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Sample records for koka vello hein

  1. HeinOnline: An Online Archive of Law Journals.

    ERIC Educational Resources Information Center

    Marisa, Richard J.

    Law is grounded in the past, in the decisions and reasoning of generations of lawyers, judges, juries, and professors. Ready access to this history is vital to solid legal research, and yet, until 2000, much of it was buried in vast collections of aging paper journals. HeinOnline is a new online archive of law journals. Development of HeinOnline…

  2. 36. (Credit JTL) Detail of rear of Heine water tube ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. (Credit JTL) Detail of rear of Heine water tube boiler showing steam drum inspection manhole and blow-down valve. Note inspection plugs for water tubes in tube header below drum. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

  3. Stock assessment of fishery target species in Lake Koka, Ethiopia.

    PubMed

    Tesfaye, Gashaw; Wolff, Matthias

    2015-09-01

    Effective management is essential for small-scale fisheries to continue providing food and livelihoods for households, particularly in developing countries where other options are often limited. Studies on the population dynamics and stock assessment on fishery target species are thus imperative to sustain their fisheries and the benefits for the society. In Lake Koka (Ethiopia), very little is known about the vital population parameters and exploitation status of the fishery target species: tilapia Oreochromis niloticus, common carp Cyprinus carpio and catfish Clarias gariepinus. Our study, therefore, aimed at determining the vital population parameters and assessing the status of these target species in Lake Koka using length frequency data collected quarterly from commercial catches from 2007-2012. A total of 20,097 fish specimens (distributed as 7,933 tilapia, 6,025 catfish and 6,139 common carp) were measured for the analysis. Von Bertalarffy growth parameters and their confidence intervals were determined from modal progression analysis using ELEFAN I and applying the jackknife technique. Mortality parameters were determined from length-converted catch curves and empirical models. The exploitation status of these target species were then assessed by computing exploitation rates (E) from mortality parameters as well as from size indicators i.e., assessing the size distribution of fish catches relative to the size at maturity (Lm), the size that provides maximum cohort biomass (Lopt) and the abundance of mega-spawners. The mean value of growth parameters L∞, K and the growth performance index ø' were 44.5 cm, 0.41/year and 2.90 for O. niloticus, 74.1 cm, 0.28/year and 3.19 for C. carpio and 121.9 cm, 0.16/year and 3.36 for C. gariepinus, respectively. The 95 % confidence intervals of the estimates were also computed. Total mortality (Z) estimates were 1.47, 0.83 and 0.72/year for O. niloticus, C. carpio and C. gariepinus, respectively. Our study suggest that

  4. Stock assessment of fishery target species in Lake Koka, Ethiopia.

    PubMed

    Tesfaye, Gashaw; Wolff, Matthias

    2015-09-01

    Effective management is essential for small-scale fisheries to continue providing food and livelihoods for households, particularly in developing countries where other options are often limited. Studies on the population dynamics and stock assessment on fishery target species are thus imperative to sustain their fisheries and the benefits for the society. In Lake Koka (Ethiopia), very little is known about the vital population parameters and exploitation status of the fishery target species: tilapia Oreochromis niloticus, common carp Cyprinus carpio and catfish Clarias gariepinus. Our study, therefore, aimed at determining the vital population parameters and assessing the status of these target species in Lake Koka using length frequency data collected quarterly from commercial catches from 2007-2012. A total of 20,097 fish specimens (distributed as 7,933 tilapia, 6,025 catfish and 6,139 common carp) were measured for the analysis. Von Bertalarffy growth parameters and their confidence intervals were determined from modal progression analysis using ELEFAN I and applying the jackknife technique. Mortality parameters were determined from length-converted catch curves and empirical models. The exploitation status of these target species were then assessed by computing exploitation rates (E) from mortality parameters as well as from size indicators i.e., assessing the size distribution of fish catches relative to the size at maturity (Lm), the size that provides maximum cohort biomass (Lopt) and the abundance of mega-spawners. The mean value of growth parameters L∞, K and the growth performance index ø' were 44.5 cm, 0.41/year and 2.90 for O. niloticus, 74.1 cm, 0.28/year and 3.19 for C. carpio and 121.9 cm, 0.16/year and 3.36 for C. gariepinus, respectively. The 95 % confidence intervals of the estimates were also computed. Total mortality (Z) estimates were 1.47, 0.83 and 0.72/year for O. niloticus, C. carpio and C. gariepinus, respectively. Our study suggest that

  5. Genetics and Human Agency: Comment on Dar-Nimrod and Heine (2011)

    ERIC Educational Resources Information Center

    Turkheimer, Eric

    2011-01-01

    Dar-Nimrod and Heine (2011) decried genetic essentialism without denying the importance of genetics in the genesis of human behavior, and although I agree on both counts, a deeper issue remains unaddressed: how should we adjust our cognitions about our own behavior in light of genetic influence, or is it perhaps not necessary to take genetics into…

  6. Genetic Essentialism, Neuroessentialism, and Stigma: Commentary on Dar-Nimrod and Heine (2011)

    ERIC Educational Resources Information Center

    Haslam, Nick

    2011-01-01

    Dar-Nimrod and Heine (2011) presented a masterfully broad review of the implications of genetic essentialism for understandings of human diversity. This commentary clarifies the reasons that essentialist thinking has problematic social consequences and links genetic forms of essentialism to those invoking neural essences. The mounting evidence…

  7. [Eros and thanatos in the life and work of Heinrich Heine--a study on the occasion of the 200th birthday of the poet].

    PubMed

    Wilkes, J

    1997-01-01

    Themes of love and death in combination determine Heinrich Heines early lyrics. Heine's psychosexual development ist analyzed by emphasising the female influence. His fantasies during adolescence, masochistic tendencies and his inclination to duels are highlighted by referring to Freud's concept of eros and thanatos. PMID:9206793

  8. [Morphine by external route, prescribed to Heinrich Heine by David Gruby].

    PubMed

    Chast, F

    1998-01-01

    The exhibition held in Paris commemorating the bicentenial of Heinrich Heine showed three prescriptions by Dr. D. Gruby, through which morphine was prescribed for the poet by external route. The use of morphine was justified in a patient with unrelieved pain caused by neurosyphilis during the last twelve years of his life. This way of morphine administration (endemic method) was quite popular between 1830 and 1860. The process consisted in stripping the derm with the help of a vesicant and in applying directly on it morphine salts crystals. Several authors commented the interest of this way of administration rather uncomfortable for the patient but apparently very effective. PMID:11625475

  9. A Mehler-Heine-type formula for Hermite-Sobolev orthogonal polynomials

    NASA Astrophysics Data System (ADS)

    Castaño-García, Laura; Moreno-Balcázar, Juan J.

    2003-01-01

    We consider a Sobolev inner product such as (f,g)S=[integral operator]f(x)g(x) d[mu]0(x)+[lambda][integral operator]f'(x)g'(x) d[mu]1(x), [lambda]>0,with ([mu]0,[mu]1) being a symmetrically coherent pair of measures with unbounded support. Denote by Qn the orthogonal polynomials with respect to (1) and they are so-called Hermite-Sobolev orthogonal polynomials. We give a Mehler-Heine-type formula for Qn when [mu]1 is the measure corresponding to Hermite weight on , that is, d[mu]1=e-x2 dx and as a consequence an asymptotic property of both the zeros and critical points of Qn is obtained, illustrated by numerical examples. Some remarks and numerical experiments are carried out for d[mu]0=e-x2 dx. An upper bound for Qn on is also provided in both cases.

  10. ["Utilitarian system" : Heine's legacy poem "legs, to each man two were given" with his lyrical comments on the field of urology].

    PubMed

    Kruse, J A

    2015-08-01

    The chequered biography as well as the enormous and controversial impact history of the poet Heinrich Heine form the notably changing sum of, in his time but also with a view to the future, the more than difficult and manifold relationships from political, social, religious, cultural and economic as well as industrial historical conditions and problems. The works and personality of the poet can rightly be characterized by the subtitle as a current biography laced with innuendo as "the discovery of the European intellectual". PMID:26246212

  11. ["Utilitarian system" : Heine's legacy poem "legs, to each man two were given" with his lyrical comments on the field of urology].

    PubMed

    Kruse, J A

    2015-08-01

    The chequered biography as well as the enormous and controversial impact history of the poet Heinrich Heine form the notably changing sum of, in his time but also with a view to the future, the more than difficult and manifold relationships from political, social, religious, cultural and economic as well as industrial historical conditions and problems. The works and personality of the poet can rightly be characterized by the subtitle as a current biography laced with innuendo as "the discovery of the European intellectual".

  12. The effect of physical water quality and water level changes on the occurrence and density of Anopheles mosquito larvae around the shoreline of the Koka reservoir, central Ethiopia

    NASA Astrophysics Data System (ADS)

    Teklu, B. M.; Tekie, H.; McCartney, M.; Kibret, S.

    2010-12-01

    Entomological studies to determine the effect of the physical characteristics of mosquito larval breeding water bodies and reservoir water level changes on the occurrence of Anopheles mosquito larvae were conducted in two villages at Koka reservoir in central Ethiopia between August and December 2007. Of the two study villages, Ejersa is located close to the reservoir, and Kuma is 5 km away from it. Data on the type, number and physical characteristics of Anopheles larval breeding habitat, species composition and densities of anopheles mosquitoes in and around the study villages were investigated and recorded. Meteorological and reservoir water level data were compared with availability of Anopheles larval breeding sites and densities. Entomological data, derived from weekly larval collections, showed that Anopheles pharoensis Theobald, Anopheles gambiae s.l. Giles, Anopheles coustani Laveran and Anopheles squamosus Theobald were breeding in the study area. The mean larval density of An. gambiae s.l. in this study was higher in slightly turbid and shallow aquatic habitat than in turbid and relatively deep aquatic habitat. The density of An. pharoensis in habitat with floating vegetation and with relatively shady conditions was significantly higher than that of less shaded aquatic habitat and greater emergent vegetation. There was also a positive correlation between the occurrence of Anopheles larvae with the water and daily minimum atmospheric temperature. Similarly at Ejersa, over the sampling period, there was a positive correlation between falling reservoir water levels and the number of positive breeding habitats. These results confirm that physical characteristics of the water bodies play an important role in the species composition, total Anopheles larval count, and the density of Anopheles mosquitoes. Suitable breeding habitat in the vicinity of the reservoir village was strongly associated with the reservoir. This is particularly important for An

  13. Portent of Heine's Reciprocal Square Root Identity

    SciTech Connect

    Cohl, H W

    2003-01-13

    Precise efforts in theoretical astrophysics are needed to fully understand the mechanisms that govern the structure, stability, dynamics, formation, and evolution of differentially rotating stars. Direct computation of the physical attributes of a star can be facilitated by the use of highly compact azimuthal and separation angle Fourier formulations of the Green's functions for the linear partial differential equations of mathematical physics.

  14. Portent of Heine's Reciprocal Square Root Identity

    SciTech Connect

    Cohl, H S

    2002-10-12

    Precise efforts in theoretical astrophysics are needed to fully understand the mechanisms that govern the structure, stability, dynamics, formation, and evolution of differentially rotating stars. Direct computation of the physical attributes of a star can be facilitated by the use of highly compact azimuthal and separation angle Fourier formulations of the Green's functions for the linear partial differential equations of mathematical physics.

  15. Imaging Thermal He(+)in Geospace from the Lunar Surface

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Sandel, B. R.; Adrian, Mark L.; Goldstein, Jerry; Jahn, Joerg-Micha; Spasojevic, Maria; Griffin, Brand

    2007-01-01

    By mass, thermal plasma dominates near-earth space and strongly influences the transport of energy and mass into the earth's atmosphere. It is proposed to play an important role in modifying the strength of space weather storms by its presence in regions of magnetic reconnection in the dayside magnetopause and in the near to mid-magnetotail. Ionospheric-origin thermal plasma also represents the most significant potential loss of atmospheric mass from our planet over geological time. Knowledge of the loss of convected thermal plasma into the solar wind versus its recirculation across high latitudes and through the magnetospheric flanks into the magnetospheric tail will enable determination of the mass balance for this mass-dominant component of the Geospace system and of its influence on global magnetospheric processes that are critical to space weather prediction and hence to the impact of space processes on human technology in space and on Earth. Our proposed concept addresses this basic issue of Geospace dynamics by imaging thermal He(+) ions in extreme ultraviolet light with an instrument on the lunar surface. The concept is derived from the highly successful Extreme Ultraviolet imager (EUV) flown on the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft. From the lunar surface an advanced EUV imager is anticipated to have much higher sensitivity, lower background noise, and higher communication bandwidth back to Earth. From the near-magnetic equatorial location on the lunar surface, such an imager would be ideally located to follow thermal He(+) ions to high latitudes, into the magnetospheric flanks, and into the magnetotail.

  16. The Enigmatic Core L1451-mm: A First Hydrostatic Core? Or a Hidden VeLLO?

    NASA Astrophysics Data System (ADS)

    Pineda, Jaime E.; Arce, Héctor G.; Schnee, Scott; Goodman, Alyssa A.; Bourke, Tyler; Foster, Jonathan B.; Robitaille, Thomas; Tanner, Joel; Kauffmann, Jens; Tafalla, Mario; Caselli, Paola; Anglada, Guillem

    2011-12-01

    We present the detection of a dust continuum source at 3 mm (CARMA) and 1.3 mm (Submillimeter Array, SMA), and 12CO (2-1) emission (SMA) toward the L1451-mm dense core. These detections suggest a compact object and an outflow where no point source at mid-infrared wavelengths is detected using Spitzer. An upper limit for the dense core bolometric luminosity of 0.05 L ⊙ is obtained. By modeling the broadband spectral energy distribution and the continuum interferometric visibilities simultaneously, we confirm that a central source of heating is needed to explain the observations. This modeling also shows that the data can be well fitted by a dense core with a young stellar object (YSO) and a disk, or by a dense core with a central first hydrostatic core (FHSC). Unfortunately, we are not able to decide between these two models, which produce similar fits. We also detect 12CO (2-1) emission with redshifted and blueshifted emission suggesting the presence of a slow and poorly collimated outflow, in opposition to what is usually found toward YSOs but in agreement with prediction from simulations of an FHSC. This presents the best candidate, so far, for an FHSC, an object that has been identified in simulations of collapsing dense cores. Whatever the true nature of the central object in L1451-mm, this core presents an excellent laboratory to study the earliest phases of low-mass star formation. Based on observations carried out with the IRAM 30 m Telescope, the Submillimeter Array, and CARMA. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain). The Submillimeter Array is a joint project between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics and is funded by the Smithsonian Institution and the Academia Sinica. Support for CARMA construction was derived from the states of California, Illinois, and Maryland, the James S. McDonnell Foundation, the Gordon and Betty Moore Foundation, the Kenneth T. and Eileen L. Norris Foundation, the University of Chicago, the Associates of the California Institute of Technology, and the National Science Foundation. Ongoing CARMA development and operations are supported by the National Science Foundation under a cooperative agreement and by the CARMA partner universities.

  17. Extensive clonality of the endemic Calamagrostis pseudopurpurea Gerstl. ex O.R. Heine in central Germany revealed by RAPD markers.

    PubMed

    Schiebold, S; Hensen, I; Wesche, K; Röser, M

    2009-05-01

    Calamagrostis pseudopurpurea is one of only a few endemic species in Germany and is confined to the catchment area of the River Mulde in the states of Saxony and Saxony-Anhalt. We studied the genetic structure and seed viability across its entire distribution area. Patterns of random amplified polymorphic DNA (RAPD) variation were analysed using 183 individuals from 43 stands in order to assess the overall genetic structure and the extent of clonality. In addition, four related Calamagrostis species (C. canescens, C. epigejos, C. phragmitoides and C. villosa) were included in our study to consider the probable phylogenetic origin of C. pseudopurpurea. We detected two clearly different RAPD phenotypes of C. pseudopurpurea, each distributed along the river banks of two spatially isolated stream courses. Both phenotypes are present downstream of the confluence. Our results indicate that C. pseudopurpurea originates from two distinct periods of hybridisation between the same parental taxa, and that clonal propagation is most likely the main reproduction method. In line with its hybrid origin, embryos of sampled C. pseudopurpurea caryopses were found to be mostly degraded or unviable over several years. Calamagrostis pseudopurpurea is genetically closer to C. canescens and C. phragmitoides than it is to other studied species, but C. canescens and C. phragmitoides have not been proven to be direct parental taxa of C. pseudopurpurea. Calamagrostis pseudopurpurea should therefore still be treated as a separate species that needs special attention from a conservation point of view. PMID:19470118

  18. Morphological data support the recognition of four species in the genus Sirystes Cabanis & Heine, 1859 (Aves: Tyrannidae).

    PubMed

    Lopes, Leonardo Esteves; Gonzaga, Luiz Pedreira

    2016-01-01

    Sirystes is a widespread genus in the Neotropical region. Historically, five subspecies were recognized in a single widespread species, but more recently four separate species have been recognized, based on vocalizations and limited morphological data. In this paper, we analyze individual and geographic variation in this genus on the basis of body measurements and plumage coloration of 514 specimens, including all name-bearing types available. We conclude that the four recently proposed species, S. sibilator, S. albogriseus, S. albocinereus, and S. subcanescens, can also be diagnosed by morphological data, corroborating more recent taxonomic treatments. We identified possible hybrids between S. sibilator and S. albocinereus from a narrow zone of contact in central Bolivia. We show that Sirystes sibilator atimastus Oberholser, 1902 represents a point on a cline within S. sibilator (Vieillot, 1818), and it is here regarded as a subjective junior synonym of the latter. We also provide new observations on the range and diagnosis of S. subcanescens, a name that has been frequently misused, and present a redescription of the four recognized species, as well as reviewing their range and natural history. PMID:27395633

  19. Field investigation on the repellent activity of some aromatic plants by traditional means against Anopheles arabiensis and An. pharoensis (Diptera: Culicidae) around Koka, central Ethiopia.

    PubMed

    Dugassa, Sisay; Medhin, Girmay; Balkew, Meshesha; Seyoum, Aklilu; Gebre-Michael, Teshome

    2009-10-01

    A study was undertaken to evaluate the impact of traditional application methods of mosquito repellent plants in the reduction of the human-vector contact of malaria vectors in central Ethiopia. The plants (Corymbia citriodora, Eucalyptus camaldulensis, Ocimum suave and Ocimum basilicum) were tested by thermal expulsion and direct burning on traditional stoves in the field against two important malaria vectors in Ethiopia (Anopheles arabiensis and An. pharoensis). A Latin-square design was applied for randomly assigning the treatment plants and control to experimental houses over different nights. The percentage repellency of each candidate plant by both application methods was estimated from the catches of mosquitoes in the treatment and control houses. On direct burning of the plants, O. basilicum showed the highest percentage repellency (73.11%, P<0.001) and E. camaldulensis the least repellency (65.29%, P<0.001) against An. arabiensis. By the same method of application, C. citriodora on the other hand gave the highest repellency (72.87%, P<0.001) while E. camaldulensis was still the least repellent plant (66.60%, P<0.001) against An. pharoensis. On thermal expulsion, C. citriodora exhibited the highest repellency (78.69%, P<0.001) while E. camaldulensis was the lowest repellent plant (71.91%, P<0.001) against An. arabiensis. Against An. pharoensis, C. citriodora gave the highest repellency (72.9%, P<0.001) while E. camaldulensis still gave the least repellency (72.2%, P<0.001) on the same method of application. All the tested plants by both methods of application gave partial but significant protection (>65%) against the house-entry and biting of two important malaria vectors in Ethiopia, and thus have a potential to be used at least as supplements to other control methods. However, feasibility and actual impact on disease transmission need to be known on these and other potentially useful plants. PMID:19539591

  20. Implementation of palliative care as a mandatory cross-disciplinary subject (QB13) at the Medical Faculty of the Heinrich-Heine-University Düsseldorf, Germany

    PubMed Central

    Schulz, Christian; Wenzel-Meyburg, Ursula; Karger, André; Scherg, Alexandra; in der Schmitten, Jürgen; Trapp, Thorsten; Paling, Andreas; Bakus, Simone; Schatte, Gesa; Rudolf, Eva; Decking, Ulrich; Ritz-Timme, Stephanie; Grünewald, Matthias; Schmitz, Andrea

    2015-01-01

    Background: By means of the revision of the Medical Licensure Act for Physicians (ÄAppO) in 2009, undergraduate palliative care education (UPCE) was incorporated as a mandatory cross sectional examination subject (QB13) in medical education in Germany. Its implementation still constitutes a major challenge for German medical faculties. There is a discrepancy between limited university resources and limited patient availabilities and high numbers of medical students. Apart from teaching theoretical knowledge and skills, palliative care education is faced with the particular challenge of imparting a professional and adequate attitude towards incurably ill and dying patients and their relatives. Project description: Against this background, an evidence-based longitudinal UPCE curriculum was systematically developed following Kern’s Cycle [1] and partly implemented and evaluated by the students participating in the pilot project. Innovative teaching methods (virtual standardised/simulated patient contacts, e-learning courses, interdisciplinary and interprofessional collaborative teaching, and group sessions for reflective self-development) aim at teaching palliative care-related core competencies within the clinical context and on an interdisciplinary and interprofessional basis. Results: After almost five years of development and evaluation, the UPCE curriculum comprises 60 teaching units and is being fully implemented and taught for the first time in the winter semester 2014/15. The previous pilot phases were successfully concluded. To date, the pilot phases (n=26), the subproject “E-learning in palliative care” (n=518) and the blended-learning elective course “Communication with dying patients” (n=12) have been successfully evaluated. Conclusion: All conducted development steps and all developed programmes are available for other palliative care educators (Open Access). The integrated teaching formats and methods (video, e-learning module, interprofessional education, group sessions for reflexive self-development) and their evaluations are intended to make a contribution to an evidence-based development of palliative care curricula in Germany. PMID:25699109

  1. A Search for Very Low-luminosity Objects in Gould Belt Clouds

    NASA Astrophysics Data System (ADS)

    Kim, Mi-Ryang; Lee, Chang Won; Dunham, Michael M.; Evans, Neal J., II; Kim, Gwanjeong; Allen, Lori E.

    2016-08-01

    We present the results of a search for Very Low-Luminosity Objects (VeLLOs) in the Gould Belt (GB) clouds using infrared and sub-millimeter (sub-mm) data from 1.25 to 850 μm and our {{{N}}}2{{{H}}}+ (J = 1‑0) observations. We modified the criteria by Dunham et al. to select the VeLLOs in the GB clouds, finding 95 VeLLO candidates, 79 of which are newly identified in this study. Out of 95 sources, 44 were detected in both sub-mm continuum and {{{N}}}2{{{H}}}+ emission and were classified as Group A (the VeLLOs), and 51 sources detected in either sub-mm emission or {{{N}}}2{{{H}}}+ emission were classified with Group B as candidate VeLLOs. We find that these VeLLOs and the candidates are forming in environments different from those of the likely VeLLOs. Seventy-eight sources are embedded within their molecular clouds, and thus are likely VeLLOs forming in a dense environment. The remaining 17 sources are located in low-level extinction regions ({A}V\\lt 1) connected to the clouds, and can be either background sources or candidate substellar objects forming in an isolated mode. The VeLLOs and the candidates are likely more luminous and their envelopes tend to be more massive in denser environments. The VeLLOs and the candidates are more populous in the clouds where more YSOs form, indicating that they form in a manner similar to that of normal YSOs. The bolometric luminosities and temperatures of the VeLLOs are compared to predictions of episodic accretion models, showing that the low luminosities for most VeLLOs can be well explained by their status in the quiescent phases of a cycle of episodic mass accretion.

  2. Off-shore to near-shore transects of ferromanganese crusts adjacent to the California margin Tracey A. Conrad1, James R. Hein2, Adina Paytan1 1University of California Santa Cruz, CA, 95064 (tconrad@ucsc.edu) 2USGS, Menlo Park, CA, 94025, USA (jhein@usgs.gov)

    NASA Astrophysics Data System (ADS)

    Conrad, T. A.; Hein, J. R.; Paytan, A.

    2012-12-01

    Marine ferromanganese (Fe-Mn) crusts growing on seamounts along the California Margin (CM) are influenced by terrestrial and biogenic input. These continental margin crusts have higher concentrations of Si, K, Fe, Na, Ag, Cr, B, and Ba than Fe-Mn crusts from the global open-ocean. Al is also higher but only relative to Pacific open-ocean crusts. These relative enrichments may reflect the high primary productivity near the CM caused by seasonal upwelling and high sediment transport to the region from river/eolian input and cliff erosion. Two transects with samples from five seamounts each are used to compare seaward changes. Transect A includes analyses of 66 bulk samples from Flint, Ben, and Little Joe seamounts, Patton Escarpment, and Northeast Bank. It spans ~400 km of seafloor heading ~58N and coming within ~220 km of the shoreline with samples collected at water depths ranging from 570-2925 m. Transect B includes analyses of 136 bulk samples from Adam, Hoss, San Marcos, San Juan, and Rodriguez seamounts at water depths ranging from 692-3880 m. This transect spans ~240 km heading ~10N and comes within ~75 km of the shoreline near the base of the continental slope. For both transects, mean water depth increases with mean longitude, and latitude is fairly constant varying by approximately 2 degree latitude for transect A and 1degree for B. Both transects show statistically significant trends at the 99% confidence level for element concentrations versus water depth. Concentrations of Fe, Ca, P, Co, and Pb increase as water depth decreases. For transect (A), Mn and Mg also follow this trend, as do Mo and Al for transect (B); Mn also shows this trend for transect (B) but at the 95% confidence level. For both transects, Cu and Zn show the opposite trend, with concentrations increasing in crusts with increasing water depth. For Transect (B), Ni and Al also show this trend. Si and K show no statistically significant trends for either transect. In open-ocean samples concentrations of Si generally increase in crusts with increasing water depth. The Si/Al ratio for the CM samples is 6.2 for transect (A) and 6.1 for (B). Global open-ocean crusts have a Si/Al ratio averaging about 4. This variation in CM crusts is due to input of biogenic Si; the ratio for terrestrial input would be much lower as concentrations of Al would be relatively higher. In global open-ocean samples Ca, Co, Mn, and P increase as water depth decreases while Cu and Fe increase as water depth increases. Element concentrations are influenced by the OMZ and by the chemical cycle of elements in the water column, including whether depth profiles are conservative, scavenged, or biologic. Element trends in CM Fe-Mn crusts can therefore be explained by high biological productivity, proximity to the OMZ, element profiles in the water column, and input of terrigenous debris.

  3. The Jurisprudence of "Brown" and the Dilemmas of Liberalism.

    ERIC Educational Resources Information Center

    Horwitz, Morton J.

    1979-01-01

    Examines several dilemmas of liberal jurisprudence stemming from "Brown," and concludes that they stem, ultimately, from our uncertain commitment to equality. Available from William S. Hein & Co., Inc., 1285 Main St., Buffalo, NY 14209. (IRT)

  4. Water resources implications of integrating malaria control into the operation of an Ethiopian dam

    NASA Astrophysics Data System (ADS)

    Reis, Julia; Culver, Teresa B.; McCartney, Matthew; Lautze, Jonathan; Kibret, Solomon

    2011-09-01

    This paper investigates the water resources implications of using a method of hydrological control to reduce malaria around the Koka reservoir in central Ethiopia. This method is based on recent findings that malaria is transmitted from the shoreline of the Koka reservoir, and on a similar method that was used to control malaria some 80 yr ago in the United States. To assess the feasibility of implementing hydrological control at Koka, we considered the potential impact of the modified management regime on the benefits derived from current uses of the reservoir water (i.e., hydropower, irrigation, flood control, water supply, and downstream environmental flows). We used the HEC-ResSim model to simulate lowering the reservoir by a rate designed to disrupt larval development, which is expected to reduce the abundance of adult mosquito vectors and therefore reduce malaria transmission during the season in which transmission of the disease peaks. A comparison was made of major reservoir uses with and without the malaria control measure. In the 26-yr simulation, application of the malaria control measure increased total average annual electricity generation from 87.6 GWh × y-1 to 92.2 GWh × y-1 (i.e., a 5.3% increase) but resulted in a small decline in firm power generation (i.e., guaranteed at 99.5% reliability) from 4.16 MW to 4.15 MW (i.e., a 0.2% decrease). Application of the malaria control measure did not impact the ability of the reservoir to meet downstream irrigation demand and reduced the number of days of downstream flooding from 28 to 24 d. These results indicate that targeted use of hydrological control for malaria vector management could be undertaken without sacrificing the key benefits of reservoir operation.

