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Sample records for air mole fraction

  1. Background Mole Fractions of Hydrocarbons in North America Determined from NOAA Global Reference Network Data

    NASA Astrophysics Data System (ADS)

    Mielke-Maday, I.

    2015-12-01

    The National Oceanic and Atmospheric Administration (NOAA) Global Monitoring Division (GMD) maintains a global reference network for over 50 trace gas species and analyzes discrete air samples collected by this network throughout the world at the Earth System Research Laboratory in Boulder, Colorado. In particular, flask samples are analyzed for a number of hydrocarbons with policy and health relevance such as ozone precursors, greenhouse gases, and hazardous air pollutants. Because this global network's sites are remote and therefore minimally influenced by local anthropogenic emissions, these data yield information about background ambient mole fractions and can provide a context for observations collected in intensive field campaigns, such as the Front Range Air Pollution and Photochemistry Experiment (FRAPPE), the Southeast Nexus (SENEX) study, and the DISCOVER-AQ deployments. Information about background mole fractions during field campaigns is critical for calculating hydrocarbon enhancements in the region of study and for assessing the extent to which a particular region's local emissions sources contribute to these enhancements. Understanding the geographic variability of the background and its contribution to regional ambient mole fractions is also crucial for the development of realistic regulations. We present background hydrocarbon mole fractions and their ratios in North America using data from air samples collected in the planetary boundary layer at tall towers and aboard aircraft from 2008 to 2014. We discuss the spatial and seasonal variability in these data. We present trends over the time period of measurements and propose possible explanations for these trends.

  2. Moles

    MedlinePlus

    ... sizes and shapes. Special cells that contain the pigment melanin cause the brown color. Facial moles are ... They also leave nevus cells behind and the pigment often seems to reappear. Back to Index The ...

  3. Injectant mole-fraction imaging in compressible mixing flows using planar laser-induced iodine fluorescence

    NASA Technical Reports Server (NTRS)

    Hartfield, Roy J., Jr.; Abbitt, John D., III; Mcdaniel, James C.

    1989-01-01

    A technique is described for imaging the injectant mole-fraction distribution in nonreacting compressible mixing flow fields. Planar fluorescence from iodine, seeded into air, is induced by a broadband argon-ion laser and collected using an intensified charge-injection-device array camera. The technique eliminates the thermodynamic dependence of the iodine fluorescence in the compressible flow field by taking the ratio of two images collected with identical thermodynamic flow conditions but different iodine seeding conditions.

  4. Methane mole fraction and δ13C above and below the trade wind inversion at Ascension Island in air sampled by aerial robotics

    NASA Astrophysics Data System (ADS)

    Brownlow, R.; Lowry, D.; Thomas, R. M.; Fisher, R. E.; France, J. L.; Cain, M.; Richardson, T. S.; Greatwood, C.; Freer, J.; Pyle, J. A.; MacKenzie, A. R.; Nisbet, E. G.

    2016-11-01

    Ascension Island is a remote South Atlantic equatorial site, ideal for monitoring tropical background CH4. In September 2014 and July 2015, octocopters were used to collect air samples in Tedlar bags from different heights above and below the well-defined Trade Wind Inversion (TWI), sampling a maximum altitude of 2700 m above mean sea level. Sampling captured both remote air in the marine boundary layer below the TWI and also air masses above the TWI that had been lofted by convective systems in the African tropics. Air above the TWI was characterized by higher CH4, but no distinct shift in δ13C was observed compared to the air below. Back trajectories indicate that lofted CH4 emissions from Southern Hemisphere Africa have bulk δ13CCH4 signatures similar to background, suggesting mixed emissions from wetlands, agriculture, and biomass burning. The campaigns illustrate the usefulness of unmanned aerial system sampling and Ascension's value for atmospheric measurement in an understudied region.

  5. Measurements of N2O and SF6 mole fraction between 1977 and 1998 in archived air samples from Cape Meares, Oregon

    NASA Astrophysics Data System (ADS)

    Rolfe, T.; Rice, A. L.; Radda, J.

    2015-12-01

    The quantification of greenhouse gas concentrations in the atmosphere is important for monitoring imbalances in their global budgets between sources and sinks and their changes in time. Nitrous oxide (N2O) is a strong radiative trace gas with a GWP of ~300 times CO2 over a 100 year period and an atmospheric lifetime of ~100 years. The preindustrial revolution background concentration of N2O was ~270 ppb. Today, the concentration is ~330 ppb. Sulfur hexafluoride (SF6) is another potent greenhouse gas with a long lifetime (800 to 3200 years) and very large GWP (~23000 times CO2 over a 100 year period). Its current atmospheric concentration is low (~8 ppt today). Direct measurements of N2O and SF6 in air prior to the mid-1990s are few. Over 200 archived atmospheric gas samples collected at Cape Meares, Oregon between 1977 and 1998 were analyzed for their N2O and SF6 concentrations using an Agilent (model 6890 N) gas chromatograph fitted with an electron capture detector using a two column "heart-cut" technique. Precision of measurement of N2O and SF6 is calculated at 0.13% (1σ) and 1.35% (1σ) respectively. N2O concentrations in the late 1970s and early 1980s average around 303 ppb, rising to 309 ppb in the early 1990s. Between 1980 and 1990, the increase in N2O concentrations is found to be ~0.5 ppb/yr. SF6 concentrations during the late 1970s and early 1980s average around 0.9 ppt and rise slowly, reaching 1.6 ppt in the 1990s. We find that the increase in SF6 between 1980 and 1990 to be ~0.07 ppt/yr. We also discuss sample integrity in storage and observed temporal trends of N2O and SF6.

  6. Raman line imaging for spatially and temporally resolved mole fraction measurements in internal combustion engines.

    PubMed

    Miles, P C

    1999-03-20

    An optical diagnostic system based on line imaging of Raman-scattered light has been developed to study the mixing processes in internal combustion engines. The system permits multipoint, single laser-shot measurements of CO(2), O(2), N(2), C(3)H(8), and H(2)O mole fractions with submillimeter spatial resolution. Selection of appropriate system hardware is discussed, as are subsequent data reduction and analysis procedures. Results are reported for data obtained at multiple crank angles and in two different engine flow fields. Measurements are made at 12 locations simultaneously, each location having measurement volume dimensions of 0.5 mm x 0.5 mm x 0.9 mm. The data are analyzed to obtain statistics of species mole fractions: mean, rms, histograms, and both spatial and cross-species covariance functions. The covariance functions are used to quantify the accuracy of the measured rms mole fraction fluctuations, to determine the integral length scales of the mixture inhomogeneities, and to quantify the cycle-to-cycle fluctuations in bulk mixture composition under well-mixed conditions.

  7. (H2)2 mole-fraction altitude profile in the atmosphere of Jupiter: A computational study

    NASA Technical Reports Server (NTRS)

    Slanina, Zdenek; Kim, Sang J.; Fox, Kenneth

    1994-01-01

    The mole fraction x(sub 2) of (H2)2 in equilibrium mixture with H2 under the atmospheric conditions of Jupiter is evaluated from the dimerization equilibrium constant calculated by quantum-chemical treatments and also from the Lennard-Jones potential. The treatments are of an ab initio type with the second and fourth order Moller-Plesset perturbation techniques and a basis set superposition error evaluation. The computed dimerization equilibrium constant is combined with observed height profiles of temperature and pressure. In six treatments considered it is found that the mole fraction decreases with increasing height. Various approximations suggest the dimeric mole fraction at the Jupiter 1 atm pressure level between 0.04 and 1.06%.

  8. Spatial and Temporal Variability of Methane Mole Fractions and Exchanges in and Between Soil, Snow, and the Atmosphere in a Tundra System in Northern Alaska

    NASA Astrophysics Data System (ADS)

    Agnan, Y.; Obrist, D.; Edwards, G. C.; Moore, C.; Hedge, C.; Helmig, D.; Paxton, D.; Jacques, H.

    2015-12-01

    An important global source of atmospheric methane (CH4) is production in tundra soils (an important global source). To place constraints on the potential role that tundra soils play in global CH4 cycling, we have been continuously measuring mole the air space in soils, snow, and the atmosphere as gradient-based surface-atmosphere fluxes for arctic tundra at Toolik Field Station (68° 38' N) starting in October 2014. We have found that atmospheric CH4 mole fractions were, on average, relatively constant during the first 9 months of sampling (averaging 1.93 µmol mol-1), with pronounced diel patterns starting in May and nighttime exceeding daytime mole fractions. However, gradients measured within the soil profile showed high variability in air withdrawn from different locations of these tundra soils (Typic Aquiturbels), with one soil profile indicating a CH4 sink during fall until January; mole fractions were similar to the atmospheric measurements during winter indicating no source or sink (average 1.89 µmol mol-1). A second soil profile 5 m away showed production of CH4 (average 2.48 µmol mol-1, two-times higher than atmospheric levels), even during mid-winter when soil temperatures were below -10 °C. Measurements of CH4 in interstitial snowpack air also exhibited a similar combination of sources and sinks. We used micrometeorological gradient surface flux measurements to confirm that the area was a net source of CH4 in fall, winter, and spring, with emissions averaging 26.6, 25.2, and 16.8 mg m-2 d-1, respectively. In the summer months, we saw strong diel flux patterns with deposition during day and emission at night, corresponding with observed diel variability in CH4 snowpack mole fractions. Our results indicated a high variability of tundra landscape CH4 fluxes, which locally shift from sources to sinks with high temporal variability. CH4 oxidation by methanotrophic bacteria probably occurs in tundra soils, confirming observations in one soil, snowpack, and

  9. Assessing filtering of mountaintop CO2 mole fractions for application to inverse models of biosphere-atmosphere carbon exchange

    NASA Astrophysics Data System (ADS)

    Brooks, B.-G. J.; Desai, A. R.; Stephens, B. B.; Bowling, D. R.; Burns, S. P.; Watt, A. S.; Heck, S. L.; Sweeney, C.

    2012-02-01

    There is a widely recognized need to improve our understanding of biosphere-atmosphere carbon exchanges in areas of complex terrain including the United States Mountain West. CO2 fluxes over mountainous terrain are often difficult to measure due to unusual and complicated influences associated with atmospheric transport. Consequently, deriving regional fluxes in mountain regions with carbon cycle inversion of atmospheric CO2 mole fraction is sensitive to filtering of observations to those that can be represented at the transport model resolution. Using five years of CO2 mole fraction observations from the Regional Atmospheric Continuous CO2 Network in the Rocky Mountains (Rocky RACCOON), five statistical filters are used to investigate a range of approaches for identifying regionally representative CO2 mole fractions. Test results from three filters indicate that subsets based on short-term variance and local CO2 gradients across tower inlet heights retain nine-tenths of the total observations and are able to define representative diel variability and seasonal cycles even for difficult-to-model sites where the influence of local fluxes is much larger than regional mole fraction variations. Test results from two other filters that consider measurements from previous and following days using spline fitting or sliding windows are overly selective. Case study examples showed that these windowing-filters rejected measurements representing synoptic changes in CO2, which suggests that they are not well suited to filtering continental CO2 measurements. We present a novel CO2 lapse rate filter that uses CO2 differences between levels in the model atmosphere to select subsets of site measurements that are representative on model scales. Our new filtering techniques provide guidance for novel approaches to assimilating mountain-top CO2 mole fractions in carbon cycle inverse models.

  10. Titan's Surface Brightness Temperatures and H2 Mole Fraction from Cassini CIRS

    NASA Technical Reports Server (NTRS)

    Jennings, Donald E.; Flasar, F. M.; Kunde, V. G.; Samuelson, R. E.; Pearl, J. C.; Nixon, C. A.; Carlson, R. C.; Mamoutkine, A. A.; Brasunas, J. C.; Guandique, E.; Achterberg, R. K.; Bjoraker, G. L.; Romani, P. N.; Segura, M. E.; Albright, S. A.; Elliott, M. H.; Tingley, J. S.; Calcutt, S.; Coustenis, A.; Bezard, B.; Courtin, R.

    2008-01-01

    The atmosphere of Titan has a spectral window of low opacity around 530/cm in the thermal infrared where radiation from the surface can be detected from space. The Composite Infrared spectrometer1 (CIRS) uses this window to measure the surface brightness temperature of Titan. By combining all observations from the Cassini tour it is possible to go beyond previous Voyager IRIS studies in latitude mapping of surface temperature. CIRS finds an average equatorial surface brightness temperature of 93.7+/-0.6 K, which is close to the 93.65+/-0.25 K value measured at the surface by Huygens HASi. The temperature decreases toward the poles, reaching 91.6+/-0.7 K at 90 S and 90.0+/-1.0 K at 87 N. The temperature distribution is centered in latitude at approximately 12 S, consistent with Titan's season of late northern winter. Near the equator the temperature varies with longitude and is higher in the trailing hemisphere, where the lower albedo may lead to relatively greater surface heating5. Modeling of radiances at 590/cm constrains the atmospheric H2 mole fraction to 0.12+/-0.06 %, in agreement with results from Voyager iris.

  11. Study of Pulse Laser Assisted Metalorganic Vapor Phase Epitaxy of InGaN with Large Indium Mole Fraction

    NASA Astrophysics Data System (ADS)

    Kangawa, Yoshihiro; Kawaguchi, Norihito; Hida, Ken-nosuke; Kumagai, Yoshinao; Koukitu, Akinori

    2004-08-01

    The indium composition of the InGaN film increases with decreasing growth temperature; however, the crystalline quality of the film is poor when it is grown at low temperatures. To form a high-quality InGaN film with a large indium mole fraction, Nd: YAG pulse laser assisted metalorganic vapor phase epitaxy (MOVPE) was carried out at low temperatures. The results suggest that film quality can be improved by pulse laser irradiation on the surface of the film.

  12. Comparison of the regional CO2 mole fraction filtering approaches at a WMO/GAW regional station in China

    NASA Astrophysics Data System (ADS)

    Fang, S. X.; Tans, P. P.; Steinbacher, M.; Zhou, L. X.; Luan, T.

    2015-12-01

    The identification of atmospheric CO2 observation data which are minimally influenced by very local emissions/removals is essential for trend analysis, for the estimation of regional sources and sinks, and for the modeling of long-range transport of CO2. In this study, four approaches are used to filter the atmospheric CO2 observation records from 2009 to 2011 at one World Meteorological Organization/Global Atmosphere Watch (WMO/GAW) regional station (Lin'an, LAN) in China. The methods are based on the concentration of atmospheric black carbon (BC), on a statistical approach (robust extraction of baseline signal, REBS), on CH4 as an auxiliary tracer (AUX), and on meteorological parameters (MET). All approaches do suitably well to capture the seasonal CO2 cycle at LAN. Differences are observed in the average regional mole fractions with annual values in the REBS method at least 1.7 ± 0.2 ppm higher than the other methods. The BC method may underestimate the regional CO2 mole fractions during the winter-spring period and should be treated with caution. The REBS method is a purely statistical method and it may also introduce errors on the regional CO2 mole fraction evaluations, as the filtered trend may be influenced by the "noisy" raw data series. Although there are correlations between CH4 and CO2 mole fractions at LAN, the different source/sink regimes may introduce bias on the regional CO2 estimation in the AUX method, typically in summer. Overall, the MET method seems to be the most favorable because it mainly focuses on the influence of potential local sources and sinks, and considers diurnal variations and meteorological conditions. Using the MET method, the annual growth rate of regional CO2 at LAN is determined to be 3.1 ± 0.01 ppm yr-1 (standard error) from 2009 to 2011.

  13. Study of the regional CO2 mole fractions filtering approach at a WMO/GAW regional station in China

    NASA Astrophysics Data System (ADS)

    Fang, S. X.; Tans, P. P.; Steinbacher, M.; Zhou, L. X.; Luan, T.

    2015-07-01

    The identification of atmospheric CO2 observation data which is minimally influenced by very local emissions/removals is essential for the estimation of trend analysis, regional sources and sinks, and for modeling of long-range transport of CO2. In this study, four approaches are used to filter the atmospheric CO2 observation records from 2009 to 2011 at one World Meteorological Organization/Global Atmosphere Watch (WMO/GAW) regional station (Lin'an, LAN) in China. The methods are based on the atmospheric black carbon concentration (BC), on a statistical approach (REBS), on CH4 as auxiliary tracer (AUX) and on meteorological parameters (MET). All approaches do suitably well to capture the seasonal CO2 cycle at LAN. Differences are observed in the average regional mole fractions with annual values in the REBS method at least 1.7 ± 0.2 ppm higher than the other methods. The BC method may underestimate the regional CO2 mole fractions during winter-spring period and should be treated with caution. The REBS method is a purely statistical method and it may also introduce errors on the regional CO2 mole fractions evaluations, as the filtered trend may be deviated by the "noisy" raw data series. Although there are correlations between CH4 and CO2 mole fractions at LAN, the different source/sink regimes may introduce bias on the regional CO2 estimation in the AUX method, typically in summer. Overall, the MET method seems to be the most favorable because it mainly focuses on the influence of potential local sources and sinks and considers diurnal variations, local topography, and meteorological conditions. Using the MET method, the annual growth rate of regional CO2 at LAN is determined to be 3.1 ± 0.01 ppm yr-1 (standard error) from 2009 to 2013.

  14. Insights Into the Recent Rise in Atmospheric Methane Inferred from Observed Mole Fractions and Stable Carbon Isotopes

    NASA Astrophysics Data System (ADS)

    White, J. W. C.; Michel, S. E.; Tans, P. P.; Vaughn, B. H.; Dlugokencky, E. J.; Sherwood, O.; Miller, J. B.; Masarie, K. A.

    2015-12-01

    Methane is a troublesome greenhouse gas. It has multiple natural and anthropogenic sources, including microbial production in low oxygen environments, fossil sources related to coal and natural gas production, and biomass burning, making source attribution difficult. Atmospheric methane concentration rose rapidly in the industrial period, increasing by 250%, only to stall out in the first decade this century, and then rising again after 2007. Its emission is strongly related to variables that are hard to predict, such as precipitation rates, biomass burning, and natural gas use, so future projections remain murky. And unlike CO2, which is strongly tied to energy use, anthropogenic impacts on methane are strongly tied to food production. Finally, methane is expected to be released from a thawing Arctic in large, but largely unknown quantities. Understanding methane as a greenhouse gas is imperative if anthropogenic impacts on the climate system are to be managed in the future. This talk addresses what we can say about the recent rise in methane using mole fractions and 13C data from the existing NOAA Cooperative Global Air Sampling Network. The approach is strongly data based, and while we will present model results, the data itself are clear on several points. While attention is increasingly focused on the Arctic, the north-south gradient of CH4 concentration does not support significant changes to Boreal and Arctic emissions. This finding raises the question of how methane will behave in a warmer, wetter world. We use a simple, three end-member model, run in both forward and inverse modes, to look more deeply into the sources of the recent increase. Evidence exists for recent increases in fossil sources, in line with methane production as a fuel source, although the contribution is small. Better data are needed to constrain the 13C of sources, including the fossil sources, a problem we are working on. Importantly, while the current monitoring network is adequate

  15. (30)Si mole fraction of a silicon material highly enriched in (28)Si determined by instrumental neutron activation analysis.

    PubMed

    D'Agostino, Giancarlo; Di Luzio, Marco; Mana, Giovanni; Oddone, Massimo; Pramann, Axel; Prata, Michele

    2015-06-02

    The latest determination of the Avogadro constant, carried out by counting the atoms in a pure silicon crystal highly enriched in (28)Si, reached the target 2 × 10(-8) relative uncertainty required for the redefinition of the kilogram based on the Planck constant. The knowledge of the isotopic composition of the enriched silicon material is central; it is measured by isotope dilution mass spectrometry. In this work, an independent estimate of the (30)Si mole fraction was obtained by applying a relative measurement protocol based on Instrumental Neutron Activation Analysis. The amount of (30)Si isotope was determined by counting the 1266.1 keV γ-photons emitted during the radioactive decay of the radioisotope (31)Si produced via the neutron capture reaction (30)Si(n,γ)(31)Si. The x((30)Si) = 1.043(19) × 10(-6) mol mol(-1) is consistent with the value currently adopted by the International Avogadro Coordination.

  16. Automatic processing of atmospheric CO2 and CH4 mole fractions at the ICOS Atmosphere Thematic Centre

    NASA Astrophysics Data System (ADS)

    Hazan, Lynn; Tarniewicz, Jérôme; Ramonet, Michel; Laurent, Olivier; Abbaris, Amara

    2016-09-01

    The Integrated Carbon Observation System Atmosphere Thematic Centre (ICOS ATC) automatically processes atmospheric greenhouse gases mole fractions of data coming from sites of the ICOS network. Daily transferred raw data files are automatically processed and archived. Data are stored in the ICOS atmospheric database, the backbone of the system, which has been developed with an emphasis on the traceability of the data processing. Many data products, updated daily, explore the data through different angles to support the quality control of the dataset performed by the principal operators in charge of the instruments. The automatic processing includes calibration and water vapor corrections as described in the paper. The mole fractions calculated in near-real time (NRT) are automatically revaluated as soon as a new instrument calibration is processed or when the station supervisors perform quality control. By analyzing data from 11 sites, we determined that the average calibration corrections are equal to 1.7 ± 0.3 µmol mol-1 for CO2 and 2.8 ± 3 nmol mol-1 for CH4. These biases are important to correct to avoid artificial gradients between stations that could lead to error in flux estimates when using atmospheric inversion techniques. We also calculated that the average drift between two successive calibrations separated by 15 days amounts to ±0.05 µmol mol-1 and ±0.7 nmol mol-1 for CO2 and CH4, respectively. Outliers are generally due to errors in the instrument configuration and can be readily detected thanks to the data products provided by the ATC. Several developments are still ongoing to improve the processing, including automated spike detection and calculation of time-varying uncertainties.

  17. Final report of CCQM-K129 Measurement of Mole Fractions of Cu, In, Ga and Se in Cu(In,Ga)Se2 Films

    NASA Astrophysics Data System (ADS)

    Kim, K. J.; Kim, A. S.; Jang, J. S.; Suh, J. K.; Wirth, T.; Unger, W.; Hodoroaba, V.-D.; Araujo, J. R.; Archanjo, B. S.; Galhardo, C. E.; Damasceno, J.; Achete, C. A.; Wang, H.; Wang, M.; Bennett, J.; Simon, D.; Kurokawa, A.; Terauchi, S.; Fujimoto, T.; Streeck, C.; Beckhoff, B.; Spencer, S.; Shard, A.

    2016-01-01

    CCQM key comparison K-129 for the quantitative analysis of Cu(In,Ga)Se2 (CIGS) films has been performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The objective of this key comparison is to compare the equivalency of the National Metrology Institutes (NMIs) and Designated Institutes (DIs) for the measurement of mole fractions of Cu, In, Ga and Se in a thin CIGS film. The measurand of this key comparison is the average mole fractions of Cu, In, Ga and Se of a test CIGS alloy film in the unit of mole fraction (mol/mol). Mole fraction with the metrological unit of % mol/mol can be practically converted to atomic fraction with the unit of at %. In this key comparison, a CIGS film with certified mole fractions was supplied as a reference specimen to determine the relative sensitivity factors (RSFs) of Cu, In, Ga and Se. The mole fractions of the reference specimen were certified by isotope dilution - inductively coupled plasma/mass spectrometry (ID-ICP/MS). A total number counting (TNC) method was recommended as a method to determine the signal intensities of the constituent elements acquired in the depth profiles by Secondary Ion Mass Spectrometry (SIMS), X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). Seven NMIs and one DI participated in this key comparison. The mole fractions of the CIGS films were measured by depth profiling based-SIMS, AES and XPS. In this key comparison, the average degrees of equivalence uncertainties for Cu, In, Ga and Se are 0.0093 mol/mol, 0.0123 mol/mol, 0.0047 mol/mol and 0.0228 mol/mol, respectively. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  18. Seasonality and interannual variability of CH4 fluxes from the eastern Amazon Basin inferred from atmospheric mole fraction profiles

    NASA Astrophysics Data System (ADS)

    Basso, Luana S.; Gatti, Luciana V.; Gloor, Manuel; Miller, John B.; Domingues, Lucas G.; Correia, Caio S. C.; Borges, Viviane F.

    2016-01-01

    The Amazon Basin is an important region for global CH4 emissions. It hosts the largest area of humid tropical forests, and around 20% of this area is seasonally flooded. In a warming climate it is possible that CH4 emissions from the Amazon will increase both as a result of increased temperatures and precipitation. To examine if there are indications of first signs of such changes we present here a 13 year (2000-2013) record of regularly measured vertical CH4 mole fraction profiles above the eastern Brazilian Amazon, sensitive to fluxes from the region upwind of Santarém (SAN), between SAN and the Atlantic coast. Using a simple mass balance approach, we find substantial CH4 emissions with an annual average flux of 52.8 ± 6.8 mg CH4 m-2 d-1 over an area of approximately 1 × 106 km2. Fluxes are highest in two periods of the year: in the beginning of the wet season and during the dry season. Using a CO:CH4 emission factor estimated from the profile data, we estimated a contribution of biomass burning of around 15% to the total flux in the dry season, indicating that biogenic emissions dominate the CH4 flux. This 13 year record shows that CH4 emissions upwind of SAN varied over the years, with highest emissions in 2008 (around 25% higher than in 2007), mainly during the wet season, representing 19% of the observed global increase in this year.

  19. Seasonality and interannual variability of CH4 fluxes from the eastern Amazon Basin inferred from atmospheric mole fraction profiles

    PubMed Central

    Gatti, Luciana V.; Gloor, Manuel; Miller, John B.; Domingues, Lucas G.; Correia, Caio S. C.; Borges, Viviane F.

    2016-01-01

    Abstract The Amazon Basin is an important region for global CH4 emissions. It hosts the largest area of humid tropical forests, and around 20% of this area is seasonally flooded. In a warming climate it is possible that CH4 emissions from the Amazon will increase both as a result of increased temperatures and precipitation. To examine if there are indications of first signs of such changes we present here a 13 year (2000–2013) record of regularly measured vertical CH4 mole fraction profiles above the eastern Brazilian Amazon, sensitive to fluxes from the region upwind of Santarém (SAN), between SAN and the Atlantic coast. Using a simple mass balance approach, we find substantial CH4 emissions with an annual average flux of 52.8 ± 6.8 mg CH4 m−2 d−1 over an area of approximately 1 × 106 km2. Fluxes are highest in two periods of the year: in the beginning of the wet season and during the dry season. Using a CO:CH4 emission factor estimated from the profile data, we estimated a contribution of biomass burning of around 15% to the total flux in the dry season, indicating that biogenic emissions dominate the CH4 flux. This 13 year record shows that CH4 emissions upwind of SAN varied over the years, with highest emissions in 2008 (around 25% higher than in 2007), mainly during the wet season, representing 19% of the observed global increase in this year. PMID:27642546

  20. Seasonality and interannual variability of CH4 fluxes from the eastern Amazon Basin inferred from atmospheric mole fraction profiles.

    PubMed

    Basso, Luana S; Gatti, Luciana V; Gloor, Manuel; Miller, John B; Domingues, Lucas G; Correia, Caio S C; Borges, Viviane F

    2016-01-16

    The Amazon Basin is an important region for global CH4 emissions. It hosts the largest area of humid tropical forests, and around 20% of this area is seasonally flooded. In a warming climate it is possible that CH4 emissions from the Amazon will increase both as a result of increased temperatures and precipitation. To examine if there are indications of first signs of such changes we present here a 13 year (2000-2013) record of regularly measured vertical CH4 mole fraction profiles above the eastern Brazilian Amazon, sensitive to fluxes from the region upwind of Santarém (SAN), between SAN and the Atlantic coast. Using a simple mass balance approach, we find substantial CH4 emissions with an annual average flux of 52.8 ± 6.8 mg CH4 m(-2) d(-1) over an area of approximately 1 × 10(6) km(2). Fluxes are highest in two periods of the year: in the beginning of the wet season and during the dry season. Using a CO:CH4 emission factor estimated from the profile data, we estimated a contribution of biomass burning of around 15% to the total flux in the dry season, indicating that biogenic emissions dominate the CH4 flux. This 13 year record shows that CH4 emissions upwind of SAN varied over the years, with highest emissions in 2008 (around 25% higher than in 2007), mainly during the wet season, representing 19% of the observed global increase in this year.

  1. Impact of underlap and mole-fraction on RF performance of strained-Si/Si1-xGex/strained-Si DG MOSFETs

    NASA Astrophysics Data System (ADS)

    Dutta, Arka; Koley, Kalyan; Sarkar, Chandan K.

    2014-11-01

    In this paper, a systematic RF performance analysis of double-gate strained silicon (DGSS) nMOSFETs is presented. The analysis is focused upon impact of Germanium mole-fraction variation on RF performance of underlap engineered DGSS nMOSFET. The RF performance of the device is analysed as a function of intrinsic RF figure of merits (FOMs) including non-quasi static effects (NQS). The RF FOMs are represented by the intrinsic gate to source/drain capacitance (Cgs and Cgd) and resistance (Rgs and Rgd), the transport delay (τm), the intrinsic inductance (Lsd), the cut-off frequency (fT), and the maximum oscillation frequency (fMAX). The results of the study suggested a significant improvement in the device performance, up to 40% increase in Germanium mole fraction (χ).

  2. Tunable diode laser absorption spectroscopy-based tomography system for on-line monitoring of two-dimensional distributions of temperature and H2O mole fraction

    NASA Astrophysics Data System (ADS)

    Xu, Lijun; Liu, Chang; Jing, Wenyang; Cao, Zhang; Xue, Xin; Lin, Yuzhen

    2016-01-01

    To monitor two-dimensional (2D) distributions of temperature and H2O mole fraction, an on-line tomography system based on tunable diode laser absorption spectroscopy (TDLAS) was developed. To the best of the authors' knowledge, this is the first report on a multi-view TDLAS-based system for simultaneous tomographic visualization of temperature and H2O mole fraction in real time. The system consists of two distributed feedback (DFB) laser diodes, a tomographic sensor, electronic circuits, and a computer. The central frequencies of the two DFB laser diodes are at 7444.36 cm-1 (1343.3 nm) and 7185.6 cm-1 (1391.67 nm), respectively. The tomographic sensor is used to generate fan-beam illumination from five views and to produce 60 ray measurements. The electronic circuits not only provide stable temperature and precise current controlling signals for the laser diodes but also can accurately sample the transmitted laser intensities and extract integrated absorbances in real time. Finally, the integrated absorbances are transferred to the computer, in which the 2D distributions of temperature and H2O mole fraction are reconstructed by using a modified Landweber algorithm. In the experiments, the TDLAS-based tomography system was validated by using asymmetric premixed flames with fixed and time-varying equivalent ratios, respectively. The results demonstrate that the system is able to reconstruct the profiles of the 2D distributions of temperature and H2O mole fraction of the flame and effectively capture the dynamics of the combustion process, which exhibits good potential for flame monitoring and on-line combustion diagnosis.

  3. Measurement of InAsBi mole fraction and InBi lattice constant using Rutherford backscattering spectrometry and X-ray diffraction

    NASA Astrophysics Data System (ADS)

    Shalindar, A. J.; Webster, P. T.; Wilkens, B. J.; Alford, T. L.; Johnson, S. R.

    2016-10-01

    Several 1 μm thick, nearly lattice-matched InAsBi layers grown on GaSb are examined using Rutherford backscattering spectrometry and X-ray diffraction. Random Rutherford backscattering measurements indicate that the average Bi mole fraction ranges from 0.0503 to 0.0645 for the sample set, and ion-channeling measurements indicate that the Bi atoms are substitutional. The X-ray diffraction measurements show a diffraction sideband near the main (004) diffraction peak, indicating that the Bi mole fraction is not laterally uniform in the layer. The average out-of-plane tetragonal distortion is determined by modeling the main and sideband diffraction peaks, from which the average unstrained lattice constant of each sample is determined. By comparing the Bi mole fraction measured by random Rutherford backscattering with the InAsBi lattice constant for the sample set, the lattice constant of zinc blende InBi is determined to be 6.6107 Å.

  4. Effect of the growth temperature and the AlN mole fraction on In incorporation and properties of quaternary III-nitride layers grown by molecular beam epitaxy

    SciTech Connect

    Fernandez-Garrido, S.; Pereiro, J.; Munoz, E.; Calleja, E.; Gago, R.; Bertram, F.; Christen, J.; Luna, E.; Trampert, A.

    2008-10-15

    Indium incorporation into wurtzite (0001)-oriented In{sub x}Al{sub y}Ga{sub 1-x-y}N layers grown by plasma-assisted molecular beam epitaxy was studied as a function of the growth temperature (565-635 deg. C) and the AlN mole fraction (0.01mole fractions. High resolution x-ray diffraction and transmission electron microscopy (TEM) measurements did not show evidence of phase separation. The mosaicity of the quaternary layers was found to be mainly determined by the growth temperature and independent on alloy composition within the range studied. However, depending on the AlN mole fraction, nanometer-sized composition fluctuations were detected by TEM. Photoluminescence spectra showed a single broad emission at room temperature, with energy and bandwidth S- and W-shaped temperature dependences typical of exciton localization by alloy inhomogeneities. Cathodoluminescence measurements demonstrated that the alloy inhomogeneities, responsible of exciton localization, occur on a lateral length scale below 150 nm, which is corroborated by TEM.

  5. Large Amplitude Spatial and Temporal Gradients in Atmospheric Boundary Layer CO2 Mole Fractions Detected With a Tower-Based Network in the U.S. Upper Midwest

    SciTech Connect

    Miles, Natasha; Richardson, S. J.; Davis, Kenneth J.; Lauvaux, Thomas; Andrews, A.; West, Tristram O.; Bandaru, Varaprasad; Crosson, Eric R.

    2012-02-21

    This study presents observations of atmospheric CO{sub 2} mole fraction from a nine-tower, regional network deployed during the North American Carbon Program's Mid-Continent Intensive during 2007-2009. Within this network in a largely agricultural area, mean atmospheric CO{sub 2} gradients were strongly correlated with both ground-based inventory data and estimates from satellite remote sensing. The average seasonal drawdown for corn-dominated sites (35 ppm) is significantly larger than has been observed at other continental boundary layer sites. Observed growing-season median CO{sub 2} gradients are strongly dependent on local flux. The gradients between cross-vegetation site-pairs, for example, average 2.0 ppm/100 km, four times larger than the similar-vegetation site-pair average. Daily-timescale gradients are as large as 5.5 ppm/100 km, but dominated by advection rather than local flux. Flooding in 2008 led to a region-wide 23 week delay in growing-season minima. The observations show that regional-scale CO{sub 2} mole fraction networks yield large, coherent signals governed largely by regional sources and sinks of CO{sub 2}.

  6. Analysis of CO2 mole fraction data: first evidence of large-scale changes in CO2 uptake at high northern latitudes

    NASA Astrophysics Data System (ADS)

    Barlow, J. M.; Palmer, P. I.; Bruhwiler, L. M.; Tans, P.

    2015-03-01

    Atmospheric variations of carbon dioxide (CO2) mole fraction reflect changes in atmospheric transport and regional patterns of surface emission and uptake. We report new estimates for changes in the phase and amplitude of observed high northern latitude CO2 seasonal variations, indicative of biospheric changes, by spectrally decomposing multi-decadal records of surface CO2 mole fraction using a wavelet transform to isolate the changes in the observed seasonal cycle. We also perform similar analysis of the first time derivative of CO2 mole fraction, ΔtCO2, that is a crude proxy for changes in CO2 flux. Using numerical experiments, we quantify the aliasing error associated with independently identifying trends in phase and peak uptake and release to be 10-25%, with the smallest biases in phase associated with the analysis of ΔtCO2. We report our analysis from Barrow, Alaska (BRW) during 1973-2013, which is representative of the broader Arctic region. We determine an amplitude trend of 0.09 ± 0.02 ppm yr-1, which is consistent with previous work. Using ΔtCO2 we determine estimates for the timing of the onset of net uptake and release of CO2 of -0.14 ± 0.14 and -0.25 ± 0.08 days yr-1, respectively, and a corresponding uptake period of -0.11 ± 0.16 days yr-1, which are significantly different to previously reported estimates. We find that the wavelet transform method has significant skill in characterizing changes in the peak uptake and release. We find a trend of 0.65 ± 0.34% (p< 0.01) and 0.42 ± 0.34% (p<0.05) for rates of peak uptake and release, respectively. Our analysis does not provide direct evidence about the balance between uptake and release of carbon, but changes in the peak uptake and release together with an invariant growing period length provides indirect evidence that high northern latitude ecosystems are progressively taking up more carbon.

  7. Analysis of CO2 mole fraction data: first evidence of large-scale changes in CO2 uptake at high northern latitudes

    NASA Astrophysics Data System (ADS)

    Barlow, J. M.; Palmer, P. I.; Bruhwiler, L. M.; Tans, P.

    2015-12-01

    Atmospheric variations of carbon dioxide (CO2) mole fraction reflect changes in atmospheric transport and regional patterns of surface emission and uptake. Here we present a study of changes in the observed high northern latitude CO2 seasonal cycle. We report new estimates for changes in the phase and amplitude of the seasonal variations, indicative of biospheric changes, by spectrally decomposing multi-decadal records of surface CO2 mole fraction using a wavelet transform to isolate the changes in the observed seasonal cycle. We also perform similar analysis of the first derivative of CO2 mole fraction, ΔtCO2, that is a crude proxy for changes in CO2 flux. Using numerical experiments, we quantify the aliasing error associated with independently identifying trends in phase and peak uptake and release to be 10-25 %, with the smallest biases in phase associated with the analysis of ΔtCO2. We report our analysis from Barrow, Alaska (BRW), during 1973-2013, which is representative of the broader Arctic region. We determine an amplitude trend of 0.09 ± 0.02 ppm yr-1, which is consistent with previous work. Using ΔtCO2 we determine estimates for the timing of the onset of net uptake and release of CO2 of -0.14 ± 0.14 and -0.25 ± 0.08 days yr-1 respectively and a corresponding net uptake period of -0.11 ± 0.16 days yr-1, which are significantly different to previously reported estimates. We find that the wavelet transform method has significant skill in characterizing changes in the peak uptake and release. We find a trend of 0.65 ± 0.34 % yr-1 (p < 0.01) and 0.42 ± 0.34 % yr-1 (p < 0.05) for rates of peak uptake and release respectively. Our analysis does not provide direct evidence about the balance between uptake and release of carbon when integrated throughout the year, but the increase in the seasonal amplitude of CO2 together with an invariant net carbon uptake period provides evidence that high northern latitude ecosystems are progressively taking up more

  8. On the reliable analysis of indium mole fraction within In{sub x}Ga{sub 1−x}N quantum wells using atom probe tomography

    SciTech Connect

    Riley, James R.; Lauhon, Lincoln J.; Detchprohm, Theeradetch; Wetzel, Christian

    2014-04-14

    Surface crystallography and polarity are shown to influence the detection probability of In, Ga, and N ions during atom probe tomography analysis of In{sub x}Ga{sub 1−x}N m-plane, c-plane, and (202{sup ¯}1{sup ¯}) quantum wells. A N deficit is observed in regions of the reconstruction generated from Ga-polar surfaces, and the probability of detecting group-III atoms is lower in In{sub x}Ga{sub 1−x}N quantum wells than in GaN barrier layers. Despite these artifacts, the detected In mole fraction is consistent throughout a given quantum well regardless of the crystal orientation of the quantum well or the evaporation surface from which the reconstruction was generated.

  9. Improving the Modelled Global Terrestrial Carbon Cycle by Assimilating CO2 Mole Fractions and FAPAR with the MPI Carbon Cycle Data Assimilation System (MPI-CCDAS)

    NASA Astrophysics Data System (ADS)

    Schürmann, Gregor; Köstler, Christoph; Kaminski, Thomas; Giering, Ralf; Scholze, Marko; Kattge, Jens; Carvalhais, Nuno; Voßbeck, Michael; Rödenbeck, Christian; Reick, Christian; Zaehle, Sönke

    2015-04-01

    Long-term monitoring of ecosystem carbon fluxes and atmospheric CO2 concentrations provides independent observations of the land's carbon balance at different scales. However, the scale-gap between these observations makes a direct quantification of regional carbon balances based on these data impossible. Here, we describe first results of the MPI Carbon Cycle Data Assimilation System (MPI-CCDAS), designed to use multiple data streams at different scales to constrain parameters in the biosphere model JSBACH. We constrain the MPI-CCDAS with two complementary data-streams: CO2 mole fractions observed at a network of atmospheric monitoring stations, and remotely-sensed fraction of absorbed photosynthetically active radiation (TIP-FAPAR). The assimilation procedure greatly improves the representation of the seasonal cycle of atmospheric CO2, and reduces the global gross primary productivity (GPP) from 160 PgC/year to 118 PgC/year. Applying the MPI-CCDAS separately and jointly on both data streams allows to analyse the contribution of each data stream to the improved global carbon cycle model. Evaluation against independent carbon cycle estimates based on upscaled ecosystem flux measurements corroborates the adequacy of the model improvements, and demonstrates the utility of the CCDAS framework in consistently integrating carbon cycle data.

  10. Atmospheric CO2 mole fraction affects stand-scale carbon use efficiency of sunflower by stimulating respiration in light.

    PubMed

    Gong, Xiao Ying; Schäufele, Rudi; Lehmeier, Christoph Andreas; Tcherkez, Guillaume; Schnyder, Hans

    2017-03-01

    Plant carbon-use-efficiency (CUE), a key parameter in carbon cycle and plant growth models, quantifies the fraction of fixed carbon that is converted into net primary production rather than respired. CUE has not been directly measured, partly because of the difficulty of measuring respiration in light. Here, we explore if CUE is affected by atmospheric CO2 . Sunflower stands were grown at low (200 μmol mol(-1) ) or high CO2 (1000 μmol mol(-1) ) in controlled environment mesocosms. CUE of stands was measured by dynamic stand-scale (13) C labelling and partitioning of photosynthesis and respiration. At the same plant age, growth at high CO2 (compared with low CO2 ) led to 91% higher rates of apparent photosynthesis, 97% higher respiration in the dark, yet 143% higher respiration in light. Thus, CUE was significantly lower at high (0.65) than at low CO2 (0.71). Compartmental analysis of isotopic tracer kinetics demonstrated a greater commitment of carbon reserves in stand-scale respiratory metabolism at high CO2 . Two main processes contributed to the reduction of CUE at high CO2 : a reduced inhibition of leaf respiration by light and a diminished leaf mass ratio. This work highlights the relevance of measuring respiration in light and assessment of the CUE response to environment conditions.

  11. Fractional Distillation of Air and Other Demonstrations with Condensed Gases

    ERIC Educational Resources Information Center

    Oliver-Hoyo, Maria; Switzer, William L., III; Eierman, Robert

    2005-01-01

    The learning objectives of the fractional distillation of air and other demonstrations includes observing N2, O2, CO2 and H2O in air, studying the fractional separation of components based on boiling point differences and so on. The materials, reagent and equipment preparation, experimental procedures, hazards of the demonstration are also…

  12. N2 Mole Fraction Dependence of Plasma Bullet Propagation in Premixed He/N2 Plasma Needle Discharge at Atmospheric Pressure

    NASA Astrophysics Data System (ADS)

    Ni, Gengsong; Qian, Muyang; Yang, Congying; Liu, Sanqiu; Wang, Dezhen

    2016-07-01

    In this work, a computational modeling study on the mechanism of the acceleration behavior of a plasma bullet in needle-plane configuration is presented. Above all, in our model, two sub-models of time-dependent plasma dynamics and laminar flow are connected using a oneway coupled method, and both the working gas and the surrounding gas around the plasma jet are assumed to be the same, which are premixed He/N2 gas. The mole fractions of the N2 (NMF) ingredient are set to be 0.01%, 0.1% and 1% in three cases, respectively. It is found that in each case, the plasma bullet accelerates with time to a peak velocity after it exits the nozzle and then decreases until getting to the treated surface, and that the velocity of the plasma bullet increases at each time moment with the peak value changing from 0.72×106 m/s to 0.80×106 m/s but then drops more sharply when the NMF varies from 0.01% to 1%. Besides, the electron impact ionizations of helium neutrals and nitrogen molecules are found to have key influences on the propagation of a plasma bullet instead of the penning ionization. supported by National Natural Science Foundation of China (No. 11465013), the Natural Science Foundation of Jiangxi Province, China (No. 20151BAB212012), and in part by the International Science and Technology Cooperation Program of China (No. 2015DFA61800)

  13. Ca2+ transport properties and determinants of anomalous mole fraction effects of single voltage-gated Ca2+ channels in hair cells from bullfrog saccule

    PubMed Central

    Rodriguez-Contreras, Adrian; Nonner, Wolfgang; Yamoah, Ebenezer N

    2002-01-01

    We studied the permeation properties of two distinct single voltage-gated Ca2+ channels in bullfrog saccular hair cells to assess the roles of the channels as physiological Ca2+ transporters and multi-ion pores. By varying the permeant ions (Ba2+, Ca2+) and concentrations (2–70 mm), we estimated the affinity constant (KD) of the two channels as follows (mm): L-type channel, KD,Ba = 7.4 ± 1.0, KD,Ca = 7.1 ± 2.2 (n = 7); non-L-type channel, KD,Ba = 5.3 ± 3.2, KD,Ca = 2.0 ± 1.0 (n = 8). Using ionic concentrations close to physiological conditions (2 mm Ca2+ and 1.0 mm Mg2+), the conductance of the L-type channel was ∼2 pS. We determined the mechanisms by which ions traverse the pore of these single Ca2+ channels, using mixtures of Ba2+ and Ca2+ at total concentrations above (70 mm) or close to (5 mm) the KD of the channels. We found evidence for an anomalous mole fraction effect (AMFE) only when the total divalent ion concentration was 5 mm, consistent with a multi-ion pore. We show that AMFE arises from the boundaries between the pore and bulk solution in the atria of the channel, which is derived from the presence of depletion zones that become apparent at low divalent cation concentrations. The present findings provide an explanation as to why previous whole-cell Ca2+ currents that were recorded in quasi-physiological Ca2+ concentrations (∼2–5 mm) showed clear AMFE, whereas single Ca2+ channel currents that were recorded routinely at high Ca2+ concentrations (20–110 mm) did not. PMID:11826161

  14. Tunable diode laser absorption spectroscopy-based tomography system for on-line monitoring of two-dimensional distributions of temperature and H{sub 2}O mole fraction

    SciTech Connect

    Xu, Lijun Liu, Chang; Jing, Wenyang; Cao, Zhang; Xue, Xin; Lin, Yuzhen

    2016-01-15

    To monitor two-dimensional (2D) distributions of temperature and H{sub 2}O mole fraction, an on-line tomography system based on tunable diode laser absorption spectroscopy (TDLAS) was developed. To the best of the authors’ knowledge, this is the first report on a multi-view TDLAS-based system for simultaneous tomographic visualization of temperature and H{sub 2}O mole fraction in real time. The system consists of two distributed feedback (DFB) laser diodes, a tomographic sensor, electronic circuits, and a computer. The central frequencies of the two DFB laser diodes are at 7444.36 cm{sup −1} (1343.3 nm) and 7185.6 cm{sup −1} (1391.67 nm), respectively. The tomographic sensor is used to generate fan-beam illumination from five views and to produce 60 ray measurements. The electronic circuits not only provide stable temperature and precise current controlling signals for the laser diodes but also can accurately sample the transmitted laser intensities and extract integrated absorbances in real time. Finally, the integrated absorbances are transferred to the computer, in which the 2D distributions of temperature and H{sub 2}O mole fraction are reconstructed by using a modified Landweber algorithm. In the experiments, the TDLAS-based tomography system was validated by using asymmetric premixed flames with fixed and time-varying equivalent ratios, respectively. The results demonstrate that the system is able to reconstruct the profiles of the 2D distributions of temperature and H{sub 2}O mole fraction of the flame and effectively capture the dynamics of the combustion process, which exhibits good potential for flame monitoring and on-line combustion diagnosis.

  15. Chemical Principles Revisited: The Mole.

    ERIC Educational Resources Information Center

    Kolb, Doris

    1978-01-01

    Discusses ways of teaching the mole concept in high school chemistry classes. Provides resource information on the mole and Avogadro's Number. Includes an explanation of four methods for measuring Avogadro's Number and instructions on how to use the mole. (MA)

  16. Mole gun injury.

    PubMed

    Pistré, V; Rezzouk, J

    2013-09-01

    A mole gun is a weapon, which is used to trap and kill moles. This report provides an overview of the state of knowledge of mole gun injuries, comparable to blast injuries caused by fireworks, explosive or gunshot. Over a 2-year period, the authors reported their experience with ten hand injuries caused by mole gun. Radial side of the hand was often concerned, particularly the thumb. The authors explain their choices in the management of such lesions. Surgery was performed primarily and a large debridement currently seemed to offer the best outcome for the patient. Blast, crush, burns and lacerations may explain the higher rate of amputation to the digits. A long period of physiotherapy, specifically of the hand, was needed before the patient could return to work. This ballistic hand trauma encountered by surgeons requires knowledge and understanding of these injuries. It should be in accordance with firearms law because of severe injuries encountered and possible lethal wounds.

  17. Mosaics and moles

    PubMed Central

    Sunde, Lone; Niemann, Isa; Hansen, Estrid Staehr; Hindkjaer, Johnny; Degn, Birte; Jensen, Uffe Birk; Bolund, Lars

    2011-01-01

    Hydatidiform mole (HM) is an abnormal human pregnancy, where the placenta presents with vesicular swelling of the chorionic villi. A fetus is either not present, or malformed and not viable. Most moles are diploid androgenetic as if one spermatozoon fertilized an empty oocyte, or triploid with one maternal and two paternal chromosome sets as if two spermatozoa fertilized a normal oocyte. However, diploid moles with both paternal and maternal markers of the nuclear genome have been reported. Among 162 consecutively collected diploid moles, we have earlier found indications of both maternal and paternal genomes in 11. In the present study, we have performed detailed analysis of DNA-markers in tissue and single cells from these 11 HMs. In 3/11, we identified one biparental cell population only, whereas in 8/11, we demonstrated mosaicism: one biparental cell population and one androgenetic cell population. One mosaic mole was followed by persistent trophoblastic disease (PTD). In seven of the mosaics, one spermatozoon appeared to have contributed to the genomes of both cell types. Our observations make it likely that mosaic conceptuses, encompassing an androgenetic cell population, result from various postzygotic abnormalities, including paternal pronuclear duplication, asymmetric cytokinesis, and postzygotic diploidization. This corroborates the suggestion that fertilization of an empty egg is not mandatory for the creation of an androgenetic cell population. Future studies of mosaic conceptuses may disclose details about fertilization, early cell divisions and differentiation. Apparently, only a minority of diploid moles with both paternal and maternal markers are ‘genuine' diploid biparental moles (DiBiparHMs). PMID:21654731

  18. Composition and carrier-concentration dependence of the electronic structure of InyGa1-yAs1-xNx films with nitrogen mole fraction of less than 0.012

    NASA Astrophysics Data System (ADS)

    Kang, Youn-Seon; Robins, Lawrence H.; Birdwell, Anthony G.; Shapiro, Alexander J.; Thurber, W. Robert; Vaudin, Mark D.; Fahmi, M. M. E.; Bryson, Damian; Mohammad, S. Noor

    2005-11-01

    The electronic structure of Si-doped InyGa1-yAs1-xNx films on GaAs substrates, grown by nitrogen-plasma-assisted molecular-beam epitaxy, was examined by photoreflectance (PR) spectroscopy at temperatures between 20 and 300 K. The films were approximately 0.5 μm thick and had nitrogen mole fraction between x=0.0014 and x=0.012, measured indirectly by a secondary-ion-mass spectrometry calibration; indium mole fraction between y=0.052 and y=0.075, measured by electron-dispersive x-ray spectroscopy; and carrier concentration between 2×1016 and 1.1×1018 cm-3, measured by Hall effect. Three critical-point transitions were identified by PR: the fundamental band gap (highest valence band to the lowest conduction band); the spin-orbit split valence band to the lowest conduction band; and the highest valence band to a nitrogen impurity band (above the lowest conduction band). The measured critical-point energies were described by a band anticrossing (BAC) model with the addition of a Burstein-Moss band-filling term. The fitted BAC parameters were similar to previously reported values. The N impurity level was located 0.3004+/-0.0101 eV above the conduction-band edge at 20 K and 0.3286+/-0.0089 eV above the conduction-band edge at 295 K. The BAC interaction parameter was 2.588+/-0.071 eV. From the small magnitude of the Burstein-Moss energy shift with increasing carrier concentration, it was inferred that the carrier concentration probed by PR is reduced from the bulk (Hall-effect) carrier concentration by a reduction factor of 0.266+/-0.145. The PR lines broadened with increasing carrier concentration; the line broadening tracked the predicted Burstein-Moss energy shift for the bulk carrier concentration. The surface-normal lattice constants of the films were measured by x-ray diffraction. Comparison of the measured lattice constants with Vegard's law showed the presence of tensile strain (in the surface-normal direction) with magnitude between 1.5×10-3 and 3.0×10

  19. Engineering cellulase mixtures by varying the mole fraction of Thermomonospora fusca E[sub 5] and E[sub 3], Trichoderma reesei CBHI, and Caldocellum saccharolyticum [beta]-glucosidase

    SciTech Connect

    Walker, L.P.; Belair, C.D.; Wilson, D.B.; Irwin, D.C. )

    1993-11-05

    In this study, different mole fractions of pure Thermomonospora fusca E[sub 5] and E[sub 3], plus Trichoderma reesei CBHI were studied for reducing sugar production at 2 h, degree of synergism, and cellulose binding. In addition, the effects of introducing the Caldocellum saccharolyticum [Beta]-glucosidase into this cellulase system were investigated. The cellulases used were purified to homogeneity. Avicel PH 102 was the substrate. Reactions were run at 50 C for 2 h using total cellulase concentrations of 8.3 or 12.2 [mu]M. A bimixture of T. fusca E[sub 3] and T. reesei CBHI was very effective in hydrolyzing microcrystalline cellulose. The addition of endoglucanase E[sub 5] to the mixture only increased conversion to 9.8%. However, when both E[sub 5] and [Beta]-glucosidase were added, conversion increased to 14%. It was also observed that increasing total cellulase concentration beyond 8.3 [mu]M did little to increase percent conversion of cellulose into glucose. The results of the binding studies indicate no competition for binding sites between the endo- and exocellulases.

  20. Lattice-engineered MBE growth of high-indium mole fraction InGaAs for low cost MMICs and (1.3--1.55 {micro}m) OEICs

    SciTech Connect

    Childs, T.T.; Sokolov, V.; Sullivan, C.T.

    1997-11-01

    Using molecular beam epitaxy (MBE) and lattice engineering techniques, the feasibility of combining photonic devices applicable to the 1.3 to 1.55 {micro}m wavelength range and monolithic microwave (or mm-wave) integrated circuits (MMICs) on GaAs is demonstrated. A key factor in the MBE growth is incorporation of an InGaAs active layer having an indium arsenide mole fraction of 0.35 or greater and its lattice compatibility with the underlying semi-insulating GaAs substrate. The InGaAs layer used for the photonic devices, can also serve as the active channel for the high electron mobility transistors (HEMTs) for application in MMICs. Several examples of active and passive photonic devices grown by MBE are presented including an optical ridge waveguide, and a photodetector for detection of light in the 1.3 {micro}m range. The material structure includes a 3-layer AlGaAs/GaAs/AlGaAs optical waveguide and a thin InGaAs absorbing layer situated directly above the optical waveguide. Metal-semiconductor-metal (MSM) photodetectors are formed on the top surface of the InGaAs layer for collection of the photo-induced carriers. The optical ridge waveguide is designed for lateral incidence of the light to enhance the MSM photodetector responsivity. Initial measurements on the optical waveguide and photodetector are presented.

  1. MOLES Information Model

    NASA Astrophysics Data System (ADS)

    Ventouras, Spiros; Lawrence, Bryan; Woolf, Andrew; Cox, Simon

    2010-05-01

    The Metadata Objects for Linking Environmental Sciences (MOLES) model has been developed within the Natural Environment Research Council (NERC) DataGrid project [NERC DataGrid] to fill a missing part of the ‘metadata spectrum'. It is a framework within which to encode the relationships between the tools used to obtain data, the activities which organised their use, and the datasets produced. MOLES is primarily of use to consumers of data, especially in an interdisciplinary context, to allow them to establish details of provenance, and to compare and contrast such information without recourse to discipline-specific metadata or private communications with the original investigators [Lawrence et al 2009]. MOLES is also of use to the custodians of data, providing an organising paradigm for the data and metadata. The work described in this paper is a high-level view of the structure and content of a recent major revision of MOLES (v3.3) carried out as part of a NERC DataGrid extension project. The concepts of MOLES v3.3 are rooted in the harmonised ISO model [Harmonised ISO model] - particularly in metadata standards (ISO 19115, ISO 19115-2) and the ‘Observations and Measurements' conceptual model (ISO 19156). MOLES exploits existing concepts and relationships, and specialises information in these standards. A typical sequence of data capturing involves one or more projects under which a number of activities are undertaken, using appropriate tools and methods to produce the datasets. Following this typical sequence, the relevant metadata can be partitioned into the following main sections - helpful in mapping onto the most suitable standards from the ISO 19100 series. • Project section • Activity section (including both observation acquisition and numerical computation) • Observation section (metadata regarding the methods used to obtained the data, the spatial and temporal sampling regime, quality etc.) • Observation collection section The key concepts in

  2. Properties of pinto beans air-classified high starch fraction and its extrudates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pinto beans were milled and air classified to obtain a high starch fraction, and then extruded. Properties of non-extruded high starch fraction (NE-HSF) and extruded high starch fraction (E-HSF) were compared with whole pinto flour (WPF). Composition (d.b.) of WPF was 4% ash, 1.6% extractable lipid ...

  3. Imaging air volume fraction in sea ice using non-destructive X-ray tomography

    NASA Astrophysics Data System (ADS)

    Crabeck, Odile; Galley, Ryan; Delille, Bruno; Else, Brent; Geilfus, Nicolas-Xavier; Lemes, Marcos; Des Roches, Mathieu; Francus, Pierre; Tison, Jean-Louis; Rysgaard, Søren

    2016-05-01

    Although the presence of a gas phase in sea ice creates the potential for gas exchange with the atmosphere, the distribution of gas bubbles and transport of gases within the sea ice are still poorly understood. Currently no straightforward technique exists to measure the vertical distribution of air volume fraction in sea ice. Here, we present a new fast and non-destructive X-ray computed tomography technique to quantify the air volume fraction and produce separate images of air volume inclusions in sea ice. The technique was performed on relatively thin (4-22 cm) sea ice collected from an experimental ice tank. While most of the internal layers showed air volume fractions < 2 %, the ice-air interface (top 2 cm) systematically showed values up to 5 %. We suggest that the air volume fraction is a function of both the bulk ice gas saturation factor and the brine volume fraction. We differentiate micro bubbles (Ø < 1 mm), large bubbles (1 mm < Ø < 5 mm) and macro bubbles (Ø > 5 mm). While micro bubbles were the most abundant type of gas bubbles, most of the air porosity observed resulted from the presence of large and macro bubbles. The ice texture (granular and columnar) as well as the permeability state of ice are important factors controlling the air volume fraction. The technique developed is suited for studies related to gas transport and bubble migration.

  4. Geochemical mole-balance modeling with uncertain data

    USGS Publications Warehouse

    Parkhurst, D.L.

    1997-01-01

    Geochemical mole-balance models are sets of chemical reactions that quantitatively account for changes in the chemical and isotopic composition of water along a flow path. A revised mole-balance formulation that includes an uncertainty term for each chemical and isotopic datum is derived. The revised formulation is comprised of mole-balance equations for each element or element redox state, alkalinity, electrons, solvent water, and each isotope; a charge-balance equation and an equation that relates the uncertainty terms for pH, alkalinity, and total dissolved inorganic carbon for each aqueous solution: inequality constraints on the size of the uncertainty terms: and inequality constraints on the sign of the mole transfer of reactants. The equations and inequality constraints are solved by a modification of the simplex algorithm combined with an exhaustive search for unique combinations of aqueous solutions and reactants for which the equations and inequality constraints can be solved and the uncertainty terms minimized. Additional algorithms find only the simplest mole-balance models and determine the ranges of mixing fractions for each solution and mole transfers for each reactant that are consistent with specified limits on the uncertainty terms. The revised formulation produces simpler and more robust mole-balance models and allows the significance of mixing fractions and mole transfers to be evaluated. In an example from the central Oklahoma aquifer, inclusion of up to 5% uncertainty in the chemical data can reduce the number of reactants in mole-balance models from seven or more to as few as three, these being cation exchange, dolomite dissolution, and silica precipitation. In another example from the Madison aquifer; inclusion of the charge-balance constraint requires significant increases in the mole transfers of calcite, dolomite, and organic matter, which reduce the estimated maximum carbon 14 age of the sample by about 10,000 years, from 22,700 years to

  5. Imaging air volume fraction in sea ice using non-destructive X-ray tomography

    NASA Astrophysics Data System (ADS)

    Crabeck, O.; Galley, R. J.; Delille, B.; Else, B. G. T.; Geilfus, N.-X.; Lemes, M.; Des Roches, M.; Francus, P.; Tison, J.-L.; Rysgaard, S.

    2015-09-01

    Although the presence of a gas phase in sea ice creates the potential for gas exchange with the atmosphere, the distribution of gas bubbles and transport of gases within the sea ice are still poorly understood. Currently no straightforward technique exists to measure the vertical distribution of air volume fraction in sea ice. Here, we present a new fast and non-destructive X-ray computed tomography technique to quantify the air volume fraction and produce separate 3-D images of air-volume inclusions in sea ice. The technique was performed on relatively thin (4-22 cm) sea ice collected from an experimental ice tank. While most of the internal layers showed air-volume fractions < 2 %, the ice-air interface (top 2 cm) systematically showed values up to 5 %. We suggest that the air volume fraction is a function of both the bulk ice gas saturation factor and the size of the brine channel. We differentiate micro bubbles (∅ < 1 mm), large bubbles (1 < ∅ < 5 mm) and macro bubbles (∅ > 5 mm). While micro bubbles were the most abundant type of air inclusions, most of the air porosity observed resulted from the presence of large and macro bubbles. The ice microstructure (granular and columnar) as well as the permeability state of ice are important factors controlling the air volume fraction. The technique developed is suited for studies related to gas transport and bubble migration and can help considerably improving parameterization of these processes in sea ice biogeochemical models.

  6. Investigation of hybrid membrane-sorption technologies for air fractionating

    NASA Astrophysics Data System (ADS)

    Laguntsov, N. I.; Kurchatov, I. M.; Korolev, M. V.; Tishin, A. V.

    2016-09-01

    Main aim of the work is to develop and to research single-circuit hybrid membrane- sorption system for enriching air with oxygen. The developed system allows to produce air, enriched with air up to 50%, purified from dust of any size, including nanoscale dust received in consequence of sorbent abrasion. In the course of the work the research of existing systems for air enrichment with oxygen, and the possibility of combining two methods of gas separation: membrane, and sorption, was conducted. The developed system differs from its analogues in that it has improved energy efficiency compared to methods of the membrane and sorption separation. Also work presents method of cyclogram determining of the hybrid system. In this methodic an algorithm for calculating of the cycles number, and determining of the stages duration in order to obtain the desired performance was presented.

  7. Common Moles, Atypical Moles (Dysplastic Nevi), and Risk of Melanoma

    MedlinePlus

    ... dysplastic nevus Having more than 50 common moles Sunlight : Sunlight is a source of UV radiation , which causes ... by spending time in the sun without protection. Sunlight can be reflected by sand, water, snow, ice, ...

  8. Modern Mathematics and the Mole.

    ERIC Educational Resources Information Center

    Henson, R.; Stumbles, A.

    1979-01-01

    Discusses several examples of the modern mathematics familiar to the pupils at the age where the mole concept is introduced, to help the teacher adopt an appropriate approach when dealing with this topic. (GA)

  9. Of Bushwahckers, Termites and Moles.

    ERIC Educational Resources Information Center

    Smelter, Richard W.

    2003-01-01

    Retired school administrator describes five types of school personnel that make an administrator's job difficult: Bushwackers, termites, CIA moles, rumor-mill addicts, and sartorial slobs. For example, termites are staff members who purposely volunteer for committees so they can sabotage the group's efforts from within. (PKP)

  10. Urban air quality assessment using monitoring data of fractionized aerosol samples, chemometrics and meteorological conditions.

    PubMed

    Yotova, Galina I; Tsitouridou, Roxani; Tsakovski, Stefan L; Simeonov, Vasil D

    2016-01-01

    The present article deals with assessment of urban air by using monitoring data for 10 different aerosol fractions (0.015-16 μm) collected at a typical urban site in City of Thessaloniki, Greece. The data set was subject to multivariate statistical analysis (cluster analysis and principal components analysis) and, additionally, to HYSPLIT back trajectory modeling in order to assess in a better way the impact of the weather conditions on the pollution sources identified. A specific element of the study is the effort to clarify the role of outliers in the data set. The reason for the appearance of outliers is strongly related to the atmospheric condition on the particular sampling days leading to enhanced concentration of pollutants (secondary emissions, sea sprays, road and soil dust, combustion processes) especially for ultra fine and coarse particles. It is also shown that three major sources affect the urban air quality of the location studied-sea sprays, mineral dust and anthropogenic influences (agricultural activity, combustion processes, and industrial sources). The level of impact is related to certain extent to the aerosol fraction size. The assessment of the meteorological conditions leads to defining of four downwind patterns affecting the air quality (Pelagic, Western and Central Europe, Eastern and Northeastern Europe and Africa and Southern Europe). Thus, the present study offers a complete urban air assessment taking into account the weather conditions, pollution sources and aerosol fractioning.

  11. Tool to Distinguish Moles from Melanoma

    Cancer.gov

    Moles to Melanoma: Recognizing the ABCDE Features” presents photos that show changes in individual pigmented lesions over time, and describes the different appearances of moles, dysplastic nevi, and melanomas.

  12. Accuracy of Geophysical Parameters Derived from AIRS/AMSU as a Function of Fractional Cloud Cover

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Barnet, Chris; Blaisdell, John; Iredell, Lena; Keita, Fricky; Kouvaris, Lou; Molnar, Gyula; Chahine, Moustafa

    2005-01-01

    AIRS was launched on EOS Aqua on May 4,2002, together with AMSU A and HSB, to form a next generation polar orbiting infrared and microwave atmospheric sounding system. The primary products of AIRS/AMSU are twice daily global fields of atmospheric temperature-humidity profiles, ozone profiles, sea/land surface skin temperature, and cloud related parameters including OLR. The sounding goals of AIRS are to produce 1 km tropospheric layer mean temperatures with an rms error of 1K, and layer precipitable water with an rms error of 20%, in cases with up to 80% effective cloud cover. The basic theory used to analyze AIRS/AMSU/HSB data in the presence of clouds, called the at-launch algorithm, was described previously. Pre-launch simulation studies using this algorithm indicated that these results should be achievable. Some modifications have been made to the at-launch retrieval algorithm as described in this paper. Sample fields of parameters retrieved from AIRS/AMSU/HSB data are presented and validated as a function of retrieved fractional cloud cover. As in simulation, the degradation of retrieval accuracy with increasing cloud cover is small. HSB failed in February 2005, and consequently HSB channel radiances are not used in the results shown in this paper. The AIRS/AMSU retrieval algorithm described in this paper, called Version 4, become operational at the Goddard DAAC in April 2005 and is being used to analyze near-real time AIRS/AMSU data. Historical AIRS/AMSU data, going backwards from March 2005 through September 2002, is also being analyzed by the DAAC using the Version 4 algorithm.

  13. Accuracy of Geophysical Parameters Derived from AIRS/AMSU as a Function of Fractional Cloud Cover

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Barnet, Chris; Blaisdell, John; Iredell, Lena; Keita, Fricky; Kouvaris, Lou; Molnar, Gyula; Chahine, Moustafa

    2006-01-01

    AIRS was launched on EOS Aqua on May 4,2002, together with AMSU A and HSB, to form a next generation polar orbiting infrared and microwave atmospheric sounding system. The primary products of AIRS/AMSU are twice daily global fields of atmospheric temperature-humidity profiles, ozone profiles, sea/land surface skin temperature, and cloud related parameters including OLR. The sounding goals of AIRS are to produce 1 km tropospheric layer mean temperatures with an rms error of lK, and layer precipitable water with an rms error of 20 percent, in cases with up to 80 percent effective cloud cover. The basic theory used to analyze Atmospheric InfraRed Sounder/Advanced Microwave Sounding Unit/Humidity Sounder Brazil (AIRS/AMSU/HSB) data in the presence of clouds, called the at-launch algorithm, was described previously. Pre-launch simulation studies using this algorithm indicated that these results should be achievable. Some modifications have been made to the at-launch retrieval algorithm as described in this paper. Sample fields of parameters retrieved from AIRS/AMSU/HSB data are presented and validated as a function of retrieved fractional cloud cover. As in simulation, the degradation of retrieval accuracy with increasing cloud cover is small and the RMS accuracy of lower tropospheric temperature retrieved with 80 percent cloud cover is about 0.5 K poorer than for clear cases. HSB failed in February 2003, and consequently HSB channel radiances are not used in the results shown in this paper. The AIRS/AMSU retrieval algorithm described in this paper, called Version 4, become operational at the Goddard DAAC (Distributed Active Archive Center) in April 2003 and is being used to analyze near-real time AIRS/AMSU data. Historical AIRS/AMSU data, going backwards from March 2005 through September 2002, is also being analyzed by the DAAC using the Version 4 algorithm.

  14. EFFECTS OF OXYGEN AND AIR MIXING ON VOID FRACTIONS IN A LARGE SCALE SYSTEM

    SciTech Connect

    Leishear, R; Hector Guerrero, H; Michael Restivo, M

    2008-09-11

    Oxygen and air mixing with spargers was performed in a 30 foot tall by 30 inch diameter column, to investigate mass transfer as air sparged up through the column and removed saturated oxygen from solution. The mixing techniques required to support this research are the focus of this paper. The fluids tested included water, water with an antifoam agent (AFA), and a high, solids content, Bingham plastic, nuclear waste simulant with AFA, referred to as AZ01 simulant, which is non-radioactive. Mixing of fluids in the column was performed using a recirculation system and an air sparger. The re-circulation system consisted of the column, a re-circulating pump, and associated piping. The air sparger was fabricated from a two inch diameter pipe concentrically installed in the column and open near the bottom of the column. The column contents were slowly re-circulated while fluids were mixed with the air sparger. Samples were rheologically tested to ensure effective mixing, as required. Once the fluids were adequately mixed, oxygen was homogeneously added through the re-circulation loop using a sintered metal oxygen sparger followed by a static mixer. Then the air sparger was re-actuated to remove oxygen from solution as air bubbled up through solution. To monitor mixing effectiveness several variables were monitored, which included flow rates, oxygen concentration, differential pressures along the column height, fluid levels, and void fractions, which are defined as the percent of dissolved gas divided by the total volume of gas and liquid. Research showed that mixing was uniform for water and water with AFA, but mixing for the AZ101 fluid was far more complex. Although mixing of AZ101 was uniform throughout most of the column, gas entrapment and settling of solids significantly affected test results. The detailed test results presented here provide some insight into the complexities of mixing and void fractions for different fluids and how the mixing process itself

  15. Foam fractionation as a tool to study the air-water interface structure-function relationship of wheat gluten hydrolysates.

    PubMed

    Wouters, Arno G B; Rombouts, Ine; Schoebrechts, Nele; Fierens, Ellen; Brijs, Kristof; Blecker, Christophe; Delcour, Jan A

    2017-03-01

    Enzymatic hydrolysis of wheat gluten protein improves its solubility and produces hydrolysates with foaming properties which may find applications in food products. First, we here investigated whether foam-liquid fractionation can concentrate wheat gluten peptides with foaming properties. Foam and liquid fractions had high and very low foam stability (FS), respectively. In addition, foam fractions were able to decrease surface tension more pronouncedly than un-fractionated samples and liquid fractions, suggesting they are able to arrange themselves more efficiently at an interface. As a second objective, foam fractionation served as a tool to study the structural properties of the peptides, causing these differences in air-water interfacial behavior. Zeta potential and surface hydrophobicity measurements did not fully explain these differences but suggested that hydrophobic interactions at the air-water interface are more important than electrostatic interactions. RP-HPLC showed a large overlap between foam and liquid fractions. However, a small fraction of very hydrophobic peptides with relatively high average molecular mass was clearly enriched in the foam fraction. These peptides were also more concentrated in un-fractionated DH 2 hydrolysates, which had high FS, than in DH 6 hydrolysates, which had low FS. These peptides most likely play a key role in stabilizing the air-water interface.

  16. Recovery of Extracellular Lipolytic Enzymes from Macrophomina phaseolina by Foam Fractionation with Air

    PubMed Central

    Germani, José Carlos

    2013-01-01

    Macrophomina phaseolina was cultivated in complex and simple media for the production of extracellular lipolytic enzymes. Culture supernatants were batch foam fractionated for the recovery of these enzymes, and column design and operation included the use of P 2 frit (porosity 40 to 100 μm), air as sparging gas at variable flow rates, and Triton X-100 added at the beginning or gradually in aliquots. Samples taken at intervals showed the progress of the kinetic and the efficiency parameters. Best results were obtained with the simple medium supernatant by combining the stepwise addition of small amounts of the surfactant with the variation of the air flow rates along the separation. Inert proteins were foamed out first, and the subsequent foamate was enriched in the enzymes, showing estimated activity recovery (R), enrichment ratio (E), and purification factor (P) of 45%, 34.7, and 2.9, respectively. Lipases were present in the enriched foamate. PMID:23738054

  17. Mold, Mould, Mole-d: The Three M's of Career Development

    ERIC Educational Resources Information Center

    Amundson, Norman E.

    2008-01-01

    The author explores a creative idea development process wherein one begins by applying the image of "breaking the mold" to career development and then extending the process further by considering other related images. In this article, the related images include synonyms for mold such as mould and mole-d (the mole is a small burrowing animal with…

  18. Avogadro Number and Mole: A Royal Confusion.

    ERIC Educational Resources Information Center

    Emiliani, Cesare

    1991-01-01

    There is a great deal of confusion in physics and chemistry textbooks, dictionaries, manuals, and handbooks about the definition of Avogadro's number and the term "mole." Avogadro's number is defined simply as the number of atomic mass units in one gram. Mole is defined as the mass of one Avogadro number of identical items. (Author/PR)

  19. Chemical analysis and biological testing of a polar fraction of ambient air, diesel engine, and gasoline engine particulate extracts.

