperature derived from the OPR possibly reflects the formation conditions of the molecule. For the comet Hale-Bopp, there are many studies about the formation conditions of the comet and cometary materials, e.g., the OPR of water, D/H ratios in water and hydrogen cyanide, argon and neon abundances, and so on. We demonstrated that the OPR of ammonia could be determined from cometary NH2 observations for comet LINEAR (C/1999S4). In this presentation, we determine the OPR of cometary ammonia in comet Hale -Bopp based on the high-dispersion, optical spectra taken by Zhang et al. (2001). We compare the spin temperature of ammonia with that of water derived in comet Hale - Bopp, and the spin temperatures are compared with other temperature ranges indicated by other observations of the same comet.

  3. The new ParaDIgm: IgM from bench to clinic

    PubMed Central

    Hanala, Sherif

    2012-01-01

    The inaugural IgM event entitled “The new ParaDIgm: IgM from bench to clinic” brought together the increasingly active and growing IgM antibody community to discuss recent advances and challenges facing the discovery and development of IgM antibody therapies and technologies. Researchers, clinicians and biomanufacturing experts delivered 21 talks on the basic science and isolation of IgM, upstream and downstream development, and formulation and clinical development of the molecules. Participants networked around topics aimed at exploring the full potential of IgM antibodies. The meeting was held at DECHEMA Gesellschaft für Chemische Technik und Biotechnologie e. V. (Society for Chemical Engineering and Biotechnology), a non-profit scientific and technical society based in Frankfurt am Main, Germany. The meeting was sponsored by Patrys, Laureate Biopharma, Bio-Rad Laboratories, BIA Separations, Percivia and the Bio Affinity Company (BAC). The second New ParaDIgm: IgM from bench to clinic meeting, will be held on April 23–24, 2013 in Frankfurt, Germany. PMID:22864407

  4. Determining the Conformational Landscape of ? and ? Coupling Using para-Phenylene and "Aviram-Ratner" Bridges.

    PubMed

    Stasiw, Daniel E; Zhang, Jinyuan; Wang, Guangbin; Dangi, Ranjana; Stein, Benjamin W; Shultz, David A; Kirk, Martin L; Wojtas, Lukasz; Sommer, Roger D

    2015-07-29

    The torsional dependence of donor-bridge-acceptor (D-B-A) electronic coupling matrix elements (H(DA), determined from the magnetic exchange coupling, J) involving a spin SD = 1/2 metal semiquinone (Zn-SQ) donor and a spin S(A) = 1/2 nitronylnitroxide (NN) acceptor mediated by the ?/?-systems of para-phenylene and methyl-substituted para-phenylene bridges and by the ?-system of a bicyclo[2.2.2]octane (BCO) bridge are presented and discussed. The positions of methyl group(s) on the phenylene bridge allow for an experimentally determined evaluation of conformationally dependent (?) and conformationally independent (?) contributions to the electronic and magnetic exchange couplings in these D-B-A biradicals at parity of D and A. The trend in the experimental magnetic exchange couplings are well described by CASSCF calculations. The torsional dependence of the pairwise exchange interactions are further illuminated in three-dimensional, "Ramachandran-type" plots that relate D-B and B-A torsions to both electronic and exchange couplings. Analysis of the magnetic data shows large variations in magnetic exchange (J ? 1-175 cm(-1)) and electronic coupling (H(DA) ? 450-6000 cm(-1)) as a function of bridge conformation relative to the donor and acceptor. This has allowed for an experimental determination of both the ?- and ?-orbital contributions to the exchange and electronic couplings. PMID:26153657

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

    SciTech Connect

    Denis-Alpizar, Otoniel; Departamento de Física, Universidad de Matanzas, Matanzas 40100 ; 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. 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.

  7. 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

  8. 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

  9. Molecularly imprinted polyaniline-polyvinyl sulphonic acid composite based sensor for para-nitrophenol detection.

    PubMed

    Roy, Abhijit Chandra; Nisha, V S; Dhand, Chetna; Ali, Md Azahar; Malhotra, B D

    2013-05-13

    We report results of the studies relating to the fabrication and characterization of a conducting polymer based molecularly imprinted para-nitrophenol (PNP) sensor. A water pollutant, para-nitrophenol is electrochemically imprinted with polyvinyl sulphonic acid (PVSA) doped polyaniline onto indium tin oxide (ITO) glass substrate. This PNP imprinted electrode (PNPI-PANI-PVSA/ITO) prepared via chronopotentiometric polymerization and over-oxidation is characterized by Fourier transform infra-red spectroscopy (FT-IR), UV-visible (UV-vis) spectroscopy, contact angle (CA), scanning electron microscopy (SEM), cyclic voltammetry (CV) and differential pulse voltammetry (DPV) studies. The response studies of PNPI-PANI-PVSA/ITO electrode carried out using DPV reveal a lower detection limit of 1×10(-3) mM, improved sensitivity as 1.5×10(-3) A mM(-1) and stability of 45 days. The PNPI-PANI-PVSA/ITO electrode shows good precision with relative standard deviation of 2.1% and good reproducibility with standard deviation of 3.78%. PMID:23622966

  10. [Morbidity of pelvic lymphadenectomy and para-aortic lymphadenectomy in endometrial cancer].

    PubMed

    Agar, Nicolas; Philippe, Anne-Cécile; Bourdel, Nicolas; Rabischong, Benoît; Canis, Michel; Le Bouedec, Guillaume; Mulliez, Aurélien; Dauplat, Jacques; Pomel, Christophe

    2015-05-01

    The aim of this study was to evaluate the complication rate of pelvic and para-aortic lymphadenectomy in the management of endometrial cancer following the changes to the recommendations of INCa 2010. This is a retrospective study of 208 patients operated for endometrial cancer between July 2010 and March 2014 in two referral centers. Eighty lymphadenectomy were performed, 65 with hysterectomy and bilateral annexectomy and 18 lymphadenectomy were performed for restaging. Complications assessment is based on the Dindo Clavien classification. We report 17 severe complications (grade 3a and over) (P<0.001), including 14 among patients receiving lymphadenectomy. Morbidity increases with the number of lymphnodes removed and their positivity (P<0.001). The para-aortic lymphadenectomy is primarily responsible for complications (P <0.001). We describe 7 lower limbs lymphedema, 12 nerve injuries, 8 ileus, 5 venous or arterial thromboembolism, 17 blood transfusions, 13 lymphoceles including 9 infected. The rate of intraoperative complications on a first lymphadenectomy is 8% while it reached 22% for restaging. Restaging is significantly more at risk of serious complications (P=0.03) with two deaths. Twenty-four chronic disorders with impaired quality of life (2 without lymphadenectomy) are reported. They are present in 50% of restaging (P=0.033 compared to first lymphadenectomy). Lymphadenectomy is a source of severe morbidity (17.5%) with 2.5% mortality. The benefit of this surgery should probably be discussed again. PMID:25956349

  11. 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

  12. Construction and characterization of two recombinant bacteria that grow on ortho- and para-substituted chlorobiphenyls

    SciTech Connect

    Hrywna, Y.; Tsoi, T.V.; Maltseva, O.V.; Quensen, J.F. III; Tiedje, J.M.

    1999-05-01

    Cloning and expression of the aromatic ring dehalogenation genes in biphenyl-growing, polychlorinated biphenyl (PCB)-cometabolizing Comamonas testosteroni VP44 resulted in recombinant pathways allowing growth on ortho- and para-chlorobiphenyls (CBs) as a sole carbon source. The recombinant variants were constructed by transformation of strain VP44 with plasmids carrying specific genes for dehalogenation of chlorobenzoates (CBAs). Plasmid pE43 carries the Pseudomonas aeruginosa 142 ohb genes coding for the terminal oxygenase (ISP{sub OHB}) of the ortho-halobenzoate 1,2-dioxygenase, whereas plasmid pPC3 contains the Arthrobacter globiformis KZT1 fcb genes, which catalyze the hydrolytic para-dechlorination of 4-CBA. The parental strain, VP44, grew only on low concentrations of 2- and 4-CB by using the products from the fission of the nonchlorinated ring of the CBs (pentadiene) and accumulated stoichiometric amounts of the corresponding CBAs. The recombinant strains VP44(pPC3) and VP44(pE43) grew on, and completely dechlorinated high concentrations (up to 10 mM), of 4-CBA and 4-CB and 2-CBA and 2-CB, respectively. Cell protein yield corresponded to complete oxidation of both biphenyl rings, thus confirming mineralization of the CBs. Hence, the use of CBA dehalogenase genes appears to be an effective strategy for construction of organisms that will grow on at least some congeners important for remediation of PCBs.

  13. 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 modelizacion, y aplicacion en convertidores PWM, esta aun por estudiar y valorar. El primer Capitulo consiste en una breve introduccion al problema de la regulacion cruzada y la impedancia cruzada para posteriormente describir las tecnicas de post-regulacion actualmente mas empleadas, con especial atencion al post-regulador con transformador controlado. El Capitulo segundo trata del estudio de las caracteristicas estaticas del postregulador con transformador controlado. Partiendo de los estudios disponibles sobre el postregulador se plantean mejoras en su modo de actuacion y se discuten tres alternativas diferentes para controlar el transformador. Las dos primeras consisten en emplear un convertidor auxiliar Boost en sus dos modos de funcionamiento, continuo y discontinuo. La tercera consiste en controlar el transformador con una tension PWM directamente, sin filtrado. Finalmente se comprueba experimentalmente, para el estado estacionario, el funcionamiento del post-regulador para cada uno de los tres metodos de control. El Capitulo tercero trata de la dinamica de la salida controlada con el post-regulador cuando este emplea un convertidor auxiliar tipo Boost. Mediante la tecnica de promediado de variables de estado se propone el modelo de pequena senal, tanto para el modo continuo como para el modo discontinuo de funcionamiento del convertidor auxiliar. Los resultados mas significativos de esta seccion son las expresiones analiticas de las impedancias cruzadas y de la impedancia de la salida post-regulada. Como complemento al modelo de pequena senal se plantea un modelo de gran senal implementado sobre el simulador Pspice. Con este nuevo modelo se reproducen los resultados obtenidos con el modelo de pequena senal y ademas es posible simular los transitorios en las tensiones de salida ante cambios de carga. La modelizacion del convertidor cuando el transformador se controla con una tension PWM sin filtrar es el objetivo del Capitulo 4. En las secciones siguientes del Capitulo se plantea el correspondiente modelo de gran senal aplicado a un nuevo prototipo experimental, de mayor tension de entrada y mayores corrientes de salida. El final del Capitulo contrasta los resultados experimentales con los teoricos confirmando la utilidad del modelo de gran senal como una herramienta basica de diseno. Finalmente, en el Capitulo 5, se presentan las conclusiones y la valoracion de los diferentes estudios plateados a lo largo de la Tesis Doctoral.

  14. Para-phenylenediamine-specific lymphocyte activation test: a sensitive in vitro assay to detect para-phenylenediamine sensitization in patients with severe allergic reactions.