  5. Children's Classics. Fifth Edition.

    ERIC Educational Resources Information Center

    Jordan, Alice M.

    "Children's Classics," a 1947 article by Alice M. Jordan reprinted from "The Horn Book Magazine," examines the dynamics and appeal of some of the most famous books for young readers, including "Alice in Wonderland,""The Wind in the Willows,""Robinson Crusoe," and "Andersen's Fairy Tales." Paul Hein's annotated bibliography, a revision of Jordan's…

  6. Book Reviews.

    ERIC Educational Resources Information Center

    Journal of Chemical Education, 1983

    1983-01-01

    Reviews two textbooks: "Principles of Biochemistry" by Albert L. Lehninger and "Inorganic Chemistry, A Modern Introduction" by Therald Moeller. Also reviews text, study guide, and laboratory manual for Morris Hein's "Foundations of College Chemistry, Fifth Edition" and text/study guide for David A. Ucko's "Basics for Chemistry." (JN)

  7. High-Profile Plagiarism Prompts Soul-Searching in German Universities

    ERIC Educational Resources Information Center

    Hockenos, Paul

    2013-01-01

    Rarely do political scandal and academe collide so publicly as they have now, in Europe. In February, Germany's education minister stepped down after Heinrich Heine University, in Dusseldorf, revoked her doctorate because her thesis lifted passages from other sources without proper attribution. Her departure came after scandals over plagiarized…

  8. 78 FR 73524 - Environmental Impact Statements; Notice of Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-06

    ... AGENCY Environmental Impact Statements; Notice of Availability RESPONSIBLE AGENCY: Office of Federal... Environmental Impact Statements Filed 11/25/2013 Through 11/29/2013 Pursuant to 40 CFR 1506.9. Notice Section..., Comment Period Ends: 02/03/2014, Contact: Hugh Heine 910-251-4070. Revision to the FR Notice Published...

  9. Censoring History: Citizenship and Memory in Japan, Germany, and the United States. Asia and the Pacific.

    ERIC Educational Resources Information Center

    Hein, Laura, Ed.; Selden, Mark, Ed.

    This collection of essays focuses on textbook treatments of World War II in Japan, Germany, and the United States and gives readers a new perspective on the creation of national identities and international misunderstandings. Essays in the collection are: (1) "The Lessons of War, Global Power, and Social Change" (Laura Hein; Mark Selden); (2) "The…

  10. Body Part Terms as a Semantic Basis for Grammaticalization: A Mordvin Case Study into Spatial Reference and beyond

    ERIC Educational Resources Information Center

    van Pareren, Remco

    2013-01-01

    Body parts have played an important role in the development of theories describing grammaticalization processes (Heine and Kuteva, 2002, pp. 62-63 and 165-171). Within Uralic linguistics, this particular area of study has not yet received a great deal of attention, although the agglutinative character of most of these languages is known to have…

  11. Some Thoughts on Essence Placeholders, Interactionism, and Heritability: Reply to Haslam (2011) and Turkheimer (2011)

    ERIC Educational Resources Information Center

    Dar-Nimrod, Ilan; Heine, Steven J.

    2011-01-01

    In the target article (Dar-Nimrod & Heine, 2011), we provided a social-cognitive framework which identified genetic essentialist biases and their implications. In their commentaries, Haslam (2011) and Turkheimer (2011) indicated their general agreement with this framework but highlighted some important points for consideration. Haslam suggested…

  12. Library Schools and Other Training Aspects Section. Education and Research Division. Papers.

    ERIC Educational Resources Information Center

    International Federation of Library Associations, The Hague (Netherlands).

    Papers on library education presented at the 1982 International Federation of Library Associations (IFLA) conference include: (1) "Learning and Library Networks at Mid-Career Level: The Possible Contribution of the Library Schools" by M. H. Heine (United Kingdom); (2) "Network Implications for Library Education: Planning for (the) Future of (the)…

  13. 10. Photo copy of historic photograph, Nov. 4, 1944. Building ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Photo copy of historic photograph, Nov. 4, 1944. Building 60, INTERIOR, WEST END, LOOKING SOUTH BETWEEN BANKS OF HEINE BOILERS. File No. 74, Copy print on file, Library, U.S. Army Corps of Engineers, New England Division, Waltham, Massachusetts. - Watertown Arsenal, Building No. 60, Arsenal Street, Watertown, Middlesex County, MA

  14. Meeting New Challenges in the Foreign Language Classroom. Selected Papers from the Annual Central States Conference on the Teaching of Foreign Languages Kansas City, Missouri, April 21-24, 1994).

    ERIC Educational Resources Information Center

    Crouse, Gale K., Ed.; And Others

    Papers in this volume are: "National Standards and Assessments" (June K. Phillips; Jamie B. Draper); "Cultural Roots and Academic Achievement" (Charles R. Hancock); "The At-Risk Student in the Foreign Language Classroom" (Audrey Heining-Boynton); "I Can't Get Them To Talk" (Robert L. Davis; H. Jay Siskin); "Preparing Foreign Language Teachers for…

  15. Addressing the Standards for Foreign Language Learning. Dimension '97. Selected Proceedings of the Joint Conference of the Southern Conference on Language Teaching and the South Carolina Foreign Language Teachers' Association (Myrtle Beach, South Carolina).

    ERIC Educational Resources Information Center

    Terry, Robert M., Ed.

    Seven papers from the annual conference are presented. "Developing Tomorrow's Technology-Using Foreign Language Teachers: Where We Are, Where We Are Going" (Marjorie H. DeWert, Audrey Heining-Boynton) looks at whether language teachers are being trained to take full advantage of educational technology. "Foreign Language Placement in Postsecondary…

  16. For Your Bookshelf.

    ERIC Educational Resources Information Center

    Jones, Rebecca

    2002-01-01

    Reviews notable education books of 2001: "Not in Front of the Children" (Marjorie Heins); "The other Boston Busing Story" (Susan E. Eaton); "Another Planet" (Elinor Burkett); "Parents Under Siege" (James Garbarino and Claire Bedard); "Radical Equations" (Robert P. Moses and Charles E. Cobb, Jr.); "School" (Sheila Curran Bernard and Sarah Mondale);…

  17. Trace element mobility and transfer to vegetation within the Ethiopian Rift Valley lake areas.

    PubMed

    Kassaye, Yetneberk A; Skipperud, Lindis; Meland, Sondre; Dadebo, Elias; Einset, John; Salbu, Brit

    2012-10-26

    To evaluate critical trace element loads in native vegetation and calculate soil-to-plant transfer factors (TFs), 11 trace elements (Cr, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Pb and Mn) have been determined in leaves of 9 taxonomically verified naturally growing terrestrial plant species as well as in soil samples collected around 3 Ethiopian Rift Valley lakes (Koka, Ziway and Awassa). The Cr concentration in leaves of all the plant species was higher than the "normal" range, with the highest level (8.4 mg per kg dw) being observed in Acacia tortilis from the Lake Koka area. Caper species (Capparis fascicularis) and Ethiopian dogstooth grass (Cynodon aethiopicus) from Koka also contained exceptionally high levels of Cd (1 mg per kg dw) and Mo (32.8 mg per kg dw), respectively. Pb, As and Cu concentrations were low in the plant leaves from all sites. The low Cu level in important fodder plant species (Cynodon aethiopicus, Acacia tortilis and Opuntia ficus-indicus) implies potential deficiency in grazing and browsing animals. Compared to the Canadian environmental quality guideline and maximum allowable concentration in agricultural soils, the total soil trace element concentrations at the studied sites are safe for agricultural crop production. Enrichment factor was high for Zn in soils around Lakes Ziway and Awassa, resulting in moderate to high transfer of Zn to the studied plants. A six step sequential extraction procedure on the soils revealed a relatively high mobility of Cd, Se and Mn. Strong association of most trace elements with the redox sensitive fraction and mineral lattice was also confirmed by partial redundancy analysis. TF (mg per kg dw plants/mg per kg dw soil) values based on the total (TF(total)) and mobile fractions (TF(mobile)) of soil trace element concentrations varied widely among elements and plant species, with the averaged TF(total) and TF(mobile) values ranging from 0.01-2 and 1-60, respectively. Considering the mobile fraction in soils should

  18. Why Do Some Cores Remain Starless?

    NASA Astrophysics Data System (ADS)

    Anathpindika, S.

    2016-08-01

    Prestellar cores, by definition, are gravitationally bound but starless pockets of dense gas. Physical conditions that could render a core starless (in the local Universe) is the subject of investigation in this work. To this end, we studied the evolution of four starless cores, B68, L694-2, L1517B, L1689, and L1521F, a VeLLO. We demonstrate: (i) cores contracted in quasistatic manner over a timescale on the order of ~ 105 yr. Those that remained starless briefly acquired a centrally concentrated density configuration that mimicked the profile of a unstable BonnorEbert sphere before rebounding, (ii) three cores viz. L694-2, L1689-SMM16, and L1521F remained starless despite becoming thermally super-critical. By contrast, B68 and L1517B remained sub-critical; L1521F collapsed to become a VeLLO only when gas-cooling was enhanced by increasing the size of dust-grains. This result is robust, for other starless cores viz. B68, L694-2, L1517B, and L1689 could also be similarly induced to collapse. The temperature-profile of starless cores and those that collapsed was found to be radically different. While in the former type, only very close to the centre of a core was there any evidence of decline in gas temperature, by contrast, a core of the latter type developed a more uniformly cold interior. Our principle conclusions are: (a) thermal super-criticality of a core is insufficient to ensure it will become protostellar, (b) potential star-forming cores (the VeLLO L1521F here), could be experiencing dust-coagulation that must enhance gasdust coupling and in turn lower gas temperature, thereby assisting collapse. This also suggests, mere gravitational/virial boundedness of a core is insufficient to ensure it will form stars.

  19. A SYSTEMATIC SEARCH FOR MOLECULAR OUTFLOWS TOWARD CANDIDATE LOW-LUMINOSITY PROTOSTARS AND VERY LOW LUMINOSITY OBJECTS

    SciTech Connect

    Schwarz, Kamber R.; Shirley, Yancy L.; Dunham, Michael M.

    2012-10-01

    We present a systematic single-dish search for molecular outflows toward a sample of nine candidate low-luminosity protostars and 30 candidate very low luminosity objects (VeLLOs; L{sub int} {<=} 0.1 L{sub Sun }). The sources are identified using data from the Spitzer Space Telescope cataloged by Dunham et al. toward nearby (D < 400 pc) star-forming regions. Each object was observed in {sup 12}CO and {sup 13}CO J = 2 {yields} 1 simultaneously using the sideband separating ALMA Band-6 prototype receiver on the Heinrich Hertz Telescope at 30'' resolution. Using five-point grid maps, we identify five new potential outflow candidates and make on-the-fly maps of the regions surrounding sources in the dense cores B59, L1148, L1228, and L1165. Of these new outflow candidates, only the map of B59 shows a candidate blue outflow lobe associated with a source in our survey. We also present larger and more sensitive maps of the previously detected L673-7 and the L1251-A-IRS4 outflows and analyze their properties in comparison to other outflows from VeLLOs. The accretion luminosities derived from the outflow properties of the VeLLOs with detected CO outflows are higher than the observed internal luminosity of the protostars, indicating that these sources likely had higher accretion rates in the past. The known L1251-A-IRS3 outflow is detected but not re-mapped. We do not detect clear, unconfused signatures of red and blue molecular wings toward the other 31 sources in the survey indicating that large-scale, distinct outflows are rare toward this sample of candidate protostars. Several potential outflows are confused with the kinematic structure in the surrounding core and cloud. Interferometric imaging is needed to disentangle large-scale molecular cloud kinematics from these potentially weak protostellar outflows.

  20. A Systematic Search for Molecular Outflows Toward Candidate Low-luminosity Protostars and Very Low Luminosity Objects

    NASA Astrophysics Data System (ADS)

    Schwarz, Kamber R.; Shirley, Yancy L.; Dunham, Michael M.

    2012-10-01

    We present a systematic single-dish search for molecular outflows toward a sample of nine candidate low-luminosity protostars and 30 candidate very low luminosity objects (VeLLOs; L int <= 0.1 L ⊙). The sources are identified using data from the Spitzer Space Telescope cataloged by Dunham et al. toward nearby (D < 400 pc) star-forming regions. Each object was observed in 12CO and 13CO J = 2 → 1 simultaneously using the sideband separating ALMA Band-6 prototype receiver on the Heinrich Hertz Telescope at 30'' resolution. Using five-point grid maps, we identify five new potential outflow candidates and make on-the-fly maps of the regions surrounding sources in the dense cores B59, L1148, L1228, and L1165. Of these new outflow candidates, only the map of B59 shows a candidate blue outflow lobe associated with a source in our survey. We also present larger and more sensitive maps of the previously detected L673-7 and the L1251-A-IRS4 outflows and analyze their properties in comparison to other outflows from VeLLOs. The accretion luminosities derived from the outflow properties of the VeLLOs with detected CO outflows are higher than the observed internal luminosity of the protostars, indicating that these sources likely had higher accretion rates in the past. The known L1251-A-IRS3 outflow is detected but not re-mapped. We do not detect clear, unconfused signatures of red and blue molecular wings toward the other 31 sources in the survey indicating that large-scale, distinct outflows are rare toward this sample of candidate protostars. Several potential outflows are confused with the kinematic structure in the surrounding core and cloud. Interferometric imaging is needed to disentangle large-scale molecular cloud kinematics from these potentially weak protostellar outflows.

  1. Solar UV-treatment of water samples for stripping-voltammetric determination of trace heavy metals in Awash river, Ethiopia.

    PubMed

    Woldemichael, Gelaneh; Tulu, Taffa; Flechsig, Gerd-Uwe

    2016-03-01

    We report about testing a new mobile and sustainable water sample digestion method in a preliminary field trial in Ethiopia. In order to determine heavy metals at the ultra-trace level by stripping voltammetric techniques in water samples from Awash River, we applied our new method of solar UV-assisted sample pretreatment to destroy the relevant interfering dissolved organic matter. The field tests revealed that 24 h of solar UV irradiation were sufficient to achieve the same sample pretreatment results as with classic digestion method based on intense and hard UV. Analytical results of this study suggest that both a hydroelectric power station and agrichemical applications at Koka Lake have increased the levels of the investigated metals zinc, cadmium, lead, copper, cobalt, nickel, and uranium. PMID:27441266

  2. Carrots, tomatoes and cocoa: Research on dietary antioxidants in Düsseldorf.

    PubMed

    Stahl, Wilhelm

    2016-04-01

    Dietary antioxidants, their biological effects and underlying mechanisms of action are key topics of research at the Institute of Biochemistry and Molecular Biology I at the Heinrich-Heine University in Düsseldorf where Helmut Sies is active now since more than 35 years. In the present article his research activity on carotenoids is summarized including studies on their bioavailability, antioxidant properties, cellular signaling and dermatological effects. Additionally, comparable studies on cocoa polyphenols are described. PMID:27095228

  3. Smallest zeros of some types of orthogonal polynomials: asymptotics

    NASA Astrophysics Data System (ADS)

    Moreno-Balcazar, Juan Jose

    2005-07-01

    We establish Mehler-Heine-type formulas for orthogonal polynomials related to rational modifications of Hermite weight on the real line and for Hermite-Sobolev orthogonal polynomials. These formulas give us the asymptotic behaviour of the smallest zeros of the corresponding orthogonal polynomials. Furthermore, we solve a conjecture posed in a previous paper about the asymptotics of the smallest zeros of the Hermite-Sobolev polynomials as well as an open problem concerning the asymptotics of these Sobolev orthogonal polynomials.

  4. Carrots, tomatoes and cocoa: Research on dietary antioxidants in Düsseldorf.

    PubMed

    Stahl, Wilhelm

    2016-04-01

    Dietary antioxidants, their biological effects and underlying mechanisms of action are key topics of research at the Institute of Biochemistry and Molecular Biology I at the Heinrich-Heine University in Düsseldorf where Helmut Sies is active now since more than 35 years. In the present article his research activity on carotenoids is summarized including studies on their bioavailability, antioxidant properties, cellular signaling and dermatological effects. Additionally, comparable studies on cocoa polyphenols are described.

  5. 41. (Credit JTL) View looking south at #1 low service ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. (Credit JTL) View looking south at #1 low service engine as it appeared in 1980. Original 3 mdg pump ends were replaced in 1911 with Epping-Carpenter pump ends capable of delivering a total of 5 mgd. Engine was retired in the 1960's. Heine water tube boilers in the background. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

  6. 34. (Credit JTL) Front (north side) of three water tube ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. (Credit JTL) Front (north side) of three water tube boilers built by the Heine Safety Boiler Co. of St. Louis, Missouri in 1917; rebuilt in 1938. Front doors opened on center boiler to show water header and inspection plugs for water tubes. Smaller doors beneath open into firebox; boilers presently equipped for gas firing. Operating pressure approx. 150 psi (saturated steam). - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

  7. SMA Observations on a Very Low Luminosity Object

    NASA Astrophysics Data System (ADS)

    Hung, Chao-Ling; Lai, S.; Ohashi, N.; Lee, C.; Karr, J.; Takahashi, S.; Ching, T.

    2010-01-01

    Studying young stellar objects with extremely low luminosity (Very Low Luminosity Objects, VeLLOs) provide us great opportunity for investigating the initial conditions of star formation and the formation of brown dwarfs. We study the dynamical and chemical properties of a VeLLO - DCE 065 using Submillimeter Array (SMA). The most promising result from DCE 065 is that both CO and N2D+ are depleted toward the protostar, confirming that the core is extremely young. We also detect high velocity red and blue shifted components in 12CO, suggesting the possible outflow activities. Although the missing flux prevents us to see the whole picture of the outflows, the proto (or pseudo) disk is clearly detected in the dust continuum and N2D+. The N2D+ line is extremely narrow ( 0.2 km/s) and the line width is comparable to its velocity gradient across the major axis. Assuming the rotation of proto disk is contributed by central protostar, the derived mass of central star is 0.02 solar mass. With the consideration of the sub solar mass envelope, DCE 065 may present a scenario that a brown dwarf can be formed from the collapsing processes of a core. CLH and SPL are supported by National Science Council of Taiwan under grant NSC 96-2112-M-007-019-MY2 and NSC 98-2112-M-007-007-MY3.

  8. MAMBO mapping of Spitzer c2d small clouds and cores

    NASA Astrophysics Data System (ADS)

    Kauffmann, J.; Bertoldi, F.; Bourke, T. L.; Evans, N. J., II; Lee, C. W.

    2008-09-01

    Aims: To study the structure of nearby (<500 pc) dense starless and star-forming cores with the particular goal to identify and understand evolutionary trends in core properties, and to explore the nature of Very Low Luminosity Objects (≤0.1 L⊙; VeLLOs). Methods: Using the MAMBO bolometer array, we create maps unusually sensitive to faint (few mJy per beam) extended (≈5 arcmin) thermal dust continuum emission at 1.2 mm wavelength. Complementary information on embedded stars is obtained from Spitzer, IRAS, and 2MASS. Results: Our maps are very rich in structure, and we characterize extended emission features (“subcores”) and compact intensity peaks in our data separately to pay attention to this complexity. We derive, e.g., sizes, masses, and aspect ratios for the subcores, as well as column densities and related properties for the peaks. Combination with archival infrared data then enables the derivation of bolometric luminosities and temperatures, as well as envelope masses, for the young embedded stars. Conclusions: Starless and star-forming cores occupy the same parameter space in many core properties; a picture of dense core evolution in which any dense core begins to actively form stars once it exceeds some fixed limit in, e.g., mass, density, or both, is inconsistent with our data. A concept of necessary conditions for star formation appears to provide a better description: dense cores fulfilling certain conditions can form stars, but they do not need to, respectively have not done so yet. Comparison of various evolutionary indicators for young stellar objects in our sample (e.g., bolometric temperatures) reveals inconsistencies between some of them, possibly suggesting a revision of some of these indicators. Finally, we challenge the notion that VeLLOs form in cores not expected to actively form stars, and we present a first systematic study revealing evidence for structural differences between starless and candidate VeLLO cores. Based on

  9. DIRECT IMAGING OF A COMPACT MOLECULAR OUTFLOW FROM A VERY LOW LUMINOSITY OBJECT: L1521F-IRS

    SciTech Connect

    Takahashi, Satoko; Ohashi, Nagayoshi; Bourke, Tyler L.

    2013-09-01

    Studying the physical conditions of very low luminosity objects (VeLLOs; L{sub bol} < 0.1 L{sub Sun }) is important for understanding the earliest evolutionary stage of protostars and brown dwarfs. We report interferometric observations of the VeLLO L1521F-IRS, in {sup 12}CO (2-1) line emission and the 1.3 mm continuum emission, using the Submillimeter Array. With the {sup 12}CO (2-1) high-resolution observations, we have spatially resolved a compact but poorly collimated molecular outflow associated with L1521F-IRS for the first time. The blueshifted and redshifted lobes are aligned along the east and west side of L1521F-IRS with a lobe size of Almost-Equal-To 1000 AU. The estimated outflow mass, maximum outflow velocity, and outflow force are (9.0-80) Multiplication-Sign 10{sup -4} M{sub Sun }, 7.2 km s{sup -1}, and (7.4-66) Multiplication-Sign 10{sup -7} M{sub Sun} km s{sup -1} yr{sup -1}, respectively. The estimated outflow parameters such as size, mass, and momentum rate are similar to values derived for other VeLLOs, and are located at the lower end of values compared to previously studied outflows associated with low- to high-mass star-forming regions. Low-velocity less collimated (1.5 km s{sup -1}/1200 AU) and higher-velocity compact (4.0 km s{sup -1}/920 AU) outflow components are suggested by the data. These velocity structures are not consistent with those expected in the jet-driven or wind-driven outflow models, perhaps suggesting a remnant outflow from the first hydrostatic core as well as an undeveloped outflow from the protostar. Detection of an infrared source and compact millimeter continuum emission suggests the presence of the protostar, while its low bolometric luminosity (0.034-0.07 L{sub Sun }) and small outflow suggests that L1521F is in the earliest protostellar stage (<10{sup 4} yr) and contains a substellar mass object. The bolometric (or internal) luminosity of L1521F-IRS suggests that the current mass accretion rate is an order of

  10. VLA Ammonia Observations of IRAS 16253-2429: A Very Young and Low Mass Protostellar System

    NASA Technical Reports Server (NTRS)

    Wiseman, Jennifer J.

    2011-01-01

    IRAS l6253-2429. the source of the Wasp-Waist Nebula seen in Spitzer IRAC images, is an isolated very low luminosity ("VeLLO") Class 0 protostar in the nearby rho Ophiuchi cloud. We present VLA ammonia mapping observations of the dense gas envelope feeding the central core accreting system. We find a flattened envelope perpendicular to the outflow axis, and gas cavities that appear to cradle the outflow lobes as though carved out by the flow and associated (apparently precessing) jet. Based on the NH3 (1,1) and (2,2) emission distribution, we derive the mass, velocity fields and temperature distribution for the envelope. We discuss the combined evidence for this source as possibly one of the youngest and lowest mass sources in formation yet known.

  11. IRAS 16253-2429: The First Proto-brown Dwarf Binary Candidate Identified through the Dynamics of Jets

    NASA Astrophysics Data System (ADS)

    Hsieh, Tien-Hao; Lai, Shih-Ping; Belloche, Arnaud; Wyrowski, Friedrich

    2016-07-01

    The formation mechanism of brown dwarfs (BDs) is one of the long-standing problems in star formation because the typical Jeans mass in molecular clouds is too large to form these substellar objects. To answer this question, it is crucial to study a BD in the embedded phase. IRAS 16253-2429 is classified as a very low-luminosity object (VeLLO) with an internal luminosity of <0.1 L ⊙. VeLLOs are believed to be very low-mass protostars or even proto-BDs. We observed the jet/outflow driven by IRAS 16253-2429 in CO (2-1), (6-5), and (7-6) using the IRAM 30 m and Atacama Pathfinder Experiment telescopes and the Submillimeter Array (SMA) in order to study its dynamical features and physical properties. Our SMA map reveals two protostellar jets, indicating the existence of a proto-binary system as implied by the precessing jet detected in H2 emission. We detect a wiggling pattern in the position-velocity diagrams along the jet axes, which is likely due to the binary orbital motion. Based on this information, we derive the current mass of the binary as ˜0.032 M⊙. Given the low envelope mass, IRAS 16253-2429 will form a binary that probably consist of one or two BDs. Furthermore, we found that the outflow force as well as the mass accretion rate are very low based on the multi-transition CO observations, which suggests that the final masses of the binary components are at the stellar/substellar boundary. Since IRAS 16253 is located in an isolated environment, we suggest that BDs can form through fragmentation and collapse, similar to low-mass stars. Based on observations carried out with the IRAM 30 m Telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).

  12. EARLY STAR-FORMING PROCESSES IN DENSE MOLECULAR CLOUD L328; IDENTIFICATION OF L328-IRS AS A PROTO-BROWN DWARF

    SciTech Connect

    Lee, Chang Won; Kim, Mi-Ryang; Kim, Gwanjeong; Saito, Masao; Kurono, Yasutaka; Myers, Philip C.

    2013-11-01

    This paper presents the results of millimeter to sub-millimeter observations of CO, HCN, N{sub 2}H{sup +}, and HCO{sup +} lines in the dense molecular cloud L328, which harbors L328-IRS, a Very Low Luminosity Object (VeLLO). Our analysis of the line width finds that {sup 13}CO and N{sub 2}H{sup +} lines are broadened right over the smallest sub-core S2 where L328-IRS is located, while they are significantly narrower in other regions of L328. Thus, L328-IRS has a direct association with the sub-core. CO observations show a bipolar outflow from this VeLLO with an extent of ∼0.08 pc. The outflow momentum flux and efficiency are much less than those of low-mass protostars. The most likely mass accretion rate (∼3.6 × 10{sup –7} M{sub ☉} yr{sup –1}) inferred from the analysis of the CO outflow is an order of magnitude smaller than the canonical value for a protostar. If the main accretion lasts during the typical Class 0 period of a protostar, L328-IRS will accrete the mass of a brown dwarf, but not that of a star. Given that its envelope mass is small (∼0.09 M{sub ☉}) and 100% star formation rate is unlikely, we suggest that L328-IRS is likely a proto-brown dwarf. Inward motions are found in global scale in the L328 cloud and its sub-cores with a typical infall speed found in starless cores. L328 is found to be fairly well isolated from other nearby clouds and seems to be forming three sub-cores simultaneously through a gravitational fragmentation process. Altogether, these all leave L328-IRS as the best example supporting the idea that a brown dwarf forms like a normal star.