    PubMed Central

    Strandell, M; Zakrisson, S; Alsberg, T; Westerholm, R; Winquist, L; Rannug, U

    1994-01-01

    Extracts of gasoline and diesel vehicle exhaust and ambient air particles were fractionated into five fractions according to polarity on a silica gel column. Two medium polar fractions showing high genotoxic activity in the Ames test were further subfractionated, using normal-phase high-performance liquid chromatography. Chemical analyses were performed by means of gas chromatography combined with mass spectrometry and flame ionization and detection. The crude extracts, fractions, and subfractions were assayed with the Ames test, with and without S9, and the most abundant compounds in the subfractions are reported. PMID:7529708

  20. Measurement of air distribution and void fraction of an upwards air-water flow using electrical resistance tomography and a wire-mesh sensor

    NASA Astrophysics Data System (ADS)

    Olerni, Claudio; Jia, Jiabin; Wang, Mi

    2013-03-01

    Measurements on an upwards air-water flow are reported that were obtained simultaneously with a dual-plane electrical resistance tomograph (ERT) and a wire-mesh sensor (WMS). The ultimate measurement target of both ERT and WMS is the same, the electrical conductivity of the medium. The ERT is a non-intrusive device whereas the WMS requires a net of wires that physically crosses the flow. This paper presents comparisons between the results obtained simultaneously from the ERT and the WMS for evaluation and calibration of the ERT. The length of the vertical testing pipeline section is 3 m with an internal diameter of 50 mm. Two distinct sets of air-water flow rate scenarios, bubble and slug regimes, were produced in the experiments. The fast impedance camera ERT recorded the data at an approximate time resolution of 896 frames per second (fps) per plane in contrast with the 1024 fps of the wire-mesh sensor WMS200. The set-up of the experiment was based on well established knowledge of air-water upwards flow, particularly the specific flow regimes and wall peak effects. The local air void fraction profiles and the overall air void fraction were produced from two systems to establish consistency for comparison of the data accuracy. Conventional bulk flow measurements in air mass and electromagnetic flow metering, as well as pressure and temperature, were employed, which brought the necessary calibration to the flow measurements. The results show that the profiles generated from the two systems have a certain level of inconsistency, particularly in a wall peak and a core peak from the ERT and WMS respectively, whereas the two tomography instruments achieve good agreement on the overall air void fraction for bubble flow. For slug flow, when the void fraction is over 30%, the ERT underestimates the void fraction, but a linear relation between ERT and WMS is still observed.

  1. Genetics Home Reference: recurrent hydatidiform mole

    MedlinePlus

    ... hydatidiform mole occurs early in pregnancy when an embryo does not fully develop and the placenta develops ... that they will be inactive in the developing embryo; the corresponding paternal genes are active. NLRP7 or ...

  2. Measurement Corner Mass, Moles and Avogadro's Number

    ERIC Educational Resources Information Center

    Todd, Robert M.

    1977-01-01

    Discusses and clarifies the confusion arising from the use of the terms "mass,""volume,""matter,""mole," and "Avogadro's number." Suggests three laboratory activities concerning mass, volume, and number of particles in a given volume. (CS)

  3. Moles and Mole Control on British Farms, Amenities and Gardens after Strychnine Withdrawal

    PubMed Central

    Baker, Sandra E.; Ellwood, Stephen A.; Johnson, Paul J.; Macdonald, David W.

    2016-01-01

    Simple Summary Moles are burrowing mammals that are regarded as pests in Britain, and until 2006 they could legally be killed using strychnine poison. When strychnine was withdrawn there were fears that mole populations would increase. We surveyed farmers, amenity managers and householders about moles and mole control on their land in 2007, post strychnine withdrawal. Kill-trapping was by far the preferred control method used and control may be used more than can be justified by damage levels or the effect of control on damage. Mole traps are unregulated, unlike most other spring traps, and some might not meet current welfare standards. We found no evidence that mole activity had increased since a 1992 survey of farms. Abstract Moles are considered pests in Britain, but this issue has been little studied. Lower welfare standards have been tolerated for moles than for most other managed wild mammal species, as use of both the controversial poison, strychnine, and unregulated traps have been permitted. Strychnine was withdrawn in 2006 and there were fears that mole populations would increase as a result. In 2007, we conducted a comprehensive, nationwide survey of land manager perceptions, opinions and behaviour regarding moles and mole control on farms, amenities and domestic gardens in Britain. We surveyed 2150 land managers (achieving a 59% response rate) and ground-truthed 29 responses. Moles were reported to be present on most farms and amenities, and 13% of gardens, and were more common in lighter soils. Where present, moles were usually considered pests, this being more likely in Wales, Scotland and northern England, on livestock and mixed farms, and on large, high-value amenities, e.g., racecourses and golf courses. Mole control followed similar patterns to mole presence. More control may occur than is economically, and therefore potentially ethically, justified. Control should be more carefully considered and, where necessary, more effectively targeted. Kill

  4. Assessing changes in stratospheric mean age of air and fractional release using historical trace gas observations

    NASA Astrophysics Data System (ADS)

    Laube, Johannes; Bönisch, Harald; Engel, Andreas; Röckmann, Thomas; Sturges, William

    2014-05-01

    Large-scale stratospheric transport is pre-dominantly governed by the Brewer-Dobson circulation. Due to climatic change a long-term acceleration of this residual stratospheric circulation has been proposed (e.g. Austin et al.,2006). Observational evidence has revealed indications for temporary changes (e.g. Bönisch et al., 2011) but a confirmation of a significant long-term trend is missing so far (e.g. Engel et al., 2009). A different aspect is a possible long-term change in the break-down of chemically important species such as chlorofluorocarbons as proposed by Butchart et al. 2001. Recent studies show significant differences adding up to more than 20 % in the chlorine released from such compounds (Newman et al., 2007; Laube et al., 2013). We here use a data set of three long-lived trace gases, namely SF6, CF2Cl2, and N2O, as measured in whole-air samples collected during balloon and aircraft flights between 1975 and 2011, to assess changes in stratospheric transport and chemistry. For this purpose we utilise the mean stratospheric transit times (or mean ages of air) in combination with a measure of the chemical decomposition (i.e. fractional release factors). We also evaluate the influence of different trend correction methods on these quantities and explore their variability with latitude, altitude, and season. References Austin, J. & Li, F.: On the relationship between the strength of the Brewer-Dobson circulation and the age of stratospheric air, Geophys. Res. Lett., 33, L17807, 2006. Bönisch, H., Engel, A., Birner, Th., Hoor, P., Tarasick, D. W., and Ray, E. A.: On the structural changes in the Brewer-Dobson circulation after 2000, Atmos. Chem. Phys., 11, 3937-3948, 2011. Butchart, N. & Scaife, A. A. Removal of chlorofluorocarbons by increased mass exchange between the stratosphere and troposphere in a changing climate. Nature, 410, 799-802, 2001. Engel, A., Möbius, T., Bönisch, H., Schmidt, U., Heinz, R., Levin, I., Atlas, E., Aoki, S., Nakazawa, T

  5. In vitro effects of pollutants from particulate and volatile fractions of air samples-day and night variability.

    PubMed

    Novák, Jiří; Giesy, John P; Klánová, Jana; Hilscherová, Klára

    2013-09-01

    Chemicals in air were characterized for potential interference with signaling of estrogen, androgen, and arylhydrocarbon (AhR) receptors, which are known to play an important role in endocrine-disruptive changes in vivo. Previously, effects of this type have been studied mainly in particulate matter in the ambient air from various localities. In this study, both volatile and particulate fractions of air from three sites in Banja Luka region (Bosnia and Herzegovina) were investigated to describe the distribution of endocrine-disrupting contaminants on a small spatial scale. Circadian variability of air pollution was investigated by collecting samples during both day and night. Air samples collected from urban localities at night were more potent in producing the AhR-mediated effects than those collected during daytime. This trend was not observed at the reference rural location. None of the samples showed significant estrogenic or androgenic activity. On the other hand, anti-androgenicity was detected in both particulate and vapor phases, while anti-estrogenicity was detected only in the particulate fraction of air from all localities. The AhR-mediated potencies of samples were associated primarily with non-persistent compounds. Based on the concentrations of 28 individual compounds, PAHs accounted for approximately 30 % of the AhR-mediated potency determined by the bioassay. The results show that there can be a significant difference between levels of bioactive compounds in air between daytime and nighttime.

  6. Moles and Mole Control on British Farms, Amenities and Gardens after Strychnine Withdrawal.

    PubMed

    Baker, Sandra E; Ellwood, Stephen A; Johnson, Paul J; Macdonald, David W

    2016-06-08

    Moles are considered pests in Britain, but this issue has been little studied. Lower welfare standards have been tolerated for moles than for most other managed wild mammal species, as use of both the controversial poison, strychnine, and unregulated traps have been permitted. Strychnine was withdrawn in 2006 and there were fears that mole populations would increase as a result. In 2007, we conducted a comprehensive, nationwide survey of land manager perceptions, opinions and behaviour regarding moles and mole control on farms, amenities and domestic gardens in Britain. We surveyed 2150 land managers (achieving a 59% response rate) and ground-truthed 29 responses. Moles were reported to be present on most farms and amenities, and 13% of gardens, and were more common in lighter soils. Where present, moles were usually considered pests, this being more likely in Wales, Scotland and northern England, on livestock and mixed farms, and on large, high-value amenities, e.g., racecourses and golf courses. Mole control followed similar patterns to mole presence. More control may occur than is economically, and therefore potentially ethically, justified. Control should be more carefully considered and, where necessary, more effectively targeted. Kill-trapping was the favoured recent and future method on farms and amenities, even if strychnine was to be reintroduced; however, because mole traps are currently unregulated, some might not meet current welfare standards if tested. We found no evidence for an increase in moles since a farm questionnaire survey conducted in 1992; this could have wider implications for future wildlife management policy changes.

  7. Response of sugarcane to carbon dioxide enrichment and elevated air temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four sugarcane cultivars (CP 72-2086, CP 73-1547, CP 88-1508, and CP 80-1827) were grown in elongated temperature-gradient greenhouses (TGG) at ambient or elevated carbon dioxide (CO2) of 360 or 720 µmol CO2 mol-1 air (ppm, mole fraction basis), respectively. Elevated CO2 was maintained by injection...

  8. Air-Quality Impacts and Intake Fraction of PM2.5 during the 2013 Rim Megafire.

    PubMed

    Navarro, Kathleen M; Cisneros, Ricardo; O'Neill, Susan M; Schweizer, Don; Larkin, Narasimhan K; Balmes, John R

    2016-11-01

    The 2013 Rim Fire was the third largest wildfire in California history and burned 257 314 acres in the Sierra Nevada Mountains. We evaluated air-quality impacts of PM2.5 from smoke from the Rim Fire on receptor areas in California and Nevada. We employed two approaches to examine the air-quality impacts: (1) an evaluation of PM2.5 concentration data collected by temporary and permanent air-monitoring sites and (2) an estimation of intake fraction (iF) of PM2.5 from smoke. The Rim Fire impacted locations in the central Sierra nearest to the fire and extended to the northern Sierra Nevada Mountains of California and Nevada monitoring sites. Daily 24-h average PM2.5 concentrations measured at 22 air monitors had an average concentration of 20 μg/m(3) and ranged from 0 to 450 μg/m(3). The iF for PM2.5 from smoke during the active fire period was 7.4 per million, which is slightly higher than representative iF values for PM2.5 in rural areas and much lower than for urban areas. This study is a unique application of intake fraction to examine emissions-to-exposure for wildfires and emphasizes that air-quality impacts are not only localized to communities near large fires but can extend long distances and affect larger urban areas.

  9. The Origin of the Mole Concept

    ERIC Educational Resources Information Center

    Jensen, William B.

    2004-01-01

    German Chemist, August Wilhelm Hofmann first introduced the term "molar" (from the Latin moles, meaning "a large mass") into chemistry, around 1865. The particular use of the term molar gained currency in the physics literature, where it was in common use at least through the 1940s.

  10. Relating the Mole Concept and Fundamental Mathematics.

    ERIC Educational Resources Information Center

    Phillips, Kenneth L.

    The high percentage of students who have difficulty in solving free-response problems related to the mole concept was addressed by implementation of reading skill strategies and computer assisted instruction. Frayer models, semantic mapping, and graphic organizers from Reading in the Content Area (RICA) were used to increase student understanding…

  11. Air fractionation in plate-like inclusions within the EPICA-DML deep ice core

    NASA Astrophysics Data System (ADS)

    Nedelcu, A.; Faria, S. H.; Kipfstuhl, S.; Schmidt, B.; Kuhs, W. F.

    2009-04-01

    than this, they suggest that the diffusion of chemical traces in the ice matrix may not be negligible, at least locally, on a timescale of few years. These results could be important for the interpretation of ice-core paleoclimate records. Muguruma, J., S. Mae and A. Higashi, 1966. Void formation by non-basal glide in ice single crystals, Philos. Mag., 13(123), 625-629. Mae, S., 1968. Void formation during non-basal glide in ice single crystals under tension, Philos. Mag., 18(151), 101-114. Gow, A. J., 1971. Relaxation of ice in deep drill cores from Antarctica, J. Glaciol., 76(11), 2533-2541. Nedelcu, A. F., S. H. Faria and W. F. Kuhs, in press. Raman spectra of plate-like inclusions in the EPICA-DML ice core. J. Glaciol., 55(189) Nakahara, J., Y. Shigesato, A. Higashi, T. Hondoh and C.C. Langway, 1988. Raman spectra of natural clathrates in deep ice cores, Philos. Mag. B, 57(3), 421-430. Ikeda, T., H. Fukazawa, S. Mae, L. Pepin, P. Duval, B. Champagnon, V. Y. Lipenkov and T. Hondoh, 1999. Extreme fractionation of gases caused by formation of clathrate hydrates in Vostok Antarctic ice, Geophys. Res. Lett., 26(1), 91-94. Ikeda-Fukazawa, T., T. Hondoh, T. Fukumura, H. Fukazawa and S. Mae, 2001. Variation in N2/O2 ratio of occluded air in Dome Fuji antarctic ice, J. Geophys. Res., 106(D16), 17799-17810. Ikeda-Fukazawa, T., K. Fukumizu, K. Kawamura, S. Aoki, T. Nakazawa and T. Hondoh, 2005. Effects of molecular diffusion on trapped gas composition in polar ice cores, Earth Planet.Sci.Lett.,229(3-4),183-192. Severinghaus, J. P., and M. O. Battle, 2006. Fractionation of gases in polar ice during bubble close-off: new constraints from firn air, Ne, Kr and Xe observations, Earth Planet. Sci. Lett., 244(1-2), 474-500.

  12. Social Structure Predicts Genital Morphology in African Mole-Rats

    PubMed Central

    Seney, Marianne L.; Kelly, Diane A.; Goldman, Bruce D.; Šumbera, Radim; Forger, Nancy G.

    2009-01-01

    Background African mole-rats (Bathyergidae, Rodentia) exhibit a wide range of social structures, from solitary to eusocial. We previously found a lack of sex differences in the external genitalia and morphology of the perineal muscles associated with the phallus in the eusocial naked mole-rat. This was quite surprising, as the external genitalia and perineal muscles are sexually dimorphic in all other mammals examined. We hypothesized that the lack of sex differences in naked mole-rats might be related to their unusual social structure. Methodology/Principal Findings We compared the genitalia and perineal muscles in three African mole-rat species: the naked mole-rat, the solitary silvery mole-rat, and the Damaraland mole-rat, a species considered to be eusocial, but with less reproductive skew than naked mole-rats. Our findings support a relationship between social structure, mating system, and sexual differentiation. Naked mole-rats lack sex differences in genitalia and perineal morphology, silvery mole-rats exhibit sex differences, and Damaraland mole-rats are intermediate. Conclusions/Significance The lack of sex differences in naked mole-rats is not an attribute of all African mole-rats, but appears to have evolved in relation to their unusual social structure and reproductive biology. PMID:19829697

  13. Insights: A LAP on Moles: Teaching an Important Concept.

    ERIC Educational Resources Information Center

    Ihde, John

    1985-01-01

    Describes a learning activity packet (LAP) designed to help students understand the basic concept of the mole as a chemical unit; know relationships between the mole and atomic weights in the periodic table; and solve basic conversion problems involving moles, atoms, and molecules. (JN)

  14. Performance of a hydrogen burner to simulate air entering scramjet combustors. [simulation of total temperature, total pressure, and volume fraction of oxygen of air at flight conditions

    NASA Technical Reports Server (NTRS)

    Russin, W. R.

    1974-01-01

    Tests were conducted to determine the performance of a hydrogen burner used to produce a test gas that simulates air entering a scramjet combustor at various flight conditions. The test gas simulates air in that it duplicates the total temperature, total pressure, and the volume fraction of oxygen of air at flight conditions. The main objective of the tests was to determine the performance of the burner as a function of the effective exhaust port area. The conclusions were: (1) pressure oscillations of the chugging type were reduced in amplitude to plus or minus 2 percent of the mean pressure level by proper sizing of hydrogen, oxygen, and air injector flow areas; (2) combustion efficiency remained essentially constant as the exhaust port area was increased by a factor of 3.4; (3) the mean total temperature determined from integrating the exit radial gas property profiles was within plus or minus 5 percent of the theoretical bulk total temperature; (4) the measured exit total temperature profile had a local peak temperature more than 30 percent greater than the theoretical bulk total temperature; and (5) measured heat transfer to the burner liner was 75 percent of that predicted by theory based on a flat radial temperature profile.

  15. [Fractional and component composition of dust in the air of workplace at machinery enterprise].

    PubMed

    Maĭ, I V; Zagorodnov, S Iu; Maks, A A

    2012-01-01

    The authors present results of assessment of fractional and component composition of dust entering workplace of machinery enterprises. The results prove topicality of data accumulation on actual contents of dusts for more reliable and precise evaluation of the dusts mixture influence on the workers' health.

  16. FRACTIONAL AEROSOL FILTRATION EFFICIENCY OF IN-DUCT VENTILATION AIR CLEANERS

    EPA Science Inventory

    The filtration efficiency of ventilation air cleaners is highly particle-size dependent over the 0.01 to 3 μm diameter size range. Current standardized test methods, which determine only overall efficiencies for ambient aerosol or other test aerosols, provide data of limited util...

  17. CARS Temperature and Species Measurements For Air Vehicle Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Danehy, Paul M.; Gord, James R.; Grisch, Frederic; Klimenko, Dmitry; Clauss, Walter

    2005-01-01

    The coherent anti-Stokes Raman spectroscopy (CARS) method has recently been used in the United States and Europe to probe several different types of propulsion systems for air vehicles. At NASA Langley Research Center in the United States, CARS has been used to simultaneously measure temperature and the mole fractions of N2, O2 and H2 in a supersonic combustor, representative of a scramjet engine. At Wright- Patterson Air Force Base in the United States, CARS has been used to simultaneously measure temperature and mole fractions of N2, O2 and CO2, in the exhaust stream of a liquid-fueled, gas-turbine combustor. At ONERA in France and the DLR in Germany researchers have used CARS to measure temperature and species concentrations in cryogenic LOX-H2 rocket combustion chambers. The primary aim of these measurements has been to provide detailed flowfield information for computational fluid dynamics (CFD) code validation.

  18. Low pressure premixed CH4/air flames with forced periodic mixture fraction oscillations: experimental approach

    NASA Astrophysics Data System (ADS)

    Ax, H.; Kutne, P.; Meier, W.; König, K.; Maas, U.; Class, A.; Aigner, M.

    2009-03-01

    An experimental setup for the generation and investigation of periodic equivalence ratio oscillations in laminar premixed flames is presented. A special low-pressure burner was developed which generates stable flames in a wide pressure range down to 20 mbar and provides the possibility of rapid mixture fraction variations. The technical realization of the mixture fraction variations and the characteristics of the burner are described. 1D laser Raman scattering was applied to determine the temperature and concentration profiles of the major species through the flame front in correlation to the phase-angle of the periodic oscillation. OH* chemiluminescence was detected to qualitatively analyze the response of the flame to mixture fraction variations by changing shape and position. Exemplary results from a flame at p=69 mbar, forced at a frequency of 10 Hz, are shown and discussed. The experiments are part of a cooperative research project including the development of kinetic models and numerical simulation tools with the aim of a better understanding and prediction of periodic combustion instabilities in gas turbines. The focus of the current paper lies on the presentation of the experimental realization and the measuring techniques.

  19. Instrumented Moles for Planetary Subsurface Regolith Studies

    NASA Astrophysics Data System (ADS)

    Richter, L. O.; Coste, P. A.; Grzesik, A.; Knollenberg, J.; Magnani, P.; Nadalini, R.; Re, E.; Romstedt, J.; Sohl, F.; Spohn, T.

    2006-12-01

    Soil-like materials, or regolith, on solar system objects provide a record of physical and/or chemical weathering processes on the object in question and as such possess significant scientific relevance for study by landed planetary missions. In the case of Mars, a complex interplay has been at work between impact gardening, aeolian as well as possibly fluvial processes. This resulted in regolith that is texturally as well as compositionally layered as hinted at by results from the Mars Exploration Rover (MER) missions which are capable of accessing shallow subsurface soils by wheel trenching. Significant subsurface soil access on Mars, i.e. to depths of a meter or more, remains to be accomplished on future missions. This has been one of the objectives of the unsuccessful Beagle 2 landed element of the ESA Mars Express mission having been equipped with the Planetary Underground Tool (PLUTO) subsurface soil sampling Mole system capable of self-penetration into regolith due to an internal electro-mechanical hammering mechanism. This lightweight device of less than 900 g mass was designed to repeatedly obtain and deliver to the lander regolith samples from depths down to 2 m which would have been analysed for organic matter and, specifically, organic carbon from potential extinct microbial activity. With funding from the ESA technology programme, an evolved Mole system - the Instrumented Mole System (IMS) - has now been developed to a readiness level of TRL 6. The IMS is to serve as a carrier for in situ instruments for measurements in planetary subsurface soils. This could complement or even eliminate the need to recover samples to the surface. The Engineering Model hardware having been developed within this effort is designed for accommodating a geophysical instrument package (Heat Flow and Physical Properties Package, HP3) that would be capable of measuring regolith physical properties and planetary heat flow. The chosen design encompasses a two-body Mole

  20. Global intraurban intake fractions for primary air pollutants from vehicles and other distributed sources.

    PubMed

    Apte, Joshua S; Bombrun, Emilie; Marshall, Julian D; Nazaroff, William W

    2012-03-20

    We model intraurban intake fraction (iF) values for distributed ground-level emissions in all 3646 global cities with more than 100,000 inhabitants, encompassing a total population of 2.0 billion. For conserved primary pollutants, population-weighted median, mean, and interquartile range iF values are 26, 39, and 14-52 ppm, respectively, where 1 ppm signifies 1 g inhaled/t emitted. The global mean urban iF reported here is roughly twice as large as previous estimates for cities in the United States and Europe. Intake fractions vary among cities owing to differences in population size, population density, and meteorology. Sorting by size, population-weighted mean iF values are 65, 35, and 15 ppm, respectively, for cities with populations larger than 3, 0.6-3, and 0.1-0.6 million. The 20 worldwide megacities (each >10 million people) have a population-weighted mean iF of 83 ppm. Mean intraurban iF values are greatest in Asia and lowest in land-rich high-income regions. Country-average iF values vary by a factor of 3 among the 10 nations with the largest urban populations.

  1. Detection of the cytotoxicity of water-insoluble fraction of cigarette smoke by direct exposure to cultured cells at an air-liquid interface.

    PubMed

    Nara, Hidenori; Fukano, Yasuo; Nishino, Tomoki; Aufderheide, Michaela

    2013-07-01

    For the biological evaluation of cigarette smoke in vitro, the particulate phase (PP) and the gas vapor phase (GVP) of mainstream smoke have usually been collected individually and exposed to biological material such as cultured cells. Using this traditional method, the GVP is collected by bubbling in an aqueous solution such as phosphate-buffered saline (PBS). In such a way the water-insoluble GVP fraction is excluded from the GVP, meaning that the toxic potential of the water-insoluble GVP fraction has hardly been investigated so far. In our experiments we used a direct exposure method to expose cells at the air-liquid interface (ALI) to the water-insoluble GVP fraction for demonstrating its toxicological/biological activity. In order to isolate the water-insoluble GVP fraction from mainstream smoke, the GVP was passed through 6 impingers connected in series with PBS. After direct exposure of Chinese hamster ovary cells (CHO-K1) with the water-insoluble GVP fraction in the CULTEX(®) system its cytotoxicity was assayed by using the neutral red uptake assay. The water-insoluble GVP fraction was proven to be less cytotoxic than the water-soluble GVP fraction, but showed a significant effect in a dose-dependent manner. The results of this study showed that the direct exposure of cultivated cells at the air-liquid interface offers the possibility to analyze the biological and toxicological activities of all fractions of cigarette smoke including the water-insoluble GVP fraction.

  2. Mole guns in Turkey in 2003-2005.

    PubMed

    Yilmaz, Riza; Birincioğlu, Ismail; Cakir, Ismail; Uner, H Bülent; Açikgöz, Dinç; Seçkin, Cetin

    2007-01-01

    This study describes the frequency of mole guns in Turkey by examining the cases sent to the Council of Forensic Medicine of Turkey between 2003 and 2005. In total, 11 mole guns were examined. Mole guns are manufactured to be used as a trap against detrimental animals. Although they are not meant to be used as a firearm, they are able to cause death. Mole guns appearing in regular casework were evaluated in terms of type of the gun, number of barrels, size and caliber, rifling, design, mechanism, fitness for use, legality, and geographical distribution. Ninety-one percent of the guns were 12 gauge. Most commonly they originate from Inner Anatolia. Mole guns are typically handmade. Some examples of injuries and deaths caused by mole guns are also offered.

  3. Entomopathogenic fungi detection and avoidance by mole crickets (Orthoptera: Gryllotalpidae).

    PubMed

    Thompson, Sarah R; Brandenburg, Rick L; Roberson, Gary T

    2007-02-01

    A chamber to monitor mole cricket behavior was designed using two different soil-filled containers and photosensors constructed from infrared emitters and detectors. Mole crickets (Scapteriscus spp.) were introduced into a center tube that allowed them to choose whether to enter and tunnel in untreated soil or soil treated with Beauveria bassiana (Balsamo) Vuillemin. Each time the cricket passed through the photosensor located near the entrance of soil-filled containers, the infrared light was blocked and the exact moment that this occurred was logged onto a computer using custom-written software. Data examined included the first photosensor trigger, total number of sensor triggers, presence of tunneling, and final location of the cricket after 18 h. These behaviors were analyzed to discern differences in mole cricket behavior in the presence of different treatments and to elucidate the mechanism that mole crickets use to detect fungal pathogens. The first study examined substrate selection and tunneling behavior of the southern mole cricket, Scapteriscus borellii Giglio-Tos, to the presence of five strains of B. bassiana relative to a control. There were no differences between the first sensor trigger and total number of triggers, indicating the mole crickets are not capable of detecting B. bassiana at a distance of 8 cm. Changes in mole cricket tunneling and residence time in treated soil occurred for some strains of B. bassiana but not others. One of the strains associated with behavioral changes in the southern mole cricket was used in a second experiment testing behavioral responses of the tawny mole cricket, S. vicinus Scudder. In addition to the formulated product of this strain, the two separate components of that product (conidia and carrier) and bifenthrin, an insecticide commonly used to control mole crickets, were tested. There were no differences in mole cricket behavior between treatments in this study. The differences in behavioral responses between

  4. Structural, magnetic and microwave properties of barium hexaferrite thick films with different Fe/Ba mole ratio

    NASA Astrophysics Data System (ADS)

    Verma, Samiksha; Dhawan, S. K.; Paesano, Andrea; Pandey, O. P.; Sharma, Puneet

    2015-12-01

    Barium hexaferrite (BaFe12O19) thick films (∼60 μm) with different BaO·xFe2O3 mole ratio (x=5.0-6.0) were prepared by screen printing method. X-ray diffraction analysis confirmed the formation of single phase BaFe12O19 (BaM). Preferential site occupation of Fe3+ ion at five different crystallographic sites, with varied mole ratio was measured by Mössbauer spectroscopy. Vacancy fraction found to be higher at 4f1, 4f2 and 2b sites for mole ratio 5.5 and 5.0 respectively. Magnetic measurement shows that the magnetization (M) and magnetocrystalline anisotropy field (Ha) depends upon mole ratio. M and Ha are found to be maximum for mole ratio 5.5, while the coercivity (Hc) remains constant. Reflection losses (RL) in the frequency range of 12-18 GHz were also studied. Present investigation demonstrates the effect of mole ratio on structural, magnetic and microwave absorption properties of BaM thick films for microwave device applications.

  5. Associations between size-fractionated particulate air pollution and blood pressure in a panel of type II diabetes mellitus patients.

    PubMed

    Zhao, Ang; Chen, Renjie; Wang, Cuicui; Zhao, Zhuohui; Yang, Changyuan; Lu, Jianxiong; Chen, Xuan; Kan, Haidong

    2015-07-01

    Little is known regarding how the size distribution of particulate matter (PM) air pollution influences its effect on blood pressure (BP), especially among patients with diabetes. The objective of this study was to explore the short-term associations between size-fractionated PM and BP among diabetes patients. We scheduled 6 repeated BP examinations every 2 weeks from 13 April 2013 to 30 June 2013 in a panel of 35 type 2 diabetes mellitus patients recruited from an urban community in Shanghai, China. We measured real-time PM concentrations in the size range of 0.25 to 10 μm. We used linear mixed-effect models to examine the short-term association of size-fractionated PM and BP after controlling for individual characteristics, mean temperature, relative humidity, day of the week, years with diabetes and use of antihypertensive medication. The association with systolic BP and pulse pressure strengthened with decreasing diameter. The size fractions with the strongest associations were 0.25 to 0.40 μm for number concentrations and ≤ 2.5 μm for mass concentrations. Furthermore, these effects occurred immediately even after 0-2h and lasted for up to 48 h following exposure. An interquartile range increase in 24-h average number concentrations of PM0.25-0.40 was associated with increases of 3.61 mmHg in systolic BP and 2.96 mmHg in pulse pressure. Females, patients younger than 65 years of age and patients without antihypertensive treatment were more susceptible to these effects. Our results revealed important size and temporal patterns of PM in elevating BP among diabetes patients in China.

  6. Significance of High-Speed Air Temperature Measurements in the Sampling Cell of a Closed-Path Gas Analyzer with a Short Tube

    NASA Astrophysics Data System (ADS)

    Kathilankal, James; Fratini, Gerardo; Burba, George

    2015-04-01

    Eddy covariance gas analyzers measure gas content in a known volume, thus essentially measuring gas density. The fundamental flux equation, however, is based on the dry mole fraction. The relationship between dry mole fraction and density is regulated by the ideal gas law describing the processes of temperature- and pressure-related expansions and contractions, and by the law of partial pressures, describing the process of dilution. As a result, this relationship depends on water vapor content, temperature and pressure of the air sample. If the instrument is able to output precise high-speed dry mole fraction, the flux processing is significantly simplified and WPL density terms accounting for the air density fluctuations are no longer required. This should also lead to the reduction in uncertainties associated with the density terms resulting from the eddy covariance measurements of sensible and latent heat fluxes used in these terms. In this framework, three main measurement approaches may be considered: Open-path approach Outputting correct high-speed dry mole fraction from the open-path instrument is difficult because of complexities with maintaining reliable fast temperature measurements integrated over the entire measuring path, and also because of extraordinary challenges with accurate measurements of fast pressure in the open air flow. Classical long-tube closed-path approach For instruments utilizing traditional long-tube closed-path design, with tube length 1000 or more times the tube diameter, the fast dry mole fraction can be used successfully when instantaneous fluctuations in the air temperature of the sampled air are effectively dampened to negligible levels, instantaneous pressure fluctuations are regulated or negligible, and water vapor is measured simultaneously with gas or the air sample is dried. Short-tube closed-path approach, the enclosed design For instruments with a short-tube enclosed design, most - but not all - of the temperature

  7. Distribution of PM(2.5) and PM(10-2.5) in PM(10) fraction in ambient air due to vehicular pollution in Kolkata megacity.

    PubMed

    Das, Manab; Maiti, Subodh Kumar; Mukhopadhyay, Ujjal

    2006-11-01

    This research paper aims at establishing baseline PM(10) and PM(2.5) concentration levels, which could be effectively used to develop and upgrade the standards in air pollution in developing countries. The relative contribution of fine fractions (PM(2.5)) and coarser fractions (PM(10-2.5)) to PM(10) fractions were investigates in a megacity which is overcrowded and congested due to lack of road network and deteriorated air quality because of vehicular pollution. The present study was carried out during the winter of 2002. The average 24h PM(10) concentration was 304 microg/m(3), which is 3 times more than the Indian National Ambient Air Quality Standards (NAAQS) and higher PM(10) concentration was due to fine fraction (PM(2.5)) released by vehicular exhaust. The 24h average PM(2.5) concentration was found 179 microg/m(3), which is exceeded USEPA and EU standards of 65 and 50 microg/m(3) respectively for the winter. India does not have any PM(2.5) standards. The 24 h average PM(10-2.5) concentrations were found 126 microg/m(3). The PM(2.5) constituted more than 59% of PM(10) and whereas PM(10)-PM(2.5) fractions constituted 41% of PM(10). The correlation between PM(10) and PM(2.5) was found higher as PM(2.5) comprised major proportion of PM(10) fractions contributed by vehicular emissions.

  8. For Mole Problems, Call Avogadro: 602-1023.

    ERIC Educational Resources Information Center

    Uthe, R. E.

    2002-01-01

    Describes techniques to help introductory students become familiar with Avogadro's number and mole calculations. Techniques involve estimating numbers of common objects then calculating the length of time needed to count large numbers of them. For example, the immense amount of time required to count a mole of sand grains at one grain per second…

  9. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  10. Development of traceable precision dynamic dilution method to generate dimethyl sulphide gas mixtures at sub-nanomole per mole levels for ambient measurement.

    PubMed

    Kim, Mi Eon; Kim, Yong Doo; Kang, Ji Hwan; Heo, Gwi Suk; Lee, Dong Soo; Lee, Sangil

    2016-04-01

    Dimethyl sulphide (DMS) is an important compound in global atmospheric chemistry and climate change. Traceable international standards are essential for measuring accurately the long-term global trend in ambient DMS. However, developing accurate gas standards for sub-nanomole per mole (nmol/mol) mole fractions of DMS in a cylinder is challenging, because DMS is reactive and unstable. In this study, a dynamic dilution method that is traceable and precise was developed to generate sub-nmol/mol DMS gas mixtures with a dynamic dilution system based on sonic nozzles and a long-term (>5 years) stable 10 μmol/mol parent DMS primary standard gas mixtures (PSMs). The dynamic dilution system was calibrated with traceable methane PSMs, and its estimated dilution factors were used to calculate the mole fractions of the dynamically generated DMS gas mixtures. A dynamically generated DMS gas mixture and a 6 nmol/mol DMS PSM were analysed against each other by gas chromatography with flame-ionisation detection (GC/FID) to evaluate the dilution system. The mole fractions of the dynamically generated DMS gas mixture determined against a DMS PSM and calculated with the dilution factor agreed within 1% at 6 nmol/mol. In addition, the dynamically generated DMS gas mixtures at various mole fractions between 0.4 and 11.7 nmol/mol were analysed by GC/FID and evaluated for their linearity. The analytically determined mole fractions showed good linearity with the mole fractions calculated with the dilution factors. Results showed that the dynamic dilution method generates DMS gas mixtures ranging between 0.4 nmol/mol and 12 nmol/mol with relative expanded uncertainties of less than 2%. Therefore, the newly developed dynamic dilution method is a promising reference method for generating sub-nmol/mol DMS gas standards for accurate ambient measurements.

  11. Deaths caused by mole guns: three case reports.

    PubMed

    Demirci, Serafettin; Gunaydin, Gursel; Dogan, Kamil Hakan; Erkol, Zerrin

    2008-07-01

    Possession of firearms is limited because of the technological requirements in production and strict laws. However, anyone can manufacture a handmade firearm by following simple instructions and has no legal liability. A mole gun is an unusual weapon used to kill moles in agricultural areas. It propels pellets in a similar way as a shotgun. This study presents three cases of death caused by mole guns. Two of the cases were accidental, and the other case was suicidal. The first case involved a 51-year-old man who was checking the mole gun when it fired, injuring his left eye and the left region of his face. He died in the hospital after 3 days of medical treatment. The second case was a 78-year-old man, who had been intermittently treated for depression over the last 15 years. He died instantly after placing the mole gun vertically against his head and firing it. The third case was a 43-year-old man who had been trying to set up a mole gun device in his potato field when the weapon accidentally discharged. The victim was injured seriously and died in the hospital a short time later. In conclusion, because the mole gun may cause lethal wounds in humans when fired from a short distance, the researchers believe that its production and use should be in accordance with firearms laws.

  12. Nutrient digestibility of solvent-extracted Brassica napus and Brassica juncea canola meals and their air-classified fractions fed to ileal-cannulated grower pigs.

    PubMed

    Zhou, X; Zijlstra, R T; Beltranena, E

    2015-01-01

    Energy and nutrient digestibility of solvent-extracted canola meal (CM) is limited in pigs by its relatively high fiber content. The seed hull, which greatly contributes to the fiber content of CM, is denser than the oil-free cotyledon. By utilizing streams of air, air classification partially separates these seed components on the basis of their different sizes and densities to produce a low-fiber, light-particle fraction and a high-fiber, heavy-particle fraction. Compared with parent CM, ADF and NDF were reduced by 31.9% and 29.5% in the light-particle fraction and were enriched by 16.5% and 9.0% in the heavy-particle fraction (DM basis), respectively. Particle size was 638, 18.9, and 76.1 µm for the parent CM and light- and heavy-particle fractions, respectively. To determine the nutrient digestibility of CM and their air-classified fractions, Brassica napus and B. juncea CM and their 2 air-classified fractions were evaluated in a 2 × 3 factorial arrangement together with a basal diet and an N-free diet. The experiment was conducted as an 8 × 8 Latin square in which diets contained 40% B. napus or B. juncea CM or their air-classified fractions and 60% basal diet. Digesta data from pigs fed the N-free diet served to subtract basal endogenous AA losses. Eight ileal-cannulated barrows (32 kg initial BW) were fed the 8 diets at 2.7 times maintenance DE for eight 11-d periods. At the end of each period, feces were collected for 48 h, and ileal digesta were collected for two 12-h periods. The DE and calculated NE values and the apparent total tract digestibility (ATTD) of GE were 6.3%, 10.0%, and 7.8% greater (P < 0.001) for B. juncea CM than for B. napus CM; 6.1%, 10.8%, and 5.3% greater (P < 0.001) for the light-particle fraction than for parent CM; and 5.4%, 7.2%, and 3.8% lower (P < 0.001) for the heavy-particle fraction than for parent CM, respectively. The standardized ileal digestibilities (SID) of His, Ile, Val, Asp, and Tyr were greater (P < 0.05) for B

  13. Results of the mole penetration tests in different materials

    NASA Astrophysics Data System (ADS)

    Wawrzaszek, Roman; Seweryn, Karol; Grygorczuk, Jerzy; Banaszkiewicz, Marek; Rybus, Tomasz; Wisniewski, Lukasz; Neal, Clive R.; Huang, Shaopeng

    2010-05-01

    Mole devices are low velocity, medium to high energy, self-driven penetrators, designed as a carrier of different sensors for in situ investigations of subsurface layers of planetary bodies. The maximum insertion depth of such devices is limited by energy of single mole's stroke and soil resistance for the dynamic penetration. A mole penetrator ‘KRET' has been designed, developed, and successfully tested at Space Research Centre PAS in Poland. The principle of operation of the mole bases on the interaction between three masses: the cylindrical casing, the hammer, and the rest of the mass, acting as a support mass. This approach takes advantage of the MUPUS penetrator (a payload of Philae lander on Rosetta mission) insertion tests knowledge. Main parameters of the mole KRET are listed below: - outer diameter: 20.4mm, - length: 330mm, - total mass: 488g, - energy of the driving spring: 2.2J, - average power consumption: 0.28W, - average insertion progress/stroke: 8.5mm, The present works of Space Research Center PAS team are focused on three different activities. First one includes investigations of the mole penetration effectiveness in the lunar analogues (supported by ESA PECS project). Second activity, supported by Polish national fund, is connected with numerical calculation of the heat flow investigations and designing and developing the Heat Flow Probe Hardware Component (HPHC) for L-GIP NASA project. It's worth noting that L-GIP project refers to ILN activity. Last activity focuses on preparing the second version of the mole ready to work in low thermal and pressure conditions. Progress of a mole penetrator in granular medium depends on the mechanical properties of this medium. The mole penetrator ‘KRET' was tested in different materials: dry quartz sand (0.3 - 0.8 grain size), wet quartz sand, wheat flour and lunar regolith mechanical simulant - Chemically Enhanced OB-1 (CHENOBI). Wheat flour was selected due to its high cohesion rate and small grain size

  14. Air quality in the German-Czech border region: A focus on harmful fractions of PM and ultrafine particles

    NASA Astrophysics Data System (ADS)

    Schladitz, Alexander; Leníček, Jan; Beneš, Ivan; Kováč, Martin; Skorkovský, Jiří; Soukup, Aleš; Jandlová, Jana; Poulain, Laurent; Plachá, Helena; Löschau, Gunter; Wiedensohler, Alfred

    2015-12-01

    A comprehensive air quality study has been carried out at two urban background sites in Annaberg-Buchholz (Germany) and Ústí nad Labem (Czech Republic) in the German-Czech border region between January 2012 and June 2014. Special attention was paid to quantify harmful fractions of particulate matter (PM) and ultrafine particle number concentration (UFP) from solid fuel combustion and vehicular traffic. Source type contributions of UFP were quantified by using the daily concentration courses of UFP and nitrogen oxide. Two different source apportionment techniques were used to quantify relative and absolute mass contributions: positive matrix factorization for total PM2.5 and elemental carbon in PM2.5 and chemical mass balance for total PM1 and organic carbon in PM1. Contributions from solid fuel combustion strongly differed between the non-heating period (April-September) and the heating period (October-March). Major sources of solid fuel combustion in this study were wood and domestic coal combustion, while the proportion of industrial coal combustion was low (<3%). In Ústí nad Labem combustion of domestic brown coal was the most important source of organic carbon ranging from 34% to 43%. Wood combustion was an important source of organic carbon in Annaberg-Buchholz throughout the year. Heavy metals and less volatile polycyclic aromatic hydrocarbons (PAH) in the accumulation mode were related to solid fuel combustion with enhanced concentrations during the heating period. In contrast, vehicular PAH emissions were allocated to the Aitken mode. Only in Ústí nad Labem a significant contribution of photochemical new particle formation (e.g. from sulfur dioxide) to UFP of almost 50% was observed during noontime. UFPs from traffic emissions (nucleation particles) and primary emitted soot particles dominated at both sites during the rest of the day. The methodology of a combined source apportionment of UFP and PM can be adapted to other regions of the world with

  15. Coherent Anti-Stokes Raman Scattering (CARS) as a Probe for Supersonic Hydrogen-Fuel/Air Mixing

    NASA Technical Reports Server (NTRS)

    Danehy, P. M.; O'Byrne, S.; Cutler, A. D.; Rodriguez, C. G.

    2003-01-01

    The dual-pump coherent anti-Stokes Raman spectroscopy (CARS) method was used to measure temperature and the absolute mole fractions of N2, O2 and H2 in a supersonic non-reacting fuel-air mixing experiment. Experiments were conducted in NASA Langley Research Center s Direct Connect Supersonic Combustion Test Facility. Under normal operation of this facility, hydrogen and air burn to increase the enthalpy of the test gas and O2 is added to simulate air. This gas is expanded through a Mach 2 nozzle and into a combustor model where fuel is then injected, mixes and burns. In the present experiment the O2 of the test gas is replaced by N2. The lack of oxidizer inhibited combustion of the injected H2 fuel jet allowing the fuel/air mixing process to be studied. CARS measurements were performed 427 mm downstream of the nozzle exit and 260 mm downstream of the fuel injector. Maps were obtained of the mean temperature, as well as the N2, O2 and H2 mean mole fraction fields. A map of mean H2O vapor mole fraction was also inferred from these measurements. Correlations between different measured parameters and their fluctuations are presented. The CARS measurements are compared with a preliminary computational prediction of the flow.

  16. Anatomy of mole external genitalia: Setting the record straight.

    PubMed

    Sinclair, Adriane Watkins; Glickman, Stephen E; Baskin, Laurence; Cunha, Gerald R

    2016-03-01

    Anatomy of male and female external genitalia of adult mice (Mus musculus) and broad-footed moles (Scapanus latimanus) was re-examined to provide more meaningful anatomical terminology. In the past the perineal appendage of male broad-footed moles has been called the penis, while the female perineal appendage has been given several terms (e.g. clitoris, penile clitoris, peniform clitoris and others). Histological examination demonstrates that perineal appendages of male and female broad-footed moles are the prepuce, which in both sexes are covered externally with a hair-bearing epidermis and lacks erectile bodies. The inner preputial epithelium is non-hair-bearing and defines the preputial space in both sexes. The penis of broad-footed moles lies deep within the preputial space, is an "internal organ" in the resting state and contains the penile urethra, os penis, and erectile bodies. The clitoris of broad-footed moles is defined by a U-shaped clitoral epithelial lamina. Residing within clitoral stroma encompassed by the clitoral epithelial lamina is the corpus cavernosum, blood-filled spaces and the urethra. External genitalia of male and female mice are anatomically similar to that of broad-footed moles with the exception that in female mice the clitoris contains a small os clitoridis and lacks defined erectile bodies, while male mice have an os penis and a prominent distal cartilaginous structure within the male urogenital mating protuberance (MUMP). Clitori of female broad-footed moles lack an os clitoridis but contain defined erectile bodies, while male moles have an os penis similar to the mouse but lack the distal cartilaginous structure.

  17. Amount of substance and the proposed redefinition of the mole

    NASA Astrophysics Data System (ADS)

    Milton, M. J. T.; Mills, I. M.

    2009-06-01

    There has been considerable discussion about the merits of redefining four of the base units of the SI, including the mole. In this paper, the options for implementing a new definition for the mole based on a fixed value for the Avogadro constant are discussed. They are placed in the context of the macroscopic nature of the quantity amount of substance and the opportunity to introduce a system for molar and atomic masses with unchanged values and consistent relative uncertainties.

  18. Unusual Presentation of Invasive Mole: A Case Report

    PubMed Central

    Aminimoghaddam, Soheila; Maghsoudnia, Andisheh

    2017-01-01

    Background: Invasive mole is responsible for most cases of localized gestational trophoblastic neoplasia. Gestational trophoblastic disease describes a number of gynecologic tumors that originate in trophoblastic layer including hydatidiform mole (complete or partial), invasive mole, choriocarcinoma, placental site trophoblastic tumor and epitheloid trophoblastic tumor. Invasive mole may arise from any pregnancy event although in most cases is diagnosed after molar pregnancy. Overall cure rate in low risk patients is nearly 100% and in high-risk patient 90%. In rare cases, molar tissue traverses thickness of myometrium and leads to perforation and acute abdomen and invasive mole infrequently metastasis. The best treatment option is chemotherapy (according to stage and score with single or multiple agent) and in patients that fertility is not the matter, hysterectomy can be done. Case Presentation: A 41 years old G3P2ab1 woman referred to Firouzgar hospital 2 months after curettage of molar pregnancy with vaginal bleeding and acute abdomen. In workup, HCG 224000 mIU/ml and evidence of metastasis was detected. Chemotherapy due to stage 3 and score 9 and surgery due to acute abdomen was done. This case was reported for its rarity. Discussion: This case reported about ovarian metastasis and uterine rupture with acute abdomen and involvement of omentum in metastatic invasive mole. Lack of surveillance led to extensive morbidity. Management of this patient was successful. In follow up, she was free of disease without sequel of any kind for five years now. PMID:28377901

  19. Infrared Signature Masking by Air Plasma Radiation

    NASA Technical Reports Server (NTRS)

    Kruger, C. H.; Laux, C. O.

    1998-01-01

    Detailed measurements and modeling of the spectral emission of an atmospheric pressure air plasma at temperatures up to -3400 K have been made. The cold gas injected in the plasma torch contained an estimated mole fraction of water vapor of approximately 4.5 x 10(exp -3) and an estimated carbon dioxide mole fraction of approximately 3.3 x 10(exp -4). Under these conditions, the minimum level of air plasma emission is found to be between 3.9 and 4.15 microns. Outside this narrow region, significant spectral emission is detected that can be attributed to the fundamental and overtone bands of NO and OH, and to the v(sub 3) and the (v(sub 1)+v(sub 3)) bands Of CO2. Special attention was paid to the effects of ambient air absorption in the optical path between the plasma and the detector. Excellent quantitative agreement is obtained between the measured and simulated spectra, which are both on absolute intensity scales, thus lending confidence in the radiation models incorporated into NEQAIR2-IR over the course of this research program.

  20. Genetic variants of Cao Bang hantavirus in the Chinese mole shrew (Anourosorex squamipes) and Taiwanese mole shrew (Anourosorex yamashinai).

    PubMed

    Gu, Se Hun; Arai, Satoru; Yu, Hon-Tsen; Lim, Burton K; Kang, Hae Ji; Yanagihara, Richard

    2016-06-01

    To determine the genetic diversity and geographic distribution of Cao Bang virus (CBNV) and to ascertain the existence of CBNV-related hantaviruses, natural history collections of archival tissues from Chinese mole shrews (Anourosorex squamipes) and Taiwanese mole shrews (Anourosorex yamashinai), captured in Guizho Province, People's Republic of China, and in Nantou County, Taiwan, in 2006 and 1989, respectively, were analyzed for hantavirus RNA by RT-PCR. Pair-wise alignment and comparison of the S-, M- and L-segment sequences indicated CBNV in two of five Chinese mole shrews and a previously unrecognized hantavirus, named Xinyi virus (XYIV), in seven of 15 Taiwanese mole shrews. XYIV was closely related to CBNV in Vietnam and China, as well as to Lianghe virus (LHEV), recently reported as a distinct hantavirus species in Chinese mole shrews from Yunnan Province in China. Phylogenetic analyses, using maximum-likelihood and Bayesian methods, showed that XYIV shared a common ancestry with CBNV and LHEV, in keeping with the evolutionary relationship between Anourosorex mole shrews. Until such time that tissue culture isolates of CBNV, LHEV and XYIV can be fully analyzed, XYIV and LHEV should be regarded as genetic variants, or genotypes, of CBNV.

  1. Nature of organo-mineral particles across density fractions in a volcanic-ash soil: air-drying and sonication effect

    NASA Astrophysics Data System (ADS)

    Wagai, R.; Kajiura, M.; Shirato, Y.; Uchida, M.

    2011-12-01

    Interactions of plant- and microbially-derived organic matter with mineral phases exert significant controls on the stabilization of organic matter (OM) as well as other biogeochemical processes in soil. Density fractionation techniques have been successful in distinguishing soil organo-mineral particles of different degrees of microbial alteration, turnover rate of C, mineral associations. A major methodological difference among the density fractionation studies is the choice of sample pre-treatment. Presence or absence of sonication to disrupt and disperse soil particles and aggregates is a particularly important choice which could significantly alter the nature and distribution of organo-mineral particle and thus the resultant elemental concentration in each density fraction. Soil moisture condition (air-dry vs. field-moist) may also have strong impact especially for soils rich in Fe oxides/hydroxides and/or poorly-crystalline minerals that are prone for (possibly irreversible) aggregation. We thus tested these two effects on the concentration and distribution of C, N, and extractable phases of Fe and Al (by pyrophosphate and acid oxalate) across six density fractions (from <1.6 to >2.5 g/cm^3) using a surface-horizon of volcanic-ash soil which contained large amounts of poorly-crystalline minerals and organo-metal complexes. Compared to field-moist sample, air-drying had little effects on the elemental concentration or distribution across the fractions. In contrast, sonication on air-dried sample at each density cutoff during fractionation process caused significant changes. In addition to well-known increase in low-density material due to the liberation of plant detritus upon aggregate disruption, we found clear increase in C, N, and metals in 2.0-2.3 g/cm^3 fraction, which was largely compensated by the reduction in 1.8-2.0 g/cm^3 and, to a less extent, 2.3-2.5 g/cm^3 particles. Overall, sonication led to the redistribution of C and N by 15-20% and that of

  2. Extractive probe/TDLAS measurements of acetylene in atmospheric-pressure fuel-rich premixed methane/air flames

    SciTech Connect

    Gersen, S.; Mokhov, A.V.; Levinsky, H.B.

    2005-11-01

    The profiles of C{sub 2}H{sub 2} mole fractions were measured in flat atmospheric-pressure rich-premixed methane/air flames using microprobe gas sampling followed by tunable diode laser absorption spectroscopy (TDLAS), and compared the results with predictions of one-dimensional flame calculations. Acetylene concentrations are also determined by spontaneous Raman scattering to quantify possible uncertainties due to chemical reactions on the probe surface or acceleration of the combustion products into the probe.

  3. Thermodynamic and transport combustion properties of hydrocarbons with air. Part 2: Compositions corresponding to Kelvin temperature schedules in part 1

    NASA Technical Reports Server (NTRS)

    Gordon, S.

    1982-01-01

    The equilibrium compositions that correspond to the thermodynamic and transport combustion properties for a wide range of conditions for the reaction of hydrocarbons with air are presented. Initially 55 gaseous species and 3 coin condensed species were considered in the calculations. Only 17 of these 55 gaseous species had equilibrium mole fractions greater than 0.000005 for any of the conditions studied and therefore these were the only ones retained in the final tables.

  4. Adult neurogenesis in the hedgehog (Erinaceus concolor) and mole (Talpa europaea).

    PubMed

    Bartkowska, K; Turlejski, K; Grabiec, M; Ghazaryan, A; Yavruoyan, E; Djavadian, R L

    2010-01-01

    We investigated adult neurogenesis in two species of mammals belonging to the superorder Laurasiatheria, the southern white-breasted hedgehog (order Erinaceomorpha, species Erinaceus concolor) from Armenia and the European mole (order Soricomorpha, species Talpa europaea) from Poland. Neurogenesis in the brain of these species was examined immunohistochemically, using the endogenous markers doublecortin (DCX) and Ki-67, which are highly conserved among species. We found that in both the hedgehog and mole, like in the majority of earlier investigated mammals, neurogenesis continues in the subventricular zone (SVZ) of the lateral ventricles and in the dentate gyrus (DG). In the DG of both species, DCX-expressing cells and Ki-67-labeled cells were present in the subgranular and granular layers. In the mole, a strong bundle of DCX-labeled processes, presumably axons of granule cells, was observed in the center of the hilus. Proliferating cells (expressing Ki-67) were identified in the SVZ of lateral ventricles of both species, but neuronal precursor cells (expressing DCX) were also observed in the olfactory bulb (OB). In both species, the vast majority of cells expressing DCX in the OB were granule cells with radially orientated dendrites, although some periglomerular cells surrounding the glomeruli were also labeled. In addition, this paper is the first to show DCX-labeled fibers in the anterior commissure of the hedgehog and mole. These fibers must be axons of new neurons making interhemispheric connections between the two OB or piriform (olfactory) cortices. DCX-expressing neurons were observed in the striatum and piriform cortex of both hedgehog and mole. We postulate that in both species a fraction of cells newly generated in the SVZ migrates along the rostral migratory stream to the piriform cortex. This pattern of migration resembles that of the 'second-wave neurons' generated during embryonal development of the neocortex rather than the pattern observed during

  5. A case of true tubal hydatidiform mole and literature review.

    PubMed

    Siozos, A; Sriemevan, A

    2010-08-09

    Tubal hydatidiform mole is an uncommon condition with about 40 confirmed cases in the accessible literature. The patient usually presents with symptoms and signs of a classical ectopic pregnancy and it is only after histological examination and DNA ploidy analysis of the conceptus that a hydatidiform mole is diagnosed. Management requires complete removal of the conceptus and follow-up needs to be arranged with an appropriate supraregional centre. The authors present a case of complete molar tubal pregnancy and a review of the literature.

  6. A cytosolic protein factor from the naked mole-rat activates proteasomes of other species and protects these from inhibition.

    PubMed

    Rodriguez, Karl A; Osmulski, Pawel A; Pierce, Anson; Weintraub, Susan T; Gaczynska, Maria; Buffenstein, Rochelle

    2014-11-01

    The naked mole-rat maintains robust proteostasis and high levels of proteasome-mediated proteolysis for most of its exceptional (~31years) life span. Here, we report that the highly active proteasome from the naked mole-rat liver resists attenuation by a diverse suite of proteasome-specific small molecule inhibitors. Moreover, mouse, human, and yeast proteasomes exposed to the proteasome-depleted, naked mole-rat cytosolic fractions, recapitulate the observed inhibition resistance, and mammalian proteasomes also show increased activity. Gel filtration coupled with mass spectrometry and atomic force microscopy indicates that these traits are supported by a protein factor that resides in the cytosol. This factor interacts with the proteasome and modulates its activity. Although Heat shock protein 72 kDa (HSP72) and Heat shock protein 40 kDa (Homolog of bacterial DNAJ1) (HSP40(Hdj1)) are among the constituents of this factor, the observed phenomenon, such as increasing peptidase activity and protecting against inhibition cannot be reconciled with any known chaperone functions. This novel function may contribute to the exceptional protein homeostasis in the naked mole-rat and allow it to successfully defy aging.

  7. Storage Stability of Keratinocyte Growth Factor-2 in Lyophilized Formulations: Effects of Formulation Physical Properties and Protein Fraction at the Solid-Air Interface

    PubMed Central

    Devineni, Dilip; Gonschorek, Christoph; Cicerone, Marcus T; Xu, Yemin; Carpenter, John F.; Randolph, Theodore W.

    2014-01-01

    Lyophilized formulations of keratinocyte growth factor-2 (KGF-2) were prepared with a range of disaccharide (sucrose or trehalose) and hydroxyethyl starch (HES) mass ratios. Protein degradation was assessed as a function of time of storage of the dried formulations at 40, 50 and 60 °C. Lyophilized and stored samples were rehydrated, and protein degradation was quantified by measuring loss of monomeric protein with size exclusion chromatography and by determining chemical degradation in the soluble fraction with reverse-phase chromatography. The secondary structure of the protein in the lyophilized formulations was studied with infrared spectroscopy. The magnitudes of degradation were compared the key physical properties of the formulations including retention of protein native secondary structure, glass transition temperature (Tg), inverse mean square displacements −1 for hydrogen atoms (fast β relaxation), and the relaxation time τβ, which correlates with relaxation due to fast Johari-Goldstein motions in the glass[1]. In addition, specific surface areas of the lyophilized formulations were determined by Brunauer-Emmet-Teller analysis of krypton adsorption isotherms and used to estimate the fraction of the KGF-2 molecules residing at the solid-air interface. KGF-2 degradation rates were highest in formulations wherein the protein’s structure was most perturbed, and wherein β relaxations were fastest, but the dominant factor governing KGF-2 degradation in freeze-dried formulations was the fraction of the protein found at the glass solid-air interface. PMID:24859390

  8. Effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco.

    PubMed

    Makan, Abdelhadi; Assobhei, Omar; Mountadar, Mohammed

    2013-01-03

    This study aimed to evaluate the effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco in terms of internal temperature, produced gases quantity, organic matter conversion rate, and the quality of the final composts.For this purpose, in-vessel bioreactor was designed and used to evaluate both appropriate initial air pressure and appropriate initial moisture content for the composting process. Moreover, 5 experiments were carried out within initial moisture content of 55%, 65%, 70%, 75% and 85%. The initial air pressure and the initial moisture content of the mixture showed a significant effect on the aerobic composting. The experimental results demonstrated that for composting organic waste, relatively high moisture contents are better at achieving higher temperatures and retaining them for longer times.This study suggested that an initial moisture content of around 75%, under 0.6 bar, can be considered as being suitable for efficient composting of organic fraction of municipal solid waste. These last conditions, allowed maximum value of temperature and final composting product with good physicochemical properties as well as higher organic matter degradation and higher gas production. Moreover, final compost obtained showed good maturity levels and can be used for agricultural applications.

  9. The mole, amount of substance and primary methods

    NASA Astrophysics Data System (ADS)

    Milton, Martin J. T.

    2013-04-01

    This paper is an introduction to the principles developed for the application of metrology to the field of chemistry and particularly to analytical chemistry. It starts with a discussion of the mole, the base unit of the SI that is most relevant to analytical chemistry. The mole has become the subject of particular discussion recently, since the publication of proposals to re-define it along with three other base units of the SI. This discussion has also generated interest in the origin of the term ‘amount of substance’ used as the quantity for which the mole is the unit. This paper reviews the origin of this term and explains why it is not sufficient to replace it with an alternative such as a ‘number of entities’. The paper concludes with some discussion of how the mole is realized through the use of primary methods of measurement. This paper is based on a lecture given at the International School of Physics ‘Enrico Fermi’, Course CLXXXV: Metrology and Physical Constants,held in Varenna on 17-27 July 2012. It will also be published in the proceedings of the school, edited by E Bava, M Kühne and A M Rossi (IOS Press, Amsterdam and SIF, Bologna).

  10. Hydatidiform mole presentation as a tubal ectopic pregnancy.

    PubMed

    Nakeer, Tabassum; Shahid, Muhammad; Ansari, Muhammad Asad; Nakeer, Rooham

    2014-05-01

    Presentation of hydatidiform mole as tubal ectopic pregnancy is very rare. These patients usually present with ectopic pregnancy and are later diagnosed with hydatidiform mole on the basis of histological examination following surgery. We present the case of a 32-year-old female who presented with abdominal pain and vaginal bleed since 2 days of presentation. She was vitally stable. There was mild tenderness in hypogastrium and left iliac fossa. Pelvic examination showed mild bleeding per vaginum and fullness in both fornices. The patient was suspected of having an ectopic pregnancy. Ultrasonography of pelvis revealed fluid in cul-de-sac and a sac like mass of 1.8 cm attached to the left ovary. On laparotomy, there was a left sided tubal ectopic pregnancy and subsequently left salpingectomy was done. Histopathology of the tissue sample showed features of partial hydatidiform mole. Ectopic pregnancy can present as hydatidiform mole in rare cases for which histological examination of the tissue is required to establish the diagnosis.

  11. Size-fractionated sampling and chemical analysis by total-reflection X-ray fluorescence spectrometry of PMx in ambient air and emissions

    NASA Astrophysics Data System (ADS)

    John, A. C.; Kuhlbusch, T. A. J.; Fissan, H.; Schmidt, K.-G.

    2001-11-01

    concentrations obtained in two different processes (steel industry) show that the new PM 10/PM 2.5 cascade impactor and measurements with TXRF give characteristic fingerprints for different sources. Size-fractionated ambient air and emission sampling, together with multi-element analysis, prove to be a useful approach to derive information for source-receptor modeling, a method necessary to set up effective abatement strategies to reduce PMx mass concentrations.

  12. GENERATION, TRANSPORT AND DEPOSITION OF TUNGSTEN-OXIDE AEROSOLS AT 1000 C IN FLOWING AIR-STEAM MIXTURES.

    SciTech Connect

    GREENE,G.A.; FINFROCK,C.C.

    2001-10-01

    Experiments were conducted to measure the rates of oxidation and vaporization of pure tungsten rods in flowing air, steam and air-steam mixtures in laminar flow. Also measured were the downstream transport of tungsten-oxide condensation aerosols and their region of deposition, including plateout in the superheated flow tube, rainout in the condenser and ambient discharge which was collected on an array of sub-micron aerosol filters. The nominal conditions of the tests, with the exception of the first two tests, were tungsten temperatures of 1000 C, gas mixture temperatures of 200 C and wall temperatures of 150 C to 200 C. It was observed that the tungsten oxidation rates were greatest in all air and least in all steam, generally decreasing non-linearly with increasing steam mole fraction. The tungsten oxidation rates in all air were more than five times greater than the tungsten oxidation rates in all steam. The tungsten vaporization rate was zero in all air and increased with increasing steam mole fraction. The vaporization rate became maximum at a steam mole fraction of 0.85 and decreased thereafter as the steam mole fraction was increased to unity. The tungsten-oxide was transported downstream as condensation aerosols, initially flowing upwards from the tungsten rod through an 18-inch long, one-inch diameter quartz tube, around a 3.5-inch radius, 90{sup o} bend and laterally through a 24-inch horizontal run. The entire length of the quartz glass flow path was heated by electrical resistance clamshell heaters whose temperatures were individually controlled and measured. The tungsten-oxide plateout in the quartz tube was collected, nearly all of which was deposited at the end of the heated zone near the entrance to the condenser which was cold. The tungsten-oxide which rained out in the condenser as the steam condensed was collected with the condensate and weighed after being dried. The aerosol smoke which escaped the condenser was collected on the sub

  13. Flow pattern, void fraction and pressure drop of two-phase air-water flow in a horizontal circular micro-channel

    SciTech Connect

    Saisorn, Sira; Wongwises, Somchai

    2008-01-15

    Adiabatic two-phase air-water flow characteristics, including the two-phase flow pattern as well as the void fraction and two-phase frictional pressure drop, in a circular micro-channel are experimentally studied. A fused silica channel, 320 mm long, with an inside diameter of 0.53 mm is used as the test section. The test runs are done at superficial velocity of gas and liquid ranging between 0.37-16 and 0.005-3.04 m/s, respectively. The flow pattern map is developed from the observed flow patterns i.e. slug flow, throat-annular flow, churn flow and annular-rivulet flow. The flow pattern map is compared with those of other researchers obtained from different working fluids. The present single-phase experiments also show that there are no significant differences in the data from the use of air or nitrogen gas, and water or de-ionized water. The void fraction data obtained by image analysis tends to correspond with the homogeneous flow model. The two-phase pressure drops are also used to calculate the frictional multiplier. The multiplier data show a dependence on flow pattern as well as mass flux. A new correlation of two-phase frictional multiplier is also proposed for practical application. (author)

  14. Development of a southern oceanic air standard reference material.

    PubMed

    Rhoderick, George C; Kelley, Michael E; Miller, Walter R; Brailsford, Gordon; Possolo, Antonio

    2016-02-01

    In 2009, the United States Congress charged the National Institute of Standards and Technology (NIST) with supporting climate change research. As part of this effort, the Gas Sensing Metrology Group at NIST began developing new gas standard mixtures for greenhouse gas mixtures relevant to atmospheric measurements. Suites of gravimetrically prepared primary standard mixtures (PSMs) were prepared at ambient concentration levels for carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in a dry-air balance. In parallel, 30 gas cylinders were filled, by the National Institute of Water and Atmospheric Research (NIWA) in Wellington, New Zealand, to high pressure from pristine southern oceanic air at Baring Head, New Zealand, and shipped to NIST. Using spectroscopic instrumentation, NIST analyzed the 30 cylinder samples for mole fractions of CO2, CH4, and N2O. Certified values were assigned to these mixtures by calibrating the instrumentation with the PSM suites that were recently developed at NIST. These mixtures became NIST Standard Reference Material (SRM) 1721 Southern Oceanic Air and are certified for ambient mole fraction, the first of their kind for NIST. The relative expanded uncertainties corresponding to coverage intervals with 95% probability are no larger than 0.06% of the certified values, representing the smallest uncertainties to date ever assigned to an NIST gas SRM.

  15. Performance of a combined three-hole conductivity probe for void fraction and velocity measurement in air-water flows

    NASA Astrophysics Data System (ADS)

    Borges, João Eduardo; Pereira, Nuno H. C.; Matos, Jorge; Frizell, Kathleen H.

    2010-01-01

    The development of a three-hole pressure probe with back-flushing combined with a conductivity probe, used for measuring simultaneously the magnitude and direction of the velocity vector in complex air-water flows, is described in this paper. The air-water flows envisaged in the current work are typically those occurring around the rotors of impulse hydraulic turbines (like the Pelton and Cross-Flow turbines), where the flow direction is not known prior to the data acquisition. The calibration of both the conductivity and three-hole pressure components of the combined probe in a rig built for the purpose, where the probe was placed in a position similar to that adopted for the flow measurements, will be reported. After concluding the calibration procedure, the probe was utilized in the outside region of a Cross-Flow turbine rotor. The experimental results obtained in the present study illustrate the satisfactory performance of the combined probe, and are encouraging toward its use for characterizing the velocity field of other complex air-water flows.

  16. The complete mitogenome of Chinese Mole Shrew, Anourosorex squamipes (Soricidae).

    PubMed

    Li, Qun; Wang, Qiong; Chen, Guiying; Fu, Changkun; Chen, Shunde

    2016-01-01

    The Chinese Mole Shrew, Anourosorex squamipes belongs to the family Soricidae, and widely distributes in central and southern China, northern and south Burma, east India, northern Vietnam and Thailand. In this study, the complete mitochondrial genome sequence of Anourosorex squamipes was determined. The mitogenome is 17,121 base pairs in length and contains 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and 1 control region, with base composition of 34.0% A, 31.3% T, 22.0% C, and 12.7% G. The genome organization, nucleotide composition and codon usage did not differ significantly from those of other shrews. The study contributes to illuminating taxonomic status of Chinese Mole Shrew Anourosorex squamipes.

  17. Fuel-air munition and device

    DOEpatents

    Carlson, Gary A.

    1976-01-01

    An aerially delivered fuel-air munition consisting of an impermeable tank filled with a pressurized liquid fuel and joined at its two opposite ends with a nose section and a tail assembly respectively to complete an aerodynamic shape. On impact the tank is explosively ruptured to permit dispersal of the fuel in the form of a fuel-air cloud which is detonated after a preselected time delay by means of high explosive initiators ejected from the tail assembly. The primary component in the fuel is methylacetylene, propadiene, or mixtures thereof to which is added a small mole fraction of a relatively high vapor pressure liquid diluent or a dissolved gas diluent having a low solubility in the primary component.

  18. Mole and Chemical Amount: A Discussion of the Fundamental Measurements of Chemistry.

    ERIC Educational Resources Information Center

    Gorin, George

    1994-01-01

    Teachers and students alike report difficulties with the measurement unit called mole. This article tries to demonstrate that mole and the corresponding quantity are not exceptional. Mole lacks the context of a given amount because the unit measures the relative number of atoms compared with those present in a standard. Discusses history of…

  19. Teaching the Mole Concept Using a Conceptual Change Method at College Level

    ERIC Educational Resources Information Center

    Uce, Musa

    2009-01-01

    Chemistry is a subject area that is difficult to understand for some students as it contains abstract concepts, such as mole, molecule and particle. The mole concept is one of the most important topics in which students have difficulty in understanding. There are many studies in the literature on the mole concept. Students who do not fully…

  20. Unpacking the Meaning of the Mole Concept for Secondary School Teachers and Students

    ERIC Educational Resources Information Center

    Fang, Su-Chi; Hart, Christina; Clarke, David

    2014-01-01

    The "mole" is a fundamental concept in quantitative chemistry, yet research has shown that the mole is one of the most perplexing concepts in the teaching and learning of chemistry. This paper provides a survey of the relevant literature, identifies the necessary components of a sound understanding of the mole concept, and unpacks and…

  1. A Novel Calibration-Minimum Method for Prediction of Mole Fraction in Non-Ideal Mixture.

    PubMed

    Shibayama, Shojiro; Kaneko, Hiromasa; Funatsu, Kimito

    2017-04-01

    This article proposes a novel concentration prediction model that requires little training data and is useful for rapid process understanding. Process analytical technology is currently popular, especially in the pharmaceutical industry, for enhancement of process understanding and process control. A calibration-free method, iterative optimization technology (IOT), was proposed to predict pure component concentrations, because calibration methods such as partial least squares, require a large number of training samples, leading to high costs. However, IOT cannot be applied to concentration prediction in non-ideal mixtures because its basic equation is derived from the Beer-Lambert law, which cannot be applied to non-ideal mixtures. We proposed a novel method that realizes prediction of pure component concentrations in mixtures from a small number of training samples, assuming that spectral changes arising from molecular interactions can be expressed as a function of concentration. The proposed method is named IOT with virtual molecular interaction spectra (IOT-VIS) because the method takes spectral change as a virtual spectrum x nonlin,i into account. It was confirmed through the two case studies that the predictive accuracy of IOT-VIS was the highest among existing IOT methods.

  2. Electrical Activation Studies of Silicon Implanted Aluminum Gallium Nitride with High Aluminum Mole Fraction

    DTIC Science & Technology

    2007-12-01

    functioned at room temperature. Numerous other electronic inventions followed, such as the microprocessor in 1971, the charged couple device (CCD...the yellow band in GaN and in AlxGa1-xN materials in the literature. Glaser et al. claim the band is the result of radiative recombination between...grown sample exhibits two phonon coupled replicas separated by 80 meV on the low energy side of the (Do,X) peak at 4.33 and 4.25 eV (49

  3. The effects of channel diameter on flow pattern, void fraction and pressure drop of two-phase air-water flow in circular micro-channels

    SciTech Connect

    Saisorn, Sira; Wongwises, Somchai

    2010-05-15

    Two-phase air-water flow characteristics are experimentally investigated in horizontal circular micro-channels. Test sections are made of fused silica. The experiments are conducted based on three different inner diameters of 0.53, 0.22 and 0.15 mm with the corresponding lengths of 320, 120 and 104 mm, respectively. The test runs are done at superficial velocities of gas and liquid ranging between 0.37-42.36 and 0.005-3.04 m/s, respectively. The flow visualisation is facilitated by systems mainly including stereozoom microscope and high-speed camera. The flow regime maps developed from the observed flow patterns are presented. The void fractions are determined based on image analysis. New correlation for two-phase frictional multiplier is also proposed for practical applications. (author)

  4. Evaluation of In Vitro Cytoxicity and Genotoxicity of Size-Fractionated Air Particles Sampled during Road Tunnel Construction

    PubMed Central

    Dominici, Luca; Guerrera, Elena; Villarini, Milena; Fatigoni, Cristina; Moretti, Massimo; Blasi, Paolo; Monarca, Silvano

    2013-01-01

    In tunnel construction, workers exposed to dust from blasting, gases, diesel exhausts, and oil mist have shown higher risk for pulmonary diseases. A clear mechanism to explain how these pollutants determine diseases is lacking, and alveolar epithelium's capacity to ingest inhaled fine particles is not well characterized. The objective of this study was to assess the genotoxic effect exerted by fine particles collected in seven tunnels using the cytokinesis-block micronuclei test in an in vitro model on type II lung epithelium A549 cells. For each tunnel, five fractions with different aerodynamic diameters of particulate matter were collected with a multistage cascade sampler. The human epithelial cell line A549 was exposed to 0.2 m3/mL equivalent of particulate for 24 h before testing. The cytotoxic effects of particulate matter on A549 cells were also evaluated in two different viability tests. In order to evaluate the cells' ability to take up fine particles, imaging with transmission electron microscopy of cells after exposure to particulate matter was performed. Particle endocytosis after 24 h exposure was observed as intracellular aggregates of membrane-bound particles. This morphologic evidence did not correspond to an increase in genotoxicity detected by the micronucleus test. PMID:24069598

  5. A content analysis of the presentation of the mole concept in chemistry textbooks

    NASA Astrophysics Data System (ADS)

    Staver, John R.; Lumpe, Andrew T.