    PubMed

    Kneilling, Manfred; Caroli, Ulrich; Grimmel, Cornelia; Fischer, Jörg; Eichner, Martin; Wieder, Thomas; Maier, Florian C; Röcken, Martin; Biedermann, Tilo

    2010-05-01

    Patients sensitized to para-phenylenediamine (PPD) by semi-permanent tattoos increasingly develop threatening allergic reactions in response to black hair dye. The gold standard to diagnose allergic contact dermatitis is to perform epicutaneous patch tests, however, iatrogenic sensitizations and severe patch test reactions to PPD have been described, the latter especially in patients with severe allergic reactions. We examined nine patients with severe allergic reactions in response to permanent hair dyes. Patch tests using the standard concentration of 1% or 0.5% PPD resulted in severe and sometimes even bullous reactions in all patients responsive to PPD. Titration revealed that at 1% of the standard concentration (0.01% PPD), patch test sensitivity decreased and only 50% of patients responded. Consequently, we established an in vitro assay to diagnose PPD allergy. Freshly isolated peripheral blood mononuclear cells (PBMC) were cultured with titrated concentrations of PPD with or without IL-2 supplementation, and cell proliferation was determined by [3H]-thymidine incorporation. Lymphocyte activation test (LAT) detected PBMC cell proliferation specific to PPD, with at least 3.5-fold increase in [3H]-thymidine uptake in all PPD allergic patients. Most importantly, PPD-LAT without IL-2 supplementation remained negative in three out of eight PPD allergic patients. Thus, PPD-LAT with IL-2 supplementation demonstrated a sensitivity of 100%, remained unresponsive in controls not sensitized to PPD, and in one patient sensitive to other p-amino compounds. These data demonstrate that LAT with PPD can be used to detect PPD sensitization as a possible alternative to patch testing at least in patients with severe allergic reactions to PPD. PMID:20113350

  15. 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).

  16. Sensitization to para-amino compounds in swim fins in a 10-year-old boy.

    PubMed

    Seyfarth, Florian; Krautheim, Andrea; Schliemann, Sibylle; Elsner, Peter

    2009-09-01

    A ten-year-old boy presented with recurrent eczema on the dorsal of both feet and the thighs. His symptoms became worse when he used racing swim fins. Patch testing included the standard, ointments, preservatives, leather, textile dyes, rubber component, and corticosteroid series of the German Contact Dermatitis Research Group (DKG) as well as the patient's own materials (fin material). At 72 hours positive reactions were observed to blue flipper material, Acid Yellow 36, Bismarck Brown R, and DPPD. DPPD is widely used as an antioxidant in the rubber industries. Therefore, the dermatitis was most probably attributable to DPPD in the blue flipper material, although we were not able to prove this due to lack of cooperation of the manufacturer. Sensitization to Acid Yellow 36 and Bismarck Brown R are interpreted as cross sensitizations, since all substances are para-amino compounds. PMID:19386021

  17. The barrier to internal rotation and electronic effects in para-halogenophenols: theoretical study

    NASA Astrophysics Data System (ADS)

    Zierkiewicz, Wiktor; Michalska, Danuta; Hobza, Pavel

    2004-03-01

    The OH rotational barrier height in phenol and para-halogenophenols systematically decreases in the series Br, Cl and F, while the changes in the CO bond length and CO bond strength do not follow this order. On the basis of the NBO analysis it is suggested that lowering of the barrier height in p-halogenophenols is caused by the decrease of electron density in the sigma antibonding orbital, σ *(CO), and a weak occupancy of this orbital is due to the electron delocalization from the σ(CC) ring orbitals. This effect can be either reinforced or reduced, depending on the extent of conjugation between the p z-type lone electron pair on the oxygen atom and the π *(CC) acceptor orbitals in the aromatic ring.

  18. Severe inflammatory and keloidal, allergic reaction due to para-phenylenediamine in temporary tattoos.

    PubMed

    Gunasti, Suhan; Aksungur, Varol Lutfu

    2010-01-01

    Hair coloring with henna has been popular in Turkey for years. In recent years since the tattoos are applied by the street vendors in most of the beach places in Turkey, skin coloring with henna has also increased. Henna can be used alone or in combination with other coloring agents. Henna alone can be safe but due to additives such as para-phenylenediamine (PPD), p-toluenediamine and various essential oils, allergic contact reactions may occur. We report a 22-year-old man who developed severe inflammatory and keloidal, moderately bullous allergic reaction after henna paint-on tattoo. We did a patch test separately with these painting products (henna powder, PPD) and with the European standard series. PPD was strongly positive (+++) on day 2 and remained positive for following days. After treating with topical clobetasol-17 butyrate, resolution was obtained in two weeks. But some keloidal reaction remained. PMID:20228546

  19. Exo Diels-Alder adducts between ortho- and para-N-acetoxyphenylmaleimides and furan.

    PubMed

    Trujillo-Ferrara, Jose G; García-Báez, Efrén V; Padilla-Martínez, Itzia I; Martínez-Martínez, Francisco J; Farfan-García, Norberto

    2004-06-01

    In exo-2-(3,5-dioxo-10-oxa-4-azatricyclo[5.2.1.0(2,6)]dec-8-en-4-yl)phenyl acetate, C(16)H(13)NO(5), the plane of the acetoxy group lies almost perpendicular to that of the phenyl ring [dihedral angle = 89.8 (1) degrees ], in contrast with the smaller deviations found in the para isomer exo-4-(3,5-dioxo-10-oxa-4-azatricyclo[5.2.1.0(2,6)]dec-8-en-4-yl)phenyl acetate, C(16)H(13)NO(5), these being 63.6 (1) and 37.0 (1) degrees for the two crystallographically independent molecules. Irrespective of the position of the acetoxy group, both compounds pack through soft C-H.X (X is O or phenyl) interactions, forming interlinked centrosymmetric tetramers in the bc plane. PMID:15178871

  20. High-pressure dissociation of crystalline para-diiodobenzene: optical experiments and Car-Parrinello calculations.

    PubMed

    Brillante, Aldo; Della Valle, Raffaele G; Farina, Luca; Venuti, Elisabetta; Cavazzoni, Carlo; Emerson, Andrew P J; Syassen, Karl

    2005-03-01

    We have investigated the high-pressure properties of the molecular crystal para-diiodobenzene, by combining optical absorption, reflectance, and Raman experiments with Car-Parrinello simulations. The optical absorption edge exhibits a large red shift from 4 eV at ambient conditions to about 2 eV near 30 GPa. Reflectance measurements up to 80 GPa indicate a redistribution of oscillator strength toward the near-infrared. The calculations, which describe correctly the two known molecular crystal phases at ambient pressure, predict a nonmolecular metallic phase, stable at high pressure. This high-density phase is characterized by an extended three-dimensional network, in which chemically bound iodine atoms form layers connected by hydrocarbon bridges. Experimentally, Raman spectra of samples recovered after compression show vibrational modes of elemental solid iodine. This result points to a pressure-induced molecular dissociation process which leads to the formation of domains of iodine and disordered carbon. PMID:15740142

  1. 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

  2. Genomic organization of Hox and ParaHox clusters in the echinoderm, Acanthaster planci.

    PubMed

    Baughman, Kenneth W; McDougall, Carmel; Cummins, Scott F; Hall, Mike; Degnan, Bernard M; Satoh, Nori; Shoguchi, Eiichi

    2014-12-01

    The organization of echinoderm Hox clusters is of interest due to the role that Hox genes play in deuterostome development and body plan organization, and the unique gene order of the Hox complex in the sea urchin Strongylocentrotus purpuratus, which has been linked to the unique development of the axial region. Here, it has been reported that the Hox and ParaHox clusters of Acanthaster planci, a corallivorous starfish found in the Pacific and Indian oceans, generally resembles the chordate and hemichordate clusters. The A. planci Hox cluster shared with sea urchins the loss of one of the medial Hox genes, even-skipped (Evx) at the anterior of the cluster, as well as organization of the posterior Hox genes. PMID:25394327

  3. 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.

  4. 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

  5. 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

  6. 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.

  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. Statistical ortho-to-para ratio of water desorbed from ice at 10 kelvin.

    PubMed

    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. PMID:26721994

  9. Fluorescence resonance energy transfer for investigation of the interaction of Para Red with serum albumins.

    PubMed

    Zhu, Lin; Zeng, Xiaodan; Zhang, Fusheng

    2016-03-01

    Para Red (PR) has been isolated from food additives, and shown to be toxic to humans. To facilitate examination of its toxicity, the interaction between PR and serum albumins (SA) was studied using fluorescence quenching and circular dichroism (CD) spectrophotometry. The experiments showed that the fluorescence intensity of serum albumins decreased with increasing concentrations of PR, which resulted from the binding of PR and SA. The binding constant, number of binding sites and thermodynamic parameters were calculated and hydrogen bond and van der Waals interactions were shown to play a key role in the binding process. Competition experiments indicated that PR mainly binds to Trp residues of SA within the site I. As the CD and three-dimensional spectra revealed, the addition of PR induced a conformational change in SA. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26178918

  10. Searching for auxetics with DYNA3D and ParaDyn

    NASA Astrophysics Data System (ADS)

    Hoover, Wm. G.; Hoover, C. G.

    2005-03-01

    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.

  11. 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.

  12. 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

  13. 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.

  14. Photocarcinogenesis is retarded by a partly photodegraded solution of para-aminobenzoic acid.

    PubMed

    Flindt-Hansen, H; Thune, P; Nielsen, C J

    1989-12-01

    A solution of para-aminobenzoic acid (PABA) was exposed to ultraviolet (UV) radiation emitted from a Philips TL 40 W/12 sunlamp and the degree of photodegradation following an exposure of 27 J/cm2 was estimated to be approximately 40%. The formation of the photoproducts was confirmed by mass spectroscopy and UV spectroscopy. The solution was painted on the backs of hairless light-pigmented mice prior to daily UV irradiation by the above sunlamp, and this procedure was continued for 30 weeks. The preirradiated solution of PABA significantly retarded the tumor induction time and reduced significantly the number of squamous cell carcinomas compared with nonprotected controls. This tumor-retarding ability did not differ significantly from the effect achieved when using nonirradiated PABA. PMID:2636981

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. Monomers that form conducting polymers as structure-directing agents: synthesis of microporous molecular sieves encapsulating poly-para-phenylenevinylene.

    PubMed

    Atienzar, Pedro; Díaz-Cabañas, María J; Moliner, Manuel; Peris, Encarna; Corma, Avelino; García, Hermenegildo

    2007-01-01

    We have developed a novel concept that uses monomers required for making conducting polymers as organic structure-directing agents, for the synthesis of microporous molecular sieves. We show that these monomers facilitate the formation of crystalline and amorphous molecular sieves depending on the synthesis procedure. The monomers filling the pores of the silicates can be polymerized under certain conditions, resulting in a polymer immobilized and protected inside the matrix. The concept was exemplified with para-phenylenemethylene-bis(1-tetrahydrothiophenium) and para-phenylenemethylene-bis(trimethylammonium) that were used to template microporous molecular sieves and subsequently to obtain poly-para-phenylenevinylene (PPV) inside the matrix. The organic self-assembled organic-inorganic material was extensively characterized and the implication on electrical conductivity is presented. PMID:17665376

  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. 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.

  2. 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.

  3. 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.