  13. IRAS 16253–2429: The First Proto-brown Dwarf Binary Candidate Identified through the Dynamics of Jets

    NASA Astrophysics Data System (ADS)

    Hsieh, Tien-Hao; Lai, Shih-Ping; Belloche, Arnaud; Wyrowski, Friedrich

    2016-07-01

    The formation mechanism of brown dwarfs (BDs) is one of the long-standing problems in star formation because the typical Jeans mass in molecular clouds is too large to form these substellar objects. To answer this question, it is crucial to study a BD in the embedded phase. IRAS 16253–2429 is classified as a very low-luminosity object (VeLLO) with an internal luminosity of <0.1 L ⊙. VeLLOs are believed to be very low-mass protostars or even proto-BDs. We observed the jet/outflow driven by IRAS 16253–2429 in CO (2–1), (6–5), and (7–6) using the IRAM 30 m and Atacama Pathfinder Experiment telescopes and the Submillimeter Array (SMA) in order to study its dynamical features and physical properties. Our SMA map reveals two protostellar jets, indicating the existence of a proto-binary system as implied by the precessing jet detected in H2 emission. We detect a wiggling pattern in the position–velocity diagrams along the jet axes, which is likely due to the binary orbital motion. Based on this information, we derive the current mass of the binary as ˜0.032 M⊙. Given the low envelope mass, IRAS 16253–2429 will form a binary that probably consist of one or two BDs. Furthermore, we found that the outflow force as well as the mass accretion rate are very low based on the multi-transition CO observations, which suggests that the final masses of the binary components are at the stellar/substellar boundary. Since IRAS 16253 is located in an isolated environment, we suggest that BDs can form through fragmentation and collapse, similar to low-mass stars. Based on observations carried out with the IRAM 30 m Telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).

  14. Clay mineral content of continental shelf and river sediments, southern California

    USGS Publications Warehouse

    Hein, James R.; Dowling, Jennifer S.

    2001-01-01

    This report contains data on the clay mineral content of 250 shelf surface-sediment samples from the California Continental Borderland (Tables 1, 2; Figures 1-7), 79 samples with depth in cores from Santa Monica Bay (Table 3; see Table 1 for surface sediment data for those same cores and for core locations), 24 suspended and 13 bottom sediment samples from rivers draining Southern California (Table 4), and six rock samples or composite rock samples from the Palos Verdes Headland (Table 4). This report is designed as the data repository and these data are discussed in a paper by Hein et al. (2001).

  15. Harnessing molecular excited states with Lanczos chains

    NASA Astrophysics Data System (ADS)

    Baroni, Stefano; Gebauer, Ralph; Bariş Malcioğlu, O.; Saad, Yousef; Umari, Paolo; Xian, Jiawei

    2010-02-01

    The recursion method of Haydock, Heine and Kelly is a powerful tool for calculating diagonal matrix elements of the resolvent of quantum-mechanical Hamiltonian operators by elegantly expressing them in terms of continued fractions. In this paper we extend the recursion method to off-diagonal matrix elements of general (possibly non-Hermitian) operators and apply it to the simulation of molecular optical absorption and photoemission spectra within time-dependent density-functional and many-body perturbation theories, respectively. This method is demonstrated with a couple of applications to the optical absorption and photoemission spectra of the caffeine molecule.

  16. Grand-canonical quantized liquid density-functional theory in a Car-Parrinello implementation.

    PubMed

    Walther, Christian F J; Patchkovskii, Serguei; Heine, Thomas

    2013-07-21

    Quantized Liquid Density-Functional Theory (QLDFT) [S. Patchkovskii and T. Heine, Phys. Rev. E 80, 031603 (2009)], a method developed to assess the adsorption of gas molecules in porous nanomaterials, is reformulated within the grand canonical ensemble. With the grand potential it is possible to compare directly external and internal thermodynamic quantities. In our new implementation, the grand potential is minimized utilizing the Car-Parrinello approach and gives, in particular for low temperature simulations, a significant computational advantage over the original canonical approaches. The method is validated against original QLDFT, and applied to model potentials and graphite slit pores.

  17. The effect of steam sterilisation at 134 degrees C on light intensity provided by fibrelight Macintosh laryngoscopes.

    PubMed

    Bucx, M J; Veldman, D J; Beenhakker, M M; Koster, R

    1999-09-01

    We studied the repeated effect of sterilisation on light intensity in laryngoscopes from Penlon, Riester, Heine (two different blades), Medicon and Upsher. Light intensity was measured by a light meter using two methods. Measurements were performed before the decontamination procedure was carried out and subsequently after each series of 25 procedures until a total of 200 cycles was reached. Using method 1 (and 2), the reduction in light intensity after 200 cycles was 100% (100%; no light emitted), 37% (13%), 75% (69%), 79% (60%), 37% (14%) and 63% (55%) for each blade, respectively.

  18. Genetic differentiation among natural populations of the Nile tilapia Oreochromis niloticus (Teleostei, cichlidae).

    PubMed

    Agnèse, J F; Adépo-Gourène, B; Abban, E K; Fermon, Y

    1997-07-01

    We analysed the genetic differentiation among 17 natural populations of the Nile tilapia Oreochromis niloticus (Linnaeus, 1758) using allozymes and restriction fragment length polymorphism (RFLP) of mitochondrial DNA (mtDNA). The populations studied, from the River Senegal to Lake Tana and from Lake Manzalla to Lake Baringo, represent all subspecies which have been previously described. Sixteen variable nuclear loci showed that these populations can be clustered in three groups: (1) West African populations (Senegal, Niger, Volta and Chad drainages), (2) Ethiopian Rift Valley populations (Lakes Awasa, Ziway, Koka and the Awash River) and (3) Nile drainage (Manzalla, Cairo, Lake Edward) and Kenyan Rift Valley populations (Lakes Turkana, Baringo and River Suguta). Nine different mtDNA haplotypes were found in the RFLP analysis of a 1 kb portion of the D-loop region. The network obtained showed that there are three geographically distinct groups; all West African populations and O. aureus are clustered, the two Ethiopian Rift Valley populations are distinct and between these two groups are the Kenyan and Ugandan Rift Valley populations. Nile populations show affinities both with West African populations and with specimens from Lakes Tana and Turkana. Taxonomic and biogeographical implications of these results are discussed. PMID:9253615

  19. Genetic differentiation among natural populations of the Nile tilapia Oreochromis niloticus (Teleostei, cichlidae).

    PubMed

    Agnèse, J F; Adépo-Gourène, B; Abban, E K; Fermon, Y

    1997-07-01

    We analysed the genetic differentiation among 17 natural populations of the Nile tilapia Oreochromis niloticus (Linnaeus, 1758) using allozymes and restriction fragment length polymorphism (RFLP) of mitochondrial DNA (mtDNA). The populations studied, from the River Senegal to Lake Tana and from Lake Manzalla to Lake Baringo, represent all subspecies which have been previously described. Sixteen variable nuclear loci showed that these populations can be clustered in three groups: (1) West African populations (Senegal, Niger, Volta and Chad drainages), (2) Ethiopian Rift Valley populations (Lakes Awasa, Ziway, Koka and the Awash River) and (3) Nile drainage (Manzalla, Cairo, Lake Edward) and Kenyan Rift Valley populations (Lakes Turkana, Baringo and River Suguta). Nine different mtDNA haplotypes were found in the RFLP analysis of a 1 kb portion of the D-loop region. The network obtained showed that there are three geographically distinct groups; all West African populations and O. aureus are clustered, the two Ethiopian Rift Valley populations are distinct and between these two groups are the Kenyan and Ugandan Rift Valley populations. Nile populations show affinities both with West African populations and with specimens from Lakes Tana and Turkana. Taxonomic and biogeographical implications of these results are discussed.

  20. Hydrology and Mosquito Population Dynamics around a Hydropower Reservoir in Africa

    NASA Astrophysics Data System (ADS)

    Endo, N.; Eltahir, E. A.

    2013-12-01

    Malaria is associated with dams because their reservoirs provide mosquitoes, the vector of malaria, with permanent breeding sites. The risk of contracting malaria is likely to be enhanced following the increasing trend of hydropower dam construction to satisfy the expanding energy needs in developing countries. A close examination of its adverse health impacts is critical in the design, construction, and operation phases. We will present results of extensive field studies in 2012 and 2013 around the Koka Reservoir, Ethiopia. The results uncover the importance of reservoir management especially after the rainy seasons. Furthermore, we show the capability of a newly modified hydrology, entomology and malaria transmission simulator, HYDREMATS (Bomblies et al, 2008), and its potential as a tool for evaluating environmental management strategies to control malaria. HYDREMATS was developed to represent how the hydrology in nearby villages is impacted by the reservoir system, and the role of different types of vector ecologies associated with different Anopheles mosquito species. The hydrology component of HYDREMATS simulates three different mosquito breeding habitats: rain-fed pools, groundwater pools, and shoreline water. The entomology component simulates the life cycles of An. funestus and An. arabiensis, the two main vectors around the reservoir. The model was calibrated over the 2012-2013 period. The impact of reservoir water level management on the mosquito population is explored based on numerical model simulations and field experiments.

  1. Towards an optimal integrated reservoir system management for the Awash River Basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Müller, Ruben; Gebretsadik, Henok Y.; Schütze, Niels

    2016-05-01

    Recently, the Kessem-Tendaho project is completed to bring about socioeconomic development and growth in the Awash River Basin, Ethiopia. To support reservoir Koka, two new reservoirs where built together with extensive infrastructure for new irrigation projects. For best possible socioeconomic benefits under conflicting management goals, like energy production at three hydropower stations and basin wide water supply at various sites, an integrated reservoir system management is required. To satisfy the multi-purpose nature of the reservoir system, multi-objective parameterization-simulation-optimization model is applied. Different Pareto-optimal trade-off solutions between water supply and hydro-power generation are provided for two scenarios (i) recent conditions and (ii) future planned increases for Tendaho and Upper Awash Irrigation projects. Reservoir performance is further assessed under (i) rule curves with a high degree of freedom - this allows for best performance, but may result in rules curves to variable for real word operation and (ii) smooth rule curves, obtained by artificial neuronal networks. The results show no performance penalty for smooth rule curves under future conditions but a notable penalty under recent conditions.

  2. Skin surface microscopy of port-wine stains: preliminary data on classification and assessment of laser therapy results

    NASA Astrophysics Data System (ADS)

    Rotteleur, Guy; Huan, P.; Mordon, Serge R.; Beacco, Claire; Brunetaud, Jean Marc

    1994-12-01

    In order to characterize port-wine stains (PWS) before and after laser-therapy, a study using epiluminescence microscopy is achieved. The technique consists in placing a thin layer of mineral oil on the skin surface and inspecting the PWS with a Delta 10 dermatoscope (HEINE). A contact microphotography is then performed in a similar manner by means of a Dermaphot optical module (HEINE). One hundred and sixteen patients have been explored prior to laser treatment. Twenty eight have been explored at the same place three months after the first treatment and four three months after two treatments. The preliminary results are compared with Jones, Shakespeare, and Carruth's studies on transcutaneous microscopy. It is possible to classify PWS according to their epiluminescence microscopic aspect. The classification proposed by the English authors is not ideal and some adaptations are desirable, regarding particularly the background condition. Some correlation can be established between the macroscopic and microscopic aspect of PWS. It is far too early to correlate epiluminescence aspect before treatment and long term results of laser-therapy.

  3. Magnetic field structure around cores with very low luminosity objects

    NASA Astrophysics Data System (ADS)

    Soam, A.; Maheswar, G.; Lee, Chang Won; Dib, Sami; Bhatt, H. C.; Tamura, Motohide; Kim, Gwanjeong

    2015-01-01

    Aims: We carried out optical polarimetry of five dense cores, (IRAM 04191, L1521F, L328, L673-7, and L1014) which are found to harbour very low luminosity objects (VeLLOs; Lint ≲ 0.1 L⊙). This study was conducted mainly to understand the role played by the magnetic field in the formation of very low and substellar mass range objects. Methods: Light from the stars, while passing through the dust grains that are aligned with their short axis parallel to an external magnetic field, becomes linearly polarised. The polarisation position angles measured for the stars can provide the plane-of-the sky magnetic field orientation. Because the light in the optical wavelength range is most efficiently polarised by the dust grains typically found at the outer layers of the molecular clouds, optical polarimetry mostly traces the magnetic field orientation of the core envelope. Results: The polarisation observations of stars projected on IRAM 04191, L328, L673-7, and L1014 were obtained in the R-band and those of L1521F were obtained in the V-band. The angular offsets between the envelope magnetic field direction (inferred from optical polarisation measurements) and the outflow position angles from the VeLLOs in IRAM 04191, L1521F, L328, L673-7, and L1014 are found to be 84°, 53°, 24°, 08°, and 15°, respectively. The mean value of the offsets for all the five clouds is ~ 37°. If we exclude IRAM 04191, the mean value reduces to become ~ 25°. In IRAM 04191, the offset between the projected envelope and the inner magnetic field (inferred from the submillimetre data obtained using SCUBA-POL) is found to be ~ 68°. The inner magnetic field, however, is found to be nearly aligned with the projected position angles of the minor axis, the rotation axis of the cloud, and the outflow from the IRAM 04191-IRS. We discuss a possible explanation for the nearly perpendicular orientation between the envelope and core scale magnetic fields in IRAM 04191. The angular offset between the

  4. THE SPITZER c2d SURVEY OF NEARBY DENSE CORES. IX. DISCOVERY OF A VERY LOW LUMINOSITY OBJECT DRIVING A MOLECULAR OUTFLOW IN THE DENSE CORE L673-7

    SciTech Connect

    Dunham, Michael M.; Evans, Neal J.; Bourke, Tyler L.; Myers, Philip C.; Huard, Tracy L.; Stutz, Amelia M.

    2010-10-01

    We present new infrared, submillimeter, and millimeter observations of the dense core L673-7 and report the discovery of a low-luminosity, embedded Class 0 protostar driving a molecular outflow. L673-7 is seen in absorption against the mid-infrared background in 5.8, 8, and 24 {mu}m Spitzer images, allowing for a derivation of the column density profile and total enclosed mass of L673-7, independent of dust temperature assumptions. Estimates of the core mass from these absorption profiles range from 0.2to4.5 M{sub sun}. Millimeter continuum emission indicates a mass of {approx}2 M{sub sun}, both from a direct calculation assuming isothermal dust and from dust radiative transfer models constrained by the millimeter observations. We use dust radiative transfer models to constrain the internal luminosity of L673-7, defined to be the luminosity of the central source and excluding the luminosity from external heating, to be L{sub int} = 0.01-0.045 L{sub sun}, with L{sub int} {approx} 0.04 L{sub sun} the most likely value. L673-7 is thus classified as a very low luminosity object (VeLLO), and is among the lowest luminosity VeLLOs yet studied. We calculate the kinematic and dynamic properties of the molecular outflow in the standard manner. From the outflow properties and standard assumptions regarding the driving of outflows, we calculate the time-averaged protostellar mass accretion rate, total protostellar mass accreted, and expected accretion luminosity to be {>=}1.2 x 10{sup -6} (sin i)/(co{sup 2} i) M{sub sun} yr{sup -1}, M{sub acc{>=}}0.07 1/cos i M{sub sun}, and L{sub acc} {>=} 0.36 L{sub sun}, respectively. The discrepancy between this calculated L{sub acc} and the L{sub int} derived from dust radiative transfer models indicates that the current accretion rate is much lower than the average rate over the lifetime of the outflow. Although the protostar embedded within L673-7 is consistent with currently being substellar, it is unlikely to remain as

  5. The Spitzer c2d Survey of Nearby Dense Cores. IX. Discovery of a Very Low Luminosity Object Driving a Molecular Outflow in the Dense Core L673-7

    NASA Astrophysics Data System (ADS)

    Dunham, Michael M.; Evans, Neal J.; Bourke, Tyler L.; Myers, Philip C.; Huard, Tracy L.; Stutz, Amelia M.

    2010-10-01

    We present new infrared, submillimeter, and millimeter observations of the dense core L673-7 and report the discovery of a low-luminosity, embedded Class 0 protostar driving a molecular outflow. L673-7 is seen in absorption against the mid-infrared background in 5.8, 8, and 24 μm Spitzer images, allowing for a derivation of the column density profile and total enclosed mass of L673-7, independent of dust temperature assumptions. Estimates of the core mass from these absorption profiles range from 0.2to4.5 M sun. Millimeter continuum emission indicates a mass of ~2 M sun, both from a direct calculation assuming isothermal dust and from dust radiative transfer models constrained by the millimeter observations. We use dust radiative transfer models to constrain the internal luminosity of L673-7, defined to be the luminosity of the central source and excluding the luminosity from external heating, to be L int = 0.01-0.045 L sun, with L int ~ 0.04 L sun the most likely value. L673-7 is thus classified as a very low luminosity object (VeLLO), and is among the lowest luminosity VeLLOs yet studied. We calculate the kinematic and dynamic properties of the molecular outflow in the standard manner. From the outflow properties and standard assumptions regarding the driving of outflows, we calculate the time-averaged protostellar mass accretion rate, total protostellar mass accreted, and expected accretion luminosity to be < \\dot{M}_acc > ≥ 1.2 × 10^{-6} sin i {cos}^2 i Msun yr-1, M_acc ≥ 0.07 {1}/{cos } M sun, and Lacc >= 0.36 L sun, respectively. The discrepancy between this calculated L acc and the L int derived from dust radiative transfer models indicates that the current accretion rate is much lower than the average rate over the lifetime of the outflow. Although the protostar embedded within L673-7 is consistent with currently being substellar, it is unlikely to remain as such given the substantial mass reservoir remaining in the core.

  6. Functional-integral study of spin fluctuations in small Fe clusters

    NASA Astrophysics Data System (ADS)

    Garibay-Alonso, R.; Dorantes-Dávila, J.; Pastor, G. M.

    2009-04-01

    Finite temperature magnetic properties of small FeN clusters (N ≤6) are determined in the framework of a spin-fluctuation itinerant-electron theory based on a functional integral formulation of the canonical partition function and derived statistical averages. The free energy associated to each configuration of the exchange fields throughout the cluster are calculated by using Haydock-Heine-Kellys recursion method. The statistical averages of physical interest are obtained by performing parallel-tempering Monte Carlo simulations. Representative results are discussed for the average magnetization per atom as a function of temperature. The interplay between local environment and magnetization curves is analyzed by considering the low-temperature limit of the local spin-fluctuations energies ΔFl(ξ) at different atoms l. The electronic calculations are contrasted with the predictions of simple of phenomenological Heisenberg-like models.

  7. Embodied learning across the life span.

    PubMed

    Kontra, Carly; Goldin-Meadow, Susan; Beilock, Sian L

    2012-10-01

    Developmental psychologists have long recognized the extraordinary influence of action on learning (Held & Hein, 1963; Piaget, 1952). Action experiences begin to shape our perception of the world during infancy (e.g., as infants gain an understanding of others' goal-directed actions; Woodward, 2009) and these effects persist into adulthood (e.g., as adults learn about complex concepts in the physical sciences; Kontra, Lyons, Fischer, & Beilock, 2012). Theories of embodied cognition provide a structure within which we can investigate the mechanisms underlying action's impact on thinking and reasoning. We argue that theories of embodiment can shed light on the role of action experience in early learning contexts, and further that these theories hold promise for using action to scaffold learning in more formal educational settings later in development. PMID:22961943

  8. [The human being from the point of view of animals or, "Who knows whether the breath of men goes upwards?" (Ecclesiastes 3:21)].

    PubMed

    Arendt, D

    1999-05-01

    The question of whether animals have souls has been asked since as early as the Old Testament. Where this is believed to be true, fiction has provided interesting models in literature: The human being as seen by animals has been a popular subject since Apuleius' 'Asinus aureus' and how man appears from the perspective of a donkey or a beetle, that is to say the perspective from below, becomes controversial. Examples may be found in all languages and centuries in Jonathan Swift, Miguel Cervantes, E. T. A. Hoffmann, Ludwig Tieck, Heinrich Heine, Viktor von Scheffel, Franz Kafka and others. Résumé at the end: How does man answer this question or his own self-questioning?

  9. Liberals think more analytically (more "WEIRD") than conservatives.

    PubMed

    Talhelm, Thomas; Haidt, Jonathan; Oishi, Shigehiro; Zhang, Xuemin; Miao, Felicity F; Chen, Shimin

    2015-02-01

    Henrich, Heine, and Norenzayan summarized cultural differences in psychology and argued that people from one particular culture are outliers: people from societies that are Western, educated, industrialized, rich, and democratic (WEIRD). This study shows that liberals think WEIRDer than conservatives. In five studies with more than 5,000 participants, we found that liberals think more analytically (an element of WEIRD thought) than moderates and conservatives. Study 3 replicates this finding in the very different political culture of China, although it held only for people in more modernized urban centers. These results suggest that liberals and conservatives in the same country think as if they were from different cultures. Studies 4 to 5 show that briefly training people to think analytically causes them to form more liberal opinions, whereas training them to think holistically causes shifts to more conservative opinions. PMID:25540328

  10. Asymptotics of multiple orthogonal polynomials associated with the modified Bessel functions of the first kind

    NASA Astrophysics Data System (ADS)

    Coussement, Els; van Assche, Walter

    2003-04-01

    We consider polynomials which are orthogonal with respect to weight functions which are defined in terms of the modified Bessel functions I[nu] and I[nu]+1. These multiple orthogonal polynomials Pn[nu],c of type II were introduced earlier by the authors. The aim of this paper is to study some asymptotics of these polynomials, such as Plancherel-Rotach asymptotics. As a consequence of these results, we obtain the accumulation set of the scaled zeros of Pn[nu],c. We also give a Mehler-Heine-type formula for these polynomials which is valid on compact subsets of . Hence, we obtain a more precise result about the asymptotic behavior of the small zeros of Pn[nu],c.

  11. Stochastic Approach to Phonon-Assisted Optical Absorption

    NASA Astrophysics Data System (ADS)

    Zacharias, Marios; Patrick, Christopher E.; Giustino, Feliciano

    2015-10-01

    We develop a first-principles theory of phonon-assisted optical absorption in semiconductors and insulators which incorporates the temperature dependence of the electronic structure. We show that the Hall-Bardeen-Blatt theory of indirect optical absorption and the Allen-Heine theory of temperature-dependent band structures can be derived from the present formalism by retaining only one-phonon processes. We demonstrate this method by calculating the optical absorption coefficient of silicon using an importance sampling Monte Carlo scheme, and we obtain temperature-dependent line shapes and band gaps in good agreement with experiment. The present approach opens the way to predictive calculations of the optical properties of solids at finite temperature.

  12. Ground state phase transition in the Nilsson mean-field plus standard pairing model

    NASA Astrophysics Data System (ADS)

    Guan, Xin; Xu, Haocheng; Zhang, Yu; Pan, Feng; Draayer, Jerry P.

    2016-08-01

    The ground state phase transition in Nd, Sm, and Gd isotopes is investigated by using the Nilsson mean-field plus standard pairing model based on the exact solutions obtained from the extended Heine-Stieltjes correspondence. The results of the model calculations successfully reproduce the critical phenomena observed experimentally in the odd-even mass differences, odd-even differences of two-neutron separation energy, and the α -decay and double β--decay energies of these isotopes. Since the odd-even effects are the most important signatures of pairing interactions in nuclei, the model calculations yield microscopic insight into the nature of the ground state phase transition manifested by the standard pairing interaction.

  13. Asymptotic distribution of motifs in a stochastic context-free grammar model of RNA folding.

    PubMed

    Poznanović, Svetlana; Heitsch, Christine E

    2014-12-01

    We analyze the distribution of RNA secondary structures given by the Knudsen-Hein stochastic context-free grammar used in the prediction program Pfold. Our main theorem gives relations between the expected number of these motifs--independent of the grammar probabilities. These relations are a consequence of proving that the distribution of base pairs, of helices, and of different types of loops is asymptotically Gaussian in this model of RNA folding. Proof techniques use singularity analysis of probability generating functions. We also demonstrate that these asymptotic results capture well the expected number of RNA base pairs in native ribosomal structures, and certain other aspects of their predicted secondary structures. In particular, we find that the predicted structures largely satisfy the expected relations, although the native structures do not.

  14. Embodied Learning across the Lifespan

    PubMed Central

    Kontra, Carly; Goldin-Meadow, Susan; Beilock, Sian L.

    2013-01-01

    Developmental psychologists have long recognized the extraordinary influence of action on learning (Piaget 1952; Held & Hein, 1963). Action experiences begin to shape our perception of the world during infancy (e.g., as infants gain an understanding of others’ goal-directed actions; Woodward, 2009) and these effects persist into adulthood (e.g., as adults learn about complex concepts in the physical sciences; Kontra et al., 2012). Theories of embodied cognition provide a structure within which we can investigate the mechanisms underlying action’s impact on thinking and reasoning. We argue that theories of embodiment can shed light on the role of action experience in early learning contexts, and further that these theories hold promise for using action to scaffold learning in more formal educational settings later in development. PMID:22961943

  15. Dynamical and anharmonic effects on the electron-phonon coupling and the zero-point renormalization of the electronic structure

    NASA Astrophysics Data System (ADS)

    Antonius, G.; Poncé, S.; Lantagne-Hurtubise, E.; Auclair, G.; Gonze, X.; Côté, M.

    2015-08-01

    The renormalization of the band structure at zero temperature due to electron-phonon coupling is explored in diamond, BN, LiF, and MgO crystals. We implement a dynamical scheme to compute the frequency-dependent self-energy and the resulting quasiparticle electronic structure. Our calculations reveal the presence of a satellite band below the Fermi level of LiF and MgO. We show that the renormalization factor (Z ), which is neglected in the adiabatic approximation, can reduce the zero-point renormalization (ZPR) by as much as 40 % . Anharmonic effects in the renormalized eigenvalues at finite atomic displacements are explored with the frozen-phonon method. We use a nonperturbative expression for the ZPR, going beyond the Allen-Heine-Cardona theory. Our results indicate that high-order electron-phonon coupling terms contribute significantly to the zero-point renormalization for certain materials.

  16. Asymptotic distribution of motifs in a stochastic context-free grammar model of RNA folding

    PubMed Central

    Poznanović, Svetlana; Heitsch, Christine E.

    2014-01-01

    We analyze the distribution of RNA secondary structures given by the Knudsen-Hein stochastic context-free grammar used in the prediction program Pfold. Our main theorem gives relations between the expected number of these motifs — independent of the grammar probabilities. These relations are a consequence of proving that the distibution of base pairs, of helices, and of different types of loops is asympotically Gaussian in this model of RNA folding. Proof techniques use singularity analysis of probability generating functions. We also demonstrate that these asymptotic results capture well the expected number of RNA base pairs in native ribosomal structures, and certain other aspects of their predicted secondary structures. In particular, we find that the predicted structures largely satisfy the expected relations, although the native structures do not. PMID:24384698

  17. [Limb prosthesis of the 19th and 20th century].

    PubMed

    Knoche, W

    2009-02-01

    Wouldn't the thought of a separate stump-cushioning, as mentioned by Heine, Eichler and others, make sense even today, regarding difficult and badly blood-supplied amputation-stumps? Shouldn't the thought of Hermann and Habermann, to do a knee-saving interference, be updated, especially for the weak and helpless patients? It is safe to say that one has to challenge the question, which objective methods of inspection are under consideration, to check and control the correct fit and construction for every individual patient. It is a credit to the executive of the orthopaedic-supply-center Hamburg-Altona, zur Verth, who challenged that question almost one hundred years ago. Not only zur Verth rated the value of amputation-levels in his amputation-scheme, but Arnsberger invented 1927 a device to objectify the composition of a prosthesis. PMID:19259935

  18. Fundamentals of charged devices: Energy changes in a capacitor medium

    NASA Astrophysics Data System (ADS)

    Young, J. S.; Baudry, L.

    2013-03-01

    Capacitors and derivative devices continue to be as relevant as ever, both at the frontiers of scientific and technological research and in the development of commercial products. Central to such pursuits is the essential requirement that all aspects of the work done in charging or discharging capacitors are clearly understood. Surprisingly, there is a very significant disagreement among standard texts and journal publications regarding this topic. The present work elaborates a thorough analysis of energy changes in a capacitor medium in terms of thermodynamic work and its extension to the more general, electrostatic energy change. Our conclusions agree, for example, with those of Volker Heine, but not with texts by Pippard or Callen. We also note that electric and magnetic analogues are not equivalent.