    The goal of this study was to examine the means used by textbook authors to introduce, define, and explain the mole concept in high school and introductory college chemistry textbooks. The analysis was framed by four questions:1How is the mole defined?2What concepts about the atom are introduced prior to the mole?3Is Avogadro's constant presented as an experimentally determined value?4What is the context for introducing the mole?Twenty-nine high school and introductory college level chemistry texts were examined. After independent reading of appropriate sections of each text, discussion of differences, second or third readings of texts, and subsequent discussions, both authors reach 100% agreement concerning the results. Major conclusions were: Two ways of defining the mole dominate the texts. One way defines the mole as Avogadro's number (6.02 × 1023) particles; the other method defines the mole in terms of carbon-12. All texts that present a definition in terms of C-12 introduce and define concepts about the atom prior to introducing the mole. Most texts at all levels point out that the value 6.02 × 1023 is an experimentally determined quantity. Nearly all texts discuss the mole in relation to die problem of finding a way to count particles that are too small to be directly weighed. Most texts also use a familiar counting unit, such as the dozen, to introduce the mole by analogy. Four issues were discussed: (a) the defining attributes of the mole concept itself and the cognitive requirements for comprehending the two most frequently used definitions; (b) the connection between the definition of the mole presented in the text and the concepts about atoms that are introduced before the mole concept is developed; (c) the experimental nature of Avogadro's number; and (d) the context or setting for developing the mole concept.

  6. Experimental Determination of the Liquidus Surface of the Cu-O-ZnO-CaO System in Equilibrium with Air

    NASA Astrophysics Data System (ADS)

    Xia, Longgong; Liu, Zhihong; Taskinen, Pekka

    2016-12-01

    Phase relationships of the Cu-O-ZnO-CaO system in equilibrium with air ( p tot = 1 atm, p_{{{{O}}2 }} = 0.21 {{atm}} ) have been studied using the equilibration and quenching technique within the temperature range from 1273 K to 1773 K (1000 °C to 1500 °C). The chemical compositions of the molten oxide and solid phases in equilibrium were analyzed by EPMA. The eutectic point in the Cu-O-ZnO-CaO system was found to be 1293 K ± 2 K (1020 °C ± 2 °C) and 0.6785 mole fraction tenorite (`CuO'), 0.1793 mole fraction halite (CaO), and 0.1422 mole fraction wurtzite (ZnO). The results from the present study have been used in constructing the liquidus surface of the Cu-O-ZnO-CaO system. The liquidus surface expands dramatically along with increasing temperature, and it moves simultaneously toward the primary phase fields of wurtzite (ZnO) and halite (CaO). The constructed liquidus surfaces have been compared with the isothermal sections (`Cu2O'-ZnO-CaO) calculated by MTDATA 5.10 software and its Mtox 8.1 database. Deviations between the thermodynamically assessed diagrams and the experimental results are significant. Thus, the system requires a reassessment.

  7. Diode laser absorption measurement and analysis of HCN in atmospheric-pressure, fuel-rich premixed methane/air flames

    SciTech Connect

    Gersen, S.; Mokhov, A.V.; Levinsky, H.B.

    2008-10-15

    Measurements of HCN in flat, fuel-rich premixed methane/air flames at atmospheric pressure are reported. Quartz-microprobe sampling followed by wavelength modulation absorption spectroscopy with second harmonic detection was used to obtain an overall measurement uncertainty of better than 20% for mole fractions HCN on the order of 10 ppm. The equivalence ratio, {phi}, was varied between 1.3 and 1.5, while the flame temperature was varied independently by changing the mass flux through the burner surface at constant equivalence ratio. Under the conditions of the experiments, the peak mole fractions vary little, in the range of 10-15 ppm. Increasing the flame temperature by increasing the mass flux had little influence on the peak mole fraction, but accelerated HCN burnout substantially. At high equivalence ratio and low flame temperature, HCN burnout is very slow: at {phi}=1.5, {proportional_to}10ppm HCN is still present 7 mm above the burner surface. Substantial quantitative disagreement is observed between the experimental profiles and those obtained from calculations using GRI-Mech 3.0, with the calculations generally overpredicting the results significantly. Changing the rates of key formation and consumption reactions for HCN can improve the agreement, but only by making unreasonable changes in these rates. Inclusion of reactions describing NCN formation and consumption in the calculations improves the agreement with the measurements considerably. (author)

  8. Description of the mitogenome of Gansu mole (Scapanulus oweni).

    PubMed

    Xu, Yu; Huang, Xiaofeng; Hu, Yunting; Tu, Feiyun

    2016-05-01

    The Gansu mole Scapanulus oweni belongs to family Talpidae, and is distributed in the Central and Southwest China. In this study, the total mitochondrial genome of S. oweni was firstly determined. The genome is 16,826 bases in length and contains 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and a displacement loop region, with a base composition of A 34.0%, G 13.5%, T 28.7% and C 23.9%. All of the protein-coding genes initiate with the orthodox ATG start codon execpt for Nd2 and Nd3 begin with ATT, Nd4 and Nd5, start with GTG and ATA, respectively. Four types of stop codons are used by the coding genes, including TAA for Nd1, Cox1, Cox2, Atp8, Atp6, Nd4L, Nd5, Nd6, TAG for Nd2, AGA for Cytb, and an incomplete stop codon T for Cox3, Nd3 and Nd4. The mito-genomic data of Gansu mole, S. oweni will be useful in determining its taxonomic status within Talpidae.

  9. Iridescent colour production in hairs of blind golden moles (Chrysochloridae).

    PubMed

    Snyder, Holly K; Maia, Rafael; D'Alba, Liliana; Shultz, Allison J; Rowe, Karen M C; Rowe, Kevin C; Shawkey, Matthew D

    2012-06-23

    Relative to other metazoans, the mammalian integument is thought to be limited in colour. In particular, while iridescence is widespread among birds and arthropods, it has only rarely been reported in mammals. Here, we examine the colour, morphology and optical mechanisms in hairs from four species of golden mole (Mammalia: Chrysochloridae) that are characterized by sheens ranging from purple to green. Microspectrophotometry reveals that this colour is weak and variable. Iridescent hairs are flattened and have highly reduced cuticular scales, providing a broad and smooth surface for light reflection. These scales form multiple layers of light and dark materials of consistent thickness, strikingly similar to those in the elytra of iridescent beetles. Optical modelling suggests that the multi-layers produce colour through thin-film interference, and that the sensitivity of this mechanism to slight changes in layer thickness and number explains colour variability. While coloured integumentary structures are typically thought to evolve as sexual ornaments, the blindness of golden moles suggests that the colour may be an epiphenomenon resulting from evolution via other selective factors, including the ability to move and keep clean in dirt and sand.

  10. Infrared Signature Masking by Air Plasma Radiation

    NASA Technical Reports Server (NTRS)

    Kruger, Charles H.; Laux, C. O.

    2001-01-01

    This report summarizes the results obtained during a research program on the infrared radiation of air plasmas conducted in the High Temperature Gasdynamics Laboratory at Stanford University under the direction of Professor Charles H. Kruger, with Dr. Christophe O. Laux as Associate Investigator. The goal of this research was to investigate the masking of infrared signatures by the air plasma formed behind the bow shock of high velocity missiles. To this end, spectral measurements and modeling were made of the radiation emitted between 2.4 and 5.5 micrometers by an atmospheric pressure air plasma in chemical and thermal equilibrium at a temperature of approximately 3000 K. The objective was to examine the spectral emission of air species including nitric oxide, atomic oxygen and nitrogen lines, molecular and atomic continua, as well as secondary species such as water vapor or carbon dioxide. The cold air stream injected in the plasma torch contained approximately 330 parts per million of CO2, which is the natural CO2 concentration in atmospheric air at room temperatures, and a small amount of water vapor with an estimated mole fraction of 3.8x10(exp -4).

  11. Stratospheric Air Sub-sampler (SAS) and its application to analysis of Δ17O(CO2) from small air samples collected with an AirCore

    NASA Astrophysics Data System (ADS)

    Janina Mrozek, Dorota; van der Veen, Carina; Hofmann, Magdalena E. G.; Chen, Huilin; Kivi, Rigel; Heikkinen, Pauli; Röckmann, Thomas

    2016-11-01

    We present the set-up and a scientific application of the Stratospheric Air Sub-sampler (SAS), a device to collect and to store the vertical profile of air collected with an AirCore (Karion et al., 2010) in numerous sub-samples for later analysis in the laboratory. The SAS described here is a 20 m long 1/4 inch stainless steel tubing that is separated by eleven valves to divide the tubing into 10 identical segments, but it can be easily adapted to collect smaller or larger samples. In the collection phase the SAS is directly connected to the outlet of an optical analyzer that measures the mole fractions of CO2, CH4 and CO from an AirCore sampler. The stratospheric part (or if desired any part of the AirCore air) is then directed through the SAS. When the SAS is filled with the selected air, the valves are closed and the vertical profile is maintained in the different segments of the SAS. The segments can later be analysed to retrieve vertical profiles of other trace gas signatures that require slower instrumentation. As an application, we describe the coupling of the SAS to an analytical system to determine the 17O excess of CO2, which is a tracer for photochemical processing of stratospheric air. For this purpose the analytical system described by Mrozek et al. (2015) was adapted for analysis of air directly from the SAS. The performance of the coupled system is demonstrated for a set of air samples from an AirCore flight in November 2014 near Sodankylä, Finland. The standard error for a 25 mL air sample at stratospheric CO2 mole fraction is 0.56 ‰ (1σ) for δ17O and 0.03 ‰ (1σ) for both δ18O and δ13C. Measured Δ17O(CO2) values show a clear correlation with N2O in agreement with already published data.

  12. Altered composition of liver proteasome assemblies contributes to enhanced proteasome activity in the exceptionally long-lived naked mole-rat.

    PubMed

    Rodriguez, Karl A; Edrey, Yael H; Osmulski, Pawel; Gaczynska, Maria; Buffenstein, Rochelle

    2012-01-01

    The longest-lived rodent, the naked mole-rat (Bathyergidae; Heterocephalus glaber), maintains robust health for at least 75% of its 32 year lifespan, suggesting that the decline in genomic integrity or protein homeostasis routinely observed during aging, is either attenuated or delayed in this extraordinarily long-lived species. The ubiquitin proteasome system (UPS) plays an integral role in protein homeostasis by degrading oxidatively-damaged and misfolded proteins. In this study, we examined proteasome activity in naked mole-rats and mice in whole liver lysates as well as three subcellular fractions to probe the mechanisms behind the apparently enhanced effectiveness of UPS. We found that when compared with mouse samples, naked mole-rats had significantly higher chymotrypsin-like (ChT-L) activity and a two-fold increase in trypsin-like (T-L) in both whole lysates as well as cytosolic fractions. Native gel electrophoresis of the whole tissue lysates showed that the 20S proteasome was more active in the longer-lived species and that 26S proteasome was both more active and more populous. Western blot analyses revealed that both 19S subunits and immunoproteasome catalytic subunits are present in greater amounts in the naked mole-rat suggesting that the observed higher specific activity may be due to the greater proportion of immunoproteasomes in livers of healthy young adults. It thus appears that proteasomes in this species are primed for the efficient removal of stress-damaged proteins. Further characterization of the naked mole-rat proteasome and its regulation could lead to important insights on how the cells in these animals handle increased stress and protein damage to maintain a longer health in their tissues and ultimately a longer life.

  13. Application of the MOLE in post-nuclear accident characterization

    SciTech Connect

    Johnson, S.J.; Alvarez, J.L.

    1981-01-01

    Following a nuclear accident there is a need to determine the chemical composition of materials in liquid, solid and gaseous form, the crystalline structure of solids, the size and chemical composition of particles, and the chemical characterization of contaminants on surfaces. This analytical information is required to reconstruct the accident scenario, to select decontamination methods, and to determine future safety requirements. The MOLE (Molecular Optical Laser Examiner) is a Raman microprobe system which has proven to be a valuable analytical tool in providing this type of chemical information. It can determine the chemical species of polyatomic molecules and ions having characteristic Raman spectra. As little as 1 picogram of a component or a 1 ..mu..m particle can be analyzed. The imaging system can also provide mapping of selected components on a surface. A system description, sample handling techniques, and applications are presented. Specific applications to the Three Mile Island-Unit 2 accident are also addressed.

  14. Adult neurogenesis and its anatomical context in the hippocampus of three mole-rat species

    PubMed Central

    Amrein, Irmgard; Becker, Anton S.; Engler, Stefanie; Huang, Shih-hui; Müller, Julian; Slomianka, Lutz; Oosthuizen, Maria K.

    2014-01-01

    African mole-rats (family Bathyergidae) are small to medium sized, long-lived, and strictly subterranean rodents that became valuable animal models as a result of their longevity and diversity in social organization. The formation and integration of new hippocampal neurons in adult mammals (adult hippocampal neurogenesis, AHN) correlates negatively with age and positively with habitat complexity. Here we present quantitative data on AHN in wild-derived mole-rats of 1 year and older, and briefly describe its anatomical context including markers of neuronal function (calbindin and parvalbumin). Solitary Cape mole-rats (Georychus capensis), social highveld mole-rats (Cryptomys hottentotus pretoriae), and eusocial naked mole-rats (Heterocephalus glaber) were assessed. Compared to other rodents, the hippocampal formation in mole-rats is small, but shows a distinct cytoarchitecture in the dentate gyrus and CA1. Distributions of the calcium-binding proteins differ from those seen in rodents; e.g., calbindin in CA3 of naked mole-rats distributes similar to the pattern seen in early primate development, and calbindin staining extends into the stratum lacunosum-moleculare of Cape mole-rats. Proliferating cells and young neurons are found in low numbers in the hippocampus of all three mole-rat species. Resident granule cell numbers are low as well. Proliferating cells expressed as a percentage of resident granule cells are in the range of other rodents, while the percentage of young neurons is lower than that observed in surface dwelling rodents. Between mole-rat species, we observed no difference in the percentage of proliferating cells. The percentages of young neurons are high in social highveld and naked mole-rats, and low in solitary Cape mole-rats. The findings support that proliferation is regulated independently of average life expectancy and habitat. Instead, neuronal differentiation reflects species-specific demands, which appear lower in subterranean rodents. PMID

  15. Possible incipient sympatric ecological speciation in blind mole rats (Spalax)

    PubMed Central

    Hadid, Yarin; Tzur, Shay; Pavlíček, Tomáš; Šumbera, Radim; Šklíba, Jan; Lövy, Matěj; Fragman-Sapir, Ori; Beiles, Avigdor; Arieli, Ran; Raz, Shmuel; Nevo, Eviatar

    2013-01-01

    Sympatric speciation has been controversial since it was first proposed as a mode of speciation. Subterranean blind mole rats (Spalacidae) are considered to speciate allopatrically or peripatrically. Here, we report a possible incipient sympatric adaptive ecological speciation in Spalax galili (2n = 52). The study microsite (0.04 km2) is sharply subdivided geologically, edaphically, and ecologically into abutting barrier-free ecologies divergent in rock, soil, and vegetation types. The Pleistocene Alma basalt abuts the Cretaceous Senonian Kerem Ben Zimra chalk. Only 28% of 112 plant species were shared between the soils. We examined mitochondrial DNA in the control region and ATP6 in 28 mole rats from basalt and in 14 from chalk habitats. We also sequenced the complete mtDNA (16,423 bp) of four animals, two from each soil type. Remarkably, the frequency of all major haplotype clusters (HC) was highly soil-biased. HCI and HCII are chalk biased. HC-III was abundant in basalt (36%) but absent in chalk; HC-IV was prevalent in basalt (46.5%) but was low (20%) in chalk. Up to 40% of the mtDNA diversity was edaphically dependent, suggesting constrained gene flow. We identified a homologous recombinant mtDNA in the basalt/chalk studied area. Phenotypically significant divergences differentiate the two populations, inhabiting different soils, in adaptive oxygen consumption and in the amount of outside-nest activity. This identification of a possible incipient sympatric adaptive ecological speciation caused by natural selection indirectly refutes the allopatric alternative. Sympatric ecological speciation may be more prevalent in nature because of abundant and sharply abutting divergent ecologies. PMID:23359700

  16. Comparative Morphology of the Penis and Clitoris in Four Species of Moles (Talpidae).

    PubMed

    Sinclair, Adriane Watkins; Glickman, Stephen; Catania, Kenneth; Shinohara, Akio; Baskin, Lawrence; Cunha, Gerald R

    2017-03-02

    The penile and clitoral anatomy of four species of Talpid moles (broad-footed, star-nosed, hairy-tailed, and Japanese shrew moles) were investigated to define penile and clitoral anatomy and to examine the relationship of the clitoral anatomy with the presence or absence of ovotestes. The ovotestis contains ovarian tissue and glandular tissue resembling fetal testicular tissue and can produce androgens. The ovotestis is present in star-nosed and hairy-tailed moles, but not in broad-footed and Japanese shrew moles. Using histology, three-dimensional reconstruction, and morphometric analysis, sexual dimorphism was examined with regard to a nine feature masculine trait score that included perineal appendage length (prepuce), anogenital distance, and presence/absence of bone. The presence/absence of ovotestes was discordant in all four mole species for sex differentiation features. For many sex differentiation features, discordance with ovotestes was observed in at least one mole species. The degree of concordance with ovotestes was highest for hairy-tailed moles and lowest for broad-footed moles. In relationship to phylogenetic clade, sex differentiation features also did not correlate with the similarity/divergence of the features and presence/absence of ovotestes. Hairy-tailed and Japanese shrew moles reside in separated clades, but they exhibit a high degree of congruence. Broad-footed and hairy-tailed moles reside within the same clade but had one of the lowest correlations in features and presence/absence of ovotestes. Thus, phylogenetic affinity and the presence/absence of ovotestes are poor predictors for most sex differentiation features within mole external genitalia.

  17. High-molecular-mass hyaluronan mediates the cancer resistance of the naked mole rat.

    PubMed

    Tian, Xiao; Azpurua, Jorge; Hine, Christopher; Vaidya, Amita; Myakishev-Rempel, Max; Ablaeva, Julia; Mao, Zhiyong; Nevo, Eviatar; Gorbunova, Vera; Seluanov, Andrei

    2013-07-18

    The naked mole rat (Heterocephalus glaber) displays exceptional longevity, with a maximum lifespan exceeding 30 years. This is the longest reported lifespan for a rodent species and is especially striking considering the small body mass of the naked mole rat. In comparison, a similarly sized house mouse has a maximum lifespan of 4 years. In addition to their longevity, naked mole rats show an unusual resistance to cancer. Multi-year observations of large naked mole-rat colonies did not detect a single incidence of cancer. Here we identify a mechanism responsible for the naked mole rat's cancer resistance. We found that naked mole-rat fibroblasts secrete extremely high-molecular-mass hyaluronan (HA), which is over five times larger than human or mouse HA. This high-molecular-mass HA accumulates abundantly in naked mole-rat tissues owing to the decreased activity of HA-degrading enzymes and a unique sequence of hyaluronan synthase 2 (HAS2). Furthermore, the naked mole-rat cells are more sensitive to HA signalling, as they have a higher affinity to HA compared with mouse or human cells. Perturbation of the signalling pathways sufficient for malignant transformation of mouse fibroblasts fails to transform naked mole-rat cells. However, once high-molecular-mass HA is removed by either knocking down HAS2 or overexpressing the HA-degrading enzyme, HYAL2, naked mole-rat cells become susceptible to malignant transformation and readily form tumours in mice. We speculate that naked mole rats have evolved a higher concentration of HA in the skin to provide skin elasticity needed for life in underground tunnels. This trait may have then been co-opted to provide cancer resistance and longevity to this species.

  18. A hypothetical model of organic matter sea-to-air exchange processes based on stable carbon fractionation in the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Ceburnis, D.; Masalaite, A.; Garbaras, A.; Ovadnevaite, J.; Maenhaut, W.; Claeys, M.; Sciare, J.; O'Dowd, C. D. D.; Remeikis, V.

    2015-12-01

    Marine aerosol contributes significantly to the global aerosol loading and consequently has a significant impact on both the Earth's albedo and climate. Biological productivity in the global ocean is often resulting in significant amounts of primary organic matter in the aerosol phase. The North Atlantic Ocean is among the most productive oceanic regions and is the most studied ocean on Earth. The Southern Ocean, on the other hand, has been far less studied, even though similar organic matter enrichment patterns have been observed in marine aerosol. While numerous processes can contribute to organic matter in marine aerosols, carbon isotope analysis offers the most unambiguous estimates of the contributing sources. The stable carbon isotope ratios in marine aerosol samples collected during austral summer of 2007 at Amsterdam Island (Southern Indian Ocean) were examined. The measured δ13C values in the fine (Da <2.5µm) and coarse (Da >2.5µm) particle fractions were found to be evenly distributed between -28.2‰ and -20.0‰. These values are far lower than the previously reported ones as typical of unperturbed marine aerosol (-20‰). The δ13C values in the fine and coarse particle fractions were correlated with organic matter enrichment in sea spray. It was attempted to explain the variation of the δ13C values by the competition of the "fresh" and "old" organic matter pools in sea water during transfer into the aerosol phase, thereby implicating trophic level interactions. The hypothetical model suggests that fresh organic matter readily results in organic matter enrichment in sea spray particles and likely contains fresh colloidal and nanogel particulate matter, while the old organic matter is largely dissolved and unable to significantly enrich sea spray. Air mass back trajectory analysis suggests that the most productive regions, where sea spray particles are the most enriched in organic matter, are associated with low sea-water temperatures around the

  19. A bench evaluation of fraction of oxygen in air delivery and tidal volume accuracy in home care ventilators available for hospital use

    PubMed Central

    Baboi, Loredana; Subtil, Fabien

    2016-01-01

    Background Turbine-powered ventilators are not only designed for long-term ventilation at home but also for hospital use. It is important to verify their capabilities in delivering fraction of oxygen in air (FIO2) and tidal volume (VT). Methods We assessed the FIO2 accuracy and the VT delivery in four home care ventilators (HCV) on the bench. The four HCV were Astral 150, Elisée 150, Monnal T50 and Trilogy 200 HCV, which were connected to a lung model (ASL 5000). For assessing FIO2 accuracy, lung model was set to mimic an obstructive lung and HCV were set in volume controlled mode (VC). They supplied with air, 3 or 15 L/min oxygen and FIO2 was measured by using a ventilator tester (Citrex H4TM). For the VT accuracy, the lung model was set in a way to mimic three adult configurations (normal, obstructive, or restrictive respiratory disorder) and one pediatric configuration. Each HCV was set in VC. Two VT (300 and 500 mL) in adult lung configuration and one 50 mL VT in pediatric lung configuration, at two positive end expiratory pressures 5 and 10 cmH2O, were tested. VT accuracy was measured as volume error (the relative difference between set and measured VT). Statistical analysis was performed by suing one-factor ANOVA with a Bonferroni correction for multiple tests. Results For Astral 150, Elisée 150, Monnal T50 and Trilogy 200, FIO2 averaged 99.2%, 93.7%, 86.3%, and 62.1%, respectively, at 15 L/min oxygen supplementation rate (P<0.001). Volume error was 0.5%±0%, −38%±0%, −9%±0%, −29%±0% and −36%±0% for pediatric lung condition (P<0.001). In adult lung configurations, Monnal T50 systematically over delivered VT and Trilogy 150 was sensitive to lung configuration when VT was set to 300 mL at either positive end-expiratory pressure (PEEP). Conclusions HCV are different in terms of FIO2 efficiency and VT delivery. PMID:28149559

  20. Pacific Mole Crab (Emerita analoga) Abundance in Correlation with Waste Water Effluence

    NASA Astrophysics Data System (ADS)

    Sun, L.; Dangerfield, L.; Minor, D.; Subedar, R.

    2012-12-01

    Previous studies have shown that pollutants such as ammonia and copper have had negative effects on marine invertebrate lifecycles. Along the Pacific Coast of California, a filter feeding invertebrate, the Pacific mole crab, Emerita analoga, is exposed to such pollutants regularly. In San Francisco, habitats for populations of Pacific mole crabs are located near the Oceanside Water Pollution Control Plant, which dumps waste water 4.5 miles off the coast. Due to this disturbance at the south end of Ocean Beach, we hypothesize that there is a negative correlation between the abundance of mole crabs and the levels of copper, zinc and ammonia in sewage released from the Oceanside plant each year. By analyzing four years of Pacific mole crab abundance data and utilizing yearly waste water discharge figures, we found that there is a slight negative correlation (-0.67057) between mole crab abundances and the total amount of waste water being released annually. The amount of copper released from 2007-2010 and the abundance of E. analoga also has a slight negative correlation (-0.6714). The correlation between Pacific mole crab abundance and the total amount of zinc is also a slightly negative (-0.48434). However, the correlation between the abundance of mole crabs and total amount of ammonia released is positive (0.4497). Further data are needed to ascertain the relationship between the abundance of the Pacific mole crab and the amount of pollutants released from nearby waste water treatment plants.

  1. Whole-Genome Sequence of a Novel Hantavirus Isolated from the European Mole (Talpa europaea)

    PubMed Central

    Gu, Se Hun; Hejduk, Janusz; Markowski, Janusz; Markowski, Marcin; Liberski, Paweł P.

    2015-01-01

    The complete genome sequence of Nova virus, a novel hantavirus isolated from a European mole (Talpa europaea) captured in central Poland, was determined. The availability of this sequence will facilitate the search for other mole-borne hantaviruses and will accelerate the acquisition of new knowledge about their phylogeography and evolutionary origin. PMID:26021917

  2. What's the Diagnosis? An Inquiry-Based Activity Focusing on Mole-Mass Conversions

    ERIC Educational Resources Information Center

    Bruck, Laura B.; Towns, Marcy H.

    2011-01-01

    An inquiry-based mole-to-mass activity is presented associated with the analysis of blood. Students working in groups choose between two medical cases to determine if the "patient" has higher or lower concentrations of minerals than normal. The data are presented such that students must convert moles to mass in order to compare the patient values…

  3. The Naked Mole Rat Genome Resource: facilitating analyses of cancer and longevity-related adaptations

    PubMed Central

    Keane, Michael; Craig, Thomas; Alföldi, Jessica; Berlin, Aaron M.; Johnson, Jeremy; Seluanov, Andrei; Gorbunova, Vera; Di Palma, Federica; Lindblad-Toh, Kerstin; Church, George M.; de Magalhães, João Pedro

    2014-01-01

    Motivation: The naked mole rat (Heterocephalus glaber) is an exceptionally long-lived and cancer-resistant rodent native to East Africa. Although its genome was previously sequenced, here we report a new assembly sequenced by us with substantially higher N50 values for scaffolds and contigs. Results: We analyzed the annotation of this new improved assembly and identified candidate genomic adaptations which may have contributed to the evolution of the naked mole rat’s extraordinary traits, including in regions of p53, and the hyaluronan receptors CD44 and HMMR (RHAMM). Furthermore, we developed a freely available web portal, the Naked Mole Rat Genome Resource (http://www.naked-mole-rat.org), featuring the data and results of our analysis, to assist researchers interested in the genome and genes of the naked mole rat, and also to facilitate further studies on this fascinating species. Availability and implementation: The Naked Mole Rat Genome Resource is freely available online at http://www.naked-mole-rat.org. This resource is open source and the source code is available at https://github.com/maglab/naked-mole-rat-portal. Contact: jp@senescence.info PMID:25172923

  4. Trading new neurons for status: Adult hippocampal neurogenesis in eusocial Damaraland mole-rats.

    PubMed

    Oosthuizen, M K; Amrein, I

    2016-06-02

    Diversity in social structures, from solitary to eusocial, is a prominent feature of subterranean African mole-rat species. Damaraland mole-rats are eusocial, they live in colonies that are characterized by a reproductive division of labor and a subdivision into castes based on physiology and behavior. Damaraland mole-rats are exceptionally long lived and reproductive animals show delayed aging compared to non-reproductive animals. In the present study, we described the hippocampal architecture and the rate of hippocampal neurogenesis of wild-derived, adult Damaraland mole-rats in relation to sex, relative age and social status or caste. Overall, Damaraland mole-rats were found to have a small hippocampus and low rates of neurogenesis. We found no correlation between neurogenesis and sex or relative age. Social status or caste was the most prominent modulator of neurogenesis. An inverse relationship between neurogenesis and social status was apparent, with queens displaying the lowest neurogenesis while the worker mole-rats had the most. As there is no natural progression from one caste to another, social status within a colony was relatively stable and is reflected in the level of neurogenesis. Our results correspond to those found in the naked mole-rat, and may reflect an evolutionary and environmentally conserved trait within social mole-rat species.

  5. Eye development in the Cape dune mole rat.

    PubMed

    Nikitina, Natalya V; Kidson, Susan H

    2014-03-01

    Studies on mammalian species with naturally reduced eyes can provide valuable insights into the evolutionary developmental mechanisms underlying the reduction of the eye structures. Because few naturally microphthalmic animals have been studied and eye reduction must have evolved independently in many of the modern groups, novel evolutionary developmental models for eye research have to be sought. Here, we present a first report on embryonic eye development in the Cape dune mole rat, Bathyergus suillus. The eyes of these animals contain all the internal structures characteristic of the normal eye but exhibit abnormalities in the anterior chamber structures. The lens is small but develops normally and exhibits a normal expression of α- and γ-crystallins. One of the interesting features of these animals is an extremely enlarged and highly pigmented ciliary body. In order to understand the molecular basis of this unusual feature, the expression pattern of an early marker of the ciliary zone, Ptmb4, was investigated in this animal. Surprisingly, in situ hybridization results revealed that Ptmb4 expression was absent from the ciliary body zone of the developing Bathyergus eye.

  6. Acanthocephala Parasite (Profilicollis spp.) Loads in Correlation to Pacific Mole Crab (Emerita analoga) Size

    NASA Astrophysics Data System (ADS)

    Cheng, T.; Huang, S.; Galathe, M.; Jenkins, M.; Ramirez, A.; Crosby, L.; Barrera, J.; FitzHoward, S.

    2013-12-01

    Since 2002, San Francisco Bay students have been conducting marine ecosystem monitoring through a joint project with the Long-term Monitoring Program and Experiential Training for Students (LiMPETS), in conjunction with the Gulf of Farallones National Marine Sanctuary. Each year students collect population and demographic data on Pacific mole crabs (Emerita analoga), an indicator species that lives in the sandy beach habitat in temperate regions along the Pacific Ocean. Pacific mole crabs are filter feeding crustaceans that inhabit the intertidal swash zone and are known to be an intermediate host for parasitic ';spiny-headed' worms in the phylum Acanthocephala (Profilicollis spp.). Sampling takes place during their reproductive period, which occurs from spring to fall, and includes measuring total body length of the Pacific mole crabs and dissecting them to determine presence of Acanthocephalan parasites. We hypothesize that due to larger body mass, larger Pacific mole crabs will have a greater number of Acanthocephala parasites.We conducted several analyses using the LiMPETS long-term data. Specifically, we compared body length, crab gender, and parasite abundance from Pacific mole crabs sampled from four beaches located in the county and city of San Francisco. Our results indicated that larger Pacific mole crabs do not necessarily have more parasites, but are more likely to have at least one parasite, while female Pacific mole crabs carrying eggs, have more parasites than males or females without eggs. We also found that parasite loads per mole crab was highest in the spring. Further analysis will be conducted to determine factors affecting Pacific mole crab parasite loads. Studying Pacific mole crabs help evaluate the health of California's intertidal systems and how human activities, geologic changes, and climate changes all make huge impacts to the intertidal ecosystems.

  7. Fractional randomness

    NASA Astrophysics Data System (ADS)

    Tapiero, Charles S.; Vallois, Pierre

    2016-11-01

    The premise of this paper is that a fractional probability distribution is based on fractional operators and the fractional (Hurst) index used that alters the classical setting of random variables. For example, a random variable defined by its density function might not have a fractional density function defined in its conventional sense. Practically, it implies that a distribution's granularity defined by a fractional kernel may have properties that differ due to the fractional index used and the fractional calculus applied to define it. The purpose of this paper is to consider an application of fractional calculus to define the fractional density function of a random variable. In addition, we provide and prove a number of results, defining the functional forms of these distributions as well as their existence. In particular, we define fractional probability distributions for increasing and decreasing functions that are right continuous. Examples are used to motivate the usefulness of a statistical approach to fractional calculus and its application to economic and financial problems. In conclusion, this paper is a preliminary attempt to construct statistical fractional models. Due to the breadth and the extent of such problems, this paper may be considered as an initial attempt to do so.

  8. Real-time analysis of δ13C- and δD-CH4 in ambient air with laser spectroscopy: method development and first intercomparison results

    NASA Astrophysics Data System (ADS)

    Eyer, S.; Tuzson, B.; Popa, M. E.; van der Veen, C.; Röckmann, T.; Rothe, M.; Brand, W. A.; Fisher, R.; Lowry, D.; Nisbet, E. G.; Brennwald, M. S.; Harris, E.; Zellweger, C.; Emmenegger, L.; Fischer, H.; Mohn, J.

    2015-08-01

    In situ and simultaneous measurement of the three most abundant isotopologues of methane using mid-infrared laser absorption spectroscopy is demonstrated. A field-deployable, autonomous platform is realized by coupling a compact quantum cascade laser absorption spectrometer (QCLAS) to a preconcentration unit, called TRace gas EXtractor (TREX). This unit enhances CH4 mole fractions by a factor of up to 500 above ambient levels and quantitatively separates interfering trace gases such as N2O and CO2. The analytical precision of the QCLAS isotope measurement on the preconcentrated (750 ppm, parts-per-million, μmole/mole) methane is 0.1 and 0.5 ‰ for δ13C- and δD-CH4 at 10 min averaging time. Based on replicate measurements of compressed air during a two-week intercomparison campaign, the repeatability of the TREX-QCLAS was determined to be 0.19 and 1.9 ‰ for δ13C and δD-CH4, respectively. In this intercomparison campaign the new in situ technique is compared to isotope-ratio mass-spectrometry (IRMS) based on glass flask and bag sampling and real time CH4 isotope analysis by two commercially available laser spectrometers. Both laser-based analyzers were limited to methane mole fraction and δ13C-CH4 analysis, and only one of them, a cavity ring down spectrometer, was capable to deliver meaningful data for the isotopic composition. After correcting for scale offsets, the average difference between TREX-QCLAS data and bag/flask sampling-IRMS values are within the extended WMO compatibility goals of 0.2 and 5 ‰ for δ13C- and δD-CH4, respectively. Thus, the intercomparison also reveals the need for reference air samples with accurately determined isotopic composition of CH4 to further improve the interlaboratory compatibility.

  9. Making Mountains out of Molehills: Sediment Transport by the European Mole (Talpa europaea)

    NASA Astrophysics Data System (ADS)

    Milledge, D.; Loveless, J. C.; Warburton, J.; Densmore, A. L.

    2013-12-01

    Despite its widespread occurrence (across Europe and Eastern North America) the significance of the burrowing activity of the European Mole for sediment transport in the Northern Hemisphere has not been well quantified. In many areas this may have been the dominant mechanism of hillslope sediment transport over the last one to two millenia. The European Mole (Talpa europaea) is prevalent across the UK, particularly in fertile soils. It is highly fossorial, living almost its entire 3-6 year life in a network of tunnels that it maintains to catch prey. Moles can rapidly excavate large amounts of soil (~6 kg in 20 minutes) with waste soil generally pushed to the surface to form molehills. In this study we quantify sediment flux due to mole burrowing based on measured molehill sizes and geometries and estimates of mole hill production rates from time lapse photography. We examine the evolution of the molehills after production through repeat survey of in-situ molehills in the field and rainfall simulation experiments to accelerate degradation in the laboratory. Our initial findings suggest that: 1) molehill masses are generally log-normally distributed with a geometric mean ~1.4 kg; 2) moles move approximately 1.5 times as much soil as earthworms; and 3) the sediment flux due to moles is a non-linear function of the local slope.

  10. Selective inflammatory pain insensitivity in the African naked mole-rat (Heterocephalus glaber).

    PubMed

    Park, Thomas J; Lu, Ying; Jüttner, René; Smith, Ewan St J; Hu, Jing; Brand, Antje; Wetzel, Christiane; Milenkovic, Nevena; Erdmann, Bettina; Heppenstall, Paul A; Laurito, Charles E; Wilson, Steven P; Lewin, Gary R

    2008-01-01

    In all mammals, tissue inflammation leads to pain and behavioral sensitization to thermal and mechanical stimuli called hyperalgesia. We studied pain mechanisms in the African naked mole-rat, an unusual rodent species that lacks pain-related neuropeptides (e.g., substance P) in cutaneous sensory fibers. Naked mole-rats show a unique and remarkable lack of pain-related behaviors to two potent algogens, acid and capsaicin. Furthermore, when exposed to inflammatory insults or known mediators, naked mole-rats do not display thermal hyperalgesia. In contrast, naked mole-rats do display nocifensive behaviors in the formalin test and show mechanical hyperalgesia after inflammation. Using electrophysiology, we showed that primary afferent nociceptors in naked mole-rats are insensitive to acid stimuli, consistent with the animal's lack of acid-induced behavior. Acid transduction by sensory neurons is observed in birds, amphibians, and fish, which suggests that this tranduction mechanism has been selectively disabled in the naked mole-rat in the course of its evolution. In contrast, nociceptors do respond vigorously to capsaicin, and we also show that sensory neurons express a transient receptor potential vanilloid channel-1 ion channel that is capsaicin sensitive. Nevertheless, the activation of capsaicin-sensitive sensory neurons in naked mole-rats does not produce pain-related behavior. We show that capsaicin-sensitive nociceptors in the naked mole-rat are functionally connected to superficial dorsal horn neurons as in mice. However, the same nociceptors are also functionally connected to deep dorsal horn neurons, a connectivity that is rare in mice. The pain biology of the naked mole-rat is unique among mammals, thus the study of pain mechanisms in this unusual species can provide major insights into what constitutes "normal" mammalian nociception.

  11. Development of a Northern Continental Air Standard Reference Material.

    PubMed

    Rhoderick, George C; Kitzis, Duane R; Kelley, Michael E; Miller, Walter R; Hall, Bradley D; Dlugokencky, Edward J; Tans, Pieter P; Possolo, Antonio; Carney, Jennifer

    2016-03-15

    The National Institute of Standards and Technology (NIST) recently began to develop standard mixtures of greenhouse gases as part of a broad program mandated by the 2009 United States Congress to support research in climate change. To this end, NIST developed suites of gravimetrically assigned primary standard mixtures (PSMs) comprising carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in a dry-natural air balance at ambient mole fraction levels. In parallel, the National Oceanic and Atmospheric Administration (NOAA) in Boulder, Colorado, charged 30 aluminum gas cylinders with northern hemisphere air at Niwot Ridge, Colorado. These mixtures, which constitute NIST Standard Reference Material (SRM) 1720 Northern Continental Air, were certified by NIST for ambient mole fractions of CO2, CH4, and N2O relative to NIST PSMs. NOAA-assigned values are also provided as information in support of the World Meteorological Organization (WMO) Global Atmosphere Watch (GAW) Program for CO2, CH4, and N2O, since NOAA serves as the WMO Central Calibration Laboratory (CCL) for CO2, CH4, and N2O. Relative expanded uncertainties at the 95% confidence interval are <±0.06% of the certified values for CO2 and N2O and <0.2% for CH4, which represents the smallest relative uncertainties specified to date for a gaseous SRM produced by NIST. Agreement between the NOAA (WMO/GAW) and NIST values based on their respective calibration standards suites is within 0.05%, 0.13%, and 0.06% for CO2, CH4, and N2O, respectively. This collaborative development effort also represents the first of its kind for a gaseous SRM developed by NIST.

  12. Pregnancy outcome with coexisting mole after intracytoplasmic sperm injection: A case series

    PubMed Central

    Rao, Asha R.; Dafle, Karishma; Padmashri, G.; Rao, Damodar R.; Sivakumar, N. C.

    2015-01-01

    Partial/complete hydatidiform mole with coexisting fetus is a rare condition. Optimal management is a challenge that remains a dilemma since these pregnancies are associated with maternal as well as fetal complications including hemorrhage, preeclampsia, thromboembolic disease, intra uterine demise and increased risk of persistent trophoblastic disease. Here we report 2 cases of partial mole with live fetus after ICSI and a case of complete mole with coexisting fetus after ICSI in a turner mosaic that resulted in a live birth. PMID:26538863

  13. What Are Students' Initial Ideas about "Amount of Substance"? "Is There a Specific Weight for a Mole?"

    ERIC Educational Resources Information Center

    Claesgens, Jennifer; Stacy, Angelica

    Analyzes the role of students' prior knowledge in their emerging understanding of the mole. The research question this study seeks to answer is what knowledge, if any, do student have regarding the mole and what prior knowledge do they access when presented problems regarding the nature of the mole. Data collection focuses on student knowledge…

  14. The Mole and Avogadro's Number: A Forced Fusion of Ideas for Teaching Purposes

    ERIC Educational Resources Information Center

    Hawthorne, Robert M., Jr.

    1973-01-01

    Reports a review of existing texts in which it was found that many textbooks exist which do not make any particular connection between Avogadro's number and the mole. Some books do not mention or use Avogadro's number at all. (DF)

  15. Genome sequencing reveals insights into physiology and longevity of the naked mole rat.

    PubMed

    Kim, Eun Bae; Fang, Xiaodong; Fushan, Alexey A; Huang, Zhiyong; Lobanov, Alexei V; Han, Lijuan; Marino, Stefano M; Sun, Xiaoqing; Turanov, Anton A; Yang, Pengcheng; Yim, Sun Hee; Zhao, Xiang; Kasaikina, Marina V; Stoletzki, Nina; Peng, Chunfang; Polak, Paz; Xiong, Zhiqiang; Kiezun, Adam; Zhu, Yabing; Chen, Yuanxin; Kryukov, Gregory V; Zhang, Qiang; Peshkin, Leonid; Yang, Lan; Bronson, Roderick T; Buffenstein, Rochelle; Wang, Bo; Han, Changlei; Li, Qiye; Chen, Li; Zhao, Wei; Sunyaev, Shamil R; Park, Thomas J; Zhang, Guojie; Wang, Jun; Gladyshev, Vadim N

    2011-10-12

    The naked mole rat (Heterocephalus glaber) is a strictly subterranean, extraordinarily long-lived eusocial mammal. Although it is the size of a mouse, its maximum lifespan exceeds 30 years, making this animal the longest-living rodent. Naked mole rats show negligible senescence, no age-related increase in mortality, and high fecundity until death. In addition to delayed ageing, they are resistant to both spontaneous cancer and experimentally induced tumorigenesis. Naked mole rats pose a challenge to the theories that link ageing, cancer and redox homeostasis. Although characterized by significant oxidative stress, the naked mole rat proteome does not show age-related susceptibility to oxidative damage or increased ubiquitination. Naked mole rats naturally reside in large colonies with a single breeding female, the 'queen', who suppresses the sexual maturity of her subordinates. They also live in full darkness, at low oxygen and high carbon dioxide concentrations, and are unable to sustain thermogenesis nor feel certain types of pain. Here we report the sequencing and analysis of the naked mole rat genome, which reveals unique genome features and molecular adaptations consistent with cancer resistance, poikilothermy, hairlessness and insensitivity to low oxygen, and altered visual function, circadian rythms and taste sensing. This information provides insights into the naked mole rat's exceptional longevity and ability to live in hostile conditions, in the dark and at low oxygen. The extreme traits of the naked mole rat, together with the reported genome and transcriptome information, offer opportunities for understanding ageing and advancing other areas of biological and biomedical research.

  16. Hypersensitivity to contact inhibition provides a clue to cancer resistance of naked mole-rat.

    PubMed

    Seluanov, Andrei; Hine, Christopher; Azpurua, Jorge; Feigenson, Marina; Bozzella, Michael; Mao, Zhiyong; Catania, Kenneth C; Gorbunova, Vera

    2009-11-17

    The naked mole-rat is the longest living rodent with a maximum lifespan exceeding 28 years. In addition to its longevity, naked mole-rats have an extraordinary resistance to cancer as tumors have never been observed in these rodents. Furthermore, we show that a combination of activated Ras and SV40 LT fails to induce robust anchorage-independent growth in naked mole-rat cells, while it readily transforms mouse fibroblasts. The mechanisms responsible for the cancer resistance of naked mole-rats were unknown. Here we show that naked mole-rat fibroblasts display hypersensitivity to contact inhibition, a phenomenon we termed "early contact inhibition." Contact inhibition is a key anticancer mechanism that arrests cell division when cells reach a high density. In cell culture, naked mole-rat fibroblasts arrest at a much lower density than those from a mouse. We demonstrate that early contact inhibition requires the activity of p53 and pRb tumor suppressor pathways. Inactivation of both p53 and pRb attenuates early contact inhibition. Contact inhibition in human and mouse is triggered by the induction of p27(Kip1). In contrast, early contact inhibition in naked mole-rat is associated with the induction of p16(Ink4a). Furthermore, we show that the roles of p16(Ink4a) and p27(Kip1) in the control of contact inhibition became temporally separated in this species: the early contact inhibition is controlled by p16(Ink4a), and regular contact inhibition is controlled by p27(Kip1). We propose that the additional layer of protection conferred by two-tiered contact inhibition contributes to the remarkable tumor resistance of the naked mole-rat.

  17. Atypical mole syndrome and dysplastic nevi: identification of populations at risk for developing melanoma - review article

    PubMed Central

    Silva, Juliana Hypólito; de Sá, Bianca Costa Soares; de Ávila, Alexandre Leon Ribeiro; Landman, Gilles; Neto, João Pedreira Duprat

    2011-01-01

    Atypical Mole Syndrome is the most important phenotypic risk factor for developing cutaneous melanoma, a malignancy that accounts for about 80% of deaths from skin cancer. Because the diagnosis of melanoma at an early stage is of great prognostic relevance, the identification of Atypical Mole Syndrome carriers is essential, as well as the creation of recommended preventative measures that must be taken by these patients. PMID:21552679

  18. Australia's first fossil marsupial mole (Notoryctemorphia) resolves controversies about their evolution and palaeoenvironmental origins.

    PubMed

    Archer, Michael; Beck, Robin; Gott, Miranda; Hand, Suzanne; Godthelp, Henk; Black, Karen

    2011-05-22

    Fossils of a marsupial mole (Marsupialia, Notoryctemorphia, Notoryctidae) are described from early Miocene deposits in the Riversleigh World Heritage Area, northwestern Queensland, Australia. These represent the first unequivocal fossil record of the order Notoryctemorphia, the two living species of which are among the world's most specialized and bizarre mammals, but which are also convergent on certain fossorial placental mammals (most notably chrysochlorid golden moles). The fossil remains are genuinely 'transitional', documenting an intermediate stage in the acquisition of a number of specializations and showing that one of these-the dental morphology known as zalambdodonty-was acquired via a different evolutionary pathway than in placentals. They, thus, document a clear case of evolutionary convergence (rather than parallelism) between only distantly related and geographically isolated mammalian lineages-marsupial moles on the island continent of Australia and placental moles on most other, at least intermittently connected continents. In contrast to earlier presumptions about a relationship between the highly specialized body form of the blind, earless, burrowing marsupial moles and desert habitats, it is now clear that archaic burrowing marsupial moles were adapted to and probably originated in wet forest palaeoenvironments, preadapting them to movement through drier soils in the xeric environments of Australia that developed during the Neogene.

  19. SHORT COMMUNICATION: Comments on recent proposals for redefining the mole and kilogram

    NASA Astrophysics Data System (ADS)

    Leonard, B. P.

    2010-06-01

    The fundamental concept of the mole requires the number of entities comprising one mole, i.e. Avogadro's number, to be exactly equal to the gram-to-dalton mass ratio. If this compatibility condition is to be satisfied, the mole, the kilogram and the dalton cannot all be defined independently. This note concerns recent Metrologia publications that do, however, propose independent definitions of all three quantities: the mole by fixing the value of Avogadro's number and the kilogram by fixing the value of the Planck constant, while retaining the current carbon-12-based dalton. Adoption of these incompatible definitions would likely cause serious widespread confusion and might even result in a split in scholarly and technical communication between the quantum physics and chemistry communities. Other entirely compatible alternatives are possible: either retaining the current (inexact) carbon-12-based mole and dalton with an independently redefined kilogram or redefining the mole by fixing the value of Avogadro's number, with a compatible dalton that is exact in terms of the redefined kilogram.

  20. Blunted neuronal calcium response to hypoxia in naked mole-rat hippocampus.

    PubMed

    Peterson, Bethany L; Larson, John; Buffenstein, Rochelle; Park, Thomas J; Fall, Christopher P

    2012-01-01

    Naked mole-rats are highly social and strictly subterranean rodents that live in large communal colonies in sealed and chronically oxygen-depleted burrows. Brain slices from naked mole-rats show extreme tolerance to hypoxia compared to slices from other mammals, as indicated by maintenance of synaptic transmission under more hypoxic conditions and three fold longer latency to anoxic depolarization. A key factor in determining whether or not the cellular response to hypoxia is reversible or leads to cell death may be the elevation of intracellular calcium concentration. In the present study, we used fluorescent imaging techniques to measure relative intracellular calcium changes in CA1 pyramidal cells of hippocampal slices during hypoxia. We found that calcium accumulation during hypoxia was significantly and substantially attenuated in slices from naked mole-rats compared to slices from laboratory mice. This was the case for both neonatal (postnatal day 6) and older (postnatal day 20) age groups. Furthermore, while both species demonstrated more calcium accumulation at older ages, the older naked mole-rats showed a smaller calcium accumulation response than even the younger mice. A blunted intracellular calcium response to hypoxia may contribute to the extreme hypoxia tolerance of naked mole-rat neurons. The results are discussed in terms of a general hypothesis that a very prolonged or arrested developmental process may allow adult naked mole-rat brain to retain the hypoxia tolerance normally only seen in neonatal mammals.

  1. Epidermal sensory organs of moles, shrew moles, and desmans: a study of the family talpidae with comments on the function and evolution of Eimer's organ.

    PubMed

    Catania, K C

    2000-09-01

    The epidermal sensory organs of members of the family Talpidae (moles, shrew-moles, and desmans) were investigated and compared to determine the range of sensory specializations and better understand how they evolved. Small domed mechanosensory organs called 'Eimer's organs' were present on the rhinarium of nearly all species of talpids, but not among the sister group of shrews (Soricidae) or other insectivore families. This suggests that the common ancestor to the talpids possessed Eimer's organs. Two species of moles from the driest habitats did not exhibit Eimer's organs - suggesting that their sensory organs degenerated in response to harsh, abrasive soil conditions. The semi-aquatic desmans uniquely possessed tiny sensory hairs interspersed with their Eimer's organs; these may act to sense water currents. Some species exhibited a subdivided, star-like, rhinarium - resembling an early embryonic stage of the star-nosed mole and providing clues to the evolution of the star. A single genera (Uropsilus) that branched off early in the evolution of the talpids had Eimer's organ-like structures but lacked some typical components. These findings fill a major gap in our knowledge of talpid sensory biology and suggest (1) how Eimer's organs evolved, (2) how the unusual appendages of the star-nosed mole evolved, (3) that the evolution of Eimer's organ is convergent with the mechanosensory push-rod of monotremes. The results also demonstrate the features that distinguish Eimer's organ from similar configurations of sensory receptors in other mammalian skin surfaces. Finally, a mechanism for Eimer's organ function in detecting object and prey specific surface features is proposed.

  2. In-situ Subsurface Science Addressed By The "mole" On The Beagle 2 Mars Lander

    NASA Astrophysics Data System (ADS)

    Richter, L.; Gromov, V. V.; Möhlmann, D.; Kochan, H.; Tokano, T.

    The payload of the Beagle 2 lander of ESA's Mars Express mission includes a regolith- penetrating, tethered "Mole" intended for acquisition of several subsurface soil sam- ples from depths between about 30 cm and some 1E1.5 m. These samples will then be analysed by the Gas Analysis Package instrument on the lander, primarily with re- gard to isotopic composition and to organic molecules. However, after giving a brief overview of the Mole experiment, this paper focuses on additional in-situ science con- ducted by the Beagle 2 Mole system, also referred to as the PLanetary Underground TOol (PLUTO): while it penetrates into the Martian regolith by way of soil displace- ment through the action of an internal hammering mechanism, the Mole will allow mechanical properties of the regolith to be studied as a function of depth - being a first on a Mars mission - and additionally, a temperature sensor mounted on the outside of the Mole will support investigations of soil thermophysical properties and measure- ments of the subsurface temperature profile, again as a first-time achievement. Using a Mole soil penetration theory calibrated by ground-based experiments, regolith bulk density, cohesion, and internal friction angle can be constrained as a function of depth using the Mole penetration path (and retrieval path) vs. time which is measured by a winch rotation sensor indicating the amount of tether extracted by the Mole. The obtained depth profiles of these quantities should provide insight into the depositional history and stratigraphy of the regolith at the site. Measurements of the regolith tem- perature will be conducted by the Mole both as a function of depth during soil in- trusion, and as a function of time for constant depth, as the Mole can be left in the subsurface for periods of days or weeks before it is retrieved, especially during the later part of the Beagle 2 landed mission. Subsurface temperature measurements will support calibrations of Mars regolith

  3. In-situ subsurface science addressed by the Mole on the Beagle 2 Mars lander

    NASA Astrophysics Data System (ADS)

    Richter, L.; Gromov, V.; Kochan, H.; Möhlmann, D.; Tokano, T.

    The payload of the Beagle 2 lander of ESA's Mars Express mission includes a regolithpenetrating, tethered "Mole" intended for acquisition of several subsurface soil sam ples from depths between about 30 cm and some 1E1.5 m. These samples will then be analysed by the Gas Analysis Package instrument on the lander, primarily with regard to isotopic composition and to organic molecules. However, after giving a brief overview of the Mole experiment, this paper focuses on additional in-situ science conducted by the Beagle 2 Mole system, also referred to as the PLanetary Underground TOol (PLUTO): while it penetrates into the Martian regolith by way of soil displacement through the action of an internal hammering mechanism, the Mole will allow mechanical properties of the regolith to be studied as a function of depth - being a first on a Mars mission - and additionally, a temperature sensor mounted on the outside of the Mole will support investigations of soil thermophysical properties and measurements of the subsurface temperature profile, again as a first-time achievement. Using a Mole soil penetration theory calibrated by ground-based experiments, regolith bulk density, cohesion, and internal friction angle can be constrained as a function of depth using the Mole penetration path (and retrieval path) vs. time which is measured by a winch rotation sensor indicating the amount of tether extracted by the Mole. The obtained depth profiles of these quantities should provide insight into the depositional history and stratigraphy of the regolith at the site. Measurements of the regolith temperature will be conducted by the Mole both as a function of depth during soil intrusion, and as a function of time for constant depth, as the Mole can be left in the subsurface for periods of days or weeks before it is retrieved, especially during the later part of the Beagle 2 landed mission. Subsurface temperature measurements will support calibrations of Mars regolith thermophysical

  4. Release Fraction Evaluation

    SciTech Connect

    Bamberger, Judith A.; Glissmeyer, John A.

    2004-01-01

    This document presents results of experiments conducted to measure release fractions during certain tank retrieval processes. The tests were performed in a 1/4 scale model of a waste storage tank. The retrieval processes simulated were: (1) Discharging liquid or slurry from the mouth of a vertically oriented two-in. Schedule 40 pipe. The discharging material was in free-fall from the mouth of the pipe near the top of the tank into a liquid or slurry pool at the bottom of the tank. (2) The jet from a 9/16-in.-diameter nozzle transferring liquid or slurry waste from one side of the tank to the other. The discharging liquid was aimed at the opposite side of the tank from the nozzle and either impacted the tank wall or fell into a liquid or slurry pool in the bottom of the tank. (3) A high pressure fan jet of liquid striking a steel plate or simulated waste from a stand-off distance of a few inches. For each process, a water-soluble fluorescent dye was added to the liquid fraction as a tracer. Kaolin clay was used to represent the solids. The tank was covered and there was no forced ventilation in the tank during the tests. Six air samples were collected during each test. The air samples were collected at fixed positions in the tank. The air sample filters were dried and weighed to determine the solids collection. The fluorescent dye was then leached from each filter and quantified with a fluorometer to determine the collection of liquid. Samples of the slurry and liquid simulants were also collected to determine the quantities of simulant used in each test. To calculate the release fraction, the quantity collected on each air sample was adjusted for the fraction of the tank volume sampled and divided by the quantity of material exposed in the simulation. The method was not as sensitive for the solids content as it was for the liquid content, but in those instances where a solids release fraction was determined, it was in relatively good agreement with that of the

  5. The molecular basis of defective lens development in the Iberian mole

    PubMed Central

    Carmona, F David; Jiménez, Rafael; Collinson, J Martin

    2008-01-01

    Background Fossorial mammals face natural selection pressures that differ from those acting on surface dwelling animals, and these may lead to reduced visual system development. We have studied eye development in a species of true mole, the Iberian mole Talpa occidentalis, and present the molecular basis of abnormal lens development. This is the first embryological developmental study of the eyes of any fossorial mammal at the molecular level. Results Lens fibre differentiation is not completed in the Iberian mole. Although eye development starts normally (similar to other model species), defects are seen after closure of the lens vesicle. PAX6 is not down-regulated in developing lens fibre nuclei, as it is in other species, and there is ectopic expression of FOXE3, a putative downstream effector of PAX6, in some, but not all lens fibres. FOXE3-positive lens fibres continue to proliferate within the posterior compartment of the embryonic lens, but unlike in the mouse, no proliferation was detected anywhere in the postnatal mole lens. The undifferentiated status of the anterior epithelial cells was compromised, and most of them undergo apoptosis. Furthermore, β-crystallin and PROX1 expression patterns are abnormal and our data suggest that genes encoding β-crystallins are not directly regulated by PAX6, c-MAF and PROX1 in the Iberian mole, as they are in other model vertebrates. Conclusion In other model vertebrates, genetic pathways controlling lens development robustly compartmentalise the lens into a simple, undifferentiated, proliferative anterior epithelium, and quiescent, anuclear, terminally differentiated posterior lens fibres. These pathways are not as robust in the mole, and lead to loss of the anterior epithelial phenotype and only partial differentiation of the lens fibres, which continue to express 'epithelial' genes. Paradigms of genetic regulatory networks developed in other vertebrates appear not to hold true for the Iberian mole. PMID:18939978

  6. Differences in cooperative behavior among Damaraland mole rats are consequences of an age-related polyethism

    PubMed Central

    Zöttl, Markus; Vullioud, Philippe; Mendonça, Rute; Torrents Ticó, Miquel; Gaynor, David; Mitchell, Adam; Clutton-Brock, Tim

    2016-01-01

    In many cooperative breeders, the contributions of helpers to cooperative activities change with age, resulting in age-related polyethisms. In contrast, some studies of social mole rats (including naked mole rats, Heterocephalus glaber, and Damaraland mole rats, Fukomys damarensis) suggest that individual differences in cooperative behavior are the result of divergent developmental pathways, leading to discrete and permanent functional categories of helpers that resemble the caste systems found in eusocial insects. Here we show that, in Damaraland mole rats, individual contributions to cooperative behavior increase with age and are higher in fast-growing individuals. Individual contributions to different cooperative tasks are intercorrelated and repeatability of cooperative behavior is similar to that found in other cooperatively breeding vertebrates. Our data provide no evidence that nonreproductive individuals show divergent developmental pathways or specialize in particular tasks. Instead of representing a caste system, variation in the behavior of nonreproductive individuals in Damaraland mole rats closely resembles that found in other cooperatively breeding mammals and appears to be a consequence of age-related polyethism. PMID:27588902

  7. Differences in cooperative behavior among Damaraland mole rats are consequences of an age-related polyethism.

    PubMed

    Zöttl, Markus; Vullioud, Philippe; Mendonça, Rute; Torrents Ticó, Miquel; Gaynor, David; Mitchell, Adam; Clutton-Brock, Tim

    2016-09-13

    In many cooperative breeders, the contributions of helpers to cooperative activities change with age, resulting in age-related polyethisms. In contrast, some studies of social mole rats (including naked mole rats, Heterocephalus glaber, and Damaraland mole rats, Fukomys damarensis) suggest that individual differences in cooperative behavior are the result of divergent developmental pathways, leading to discrete and permanent functional categories of helpers that resemble the caste systems found in eusocial insects. Here we show that, in Damaraland mole rats, individual contributions to cooperative behavior increase with age and are higher in fast-growing individuals. Individual contributions to different cooperative tasks are intercorrelated and repeatability of cooperative behavior is similar to that found in other cooperatively breeding vertebrates. Our data provide no evidence that nonreproductive individuals show divergent developmental pathways or specialize in particular tasks. Instead of representing a caste system, variation in the behavior of nonreproductive individuals in Damaraland mole rats closely resembles that found in other cooperatively breeding mammals and appears to be a consequence of age-related polyethism.

  8. Unraveling the message: insights into comparative genomics of the naked mole-rat.

    PubMed

    Lewis, Kaitlyn N; Soifer, Ilya; Melamud, Eugene; Roy, Margaret; McIsaac, R Scott; Hibbs, Matthew; Buffenstein, Rochelle

    2016-08-01

    Animals have evolved to survive, and even thrive, in different environments. Genetic adaptations may have indirectly created phenotypes that also resulted in a longer lifespan. One example of this phenomenon is the preternaturally long-lived naked mole-rat. This strictly subterranean rodent tolerates hypoxia, hypercapnia, and soil-based toxins. Naked mole-rats also exhibit pronounced resistance to cancer and an attenuated decline of many physiological characteristics that often decline as mammals age. Elucidating mechanisms that give rise to their unique phenotypes will lead to better understanding of subterranean ecophysiology and biology of aging. Comparative genomics could be a useful tool in this regard. Since the publication of a naked mole-rat genome assembly in 2011, analyses of genomic and transcriptomic data have enabled a clearer understanding of mole-rat evolutionary history and suggested molecular pathways (e.g., NRF2-signaling activation and DNA damage repair mechanisms) that may explain the extraordinarily longevity and unique health traits of this species. However, careful scrutiny and re-analysis suggest that some identified features result from incorrect or imprecise annotation and assembly of the naked mole-rat genome: in addition, some of these conclusions (e.g., genes involved in cancer resistance and hairlessness) are rejected when the analysis includes additional, more closely related species. We describe how the combination of better study design, improved genomic sequencing techniques, and new bioinformatic and data analytical tools will improve comparative genomics and ultimately bridge the gap between traditional model and nonmodel organisms.

  9. Naked mole rats exhibit metabolic but not ventilatory plasticity following chronic sustained hypoxia.

    PubMed

    Chung, Danielle; Dzal, Yvonne A; Seow, Allison; Milsom, William K; Pamenter, Matthew E

    2016-03-30

    Naked mole rats are among the most hypoxia-tolerant mammals identified and live in chronic hypoxia throughout their lives. The physiological mechanisms underlying this tolerance, however, are poorly understood. Most vertebrates hyperventilate in acute hypoxia and exhibit an enhanced hyperventilation following acclimatization to chronic sustained hypoxia (CSH). Conversely, naked mole rats do not hyperventilate in acute hypoxia and their response to CSH has not been examined. In this study, we explored mechanisms of plasticity in the control of the hypoxic ventilatory response (HVR) and hypoxic metabolic response (HMR) of freely behaving naked mole rats following 8-10 days of chronic sustained normoxia (CSN) or CSH. Specifically, we investigated the role of the major inhibitory neurotransmitter γ-amino butyric acid (GABA) in mediating these responses. Our study yielded three important findings. First, naked mole rats did not exhibit ventilatory plasticity following CSH, which is unique among adult animals studied to date. Second, GABA receptor (GABAR) antagonism altered breathing patterns in CSN and CSH animals and modulated the acute HVR in CSN animals. Third, naked mole rats exhibited GABAR-dependent metabolic plasticity following long-term hypoxia, such that the basal metabolic rate was approximately 25% higher in normoxic CSH animals than CSN animals, and GABAR antagonists modulated this increase.

  10. Reversed palatal perforation by upper incisors in ageing blind mole-rats (Spalax ehrenbergi)

    PubMed Central

    ZURI, I.; TERKEL, J.

    2001-01-01

    Blind mole-rats (Spalax ehrenbergi) are fossorial solitary rodents that present striking morphological, physiological and behavioural adaptations to the subterranean environment in which they live. Previous studies have shown that mole-rats are specialised in tooth-digging. The rapid eruption-rate of their incisors has evolved to compensate for their excessive wear by excavation. Males use their incisors more than females for digging and fighting, and their rate of incisor eruption is significantly more rapid than in females. Since mole-rats use their incisors for digging throughout the year, we suggest that continuous mechanical pressure on their oral tissues concentrated at the apical sites of the upper incisors leads to cell and tissue fatigue. We provide evidence for 5 stages of palatal perforation by the upper incisors at their apical sites, with maximum perforation characterising aged males. Interspecies comparisons with 7 other fossorial and semi-fossorial rodent species, and with beavers, which expose their incisors to enormous mechanical pressure, revealed that this palatal perforation is unique to the male mole-rat. We suggest that while the fast eruption rate of incisors in the mole-rat compensates for the rapid wear resulting from digging, evolutionary adaptation to continuous tooth-digging is still ongoing, since the physical pressure of digging at the apical sites of the upper incisors leads to tissue destruction, breakage of the palatal bone and possibly to death, as a result of maxillary inflammation. PMID:11760890

  11. iMole, a web based image retrieval system from biomedical literature.

    PubMed

    Giordano, Manuela; Natale, Massimo; Cornaz, Moreno; Ruffino, Andrea; Bonino, Dario; Bucci, Enrico M

    2013-07-01

    iMole is a platform that automatically extracts images and captions from biomedical literature. Images are tagged with terms contained in figure captions by means of a sophisticate text-mining tool. Moreover, iMole allows the user to upload directly their own images within the database and manually tag images by curated dictionary. Using iMole the researchers can develop a proper biomedical image database, storing the images extracted from paper of interest, image found on the web repositories, and their own experimental images. In order to show the functioning of the platform, we used iMole to build a 2DE database. Briefly, tagged 2DE gel images were collected and stored in a searchable 2DE gel database, available to users through an interactive web interface. Images were obtained by automatically parsing 16,608 proteomic publications, which yielded more than 16,500 images. The database can be further expanded by users with images of interest trough a manual uploading process. iMole is available with a preloaded set of 2DE gel data at http://imole.biodigitalvalley.com.

  12. Understanding Multiplication of Fractions.

    ERIC Educational Resources Information Center

    Sweetland, Robert D.

    1984-01-01

    Discussed the use of Cuisenaire rods in teaching the multiplication of fractions. Considers whole number times proper fraction, proper fraction multiplied by proper fraction, mixed number times proper fraction, and mixed fraction multiplied by mixed fractions. (JN)

  13. Laser-based measurements of OH in high pressure CH4/air flames

    NASA Technical Reports Server (NTRS)

    Battles, B. E.; Hanson, R. K.

    1991-01-01

    Narrow-linewidth laser absorption measurements are reported from which mole fraction and temperature of OH are determined in high-pressure (1-10 atm), lean CH4/air flames. These measurements were made in a new high pressure combustion facility which incorporates a traversable flat flame burner, providing spatially and temporally uniform combustion gases at pressures up to 10 am. A commercially avialable CW ring dye laser was used with an intracavity doubling crystal to provide near-UV single mode output at approximately 306 nm. The UV beam was rapidly scanned over 120 GHz (0.1 sec scan duration) to resolve the absorption lineshape of the A-X (0,0) R1(7)/R1(11) doublet of the OH radical. From the doublet's absorption lineshape, the temperature was determined; and from peak absorption, Beer's Law was employed to find the mole fraction of OH. These data were obtained as a function of height above the flame at various pressures.

  14. Computer Programs for Calculating the Isentropic Flow Properties for Mixtures of R-134a and Air

    NASA Technical Reports Server (NTRS)

    Kvaternik, Raymond G.

    2000-01-01

    Three computer programs for calculating the isentropic flow properties of R-134a/air mixtures which were developed in support of the heavy gas conversion of the Langley Transonic Dynamics Tunnel (TDT) from dichlorodifluoromethane (R-12) to 1,1,1,2 tetrafluoroethane (R-134a) are described. The first program calculates the Mach number and the corresponding flow properties when the total temperature, total pressure, static pressure, and mole fraction of R-134a in the mixture are given. The second program calculates tables of isentropic flow properties for a specified set of free-stream Mach numbers given the total pressure, total temperature, and mole fraction of R-134a. Real-gas effects are accounted for in these programs by treating the gases comprising the mixture as both thermally and calorically imperfect. The third program is a specialized version of the first program in which the gases are thermally perfect. It was written to provide a simpler computational alternative to the first program in those cases where real-gas effects are not important. The theory and computational procedures underlying the programs are summarized, the equations used to compute the flow quantities of interest are given, and sample calculated results that encompass the operating conditions of the TDT are shown.

  15. Fuel Cells Utilizing Oxygen From Air at Low Pressures

    NASA Technical Reports Server (NTRS)

    Cisar, Alan; Boyer, Chris; Greenwald, Charles

    2006-01-01

    A fuel cell stack has been developed to supply power for a high-altitude aircraft with a minimum of air handling. The fuel cell is capable of utilizing oxygen from ambient air at low pressure with no need for compression. For such an application, it is advantageous to take oxygen from the air (in contradistinction to carrying a supply of oxygen onboard), but it is a challenging problem to design a fuel-cell stack of reasonable weight that can generate sufficient power while operating at reduced pressures. The present fuel-cell design is a response to this challenge. The design features a novel bipolar plate structure in combination with a gas-diffusion structure based on a conductive metal core and a carbon gas-diffusion matrix. This combination makes it possible for the flow fields in the stack to have a large open fraction (ratio between open volume and total volume) to permit large volumes of air to flow through with exceptionally low backpressure. Operations at reduced pressure require a corresponding increase in the volume of air that must be handled to deliver the same number of moles of oxygen to the anodes. Moreover, the increase in the open fraction, relative to that of a comparable prior fuel-cell design, reduces the mass of the stack. The fuel cell has been demonstrated to operate at a power density as high as 105 W/cm2 at an air pressure as low as 2 psia (absolute pressure 14 kPa), which is the atmospheric pressure at an altitude of about 50,000 ft ( 15.2 km). The improvements in the design of this fuel cell could be incorporated into designs of other fuel cells to make them lighter in weight and effective at altitudes higher than those of prior designs. Potential commercial applications for these improvements include most applications now under consideration for fuel cells.

  16. Twin Pregnancy with a Complete Hydatidiform Mole and a Coexisting Live Fetus: Rare entity.

    PubMed

    Sheik, Shahila; Al-Riyami, Nihal; Mathew, Namitha R; Al-Sukaiti, Rashid; Qureshi, Asim; Mathew, Mariam

    2015-11-01

    A hydatidiform mole with a coexisting live fetus is a rare occurrence and the optimal management for this condition is not yet known. We report the case of a 32-year-old woman (gravida 3, para 2) who presented to the Sultan Qaboos University Hospital, Muscat, Oman, in March 2012 at 13 gestational weeks with abdominal pain and vaginal bleeding. An ultrasound examination revealed a hydatidiform mole pregnancy coexisting with a live fetus. After extensive counselling, the patient and her husband opted for a conservative management approach. Unfortunately, a hysterotomy had to be performed at 17 gestational weeks due to severe haemorrhage. The postoperative period was uneventful and histopathology results confirmed one complete mole with a coexisting fetus and normal placenta. The patient's serum β-human chorionic gonadotropin level remained normal for 18 months following her surgery.

  17. Infrared Signature Masking by Air Plasma Radiation

    NASA Technical Reports Server (NTRS)

    Kruger, C. H.; Laux, C. O.

    1998-01-01

    This report describes progress during the second year of our research program on Infrared Signature Masking by Air Plasmas at Stanford University. This program is intended to investigate the masking of infrared signatures by the air plasma formed behind the bow shock of high velocity missiles. Our previous annual report described spectral measurements and modeling of the radiation emitted between 3.2 and 5.5 microns by an atmospheric pressure air plasma in chemical and thermal equilibrium at a temperature of approximately 3100 K. One of our goals was to examine the spectral emission of secondary species such as water vapor or carbon dioxide. The cold air stream injected in the plasma torch contained approximately 330 parts per million Of CO2, which is the natural CO2 concentration in atmospheric air at room temperature, and a small amount of water vapor with an estimated mole fraction of 3.8 x 10(exp -4). As can be seen from Figure 1, it was found that the measured spectrum exhibited intense spectral features due to the fundamental rovibrational bands of NO at 4.9 - 5.5 microns and the V(3) band of CO2 (antisymmetric stretch) at 4.2-4.8 microns. These observations confirmed the well-known fact that infrared signatures between 4.15 - 5.5 microns can be masked by radiative emission in the interceptor's bow-shock. Figure I also suggested that the range 3.2 - 4.15 microns did not contain any significant emission features (lines or continuum) that could mask IR signatures. However, the signal-to-noise level, close to one in that range, precluded definite conclusions. Thus, in an effort to further investigate the spectral emission in the range of interest to signature masking problem, new measurements were made with a higher signal-to-noise ratio and an extended wavelength range.

  18. Moles of a Substance per Cell Is a Highly Informative Dosing Metric in Cell Culture

    PubMed Central

    Wagner, Brett A.; Buettner, Garry R.