  4. 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 descubierta, que va en contra de lo esperado en otros sistemas físicos y que consiste en que los altos estados Rydberg de átomos, moléculas y sus complejos de van der Waals (o de los iones) tienen tiempos de vida de centenas de μ s. En resumen, el experimento y la espectroscopía ZEKE consiste en excitar un átomo, molécula o cluster sucesivamente a dos estados excitados selectivos de manera que el final sea un estado Rydberg. A continuación se aplica un campo eléctrico variable que lo ioniza y después de un cierto retraso se aplica un campo eléctrico de extracción, tanto para el electrón como para el ión. El espectro de los iones, es un espectro ZEKE. Hay varias alternativas para hacer este último proceso. El estudio de la espectroscopía y propiedades de iones y sus clusters requiere el conocimiento detallado de la espectroscopía de la molécula neutra, los estados Rydberg, de los confórmeros y sus complejos. Todo ello implica el haber estudiado los sistemas por LIF, REMPI y doble resonancia (hole burning IR-UV, UV-UV). Además solo es posible interpretar los resultados y obtener la información contenida en los espectros con ayuda de cálculos cuánticos ab initio. Hasta el momento hemos aplicado tanto el ZEKE como el conjunto de técnicas mencionadas anteriormente, a varias molécula de interés químico general como anilina y sus derivados, así como sus complejos con agua y amoniaco. Sin embargo, el método es muy versátil y puede aplicarse a iones de átomos, iones múltiples, moléculas sencillas y sus clusters así como a sus semi-reacciones. Como ejemplo de uno de estos espectros PFI-ZEKE se presenta aquí el caso del amonibenzonitrilo, ABN y solamente en su estado fundamental. En la conferencia se presentarán espectros ZEKE del ABN y moléculas similares en estados vibracionales intermedios (islas de estabilidad), así como la determinación de potenciales de ionización precisos, energías de enlace de compuestos del ión con varios disolventes y otras propiedades de interés, discutiendo sus resultados.

  5. 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, actividades, evaluación, entre otros. Estos planteamientos definen la unidad curricular que se propone en el cuatro capítulo.

  6. Toluene 3-Monooxygenase of Ralstonia pickettii PKO1 Is a para-Hydroxylating Enzyme

    PubMed Central

    Fishman, Ayelet; Tao, Ying; Wood, Thomas K.

    2004-01-01

    Oxygenases are promising biocatalysts for performing selective hydroxylations not accessible by chemical methods. Whereas toluene 4-monooxygenase (T4MO) of Pseudomonas mendocina KR1 hydroxylates monosubstituted benzenes at the para position and toluene ortho-monooxygenase (TOM) of Burkholderia cepacia G4 hydroxylates at the ortho position, toluene 3-monooxygenase (T3MO) of Ralstonia pickettii PKO1 was reported previously to hydroxylate toluene at the meta position, producing primarily m-cresol (R. H. Olsen, J. J. Kukor, and B. Kaphammer, J. Bacteriol. 176:3749-3756, 1994). Using gas chromatography, we have discovered that T3MO hydroxylates monosubstituted benzenes predominantly at the para position. TG1/pBS(Kan)T3MO cells expressing T3MO oxidized toluene at a maximal rate of 11.5 ± 0.33 nmol/min/mg of protein with an apparent Km value of 250 ?M and produced 90% p-cresol and 10% m-cresol. This product mixture was successively transformed to 4-methylcatechol. T4MO, in comparison, produces 97% p-cresol and 3% m-cresol. Pseudomonas aeruginosa PAO1 harboring pRO1966 (the original T3MO-bearing plasmid) also exhibited the same product distribution as that of TG1/pBS(Kan)T3MO. TG1/pBS(Kan)T3MO produced 66% p-nitrophenol and 34% m-nitrophenol from nitrobenzene and 100% p-methoxyphenol from methoxybenzene, as well as 62% 1-naphthol and 38% 2-naphthol from naphthalene; similar results were found with TG1/pBS(Kan)T4MO. Sequencing of the tbu locus from pBS(Kan)T3MO and pRO1966 revealed complete identity between the two, thus eliminating any possible cloning errors. 1H nuclear magnetic resonance analysis confirmed the structural identity of p-cresol in samples containing the product of hydroxylation of toluene by pBS(Kan)T3MO. PMID:15126473

  7. 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).

  8. 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 (?) and the odds of choosing one option over an alternative. Trade-offs between attributes will also be calculated. Discussion By providing a better understanding of current community preferences in relation to organ donation and allocation, the PAraDOx study will highlight options for firstly, increasing the rate of organ donation and secondly, allow for more transparent and equitable policies in relation to organ allocation. PMID:21612584

  9. 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

  10. 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…

  11. Contribuições para o projeto da câmara infravermelha Spartan do telescópio SOAR

    NASA Astrophysics Data System (ADS)

    Laporte, R.; Jablonski, F.; Loh, E.

    2003-08-01

    Como parte de uma colaboração entre a Divisão de Astrofísica do INPE, IAG-USP, Instituto do Milênio MEGALIT e a Michigan State University, trabalhamos durante um ano junto ao grupo do Dr. Edwin Loh (MSU) no projeto e detalhamento de diversos subsistemas para a câmara infravermelho Spartan do telescópio SOAR. Trata-se de um imageador para as bandas J, H e K que explora todo o potencial, em termos de qualidade de imagem e campo de visada, fornecido pelo sistema de óptica adaptativa de primeira ordem do telescópio SOAR. Projetamos soluções detalhadas para os subsistemas de rodas de filtros/grismas/máscaras de Lyot; subsistema de compactação do mosaico de detectores em duas versões distintas; subsistema de alimentação de Nitrogênio líquido. Mantivemos sempre uma supervisão geral sobre todas as partes restantes e os respectivos envelopes volumétricos produzindo soluções para a integração de todos os componentes. Neste trabalho, ilustramos as principais contribuições e fornecemos um resumo do estado atual do instrumento.

  12. 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…

  13. Leyendo con tu hijo: Consejos practicos para los padres... (Reading with Your Child: Practical Advice for Parents...).

    ERIC Educational Resources Information Center

    Colorado State Dept. of Education, Denver.

    This brochure (in Spanish) offers some practical tips for Spanish-speaking parents who wish to read to their young children. The brochure first provides general tips, such as "Lea a su hijo en voz alto por lo menos unos 15 minutos todos los dias" (Read to your child aloud for at least 15 minutes daily), and "Estabeleza una rotina y un lugar para…

  14. 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

  15. 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)

  16. TOXICOKINETICS AND STRUCTURE-ACTIVITY RELATIONSHIPS OF NINE PARA-SUBSTITUTED PHENOLS IN RAT EMBRYOS IN VITRO

    EPA Science Inventory

    The purpose of this study was to examine the pharmacokinetics of embryo uptake following exposure to a variety of related chemicals in rodent embryo culture. he uptake of nine radiolabeled para-substituted phenols by day 10 (9-13 somite stage) rat embryos in vitro was determined ...

  17. 75 FR 34943 - Defense Federal Acquisition Regulation Supplement; Para-Aramid Fibers and Yarns Manufactured in a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-21

    ... the Federal Register on December 18, 2008 (73 FR 76970). The comment period closed on February 17... Accordingly, the interim rule amending 48 CFR parts 225 and 252, which was published at 73 FR 76970 on... Regulation Supplement; Para-Aramid Fibers and Yarns Manufactured in a Qualifying Country AGENCY:...

  18. 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.

  19. 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.

  20. Familiares a cargo de pacientes de cáncer: funciones y desafíos (PDQ)—Versión para profesionales de salud

    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.

  1. 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.

  2. 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.

  3. 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.

  4. ParaCalc®--a novel tool to evaluate the economic importance of worm infections on the dairy farm.

    PubMed

    Charlier, Johannes; Van der Voort, Mariska; Hogeveen, Henk; Vercruysse, Jozef

    2012-03-23

    Subclinical infections with gastrointestinal nematodes and liver fluke are important causes of production losses in grazing cattle. Although there is an extensive compilation of literature describing the effect of these infections on animal performance, only a few attempts have been made to convert these production losses to an economic cost. Here, we propose a novel tool (ParaCalc(®)), available as a web-application, to provide herd-specific estimates of the costs of these infections on dairy farms. ParaCalc(®) is a deterministic spread-sheet model where results from diagnostic methods to monitor the helminth infection status on a herd and anthelmintic usage are used as input parameters. Default values are provided to describe the effects of the infections on production and the cost of these production losses, but the latter can be adapted to improve the herd-specificity of the cost estimate. After development, ParaCalc(®) was applied on input parameters that were available for 93 Belgian dairy herds. In addition, the tool was provided to 6 veterinarians and their user experiences were evaluated. The estimated median [25th-75th percentile] cost per year per cow was € 46 [29-58] and € 6 [0-19] for gastrointestinal nematode and liver fluke infection, respectively. For both infections, the major components in the total costs were those associated with milk production losses in the adult cows. The veterinarians evaluated ParaCalc(®) as a useful tool to raise the farmers' awareness on the costs of worm infections, providing added value for their services. However, the score given for user-friendliness was diverse among users. Although the model behind ParaCalc(®) is a strong simplification of the real herd processes inducing economic losses, the tool may be used in the future to support economic decisions on helminth control. PMID:21978741

  5. 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.

  6. Mini-mastoidectomía para anastomosis hipogloso-facial con sección parcial del nervio hipogloso

    PubMed Central

    Campero, Álvaro; Ajler, Pablo; Socolovsky, Mariano; Martins, Carolina; Rhoton, Albert

    2012-01-01

    Introducción: La anastomosis hipogloso-facial es la técnica de elección para la reparación de la parálisis facial cuando no se dispone de un cabo proximal sano del nervio facial. La técnica de anastomosis mediante fresado mastoideo y sección parcial del hipogloso minimiza la atrofia lingual sin sacrificar resultados a nivel facial. Método: La porción mastoidea del nervio facial transcurre por la pared anterior de la AM, a un promedio de 18+/-3 mm de profundidad respecto de la pared lateral. Se debe reconocer la cresta supramastoidea, desde la cual se marca una línea vertical paralela al eje mayor de la AM, 1 cm por detrás de la pared posterior del CAE El fresado se comienza desde la línea medio mastoidea hasta la pared posterior del CAE. Una vez encontrado el nervio facial en el tercio medio del canal mastoideo, el mismo es seguido hacia proximal y distal. Resultados: El abordaje descripto permite acceder al nervio facial intratemporal en su porción mastoidea, y efectuar un fresado óseo sin poner en riesgo al nervio o a estructuras vasculares cercanas. Se trata de un procedimiento técnicamente más sencillo que los abordajes amplios habitualmente utilizados al hueso temporal; no obstante su uso debe ser restringido mayormente a la anastomosis hipogloso-facial. Conclusión: Esta es una técnica relativamente sencilla, que puede ser reproducida por cirujanos sin mayor experiencia en el tema, luego de su paso por el laboratorio de anatomía. PMID:23596555

  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. 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

  9. Defect-induced effects on carrier migration through one-dimensional poly(para-phenylenevinylene) chains

    NASA Astrophysics Data System (ADS)

    Zoppi, L.; Calzolari, A.; Ruini, A.; Ferretti, A.; Caldas, M. J.

    2008-10-01

    Defects in one-dimensional (1D) systems can be intrinsically distinct from its three-dimensional counterparts, and polymer films are good candidates for showing both extremes that are difficult to individuate in the experimental data. We study theoretically the impact of simple hydrogen and oxygen defects on the electron transport properties of one-dimensional poly(para-phenylenevinylene) chains through a multiscale technique, starting from classical structural simulations for crystalline films to extensive ab initio calculations within density functional theory for the defects in single crystalline-constrained chains. The most disruptive effect on carrier transport comes from conjugation breaking imposed by the overcoordination of a carbon atom in the vinyl group independently from the chemical nature of the defect. The particular case of the [C=O] (keto-defect) shows in addition unexpected electron-hole separation, suggesting that the experimentally detected photoluminescence bleaching and photoconductivity enhancement could be due to exciton dissociation caused by the 1D characteristics of the defect.