  19. [Sarcocystis species in Vietnamese workers].

    PubMed

    Straka, S; Skraciková, J; Konvit, I; Szilágyiová, M; Michal, L

    1991-11-01

    The authors give an account of the finding of sporocysts of the Sarcocystis spp. in 14 Vietnamese apprentices from a total of 1228 examined (1.1%) who came to Central Slovakia in the course of 18 months in 1987-1989. The mean period of sporocyst excretion was 49.2 days. The positive subjects did not report gastrointestinal complaints despite mixed intestinal parasitoses. The subjects were from the north eastern part of the country from Hanoi-Haiphong areas and they did not report that they ate raw meat. The authors evaluate the diagnostic value of different coprological methods whereby they found the highest detection rate in faecal smears examined by Heine's method. The authors draw attention to the fact that the diagnosis of sporocysts of human coccidiae calls for personal diagnostic experience as they may escape attention or be mistaken for cysts of other intestinal protozoa.

  20. Development of an interdisciplinary model cluster for tidal water environments

    NASA Astrophysics Data System (ADS)

    Dietrich, Stephan; Winterscheid, Axel; Jens, Wyrwa; Hartmut, Hein; Birte, Hein; Stefan, Vollmer; Andreas, Schöl

    2013-04-01

    Global climate change has a high potential to influence both the persistence and the transport pathways of water masses and its constituents in tidal waters and estuaries. These processes are linked through dispersion processes, thus directly influencing the sediment and solid suspend matter budgets, and thus the river morphology. Furthermore, the hydrologic regime has an impact on the transport of nutrients, phytoplankton, suspended matter, and temperature that determine the oxygen content within water masses, which is a major parameter describing the water quality. This project aims at the implementation of a so-called (numerical) model cluster in tidal waters, which includes the model compartments hydrodynamics, morphology and ecology. For the implementation of this cluster it is required to continue with the integration of different models that work in a wide range of spatial and temporal scales. The model cluster is thus suggested to lead to a more precise knowledge of the feedback processes between the single interdisciplinary model compartments. In addition to field measurements this model cluster will provide a complementary scientific basis required to address a spectrum of research questions concerning the integral management of estuaries within the Federal Institute of Hydrology (BfG, Germany). This will in particular include aspects like sediment and water quality management as well as adaptation strategies to climate change. The core of the model cluster will consist of the 3D-hydrodynamic model Delft3D (Roelvink and van Banning, 1994), long-term hydrodynamics in the estuaries are simulated with the Hamburg Shelf Ocean Model HAMSOM (Backhaus, 1983; Hein et al., 2012). The simulation results will be compared with the unstructured grid based SELFE model (Zhang and Bapista, 2008). The additional coupling of the BfG-developed 1D-water quality model QSim (Kirchesch and Schöl, 1999; Hein et al., 2011) with the morphological/hydrodynamic models is an

  1. Compact set of invariants characterizing graph states of up to eight qubits

    NASA Astrophysics Data System (ADS)

    Cabello, Adán; López-Tarrida, Antonio J.; Moreno, Pilar; Portillo, José R.

    2009-07-01

    The set of entanglement measures proposed by Hein, Eisert, and Briegel for n -qubit graph states [Phys. Rev. A 69, 062311 (2004)] fails to distinguish between inequivalent classes under local Clifford operations if n≥7 . On the other hand, the set of invariants proposed by van den Nest, Dehaene, and De Moor (VDD) [Phys. Rev. A 72, 014307 (2005)] distinguishes between inequivalent classes, but contains too many invariants (more than 2×1036 for n=7 ) to be practical. Here we solve the problem of deciding which entanglement class a graph state of n≤8 qubits belongs to by calculating some of the state’s intrinsic properties. We show that four invariants related to those proposed by VDD are enough for distinguishing between all inequivalent classes with n≤8 qubits.

  2. [Sarcocystis species in Vietnamese workers].

    PubMed

    Straka, S; Skraciková, J; Konvit, I; Szilágyiová, M; Michal, L

    1991-11-01

    The authors give an account of the finding of sporocysts of the Sarcocystis spp. in 14 Vietnamese apprentices from a total of 1228 examined (1.1%) who came to Central Slovakia in the course of 18 months in 1987-1989. The mean period of sporocyst excretion was 49.2 days. The positive subjects did not report gastrointestinal complaints despite mixed intestinal parasitoses. The subjects were from the north eastern part of the country from Hanoi-Haiphong areas and they did not report that they ate raw meat. The authors evaluate the diagnostic value of different coprological methods whereby they found the highest detection rate in faecal smears examined by Heine's method. The authors draw attention to the fact that the diagnosis of sporocysts of human coccidiae calls for personal diagnostic experience as they may escape attention or be mistaken for cysts of other intestinal protozoa. PMID:1838711

  3. Are herbal mouthwash efficacious over chlorhexidine on the dental plaque?

    PubMed Central

    Gupta, Devanand; Nayan, Swapna; Tippanawar, Harshad K.; Patil, Gaurav I.; Jain, Ankita; Momin, Rizwan K.; Gupta, Rajendra Kumar

    2015-01-01

    Aim: To compare the effect of herbal extract mouthwash and chlorhexidine mouthwash on the dental plaque level. Materials and Methods: The subjects (60 healthy medical students aged ranges between 20 and 25 years) were randomly divided into two groups, that is, the herbal group and the chlorhexidine gluconate mouthwash group. The data were collected at the baseline and 3 days. The plaque was disclosed using erythrosine disclosing agent and their scores were recorded using the Quigley and Hein plaque index modified by Turesky-Gilmore-Glickman. Statistical analysis was carried out later to compare the effect of all the two groups. Results: Our result showed that the chlorhexidine group shows a greater decrease in plaque score followed by herbal extract, but the result was statistically insignificant. Conclusion: The results indicate that herbal mouthwash may prove to be an effective agent owing to its ability to reduce plaque level, especially in low socioeconomic strata. PMID:26130940

  4. SOPROCARE - 450 nm wavelength detection tool for microbial plaque and gingival inflammation: a clinical study

    NASA Astrophysics Data System (ADS)

    Rechmann, P.; Liou, Shasan W.; Rechmann, Beate M.; Featherstone, John D.

    2014-02-01

    Gingivitis due to microbial plaque and calculus can lead over time if left untreated to advanced periodontal disease with non-physiological pocket formation. Removal of microbial plaque in the gingivitis stage typically achieves gingival health. The SOPROCARE camera system emits blue light at 450 nm wavelength using three blue diodes. The 450 nm wavelength is located in the non-ionizing, visible spectral wavelength region and thus is not dangerous. It is assumed that using the SOPROCARE camera in perio-mode inflamed gingiva can easily be observed and inflammation can be scored due to fluorescence from porphyrins in blood. The assumption is also that illumination of microbial plaque with blue light induces fluorescence due to the bacteria and porphyrin content of the plaque and thus can help to make microbial plaque and calculus visible. Aim of the study with 55 subjects was to evaluate the ability of the SOPROCARE fluorescence camera system to detect, visualize and allow scoring of microbial plaque in comparison to the Turesky modification of the Quigley and Hein plaque index. A second goal was to detect and score gingival inflammation and correlated the findings to the Silness and Löe gingival inflammation index. The study showed that scoring of microbial plaque as well as gingival inflammation levels similar to the established Turesky modified Quigley Hein index and the Silness and Löe gingival inflammation index can easily be done using the SOPROCARE fluorescence system in periomode. Linear regression fits between the different clinical indices and SOPROCARE scores in fluorescence perio-mode revealed the system's capacity for effective discrimination between scores.

  5. Extremely Low Mass: The Circumstellar Envelope of a Potential Proto-Brown Dwarf

    NASA Technical Reports Server (NTRS)

    Wiseman, Jennifer

    2011-01-01

    What is the environment for planet formation around extremely low mass stars? Is the environment around brown dwarfs and extremely low mass stars conducive and sufficiently massive for planet production? The determining conditions may be set very early in the process of the host object's formation. IRAS 16253-2429, the source of the Wasp-Waist Nebula seen in Spitzer IRAC images, is an isolated, very low luminosity ("VeLLO") Class 0 protostar in the nearby rho Ophiuchi cloud. We present VLA ammonia mapping observations of the dense gas envelope feeding the central core accreting system. We find a flattened envelope perpendicular to the outflow axis, and gas cavities that appear to cradle the outflow lobes as though carved out by the flow and associated (apparently precessing) jet, indicating environmental disruption. Based on the NH3 (1,1) and (2,2) emission distribution, we derive the mass, velocity fields and temperature distribution for the envelope. We discuss the combined evidence for this source to be one of the youngest and lowest mass sources in formation yet known, and discuss the ramifications for planet formation potential in this extremely low mass system.

  6. A Systematic Search for Molecule Outflows Toward Candiate Low-Luminosity Protostars

    NASA Astrophysics Data System (ADS)

    Schwarz, Kamber R.; Shirley, Y. L.; Dunham, M. M.

    2012-05-01

    We present a systematic search for molecular outflows toward a sample of 39 candidate low-luminosity protostars in 12CO and 13CO 2-1 using the 10 meter Heinrich Hertz Telescope at 30’’ resolution. The sample of sources is drawn from the catalog of Dunham et al. of candidate low-luminosity protostars and VeLLOs in observed by the Spitzer Space Telescope in nearby molecular clouds. We present maps of the previously known outflow L673-7 and L1251-A IRS4 with more sensitivity than previously available and analyze their properties. Potential outflow candidates were identified in the dense cores B59, L1148, L1228, and L1165 based on the presence of line wings. Of these, only one source, in B59, shows a distinct blue outflow lobe in the mapped emission. The remaining sources do not show clear evidence for outflows at our resolution. Partial Funding for KRS was provided by the Arizona Space Grant Consortium. YSL is partially supported by NSF grant AST-1008577.

  7. Evidence for Neoarchaean extensional faults in the Vredefort Dome, South Africa.

    NASA Astrophysics Data System (ADS)

    mashabela, sello

    2013-04-01

    -2643 Ma) of the Ventersdorp Supergroup. The association potentially means that the Vredefort collar hosts rotated Ventersdorp-age extensional faults or a rift system of faults that predate impact-induced structures. 1. Manzi, M.S.D., Durrheim, R.J., Hein, K.A.A., King N., 2012. 3D edge detection seismic attributes used to map potential conduits for water and methane in deep gold mines in the Witwatersrand basin, South Africa. Geophysics 77 (5), 1-16. 2. Manzi, M., Gibson, M. A.S., Hein, K.A.A., King, N., Durrheim, R.J., 2012. Application of 3D Seismic techniques in evaluation of ore resources in the West Wits Line goldfield and portions of the West Rand Goldfield, South Africa. Geophysics 77, 1-9. 3. Manzi, M., Hein, K.A.A., King, N, Durrheim, R.J., submitted. NeoArchaean tectonic history of the Witwatersrand Basin and Ventersdorp Supergroup: New Constraints from high-resolution 3D seismic reflection data. Tectonophysics

  8. Computer-aided therapy in aphasia therapy: evaluation of assignment criteria.

    PubMed

    Schröder, Christina; Schupp, Wilfried; Seewald, Barbara; Haase, Ingo

    2007-12-01

    Recent studies in neurorehabilitation research show that success in aphasia therapy is linked to a high treatment frequency. Computer-aided therapy offers a solution to the dilemma of increasing therapy frequency while maintaining or reducing the load on therapists' resources. Until now it has, however, been unclear which patients can reasonably be treated with computer-aided therapy. The study investigates therapists' indication choices of a new computer-aided training programme designed to supplement conventional speech therapy for aphasics (EvoCare therapy, Dr Hein GmbH, Nuremberg, Germany). The goal was to ascertain which patients were suitable for the training and which (individual) allocation criteria played a role in the therapists' decision for or against the new therapy concept. The study is an explorative prospective application study in inpatient rehabilitation care. To determine the allocation criteria, comprehensive medical, psychosocial and neurolinguistic questionnaires were used. The speech therapists were surveyed separately. Forty-nine of the 75 patients were treated with EvoCare therapy; the others received purely conventional speech therapy. Patients chosen for computer-aided therapy suffered more frequently from problems with everyday mobility and serious neurolinguistic disorders. Type and extent of brain damage, degree of reliance on caregivers, sensomotoric and cognitive deficits and depression were irrelevant to the allocation. PMID:17975448

  9. Neutron scattering studies of short-range order, atomic displacements, and effective pair interactions in a null-matrix Ni0.5262Pt0.48 crystal

    NASA Astrophysics Data System (ADS)

    Rodriguez, J. A.; Moss, S. C.; Robertson, J. L.; Copley, J. R. D.; Neumann, D. A.; Major, J.

    2006-09-01

    The best known exception to the Heine-Sampson and Bieber-Gauthier arguments for ordering effects in transition metal alloys (similar to the Hume-Rothery rules) is a NiPt alloy, whose phase diagram is similar to that of the CuAu system. Using neutron scattering we have investigated the local atomic order in a null-matrix Ni0.5262Pt0.48 single crystal. In a null-matrix alloy, the isotopic composition is adjusted so that the average neutron scattering length vanishes ( Ni62 has a negative scattering length nearly equal in magnitude to that of Pt). Consequently, all contributions to the total scattering depending on the average lattice are suppressed. The only remaining components of the elastic scattering are the short-range order (SRO) and size effect terms. These data permit the extraction of the SRO parameters (concentration-concentration correlations) as well as the displacement parameters (concentration-displacement correlations). Using the Krivoglaz-Clapp-Moss theory, we obtain the effective pair interactions (EPIs) between near neighbors in the alloy. The results can be used by theorists to model the alloy in the context of the electronic theory of alloy phase stability, including a preliminary evaluation of the local species-dependent displacements. Our maps of V(q) , the Fourier transform of the EPIs, show very similar shapes in the experimental and reconstructed data. This is of importance when comparing to electronic structure calculations.

  10. Neutron scattering studies of short-range order and atomic displacements in a null-matrix nickel-62 platinum crystal

    NASA Astrophysics Data System (ADS)

    Rodriguez, Jose Abelardo

    The best known exception to the Heine-Samson and Bieber-Gautier arguments for ordering effects in transition metal alloys (similar to the Hume-Rothery rules) is a NiPt alloy, where the phase diagram is similar to the CuAu system. Using the Disk Chopper Spectrometer (DCS) at NIST, we have investigated a Null-Matrix Crystal 62 Ni0.52Pt0.48, (62 Ni has a negative scattering length, nearly equal in magnitude to Pt). Its composition has therefore been chosen whereby all effects depending on the average lattice scattering vanish. The only remaining contributions to the diffuse scattering are the Short Range Order (SRO) and Size Effect (SE) terms, to be discussed within. Such data permit the extraction of the SRO parameters (concentration-concentration correlations) as well as the displacement parameters (concentration-displacement correlations). Using the Krivoglaz-Clapp-Moss theory, we obtained the Effective Pair Interactions (EPI) between the several neighbors in the alloy. The results can be used to model the alloy in the context of electronic theory of alloy phase stability, including an evaluation of the potentially important aspect of charge transfer and ionicity.

  11. Reflections on Sigmund Freud's relationship to the German language and to some German-speaking authors of the enlightenment.

    PubMed

    Grubrich-Simitis, I

    1986-01-01

    The discussion of the papers of Anzieu and Ticho on 'The Influence of the German-Language Culture on Freud's Thought' concentrates on two aspects of the theme. Firstly, the question is considered in how far specific individual words (e.g. 'Trieb'), as well as specific basic grammatical structures of the German language (e.g. certain forms of the passive voice; the flexibility in changing between the parts of speech) made the verbal grasp of unconscious and preconscious phenomena easier for Freud, i.e. facilitated the conceptualization of psychoanalysis. The second aspect deals with the young reader Freud's predilection for those German-speaking authors--from Lessing to Heine--writing in the Enlightenment tradition. identification with these critical, rebellious thinkers contributed to the consolidation of Freud's personality. He himself stressed again and again the overriding importance of his steadfastness of character and his disbelief in authority for his life's achievement: the discovery of the unconscious in spite of inner and outer resistance.

  12. Effectiveness of supervised toothbrushing and oral health education in improving oral hygiene status and practices of urban and rural school children: A comparative study

    PubMed Central

    Damle, Satyawan G.; Patil, Anil; Jain, Saru; Damle, Dhanashree; Chopal, Nilika

    2014-01-01

    Objective: To evaluate and compare the oral health status and the impact of supervised toothbrushing and oral health education among school children of urban and rural areas of Maharashtra, India. Materials and Methods: A total of 200 school children in the age group 12-15 years were selected by stratified random sampling technique from two schools and were further divided into two groups: Group A (urban school) and Group B (rural school). Both the groups were again subdivided into control group and study group. Supervised toothbrushing was recommended for both the groups. The toothbrushing teaching program included session on oral health education, individual toothbrushing instructions, and supervised toothbrushing. Dental caries increment, plaque scores, and gingival status were assessed as per the World Health Organization (WHO) criteria (1997), Turesky-Gilmore-Glickman modification of the Quigley Hein Plaque Index, and Loe-Silness Gingival Index (1963), respectively. Cronbach's alpha, Chi-square test, paired t-test, and unpaired t-test were utilized for data analysis. Results: The mean plaque and gingival score reduction was significantly higher in the study groups as compared to the control groups. An increase in the mean of Decayed, missing, filled teeth (DMFT) and Decayed, missing, filled teeth and surfaces (DMFS) scores throughout the study period was seen in children who participated in study. Conclusion: Oral health education was effective in establishing good oral health habits among school children and also in enhancing the knowledge of their parents about good oral health. PMID:25374836

  13. Reconstructing phylogenetic networks using maximum parsimony.

    PubMed

    Nakhleh, Luay; Jin, Guohua; Zhao, Fengmei; Mellor-Crummey, John

    2005-01-01

    Phylogenies - the evolutionary histories of groups of organisms - are one of the most widely used tools throughout the life sciences, as well as objects of research within systematics, evolutionary biology, epidemiology, etc. Almost every tool devised to date to reconstruct phylogenies produces trees; yet it is widely understood and accepted that trees oversimplify the evolutionary histories of many groups of organims, most prominently bacteria (because of horizontal gene transfer) and plants (because of hybrid speciation). Various methods and criteria have been introduced for phylogenetic tree reconstruction. Parsimony is one of the most widely used and studied criteria, and various accurate and efficient heuristics for reconstructing trees based on parsimony have been devised. Jotun Hein suggested a straightforward extension of the parsimony criterion to phylogenetic networks. In this paper we formalize this concept, and provide the first experimental study of the quality of parsimony as a criterion for constructing and evaluating phylogenetic networks. Our results show that, when extended to phylogenetic networks, the parsimony criterion produces promising results. In a great majority of the cases in our experiments, the parsimony criterion accurately predicts the numbers and placements of non-tree events.

  14. Are vegans the same as vegetarians? The effect of diet on perceptions of masculinity.

    PubMed

    Thomas, Margaret A

    2016-02-01

    Food and food consumption matters in interpersonal interactions. Foods consumed can affect how a person is perceived by others in terms of morality, likeability, and gender. Food consumption can be used as a strategy for gendered presentation, either in terms of what foods are consumed or in the amount of food consumed. Finally, foods themselves are associated with gender. Previous research (Browarnik, 2012; Ruby & Heine, 2011) shows inconsistent patterns in the association between vegetarianism and masculinity. The current research conceptually replicates and extends this research by including the explicit label of vegetarian. The four studies in this article provide increased information about the effects of diet on gendered perceptions. Study 1 shows that vegetarian and omnivorous targets are rated equally in terms of masculinity. Study 2 shows that perceptions of vegetarians and vegans are similar, though comparing this research with past research indicates that perceptions of vegetarians are more variable. Study 3 shows that veganism leads perceptions of decreased masculinity relative to omnivores. Finally, Study 4 tests one possible mechanism for the results of Study 3, that it is the choice to be vegan that impacts perceptions of gender. Implications include increased knowledge about how meatless diets can affect the perceptions of gender in others. Multiple directions for future research are discussed.

  15. Assessment of Effectiveness of Barleria prionitis on Oral Health

    PubMed Central

    Gupta, Devanand; Gupta, Rajendra Kumar; Jain, Ankita; Bindhumadhav, Suresh; Sangeeta; Garg, Purnima; Chaturvedi, Saurabh; Chattu, Vijay Kumar

    2016-01-01

    Aim: To evaluate the efficacy of Barleria prionitis extract mouthwash in comparison with gold standard chlorhexidine (CHX) mouthwash on the oral health. Materials and Methods: A total of 30 subjects were randomly divided into two groups, B. prionitis group and the CHX gluconate mouthwash group. The data were collected at the baseline and 3 days. The plaque was disclosed using erythrosine disclosing agent and their scores were recorded using the Quigley and Hein plaque index modified by Turesky-Gilmore-Glickman. Statistical analysis was performed to compare the effect of the two drug regime. Results: Our result showed that the CHX and the B. prionitis were statistically equally effective against dental plaque. Although the action of CHX was more pronounced. Conclusions: This study has confirmed antimicrobial potential of the plant B. prionitis, thus supporting its folklore application as preventive remedy against oral microbial diseases. SUMMARY Within the limitation of this trial, herbal mouthwash has been shown to demonstrate similar effects on plaque as compared to the standard drug CHX. Further long term research needs to be done to check the efficacy and effectiveness of herbal products over standard drug regime. PMID:27365983

  16. Efficacy of chlorhexidine and green tea mouthwashes in the management of dental plaque-induced gingivitis: A comparative clinical study

    PubMed Central

    Priya, B. Meena; Anitha, V.; Shanmugam, M.; Ashwath, B.; Sylva, Suganthi D.; Vigneshwari, S. K.

    2015-01-01

    Background: The intake of green tea has been increased recently due to its medicinal values. The antibacterial and antioxidant properties of green tea were found to be beneficial in the treatment of gingival and periodontal diseases. The aim of this comparative study was to compare the efficacy of the mouthwash containing green tea and chlorhexidine in the management of dental plaque-induced gingivitis. Materials and Methods: Thirty patients who participated in the study were divided randomly into two groups, each group of 15 patients was prescribed with either chlorhexidine or green tea mouthwash. Turesky modification of Quigley-Hein plaque index, Löe and Silness gingival index, Ainamo and Bay bleeding index, tooth stain, and tongue stain (TS) were recorded at baseline, 15 days, and 1 month. The subjects were asked to report any discomfort or alteration in taste. Results: There was a significant decrease in plaque index, gingival index, and bleeding index in both the groups. However, green tea mouthwash resulted in a statistically significant decrease in bleeding index compared to chlorhexidine group. There was no significant difference in tooth stain and TS in both the groups. Conclusion: The green tea-containing mouthwash is equally effective in reducing the gingival inflammation and plaque to chlorhexidine. PMID:26681856

  17. TRANSFER EFFECTS IN TASK-SET COST AND DUAL-TASK COST AFTER DUAL-TASK TRAINING IN OLDER AND YOUNGER ADULTS: FURTHER EVIDENCE FOR COGNITIVE PLASTICITY IN ATTENTIONAL CONTROL IN LATE ADULTHOOD

    PubMed Central

    Bherer, Louis; Kramer, Arthur F.; Peterson, Matthew S.; Colcombe, Stanley; Erickson, Kirk; Becic, Ensar

    2010-01-01

    Older adults’ difficulties in performing two tasks concurrently have been well documented (Kramer & Madden, 2008). It has been observed that the age-related differences in dual-task performance are larger when the two tasks require similar motor responses (Hartley, 2001) and that in some conditions older adults also show greater susceptibility than younger adults to input interference (Hein & Schubert, 2004). The authors recently observed that even when the two tasks require motor responses, both older and younger adults can learn to perform a visual discrimination task and an auditory discrimination task faster and more accurately (Bherer et al., 2005). In the present study, the authors extended this finding to a dual-task condition that involves two visual tasks requiring two motor responses. Older and younger adults completed a dual-task training program in which continuous individualized adaptive feedback was provided to enhance performance. The results indicate that, even with similar motor responses and two visual stimuli, both older and younger adults showed substantial gains in performance after training and that the improvement generalized to new task combinations involving new stimuli. These results suggest that dual-task skills can be substantially improved in older adults and that cognitive plasticity in attentional control is still possible in old age. PMID:18568979

  18. Effect on de novo plaque formation of rinsing with toothpaste slurries and water solutions with a high fluoride concentration (5,000 ppm).

    PubMed

    Nordström, A; Mystikos, C; Ramberg, P; Birkhed, D

    2009-10-01

    The aim of this study was to evaluate the effect, on de novo plaque formation, of rinsing with toothpaste slurries and water solutions containing a high concentration of fluoride (F). Sixteen subjects rinsed three times per day for 4 d with dentifrice slurries containing 5,000, 1,500, and 500 ppm F, while 12 subjects rinsed with water solutions containing 5,000, 1,500, 500, and 0 ppm F, and 1.5% sodium lauryl sulphate (SLS). Plaque was scored [using the Quigley & Hein index (QHI)] after each 4-d period. Plaque samples for F analysis were collected. Significantly less plaque was scored for the dentifrice slurry containing 5,000 ppm F (buccal and all surfaces) and for 1.5% SLS (buccal surfaces). The differences in plaque scores between dentifrice containing 5,000 and 1,500 ppm F were 19% for all surfaces and 33% for buccal surfaces. The difference between the water solutions containing 1.5% SLS and 1,500 ppm F for buccal surfaces was 23%; the corresponding difference for 5,000 ppm F was 17%. The dentifrice slurry containing 5,000 ppm F accumulated 56% more F in plaque. The combination of high levels of F and SLS in dentifrice reduces de novo plaque formation and increases the accumulation of F in plaque after 4 d.

  19. The presence of Spinoza in the exchanges between Sigmund Freud and Romain Rolland.

    PubMed

    Vermorel, Henri

    2009-12-01

    Although Freud recognized his profound affinity with Spinoza, we seldom find explicit and direct references to the philosopher in his works. The correspondence between Romain Rolland, the 'Christian without a church', and Freud, the 'atheist Jew', is full of Spinozian reminiscences that nourish their works of this period and are underpinned by their mutual transference. The Future of an Illusion is written according to a Spinozian blueprint and aims at replacing religion, qualified as superstition, by psychoanalysis. A quotation from Heine, 'brother in unbelief', is a direct reference to Spinoza. Concurring with Freud's critiques of dogmas and churches, Rolland proposes an analysis of the 'oceanic feeling' as a basis of the religious sentiment. Freud replies with Civilization and Its Discontents. In 1936, on the occasion of Rolland's 70th birthday, Freud sends him an open letter, A disturbance of memory on the Acropolis, where the strange feeling that he has experienced in front of the Parthenon refers inter alia to his double culture: Jewish and German. In the light of this correspondence, the creation of psychoanalysis turns out to be a quest for the sacred that has disappeared in modernity; Freud, though, was able to find it inside man's unconscious.

  20. Antiplaque and antigingivitis effects of a mouthrinse containing cetylpyridinium chloride, triclosan and dipotassium glycyrrhizinate

    PubMed Central

    Shim, Jae-Yong; Yim, Sung-Bin; Chung, Jin-Hyung

    2012-01-01

    Purpose The goal of this study was to evaluate the clinical anitplaque and antigingivitis effects of a mouthrinse containing cetylpyridinium chloride (CPC), triclosan and dipotassium glycyrrhizinate (DPZ) in patients with gingivitis and mild periodontitis. Methods Thirty-two subjects were randomized into 2 groups. The test group used a mouthrinse containing 0.05% CPC, 0.02% triclosan and 0.02% DPZ, while the control group used a placebo mouthrinse. At baseline, 2 weeks and 4 weeks, the papillary bleeding index (PBI), Turesky-Quigley-Hein plaque index (PI) and Löe-Silness gingival index (GI) were assessed. During the experimental period, the patients used the mouthrinse for 30 seconds, 4 to 5 times/day (10 mL/time) within 30 minutes after toothbrushing. Results No adverse effects appeared in either the experimental or the control group. Regarding PBI, PI and GI values, statistical significance was detected between values at baseline and 2 weeks for both groups (P<0.05). In the experimental group, statistically significantly lower values were detected at 4 weeks compared to at 2 weeks. However, in the control group, no statistically significant difference was detected between the values at 2 weeks and 4 weeks. Additionally, the mean value after 4 weeks for the control group was slightly higher than the mean value after 2 weeks for the control group. Conclusions This study for 4 weeks demonstrated that mouthrinses containing CPC, triclosan and DPZ may contribute to the reduction of supragingival plaque and gingivitis. PMID:22586520

  1. Professional brushing study comparing the effectiveness of sonic brush heads with manual toothbrushes: a single blinded, randomized clinical trial.