    2015-01-01

    Background The biological consequences upon exposure of cells in culture to a dose of xenobiotic are not only dependent on biological variables, but also the physical aspects of experiments e.g. cell number and media volume. Dependence on physical aspects is often overlooked due to the unrecognized ambiguity in the dominant metric used to express exposure, i.e. initial concentration of xenobiotic delivered to the culture medium over the cells. We hypothesize that for many xenobiotics, specifying dose as moles per cell will reduce this ambiguity. Dose as moles per cell can also provide additional information not easily obtainable with traditional dosing metrics. Methods Here, 1,4-benzoquinone and oligomycin A are used as model compounds to investigate moles per cell as an informative dosing metric. Mechanistic insight into reactions with intracellular molecules, differences between sequential and bolus addition of xenobiotic and the influence of cell volume and protein content on toxicity are also investigated. Results When the dose of 1,4-benzoquinone or oligomycin A was specified as moles per cell, toxicity was independent of the physical conditions used (number of cells, volume of medium). When using moles per cell as a dose-metric, direct quantitative comparisons can be made between biochemical or biological endpoints and the dose of xenobiotic applied. For example, the toxicity of 1,4-benzoquinone correlated inversely with intracellular volume for all five cell lines exposed (C6, MDA-MB231, A549, MIA PaCa-2, and HepG2). Conclusions Moles per cell is a useful and informative dosing metric in cell culture. This dosing metric is a scalable parameter that: can reduce ambiguity between experiments having different physical conditions; provides additional mechanistic information; allows direct comparison between different cells; affords a more uniform platform for experimental design; addresses the important issue of repeatability of experimental results, and could

  19. The Naked Mole-Rat Response to Oxidative Stress: Just Deal with It

    PubMed Central

    Lewis, Kaitlyn N.; Andziak, Blazej; Yang, Ting

    2013-01-01

    Abstract Significance: The oxidative stress theory of aging has been the most widely accepted theory of aging providing insights into why we age and die for over 50 years, despite mounting evidence from a multitude of species indicating that there is no direct relationship between reactive oxygen species (ROS) and longevity. Here we explore how different species, including the longest lived rodent, the naked mole-rat, have defied the most predominant aging theory. Recent Advances: In the case of extremely long-lived naked mole-rat, levels of ROS production are found to be similar to mice, antioxidant defenses unexceptional, and even under constitutive conditions, naked mole-rats combine a pro-oxidant intracellular milieu with high, steady state levels of oxidative damage. Clearly, naked mole-rats can tolerate this level of oxidative stress and must have mechanisms in place to prevent its translation into potentially lethal diseases. Critical Issues: In addition to the naked mole-rat, other species from across the phylogenetic spectrum and even certain mouse strains do not support this theory. Moreover, overexpressing or knocking down antioxidant levels alters levels of oxidative damage and even cancer incidence, but does not modulate lifespan. Future Directions: Perhaps, it is not oxidative stress that modulates healthspan and longevity, but other cytoprotective mechanisms that allow animals to deal with high levels of oxidative damage and stress, and nevertheless live long, relatively healthy lifespans. Studying these mechanisms in uniquely long-lived species, like the naked mole-rat, may help us tease out the key contributors to aging and longevity. Antioxid. Redox Signal. 19, 1388–1399. PMID:23025341

  20. Mechanical Performance of Rat, Mouse and Mole Spring Traps, and Possible Implications for Welfare Performance

    PubMed Central

    Baker, Sandra E.; Ellwood, Stephen A.; Tagarielli, Vito L.; Macdonald, David W.

    2012-01-01

    Lethal spring traps are widely used for killing small mammals in the UK. Many require government approval, based primarily on humaneness. However, mole traps and break-back traps for rats and mice are exempt; those available vary widely in price and apparent quality. The EU is considering implementing a Trapping Directive that would alter UK legislation, and a recent report advised the EU that trapping legislation should cover all trapped species and encourage improvement of traps. Mechanical trap performance is often used as an indicator of welfare impact. We examined the mechanical evidence for scope to improve the welfare standards of rat, mouse and mole spring traps. We measured mechanical performance among a range of rat, mouse and mole traps. Impact momentum values varied 6-8 fold, and clamping force values 4-5.5 fold, among traps for killing each species. There was considerable overlap in the performance of rat and mouse traps. Trap-opening angle and spring type were related to impact momentum and clamping force in traps for both species. There was no relationship between price and mechanical performance in traps for any species, except talpa mole traps. We are unable to judge the direct welfare impact of the traps tested, but rather the potential welfare threat associated with their exemption from approval. The wide variation in mechanical performance in traps for each species, overlap in performance between rat and mouse traps and increasing availability of weaker plastic rodent traps indicate considerable scope for improving the humaneness of spring traps for rats, mice and moles. We conclude that all such traps should be subject to the UK approval process. New welfare categories might improve trap standards further. Our results could also help improve rodent trap design and assist consumers in selecting more powerful traps. Many thousands of rats, mice and moles might benefit. PMID:22768073

  1. Mystery Fractions

    ERIC Educational Resources Information Center

    Bhattacharyya, Sonalee; Namakshi, Nama; Zunker, Christina; Warshauer, Hiroko K.; Warshauer, Max

    2016-01-01

    Making math more engaging for students is a challenge that every teacher faces on a daily basis. These authors write that they are constantly searching for rich problem-solving tasks that cover the necessary content, develop critical-thinking skills, and engage student interest. The Mystery Fraction activity provided here focuses on a key number…

  2. Pitch Fractionation.

    DTIC Science & Technology

    1981-12-15

    13 3. Solvent Fractionation Experiments .................................... 15 4. Fourier Transform Infrared Spectra for A240 Petrolem Pitch AG 12...34 and Mesophase Pitch AG 164B ............................... 21 5. Fourier Transform Infrared Spectra ................................... 23 6...compared by Fourier transform infrared (FTIR) analysis using a Digilab Model FTS 14 spectrophotometer (Rockwell International, Anaheim, California

  3. Electronic properties of Si-doped Alx Ga 1 - x N with aluminum mole fractions above 80%

    NASA Astrophysics Data System (ADS)

    Mehnke, Frank; Trinh, Xuan Thang; Pingel, Harald; Wernicke, Tim; Janzén, Erik; Son, Nguyen Tien; Kneissl, Michael

    2016-10-01

    The dependence of the activation energy as well as the energetic levels of the neutral charge state and the DX center of the Si donor in Alx Ga 1 - x N:Si samples on aluminum content and SiH4/III ratio were investigated by electron paramagnetic resonance (EPR) measurements, Van-der-Pauw resistivity measurements, and Hall-effect measurements. It was found by EPR measurements that the energy distance of the neutral charge state of the Si donor from the conduction band increases with increasing aluminum content from 61 meV for x = 0.82 to 106 meV for x = 0.89. Additionally, the formation of a DX center below the neutral charge state which is deepening from 6 meV for x = 0.82 to 58 meV for x = 0.89 is observed. This results in a linearly increasing activation energy with increasing aluminum content from 67 meV for x = 0.82 to 164 meV for x = 0.89. This is consistent with the activation energies as determined by Hall-effect measurements showing a linear increase from 24 meV for x = 0.85 to 211 meV for x = 0.96, as well as the activation energies as determined by Van-der-Pauw resistivity measurements. By varying the SiH4/III ratio we observed a formation of a minimum resistivity in accordance with the room temperature charge carrier density. However, no clear dependence of the activation energy was observed. EPR measurements of samples with a high SiH4/III ratio hint to an increased incorporation probability of a deep secondary donor species which might explain the increase in resistivity.

  4. Advantages of ion-based mole fractions for describing phase equilibria in ionic liquids: application to gas solubility.

    PubMed

    Longinotti, María Paula; Alvarez, Jorge L; Japas, M Laura

    2009-03-19

    Despite the obvious ionic character of ionic liquids (ILs), previous studies of phase equilibria in these media were formulated implicitly assuming a "molecular" behavior of the ionic solvent. In this work, a more appropriate thermodynamic treatment is applied to describe the solubility of gases in ILs. According to our results, if the concentration is expressed on an ionic basis, solutions of simple gases in ILs display rather small deviations from ideal behavior in wide composition ranges, whereas deviations are larger when the solvent is considered as an anion-cation pair. The present thermodynamic formulation also accounts for the observed solid-liquid phase equilibria of molecular and IL binary mixtures.

  5. Measured phenol concentrations in air and rain water samples collected near a wood preserving facility

    SciTech Connect

    Allen, S.K.; Allen, C.W.

    1995-12-31

    Phenol concentrations were determined in air and rain water samples collected downwind from a coal tar creosote wood preserving facility in Terre Haute, IN. Coal tar creosote is known to contain a large number of constituents and is composed chiefly of polycyclic aromatic hydrocarbons (PAH), phenols, and N-, S-, and O-heterocycles. Phenol was chosen as a marker compound for coal tar creosote emissions because it is present at a large mole fraction in coal tar creosote. Phenol was determined by HPLC with UV-Visible detection. Phenol in collected rain water samples was determined directly by HPLC after acidification and filtration. Phenol concentrations in collected air samples ranged from 4.1 to 15.7 {micro}g/m3 while rain water concentrations ranged from 7.9 to 28.2 {micro}g/L. Using a value for the thermodynamic Henry`s law constant of K{sub H} = 4.5 {times} 10{sup {minus}4} L atm/mole at 20 C for phenol and measured gas-phase phenol concentrations, even higher rain water concentrations would be expected if equilibrium was established. This indicates that the amount of phenol present in the air parcels sampled exceeded the amount that could be scavenged by rain drops under the conditions prevailing at the time of sampling. The values for phenol concentrations reported here are roughly two orders of magnitude higher than results from previous studies where phenol concentrations in air and rain water samples collected in urban areas were reported. It is likely that other more toxic constituents of coal tar creosote are also present at high concentrations in air parcels that receive emissions from wood treatment facilities.

  6. Real-time analysis of δ13C- and δD-CH4 in ambient air with laser spectroscopy: Method development and intercomparison

    NASA Astrophysics Data System (ADS)

    Harris, E. J.; Eyer, S.; Mohn, J.; Röckmann, T.; Popa, E.; Lowry, D.; Nisbet, E. G.; Fisher, R. E.; Brennwald, M. S.; Fischer, H.; Emmenegger, L.; Tuzson, B.; Zellweger, C.

    2015-12-01

    Methane (CH4) is the second most important anthropogenically emitted greenhouse gas after carbon dioxide (CO2). Its mole fraction has increased from around 722 ppb in pre-industrial times to 1824 ppb in 2013 and the anthropogenic fraction is estimated to be 60 % of the total emissions. A promising approach to improve the understanding of the CH4 budget is the use of isotopologues to distinguish between various CH4 source processes. In the presented study in situ and simultaneous measurement of the three most abundant isotopologues of methane using mid-infrared laser absorption spectroscopy is demonstrated. A field-deployable, autonomous platform is realized by coupling a compact quantum cascade laser absorption spectrometer (QCLAS) to a preconcentration unit, called TRace gas EXtractor (TREX). This unit enhances CH4 mole fractions by a factor of up to 500 above ambient levels and quantitatively separates interfering trace gases such as N2O and CO2. The analytical precision of the QCLAS isotope measurement on the preconcentrated (750 ppm, parts-per-million, mmole/mole) methane is 0.1‰ and 0.5 ‰ for δ13C- and δD-CH4 at 10 min averaging time. [1] Based on replicate measurements of compressed air during a two-week intercomparison campaign, the repeatability of the TREX-QCLAS was determined to be 0.19 ‰ and 1.9 ‰ for δ13C and δD-CH4, respectively. In this intercomparison campaign the new in situ technique is compared to IRMS based on glass flask and bag sampling and real time CH4 isotope analysis by two commercially available laser spectrometers (Figure). Both laser-based analyzers were limited to methane mole fraction and δ13C-CH4 analysis, and only one of them, a cavity ring down spectrometer, was capable to deliver meaningful data for the isotopic composition. After correcting for scale offsets, the average difference between TREX-QCLAS data and bag/flask sampling-IRMS values are within the extended WMO compatibility goals of 0.2 and 5 ‰ for δ13C- and

  7. Fraction Reduction through Continued Fractions

    ERIC Educational Resources Information Center

    Carley, Holly

    2011-01-01

    This article presents a method of reducing fractions without factoring. The ideas presented may be useful as a project for motivated students in an undergraduate number theory course. The discussion is related to the Euclidean Algorithm and its variations may lead to projects or early examples involving efficiency of an algorithm.

  8. Trauma and humanitarian translation in Liberia: the tale of open mole.

    PubMed

    Abramowitz, Sharon Alane

    2010-06-01

    The focus of this paper is the intercultural process through which Open Mole and trauma-related mental illnesses are brought together in the postconflict mental health encounter. In this paper, I explore the historical dimension of this process by reviewing the history of Open Mole, and the ways in which it has been interpreted, acted on, and objectified by external observers over the last half-century. Moving into Liberia's recent war and postconflict period, I examine the process by which Open Mole is transformed from a culture-bound disorder into a local idiom of trauma, and how it has become a gateway diagnosis of PTSD-related mental illnesses, and consider how it is produced as an objectified experience of psychiatric disorder in clinical humanitarian contexts. By studying how Open Mole is transformed in the humanitarian encounter, I address the structure and teleology of the humanitarian encounter and challenge some of the foundational assumptions about cultural sensitivity and community-based mental health care in postconflict settings that are prevalent in scholarship and practice today.

  9. A new species of Gryllotalpa mole cricket (Orthoptera: Gryllotalpidae: Gryllotalpinae) from Peninsular Malaysia.

    PubMed

    Tan, Ming Kai; Kamaruddin, Khairul Nizam

    2016-01-19

    A new species of Gryllotalpa mole cricket (Orthoptera: Gryllotalpidae) is described from Bukit Larut, Perak, Peninsular Malaysia: Gryllotalpa permai sp. n. Acoustic analysis of the male calling songs were also provided for Gryllotalpa permai sp. n. and the morphologically similar Gryllotalpa fulvipes.

  10. Plasticity and constraints on social evolution in African mole-rats: ultimate and proximate factors

    PubMed Central

    Faulkes, Chris G.; Bennett, Nigel C.

    2013-01-01

    Here, we review comparative studies of African mole-rats (family Bathyergidae) to explain how constraints acting at the ultimate (environmental) and proximate (organismal) levels have led to convergent gains and losses of sociality within this extensive adaptive radiation of subterranean rodents endemic to sub-Saharan Africa. At the ultimate level, living in environments that range from mesic through to arid has led to both variation and flexibility in social organization among species, culminating in the pinnacle of social evolution in the eusocial naked and Damaraland mole-rats (Heterocephalus glaber and Fukomys damarensis). The common mole-rat (Cryptomys hottentotus) provides a model example of how plasticity in social traits exists within a single species inhabiting areas with different ecological constraint. At the proximate level, reproductive strategies and cooperative breeding may be constrained by the correlated evolution of a suite of traits including physiological suppression of reproduction, the development of physiological and morphological castes, and the mode of ovulatory control and seasonality in breeding. Furthermore, recent neurobiological advances indicate that differential patterns of neurotransmitter expression within the forebrain may underpin (and limit) either a solitary or group living/cooperative lifestyle not only in mole-rats, but also more widely among disparate mammalian taxa. PMID:23569295

  11. Effectiveness of Using Computer-Assisted Supplementary Instruction for Teaching the Mole Concept.

    ERIC Educational Resources Information Center

    Yalcinalp, Serpil; And Others

    1995-01-01

    Examines the effect of computer-assisted instruction (CAI) on students' understanding of chemical formulas and mole concept, and their attitudes toward chemistry and CAI. Reports that students who used the CAI accompanied with lectures scored significantly higher and demonstrated significant improvement in attitudes compared to the control group…

  12. The Atomic Mass Unit, the Avogadro Constant, and the Mole: A Way to Understanding

    ERIC Educational Resources Information Center

    Baranski, Andrzej

    2012-01-01

    Numerous articles have been published that address problems encountered in teaching basic concepts of chemistry such as the atomic mass unit, Avogadro's number, and the mole. The origin of these problems is found in the concept definitions. If these definitions are adjusted for teaching purposes, understanding could be improved. In the present…

  13. Family Wide Molecular Adaptations to Underground Life in African Mole-Rats Revealed by Phylogenomic Analysis.

    PubMed

    Davies, Kalina T J; Bennett, Nigel C; Tsagkogeorga, Georgia; Rossiter, Stephen J; Faulkes, Christopher G

    2015-12-01

    During their evolutionary radiation, mammals have colonized diverse habitats. Arguably the subterranean niche is the most inhospitable of these, characterized by reduced oxygen, elevated carbon dioxide, absence of light, scarcity of food, and a substrate that is energetically costly to burrow through. Of all lineages to have transitioned to a subterranean niche, African mole-rats are one of the most successful. Much of their ecological success can be attributed to a diet of plant storage organs, which has allowed them to colonize climatically varied habitats across sub-Saharan Africa, and has probably contributed to the evolution of their diverse social systems. Yet despite their many remarkable phenotypic specializations, little is known about molecular adaptations underlying these traits. To address this, we sequenced the transcriptomes of seven mole-rat taxa, including three solitary species, and combined new sequences with existing genomic data sets. Alignments of more than 13,000 protein-coding genes encompassed, for the first time, all six genera and the full spectrum of ecological and social variation in the clade. We detected positive selection within the mole-rat clade and along ancestral branches in approximately 700 genes including loci associated with tumorigenesis, aging, morphological development, and sociality. By combining these results with gene ontology annotation and protein-protein networks, we identified several clusters of functionally related genes. This family wide analysis of molecular evolution in mole-rats has identified a suite of positively selected genes, deepening our understanding of the extreme phenotypic traits exhibited by this group.

  14. The sense of touch in the star-nosed mole: from mechanoreceptors to the brain.

    PubMed

    Catania, Kenneth C

    2011-11-12

    Star-nosed moles are somatosensory specialists that explore their environment with 22 appendages that ring their nostrils. The appendages are covered with sensory domes called Eimer's organs. Each organ is associated with a Merkel cell-neurite complex, a lamellated corpuscle, and a series of 5-10 free nerve endings that form a circle of terminal swellings. Anatomy and electrophysiological recordings suggest that Eimer's organs detect small shapes and textures. There are parallels between the organization of the mole's somatosensory system and visual systems of other mammals. The centre of the star is a tactile fovea used for detailed exploration of objects and prey items. The tactile fovea is over-represented in the neocortex, and this is evident in the modular, anatomically visible representation of the star. Multiple maps of the star are visible in flattened cortical preparations processed for cytochrome oxidase or NADPH-diaphorase. Star-nosed moles are the fastest known foragers among mammals, able to identify and consume a small prey item in 120 ms. Together these behavioural and nervous system specializations have made star-nosed moles an intriguing model system for examining general and specialized aspects of mammalian touch.

  15. Reading about the Power of Music: "Mole Music" and "Children of the Stone"

    ERIC Educational Resources Information Center

    Cardany, Audrey Berger

    2016-01-01

    In this article, I review two books that address the power of music for the individual and group. Both books address the benefits of making, learning, and listening to music during times of conflict. The first brief review is David McPhail's picture book "Mole Music." The second is "Children of the Stone: The Power of Music in a…

  16. Shared ancestry between a newfound mole-borne hantavirus and hantaviruses harbored by cricetid rodents.

    PubMed

    Kang, Hae Ji; Bennett, Shannon N; Hope, Andrew G; Cook, Joseph A; Yanagihara, Richard

    2011-08-01

    Discovery of genetically distinct hantaviruses in multiple species of shrews (order Soricomorpha, family Soricidae) and moles (family Talpidae) contests the conventional view that rodents (order Rodentia, families Muridae and Cricetidae) are the principal reservoir hosts and suggests that the evolutionary history of hantaviruses is far more complex than previously hypothesized. We now report on Rockport virus (RKPV), a hantavirus identified in archival tissues of the eastern mole (Scalopus aquaticus) collected in Rockport, TX, in 1986. Pairwise comparison of the full-length S, M, and L genomic segments indicated moderately low sequence similarity between RKPV and other soricomorph-borne hantaviruses. Phylogenetic analyses, using maximum-likelihood and Bayesian methods, showed that RKPV shared a most recent common ancestor with cricetid-rodent-borne hantaviruses. Distributed widely across the eastern United States, the fossorial eastern mole is sympatric and syntopic with cricetid rodents known to harbor hantaviruses, raising the possibility of host-switching events in the distant past. Our findings warrant more-detailed investigations on the dynamics of spillover and cross-species transmission of present-day hantaviruses within communities of rodents and moles.

  17. Identifying the Critical Components for a Conceptual Understanding of the Mole in Secondary Science Classrooms

    ERIC Educational Resources Information Center

    Fang, Su-Chi; Hart, Christina; Clarke, David

    2016-01-01

    The amount of substance and its unit the mole is a basic concept in chemistry. However, previous research has shown that teaching and learning the concept are challenging tasks for both teachers and students. The purpose of this study was to pinpoint the problems which emerge in the teaching and learning process, and provide integrated suggestions…

  18. Neoteny, Prolongation of Youth: From Naked Mole Rats to "Naked Apes" (Humans).

    PubMed

    Skulachev, Vladimir P; Holtze, Susanne; Vyssokikh, Mikhail Y; Bakeeva, Lora E; Skulachev, Maxim V; Markov, Alexander V; Hildebrandt, Thomas B; Sadovnichii, Viktor A

    2017-04-01

    It has been suggested that highly social mammals, such as naked mole rats and humans, are long-lived due to neoteny (the prolongation of youth). In both species, aging cannot operate as a mechanism facilitating natural selection because the pressure of this selection is strongly reduced due to 1) a specific social structure where only the "queen" and her "husband(s)" are involved in reproduction (naked mole rats) or 2) substituting fast technological progress for slow biological evolution (humans). Lists of numerous traits of youth that do not disappear with age in naked mole rats and humans are presented and discussed. A high resistance of naked mole rats to cancer, diabetes, cardiovascular and brain diseases, and many infections explains why their mortality rate is very low and almost age-independent and why their lifespan is more than 30 years, versus 3 years in mice. In young humans, curves of mortality versus age start at extremely low values. However, in the elderly, human mortality strongly increases. High mortality rates in other primates are observed at much younger ages than in humans. The inhibition of the aging process in humans by specific drugs seems to be a promising approach to prolong our healthspan. This might be a way to retard aging, which is already partially accomplished via the natural physiological phenomenon neoteny.

  19. Somatosensory organ topography across the star of the star-nosed mole (Condylura cristata).

    PubMed

    Sawyer, Eva K; Catania, Kenneth C

    2016-04-01

    Quantifying somatosensory receptor distribution in glabrous skin is usually difficult because of the diversity of skin receptor subtypes and their location within the dermis and epidermis. However, the glabrous noses of moles are an exception. In most species of moles, the skin on the nose is covered with domed mechanosensory units known as an Eimer's organs. Eimer's organs contain a stereotyped array of different mechanosensory neurons, meaning that the distribution of mechanosensitive nerve endings can be inferred by visual inspection of the skin surface. Here we detail the distribution of Eimer's organs on the highly derived somatosensory star on the rostrum of the star-nosed mole (Condylura cristata). The star consists of 22 fleshy appendages, or rays, that are covered in Eimer's organs. We find that the density of Eimer's organs increases from proximal to distal locations along the length of the star's rays with a ratio of 1:2.3:3.1 from the surface nearest to the nostril, to the middle part of ray, to the ray tip, respectively. This ratio is comparable to the increase in receptor unit density reported for the human hand, from the palm, to the middle of the digits, to the distal fingertips. We also note that the tactile fovea of the star-nosed mole, located on the medial ventral ray, does not have increased sensory organ density, and we describe these findings in comparison with other sensory fovea.

  20. Somatosensory organ topography across the star of the star-nosed mole (Condylura cristata)

    PubMed Central

    Sawyer, Eva K.; Catania, Kenneth C.

    2015-01-01

    Quantifying somatosensory receptor distribution in glabrous skin is usually difficult due to the diversity of skin receptor subtypes and their location within the dermis and epidermis. However, the glabrous noses of moles are an exception. In most species of moles, the skin on the nose is covered with domed mechanosensory units known as an Eimer’s organs. Eimer’s organs contain a stereotyped array of different mechanosensory neurons, meaning the distribution of mechanosensitive nerve endings can be inferred by visual inspection of the skin surface. Here we detail the distribution of Eimer’s organs on the highly derived somatosensory star on the rostrum of the star-nosed mole (Condylura cristata). The star consists of 22 fleshy appendages, or rays, that are covered in Eimer’s organs. We find that the density of Eimer’s organs increases from proximal to distal along the length of the star’s rays with a ratio of 1: 2.3: 3.1 from the surface nearest to the nostril, to the middle part of ray, to the ray tip, respectively. This ratio is comparable to the increase in receptor unit density reported in the human hand, from the palm to the middle of the digits, to the distal fingertips. We also note that the tactile fovea of the star nosed mole, located on the medial ventral ray, does not have increased sensory organ density, and we describe these findings in comparison to other sensory fovea. PMID:26659700

  1. Isotope fractionation

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    A rash of new controversy has emerged around the subject of mass-independent isotope fractionation effects, particularly in the case of the oxygen isotopes. To be sure, the controversy has been around for awhile, but it has been given new impetus by the results of a recent study by Mark H. Thiemens and John E. Heidenreich III of the University of California, San Diego (Science, March 4, 1983).Gustav Arrhenius has been trying to convince the planetary science community that chemical effects in isotope fractionation processes could explain observations in meteorites that appear to be outside of the traditionally understood mass-dependent fractionations (G. Arrhenius, J . L. McCrumb, and N. F. Friedman, Astrophys. Space Sci, 65, 297, 1974). Robert Clayton had made the basic observations of oxygen in carbonaceous chondrites that the slope of the δ17 versus δ18 line was 1 instead of the slope of ½ characteristic of terrestrial rocks and lunar samples (Ann. Rev. Nucl. Part. Sci., 28, 501, 1978). The mass-independent effects were ascribed to the apparent contribution of an ancient presolar system component of O16.

  2. Aqueous solubility, Henry's law constants and air/water partition coefficients of n-octane and two halogenated octanes.

    PubMed

    Sarraute, S; Delepine, H; Costa Gomes, M F; Majer, V

    2004-12-01

    New data on the aqueous solubility of n-octane, 1-chlorooctane and 1-bromooctane are reported between 1 degree C and 45 degrees C. Henry's law constants, K(H), and air/water partition coefficients, K(AW), were calculated by associating the measured solubility values to vapor pressures taken from literature. The mole fraction aqueous solubility varies between (1.13-1.60)x10(-7) for n-octane with a minimum at approximately 23 degrees C, (3.99-5.07)x10(-7) for 1-chlorooctane increasing monotonically with temperature and (1.60-3.44)x10(-7) for 1-bromooctane with a minimum near 18 degrees C. The calculated air-water partition coefficients increase with temperature and are two orders of magnitude lower for the halogenated derivatives compared to octane. The precision of the results, taken as the average absolute deviations of the aqueous solubility, the Henry's law constants, or the air/water partition coefficients, from appropriate smoothing equations as a function of temperature is of 3% for n-octane and of 2% and 4% for 1-chlorooctane and 1-bromooctane, respectively. A new apparatus based on the dynamic saturation column method was used for the solubility measurements. Test measurements with n-octane indicated the capability of measuring solubilities between 10(-6) and 10(-10) in mole fraction, with an estimated accuracy better than +/-10%. A thorough thermodynamic analysis of converting measured data to air/water partition coefficients is presented.

  3. No evidence for mutations in NLRP7 and KHDC3L in women with androgenetic hydatidiform moles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate the mutational spectrum of NLRP7 and KHDC3L (C6orf221) in women with sporadic and recurrent androgenetic complete hydatidiform moles (AnCHM) and biparental hydatidiform moles (BiHM) to address the hypothesis that autosomal recessive mutations in these gene...

  4. The Mole Mapper Study, mobile phone skin imaging and melanoma risk data collected using ResearchKit

    PubMed Central

    Webster, Dan E.; Suver, Christine; Doerr, Megan; Mounts, Erin; Domenico, Lisa; Petrie, Tracy; Leachman, Sancy A.; Trister, Andrew D.; Bot, Brian M.

    2017-01-01

    Sensor-embedded phones are an emerging facilitator for participant-driven research studies. Skin cancer research is particularly amenable to this approach, as phone cameras enable self-examination and documentation of mole abnormalities that may signal a progression towards melanoma. Aggregation and open sharing of this participant-collected data can be foundational for research and the development of early cancer detection tools. Here we describe data from Mole Mapper, an iPhone-based observational study built using the Apple ResearchKit framework. The Mole Mapper app was designed to collect participant-provided images and measurements of moles, together with demographic and behavioral information relating to melanoma risk. The study cohort includes 2,069 participants who contributed 1,920 demographic surveys, 3,274 mole measurements, and 2,422 curated mole images. Survey data recapitulates associations between melanoma and known demographic risks, with red hair as the most significant factor in this cohort. Participant-provided mole measurements indicate an average mole size of 3.95 mm. These data have been made available to engage researchers in a collaborative, multidisciplinary effort to better understand and prevent melanoma. PMID:28195576

  5. The Mole Mapper Study, mobile phone skin imaging and melanoma risk data collected using ResearchKit.

    PubMed

    Webster, Dan E; Suver, Christine; Doerr, Megan; Mounts, Erin; Domenico, Lisa; Petrie, Tracy; Leachman, Sancy A; Trister, Andrew D; Bot, Brian M

    2017-02-14

    Sensor-embedded phones are an emerging facilitator for participant-driven research studies. Skin cancer research is particularly amenable to this approach, as phone cameras enable self-examination and documentation of mole abnormalities that may signal a progression towards melanoma. Aggregation and open sharing of this participant-collected data can be foundational for research and the development of early cancer detection tools. Here we describe data from Mole Mapper, an iPhone-based observational study built using the Apple ResearchKit framework. The Mole Mapper app was designed to collect participant-provided images and measurements of moles, together with demographic and behavioral information relating to melanoma risk. The study cohort includes 2,069 participants who contributed 1,920 demographic surveys, 3,274 mole measurements, and 2,422 curated mole images. Survey data recapitulates associations between melanoma and known demographic risks, with red hair as the most significant factor in this cohort. Participant-provided mole measurements indicate an average mole size of 3.95 mm. These data have been made available to engage researchers in a collaborative, multidisciplinary effort to better understand and prevent melanoma.

  6. Reproducible Large-Scale Neuroimaging Studies with the OpenMOLE Workflow Management System.

    PubMed

    Passerat-Palmbach, Jonathan; Reuillon, Romain; Leclaire, Mathieu; Makropoulos, Antonios; Robinson, Emma C; Parisot, Sarah; Rueckert, Daniel

    2017-01-01

    OpenMOLE is a scientific workflow engine with a strong emphasis on workload distribution. Workflows are designed using a high level Domain Specific Language (DSL) built on top of Scala. It exposes natural parallelism constructs to easily delegate the workload resulting from a workflow to a wide range of distributed computing environments. OpenMOLE hides the complexity of designing complex experiments thanks to its DSL. Users can embed their own applications and scale their pipelines from a small prototype running on their desktop computer to a large-scale study harnessing distributed computing infrastructures, simply by changing a single line in the pipeline definition. The construction of the pipeline itself is decoupled from the execution context. The high-level DSL abstracts the underlying execution environment, contrary to classic shell-script based pipelines. These two aspects allow pipelines to be shared and studies to be replicated across different computing environments. Workflows can be run as traditional batch pipelines or coupled with OpenMOLE's advanced exploration methods in order to study the behavior of an application, or perform automatic parameter tuning. In this work, we briefly present the strong assets of OpenMOLE and detail recent improvements targeting re-executability of workflows across various Linux platforms. We have tightly coupled OpenMOLE with CARE, a standalone containerization solution that allows re-executing on a Linux host any application that has been packaged on another Linux host previously. The solution is evaluated against a Python-based pipeline involving packages such as scikit-learn as well as binary dependencies. All were packaged and re-executed successfully on various HPC environments, with identical numerical results (here prediction scores) obtained on each environment. Our results show that the pair formed by OpenMOLE and CARE is a reliable solution to generate reproducible results and re-executable pipelines. A

  7. Reproducible Large-Scale Neuroimaging Studies with the OpenMOLE Workflow Management System

    PubMed Central

    Passerat-Palmbach, Jonathan; Reuillon, Romain; Leclaire, Mathieu; Makropoulos, Antonios; Robinson, Emma C.; Parisot, Sarah; Rueckert, Daniel

    2017-01-01

    OpenMOLE is a scientific workflow engine with a strong emphasis on workload distribution. Workflows are designed using a high level Domain Specific Language (DSL) built on top of Scala. It exposes natural parallelism constructs to easily delegate the workload resulting from a workflow to a wide range of distributed computing environments. OpenMOLE hides the complexity of designing complex experiments thanks to its DSL. Users can embed their own applications and scale their pipelines from a small prototype running on their desktop computer to a large-scale study harnessing distributed computing infrastructures, simply by changing a single line in the pipeline definition. The construction of the pipeline itself is decoupled from the execution context. The high-level DSL abstracts the underlying execution environment, contrary to classic shell-script based pipelines. These two aspects allow pipelines to be shared and studies to be replicated across different computing environments. Workflows can be run as traditional batch pipelines or coupled with OpenMOLE's advanced exploration methods in order to study the behavior of an application, or perform automatic parameter tuning. In this work, we briefly present the strong assets of OpenMOLE and detail recent improvements targeting re-executability of workflows across various Linux platforms. We have tightly coupled OpenMOLE with CARE, a standalone containerization solution that allows re-executing on a Linux host any application that has been packaged on another Linux host previously. The solution is evaluated against a Python-based pipeline involving packages such as scikit-learn as well as binary dependencies. All were packaged and re-executed successfully on various HPC environments, with identical numerical results (here prediction scores) obtained on each environment. Our results show that the pair formed by OpenMOLE and CARE is a reliable solution to generate reproducible results and re-executable pipelines. A

  8. Effect of feeding low-fiber fraction of air-classified sunflower (Helianthus annus L.) meal on laying hen productive performance and egg yolk cholesterol.

    PubMed

    Laudadio, V; Ceci, E; Lastella, N M B; Tufarelli, V

    2014-11-01

    The present study was designed to determine the effect on laying performance and egg quality resulting from total substitution of soybean meal (SBM) with low-fiber sunflower meal (SFM; Helianthus annus L.) meal in diet of hens. ISA Brown layers, 28 wk of age, were randomly allocated to 2 dietary treatments and fed for 10 wk. The hens were kept in a free-range environment and fed 2 wheat middling-based diets consisting of a control diet, which contained SBM (153 g/kg of diet), and a test diet containing low-fiber SFM (160 g/kg of diet) as the main protein source. Each dietary treatment was replicated 4 times. Low-fiber SFM was obtained by a combination of sieving and air classification processes. Feed consumption was recorded daily and egg production was calculated on a hen-day basis; eggs from each group were collected weekly to evaluate egg components and quality. The total substitution of SBM with low-fiber SFM had no adverse effect on growth performance of laying hens. Egg production and none of egg quality traits examined were influenced by dietary treatment, except for yolk color (P < 0.05) and percentage of large-size eggs (P < 0.05) that were improved in hens fed the low-fiber SFM diet. Including low-fiber SFM decreased serum and egg yolk total cholesterol and low-density lipoprotein cholesterol concentrations (P < 0.001), and increased high-density lipoprotein cholesterol level. Our results suggest that the replacement of conventional soybean with low-fiber sunflower meal may be a valid alternative in diets for laying hens to improve egg quality and to develop low-cholesterol eggs.

  9. Sociality and the telencephalic distribution of corticotrophin-releasing factor, urocortin 3, and binding sites for CRF type 1 and type 2 receptors: A comparative study of eusocial naked mole-rats and solitary Cape mole-rats.

    PubMed

    Coen, Clive W; Kalamatianos, Theodosis; Oosthuizen, Maria K; Poorun, Ravi; Faulkes, Christopher G; Bennett, Nigel C

    2015-11-01

    Various aspects of social behavior are influenced by the highly conserved corticotrophin-releasing factor (CRF) family of peptides and receptors in the mammalian telencephalon. This study has mapped and compared the telencephalic distribution of the CRF receptors, CRF1 and CRF2 , and two of their ligands, CRF and urocortin 3, respectively, in African mole-rat species with diametrically opposed social behavior. Naked mole-rats live in large eusocial colonies that are characterized by exceptional levels of social cohesion, tolerance, and cooperation in burrowing, foraging, defense, and alloparental care for the offspring of the single reproductive female. Cape mole-rats are solitary; they tolerate conspecifics only fleetingly during the breeding season. The telencephalic sites at which the level of CRF1 binding in naked mole-rats exceeds that in Cape mole-rats include the basolateral amygdaloid nucleus, hippocampal CA3 subfield, and dentate gyrus; in contrast, the level is greater in Cape mole-rats in the shell of the nucleus accumbens and medial habenular nucleus. For CRF2 binding, the sites with a greater level in naked mole-rats include the basolateral amygdaloid nucleus and dentate gyrus, but the septohippocampal nucleus, lateral septal nuclei, amygdalostriatal transition area, bed nucleus of the stria terminalis, and medial habenular nucleus display a greater level in Cape mole-rats. The results are discussed with reference to neuroanatomical and behavioral studies of various species, including monogamous and promiscuous voles. By analogy with findings in those species, we speculate that the abundance of CRF1 binding in the nucleus accumbens of Cape mole-rats reflects their lack of affiliative behavior.

  10. Moles (Nevi)

    MedlinePlus

    ... Us Media contacts Advertising contacts AAD logo Advertising, marketing and sponsorships Legal notice Copyright © 2017 American Academy ... prohibited without prior written permission. AAD logo Advertising, marketing and sponsorships Legal notice Copyright © 2017 American Academy ...

  11. Hydatidiform mole

    MedlinePlus

    ... egg). It results in an abnormal fetus. The placenta grows normally with little or no growth of ... types: Partial molar pregnancy. There is an abnormal placenta and some fetal development. Complete molar pregnancy. There ...

  12. Atypical Moles

    MedlinePlus

    ... Sections of the JAOCD JAOCD Archive Published Members Online Dermatology Journals Edit This Favorite Name: Category: Share: Yes ... About Tanning 4/24/2013 Sun Safety IQ Online Surveys ... Osteopathic Association. The AOCD now oversees 32 dermatology residency programs that are currently training 163 residents ...

  13. Uterine rupture in twin pregnancy with normal fetus and complete hydatidiform mole.

    PubMed

    Sánchez-Ferrer, María Luisa; Hernández-Martínez, Florentina; Machado-Linde, Francisco; Ferri, Belén; Carbonel, Pablo; Nieto-Diaz, Anibal

    2014-01-01

    We describe a rare case of complete hydatidiform mole with twin live fetus (CHMTF) confirmed by histopathology, flow cytometry and polymerase chain reaction techniques. No malformations were observed, fetal karyotype was normal and β-human chorionic gonadotropin levels were high (>100,000 IU/ml). The patient was informed of the risks and decided to continue with the pregnancy, but at week 15, she had to undergo hysterectomy due to uterine rupture. She subsequently developed persistent trophoblastic disease (PTD) with pulmonary metastases that required treatment with polychemotherapy. Patients with CHMTF should be informed of all known risks, including the considerable risk of PTD, which is similar to or, even higher than that associated with a singleton complete mole. The risk does not appear to be increased by continuing the pregnancy. Because so few series have been published, there is a lack of evidence-based clinical management guidelines. To our knowledge, this is the first report of uterine rupture in CHMTF.

  14. The effects of ultraviolet C radiation on the ultrastructure of the liver cells of mole rats.

    PubMed

    Tekın, Saban; Türker, Hüseyin; Güven, Turan; Yel, Mustafa

    2016-01-01

    The aim of this study was to elucidate the ultrastructural changes in the liver cells of mole rats (Spalax leucodon) exposed to ultraviolet radiation (UVR). Thirteen mole rats used in this study were caught from nature. They were divided into four groups. The first group was separated as a control and was not given any radiation. The rest were exposed to ultraviolet C (UVC) radiation for 7, 14, and 21 days. The electron microscopic examinations revealed that significant ultrastructural changes occurred in the liver tissue. These changes were the reduction in cytoplasmic organelles, dilatation in rough endoplasmic reticulum, impairment of nucleus membrane, and broadened and vacuolated mitochondria in the cytoplasm. Also, UVC radiation caused significant changes in liver enzymes of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and gama-glutamiltransferase values. After long-term exposure to radiation, some excessive ultrastructural changes occurred. These results indicated that longer exposure to UVR would cause more ultrastructural effects on the liver cells and liver enzymes.

  15. Androgen receptor distribution in the social decision-making network of eusocial naked mole-rats.

    PubMed

    Holmes, Melissa M; Van Mil, Spencer; Bulkowski, Camila; Goldman, Sharry L; Goldman, Bruce D; Forger, Nancy G

    2013-11-01

    Naked mole-rats are highly social rodents that live in large groups and exhibit a strict reproductive and social hierarchy. Only a few animals in each colony breed; the remainder are non-reproductive and are socially subordinate to breeders. We have examined androgen receptor immunoreactive (AR+) cells in brain regions comprising the recently described social decision-making network in subordinate and breeder naked mole-rats of both sexes. We find that subordinates have a significantly higher percentage of AR+ cells in all brain regions expressing this protein. By contrast, there were no significant effects of sex and no sex-by-status interactions on the percentage of AR+ cells. Taken together with previous findings, the present data complete a systematic assessment of the distribution of AR protein in the social decision-making network of the eusocial mammalian brain and demonstrate a significant role for social status in the regulation of this protein throughout many nodes of this network.

  16. Geographic dialects in blind mole rats: role of vocal communication in active speciation.

    PubMed Central

    Nevo, E; Heth, G; Beiles, A; Frankenberg, E

    1987-01-01

    We compared and contrasted the physical structure of male "courtship" calls of 59 subterranean mole rats belonging to the Spalax ehrenbergi superspecies in Israel, comprising 11 populations of four chromosomal species (2N = 52, 54, 58, and 60). We also conducted behavioral auditory discrimination tests of 144 females of the four species in the laboratory. The results indicate that each chromosomal species has a vocal dialect significantly different from all others, although the call of 2N = 60, the last derivative of speciation, is not yet fully differentiated. Females of 2N = 52, 54, and 58 preferred their homospecific mates' calls, whereas females of 2N = 60 did not. We conclude that call differentiation builds up gradually and provides an efficient ethological reproductive premating isolation mechanism between the emerging species in the active speciation of mole rats in Israel. PMID:3472211

  17. Seasonal changes in burrow geometry of the common mole rat (Rodentia: Bathyergidae)

    NASA Astrophysics Data System (ADS)

    Thomas, H. G.; Scantlebury, M.; Swanepoel, D.; Bateman, P. W.; Bennett, N. C.

    2013-11-01

    Sociality in mole rats has been suggested to have evolved as a response to the widely dispersed food resources and the limited burrowing opportunities that result from sporadic rainfall events. In the most arid regions, individual foraging efficiency is reduced, and energetic constraints increase. In this study, we investigate seasonal differences in burrow architecture of the social Cryptomys hottentotus hottentotus in a mesic region. We describe burrow geometry in response to seasonal weather conditions for two seasons (wet and dry). Interactions occurred between seasons and colony size for the size of the burrow systems, but not the shape of the burrow systems. The fractal dimension values of the burrow systems did not differ between seasons. Thus, the burrow complexity was dependent upon the number of mole rats present in the social group.

  18. The number of cysteine residues per mole in apolipoprotein E affects systematically synchronous neural interactions in women's healthy brains.

    PubMed

    Leuthold, Arthur C; Mahan, Margaret Y; Stanwyck, John J; Georgopoulos, Angeliki; Georgopoulos, Apostolos P

    2013-05-01

    Apolipoprotein E (apoE) is involved in lipid metabolism in the brain, but its effects on brain function are not understood. Three apoE isoforms (E4, E3, and E2) are the result of cysteine-arginine interchanges at two sites: there are zero interchanges in E4, one interchange in E3, and two interchanges in E2. The resulting six apoE genotypes (E4/4, E4/3, E4/2, E3/3, E3/2, E2/2) yield five groups with respect to the number of cysteine residues per mole (CysR/mole), as follows. ApoE4/4 has zero cysteine residues per mole (0-CysR/mole), E4/3 has one (1-CysR/mole), E4/2 and E3/3 each has two (2-CysR/mole), E3/2 has three (3-CysR/mole), and E2/2 has four (4-CysR/mole). The use of the number of CysR/mole to characterize the apoE molecule converts the categorical apoE genotype scale, consisting of 6 distinct genotypes above, to a 5-point continuous scale (0-4 CysR/mole). This allows the use of statistical analyses suitable for continuous variables (e.g. regression) to quantify the relations between various variables and apoE. Using such analyses, here, we show for the first time that apoE affects in a graded and orderly manner neural communication, as assessed by analyzing the relation between the number of CysR/mole and synchronous neural interactions (SNI) measured by magnetoencephalography (MEG) in 130 cognitively healthy women. At the one end of the CysR/mole range, the 4-CysR/mole (E2/2) SNI distribution had the highest mean, lowest variance, lowest range, and lowest coefficient of variation, whereas at the other end, 0-CysR/mole (E4/4) SNI distribution had the lowest mean, highest variance, highest range, and highest coefficient of variation. The special status of the 4-CysR/mole distribution was reinforced by the results of a hierarchical tree analysis where the 4-CysR/mole (E2/2) SNI distribution occupied a separate branch by itself and the remaining CysR/mole SNI distributions were placed at increasing distances from the 4-CysR/mole distribution, according to

  19. Digital dissection of the masticatory muscles of the naked mole-rat, Heterocephalus glaber (Mammalia, Rodentia)

    PubMed Central

    Faulkes, Chris G.

    2014-01-01

    The naked mole-rat, Heterocephalus glaber, of the family Bathyergidae is a subterranean rodent that feeds on underground roots and tubers and digs extensive tunnel systems with its incisors. It is a highly unusual mammal with regard to its social structure, longevity, pain insensitivity and cancer resistance, all of which have made it the subject of a great deal of research in recent years. Yet, much of the basic anatomy of this species remains undocumented. In this paper, we describe the morphology of the jaw-closing musculature of the naked mole-rat, as revealed by contrast-enhanced micro-computed tomography. This technique uses an iodine stain to enable the imaging of soft tissues with microCT. The iodine-enhanced scans were used to create 3D reconstructions of the naked mole-rat masticatory muscles from which muscle masses were calculated. The jaw-closing musculature of Heterocephalus glaber is relatively very large compared to other rodents and is dominated by the superficial masseter, the deep masseter and the temporalis. The temporalis in particular is large for a rodent, covering the entirety of the braincase and much of the rear part of the orbit. The morphology of the masseter complex described here differs from two other published descriptions of bathyergid masticatory muscles, but is more similar to the arrangement seen in other rodent families. The zygomaticomandibularis (ZM) muscle does not protrude through the infraorbital foramen on to the rostrum and thus the naked mole-rat should be considered protrogomorphous rather than hystricomorphous, and the morphology is consistent with secondarily lost hystricomorphy as has been previously suggested for Bathyergidae. Overall, the morphology of the masticatory musculature indicates a species with a high bite force and a wide gape–both important adaptations for a life dominated by digging with the incisors. PMID:25024917

  20. Family Wide Molecular Adaptations to Underground Life in African Mole-Rats Revealed by Phylogenomic Analysis

    PubMed Central

    Davies, Kalina T.J.; Bennett, Nigel C.; Tsagkogeorga, Georgia; Rossiter, Stephen J.; Faulkes, Christopher G.

    2015-01-01

    During their evolutionary radiation, mammals have colonized diverse habitats. Arguably the subterranean niche is the most inhospitable of these, characterized by reduced oxygen, elevated carbon dioxide, absence of light, scarcity of food, and a substrate that is energetically costly to burrow through. Of all lineages to have transitioned to a subterranean niche, African mole-rats are one of the most successful. Much of their ecological success can be attributed to a diet of plant storage organs, which has allowed them to colonize climatically varied habitats across sub-Saharan Africa, and has probably contributed to the evolution of their diverse social systems. Yet despite their many remarkable phenotypic specializations, little is known about molecular adaptations underlying these traits. To address this, we sequenced the transcriptomes of seven mole-rat taxa, including three solitary species, and combined new sequences with existing genomic data sets. Alignments of more than 13,000 protein-coding genes encompassed, for the first time, all six genera and the full spectrum of ecological and social variation in the clade. We detected positive selection within the mole-rat clade and along ancestral branches in approximately 700 genes including loci associated with tumorigenesis, aging, morphological development, and sociality. By combining these results with gene ontology annotation and protein–protein networks, we identified several clusters of functionally related genes. This family wide analysis of molecular evolution in mole-rats has identified a suite of positively selected genes, deepening our understanding of the extreme phenotypic traits exhibited by this group. PMID:26318402

  1. Compartmentation of the cerebellar cortex: adaptation to lifestyle in the star-nosed mole Condylura cristata.

    PubMed

    Marzban, Hassan; Hoy, Nathan; Buchok, Matthew; Catania, Kenneth C; Hawkes, Richard

    2015-04-01

    The adult mammalian cerebellum is histologically uniform. However, concealed beneath the simple laminar architecture, it is organized rostrocaudally and mediolaterally into complex arrays of transverse zones and parasagittal stripes that is both highly reproducible between individuals and generally conserved across mammals and birds. Beyond this conservation, the general architecture appears to be adapted to the animal's way of life. To test this hypothesis, we have examined cerebellar compartmentation in the talpid star-nosed mole Condylura cristata. The star-nosed mole leads a subterranean life. It is largely blind and instead uses an array of fleshy appendages (the "star") to navigate and locate its prey. The hypothesis suggests that cerebellar architecture would be modified to reduce regions receiving visual input and expand those that receive trigeminal afferents from the star. Zebrin II and phospholipase Cß4 (PLCß4) immunocytochemistry was used to map the zone-and-stripe architecture of the cerebellum of the adult star-nosed mole. The general zone-and-stripe architecture characteristic of all mammals is present in the star-nosed mole. In the vermis, the four typical transverse zones are present, two with alternating zebrin II/PLCß4 stripes, two wholly zebrin II+/PLCß4-. However, the central and nodular zones (prominent visual receiving areas) are proportionally reduced in size and conversely, the trigeminal-receiving areas (the posterior zone of the vermis and crus I/II of the hemispheres) are uncharacteristically large. We therefore conclude that cerebellar architecture is generally conserved across the Mammalia but adapted to the specific lifestyle of the species.

  2. Digital dissection of the masticatory muscles of the naked mole-rat, Heterocephalus glaber (Mammalia, Rodentia).

    PubMed

    Cox, Philip G; Faulkes, Chris G

    2014-01-01

    The naked mole-rat, Heterocephalus glaber, of the family Bathyergidae is a subterranean rodent that feeds on underground roots and tubers and digs extensive tunnel systems with its incisors. It is a highly unusual mammal with regard to its social structure, longevity, pain insensitivity and cancer resistance, all of which have made it the subject of a great deal of research in recent years. Yet, much of the basic anatomy of this species remains undocumented. In this paper, we describe the morphology of the jaw-closing musculature of the naked mole-rat, as revealed by contrast-enhanced micro-computed tomography. This technique uses an iodine stain to enable the imaging of soft tissues with microCT. The iodine-enhanced scans were used to create 3D reconstructions of the naked mole-rat masticatory muscles from which muscle masses were calculated. The jaw-closing musculature of Heterocephalus glaber is relatively very large compared to other rodents and is dominated by the superficial masseter, the deep masseter and the temporalis. The temporalis in particular is large for a rodent, covering the entirety of the braincase and much of the rear part of the orbit. The morphology of the masseter complex described here differs from two other published descriptions of bathyergid masticatory muscles, but is more similar to the arrangement seen in other rodent families. The zygomaticomandibularis (ZM) muscle does not protrude through the infraorbital foramen on to the rostrum and thus the naked mole-rat should be considered protrogomorphous rather than hystricomorphous, and the morphology is consistent with secondarily lost hystricomorphy as has been previously suggested for Bathyergidae. Overall, the morphology of the masticatory musculature indicates a species with a high bite force and a wide gape-both important adaptations for a life dominated by digging with the incisors.

  3. [From human andro- and parthenogenesis (hydatidiform moles and benign ovarian teratomas) to cancer].

    PubMed

    Coullin, P

    2005-01-01

    Genomic imprinting is a process that appeared in mammals. This phenomenon blocks the normal development of parthenogenic and androgenic conceptuses, that is to say benign ovarian teratomas and hydatidiform moles respectively. Pathological modifications of these conceptuses depend on whether the chromosomes come from the mother or father. These pathologies are associated with an accidental anomaly during gametogenesis and/or fertilizing. These reproductive anomalies are sporadic and some familial cases may exist suggesting a genetic control of such diseases. The human andro- and parthenogenetic conceptuses, but more frequently the moles, may be invasive (choriocarcinoma). An imbalance of the imprinting genes may initiate the deregulation of other genes, including oncogenes and anti-oncogenes, which can explain the cancerous modification. Immunological and environmental factors must be also considered (presence of the only paternal chromosomes in the choriocarcinoma). Numerous works on this subject are published and some recent important discoveries underline the roles of genes HOX, Tim P3, E-cad and p-16, and the recurrent chromosome anomalies 7q21+and 8p21- in the mole to choriocarcinoma processing. Although these phenomena are complex and heterogeneous, the andro- and parthenogenote conceptuses are particularly interesting models with which to understand developmental disorders and cancerous progression.

  4. Considerations on future redefinitions of the kilogram, the mole and of other units

    NASA Astrophysics Data System (ADS)

    Becker, P.; DeBièvre, P.; Fujii, K.; Glaeser, M.; Inglis, B.; Luebbig, H.; Mana, G.

    2007-02-01

    The definitions of some units of the Système International are likely to be revised as early as 2011 by basing them on fixed values of fundamental constants of nature, provided experimental realizations are demonstrated with sufficiently small uncertainties. As regards the kilogram, experiments aiming at linking it to the Planck constant and the atomic mass constant are under way in several laboratories. The other units likely to be redefined are the ampere, the kelvin and the mole. We discuss the advantages and disadvantages of different alternatives for revised definitions of the kilogram and the mole. From physical considerations, metrological consequences and ease of understanding, a definition of the kilogram based on the mass of a particle, such as an atom or the electron, is favoured. One of the proposed definitions fixes the value of the Planck constant through the Compton frequency of a material, though unphysical, particle. Finally, a redefinition of the mole, the counting unit of the amount-of-substance, is proposed which fixes the Avogadro constant as a dimensionless number.

  5. Cutaneous and periodontal inputs to the cerebellum of the naked mole-rat (Heterocephalus glaber).

    PubMed

    Sarko, Diana K; Leitch, Duncan B; Catania, Kenneth C

    2013-01-01

    The naked mole-rat (Heterocephalus glaber) is a small fossorial rodent with specialized dentition that is reflected by the large cortical area dedicated to representation of the prominent incisors. Due to naked mole-rats' behavioral reliance on the incisors for digging and for manipulating objects, as well as their ability to move the lower incisors independently, we hypothesized that expanded somatosensory representations of the incisors would be present within the cerebellum in order to accommodate a greater degree of proprioceptive, cutaneous, and periodontal input. Multiunit electrophysiological recordings targeting the ansiform lobule were used to investigate tactile inputs from receptive fields on the entire body with a focus on the incisors. Similar to other rodents, a fractured somatotopy appeared to be present with discrete representations of the same receptive fields repeated within each folium of the cerebellum. These findings confirm the presence of somatosensory inputs to a large area of the naked mole-rat cerebellum with particularly extensive representations of the lower incisors and mystacial vibrissae. We speculate that these extensive inputs facilitate processing of tactile cues as part of a sensorimotor integration network that optimizes how sensory stimuli are acquired through active exploration and in turn adjusts motor outputs (such as independent movement of the lower incisors). These results highlight the diverse sensory specializations and corresponding brain organizational schemes that have evolved in different mammals to facilitate exploration of and interaction with their environment.

  6. Sex, social status, and CRF receptor densities in naked mole-rats.

    PubMed

    Beery, Annaliese K; Bicks, Lucy; Mooney, Skyler J; Goodwin, Nastacia L; Holmes, Melissa M

    2016-02-01

    Naked mole-rats (Heterocephalus glaber) live in groups that are notable for their large size and caste structure, with breeding monopolized by a single female and a small number of males. Recent studies have demonstrated substantial differences between the brains of breeders and subordinates induced by changes in social standing. Corticotropin-releasing factor (CRF) receptors-which bind the hormone CRF as well as related peptides-are important regulators of stress and anxiety, and are emerging as factors affecting social behavior. We conducted autoradiographic analyses of CRF1 and CRF2 receptor binding densities in female and male naked mole-rats varying in breeding status. Both globally and in specific brain regions, CRF1 receptor densities varied with breeding status. CRF1 receptor densities were higher in subordinates across brain regions, and particularly in the piriform cortex and cortical amygdala. Sex differences were present in CRF2 receptor binding densities, as is the case in multiple vole species. CRF2 receptor densities were higher in females, both globally and in the cortical amygdala and lateral amygdalar nucleus. These results provide novel insights into the neurobiology of social hierarchy in naked mole-rats, and add to a growing body of work that links changes in the CRF system with social behavior.

  7. Locomotor Activity and Body Temperature Patterns over a Temperature Gradient in the Highveld Mole-Rat (Cryptomys hottentotus pretoriae).

    PubMed

    Haupt, Meghan; Bennett, Nigel C; Oosthuizen, Maria K

    2017-01-01

    African mole-rats are strictly subterranean mammals that live in extensive burrow systems. High humidity levels in the burrows prevent mole-rats from thermoregulating using evaporative cooling. However, the relatively stable environment of the burrows promotes moderate temperatures and small daily temperature fluctuations. Mole-rats therefore display a relatively wide range of thermoregulation abilities. Some species cannot maintain their body temperatures at a constant level, whereas others employ behavioural thermoregulation. Here we test the effect of ambient temperature on locomotor activity and body temperature, and the relationship between the two parameters, in the highveld mole-rat. We exposed mole-rats to a 12L:12D and a DD light cycle at ambient temperatures of 30°C, 25°C and 20°C while locomotor activity and body temperature were measured simultaneously. In addition, we investigated the endogenous rhythms of locomotor activity and body temperature at different ambient temperatures. Mole-rats displayed nocturnal activity at all three ambient temperatures and were most active at 20°C, but least active at 30°C. Body temperature was highest at 30°C and lowest at 20°C, and the daily cycle was highly correlated with locomotor activity. We show that the mole-rats have endogenous rhythms for both locomotor activity and body temperature. However, the endogenous body temperature rhythm appears to be less robust compared to the locomotor activity rhythm. Female mole-rats appear to be more sensitive to temperature changes than males, increased heterothermy is evident at lower ambient temperatures, whilst males show smaller variation in their body temperatures with changing ambient temperatures. Mole-rats may rely more heavily on behavioural thermoregulation as it is more energy efficient in an already challenging environment.

  8. Locomotor Activity and Body Temperature Patterns over a Temperature Gradient in the Highveld Mole-Rat (Cryptomys hottentotus pretoriae)

    PubMed Central

    Haupt, Meghan; Bennett, Nigel C.

    2017-01-01

    African mole-rats are strictly subterranean mammals that live in extensive burrow systems. High humidity levels in the burrows prevent mole-rats from thermoregulating using evaporative cooling. However, the relatively stable environment of the burrows promotes moderate temperatures and small daily temperature fluctuations. Mole-rats therefore display a relatively wide range of thermoregulation abilities. Some species cannot maintain their body temperatures at a constant level, whereas others employ behavioural thermoregulation. Here we test the effect of ambient temperature on locomotor activity and body temperature, and the relationship between the two parameters, in the highveld mole-rat. We exposed mole-rats to a 12L:12D and a DD light cycle at ambient temperatures of 30°C, 25°C and 20°C while locomotor activity and body temperature were measured simultaneously. In addition, we investigated the endogenous rhythms of locomotor activity and body temperature at different ambient temperatures. Mole-rats displayed nocturnal activity at all three ambient temperatures and were most active at 20°C, but least active at 30°C. Body temperature was highest at 30°C and lowest at 20°C, and the daily cycle was highly correlated with locomotor activity. We show that the mole-rats have endogenous rhythms for both locomotor activity and body temperature. However, the endogenous body temperature rhythm appears to be less robust compared to the locomotor activity rhythm. Female mole-rats appear to be more sensitive to temperature changes than males, increased heterothermy is evident at lower ambient temperatures, whilst males show smaller variation in their body temperatures with changing ambient temperatures. Mole-rats may rely more heavily on behavioural thermoregulation as it is more energy efficient in an already challenging environment. PMID:28072840

  9. Global and regional emissions estimates of 1,1-difluoroethane (HFC-152a, CH3CHF2) from in situ and air archive observations

    NASA Astrophysics Data System (ADS)

    Simmonds, P. G.; Rigby, M.; Manning, A. J.; Lunt, M. F.; O'Doherty, S.; McCulloch, A.; Fraser, P. J.; Henne, S.; Vollmer, M. K.; Mühle, J.; Weiss, R. F.; Salameh, P. K.; Young, D.; Reimann, S.; Wenger, A.; Arnold, T.; Harth, C. M.; Krummel, P. B.; Steele, L. P.; Dunse, B. L.; Miller, B. R.; Lunder, C. R.; Hermansen, O.; Schmidbauer, N.; Saito, T.; Yokouchi, Y.; Park, S.; Li, S.; Yao, B.; Zhou, L. X.; Arduini, J.; Maione, M.; Wang, R. H. J.; Ivy, D.; Prinn, R. G.

    2016-01-01

    High frequency, in situ observations from 11 globally distributed sites for the period 1994-2014 and archived air measurements dating from 1978 onward have been used to determine the global growth rate of 1,1-difluoroethane (HFC-152a, CH3CHF2). These observations have been combined with a range of atmospheric transport models to derive global emission estimates in a top-down approach. HFC-152a is a greenhouse gas with a short atmospheric lifetime of about 1.5 years. Since it does not contain chlorine or bromine, HFC-152a makes no direct contribution to the destruction of stratospheric ozone and is therefore used as a substitute for the ozone depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). The concentration of HFC-152a has grown substantially since the first direct measurements in 1994, reaching a maximum annual global growth rate of 0.84 ± 0.05 ppt yr-1 in 2006, implying a substantial increase in emissions up to 2006. However, since 2007, the annual rate of growth has slowed to 0.38 ± 0.04 ppt yr-1 in 2010 with a further decline to an annual average rate of growth in 2013-2014 of -0.06 ± 0.05 ppt yr-1. The annual average Northern Hemisphere (NH) mole fraction in 1994 was 1.2 ppt rising to an annual average mole fraction of 10.1 ppt in 2014. Average annual mole fractions in the Southern Hemisphere (SH) in 1998 and 2014 were 0.84 and 4.5 ppt, respectively. We estimate global emissions of HFC-152a have risen from 7.3 ± 5.6 Gg yr-1 in 1994 to a maximum of 54.4 ± 17.1 Gg yr-1 in 2011, declining to 52.5 ± 20.1 Gg yr-1 in 2014 or 7.2 ± 2.8 Tg-CO2 eq yr-1. Analysis of mole fraction enhancements above regional background atmospheric levels suggests substantial emissions from North America, Asia, and Europe. Global HFC emissions (so called "bottom up" emissions) reported by the United Nations Framework Convention on Climate Change (UNFCCC) are based on cumulative national emission data reported to the UNFCCC, which in turn are based on

  10. Four Cases of Spontaneous Neoplasia in the Naked Mole-Rat (Heterocephalus glaber), A Putative Cancer-Resistant Species.

    PubMed

    Taylor, Kyle R; Milone, Nicholas A; Rodriguez, Carlos E

    2017-01-01

    The naked mole-rat (Heterocephalus glaber) is widely acclaimed to be cancer-resistant and of considerable research interest based on a paucity of reports of neoplasia in this species. We have, however, encountered four spontaneous cases of neoplasia and one presumptive case of neoplasia through routine necropsy and biopsy of individuals in a zoo collection of nonhybrid naked mole-rats bred from a single pair. One case each of metastasizing hepatocellular carcinoma, nephroblastoma (Wilms' tumor), and multicentric lymphosarcoma, as well as presumptive esophageal adenocarcinoma (Barrett's esophagus-like) was identified postmortem among 37 nonautolyzed necropsy submissions of naked mole-rats over 1-year-old that were submitted for necropsy between 1998 and August 2015. One incidental case of cutaneous hemangioma was also identified antemortem by skin biopsy from one naked mole-rat examined for trauma.

  11. Nitric oxide density measurements in air and air/fuel nanosecond pulse discharges by laser induced fluorescence

    NASA Astrophysics Data System (ADS)

    Uddi, M.; Jiang, N.; Adamovich, I. V.; Lempert, W. R.

    2009-04-01

    Laser induced fluorescence is used to measure absolute nitric oxide concentrations in air, methane-air and ethylene-air non-equilibrium plasmas, as a function of time after initiation of a single pulse, 20 kV peak voltage, 25 ns pulse duration discharge. A mixture of NO and nitrogen with known composition (4.18 ppm NO) is used for calibration. Peak NO density in air at 60 Torr, after a single pulse, is ~8 × 1012 cm-3 (~4.14 ppm) occurring at ~250 µs after the pulse, with decay time of ~16.5 ms. Peak NO atom mole fraction in a methane-air mixture with equivalence ratio of phiv = 0.5 is found to be approximately equal to that in air, with approximately the same rise and decay rate. In an ethylene-air mixture (also with equivalence ratio of phiv = 0.5), the rise and decay times are comparable to air and methane-air, but the peak NO concentration is reduced by a factor of approximately 2.5. Spontaneous emission measurements show that excited electronic states N2(C 3Π) and NO(A 2Σ) in air at P = 60 Torr decay within ~20 ns and ~1 µs, respectively. Kinetic modelling calculations incorporating air plasma kinetics complemented with the GRI Mech 3.0 hydrocarbon oxidation mechanism are compared with the experimental data using three different NO production mechanisms. It is found that NO concentration rise after the discharge pulse is much faster than predicted by Zel'dovich mechanism reactions, by two orders of magnitude, but much slower compared with reactions of electronically excited nitrogen atoms and molecules, also by two orders of magnitude. It is concluded that processes involving long lifetime (~100 µs) metastable states, such as N2(X 1Σ,v) and O2(b 1Σ), formed by quenching of the metastable N2(A 3Σ) state by ground electronic state O2, may play a dominant role in NO formation. NO decay, in all cases, is found to be dominated by the reverse Zel'dovich reaction, NO + O → N + O2, as well as by conversion into NO2 in a reaction of NO with ozone.

  12. Clinical Usefulness of Immunohistochemical Staining of p57kip2 for the Differential Diagnosis of Complete Mole

    PubMed Central

    Sasaki, Shigeru; Sasaki, Yasushi; Kunimura, Toshiaki; Sekizawa, Akihiko; Kojima, Yoshihiro; Iino, Koichi

    2015-01-01

    Objective. Can polymer-based immunohistochemical staining of p57kip2 replace DNA analysis as an inexpensive means of differentiating complete mole from partial mole or hydropic abortion? Methods and Materials. Original paraffin-embedded tissue blocks from 14 equivocal cases were turned over to our laboratory and examined by immunohistochemical staining of p57kip2. Results. Four of the 14 cases showed clearly negative nuclear staining in cytotrophoblasts and villous stromal cells: these results were fully concordant with the control staining. The remaining 10 cases showed apparently positive staining in cytotrophoblasts and villous stromal cells. Without DNA analysis we are able to clearly differentiate the 4 cases of complete mole among the 14 equivocal cases. During follow-up, secondary low-risk gestational trophoblastic neoplasia (GTN) developed in 1 of the 4 cases of complete mole: the GTN was treated by single-agent chemotherapy. No subsequent changes were observed during follow-up in the other cases. Conclusion. Polymer-based immunohistochemical staining of p57kip2 (paternally imprinted gene, expressed from maternal allele) is a very effective method that can be used to differentiate androgenetic complete mole from partial mole and hydropic abortion. We might be able to avoid the cost of DNA analysis. PMID:26161420

  13. Hypofunctional TrkA Accounts for the Absence of Pain Sensitization in the African Naked Mole-Rat.

    PubMed

    Omerbašić, Damir; Smith, Ewan St J; Moroni, Mirko; Homfeld, Johanna; Eigenbrod, Ole; Bennett, Nigel C; Reznick, Jane; Faulkes, Chris G; Selbach, Matthias; Lewin, Gary R

    2016-10-11

    The naked mole-rat is a subterranean rodent lacking several pain behaviors found in humans, rats, and mice. For example, nerve growth factor (NGF), an important mediator of pain sensitization, fails to produce thermal hyperalgesia in naked mole-rats. The sensitization of capsaicin-sensitive TRPV1 ion channels is necessary for NGF-induced hyperalgesia, but naked mole-rats have fully functional TRPV1 channels. We show that exposing isolated naked mole-rat nociceptors to NGF does not sensitize TRPV1. However, the naked mole-rat NGF receptor TrkA displays a reduced ability to engage signal transduction pathways that sensitize TRPV1. Between one- and three-amino-acid substitutions in the kinase domain of the naked mole-rat TrkA are sufficient to render the receptor hypofunctional, and this is associated with the absence of heat hyperalgesia. Our data suggest that evolution has selected for a TrkA variant that abolishes a robust nociceptive behavior in this species but is still compatible with species fitness.

  14. Investigation of the presence and antinociceptive function of muscarinic acetylcholine receptors in the African naked mole-rat (Heterocephalus glaber).

    PubMed

    Jørgensen, Kristine B; Krogh-Jensen, Karen; Pickering, Darryl S; Kanui, Titus I; Abelson, Klas S P

    2016-01-01

    The present study investigated the cholinergic system in the African naked mole-rat (Heterocephalus glaber) with focus on the muscarinic acetylcholine receptor subtypes M1 and M4. The protein sequences for the subtypes m 1-5 of the naked mole-rat were compared to that of the house mouse (Mus musculus) using basic local alignment search tool (BLAST). The presence and function of M1 and M4 was investigated in vivo, using the formalin test with the muscarinic receptor agonists xanomeline and VU0152100. Spinal cord tissue from the naked mole-rat was used for receptor saturation binding studies with [(3)H]-N-methylscopolamine. The BLAST test revealed 95 % protein sequence homology showing the naked mole-rat to have the genetic potential to express all five muscarinic acetylcholine receptor subtypes. A significant reduction in pain behavior was demonstrated after administration of 8.4 mg/kg in the formalin test. Administration of 50 mg/kg VU0152100 resulted in a non-significant tendency towards antinociception. The antinociceptive effects were reversed by the muscarinic acetylcholine receptor antagonist atropine. Binding studies indicated presence of muscarinic acetylcholine receptors with a radioligand affinity comparable to that reported in mice. In conclusion, muscarinic acetylcholine receptor subtypes are present in the naked mole-rat and contribute to antinociception in the naked mole-rat.

  15. Management of pest mole crickets in Florida and Puerto Rico with a nematode and parasitic wasp

    SciTech Connect

    Leppla, N.C.; Frank, J.H.; Adjei, M.B.; Vicente, N.E.

    2007-03-15

    Non-indigenous invasive mole crickets, Scapteriscus vicinus Scudder (Orthoptera: Gryllotalpidae) in Florida and S. didactylus (Latreille) (the 'changa') in Puerto Rico, are being managed with an entomopathogenic nematode, Steinernema scapterisci (Nguyen and Smart) (Rhabditida: Steinernematidae), and a parasitic wasp, Larra bicolor L. (Hymenoptera: Sphecidae). Pest mole cricket populations have declined by 95% in north central Florida since these specialist natural enemies were released and established in the 1980s. Commercial production of the nematode was initiated, nearly 70 billion were applied in 34 Florida counties, and their establishment, spread, and impact on mole crickets were monitored. The infected mole crickets dispersed the nematode rapidly, so that within 6 months these parasites were present in most of the insects trapped in experimental pastures. Three years later, mole cricket populations were reduced to acceptable levels and the bahiagrass had recovered. The nematode was released for the first time in Puerto Rico during 2001 and has persisted; the wasp was introduced in the late 1930s. The geographical distribution of the wasp is being expanded in Florida and Puerto Rico by planting plots of Spermacoce verticillata (L.), a wildflower indigenous to Puerto Rico and widely distributed in southern Florida. Pastures, sod farms, golf courses, landscapes, and vegetable farms in Florida and Puerto Rico are benefiting from biological control of invasive mole crickets. (author) [Spanish] Los grillotopos invasores no indigenas, Scapteriscus vicinus (Orthoptera: Gryllotalpidae) en el estado de Florida y S. didactylus ('changa') en Puerto Rico, estan siendo manejados por el nematodo entomopathogeno, Steinernema scapterisci (Rhabditida: Steinernematidae) y la avispa parasitica, Larra bicolor (Hymenoptera: Sphecidae). Las poblaciones de los grillotopo plagas han declinado un 95% en el norte central de la Florida desde que estos enemigos naturales especialistas

  16. Computational Fluid Dynamics Analyses on Very High Temperature Reactor Air Ingress

    SciTech Connect

    Chang H Oh; Eung S. Kim; Richard Schultz; David Petti; Hyung S. Kang

    2009-07-01

    A preliminary computational fluid dynamics (CFD) analysis was performed to understand density-gradient-induced stratified flow in a Very High Temperature Reactor (VHTR) air-ingress accident. Various parameters were taken into consideration, including turbulence model, core temperature, initial air mole-fraction, and flow resistance in the core. The gas turbine modular helium reactor (GT-MHR) 600 MWt was selected as the reference reactor and it was simplified to be 2-D geometry in modeling. The core and the lower plenum were assumed to be porous bodies. Following the preliminary CFD results, the analysis of the air-ingress accident has been performed by two different codes: GAMMA code (system analysis code, Oh et al. 2006) and FLUENT CFD code (Fluent 2007). Eventually, the analysis results showed that the actual onset time of natural convection (~160 sec) would be significantly earlier than the previous predictions (~150 hours) calculated based on the molecular diffusion air-ingress mechanism. This leads to the conclusion that the consequences of this accident will be much more serious than previously expected.

  17. Computing Isentropic Flow Properties of Air/R-134a Mixtures

    NASA Technical Reports Server (NTRS)

    Kvaternik, Ray

    2006-01-01

    MACHRK is a computer program that calculates isentropic flow properties of mixtures of air and refrigerant R-134a (tetrafluoroethane), which are used in transonic aerodynamic testing in a wind tunnel at Langley Research Center. Given the total temperature, total pressure, static pressure, and mole fraction of R-134a in a mixture, MACHRK calculates the Mach number and the following associated flow properties: dynamic pressure, velocity, density, static temperature, speed of sound, viscosity, ratio of specific heats, Reynolds number, and Prandtl number. Real-gas effects are taken into account by treating the gases comprising the mixture as both thermally and calorically imperfect. The Redlich-Kwong equation of state for mixtures and the constant-pressure ideal heat-capacity equation for the mixture are used in combination with the departure- function approach of thermodynamics to obtain the equations for computing the flow properties. In addition to the aforementioned calculations for air/R-134a mixtures, a research version of MACHRK can perform the corresponding calculations for mixtures of air and R-12 (dichlorodifluoromethane) and for air/SF6 mixtures. [R-12 was replaced by R-134a because of environmental concerns. SF6 has been considered for use in increasing the Reynolds-number range.