  10. 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.

  11. Agregación de para-H2 en chorros supersónicos: del dímero al sólido

    NASA Astrophysics Data System (ADS)

    María Fernández, José

    En este trabajo se mostrarán los estudios de expansiones supersónicas de para-H2 desde toberas criogénicas, realizados en el laboratorio de Fluidodinámica Molecular del IEM. Hemos registrado los espectros Raman de dichas expansiones en el intervalo de frecuencias de 4145 a 4162 cm-1, próximo a la línea Q(0) del monómero no rotante H2, a 4161.18 cm-1. En el espectro Raman, además de la línea Q(0) del monómero, se observan unos picos débiles, que, por su comportamiento con la temperatura de la tobera y la distancia a la misma, asignamos a la transición homóloga en agregados de p-H2. Dependiendo de las condiciones, se observan agregados pequeños (de 2 a 13 moléculas de p-H2), agregados medios y masivos, y se llega incluso al líquido y al sólido. Las asignaciones se apoyan en un modelo sencillo, basado en la perturbación, debida al potencial intermolecular, de los estados vibracionales v=0 y v=1 en los agregados de p-H2. Se mostrarán detalles de la instalación experimental, ejemplos de los espectros obtenidos en diversas condiciones, y detalles de la interpretación cuantitativa.

  12. 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

  13. Selective plasmon-driven catalysis for para-nitroaniline in aqueous environments.

    PubMed

    Cui, Lin; Wang, Peijie; Li, Yuanzuo; Sun, Mengtao

    2016-01-01

    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. PMID:26857259

  14. 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.

  15. Interface Properties of Organic para-Hexaphenyl/?-Sexithiophene Heterostructures Deposited on Highly Oriented Pyrolytic Graphite

    PubMed Central

    2013-01-01

    It was recently reported, that heterostructures of para-hexaphenyl (p-6P) and ?-sexithiophene (6T) deposited on muscovite mica exhibit the intriguing possibility to prepare lasing nanofibers of tunable emission wavelength. For p-6P/6T heterostructures, two different types of 6T emission have been observed, namely, the well-known red emission of bulk 6T crystals and additionally a green emission connected to the interface between p-6P and 6T. In this study, the origin of the green fluorescence is investigated by photoelectron spectroscopy (PES). As a prerequisite, it is necessary to prepare structurally similar organic crystals on a conductive surface, which leads to the choice of highly oriented pyrolytic graphite (HOPG) as a substrate. The similarity between p-6P/6T heterostructures on muscovite mica and on HOPG is evidenced by X-ray diffraction (XRD), scanning force microscopy (SFM), and optical spectroscopy. PES measurements show that the interface between p-6P and 6T crystals is sharp on a molecular level without any sign of interface dipole formation or chemical interaction between the molecules. We therefore conclude that the different emission colors of the two 6T phases are caused by different types of molecular aggregation. PMID:24156627

  16. Performance of three different anodes in electrochemical degradation of 4-para-nitrophenol.

    PubMed

    Murugaesan, Pramila; Aravind, Priyadharshini; Guruswamy Muniyandi, Neelavannan; Kandasamy, Subramanian

    2015-10-01

    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

  17. Serotypes associated with the development of pneumococcal para-pneumonic effusion in adults.

    PubMed

    Bewick, Thomas; Sheppard, Carmen; Greenwood, Sonia; Slack, Mary; Trotter, Caroline; George, Robert; Lim, Wei Shen

    2013-09-01

    Serotypes 1, 3, 7F and 19A are implicated in childhood pneumococcal para-pneumonic effusion (PPE). It is not known whether the same is true for adult PPE. A prospective cohort study was conducted over a 2-year period. Consecutive adults admitted with community-acquired pneumonia (CAP) were studied. Pneumococcal serotype was identified from urine samples using a multiplex immunoassay. Of 920 patients recruited, 366 had pneumococcal CAP; 100 of these had PPE and a serotype was determined in 73 patients. Factors associated with PPE were age, pneumonia severity index score and serotype. Serotypes most associated with PPE were 1 (18 (45%) out of 40), 19A (9 (45%) out of 20) and 3 (8 (40%) out of 20). Serotypes common in childhood PPE were independently associated with adult PPE (adjusted OR 2.3; p = 0.003). Serotypes not included in the 7-valent pneumococcal conjugate vaccine (PCV) were more likely to be associated with PPE (OR 2.1; p = 0.024) compared with those in the vaccine. Serotypes included in PCV-13 were as likely to be associated with PPE as those that are not (OR 0.8; p = 0.301). Serotypes 1, 3, 7F and 19A are independently associated with adult PPE, a similar finding to childhood PPE. Serotype replacement following pneumococcal vaccine implementation may influence the spectrum of clinical disease. PMID:23258784

  18. Para-toluenesulfonamide induces tongue squamous cell carcinoma cell death through disturbing lysosomal stability

    PubMed Central

    Liu, Zhe; Liang, Chenyuan; Zhang, Zhuoyuan; Pan, Jian; Xia, Hui; Zhong, Nanshan

    2015-01-01

    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

  19. Comparison of the photoconversion of para-chlorophenol under simulated sunlight and UV irradiation in ice.

    PubMed

    Gao, Hong-Jie; Kang, Chun-Li; Song, Yong-Hui; Guo, Ping; Lang, Xing-Hua; Peng, Fei

    2011-01-01

    The photochemistry of para-chlorophenol (4-CP) was studied under simulated sunlight (lambda > 300 nm) and UV irradiation by using a 125 W high-pressure mercury lamp with or without a hard glass as light source in an ice matrix. The experiments were carried out in a photochemical cold chamber reactor at -14 to -12 degrees C. The photoconversion rate, photoproducts and photoconversion mechanism of 4-CP were all inspected and compared. The results show that the 4-CP photoconversion obeys the first order kinetic model and its photoconversion rate is highly affected by the initial concentration of 4-CP, light intensity and water quality. It is found that the conversion rate of 4-CP under UV irradiation is higher than that under simulated sunlight irradiation. The intermediate products of 4-CP were characterized by GC-MS, HPLC-ESI-MS and HPLC techniques and the possible photoconversion mechanism was proposed accordingly. It is concluded that the mechanism and photoproducts of 4-CP photolysis in ice are different from those in water, and the photoproducts and photoconversion pathways of 4-CP in ice varied with different light sources. PMID:22097069

  20. Coarse-grain model of the benzene ring with para-substituents in the molecule

    NASA Astrophysics Data System (ADS)

    Neverov, Vladimir S.; Komolkin, Andrei V.

    2012-03-01

    A new two-site coarse-grain model of the benzene ring with substituents in the para-position is proposed for use with multiscale simulations. The model uses a modified Lennard-Jones potential and introduces an additional shifting parameter to the description of the atom-atom interactions. Furthermore, the model separates sets of parameters of Van-der-Waals interactions into inter- and intramolecular. The shifting parameter is specified separately for each pair of atom types for both inter- and intramolecular interactions. The model itself consists of two superatoms. It allows for high speed calculations, "remembers" the benzene ring orientation in multiscale simulations, and can be used together with well-known sets of "united atoms" potentials. This model was tested on p-xylene, 1-ethyl-4-methylbenzene, and 1-methyl-4-propylbenzene. Structural properties for all three substances in the full-atomic model, the "united atoms" model, and the suggested coarse-grained model are discussed. The results demonstrate that the local structure derived from the coarse-grained model is very similar to that derived from the "united atoms" model.

  1. Coarse-grain model of the benzene ring with para-substituents in the molecule.

    PubMed

    Neverov, Vladimir S; Komolkin, Andrei V

    2012-03-01

    A new two-site coarse-grain model of the benzene ring with substituents in the para-position is proposed for use with multiscale simulations. The model uses a modified Lennard-Jones potential and introduces an additional shifting parameter to the description of the atom-atom interactions. Furthermore, the model separates sets of parameters of Van-der-Waals interactions into inter- and intramolecular. The shifting parameter is specified separately for each pair of atom types for both inter- and intramolecular interactions. The model itself consists of two superatoms. It allows for high speed calculations, "remembers" the benzene ring orientation in multiscale simulations, and can be used together with well-known sets of "united atoms" potentials. This model was tested on p-xylene, 1-ethyl-4-methylbenzene, and 1-methyl-4-propylbenzene. Structural properties for all three substances in the full-atomic model, the "united atoms" model, and the suggested coarse-grained model are discussed. The results demonstrate that the local structure derived from the coarse-grained model is very similar to that derived from the "united atoms" model. PMID:22401424

  2. 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.

  3. 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).

  4. Mass gathering preparedness: the experience of the Athens 2004 Olympic and Para-Olympic Games.

    PubMed

    Hadjichristodoulou, Christos; Mouchtouri, Varvara; Soteriades, Elpidoforos S; Vaitsi, Vasiliki; Kolonia, Virginia; Vasilogiannacopoulos, Antonios P; Kremastinou, Jeni

    2005-05-01

    Planning for environmental health management of the Athens 2004 Olympic Games included assessment of the capacity and deficiencies of relevant public health agencies in Athens and the other four Olympic cities with 17 detailed questionnaires. Different estimates of the expected number of visitors were made on the basis of experience from previous Olympic Games. Potential public health risks were identified and prioritized. A number of deficiencies in personnel, resources, training, and coordination were identified in most agencies. One hundred and ninety-six environmental health inspectors were expected to work during the Olympic period. Around 18,000 athletes and escorts from 201 countries were expected to participate in the Olympic Games and 7,000 to participate in the Para-Olympic Games. Three different scenarios regarding the number of expected visitors were explored; the most probable estimate being 1,950,000 visitors. Foodborne diseases, waterborne diseases, and heat-related illnesses were considered of high priority during the Olympic period, as were traffic accidents. The Olympic Games are a difficult assignment that demands extensive planning, appropriate resources, and timely reporting and coordination among the various public health agencies. PMID:15957323

  5. Dynamics and lithium binding energies of polyelectrolytes based on functionalized poly(para-phenylene terephthalamide).

    PubMed

    Grozema, F C; Best, A S; van Eijck, L; Stride, J; Kearley, G J; de Leeuw, S W; Picken, S J

    2005-04-28

    Polyelectrolyte materials are an interesting class of electrolytes for use in fuel cell and battery applications. Poly(para-phenylene terephthalamide) (PPTA, Kevlar) is a liquid crystalline polymer that, when sulfonated, is a polyelectrolyte that exhibits moderate ion conductivity at elevated temperatures. In this work, quasi-elastic neutron scattering (QENS) experiments were performed to gain insight into the effect of the presence of lithium counterions on the chain dynamics in the material. It was found that the addition of lithium ions decreases the dynamics of the chains. Additionally, the binding of lithium ions to the sulfonic acids groups was investigated by density functional theory (DFT) calculations. It was found that the local surroundings of the sulfonic acid group have very little effect on the lithium-ion binding energy. Binding energies for a variety of different systems were all calculated to be around 150 kcal/mol. The DFT calculations also show the existence of a structure in which a single lithium ion interacts with two sulfonic acid moieties on different chains. The formation of such "electrostatic cross-links" is believed to be the source of the increased tendency to aggregate and the reduced dynamics in the presence of lithium ions. PMID:16851895

  6. 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.