    PubMed

    Pelka, Anna-Kristina; Nagler, Tonia; Hopp, Imke; Petschelt, Anselm; Pelka, Matthias Anton

    2011-08-01

    The aim of this study was to evaluate the plaque removal efficacy of four toothbrushes: the Philips Sonicare Elite with medium and mini brush heads, the Elmex Sensitive, and the American Dental Association (ADA) reference toothbrush. This study was a randomized, controlled, investigator-blinded, four-brush crossover design study, which examined plaque removal following a consecutive repeated use. All brushes were used on each participant in a randomly assigned quadrant of the mouth. A total of 90 subjects participated in the study. Prior to the experiment, they received a professional prophylaxis and were requested to refrain from toothbrushing for 48 h. Teeth were professionally brushed consecutively for 10 to 90 s per quadrant. A Turesky-modified Quigley Hein Index score was assessed at baseline and after each brushing interval by one blinded investigator. Results showed reduction of mean plaque scores for all brushes with time from 10 to 90 s. After 30 s (2-min whole mouth equivalent) of brushing, the Sonicare brushes cleaned 19, the ADA brush 16, and the Elmex Sensitive 10 of in average 28 tooth surfaces. With time, the number of additional cleaned surfaces decreased. Time is an important variable in the evaluation of plaque-removing efficacy since absolute efficacy increases with time and differs per toothbrush. No differences could be found between the two brush heads of the Sonicare.

  2. Plaque reduction over time of an integrated oral hygiene system.

    PubMed

    Nunn, Martha E; Ruhlman, C Douglas; Mallatt, Philip R; Rodriguez, Sally M; Ortblad, Katherine M

    2004-10-01

    This article compares the efficacy of a prototype integrated system (the IntelliClean System from Sonicare and Crest) in the reduction of supragingival plaque to that of a manual toothbrush and conventional toothpaste. The integrated system was compared to a manual toothbrush with conventional toothpaste in a randomized, single-blinded, parallel, 4-week, controlled clinical trial with 100 subjects randomized to each treatment group. There was a low dropout rate, with 89 subjects in the manual toothbrush group (11% loss to follow-up) and 93 subjects in the integrated system group (7% loss to follow-up) completing the study. The Turesky modification of the Quigley and Hein Plaque Index was used to assess full-mouth plaque scores for each subject. Prebrushing plaque scores were obtained at baseline and at 4 weeks after 14 to 20 hours of plaque accumulation. A survey also was conducted at the conclusion of the study to determine the attitude toward the two oral hygiene systems. The integrated system was found to significantly reduce overall and interproximal prebrushing plaque scores over 4 weeks, both by 8.6%, demonstrating statistically significant superiority in overall plaque reduction (P = .002) and interproximal plaque reduction (P < .001) compared to the manual toothbrush with conventional toothpaste, which showed no significant reduction in either overall plaque or interproximal plaque. This study demonstrates that the IntelliClean System from Sonicare and Crest is superior to a manual toothbrush with conventional toothpaste in reducing overall plaque and interproximal plaque over time.

  3. Electron-Phonon Renormalization of Electronic Band Structures of C Allotropes and BN Polymorphs

    NASA Astrophysics Data System (ADS)

    Tutchton, Roxanne M.; Marchbanks, Christopher; Wu, Zhigang

    The effect of lattice vibration on electronic band structures has been mostly neglected in first-principles calculations because the electron-phonon (e-ph) renormalization of quasi-particle energies is often small (< 100 meV). However, in certain materials, such as diamond, the electron-phonon coupling reduces the band gap by nearly 0.5 eV, which is comparable to the many-body corrections of the electronic band structures calculated using the density functional theory (DFT). In this work, we compared two implementations of the Allen-Heine-Cardona theory in the EPW code and the ABINIT package respectively. Our computations of Si and diamond demonstrate that the ABINIT implementation converges much faster. Using this method, the e-ph renormalizations of electronic structures of three C allotropes (diamond, graphite, graphene) and four BN polymorphs (zincblend, wurtzite, mono-layer, and layered-hexagonal) were calculated. Our results suggest that (1) all of the zero-point renormalizations of band gaps in these materials, except for graphene, are larger than 100 meV, and (2) there are large variations in e-ph renormalization of band gaps due to differences in crystal structure. This work was supported by a U.S. DOE Early Career Award (Grant No. DE-SC0006433). Computations were carried out at the Golden Energy Computing Organization at CSM and the National Energy Research Scientific Computing Center (NERSC).

  4. Subsurface temperature signature of a large Pleistocene - Holocene surface warming in the North Alberta, Canada

    NASA Astrophysics Data System (ADS)

    Majorowicz, J.; Šafanda, J.; Gosnold, W.; Unsworth, M.

    2012-04-01

    Recent results from a 2.3km deep temperature log in northern Alberta, Canada acquired as part of the University of Alberta Helmholtz-Alberta Initiative (HAI) geothermal energy project in 2010-2011shows that there is a significant increase in thermal gradient in the granites. Inversion of the measured T-z profile between 550 - 2320 m indicates a temperature increase of 9.6 ± 0.3 °C, at 13.0 ± 0.6 ka and that the glacial base surface temperature was - 4.4± 0.3 °C. This inversion computation accounted for granite heat production of 3 µW/m3. This is the largest amplitude of Pleistocene - Holocene surface warming in Canada inferred from borehole temperature logs, and is compatible with the results of similar studies in Eurasia (KTB, Outokumpu, Torun-1 etc.) reported previously. Reference: Majorowicz, J., Unsworth, M., Chacko, T., Gray, A., Heaman L., Potter, D., Schmitt, D., and Babadagli, T., 2011. Geothermal energy as a source of heat for oilsands processing in northern Alberta, Canada, in: Hein, F. J., Leckie, D., Suter , J., and Larter, S., (Eds), Heavy Oil/Bitumen Petroleum Systems in Alberta and beyond, AAPG Mem., in press.

  5. Temperature dependence of electronic eigenenergies in the adiabatic harmonic approximation

    NASA Astrophysics Data System (ADS)

    Poncé, S.; Antonius, G.; Gillet, Y.; Boulanger, P.; Laflamme Janssen, J.; Marini, A.; Côté, M.; Gonze, X.

    2014-12-01

    The renormalization of electronic eigenenergies due to electron-phonon interactions (temperature dependence and zero-point motion effect) is important in many materials. We address it in the adiabatic harmonic approximation, based on first principles (e.g., density-functional theory), from different points of view: directly from atomic position fluctuations or, alternatively, from Janak's theorem generalized to the case where the Helmholtz free energy, including the vibrational entropy, is used. We prove their equivalence, based on the usual form of Janak's theorem and on the dynamical equation. We then also place the Allen-Heine-Cardona (AHC) theory of the renormalization in a first-principles context. The AHC theory relies on the rigid-ion approximation, and naturally leads to a self-energy (Fan) contribution and a Debye-Waller contribution. Such a splitting can also be done for the complete harmonic adiabatic expression, in which the rigid-ion approximation is not required. A numerical study within the density-functional perturbation theory framework allows us to compare the AHC theory with frozen-phonon calculations, with or without the rigid-ion approximation. For the two different numerical approaches without non-rigid-ion terms, the agreement is better than 7 μ eV in the case of diamond, which represent an agreement to five significant digits. The magnitude of the non-rigid-ion terms in this case is also presented, distinguishing specific phonon modes contributions to different electronic eigenenergies.

  6. Dynamical and anharmonic effects on the electron-phonon coupling and the zero-point renormalization of the band structure

    NASA Astrophysics Data System (ADS)

    Antonius, Gabriel; Poncé, Samuel; Lantagne-Hurtubise, Étienne; Auclair, Gabriel; Côté, Michel; Gonze, Xavier

    2015-03-01

    The electron-phonon coupling in solids renormalizes the band structure, reducing the band gap by several tenths of an eV in light-atoms semiconductors. Using the Allen-Heine-Cardona theory (AHC), we compute the zero-point renormalization (ZPR) as well as the quasiparticle lifetimes of the full band structure in diamond, BN, LiF and MgO. We show how dynamical effects can be included in the AHC theory, and still allow for the use of a Sternheimer equation to avoid the summation over unoccupied bands. The convergence properties of the electron-phonon coupling self-energy with respect to the Brillouin zone sampling prove to be strongly affected by dynamical effects. We complement our study with a frozen-phonon approach, which reproduces the static AHC theory, but also allows to probe the phonon wavefunctions at finite displacements and include anharmonic effects in the self-energy. We show that these high-order components tend to reduce the strongest electron-phonon coupling elements, which affects significantly the band gap ZPR.

  7. An evaluation of a commercial chewing gum in combination with normal toothbrushing for reducing dental plaque and gingivitis.

    PubMed

    Sharma, N C; Galustians, J H; Qaqish, J G

    2001-07-01

    New evidence suggests a beneficial outcome to chewing a sugarless gum as an added component to a regular, twice-daily toothbrushing regimen. Results of a 4-week study performed on 78 adults with preexisting gingivitis showed a significant reduction of dental plaque and gingivitis when the test group of 39 adults chewed 2 pieces of ARM & HAMMER Dental Care The Baking Soda Gum (AHDC)--a sugar-free chewing gum containing sorbitol, malitol, xylitol, and sodium bicarbonate--for 20 minutes twice a day in conjunction with once-daily toothbrushing for 60 seconds. The control group, also comprised of 39 adults, used breath mints (the study placebo) twice a day in conjunction with the same toothbrushing regimen. There were no statistically significant differences in plaque and gingivitis scores at the baseline examination. Using the Quigley-Hein Plaque Index, the test group experienced a 17% reduction in plaque over 4 weeks, while the control group reduced their plaque amounts by approximately 9% over the same period. Lobene's Mean Gingivitis Index scores were equally significant: a nearly 10% decline for the test group compared to almost 2% for the control group. This article describes the 4-week study and its promising results. PMID:11913304

  8. History of operative treatment of forearm diaphyseal fractures.

    PubMed

    Bartoníček, Jan; Kozánek, Michal; Jupiter, Jesse B

    2014-02-01

    Diaphyseal fractures of the forearm have accompanied humanity throughout its history. Nonsurgical techniques dominated the treatment for centuries, and complications including nonunion and malunion were common. The 19th century featured the recognition of distinct injury patterns. With the development of anesthesia and antisepsis, the operative treatment became widespread. In 1878, Heine described fixation of the diaphyseal nonunion of the distal ulna using an intramedullary ivory peg. Parkhill reported on the application of external fixation for forearm fractures in 1897-1898. Hansmann published the case of plate osteosynthesis of an acute fracture of the radius in 1886. In 1913, Schöne published the technique of closed intramedullary fixation of diaphyseal fractures of the forearm using a silver wire. During the first 2 decades of the 20th century, plate osteosynthesis quickly spread across Europe and North America owing to the influence of Lambotte and Lane. After the World War II, plate osteosynthesis became the surgical treatment of choice for forearm diaphyseal fractures.

  9. Efficacy of antiplaque mouthwashes: a five-day clinical trial.

    PubMed

    Haq, Muhammad Wasif; Batool, Mehwish; Ahsan, Syed Hammad; Sharma, Gaurav

    2011-01-01

    The aim of this study was to evaluate and compare the efficacy of antiplaque mouthwashes. Plaque levels were determined by applying a plaque-disclosing solution using the Turesky et al modification of the Quigley Hein plaque index. The control group (n = 6) brushed twice per day with fluoride toothpaste for one minute and rinsed with water, while the study groups (n = 6) brushed once per day with fluoride toothpaste for one minute, followed by rinsing with 5.0 mL of mouthwash diluted with 10.0 mL of water for 30 seconds. The control group brushed and rinsed with water twice per day. The results indicated that cetylpyridinium chloride in combination with sodium fluoride offered maximum plaque inhibition, followed by chlorhexidine gluconate and sodium monofluorophosphate, while plaque levels increased in the control group and with the combination of chlorhexidine gluconate and sodium fluoride. The only antiplaque agents to demonstrate a statistically significant difference from the control were cetylpyridinium chloride in combination with sodium fluoride, and chlorhexidine gluconate. Increasing the fluoride concentration had no impact on antiplaque activity.

  10. Cage-Core Interactions in Fullerenes Enclosing Metal Clusters with Multiple Scandium and Yttrium Atoms.

    NASA Astrophysics Data System (ADS)

    Dan, Liu; Hagelberg, Frank

    2007-03-01

    Pronounced stability has been reported for metallofullerenes of the form NSc3@CN (N = 68, 78) /1/. In response of these and related findings, Density Functional Theory studies have been performed on the relation between cage-core interactions and the geometry as well as stability of endofullerenes with metal impurities containing Sc and Y. Substantial electron transfer from the metal core to the fullerene cage combines with electron backdonation, involving the interaction between the occupied orbitals of the negatively charged cage and the unoccupied d orbitals of the positively charged core. The Hueckel 4n+2 rule, well established in organic chemistry, is shown to provide a valuable heuristic tool for understanding the intramolecular electron transfer and the related stability gain /1/. The usefulness of the aromaticity concept for explaining and predicting the architecture of metallofullerenes is further exemplified by the units Sc2@C84 and Y2@C84 which were analyzed in spin triplet and singlet conditions. The Sc2 core turns out to be realized by two separated ions, while Y2 forms a bound subunit. These findings are in agreement with conclusions based on the 4n + 2 rule, assisted by Nucleus Independent Chemical Shift (NICS) calculations. /1/ Stevenson, S.; Fowler, P.W.; Heine, T.; Duchamp, J.C.; Rice, G.; Glass, T.; Harich, K.; Hadju, F.; Bible, R.; Dorn, H.C. Nature, 2000, 408, 427, /2/ S. S. Park, D. Liu, F. Hagelberg, J. Phys. Chem. A 109, 8865 (2005).

  11. Comparative evaluation of the antiplaque effectiveness of green tea catechin mouthwash with chlorhexidine gluconate

    PubMed Central

    Kaur, Harjit; Jain, Sanjeev; Kaur, Amritpal

    2014-01-01

    Aim: The aim of this study is to compare the antiplaque efficacy of green tea catechin mouthwash with chlorhexidine gluconate mouthwash. Materials and Methods: A single blinded cross-over study was conducted among 30 participants in the age group of 18-25 years. The mouthwash samples for the study were previously labeled assigning the letters: A (0.25% of green tea catechin mouthwash) and B (0.12% of chlorhexidine mouthwash). The study subjects were randomly divided into two groups of 15 each and the study was divided into two phases. In phase I, the mouthwash A was given to one group and other group was given mouthwash B. After a 15 day washout period, in phase II, both groups were given other mouthwash. At the end of each phase of 1 week, plaque score was recorded by using Turesky modification of the Quigley-Hein plaque index. Results: The plaque scores were compared and the difference between the green tea catechin and chlorhexidine mouthwash was determined by t-test. The difference between plaque scores were not statistically significant (P > 0.05). The results showed that both the groups that is green tea catechin mouthwash (0.25%) and chlorhexidine mouthwash (0.12%) have comparable results in plaque reduction. Conclusion: This study supports the effectiveness of green tea catechin mouthwash as an antiplaque agent. It should be explored as a cost-effective, long-term antiplaque rinse with prophylactic benefits. PMID:24872625

  12. Effects of a Novel Dental Gel on Plaque and Gingivitis: A Comparative Study

    PubMed Central

    Dadkhah, M; Chung, NE; Ajdaharian, J; Wink, C; Klokkevold, P; Wilder-Smith, P

    2015-01-01

    Objectives The goal of this prospective, randomized, controlled, double-blinded study was to evaluate the effects of a novel dental gel on plaque and gingival health. The dental gel was designed to (1) break up and prevent re-accumulation of microbial biofilm, and (2) inhibit metal mediated inflammation. Materials and Methods Twenty-five subjects with moderate gingival inflammation (Löe and Silness Gingival Index ≥2) and pocket depths <4 were randomly assigned to brush twice daily for 21 days with the test or the control dental gel. On Days 0, 7, 14 and 21, plaque levels (Quigley-Hein, Turesky Modification Plaque Index), gingival inflammation (Löe and Silness Gingival Index) and gingival bleeding (modified Sulcus Bleeding Index) were determined by one blinded, investigator using a pressure sensitive probe. Results After 3 weeks, all 3 clinical indices were significantly improved in both groups (P<0.05) and significantly lower in the test group (P<0.05). Conclusion The novel dental gel formulation was provided effective plaque control and reduced gingival inflammation. Clinical Relevance A novel dentifrice formulation may be an effective tool for plaque removal and maintaining gingival health. PMID:26052472

  13. Are vegans the same as vegetarians? The effect of diet on perceptions of masculinity.

    PubMed

    Thomas, Margaret A

    2016-02-01

    Food and food consumption matters in interpersonal interactions. Foods consumed can affect how a person is perceived by others in terms of morality, likeability, and gender. Food consumption can be used as a strategy for gendered presentation, either in terms of what foods are consumed or in the amount of food consumed. Finally, foods themselves are associated with gender. Previous research (Browarnik, 2012; Ruby & Heine, 2011) shows inconsistent patterns in the association between vegetarianism and masculinity. The current research conceptually replicates and extends this research by including the explicit label of vegetarian. The four studies in this article provide increased information about the effects of diet on gendered perceptions. Study 1 shows that vegetarian and omnivorous targets are rated equally in terms of masculinity. Study 2 shows that perceptions of vegetarians and vegans are similar, though comparing this research with past research indicates that perceptions of vegetarians are more variable. Study 3 shows that veganism leads perceptions of decreased masculinity relative to omnivores. Finally, Study 4 tests one possible mechanism for the results of Study 3, that it is the choice to be vegan that impacts perceptions of gender. Implications include increased knowledge about how meatless diets can affect the perceptions of gender in others. Multiple directions for future research are discussed. PMID:26593101

  14. Some results and a conjecture on the degree of ill-posedness for integration operators with weights

    NASA Astrophysics Data System (ADS)

    Hofmann, Bernd; von Wolfersdorf, Lothar

    2005-04-01

    In this paper, we are looking for answers to the question whether a non-compact linear operator with non-closed range applied to a compact linear operator mapping between Hilbert spaces can, in a specific situation, destroy the degree of ill-posedness determined by the singular value decay rate of the compact operator. We partially generalize a result of Vu Kim Tuan and Gorenflo (1994 Inverse Problems 10 949-55) concerning the non-changing degree of ill-posedness of linear operator equations with fractional integral operators in L2(0, 1) when weight functions appear. For power functions m(t) = tα(α > -1), we prove the asymptotics \\sigma_n(A)\\sim \\frac{\\int_0^1 m(t)\\,dt}{\\pi n} for the singular values of the composite operator [Ax](s) = m(s)∫s0x(t) dt in L2(0, 1). We conjecture this asymptotic behaviour also for exponential functions m(t) = exp(-1/tα)(α > 0) that play some role for the local degree of ill-posedness for a nonlinear inverse problem in option pricing in Hein and Hofmann (2003 Inverse Problems 19 1319-38).

  15. A randomized clinical study for comparative evaluation of Aloe Vera and 0.2% chlorhexidine gluconate mouthwash efficacy on de-novo plaque formation

    PubMed Central

    Chhina, Shivjot; Singh, Avnish; Menon, Ipseeta; Singh, Rickypal; Sharma, Anubhav; Aggarwal, Vartika

    2016-01-01

    Objective: To comparatively assess the antiplaque efficacy of Aloe vera mouthwash and 0.2% chlorhexidine gluconate mouthwash on de novo plaque formation. Materials and Methods: This was a randomized, single blind, parallel, controlled clinical study with 90 healthy participants, with mean age of 27.19 ± 12.08 years. After thorough oral prophylaxis, participants were instructed to discontinue mechanical plaque control. Participants were divided randomly into three groups; pure Aloe vera mouthwash was dispensed to the test group; control group received 0.2% chlorhexidine gluconate mouthwash; in Placebo group, flavored distilled water was used as oral rinse twice daily. Effect on 4-day de novo plaque formation was assessed by comparing pre-rinsing Quigley Hein Modified Plaque Scores were analyzed statistically using analysis of variance and Student's t-test. Results: Post-rinsing control group showed the least plaque score which was comparable to the test group. Both the control group and test group showed significant difference with the placebo group. Conclusions: Herbal mouthwash containing Aloe vera mouthwash has comparable antiplaque efficacy as the gold standard 0.2% chlorhexidine gluconate with fewer side effects and can be considered as an alternative. PMID:27382543

  16. Peak Effect in High-Tc Superconductors

    NASA Astrophysics Data System (ADS)

    Ling, Xinsheng

    1996-03-01

    Like many low-Tc superconductors, high-quality YBCO single crystals are found(X.S. Ling and J.I. Budnick, in Magnetic Susceptibility of Superconductors and Other Spin Systems), edited by R.A. Hein, T.L. Francavilla, and D.H. Liebenberg (Plenum Press, New York, 1991), p.377. to exhibit a striking peak effect. In a magnetic field, the temperature dependence of the critical current has a pronounced peak below T_c(H). Pippard(A.B. Pippard, Phil. Mag. 19), 217 (1969)., and subsequently Larkin and Ovchinnikov(A.I. Larkin and Yu.N. Ovchinnikov, J. Low Temp. Phys. 34), 409 (1979)., attributed the onset of the peak effect to a softening of the vortex lattice. In this talk, the experimental discovery^1 of the peak effect in high-Tc superconductors will be described, followed by a brief historical perspective of the understanding of this phenomenon and a discussion of a new model(X.S. Ling, C. Tang, S. Bhattacharya, and P.M. Chaikin, cond-mat/9504109, (NEC Preprint 1995).) for the peak effect. In this model, the peak effect is an interesting manifestation of the vortex-lattice melting in the presence of weak random pinning potentials. The rise of critical current with increasing temperature is a signature of the ``melting'' of the Larkin domains. This work is done in collaboration with Joe Budnick, Chao Tang, Shobo Bhattacharya, Paul Chaikin, and Boyd Veal.

  17. In Vivo Antiplaque Effect of Three Edible Toothpastes

    PubMed Central

    Fernández-Feijoo, Javier; Limeres, Jacobo; García-Caballero, Lucía; Abeleira, María T.; Diz, Pedro

    2014-01-01

    Objectives: The objective of this study was to analyse the antibacterial and antiplaque activity of three edible toothpastes with the widest worldwide distribution: KidScents™, which contains essential oils; Browning B&B™, with medicinal plants; and Wysong Probiodent™, which contains probiotics. Study Design: The study group was formed of twenty healthy volunteers (dental students) with a good oral health status. Using a balanced randomisation system, all volunteers performed toothbrushing with four products (the three edible toothpastes and water) at intervals of one week. Bacterial vitality in the saliva was analysed by epifluorescence microscopy and plaque regrowth was evaluated using the Turesky-Quigley-Hein plaque index. Results: Bacterial vitality in the saliva was significantly higher after toothbrushing with water (positive control) than with the three toothpastes (P=0.002, P=0.003 and P<0.001, respectively). The plaque index was significantly higher after using these three toothpastes than after toothbrushing with water (P=0.047, P=0.032 and P<0.001, respectively). Conclusions: The three edible toothpastes analysed have some antimicrobial activity but favour plaque regrowth. Key words:Edible toothpaste, dental plaque, oral bacteria. PMID:23986022

  18. RF waves - Measuring their energy (dBm) in three points into Baia Mare, Romania

    NASA Astrophysics Data System (ADS)

    Pop-Vǎdean, A.; Pop, P. P.; Barz, C.; Lung, C.

    2016-02-01

    For the general public - and even for people with a science education - knowing to be subject to Radio Frequency (RF) radiation may arouse a feeling of uneasiness or even fear. Those feelings are instigated by the fact that you cannot see, hear, smell or feel RF radiation. Furthermore, the term „radiation” in itself has become very sensitive from the moment that the hazardous health effects of excessive radioactive decay (ionizing radiation) have become apparent. Media announcements of mostly unconfirmed scientific studies add to the feeling of uneasiness. So, naturally, whenever a new Global System of Mobile communications (GSM) base station is installed in an urban environment, the people living in the neighborhood may get worried. The same applies when we propose to use RF radiation for powering wireless sensors in office and home spaces using harvesting energy sistem (HE).In this paper we determine if the electromagnetic field intensity values, measured at certain points, respect the limits set by law, the protection against risks to human health.

  19. An evaluation of a commercial chewing gum in combination with normal toothbrushing for reducing dental plaque and gingivitis.

    PubMed

    Sharma, N C; Galustians, J H; Qaqish, J G

    2001-07-01

    New evidence suggests a beneficial outcome to chewing a sugarless gum as an added component to a regular, twice-daily toothbrushing regimen. Results of a 4-week study performed on 78 adults with preexisting gingivitis showed a significant reduction of dental plaque and gingivitis when the test group of 39 adults chewed 2 pieces of ARM & HAMMER Dental Care The Baking Soda Gum (AHDC)--a sugar-free chewing gum containing sorbitol, malitol, xylitol, and sodium bicarbonate--for 20 minutes twice a day in conjunction with once-daily toothbrushing for 60 seconds. The control group, also comprised of 39 adults, used breath mints (the study placebo) twice a day in conjunction with the same toothbrushing regimen. There were no statistically significant differences in plaque and gingivitis scores at the baseline examination. Using the Quigley-Hein Plaque Index, the test group experienced a 17% reduction in plaque over 4 weeks, while the control group reduced their plaque amounts by approximately 9% over the same period. Lobene's Mean Gingivitis Index scores were equally significant: a nearly 10% decline for the test group compared to almost 2% for the control group. This article describes the 4-week study and its promising results.