  18. Social cues elicit sexual behavior in subordinate Damaraland mole-rats independent of gonadal status.

    PubMed

    Carter, Sara N; Goldman, Bruce D; Goldman, Sharry L; Freeman, David A

    2014-01-01

    Damaraland mole-rats (Fukomys damarensis) are among a small number of eusocial mammals. Eusociality is a social system where only a few individuals within a colony engage in direct reproduction, while remaining subordinate members are non-breeders and support reproductive efforts of breeding individuals. Inbreeding avoidance precludes mating between subordinate siblings and between offspring and parents. Interestingly, non-breeders readily attempt to mate with unrelated opposite-sex individuals. This is unusual since the non-breeding females do not attain puberty while in their natal colony. Based on this finding, the present study investigated the role of the gonads in the regulation of mating behaviors in this species and identified the mechanism of inbreeding avoidance. Gonadal-intact and gonadectomized non-breeders from different colonies were removed from their colonies and tested for the expression of sexual behavior. Results indicated that gonadal status had only minor effects on the expression of sexual behavior in either males or females. In a second experiment, sexual behaviors were absent between opposite-sex siblings so long as they had frequent contact with each other; however, following 5 weeks of separation, sexual behavior between these siblings was robustly expressed. Thus, Damaraland mole-rats avoid establishing mating relationships with familiar individuals but will readily mate with unfamiliar individuals of the opposite sex, with genetic relatedness apparently playing little role. The initiation of sexual behavior in Damaraland mole-rats does not require the presence of the gonads, but does require that the members of the pair have not been in contact with one another for at least several weeks.

  19. Genetic Signatures for Enhanced Olfaction in the African Mole-Rats

    PubMed Central

    Stathopoulos, Sofia; Bishop, Jacqueline M.; O’Ryan, Colleen

    2014-01-01

    The Olfactory Receptor (OR) superfamily, the largest in the vertebrate genome, is responsible for vertebrate olfaction and is traditionally subdivided into 17 OR families. Recent studies characterising whole-OR subgenomes revealed a ‘birth and death’ model of evolution for a range of species, however little is known about fine-scale evolutionary dynamics within single-OR families. This study reports the first assessment of fine-scale OR evolution and variation in African mole-rats (Bathyergidae), a family of subterranean rodents endemic to sub-Saharan Africa. Because of the selective pressures of life underground, enhanced olfaction is proposed to be fundamental to the evolutionary success of the Bathyergidae, resulting in a highly diversified OR gene-repertoire. Using a PCR-sequencing approach, we analysed variation in the OR7 family across 14 extant bathyergid species, which revealed enhanced levels of functional polymorphisms concentrated across the receptors’ ligand-binding region. We propose that mole-rats are able to recognise a broad range of odorants and that this diversity is reflected throughout their OR7 gene repertoire. Using both classic tests and tree-based methods to test for signals of selection, we investigate evolutionary forces across the mole-rat OR7 gene tree. Four well-supported clades emerged in the OR phylogeny, with varying signals of selection; from neutrality to positive and purifying selection. Bathyergid life-history traits and environmental niche-specialisation are explored as possible drivers of adaptive OR evolution, emerging as non-exclusive contributors to the positive selection observed at OR7 genes. Our results reveal unexpected complexity of evolutionary mechanisms acting within a single OR family, providing insightful perspectives into OR evolutionary dynamics. PMID:24699281

  20. Investigating the major carbon input to cave-air CO2 and speleothem calcite by using the respiratory quotient

    NASA Astrophysics Data System (ADS)

    Bergel, S.; Breecker, D.; Carlson, P.; Larson, T.; Banner, J. L.

    2014-12-01

    Speleothems (cave mineral deposits) are used to reconstruct changes in rainfall, moisture sources, atmospheric temperatures, and vegetation. Soil respiration is generally considered to be one of the major sources of cave-air CO2, and by extension a major source of carbon in speleothem calcite. However, the δ13C values from speleothem calcite are difficult to interpret. The purpose of this study is to investigate the major source of carbon in cave-air CO2 using a novel tracer, and thereby increase the accuracy of δ13C from speleothem calcite as a paleoenvironmental proxy. Potential sources of CO2 in cave-air include (1) soil respiration (primarily from roots and microbes), (2) animal respiration, (3) in-cave decomposition of organic matter, (4) deep magmatic or metamorphic sources, and (5) atmospheric air. Of these potential sources, soil respiration and atmospheric air are currently considered to be most significant in most caves. We use the respiratory quotient (RQ, which is the number of moles of CO2 produced per mole of O2 consumed, defined here in relation to atmospheric air) to compare cave air and overlying soil gas at two localities in central Texas: Natural Bridge Caverns and Inner Space Cavern. Soil gas samples (RQ = 1.32) follow a trend expected for respiration followed by diffusion whereas cave air samples (RQ = 0.97) follow a trend expected for respiration without subsequent diffusion. We suggest that root and rhizomicrobial respiration below the soil in the epikarst fracture network, where gas transport is dominated by advection rather than diffusion, contributes significantly to cave-air CO2. This is important because 12CO2 preferentially diffuses out of soils, elevating the d13C values of residual soil CO2, whereas no carbon isotope fractionation occurs during advection. Our interpretation of RQ values suggests that the d13C value of cave-air CO2 is not influenced by diffusive loss of CO2. In order to further investigate soil and cave carbon

  1. [Twin pregnancy with complete mole and coexisting fetus: Reach fetal viability is possible].

    PubMed

    Arsène, E; Clouqueur, E; Stichelbout, M; Devisme, L; Vaast, P; Subtil, D

    2015-11-01

    Twin pregnancies combining complete hydatidiform mole and coexistent fetus are a rare situation (incidence in 1/20,000 in 1/100,000 pregnancies) and a challenge for diagnosis. Their complications can be important - bleeding, preeclampsia, miscarriage - and their management remains complex and controversial. In case of continuing the pregnancy, nearly 40% of women have lives babies. Three quarters of fetal loss occur before 24weeks gestation. We report here three new cases; only one of these cases had a favorable outcome.

  2. Mechanisms regulating proteostasis are involved in sympatric speciation of the blind mole rat, Spalax galili.

    PubMed

    Rodriguez, Karl A; Li, Kexin; Nevo, Eviatar; Buffenstein, Rochelle

    2016-01-01

    Genome-wide analysis demonstrates extensive genomic adaptive complexes involved in sympatric speciation between blind mole rats (Spalax galili) in abutting populations living in basalt and chalk soils. Among the gene ontology (GO) enrichment, musculature and metabolism stood out in basalt dwellers while nutrition and neurogenetics were highlighted in chalk residents. Measurements of mechanisms regulating protein homeostasis inspired by these GO terms suggest that at the proteomic level there is also a habitat/soil-type driven divergence with the basalt residents exhibiting higher proteasome activity whereas elevated levels of markers of autophagy are evident in the chalk inhabitants.

  3. Metabolic regulatory clues from the naked mole rat: toward brain regulatory functions during stroke.

    PubMed

    Nathaniel, Thomas I; Otukonyong, Effiong E; Okon, Marvin; Chaves, Jose; Cochran, Thomas; Nathaniel, Adebobola I

    2013-09-01

    Resistance to tissue hypoxia is a robust fundamental adaptation to low oxygen supply, and represents a novel neuroscience problem with significance to mammalian physiology as well as human health. With the underlying mechanisms strongly conserved in evolution, the ability to resist tissue hypoxia in natural systems has recently emerged as an interesting model in mammalian physiology research to understand mechanisms that can be manipulated for the clinical management of stroke. The extraordinary ability to resist tissue hypoxia by the naked mole rat (NMR) indicates the presence of a unique mechanism that underlies the remarkable healthy life span and exceptional hypoxia resistance. This opens an interesting line of research into understanding the mechanisms employed by the naked mole rat (Heterocephalus glaber) to protect the brain during hypoxia. In a series of studies, we first examined the presence of neuroprotection in the brain cells of naked mole rats (NMRs) subjected to hypoxic insults, and then characterized the expression of such neuroprotection in a wide range of time intervals. We used oxygen nutrient deprivation (OND), an in vitro model of resistance to tissue hypoxia to determine whether there is evidence of neuronal survival in the hippocampal (CA1) slices of NMRs that are subjected to chronic hypoxia. Hippocampus neurons of NMRs that were kept in hypoxic condition consistently tolerated OND right from the onset time of 5h. This tolerance was maintained for 24h. This finding indicates that there is evidence of resistance to tissue hypoxia by CA1 neurons of NMRs. We further examined the effect of hypoxia on metabolic rate in the NMR. Repeated measurement of metabolic rates during exposure of naked mole rats to hypoxia over a constant ambient temperature indicates that hypoxia significantly decreased metabolic rates in the NMR, suggesting that the observed decline in metabolic rate during hypoxia may contribute to the adaptive mechanism used by the NMR

  4. Mechanisms regulating proteostasis are involved in sympatric speciation of the blind mole rat, Spalax galili

    PubMed Central

    Rodriguez, Karl A.; Li, Kexin; Nevo, Eviatar; Buffenstein, Rochelle

    2016-01-01

    ABSTRACT Genome-wide analysis demonstrates extensive genomic adaptive complexes involved in sympatric speciation between blind mole rats (Spalax galili) in abutting populations living in basalt and chalk soils. Among the gene ontology (GO) enrichment, musculature and metabolism stood out in basalt dwellers while nutrition and neurogenetics were highlighted in chalk residents. Measurements of mechanisms regulating protein homeostasis inspired by these GO terms suggest that at the proteomic level there is also a habitat/soil-type driven divergence with the basalt residents exhibiting higher proteasome activity whereas elevated levels of markers of autophagy are evident in the chalk inhabitants. PMID:27050459

  5. External influences on Europe's air quality: Baseline methane, carbon monoxide and ozone from 1990 to 2030 at Mace Head, Ireland

    NASA Astrophysics Data System (ADS)

    Derwent, R. G.; Simmonds, P. G.; O'Doherty, S.; Stevenson, D. S.; Collins, W. J.; Sanderson, M. G.; Johnson, C. E.; Dentener, F.; Cofala, J.; Mechler, R.; Amann, M.

    A global 3-D chemistry-transport model STOCHEM has been employed to study trends in the mole fractions of methane, carbon monoxide and ozone in baseline air masses entering Europe from the Atlantic Ocean over the period from 1990 to 2030. With a range of emission scenarios for man-made ozone precursor emission sources available, a wide range of model trends were predicted for the period up to 2030. In the scenario based on current planned air pollution controls, IIASA CLE, methane shows a strong upward trend, ozone shows a weaker upward trend, and carbon monoxide is approximately flat in baseline air masses. In one of the more pessimistic IPCC SRES scenarios, A2, all three gases show future increases. However, in the scenario based on maximum feasible emission reductions, IIASA MFR all three trace gases decline. By 2030, projected climate change reduces the growth in CH 4, but has insignificant effects on baseline CO and O 3 in these simulations. Global or hemispheric ozone precursor emissions and their controls exert a potentially large external influence on Europe's air quality. This influence is currently not taken into account in future European air quality policy formulation.

  6. Absence of histamine-induced itch in the African naked mole-rat and "rescue" by Substance P.

    PubMed

    Smith, Ewan St John; Blass, Gregory R C; Lewin, Gary R; Park, Thomas J

    2010-05-24

    Recent research has proposed a pathway in which sensory neurons expressing the capsaicin activated ion channel TRPV1 are required for histamine-induced itch and subsequent scratching behavior. We examined histamine-induced itch in the African naked mole-rat (Heterocephalus glaber) and found that although naked mole-rats display innate scratching behavior, histamine was unable to evoke increased scratching as is observed in most mouse strains. Using calcium imaging, we examined the histamine sensitivity of naked mole-rat dorsal root ganglia (DRG) neurons and identified a population of small diameter neurons activated by histamine, the majority of which are also capsaicin-sensitive. This suggested that naked mole-rat sensory neurons are activated by histamine, but that spinal dorsal horn processing of sensory information is not the same as in other rodents. We have previously shown that naked mole-rats naturally lack substance P (SP) in cutaneous C-fibers, but that the neurokinin-1 receptor is expressed in the superficial spinal cord. This led us to investigate if SP deficiency plays a role in the lack of histamine-induced scratching in this species. After intrathecal administration of SP into the spinal cord we observed robust scratching behavior in response to histamine injection. Our data therefore support a model in which TRPV1-expressing sensory neurons are important for histamine-induced itch. In addition, we demonstrate a requirement for active, SP-induced post-synaptic drive to enable histamine sensitive afferents to drive itch-related behavior in the naked mole-rat. These results illustrate that it is altered dorsal horn connectivity of nociceptors that underlies the lack of itch and pain-related behavior in the naked mole-rat.

  7. Dominance and queen succession in captive colonies of the eusocial naked mole-rat, Heterocephalus glaber.

    PubMed Central

    Clarke, F M; Faulkes, C G

    1997-01-01

    Naked mole-rat colonies exhibit a high reproductive skew, breeding being typically restricted to one female (the 'queen') and one to three males. Other colony members are reproductively suppressed, although this suppression can be reversed following the removal or death of the queen. We examined dominance and queen succession within captive colonies to investigate the relationship between urinary testosterone and cortisol, dominance rank and reproductive status; and to determine if behavioural and/or physiological parameters can be used as predictors of queen succession. Social structure was characterized by a linear dominance hierarchy before and after queen removal. Prior to queen removal, dominance rank was negatively correlated with body weight and urinary testosterone and cortisol titres in males and females. Queen removal results in social instability and aggression between high ranking individuals. Dominance rank appears to be a good predictor of reproductive status: queens are the highest ranking colony females and are succeeded by the next highest ranking females. The intense dominance-related aggression that accompanies reproductive succession in naked mole-rats provides empirical support for optimal skew theory. PMID:9263466

  8. Adaptations to a subterranean environment and longevity revealed by the analysis of mole rat genomes

    PubMed Central

    Fang, Xiaodong; Seim, Inge; Huang, Zhiyong; Gerashchenko, Maxim V.; Xiong, Zhiqiang; Turanov, Anton A.; Zhu, Yabing; Lobanov, Alexei V.; Fan, Dingding; Yim, Sun Hee; Yao, Xiaoming; Ma, Siming; Yang, Lan; Lee, Sang-Goo; Kim, Eun Bae; Bronson, Roderick T.; Šumbera, Radim; Buffenstein, Rochelle; Zhou, Xin; Krogh, Anders; Park, Thomas J.; Zhang, Guojie; Wang, Jun; Gladyshev, Vadim N.

    2014-01-01

    SUMMARY Subterranean mammals spend their lives in dark, unventilated environments rich in carbon dioxide and ammonia, and low in oxygen. Many of these animals are also long-lived and exhibit reduced aging-associated diseases, such as neurodegenerative disorders and cancer. We sequenced the genome of the Damaraland mole rat (DMR, Fukomys damarensis) and improved the genome assembly of the naked mole rat (NMR, Heterocephalus glaber). Comparative genome analysis, along with transcriptomes of related subterranean rodents, reveal candidate molecular adaptations for subterranean life and longevity, including a divergent insulin peptide, expression of oxygen-carrying globins in the brain, prevention of high CO2-induced pain perception, and enhanced ammonia detoxification. Juxtaposition of the genomes of DMR and other more conventional animals with the genome of NMR revealed several truly exceptional NMR features: unusual thermogenesis, aberrant melatonin system, pain insensitivity, and novel processing of 28S rRNA. Together, the new genomes and transcriptomes extend our understanding of subterranean adaptations, stress resistance and longevity. PMID:25176646

  9. Effects of Freshwater Discharge in Sandy Beach Populations: The Mole Crab Emerita brasiliensis in Uruguay

    NASA Astrophysics Data System (ADS)

    Lercari, D.; Defeo, O.

    1999-10-01

    Sandy beaches are ecosystems which are heavily affected by human activities. An example of this is freshwater discharges, which are known to change salinity, temperature and nutrient regimes and degrade nearshore environments. However, the effects of this kind of disturbance on sandy beach fauna have been little studied. This paper reports the spatial effects of a man-made freshwater canal discharge on the population structure, abundance and reproductive characteristics of the sandy beach mole crab Emerita brasiliensis. Along the 22 km of sandy beach sampled, the mole crab showed a marked longshore variability in population structure and abundance. Abundance of different population components (juveniles, males, females and ovigerous females) significantly decreased towards the canal. Population structure by sex and size, individual weight, fecundity and female maturity patterns at size also displayed a non-linear response to the distance from the freshwater discharge. Only the size structure of males did not follow this pattern. For males, spatial heterogeneity enhanced the detection of density-dependence at less disturbed sites. The authors conclude that artificial freshwater discharges could significantly influence the distribution, abundance and life-history traits of the biota of sandy beaches, and that further study of these ecosystems should include human activities as important factors affecting spatial and temporal trends. The need to consider different spatial and temporal scales in order to detect the effect of anthropogenically-driven impacts in sandy beach populations is stressed.

  10. Structural Features of the Telomerase RNA Gene in the Naked Mole Rat Heterocephalus glaber

    PubMed Central

    Evfratov, S. A.; Smekalova, E. M.; Golovin, A. V.; Logvina, N. A.; Zvereva, M. I.; Dontsova, O. A.

    2014-01-01

    Telomere length, an important feature of life span control, is dependent on the activity of telomerase (a key enzyme of the telomere-length-maintaining system). Telomerase RNA is a component of telomerase and, thus, is crucial for its activity. The structures of telomerase RNA genes and their promoter regions were compared for the long-living naked mole rat and different organisms. Two rare polymorphisms in Heterocephalus glaber telomerase RNA (hgTER) were identified: A→G in the first loop of pseudoknot P2b-p3 (an equivalent of 111nt in hTR) and G→A in the scaRNA domain CR7-p8b (an equivalent of 421nt in hTR). Analysis of TER promoter regions allowed us to identify two new transcription factor binding sites. The first one is the ETS family site, which was found to be a conserved element for all the analyzed TER promoters. The second site is unique for the promoter region of TER of the naked mole rat and is a binding site for the SOX17 transcription factor. The absence of one Sp1 site in the TER promoter region of the naked small rat is an additional specific feature of the promoter area of hgTER. Such variation in the hgTER transcription regulation region and hgTER itself could provide increased telomerase activity in stem cells and an extended lifespan to H. glaber. PMID:25093110

  11. Retinal ganglion cell survival and axon regeneration after optic nerve injury in naked mole-rats.

    PubMed

    Park, Kevin K; Luo, Xueting; Mooney, Skyler J; Yungher, Benjamin J; Belin, Stephane; Wang, Chen; Holmes, Melissa M; He, Zhigang

    2017-02-01

    In the adult mammalian central nervous system (CNS), axonal damage often triggers neuronal cell death and glial activation, with very limited spontaneous axon regeneration. In this study, we performed optic nerve injury in adult naked mole-rats, the longest living rodent, with a maximum life span exceeding 30 years, and found that injury responses in this species are quite distinct from those in other mammalian species. In contrast to what is seen in other mammals, the majority of injured retinal ganglion cells (RGCs) survive with relatively high spontaneous axon regeneration. Furthermore, injured RGCs display activated signal transducer and activator of transcription-3 (STAT3), whereas astrocytes in the optic nerve robustly occupy and fill the lesion area days after injury. These neuron-intrinsic and -extrinsic injury responses are reminiscent of those in "cold-blooded" animals, such as fish and amphibians, suggesting that the naked mole-rat is a powerful model for exploring the mechanisms of neuronal injury responses and axon regeneration in mammals. J. Comp. Neurol. 525:380-388, 2017. © 2016 Wiley Periodicals, Inc.

  12. Differential effects of chronic fluoxetine on the behavior of dominant and subordinate naked mole-rats.

    PubMed

    Mongillo, Daniel L; Kosyachkova, Ekaterina A; Nguyen, Tam M; Holmes, Melissa M

    2014-01-01

    Naked mole-rats are eusocial rodents that live in large subterranean colonies with a strict reproductive and social hierarchy. The breeding female (referred to as the queen) and 1 to 3 breeding males are the only reproductive members of the colony. Breeders are socially dominant and all other colony members are non-reproductive subordinates. The effects of manipulating the serotonergic neurotransmitter system on aggression and dominance behaviors are well studied in many species, but not in eusocial rodents like the naked mole-rat. The current study investigated how the serotonergic system influences aggressive/dominant behaviors in this species. To do this, two separate but related experiments were conducted: the effects of fluoxetine hydrochloride (FLX) on status-specific behaviors of subordinates (Experiment 1) and dominant queens (Experiment 2) were evaluated both in-colony and in a social-pairing paradigm. In accordance with our main hypothesis, chronic treatment of FLX attenuated the frequency and duration of aggression in queens, but not subordinates, when paired with an unfamiliar conspecific. Further exploration of pharmacological manipulation on status-specific behaviors of this eusocial species may elucidate the neurobiological mechanisms underlying their unique and rigid social hierarchy.

  13. Complete Hydatidiform Mole Coexisting with Three Viable Fetuses in a Quadruplet Pregnancy.

    PubMed

    Tariq, Nabia; Ghazali, Usman; Uddin, Zeeshan; Rasheed, Kamran; Tariq, Hina

    2016-04-01

    We hereby report a case of quadruplet pregnancy with delivery of 3 viable infants and a complete mole. This was an induced conception with clomiphene citrate. At 22 weeks, cystic structures were noticed in one of the placentae and a suspicion of co-existant molar pregnancy was made. The case discussed with oncologist and pregnancy was continued with close monitoring of β-hCG and Ultrasound. Her β-hCG at 23 weeks was 748 mIU/ml, which continued to rise until the 29th week of gestation to a level of 305881.68 mIU/ml and declined gradually thereafter. Similarly, hydropic change in placenta also continued to increase progressively. She was given steroid cover at 32 weeks and delivery was aimed at 34 weeks of gestation. The patient went into preterm labour at 33 weeks and 3 female infants delivered by lower segment cesarean section (LSCS) followed by removal of 3 placentae along with copious molar tissue at the end. The newborns were kept in the nursery, non-requiring assisted ventilation and discharged in satisfactory condition. The histopathologyand immunohistochemistry confirmed the diagnosis of a quadruplet pregnancy comprising of one complete mole with 3 normal placentae.

  14. Community structure variability of Uropodina mites (Acari: Mesostigmata) in nests of the common mole, Talpa europaea, in Central Europe.

    PubMed

    Napierała, Agnieszka; Mądra, Anna; Leszczyńska-Deja, Kornelia; Gwiazdowicz, Dariusz J; Gołdyn, Bartłomiej; Błoszyk, Jerzy

    2016-04-01

    Underground nests of Talpa europaea, known as the common mole, are very specific microhabitats, which are also quite often inhabited by various groups of arthropods. Mites from the suborder Uropodina (Acari: Mesostigmata) are only one of them. One could expect that mole nests that are closely located are inhabited by communities of arthropods with similar species composition and structure. However, results of empirical studies clearly show that even nests which are close to each other can be different both in terms of the species composition and abundance of Uropodina communities. So far, little is known about the factors that can cause these differences. The major aim of this study was to identify factors determining species composition, abundance, and community structure of Uropodina communities in mole nests. The study is based on material collected during a long-term investigation conducted in western parts of Poland. The results indicate that the two most important factors influencing species composition and abundance of Uropodina communities in mole nests are nest-building material and depth at which nests are located. Composition of Uropodina communities in nests of moles was also compared with that of other microhabitats (e.g. rotten wood, forest litter, soil) based on data from 4421 samples collected in Poland. Communities of this habitat prove most similar to these of open areas, especially meadows, as well as some forest types.

  15. Expression pattern of cadherins in the naked mole rat (Heterocephalus glaber) suggests innate cortical diversification of the cerebrum.

    PubMed

    Matsunaga, Eiji; Nambu, Sanae; Iriki, Atsushi; Okanoya, Kazuo

    2011-06-15

    The cerebral cortex is an indispensable region for higher cognitive function that is remarkably diverse among mammalian species. Although previous research has shown that the cortical area map in the mammalian cerebral cortex is formed by innate and activity-dependent mechanisms, it remains unknown how these mechanisms contribute to the evolution and diversification of the functional cortical areas in various species. The naked mole rat (Heterocephalus glaber) is a subterranean, eusocial rodent. Physiological and anatomical studies have revealed that the visual system is regressed and the somatosensory system is enlarged. To examine whether species differences in cortical area development are caused by intrinsic factors or environmental factors, we performed comparative gene expression analysis of neonatal naked mole rat and mouse brains. The expression domain of cadherin-6, a somatosensory marker, was expanded caudally and shifted dorsally in the cortex, whereas the expression domain of cadherin-8, a visual marker, was reduced caudally in the neonatal naked mole rat cortex. The expression domain of cadherin-8 was also reduced in other visual areas, such as the lateral geniculate nucleus and superior colliculus. Immunohistochemical analysis of thalamocortical fibers further suggested that somatosensory input did not affect cortical gene expression in the neonatal naked mole rat brain. These results suggest that the development of the somatosensory system and the regression of the visual system in the naked mole rat cortex are due to intrinsic genetic mechanisms as well as sensory input-dependent mechanisms. Intrinsic genetic mechanisms thus appear to contribute to species diversity in cortical area formation.

  16. Effect of hypoxia on metabolic rate, core body temperature, and c-fos expression in the naked mole rat.

    PubMed

    Nathaniel, Thomas I; Otukonyong, Effiong; Abdellatif, Ahmed; Soyinka, Julius O

    2012-10-01

    Recent investigations of hypoxia physiology in the naked mole rat have opened up an interesting line of research into the basic physiological and genomic alterations that accompany hypoxia survival. The extent to which such findings connect the effect of hypoxia to metabolic rate (O₂ consumption), core body temperature (Tb), and transcripts encoding the immediate early gene product (such as c-fos) under a constant ambient temperature (Ta) is not well known. We investigated this issue in the current study. Our first sets of experiments measured Tb and metabolic rates during exposure of naked mole rats to hypoxia over a constant Ta. Hypoxia significantly decreased metabolic rates in the naked mole rat. Although core Tb also decreased during hypoxia, the effect of hypoxia in suppressing core Tb was not significant. The second series of experiments revealed that c-fos protein and mRNA expression in the hippocampus neurons (CA1) increased in naked mole rats that were repeatedly exposed to 3% O₂ for 60 min per day for 5 days when compared to normoxia. Our findings provide evidence for the up-regulation of c-fos and suppression of metabolic rate in hypoxia tolerating naked mole rats under constant ambient temperature. Metabolic suppression and c-fos upregulation constitute part of the physiological complex associated with adaptation to hypoxia.

  17. Heavy metal accumulation in the mole, Talpa europea, and earthworms as an indicator of metal bioavailability in terrestrial environments

    SciTech Connect

    Ma, W.

    1987-12-01

    Bioaccumulation studies in animals can supply valuable information to supplement the data obtained by chemical analysis of pollutants in abiotic samples. With respect to the terrestrial ecosystem, suitable indicator species in the decomposer subsystem can be identified on the basis of functional characteristics and trophic level. Investigations on metal behavior at the first trophic level, done in lumbricid earthworms showed that the potential for bioaccumulation depends on the degree of contamination as well as on the metal-binding capacity of the soil. The present study was performed to investigate metal behavior at a higher trophic level, and the mole (Talpa europea) was chosen a representative of the terrestrial decomposer subsystem. As earthworms are the preferred food of moles, they provide the major source of ingested metals to these animals. The food chain involving earthworms and moles provides an example of a critical pathway for potentially toxic non-essential metals such as cadmium and lead.

  18. Evaluation of germline CDKN2A, ARF, CDK4, PTEN, and BRAF alterations in atypical mole syndrome.

    PubMed

    Celebi, J T; Ward, K M; Wanner, M; Polsky, D; Kopf, A W

    2005-01-01

    Atypical mole syndrome is a sporadic or an inherited condition with an increased risk of melanoma. Germline mutations in the CDKN2A, ARF, CDK4 and somatic mutations in the PTEN and BRAF genes have been associated with melanoma. In this study, we evaluated genes associated with familial and sporadic melanoma for mutations in 28 probands with the atypical mole syndrome. No sequence alterations in the coding regions or in the splice junctions of CDKN2A, ARF, CDK4, PTEN or BRAF were identified. These data suggest that genes evaluated in this study are unlikely to be candidate genes for atypical mole syndrome and support the notion that unknown susceptibility gene/s for this disease exist.

  19. Comparative analysis of genome maintenance genes in naked mole rat, mouse, and human.

    PubMed

    MacRae, Sheila L; Zhang, Quanwei; Lemetre, Christophe; Seim, Inge; Calder, Robert B; Hoeijmakers, Jan; Suh, Yousin; Gladyshev, Vadim N; Seluanov, Andrei; Gorbunova, Vera; Vijg, Jan; Zhang, Zhengdong D

    2015-04-01

    Genome maintenance (GM) is an essential defense system against aging and cancer, as both are characterized by increased genome instability. Here, we compared the copy number variation and mutation rate of 518 GM-associated genes in the naked mole rat (NMR), mouse, and human genomes. GM genes appeared to be strongly conserved, with copy number variation in only four genes. Interestingly, we found NMR to have a higher copy number of CEBPG, a regulator of DNA repair, and TINF2, a protector of telomere integrity. NMR, as well as human, was also found to have a lower rate of germline nucleotide substitution than the mouse. Together, the data suggest that the long-lived NMR, as well as human, has more robust GM than mouse and identifies new targets for the analysis of the exceptional longevity of the NMR.

  20. A mobile one-sided NMR sensor with a homogeneous magnetic field: the NMR-MOLE.

    PubMed

    Manz, B; Coy, A; Dykstra, R; Eccles, C D; Hunter, M W; Parkinson, B J; Callaghan, P T

    2006-11-01

    A new portable NMR sensor with a novel one-sided access magnet design, termed NMR-MOLE (MObile Lateral Explorer), has been characterised in terms of sensitivity and depth penetration. The magnet has been designed to be portable and create a volume with a relatively homogeneous magnetic field, 15,000 ppm over a region from 4 to 16 mm away from the probe, with maximum sensitivity at a depth of 10 mm. The proton NMR frequency is 3.3 MHz. We have demonstrated that with this approach a highly sensitive, portable, unilateral NMR sensor can be built. Such a design is especially suited for the characterisation of liquids in situations where unilateral or portable access is required.

  1. Fingerprinting: Modelling and mapping physical top soil properties with the Mole

    NASA Astrophysics Data System (ADS)

    Loonstra, Eddie; van Egmond, Fenny

    2010-05-01

    The Mole is a passive gamma ray soil sensor system. It is designed for the mobile collection of radioactive energy stemming from soil. As the system is passive, it only measures energy that reaches the surface of soil. In general, this energy comes from upto 30 to 40 cm deep, which can be considered topsoil. The gathered energy spectra are logged every second, are processed with the method of Full Spectrum Analysis. This method uses all available spectral data and processes it with a Chi square optimalisation using a set of standard spectra into individual nuclide point data. A standard spectrum is the measured full spectrum of a specific detector derived when exposed to 1 Bq/kg of a nuclide. With this method the outcome of the surveys become quantitative.The outcome of a field survey with the Mole results in a data file containing point information of position, Total Counts and the decay products of 232Th, 238U, 40K and 137Cs. Five elements are therefor available for the modelling of soil properties. There are several ways for the modelling of soil properties with sensor derived gamma ray data. The Mole generates ratio scale output. For modelling a quantitative deterministic approach is used based on sample locations. This process is called fingerprinting. Fingerprinting is a comparison of the concentration of the radioactive trace elements and the lab results (pH, clay content, etc.) by regression analysis. This results in a mathematical formula describing the relationship between a dependent and independent property. The results of the sensor readings are interpolated into a nuclide map with GIS software. With the derived formula a soil property map is composed. The principle of fingerprinting can be applied on large geographical areas for physical soil properties such as clay, loam or sand (50 micron), grain size and organic matter. Collected sample data of previous field surveys within the same region can be used for the prediction of soil properties elsewhere

  2. Comparative cytogenetics of moles (Eulipotyphla, Talpidae): chromosomal differences in Talpa romana and T. europaea.

    PubMed

    Gornung, E; Volleth, M; Capanna, E; Castiglia, R

    2008-01-01

    The genus Talpa is the most specious and widespread one in the family Talpidae. The existing karyological records are predominantly basic morphological descriptions. To further investigate the case in point, we performed a comparative cytogenetic study in the genus by comparing G- and C-chromosome banding and NOR patterns of the two European species, T. romana and T. europaea, along with available data regarding several other mole species. Chromosomal hybridization patterns for telomeric repeats and major and 5S ribosomal RNA genes were obtained in T. romana and T. europaea for the first time. The comparison of these patterns revealed differences in distribution of interstitial telomeric repeats and 5S ribosomal RNA genes in the two species with apparently identical karyotypes but different evolutionary histories.

  3. Whack-A-Mole Model: Towards a Unified Description of Biological Effects Caused by Radiation Exposure

    NASA Astrophysics Data System (ADS)

    Manabe, Yuichiro; Wada, Takahiro; Tsunoyama, Yuichi; Nakajima, Hiroo; Nakamura, Issei; Bando, Masako

    2015-04-01

    We present a novel model to for estimating biological effects caused by artificial radiation exposure, i.e., the Whack-A-Mole (WAM) model. It is important to take into account the recovery effects during the time course of cellular reactions. The inclusion of dose-rate dependence is essential in the risk estimation of low-dose radiation, while nearly all the existing theoretical models rely on the total dose dependence only. By analyzing experimental data of the relationship between the radiation dose and the induced mutation frequency of five organisms, namely, mouse, Drosophila, chrysanthemum, maize, Tradescantia, we found that all the data can be reproduced by the WAM model. Most remarkably, a scaling function, which is derived from the WAM model, consistently accounts for the observed mutation frequencies of the five organisms. This is the first rationale to account for the dose rate dependence as well as to provide a unified understanding of a general feature of organisms.

  4. Incidental Finding of Persistent Hydatidiform Mole in an Adolescent on Depo-Provera

    PubMed Central

    McKendrick, Rebecca; Nokkaew, May

    2016-01-01

    Molar pregnancies represent an uncommon yet important obstetric problem with potentially fatal outcomes. Patients typically present with signs and symptoms of early pregnancy, and physicians most often suspect nonmolar pregnancy complications initially; however a hydatidiform mole should be included in the differential diagnosis of a woman with a positive pregnancy test and abnormal vaginal bleeding irrespective of the use of contraception. Our case is that of an adolescent female on Depo-Provera injectable contraceptive with increased vaginal bleeding, abdominal pain, nausea, and vomiting who was incidentally found to be pregnant and subsequently diagnosed with a molar pregnancy despite persistent denial of having initiated sexual intercourse. Though gestational trophoblastic disease is uncommon with an incidence of about 1-2 cases per 1,000 pregnancies, a clinician has to display a high index of suspicion when dealing with patients at extremes of age in order to avoid potentially life-threatening outcomes. PMID:28116190

  5. [Twin pregnancy with a complete hydatiform mole and a viable co-twin].

    PubMed

    Godinho, Ana Beatriz; Martins, Diana; Araújo, Cláudia; Melo, Maria Antonieta; Mendes Graça, Luís

    2014-01-01

    A complete hydatiform mole coexisting with a live, viable twin is a rare event. The diagnosis is challenging, and is normally achieved only at second trimester. It may be associated with thyrotoxicosis, vaginal bleeding, preeclampsia, fetal death or persistent throphoblastic disease. The authors describe the case of a pregnant woman presenting with first trimester bleeding. Ultrasound revealed a twin pregnancy with a viable twin and another placenta apparently detached. At 16 gestational weeks ultrasound revealed a live fetus with a normal placenta and a separate vacuolated and vascularized mass. Facing the hypothesis of gestational trophoblastic disease, the couple chose pregnancy interruption. Given the rarity of this situation, a high index of suspicion is needed to achieve the diagnosis. Despite the existence of case reports with good fetal and maternal outcome, the decision of pregnancy continuation should be made by the informed parents.

  6. On the dimensionality of the Avogadro constant and the definition of the mole

    NASA Astrophysics Data System (ADS)

    Wheatley, Nigel

    2011-06-01

    There is a common misconception among educators, and even some metrologists, that the Avogadro constant NA is (or should be) a pure number, and not a constant of dimension N-1 (where N is the dimension amount of substance). Amount of substance is (and always has been) measured as a ratio of other physical quantities, and not in terms of a specified pure number of elementary entities. Hence the Avogadro constant has always been defined in terms of the unit of amount of substance, and not vice versa. The proposed redefinition of the mole in terms of a fixed value of the Avogadro constant is examined, and it is shown that such a redefinition would not bring any significant metrological benefit. It is contended that such a redefinition would only add to the confusion in this field, and so should be rejected.

  7. Opposed jet burner studies of hydrogen combustion with pure and N2, NO-contaminated air

    NASA Technical Reports Server (NTRS)

    Guerra, Rosemary; Pellett, Gerald L.; Northam, G. Burton; Wilson, Lloyd G.

    1987-01-01

    A counterflow diffusion flame formed by an argon-bathed tubular-opposed jet burner (OJB) was used to determine the 'blowoff' and 'restore' combustion characteristics for jets of various H2/N2 mixtures and for jets of air contaminated by NO (which normally occurs in high-enthalpy airflows supplied to hypersonic test facilities for scramjet combustors). Substantial divergence of 'blowoff' and 'restore' limits occurred as H2 mass flux, M(H)2, increased, the H2 jet became richer, and the M(air)/M(H2 + N2) ratio increased from 1 to 3 (molar H2/O2 from 1 to 16). Both OJB limits were sensitive to reactant composition. One to six percent NO in air led to significant N2-corrected decreases in the M(H2) values for 'blowoff' (2-8 percent) and 'restore' (6-12 percent) for mole fractions of H2 ranging from 0.5 to 0.95. However, when H2/O2 was held constant, all N2-corrected changes in M(H2) were negligible.

  8. Fractional vector calculus and fractional Maxwell's equations

    SciTech Connect

    Tarasov, Vasily E.

    2008-11-15

    The theory of derivatives and integrals of non-integer order goes back to Leibniz, Liouville, Grunwald, Letnikov and Riemann. The history of fractional vector calculus (FVC) has only 10 years. The main approaches to formulate a FVC, which are used in the physics during the past few years, will be briefly described in this paper. We solve some problems of consistent formulations of FVC by using a fractional generalization of the Fundamental Theorem of Calculus. We define the differential and integral vector operations. The fractional Green's, Stokes' and Gauss's theorems are formulated. The proofs of these theorems are realized for simplest regions. A fractional generalization of exterior differential calculus of differential forms is discussed. Fractional nonlocal Maxwell's equations and the corresponding fractional wave equations are considered.

  9. Ear Structures of the Naked Mole-Rat, Heterocephalus glaber, and Its Relatives (Rodentia: Bathyergidae)

    PubMed Central

    Mason, Matthew J.; Cornwall, Hannah L.; Smith, Ewan St. J.

    2016-01-01

    Although increasingly popular as a laboratory species, very little is known about the peripheral auditory system of the naked mole-rat, Heterocephalus glaber. In this study, middle and inner ears of naked mole-rats of a range of ages were examined using micro-computed tomography and dissection. The ears of five other bathyergid species (Bathyergus suillus, Cryptomys hottentotus, Fukomys micklemi, Georychus capensis and Heliophobius argenteocinereus) were examined for comparative purposes. The middle ears of bathyergids show features commonly found in other members of the Ctenohystrica rodent clade, including a fused malleus and incus, a synovial stapedio-vestibular articulation and the loss of the stapedius muscle. Heterocephalus deviates morphologically from the other bathyergids examined in that it has a more complex mastoid cavity structure, poorly-ossified processes of the malleus and incus, a ‘columelliform’ stapes and fewer cochlear turns. Bathyergids have semicircular canals with unusually wide diameters relative to their radii of curvature. How the lateral semicircular canal reaches the vestibule differs between species. Heterocephalus has much more limited high-frequency hearing than would be predicted from its small ear structures. The spongy bone forming its ossicular processes, the weak incudo-stapedial articulation, the columelliform stapes and (compared to other bathyergids) reduced cochlear coiling are all potentially degenerate features which might reflect a lack of selective pressure on its peripheral auditory system. Substantial intraspecific differences were found in certain middle and inner ear structures, which might also result from relaxed selective pressures. However, such interpretations must be treated with caution in the absence of experimental evidence. PMID:27926945

  10. EVALUATION OF VIRULENCE OF STEINERNEMA CARPOCAPSAE TO EUROPEAN MOLE CRICKET GRYLLOTALPA GRYLOTALPA L.

    PubMed

    Stefanovska, T; Pisdlisnyuk, V

    2014-01-01

    Common European mole cricket (CEML) Grillotalpa grillotalpa L causes damage to field, vegetable crops, and small fruits growing at commercial plantations and nurseries. Chemical control if insecticides are used in poison bates, soil application or seedling/bulbs treatment is not environmentally friendly. Inundative and innoculative release of CTVL biocontrol agents, in particularly, Entomopathogenic nematode is a reliable alternative to chemical control. At the laboratory study the comparison of the ability of commercial strain (Nemastar) and local Ukrainian isolate of Steinernema carpocapsae in various concentrations to parasite in last instar nymph and adults of G. grillotalpa was investigated. Grillotalpa grillotalpa was found as a susceptible host for both commercial and local strains of S. carpocapsae. The life cycle of S. carpocapsae both strains in the adults of G. grillotapla with concentration 50 IJs per larva has been completed 12-15 days at t=25 C. Two generations of S. carpocapsae were able to develop in mole cricket for both strains. Two strains of S. carpocapsae nematode species tested were pathogenic to adults of G. grillotalpa. The mortalities of G. grillotapla last last instars' larva caused by S. carpocapsae were recorded in every concentration tested at least 20 to 150 IJs per larva. Mean larval mortality ranged from 48% to 95% depending upon nematode strain and rate of application. Larval mortality generally increased with increasing of nematode rates. It was significant for both S. carpocapsae strains (Ukr. Isolate F = 26 > 2,86) and commercial strain (Nemastar F = 102,95 > 2,86). Ukrainian local isolate caused a greater percentage of mortality of G. grillotapla adult than commercial strain of S. carpocapsae tested but interactions between nematode strains, application rates were not significant. This study presents new data on effect of S. carpocapsae isolated for Ukraine to key agricultural polyphagous pest G. grillotalpa susceptibility

  11. Transcriptome, genetic editing, and microRNA divergence substantiate sympatric speciation of blind mole rat, Spalax.

    PubMed

    Li, Kexin; Wang, Liuyang; Knisbacher, Binyamin A; Xu, Qinqin; Levanon, Erez Y; Wang, Huihua; Frenkel-Morgenstern, Milana; Tagore, Satabdi; Fang, Xiaodong; Bazak, Lily; Buchumenski, Ilana; Zhao, Yang; Lövy, Matěj; Li, Xiangfeng; Han, Lijuan; Frenkel, Zeev; Beiles, Avigdor; Cao, Yi Bin; Wang, Zhen Long; Nevo, Eviatar

    2016-07-05

    Incipient sympatric speciation in blind mole rat, Spalax galili, in Israel, caused by sharp ecological divergence of abutting chalk-basalt ecologies, has been proposed previously based on mitochondrial and whole-genome nuclear DNA. Here, we present new evidence, including transcriptome, DNA editing, microRNA, and codon usage, substantiating earlier evidence for adaptive divergence in the abutting chalk and basalt populations. Genetic divergence, based on the previous and new evidence, is ongoing despite restricted gene flow between the two populations. The principal component analysis, neighbor-joining tree, and genetic structure analysis of the transcriptome clearly show the clustered divergent two mole rat populations. Gene-expression level analysis indicates that the population transcriptome divergence is displayed not only by soil divergence but also by sex. Gene ontology enrichment of the differentially expressed genes from the two abutting soil populations highlights reproductive isolation. Alternative splicing variation of the two abutting soil populations displays two distinct splicing patterns. L-shaped FST distribution indicates that the two populations have undergone divergence with gene flow. Transcriptome divergent genes highlight neurogenetics and nutrition characterizing the chalk population, and energetics, metabolism, musculature, and sensory perception characterizing the abutting basalt population. Remarkably, microRNAs also display divergence between the two populations. The GC content is significantly higher in chalk than in basalt, and stress-response genes mostly prefer nonoptimal codons. The multiple lines of evidence of ecological-genomic and genetic divergence highlight that natural selection overrules the gene flow between the two abutting populations, substantiating the sharp ecological chalk-basalt divergence driving sympatric speciation.

  12. Life history plasticity does not confer resilience to environmental change in the mole salamander (Ambystoma talpoideum)

    USGS Publications Warehouse

    Courtney L. Davis,; David A.W. Miller,; Walls, Susan; Barichivich, William J.; Riley, Jeffrey W.; Brown, Mary E.

    2017-01-01

    Plasticity in life history strategies can be advantageous for species that occupy spatially or temporally variable environments. We examined how phenotypic plasticity influences responses of the mole salamander, Ambystoma talpoideum, to disturbance events at the St. Marks National Wildlife Refuge (SMNWR), FL, USA from 2009 to 2014. We observed periods of extensive drought early in the study, in contrast to high rainfall and expansive flooding events in later years. Flooding facilitated colonization of predatory fishes to isolated wetlands across the refuge. We employed multistate occupancy models to determine how this natural experiment influenced the occurrence of aquatic larvae and paedomorphic adults and what implications this may have for the population. We found that, in terms of occurrence, responses to environmental variation differed between larvae and paedomorphs, but plasticity (i.e. the ability to metamorphose rather than remain in aquatic environment) was not sufficient to buffer populations from declining as a result of environmental perturbations. Drought and fish presence negatively influenced occurrence dynamics of larval and paedomorphic mole salamanders and, consequently, contributed to observed short-term declines of this species. Overall occurrence of larval salamanders decreased from 0.611 in 2009 to 0.075 in 2014 and paedomorph occurrence decreased from 0.311 in 2009 to 0.121 in 2014. Although variation in selection pressures has likely maintained this polyphenism previously, our results suggest that continued changes in environmental variability and the persistence of fish in isolated wetlands could lead to a loss of paedomorphosis in the SMNWR population and, ultimately, impact regional persistence in the future.

  13. Middle ear dynamics in response to seismic stimuli in the Cape golden mole (Chrysochloris asiatica).

    PubMed

    Willi, U B; Bronner, G N; Narins, P M

    2006-01-01

    The hypertrophied malleus in the middle ear of some golden moles has been assumed to be an adaptation for sensing substrate vibrations by inertial bone conduction, but this has never been conclusively demonstrated. The Cape golden mole (Chrysochloris asiatica) exhibits this anatomical specialization, and the dynamic properties of its middle ear response to vibrations were the subjects of this study. Detailed three-dimensional middle ear anatomy was obtained by x-ray microcomputed tomography (muCT) at a resolution of 12 microm. The ossicular chain exhibits large malleus mass, selective reduction of stiffness and displacement of the center of mass from the suspension points, all favoring low-frequency tuning of the middle ear response. Orientation of the stapes relative to the ossicular chain and the structure of the stapes footplate enable transmission of substrate vibrations arriving from multiple directions to the inner ear. With the long axes of the mallei aligned parallel to the surface, the animal's head was stimulated by a vibration exciter in the vertical and lateral directions over a frequency range from 10 to 600 Hz. The ossicular chain was shown to respond to both vertical and lateral vibrations. Resonant frequencies were found between 71 and 200 Hz and did not differ significantly between the two stimulation directions. Below resonance, the ossicular chain moves in phase with the skull. Near resonance and above, the malleus moves at a significantly larger mean amplitude (5.8+/-2.8 dB) in response to lateral vs vertical stimuli and is 180 degrees out of phase with the skull in both cases. A concise summary of the propagation characteristics of both seismic body (P-waves) and surface (R-waves) is provided. Potential mechanisms by which the animal might exploit the differential response of the ossicular chain to vertical and lateral excitation are discussed in relation to the properties of surface seismic waves.

  14. Social condition and oxytocin neuron number in the hypothalamus of naked mole-rats (Heterocephalus glaber).

    PubMed

    Mooney, S J; Holmes, M M

    2013-01-29

    The naked mole-rat is a subterranean colonial rodent. In each colony, which can grow to as many as 300 individuals, there is only one female and 1-3 males that are reproductive and socially dominant. The remaining animals are reproductively suppressed subordinates that contribute to colony survival through their cooperative behaviors. Oxytocin is a peptide hormone that has shown relatively widespread effects on prosocial behaviors in other species. We examined whether social status affects the number of oxytocin-immunoreactive neurons in the paraventricular nucleus and the supraoptic nucleus by comparing dominant breeding animals to subordinate non-breeding workers from intact colonies. We also examined these regions in subordinate animals that had been removed from their colony and paired with an opposite- or same-sex conspecific for 6 months. Stereological analyses indicated that subordinates had significantly more oxytocin neurons in the paraventricular nucleus than breeders. Animals in both opposite- and same-sex pairs showed a decreased oxytocin neuron number compared to subordinates suggesting that status differences may be due to social condition rather than the reproductive activity of the animal per se. The effects of social status appear to be region specific as no group differences were found for oxytocin neuron number in the supraoptic nucleus. Given that subordinate naked mole-rats are kept reproductively suppressed through antagonism by the queen, we speculate that status differences are due either to oxytocin's anxiolytic properties to combat the stress of this antagonism or to its ability to promote the prosocial behaviors of subordinates.

  15. Molecular basis of a novel adaptation to hypoxic-hypercapnia in a strictly fossorial mole

    PubMed Central

    2010-01-01

    Background Elevated blood O2 affinity enhances survival at low O2 pressures, and is perhaps the best known and most broadly accepted evolutionary adjustment of terrestrial vertebrates to environmental hypoxia. This phenotype arises by increasing the intrinsic O2 affinity of the hemoglobin (Hb) molecule, by decreasing the intracellular concentration of allosteric effectors (e.g., 2,3-diphosphoglycerate; DPG), or by suppressing the sensitivity of Hb to these physiological cofactors. Results Here we report that strictly fossorial eastern moles (Scalopus aquaticus) have evolved a low O2 affinity, DPG-insensitive Hb - contrary to expectations for a mammalian species that is adapted to the chronic hypoxia and hypercapnia of subterranean burrow systems. Molecular modelling indicates that this functional shift is principally attributable to a single charge altering amino acid substitution in the β-type δ-globin chain (δ136Gly→Glu) of this species that perturbs electrostatic interactions between the dimer subunits via formation of an intra-chain salt-bridge with δ82Lys. However, this replacement also abolishes key binding sites for the red blood cell effectors Cl-, lactate and DPG (the latter of which is virtually absent from the red cells of this species) at δ82Lys, thereby markedly reducing competition for carbamate formation (CO2 binding) at the δ-chain N-termini. Conclusions We propose this Hb phenotype illustrates a novel mechanism for adaptively elevating the CO2 carrying capacity of eastern mole blood during burst tunnelling activities associated with subterranean habitation. PMID:20637064

  16. Life history plasticity does not confer resilience to environmental change in the mole salamander (Ambystoma talpoideum).

    PubMed

    Davis, Courtney L; Miller, David A W; Walls, Susan C; Barichivich, William J; Riley, Jeffrey; Brown, Mary E

    2017-03-01

    Plasticity in life history strategies can be advantageous for species that occupy spatially or temporally variable environments. We examined how phenotypic plasticity influences responses of the mole salamander, Ambystoma talpoideum, to disturbance events at the St. Marks National Wildlife Refuge (SMNWR), FL, USA from 2009 to 2014. We observed periods of extensive drought early in the study, in contrast to high rainfall and expansive flooding events in later years. Flooding facilitated colonization of predatory fishes to isolated wetlands across the refuge. We employed multistate occupancy models to determine how this natural experiment influenced the occurrence of aquatic larvae and paedomorphic adults and what implications this may have for the population. We found that, in terms of occurrence, responses to environmental variation differed between larvae and paedomorphs, but plasticity (i.e. the ability to metamorphose rather than remain in aquatic environment) was not sufficient to buffer populations from declining as a result of environmental perturbations. Drought and fish presence negatively influenced occurrence dynamics of larval and paedomorphic mole salamanders and, consequently, contributed to observed short-term declines of this species. Overall occurrence of larval salamanders decreased from 0.611 in 2009 to 0.075 in 2014 and paedomorph occurrence decreased from 0.311 in 2009 to 0.121 in 2014. Although variation in selection pressures has likely maintained this polyphenism previously, our results suggest that continued changes in environmental variability and the persistence of fish in isolated wetlands could lead to a loss of paedomorphosis in the SMNWR population and, ultimately, impact regional persistence in the future.

  17. Transcriptome, genetic editing, and microRNA divergence substantiate sympatric speciation of blind mole rat, Spalax

    PubMed Central

    Li, Kexin; Wang, Liuyang; Knisbacher, Binyamin A.; Xu, Qinqin; Levanon, Erez Y.; Wang, Huihua; Frenkel-Morgenstern, Milana; Tagore, Satabdi; Fang, Xiaodong; Bazak, Lily; Buchumenski, Ilana; Zhao, Yang; Lövy, Matěj; Li, Xiangfeng; Han, Lijuan; Frenkel, Zeev; Beiles, Avigdor; Cao, Yi Bin; Wang, Zhen Long; Nevo, Eviatar

    2016-01-01

    Incipient sympatric speciation in blind mole rat, Spalax galili, in Israel, caused by sharp ecological divergence of abutting chalk–basalt ecologies, has been proposed previously based on mitochondrial and whole-genome nuclear DNA. Here, we present new evidence, including transcriptome, DNA editing, microRNA, and codon usage, substantiating earlier evidence for adaptive divergence in the abutting chalk and basalt populations. Genetic divergence, based on the previous and new evidence, is ongoing despite restricted gene flow between the two populations. The principal component analysis, neighbor-joining tree, and genetic structure analysis of the transcriptome clearly show the clustered divergent two mole rat populations. Gene-expression level analysis indicates that the population transcriptome divergence is displayed not only by soil divergence but also by sex. Gene ontology enrichment of the differentially expressed genes from the two abutting soil populations highlights reproductive isolation. Alternative splicing variation of the two abutting soil populations displays two distinct splicing patterns. L-shaped FST distribution indicates that the two populations have undergone divergence with gene flow. Transcriptome divergent genes highlight neurogenetics and nutrition characterizing the chalk population, and energetics, metabolism, musculature, and sensory perception characterizing the abutting basalt population. Remarkably, microRNAs also display divergence between the two populations. The GC content is significantly higher in chalk than in basalt, and stress-response genes mostly prefer nonoptimal codons. The multiple lines of evidence of ecological–genomic and genetic divergence highlight that natural selection overrules the gene flow between the two abutting populations, substantiating the sharp ecological chalk–basalt divergence driving sympatric speciation. PMID:27339131

  18. Initialized Fractional Calculus

    NASA Technical Reports Server (NTRS)

    Lorenzo, Carl F.; Hartley, Tom T.

    2000-01-01

    This paper demonstrates the need for a nonconstant initialization for the fractional calculus and establishes a basic definition set for the initialized fractional differintegral. This definition set allows the formalization of an initialized fractional calculus. Two basis calculi are considered; the Riemann-Liouville and the Grunwald fractional calculi. Two forms of initialization, terminal and side are developed.

  19. Tempered fractional calculus

    SciTech Connect

    Sabzikar, Farzad; Meerschaert, Mark M.; Chen, Jinghua

    2015-07-15

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series.

  20. Global Air Quality and Climate Impacts of Mitigating Short-lived Climate Pollution in China

    NASA Astrophysics Data System (ADS)

    Harper, K.; Unger, N.; Heyes, C.; Kiesewetter, G.; Klimont, Z.; Schoepp, W.; Wagner, F.

    2014-12-01

    China is a major emitter of harmful air pollutants, including the short-lived climate pollutants (SLCPs) and their precursors. Implementation of pollution control technologies provides a mechanism for simultaneously protecting human and ecosystem health and achieving near-term climate co-benefits; however, predicting the outcomes of technical and policy interventions is challenging because the SLCPs participate in both climate warming and cooling and share many common emission sources. Here, we present the results of a combined regional integrated assessment and global climate modeling study aimed at quantifying the near-term climate and air quality co-benefits of selective control of Chinese air pollution emissions. Results from IIASA's Greenhouse Gas - Air Pollution Interactions and Synergies (GAINS) integrated assessment model indicate that methane emission reductions make up > 75% of possible CO2-equivalent emission reductions of the SLCPs and their precursors in China in 2030. A multi-pollutant emission reduction scenario incorporating the 2030 Chinese pollution control measures with the highest potential for future climate impact is applied to the NASA ModelE2 - Yale Interactive Terrestrial Biosphere (NASA ModelE2-YIBs) global carbon - chemistry - climate model to assess the regional and long-range impacts of Chinese SLCP mitigation measures. Using model simulations that incorporate dynamic methane emissions and photosynthesis-dependent isoprene emissions, we quantify the impacts of Chinese reductions of the short-lived air pollutants on radiative forcing and on surface ozone and particulate air pollution. Present-day modeled methane mole fractions are evaluated against SCIAMACHY methane columns and NOAA ESRL/GMD surface flask measurements.

  1. A modified mole cricket lure and description of Scapteriscus borellii (Orthoptera: Gryllotalpidae) range expansion and calling song in California.

    PubMed

    Dillman, Adler R; Cronin, Christopher J; Tang, Joseph; Gray, David A; Sternberg, Paul W

    2014-02-01

    Invasive mole cricket species in the genus Scapteriscus have become significant agricultural pests and are continuing to expand their range in North America. Though largely subterranean, adults of some species, such as Scapteriscus borellii Giglio-Tos 1894, are capable of long dispersive flights and phonotaxis to male calling songs to find suitable habitats and mates. Mole crickets in the genus Scapteriscus are known to be attracted to and can be caught by audio lure traps that broadcast synthesized or recorded calling songs. We report improvements in the design and production of electronic controllers for the automation of semipermanent mole cricket trap lures as well as highly portable audio trap collection designs. Using these improved audio lure traps, we collected the first reported individuals of the pest mole cricket S. borellii in California. We describe several characteristic features of the calling song of the California population including that the pulse rate is a function of soil temperature, similar to Florida populations of S. borellii. Further, we show that other calling song characteristics (carrier frequency, intensity, and pulse rate) are significantly different between the populations.

  2. Habitat and Burrow System Characteristics of the Blind Mole Rat Spalax galili in an Area of Supposed Sympatric Speciation

    PubMed Central

    Lövy, Matěj; Šklíba, Jan; Hrouzková, Ema; Dvořáková, Veronika; Nevo, Eviatar; Šumbera, Radim

    2015-01-01

    A costly search for food in subterranean rodents resulted in various adaptations improving their foraging success under given ecological conditions. In Spalax ehrenbergi superspecies, adaptations to local ecological conditions can promote speciation, which was recently supposed to occur even in sympatry at sites where two soil types of contrasting characteristics abut each other. Quantitative description of ecological conditions in such a site has been, nevertheless, missing. We measured characteristics of food supply and soil within 16 home ranges of blind mole rats Spalax galili in an area subdivided into two parts formed by basaltic soil and pale rendzina. We also mapped nine complete mole rat burrow systems to compare burrowing patterns between the soil types. Basaltic soil had a higher food supply and was harder than rendzina even under higher moisture content and lower bulk density. Population density of mole rats was five-times lower in rendzina, possibly due to the lower food supply and higher cover of Sarcopoterium shrubs which seem to be avoided by mole rats. A combination of food supply and soil parameters probably influences burrowing patterns resulting in shorter and more complex burrow systems in basaltic soil. PMID:26192762

  3. A recurrent intragenic genomic duplication, other novel mutations in NLRP7 and imprinting defects in recurrent biparental hydatidiform moles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A complete hydatidiform mole (CHM) is an abnormal pregnancy with hyperproliferative vesicular trophoblast and no fetal development. Most CHM are sporadic and androgenetic, but recurrent HM have biparental inheritance (BiHM) with disrupted DNA methylation at differentially methylated regions (DMRs) o...

  4. A Study Comparing the Efficacy of a Mole Ratio Flow Chart to Dimensional Analysis for Teaching Reaction Stoichiometry.

    ERIC Educational Resources Information Center

    Wagner, Eugene P.

    2001-01-01

    Reaction stoichiometry calculations have always been difficult for students. Offers the use of a mole ratio flow chart (MRFC) as a logistical sequence of steps that incorporates molar proportions as alternative problem solving techniques to improve student understanding. Indicates that MRFC users performed as well on exam problems covering…

  5. Fraction Sense: Foundational Understandings.

    PubMed

    Fennell, Francis Skip; Karp, Karen

    2016-08-09

    The intent of this commentary is to identify elements of fraction sense and note how the research studies provided in this special issue, in related but somewhat different ways, validate the importance of such understandings. Proficiency with fractions serves as a prerequisite for student success in higher level mathematics, as well as serving as a gateway to many occupations and varied contexts beyond the mathematics classroom. Fraction sense is developed through instructional opportunities involving fraction equivalence and magnitude, comparing and ordering fractions, using fraction benchmarks, and computational estimation. Such foundations are then extended to operations involving fractions and decimals and applications involving proportional reasoning. These components of fraction sense are all addressed in the studies provided in this issue, with particular consideration devoted to the significant importance of the use of the number line as a central representational tool for conceptually understanding fraction magnitude.

  6. TEMPERED FRACTIONAL CALCULUS

    PubMed Central

    MEERSCHAERT, MARK M.; SABZIKAR, FARZAD; CHEN, JINGHUA

    2014-01-01

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series. PMID:26085690

  7. HP3 on ExoMars - Cutting airbag cloths with the sharp tip of a mechanical mole

    NASA Astrophysics Data System (ADS)

    Krause, C.; Izzo, M.; Re, E.; Mehls, C.; Richter, L.; Coste, P.

    2009-04-01

    The HP3 - Heat Flow and Physical Properties Package - is planned to be one of the Humboldt lander-based instruments on the ESA ExoMars mission. HP3 will allow the measurement of the subsurface temperature gradient and physical as well as thermophysical properties of the subsurface regolith of Mars down to a depth of 5 meters. From these measurements, the planetary heat flux can be inferred. The HP³ instrument package consists of a mole trailing a package of thermal and electrical sensors into the regolith. Beside the payload elements Thermal Excitation and Measurement Suite and a Permittivity Probe the HP3 experiment includes sensors to detect the forward motion and the tilt of the HP3 payload compartment. The HP3 experiment will be integrated into the lander platform of the ExoMars mission. The original accommodation featured a deployment device or a robotic arm to place HP3 onto the soil outside the deflated lander airbags. To avoid adding such deployment devices, it was suggested that the HP3 mole should be capable of piercing the airbags under the lander. The ExoMars lander airbag is made of 4 Kevlar layers (2 abrasive and 2 bladders). A double fold of the airbag (a worst case) would represent a pile of 12 layers. An exploratory study has examined the possibility of piercing airbag cloths by adding sharp cutting blades on the tip of a penetrating mole. In the experimental setup representative layers were laid over a Mars soil simulant. Initial tests used a hammer-driven cutting tip and had moderate to poor results. More representative tests used a prototype of the HP3 mole and were fully successful: the default 4 layer configuration was pierced as well as the 12 layer configuration, the latter one within 3 hours and about 3000 mole strokes This improved behaviour is attributed to the use of representative test hardware where guidance and suppression of mole recoil were concerned. The presentation will provide an explanation of the technical requirements on

  8. Expression of acid-sensing ion channels and selection of reference genes in mouse and naked mole rat.

    PubMed

    Schuhmacher, Laura-Nadine; Smith, Ewan St John

    2016-12-13

    Acid-sensing ion channels (ASICs) are a family of ion channels comprised of six subunits encoded by four genes and they are expressed throughout the peripheral and central nervous systems. ASICs have been implicated in a wide range of physiological and pathophysiological processes: pain, breathing, synaptic plasticity and excitotoxicity. Unlike mice and humans, naked mole-rats do not perceive acid as a noxious stimulus, even though their sensory neurons express functional ASICs, likely an adaptation to living in a hypercapnic subterranean environment. Previous studies of ASIC expression in the mammalian nervous system have often not examined all subunits, or have failed to adequately quantify expression between tissues; to date there has been no attempt to determine ASIC expression in the central nervous system of the naked mole-rat. Here we perform a geNorm study to identify reliable housekeeping genes in both mouse and naked mole-rat and then use quantitative real-time PCR to estimate the relative amounts of ASIC transcripts in different tissues of both species. We identify RPL13A (ribosomal protein L13A) and CANX (calnexin), and β-ACTIN and EIF4A (eukaryotic initiation factor 4a) as being the most stably expressed housekeeping genes in mouse and naked mole-rat, respectively. In both species, ASIC3 was most highly expressed in dorsal root ganglia (DRG), and ASIC1a, ASIC2b and ASIC3 were more highly expressed across all brain regions compared to the other subunits. We also show that ASIC4, a proton-insensitive subunit of relatively unknown function, was highly expressed in all mouse tissues apart from DRG and hippocampus, but was by contrast the lowliest expressed ASIC in all naked mole-rat tissues.

  9. Experimental studies on the extinction of hydrogen-air counterflow diffusion flames

    NASA Technical Reports Server (NTRS)

    Pellett, G. L.; Wilson, L. G.; Northam, G. B.

    1990-01-01

    The paper presents data on the extinction of hydrogen-air counterflow diffusion flames (CFDFs). In the experiments, five coaxial tubular opposed jet burners were used to form dish-shaped CFDFs, centered by opposing laminar jets of N2-diluted H2 and both clean and contaminated air in the argon-purged chamber at 1 atm. Air jet velocities, U(air), characterized extinction of the air-side flame (blowoff) as functions of input H2/N2 (20-100 mole pct) on the fuel side, and air contaminant (0-20 percent) steam, CO2 and O2 (16-30 percent) on the air side.

  10. Request for approval, vented container annual release fraction

    SciTech Connect

    HILL, J.S.

    1999-10-12

    In accordance with the approval conditions for Modification to the Central Waste Complex (CWC) Radioactive Air Emissions Notice of Construction (NOC). dated August 24,1998, a new release fraction has been developed for submittal to the Washington State Department of Health (WDOH). The proposed annual release fraction of 2.50 E-14 is proposed for use in future NOCs involving the storage and handling operations associated with vented containers on the Hanford Site. The proposed annual release fraction was the largest release fraction calculated from alpha measurements of the NucFil filters from 10 vented containers consisting of nine 55-gallon drums and one burial box with dimensions of 9.3 x 5.7 x 6.4 feet. An annual release fraction of 2.0 E-09 was used in the modification to the CWC radioactive air emissions NOC. This study confirmed that the release fraction used in the CWC radioactive air emissions NOC was conservative.

  11. Molecular weight distribution of soluble fiber fractions and short chain fatty acids in ileal digesta of growing pigs.

    PubMed

    Ivarsson, E; Andersson, R; Lindberg, J E

    2012-12-01

    The effect of dietary fiber source on molecular weight (MW) distribution of soluble fiber fractions and short chain fatty acids (SCFA) in ileal digesta of 7 post valve T-cecum (PVTC) cannulated growing pigs was studied. Pigs were fed semisynthetic diets with sugar beet (Beta vulgaris) pulp (SBP) or chicory (Cichorium intybus) forage (CFO) as fiber sources of which the soluble nonstarch polysaccharide (NSP) fraction originated mainly from pectin. Three MW intervals were selected-large MW (MWL): 10,000,000 to 1,000,000 g/mol, medium MW (MWM): 1,000,000 to 200,000 g/mol, and small MW (MWS): 200,000 to 10,000 g/mol-and the relative distribution (% of total) of molecules in each interval was calculated. The MWM fraction was higher (P < 0.05) in ileal digesta of pigs fed diet SBP and the MWS fraction was higher (P < 0.05) in ileal digesta of pigs fed diet CFO. The mole/100 mole of propionic acid (HPr) was higher (P < 0.010) in pigs fed diet SBP whereas pigs fed diet CFO had higher (P < 0.010) mole/100 mole of acetic acid (HAc). The proportion of the MWL and MWM fractions in ileal digesta were negatively correlated to HAc (r = -0.52, P = 0.05, and r = -0.62, P = 0.02, respectively). The proportion of MWM in ileal digesta was positively correlated to HPr (r = 0.83; P = 0.001) whereas MWS and HPr were negatively correlated (r = -0.76; P = 0.002). In conclusion, the bacterial degradation of the soluble NSP fraction is selective and MW distribution may explain differences in SCFA production.

  12. Tumour resistance in induced pluripotent stem cells derived from naked mole-rats.

    PubMed

    Miyawaki, Shingo; Kawamura, Yoshimi; Oiwa, Yuki; Shimizu, Atsushi; Hachiya, Tsuyoshi; Bono, Hidemasa; Koya, Ikuko; Okada, Yohei; Kimura, Tokuhiro; Tsuchiya, Yoshihiro; Suzuki, Sadafumi; Onishi, Nobuyuki; Kuzumaki, Naoko; Matsuzaki, Yumi; Narita, Minoru; Ikeda, Eiji; Okanoya, Kazuo; Seino, Ken-Ichiro; Saya, Hideyuki; Okano, Hideyuki; Miura, Kyoko

    2016-05-10

    The naked mole-rat (NMR, Heterocephalus glaber), which is the longest-lived rodent species, exhibits extraordinary resistance to cancer. Here we report that NMR somatic cells exhibit a unique tumour-suppressor response to reprogramming induction. In this study, we generate NMR-induced pluripotent stem cells (NMR-iPSCs) and find that NMR-iPSCs do not exhibit teratoma-forming tumorigenicity due to the species-specific activation of tumour-suppressor alternative reading frame (ARF) and a disruption mutation of the oncogene ES cell-expressed Ras (ERAS). The forced expression of Arf in mouse iPSCs markedly reduces tumorigenicity. Furthermore, we identify an NMR-specific tumour-suppression phenotype-ARF suppression-induced senescence (ASIS)-that may protect iPSCs and somatic cells from ARF suppression and, as a consequence, tumorigenicity. Thus, NMR-specific ARF regulation and the disruption of ERAS regulate tumour resistance in NMR-iPSCs. Our findings obtained from studies of NMR-iPSCs provide new insight into the mechanisms of tumorigenicity in iPSCs and cancer resistance in the NMR.

  13. Macroalgal fouling on the intertidal mole crab Emerita analoga facilitates bird predation

    NASA Astrophysics Data System (ADS)

    Hidalgo, Fernando J.; Firstater, Fausto N.; Lomovasky, Betina J.; Gallegos, Percy; Gamero, Patricia; Iribarne, Oscar O.

    2010-12-01

    In this work, we studied the effects of predation by birds on the intertidal mole crab Emerita analoga fouled by macroalgae in a sandy beach of central Peru (11° S). The epibiosis affected mostly the larger animals, especially adult females. Epibiosis prevalence for the entire intertidal population was relatively low (1-2%), however, within the size range affected by epibiosis in the intertidal zone (18-23 mm in carapace length), 20-38% of the animals were fouled. Focal observations of birds showed that fouled animals are preferred over those non-fouled of the same size class and hence the same sex, being consumed at a higher rate than their proportion in the intertidal (Chesson’s alpha index of prey selection >0.96), and estimations of mortality rates indicated that more than 35% of the intertidal fouled animals are removed everyday by birds. The effect of epibiosis may be mainly attributed to a higher burrowing time or an increased visual attractive effect of the algae, which make fouled animals more conspicuous to predatory birds, or because of fouling enhances profitability of the animals. The results show that epibiosis has negative effects on E. analoga through increasing predation by birds, which in turn restricts the distribution and abundance of fouled E. analoga in the intertidal zone.

  14. Influence of the mole penetrator on measurements of heat flow in lunar subsurface layers

    NASA Astrophysics Data System (ADS)

    Wawrzaszek, Roman; Drogosz, Michal; Seweryn, Karol; Banaszkiewicz, Marek; Grygorczuk, Jerzy

    Measuring the thermal gradient in subsurface layers is a basic method of determination the heat flux from the interior of a planetary body to its surface. In case of the Moon, such measurements complemented with the results of theoretical analysis and modeling can significantly improve our understanding of the thermal and geological evolution of the Moon. In practice, temperature gradient measurements are performed by at least two sensors located at different depths under the surface. These sensors will be attached to a penetrator [1] or to a cable pulled behind the penetrator. In both cases the object that carries the sensors, e.g. penetrator, perturb temperature measurements. In our study we analyze a case of two thermal sensors attached to the ends of 350mm long penetrator made of a composite material. In agreement with the studies of other authors we have found that the penetrator should be placed at the depth of 2-3 meters, where periodic changes of the temperature due to variation of solar flux at the surface are significantly smaller than the error of temperature measurement. The most important result of our analysis is to show how to deconvolve the real gradient of the temperature from the measurements perturbed by the penetrator body. In this way it will be possible to more accurately determine heat flux in the lunar regolith. [1] Grygorczuk J., Seweryn K., Wawrzaszek R., Banaszkiewicz M., Insertion of a Mole Pene-trator -Experimental Results, /39th Lunar and Planetary Science Conference /League City, Texas 2008

  15. The energy costs of sexual dimorphism in mole-rats are morphological not behavioural

    PubMed Central

    Scantlebury, M; Speakman, J.R; Bennett, N.C

    2005-01-01

    Different reproductive strategies of males and females may lead to the evolution of differences in their energetic costs of reproduction, overall energetic requirements and physiological performances. Sexual dimorphism is often associated with costly behaviours (e.g. large males might have a competitive advantage in fighting, which is energetically expensive). However, few studies of mammals have directly compared the energy costs of reproductive activities between sexes. We compared the daily energy expenditure (DEE) and resting metabolic rate (RMR) of males and females of two species of mole-rat, Bathyergus janetta and Georychus capensis (the former is sexually dimorphic in body size and the latter is not) during a period of intense digging when males seek females. We hypothesized that large body size might be indicative of greater digging or fighting capabilities, and hence greater mass-independent DEE values in males of the sexually dimorphic species. In contrast to this prediction, although absolute values of DEE were greater in B. janetta males, mass-independent values were not. No differences were apparent between sexes in G. capensis. By comparison, although RMR values were greater in B. janetta than G. capensis, no differences were apparent between the sexes for either species. The energy cost of dimorphism is most likely to be the cost of maintenance of a large body size, and not the cost of behaviours performed when an individual is large. PMID:16519235

  16. Adaptive methylation regulation of p53 pathway in sympatric speciation of blind mole rats, Spalax.

    PubMed

    Zhao, Yang; Tang, Jia-Wei; Yang, Zhi; Cao, Yi-Bin; Ren, Ji-Long; Ben-Abu, Yuval; Li, Kexin; Chen, Xue-Qun; Du, Ji-Zeng; Nevo, Eviatar

    2016-02-23

    Epigenetic modifications play significant roles in adaptive evolution. The tumor suppressor p53, well known for controlling cell fate and maintaining genomic stability, is much less known as a master gene in environmental adaptation involving methylation modifications. The blind subterranean mole rat Spalax eherenbergi superspecies in Israel consists of four species that speciated peripatrically. Remarkably, the northern Galilee species Spalax galili (2n = 52) underwent adaptive ecological sympatric speciation, caused by the sharply divergent chalk and basalt ecologies. This was demonstrated by mitochondrial and nuclear genomic evidence. Here we show that the expression patterns of the p53 regulatory pathway diversified between the abutting sympatric populations of S. galili in sharply divergent chalk-basalt ecologies. We identified higher methylation on several sites of the p53 promoter in the population living in chalk soil (chalk population). Site mutagenesis showed that methylation on these sites linked to the transcriptional repression of p53 involving Cut-Like Homeobox 1 (Cux1), paired box 4 (Pax 4), Pax 6, and activator protein 1 (AP-1). Diverse expression levels of p53 between the incipiently sympatrically speciating chalk-basalt abutting populations of S. galili selectively affected cell-cycle arrest but not apoptosis. We hypothesize that methylation modification of p53 has adaptively shifted in supervising its target genes during sympatric speciation of S. galili to cope with the contrasting environmental stresses of the abutting divergent chalk-basalt ecologies.