  7. LabVIEW-based control software for para-hydrogen induced polarization instrumentation

    SciTech Connect

    Agraz, Jose Grunfeld, Alexander; Li, Debiao; BIRI, Cedars Sinai Medical Center, West Hollywood, California 90048 ; 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.

  8. Determination of para-phenylenediamine (PPD) in henna in the United Arab Emirates.

    PubMed

    Al-Suwaidi, Ayesha; Ahmed, Hafiz

    2010-04-01

    Henna is very popular in the United Arab Emirates (UAE); it is part of the culture and traditions. Allergy to natural henna is not usual; however the addition of para-phenylenediamine (PPD) to the natural henna increases the risk of allergic contact dermatitis. The objectives of the study were to identify the presence and concentration of PPD in henna available in UAE. Fifteen henna salons were selected randomly from three cities in UAE. Twenty five henna samples were acquired from these selected salons. The presence of PPD in henna samples was determined qualitatively and quantitatively using High Performance Liquid Chromatography (HPLC). The study showed that PPD was present in all of the black henna samples at concentrations ranging between 0.4% and 29.5% and higher than that recommended for hair dyes in most of the black henna samples. The presence of PPD in the black henna increases the risk of allergic contact dermatitis among users of black henna and a number of cases have already been reported in UAE. PMID:20617053

  9. Acute allergic contact dermatitis due to para-phenylenediamine after temporary henna painting.

    PubMed

    Nawaf, Al-Mutairi; Joshi, Arun; Nour-Eldin, Osama

    2003-11-01

    The use of temporary natural henna painting for body adornment and hair dyeing is very common in several countries of the Indian subcontinent, Middle East, and North Africa, and the fad is spreading in other parts of the world. Several cases of para-phenylenediamine (PPD) contaminated, temporary traditional/natural henna induced sensitization and acute allergic reaction have been reported, along with occasional serious long term and rare fatal consequences. We report here a 17-year-old girl with blisters over her hands of five-days duration that appeared within 72 hours of applying a temporary henna paint to her hands during a social occasion. Similar lesions were noted on her face. She had previously applied black henna only once, a year earlier without developing any lesions. Clinical diagnosis of acute allergic contact dermatitis (ACD) was made. After a short course of oral corticosteroids, topical mometasone furaote 1.0% cream, and oral antihistamines, the lesions healed completely over the next four weeks leaving post-inflammatory hypopigmentation. Patch testing done with standard European battery, PPD 1% in petrolatum, and commercially available natural henna powder revealed a 3+ reaction to PPD at 48 hours. No reaction was seen at the natural henna site. Awareness of the condition among physicians and the public and regulation regarding warnings of the risks of using such products is urgently warranted. PMID:14684936

  10. Selective plasmon-driven catalysis for para-nitroaniline in aqueous environments

    PubMed Central

    Cui, Lin; Wang, Peijie; Li, Yuanzuo; Sun, Mengtao

    2016-01-01

    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. PMID:26857259

  11. 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

  12. Protective role of sodium para-amino salicylic acid against manganese-induced hippocampal neurons damage.

    PubMed

    Wang, Fang; Wang, Chan; Jiang, Yueming; Deng, Xiangfa; Lu, Jipei; Ou, Shiyan

    2014-05-01

    Manganese (Mn) is an essential trace element of human. However, excessive Mn can cause manganism. Mn selectively accumulated in Mn-exposed workers' hippocampus which is crucial for higher brain functions such as learning, memory, and motivation during our postnatal life. Studies suggested sodium para-aminosalicylic acid (PAS) appeared to be therapeutic for manganism. We aimed to explore whether PAS could block Mn-induced neuronal injury in hippocampus in vitro. Hippocampal neurons were exposed to 50 ?M manganese chloride (MnCl(2)) for 24 h, following by 50, 500, or 5000 ?M PAS treatment for 24 h. Cell viability, apoptosis rate, mean fluorescence intensity of mitochondrial and DNA damage were respectively performed. MnCl(2) significantly decreased neurons' viability and fluorescence intensity of comet head of DNA, while increasing the apoptosis rate, mean fluorescence intensity of mitochondrial, percentage of tail DNA, and Olive tail moment of DNA. PAS reduced the percentage of tail DNA and Olive tail moment of Mn-exposed neurons. These data suggested that Mn caused hippocampal neurons' injury, and 50-5000 ?M PAS could inhibit Mn-induced DNA damage. PMID:24769799

  13. 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.

  14. [La Junta para Ampliación de Estudios and the development of Spanish psychology].

    PubMed

    Carpintero, Helio; Herrero, Fania

    2007-01-01

    During the last decades of the XIXth century, there was an awakening of consciousness for the need of a Spanish cultural renovation, of which one of the aims was to create and develop a Spanish science, resembling the scientific models already established in more advanced countries. There was a desire of Europeanization. Since it was a global social objective, it was necessary to start from the educator's training. In this climate the Junta para Ampliación de Estudios e Investigaciones Científicas, appeared. The role that the Junta played in Spanish research and in the innovation in the Psychopedagogical field through the first third of the XXth century was extremely important. The Junta's policy of scholarship was one of its most substantial achievements, for it made possible that the country reached in a few decades (1907-1936) the European scientific and psychological level. The relations among Spanish teachers and the Institute J.J. Rousseau is to highlighted, as "Geneva School" was to influence deeply the further development of psychology in Spain. PMID:19845072

  15. 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].

  16. Para-iliac actinomycetoma presenting as sarcoma, a late complication of appendicitis: A case report?

    PubMed Central

    Navarre, Pierre; Cantin, Marie-Andrée; Isler, Marc H.

    2013-01-01

    INTRODUCTION Actinomycosis is known to mimic several types of neoplasms, leading to morbid surgical interventions. PRESENTATION OF CASE We report the particular case of an extensive right para-iliac actinomycetoma presenting as a sarcoma, which to our knowledge has not yet been described in the literature, in a patient with previous ruptured appendicitis. Thanks to the collaborative work between the orthopedic and general surgeons, pathologist and microbiologist, the diagnosis of actinomycosis was made pre-operatively, saving this 15-year-old patient from a tumor resection protocol. DISCUSSION Actinomycetomas have often been reported to present in the same way as several abdominal and gynecological neoplasms, and on rare occasions been described as mimicking other soft-tissue sarcomas, leading to unnecessary morbid tumor resection protocols. The most common cause of abdominal actinomycosis is perforated appendicitis, and may present several years later. CONCLUSION While faced with a soft tissue mass transgressing tissue planes and possibly extending to the region of the right lower quadrant, especially with a history of previous perforated appendicitis, one should consider the possibility of an abscess caused by pathogens of intestinal origin, including the gram positive anaerobe Actinomycosis israelii. Failure to actively search for this pathogen, which is not detectable with routine staining techniques and may take up to 1–2 weeks to isolate, may lead to unnecessary morbid surgical procedures. PMID:24434727

  17. Contact allergy to para-phenylenediamine in a permanent eyelash dye.

    PubMed

    Teixeira, Marta; de Wachter, Liesbet; Ronsyn, Elke; Goossens, An

    2006-08-01

    We present the case of a 30-year-old atopic lady with a known history of intolerance to several materials, including dark stockings, who developed a severe dermatitis on the eyelids and peri-orbital regions, as well as a conjunctivitis after having her eyelashes tinted by a beautician with a permanent black eyelash and eyebrow dye (Combinal, Dr Temt Laboratories, Austria). Patch tests revealed positive reactions to para-phenylenediamine (PPD), both diluted 0.01% and 1% in pet., to the eyelash dye (tested semiopen as is) and to some of the azo-dyes tested. The permanent eyelash dye did contain PPD, the use of which is illegal but seems to be a common practice. The patient had most probably been sensitized through nylon stockings containing azo-dyes, with PPD itself cross-reacting to them. With the growth in popularity of tattooing and permanent make-up, doctors should be aware of the new uses of this old allergen. Moreover, although many manufacturers have made great efforts to improve cosmetics concerning their safety, some of them remain uninformed about cosmetic legislation or do not respect it at all. Because many of these products are acquired via internet, lack of legislation about this shopping modality is also a serious problem. PMID:16930233

  18. Ortho-Para Transition in Muonic Hydrogen and the Proton's Induced Pseudoscalar Coupling

    NASA Astrophysics Data System (ADS)

    Armstrong, D. S.

    2004-05-01

    The induced weak pseudoscalar coupling form factor is a particularly poorly-known aspect of the axial structure of the nucleon, although its value is of significant interest as a test of chiral symmetry breaking. Muon capture experiments (Jonkmans et al., Phys. Rev. Lett. 77(1996)4512, Bardin et al., Phys. Lett. 104B(1981)320) have been used to measure this form factor gp at modest Q^2. However, the interpretation of these muon capture experiments hinges on knowing the relative population of the atomic and molecular states occupied by muons in liquid hydrogen. In particular, ?_op, the transition rate between the ortho- and para- molecular states of the p ? p molecule, needs to be known with precision. The only previous measurement (Bardin et al., ibid.) of ? _op yielded a value of (4.1 ± 1.4) × 10^4 ; s-1, significantly different than the theoretically predicted value 7.1 × 10^4 ; s-1 (Bakalov et al., Nucl. Phys. A384(1982)302). A new measurement of ?_op using the time distribution of neutrons from muon capture in protium was performed at TRIUMF. The substantially larger value ?_op = (11 ± 2) × 10^4 s-1 was obtained. The uncertainty is dominated by the statistical precision of the fit and the background due to the deuterium contamination in the protium target. The implications of this result for gp are discussed.

  19. Ortho-Para Transition in Muonic Molecular Hydrogen and the Induced Pseudoscalar Coupling

    NASA Astrophysics Data System (ADS)

    Clark, Jessica H. D.

    2003-04-01

    A precise measurement of the induced weak pseudoscalar coupling constant of the proton, g_p, is of interest as a basic test of chiral symmetry breaking. This is the least well-known weak form factor of the nucleon. Muon capture experiments(Jonkmans et al. al)., Phys. Rev. Lett. 77(1996)4512. have been used to measure g_p. However, the interpretation of these muon capture experiments requires knowledge of the relative population of the muonic atomic and molecular states for muons in liquid hydrogen. In particular, ? _op, the transition rate between the ortho- and para- molecular states of the p? p molecule, needs to be known with precision. The only previous measurement(Bardin et al. al)., Phys. Lett. 104B(1981)320. of ? _op yielded a value of (4.1 ± 1.4) × 10^4 ; s-1, significantly different than the theoretical prediction(Bakalov et al. al)., Nucl. Phys. A384(1982)302. of 7.1 × 10^4 ; s-1. A measurement of ?_op using the time distribution of neutrons from muon capture was performed at TRIUMF during June-July 1999 and November 1999. The ? _op measured in this experiment is (13.8 ± 1.6) × 10^4 s-1. The uncertainty is dominated by the statistical precision of the fit and the background due to the deuterium contamination in the protium target. The implications of this result for gp are discussed.

  20. Searching for auxetics with DYNA3D and ParaDyn

    NASA Astrophysics Data System (ADS)

    Hoover, Wm. G.; Hoover, C. G.