  20. 3-D ore body modeling and structural settings of syn-to late orogenic Variscan hydrothermal mineralization, Siegerland district, Rhenish Massif, NW Germany

    NASA Astrophysics Data System (ADS)

    Peters, Meike; Hellmann, André; Meyer, Franz Michael

    2013-04-01

    The Siegerland district is located in the fold-and thrust-belt of the Rhenish Massif and hosts diverse syn-to late orogenic mineralization styles. Peak-metamorphism and deformation occurred at 312-316±10 Ma (Ahrendt et al., 1978) at temperature-pressure conditions of 280-320°C and 0.7-1.4 kbar (Hein, 1993). In addition to syn-orogenic siderite-quartz mineralization at least four different syn-to late orogenic mineralization stages are identified comprising Co-Ni-Cu-Au, Pb-Zn-Cu, Sb-Au, and hematite-digenite-bornite ores (Hellmann et al., 2012). The earliest type of syn-orogenic ore mineralization is formed by siderite-quartz veins, trending N-S, E-W and NE-SW. The vein systems are closely related to fold and reverse fault geometries (Hellmann et al., 2012). The most important structural feature is the first-order Siegen main reverse fault showing an offset into three major faults (Peters et al., 2012). The structural control on ore formation is demonstrated by the Co-Ni-Cu-Au mineralization generally hosted by NE-ENE trending reverse faults and associated imbrication zones that have reactivated the older siderite-quartz veins. In this study, we developed a 3-D model of the Alte Buntekuh ore bodies in the Siegerland district, using Datamine Studio3 to investigate the structural setting of Co-Ni-Cu-Au mineralization. The salient structural and spatial data for the 3-D model were taken from old mine level plans as well as from geological and topographical maps. The ore bodies are located immediately in the hanging wall of the southern branch of the Siegen main reverse fault (Peters et al., 2012). From the model it becomes obvious, that the earlier siderite-quartz veins, dipping steeply to the NW, are cross-cut and segmented by oppositely dipping oblique reverse faults. Individual ore body segments are rotated and displaced, showing a plunge direction to the SW. The 3-D model further reveals the presence of hook-like, folded vein arrays, highly enriched in cobalt

  1. Plaque removal efficacy of Colgate 360 toothbrush: A clinical study

    PubMed Central

    Iyer, Nageshwar; Chandna, Shalu; Dhindsa, Abhishek; Damle, Dhanashree; Loomba, Ashish

    2016-01-01

    Aim: The aim of this clinical study was to confirm the plaque removal efficacy of the Colgate 360 Whole Mouth Clean Toothbrush. Study Design: This was a single-center, monadic, case–controlled study with the 7 days duration. Materials and Methods: A total of eighty participants (56 male and 24 female) aged between 18 and 45 years with a minimum of 20 permanent teeth (excluding the third molars) without any prosthetic crowns and an initial plaque score of minimum 1.5 as determined by Modified Quigley-Hein Plaque Index (1970) participated in the study. There were two dropouts during the study duration, one male and one female. The participants were instructed to brush for 1 min, after which plaque index was recorded again. They were then instructed to brush their teeth twice a day for 1 min with the assigned toothbrush (Colgate 360 Whole Mouth Clean Toothbrush) and a commercially available fluoride toothpaste for the next 7 days. On the 7th day, all the participants were recalled for follow-up and plaque examination. The plaque index scores (pre- and post-brushing) were recorded, tabulated, and analyzed statistically. Results: The mean plaque indices reduced after brushing both on day 1 and day 7. There was also a reduction in mean plaque indices from day 1 to day 7. All these reductions were statistically significant (P < 0.001). The reduction in plaque scores was independent of the gender of the participants however female participants showed lower scores as compared to male participants (P < 0.001). Conclusion: The present study demonstrated a significant reduction in plaque scores with the use of Colgate 360 Whole Mouth Clean Soft Toothbrush throughout the study period. Continued use resulted in a further significant reduction in plaque scores irrespective of the gender of participants.

  2. Effect of Chlorhexidine with Fluoride Mouthrinse on Plaque Accumulation, Plaque pH - A Double Blind Parallel Randomized Clinical Trial

    PubMed Central

    Saha, Sabyasachi; Singh, Sanjay

    2016-01-01

    Introduction Mouthwashes are important means used in chemical control of dental plaque. There is strong evidence suggestive of better effectiveness, when fluoride is added to chlorhexidine mouthwash. Aim To assess the anti-plaque efficacy of Chlorhexidine combined with Fluoride mouthwash and to measure its impact on plaque accumulation and on plaque pH. Materials and Methods Initially 100 subjects were screened. A double blind, parallel randomized clinical trial was conducted on 30 subjects after applying inclusion and exclusion criteria. Other independent variables were matched before randomly allocating them in three groups: Group A-Chlorhexidine as positive control, Group B-Chlorhexidine + Fluoride as test group and Group C- Distilled water as negative control. Oral prophylaxis of participants was done before onset of the study. Plaque pH was assessed before and immediately after rinsing at 0, 5 and 10 minutes interval and after 7 days with digital pH electrode (pHepR pH meter, Hanna Instruments R10285) and accumulation of plaque was recorded by Turesky et al., modification of Quigley Hein Plaque Index (1970). ANOVA test was used for statistical analysis. Results Although there was a statistically significant reduction in mean plaque scores from baseline to seven days in both Groups A and B, Group B showed better anti-plaque efficacy . Almost equal drop in plaque pH was seen for both the groups at 5 and 10 minutes. Conclusion Better anti-plaque efficacy was observed in Group B (Chlorhexidine and Fluoride combination) with minimum variation of plaque pH.

  3. Temperature dependence of the electronic structure of semiconductors and insulators

    SciTech Connect

    Poncé, S. Gillet, Y.; Laflamme Janssen, J.; Gonze, X.; Marini, A.; Verstraete, M.

    2015-09-14

    The renormalization of electronic eigenenergies due to electron-phonon coupling (temperature dependence and zero-point motion effect) is sizable in many materials with light atoms. This effect, often neglected in ab initio calculations, can be computed using the perturbation-based Allen-Heine-Cardona theory in the adiabatic or non-adiabatic harmonic approximation. After a short description of the recent progresses in this field and a brief overview of the theory, we focus on the issue of phonon wavevector sampling convergence, until now poorly understood. Indeed, the renormalization is obtained numerically through a slowly converging q-point integration. For non-zero Born effective charges, we show that a divergence appears in the electron-phonon matrix elements at q → Γ, leading to a divergence of the adiabatic renormalization at band extrema. This problem is exacerbated by the slow convergence of Born effective charges with electronic wavevector sampling, which leaves residual Born effective charges in ab initio calculations on materials that are physically devoid of such charges. Here, we propose a solution that improves this convergence. However, for materials where Born effective charges are physically non-zero, the divergence of the renormalization indicates a breakdown of the adiabatic harmonic approximation, which we assess here by switching to the non-adiabatic harmonic approximation. Also, we study the convergence behavior of the renormalization and develop reliable extrapolation schemes to obtain the converged results. Finally, the adiabatic and non-adiabatic theories, with corrections for the slow Born effective charge convergence problem (and the associated divergence) are applied to the study of five semiconductors and insulators: α-AlN, β-AlN, BN, diamond, and silicon. For these five materials, we present the zero-point renormalization, temperature dependence, phonon-induced lifetime broadening, and the renormalized electronic band structure.

  4. Comparison of Dill Seed Oil Mouth Rinse and Chlorhexidine Mouth Rinse on Plaque Levels and Gingivitis - A Double Blind Randomized Clinical Trial

    PubMed Central

    Eshwar, Shruthi; K, Rekha; Jain, Vipin; Manvi, Supriya; Kohli, Shivani; Bhatia, Shekhar

    2016-01-01

    Introduction: Mouthrinses have been in use for centuries as breath fresheners, medicaments, and antiseptics. Dill is said to be a good source of calcium, manganese and iron. It contains flavonoids known for their antioxidant, anti-inflammatory, and antiviral properties. Dill can help with microbial infections in the mouth; and its anti-oxidants minimize damage caused by free radicals to the gums and teeth. Being a good source of calcium, dill also helps with bone and dental health. Aims and Objectives: To compare the effectiveness of commercially available 0.2% chlorhexidine gluconate mouthrinse and dill seed oil mouthrinse on plaque levels and gingivitis. Material and Methods: A randomized controlled, double blind parallel arm study was conducted over 90 days on 90 subjects. The subjects were randomly divided into 2 groups and baseline data was collected using Loe and Silness gingival index and Quigley Hein plaque index and oral prophylaxis was performed on all the subjects. The mouthrinses included in the present study were dill seed oil and Hexodent (0.2% chlorhexidine gluconate). Intervention regarding the mouthrinsing was given to the subjects and were followed up for 45 days and 90 days, after this post intervention changes were assessed using the respective indices. Results: It was observed that there is no significant difference in gingival & plaque scores among two mouthrinses from baseline to 45 days and 90 days. It was observed that there is statistical difference in gingival and plaque scores when compared with baseline to 45 days (p<0.001), baseline to 90 days (p<0.001) and 45 days to 90 days (p<0.001) when intergroup comparisons were done. Conclusion: It was concluded that dill seed oil and Hexodent (0.2% chlorhexidine gluconate) mouthrinse have similar antiplaque and antigingival effectiveness. PMID:27386006

  5. Comparison of soft toothbrush and new ultra-soft cleaner in ability to remove plaque from teeth.

    PubMed

    Stewart, William J; Gratzel, Kristen; Gearity, Erin J; Akerman, Meredith; Hill, Jennifer M

    2014-11-01

    In this single-blind, crossover study, the difference between a brushless tooth cleaner and a soft toothbrush was studied to compare plaque removal efficiency. The sample was composed of 15 human subjects who were categorized into two groups. Group 1 was composed of subjects randomly assigned to the brushless tooth cleaner for the first two weeks. Group 2 was composed of those randomly assigned to begin the study using the soft toothbrush. After two weeks of brushing with their assigned device, subjects returned to their normal modality to brush their teeth for one week. For the last two weeks of the study, subjects were told to brush with the opposite device they were originally assigned to at the beginning of the trial. Investigators recorded the subjects' gingival indices (based on probe depths) and Quigley scores (based on plaque indices using disclosing solution) at the beginning of week one, the end of week two, the end of week three and the end of week five. The main outcomes in this study were the Silness Loe Index (SLI) and the Quigley Hein Index (QHI). The SLI was assessed on the buccal, lingual, mesial and distal surfaces of six teeth, for a total of 24 surfaces. The QHI was assessed on the buccal and lingual surfaces of six teeth, for a total of 12 surfaces. Each index was measured at each visit by the sum total score divided by the total number of surfaces. The data were analyzed separately using a mixed-effects repeated measures analysis of variance (RMANOVA) for crossover designs. Results indicate that, according to the SLI, there is no significant difference between the two treatments after the first or second weeks. However, based on the QHI, statistically significant differences existed between the two treatments after week one and two. After week one, the soft toothbrush use had a higher QHI than the brushless tooth cleaner. After week two, the brushless tooth cleaner had a higher QHI than the soft toothbrush.

  6. An evaluation of sodium bicarbonate chewing gum as a supplement to toothbrushing for removal of dental plaque from children's teeth.

    PubMed

    Kleber, C J; Davidson, K R; Rhoades, M L

    2001-07-01

    The purpose of this human clinical study was to determine whether a commercial chewing gum containing 5% sodium bicarbonate (ARM & HAMMER DENTAL CARE The Baking Soda Gum [AHDC]) was effective in removing dental plaque when used as a supplement to regular toothbrushing by children. Healthy children (N = 28, average age = 11 years) were randomly distributed into 2 groups. One group was instructed to chew 2 tablets of AHDC chewing gum for 20 minutes 2 times each day (after lunch and dinner) in addition to their normal toothbrushing regimen. The other group used a sugarless mint tablet twice daily during the same period in addition to toothbrushing. After 1 week of using their assigned product, all participants were again examined for oral health and plaque. After a 1-week washout period, subjects were crossed over to the opposite group. Among the 21 participants completing the study, the AHDC chewing gum significantly (P < .0001) reduced plaque by 15% after 1 week compared to the mint tablet control, as measured by the Modified Quigley-Hein Plaque Index. When longitudinally compared to the baseline plaque scores, the gum resulted in a significant (P < .01) 10% reduction of plaque on the teeth. Subanalysis of the data showed that the AHDC chewing gum was particularly effective on the lingual surfaces and the posterior teeth and least effective on the facial surfaces of the anterior teeth, which do not readily come into direct contact with the gum during mastication. The bicarbonate gum demonstrated significant plaque reduction in all other areas of the mouth, even on tooth surfaces not directly contacted during chewing. Compliance with the chewing gum regimen was excellent, and oral health exams did not indicate any adverse events among children using either the chewing gum or mint tablets. In this study, regular use of AHDC chewing gum was safe and effective in removing dental plaque and served as a significant complement to the daily toothbrushing regimen of children

  7. New portable system for dental plaque measurement using a digital single-lens reflex camera and image analysis: Study of reliability and validation

    PubMed Central

    Rosa, Guillermo Martin; Elizondo, Maria Lidia

    2015-01-01

    Background: The quantification of the dental plaque (DP) by indices has limitations: They depend on the subjective operator's evaluation and are measured in an ordinal scale. The purpose of this study was to develop and evaluate a method to measure DP in a proportional scale. Materials and Methods: A portable photographic positioning device (PPPD) was designed and added to a photographic digital single-lens reflex camera. Seventeen subjects participated in this study, after DP disclosure with the erythrosine, their incisors, and a calibration scale ware photographed by two operators in duplicate, re-positioning the PPPD among each acquisition. A third operator registered the Quigley-Hein modified by Turesky DP index (Q-H/TPI). After tooth brushing, the same operators repeated the photographs and the Q-H/TPI. The image analysis system (IAS) technique allowed the measurement in mm2 of the vestibular total tooth area and the area with DP. Results: The reliability was determined with the intra-class correlation coefficient that was 0.9936 (P < 0.05) for the intra-operator repeatability and 0.9931 (P < 0.05) for inter-operator reproducibility. The validity was assessed using the Spearman's correlation coefficient that indicated a strong positive correlation with the Q-H/TPI rs = 0.84 (P < 0.01). The sensitivity of the IAS was evaluated with two sample sizes, only the IAS was able to detect significant differences (P < 0.05) with the sample of smaller size (n = 8). Conclusions: Image analysis system showed to be a reliable and valid method to measure the quantity of DP in a proportional scale, allowing a more powerful statistical analysis, thus facilitating trials with a smaller sample size. PMID:26229267

  8. The coral reef aorta – a single centre experience in 70 patients

    PubMed Central

    Grotemeyer, Dirk; Pourhassan, Siamak; Rehbein, Hermann; Voiculescu, Adina; Reinecke, Petra; Sandmann, Wilhelm

    2007-01-01

    Coral reef aorta (CRA) is described as rock-hard calcifications in the visceral part of the aorta. These heavily calcified plaques grow into the lumen and can cause significant stenoses, which may lead to malperfusion of the lower limbs, visceral ischemia or hypertension due to renal ischemia. From January 1984 to February 2007, 70 patients (24 men, 46 women, mean age 59.5 years, range 14 to 81 years) underwent treatment in the Department of Vascular Surgery and Renal Transplantation, University Hospital, Heinrich-Heine-University (Düsseldorf, Germany) for CRA. The present study is based on a review of patients’ records and the prospective follow-up in the outpatient clinic. The most frequent finding was renovascular arterial hypertension (44.3%) causing headache, vertigo and visual symptoms. Intermittent claudication due to peripheral arterial occlusive disease was found in 28 patients (40.0%). Seventeen patients (24.3%) presented with chronic visceral ischemia causing diarrhea, weight loss and abdominal pain. Sixty-nine of the 70 patients (98.6%) underwent surgery; in 57 patients, aortic reconstruction was achieved with thromboendarterectomy, performed on an isolated suprarenal segment in six cases (8.7%), an infrarenal segment in 15 cases (21.7%), and the supra- and infrarenal aorta in 43 cases (62.3%). Eight patients (11.6%) died during or soon after surgery. Postoperative complications requiring corrective surgery occurred in 11 patients (15.9%). Almost one-third of the patients (n=19, 27.5%) returned for follow-up after a mean of 52.6 months (range six to 215 months). Of the 19 patients, there was significant clinical and diagnostic improvement in 16 patients (84.2%) and three patients (15.8%) were unchanged. Impairment was not observed. Despite the existing and improving surgical techniques for the treatment of CRA, its pathophysiological basis and genesis is not yet understood. PMID:22477301

  9. Effect of Chlorhexidine with Fluoride Mouthrinse on Plaque Accumulation, Plaque pH - A Double Blind Parallel Randomized Clinical Trial

    PubMed Central

    Saha, Sabyasachi; Singh, Sanjay

    2016-01-01

    Introduction Mouthwashes are important means used in chemical control of dental plaque. There is strong evidence suggestive of better effectiveness, when fluoride is added to chlorhexidine mouthwash. Aim To assess the anti-plaque efficacy of Chlorhexidine combined with Fluoride mouthwash and to measure its impact on plaque accumulation and on plaque pH. Materials and Methods Initially 100 subjects were screened. A double blind, parallel randomized clinical trial was conducted on 30 subjects after applying inclusion and exclusion criteria. Other independent variables were matched before randomly allocating them in three groups: Group A-Chlorhexidine as positive control, Group B-Chlorhexidine + Fluoride as test group and Group C- Distilled water as negative control. Oral prophylaxis of participants was done before onset of the study. Plaque pH was assessed before and immediately after rinsing at 0, 5 and 10 minutes interval and after 7 days with digital pH electrode (pHepR pH meter, Hanna Instruments R10285) and accumulation of plaque was recorded by Turesky et al., modification of Quigley Hein Plaque Index (1970). ANOVA test was used for statistical analysis. Results Although there was a statistically significant reduction in mean plaque scores from baseline to seven days in both Groups A and B, Group B showed better anti-plaque efficacy . Almost equal drop in plaque pH was seen for both the groups at 5 and 10 minutes. Conclusion Better anti-plaque efficacy was observed in Group B (Chlorhexidine and Fluoride combination) with minimum variation of plaque pH. PMID:27630956

  10. Comparison of a sonic and a manual toothbrush for efficacy in supragingival plaque removal and reduction of gingivitis.

    PubMed

    Tritten, C B; Armitage, G C

    1996-07-01

    A new sonic electric toothbrush (Sonicare) and a traditional manual toothbrush were compared for efficacy in removing supragingival plaque and reducing gingival inflammation in a 12-week, single-blind clinical trial. 60 subjects with a gingival index (GI) of > 1.5 and no probing depths > 5 mm were randomly assigned to use either the manual or sonic brush, instructed in its use, and asked to brush each morning and evening for 2 minutes. Plaque scores were taken at baseline and at 1, 2, 4, and 12 weeks using the Turesky modification of the Quigley-Hein plaque index. Gingival inflammation was assessed by the GI, bleeding tendency score, presence or absence of bleeding on probing, volumetric measurements of gingival crevicular fluid (GCF), and aspartate aminotransferase (AST) levels in GCF. Repeated measures multivariate analyses of variance were used to detect time- and device-dependent differences for all clinical assessments between the 2 groups over the 5 visits. Both types of brush were effective in removing supragingival plaque. The sonic brush was statistically superior, on a percentage reduction basis, in removing supragingival plaque from the dentition taken as a whole (F-statistic; p = 0.012) and was particularly better in hard-to-reach areas such as posterior teeth (F-statistic; p = 0.003) and interproximal sites (F-statistic; p = 0.004). Both devices were equally effective in reducing gingival inflammation. The sonic brush exhibited less tendency to cause gingival abrasion than the manual brush (1 incident with sonic, 5 incidents with manual), confirming the safety of this product as an oral hygiene device.

  11. Clinical comparison of plaque removal and gingival bleeding reduction by two different brush heads on a sonic toothbrush.

    PubMed

    Harpenau, L

    2000-01-01

    Previous clinical studies have demonstrated the efficacy of a sonic toothbrush (Sonicare) in plaque removal and reduction of gingival inflammation. Currently, several different brush heads are available for this sonic toothbrush. The purpose of this clinical study was to compare two different brush heads (nine row and eight row) with respect to their ability to remove dental plaque and reduce gingival bleeding. One-hundred twenty-one young adults, in good general and periodontal health, volunteered as subjects in this five-week, single-blind, crossover study. All subjects used one brush for a two-week period, brushing twice daily for two minutes. Subjects used a manual toothbrush during a one-week washout period, and then used the other head for two weeks. At the beginning and end of each two-week trial period, subjects were scored for plaque and bleeding by means of the Turesky modification of the Quigley-Hein Plaque Index and the Mombelli et al. modification of the Sulcus Bleeding Index of Mühlemann and Son. Findings of reductions were limited to "before vs. after" assessments. The nine-row brush demonstrated a significant reduction (p < 0.05) in plaque removal on the smooth surfaces (p = 0.02) as well as significant reductions in bleeding at interproximal (p = 0.04) and posterior sites (p = 0.031). Overall, both brushes appeared to be effective in reducing dental plaque and bleeding. A questionnaire administered to all subjects at the end of the five-week study revealed a preference for the smaller of the brush heads.

  12. Metal-semiconductor contacts: electronic properties

    NASA Astrophysics Data System (ADS)

    Mönch, Winfried

    1994-01-01

    Rectification in metal-semiconductor contacts was first described by Braun in 1874. We owe the explanation of this observation to Schottky. He demonstrated that depletion layers exist on the semiconductor side of such interfaces. The current transport across such contacts is determined by their barrier heights, i.e., the respective energy difference between the Fermi level and the edge of the majority-carrier band. Since Schottky had published his pioneering work in 1938 the mechanisms, which determine the barrier heights of metal-semiconductor contacts, have remained under discussion. In 1947, Bardeen attributed the failure of the early Schottky-Mott rule to the neglect of electronic interface states. The foundations for a microscopic description of interface states in ideal Schottky contacts was laid by Heine in 1965. He demonstrated that a continuum of metal-induced gap states (MIGS), as they were called later, derives from the virtual gap states of the complex semiconductor band-structure. Neither this MIGS model nor any of the many other monocausal approaches, the most prominent is Spicer's Unified Defect Model, can explain the experimental data. In 1987, Mönch concluded that the continuum of MIG states represents the primary mechanism, which determines the barrier heights in ideal, i.e., intimate, abrupt, and homogeneous metal-semiconductor contacts. He attributed deviations from what is predicted by the MIGS model to other and then secondary mechanisms. In this respect, interface defects, structure-related interface dipoles. interface strain, interface compound formation, and interface intermixing, to name a few examples, were considered.

  13. Plaque removal efficacy of Colgate 360 toothbrush: A clinical study

    PubMed Central

    Iyer, Nageshwar; Chandna, Shalu; Dhindsa, Abhishek; Damle, Dhanashree; Loomba, Ashish

    2016-01-01

    Aim: The aim of this clinical study was to confirm the plaque removal efficacy of the Colgate 360 Whole Mouth Clean Toothbrush. Study Design: This was a single-center, monadic, case–controlled study with the 7 days duration. Materials and Methods: A total of eighty participants (56 male and 24 female) aged between 18 and 45 years with a minimum of 20 permanent teeth (excluding the third molars) without any prosthetic crowns and an initial plaque score of minimum 1.5 as determined by Modified Quigley-Hein Plaque Index (1970) participated in the study. There were two dropouts during the study duration, one male and one female. The participants were instructed to brush for 1 min, after which plaque index was recorded again. They were then instructed to brush their teeth twice a day for 1 min with the assigned toothbrush (Colgate 360 Whole Mouth Clean Toothbrush) and a commercially available fluoride toothpaste for the next 7 days. On the 7th day, all the participants were recalled for follow-up and plaque examination. The plaque index scores (pre- and post-brushing) were recorded, tabulated, and analyzed statistically. Results: The mean plaque indices reduced after brushing both on day 1 and day 7. There was also a reduction in mean plaque indices from day 1 to day 7. All these reductions were statistically significant (P < 0.001). The reduction in plaque scores was independent of the gender of the participants however female participants showed lower scores as compared to male participants (P < 0.001). Conclusion: The present study demonstrated a significant reduction in plaque scores with the use of Colgate 360 Whole Mouth Clean Soft Toothbrush throughout the study period. Continued use resulted in a further significant reduction in plaque scores irrespective of the gender of participants. PMID:27630494

  14. One-shot calculation of temperature-dependent optical spectra and phonon-induced band-gap renormalization

    NASA Astrophysics Data System (ADS)

    Zacharias, Marios; Giustino, Feliciano

    2016-08-01

    Recently, Zacharias et al. [Phys. Rev. Lett. 115, 177401 (2015), 10.1103/PhysRevLett.115.177401] developed an ab initio theory of temperature-dependent optical absorption spectra and band gaps in semiconductors and insulators. In that work, the zero-point renormalization and the temperature dependence were obtained by sampling the nuclear wave functions using a stochastic approach. In the present work, we show that the stochastic sampling of Zacharias et al. can be replaced by fully deterministic supercell calculations based on a single optimal configuration of the atomic positions. We demonstrate that a single calculation is able to capture the temperature-dependent band-gap renormalization including quantum nuclear effects in direct-gap and indirect-gap semiconductors, as well as phonon-assisted optical absorption in indirect-gap semiconductors. In order to demonstrate this methodology, we calculate from first principles the temperature-dependent optical absorption spectra and the renormalization of direct and indirect band gaps in silicon, diamond, and gallium arsenide, and we obtain good agreement with experiment and with previous calculations. In this work we also establish the formal connection between the Williams-Lax theory of optical transitions and the related theories of indirect absorption by Hall, Bardeen, and Blatt, and of temperature-dependent band structures by Allen and Heine. The present methodology enables systematic ab initio calculations of optical absorption spectra at finite temperature, including both direct and indirect transitions. This feature will be useful for high-throughput calculations of optical properties at finite temperature and for calculating temperature-dependent optical properties using high-level theories such as G W and Bethe-Salpeter approaches.

  15. Effect of Manuka honey, chlorhexidine gluconate and xylitol on the clinical levels of dental plaque

    PubMed Central

    Nayak, Prathibha A.; Nayak, Ullal A.; Mythili, R.

    2010-01-01

    Aims: To compare the effect of Manuka honey, chlorhexidine gluconate (0.2%) mouthwash and xylitol chewing gum on the dental plaque levels. Materials and Methods: Sixty healthy male dental students aged between 21 and 25 years (mean age 23.4 years) participated in the study. All the subjects received a professional prophylaxis at the start of the study, with the purpose of making the dentition 100% free of plaque and calculus. The subjects were then randomly divided into three groups, i.e. the Manuka honey group, the chlorhexidine gluconate mouthwash group and the xylitol chewing gum group. Rinsing with water or any other fluid after the procedure was not allowed as also any form of mechanical oral hygiene for all the subjects during the experimental period of 72 h. After the experimental period, the plaque was disclosed using disclosing solution and their scores were recorded at six sites per tooth using the Quigley and Hein plaque index modified by Turesky-Gilmore-Glickman. Results: The mean plaque scores for Groups I, II and III were 1.37, 1.35 and 1.57, respectively. The ANOVA revealed that between-group comparison was significant, with an F-value of 5.99 and a probability value of 0.004. The T-test was carried out to evaluate the inter-group significance, which revealed that the plaque inhibition by Manuka honey was similar to that of chlorhexidine mouthwash. Both Manuka honey and chlorhexidine mouthwash reduced plaque formation significantly, better than the xylitol chewing gum. Conclusion: Manuka honey and chlorhexidine mouthwash reduced plaque formation significantly better than xylitol chewing gum. PMID:22114423

  16. Enhanced Stage Variability on the Lower Missouri River as Benchmarked by Lewis and Clark: Implications for Ecosystem Restoration

    NASA Astrophysics Data System (ADS)

    Ehlmann, B. L.; Criss, R. E.