  17. Soboliphyme occidentalis sp. nov. (Nematoda, Soboliphymidae) from the Iberian mole Talpa occidentalis (Insectivora, Talpidae) in Spain.

    PubMed

    Ribas, Alexis; Casanova, Joan Carles

    2004-08-01

    A new species of Soboliphyme from the endemic Iberian mole (Talpa occidentalis) is described. Soboliphyme occidentalis sp. nov. can be readily distinguished from all of its congeners primarily by the position of the vulva, which clearly shows a posterior oesophageal location, and the number of male caudal papillae. S. occidentalis sp. nov. is the only species that has four pairs of caudal papillae. S. abei, S. caucasica and S. jamesoni can be distinguished from S. occidentalis sp. nov. by not having a notched sucker, the anterior position of the vulva and two polar plugs in the eggs. S. jamesoni has an armate oral sucker and longer spicule; S. caucasica a longer spicule and shorter eggs, and S. abei has shorter eggs, which separate these species from S. occidentalis sp. nov. In the rest of the species with a notched oral sucker, S. baturini and S. hirudiniformis are differentiated from S. occidentalis sp. nov. by the anterior position of the vulva, two polar plugs in the egg and the spicule length in S. baturini and S. hirudiniformis and the size of eggs in S. baturini and S. hirudiniformis. S. ataahai, S. soricis and S. urotrichi have the vulva at the oesophago-intestinal junction, 9-10 male caudal papillae (S. ataahai and S. urotrichi), absence of male caudal papillae (S. soricis), armate oral sucker and long spicule in S. ataahai and one row of six circumoral spines in S. urotrichi. A key to the species of Soboliphyme is presented.

  18. Analysis of dental anomalies in the Siberian mole, Talpa altaica (Insectivora, Talpidae).

    PubMed

    Kawada, Shin-ichiro; Koyasu, Kazuhiro; Zholnerovskaya, Elena I; Oda, Sen-ichi

    2006-11-01

    We re-examined tooth variation in specimens of the Siberian mole, Talpa altaica, from the collection of the Siberian Zoological Museum and discuss the mechanisms of dental evolution. The number of teeth counted in 1789 specimens ranged from 34 to 47, and supernumerary, absent, and connate teeth were observed. The most frequent tooth anomaly was an absent tooth in the premolar region (200 maxillary first premolars and 190 mandibular third premolars), which does not support Fujita and Kirino's terminal reduction hypothesis in the mandible [Fujita T, Kirino T. Ha No Kaibougaku. 21st ed. Tokyo: Kanehara Publishers Inc.; 1976 (in Japanese)]. Supernumerary teeth were found in premolar rows and in the incisor and molar regions. An maxillary fourth molar, positioned distal to the normal third molar, was thought to result from a genetically programmed atavistic event during the natal stages. Connate teeth were observed only in the premolar rows and were thought to have developed with the fusion of two independent tooth germs. Connate premolars appeared to result from an expression of an incomplete division of tooth germ at an early developmental stage or a reunion of independent tooth germs, based on the morphological similarity of the normal and supernumerary premolars. These extraordinarily frequent tooth anomalies of T. altaica are of much interest both in terms of tooth development and classification.

  19. Cryptic sex? Estimates of genome exchange in unisexual mole salamanders (Ambystoma sp.).

    PubMed

    Gibbs, H Lisle; Denton, Robert D

    2016-06-01

    Cryptic sex has been argued to explain the exceptional longevity of certain parthenogenetic vertebrate lineages, yet direct measurements of genetic exchange between sexual and apparently parthenogenetic forms are rare. Female unisexual mole salamanders (Ambystoma sp.) are the oldest known unisexual vertebrate lineage (~5 million years), and one hypothesis for their persistence is that allopolyploid female unisexuals periodically exchange haploid genomes 'genome exchange' during gynogenetic reproduction with males from sympatric sexual species. We test this hypothesis by using genome-specific microsatellite DNA markers to estimate the rates of genome exchange between sexual males and unisexual females in two ponds in NE Ohio. We also test the prediction that levels of gene flow should be higher for 'sympatric' (sexual males present) genomes in unisexuals compared to 'allopatric' (sexual males absent) unisexual genomes. We used a model testing framework in the coalescent-based program MIGRATE-N to compare models where unidirectional gene flow is present and absent between sexual species and unisexuals. As predicted, our results show higher levels of gene flow between sexuals and sympatric unisexual genomes compared to lower (likely artefactual) levels of gene flow between sexuals and allopatric unisexual genomes. Our results provide direct evidence that genome exchange between sexual and unisexual Ambystoma occurs and demonstrate that the magnitude depends on which sexual species are present. The relatively high levels of gene flow suggest that unisexuals must be at a selective advantage over sexual forms so as to avoid extinction due to genetic swamping through genome exchange.

  20. Adaptive methylation regulation of p53 pathway in sympatric speciation of blind mole rats, Spalax

    PubMed Central

    Zhao, Yang; Tang, Jia-Wei; Yang, Zhi; Cao, Yi-Bin; Ren, Ji-Long; Ben-Abu, Yuval; Li, Kexin; Chen, Xue-Qun; Du, Ji-Zeng; Nevo, Eviatar

    2016-01-01

    Epigenetic modifications play significant roles in adaptive evolution. The tumor suppressor p53, well known for controlling cell fate and maintaining genomic stability, is much less known as a master gene in environmental adaptation involving methylation modifications. The blind subterranean mole rat Spalax eherenbergi superspecies in Israel consists of four species that speciated peripatrically. Remarkably, the northern Galilee species Spalax galili (2n = 52) underwent adaptive ecological sympatric speciation, caused by the sharply divergent chalk and basalt ecologies. This was demonstrated by mitochondrial and nuclear genomic evidence. Here we show that the expression patterns of the p53 regulatory pathway diversified between the abutting sympatric populations of S. galili in sharply divergent chalk–basalt ecologies. We identified higher methylation on several sites of the p53 promoter in the population living in chalk soil (chalk population). Site mutagenesis showed that methylation on these sites linked to the transcriptional repression of p53 involving Cut-Like Homeobox 1 (Cux1), paired box 4 (Pax 4), Pax 6, and activator protein 1 (AP-1). Diverse expression levels of p53 between the incipiently sympatrically speciating chalk–basalt abutting populations of S. galili selectively affected cell-cycle arrest but not apoptosis. We hypothesize that methylation modification of p53 has adaptively shifted in supervising its target genes during sympatric speciation of S. galili to cope with the contrasting environmental stresses of the abutting divergent chalk–basalt ecologies. PMID:26858405

  1. Macroscopic anatomy of the lower respiratory system in mole rats (Spalax leucodon).

    PubMed

    İlgun, R; Yoldas, A; Kuru, N; Özkan, Z E

    2014-12-01

    The morphologic and morphometric features of the lower respiratory system in mole rats were examined. It was seen that the low respiratory system of this species leading a special life under highly hypoxic/hypercapnic conditions underground is structurally similar to other mammals living on land in terms of the parts examined; trachea was formed by 29.5 ± 4 oval-formed cartilaginous tracheals arranged backwards and became gradually more stenotic diameter from cranial to the caudal of the neck. The trachea was separated in two principal bronchus at the fourth thoracal intercostal spatium level. The angle between the two main principal bronchi was 60.5 ± 2.35°. The lung constituted 1.29 ± 0.03% of the body weight and the right lung was heavier than the left lung. Fissura inter-lobaris was deep and separated the lung lobes wholly, and the right lung was separated in four lobes, whereas the left lung was not separated into the lobes. Also, the medial lobe of the left lung was the lightest lobe.

  2. Stress, adaptation, and speciation in the evolution of the blind mole rat, Spalax, in Israel.

    PubMed

    Nevo, Eviatar

    2013-02-01

    Environmental stress played a major role in the evolution of the blind mole rat superspecies Spalax ehrenbergi, affecting its adaptive evolution and ecological speciation underground. Spalax is safeguarded all of its life underground from aboveground climatic fluctuations and predators. However, it encounters multiple stresses in its underground burrows including darkness, energetics, hypoxia, hypercapnia, food scarcity, and pathogenicity. Consequently, it evolved adaptive genomic, proteomic, and phenomic complexes to cope with those stresses. Here I describe some of these adaptive complexes, and their theoretical and applied perspectives. Spalax mosaic molecular and organismal evolution involves reductions or regressions coupled with expansions or progressions caused by evolutionary tinkering and natural genetic engineering. Speciation of Spalax in Israel occurred in the Pleistocene, during the last 2.00-2.35 Mya, generating four species associated intimately with four climatic regimes with increasing aridity stress southwards and eastwards representing an ecological speciational adaptive trend: (Spalax golani, 2n=54→S. galili, 2n=52→S. carmeli, 2n=58→S. judaei, 2n=60). Darwinian ecological speciation occurred gradually with relatively little genetic change by Robertsonian chromosomal and genic mutations. Spalax genome sequencing has just been completed. It involves multiple adaptive complexes to life underground and is an evolutionary model to a few hundred underground mammals. It involves great promise in the future for medicine, space flight, and deep-sea diving.

  3. Initial Case Reports of Cancer in Naked Mole-rats (Heterocephalus glaber).

    PubMed

    Delaney, M A; Ward, J M; Walsh, T F; Chinnadurai, S K; Kerns, K; Kinsel, M J; Treuting, P M

    2016-05-01

    Naked mole-rats (NMRs;Heterocephalus glaber) are highly adapted, eusocial rodents renowned for their extreme longevity and resistance to cancer. Because cancer has not been formally described in this species, NMRs have been increasingly utilized as an animal model in aging and cancer research. We previously reported the occurrence of several age-related diseases, including putative pre-neoplastic lesions, in zoo-housed NMR colonies. Here, we report for the first time 2 cases of cancer in zoo-housed NMRs. In Case No. 1, we observed a subcutaneous mass in the axillary region of a 22-year-old male NMR, with histologic, immunohistochemical (pancytokeratin positive, rare p63 immunolabeling, and smooth muscle actin negative), and ultrastructural characteristics of an adenocarcinoma possibly of mammary or salivary origin. In Case No. 2, we observed a densely cellular, poorly demarcated gastric mass of polygonal cells arranged in nests with positive immunolabeling for synaptophysin and chromogranin indicative of a neuroendocrine carcinoma in an approximately 20-year-old male NMR. We also include a brief discussion of other proliferative growths and pre-cancerous lesions diagnosed in 1 zoo colony. Although these case reports do not alter the longstanding observation of cancer resistance, they do raise questions about the scope of cancer resistance and the interpretation of biomedical studies in this model. These reports also highlight the benefit of long-term disease investigations in zoo-housed populations to better understand naturally occurring disease processes in species used as models in biomedical research.

  4. Renal Pathology in a Nontraditional Aging Model: The Naked Mole-Rat (Heterocephalus glaber).

    PubMed

    Delaney, M A; Kinsel, M J; Treuting, P M

    2016-03-01

    The naked mole-rat (NMR; Heterocephalus glaber) is growing in popularity as a model for aging research due to its extreme longevity (up to 30 years), highly adapted physiology, and resistance to cancer, particularly when compared with traditional aging models such as laboratory mice and rats. Despite the NMR's seemingly lengthy health span, several age-related lesions have been documented. During a 15-year retrospective evaluation of a zoo-housed population, histologic changes in the kidneys were reported in 127 of 138 (92%) adult NMRs. Of these, renal tubular mineralization was very common (115 of 127; 90.6%) and found in NMRs without concurrent renal lesions (36 of 127; 28.3%). Many of the other described lesions were considered progressive stages of a single process, generally referred to as chronic nephritis or nephropathy, and diagnosed in 73 of 127 (57.5%), while end-stage renal disease was reported in only 12 (9.4%) NMRs. Renal lesions of these NMRs were comparable to disease entities reported in laboratory rats and certain strains of inbred and noninbred mice. Although many lesions of NMR kidneys were similar to those found in aged laboratory rodents, some common urinary diseases were not represented in the examined colonies. The goal of this study was to describe renal lesions in NMRs from a zoologic setting to familiarize investigators and pathologists with an apparently common and presumably age-related disease in this nontraditional model.

  5. Ectoparasite Burdens of the Damaraland Mole-Rat (Fukomys damarensis) from Southern Africa.

    PubMed

    Lutermann, Heike; Carpenter-Kling, Tegan; Ueckermann, Edward A; Gutjahr, Gundula; Bennett, Nigel C

    2015-12-01

    Damaraland mole-rats (Fukomys damarensis) of the family Bathyergidae are widely distributed subterranean rodents in sub-Saharan Africa. No parasites have ever been reported for this species and only 1 ectoparasite is described for the entire genus. In the current study ectoparasites were collected from individuals captured at 3 localities in South Africa and Namibia to document the ectoparasite community of F. damarensis, investigate their aggregation patterns, and evaluate the influence of season on ectoparasite burden. A total of 2,071 arthropods from 9 mite taxa and 1 louse species (Eulinognathus hilli) were collected from 293 hosts sampled. Of these, 5 mite species (Androlaelaps scapularis, Androlaelaps capensis, Androlaelaps tauffliebi, Radfordia sp., and unidentified chiggers) and the louse were parasites while the remainder was soil mites. All ectoparasites were highly aggregated and the species richness as well as the prevalence and abundance of 4 of them were significantly greater in summer compared to winter, possibly as a result of seasonal changes in rainfall patterns affecting the ectoparasites, host behavior, or both.

  6. DIY Fraction Pack.

    ERIC Educational Resources Information Center

    Graham, Alan; Graham, Louise

    2003-01-01

    Describes a very successful attempt to teach fractions to year 5 pupils based on pupils making their own fraction pack. Children decided for themselves how to make the fractional slices used in the activity using colored cardboard sheets and templates of a paper circle consisting of 24 equal slices. (Author/NB)

  7. Pitch fractionation. Technical report

    SciTech Connect

    Weinberg, V.L.; White, J.L.

    1981-12-15

    Petroleum pitch (Ashland A240) has been subjected to thermal treatment and solvent fractionation to produce refined pitches to be evaluated as impregnants for carbon-carbon composites. The solvent fractions were obtained by sequential Soxhlet extraction with solvents such as hexane, cyclohexane, toluene, and pyridine. The most severe thermal treatment produced a mesophase pitch (approximately 50% mesophase); an appreciable portion of the mesophase was soluble in strong solvents. There were substantial differences in chemical composition and in pyrolysis behavior of the fractions. As the depth of fraction increased, the pyrolysis yield and bloating increased, and the microstructure of the coke became finer until glassy microconstituents were formed in the deepest fractions.

  8. Bovine insulin-phosphatidylcholine mixed Langmuir monolayers: behavior at the air-water interface.

    PubMed

    Pérez-López, S; Blanco-Vila, N M; Vila-Romeu, N

    2011-08-04

    The behavior of the binary mixed Langmuir monolayers of bovine insulin (INS) and phosphatidylcholine (PC) spread at the air-water interface was investigated under various subphase conditions. Pure and mixed monolayers were spread on water, on NaOH and phosphate-buffered solutions of pH 7.4, and on Zn(2+)-containing solutions. Miscibility and interactions between the components were studied on the basis of the analysis of the surface pressure (π)-mean molecular area (A) isotherms, surface compression modulus (C(s)(-1))-π curves, and plots of A versus mole fraction of INS (X(INS)). Our results indicate that intermolecular interactions between INS and PC depend on both the monolayer state and the structural characteristics of INS at the interface, which are strongly influenced by the subphase pH and salt content. Brewster angle microscopy (BAM) was applied to investigate the peptide aggregation pattern at the air-water interface in the presence of the studied lipid under any experimental condition investigated. The influence of the lipid on the INS behavior at the interface strongly depends on the subphase conditions.

  9. Geochemical and Petrologic Constraints on the Source of Eocene Volcanism at Mole Hill, Rockingham County, VA

    NASA Astrophysics Data System (ADS)

    Johnson, E. A.; Beard, J. S.

    2010-12-01

    Mole Hill is an Eocene (48 Ma) basaltic volcanic neck located west of Harrisonburg, VA, and provides a unique opportunity to probe the mantle beneath the Shenandoah Valley. It lies on the northeastern edge of a swarm of alkaline-series volcanic plugs, dikes, and diatremes extending through Rockingham and Highland Counties, VA, and Pendleton County, WV. The Eocene volcanics are thought to have exploited extensive basement fracture systems originally formed during the Alleghenian Orogeny and subsequent rifting. The Eocene volcanism may have been triggered by reactivation of faults due to global shifts in relative plate motions (Southworth 1993, USGS Bull, B1839-I) but the source material and magmatic processes for the Eocene volcanism are largely unknown. Compositional and texture analyses of xenocrystic and groundmass clinopyroxene, olivine, and spinel were completed either at Virginia Tech on the Cameca SX-50 electron microprobe in the Dept of Geological Sciences, or in the Dept of Mineral Sciences, Smithsonian Institution, Washington, D.C using the JEOL JXA-8900R WD/EDS microanalyzer or the FEI NOVA nanoSEM600 FEG Variable Pressure Scanning Electron Microscope. Xenocrysts up to 2cm in diameter are distributed throughout the volcanic neck, with clinopyroxene >>spinel>olivine. The clinopyroxene and olivine xenocrysts show undulatory extinction in cross-polarized light and are found as individual crystals or as aggregates. Clinopyroxene xenocryst cores are high-Al, low-Cr augite ( ˜Wo44En46Fs10) with Mg# 78.5-85.9. The clinopyroxene xenocrysts have compositionally zoned rims 100-250 μm-wide containing abundant plagioclase inclusions and sparse melt inclusions in a sieve texture. The outer edges of xenocrysts approach the compositions of groundmass and microphenocryst clinopyroxenes ( ˜Wo47En38Fs15; Mg# 67.9-74.5). Olivine xenocrysts contain sulfide inclusions and Cr-rich spinel and have Mg-rich ( ˜Fo86-90) cores with more Fe- and Ca-rich rims (Fo70

  10. Local and Regional Scale Genetic Variation in the Cape Dune Mole-Rat, Bathyergus suillus

    PubMed Central

    Visser, Jacobus H.; Bennett, Nigel C.; Jansen van Vuuren, Bettine

    2014-01-01

    The distribution of genetic variation is determined through the interaction of life history, morphology and habitat specificity of a species in conjunction with landscape structure. While numerous studies have investigated this interplay of factors in species inhabiting aquatic, riverine, terrestrial, arboreal and saxicolous systems, the fossorial system has remained largely unexplored. In this study we attempt to elucidate the impacts of a subterranean lifestyle coupled with a heterogeneous landscape on genetic partitioning by using a subterranean mammal species, the Cape dune mole-rat (Bathyergus suillus), as our model. Bathyergus suillus is one of a few mammal species endemic to the Cape Floristic Region (CFR) of the Western Cape of South Africa. Its distribution is fragmented by rivers and mountains; both geographic phenomena that may act as geographical barriers to gene-flow. Using two mitochondrial fragments (cytochrome b and control region) as well as nine microsatellite loci, we determined the phylogeographic structure and gene-flow patterns at two different spatial scales (local and regional). Furthermore, we investigated genetic differentiation between populations and applied Bayesian clustering and assignment approaches to our data. Nearly every population formed a genetically unique entity with significant genetic structure evident across geographic barriers such as rivers (Berg, Verlorenvlei, Breede and Gourits Rivers), mountains (Piketberg and Hottentots Holland Mountains) and with geographic distance at both spatial scales. Surprisingly, B. suillus was found to be paraphyletic with respect to its sister species, B. janetta–a result largely overlooked by previous studies on these taxa. A systematic revision of the genus Bathyergus is therefore necessary. This study provides a valuable insight into how the biology, life-history and habitat specificity of animals inhabiting a fossorial system may act in concert with the structure of the surrounding

  11. Nutrition and burrowing energetics of the Cape mole-rat Georychus capensis.

    PubMed

    Du Toit, J T; Jarvis, J U M; Louw, G N

    1985-04-01

    At 22°C the resting oxygen consumption of G. capensis is 1.13±0.05 cm(3)O2·g(-1)·h(-1) (mean± S.E.). In loose sandy soil the burrowing metabolic rate was approximately three times that of resting (3.41±0.19 cm(3)O2·g(-1)· h(-1)). Rate of oxygen consumption while burrowing bears a linear relationship with rate of burrowing. The equation of the regression line describing this relationship was used to construct a model for calculating energy expenditure of burrowing in free-living mole-rats. The diet of G. capensis consists of some green plant material and geophyte corms. The latter has a mean gross energy content of 16.36 kJ·g(-1) dry weight. The digestibility coefficient for captive G. capensis fed on sweet potato, was 97.42±0.41%. Data collected from an excavated burrow system revealed that the total energetic cost of constructing the burrow amounted to 79% of the estimated digestible energy available from geophyte corms in the area. A food store in the same burrow system was sufficient to meet the maintenance requirements of an adult G. capensis, resting at 22°C, for approximately 80-85 days. Soil samples taken at random adjacent to the burrow contained corms with a mean estimated digestible energy value of 2084 kJ per m(3) of soil. A comparison of energetic cost of burrowing and randomly available digestible energy in the field suggests that foraging patterns are not random.

  12. Evolutionary basis of mitonuclear discordance between sister species of mole salamanders (Ambystoma sp.).

    PubMed

    Denton, Robert D; Kenyon, Laura J; Greenwald, Katherine R; Gibbs, H Lisle

    2014-06-01

    Distinct genetic markers should show similar patterns of differentiation between species reflecting their common evolutionary histories, yet there are increasing examples of differences in the biogeographic distribution of species-specific nuclear (nuDNA) and mitochondrial DNA (mtDNA) variants within and between species. Identifying the evolutionary processes that underlie these anomalous patterns of genetic differentiation is an important goal. Here, we analyse the putative mitonuclear discordance observed between sister species of mole salamanders (Ambystoma barbouri and A. texanum) in which A. barbouri-specific mtDNA is found in animals located within the range of A. texanum. We test three hypotheses for this discordance (undetected range expansion, mtDNA introgression, and hybridization) using nuDNA and mtDNA data analysed with methods that varied in the parameters estimated and the timescales measured. Results from a Bayesian clustering technique (structure), bidirectional estimates of gene flow (migrate-n and IMa2) and phylogeny-based methods (*beast, bucky) all support the conclusion that the discordance is due to geographically restricted mtDNA introgression from A. barbouri into A. texanum. Limited data on species-specific tooth morphology match this conclusion. Significant differences in environmental conditions exist between sites where A. texanum with and without A. barbouri-like mtDNA occur, suggesting a possible role for selection in the process of introgression. Overall, our study provides a general example of the value of using complimentary analyses to make inferences of the directionality, timescale, and source of mtDNA introgression in animals.

  13. Local and regional scale genetic variation in the Cape dune mole-rat, Bathyergus suillus.

    PubMed

    Visser, Jacobus H; Bennett, Nigel C; Jansen van Vuuren, Bettine

    2014-01-01

    The distribution of genetic variation is determined through the interaction of life history, morphology and habitat specificity of a species in conjunction with landscape structure. While numerous studies have investigated this interplay of factors in species inhabiting aquatic, riverine, terrestrial, arboreal and saxicolous systems, the fossorial system has remained largely unexplored. In this study we attempt to elucidate the impacts of a subterranean lifestyle coupled with a heterogeneous landscape on genetic partitioning by using a subterranean mammal species, the Cape dune mole-rat (Bathyergus suillus), as our model. Bathyergus suillus is one of a few mammal species endemic to the Cape Floristic Region (CFR) of the Western Cape of South Africa. Its distribution is fragmented by rivers and mountains; both geographic phenomena that may act as geographical barriers to gene-flow. Using two mitochondrial fragments (cytochrome b and control region) as well as nine microsatellite loci, we determined the phylogeographic structure and gene-flow patterns at two different spatial scales (local and regional). Furthermore, we investigated genetic differentiation between populations and applied Bayesian clustering and assignment approaches to our data. Nearly every population formed a genetically unique entity with significant genetic structure evident across geographic barriers such as rivers (Berg, Verlorenvlei, Breede and Gourits Rivers), mountains (Piketberg and Hottentots Holland Mountains) and with geographic distance at both spatial scales. Surprisingly, B. suillus was found to be paraphyletic with respect to its sister species, B. janetta-a result largely overlooked by previous studies on these taxa. A systematic revision of the genus Bathyergus is therefore necessary. This study provides a valuable insight into how the biology, life-history and habitat specificity of animals inhabiting a fossorial system may act in concert with the structure of the surrounding

  14. Simulation of the shallow groundwater-flow system near Mole Lake, Forest County, Wisconsin

    USGS Publications Warehouse

    Fienen, Michael N.; Juckem, Paul F.; Hunt, Randall J.

    2011-01-01

    The shallow groundwater system near Mole Lake, Forest County, Wis. was simulated using a previously calibrated regional model. The previous model was updated using newly collected water-level measurements and refinements to surface-water features. The updated model was then used to calculate the area contributing recharge for one existing and two proposed pumping locations on lands of the Sokaogon Chippewa Community. Delineated 1-, 5-, and 10-year areas contributing recharge for existing and proposed wells extend from the areas of pumping to the northeast of the pumping locations. Steady-state pumping was simulated for two scenarios: a base pumping scenario using pumping rates that reflect what the Tribe expects to pump and a high pumping scenario, in which the rate was set to the maximum expected from wells installed in this area. In the base pumping scenario, pumping rates of 32 gallons per minute (gal/min; 46,000 gallons per day (gal/d)) from the existing well and 30 gal/min (43,000 gal/d) at each of the two proposed wells were simulated. The high pumping scenario simulated a rate of 70 gal/min (101,000 gal/d) from each of the three pumping wells to estimate of the largest areas contributing recharge that might be expected given what is currently known about the shallow groundwater system. The areas contributing recharge for both the base and high pumping scenarios did not intersect any modeled surface-water bodies; however, the high pumping scenario had a larger areal extent than the base pumping scenario and intersected a septic separator.

  15. Dividing Fractions: A Pedagogical Technique

    ERIC Educational Resources Information Center

    Lewis, Robert

    2016-01-01

    When dividing one fraction by a second fraction, invert, that is, flip the second fraction, then multiply it by the first fraction. To multiply fractions, simply multiply across the denominators, and multiply across the numerators to get the resultant fraction. So by inverting the division of fractions it is turned into an easy multiplication of…

  16. RNA sequencing reveals differential expression of mitochondrial and oxidation reduction genes in the long-lived naked mole-rat when compared to mice.

    PubMed

    Yu, Chuanfei; Li, Yang; Holmes, Andrew; Szafranski, Karol; Faulkes, Chris G; Coen, Clive W; Buffenstein, Rochelle; Platzer, Matthias; de Magalhães, João Pedro; Church, George M

    2011-01-01

    The naked mole-rat (Heterocephalus glaber) is a long-lived, cancer resistant rodent and there is a great interest in identifying the adaptations responsible for these and other of its unique traits. We employed RNA sequencing to compare liver gene expression profiles between naked mole-rats and wild-derived mice. Our results indicate that genes associated with oxidoreduction and mitochondria were expressed at higher relative levels in naked mole-rats. The largest effect is nearly 300-fold higher expression of epithelial cell adhesion molecule (Epcam), a tumour-associated protein. Also of interest are the protease inhibitor, alpha2-macroglobulin (A2m), and the mitochondrial complex II subunit Sdhc, both ageing-related genes found strongly over-expressed in the naked mole-rat. These results hint at possible candidates for specifying species differences in ageing and cancer, and in particular suggest complex alterations in mitochondrial and oxidation reduction pathways in the naked mole-rat. Our differential gene expression analysis obviated the need for a reference naked mole-rat genome by employing a combination of Illumina/Solexa and 454 platforms for transcriptome sequencing and assembling transcriptome contigs of the non-sequenced species. Overall, our work provides new research foci and methods for studying the naked mole-rat's fascinating characteristics.

  17. Adult naked mole-rat brain retains the NMDA receptor subunit GluN2D associated with hypoxia tolerance in neonatal mammals.

    PubMed

    Peterson, Bethany L; Park, Thomas J; Larson, John

    2012-01-11

    Adult naked mole-rats show a number of systemic adaptations to a crowded underground habitat that is low in oxygen and high in carbon dioxide. Remarkably, brain slice tissue from adult naked mole-rats also is extremely tolerant to oxygen deprivation as indicated by maintenance of synaptic transmission under hypoxic conditions as well as by a delayed neuronal depolarization during anoxia. These characteristics resemble hypoxia tolerance in brain slices from neonates in a variety of mammal species. An important component of neonatal tolerance to hypoxia involves the subunit composition of NMDA receptors. Neonates have a high proportion of NMDA receptors with GluN2D subunits which are protective because they retard calcium entry into neurons during hypoxic episodes. Therefore, we hypothesized that adult naked mole-rats retain a protective, neonatal-like, NMDA receptor subunit profile. We used immunoblotting to assess age-related changes in NMDA receptor subunits in naked mole-rats and mice. The results show that adult naked mole-rat brain retains a much greater proportion of the hypoxia-protective GluN2D subunit compared to adult mice. However, age-related changes in other subunits (GluN2A and GluN2B) from the neonatal period to adulthood were comparable in mice and naked mole-rats. Hence, adult naked mole-rat brain only retains the neonatal NMDA receptor subunit that is associated with hypoxia tolerance.

  18. Multiple primary cutaneous melanomas in patients with FAMMM syndrome and sporadic atypical mole syndrome (AMS): what's worse?

    PubMed

    Tchernev, Georgi; Ananiev, Julian; Cardoso, José-Carlos; Chokoeva, Anastasiya Atanasova; Philipov, Stanislav; Penev, Plamen Kolev; Lotti, Torello; Wollina, Uwe

    2014-08-01

    Atypical Mole Syndrome is the most important phenotypic risk factor for cutaneous melanoma, a malignancy that accounts for about 80% of deaths from skin cancer. Since early diagnosis of melanoma is of great prognostic relevance, the identification of Atypical Mole Syndrome carriers (sporadic and familial) is essential, as well as the recommendation of preventative measures that must be undertaken by these patients.We report two rare cases concerning patients with multiple primary skin melanomas in the setting of a familial and a sporadic syndrome of dysplastic nevi: the first patient is a 67-year-old patient with a history of multiple superficial spreading melanomas localized on his back. The second patient presented with multiple primary melanomas in advanced stage in the context of the so-called sporadic form of the syndrome of dysplastic nevi-AMS (atypical mole syndrome). In the first case, excision of the melanomas was carried out with an uneventful post-operative period. In the second case, disseminated metastases were detected, involving the right fibula, the abdominal cavity as well as multiple lesions in the brain. The patient declined BRAF mutation tests as well as chemotherapy or targeted therapies, and suffered a rapid deterioration in his general condition leading to death. We classified the second case as a sporadic form of the atypical mole syndrome, associated with one nodular and two superficial spreading melanomas.There are no data in the literature to allow us to understand if, in patients with multiple primary melanomas, there is any difference in terms of prognosis between those with and without a family history of a similar phenotype. To answer this and other questions related to these rare cases, further studies with a significant number of patients should be carried out.

  19. Organization of the main olfactory bulbs of some mammals: musk shrews, moles, hedgehogs, tree shrews, bats, mice, and rats.

    PubMed

    Kosaka, Katsuko; Kosaka, Toshio

    2004-04-19

    We immunohistochemically examined the organization of the main olfactory bulbs (MOBs) in seven mammalian species, including moles, hedgehogs, tree shrews, bats, and mice as well as laboratory musk shrews and rats. We focused our investigation on two points: 1) whether nidi, particular spheroidal synaptic regions subjacent to glomeruli, which we previously reported for the laboratory musk shrew MOBs, are also present in other animals and 2) whether the compartmental organization of glomeruli and two types of periglomerular cells we proposed for the rat MOBs are general in other animals. The general laminar pattern was similar among these seven species, but discrete nidi and the nidal layer were recognized only in two insectivores, namely, the mole and laboratory musk shrew. Olfactory marker protein-immunoreactive (OMP-IR) axons extended beyond the limits of the glomerular layer (GL) into the superficial region of the external plexiform layer (EPL) or the nidal layer in the laboratory musk shrew, mole, hedgehog, and tree shrew but not in bat, mouse, and rat. We observed, in nidi and the nidal layer in the mole and laboratory musk shrew MOBs, only a few OMP-IR axons. In the hedgehog, another insectivore, OMP-IR processes extending from the glomeruli were scattered and intermingled with calbindin D28k-IR cells at the border between the GL and the EPL. In the superficial region of the EPL of the tree shrew MOBs, there were a small number of tiny glomerulus-like spheroidal structures where OMP-IR axons protruding from glomeruli were intermingled with dendritic branches of surrounding calbindin D28k-IR cells. Furthermore, we recognized the compartmental organization of glomeruli and two types of periglomerular cells in the MOBs of all of the mammals we examined. These structural features are therefore considered to be common and important organizational principles of the MOBs.

  20. Challenging the inbreeding hypothesis in a eusocial mammal: population genetics of the naked mole-rat, Heterocephalus glaber.

    PubMed

    Ingram, Colleen M; Troendle, Nicholas J; Gill, Clare A; Braude, Stanton; Honeycutt, Rodney L

    2015-10-01

    The role of genetic relatedness in the evolution of eusociality has been the topic of much debate, especially when contrasting eusocial insects with vertebrates displaying reproductive altruism. The naked mole-rat, Heterocephalus glaber, was the first described eusocial mammal. Although this discovery was based on an ecological constraints model of eusocial evolution, early genetic studies reported high levels of relatedness in naked mole-rats, providing a compelling argument that low dispersal rates and consanguineous mating (inbreeding as a mating system) are the driving forces for the evolution of this eusocial species. One caveat to accepting this long-held view is that the original genetic studies were based on limited sampling from the species' geographic distribution. A growing body of evidence supports a contrary view, with the original samples not representative of the species-rather reflecting a single founder event, establishing a small population south of the Athi River. Our study is the first to address these competing hypotheses by examining patterns of molecular variation in colonies sampled from north and south of the Athi and Tana rivers, which based on our results, serve to isolate genetically distinct populations of naked mole-rats. Although colonies south of the Athi River share a single mtDNA haplotype and are fixed at most microsatellite loci, populations north of the Athi River are considerably more variable. Our findings support the position that the low variation observed in naked mole-rat populations south of the Athi River reflects a founder event, rather than a consequence of this species' unusual mating system.

  1. Naked mole-rats maintain healthy skeletal muscle and Complex IV mitochondrial enzyme function into old age

    PubMed Central

    Stoll, Elizabeth A; Karapavlovic, Nevena; Rosa, Hannah; Woodmass, Michael; Rygiel, Karolina; White, Kathryn; Turnbull, Douglass M; Faulkes, Chris G

    2016-01-01

    The naked mole-rat (NMR) Heterocephalus glaber is an exceptionally long-lived rodent, living up to 32 years in captivity. This extended lifespan is accompanied by a phenotype of negligible senescence, a phenomenon of very slow changes in the expected physiological characteristics with age. One of the many consequences of normal aging in mammals is the devastating and progressive loss of skeletal muscle, termed sarcopenia, caused in part by respiratory enzyme dysfunction within the mitochondria of skeletal muscle fibers. Here we report that NMRs avoid sarcopenia for decades. Muscle fiber integrity and mitochondrial ultrastructure are largely maintained in aged animals. While mitochondrial Complex IV expression and activity remains stable, Complex I expression is significantly decreased. We show that aged naked mole-rat skeletal muscle tissue contains some mitochondrial DNA rearrangements, although the common mitochondrial DNA deletions associated with aging in human and other rodent skeletal muscles are not present. Interestingly, NMR skeletal muscle fibers demonstrate a significant increase in mitochondrial DNA copy number. These results have intriguing implications for the role of mitochondria in aging, suggesting Complex IV, but not Complex I, function is maintained in the long-lived naked mole rat, where sarcopenia is avoided and healthy muscle function is maintained for decades. PMID:27997359

  2. The neuronal structure of the preoptic area in the mole and the rabbit: Golgi and Nissl studies.

    PubMed

    Bogus-Nowakowska, K; Robak, A; Szteyn, S; Równiak, M; Najdzion, J; Wasilewska, B

    2006-11-01

    The present studies were carried out on the brains of the adult mole and rabbit. The preparations were made by means of the Golgi technique and the Nissl method. Two types of neurons were distinguished in the preoptic area (POA) of both species: bipolar and multipolar. The bipolar neurons have oval, fusiform or round perikarya and two dendritic trunks arising from the opposite poles of the cell body. The dendrites bifurcate once or twice. The dendritic branches have swellings, single spine-like and filiform processes. The multipolar neurons usually have triangular and quadrangular perikarya and from 3 to 5 dendritic trunks. The dendrites of the mole neurons branch sparsely, whereas the dendrites of the rabbit neurons display 2 or 3 divisions. On the dendritic branches varicosities and different protuberances were observed. The general morphology of the bipolar and multipolar neurons is similar in the mammals studied, although the neurons of the rabbit POA display a more complicated structure. Their dendritic branches show more divisions and possess more swellings and different processes than the dendrites of the neurons of the mole POA. Furthermore, of the multipolar neurons only the dendrites in POA of the rabbit were observed to have a rosary-like beaded appearance.

  3. Isolation and partial characterization of a highly divergent lineage of hantavirus from the European mole (Talpa europaea).

    PubMed

    Gu, Se Hun; Kumar, Mukesh; Sikorska, Beata; Hejduk, Janusz; Markowski, Janusz; Markowski, Marcin; Liberski, Paweł P; Yanagihara, Richard

    2016-02-19

    Genetically distinct hantaviruses have been identified in five species of fossorial moles (order Eulipotyphla, family Talpidae) from Eurasia and North America. Here, we report the isolation and partial characterization of a highly divergent hantavirus, named Nova virus (NVAV), from lung tissue of a European mole (Talpa europaea), captured in central Poland in August 2013. Typical hantavirus-like particles, measuring 80-120 nm in diameter, were found in NVAV-infected Vero E6 cells by transmission electron microscopy. Whole-genome sequences of the isolate, designated NVAV strain Te34, were identical to that amplified from the original lung tissue, and phylogenetic analysis of the full-length L, M and S segments, using maximum-likelihood and Bayesian methods, showed that NVAV was most closely related to hantaviruses harbored by insectivorous bats, consistent with an ancient evolutionary origin. Infant Swiss Webster mice, inoculated with NVAV by the intraperitoneal route, developed weight loss and hyperactivity, beginning at 16 days, followed by hind-limb paralysis and death. High NVAV RNA copies were detected in lung, liver, kidney, spleen and brain by quantitative real-time RT-PCR. Neuropathological examination showed astrocytic and microglial activation and neuronal loss. The first mole-borne hantavirus isolate will facilitate long-overdue studies on its infectivity and pathogenic potential in humans.

  4. A new definition for the mole based on the Avogadro constant: a journey from physics to chemistry.

    PubMed

    Milton, Martin J T

    2011-10-28

    The mole is the most recent addition to the set of base units that form the International System of Units, although its pre-cursor the 'gram-molecule', had been in use by both physicists and chemists for more than 120 years. A proposal has been published recently to establish a new definition for the mole based on a fixed value for the Avogadro constant. This would introduce consistent relative uncertainties for the molar and the atomic masses while making no change to the system of relative atomic masses ('atomic weights'). Although the proposal would have little impact on the measurement uncertainty of practical work, it has stimulated considerable debate about the mole and the nature of the quantity amount of substance. In this paper, the rationale for the new definition is explained against the background of changes in the way the quantity amount of substance has been used, from its first use during the early development of thermodynamics through to the use of the 'number of gram-molecules' at the end of the nineteenth century.

  5. Naked mole-rats maintain healthy skeletal muscle and Complex IV mitochondrial enzyme function into old age.

    PubMed

    Stoll, Elizabeth A; Karapavlovic, Nevena; Rosa, Hannah; Woodmass, Michael; Rygiel, Karolina; White, Kathryn; Turnbull, Douglass M; Faulkes, Chris G

    2016-12-19

    The naked mole-rat (NMR) Heterocephalus glaber is an exceptionally long-lived rodent, living up to 32 years in captivity. This extended lifespan is accompanied by a phenotype of negligible senescence, a phenomenon of very slow changes in the expected physiological characteristics with age. One of the many consequences of normal aging in mammals is the devastating and progressive loss of skeletal muscle, termed sarcopenia, caused in part by respiratory enzyme dysfunction within the mitochondria of skeletal muscle fibers. Here we report that NMRs avoid sarcopenia for decades. Muscle fiber integrity and mitochondrial ultrastructure are largely maintained in aged animals. While mitochondrial Complex IV expression and activity remains stable, Complex I expression is significantly decreased. We show that aged naked mole-rat skeletal muscle tissue contains some mitochondrial DNA rearrangements, although the common mitochondrial DNA deletions associated with aging in human and other rodent skeletal muscles are not present. Interestingly, NMR skeletal muscle fibers demonstrate a significant increase in mitochondrial DNA copy number. These results have intriguing implications for the role of mitochondria in aging, suggesting Complex IV, but not Complex I, function is maintained in the long-lived naked mole rat, where sarcopenia is avoided and healthy muscle function is maintained for decades.

  6. Isolation and partial characterization of a highly divergent lineage of hantavirus from the European mole (Talpa europaea)

    PubMed Central

    Gu, Se Hun; Kumar, Mukesh; Sikorska, Beata; Hejduk, Janusz; Markowski, Janusz; Markowski, Marcin; Liberski, Paweł P.; Yanagihara, Richard

    2016-01-01

    Genetically distinct hantaviruses have been identified in five species of fossorial moles (order Eulipotyphla, family Talpidae) from Eurasia and North America. Here, we report the isolation and partial characterization of a highly divergent hantavirus, named Nova virus (NVAV), from lung tissue of a European mole (Talpa europaea), captured in central Poland in August 2013. Typical hantavirus-like particles, measuring 80–120 nm in diameter, were found in NVAV-infected Vero E6 cells by transmission electron microscopy. Whole-genome sequences of the isolate, designated NVAV strain Te34, were identical to that amplified from the original lung tissue, and phylogenetic analysis of the full-length L, M and S segments, using maximum-likelihood and Bayesian methods, showed that NVAV was most closely related to hantaviruses harbored by insectivorous bats, consistent with an ancient evolutionary origin. Infant Swiss Webster mice, inoculated with NVAV by the intraperitoneal route, developed weight loss and hyperactivity, beginning at 16 days, followed by hind-limb paralysis and death. High NVAV RNA copies were detected in lung, liver, kidney, spleen and brain by quantitative real-time RT-PCR. Neuropathological examination showed astrocytic and microglial activation and neuronal loss. The first mole-borne hantavirus isolate will facilitate long-overdue studies on its infectivity and pathogenic potential in humans. PMID:26892544

  7. Neuroanatomical evidence for segregation of nerve fibers conveying light touch and pain sensation in Eimer's organ of the mole.

    PubMed

    Marasco, Paul D; Tsuruda, Pamela R; Bautista, Diana M; Julius, David; Catania, Kenneth C

    2006-06-13

    Talpid moles are small insectivores that live in dark underground tunnels. They depend heavily on touch to navigate and find food. Most species have an array of complex epidermal sensory structures called Eimer's organs that cover the tip of the nose. In this study, the anatomy of Eimer's organ was examined in the coast mole and star-nosed mole by using the fluorescent styryl pyridinium dye AM1-43 and immunocytochemical staining for neurofilament 200 and substance P. In addition, DiI was used to label neural components of Eimer's organ. AM1-43 labeled all of the Eimer's organ receptors after systemic injection, suggesting a role in mechanotransduction. Immunostaining with neurofilament 200 and substance P labeled distinct subtypes of sensory fibers. Substance P labeled a group of free nerve endings along the outer edge of Eimer's organ, indicating a nociceptive role for these fibers. In contrast, neurofilament 200 labeled a more central set of nerve endings, suggesting that these fibers function as low-threshold mechanoreceptors. By labeling subsets of trigeminal afferents distant from the receptor array with DiI, we revealed innervation patterns indicating that one afferent supplies the outer, substance P-positive set of free nerve endings, whereas several afferents differentially innervate the central free nerve endings. Our results suggest that the free nerve endings innervating Eimer's organ are largely mechanosensitive and may play an important role in the rapid sensory discrimination observed in these species.

  8. Ectoparasite burdens of the common mole-rat (Cryptomys hottentotus hottentotus) from the Cape Provinces of South Africa.

    PubMed

    Archer, Elizabeth K; Bennett, Nigel C; Ueckermann, Edward A; Lutermann, Heike

    2014-02-01

    The members of the African mole-rat family Bathyergidae are widely distributed across sub-Saharan Africa. Despite their well-studied biology and reproductive physiology, the current knowledge of their ectoparasite fauna is limited and ambiguous due to recent revisions of the bathyergid taxonomy. The common mole-rat (Cryptomys hottentotus hottentotus) is 1 of the most widely distributed species of these subterranean rodents. Ectoparasites were collected from 268 common mole-rats at 2 localities (Western and Northern Cape provinces) in South Africa over the course of 18 mo with the aim to document species richness, prevalence, and abundance of these ectoparasites. The aggregation of parasite species, sex bias within a species, and seasonal variation in ectoparasite burdens were investigated. A total of 4,830 individual parasites from 4 mite species (Androlaelaps scapularis, Androlaelaps capensis, Radfordia ensifera, and 1 undetermined chigger [family Trombiculidae]), 1 flea species (Cryptopsylla ingrami), and 1 louse species (Eulinognathus hilli) were collected. With the exception of R. ensifera and the chigger, all of these ectoparasites appear to be host specific either for the host species or the Bathyergidae. Aggregation indices indicated that with the exception of E. hilli, the distribution of all parasite species was highly aggregated among hosts and sex biased. Seasonal variation in prevalence, abundance, and species richness was apparent, with greater burdens in the rainy winter season. This is likely related to seasonal variation in abiotic factors but may also be affected by the timing of host reproduction and dispersal behavior.

  9. FRACTIONAL PEARSON DIFFUSIONS.

    PubMed

    Leonenko, Nikolai N; Meerschaert, Mark M; Sikorskii, Alla

    2013-07-15

    Pearson diffusions are governed by diffusion equations with polynomial coefficients. Fractional Pearson diffusions are governed by the corresponding time-fractional diffusion equation. They are useful for modeling sub-diffusive phenomena, caused by particle sticking and trapping. This paper provides explicit strong solutions for fractional Pearson diffusions, using spectral methods. It also presents stochastic solutions, using a non-Markovian inverse stable time change.

  10. FRACTIONAL PEARSON DIFFUSIONS

    PubMed Central

    Leonenko, Nikolai N.; Meerschaert, Mark M.

    2013-01-01

    Pearson diffusions are governed by diffusion equations with polynomial coefficients. Fractional Pearson diffusions are governed by the corresponding time-fractional diffusion equation. They are useful for modeling sub-diffusive phenomena, caused by particle sticking and trapping. This paper provides explicit strong solutions for fractional Pearson diffusions, using spectral methods. It also presents stochastic solutions, using a non-Markovian inverse stable time change. PMID:23626377

  11. Flammability measurements of difluoromethane in air at 100 C

    SciTech Connect

    Grosshandler, W.L.; Donnelly, M.K.; Womeldorf, C.

    1999-07-01

    Difluoromethane (CH{sub 2}F{sub 2}, or R-32) is a candidate to replace currently used ozone-depleting chlorofluorocarbon refrigerants. Because CH{sub 2}F{sub 2} is flammable, it is necessary to assess the hazard posed by a leak in a refrigeration machine. The currently accepted method for determining flammability, ASTM E 681, has difficulty discerning the flammability boundary for weak fuels such as CH{sub 2}F{sub 2}. This paper describes an alternative approach to identify the limits of flammability, using a twin, premixed counter-flow flame. By using the extinction of an already established flame, the point dividing flammable from non-flammable becomes unambiguous. The limiting extinction mixture changes with stretch rate, so it is convenient to report the flammability limit as the value extrapolated to a zero stretch condition. In the burner, contoured nozzles with outlet diameters of 12 mm are aligned counter to each other and spaced 12 mm apart. The lean flammability limit of CH{sub 2}F{sub 2} in dry air at room temperature was previously reported by the authors to be a mole fraction of 0.14, using the twin counter-flow flame method. In the current study, relative humidity was not found to affect the lean limit. Increasing the temperature of the premixed fuel and air to 100 C is shown to extend the flammability limit in the lean direction to 0.13. The rich limit of CH{sub 2}F{sub 2} found using the counter-flow method is around 0.27. The uncertainties of the measurements are presented and the results compared to data in the literature.

  12. Air Research

    EPA Pesticide Factsheets

    EPA's air research provides the critical science to develop and implement outdoor air regulations under the Clean Air Act and puts new tools and information in the hands of air quality managers and regulators to protect the air we breathe.

  13. Effect of Al-mole fraction in Al{sub x}Ga{sub 1−x}N grown by MOCVD

    SciTech Connect

    Jayasakthi, M. Ramesh, R. Prabakaran, K. Loganathan, R. Kuppulingam, B. Balaji, M. Arivazhagan, P. Sankaranarayanan, S. Singh, Shubra Baskar, K.

    2014-04-24

    AlGaN/AlN layers were grown by metalorganic chemical vapor deposition (MOCVD) on sapphire substrates. The Al{sub x}Ga{sub 1−x}N layer composition was varied from 15% to 25%. The crystalline quality, thickness and aluminum (Al) composition of AlGaN were determined using high resolution X-ray diffraction (HRXRD). The growth rate decreases on increasing Al composition. Reciprocal space mapping (RSM) was used to estimate the strain and relaxation between AlGaN and AlN. The optical properties of AlGaN layers were investigated by room temperature Photoluminescence (PL). The AlGaN peak shifts towards lower wavelength with Al composition. The surface morphology of AlGaN was studied by atomic force microscopy (AFM). Root mean square (RMS) roughness values were found to be increased in AlGaN layers with composition.

  14. FOREWORD: International Workshop on the Avogadro Constant and the Representation of the Silicon Mole

    NASA Astrophysics Data System (ADS)

    Basile, Giuseppe; Garfagnini, Raffaello; Mana, Giovanni; Peuto, Anna; Zosi, Gianfranco

    1994-01-01

    This special issue of Metrologia brings together contributions to the International Workshop on the Avogadro Constant and the Representation of the Silicon Mole, held in Turin, Italy, from 9 to 10 March 1994. It was organized by the Istituto di Metrologia "G Colonnetti" (IMGC) del Consiglio Nazionale delle Ricerche (CNR) and the Istituto di Fisica Generale "A Avogadro" (IFG) dell'Università di Tonno. It was sponsored by the CNR, the University of Turin, the Regione Piemonte, and the Commission of the European Communities DG XII. The workshop was a follow-up to previous international meetings held in Turin to commemorate Amedeo Avogadro, one in 1911 (the centenary of the publication of his hypothesis) and another in 1957 (the centenary of his death). On this occasion the workshop was motivated by the requirements of researchers engaged in the international project on the determination of the Avogadro constant by the x-ray crystal density method. Sixty-four participants representing eight countries attended the workshop. Doctoral students in metrology from Turin University and researchers working in adjacent fields were also present. The lectures were chosen so as to review the different aspects of this project, to illustrate progress in research, and to indicate future developments to scientists working in different fields of physics, metrology and technology. Complementary approaches to the NA determination based on electrical measurements were also reported and analysed. During the workshop, a number of specialist meetings allowed experts to discuss specific topics, to exchange information on results and techniques, and to improve the coordination of their activities. In their opening addresses, Prof. C Castagnoli (Director of the IFG) and Prof. L Crovini (Director of the IMGC) welcomed the participants and introduced the work in progress with a view to making a more precise determination of the Avogadro constant. They mentioned the expected influence of this

  15. FLAME facility: The effect of obstacles and transverse venting on flame acceleration and transition on detonation for hydrogen-air mixtures at large scale

    SciTech Connect

    Sherman, M.P.; Tieszen, S.R.; Benedick, W.B.

    1989-04-01

    This report describes research on flame acceleration and deflagration-to-detonation transition (DDT) for hydrogen-air mixtures carried out in the FLAME facility, and describes its relevance to nuclear reactor safety. Flame acceleration and DDT can generate high peak pressures that may cause failure of containment. FLAME is a large rectangular channel 30.5 m long, 2.44 m high, and 1.83 m wide. It is closed on the ignition end and open on the far end. The three test variables were hydrogen mole fraction (12--30%), degree of transverse venting (by moving steel top plates---0%, 13%, and 50%), and the absence or presence of certain obstacles in the channel (zero or 33% blockage ratio). The most important variable was the hydrogen mole fraction. The presence of the obstacles tested greatly increased the flame speeds, overpressures, and tendency for DDT compared to similar tests without obstacles. Different obstacle configurations could have greater or lesser effects on flame acceleration and DDT. Large degrees of transverse venting reduced the flame speeds, overpressures, and possibility of DDT. For small degrees of transverse venting (13% top venting), the flame speeds and overpressures were higher than for no transverse venting with reactive mixtures (>18% H/sub 2/), but they were lower with leaner mixtures. The effect of the turbulence generated by the flow out the vents on increasing flame speed can be larger than the effect of venting gas out of the channel and hence reducing the overpressure. With no obstacles and 50% top venting, the flame speeds and overpressures were low, and there was no DDT. For all other cases, DDT was observed above some threshold hydrogen concentration. DDT was obtained at 15% H/sub 2/ with obstacles and no transverse venting. 67 refs., 62 figs.

  16. U.S. emissions of HFC-134a derived for 2008-2012 from an extensive flask-air sampling network

    NASA Astrophysics Data System (ADS)

    Hu, Lei; Montzka, Stephen A.; Miller, John B.; Andrews, Aryln E.; Lehman, Scott J.; Miller, Benjamin R.; Thoning, Kirk; Sweeney, Colm; Chen, Huilin; Godwin, David S.; Masarie, Kenneth; Bruhwiler, Lori; Fischer, Marc L.; Biraud, Sebastien C.; Torn, Margaret S.; Mountain, Marikate; Nehrkorn, Thomas; Eluszkiewicz, Janusz; Miller, Scot; Draxler, Roland R.; Stein, Ariel F.; Hall, Bradley D.; Elkins, James W.; Tans, Pieter P.

    2015-01-01

    national and regional emissions of HFC-134a are derived for 2008-2012 based on atmospheric observations from ground and aircraft sites across the U.S. and a newly developed regional inverse model. Synthetic data experiments were first conducted to optimize the model assimilation design and to assess model-data mismatch errors and prior flux error covariances computed using a maximum likelihood estimation technique. The synthetic data experiments also tested the sensitivity of derived national and regional emissions to a range of assumed prior emissions, with the goal of designing a system that was minimally reliant on the prior. We then explored the influence of additional sources of error in inversions with actual observations, such as those associated with background mole fractions and transport uncertainties. Estimated emissions of HFC-134a range from 52 to 61 Gg yr-1 for the contiguous U.S. during 2008-2012 for inversions using air transport from Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model driven by the 12 km resolution meteorogical data from North American Mesoscale Forecast System (NAM12) and all tested combinations of prior emissions and background mole fractions. Estimated emissions for 2008-2010 were 20% lower when specifying alternative transport from Stochastic Time-Inverted Lagrangian Transport (STILT) model driven by the Weather Research and Forecasting (WRF) meteorology. Our estimates (for HYSPLIT-NAM12) are consistent with annual emissions reported by U.S. Environmental Protection Agency for the full study interval. The results suggest a 10-20% drop in U.S. national HFC-134a emission in 2009 coincident with a reduction in transportation-related fossil fuel CO2 emissions, perhaps related to the economic recession. All inversions show seasonal variation in national HFC-134a emissions in all years, with summer emissions greater than winter emissions by 20-50%.

  17. Can Kindergartners Do Fractions?

    ERIC Educational Resources Information Center

    Cwikla, Julie

    2014-01-01

    Mathematics professor Julie Cwikla decided that she needed to investigate young children's understandings and see what precurricular partitioning notions young minds bring to the fraction table. Cwikla realized that only a handful of studies have examined how preschool-age and early elementary school-age students solve fraction problems (Empson…

  18. An Appetite for Fractions

    ERIC Educational Resources Information Center

    Wilkerson, Trena L.; Bryan, Tommy; Curry, Jane

    2012-01-01

    This article describes how using candy bars as models gives sixth-grade students a taste for learning to represent fractions whose denominators are factors of twelve. Using paper models of the candy bars, students explored and compared fractions. They noticed fewer different representations for one-third than for one-half. The authors conclude…

  19. On fractional programming

    SciTech Connect

    Bajona-Xandri, C.; Martinez-Legaz, J.E.

    1994-12-31

    This paper studies the minimax fractional programming problem, assuming quasiconvexity of the objective function, under the lower subdifferentiability viewpoint. Necessary and sufficient optimality conditions and dual properties are found. We present applications of this theory to find the Pareto efficient solutions of a multiobjective fractional problem and to solve several economic models.

  20. (Carbon isotope fractionation inplants)

    SciTech Connect

    O'Leary, M.H.

    1990-01-01

    The objectives of this research are: To develop a theoretical and experimental framework for understanding isotope fractionations in plants; and to develop methods for using this isotope fractionation for understanding the dynamics of CO{sub 2} fixation in plants. Progress is described.

  1. Fractional dissipative standard map.

    PubMed

    Tarasov, Vasily E; Edelman, M

    2010-06-01

    Using kicked differential equations of motion with derivatives of noninteger orders, we obtain generalizations of the dissipative standard map. The main property of these generalized maps, which are called fractional maps, is long-term memory. The memory effect in the fractional maps means that their present state of evolution depends on all past states with special forms of weights. Already a small deviation of the order of derivative from the integer value corresponding to the regular dissipative standard map (small memory effects) leads to the qualitatively new behavior of the corresponding attractors. The fractional dissipative standard maps are used to demonstrate a new type of fractional attractors in the wide range of the fractional orders of derivatives.

  2. Membrane phospholipid composition may contribute to exceptional longevity of the naked mole-rat (Heterocephalus glaber): a comparative study using shotgun lipidomics.

    PubMed

    Mitchell, Todd W; Buffenstein, Rochelle; Hulbert, A J

    2007-11-01

    Phospholipids containing highly polyunsaturated fatty acids are particularly prone to peroxidation and membrane composition may therefore influence longevity. Phospholipid molecules, in particular those containing docosahexaenoic acid (DHA), from the skeletal muscle, heart, liver and liver mitochondria were identified and quantified using mass-spectrometry shotgun lipidomics in two similar-sized rodents that show an approximately 9-fold difference in maximum lifespan. The naked mole rat is the longest-living rodent known with a maximum lifespan of >28 years. Total phospholipid distribution is similar in tissues of both species; DHA is only found in phosphatidylcholines (PC), phosphatidylethanolamines (PE) and phosphatidylserines (PS), and DHA is relatively more concentrated in PE than PC. Naked mole-rats have fewer molecular species of both PC and PE than do mice. DHA-containing phospholipids represent 27-57% of all phospholipids in mice but only 2-6% in naked mole-rats. Furthermore, while mice have small amounts of di-polyunsaturated PC and PE, these are lacking in naked mole-rats. Vinyl ether-linked phospholipids (plasmalogens) are higher in naked mole-rat tissues than in mice. The lower level of DHA-containing phospholipids suggests a lower susceptibility to peroxidative damage in membranes of naked mole-rats compared to mice. Whereas the high level of plasmalogens might enhance membrane antioxidant protection in naked mole-rats compared to mice. Both characteristics possibly contribute to the exceptional longevity of naked mole-rats and may indicate a special role for peroxisomes in this extended longevity.

  3. CFD Analyses of Air-Ingress Accident for VHTRs

    NASA Astrophysics Data System (ADS)

    Ham, Tae Kyu

    -ingress mechanism and to utilize the CFD simulation in the analysis of the phenomenon. Previous air-ingress studies simulated the depressurization process using simple assumptions or 1-D system code results. However, recent studies found flow oscillations near the end of the depressurization which could influence the next stage of the air-ingress accident. Therefore, CFD simulations were performed to examine the air-ingress mechanisms from the depressurization through the establishment of local natural circulation initiate. In addition to the double-guillotine break scenario, there are other scenarios that can lead to an air-ingress event such as a partial break were in the cross vessel with various break locations, orientations, and shapes. These additional situations were also investigated. The simulation results for the OSU test facility showed that the discharged helium coolant from a reactor vessel during the depressurization process will be mixed with the air in the containment. This process makes the density of the gas mixture in the containment lower and the density-driven air-ingress flow slower because the density-driven flow is established by the density difference of the gas species between the reactor vessel and the containment. In addition, for the simulations with various initial and boundary conditions, the simulation results showed that the total accumulated air in the containment collapsed within 10% standard deviation by: 1. multiplying the density ratio and viscosity ratio of the gas species between the containment and the reactor vessel and 2. multiplying the ratio of the air mole fraction and gas temperature to the reference value. By replacing the gas mixture in the reactor cavity with a gas heavier than the air, the air-ingress speed slowed down. Based on the understanding of the air-ingress phenomena for the GT-MHR air-ingress scenario, several mitigation measures of air-ingress accident are proposed. The CFD results are utilized to plan experimental

  4. Naked mole-rat has increased translational fidelity compared with the mouse, as well as a unique 28S ribosomal RNA cleavage.

    PubMed

    Azpurua, Jorge; Ke, Zhonghe; Chen, Iris X; Zhang, Quanwei; Ermolenko, Dmitri N; Zhang, Zhengdong D; Gorbunova, Vera; Seluanov, Andrei

    2013-10-22

    The naked mole-rat (Heterocephalus glaber) is a subterranean eusocial rodent with a markedly long lifespan and resistance to tumorigenesis. Multiple data implicate modulation of protein translation in longevity. Here we report that 28S ribosomal RNA (rRNA) of the naked mole-rat is processed into two smaller fragments of unequal size. The two breakpoints are located in the 28S rRNA divergent region 6 and excise a fragment of 263 nt. The excised fragment is unique to the naked mole-rat rRNA and does not show homology to other genomic regions. Because this hidden break site could alter ribosome structure, we investigated whether translation rate and amino acid incorporation fidelity were altered. We report that naked mole-rat fibroblasts have significantly increased translational fidelity despite having comparable translation rates with mouse fibroblasts. Although we cannot directly test whether the unique 28S rRNA structure contributes to the increased fidelity of translation, we speculate that it may change the folding or dynamics of the large ribosomal subunit, altering the rate of GTP hydrolysis and/or interaction of the large subunit with tRNA during accommodation, thus affecting the fidelity of protein synthesis. In summary, our results show that naked mole-rat cells produce fewer aberrant proteins, supporting the hypothesis that the more stable proteome of the naked mole-rat contributes to its longevity.

  5. Fractional calculus in bioengineering.

    PubMed

    Magin, Richard L

    2004-01-01

    Fractional calculus (integral and differential operations of noninteger order) is not often used to model biological systems. Although the basic mathematical ideas were developed long ago by the mathematicians Leibniz (1695), Liouville (1834), Riemann (1892), and others and brought to the attention of the engineering world by Oliver Heaviside in the 1890s, it was not until 1974 that the first book on the topic was published by Oldham and Spanier. Recent monographs and symposia proceedings have highlighted the application of fractional calculus in physics, continuum mechanics, signal processing, and electromagnetics, but with few examples of applications in bioengineering. This is surprising because the methods of fractional calculus, when defined as a Laplace or Fourier convolution product, are suitable for solving many problems in biomedical research. For example, early studies by Cole (1933) and Hodgkin (1946) of the electrical properties of nerve cell membranes and the propagation of electrical signals are well characterized by differential equations of fractional order. The solution involves a generalization of the exponential function to the Mittag-Leffler function, which provides a better fit to the observed cell membrane data. A parallel application of fractional derivatives to viscoelastic materials establishes, in a natural way, hereditary integrals and the power law (Nutting/Scott Blair) stress-strain relationship for modeling biomaterials. In this review, I will introduce the idea of fractional operations by following the original approach of Heaviside, demonstrate the basic operations of fractional calculus on well-behaved functions (step, ramp, pulse, sinusoid) of engineering interest, and give specific examples from electrochemistry, physics, bioengineering, and biophysics. The fractional derivative accurately describes natural phenomena that occur in such common engineering problems as heat transfer, electrode/electrolyte behavior, and sub

  6. The comparative anatomy of the abdominal gastrointestinal tract of six species of African mole-rats (Rodentia, Bathyergidae).

    PubMed

    Kotzé, Sanet H; Van Der Merwe, Elizabeth L; Bennett, Nigel C; O'Riain, M Justin

    2010-01-01

    The gastrointestinal tracts (GITs) of six species of African mole-rats (Bathyergidae) were compared. The aim was to provide a comprehensive anatomical comparison between the different species. The relative shape, length, and surface areas were taken into account to determine whether the GITs are phylogenetically constrained or exhibit anatomical adaptations in response to diets. In all six species the stomach was simple and glandular. With the exception of Heterocephalus glaber, the caecum was coiled in a flat spiral, the ascending colon was arranged in a loop of varying lengths, and a mucosal colonic papillary-lined groove was present in the ascending colon in all species. By contrast, the caecum in H. glaber was uncoiled, the ascending colon was not looped, and the groove was not papillated. A caeco-appendix was observed only in Bathyergus suillus and Georychus capensis. Hierarchical multivariate cluster analysis on the presence/absence of nine anatomical structures associated with the GIT of mole-rats revealed that H. glaber was anatomically the least similar of the six species (77.6% similarity) with respect to the nine GIT variables included. All Cryptomys species were the same (100% similarity), and two species B. suillus and G. capensis grouped together and were more similar to the Cryptomys genus (95% similarity) than they were to H. glaber. These findings support previous phylogenetic classifications. The voluminous caeco-colon in B. suillus may be explained by its ingestion of grasses in addition to below-ground storage organs of plants. We conclude that phylogeny and diet affect the GIT anatomy of the African mole rats studied here.

  7. Extended Pile Driving Model to Predict the Penetration of the Insight/HP3 Mole into the Martian Soil

    NASA Astrophysics Data System (ADS)

    Poganski, Joshua; Kömle, Norbert I.; Kargl, Günter; Schweiger, Helmut F.; Grott, Matthias; Spohn, Tilman; Krömer, Olaf; Krause, Christian; Wippermann, Torben; Tsakyridis, Georgios; Fittock, Mark; Lichtenheldt, Roy; Vrettos, Christos; Anrade, Jose E.

    2016-11-01

    The NASA InSight mission will provide an opportunity for soil investigations using the penetration data of the heat flow probe built by the German Aerospace Center DLR. The Heat flow and Physical Properties Probe (HP3) will penetrate 3 to 5 meter into the Martian subsurface to investigate the planetary heat flow. The measurement of the penetration rate during the insertion of the HP3 will be used to determine the physical properties of the soil at the landing site. For this purpose, numerical simulations of the penetration process were performed to get a better understanding of the soil properties influencing the penetration performance of HP3. A pile driving model has been developed considering all masses of the hammering mechanism of HP3. By cumulative application of individual stroke cycles it is now able to describe the penetration of the Mole into the Martian soil as a function of time, assuming that the soil parameters of the material through which it penetrates are known. We are using calibrated materials similar to those expected to be encountered by the InSight/HP3 Mole when it will be operated on the surface of Mars after the landing of the InSight spacecraft. We consider various possible scenarios, among them a more or less homogeneous material down to a depth of 3-5 m as well as a layered ground, consisting of layers with different soil parameters. Finally we describe some experimental tests performed with the latest prototype of the InSight Mole at DLR Bremen and compare the measured penetration performance in sand with our modeling results. Furthermore, results from a 3D DEM simulation are presented to get a better understanding of the soil response.

  8. SOCIAL STATUS AND SEX INDEPENDENTLY INFLUENCE ANDROGEN RECEPTOR EXPRESSION IN THE EUSOCIAL NAKED MOLE-RAT BRAIN

    PubMed Central

    Holmes, Melissa M.; Goldman, Bruce D.; Forger, Nancy G.

    2009-01-01

    Naked mole-rats (Heterocephalus glaber) are eusocial rodents that live in large subterranean colonies including a single breeding female and 1-3 breeding males; all other members of the colony, known as subordinates, are reproductively suppressed. We recently found that naked mole-rats lack many of the sex differences in the brain and spinal cord commonly found in other rodents. Instead, neural morphology is influenced by breeding status, such that breeders, regardless of sex, have more neurons than subordinates in the ventromedial nucleus of the hypothalamus (VMH), and larger overall volumes of the bed nucleus of the stria terminalis (BST), paraventricular nucleus (PVN) and medial amygdala (MeA). To begin to understand how breeding status influences brain morphology, we examined the distribution of androgen receptor (AR) immunoreactivity in gonadally intact breeders and subordinates of both sexes. All animals had AR+ nuclei in many of the same regions positive for AR in other mammals, including the VMH, BST, PVN, MeA, and the ventral portion of the premammillary nucleus (PMv). We also observed diffuse labeling throughout the pre-optic area demonstrating that distribution of the AR protein in presumptive reproductive brain nuclei is well-conserved, even in a species that exhibits remarkably little sexual dimorphism. In contrast to other rodents, however, naked mole-rats lacked AR+ nuclei in the suprachiasmatic nucleus and hippocampus. Males had more AR+ nuclei in the MeA, VMH, and PMv than did females. Surprisingly, breeders had significantly fewer AR+ nuclei than subordinates in all brain regions examined (VMH, BST, PVN, MeA, and PMv). Thus, social status is strongly correlated with AR immunoreactivity in this eusocial species. PMID:18455726

  9. Unusual Ratio between Free Thyroxine and Free Triiodothyronine in a Long-Lived Mole-Rat Species with Bimodal Ageing

    PubMed Central

    Henning, Yoshiyuki; Vole, Christiane; Begall, Sabine; Bens, Martin; Broecker-Preuss, Martina; Sahm, Arne; Szafranski, Karol; Burda, Hynek; Dammann, Philip

    2014-01-01

    Ansell's mole-rats (Fukomys anselli) are subterranean, long-lived rodents, which live in eusocial families, where the maximum lifespan of breeders is twice as long as that of non-breeders. Their metabolic rate is significantly lower than expected based on allometry, and their retinae show a high density of S-cone opsins. Both features may indicate naturally low thyroid hormone levels. In the present study, we sequenced several major components of the thyroid hormone pathways and analyzed free and total thyroxine and triiodothyronine in serum samples of breeding and non-breeding F. anselli to examine whether a) their thyroid hormone system shows any peculiarities on the genetic level, b) these animals have lower hormone levels compared to euthyroid rodents (rats and guinea pigs), and c) reproductive status, lifespan and free hormone levels are correlated. Genetic analyses confirmed that Ansell's mole-rats have a conserved thyroid hormone system as known from other mammalian species. Interspecific comparisons revealed that free thyroxine levels of F. anselli were about ten times lower than of guinea pigs and rats, whereas the free triiodothyronine levels, the main biologically active form, did not differ significantly amongst species. The resulting fT4:fT3 ratio is unusual for a mammal and potentially represents a case of natural hypothyroxinemia. Comparisons with total thyroxine levels suggest that mole-rats seem to possess two distinct mechanisms that work hand in hand to downregulate fT4 levels reliably. We could not find any correlation between free hormone levels and reproductive status, gender or weight. Free thyroxine may slightly increase with age, based on sub-significant evidence. Hence, thyroid hormones do not seem to explain the different ageing rates of breeders and non-breeders. Further research is required to investigate the regulatory mechanisms responsible for the unusual proportion of free thyroxine and free triiodothyronine. PMID:25409169

  10. Circadian rhythms of locomotor activity in solitary and social species of African mole-rats (family: Bathyergidae).

    PubMed

    Oosthuizen, Maria K; Cooper, Howard M; Bennett, Nigel C

    2003-12-01

    Mole-rats are strictly subterranean and hardly, if ever, come into contact with external light. As a result, their classical visual system is severely regressed and the circadian system proportionally expanded. The family Bathyergidae presents a unique opportunity to study the circadian system in the absence of the classical visual system in a range of species. Daily patterns of activity were studied in the laboratory under constant temperature but variable lighting regimes in individually housed animals from 3 species of mole-rat exhibiting markedly different degrees of sociality. All 3 species possessed individuals that exhibited endogenous circadian rhythms under constant darkness that entrained to a light-dark cycle. In the solitary species, Georychus capensis, 9 animals exhibited greater activity during the dark phase of the light cycle, while 2 individuals expressed more activity in the light phase of the light cycle. In the social, Cryptomys hottentotus pretoriae, 5 animals displayed the majority of their activity during the dark phase of the light cycle and the remaining 2 exhibited more activity during the light phase of the light cycle. Finally in the eusocial Cryptomys damarensis, 6 animals displayed more activity during the light phase of the light cycle, and the other 2 animals displayed more activity during the dark phase of the light cycle. Since all three mole-rat species are able to entrain their locomotor activity to an external light source, light must reach the SCN, suggesting a functional circadian clock. In comparison to the solitary species, the 2 social species display a markedly poorer response to light in all aspects. Thus, in parallel with the sociality continuum, there exists a continuum of sensitivity of the circadian clock to light.

  11. Fractional market dynamics

    NASA Astrophysics Data System (ADS)

    Laskin, Nick

    2000-12-01

    A new extension of a fractality concept in financial mathematics has been developed. We have introduced a new fractional Langevin-type stochastic differential equation that differs from the standard Langevin equation: (i) by replacing the first-order derivative with respect to time by the fractional derivative of order μ; and (ii) by replacing “white noise” Gaussian stochastic force by the generalized “shot noise”, each pulse of which has a random amplitude with the α-stable Lévy distribution. As an application of the developed fractional non-Gaussian dynamical approach the expression for the probability distribution function (pdf) of the returns has been established. It is shown that the obtained fractional pdf fits well the central part and the tails of the empirical distribution of S&P 500 returns.

  12. Catalytic reforming of naphtha fractions

    SciTech Connect

    Bishop, K.C.; Vorhis, F.H.