    2005-03-01

    The present special issue of physica status solidi (b), guest-edited by Krzysztof W. Wojciechowski, Andrew Alderson, Arkadiusz Braka, and Kim L. Alderson, is dedicated to Auxetics and Related Systems - materials which exhibit negative Poisson's ratio behaviour. Most papers were presented at a workshop which was held in Pozna-Bdlewo, 27-30 June 2004.In our Editor's Choice [1] novel simulations with a parallel finite element program, ParaDyn, have been conducted to study the formation of auxetic materials. Structures composed of either brick elements (hexahedra) or shell elements are constructed in a regular array of panels. These structures are compressed and relaxed to form an initial state for an auxetic (foam-like) material. The foam structure shown is composed of 208896 shell elements arranged in four by four panels. Applying a uniaxial compression to this structure characterizes the material behaviour of the lateral surfaces as normal (expanding) or auxetic (compressing).The first author, William G. Hoover, has been working in areas such as statistical and applied mechanics, nonlinear and molecular dynamics and is now pursuing, as he states on his own webpage, an active retired research career as Professor Emeritus of UC Davis.

  1. 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.

  2. Force field of para- and metabenzyne diradicals: A multireference coupled-cluster study

    NASA Astrophysics Data System (ADS)

    Li, Xiangzhu; Paldus, Josef

    2010-03-01

    The reduced multireference (RMR) coupled-cluster (CC) method with singles and doubles (RMR CCSD) that exploits a modest size MR CISD wave function as an external source for a small subset of the most important (primary) triples and quadruples to account for quasidegeneracy due to a MR nature of the states considered, as well as its RMR CCSD(T) version corrected for the secondary triples, are employed to compute fundamental vibrational frequencies for the para- and metabenzene diradicals. A comparison is made with the available experimental data and with other methods, namely, the state selective or Mukherjee CCSD and completely renormalized, size-extensive version of CCSD(T), the so-called CR-CC(2,3), methods. Both the restricted Hartree-Fock and multiconfiguration self-consistent-field (MCSCF) molecular orbitals (MOs) are employed. The four-reference RMR CCSD using MCSCF MOs gives particularly satisfactory results. The breakdown of CCSD(T) and shortcomings of some other approaches are pointed out and the role of invariance with respect to MO rotation is analyzed. Correlation with triplet-singlet splittings is also pointed out.

  3. 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 (? 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 (? 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

  4. 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.

  5. 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.

  6. Cobalt-Schiff base complex catalyzed oxidation of para-substituted phenolics. Preparation of benzoquinones

    SciTech Connect

    Bozell, J.J.; Hames, B.R.; Dimmel, D.R.

    1995-04-21

    Para-substituted phenolics, serving as models for lignin (a renewable source of carbon), are oxidized to the corresponding benzoquinone with oxygen in the presence of catalytic amounts of Co-Schiff base complexes. The reaction products observed depend on the structure of the catalyst. The 5-coordinate catalysts (pyridine)[bis(salicylidene)ethylenediamine]cobalt[(pyr)Co(salen)]and[bis(salicylideneamino)ethylamine]cobalt [Co(n-Me salpr)] convert syringyl alcohol (3,5-dimethoxy-4-hydroxybenzyl alcohol) to 2,6-dimethoxybenzoquinone in high yield. In contrast, syringaldehyde (3,5-dimethoxy-4-hydroxybenzaldehyde) is unreactive toward these catalysts. However, the 4-coordinate Co(salen) converts syringaldehyde to 2,6-dimethoxybenzoiquinone in 72% isolated yield. Phenols bearing a single methoxy group on the ring are unreactive toward any catalyst in MeOH. However, vanillyl alcohol (3-methoxy-4-hydroxybenzyl alcohol) is converted to 2-methoxybenzo-quinone with Co(N-Me salpr) and oxygen in 43% yield in CH{sub 2}Cl{sub 2} and 58% yield in CH{sub 2}Cl{sub 2} in the presence of 1% CuCl{sub 2}. The success of the oxidations appears to be related to the ease of removal of the phenolic hydrogen by the Co/O{sub 2} complex. Competitive deactivation of the catalyst occurs with substrates of lower reactivity. 84 tabs.

  7. 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

  8. 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

  9. Creation and evolution of net proton hyperpolarization arising from para-hydrogenation.

    PubMed

    Reineri, Francesca; Bouguet-Bonnet, Sabine; Canet, Daniel

    2011-05-01

    When a hydrogenation reaction is carried out with gaseous hydrogen enriched in its para- isomer in the earth magnetic field (prior to adiabatic insertion of the sample in the NMR magnet), enhanced proton longitudinal order (represented by 2I(z)(A)I(z)(B)) is created but also difference of enhanced polarizations (I(z)(A)-I(z)(B)). In a first part, it is shown theoretically and experimentally that the longitudinal relaxation time of this polarization difference is roughly twice the ones of individual polarizations. The second part is devoted to a pulse sequence designed for transforming this difference into net hyperpolarization. The evolution of this global hyperpolarization is studied experimentally in a third part and it is observed that a fraction of hyperpolarization possesses an effective longitudinal relaxation time similar to the one of the initial polarization difference. Those experimental results are interpreted by numerical calculations based on Solomon-type equations including the longitudinal order and possibly dipolar-csa cross correlation rates. PMID:21402486

  10. 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

  11. LabVIEW-based control software for para-hydrogen induced polarization instrumentation.

    PubMed

    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 ((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 (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 (13)C based endogenous contrast agents used in molecular imaging. PMID:24784636

  12. A Neurostimulant para-Chloroamphetamine Inhibits the Arginylation Branch of the N-end Rule Pathway

    PubMed Central

    Jiang, Yanxialei; Choi, Won Hoon; Lee, Jung Hoon; Han, Dong Hoon; Kim, Ji Hyeon; Chung, Young-Shin; Kim, Se Hyun; Lee, Min Jae

    2014-01-01

    In the arginylation branch of the N-end rule pathway, unacetylated N-terminal destabilizing residues function as essential determinants of protein degradation signals (N-degron). Here, we show that a neurostimulant, para-chloroamphetamine (PCA), specifically inhibits the Arg/N-end rule pathway, delaying the degradation of its artificial and physiological substrates, including regulators of G protein signaling 4 (RGS4), in vitro and in cultured cells. In silico computational analysis indicated that PCA strongly interacts with both UBR box and ClpS box, which bind to type 1 and type 2 N-degrons, respectively. Moreover, intraperitoneal injection of PCA significantly stabilized endogenous RGS4 proteins in the whole mouse brain and, particularly, in the frontal cortex and hippocampus. Consistent with the role of RGS4 in G protein signaling, treatment with PCA impaired the activations of GPCR downstream effectors in N2A cells, phenocopying ATE1-null mutants. In addition, levels of pathological C-terminal fragments of TDP43 bearing N-degrons (Arg208-TDP25) were significantly elevated in the presence of PCA. Thus, our study identifies PCA as a potential tool to understand and modulate various pathological processes regulated by the Arg/N-end rule pathway, including neurodegenerative processes in FTLD-U and ALS. PMID:25212999

  13. Quantification of para-phenylenediamine and heavy metals in henna dye.

    PubMed

    Kang, Ik-Joon; Lee, Mu-Hyoung

    2006-07-01

    Henna (Lawsonia inermis, family Lythraceae) is a shrub cultivated in India, Sri Lanka and North Africa and contains the active dye lawsone (2-hydroxy-1,4-naphthoquinone). Henna dye is obtained from the dried leaves, which are powdered and mixed with oil or water and are used to prepare hair and body dyes. Temporary henna tattoos are readily available worldwide, last on the skin for several weeks and offer a self-limited, convenient alternative to a permanent tattoo. The addition of para-phenylenediamine (PPD), which is widely recognised as a sensitizer, increases the risk of allergic contact dermatitis from henna tattoo mixtures, and a number of cases have been reported. We examined 15 henna samples available in Korea for the presence of PPD and heavy metals such as nickel, cobalt, chromium, lead and mercury using high-performance liquid chromatography (HPLC), atomic absorption spectroscopy (AAS), mercury analyser and inductively coupled plasma emission spectroscopy. PPD, nickel and cobalt were detected in 3, 11 and 4 samples, respectively. PMID:16842550

  14. 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

  15. The Degree of Ergodicity of ortho- and para-Aminobenzonitrile in an Electric Field.

    PubMed

    Pittman, S M; Heller, E J

    2015-10-22

    We study the dynamics of the two molecules ortho-aminobenzonitrile (OABN) and para-aminobenzonitrile (PABN). They are structural isomers, with differing asymmetries and dipole moments. In this paper, we show that the dynamics of the system strongly depends on the region of phase space of the initial rotational state, the asymmetry of the molecule, and on the direction of the dipole. We also show that the ergodicity of the system varies gradually with energy, except where the rotational energy of the initial state is much less than the Stark interaction. In this regime, the projection of the dipole along the lab-frame z-axis varies linearly with increasing energy and follows the microcanonical ergodic estimate. Both molecules are far from full chaos for total angular momentum quanta J ? [0,45]. However, the initial rotational states in OABN access much more of the available phase space than in PABN. We show that this is a likely cause for the experimental discrepancies in molecular beam deflection experiments. PMID:26393275

  16. 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.

  17. 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.

  18. 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 increased in the later stages of the race, demonstrating a positive pacing strategy. In the shorter women's 500-m TT, rank at the first split was more strongly correlated with final position than in the longer men's 1-km TT. In conclusion, a positive pacing strategy was adopted by the different para-cycling classes. PMID:26834643

  19. 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 increased in the later stages of the race, demonstrating a positive pacing strategy. In the shorter women's 500-m TT, rank at the first split was more strongly correlated with final position than in the longer men's 1-km TT. In conclusion, a positive pacing strategy was adopted by the different para-cycling classes. PMID:26834643

  20. 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.

  1. 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.

  2. Polymer electrophosphorescent devices utilizing a ladder-type poly(para-phenylene) host

    NASA Astrophysics Data System (ADS)

    Yang, X. H.; Neher, D.; Scherf, U.; Bagnich, S. A.; Bässler, H.

    2003-04-01

    The properties of light-emitting diodes based on the electrophorescent platinum-porphyrin dye PtOEP blended into a ladder-type poly(para-phenylene) (LPPP) polymer host are presented. Due to the small difference between the highest occupied molecular orbital (HOMO) levels of the guest and the host, the operating voltage of single layer devices is almost independent of the dopant concentration in clear contrast to what has been observed in the case of wide-band gap host polymers. However, the efficiency and the color purity of these single-layer devices is quite poor, which can be attributed to the weak trapping of carriers on the phosphorescent dye. Incorporating an electron-transporting/hole-blocking layer greatly increases the efficiency of the devices but at the same time emission from the host becomes more significant. Adding a hole-transporting/electron-blocking layer further increases the efficiency of the devices. Pure red emission is, however, only obtained if the HOMO of the hole-transporting layer is well above that of the LPPP host. This effect is interpreted in terms of a direct injection of holes from the hole-transporting layer into the HOMO level of the dopant. Further, prompt fluorescence and phosphorescence studies indicate that energy transfer from LPPP singlet excitons contributes to the emission from the dopant, but that the efficiency of singlet exciton transfer is too small to explain the almost complete absence of host emission in the electroluminescence spectra of single- and three-layer devices.

  3. 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.

  4. 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.