    2006-12-01

    Because lower Missouri River management began in the early 1800s, a challenge for present-day ecosystem restoration efforts is a lack of quantitative data on pre-management river hydrology and long-term (100+ yr.) river response to changing management practice and intensity. We address this challenge and report new results from a study spanning 200 years of lower Missouri River hydrology, encompassing natural, channelization-only, and channelization with reservoir release regimes (Ehlmann &Criss, Geology, forthcoming, Nov/Dec 2006). Data from the 1803-6 Lewis and Clark expedition and continuous daily stage records extending from the 1870s were used to quantitatively benchmark pre-management hydrology of the lower Missouri River. Magnitude and timing of hydrologic change was assessed using a new, robust stage change technique which tracks variability in water level. Before 1900, daily stage change approximated pre-settlement values. However, doubling in daily stage variability occurred from 1900 to 2005. Annual maximum stages have, at some sites, become 40% more extreme relative to the median, and seasonality is more variable. Observed changes in stage variability began as early as 1900, suggesting that channelization is the major driver, not release from upstream reservoirs constructed since 1933. Enhanced flood stages at high discharges are observed, consistent with previous work (Criss &Shock, 2001; Pinter &Heine, 2005). Enhanced stage fluctuations also adversely affect stability of river habitats, in particular sand bar availability for nesting sites and provision of shallow water habitat for spawning. Present ecosystem restoration efforts focused on timed reservoir releases will not ameliorate these unnatural fluctuations. We suggest that restoring hydrologic parameters similar to those recorded by Lewis and Clark requires addressing channel morphology, i.e. widening the river in selected reaches. Efforts to reunite the Missouri River with its floodplain, via

  17. Comparison of soft toothbrush and new ultra-soft cleaner in ability to remove plaque from teeth.

    PubMed

    Stewart, William J; Gratzel, Kristen; Gearity, Erin J; Akerman, Meredith; Hill, Jennifer M

    2014-11-01

    In this single-blind, crossover study, the difference between a brushless tooth cleaner and a soft toothbrush was studied to compare plaque removal efficiency. The sample was composed of 15 human subjects who were categorized into two groups. Group 1 was composed of subjects randomly assigned to the brushless tooth cleaner for the first two weeks. Group 2 was composed of those randomly assigned to begin the study using the soft toothbrush. After two weeks of brushing with their assigned device, subjects returned to their normal modality to brush their teeth for one week. For the last two weeks of the study, subjects were told to brush with the opposite device they were originally assigned to at the beginning of the trial. Investigators recorded the subjects' gingival indices (based on probe depths) and Quigley scores (based on plaque indices using disclosing solution) at the beginning of week one, the end of week two, the end of week three and the end of week five. The main outcomes in this study were the Silness Loe Index (SLI) and the Quigley Hein Index (QHI). The SLI was assessed on the buccal, lingual, mesial and distal surfaces of six teeth, for a total of 24 surfaces. The QHI was assessed on the buccal and lingual surfaces of six teeth, for a total of 12 surfaces. Each index was measured at each visit by the sum total score divided by the total number of surfaces. The data were analyzed separately using a mixed-effects repeated measures analysis of variance (RMANOVA) for crossover designs. Results indicate that, according to the SLI, there is no significant difference between the two treatments after the first or second weeks. However, based on the QHI, statistically significant differences existed between the two treatments after week one and two. After week one, the soft toothbrush use had a higher QHI than the brushless tooth cleaner. After week two, the brushless tooth cleaner had a higher QHI than the soft toothbrush. PMID:25675612

  18. A Fuzzy Logic Study of Weighting Scheme for Satellite-Laser-Ranging Global Tracking Network

    NASA Astrophysics Data System (ADS)

    VIGO, I. M.; SOTO, J.; FLORES, A.; FERRANDIZ, J. M.

    2001-12-01

    In satellite-laser-ranging (SLR) data processing, oftentimes the weighting scheme of station observations is subjective or even quasi-arbitrary, and a somewhat arbitrary cutoff of say, 1m is applied prior to the data processing. This practice leaves something to be decided in terms of making optimal use of the available data. We intend to improve the situation by applying fuzzy-logic techniques in the editing and weighting of the data in an objective way. Many authors (e.g., Katja Heine (2001) and others in the Proceedings of the First International Symposium on Robust Statistics and Fuzzy Techniques in Geodesy an GIS ) have demonstrated the potential utility of the fuzzy logic methods in geodetic problems. The aim of this work is to test a fuzzy logic method as a tool to provide a reliable criteria for weighting scheme for satellite-laser-ranging (SLR) station observations, seeking to optimize their contribution to the precise orbit determination (POD) problem. The data regarding the stations were provided by the International Laser Ranging Service, NASA/CDDIS provided the satellite data for testing the method. The software for processing the data is GEODYN II provided by NASA/GSFC. Factors to be considered in the fuzzy-logic clustering are: the total number of LAGEOS passes during the past 12 months, the stability measure of short and long term biases, the percentage of LAGEOS normal points that were accepted in CSR weekly LAGEOS analysis, and the RMS uncertainty of the station coordinates. Fuzzy logic statistical method allows classifying the stations through a clear membership degree to each station group. This membership degree translates into a suitable weight to be assigned to observations from each station in the global solution. The first tests carried out show improvements in the RMS of the global POD solution as well as individual stations, to within a few millimeters. We expect further work would lead to further improvements.

  19. Clinical effect of miswak as an adjunct to tooth brushing on gingivitis

    PubMed Central

    Patel, Punit Vaibhav; Shruthi, S.; Kumar, Sheela

    2012-01-01

    Background: The aim of the study was to clinically evaluate the effect of miswak as an adjunct to tooth brushing on plaque levels and gingival health in subjects diagnosed with mild to moderate chronic generalized marginal gingivitis in comparison with those of toothbrush users. Materials and Methods: The study comprised of 30 systemically healthy subjects, aged 18-35 years diagnosed with mild to moderate gingivitis. The study was designed as a randomized, single-blind, parallel-armed study. Subjects were randomly divided into three groups. Group A (toothbrush users), group B (toothbrush and miswak users), and group C (miswak users). Subjects were advised to use toothbrush, miswak, or both, three times daily depending on their respective allocations. Gingival index according to Loe and Silness, Plaque index, according to Turesky modified Quigley-Hein plaque index, and the digital photographs of the total labial surfaces of the teeth were taken for image analysis. Recording of data were done at baseline, 2nd, 4th, 6th, and 8th week time intervals. Obtained data were analyzed using repeated measure ANOVA and student t test (independent samples). Results: Group B showed statistically significant (P<0.0001) decrease in plaque score and gingival score compared to group A and group C, respectively, from 2nd to 8th week, whereas no statistical significant difference was found in plaque score, when group A was compared with group C (P>0.05) from 2nd to 4th week. Further at the 6th and 8th week, there was significant difference (P<0.05) in plaque score between group A and group C. The difference in gingival score was not significant (P<0.05), when group A was compared with group C on all the indicated time intervals. Conclusion: Results showed significant improvement in plaque score and gingival health when miswak was used as an adjunct to tooth brushing. PMID:22628969

  20. Tectonic evolution of the Oudalan-Gorouol greenstone belt in NE Burkina Faso and Niger, West African craton.

    NASA Astrophysics Data System (ADS)

    Tshibubudze, Asinne; Hein, Kim A. A.

    2010-05-01

    -2130 Ma (Hein, 2009). D2 involved a period of SE-NW crustal shortening and sinistral-reverse displacement on the MSZ, and is correlated to the Eburnean Orogeny ~2.1 Ga of Feybesse et al. (2006). Deformation in D2 is characterised by NE-trending regional folds (F2) and a pervasive NE-trending foliation (S2-C to S2). Since 2007 an identical tectonic history has been established for a number of shear zones in the OGGB including the north-trending Kargouna Shear Zone, which is subtended by NW- and NE-trending shears. However the metamorphic grade and mineral assemblages vary from one shear zone to the next. Structural studies completed adjacent to the Dori batholith have indicated that the MSZ forms a shear complex that was active during pluton emplacement. However, the MSZ has two main branches that join at the location of a mylonite zone located north west of Essakane. Southwest of Essakane, a NW-trending mylonite zone crosscuts the Dori batholith and near the village of Kargouna, which is situated southeast of Essakane, the Kargouna shear crosscuts and deforms the Dori batholith. It is thus likely that the Dori batholith was emplacement prior to D1 in the OGGB. Gold mineralization in the OGGB is generally hosted in the hanging-wall of NE-trending faults and or NW-trending folds in metasiltstone-sandstone-shale sequences. Nkuna (2009) concluded that the deposits can be classified as orogenic gold deposits under the sub-class of "intrusion related" due to their proximity to plutonic masses, which concurs with geophysical studies for the OGGB. References: Feybesse, J.L., Billa, M., Guerrot, C., Duguey, E., Lescuyer, J.L., Milési, J.P., Bouchot, V., 2006. The Palaeoproterozoic Ghanaian province: Geodynamic model and ore controls, including regional stress modelling. Precambrian Research 149, 149-196. Hein, K.A.A., 2009 (In press). Structural chronologies in the Goren Greenstone belt (Burkina Faso); Implications for West African tectonics. Journal of African Earth Sciences

  1. Tectonic evolution of the Oudalan-Gorouol greenstone belt in NE Burkina Faso and Niger, West African craton.

    NASA Astrophysics Data System (ADS)

    Tshibubudze, Asinne; Hein, Kim A. A.

    2010-05-01

    -2130 Ma (Hein, 2009). D2 involved a period of SE-NW crustal shortening and sinistral-reverse displacement on the MSZ, and is correlated to the Eburnean Orogeny ~2.1 Ga of Feybesse et al. (2006). Deformation in D2 is characterised by NE-trending regional folds (F2) and a pervasive NE-trending foliation (S2-C to S2). Since 2007 an identical tectonic history has been established for a number of shear zones in the OGGB including the north-trending Kargouna Shear Zone, which is subtended by NW- and NE-trending shears. However the metamorphic grade and mineral assemblages vary from one shear zone to the next. Structural studies completed adjacent to the Dori batholith have indicated that the MSZ forms a shear complex that was active during pluton emplacement. However, the MSZ has two main branches that join at the location of a mylonite zone located north west of Essakane. Southwest of Essakane, a NW-trending mylonite zone crosscuts the Dori batholith and near the village of Kargouna, which is situated southeast of Essakane, the Kargouna shear crosscuts and deforms the Dori batholith. It is thus likely that the Dori batholith was emplacement prior to D1 in the OGGB. Gold mineralization in the OGGB is generally hosted in the hanging-wall of NE-trending faults and or NW-trending folds in metasiltstone-sandstone-shale sequences. Nkuna (2009) concluded that the deposits can be classified as orogenic gold deposits under the sub-class of "intrusion related" due to their proximity to plutonic masses, which concurs with geophysical studies for the OGGB. References: Feybesse, J.L., Billa, M., Guerrot, C., Duguey, E., Lescuyer, J.L., Milési, J.P., Bouchot, V., 2006. The Palaeoproterozoic Ghanaian province: Geodynamic model and ore controls, including regional stress modelling. Precambrian Research 149, 149-196. Hein, K.A.A., 2009 (In press). Structural chronologies in the Goren Greenstone belt (Burkina Faso); Implications for West African tectonics. Journal of African Earth Sciences

  2. A randomized crossover-design study to investigate the plaque removal efficacy of two power toothbrushes: Philips Sonicare Flexcare and Oral-B Triumph.

    PubMed

    Putt, Mark S; Milleman, Jeffery L; Jenkins, Wendy; Schmitt, Paul; Master, Aditi S; Strate, Joerg

    2008-01-01

    The Sonicare FlexCare and the Oral-B Triumph Professional Care 9000 power toothbrushes were compared in a single-use, examiner-masked, crossover clinical trial. Outcomes were evaluated using the Turesky Modified Quigley-Hein (TMQH) plaque index. Percent reduction in overall plaque score because of toothbrushing was the primary efficacy measure. Subjects were required to have a TMQH score > or = 1.8 at screening after refraining from oral hygiene for 24 hours. The study included three visits. At visit 1, subjects were randomized to one of two treatment sequences, given their first toothbrush and toothpaste, and instructed to use them twice daily for 2 minutes during a 1-week familiarization phase. Before visit 2, subjects again refrained from oral hygiene for 24 hours. At this visit, plaque scores were assessed before and after a 2-minute supervised brushing episode, then the second test product was issued. Familiarization, plaque accumulation, and clinical examinations were the same for both product use periods. Data were analyzed using a linear mixed effects model with subject as a grouping factor. Treatment effects were expressed as mean values and the appropriate 95% confidence intervals (CI). Ninety-six subjects were screened with 93 subjects completing the study. The sample's TMQH score at Visit 1 was 3.18 +/- 0.42 (mean +/- standard deviation [SD]). Full-mouth prebrushing plaque scores were 2.85 +/- 0.49 for FlexCare and 2.94 +/- 0.45 for Triumph. Respective full-mouth reductions in overall plaque score were 38.02% +/- 15.14% and 30.43% +/- 14.05%. The estimated treatment effect, expressed as difference between FlexCare and Triumph in percent plaque index reduction, was 7.59% with a 95% CI from 4.79% to 10.40%. Similar differences were observed for all subregions, including anterior, posterior, interproximal, and interproximal posterior sites. The same protocol design was used at an earlier study in another center. The combined overall treatment effect from

  3. Efficacy of a novel brush head in the comparison of two power toothbrushes on removal of plaque and naturally occurring extrinsic stain.

    PubMed

    Goyal, C R; Sharma, N C; Qaqish, J G; Cugini, M A; Thompson, M C; Warren, P R

    2005-06-01

    OBJECTIVES.: To compare the safety and efficacy of an oscillating/pulsating power toothbrush (Oral-B ProfessionalCaretrade mark 7000; PC 7000) fitted with either the standard FlexiSoft (PC 7000/EB17) brush head or the novel Pro Polisher (PC 7000/EB-Prophy) and a high-frequency toothbrush (Philips Sonicare(R) Elite(R); SE), in their relative ability to remove plaque and naturally occurring extrinsic dental stain over a six-week period. METHODS.: This randomised, examiner-blind, parallel group study involved 90 healthy subjects from a general population. All subjects received a baseline plaque (Turesky et al. modified Quigley-Hein Plaque Index), stain (Lobene Stain Index) and tooth shade (VITAPAN(R) Shade Guide) [Vita] assessment and an oral tissue examination. After training in the use of their randomly assigned device, subjects were instructed to brush twice daily for 2 min and returned after 3, 4 and 6 weeks of product use for a repeat of each clinical assessment. RESULTS.: Reductions from baseline in mean plaque and extrinsic dental stain scores were significant at Weeks 3, 4 and 6 in all three treatment groups. By Week 6, mean reductions from baseline in whole mouth plaque scores were 32%, 27% and 14% in the PC 7000/EB-Prophy, PC 7000/EB17 and SE groups, respectively. For the body of the tooth, mean reductions from baseline at Week 6 in total stain were 89%, 89% and 80%, respectively. Between treatment group comparisons consistently revealed that the PC 7000 toothbrush plus the EB-Prophy or EB17 brush head removed significantly more plaque and extrinsic stain (total stain, stain area and stain intensity) than the SE toothbrush at 3, 4 and 6 weeks. The EB-Prophy group had a greater proportion of subjects showing a 2-3+ change in Vita shade scores at each time point compared to the other two brushes; at Week 6 the proportions were 67% in the PC 7000/EB-Prophy group, 30% in the PC 7000/EB17 group, and 7% in the SE group. The PC 7000/EB17, PC 7000/EB-Prophy and the

  4. A randomized crossover-design study to investigate the plaque removal efficacy of two power toothbrushes: Philips Sonicare Flexcare and Oral-B Triumph.

    PubMed

    Putt, Mark S; Milleman, Jeffery L; Jenkins, Wendy; Schmitt, Paul; Master, Aditi S; Strate, Joerg

    2008-01-01

    The Sonicare FlexCare and the Oral-B Triumph Professional Care 9000 power toothbrushes were compared in a single-use, examiner-masked, crossover clinical trial. Outcomes were evaluated using the Turesky Modified Quigley-Hein (TMQH) plaque index. Percent reduction in overall plaque score because of toothbrushing was the primary efficacy measure. Subjects were required to have a TMQH score > or = 1.8 at screening after refraining from oral hygiene for 24 hours. The study included three visits. At visit 1, subjects were randomized to one of two treatment sequences, given their first toothbrush and toothpaste, and instructed to use them twice daily for 2 minutes during a 1-week familiarization phase. Before visit 2, subjects again refrained from oral hygiene for 24 hours. At this visit, plaque scores were assessed before and after a 2-minute supervised brushing episode, then the second test product was issued. Familiarization, plaque accumulation, and clinical examinations were the same for both product use periods. Data were analyzed using a linear mixed effects model with subject as a grouping factor. Treatment effects were expressed as mean values and the appropriate 95% confidence intervals (CI). Ninety-six subjects were screened with 93 subjects completing the study. The sample's TMQH score at Visit 1 was 3.18 +/- 0.42 (mean +/- standard deviation [SD]). Full-mouth prebrushing plaque scores were 2.85 +/- 0.49 for FlexCare and 2.94 +/- 0.45 for Triumph. Respective full-mouth reductions in overall plaque score were 38.02% +/- 15.14% and 30.43% +/- 14.05%. The estimated treatment effect, expressed as difference between FlexCare and Triumph in percent plaque index reduction, was 7.59% with a 95% CI from 4.79% to 10.40%. Similar differences were observed for all subregions, including anterior, posterior, interproximal, and interproximal posterior sites. The same protocol design was used at an earlier study in another center. The combined overall treatment effect from

  5. The Lower Molopo River super site (SW Kalahari) and its relevance for the analysis of supra-regional Late Quaternary climate and land-use changes in Southern Africa

    NASA Astrophysics Data System (ADS)

    Winkelbauer, Jennifer; Völkel, Jörg; Bens, Oliver; Heine, Klaus

    2013-04-01

    intensified by further geoarchive prospection. As such, the project delivers a very valuable input to the interdisciplinary analysis of past and future global change in the highly sensitive environments of Southern Africa. Hürkamp, K., Völkel, J., Heine, K., Bens, O., Leopold, M. & J. Winkelbauer (2011): Late Quaternary Environmental Changes from Aeolian and Fluvial Geoarchives in the Southwestern Kalahari, South Africa: Implications for Past African Climate Dynamics. - South African Journal of Geology, 114 (2).

  6. Strategies towards advanced ion track-based biosensors

    NASA Astrophysics Data System (ADS)

    Alfonta, L.; Bukelman, O.; Chandra, A.; Fahrner, W. R.; Fink, D.; Fuks, D.; Golovanov, V.; Hnatowicz, V.; Hoppe, K.; Kiv, A.; Klinkovich, I.; Landau, M.; Morante, J. R.; Tkachenko, N. V.; Vacík, J.; Valden, M.

    Three approaches towards ion track-based biosensors appear to be feasible. The development of the first one began a decade ago [Siwy, Z.; Trofin, L.; Kohl, P.; Baker, L.A.; Martin, C.R.; Trautmann, C. J. Am. Chem. Soc. 2005, 127, 5000-5001; Siwy, Z.S.; Harrell, C.C.; Heins, E.; Martin, C.R.; Schiedt, B.; Trautmann, C.; Trofin, L.; Polman, A. Presented at the 6th International Conference on Swift Heavy Ions in Matter, Aschaffenburg, Germany, May 28-31, 2005] and makes use of the concept that the presence of certain biomolecules within liquids can block the passage through narrow pores if being captured there, thus switching off the pore's electrical conductivity. The second, having been successfully tested half a year ago [Fink, D.; Klinkovich, I.; Bukelman, O.; Marks, R.S.; Fahrner, W.; Kiv, A.; Fuks, D.; Alfonta, L. Biosens. Bioelectron. 2009, 24, 2702-2706], is based on the accumulation of enzymatic reaction products within the confined volume of narrow etched ion tracks which modifies the pore's electrical conductivity. The third and most elegant, at present under development, will exploit the charge transfer from enzymes to semiconductors embedded within etched tracks, enabling the enzymes undergoing specific reactions with the biomolecules to be detected. These strategies can be realized either within carrier-free nanoporous polymeric membranes embedded in the corresponding bioliquids, or within contacted nanoporous insulating layers on semiconducting substrates, the so-called TEMPOS structures [Fink, D.; Petrov, A.; Hoppe, H.; Fahrner, W.R.; Papaleo, R.M.; Berdinsky, A.; Chandra, A.; Biswas, A.; Chadderton, L.T. Nucl. Instrum. Methods B 2004, 218, 355-361]. The latter have the advantage of exhibiting a number of peculiar electronic properties, such as the ability for logic and/or combination of input signals, tunable polarity, negative differential resistances, tunability by external parameters such as light, magnetic fields, etc. and self-pulsations, which

  7. Molecular controls on Cu and Zn isotopic fractionation in Fe-Mn crusts

    NASA Astrophysics Data System (ADS)

    Little, S. H.; Sherman, D. M.; Vance, D.; Hein, J. R.

    2014-06-01

    The isotopic systems of the transition metals are increasingly being developed as oceanic tracers, due to their tendency to be fractionated by biological and/or redox-related processes. However, for many of these promising isotope systems the molecular level controls on their isotopic fractionations are only just beginning to be explored. Here we investigate the relative roles of abiotic and biotic fractionation processes in controlling modern seawater Cu and Zn isotopic compositions. Scavenging to Fe-Mn oxides represents the principal output for Cu and Zn to sediments deposited under normal marine (oxic) conditions. Using Fe-Mn crusts as an analogue for these dispersed phases, we investigate the phase association and crystal chemistry of Cu and Zn in such sediments. We present the results of an EXAFS study that demonstrate unequivocally that Cu and Zn are predominantly associated with the birnessite (δ-MnO2) phase in Fe-Mn crusts, as previously predicted from sequential leaching experiments (e.g., Koschinsky and Hein, 2003). The crystal chemistry of Cu and Zn in the crusts implies a reduction in coordination number in the sorbed phase relative to the free metal ion in seawater. Thus, theory would predict equilibrium fractionations that enrich the heavy isotope in the sorbed phase (e.g., Schauble, 2004). In natural samples, Fe-Mn crusts and nodules are indeed isotopically heavy in Zn isotopes (at ∼1‰) compared to deep seawater (at ∼0.5‰), consistent with the predicted direction of equilibrium isotopic fractionation based on our observations of the coordination environment of sorbed Zn. Further, ∼50% of inorganic Zn‧ is chloro-complexed (the other ∼50% is present as the free Zn2+ ion), and complexation by Cl- is also predicted to favour equilibrium partitioning of light Zn isotopes into the dissolved phase. The heavy Zn isotopic composition of Fe-Mn crusts and nodules relative to seawater can therefore be explained by an inorganic fractionation during

  8. EDITORIAL: Computational materials science Computational materials science

    NASA Astrophysics Data System (ADS)

    Kahl, Gerhard; Kresse, Georg

    2011-10-01

    Special issue in honour of Jürgen Hafner On 30 September 2010, Jürgen Hafner, one of the most prominent and influential members within the solid state community, retired. His remarkably broad scientific oeuvre has made him one of the founding fathers of modern computational materials science: more than 600 scientific publications, numerous contributions to books, and a highly cited monograph, which has become a standard reference in the theory of metals, witness not only the remarkable productivity of Jürgen Hafner but also his impact in theoretical solid state physics. In an effort to duly acknowledge Jürgen Hafner's lasting impact in this field, a Festsymposium was held on 27-29 September 2010 at the Universität Wien. The organizers of this symposium (and authors of this editorial) are proud to say that a large number of highly renowned scientists in theoretical condensed matter theory—co-workers, friends and students—accepted the invitation to this celebration of Hafner's jubilee. Some of these speakers also followed our invitation to submit their contribution to this Festschrift, published in Journal of Physics: Condensed Matter, a journal which Jürgen Hafner served in 2000-2003 and 2003-2006 as a member of the Advisory Editorial Board and member of the Executive Board, respectively. In the subsequent article, Volker Heine, friend and co-worker of Jürgen Hafner over many decades, gives an account of Hafner's impact in the field of theoretical condensed matter physics. Computational materials science contents Theoretical study of structural, mechanical and spectroscopic properties of boehmite (γ-AlOOH) D Tunega, H Pašalić, M H Gerzabek and H Lischka Ethylene epoxidation catalyzed by chlorine-promoted silver oxide M O Ozbek, I Onal and R A Van Santen First-principles study of Cu2ZnSnS4 and the related band offsets for photovoltaic applicationsA Nagoya, R Asahi and G Kresse Renormalization group study of random quantum magnetsIstván A Kovács and

  9. Global Paleobathymetry for the Cenomanian-Turonian (90 Ma)

    NASA Astrophysics Data System (ADS)

    Goswami, A.; Olson, P.; Hinnov, L. A.; Gnanadesikan, A.

    2014-12-01

    , C., Steinberger, B., Heine, C., 2008a, Science, 319, 1357-1362. Scotese, C., 2011, PALEOMAP Project, Arlington, Texas. Turcotte, D., Schubert, G., 2002, Cambridge University Press, Cambridge, 456 p. Whittaker, J., Goncharov, A., Williams, S., Müller, R., Leitchenkov, G., 2013, Geochemistry, Geophysics, Geosystems. DOI:10.1002/ggge.20181

  10. Fluid Inclusion characteristics of syn-late orogenic Co-Ni-Cu-Au deposits in the Siegerland District of the Rhenish Massif, Germany

    NASA Astrophysics Data System (ADS)

    Wohlgemuth, Christoph; Hellmann, André; Meyer, Franz Michael

    2013-04-01

    The Siegerland District is located in the fold-and-thrust-belt of the Rhenish Massif and hosts various syn- late orogenic vein-hosted hydrothermal mineralization types. Peak-metamorphism and deformation occurred at 312-316 ± 10 Ma (Ahrendt et al., 1978) at pT-conditions of 280 - 320 °C and 0.7 - 1.4 kbar (Hein, 1993). The district is known for synorogenic siderite-quartz mineralization formed during peak-metamorphic conditions. At least 4 syn-late orogenic mineralization types are distinguished: Co-Ni-Cu-Au, Pb-Zn-Cu, Sb-Au and hematite-digenite-bornite mineralization (Hellmann et al., 2012b). Co-Ni-Cu-Au mineralization of the Siegerland District belongs to the recently defined class of metasediment hosted synorogenic Co-Cu-Au deposits (i.e. Slack et al, 2010). Ore minerals are Fe-Co-Ni sulpharsenides, bearing invisible gold, chalcopyrite, and minor As-bearing pyrite. The gangue is quartz. The alteration mineralogy comprises chlorite, illite-muscovite and quartz. The epigenetic quartz veins are closely related to the formation of reverse faults (Hellmann et al., 2011a). Microthermometric studies of fluid inclusions concerning the relationship between mineralization and microstructures have not been done so far for this deposit-class and this will be addressed here. Fluid inclusions are investigated in hydrothermally formed vein-quartz, selected from Co-Ni-Cu-Au mineralization bearing veins showing only minor overprints by later mineralization types. Two quartz generations are distinguished: subhedral quartz-I showing growth zonation and fine grained, recrystallized- and newly formed quartz-II grains forming irregular masses and fracture fillings in quartz-I. Co-Ni-Fe sulpharsenides and chalcopyrite are closely intergrown with quartz-II, implying their contemperaneous formation. However, fluid inclusions in quartz-II are often small, therefore fluid inclusions in quartz-I have been mostly investigated. In total, 180 inclusions from 4 different deposits have been

  11. [Steadiness and progress. Medicine in Würzburg in the mirror of the centuries - a contribution to the foundation of the University of Würzburg 600 years ago].

    PubMed

    Vollmuth, Ralf; Keil, Gundolf

    2003-01-01

    his family (like his sons Johann Barthel and Adadam Elias von Siebold), reorganized the medical faculty, which had brought her in the byname 'Academia Sieboldiana". In the beginning of the 19th century the recovery of the faculty moved on more and more: OUtstanding representatives like Ignaz Döllinger, Johann Lukas Schoenlein and Franz von Rinecker founded by their great medical-scientific and organizational achievements, the high reputation of the medical faculty of Würzburg. Especially in the second half of the 19th century the University of Würzburg was in a leading position in a lot of traditional disciplines and in the developing and establishing of new medical fields, shown by names like Franz Kiwisch Ritter von Rotterau and Friedrich Wilhelm Scanzoni von Lichtenfels, Cajetan von Textor and Wenzel von Linhart, Rudolf Virchow, Albert Kölliker, Franz von Leydig, Carl Joseph von Ringelmann, Johann Joseph von Scherer, Johann Georg Heine, Adolf Fick or Carl Gerhardt.