    1980-09-16

    Production of motor gasoline and a btx-enriched reformate by fractionating a naphtha feedstock into a mid-boiling btxprecursor fraction, a relatively high-boiling fraction and a relatively low-boiling fraction; catalytically reforming the btxprecursor fraction in a first reforming zone; combining the relatively high-boiling and low-boiling fractions and catalytically reforming the combined fractions in a second reforming zone.

  13. Intracellular Cadmium Isotope Fractionation

    NASA Astrophysics Data System (ADS)

    Horner, T. J.; Lee, R. B.; Henderson, G. M.; Rickaby, R. E.

    2011-12-01

    Recent stable isotope studies into the biological utilization of transition metals (e.g. Cu, Fe, Zn, Cd) suggest several stepwise cellular processes can fractionate isotopes in both culture and nature. However, the determination of fractionation factors is often unsatisfactory, as significant variability can exist - even between different organisms with the same cellular functions. Thus, it has not been possible to adequately understand the source and mechanisms of metal isotopic fractionation. In order to address this problem, we investigated the biological fractionation of Cd isotopes within genetically-modified bacteria (E. coli). There is currently only one known biological use or requirement of Cd, a Cd/Zn carbonic anhydrase (CdCA, from the marine diatom T. weissfloggii), which we introduce into the E. coli genome. We have also developed a cleaning procedure that allows for the treating of bacteria so as to study the isotopic composition of different cellular components. We find that whole cells always exhibit a preference for uptake of the lighter isotopes of Cd. Notably, whole cells appear to have a similar Cd isotopic composition regardless of the expression of CdCA within the E. coli. However, isotopic fractionation can occur within the genetically modified E. coli during Cd use, such that Cd bound in CdCA can display a distinct isotopic composition compared to the cell as a whole. Thus, the externally observed fractionation is independent of the internal uses of Cd, with the largest Cd isotope fractionation occurring during cross-membrane transport. A general implication of these experiments is that trace metal isotopic fractionation most likely reflects metal transport into biological cells (either actively or passively), rather than relating to expression of specific physiological function and genetic expression of different metalloenzymes.

  14. Thermodynamics in Fractional Calculus

    NASA Astrophysics Data System (ADS)

    Meilanov, R. P.; Magomedov, R. A.

    2014-11-01

    A generalization of thermodynamics in the formalism of fractional-order derivatives is given. Results of the traditional thermodynamics of Carnot, Clausius, and Helmholtz are obtained in the particular case where the exponent of a fractional-order derivative is equal to unity. A one-parametric "fractal" equation of state is obtained with account of the second virial coefficient. The application of the resulting equation of state in the case of the gas argon is considered.

  15. Symmetric continued fractions

    SciTech Connect

    Panprasitwech, Oranit; Laohakosol, Vichian; Chaichana, Tuangrat

    2010-11-11

    Explicit formulae for continued fractions with symmetric patterns in their partial quotients are constructed in the field of formal power series. Similar to the work of Cohn in 1996, which generalized the so-called folding lemma to {kappa}-fold symmetry, the notion of {kappa}-duplicating symmetric continued fractions is investigated using a modification of the 1995 technique due to Clemens, Merrill and Roeder.

  16. Chromatographic methods of fractionation.

    PubMed

    Friesen, A D

    1987-01-01

    Chromatography's functional versatility, separation efficiency, gentle non-denaturing separating process and ease of automation and scale-up make it attractive for industrial scale protein purification. The Winnipeg Rh Institute's new Plasma Fractionation facility is an example of the use of chromatography for the large scale purification of plasma protein fractions. The fractionation facility has a capacity to process 800 litres of plasma per batch into blood clotting factor VIII and IX, albumin and intravenous immune serum globulin (i.v. ISG). Albumin and i.v. ISG are purified using ion exchange columns of DEAE-Sepharose (230 litre size), DEAE-Biogel (150 litre size) and CM-Sepharose (150 litre size). The chromatographic process is automated using a Modicon 584 Programmable Logic Controller to regulate valves, pumps and sensors which control plasma flow during fractionation. The stainless steel tanks and piping are automatically cleaned-in-place. The high degree of automation and cleaning provides efficient operation and sanitary processing. Chromatographic methods (DEAE-Sepharose and metal chelation) are also being used at the pilot scale to purify the human blood products superoxide dismutase and hemoglobin from outdated red blood cells. Characterization of the protein fractions produced by chromatography has shown them to be of equal or higher quality than fractions produced by other techniques.

  17. Fractional laser skin resurfacing.

    PubMed

    Alexiades-Armenakas, Macrene R; Dover, Jeffrey S; Arndt, Kenneth A

    2012-11-01

    Laser skin resurfacing (LSR) has evolved over the past 2 decades from traditional ablative to fractional nonablative and fractional ablative resurfacing. Traditional ablative LSR was highly effective in reducing rhytides, photoaging, and acne scarring but was associated with significant side effects and complications. In contrast, nonablative LSR was very safe but failed to deliver consistent clinical improvement. Fractional LSR has achieved the middle ground; it combined the efficacy of traditional LSR with the safety of nonablative modalities. The first fractional laser was a nonablative erbium-doped yttrium aluminum garnet (Er:YAG) laser that produced microscopic columns of thermal injury in the epidermis and upper dermis. Heralding an entirely new concept of laser energy delivery, it delivered the laser beam in microarrays. It resulted in microscopic columns of treated tissue and intervening areas of untreated skin, which yielded rapid reepithelialization. Fractional delivery was quickly applied to ablative wavelengths such as carbon dioxide, Er:YAG, and yttrium scandium gallium garnet (2,790 nm), providing more significant clinical outcomes. Adjustable laser parameters, including power, pitch, dwell time, and spot density, allowed for precise determination of percent surface area, affected penetration depth, and clinical recovery time and efficacy. Fractional LSR has been a significant advance to the laser field, striking the balance between safety and efficacy.

  18. Air Pollution

    MedlinePlus

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's ...

  19. Ecology of the tawny mole cricket, Scapteriscus vicinus (Orthoptera: Gryllotalpidae): population estimation, spatial distribution, movement, and host relationships

    SciTech Connect

    Hudson, W.G.

    1985-01-01

    Scapteriscus vicinus is the most important pest of turf and pasture grasses in Florida. This study develops a method of correlating sample results with true population density and provides the first quantitative information on spatial distribution and movement patterns of mole crickets. Three basic techniques for sampling mole crickets were compared: soil flushes, soil corer, and pitfall trapping. No statistical difference was found between the soil corer and soil flushing. Soil flushing was shown to be more sensitive to changes in population density than pitfall trapping. No technique was effective for sampling adults. Regression analysis provided a means of adjusting for the effects of soil moisture and showed soil temperature to be unimportant in predicting efficiency of flush sampling. Cesium-137 was used to label females for subsequent location underground. Comparison of mean distance to nearest neighbor with the distance predicted by a random distribution model showed that the observed distance in the spring was significantly greater than hypothesized (Student's T-test, p < 0.05). Fall adult nearest neighbor distance was not different than predicted by the random distribution hypothesis.

  20. A survey of gastrointestinal parasites of olive baboons (Papio anubis) in human settlement areas of Mole National Park, Ghana.

    PubMed

    Ryan, Sadie J; Brashares, Justin S; Walsh, Chesley; Milbers, Katherine; Kilroy, Cailean; Chapman, Colin A

    2012-08-01

    Fecal samples from 55 free-ranging olive baboons (Papio anubis) in Mole National Park, Ghana, were collected 22 June-7 July 2008 and analyzed for gastrointestinal parasites. This is the first survey of baboon gastrointestinal parasites in Ghana and provides baseline data for this area. Ninety-three percent of samples were infected, leaving 7% with no parasites observed. Of those infected, there was a 76% prevalence of strongyles, 53% Strongyloides spp., 11% Abbreviata caucasica , 62% prevalence of Balantidium coli (trophozoites and cysts identified), 4% Entomeba hystolytica/dispar, and 47% unidentified protozoan parasites. Of the strongyle infections, 9% were identified as Oesophagostamum sp. One sample contained an unidentified spirurid nematode that resembled Gongylonema sp. Mole has a mixed forest-savanna habitat, and baboons frequently range into human areas, which makes them subject to parasites from each habitat and multiple sources of exposure. We found a high prevalence of nematode parasites, consistent with a wet or cooler forest environment, or high rates of fecal contamination. The presence of Strongyloides sp., E. hystolitica/dispar, and B. coli suggest potential public health risk from baboons, but molecular identification of these parasites, and documentation of their presence in local human populations, would be necessary to confirm zoonotic transmission.

  1. Walking the Oxidative Stress Tightrope: A Perspective from the Naked Mole-Rat, the Longest-Living Rodent

    PubMed Central

    Rodriguez, Karl A.; Wywial, Ewa; Perez, Viviana I.; Lambert, Adrian J.; Edrey, Yael H.; Lewis, Kaitlyn N.; Grimes, Kelly; Lindsey, Merry L.; Brand, Martin D.; Buffenstein, Rochelle

    2014-01-01

    Reactive oxygen species (ROS), by-products of aerobic metabolism, cause oxidative damage to cells and tissue and not surprisingly many theories have arisen to link ROS-induced oxidative stress to aging and health. While studies clearly link ROS to a plethora of divergent diseases, their role in aging is still debatable. Genetic knock-down manipulations of antioxidants alter the levels of accrued oxidative damage, however, the resultant effect of increased oxidative stress on lifespan are equivocal. Similarly the impact of elevating antioxidant levels through transgenic manipulations yield inconsistent effects on longevity. Furthermore, comparative data from a wide range of endotherms with disparate longevity remain inconclusive. Many long-living species such as birds, bats and mole-rats exhibit high-levels of oxidative damage, evident already at young ages. Clearly, neither the amount of ROS per se nor the sensitivity in neutralizing ROS are as important as whether or not the accrued oxidative stress leads to oxidative-damage-linked age-associated diseases. In this review we examine the literature on ROS, its relation to disease and the lessons gleaned from a comparative approach based upon species with widely divergent responses. We specifically focus on the longest lived rodent, the naked mole-rat, which maintains good health and provides novel insights into the paradox of maintaining both an extended healthspan and lifespan despite high oxidative stress from a young age. PMID:21736541

  2. Genetic structure and diversity in an isolated population of an endemic mole salamander (Ambystoma rivulare Taylor, 1940) of central Mexico.

    PubMed

    Heredia-Bobadilla, Rosa-Laura; Monroy-Vilchis, Octavio; Zarco-González, Martha M; Martínez-Gómez, Daniel; Mendoza-Martínez, Germán David; Sunny, Armando

    2016-12-01

    Human activities are affecting the distribution of species worldwide by causing fragmentation and isolation of populations. Isolation and fragmentation lead to populations with lower genetic variability and an increased chance of inbreeding and genetic drift, which results in a loss of biological fitness over time. Studies of the genetic structure of small and isolated populations are critically important for management and conservation decisions. Ambystoma rivulare is a micro-endemic Mexican mole salamander from central Mexico. It is found in the most ecologically disturbed region in Mexico, the Trans-Mexican Volcanic Belt. The goal of this study of the population genetics of the micro-endemic mole salamander was to provide information to be used as a basis for future research and conservation planning of this species and other species of the Ambystoma genus in Mexico. The structural analysis found two subpopulations, one for each river sampled, with no signs of admixture and very high levels of genetic differentiation. Medium to high levels of heterozygosity and few alleles and genotypes were observed. Evidence of an ancestral genetic bottleneck, low values of effective population size, small inbreeding coefficients, and low gene flow were also found.

  3. Walking the oxidative stress tightrope: a perspective from the naked mole-rat, the longest-living rodent.

    PubMed

    Rodriguez, Karl A; Wywial, Ewa; Perez, Viviana I; Lambert, Adriant J; Edrey, Yael H; Lewis, Kaitlyn N; Grimes, Kelly; Lindsey, Merry L; Brand, Martin D; Buffenstein, Rochelle

    2011-01-01

    Reactive oxygen species (ROS), by-products of aerobic metabolism, cause oxidative damage to cells and tissue and not surprisingly many theories have arisen to link ROS-induced oxidative stress to aging and health. While studies clearly link ROS to a plethora of divergent diseases, their role in aging is still debatable. Genetic knock-down manipulations of antioxidants alter the levels of accrued oxidative damage, however, the resultant effect of increased oxidative stress on lifespan are equivocal. Similarly the impact of elevating antioxidant levels through transgenic manipulations yield inconsistent effects on longevity. Furthermore, comparative data from a wide range of endotherms with disparate longevity remain inconclusive. Many long-living species such as birds, bats and mole-rats exhibit high-levels of oxidative damage, evident already at young ages. Clearly, neither the amount of ROS per se nor the sensitivity in neutralizing ROS are as important as whether or not the accrued oxidative stress leads to oxidative-damage-linked age-associated diseases. In this review we examine the literature on ROS, its relation to disease and the lessons gleaned from a comparative approach based upon species with widely divergent responses. We specifically focus on the longest lived rodent, the naked mole-rat, which maintains good health and provides novel insights into the paradox of maintaining both an extended healthspan and lifespan despite high oxidative stress from a young age.

  4. Surfactant recovery from water using foam fractionation

    SciTech Connect

    Tharapiwattananon, N.; Osuwan, S.; Scamehorn, J.F.

    1996-05-01

    The purpose of this study was to investigate the use of foam fractionation to recover surfactant from water. A simple continuous mode foam fractionation was used and three surfactants were studied (two anionic and one cationic). The effects of air flow rate, foam height, liquid height, liquid feed surfactant concentration, and sparger porosity were studied. This technique was shown to be effective in either surfactant recovery or the reduction of surfactant concentration in water to acceptable levels. As an example of the effectiveness of this technique, the cetylpyridinium chloride concentration in water can be reduced by 90% in one stage with a liquid residence time of 375 minutes. The surfactant concentration in the collapsed foam is 21.5 times the feed concentration. This cationic surfactant was easier to remove from water by foam fractionation than the anionic surfactants studied.

  5. Identifying Fractions on Number Lines.

    ERIC Educational Resources Information Center

    Bright, George W.; And Others

    1988-01-01

    This study investigated the ways students represented fractions on number lines and the effects of instruction on those representations. The instruction primarily concerned representing fractions and ordering fractions on number lines. (Author/PK)

  6. Nitric Oxide PLIF Visualization of Simulated Fuel-Air Mixing in a Dual-Mode Scramjet

    NASA Technical Reports Server (NTRS)

    Cantu, Luca M. L.; Gallo, Emanuela C. A.; Cutler, Andrew D.; Bathel, Brett F.; Danehy, Paul M.; Rockwell, Robert D.; Goyne, Christopher P.; McDaniel, James C.

    2015-01-01

    Nitric oxide (NO) planar induced laser fluorescence (PLIF) measurements have been performed in a small scale scramjet combustor at the University of Virginia Aerospace Research Laboratory at nominal simulated Mach 5 flight. A mixture of NO and N2 was injected at the upstream end of the inlet isolator as a surrogate for ethylene fuel, and the mixing of this fuel simulant was studied with and without a shock train. The shock train was produced by an air throttle, which simulated the blockage effects of combustion downstream of the cavity flame holder. NO PLIF signal was imaged in a plane orthogonal to the freestream at the leading edge of the cavity. Instantaneous planar images were recorded and analyzed to identify the most uniform cases, which were achieved by varying the location of the fuel injection and shock train. This method was used to screen different possible fueling configurations to provide optimized test conditions for follow-on combustion measurements using ethylene fuel. A theoretical study of the selected NO rotational transitions was performed to obtain a LIF signal that is linear with NO mole fraction and approximately independent of pressure and temperature.

  7. Comparison of halocarbon measurements in an atmospheric dry whole air sample

    PubMed Central

    Hall, Bradley D.; Harth, Christina M.; Kim, Jin Seog; Lee, Jeongsoon; Montzka, Stephen A.; Mühle, Jens; Reimann, Stefan; Vollmer, Martin K.; Weiss, Ray F.

    2015-01-01

    The growing awareness of climate change/global warming, and continuing concerns regarding stratospheric ozone depletion, will require continued measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track atmospheric mole fractions and assess the impact of policy on emission rates, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. Precise measurements of these species aid in determining small changes in their atmospheric abundance. A common source of standards/scales and/or well-documented agreement of different scales used to calibrate the measurement instrumentation are key to understanding many sets of data reported by researchers. This report describes the results of a comparison study among National Metrology Institutes and atmospheric research laboratories for the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC-12), trichlorofluoromethane (CFC-11), and 1,1,2-trichlorotrifluoroethane (CFC-113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC-22) and 1-chloro-1,1-difluoroethane (HCFC-142b); and the hydrofluorocarbon (HFC) 1,1,1,2-tetrafluoroethane (HFC-134a), all in a dried whole air sample. The objective of this study is to compare calibration standards/scales and the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. The results of this study show agreement among four independent calibration scales to better than 2.5% in almost all cases, with many of the reported agreements being better than 1.0%. PMID:26753167

  8. FRACTIONAL CRYSTALLIZATION FEED ENVELOPE

    SciTech Connect

    HERTING DL

    2008-03-19

    Laboratory work was completed on a set of evaporation tests designed to establish a feed envelope for the fractional crystallization process. The feed envelope defines chemical concentration limits within which the process can be operated successfully. All 38 runs in the half-factorial design matrix were completed successfully, based on the qualitative definition of success. There is no feed composition likely to be derived from saltcake dissolution that would cause the fractional crystallization process to not meet acceptable performance requirements. However, some compositions clearly would provide more successful operation than other compositions.

  9. Momentum fractionation on superstrata

    SciTech Connect

    Bena, Iosif; Martinec, Emil; Turton, David; Warner, Nicholas P.

    2016-05-11

    Superstrata are bound states in string theory that carry D1, D5, and momentum charges, and whose supergravity descriptions are parameterized by arbitrary functions of (at least) two variables. In the D1-D5 CFT, typical three-charge states reside in highdegree twisted sectors, and their momentum charge is carried by modes that individually have fractional momentum. Understanding this momentum fractionation holographically is crucial for understanding typical black-hole microstates in this system. We use solution-generating techniques to add momentum to a multi-wound supertube and thereby construct the first examples of asymptotically-flat superstrata. The resulting supergravity solutions are horizonless and smooth up to well-understood orbifold singularities. Upon taking the AdS3 decoupling limit, our solutions are dual to CFT states with momentum fractionation. We give a precise proposal for these dual CFT states. Lastly, our construction establishes the very nontrivial fact that large classes of CFT states with momentum fractionation can be realized in the bulk as smooth horizonless supergravity solutions.

  10. Momentum fractionation on superstrata

    DOE PAGES

    Bena, Iosif; Martinec, Emil; Turton, David; ...

    2016-05-11

    Superstrata are bound states in string theory that carry D1, D5, and momentum charges, and whose supergravity descriptions are parameterized by arbitrary functions of (at least) two variables. In the D1-D5 CFT, typical three-charge states reside in highdegree twisted sectors, and their momentum charge is carried by modes that individually have fractional momentum. Understanding this momentum fractionation holographically is crucial for understanding typical black-hole microstates in this system. We use solution-generating techniques to add momentum to a multi-wound supertube and thereby construct the first examples of asymptotically-flat superstrata. The resulting supergravity solutions are horizonless and smooth up to well-understood orbifoldmore » singularities. Upon taking the AdS3 decoupling limit, our solutions are dual to CFT states with momentum fractionation. We give a precise proposal for these dual CFT states. Lastly, our construction establishes the very nontrivial fact that large classes of CFT states with momentum fractionation can be realized in the bulk as smooth horizonless supergravity solutions.« less

  11. Sweet Work with Fractions

    ERIC Educational Resources Information Center

    Vinogradova, Natalya; Blaine, Larry

    2013-01-01

    Almost everyone loves chocolate. However, the same cannot be said about fractions, which are loved by markedly fewer. Middle school students tend to view them with wary respect, but little affection. The authors attempt to sweeten the subject by describing a type of game involving division of chocolate bars. The activity they describe provides a…

  12. Field-Flow Fractionation.

    ERIC Educational Resources Information Center

    Caldwell, Karin D.

    1988-01-01

    Describes a technique for separating samples that range over 15 orders of magnitude in molecular weight. Discusses theory, apparatus, and sample preparation techniques. Lists several types of field-flow fractionation (FFF) and their uses: sedimentation FFF, thermal FFF, flow FFF, electrical FFF, and steric FFF. (ML)

  13. Fraction collector for electrophoresis

    NASA Technical Reports Server (NTRS)

    Bier, M.

    1977-01-01

    Rotating-tube electrophoresis apparatus employs rotating jet of eluting buffer to reduce effects of convection during separation. Designed for separation of microorganisms and biological species, system combines gravity/gradient compensating of lumen with buffer flush at fraction outlet to increase separation efficiency.

  14. Giant invasive mole presenting as a cause of abdominopelvic mass in a perimenopausal woman: An unusual presentation of a rare pathology

    PubMed Central

    Şimşek, Memet; Üçer, Özlem

    2016-01-01

    Invasive mole is a benign gestational trophoblastic disease that arises from the myometrial invasion of any gestational event via direct extension through tissue or vascular structures. Invasive mole (and other gestational trophoblastic diseases) may present with life-threatening complications including uterine perforation, excessive bleeding, acute hemoperitoneum, and abdominal pain. We report a case of invasive mole presenting as abdominal distention in a 51-year-old perimenopausal woman (gravida 12, para 12, abortion 0). The patient was admitted to the gynecology clinic with a giant uterine mass filling the pelvic and abdominal cavity. To our knowledge, this is the first case in the literature of a gestational trophoblastic neoplasia presenting with uterine mass of 28 weeks' gestational size in this age group. Interestingly, complications such as uterine rupture or invasion of the adjacent structures (such as parametrial tissues or blood vessels) had not developed in our patient despite the considerable enlargement of the uterus. PMID:27896261

  15. Low sulfide levels and a high degree of cystathionine β-synthase (CBS) activation by S-adenosylmethionine (SAM) in the long-lived naked mole-rat.

    PubMed

    Dziegelewska, Maja; Holtze, Susanne; Vole, Christiane; Wachter, Ulrich; Menzel, Uwe; Morhart, Michaela; Groth, Marco; Szafranski, Karol; Sahm, Arne; Sponholz, Christoph; Dammann, Philip; Huse, Klaus; Hildebrandt, Thomas; Platzer, Matthias

    2016-08-01

    Hydrogen sulfide (H2S) is a gaseous signalling molecule involved in many physiological and pathological processes. There is increasing evidence that H2S is implicated in aging and lifespan control in the diet-induced longevity models. However, blood sulfide concentration of naturally long-lived species is not known. Here we measured blood sulfide in the long-lived naked mole-rat and five other mammalian species considerably differing in lifespan and found a negative correlation between blood sulfide and maximum longevity residual. In addition, we show that the naked mole-rat cystathionine β-synthase (CBS), an enzyme whose activity in the liver significantly contributes to systemic sulfide levels, has lower activity in the liver and is activated to a higher degree by S-adenosylmethionine compared to other species. These results add complexity to the understanding of the role of H2S in aging and call for detailed research on naked mole-rat transsulfuration.

  16. Effect of drying on heavy metal fraction distribution in rice paddy soil.

    PubMed

    Qi, Yanbing; Huang, Biao; Darilek, Jeremy Landon

    2014-01-01

    An understanding of how redox conditions affect soil heavy metal fractions in rice paddies is important due to its implications for heavy metal mobility and plant uptake. Rice paddy soil samples routinely undergo oxidation prior to heavy metal analysis. Fraction distribution of Cu, Pb, Ni, and Cd from paddy soil with a wide pH range was investigated. Samples were both dried according to standard protocols and also preserved under anaerobic conditions through the sampling and analysis process and heavy metals were then sequentially extracted for the exchangeable and carbonate bound fraction (acid soluble fraction), iron and manganese oxide bound fraction (reducible fraction), organic bound fraction (oxidizable fraction), and residual fraction. Fractions were affected by redox conditions across all pH ranges. Drying decreased reducible fraction of all heavy metals. Curesidual fraction, Pboxidizable fraction, Cdresidual fraction, and Niresidual fraction increased by 25%, 33%, 35%, and >60%, respectively. Pbresidual fraction, Niacid soluble fraction, and Cdoxidizable fraction decreased 33%, 25%, and 15%, respectively. Drying paddy soil prior to heavy metal analysis overestimated Pb and underestimated Cu, Ni, and Cd. In future studies, samples should be stored after injecting N2 gas to maintain the redox potential of soil prior to heavy metal analysis, and investigate the correlation between heavy metal fraction distribution under field conditions and air-dried samples.

  17. A new form of the mole vole Ellobius tancrei Blasius, 1884 (Mammalia, Rodentia) with the lowest chromosome number

    PubMed Central

    Bakloushinskaya, Irina; Romanenko, Svetlana A.; Serdukova, Natalia A.; Graphodatsky, Alexander S.; Lyapunova, Elena A.

    2013-01-01

    Abstract The subterranean mole vole, Ellobius tancrei, with aspecific variability in autosomes (2n = 31–54) and unusual sex chromosomes (XX in males and females), represents an amazing model for studying the role of chromosome changes in speciation. New materials from the upper reaches of the Surkhob River in the Pamiro-Alay mountains resulted in the discovery of a new form with 2n = 30. The application of Zoo-FISH and G-banding methods allowed the detection of 13 pairs of autosomes as Robertsonian metacentrics originated after fusions of acrocentrics of an assumed ancestral karyotype of Ellobius tancrei with 2n = 54. The sex chromosomes (XX, in both sexes) and one pair of acrocentric autosomes are the only acrocentrics in this karyotype, and the set with 2n = 30 possesses the lowest possible chromosome number among populations of Ellobius tancrei. PMID:24260698

  18. Rotational diffusion of ionic and neutral solutes in mixed micelles: Effect of surfactant to block copolymer mole ratio on solute rotation

    NASA Astrophysics Data System (ADS)

    Mali, K. S.; Dutt, G. B.; Mukherjee, T.

    2007-10-01

    Rotational diffusion of an ionic solute rhodamine 110 and a neutral solute 2,5-dimethyl-1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DMDPP) has been investigated in aqueous mixtures of cetyltrimethylammonium chloride (CTAC) and poly(ethyleneoxide)20-poly(propyleneoxide)70-poly(ethyleneoxide)20 (P123). The purpose of this work is to understand how an increase in the mole ratio of surfactant to block copolymer from low to high influences the dynamics of ionic and neutral solute molecules. The variation in the mole ratio of CTAC to P123 from low to high has resulted in a drastic increase in the average reorientation time of rhodamine 110. In contrast, an exactly opposite trend has been noticed in the case of DMDPP. In the low mole ratio regime, rhodamine 110 and DMDPP are located at the interface and palisade layer, respectively, of P123 micelle-CTAC complexes. On the other hand, in the high mole ratio regime, both the probes are located in the Stern layer of CTAC-P123 complexes. The enhancement in the average reorientation time of rhodamine 110 with an increase in the mole ratio of surfactant to block copolymer has been rationalized on the basis of formation of rhodamine 110-Cl ion pair, which in turn associates with the cationic head groups of CTAC-P123 complexes. The observed decrease in the average reorientation time of DMDPP with an increase in the mole ratio of CTAC to P123 is a consequence of lower microviscosity of the Stern layer of CTAC-P123 complexes compared to the palisade layer of P123 micelle-CTAC complexes.

  19. Young Children's Notations for Fractions

    ERIC Educational Resources Information Center

    Brizuela, Barbara M.

    2006-01-01

    This paper focuses on the kinds of notations young children make for fractional numbers. The extant literature in the area of fractional numbers acknowledges children's difficulties in conceptualizing fractional numbers. Some of the research suggests possibly delaying an introduction to conventional notations for algorithms and fractions until…

  20. Creating, Naming, and Justifying Fractions

    ERIC Educational Resources Information Center

    Siebert, Daniel; Gaskin, Nicole

    2006-01-01

    For students to develop meaningful conceptions of fractions and fraction operations, they need to think of fractions in terms other than as just whole-number combinations. In this article, we suggest two powerful images for thinking about fractions that move beyond whole-number reasoning. (Contains 5 figures.)

  1. Interglacial refugia preserved high genetic diversity of the Chinese mole shrew in the mountains of southwest China

    PubMed Central

    He, K; Hu, N-Q; Chen, X; Li, J-T; Jiang, X-L

    2016-01-01

    The mountains of southwest China (MSC) harbor extremely high species diversity; however, the mechanism behind this diversity is unknown. We investigated to what degree the topography and climate change shaped the genetic diversity and diversification in these mountains, and we also sought to identify the locations of microrefugia areas in these mountains. For these purposes, we sampled extensively to estimate the intraspecific phylogenetic pattern of the Chinese mole shrew (Anourosorex squamipes) in southwest China throughout its range of distribution. Two mitochondrial genes, namely, cytochrome b (CYT B) and NADH dehydrogenase subunit 2 (ND2), from 383 archived specimens from 43 localities were determined for phylogeographic and demographic analyses. We used the continuous-diffusion phylogeographic model, extensive Bayesian skyline plot species distribution modeling (SDM) and approximate Bayesian computation (ABC) to explore the changes in population size and distribution through time of the species. Two phylogenetic clades were identified, and significantly higher genetic diversity was preserved in the southern subregion of the mountains. The results of the SDM, continuous-diffusion phylogeographic model, extensive Bayesian skyline plot and ABC analyses were congruent and supported that the Last Interglacial Maximum (LIG) was an unfavorable period for the mole shrews because of a high degree of seasonality; A. squamipes survived in isolated interglacial refugia mainly located in the southern subregion during the LIG and rapidly expanded during the last glacial period. These results furnished the first evidence for major Pleistocene interglacial refugia and a latitudinal effect in southwest China, and the results shedding light on the higher level of species richness in the southern subregion. PMID:26286667

  2. Spatial and Temporal Activity Patterns of the Free-Living Giant Mole-Rat (Fukomys mechowii), the Largest Social Bathyergid

    PubMed Central

    Lövy, Matěj; Šklíba, Jan; Šumbera, Radim

    2013-01-01

    Despite the considerable attention devoted to the biology of social species of African mole-rats (Bathyergidae, Rodentia), knowledge is lacking about their behaviour under natural conditions. We studied activity of the largest social bathyergid, the giant mole-rat Fukomys mechowii, in its natural habitat in Zambia using radio-telemetry. We radio-tracked six individuals during three continuous 72-h sessions. Five of these individuals, including a breeding male, belonged to a single family group; the remaining female was probably a solitary disperser. The non-breeders of the family were active (i.e. outside the nest) 5.8 hours per 24h-day with the activity split into 6.5 short bouts. The activity was more concentrated in the night hours, when the animals also travelled longer distances from the nest. The breeding male spent only 3.2 hours per day outside the nest, utilizing less than 20% of the whole family home range. The dispersing female displayed a much different activity pattern than the family members. Her 8.0 hours of outside-nest activity per day were split into 4.6 bouts which were twice as long as in the family non-breeders. Her activity peak in the late afternoon coincided with the temperature maximum in the depth of 10 cm (roughly the depth of the foraging tunnels). Our results suggest that the breeding individuals (at least males) contribute very little to the work of the family group. Nevertheless, the amount of an individual's activity and its daily pattern are probably flexible in this species and can be modified in response to actual environmental and social conditions. PMID:23383166

  3. DNA sequence variation in the mitochondrial control region of subterranean mole rats, Spalax ehrenbergi superspecies, in Israel.

    PubMed

    Reyes, Aurelio; Nevo, Eviatar; Saccone, Cecilia

    2003-04-01

    The complete mitochondrial control region was sequenced for 60 individuals representing different populations for each of the four species of the subterranean mole rat Spalax ehrenbergi superspecies in Israel: Spalax galili (2n = 52), S. golani (2n = 54), S. carmeli (2n = 58), and S. judaei (2n = 60). The control region of all species and populations is very similar both in length (979 to 983 bp) and in base composition. As in agreement with previous surveys on mitochondrial control regions on mammals, the mole rat control region can be divided into a central domain and two flanking domains, ETAS (extended termination associated sequences) and CSB (conserved sequence blocks). Along with the common conserved blocks found in these domains (ETAS1, ETAS2, CSB1, CSB2, and CSB3), we have also detected in all individuals an ETAS1-like and a CSB1-like element, both in the ETAS domain. The most conserved region was the central domain, followed by the CSB and ETAS domains, showing important differences in the four species analyzed. Phylogenetic analysis supported the existence of two clades. One clade contained individuals belonging to Spalax galili (2n = 52) and S. golani (2n = 54), separated in two different branches depending on the species. The other clade contained individuals belonging to S. carmeli (2n = 58) and S. judaei (2n = 60) mixed together, suggesting a more recent event of speciation. Within species we have observed a southward trend of increasing variability. These results have been explained as a consequence of the adaptation of the species to ecological factors such as aridity and temperature stresses.

  4. The Mars Underground Mole (MUM): A Subsurface Penetration Device with Infrared Reflectance and Raman Spectroscopic Sensing Capability

    NASA Technical Reports Server (NTRS)

    Stoker, C. R.; Richter, L.; Smith, W. H.; Lemke, L. G.; Hammer, P.; Dalton, J. B.; Glass, B.; Zent, A.

    2003-01-01

    Searching for evidence of life on Mars will probably require access to the subsurface. The Martian surface is bathed in ultraviolet radiation which decomposes organic compounds, destroying possible evidence for life. Also, experiments performed by the Viking Landers imply the presence of several strongly oxidizing compounds at the Martian surface that may also play a role in destroying organic compounds near the surface. While liquid water is unstable on the Martian surface, and ice is unstable at the surface at low latitudes, recent results from the Mars Odyssey Gamma Ray Spectrometer experiment indicate that water ice is widely distributed near the surface under a thin cover of dry soil. Organic compounds created by an ancient Martian biosphere might be preserved in such ice-rich layers. Furthermore, accessing the subsurface provides a way to identify unique stratigraphy such as small-scale layering associated with lacustrine sediments. Subsurface access might also provide new insights into the Mars climate record that may be preserved in the Polar Layered Deposits. Recognizing the importance of accessing the subsurface of Mars to the future scientific exploration of the planet, the Mars Surveyor 2007 Science Definition Team called for drilling beneath the surface soils. Subsurface measurements are also cited as high priority in by MEPAG. Recognizing the importance of accessing the Martian subsurface to search for life, the European Space Agency has incorporated a small automated burrowing device called a subsurface penetrometer or Mole onto the Beagle 2 lander planned for 2003 launch. This device, called the Planetary Underground Tool (PLUTO), is a pointed slender cylinder 2 cm wide and 28 cm long equipped with a small sampling device at the pointed end that collects samples and brings them to the surface for analysis. Drawing on the PLUTO design, we are developing a larger Mole carrying sensors for identifying mineralogy, organic compounds, and water.

  5. Interglacial refugia preserved high genetic diversity of the Chinese mole shrew in the mountains of southwest China.

    PubMed

    He, K; Hu, N-Q; Chen, X; Li, J-T; Jiang, X-L

    2016-01-01

    The mountains of southwest China (MSC) harbor extremely high species diversity; however, the mechanism behind this diversity is unknown. We investigated to what degree the topography and climate change shaped the genetic diversity and diversification in these mountains, and we also sought to identify the locations of microrefugia areas in these mountains. For these purposes, we sampled extensively to estimate the intraspecific phylogenetic pattern of the Chinese mole shrew (Anourosorex squamipes) in southwest China throughout its range of distribution. Two mitochondrial genes, namely, cytochrome b (CYT B) and NADH dehydrogenase subunit 2 (ND2), from 383 archived specimens from 43 localities were determined for phylogeographic and demographic analyses. We used the continuous-diffusion phylogeographic model, extensive Bayesian skyline plot species distribution modeling (SDM) and approximate Bayesian computation (ABC) to explore the changes in population size and distribution through time of the species. Two phylogenetic clades were identified, and significantly higher genetic diversity was preserved in the southern subregion of the mountains. The results of the SDM, continuous-diffusion phylogeographic model, extensive Bayesian skyline plot and ABC analyses were congruent and supported that the Last Interglacial Maximum (LIG) was an unfavorable period for the mole shrews because of a high degree of seasonality; A. squamipes survived in isolated interglacial refugia mainly located in the southern subregion during the LIG and rapidly expanded during the last glacial period. These results furnished the first evidence for major Pleistocene interglacial refugia and a latitudinal effect in southwest China, and the results shedding light on the higher level of species richness in the southern subregion.

  6. Redefinition of the kilogram, ampere, kelvin and mole: a proposed approach to implementing CIPM recommendation 1 (CI-2005)

    NASA Astrophysics Data System (ADS)

    Mills, Ian M.; Mohr, Peter J.; Quinn, Terry J.; Taylor, Barry N.; Williams, Edwin R.

    2006-06-01

    The International System of Units (SI) is founded on seven base units, the metre, kilogram, second, ampere, kelvin, mole and candela corresponding to the seven base quantities of length, mass, time, electric current, thermodynamic temperature, amount of substance and luminous intensity. At its 94th meeting in October 2005, the International Committee for Weights and Measures (CIPM) adopted a recommendation on preparative steps towards redefining the kilogram, ampere, kelvin and mole so that these units are linked to exactly known values of fundamental constants. We propose here that these four base units should be given new definitions linking them to exactly defined values of the Planck constant h, elementary charge e, Boltzmann constant k and Avogadro constant NA, respectively. This would mean that six of the seven base units of the SI would be defined in terms of true invariants of nature. In addition, not only would these four fundamental constants have exactly defined values but also the uncertainties of many of the other fundamental constants of physics would be either eliminated or appreciably reduced. In this paper we present the background and discuss the merits of these proposed changes, and we also present possible wordings for the four new definitions. We also suggest a novel way to define the entire SI explicitly using such definitions without making any distinction between base units and derived units. We list a number of key points that should be addressed when the new definitions are adopted by the General Conference on Weights and Measures (CGPM), possibly by the 24th CGPM in 2011, and we discuss the implications of these changes for other aspects of metrology.

  7. Subcaste differences in neural activation suggest a prosocial role for oxytocin in eusocial naked mole-rats.

    PubMed

    Hathaway, Georgia A; Faykoo-Martinez, Mariela; Peragine, Deane E; Mooney, Skyler J; Holmes, Melissa M

    2016-03-01

    The neuropeptide oxytocin (OT) influences prosocial behavior(s), aggression, and stress responsiveness, and these diverse effects are regulated in a species- and context-specific manner. The naked mole-rat (Heterocephalus glaber) is a unique species with which to study context-dependent effects of OT, exhibiting a strict social hierarchy with behavioral specialization within the subordinate caste: soldiers are aggressive and defend colonies against unfamiliar conspecifics while workers are prosocial and contribute to in-colony behaviors such as pup care. To determine if OT is involved in subcaste-specific behaviors, we compared behavioral responses between workers and soldiers of both sexes during a modified resident/intruder paradigm, and quantified activation of OT neurons in the hypothalamic paraventricular nucleus (PVN) and supraoptic nucleus (SON) using the immediate-early-gene marker c-fos co-localized with OT neurons. Resident workers and soldiers were age-matched with unfamiliar worker stimulus animals as intruders, and encounters were videorecorded and scored for aggressive behaviors. Colony-matched controls were left in their home colony for the duration of the encounters. Brains were extracted and cell counts were conducted for OT immunoreactive (ir), c-fos-ir, and percentage of OT-c-fos double-labeled cells. Results indicate that resident workers were less aggressive but showed greater OT neural activity than soldiers. Furthermore, a linear model including social treatment, cortisol, and subcaste revealed that subcaste was the only significant predictor of OT-c-fos double-labeled cells in the PVN. These data suggest that in naked mole-rats OT promotes prosocial behaviors rather than aggression and that even within subordinates status exerts robust effects on brain and behavior.

  8. Metabolic clues to salubrious longevity in the brain of the longest-lived rodent: the naked mole-rat.

    PubMed

    Triplett, Judy C; Swomley, Aaron; Kirk, Jessime; Lewis, Katilyn; Orr, Miranda; Rodriguez, Karl; Cai, Jian; Klein, Jon B; Buffenstein, Rochelle; Butterfield, D Allan

    2015-08-01

    Naked mole-rats (NMRs) are the oldest-living rodent species. Living underground in a thermally stable ecological niche, NMRs have evolved certain exceptional traits, resulting in sustained health spans, negligible cognitive decline, and a pronounced resistance to age-related disease. Uncovering insights into mechanisms underlying these extraordinary traits involved in successful aging may conceivably provide crucial clues to extend the human life span and health span. One of the most fundamental processes inside the cell is the production of ATP, which is an essential fuel in driving all other energy-requiring cellular activities. Not surprisingly, a prominent hallmark in age-related diseases, such as neurodegeneration and cancer, is the impairment and dysregulation of metabolic pathways. Using a two-dimensional polyacrylamide gel electrophoresis proteomics approach, alterations in expression and phosphorylation levels of metabolic proteins in the brains of NMRs, aged 2-24 years, were evaluated in an age-dependent manner. We identified 13 proteins with altered levels and/or phosphorylation states that play key roles in various metabolic pathways including glycolysis, β-oxidation, the malate-aspartate shuttle, the Tricarboxylic Acid Cycle (TCA) cycle, the electron transport chain, NADPH production, as well as the production of glutamate. New insights into potential pathways involved in metabolic aspects of successful aging have been obtained by the identification of key proteins through which the NMR brain responds and adapts to the aging process and how the NMR brain adapted to resist age-related degeneration. This study examines the changes in the proteome and phosphoproteome in the brain of the naked mole-rat aged 2-24 years. We identified 13 proteins (labeled in red) with altered expression and/or phosphorylation levels that are conceivably associated with sustained metabolic functions in the oldest NMRs that may promote a sustained health span and life span.

  9. Arbitrage with fractional Gaussian processes

    NASA Astrophysics Data System (ADS)

    Zhang, Xili; Xiao, Weilin

    2017-04-01

    While the arbitrage opportunity in the Black-Scholes model driven by fractional Brownian motion has a long history, the arbitrage strategy in the Black-Scholes model driven by general fractional Gaussian processes is in its infancy. The development of stochastic calculus with respect to fractional Gaussian processes allowed us to study such models. In this paper, following the idea of Shiryaev (1998), an arbitrage strategy is constructed for the Black-Scholes model driven by fractional Gaussian processes, when the stochastic integral is interpreted in the Riemann-Stieltjes sense. Arbitrage opportunities in some fractional Gaussian processes, including fractional Brownian motion, sub-fractional Brownian motion, bi-fractional Brownian motion, weighted-fractional Brownian motion and tempered fractional Brownian motion, are also investigated.

  10. Testing fractional action cosmology

    NASA Astrophysics Data System (ADS)

    Shchigolev, V. K.

    2016-08-01

    The present work deals with a combined test of the so-called Fractional Action Cosmology (FAC) on the example of a specific model obtained by the author earlier. In this model, the effective cosmological term is proportional to the Hubble parameter squared through the so-called kinematic induction. The reason of studying this cosmological model could be explained by its ability to describe two periods of accelerated expansion, that is in agreement with the recent observations and the cosmological inflation paradigm. First of all, we put our model through the theoretical tests, which gives a general conception of the influence of the model parameters on its behavior. Then, we obtain some restrictions on the principal parameters of the model, including the fractional index, by means of the observational data. Finally, the cosmography parameters and the observational data compared to the theoretical predictions are presented both analytically and graphically.

  11. Fractional lattice charge transport

    PubMed Central

    Flach, Sergej; Khomeriki, Ramaz

    2017-01-01

    We consider the dynamics of noninteracting quantum particles on a square lattice in the presence of a magnetic flux α and a dc electric field E oriented along the lattice diagonal. In general, the adiabatic dynamics will be characterized by Bloch oscillations in the electrical field direction and dispersive ballistic transport in the perpendicular direction. For rational values of α and a corresponding discrete set of values of E(α) vanishing gaps in the spectrum induce a fractionalization of the charge in the perpendicular direction - while left movers are still performing dispersive ballistic transport, the complementary fraction of right movers is propagating in a dispersionless relativistic manner in the opposite direction. Generalizations and the possible probing of the effect with atomic Bose-Einstein condensates and photonic networks are discussed. Zak phase of respective band associated with gap closing regime has been computed and it is found converging to π/2 value. PMID:28102302

  12. Floquet Fractional Chern Insulators

    NASA Astrophysics Data System (ADS)

    Grushin, Adolfo G.; Gómez-León, Álvaro; Neupert, Titus

    2014-04-01

    We show theoretically that periodically driven systems with short range Hubbard interactions offer a feasible platform to experimentally realize fractional Chern insulator states. We exemplify the procedure for both the driven honeycomb and the square lattice, where we derive the effective steady state band structure of the driven system by using the Floquet theory and subsequently study the interacting system with exact numerical diagonalization. The fractional Chern insulator state equivalent to the 1/3 Laughlin state appears at 7/12 total filling (1/6 filling of the upper band). The state also features spontaneous ferromagnetism and is thus an example of the spontaneous breaking of a continuous symmetry along with a topological phase transition. We discuss light-driven graphene and shaken optical lattices as possible experimental systems that can realize such a state.

  13. Fractional Trajectories: Decorrelation Versus Friction

    DTIC Science & Technology

    2013-07-27

    from the integration of fractional differential equations in time. In Section 2 we provide a general demonstration of the new perspective on fractional ...section we demonstrate the equivalence between a fractional trajectory that is the solution of a Caputo fractional differential equation , and the... fractional differential equation dα dtα V(t) = OV(t), (1) where 0 < α < 1 and O is an operator, either linear or nonlinear, acting on the vector V(t

  14. Fractional Galilean symmetries

    NASA Astrophysics Data System (ADS)

    Hosseiny, Ali; Rouhani, Shahin

    2016-09-01

    We generalize the differential representation of the operators of the Galilean algebras to include fractional derivatives. As a result a whole new class of scale invariant Galilean algebras are obtained. The first member of this class has dynamical index z = 2 similar to the Schrödinger algebra. The second member of the class has dynamical index z = 3 / 2, which happens to be the dynamical index Kardar-Parisi-Zhang equation.

  15. New Dry Fractionation Methods

    NASA Technical Reports Server (NTRS)

    McKay, David S.; Cooper, Bonnie L.

    2010-01-01

    This slide presentation describes new fractionation methods that are used to create dust that is respirable for testing the effects of inhalation of lunar dust in preparation for future manned lunar exploration. Because lunar dust is a very limited commodity, a method that does not result in loss of the material had to be developed. The dust separation system that is described incorporates some traditional methods, while preventing the dust from being contaminated or changed in reactivity properties while also limiting losses.

  16. Model Fractional Chern Insulators

    NASA Astrophysics Data System (ADS)

    Behrmann, Jörg; Liu, Zhao; Bergholtz, Emil J.

    2016-05-01

    We devise local lattice models whose ground states are model fractional Chern insulators—Abelian and non-Abelian topologically ordered states characterized by exact ground state degeneracies at any finite size and infinite entanglement gaps. Most saliently, we construct exact parent Hamiltonians for two distinct families of bosonic lattice generalizations of the Zk parafermion quantum Hall states: (i) color-entangled fractional Chern insulators at band filling fractions ν =k /(C +1 ) and (ii) nematic states at ν =k /2 , where C is the Chern number of the lowest band. In spite of a fluctuating Berry curvature, our construction is partially frustration free: the ground states reside entirely within the lowest band and exactly minimize a local (k +1 ) body repulsion term by term. In addition to providing the first known models hosting intriguing states such as higher Chern number generalizations of the Fibonacci anyon quantum Hall states, the remarkable stability and finite-size properties make our models particularly well suited for the study of novel phenomena involving, e.g., twist defects and proximity induced superconductivity, as well as being a guide for designing experiments.

  17. [Mutagenicity of 3 organic fractions of atmospheric dust and gas chromatographic analysis of the basic fraction].

    PubMed

    Gottlieb, A; Schleibinger, H; Ketseridis, G; Wullenweber, M; Rüden, H

    1983-01-01

    Suspended particulate matter (PM) with a Dae less than 0.4 micron was collected from July 1981 till January 1982. The ether/benzene soluble extract (EEOM) and the acidic, basic and neutral fractions were determined and investigated for their mutagenic activities in the Ames bioassay. In addition particles (Dae) less than 10.2 micron derived in January were investigated. Five compounds of the basic fraction were determined by gaschromatography. The following results were obtained: Suspended particulate matter (Dae less than 0.4 micron) and the ether/benzene extract increase from July to January. The lowest rates occur in July (PM: 16.9 micron/m3) and August (EEOM: 3.0 micrograms/m3), the highest in January (PM: 48.9 micrograms/m3, EEOM: 10.5 micrograms/m3). The ether/benzene soluble portion of the suspended particulate matter increases from the average rate of 16.3% (July-September) to 22.7% (November-January). The neutral fraction amounts to 44.9%, the acidic fraction to 27.3% and the basic fraction to 3.5% of the organic matter (on an average). In experiments with metabolic activation 99% of the total mutagenicity during the period of July till September can be demonstrated by summing up the mutagenicity of the three fractions on the other hand only 59.7% from November till January. The EEOMs derived from winter exhibit without metabolic activation (250 micrograms/plate) distinctively higher numbers of revertants than the single fractions. Dose-response curves of extracts derived from back-up filters (Dae less than 0.4 micron) in January show that the acidic fraction has a slightly higher mutagenic activity than the neutral fraction (mean values of tests with and without S9-mix). The basic fraction shows no mutagenicity without S9-mix, with activation the mutagenic activity is lower than that of the other fractions. Mutagenicity expressed as rev./m3 air shows, that the neutral fraction is most efficient. The number of revertants per plate reveals-in relation to

  18. [Ablative and fractional lasers].

    PubMed

    Beylot, C; Grognard, C; Michaud, T

    2009-10-01

    The use of pulsed or scanning Carbon Dioxide, and pulsed Erbium-YAG lasers allows the programmable and reproducible photocoagulation of thin layers of the epidermis and superficial dermis. Thermal damage depends on the type of laser and is greater with CO(2) lasers. The degree of neocollagenesis is proportional to the thermal damage and is better with CO(2) lasers. Their main indication is the correction of photoaged facial skin but they can also be used for corrective dermatology, e.g. for scars and genodermatosis. Results are highly satisfactory but the technique is invasive and the patient experiences a social hindrance of around two weeks. Fractionated techniques treat 25% of the defective skin area at each session in noncontiguous microzones; four sessions are therefore necessary to treat the entire cutaneous surface. The treatment is given under topical anesthesia and is much less invasive, particularly with nonablative fractional laser treatment in which photothermolysis does not penetrate below the epidermis and/or the effects are slight, with no or very little social isolation. However, the results are much less satisfactory than the results of ablative laser and there is no firming effect. Other zones than the face can be treated. With the fractional CO(2) and Erbium ablative lasers, which have multiplied over the past 2 years, the much wider impacts cause perforation of the epidermis and there is a zone of ablation by laser photovaporization, with a zone of thermal damage below. The results are better in correcting photoaging of the face, without, however, achieving the efficacy of ablative lasers, which remain the reference technique. However, the effects are not insignificant, requiring at least 5 days of social isolation.

  19. Variability of space-use patterns in a free living eusocial rodent, Ansell’s mole-rat indicates age-based rather than caste polyethism

    PubMed Central

    Šklíba, Jan; Lövy, Matěj; Burda, Hynek; Šumbera, Radim

    2016-01-01

    Eusocial species of African mole-rats live in groups cooperating on multiple tasks and employing division of labour. In captivity, individuals of the same group differ in cooperative contribution as well as in preference for a particular task. Both can be viewed as polyethism. However, little information is available from free-ranging mole-rats, which live in large burrow systems. We made an attempt to detect polyethism in the free-living Ansell’s mole-rat (Fukomys anselli) as differences in individuals’ space-use patterns. We radio-tracked 17 adults from five groups. Large individuals, including breeding males, spent more time inside the nest than smaller individuals. Breeding females were more often located <10 m from the nest in comparison to non-breeding females, who were relatively more often located 30–90 m and exclusively >90 m from the nest. One non-breeding female even conducted a brief intrusion into a neighbouring group’s territory via an open tunnel connection. A significant part of the variability in mole-rat space-use patterns was explained by body mass which is probably related to age in this species. This result can therefore be attributed to age polyethism. There was no apparent discontinuity in the space-use patterns of non-breeders that would indicate existence of castes. PMID:27922127

  20. Adenosine receptors mediate the hypoxic ventilatory response but not the hypoxic metabolic response in the naked mole rat during acute hypoxia

    PubMed Central

    Pamenter, Matthew E.; Dzal, Yvonne A.; Milsom, William K.

    2015-01-01

    Naked mole rats are the most hypoxia-tolerant mammals identified; however, the mechanisms underlying this tolerance are poorly understood. Using whole-animal plethysmography and open-flow respirometry, we examined the hypoxic metabolic response (HMR), hypoxic ventilatory response (HVR) and hypoxic thermal response in awake, freely behaving naked mole rats exposed to 7% O2 for 1 h. Metabolic rate and ventilation each reversibly decreased 70% in hypoxia (from 39.6 ± 2.9 to 12.1 ± 0.3 ml O2 min−1 kg−1, and 1412 ± 244 to 417 ± 62 ml min−1 kg−1, respectively; p < 0.05), whereas body temperature was unchanged and animals remained awake and active. Subcutaneous injection of the general adenosine receptor antagonist aminophylline (AMP; 100 mg kg−1, in saline), but not control saline injections, prevented the HVR but had no effect on the HMR. As a result, AMP-treated naked mole rats exhibited extreme hyperventilation in hypoxia. These animals were also less tolerant to hypoxia, and in some cases hypoxia was lethal following AMP injection. We conclude that in naked mole rats (i) hypoxia tolerance is partially dependent on profound hypoxic metabolic and ventilatory responses, which are equal in magnitude but occur independently of thermal changes in hypoxia, and (ii) adenosine receptors mediate the HVR but not the HMR. PMID:25520355

  1. Size variation in Tachyoryctes splendens (East African mole-rat) and its implications for late Quaternary temperature change in equatorial East Africa

    NASA Astrophysics Data System (ADS)

    Faith, J. Tyler; Patterson, David B.; Blegen, Nick; O'Neill, Chris J.; Marean, Curtis W.; Peppe, Daniel J.; Tryon, Christian A.

    2016-05-01

    This study develops a new proxy for Quaternary temperature change in tropical Africa through analysis of size variation in East African mole-rat (Tachyoryctes splendens). In modern mole-rats, mandibular alveolar length is unrelated to annual precipitation, precipitation seasonality, temperature seasonality, or primary productivity. However, it is inversely correlated with mean annual temperature, in agreement with Bergmann's rule. This relationship is observed at temperatures below ∼17.3 °C, but not at higher temperatures. We apply these observations to late Quaternary mole-rats from Wakondo (∼100 ka) and Kisaaka (∼50 ka) in the Lake Victoria region and Enkapune ya Muto (EYM; ∼7.2-3.2 ka) in Kenya's central rift. The Lake Victoria mole-rats are larger than expected for populations from warm climates typical of the area today, implying cooler temperatures in the past. The magnitude of temperature decline needed to drive the size shift is substantial (∼4-6 °C), similar in magnitude to the degree of change between the Last Glacial Maximum and Holocene, but is consistent with regional temperature records and with scenarios linking equatorial African temperature to northern hemisphere summer insolation. Size changes through time at EYM indicate that rising temperatures during the middle Holocene accompanied and potentially contributed to a decline in Lake Naivasha and expansion of grassland vegetation.

  2. Adenosine receptors mediate the hypoxic ventilatory response but not the hypoxic metabolic response in the naked mole rat during acute hypoxia.

    PubMed

    Pamenter, Matthew E; Dzal, Yvonne A; Milsom, William K

    2015-02-07

    Naked mole rats are the most hypoxia-tolerant mammals identified; however, the mechanisms underlying this tolerance are poorly understood. Using whole-animal plethysmography and open-flow respirometry, we examined the hypoxic metabolic response (HMR), hypoxic ventilatory response (HVR) and hypoxic thermal response in awake, freely behaving naked mole rats exposed to 7% O₂ for 1 h. Metabolic rate and ventilation each reversibly decreased 70% in hypoxia (from 39.6 ± 2.9 to 12.1 ± 0.3 ml O₂ min(-1) kg(-1), and 1412 ± 244 to 417 ± 62 ml min(-1) kg(-1), respectively; p < 0.05), whereas body temperature was unchanged and animals remained awake and active. Subcutaneous injection of the general adenosine receptor antagonist aminophylline (AMP; 100 mg kg(-1), in saline), but not control saline injections, prevented the HVR but had no effect on the HMR. As a result, AMP-treated naked mole rats exhibited extreme hyperventilation in hypoxia. These animals were also less tolerant to hypoxia, and in some cases hypoxia was lethal following AMP injection. We conclude that in naked mole rats (i) hypoxia tolerance is partially dependent on profound hypoxic metabolic and ventilatory responses, which are equal in magnitude but occur independently of thermal changes in hypoxia, and (ii) adenosine receptors mediate the HVR but not the HMR.

  3. Fractional channel multichannel analyzer

    DOEpatents

    Brackenbush, Larry W.; Anderson, Gordon A.

    1994-01-01

    A multichannel analyzer incorporating the features of the present invention obtains the effect of fractional channels thus greatly reducing the number of actual channels necessary to record complex line spectra. This is accomplished by using an analog-to-digital converter in the asynscronous mode, i.e., the gate pulse from the pulse height-to-pulse width converter is not synchronized with the signal from a clock oscillator. This saves power and reduces the number of components required on the board to achieve the effect of radically expanding the number of channels without changing the circuit board.

  4. Fractional channel multichannel analyzer

    DOEpatents

    Brackenbush, L.W.; Anderson, G.A.

    1994-08-23

    A multichannel analyzer incorporating the features of the present invention obtains the effect of fractional channels thus greatly reducing the number of actual channels necessary to record complex line spectra. This is accomplished by using an analog-to-digital converter in the asynchronous mode, i.e., the gate pulse from the pulse height-to-pulse width converter is not synchronized with the signal from a clock oscillator. This saves power and reduces the number of components required on the board to achieve the effect of radically expanding the number of channels without changing the circuit board. 9 figs.

  5. Solvent Fractionation of Lignin

    SciTech Connect

    Chatterjee, Sabornie; Saito, Tomonori

    2014-01-01

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. The major issues for the commercial production of value added high performance lignin products are lignin s physical and chemical heterogenities. To overcome these problems, a variety of procedures have been developed to produce pure lignin suitable for high performace applications such as lignin-derived carbon materials. However, most of the isolation procedures affect lignin s properties and structure. In this chapter, a short review of the effect of solvent fractionation on lignin s properties and structure is presented.

  6. Body Fractions: A Physical Approach to Fraction Learning

    ERIC Educational Resources Information Center

    Mills, Judith

    2011-01-01

    Many students experience great difficulty understanding the meaning of fractions. For many students who have spent their early mathematics lessons focusing on counting (whole) numbers, recognising that there are many numbers between those whole numbers called fractional numbers, is quite revolutionary. The foundation of understanding fractions is…

  7. INK4 locus of the tumor-resistant rodent, the naked mole rat, expresses a functional p15/p16 hybrid isoform.

    PubMed

    Tian, Xiao; Azpurua, Jorge; Ke, Zhonghe; Augereau, Adeline; Zhang, Zhengdong D; Vijg, Jan; Gladyshev, Vadim N; Gorbunova, Vera; Seluanov, Andrei

    2015-01-27

    The naked mole rat (Heterocephalus glaber) is a long-lived and tumor-resistant rodent. Tumor resistance in the naked mole rat is mediated by the extracellular matrix component hyaluronan of very high molecular weight (HMW-HA). HMW-HA triggers hypersensitivity of naked mole rat cells to contact inhibition, which is associated with induction of the INK4 (inhibitors of cyclin dependent kinase 4) locus leading to cell-cycle arrest. The INK4a/b locus is among the most frequently mutated in human cancer. This locus encodes three distinct tumor suppressors: p15(INK4b), p16(INK4a), and ARF (alternate reading frame). Although p15(INK4b) has its own ORF, p16(INK4a) and ARF share common second and third exons with alternative reading frames. Here, we show that, in the naked mole rat, the INK4a/b locus encodes an additional product that consists of p15(INK4b) exon 1 joined to p16(INK4a) exons 2 and 3. We have named this isoform pALT(INK4a/b) (for alternative splicing). We show that pALT(INK4a/b) is present in both cultured cells and naked mole rat tissues but is absent in human and mouse cells. Additionally, we demonstrate that pALT(INK4a/b) expression is induced during early contact inhibition and upon a variety of stresses such as UV, gamma irradiation-induced senescence, loss of substrate attachment, and expression of oncogenes. When overexpressed in naked mole rat or human cells, pALT(INK4a/b) has stronger ability to induce cell-cycle arrest than either p15(INK4b) or p16(INK4a). We hypothesize that the presence of the fourth product, pALT(INK4a/b) of the INK4a/b locus in the naked mole rat, contributes to the increased resistance to tumorigenesis of this species.

  8. Some chemical kinetics issues in reburning: The branching fraction of the HCCO + NO Reaction

    SciTech Connect

    Miller, J.A.; Durant, J.L.; Glarborg, P.

    1998-03-01

    The authors have determined theoretically some critical kinetic parameters in the mechanism of NOx reburning under flow-reactor conditions. Specifically, using a variety of electronic structure methods to investigate the potential energy surfaces and the maximum free energy method of Quack and Troe to determine the resulting rate coefficients, they have deduced the values of k{sub 2} and k{sub 3} for the reactions, HCNO+O {leftrightarrow} HCO+NO (R2) and HCNO + OH {leftrightarrow} HCOH + NO, (R3) to be k{sub 2} {approx} 7 x 10{sup 13} cm{sup 3}/mole-sec. and k{sub 3} {approx} 2 x 10{sup 13} cm{sup 3}/mole-sec. independent of temperature for 300 K < T < 2,700 K. With such fast reactions converting HCNO to NO, a critical parameter in the reburn mechanism is {alpha}(T) = k{sub 1b}(T)/k{sub 1}(T), the branching fraction of the HCCO + NO reaction, HCCO + NO {leftrightarrow} HCNO+CO (R1a); HCCO + NO {leftrightarrow} HCN + CO{sub 2} (R1b); HCCO + NO {leftrightarrow} HONC + CO (R1c). Again using PES information from a variety of electronic-structure methods, the authors have used the statistical-theoretical methodology of Miller, Parrish, and Brown to determine {alpha} (T) = 0.985 exp({minus}T/1,748), valid for 300 K < T < 2,000 K. Using a value of k{sub 1} = k{sub 1a} + k{sub 1b} + k{sub 1c} = 2.4 x 10{sup 13} cm{sup 3}/mole-sec. independent of temperature (consistent with experiment) they have determined modified Arrhenius expressions for k{sub 1a} and k{sub 1b}, k{sub 1a} = 1.17 x 10{sup 13} T{sup 0.65} cm{sup 3}/mole-sec. and k{sub 1b} = 1.45 x 10{sup 16} T{sup {minus}0.968} exp({minus}648/RT) cm{sup 3}/mole-sec for 300 K < T < 2,000 K. Reaction (R1c) never contributes as much as 1% to the total rate coefficient. The theoretical analyses and the reburn mechanism are discussed in detail.

  9. Dynamic properties of cationic diacyl-glycerol-arginine-based surfactant/phospholipid mixtures at the air/water interface.

    PubMed

    Lozano, Neus; Pinazo, Aurora; Pérez, Lourdes; Pons, Ramon

    2010-02-16

    In this Article, we study the binary surface interactions of 1,2-dimyristoyl-rac-glycero-3-O-(N(alpha)-acetyl-L-arginine) hydrochloride (1414RAc) with 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) on 0.1 M sodium chloride solutions. 1414RAc is a novel monocationic surfactant that has potential applications as an antimicrobial agent, is biodegradable, and shows a toxicity activity smaller than that of other commercial cationic surfactants. DPPC phospholipid was used as a model membrane component. The dynamic surface tension of 1414RAc/DPPC aqueous dispersions injected into the saline subphase was followed by tensiometry. The layer formation for the mixtures is always accelerated with respect to DPPC, and surprisingly, the surface tension reduction is faster and reaches lower surface tension values at surfactant concentration below its critical micellar concentration (cmc). Interfacial dilational rheology properties of mixed films spread on the air/water interface were determined by the dynamic oscillation method using a Langmuir trough. The effect of surfactant mole fraction on the rheological parameters of 1414RAc/DPPC mixed monolayers was studied at a relative amplitude of area deformation of 5% and a frequency of 50 mHz. The monolayer viscoelasticity shows a nonideal mixing behavior with predominance of the surfactant properties. This nonideal behavior has been attributed to the prevalence of electrostatic interactions.

  10. Autoignited laminar lifted flames of methane, ethylene, ethane, and n-butane jets in coflow air with elevated temperature

    SciTech Connect

    Choi, B.C.; Chung, S.H.

    2010-12-15

    The autoignition characteristics of laminar lifted flames of methane, ethylene, ethane, and n-butane fuels have been investigated experimentally in coflow air with elevated temperature over 800 K. The lifted flames were categorized into three regimes depending on the initial temperature and fuel mole fraction: (1) non-autoignited lifted flame, (2) autoignited lifted flame with tribrachial (or triple) edge, and (3) autoignited lifted flame with mild combustion. For the non-autoignited lifted flames at relatively low temperature, the existence of lifted flame depended on the Schmidt number of fuel, such that only the fuels with Sc > 1 exhibited stationary lifted flames. The balance mechanism between the propagation speed of tribrachial flame and local flow velocity stabilized the lifted flames. At relatively high initial temperatures, either autoignited lifted flames having tribrachial edge or autoignited lifted flames with mild combustion existed regardless of the Schmidt number of fuel. The adiabatic ignition delay time played a crucial role for the stabilization of autoignited flames. Especially, heat loss during the ignition process should be accounted for, such that the characteristic convection time, defined by the autoignition height divided by jet velocity was correlated well with the square of the adiabatic ignition delay time for the critical autoignition conditions. The liftoff height was also correlated well with the square of the adiabatic ignition delay time. (author)

  11. Effects of laboratory housing on exploratory behaviour, novelty discrimination and spatial reference memory in a subterranean, solitary rodent, the Cape mole-rat (Georychus capensis).

    PubMed

    Oosthuizen, Maria Kathleen; Scheibler, Anne-Gita; Bennett, Nigel Charles; Amrein, Irmgard

    2013-01-01

    A large number of laboratory and field based studies are being carried out on mole-rats, both in our research group and others. Several studies have highlighted the development of adverse behaviours in laboratory animals and have emphasised the importance of enrichment for captive animals. Hence we were interested in evaluating how laboratory housing would affect behavioural performance in mole-rats. We investigated exploratory behaviour, the ability to discriminate between novel and familiar environments and reference memory in the solitary Cape mole-rat (Georychus capensis). Our data showed that both wild and captive animals readily explore open spaces and tunnels. Wild animals were however more active than their captive counterparts. In the Y maze two trial discrimination task, wild animals failed to discriminate between novel and familiar environments, while laboratory housed mole-rats showed preferential spatial discrimination in terms of the length of time spent in the novel arm. The performance of the laboratory and wild animals were similar when tested for reference memory in the Y maze, both groups showed a significant improvement compared to the first day, from the 3rd day onwards. Wild animals made more mistakes whereas laboratory animals were slower in completing the task. The difference in performance between wild and laboratory animals in the Y-maze may be as a result of the lower activity of the laboratory animals. Laboratory maintained Cape mole-rats show classic behaviours resulting from a lack of stimulation such as reduced activity and increased aggression. However, they do display an improved novelty discrimination compared to the wild animals. Slower locomotion rate of the laboratory animals may increase the integration time of stimuli, hence result in a more thorough inspection of the surroundings. Unlike the captive animals, wild animals show flexibility in their responses to unpredictable events, which is an important requirement under

  12. Specific Paucity of Unmyelinated C-Fibers in Cutaneous Peripheral Nerves of the African Naked-Mole Rat: Comparative Analysis Using Six Species of Bathyergidae

    PubMed Central

    Smith, Ewan S; Purfürst, Bettina; Grigoryan, Tamara; Park, Thomas J; Bennett, Nigel C; Lewin, Gary R

    2012-01-01

    In mammalian peripheral nerves, unmyelinated C-fibers usually outnumber myelinated A-fibers. By using transmission electron microscopy, we recently showed that the saphenous nerve of the naked mole-rat (Heterocephalus glaber) has a C-fiber deficit manifested as a substantially lower C:A-fiber ratio compared with other mammals. Here we determined the uniqueness of this C-fiber deficit by performing a quantitative anatomical analysis of several peripheral nerves in five further members of the Bathyergidae mole-rat family: silvery (Heliophobius argenteocinereus), giant (Fukomys mechowii), Damaraland (Fukomys damarensis), Mashona (Fukomys darlingi), and Natal (Cryptomys hottentotus natalensis) mole-rats. In the largely cutaneous saphenous and sural nerves, the naked mole-rat had the lowest C:A-fiber ratio (∼1.5:1 compared with ∼3:1), whereas, in nerves innervating both skin and muscle (common peroneal and tibial) or just muscle (lateral/medial gastrocnemius), this pattern was mostly absent. We asked whether lack of hair follicles alone accounts for the C-fiber paucity by using as a model a mouse that loses virtually all its hair as a consequence of conditional deletion of the β-catenin gene in the skin. These β-catenin loss-of function mice (β-cat LOF mice) displayed only a mild decrease in C:A-fiber ratio compared with wild-type mice (4.42 compared with 3.81). We suggest that the selective cutaneous C-fiber deficit in the cutaneous nerves of naked mole-rats is unlikely to be due primarily to lack of skin hair follicles. Possible mechanisms contributing to this unique peripheral nerve anatomy are discussed. J. Comp. Neurol. 520:2785–2803, 2012. © 2012 Wiley Periodicals, Inc. PMID:22528859

  13. Dental peculiarities in the silvery mole-rat: an original model for studying the evolutionary and biological origins of continuous dental generation in mammals

    PubMed Central

    Šumbera, Radim

    2015-01-01

    Unravelling the evolutionary and developmental mechanisms that have impacted the mammalian dentition, since more than 200 Ma, is an intricate issue. Interestingly, a few mammal species, including the silvery mole-rat Heliophobius argenteocinereus, are able to replace their dentition by the addition of supernumerary molars at the back of jaw migrating then toward the front. The aim here was to demonstrate the potential interest of further studying this rodent in order to better understand the origins of continuous dental replacement in mammals, which could also provide interesting data concerning the evolution of limited dental generation occurring in first mammals. In the present study, we described the main stages of the dental eruptive sequence in the silvery mole-rat and the associated characteristics of horizontal replacement using X-ray microtomography. This was coupled to the investigation of other African mole-rats which have no dental replacement. This method permitted to establish evidence that the initial development of the dentition in Heliophobius is comparable to what it is observed in most of African mole-rats. This rodent first has premolars, but then identical additional molars, a mechanism convergent to manatees and the pygmy rock-wallaby. Evidence of continuous replacement and strong dental dynamics were also illustrated in Heliophobius, and stressed the need to deeply investigate these aspects for evolutionary, functional and developmental purposes. We also noticed that two groups of extinct non-mammalian synapsids convergently acquired this dental mechanism, but in a way differing from extant mammals. The discussion on the diverse evolutionary origins of horizontal dental replacement put emphasis on the necessity of focusing on biological parameters potentially involved in both continuous and limited developments of teeth in mammals. In that context, the silvery mole-rat could appear as the most appropriate candidate to do so. PMID:26401449

  14. Ejection Fraction Heart Failure Measurement

    MedlinePlus

    ... Thromboembolism Aortic Aneurysm More Ejection Fraction Heart Failure Measurement Updated:Feb 15,2017 The ejection fraction (EF) is an important measurement in determining how well your heart is pumping ...

  15. Pronounced cancer resistance in a subterranean rodent, the blind mole-rat, Spalax: in vivo and in vitro evidence

    PubMed Central

    2013-01-01

    Background Subterranean blind mole rats (Spalax) are hypoxia tolerant (down to 3% O2), long lived (>20 years) rodents showing no clear signs of aging or aging related disorders. In 50 years of Spalax research, spontaneous tumors have never been recorded among thousands of individuals. Here we addressed the questions of (1) whether Spalax is resistant to chemically-induced tumorigenesis, and (2) whether normal fibroblasts isolated from Spalax possess tumor-suppressive activity. Results Treating animals with 3-Methylcholantrene (3MCA) and 7,12-Dimethylbenz(a) anthracene/12-O-tetradecanoylphorbol-13-acetate (DMBA/TPA), two potent carcinogens, confirmed Spalax high resistance to chemically induced cancers. While all mice and rats developed the expected tumors following treatment with both carcinogens, among Spalax no tumors were observed after DMBA/TPA treatment, while 3MCA induced benign fibroblastic proliferation in 2 Spalax individuals out of12, and only a single animal from the advanced age group developed malignancy 18 months post-treatment. The remaining animals are still healthy 30 months post-treatment. In vitro experiments showed an extraordinary ability of normal Spalax cultured fibroblasts to restrict malignant behavior in a broad spectrum of human-derived and in newly isolated Spalax 3MCA-induced cancer cell lines. Growth of cancer cells was inhibited by either direct interaction with Spalax fibroblasts or with soluble factors released into culture media and soft agar. This was accompanied by decreased cancer cell viability, reduced colony formation in soft agar, disturbed cell cycle progression, chromatin condensation and mitochondrial fragmentation. Cells from another cancer resistant subterranean mammal, the naked mole rat, were also tested for direct effect on cancer cells and, similar to Spalax, demonstrated anti-cancer activity. No effect on cancer cells was observed using fibroblasts from mouse, rat or Acomys. Spalax fibroblast conditioned media had

  16. Line parameters including temperature dependences of air- and self-broadened line shapes of 12C16O2: 2.06-μm region

    NASA Astrophysics Data System (ADS)

    Benner, D. Chris; Devi, V. Malathy; Sung, Keeyoon; Brown, Linda R.; Miller, Charles E.; Payne, Vivienne H.; Drouin, Brian J.; Yu, Shanshan; Crawford, Timothy J.; Mantz, Arlan W.; Smith, Mary Ann H.; Gamache, Robert R.