  5. 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

  6. A review of inhalation toxicology studies with para-aramid fibrils.

    PubMed

    Warheit, D B

    1995-10-01

    The paper summarizes the results of inhalation toxicology studies associated with para-aramid (p-aramid) fibrils. The review is subdivided into two categories: the results of inhalation toxicity studies and mechanistic inhalation studies. Keratin-associated lesions were observed in the lungs of female rats following chronic exposure to high concentrations of p-aramid. These lesions were originally interpreted as cystic keratinizing squamous cell carcinomas (CKSCC). In recent years, this keratinizing lesion has been observed in the lungs of rats with greater regularity in numerous chronic inhalation studies following exposures to a variety of dusts. In an attempt to reach a consensus on an appropriate diagnosis for this lesion, an international panel of pathologists was convened to evaluate the morphological aspects of this lesion. The panel considered that the most appropriate diagnosis for this lesion was 'proliferative keratin cyst' (PKC), the biological potential of the PKC remains controversial, but it appears to be unique to the rat species and has little relevance for humans. Mechanistic studies with p-aramid have demonstrated that acute inhalation of high concentrations of fibrils produces a potent but transient pulmonary inflammatory and cell labelling response. The inhaled fibrils have low durability in the lungs of rats as evidenced by a progressive decrease in median fibre lengths with increasing residence time in the lung. In contrast, in a comparative study, size-separated chrysotile asbestos produced a sustained increase over controls in cellular proliferation responses of terminal airways, parenchyma, subpleural and mesothelial regions.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8526399

  7. 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.

  8. A structural and spectroscopic study on para-aminohippuric acid with experimental and theoretical approaches.

    PubMed

    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(9)H(10)N(2)O(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 400-4000cm(-1) and 50-4000cm(-1), respectively. The UV absorption spectra of the compound that dissolved in ethanol and water solution were recorded in the range of 190-400nm. Potential energy curve was computed by means of scanning NCCO 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. PMID:22036005

  9. Para-Aminobenzoic Acid (PABA) Synthase Enhances Thermotolerance of Mushroom Agaricus bisporus

    PubMed Central

    Lu, Zhonglei; Kong, Xiangxiang; Lu, Zhaoming; Xiao, Meixiang; Chen, Meiyuan; Zhu, Liang; Shen, Yuemao; Hu, Xiangyang; Song, Siyang

    2014-01-01

    Most mushrooms are thermo-sensitive to temperatures over 23°C, which greatly restricts their agricultural cultivation. Understanding mushroom’s innate heat-tolerance mechanisms may facilitate genetic improvements of their thermotolerance. Agaricus bisporus strain 02 is a relatively thermotolerant mushroom strain, while strain 8213 is quite thermo-sensitive. Here, we compared their responses at proteomic level to heat treatment at 33°C. We identified 73 proteins that are differentially expressed between 02 and 8213 or induced upon heat stress in strain 02 itself, 48 of which with a known identity. Among them, 4 proteins are constitutively more highly expressed in 02 than 8213; and they can be further upregulated in response to heat stress in 02, but not in 8213. One protein is encoded by the para-aminobenzoic acid (PABA) synthase gene Pabs, which has been shown to scavenge the reactive oxygen species in vitro. Pabs mRNA and its chemical product PABA show similar heat stress induction pattern as PABA synthase protein and are more abundant in 02, indicating transcriptional level upregulation of Pabs upon heat stress. A specific inhibitor of PABA synthesis impaired thermotolerance of 02, while exogenous PABA or transgenic overexpression of 02 derived PABA synthase enhanced thermotolerance of 8213. Furthermore, compared to 8213, 02 accumulated less H2O2 but more defense-related proteins (e.g., HSPs and Chitinase) under heat stress. Together, these results demonstrate a role of PABA in enhancing mushroom thermotolerance by removing H2O2 and elevating defense-related proteins. PMID:24614118

  10. Chelation Therapy of Manganese Intoxication with para-Aminosalicylic Acid (PAS) in Sprague-Dawley Rats

    PubMed Central

    Zheng, Wei; Jiang, Yue-Ming; Zhang, Yanshu; Jiang, Wendy; Wang, Xueqian; Cowan, Dallas M.

    2008-01-01

    Para-aminosalicylic acid (PAS), an FDA-approved anti-tuberculosis drug, has been used successfully in the treatment of severe manganese (Mn)-induced Parkinsonism in humans (Jiang et al., JOEM 48:644, 2006). This study was conducted to explore the capability of PAS in reducing Mn concentrations in body fluids and tissues of Mn-exposed animals. Sprague-Dawley rats received daily intraperitoneally (i.p.) injections of 6 mg Mn/kg, 5 d/wk for 4 wks, followed by a daily subcutaneously (sc.) dose of PAS (100 and 200 mg/kg as the PAS-L and PAS-H group, respectively) for another 2, 3 or 6 wks. Mn exposure significantly increased the concentrations of Mn in plasma, red blood cells (RBC), cerebrospinal fluid (CSF), brain and soft tissues. Following PAS-H treatment for 3 wks, Mn levels in liver, heart, spleen and pancreas were significantly reduced by 25 to 33%, while 3 wks of PAS-L treatment did not show any effect. Further therapy with PAS-H for 6 wk reduced Mn levels in striatum, thalamus, choroid plexus, hippocampus and frontal cortex by 16 to 29% (p<0.05). Mn exposure greatly increased iron (Fe) and copper (Cu) concentrations in CSF, brain and liver. Treatment with PAS-H restored Fe and Cu levels comparable with control. These data suggest that PAS likely acts as a chelating agent to mobilize and remove tissue Mn. A high-dose and prolonged PAS treatment appears necessary for its therapeutic effectiveness. PMID:19150464

  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?

  12. Excretion of para-aminohippurate in the isolated perfused rat kidney: net secretion and net reabsorption.

    PubMed Central

    MacDougall, M L; Wiegmann, T B

    1988-01-01

    1. The excretion of para-aminohippurate (PAH) in the isolated perfused rat kidney was examined over a wide range of perfusate PAH concentrations (15 microM to 6 mM). PAH excretion increased steadily over the range of perfusate concentrations, reaching a maximal excretion rate of 3.28 mumol/min at a free-PAH concentration of 6 mM. 2. Tubular transport of PAH was evaluated from the difference between ultrafiltered PAH and excreted PAH. Net PAH secretion was observed at low perfusate free PAH concentrations. Net PAH transport was zero at a perfusate free PAH concentration of 2.1 mM. Above this level there was progressive net reabsorption. 3. Probenecid (2.5 mM) decreased PAH secretion to 18% of the initial value at 129 microM-free PAH (P less than 0.05). Probenecid had no effect on net reabsorption of PAH at high perfusate levels of the anion. 4. Alanine (5 mM) decreased net PAH secretion by 50% at low free PAH concentrations (P less than 0.05) and decreased net PAH reabsorption by 50% at at a free PAH concentration of 6 mM (P less than 0.05). These effects could not be related to effects of PAH, probenecid or alanine on glomerular filtration rate (GFR), vascular resistance or electrolyte excretion. 5. The results confirm the existence and integrity of the proximal tubular organic anion secretory system in the isolated kidney. In addition, net PAH reabsorption occurs at high perfusate levels. PMID:3411514

  13. The transverse compression of poly(para-phenyleneterephthalamide) and other, highly oriented fibers

    NASA Astrophysics Data System (ADS)

    Singletary, James Neal

    The transverse compression of poly (para-phenyleneterephthalamide) (PPTA) and other, highly-oriented fibers is characterized by mechanical testing and microscopic observation. A review of the literature on the transverse mechanical response of highly-oriented fibers is presented, with special attention to PPTA fibers. Experimental methods to directly measure transverse elastic and failure constants are reviewed. Analyses of these tests are rederived, and their predictions for PPTA compared. Other methods for characterizing the transverse mechanical response of highly-oriented fibers are discussed. Investigations of the structure of PPTA fibers are reviewed, with emphasis placed on what observations affect the transverse mechanical response. The literature supports two possible paradigms for the transverse compressive failure of PPTA fibers: microscopically homogeneous, plastic deformation, and fibrillation, a process of dense microcracking, with cracks predominantly parallel to the fiber axis. Experimental characterization is presented from the single fiber transverse compression test, using a novel test device. The effects of fiber diameter, processing continuous filaments into staple yarns, testing fibers at various aspect ratios, heat treatment, skin thickness, and the orientation of hydrogen bonding are investigated. Test results are simulated by finite element modeling. Hypothesis about the failure process of PPTA fibers in transverse compression are supported by reflected light, confocal and interference microscopy. This thesis concludes that PPTA fibers fail in transverse compression by fibrillation, in which the fiber cracks into several smaller fibrils, which move past each other to allow the fiber to comply with increasing transverse load. During fibrillation, a significant amount of work is I absorbed. The influence of several of the above parameters on the tendency to fibrillate is discussed.

  14. 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.

  15. Trends in electron-ion dissociative recombination of benzene analogs with functional group substitutions: Negative Hammett σpara values

    NASA Astrophysics Data System (ADS)

    Osborne, David; Lawson, Patrick Andrew; Adams, Nigel; Dotan, Itzhak

    2014-06-01

    An in-depth study of the effects of functional group substitution on benzene's electron-ion dissociative recombination (e-IDR) rate constant has been conducted. The e-IDR rate constants for benzene, biphenyl, toluene, ethylbenzene, anisole, phenol, and aniline have been measured using a Flowing Afterglow equipped with an electrostatic Langmuir probe (FALP). These measurements have been made over a series of temperatures from 300 to 550 K. A relationship between the Hammett σpara values for each compound and rate constant has indicated a trend in the e-IDR rate constants and possibly in their temperature dependence data. The Hammett σpara value is a method to describe the effect a functional group substituted to a benzene ring has upon the reaction rate constant.

  16. 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.

  17. Electronic and chelation effects on the unusual C2-methylation of N-(para-substituted)phenylaziridines with lithium organocuprates.

    PubMed

    Kim, Jongtaek; Yoo, Eunjung; Chang, Sukbok; Lee, Yoon Sup

    2011-07-15

    Density functional theory calculations with the B3LYP functional were performed for the title ring-opening reaction to understand the intrinsic activating and directing effects of the N-substituents, as well as the electron donating effect of the para-substituted (Y = Cl, H, Me) phenyl group at the more hindered benzylic C2 atom. The N-tosyl group (i.e., N-Tos) or the N-(2-pyridyl)sulfonyl group (i.e., N-Py) was introduced to activate the ring nitrogen atom (N1) and the para-substituted (Y = Cl, H, Me) phenyl group for the activation of the C2 atom. Conformational searches and geometry optimizations were performed for the N-(para-substituted)phenylaziridines (1?6). Calculations indicate that the aziridine 6 (i.e., Py/Me) has the most elongated C2-N1 bond intrinsically due to the electronic activating effects, implying the aziridine 6 to be the most potent candidate for the more-hindered C2 opening. Transition states (TSs) were investigated for the prospective ring-opening paths (I?IV), considering the types of intermolecular push-pull interactions between the N-activated phenylaziridines and the cuprate. The N-Py group provides an unique C2-favored TS along the path IV, which the N-Tos group cannot afford, due to the less charge transfer from the nucleophilic CH?3?- of the cuprate into the electrophilic C2 atom. Furthermore, the e-donating effect of the para-substituents (Y = Cl, H, Me) enhances the C2 opening for the path IV. This study enables us to understand the unusual ring-opening phenomena in terms of electronic and directing effects and hence may serve as a tool to design substrates for highly regioselective ring openings. PMID:21455961

  18. 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

  19. 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.

  20. 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.