  12. Development and evaluation of a questionnaire to measure the perceived implementation of the mission statement of a competency based curriculum

    PubMed Central

    2012-01-01

    Background A mission statement (MS) sets out the long-term goals of an institution and is supposed to be suited for studying learning environments. Yet, hardly any study has tested this issue so far. The aim of the present study was the development and psychometric evaluation of an MS-Questionnaire (MSQ) focusing on explicit competencies. We investigated to what extent the MSQ captures the construct of learning environment and how well a faculty is following - in its perception - a competency orientation in a competency-based curriculum. Methods A questionnaire was derived from the MS “teaching” (Medical Faculty, Heinrich-Heine University Düsseldorf) which was based on (inter-) nationally accepted goals and recommendations for a competency based medical education. The MSQ was administered together with the Dundee Ready Education Environment Measure (DREEM) to 1119 students and 258 teachers. Cronbach’s alpha was used to analyze the internal consistency of the items. Explorative factor analyses were performed to analyze homogeneity of the items within subscales and factorial validity of the MSQ. Item discrimination was assessed by means of part-whole corrected discrimination indices, and convergent validity was analyzed with respect to DREEM. Demographic variations of the respondents were used to analyze the inter-group variations in their responses. Results Students and teachers perceived the MS implementation as “moderate” and on average, students differed significantly in their perception of the MS. They thought implementation of the MS was less successful than faculty did. Women had a more positive perception of educational climate than their male colleagues and clinical students perceived the implementation of the MS on all dimensions significantly worse than preclinical students. The psychometric properties of the MSQ were very satisfactory: Item discrimination was high. Similarly to DREEM, the MSQ was highly reliable among students (α = 0.92) and

  13. Volcanic facies and preliminary geochemical observations of the Goren greenstone belt, Burkina Faso

    NASA Astrophysics Data System (ADS)

    Peters, Luke

    2013-04-01

    Volcanic facies and preliminary geochemical observations of the Goren greenstone belt, Burkina Faso L.F.H. Peters and K.A.A Hein School of Geosciences, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa. The Goren Greenstone Belt (GGB) is a Palaeoproterozoic volcano-sedimentary belt situated in the northeast of Burkina Faso in the West African craton (WAC). Basalt is the main volcanic constituent of the GGB, specifically mid-ocean ridge basalts (MORBS), which have undergone pervasive greenschist facies metamorphism during at least 2 deformation including the Tangaean Event (2170-2130 Ma) and Eburnean Orogeny (2130-1980 Ma). Remarkably, many of the primary textures and minerals remain intact in less deformed regions of the GBB. Textural characteristics and petrographic analyses include aphyric and aphanitic textures, amygdales, hyaloclastic brecciation, pillow structures and preserved (chloritised) volcanic glass. Despite the ubiquitous presence of chlorite and epidote, plagioclase and clinopyroxene microlites are fairly common albeit altered. Phenocrysts (< 1 mm) of plagioclase and CPX are present in some samples but aphyric texture is dominant. These textures indicate that the basalts represent coherent units of sub-aqueous extrusion from a proximal volcanic facies setting relative to the original magma conduit. A repetitious succession of Fe-rich meta-siltstones, fine-grained, carbonaceous, Fe-rich exhalatives and volcaniclastic units is intercalated with the basalts. The volcaniclastic units contrast with the MORBs, which raises questions about the source region of the volcaniclastics. In hand sample, the volcaniclastic rocks show an array of various sized fragments, compared to the fine-grained nature of the MORBs. They are dominated by euhedral, zoned, brown volcanic hornblende, large (2.5-5 mm) euhedral plagioclase crystals, and sub-angular to rounded quartz grains in a poorly sorted volcanogenic sedimentary sequence. Due to the

  14. Morphology, sedimentology and stratigraphic implication of debris-covered glacier deposits from the LGM and Lateglacial (Eastern Alps, Austria)

    NASA Astrophysics Data System (ADS)

    Reitner, Jürgen M.; Seidl, Sabrina; Wagreich, Michael

    2013-04-01

    the morphostratigraphic characteristics of Younger Dryas (Egesen) stadial with multiple, sharp crested moraine ridges (e.g. Ivy-Ochs et al. 2008), the unusual large glacier extent is due to the rock avalanche debris cover and its insulating effect. In both cases the maximum elevation of lateral moraines (MELM - method) gave the most reliable estimates of ELAs with reconstructed low AARs of around 0.5 compared to the standard assumption for Lateglacial glaciers with a ratio around 0.65. Thus, stratigraphic correlations of moraines should be done not until morphological features and lithofacies have been analyzed considering the whole geological setting. Ivy-Ochs, S., Kerschner, H., Reuther, A., Preusser, F., Heine, K., Maisch, M., Kubik, P.W. and Ch. Schlüchter (2008):Chronology of the last glacial cycle in the Northern European Alps. Journal of Quaternary Science 23(6-7), 559-573.

  15. Early breakup of Gondwana: constraints from global plate motion models

    NASA Astrophysics Data System (ADS)

    Seton, Maria; Zahirovic, Sabin; Williams, Simon; Whittaker, Joanne; Gibbons, Ana; Muller, Dietmar; Brune, Sascha; Heine, Christian

    2015-04-01

    Supercontinent break-up and amalgamation is a fundamental Earth cycle, contributing to long-term sea-level fluctuations, species diversity and extinction events, long-term greenhouse-icehouse cycles and changes in the long-wavelength density structure of the mantle. The most recent and best-constrained example involves the fragmentation of Gondwana, starting with rifting between Africa/Madagascar and Antarctica in the Early Jurassic and ending with the separation of the Lord Howe microcontinental blocks east of Australia in the Late Cretaceous. Although the first order configuration of Gondwana within modern reconstructions appears similar to that first proposed by Wegener a century ago, recent studies utilising a wealth of new geophysical and geological data provide a much more detailed picture of relative plate motions both during rifting and subsequent seafloor spreading. We present our latest global plate motion model that includes extensive, new regional analyses. These include: South Atlantic rifting, which started at 150 Ma and propagated into cratonic Africa by 145 Ma (Heine et al., 2013); rifting and early seafloor spreading between Australia, India and Antarctica, which reconciles the fit between Broken Ridge-Kergulean Plateau and the eastern Tasman region (Whittaker et al., 2013); rifting of continental material from northeastern Gondwana and its accretion onto Eurasia and SE Asia including a new model of microcontinent formation and early seafloor spreading in the eastern Indian Ocean (Gibbons et al., 2012; 2013; in review; Williams et al., 2013; Zahirovic et al., 2014); and a new model for the isolation of Zealandia east of Australia, with rifting initiating at 100 Ma until the start of seafloor spreading in the Tasman Sea at ~85 Ma (Williams et al., in prep). Using these reconstructions within the open-source GPlates software, accompanied by a set of evolving plates and plate boundaries, we can explore the factors that govern the behavior of plate

  16. Using geoinformatics and cultural anthropology to identify links between land change, driving forces and actors in the Okavango catchment

    NASA Astrophysics Data System (ADS)

    Röder, Achim; Stellmes, Marion; Pröpper, Michael; Schneibel, Anne

    2015-04-01

    The recent acceleration of land use transformations, coupled with an increasing global population has manifested in an alteration of almost all terrestrial ecosystems (Millenium Ecosystem Assessment 2005). In particular, the extension and intensification of agricultural and pastoral uses has supported unprecedented rates of population growth (Ellis and Ramankutty 2008). However, this development stands opposed to increased greenhouse gas emissions, declining biodiversity, declining air quality and increasing soil degradation, being reflected in the general reduction in ecosystem services and functions (Sala, Chapin III et al. 2000; Butchart, Walpole et al. 2010; Banwart 2011; Lal 2013). Such global change processes are to a large degree driven by land-use transformations or modifications (Foley, Defries et al. 2005). These are in turn a result of the complex interaction of factors playing out at different scales, varying from global market dynamics through national policies to regional planning and local traditions (Hein, van Koppen et al. 2006). The Okavango Basin represents a highly complex social-ecological system, where the variation in physio-geographic characteristics is reflected by manifold livelihood strategies in the three adjacent countries Angola, Namibia and Botswana. In mostly rural areas, small-scale subsistence agriculture, livestock-keeping and the utilization of natural resources such as thatch grass, timber, fruits etc. have traditionally formed the basis for human well-being. These strategies are juxtaposed by recent urban and transportation infrastructure developments, the expansion of commodity markets, the creation of commercial irrigated farming schemes and dams for energy production, or the growing role of tourism, in particular in the Delta region, as a major source of income generation. At present, the three countries bordering the river have individual legislations governing the use of natural resources, which usually originate at

  17. Fluctuations in seafloor spreading predicted by tectonic reconstructions and mantle convection models

    NASA Astrophysics Data System (ADS)

    Coltice, Nicolas; Seton, Maria; Rolf, Tobias; Müller, R. Dietmar; Tackley, Paul J.

    2013-04-01

    "ground-truth" for modeling this parameter. Both kinematic reconstructions and geodynamic models suggest the rate of production of new seafloor can vary by a factor of 3 over a Wilson cycle, with concomitant changes of the shape of the area vs. age distribution. Geodynamic models show seafloor production time-series contain fluctuations of time scales exceeding 500My that depend on the strength of the lithosphere and the amount of basal heating. References Coltice, N., Rolf, T., Tackley P.J., Labrosse, S., Dynamic causes of the relation between area and age of the ocean floor, Science 336, 335-338 (2012). Moresi, L., Solomatov, V., Mantle convection with a brittle lithosphere: Thoughts on the global tectonic style of the Earth and Venus, Geophys. J. 133, 669-682 (1998). Parsons, B., 1982, Causes and consequences of the relation between area and age of the ocean floor, J. of Geophys. Res. 87, 289-302 (1982). Rowley, D. B., History of Plate Creation 180 Ma to Present, Geol. Soc. of America Bull. 114, 927-933 (2002). Seton, M., Gaina, C., Müller, R.D., and Heine, C., Mid Cretaceous Seafloor Spreading Pulse: Fact or Fiction?, Geology, 37, 687-690 (2009). Seton, M., Müller, R.D., Zahirovic, S., Gaina, C., Torsvik, T.H., Shephard, G., Talsma, A., Gurnis, M., Turner, M., Maus, S., Chandler, M. (2012), Global continental and ocean basin reconstructions since 200 Ma, Earth Sci. Rev. 113, 212-270 (2012). Tackley, P.J., Self-consistent generation of tectonic plates in time-dependent, three-dimensional mantle convection simulations, part 1: Pseudoplastic yielding, Geoch. Geophys. Geosys. 1 (2000a). Tackley, P.J., Self-consistent generation of tectonic plates in time-dependent, three-dimensional mantle convection simulations, part 2: Strain weakening and asthenosphere, Geochem. Geophys. Geosys. 1, (2000b).

  18. Fractures, not Plumes, Have Controlled Major Seamount Volcanism in the Pacific over 170 Million Years

    NASA Astrophysics Data System (ADS)

    Natland, J. H.; Winterer, E. L.

    2003-12-01

    shift laterally in response to whatever was occurring along its eastern spreading boundaries. A very consistent and strong stress regime therefore developed across the Pacific plate with a NNE direction of least principal stress. The change in stress orientation may have taken up to 10 million years, during an interval marked by little or no volcanic productivity at the western end of the Hawaiian chain. Since that time, the predominant alignment of both linear island chains and Puka Puka-type ridges, from the Kodiak-Bowie chain in the Gulf of Alaska to the Louisville Ridge south of the Antarctic convergence, has been orthogonal to this direction. Development of large-volume persistent chains and shorter small-volume chains indicates patterns of differential stress in the plate, variable fertility and geochemistry of the asthenosphere and/or shallow convective overturn of the asthenosphere rather than the action of mantle plumes of different sizes and depths of origin. Tapping of enriched mantle by widespread volcano clusters during the Mesozoic suggests the presence of a shallow asthenospheric source layer rather than multiple narrow conduits. (1) Hieronymus, C.F., and Bercovici, D. 2000. Earth Planet. Sci. Lett. 181, 539-554. (2) Davis, A.S., Gray, L.B., Clague, D.A., and Hein, J.R., 2002 Geochem. Geophys. Geosyst. 3: 10.1029/2001GC0000190, 1-28.

  19. PREFACE: A tribute to Virginio Bortolani

    NASA Astrophysics Data System (ADS)

    Brivio, Gian Paolo

    2007-08-01

    published by Plenum Press in 1990, are still a classic in surface science, and we often refer to them as the 'red book' by the colour of its cover reminiscent of another more famous book. But I do not wish to dwell upon pleasant memories of my relationship with Virginio Bortolani any longer. We should better record a few important facts of his broad activity. J P Toennies will outline Bortolani's achievements in the field of surface phonons and vibrations in a review article of this volume. So I would like to stress other very important contributions of his to the scientific development in this country and to the international community. In the late seventies surface physics was being studied by very few and tiny groups in Italy (mainly at Genova, Milano and Roma Universities). But Bortolani was able to form the first theoretical group of international reputation in this field in Italy at Modena University. In this respect he was surely helped by his previous experience at the Cavendish Laboratory working with V Heine on the theory of pseudopotentials and with N Mott. This allowed him to be at the forefront of condensed matter theory so that to propose and carry out exciting research subjects. Bortolani also supervised all the initiatives in the 70s and 80s from which Modena has grown so much as to be now considered an internationally recognized centre of surface science and nanotechnology. Second, by organizing a conference in Modena every year the week before Christmas (the so-called Congressino di Modena by the Italian participants), he promoted the diffusion of surface physics in the country: it became soon traditional for bright young physicists to come to Modena on that occasion, and, because of the exciting and friendly atmosphere, to turn to surface investigations. The catalysing activity of Bortolani is also confirmed by the number of his students who have matured into excellent scientists or technologists: Carlo Calandra, Carlo Maria Bertoni, Franca Manghi

  20. Editorial: Focus on Atom Optics and its Applications

    NASA Astrophysics Data System (ADS)

    Schmidt-Kaler, F.; Pfau, T.; Schmelcher, P.; Schleich, W.

    2010-06-01

    Atom optics employs the modern techniques of quantum optics and laser cooling to enable applications which often outperform current standard technologies. Atomic matter wave interferometers allow for ultra-precise sensors; metrology and clocks are pushed to an extraordinary accuracy of 17 digits using single atoms. Miniaturization and integration are driven forward for both atomic clocks and atom optical circuits. With the miniaturization of information-storage and -processing devices, the scale of single atoms is approached in solid state devices, where the laws of quantum physics lead to novel, advantageous features and functionalities. An upcoming branch of atom optics is the control of single atoms, potentially allowing solid state devices to be built atom by atom; some of which would be applicable in future quantum information processing devices. Selective manipulation of individual atoms also enables trace analysis of extremely rare isotopes. Additionally, sources of neutral atoms with high brightness are being developed and, if combined with photo ionization, even novel focused ion beam sources are within reach. Ultracold chemistry is fertilized by atomic techniques, when reactions of chemical constituents are investigated between ions, atoms, molecules, trapped or aligned in designed fields and cooled to ultra-low temperatures such that the reaction kinetics can be studied in a completely state-resolved manner. Focus on Atom Optics and its Applications Contents Sensitive gravity-gradiometry with atom interferometry: progress towards an improved determination of the gravitational constant F Sorrentino, Y-H Lien, G Rosi, L Cacciapuoti, M Prevedelli and G M Tino A single-atom detector integrated on an atom chip: fabrication, characterization and application D Heine, W Rohringer, D Fischer, M Wilzbach, T Raub, S Loziczky, XiYuan Liu, S Groth, B Hessmo and J Schmiedmayer Interaction of a propagating guided matter wave with a localized potential G L Gattobigio, A

  1. Update of potency factors for asbestos-related lung cancer and mesothelioma.

    PubMed

    Berman, D Wayne; Crump, Kenny S

    2008-01-01

    The most recent update of the U.S. Environmental Protection Agency (EPA) health assessment document for asbestos (Nicholson, 1986, referred to as "the EPA 1986 update") is now 20 years old. That document contains estimates of "potency factors" for asbestos in causing lung cancer (K(L)'s) and mesothelioma (K(M)'s) derived by fitting mathematical models to data from studies of occupational cohorts. The present paper provides a parallel analysis that incorporates data from studies published since the EPA 1986 update. The EPA lung cancer model assumes that the relative risk varies linearly with cumulative exposure lagged 10 years. This implies that the relative risk remains constant after 10 years from last exposure. The EPA mesothelioma model predicts that the mortality rate from mesothelioma increases linearly with the intensity of exposure and, for a given intensity, increases indefinitely after exposure ceases, approximately as the square of time since first exposure lagged 10 years. These assumptions were evaluated using raw data from cohorts where exposures were principally to chrysotile (South Carolina textile workers, Hein et al., 2007; mesothelioma only data from Quebec miners and millers, Liddell et al., 1997) and crocidolite (Wittenoom Gorge, Australia miners and millers, Berry et al., 2004) and using published data from a cohort exposed to amosite (Paterson, NJ, insulation manufacturers, Seidman et al., 1986). Although the linear EPA model generally provided a good description of exposure response for lung cancer, in some cases it did so only by estimating a large background risk relative to the comparison population. Some of these relative risks seem too large to be due to differences in smoking rates and are probably due at least in part to errors in exposure estimates. There was some equivocal evidence that the relative risk decreased with increasing time since last exposure in the Wittenoom cohort, but none either in the South Carolina cohort up to 50

  2. Editorial: Focus on Atom Optics and its Applications

    NASA Astrophysics Data System (ADS)

    Schmidt-Kaler, F.; Pfau, T.; Schmelcher, P.; Schleich, W.

    2010-06-01

    Atom optics employs the modern techniques of quantum optics and laser cooling to enable applications which often outperform current standard technologies. Atomic matter wave interferometers allow for ultra-precise sensors; metrology and clocks are pushed to an extraordinary accuracy of 17 digits using single atoms. Miniaturization and integration are driven forward for both atomic clocks and atom optical circuits. With the miniaturization of information-storage and -processing devices, the scale of single atoms is approached in solid state devices, where the laws of quantum physics lead to novel, advantageous features and functionalities. An upcoming branch of atom optics is the control of single atoms, potentially allowing solid state devices to be built atom by atom; some of which would be applicable in future quantum information processing devices. Selective manipulation of individual atoms also enables trace analysis of extremely rare isotopes. Additionally, sources of neutral atoms with high brightness are being developed and, if combined with photo ionization, even novel focused ion beam sources are within reach. Ultracold chemistry is fertilized by atomic techniques, when reactions of chemical constituents are investigated between ions, atoms, molecules, trapped or aligned in designed fields and cooled to ultra-low temperatures such that the reaction kinetics can be studied in a completely state-resolved manner. Focus on Atom Optics and its Applications Contents Sensitive gravity-gradiometry with atom interferometry: progress towards an improved determination of the gravitational constant F Sorrentino, Y-H Lien, G Rosi, L Cacciapuoti, M Prevedelli and G M Tino A single-atom detector integrated on an atom chip: fabrication, characterization and application D Heine, W Rohringer, D Fischer, M Wilzbach, T Raub, S Loziczky, XiYuan Liu, S Groth, B Hessmo and J Schmiedmayer Interaction of a propagating guided matter wave with a localized potential G L Gattobigio, A

  3. Using geoinformatics and cultural anthropology to identify links between land change, driving forces and actors in the Okavango catchment

    NASA Astrophysics Data System (ADS)

    Röder, Achim; Stellmes, Marion; Pröpper, Michael; Schneibel, Anne

    2015-04-01

    The recent acceleration of land use transformations, coupled with an increasing global population has manifested in an alteration of almost all terrestrial ecosystems (Millenium Ecosystem Assessment 2005). In particular, the extension and intensification of agricultural and pastoral uses has supported unprecedented rates of population growth (Ellis and Ramankutty 2008). However, this development stands opposed to increased greenhouse gas emissions, declining biodiversity, declining air quality and increasing soil degradation, being reflected in the general reduction in ecosystem services and functions (Sala, Chapin III et al. 2000; Butchart, Walpole et al. 2010; Banwart 2011; Lal 2013). Such global change processes are to a large degree driven by land-use transformations or modifications (Foley, Defries et al. 2005). These are in turn a result of the complex interaction of factors playing out at different scales, varying from global market dynamics through national policies to regional planning and local traditions (Hein, van Koppen et al. 2006). The Okavango Basin represents a highly complex social-ecological system, where the variation in physio-geographic characteristics is reflected by manifold livelihood strategies in the three adjacent countries Angola, Namibia and Botswana. In mostly rural areas, small-scale subsistence agriculture, livestock-keeping and the utilization of natural resources such as thatch grass, timber, fruits etc. have traditionally formed the basis for human well-being. These strategies are juxtaposed by recent urban and transportation infrastructure developments, the expansion of commodity markets, the creation of commercial irrigated farming schemes and dams for energy production, or the growing role of tourism, in particular in the Delta region, as a major source of income generation. At present, the three countries bordering the river have individual legislations governing the use of natural resources, which usually originate at

  4. FOREWORD: Some thoughts about Jürgen Hafner's work in computational materials science Some thoughts about Jürgen Hafner's work in computational materials science

    NASA Astrophysics Data System (ADS)

    Heine, Volker

    2011-10-01

    and Kresse G 1994 Structral and electronic properties of clean and hydrogenated diamond (100) surfaces Europhys. Lett. 28 659-64 [10] Krajčí and Hafner J 2008 Ab-initio studies of quasicrystalline surfaces Quasicrystals (Handbook of Metal Physics vol 2) ed T Fujiwara and Y Ishii (Amsterdam: Elsevier) chapter 9, pp 313-55 [11] Raybaud P, Hafner J, Kresse G, Kasztelan S and Toulhoat H 2000 Structure, energetics and electronic properties of the surface of a promoted MoS2 catalyst: an ab-initio local-density-functional study J. Catalysis 190 128-43 [12] Hafner J, Benco L and Bucko T 2006 Acid-based catalysis in zeolites investigated by density-functional methods Top. Catalysis 37 41-54 [13] Hafner J 1989 Formation of polyanionic clusters in liquid potassium-lead alloys: a molecular-dynamics study J. Phys.: Condens. Matter 1 1133-40 [14] Meeks P E 1976 Vibrational spectra and topological structure of tetrahedrally bonded amorphous semiconductors Phil. Mag. 33 897-908 [15] See articles by Heine V, Bullet D, Haydock R and Kelly M J 1980 Solid State Physics—Advances in Research and Applications vol 35, ed H Ehrenreich, D Turnbull and F Seitz (New York: Academic) [16] Hafner J 1980 The dynamical properties of metallic glasses Liquids and Amorphous Metals (NATO-ASI Ser. E vol 36) ed E Lüscher and H Coufal (Sijthoff and Nordhoff: Alpen van Rijn) pp 199-209 [17] Hafner J 1987 From Hamiltonians to Phase Diagrams—The Electronic and Statistical-Mechanical Theory of sp-Bonded Metals and Alloys (Solid State Sciences Series vol 70) (Berlin: Springer) p 415 [18] Hafner J and Heine V 1983 The crystal structure of the elements: pseudopotential theory revisited J. Phys. F: Met. Phys. 13 2479-501 [19] Hafner J and Kahl G 1984 The structure of the elements in the liquid state J. Phys. F: Met. Phys. 14 2259-78 [20] Denton A R and Hafner J 1997 Thermodynamically stable one-component quasicrystals: a density-functional survey of relative stabilities Phys. Rev. B 56 2469-82 [21] Hafner J

  5. FOREWORD: Tackling inverse problems in a Banach space environment: from theory to applications Tackling inverse problems in a Banach space environment: from theory to applications

    NASA Astrophysics Data System (ADS)

    Schuster, Thomas; Hofmann, Bernd; Kaltenbacher, Barbara

    2012-10-01

    of concrete instances with special properties. The aim of this special section is to provide a forum for highly topical ongoing work in the area of regularization in Banach spaces, its numerics and its applications. Indeed, we have been lucky enough to obtain a number of excellent papers both from colleagues who have previously been contributing to this topic and from researchers entering the field due to its relevance in practical inverse problems. We would like to thank all contributers for enabling us to present a high quality collection of papers on topics ranging from various aspects of regularization via efficient numerical solution to applications in PDE models. We give a brief overview of the contributions included in this issue (here ordered alphabetically by first author). In their paper, Iterative regularization with general penalty term—theory and application to L1 and TV regularization, Radu Bot and Torsten Hein provide an extension of the Landweber iteration for linear operator equations in Banach space to general operators in place of the inverse duality mapping, which corresponds to the use of general regularization functionals in variational regularization. The L∞ topology in data space corresponds to the frequently occuring situation of uniformly distributed data noise. A numerically efficient solution of the resulting Tikhonov regularization problem via a Moreau-Yosida appriximation and a semismooth Newton method, along with a δ-free regularization parameter choice rule, is the topic of the paper L∞ fitting for inverse problems with uniform noise by Christian Clason. Extension of convergence rates results from classical source conditions to their generalization via variational inequalities with a priori and a posteriori stopping rules is the main contribution of the paper Regularization of linear ill-posed problems by the augmented Lagrangian method and variational inequalities by Klaus Frick and Markus Grasmair, again in the context of some

  6. PREFACE: A tribute to Virginio Bortolani

    NASA Astrophysics Data System (ADS)

    Brivio, Gian Paolo

    2007-08-01

    published by Plenum Press in 1990, are still a classic in surface science, and we often refer to them as the 'red book' by the colour of its cover reminiscent of another more famous book. But I do not wish to dwell upon pleasant memories of my relationship with Virginio Bortolani any longer. We should better record a few important facts of his broad activity. J P Toennies will outline Bortolani's achievements in the field of surface phonons and vibrations in a review article of this volume. So I would like to stress other very important contributions of his to the scientific development in this country and to the international community. In the late seventies surface physics was being studied by very few and tiny groups in Italy (mainly at Genova, Milano and Roma Universities). But Bortolani was able to form the first theoretical group of international reputation in this field in Italy at Modena University. In this respect he was surely helped by his previous experience at the Cavendish Laboratory working with V Heine on the theory of pseudopotentials and with N Mott. This allowed him to be at the forefront of condensed matter theory so that to propose and carry out exciting research subjects. Bortolani also supervised all the initiatives in the 70s and 80s from which Modena has grown so much as to be now considered an internationally recognized centre of surface science and nanotechnology. Second, by organizing a conference in Modena every year the week before Christmas (the so-called Congressino di Modena by the Italian participants), he promoted the diffusion of surface physics in the country: it became soon traditional for bright young physicists to come to Modena on that occasion, and, because of the exciting and friendly atmosphere, to turn to surface investigations. The catalysing activity of Bortolani is also confirmed by the number of his students who have matured into excellent scientists or technologists: Carlo Calandra, Carlo Maria Bertoni, Franca Manghi

  7. Foreword: Sir John Pendry FRS Sir John Pendry FRS

    NASA Astrophysics Data System (ADS)

    Inglesfield, John; Echenique, Pedro

    2008-07-01

    John Pendry John Inglesfield and Pedro Echenique write: John Pendry's 65th birthday is on 4 July 2008, and this issue of the Journal of Physics: Condensed Matter is dedicated to him, with articles by friends, colleagues, and former students. By any standards, John Pendry is a great scientist, who has made—and continues to make—an enormous contribution to physics; the wide range of his interests is reflected in the scope of these articles. Not many scientists can establish a completely new and unexpected area of research, but this has been John's achievement in the last few years in the field of metamaterials, materials whose electromagnetic properties depend on their structure rather than the materials of which the structure is built. In this way, structures with effectively negative electrical permittivity and negative magnetic permeability can be constructed, demonstrating negative refraction; through metamaterials scientists now have access to properties not found in nature, and never previously explored experimentally. Never a week goes by without a potential new application of metamaterials, whether it is perfect lensing, or the cloak of invisibility. This has certainly led to tremendous visibility for John himself, with guest lectures all over the world, and radio and television appearances. John Pendry's first paper was published exactly 40 years ago, 'Analytic properties of pseudopotentials' [1], and since then he has published 310 articles at the latest count. But this first paper already reflected something of the way John works. His PhD project, with Volker Heine at the Cavendish Laboratory, was to interpret the scattering of low energy electrons from surfaces, the technique of LEED which was to become the method of choice for determining surface structure. Although the energy of the electrons in LEED is relatively low—say 50 eV—it is much higher than the energy of the conduction electrons, for which pseudopotentials had been devised, and John