  1. Astronomía para ciegos y amblíopes. Proyecto de construcción de un planetario especial en la ciudad de Mar del Plata

    NASA Astrophysics Data System (ADS)

    Musso, S.

    ?`Qué es la Astronomía para Ciegos?. El trabajo es una adaptación en base a la escala de magnitudes de Hipparco que cambia el concepto de luz por una adaptación sonora, donde las estrellas de magnitud 6 se escuchan en 10 dB, más o menos lo que consideramos el umbral de la audición humana. Quienes no escuchan muy bien no pueden escuchar las magnitudes 6, de la misma manera que muchos de nosotros, que no poseemos una visión perfecta, no podemos observar esas mismas estrellas en el cielo (más allá de la polución). A los astros de magnitud 5 vamos a relacionarlos a un sonido en 20 dB. Y así sucesivamente. También los colores estarán representados en una convención de graves a agudos y lo mismo algunas características del cielo. Por ejemplo, la Vía Láctea se mostrará como un ``ruido", como bien nos lo hicieron ver nuestros futuros destinatarios. En Mar del Plata nos encontramos ya trabajando en un proyecto que tiene como objetivo final la construcción del Primer Planetario Acústico del Mundo, una herramienta para la enseñanza de la astronomía, un espacio para la lucha contra la discriminación del discapacitado y una posibilidad de ``ver el cielo de un modo diferente".

  2. Transoral, retromolar, para-tonsillar approach to the styloid process in 6 patients with Eagle’s syndrome

    PubMed Central

    Eckert, Alexander W.; Scheller, Christian

    2014-01-01

    Objectives: Eagle’s syndrome is caused by an elongated or mineralised styloid process and characterised by facial and pharyngeal pain, odynophagia and dysphagia. Diagnosis is based on clinical findings. However radiologic imaging, like panoramic radiograph, helps to confirm the diagnosis. There are different treatments of the Eagle’s syndrome. Anti-inflammatory medication (carbamazepime, corticosteroids) and/or surgical interventions are established. The aim of the different surgical techniques is to resect the elongated styloid process near the skull base. Study Design: A transoral, retromolar, para-tonsillar approach was performed to expose and resect the elongated calcified styloid process in a consecutive series of six patients. The use of different angled ring curettes, generally used in hypophysis surgery, facilitated the preparation of the styloid process through the surrounding tissue to the skull base, without a compromise to the surrounding tissue. Clinical examinations were performed pre- and postoperatively (3 month and after 1 year after surgery) in all patients. Results: No intra- or postoperative complications were observed. The hypophysis ring curettes facilitated the preparation of the styloid process to the skull base. Conclusions: The transoral, retromolar, para-tonsillar approach is a secure and fast method to resect an elongated symptomatic styloid process. Side effects of the classical transoral trans-tonsillar approach did not occur. Key words:Retromolar, para-tonsillar approach, Eagle syndrome, clinical features. PMID:24121903

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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 the known chemical resistance of commercial yarn. These data suggest that at the low para-aramid fibril exposures found in the workplace, this fibril-shortening mechanism may limit the residence time of long fibers in the lungs of exposed workers. In addition, associated cascade impactor aerodynamic measurements indicate that due to their ribbon shape and curly nature, para-aramid fibrils behave aerodynamically larger than straight fibers. PMID:8258388

  8. 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 considered as a hallmark of a TSI. We optimized several experimental procedures designed to preserve and reveal dilute para-water in bulk. PMID:26399171

  9. 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.

  10. [Para-Aortic Lymphadenectomy and Subsequent Chemotherapy after Resection of the Primary Lesion for Poorly Differentiated Adenocarcinoma of the Sigmoid Colon - A Case Report].

    PubMed

    Kuribara, Tadao; Ichikawa, Tatsuo; Kaneko, Shiori; Osa, Kiyoshi; Ueda, Mamoru; Inoue, Takeshi; Asanuma, Kouzou; Sano, Takayuki; Kishimoto, Yutaka; Ishizu, Hideki; Iai, Akira

    2015-11-01

    The patient was a 68-year-old male who had bloody stools. A colonoscopy revealed a sigmoid colon stricture, and a histological examination confirmed the presence of a poorly differentiated adenocarcinoma.Computed tomography revealed the involvement of a para-aortic lymph nodes, without other metastatic lesions. The patient underwent a sigmoidectomy (with regional lymph node dissection) and a para-aortic lymph node biopsy to prove the histological conformation. Subsequently, he was provided with 6 courses of modified FOLFOX6(mFOLFOX6) chemotherapy, resulting in a marked decrease in para-aortic lymph node involvement. He subsequently underwent a para-aortic lymphadenectomy. The resected specimen was mostly composed of fibrous degenerative tissue; viable cancer cells were observed only in a 2-mm² area. The patient was provided with 6 more courses of mFOLFOX6 chemotherapy, and has since been free of recurrence (for 6 years and 1 month after the second surgery). PMID:26602407

  11. 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

  12. 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.

  13. 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

  14. Um supressor de fundo térmico para a câmara infravermelha CamIV

    NASA Astrophysics Data System (ADS)

    Jablonski, F.; Laporte, R.

    2003-08-01

    O ângulo sólido subtendido pelos pixels na câmara infravermelha do NexGal (CamIV) que operamos no OPD/LNA contém contribuições provenientes do sistema de coleta de fluxo propriamente dito - sendo esta a parte que interessa para as medidas astronômicas - e contribuições da obstrução central, sistema de suporte do espelho secundário e região exterior à pupila de entrada do telescópio. Estas últimas contribuições são devi-das à emissão de corpo negro à temperatura ambiente e aumentam exponencialmente para comprimentos de onda maiores que 2 micra (banda K, no infravermelho próximo). Embora a resultante pode ser quantificada e subtraída dos sinais relevantes, sua variância se adiciona à variância do sinal, e pode ser facilmente a contribuição domi-nante para a incerteza final das medidas, tornando ineficiente o processo de extração de informação e degradando a sensibilidade da câmara. A maneira clássica de resolver esse problema em sistemas ópticos que operam no infravermelho, onde os efeitos da emissão térmica do ambiente são importantes, é restringir o ângulo sólido subtendido pelos pixels individuais exclusivamente aos raios provenientes do sistema óptico. Para tanto, projeta-se uma imagem real, bastante reduzida, da pupila de entrada do sistema óptico num anteparo que transmita para o sistema de imageamento só o que interessa, bloqueando as contribuições das bordas externas à pupila de entrada, obstrução central do telescópio e sistema de suporte. Como a projeção é realizada em ambiente criogênico, a contribuição térmica espúria é efetivamente eliminada. Nós optamos por um sistema do tipo Offner para implementar na prática esta função. Trata-se de um sistema baseado em espelhos esféricos, bastante compacto e ajustado por construção. A opção por espelhos do mesmo material que o sistema de suporte (Alumínio) minimiza a dilatação diferencial, crítica nesse tipo de aplicação. Apresentamos as soluções detalhadas do projeto óptico-mecânico, bem como uma análise de flexões e desempenho em termos de qualidade de imagem.

  15. 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.

  16. Radiosurgery for Para-IAC Meningiomas: The Effect of Radiation Dose to the Cochlea on Hearing Outcome

    SciTech Connect

    Kim, Young-Hoon; Department of Neurosurgery, Seoul National University College of Medicine, Seoul ; Kim, Dong Gyu; Han, Jung Ho; Department of Neurosurgery, Seoul National University College of Medicine, Seoul ; Chung, Hyun-Tai; Kim, In Kyung; Song, Sang Woo; Department of Neurosurgery, Seoul National University College of Medicine, Seoul ; Park, Jeong-Hoon; Department of Neurosurgery, Seoul National University College of Medicine, Seoul ; Kim, Jin Wook; Kim, Yong Hwy; Park, Chul-Kee; Department of Neurosurgery, Seoul National University College of Medicine, Seoul ; Kim, Chae-Yong; Department of Neurosurgery, Seoul National University College of Medicine, Seoul ; Paek, Sun Ha; Jung, Hee-Won; Department of Neurosurgery, Seoul National University College of Medicine, Seoul

    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.

  17. 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

  18. Collisional excitation of CN(X2?+) by para- and ortho-H2: Fine-structure resolved transitions.

    PubMed

    Kalugina, Yulia; K?os, Jacek; Lique, François

    2013-08-21

    We present a new four dimensional potential energy surface (PES) for the CN(X(2)?(+))-H2 system. Both molecules were treated as rigid rotors. Potential energy was obtained from the electronic structure calculations using a partially spin-restricted coupled cluster with single, double, and perturbative triple excitations method. The four atoms were described using the augmented correlation-consistent triple zeta (aug-cc-pVTZ) basis sets augmented with mid-bond functions for improved description of van der Waals interactions. The global minimum is characterized by the well depth of 121.36 cm(-1) for the linear CN???H2 structure. The zero-order corrected dissociation energies D0 are 27.73 cm(-1) and 38.75 cm(-1) for the complex with para- and ortho-H2, respectively. These theoretical results obtained using our new PES are in excellent agreement with experimental values [Y. Chen and M. C. Heaven, J. Chem. Phys. 109, 5171 (1998)]. We perform fully quantum close coupling calculations of the rotationally inelastic cross sections of CN in collisions with para-H2 and ortho-H2 at low and intermediate energies. Corresponding rate coefficients were compared with experimental results of Brunet et al. [J. Chem. Phys. 116, 3617 (2002)]. A good agreement between theoretical and experimental results was found. Fine-structure resolved cross sections were then obtained through a recoupling technique. Significant differences exist between para- and ortho-H2 results. The propensity rules between fine-structure levels are also studied, and it is shown that the cross sections for ?j = ?N transitions are much larger than those for ?j ? ?N transitions, as expected from theoretical considerations. PMID:23968086

  19. Collisional excitation of CN(X2?+) by para- and ortho-H2: Fine-structure resolved transitions

    NASA Astrophysics Data System (ADS)

    Kalugina, Yulia; K?os, Jacek; Lique, François

    2013-08-01

    We present a new four dimensional potential energy surface (PES) for the CN(X2?+)-H2 system. Both molecules were treated as rigid rotors. Potential energy was obtained from the electronic structure calculations using a partially spin-restricted coupled cluster with single, double, and perturbative triple excitations method. The four atoms were described using the augmented correlation-consistent triple zeta (aug-cc-pVTZ) basis sets augmented with mid-bond functions for improved description of van der Waals interactions. The global minimum is characterized by the well depth of 121.36 cm-1 for the linear CN???H2 structure. The zero-order corrected dissociation energies D0 are 27.73 cm-1 and 38.75 cm-1 for the complex with para- and ortho-H2, respectively. These theoretical results obtained using our new PES are in excellent agreement with experimental values [Y. Chen and M. C. Heaven, J. Chem. Phys. 109, 5171 (1998)], 10.1063/1.477132. We perform fully quantum close coupling calculations of the rotationally inelastic cross sections of CN in collisions with para-H2 and ortho-H2 at low and intermediate energies. Corresponding rate coefficients were compared with experimental results of Brunet et al. [J. Chem. Phys. 116, 3617 (2002)], 10.1063/1.1446033. A good agreement between theoretical and experimental results was found. Fine-structure resolved cross sections were then obtained through a recoupling technique. Significant differences exist between para- and ortho-H2 results. The propensity rules between fine-structure levels are also studied, and it is shown that the cross sections for ?j = ?N transitions are much larger than those for ?j ? ?N transitions, as expected from theoretical considerations.

  20. 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