    2016-08-01

    This study reports the results from analyzing a number of high resolution, high signal-to-noise ratio (S/N) spectra in the 2.06-μm spectral region for pure CO2 and mixtures of CO2 in dry air. A multispectrum nonlinear least squares curve fitting technique has been used to retrieve the various spectral line parameters. The dataset includes 27 spectra: ten pure CO2, two 99% 13C-enriched CO2 and fifteen spectra of mixtures of 12C-enriched CO2 in dry air. The spectra were recorded at various gas sample temperatures between 170 and 297 K. The absorption path lengths range from 0.347 to 49 m. The sample pressures for the pure CO2 spectra varied from 1.1 to 594 Torr; for the two 13CO2 spectra the pressures were ∼10 and 146 Torr. For the air-broadened spectra, the pressures of the gas mixtures varied between 200 and 711 Torr with CO2 volume mixing ratios ranging from 0.014% to 0.203%. The multispectrum fitting technique was applied to fit simultaneously all these spectra to retrieve consistent set of line positions, intensities, and line shape parameters including their temperature dependences; for this, the Voigt line shape was modified to include line mixing (via the relaxation matrix formalism) and quadratic speed dependence. The new results are compared to select published values, including recent ab initio calculations. These results are required to retrieve the column averaged dry air mole fraction (XCO2) from space-based observations, such as the Orbiting Carbon Observatory-2 (OCO-2) satellite mission that NASA launched in July 2014.

  17. Fractional Hopfield Neural Networks: Fractional Dynamic Associative Recurrent Neural Networks.

    PubMed

    Pu, Yi-Fei; Yi, Zhang; Zhou, Ji-Liu

    2016-07-14

    This paper mainly discusses a novel conceptual framework: fractional Hopfield neural networks (FHNN). As is commonly known, fractional calculus has been incorporated into artificial neural networks, mainly because of its long-term memory and nonlocality. Some researchers have made interesting attempts at fractional neural networks and gained competitive advantages over integer-order neural networks. Therefore, it is naturally makes one ponder how to generalize the first-order Hopfield neural networks to the fractional-order ones, and how to implement FHNN by means of fractional calculus. We propose to introduce a novel mathematical method: fractional calculus to implement FHNN. First, we implement fractor in the form of an analog circuit. Second, we implement FHNN by utilizing fractor and the fractional steepest descent approach, construct its Lyapunov function, and further analyze its attractors. Third, we perform experiments to analyze the stability and convergence of FHNN, and further discuss its applications to the defense against chip cloning attacks for anticounterfeiting. The main contribution of our work is to propose FHNN in the form of an analog circuit by utilizing a fractor and the fractional steepest descent approach, construct its Lyapunov function, prove its Lyapunov stability, analyze its attractors, and apply FHNN to the defense against chip cloning attacks for anticounterfeiting. A significant advantage of FHNN is that its attractors essentially relate to the neuron's fractional order. FHNN possesses the fractional-order-stability and fractional-order-sensitivity characteristics.

  18. Development and evaluation of a suite of isotope reference gases for methane in air

    NASA Astrophysics Data System (ADS)

    Sperlich, Peter; Uitslag, Nelly A. M.; Richter, Jürgen M.; Rothe, Michael; Geilmann, Heike; van der Veen, Carina; Röckmann, Thomas; Blunier, Thomas; Brand, Willi A.

    2016-08-01

    Measurements from multiple laboratories have to be related to unifying and traceable reference material in order to be comparable. However, such fundamental reference materials are not available for isotope ratios in atmospheric methane, which led to misinterpretations of combined data sets in the past. We developed a method to produce a suite of synthetic CH4-in-air standard gases that can be used to unify methane isotope ratio measurements of laboratories in the atmospheric monitoring community. Therefore, we calibrated a suite of pure methane gases of different methanogenic origin against international referencing materials that define the VSMOW (Vienna Standard Mean Ocean Water) and VPDB (Vienna Pee Dee Belemnite) isotope scales. The isotope ratios of our pure methane gases range between -320 and +40 ‰ for δ2H-CH4 and between -70 and -40 ‰ for δ13C-CH4, enveloping the isotope ratios of tropospheric methane (about -85 and -47 ‰ for δ2H-CH4 and δ13C-CH4 respectively). Estimated uncertainties, including the full traceability chain, are < 1.5 ‰ and < 0.2 ‰ for δ2H and δ13C calibrations respectively. Aliquots of the calibrated pure methane gases have been diluted with methane-free air to atmospheric methane levels and filled into 5 L glass flasks. The synthetic CH4-in-air standards comprise atmospheric oxygen/nitrogen ratios as well as argon, krypton and nitrous oxide mole fractions to prevent gas-specific measurement artefacts. The resulting synthetic CH4-in-air standards are referred to as JRAS-M16 (Jena Reference Air Set - Methane 2016) and will be available to the atmospheric monitoring community. JRAS-M16 may be used as unifying isotope scale anchor for isotope ratio measurements in atmospheric methane, so that data sets can be merged into a consistent

  19. How Weird Are Weird Fractions?

    ERIC Educational Resources Information Center

    Stuffelbeam, Ryan

    2013-01-01

    A positive rational is a weird fraction if its value is unchanged by an illegitimate, digit-based reduction. In this article, we prove that each weird fraction is uniquely weird and initiate a discussion of the prevalence of weird fractions.

  20. The random continued fraction transformation

    NASA Astrophysics Data System (ADS)

    Kalle, Charlene; Kempton, Tom; Verbitskiy, Evgeny

    2017-03-01

    We introduce a random dynamical system related to continued fraction expansions. It uses random combinations of the Gauss map and the Rényi (or backwards) continued fraction map. We explore the continued fraction expansions that this system produces, as well as the dynamical properties of the system.

  1. Fractional diffusion on bounded domains

    DOE PAGES

    Defterli, Ozlem; D'Elia, Marta; Du, Qiang; ...

    2015-03-13

    We found that the mathematically correct specification of a fractional differential equation on a bounded domain requires specification of appropriate boundary conditions, or their fractional analogue. In this paper we discuss the application of nonlocal diffusion theory to specify well-posed fractional diffusion equations on bounded domains.

  2. Numerical approaches to fractional calculus and fractional ordinary differential equation

    NASA Astrophysics Data System (ADS)

    Li, Changpin; Chen, An; Ye, Junjie

    2011-05-01

    Nowadays, fractional calculus are used to model various different phenomena in nature, but due to the non-local property of the fractional derivative, it still remains a lot of improvements in the present numerical approaches. In this paper, some new numerical approaches based on piecewise interpolation for fractional calculus, and some new improved approaches based on the Simpson method for the fractional differential equations are proposed. We use higher order piecewise interpolation polynomial to approximate the fractional integral and fractional derivatives, and use the Simpson method to design a higher order algorithm for the fractional differential equations. Error analyses and stability analyses are also given, and the numerical results show that these constructed numerical approaches are efficient.

  3. Estimation of the vapor pressure of petroleum distillate fractions from gas chromatographic data

    SciTech Connect

    Eggertsen, F.T.; Nygard, N.R.; Nickoley, L.D.

    1980-11-01

    The vapor pressure of petroleum distillate fractions is estimated conveniently by applying ideal gas and solution laws to gas chromatographic data. The vapor pressure is computed as a summation of the partial pressures for carbon number groups in the chromatogram, each partial pressure being derived as the product of mole fraction, determined from the chromatogram, and saturation pressure, calculated using the Antoine equation. A rapid method of computation with a programmable calculator was used. The method assumes approximate conformance to Raoult's and Dalton's laws relating to partial pressures from a solution. The results generally agree well with values obtained manometrically. Advantages of the method are the general availability of suitable gas chromatographic equipment, convenience and speed of the procedure and calculations, applicability over a wide range of volatility, freedom from temperature equilibration problems, and small sample requirement. 4 figures, 6 tables.

  4. Fractional chemotaxis diffusion equations.

    PubMed

    Langlands, T A M; Henry, B I

    2010-05-01

    We introduce mesoscopic and macroscopic model equations of chemotaxis with anomalous subdiffusion for modeling chemically directed transport of biological organisms in changing chemical environments with diffusion hindered by traps or macromolecular crowding. The mesoscopic models are formulated using continuous time random walk equations and the macroscopic models are formulated with fractional order differential equations. Different models are proposed depending on the timing of the chemotactic forcing. Generalizations of the models to include linear reaction dynamics are also derived. Finally a Monte Carlo method for simulating anomalous subdiffusion with chemotaxis is introduced and simulation results are compared with numerical solutions of the model equations. The model equations developed here could be used to replace Keller-Segel type equations in biological systems with transport hindered by traps, macromolecular crowding or other obstacles.

  5. Soot Volume Fraction Imaging

    NASA Technical Reports Server (NTRS)

    Greenberg, Paul S.; Ku, Jerry C.

    1994-01-01

    A new technique is described for the full-field determination of soot volume fractions via laser extinction measurements. This technique differs from previously reported point-wise methods in that a two-dimensional array (i.e., image) of data is acquired simultaneously. In this fashion, the net data rate is increased, allowing the study of time-dependent phenomena and the investigation of spatial and temporal correlations. A telecentric imaging configuration is employed to provide depth-invariant magnification and to permit the specification of the collection angle for scattered light. To improve the threshold measurement sensitivity, a method is employed to suppress undesirable coherent imaging effects. A discussion of the tomographic inversion process is provided, including the results obtained from numerical simulation. Results obtained with this method from an ethylene diffusion flame are shown to be in close agreement with those previously obtained by sequential point-wise interrogation.

  6. Functional fractionation of platelets.

    PubMed

    Haver, V M; Gear, A R

    1981-02-01

    Studies of platelet populations suggest that they are heterogeneous in size, age, and metabolic parameters. In an attempt to correlate these parameters with efficiency of aggregation, a new technique, functional fractionation, was developed. Platelet populations are separated by their differential reactivity to aggregating agents. For example, low doses of ADP (0.1 to 0.7 microM) are added to stirred PRP, after which gentle centrifugation is used to remove aggregates from single unreacted platelets. The loose aggregates can be readily dispersed for comparison of the physical or biochemical properties of the reacted versus unreacted platelets. It was found that reactive platelets were larger (6.5 micrometer3) than unreacted platelets (5.51 micrometer3). No significant difference in density existed between the two populations, and no release of [14C]serotonin from prelabeled platelets occurred during functional fractionation. Scanning and transmission electron microscopy confirmed the size difference and revealed that in both populations platelets were structurally intact with a normal discoid shape and no significant difference in organelle content. Human platelets most reactive to ADP were also enriched in glycogen (3.6-fold), ATP (1.6-fold), and ADP (twofold), compared with less reactive cells. These "reactive" cells took up more 51[Cr] and contained 1.9 times more surface sialic acid. In an in vivo aging experiment, rats were injected with 75[Se]methionine. Shortly after labeling (1 day), the most reactive platelets possessed the highest amount of 75[Se]. These results reveal that functionally active platelets, which are also larger, are more active metabolically than less reactive platelets, possess a higher negative surface charge, and may be a younger population.

  7. Evolution of bone compactness in extant and extinct moles (Talpidae): exploring humeral microstructure in small fossorial mammals

    PubMed Central

    2013-01-01

    Background Talpids include forms with different degree of fossoriality, with major specializations in the humerus in the case of the fully fossorial moles. We studied the humeral microanatomy of eleven extant and eight extinct talpid taxa of different lifestyles and of two non-fossorial outgroups and examined the effects of size and phylogeny. We tested the hypothesis that bone microanatomy is different in highly derived humeri of fossorial taxa than in terrestrial and semi-aquatic ones, likely due to special mechanical strains to which they are exposed to during digging. This study is the first comprehensive examination of histological parameters in an ecologically diverse and small-sized mammalian clade. Results No pattern of global bone compactness was found in the humeri of talpids that could be related to biomechanical specialization, phylogeny or size. The transition zone from the medullary cavity to the cortical compacta was larger and the ellipse ratio smaller in fossorial talpids than in non-fossorial talpids. No differences were detected between the two distantly related fossorial clades, Talpini and Scalopini. Conclusions At this small size, the overall morphology of the humerus plays a predominant role in absorbing the load, and microanatomical features such as an increase in bone compactness are less important, perhaps due to insufficient gravitational effects. The ellipse ratio of bone compactness shows relatively high intraspecific variation, and therefore predictions from this ratio based on single specimens are invalid. PMID:23442022

  8. Twin pregnancy and partial hydatidiform mole following in vitro fertilization and embryos transfer: a novel case of placental mosaicism.

    PubMed

    Sun, Cheng-juan; Zhao, You-ping; Yu, Song; Fan, Ling; Wu, Qing-qing; Li, Guang-hui; Zhang, Wei-yuan

    2012-12-01

    Twin pregnancy with mosaic partial hydatidiform mole (PHM) and survival of two healthy fetuses following in vitro fertilization and embryos transfer (IVF-ET) is a rare situation and is considered a challenge for management. A 32-year-old Chinese woman conceived twin pregnancy following IVF-ET. At 22 weeks' gestation, an additional intrauterine echogenic mass with features of PHM were shown by successive ultrasound examinations. At 35 weeks' gestation, two live male infants and two placentas were delivered by caesarean section (CS). Histologic examination of the abnormal placenta confirmed mosaic PHM. Genetic study showed the abnormal placental mosaicism (expressed in molar-69XXY and normal vili-46XY), co-existing with a hypospadia new-born (46XY) in one amniotic sac. However, the other one was normal. Serial serum β-hCG levels showed a declining trend and serum β-human chorionic gonadotropin (hCG) were undetectable at 6 months after delivery. The case demonstrated that it is possible to prolonged gestation by PHM under close surveillance during the entire pregnancy.

  9. A distinct role of the queen in coordinated workload and soil distribution in eusocial naked mole-rats.

    PubMed

    Kutsukake, Nobuyuki; Inada, Masayuki; Sakamoto, Shinsuke H; Okanoya, Kazuo

    2012-01-01

    We investigated how group members achieve collective decision-making, by considering individual intrinsic behavioural rules and behavioural mechanisms for maintaining social integration. Using a simulated burrow environment, we investigated the behavioural rules of coordinated workload for soil distribution in a eusocial mammal, the naked mole-rat (Heterocephalus glaber). We tested two predictions regarding a distinct role of the queen, a socially dominant individual in the caste system: the presence of a queen would increase the workload of other caste individuals, and the cues by a queen would affect the soil distribution. In experiment 1, we placed four individuals of various castes from the same colony into an experimental burrow. Workers exhibited the highest frequency of workload compared to other castes. The presence of a queen activated the workload by other individuals. Individuals showed a consistent workload in a particular direction so as to bias the soil distribution. These results suggest that individuals have a consensus on soil distribution and that the queen plays a distinct role. In experiment 2, we placed the odour of a queen in one of four cells and observed its effect on other individuals' workload and soil distribution. Relative to other cells, individuals frequently dug in the queen cell so the amount of soil in the queen cell decreased. These results suggest that queen odour is an important cue in coordinated workload and soil distribution in this species.

  10. Brain structure volumes in the mole rat, Spalax ehrenbergi (Spalacidae, Rodentia) in comparison to the rat and subterrestrial insectivores.

    PubMed

    Frahm, H D; Rehkämper, G; Nevo, E

    1997-01-01

    Natural blindness and a subterranean, digging mode of life demand peculiar adaptations of the central nervous system in the mole rat Spalax ehrenbergi, which are the focus of this quantitative investigation. Volumes of 25 brain structures in Spalax were evaluated allometrically, using the least encephalized mammalian species, the Madagassian hedgehog-like tenrecs (Tenrecinae) as a reference base, and their sizes compared with those of the rat (as a more generalized representative of rodents) and of some subterranean Insectivora. The allometric approach reveals that Spalax has a larger brain than tenrecs and the rat. Within the brain, the neocortex and diencephalon are well developed, an observation also made in other mammalian species with a relatively high encephalization. An unique feature in Spalax is the enlargement of motor structures of the brain, such as the cerebellum (and cerebellar nuclei), and the striatum. Most conspicuous is the large size of the nucleus motorius nervi trigemini, reflecting the importance of masticatory muscles for the special digging technique, which demand an intense use of the teeth for loosening the soil.

  11. A Distinct Role of the Queen in Coordinated Workload and Soil Distribution in Eusocial Naked Mole-Rats

    PubMed Central

    Kutsukake, Nobuyuki; Inada, Masayuki; Sakamoto, Shinsuke H.; Okanoya, Kazuo

    2012-01-01

    We investigated how group members achieve collective decision-making, by considering individual intrinsic behavioural rules and behavioural mechanisms for maintaining social integration. Using a simulated burrow environment, we investigated the behavioural rules of coordinated workload for soil distribution in a eusocial mammal, the naked mole-rat (Heterocephalus glaber). We tested two predictions regarding a distinct role of the queen, a socially dominant individual in the caste system: the presence of a queen would increase the workload of other caste individuals, and the cues by a queen would affect the soil distribution. In experiment 1, we placed four individuals of various castes from the same colony into an experimental burrow. Workers exhibited the highest frequency of workload compared to other castes. The presence of a queen activated the workload by other individuals. Individuals showed a consistent workload in a particular direction so as to bias the soil distribution. These results suggest that individuals have a consensus on soil distribution and that the queen plays a distinct role. In experiment 2, we placed the odour of a queen in one of four cells and observed its effect on other individuals’ workload and soil distribution. Relative to other cells, individuals frequently dug in the queen cell so the amount of soil in the queen cell decreased. These results suggest that queen odour is an important cue in coordinated workload and soil distribution in this species. PMID:22957085

  12. A microfluidic platform for transcription- and amplification-free detection of zepto-mole amounts of nucleic acid molecules.

    PubMed

    Mayr, Reinhard; Haider, Michaela; Thünauer, Roland; Haselgrübler, Thomas; Schütz, Gerhard J; Sonnleitner, Alois; Hesse, Jan

    2016-04-15

    Here we report the development of a device for the transcription- and amplification-free detection of DNA and RNA molecules down to the zepto-mole range. A microfluidic chip with a built-in microarray was used for manipulation of nano-liter sample volumes. Specific staining and immobilization of the target molecules was achieved via a double hybridization approach thereby avoiding bias due to enzymatic processes like reverse transcription and PCR amplification. Therefore, target molecules were indirectly labeled by pre-hybridization to complementary Cy5-labeled probes. The remaining single-stranded portion of each target molecule could subsequently hybridize to complementary capture probes of a microarray. Thus a target-mediated immobilization of labeled DNA took place. By means of an ultra-sensitive fluorescence readout, all molecules hybridized to the microarray could be detected. The combination of minimized sample volume and single molecule detection yielded a detection limit of 39 fM (831 molecules in 35.4 nl assay volume) for target DNA and 16 fM (338 molecules) for target RNA after 1h on-chip hybridization.

  13. Langmuir structure of poly (2-vinylpyridine-b-hexyl isocyanate) rod-coil diblock copolymers at the air/water Interface

    NASA Astrophysics Data System (ADS)

    Ahmad, Farhan

    2005-03-01

    We conducted a systematic interfacial study for the complete range (5%-90% of rod mole percentage) of an amphiphilic rod-coil system, poly (hexyl isocyanate)-b-(2-vinylpyridine) at the air/water and air/solid interface. We applied Langmuir balance technique, scanning probe microscopy (SPM), transmission electron microscopy (TEM) and X-ray reflectivity for the complete characterization of the monolayer at the interfaces. The phase isotherms showed the well amphiphilic balance for the diblock copolymers, and the formation of stable monolayers. With the increasing rod content, the consistent increase in the monolayer packing density was observed by the phase isotherms and supported by X-ray reflectivity. SPM and TEM characterization showed their interesting surface morphology according to the varying rod mole percentage in the rod-coil system. Rod mole percentage 5%-15% showed micellar morphology. Rod mole percentage 23%-32% showed distinct and dispersed rods, whereas rod mole percentage 70%-90% showed well packed structure similar to lamella phase. We found the tendency of the diblock system to adopt a packed monomolecular structure has increased by the increasing rod content. This lead us to conclude that it is the hexyl-isocyanate (rod part) that governs mostly the interfacial behavior of rod-coil block copolymers.

  14. Fraction Reduction in Membrane Systems

    PubMed Central

    Zhang, Hong

    2014-01-01

    Fraction reduction is a basic computation for rational numbers. P system is a new computing model, while the current methods for fraction reductions are not available in these systems. In this paper, we propose a method of fraction reduction and discuss how to carry it out in cell-like P systems with the membrane structure and the rules with priority designed. During the application of fraction reduction rules, synchronization is guaranteed by arranging some special objects in these rules. Our work contributes to performing the rational computation in P systems since the rational operands can be given in the form of fraction. PMID:24772037

  15. Assessing regional intake fractions in North America.

    PubMed

    Humbert, Sebastien; Manneh, Rima; Shaked, Shanna; Wannaz, Cédric; Horvath, Arpad; Deschênes, Louise; Jolliet, Olivier; Margni, Manuele

    2009-08-15

    This paper develops the IMPACT North America model, a spatially resolved multimedia, multi-pathway, fate, exposure and effect model that includes indoor and urban compartments. IMPACT North America allows geographic differentiation of population exposure of toxic emissions for comparative risk assessment and life cycle impact assessment within U.S. and Canada. It looks at air, water, soil, sediment and vegetation media, and divides North America into several hundred zones. It is nested within a single world box to account for emissions leaving North America. It is a multi-scale model, covering three different spatial scales--indoor, urban and regional--in all zones in North America. Model results are evaluated against monitored emissions and concentrations of benzo(a)pyrene, 2,3,7,8-TCDD and mercury. Most of the chemical concentrations predicted by the model fall within two orders of magnitude of the monitored data. The model shows that urban intake fractions are one order of magnitude higher than rural intake fractions. The model application and importance is demonstrated by a case study on spatially-distributed emissions over the life cycle of diesel fuel. Depending on population densities and agricultural intensities, intake fractions can vary by eight orders of magnitudes, and even limited indoor emissions can lead to intakes comparable to those from outdoor emissions. To accurately assess these variations in intake fraction, we require the essential three original features described in the present paper: i) inclusion of the continental model within a world box for persistent pollutants, ii) addition of an urban box for short- and medium-lived substances (for grid size larger than 100 km), and iii) assess indoor emissions. This model can therefore be used to screen chemicals and assess regionalized intake fractions within North America for population-based human exposure assessment, life cycle impact assessment, and comparative risk assessment. The model can be

  16. 40 CFR 53.64 - Test procedure: Static fractionator test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Test procedure: Static fractionator test. 53.64 Section 53.64 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Performance Characteristics of Class II Equivalent Methods for PM2.5 § 53.64 Test procedure:...

  17. Applying Chemical Potential and Partial Pressure Concepts to Understand the Spontaneous Mixing of Helium and Air in a Helium-Inflated Balloon

    ERIC Educational Resources Information Center

    Jee-Yon Lee; Hee-Soo Yoo; Jong Sook Park; Kwang-Jin Hwang; Jin Seog Kim

    2005-01-01

    The spontaneous mixing of helium and air in a helium-inflated balloon is described in an experiment in which the partial pressure of the gases in the balloon are determined from the mole factions and the total pressure measured in the balloon. The results described provide a model for teaching concepts of partial pressure, chemical potential, and…

  18. Fractionally charged skyrmions in fractional quantum Hall effect.

    PubMed

    Balram, Ajit C; Wurstbauer, U; Wójs, A; Pinczuk, A; Jain, J K

    2015-11-26

    The fractional quantum Hall effect has inspired searches for exotic emergent topological particles, such as fractionally charged excitations, composite fermions, abelian and nonabelian anyons and Majorana fermions. Fractionally charged skyrmions, which support both topological charge and topological vortex-like spin structure, have also been predicted to occur in the vicinity of 1/3 filling of the lowest Landau level. The fractional skyrmions, however, are anticipated to be exceedingly fragile, suppressed by very small Zeeman energies. Here we show that, slightly away from 1/3 filling, the smallest manifestations of the fractional skyrmion exist in the excitation spectrum for a broad range of Zeeman energies, and appear in resonant inelastic light scattering experiments as well-defined resonances slightly below the long wavelength spin wave mode. The spectroscopy of these exotic bound states serves as a sensitive tool for investigating the residual interaction between composite fermions, responsible for delicate new fractional quantum Hall states in this filling factor region.

  19. Fractionally charged skyrmions in fractional quantum Hall effect

    SciTech Connect

    Balram, Ajit C.; Wurstbauer, U.; Wójs, A.; Pinczuk, A.; Jain, J. K.

    2015-11-26

    The fractional quantum Hall effect has inspired searches for exotic emergent topological particles, such as fractionally charged excitations, composite fermions, abelian and nonabelian anyons and Majorana fermions. Fractionally charged skyrmions, which support both topological charge and topological vortex-like spin structure, have also been predicted to occur in the vicinity of 1/3 filling of the lowest Landau level. The fractional skyrmions, however, are anticipated to be exceedingly fragile, suppressed by very small Zeeman energies. Here we show that, slightly away from 1/3 filling, the smallest manifestations of the fractional skyrmion exist in the excitation spectrum for a broad range of Zeeman energies, and appear in resonant inelastic light scattering experiments as well-defined resonances slightly below the long wavelength spin wave mode. The spectroscopy of these exotic bound states serves as a sensitive tool for investigating the residual interaction between composite fermions, responsible for delicate new fractional quantum Hall states in this filling factor region.

  20. Air Pollution.

    ERIC Educational Resources Information Center

    Gilpin, Alan

    A summary of one of our most pressing environmental problems, air pollution, is offered in this book by the Director of Air Pollution Control for the Queensland (Australia) State Government. Discussion of the subject is not restricted to Queensland or Australian problems and policies, however, but includes analysis of air pollution the world over.…

  1. Air Pollution

    MedlinePlus

    ... of Climate Change on Children's Health: Session Two: Air Quality Impacts MODERATOR: Susan Anenberg, EPA Meredith McCormack, Johns ... University • Effects of Climate Change on Children’s Health: Air Quality Impacts Frederica Perera, Columbia University • Air quality Impacts ...

  2. Fractional variational calculus in terms of Riesz fractional derivatives

    NASA Astrophysics Data System (ADS)

    Agrawal, O. P.

    2007-06-01

    This paper presents extensions of traditional calculus of variations for systems containing Riesz fractional derivatives (RFDs). Specifically, we present generalized Euler-Lagrange equations and the transversality conditions for fractional variational problems (FVPs) defined in terms of RFDs. We consider two problems, a simple FVP and an FVP of Lagrange. Results of the first problem are extended to problems containing multiple fractional derivatives, functions and parameters, and to unspecified boundary conditions. For the second problem, we present Lagrange-type multiplier rules. For both problems, we develop the Euler-Lagrange-type necessary conditions which must be satisfied for the given functional to be extremum. Problems are considered to demonstrate applications of the formulations. Explicitly, we introduce fractional momenta, fractional Hamiltonian, fractional Hamilton equations of motion, fractional field theory and fractional optimal control. The formulations presented and the resulting equations are similar to the formulations for FVPs given in Agrawal (2002 J. Math. Anal. Appl. 272 368, 2006 J. Phys. A: Math. Gen. 39 10375) and to those that appear in the field of classical calculus of variations. These formulations are simple and can be extended to other problems in the field of fractional calculus of variations.

  3. Carbon monoxide fractions in cigarette and hookah (hubble bubble) smoke.

    PubMed

    Sajid, K M; Akhter, M; Malik, G Q

    1993-09-01

    We studied the carbon monoxide (CO) fractions in hookah and cigarette smoke, using a carbon monoxide micro smokerlyzer (model EC50, BEDFONT, U.K.). Mean carbon monoxide fractions (% by volume) of hookah smoke, using domestic charcoal were 0.38 +/- 0.07 (large hookah; unfiltered); 1.40 +/- 0.43 (small hookah; unfiltered); 0.34 +/- 0.06 (large hookah; filtered); 1.36 +/- 0.35 (small hookah; filtered) and 0.41 +/- 0.08 (cigarette smoke). The highest fractions were obtained with small size hookah and increase in size of hookah (i.e., volume of air in water base, fire bowl volume, pipe length, etc.) reduced the CO fraction significantly (P < 0.001). The fractions of cigarette lie between large and small hookah. The fractions vary slightly with different varieties of tobacco, e.g., CO fractions with Dera wala tobacco are significantly low (P < 0.05). Use of commercial charcoal gives significant rise in CO fractions (P < 0.001). Comparison of filtered and unfiltered smoke shows no significant difference in values. We conclude that the CO hazard is as high with hookah smoking as with cigarette smoking.

  4. Body Mole Map

    MedlinePlus

    ... ETECT. PREVENT Skin Cancer: Protect Yourself From the Sun Sun exposure is the most preventable risk factor for ... including melanoma. You can have fun in the sun and decrease your risk of skin cancer. NT. ...

  5. Non-Breeding Eusocial Mole-Rats Produce Viable Sperm—Spermiogram and Functional Testicular Morphology of Fukomys anselli

    PubMed Central

    Garcia Montero, Angelica; Vole, Christiane; Burda, Hynek; Malkemper, Erich Pascal; Holtze, Susanne; Morhart, Michaela; Saragusty, Joseph; Hildebrandt, Thomas B.; Begall, Sabine

    2016-01-01

    Ansell’s mole-rats (Fukomys anselli) are subterranean rodents living in families composed of about 20 members with a single breeding pair and their non-breeding offspring. Most of them remain with their parents for their lifetime and help to maintain and defend the natal burrow system, forage, and care for younger siblings. Since incest avoidance is based on individual recognition (and not on social suppression) we expect that non-breeders produce viable sperm spontaneously. We compared the sperm of breeding and non-breeding males, obtained by electroejaculation and found no significant differences in sperm parameters between both groups. Here, we used electroejaculation to obtain semen for the first time in a subterranean mammal. Spermiogram analysis revealed no significant differences in sperm parameters between breeders and non-breeders. We found significantly larger testes (measured on autopsies and on living animals per ultrasonography) of breeders compared to non-breeders (with body mass having a significant effect). There were no marked histological differences between breeding and non-breeding males, and the relative area occupied by Leydig cells and seminiferous tubules on histological sections, respectively, was not significantly different between both groups. The seminiferous epithelium and to a lesser degree the interstitial testicular tissue are characterized by lesions (vacuolar degenerations), however, this feature does not hinder fertilization even in advanced stages of life. The continuous production of viable sperm also in sexually abstinent non-breeders might be best understood in light of the mating and social system of Fukomys anselli, and the potential to found a new family following an unpredictable and rare encounter with an unfamiliar female (“provoked or induced dispersal”). Apparently, the non-breeders do not reproduce because they do not copulate but not because they would be physiologically infertile. The significantly increased

  6. Petrosal anatomy in the fossil mammal Necrolestes: evidence for metatherian affinities and comparisons with the extant marsupial mole

    PubMed Central

    Ladevèze, Sandrine; Asher, Robert J; Sánchez-Villagra, Marcelo R

    2008-01-01

    We present reconstructions of petrosal anatomy based on high-resolution X-ray computed tomography scans for the fossil mammal Necrolestes and for the marsupial mole Notoryctes sp. Compared with other mammals, Necrolestes exhibits a mosaic of plesiomorphic and derived characters, but most of the evidence supports its metatherian status. We revised previous descriptions and report on features of phylogenetic or functional significance. Necrolestes exhibits features that support metatherian affinities, such as the presence of a short and lateral prootic canal, and the loss of the stapedial artery in adults. A deep groove at the anterior pole of the promontorium is present in front of the cochlear housing, a variant on the extrabullar pathway of the internal carotid artery. The promontorium is laterally bordered by a large bony projection resembling the eutherian tegmen tympani [De Beer GR (1937) The Development of the Vertebrate Skull, Oxford, Clarendon Press, p. 391]. Posteromedial to the secondary facial foramen and anterolateral to the fenestra vestibuli is a pronounced fossa for the tensor tympani muscle. On the medial part of the pars canalicularis there is a great inflation of the medial side of the caudal tympanic process, a structure of unknown function. The internal acoustic meatus exhibits a broad transverse septum and is bordered laterally by a broad prefacial commissure. The cochleae of Necrolestes and of Notoryctes have fewer spiral turns (1.1 and 1.6, respectively) than most marsupials. The lateral semicircular canal is more expanded than the posterior semicircular canal in Necrolestes but not in Notoryctes. Both Necrolestes and Notoryctes have a second crus commune, i.e. the lateral semicircular canal opens into the ampulla of the posterior semicircular canal. A stylomastoid foramen enclosed anterodorsally by both the pars cochlearis and pars canalicularis is present in Dasyuridae, Dromiciops gliroides and Notoryctes. PMID:19094184

  7. Immunohistochemical Characterization of the Chemosensory Pulmonary Neuroepithelial Bodies in the Naked Mole-Rat Reveals a Unique Adaptive Phenotype

    PubMed Central

    Pan, Jie; Park, Thomas J.; Cutz, Ernest; Yeger, Herman

    2014-01-01

    The pulmonary neuroepithelial bodies (NEBs) constitute polymodal airway chemosensors for monitoring and signaling ambient gas concentrations (pO2, pCO2/H+) via complex innervation to the brain stem controlling breathing. NEBs produce the bioactive amine, serotonin (5-HT), and a variety of peptides with multiple effects on lung physiology and other organ systems. NEBs in mammals appear prominent and numerous during fetal and neonatal periods, and decline in the post-natal period suggesting an important role during perinatal adaptation. The naked mole-rat (NMR), Heterocephalus glaber, has adapted to the extreme environmental conditions of living in subterranean burrows in large colonies (up to 300 colony mates). The crowded, unventilated burrows are environments of severe hypoxia and hypercapnia. However, NMRs adjust readily to above ground conditions. The chemosensory NEBs of this species were characterized and compared to those of the conventional Wistar rat (WR) to identify similarities and differences that could explain the NMR’s adaptability to environments. A multilabel immunohistochemical analysis combined with confocal microscopy revealed that the expression patterns of amine, peptide, neuroendocrine, innervation markers and chemosensor component proteins in NEBs of NMR were similar to that of WR. However, we found the following differences: 1) NEBs in both neonatal and adult NMR lungs were significantly larger and more numerous as compared to WR; 2) NEBs in NMR had a more variable compact cell organization and exhibited significant differences in the expression of adhesion proteins; 3) NMR NEBs showed a significantly greater ratio of 5-HT positive cells with an abundance of 5-HT; 4) NEBs in NMR expressed the proliferating cell nuclear antigen (PCNA) and the neurogenic gene (MASH1) indicating active proliferation and a state of persistent differentiation. Taken together our findings suggest that NEBs in lungs of NMR are in a hyperactive, functional and

  8. Non-Breeding Eusocial Mole-Rats Produce Viable Sperm--Spermiogram and Functional Testicular Morphology of Fukomys anselli.

    PubMed

    Garcia Montero, Angelica; Vole, Christiane; Burda, Hynek; Malkemper, Erich Pascal; Holtze, Susanne; Morhart, Michaela; Saragusty, Joseph; Hildebrandt, Thomas B; Begall, Sabine

    2016-01-01

    Ansell's mole-rats (Fukomys anselli) are subterranean rodents living in families composed of about 20 members with a single breeding pair and their non-breeding offspring. Most of them remain with their parents for their lifetime and help to maintain and defend the natal burrow system, forage, and care for younger siblings. Since incest avoidance is based on individual recognition (and not on social suppression) we expect that non-breeders produce viable sperm spontaneously. We compared the sperm of breeding and non-breeding males, obtained by electroejaculation and found no significant differences in sperm parameters between both groups. Here, we used electroejaculation to obtain semen for the first time in a subterranean mammal. Spermiogram analysis revealed no significant differences in sperm parameters between breeders and non-breeders. We found significantly larger testes (measured on autopsies and on living animals per ultrasonography) of breeders compared to non-breeders (with body mass having a significant effect). There were no marked histological differences between breeding and non-breeding males, and the relative area occupied by Leydig cells and seminiferous tubules on histological sections, respectively, was not significantly different between both groups. The seminiferous epithelium and to a lesser degree the interstitial testicular tissue are characterized by lesions (vacuolar degenerations), however, this feature does not hinder fertilization even in advanced stages of life. The continuous production of viable sperm also in sexually abstinent non-breeders might be best understood in light of the mating and social system of Fukomys anselli, and the potential to found a new family following an unpredictable and rare encounter with an unfamiliar female ("provoked or induced dispersal"). Apparently, the non-breeders do not reproduce because they do not copulate but not because they would be physiologically infertile. The significantly increased testes

  9. Accessible solitons of fractional dimension

    SciTech Connect

    Zhong, Wei-Ping; Belić, Milivoj; Zhang, Yiqi

    2016-05-15

    We demonstrate that accessible solitons described by an extended Schrödinger equation with the Laplacian of fractional dimension can exist in strongly nonlocal nonlinear media. The soliton solutions of the model are constructed by two special functions, the associated Legendre polynomials and the Laguerre polynomials in the fraction-dimensional space. Our results show that these fractional accessible solitons form a soliton family which includes crescent solitons, and asymmetric single-layer and multi-layer necklace solitons. -- Highlights: •Analytic solutions of a fractional Schrödinger equation are obtained. •The solutions are produced by means of self-similar method applied to the fractional Schrödinger equation with parabolic potential. •The fractional accessible solitons form crescent, asymmetric single-layer and multilayer necklace profiles. •The model applies to the propagation of optical pulses in strongly nonlocal nonlinear media.

  10. The impact of gape on the performance of the skull in chisel-tooth digging and scratch digging mole-rats (Rodentia: Bathyergidae)

    PubMed Central

    McIntosh, Andrew F.

    2016-01-01

    The African mole-rats (Bathyergidae) are a family of rodents highly adapted for life underground. Previous research has shown that chisel-tooth digging mole-rats (which use their incisors to dig burrows) are clearly distinguishable from scratch diggers (which only use the forelimbs to tunnel) on the basis of morphology of the skull, and that the differences are linked to the production of high bite forces and wide gapes. We hypothesized that the skull of a chisel-tooth digging mole-rat would perform better at wider gapes than that of a scratch digging mole-rat during incisor biting. To test this hypothesis, we created finite-element models of the cranium of the scratch digging Bathyergus suillus and the chisel-tooth digging Fukomys mechowii, and loaded them to simulate incisor bites at different gapes. Muscle loads were scaled such that the ratio of force to surface area was the same in both models. We measured three performance variables: overall stress across the cranium, mechanical efficiency of biting and degree of deformation across the skull. The Fukomys model had a more efficient incisor bite at all gapes, despite having greater average stress across the skull. In addition, the Fukomys model deformed less at wider gapes, whereas the Bathyergus model deformed less at narrower gapes. These properties of the cranial morphology of Fukomys and Bathyergus are congruent with their respective chisel-tooth and scratch digging behaviours and, all other factors being equal, would enable the more efficient production of bite force at wider gapes in Fukomys. However, in vivo measurements of muscle forces and activation patterns are needed to fully understand the complex biomechanics of tooth digging. PMID:27853575

  11. The impact of gape on the performance of the skull in chisel-tooth digging and scratch digging mole-rats (Rodentia: Bathyergidae)

    NASA Astrophysics Data System (ADS)

    McIntosh, Andrew F.; Cox, Philip G.

    2016-10-01

    The African mole-rats (Bathyergidae) are a family of rodents highly adapted for life underground. Previous research has shown that chisel-tooth digging mole-rats (which use their incisors to dig burrows) are clearly distinguishable from scratch diggers (which only use the forelimbs to tunnel) on the basis of morphology of the skull, and that the differences are linked to the production of high bite forces and wide gapes. We hypothesized that the skull of a chisel-tooth digging mole-rat would perform better at wider gapes than that of a scratch digging mole-rat during incisor biting. To test this hypothesis, we created finite-element models of the cranium of the scratch digging Bathyergus suillus and the chisel-tooth digging Fukomys mechowii, and loaded them to simulate incisor bites at different gapes. Muscle loads were scaled such that the ratio of force to surface area was the same in both models. We measured three performance variables: overall stress across the cranium, mechanical efficiency of biting and degree of deformation across the skull. The Fukomys model had a more efficient incisor bite at all gapes, despite having greater average stress across the skull. In addition, the Fukomys model deformed less at wider gapes, whereas the Bathyergus model deformed less at narrower gapes. These properties of the cranial morphology of Fukomys and Bathyergus are congruent with their respective chisel-tooth and scratch digging behaviours and, all other factors being equal, would enable the more efficient production of bite force at wider gapes in Fukomys. However, in vivo measurements of muscle forces and activation patterns are needed to fully understand the complex biomechanics of tooth digging.

  12. Trigonometric Integrals via Partial Fractions

    ERIC Educational Resources Information Center

    Chen, H.; Fulford, M.

    2005-01-01

    Parametric differentiation is used to derive the partial fractions decompositions of certain rational functions. Those decompositions enable us to integrate some new combinations of trigonometric functions.

  13. Fractional-time quantum dynamics.

    PubMed

    Iomin, Alexander

    2009-08-01

    Application of the fractional calculus to quantum processes is presented. In particular, the quantum dynamics is considered in the framework of the fractional time Schrödinger equation (SE), which differs from the standard SE by the fractional time derivative: partial differential/partial differentialt --> partial differential(alpha)/partial differentialt(alpha). It is shown that for alpha=1/2 the fractional SE is isospectral to a comb model. An analytical expression for the Green's functions of the systems are obtained. The semiclassical limit is discussed.

  14. Effect of SiO2/Na2O mole ratio on the properties of foam geopolymers fabricated from circulating fluidized bed fly ash

    NASA Astrophysics Data System (ADS)

    Liu, Ze; Shao, Ning-ning; Huang, Tian-yong; Qin, Jun-feng; Wang, Dong-min; Yang, Yu

    2014-06-01

    Geopolymers are three-dimensional aluminosilicates formed in a short time at low temperature by geopolymerization. In this paper, alkali-activated foam geopolymers were fabricated from circulating fluidized bed fly ash (CFA), and the effect of SiO2/Na2O mole ratio (0.91-1.68) on their properties was studied. Geopolymerization products were characterized by mechanical testing, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). The results show that SiO2/Na2O mole ratio plays an important role in the mechanical and morphological characteristics of geopolymers. Foam samples prepared in 28 d with a SiO2/Na2O mole ratio of 1.42 exhibit the greatest compressive strength of 2.52 MPa. Morphological analysis reveals that these foam geopolymers appear the relatively optimized pore structure and distribution, which are beneficial to the structure stability. Moreover, a combination of the Si/Al atomic ratio ranging between 1.47 and 1.94 with the Na/Al atomic ratio of about 1 produces the samples with high strength.

  15. The effect of diet on microfaunal population and function in the caecum of a subterranean naked mole-rat, Heterocephalus glaber.

    PubMed

    Buffenstein, R; Yahav, S

    1991-03-01

    The effect of dietary fibre and starch content on digestibility, microfaunal population and caecal function was investigated in a subterranean mole-rat, Heterocephalus glaber (Rodentia). Mole-rats were fed on a diet of either sweet potato (neutral-detergent fibre (NDF) 65 g/kg dry matter (DM), starch 638 g/kg DM) or carrot (NDF 157 g/kg DM, starch 258.7 g/kg DM) for 4 weeks. Daily intake and faecal output were monitored. Thereafter caecal microfaunal population, density and function were assessed using light and scanning electron microscopy and by measuring both gas and short chain fatty acid (SCFA) production. A 2.4-fold increase in fibre and 2.5-fold decrease in starch content resulted in a decrease in caecal DM content (390 g/kg). A concomitant dramatic decline (by 93%) in ciliate protozoa with a corresponding 2-fold increase in bacteria also accompanied this change in diet. Fermentative efficiency as indicated by gas production was 2.6 times greater on a carrot diet than on sweet potato. Microbial fermentation resulted in higher SCFA concentrations on the carrot diet, with a 42% reduction in SCFA concentration on the sweet potato diet. Here, SCFA contributed 5.1% of daily energy expenditure and this increased 5.0-fold on the carrot diet. Caecal micro-organism function, therefore, played an important role in the nutritional physiology of these naked mole-rats, and enabled maximum utilization of the food substrate.

  16. Existence of serotonin and neuropeptides-immunoreactive endocrine cells in the small and large intestines of the mole-rats (Spalax leucodon).

    PubMed

    Yaman, M; Bayrakdar, A; Tarakçı, B G

    2012-08-01

    The present study was conducted to clarify the regional distribution and relative frequency of endocrine cells secreting serotonin, substance P (SP), cholecystokinin-8 (CCK-8), vasoactive intestinal polypeptide (VIP) and neurotensin in the small and large intestine of the mole-rats (Spalax leucodon), by specific immunohistochemical methods. In the small and large intestine of mole-rats (Spalax leucodon), serotonin, SP and VIP were identified with various frequencies, but CCK-8 and neurotensin were not observed. Most of the IR cells in the small and large intestine were located in the intestinal crypt and epithelium however, they were more frequency in the intestinal crypt. Serotonin-IR cells were detected throughout the whole intestinal tract, predominantly in the duodenum and colon. SP-IR cells were demonstrated throughout the whole intestinal tract except for the ileum and rectum with highest frequencies in the cecum. VIP-IR cells were found in all parts of the small intestine except for the large intestine. In conclusion, the general distribution patterns and relative frequency of intestinal endocrine cells of the mole-rats (Spalax leucodon) was similar to those of some rodent species. However, some species-dependent unique distributions and frequencies characteristics of endocrine cells were also observed in the present study.

  17. The effects of oxotremorine, epibatidine, atropine, mecamylamine and naloxone in the tail-flick, hot-plate, and formalin tests in the naked mole-rat (Heterocephalus glaber).

    PubMed

    Dulu, Thomas D; Kanui, Titus I; Towett, Philemon K; Maloiy, Geoffrey M; Abelson, Klas S P

    2014-01-01

    The naked mole-rat (Heterocephalus glaber) is a promising animal model for the study of pain mechanisms, therefore a thorough characterization of this species is essential. The aim of the present study was to establish the naked mole-rat as a model for studying the cholinergic receptor system in antinociception by investigating the involvement of muscarinic, nicotinic and opioid receptors in nociceptive tests in this species. The effects of systemic administration of the muscarinic receptor agonist oxotremorine and the nicotinic receptor agonist epibatidine were investigated in the tail-flick, the hot-plate, and the formalin tests. The effects of co-administration of the muscarinic receptor antagonist atropine, the nicotinic receptor antagonist mecamylamine, and the opioid receptor antagonist naloxone were also investigated. Oxotremorine and epibatidine induced a significant, dose-dependent antinociceptive effect in the tail-flick, hot-plate, and formalin tests, respectively. The effects of oxotremorine and epibatidine were blocked by atropine and mecamylamine, respectively. In all three nociceptive tests, naloxone in combination with oxotremorine or epibatidine enhanced the antinociceptive effects of the drugs. The present study demonstrated that stimulation of muscarinic and nicotinic receptors produces antinociceptive effects in the naked-mole rat. The reversal effect of atropine and mecamylamine suggests that this effect is mediated by cholinergic receptors. As naloxone increases the antinociceptive effects of cholinergic agonists, it is suggested that the cholinergic antinociception acts via a gateway facilitated by opioid receptor blockage; however, the precise interaction between these receptor systems needs further investigation.

  18. Study of Age-Dependent Structural and Functional Changes of Mitochondria in Skeletal Muscles and Heart of Naked Mole Rats (Heterocephalus glaber).

    PubMed

    Holtze, S; Eldarov, C M; Vays, V B; Vangeli, I M; Vysokikh, M Yu; Bakeeva, L E; Skulachev, V P; Hildebrandt, T B

    2016-12-01

    Morphometric analysis of mitochondria in skeletal muscles and heart of 6- and 60-month-old naked mole rats (Heterocephalus glaber) revealed a significant age-dependent increase in the total area of mitochondrial cross-sections in studied muscle fibers. For 6- and 60-month-old animals, these values were 4.8 ± 0.4 and 12.7 ± 1.8%, respectively. This effect is mainly based on an increase in the number of mitochondria. In 6-month-old naked mole rats, there were 0.23 ± 0.02 mitochondrial cross-sections per µm(2) of muscle fiber, while in 60-month-old animals this value was 0.47 ± 0.03. The average area of a single mitochondrial cross-section also increased with age in skeletal muscles - from 0.21 ± 0.01 to 0.29 ± 0.03 µm(2). Thus, naked mole rats show a drastic enlargement of the mitochondrial apparatus in skeletal muscles with age due to an increase in the number of mitochondria and their size. They possess a neotenic type of chondriome accompanied by specific features of mitochondrial functioning in the state of oxidative phosphorylation and a significant decrease in the level of matrix adenine nucleotides.

  19. Low sulfide levels and a high degree of cystathionine β-synthase (CBS) activation by S-adenosylmethionine (SAM) in the long-lived naked mole-rat

    PubMed Central

    Dziegelewska, Maja; Holtze, Susanne; Vole, Christiane; Wachter, Ulrich; Menzel, Uwe; Morhart, Michaela; Groth, Marco; Szafranski, Karol; Sahm, Arne; Sponholz, Christoph; Dammann, Philip; Huse, Klaus; Hildebrandt, Thomas; Platzer, Matthias

    2016-01-01

    Hydrogen sulfide (H2S) is a gaseous signalling molecule involved in many physiological and pathological processes. There is increasing evidence that H2S is implicated in aging and lifespan control in the diet-induced longevity models. However, blood sulfide concentration of naturally long-lived species is not known. Here we measured blood sulfide in the long-lived naked mole-rat and five other mammalian species considerably differing in lifespan and found a negative correlation between blood sulfide and maximum longevity residual. In addition, we show that the naked mole-rat cystathionine β-synthase (CBS), an enzyme whose activity in the liver significantly contributes to systemic sulfide levels, has lower activity in the liver and is activated to a higher degree by S-adenosylmethionine compared to other species. These results add complexity to the understanding of the role of H2S in aging and call for detailed research on naked mole-rat transsulfuration. PMID:26803480

  20. Separation of the metallic and non-metallic fraction from printed circuit boards employing green technology.

    PubMed

    Estrada-Ruiz, R H; Flores-Campos, R; Gámez-Altamirano, H A; Velarde-Sánchez, E J

    2016-07-05

    The generation of electrical and electronic waste is increasing day by day; recycling is attractive because of the metallic fraction containing these. Nevertheless, conventional techniques are highly polluting. The comminution of the printed circuit boards followed by an inverse flotation process is a clean technique that allows one to separate the metallic fraction from the non-metallic fraction. It was found that particle size and superficial air velocity are the main variables in the separation of the different fractions. In this way an efficient separation is achieved by avoiding the environmental contamination coupled with the possible utilization of the different fractions obtained.

  1. Aerodynamical sealing by air curtains

    NASA Astrophysics Data System (ADS)

    Frank, Daria; Linden, Paul

    2015-11-01

    Air curtains are artificial high-velocity plane turbulent jets which are installed in a doorway in order to reduce the heat and the mass exchange between two environments. The performance of an air curtain is assessed in terms of the sealing effectiveness E, the fraction of the exchange flow prevented by the air curtain compared to the open-door situation. The main controlling parameter for air curtain dynamics is the deflection modulus Dm representing the ratio of the momentum flux of the air curtain and the transverse forces acting on it due to the stack effect. In this talk, we examine the influence of two factors on the performance of an air curtain: the presence of an additional ventilation pathway in the room, such as a small top opening, and the effects of an opposing buoyancy force which for example arises if a downwards blowing air curtain is heated. Small-scale experiments were conducted to investigate the E (Dm) -curve of an air curtain in both situations. We present both experimental results and theoretical explanations for our observations. We also briefly illustrate how simplified models developed for air curtains can be used for more complex phenomena such as the effects of wind blowing around a model building on the ventilation rates through the openings.

  2. Fractional random walk lattice dynamics

    NASA Astrophysics Data System (ADS)

    Michelitsch, T. M.; Collet, B. A.; Riascos, A. P.; Nowakowski, A. F.; Nicolleau, F. C. G. A.

    2017-02-01

    We analyze time-discrete and time-continuous ‘fractional’ random walks on undirected regular networks with special focus on cubic periodic lattices in n  =  1, 2, 3,.. dimensions. The fractional random walk dynamics is governed by a master equation involving fractional powers of Laplacian matrices {{L}\\fracα{2}}} where α =2 recovers the normal walk. First we demonstrate that the interval 0<α ≤slant 2 is admissible for the fractional random walk. We derive analytical expressions for the transition matrix of the fractional random walk and closely related the average return probabilities. We further obtain the fundamental matrix {{Z}(α )} , and the mean relaxation time (Kemeny constant) for the fractional random walk. The representation for the fundamental matrix {{Z}(α )} relates fractional random walks with normal random walks. We show that the matrix elements of the transition matrix of the fractional random walk exihibit for large cubic n-dimensional lattices a power law decay of an n-dimensional infinite space Riesz fractional derivative type indicating emergence of Lévy flights. As a further footprint of Lévy flights in the n-dimensional space, the transition matrix and return probabilities of the fractional random walk are dominated for large times t by slowly relaxing long-wave modes leading to a characteristic {{t}-\\frac{n{α}} -decay. It can be concluded that, due to long range moves of fractional random walk, a small world property is emerging increasing the efficiency to explore the lattice when instead of a normal random walk a fractional random walk is chosen.

  3. Impact of oil spill from ship on air quality around coastal regions of Korea

    NASA Astrophysics Data System (ADS)

    Shon, Zang-Ho; Song, Sang-Keun

    2010-05-01

    Regional air quality around coastal regions, where regular maritime traffic emissions from cargo, other commercial, fishing and military vessels are significantly active, can be affected by their direct emission of primary air pollutants (NOx, SO2, particulate matter (PM), etc.). For instance, harbor traffic exerted an important impact on NO2, SO2, O3, and PM levels. In addition, regional air quality around coastal regions is also affected by oil spill caused by ship accident in the coast. On 7 Dec., 2007, a barge carrying a crane hit the oil tanker MT Hebei Sprit off the west coast of the Republic of Korea, Yellow Sea (approximately 10 km off the coast), at 0700 local time, causing the spill of total estimated 12,547 tons of Iranian heavy (IH) and Kuwait Export (KE) crude oils. Since then, oil began coming on shore late in the night on 7 Dec. More than 150 km of coastline had been identified as being impacted by 17 Dec. Much of the affected area is part of the Taean-gun National Park and the nearest coastal city to spilled area is Taean. On 8 Dec., the flow of oil from the tanker was stopped when the holes were patched. The accident is the worst oil spill in Korea and the spill area is about one-third of the size of the Exxon Valdez oil spill. The short- and long-term effects of oil spill on marine environment have been numerously studied, not on atmospheric environment. In this study, the air quality impact near spilled area by the evaporation of hydrocarbons from the oil spill is studied in detail. The evaporation rates of the volatile fractions of the crude oils released by oil spill were estimated based on their mole fractions of crude oils and mass transfer coefficients. Based on a molecular diffusion process, the flux of spilled oil component (Fivap, mol m-2 s-1) can be expressed as follows: Fivap = Kivap(Civap - C∞vap) (1) where Civap is concentration (mol m-3) of a component i of crude oil vapor in the air at the oil-air interface; C∞vap is the

  4. Unwrapping Students' Ideas about Fractions

    ERIC Educational Resources Information Center

    Lewis, Rebecca M.; Gibbons, Lynsey K.; Kazemi, Elham; Lind, Teresa

    2015-01-01

    Supporting students to develop an understanding of the meaning of fractions is an important goal of elementary school mathematics. This involves developing partitioning strategies, creating representations, naming fractional quantities, and using symbolic notation. This article describes how teachers can use a formative assessment problem to…

  5. Rational Exponentials and Continued Fractions

    ERIC Educational Resources Information Center

    Denny, J. K.

    2012-01-01

    Using continued fraction expansions, we can approximate constants, such as pi and e, using an appropriate integer n raised to the power x[superscript 1/x], x a suitable rational. We review continued fractions and give an algorithm for producing these approximations.

  6. Understanding Magnitudes to Understand Fractions

    ERIC Educational Resources Information Center

    Gabriel, Florence

    2016-01-01

    Fractions are known to be difficult to learn and difficult to teach, yet they are vital for students to have access to further mathematical concepts. This article uses evidence to support teachers employing teaching methods that focus on the conceptual understanding of the magnitude of fractions.

  7. Air and water quality monitor assessment of life support subsystems

    NASA Technical Reports Server (NTRS)

    Whitley, Ken; Carrasquillo, Robyn L.; Holder, D.; Humphries, R.

    1988-01-01

    Preprotype air revitalization and water reclamation subsystems (Mole Sieve, Sabatier, Static Feed Electrolyzer, Trace Contaminant Control, and Thermoelectric Integrated Membrane Evaporative Subsystem) were operated and tested independently and in an integrated arrangement. During each test, water and/or gas samples were taken from each subsystem so that overall subsystem performance could be determined. The overall test design and objectives for both subsystem and integrated subsystem tests were limited, and no effort was made to meet water or gas specifications. The results of chemical analyses for each of the participating subsystems are presented along with other selected samples which were analyzed for physical properties and microbiologicals.

  8. Air Policing

    DTIC Science & Technology

    2009-05-01

    Iraq. To provide a background for understanding why Britain commenced the policy of air policing, this paper begins with a review of contemporary...7 Omissi, Air Power, XV. 8 policing actions or the pushing home of advantages gained by the air.” Within the context of this paper , the...control operations, and therefore within the context of this paper , the term coercive airpower refers to the threat of harming a population or the threat

  9. Vapour pressures, aqueous solubility, Henry's law constants and air/water partition coefficients of 1,8-dichlorooctane and 1,8-dibromooctane.

    PubMed

    Sarraute, Sabine; Mokbel, Ilham; Costa Gomes, Margarida F; Majer, Vladimir; Delepine, Hervé; Jose, Jacques

    2006-09-01

    New data on the vapour pressures and aqueous solubility of 1,8-dichlorooctane and 1,8-dibromooctane are reported as a function of temperature between 20 degrees C and 80 degrees C and 1 degrees C and 40 degrees C, respectively. For the vapour pressures, a static method was used during the measurements which have an estimated uncertainty between 3% and 5%. The aqueous solubilities were determined using a dynamic saturation column method and the values are accurate to within +/-10%. 1,8-Dichlorooctane is more volatile than 1,8-dibromooctane in the temperature range covered (p(sat) varies from 3 to 250 Pa and from 0.53 to 62 Pa, respectively) and is also approximately three times more soluble in water (mole fraction solubilities at 25 degrees C of 5.95 x 10(-7) and 1.92 x 10(-7), respectively). A combination of the two sets of data allowed the calculation of the Henry's law constants and the air water partition coefficients. A simple group contribution concept was used to rationalize the data obtained.

  10. Surface interactions, thermodynamics and topography of binary monolayers of Insulin with dipalmitoylphosphatidylcholine and 1-palmitoyl-2-oleoylphosphatidylcholine at the air/water interface.

    PubMed

    Grasso, E J; Oliveira, R G; Maggio, B

    2016-02-15

    The molecular packing, thermodynamics and surface topography of binary Langmuir monolayers of Insulin and DPPC (dipalmitoylphosphatidylcholine) or POCP (1-palmitoyl-2-oleoylphosphatidylcholine) at the air/water interface on Zn(2+) containing solutions were studied. Miscibility and interactions were ascertained by the variation of surface pressure-mean molecular area isotherms, surface compressional modulus and surface (dipole) potential with the film composition. Brewster Angle Microscopy was used to visualize the surface topography of the monolayers. Below 20mN/m Insulin forms stable homogenous films with DPPC and POPC at all mole fractions studied (except for films with XINS=0.05 at 10mN/m where domain coexistence was observed). Above 20mN/m, a segregation process between mixed phases occurred in all monolayers without squeezing out of individual components. Under compression the films exhibit formation of a viscoelastic or kinetically trapped organization leading to considerable composition-dependent hysteresis under expansion that occurs with entropic-enthalpic compensation. The spontaneously unfavorable interactions of Insulin with DPPC are driven by favorable enthalpy that is overcome by unfavorable entropic ordering; in films with POPC both the enthalpic and entropic effects are unfavorable. The surface topography reveals domain coexistence at relatively high pressure showing a striped appearance. The interactions of Insulin with two major membrane phospholipids induces composition-dependent and long-range changes of the surface organization that ought to be considered in the context of the information-transducing capabilities of the hormone for cell functioning.

  11. Radiating subdispersive fractional optical solitons

    NASA Astrophysics Data System (ADS)

    Fujioka, J.; Espinosa, A.; Rodríguez, R. F.; Malomed, B. A.

    2014-09-01

    It was recently found [Fujioka et al., Phys. Lett. A 374, 1126 (2010)] that the propagation of solitary waves can be described by a fractional extension of the nonlinear Schrödinger (NLS) equation which involves a temporal fractional derivative (TFD) of order α > 2. In the present paper, we show that there is also another fractional extension of the NLS equation which contains a TFD with α < 2, and in this case, the new equation describes the propagation of radiating solitons. We show that the emission of the radiation (when α < 2) is explained by resonances at various frequencies between the pulses and the linear modes of the system. It is found that the new fractional NLS equation can be derived from a suitable Lagrangian density, and a fractional Noether's theorem can be applied to it, thus predicting the conservation of the Hamiltonian, momentum and energy.

  12. Radiating subdispersive fractional optical solitons

    SciTech Connect

    Fujioka, J. Espinosa, A.; Rodríguez, R. F.; Malomed, B. A.

    2014-09-01

    It was recently found [Fujioka et al., Phys. Lett. A 374, 1126 (2010)] that the propagation of solitary waves can be described by a fractional extension of the nonlinear Schrödinger (NLS) equation which involves a temporal fractional derivative (TFD) of order α > 2. In the present paper, we show that there is also another fractional extension of the NLS equation which contains a TFD with α < 2, and in this case, the new equation describes the propagation of radiating solitons. We show that the emission of the radiation (when α < 2) is explained by resonances at various frequencies between the pulses and the linear modes of the system. It is found that the new fractional NLS equation can be derived from a suitable Lagrangian density, and a fractional Noether's theorem can be applied to it, thus predicting the conservation of the Hamiltonian, momentum and energy.

  13. A new fractional wavelet transform

    NASA Astrophysics Data System (ADS)

    Dai, Hongzhe; Zheng, Zhibao; Wang, Wei

    2017-03-01

    The fractional Fourier transform (FRFT) is a potent tool to analyze the time-varying signal. However, it fails in locating the fractional Fourier domain (FRFD)-frequency contents which is required in some applications. A novel fractional wavelet transform (FRWT) is proposed to solve this problem. It displays the time and FRFD-frequency information jointly in the time-FRFD-frequency plane. The definition, basic properties, inverse transform and reproducing kernel of the proposed FRWT are considered. It has been shown that an FRWT with proper order corresponds to the classical wavelet transform (WT). The multiresolution analysis (MRA) associated with the developed FRWT, together with the construction of the orthogonal fractional wavelets are also presented. Three applications are discussed: the analysis of signal with time-varying frequency content, the FRFD spectrum estimation of signals that involving noise, and the construction of fractional Harr wavelet. Simulations verify the validity of the proposed FRWT.

  14. Fractional active disturbance rejection control.

    PubMed

    Li, Dazi; Ding, Pan; Gao, Zhiqiang

    2016-05-01

    A fractional active disturbance rejection control (FADRC) scheme is proposed to improve the performance of commensurate linear fractional order systems (FOS) and the robust analysis shows that the controller is also applicable to incommensurate linear FOS control. In FADRC, the traditional extended states observer (ESO) is generalized to a fractional order extended states observer (FESO) by using the fractional calculus, and the tracking differentiator plus nonlinear state error feedback are replaced by a fractional proportional-derivative controller. To simplify controller tuning, the linear bandwidth-parameterization method has been adopted. The impacts of the observer bandwidth ωo and controller bandwidth ωc on system performance are then analyzed. Finally, the FADRC stability and frequency-domain characteristics for linear single-input single-output FOS are analyzed. Simulation results by FADRC and ADRC on typical FOS are compared to demonstrate the superiority and effectiveness of the proposed scheme.

  15. Water Vapor Isotopic Fractionation and Strat/trop Exchange

    NASA Astrophysics Data System (ADS)

    Jucks, K. W.; Johnson, D. G.; Traub, W. A.; Chance, K. V.

    We will present atmospheric observations of the isotopic fractionation for water vapor as observed by the Smithsonian Astrophysical Observatory far-infrared spectrometer (FIRS-2). The stratospheric observations are corrected with a photochemical model to account for methane oxidation to determine the "entry level" isotopic fractionation of water in the stratosphere. These values are then compared to a simple Rayleigh frac- tionation model that includes estimations of convection, radiative heating, and mixing to infer relative contributions to stratosphere/troposphere exchange. The observations of water vapor fractionation are most consistent with a model that mixes air uplifted from roughly 11 km with significantly more air that has been dehydrated by convec- tion to an effective temperature that is much cooler than the tropopause temperature. The water vapor mixing ratio in the stratosphere results from a combination of radia- tive heating, recirculation of stratospheric air, and deep convection that supplies the air to the upper tropical troposphere. We believe that these types of observations could be a powerful tool for constraining circulation models.

  16. Anti-fatigue activity of polysaccharide fractions from Lepidium meyenii Walp. (maca).

    PubMed

    Li, Jing; Sun, Qingrui; Meng, Qingran; Wang, Lei; Xiong, Wentao; Zhang, Lianfu

    2017-02-01

    The two fractions of polysaccharide MPS-1 and MPS-2 were extracted from Lepidium meyenii Walp. (maca) by water, and purified using a DEAE-52 and a Sephadex G-100 column. The molecular weight (MW) of MPS-1 was 7.6kDa, and the MW of MPS-2 was 6.7kDa. The MPS-1 was composed of xylose, arabinose, galactose and glucose, with the mole ratio 1:1.7:3.3:30.5; the MPS-2 was composed of arabinose, galactose and glucose, with the mole ratio 1:1.3:36.8. The IR spectrum implied that only α-pyranose existed in MPS-1, and both α-pyranose and β-pyranose existed in MPS-2. The anti-fatigue activities of MPS-1 and MPS-2 were measured by the forced swimming test, along with the determination of blood lactate (BLA), urea nitrogen (BUN), lactic dehydrogenase (LDH) activity and liver glycogen (LG). The results indicated that both MPS-1 and MPS-2 presented dose-dependently positive effects on the fatigue related parameters. Additionally, MPS-2 has a better anti-fatigue effect than MPS-1.

  17. High-Speed Rainbow Schlieren Deflectometry Analysis of Helium Jets Flowing into Air for Microgravity Applications

    NASA Technical Reports Server (NTRS)

    Leptuch, Peter A.

    2002-01-01

    The flow phenomena of buoyant jets have been analyzed by many researchers in recent years. Few, however have studied jets in microgravity conditions, and the exact nature of the flow under these conditions has until recently been unknown. This study seeks to extend the work done by researchers at the university of Oklahoma in examining and documenting the behavior of helium jets in micro-gravity conditions. Quantitative rainbow schlieren deflectometry data have been obtained for helium jets discharging vertically into quiescent ambient air from tubes of several diameters at various flow rates using a high-speed digital camera. These data have obtained before, during and after the onset of microgravity conditions. High-speed rainbow schlieren deflectometry has been developed for this study with the installation and use of a high-speed digital camera and modifications to the optical setup. Higher temporal resolution of the transitional phase between terrestrial and micro-gravity conditions has been obtained which has reduced the averaging effect of longer exposure times used in all previous schlieren studies. Results include color schlieren images, color time-space images (temporal evolution images), frequency analyses, contour plots of hue and contour plots of helium mole fraction. The results, which focus primarily on the periods before and during the onset of microgravity conditions, show that the pulsation of the jets normally found in terrestrial gravity ("earth"-gravity) conditions cease, and the gradients in helium diminish to produce a widening of the jet in micro-gravity conditions. In addition, the results show that the disturbance propagate upstream from a downstream source.

  18. Air transport

    NASA Technical Reports Server (NTRS)

    Page, F Handley

    1924-01-01

    I purpose (sic) in this paper to deal with the development in air transport which has taken place since civil aviation between England and the Continent first started at the end of August 1919. A great deal of attention has been paid in the press to air services of the future, to the detriment of the consideration of results obtained up to the present.

  19. Air Pollution.

    ERIC Educational Resources Information Center

    Fox, Donald L.

    1989-01-01

    Materials related to air pollution are reviewed for the period January 1987, to October 1988. The topics are pollution monitoring, air pollution, and environmental chemistry. The organization consists of two major analytical divisions: (1) gaseous methods; and (2) aerosol and particulate methods. (MVL)

  20. Air Pollution.

    EPA Science Inventory

    Air quality is affected by many types of pollutants that are emitted from various sources, including stationary and mobile. These sources release both criteria and hazardous air pollutants, which cause health effects, ecological harm, and material damage. They are generally categ...

  1. LTA - Recent developments. [Lighter Than Air ships

    NASA Technical Reports Server (NTRS)

    Mayer, N. J.

    1977-01-01

    NASA-sponsored studies of existing and new LTA missions showed that airships looked very promising for some two dozen civil and military applications. These include surveillance of rural and urban areas, in the form of forest and police patrols; transport of very heavy large-volume maritime, industrial, and military payloads; coastal patrol and sea control; seismographic surveys; air pollution monitoring; and moving goods to remote areas; along with a number of less important but still attractive missions. A figure of merit of productivity (payload weight, ton moles per hour) was used to compare airships of various type and size. In each case, this criterion established an index of efficiency for evaluating not only conceptual approaches but also modes of flight. Some, in part unexpected, results of these studies are described.

  2. Tunable polymeric sorbent materials for fractionation of model naphthenates.

    PubMed

    Mohamed, Mohamed H; Wilson, Lee D; Headley, John V

    2013-04-04

    The sorption properties are reported for several examples of single-component carboxylic acids representing naphthenic acids (NAs) with β-cyclodextrin (β-CD) based polyurethane sorbents. Seven single-component examples of NAs were chosen with variable z values, carbon number, and chemical structure as follows: 2-hexyldecanoic acid (z = 0 and C = 16; S1), n-caprylic acid (z = 0 and C = 8; S2), trans-4-pentylcyclohexanecarboxylic acid (z = -2 and C = 12; S3), 4-methylcyclohexanecarboxylic acid (z = -2 and C = 8; S4), dicyclohexylacetic acid (z = -4; C = 14; S5), 4-pentylbicyclo[2.2.2]octane-1-carboxylic acid (z = -4; C = 14; S6), and lithocholic acid (z = -6; C = 24; S7). The copolymer sorbents were synthesized at three relative β-CD:diisocyanate mole ratios (i.e., 1:1, 1:2, and 1:3) using 4,4'-dicyclohexylmethane diisocyanate (CDI) and 4,4'-diphenylmethane diisocyanate (MDI). The sorption properties of the copolymer sorbents were characterized using equilibrium sorption isotherms in aqueous solution at pH 9.00 with electrospray ionization mass spectrometry. The equilibrium fraction of the unbound carboxylate anions was monitored in the aqueous phase. The sorption properties of the copolymer sorbents (i.e., Qm) were obtained from the Sips isotherm model. The Qm values generally decrease as the number of accessible β-CD inclusion sites in the copolymer framework decreases. The chemical structure of the adsorbates played an important role in their relative uptake, as evidenced by the adsorbate lipophilic surface area (LSA) and the involvement of hydrophobic effects. The copolymers exhibit molecular selective sorption of the single-component carboxylates in mixtures which suggests their application as sorbents for fractionation of mixtures of NAs. By comparison, granular activated carbon (GAC) and chitosan sorbents did not exhibit any significant molecular selective sorption relative to the copolymer materials; however, evidence of variable sorption capacity was

  3. Fractionally charged skyrmions in fractional quantum Hall effect

    DOE PAGES

    Balram, Ajit C.; Wurstbauer, U.; Wójs, A.; ...

    2015-11-26

    The fractional quantum Hall effect has inspired searches for exotic emergent topological particles, such as fractionally charged excitations, composite fermions, abelian and nonabelian anyons and Majorana fermions. Fractionally charged skyrmions, which support both topological charge and topological vortex-like spin structure, have also been predicted to occur in the vicinity of 1/3 filling of the lowest Landau level. The fractional skyrmions, however, are anticipated to be exceedingly fragile, suppressed by very small Zeeman energies. Here we show that, slightly away from 1/3 filling, the smallest manifestations of the fractional skyrmion exist in the excitation spectrum for a broad range of Zeemanmore » energies, and appear in resonant inelastic light scattering experiments as well-defined resonances slightly below the long wavelength spin wave mode. The spectroscopy of these exotic bound states serves as a sensitive tool for investigating the residual interaction between composite fermions, responsible for delicate new fractional quantum Hall states in this filling factor region.« less

  4. Recalcitrant dissolved organic carbon fractions.

    PubMed

    Hansell, Dennis A

    2013-01-01

    Marine dissolved organic carbon (DOC) exhibits a spectrum of reactivity, from very fast turnover of the most bioavailable forms in the surface ocean to long-lived materials circulating within the ocean abyss. These disparate reactivities group DOC by fractions with distinctive functions in the cycling of carbon, ranging from support of the microbial loop to involvement in the biological pump to a hypothesized major source/sink of atmospheric CO(2) driving paleoclimate variability. Here, the major fractions constituting the global ocean's recalcitrant DOC pool are quantitatively and qualitatively characterized with reference to their roles in carbon biogeochemistry. A nomenclature for the fractions is proposed based on those roles.

  5. Australia's Next Top Fraction Model

    ERIC Educational Resources Information Center

    Gould, Peter

    2013-01-01

    Peter Gould suggests Australia's next top fraction model should be a linear model rather than an area model. He provides a convincing argument and gives examples of ways to introduce a linear model in primary classrooms.

  6. Xenon fractionation in porous planetesimals

    NASA Technical Reports Server (NTRS)

    Zahnle, Kevin; Pollack, James B.; Kasting, James F.

    1990-01-01

    The distinctively fractionated Xe on Mars and earth may have its root in a common source from which both planets accreted. Beginning with Ozima and Nakazawa's (1980) hypothesis that terrestrial Xe fractionation was caused by gravitational separation of adsorbed solar nebular gases inside large porous planetesimals, it is pointed out that Xe would have been trapped as the planetesimal grew and pores were squeezed shut by lithostatic pressure. It is shown that enough fractionated Xe to supply the earth could have been trapped this way. The degree of fractionation is controlled by the lithostatic pressure at the pore-closing front and so would have been roughly the same for all large planetesimals. The predicted degree of fractionation agrees well with that preserved in terrestrial and Martian Xe. Relative to Xe, this source is strongly depleted in other noble gases. In contrast to the original Ozima and Nakazawa hypothesis, the present hypothesis predicts the observed fractionation, and it allows planetary accretion to occur after the dissipation of the solar nebula.

  7. Xenon fractionation in porous planetesimals.

    PubMed

    Zahnle, K; Pollack, J B; Kasting, J F

    1990-01-01

    The distinctively fractionated Xe on Mars and Earth may have its root in a common source from which both planets accreted. We begin with Ozima and Nakazawa's hypothesis that terrestrial Xe fractionation was caused by gravitational separation of adsorbed solar nebular gases inside large porous planetesimals. We point out that Xe would have been trapped as the planetesimal grew and pores were squeezed shut by lithostatic pressure. We show that enough fractionated Xe to supply the Earth could have been trapped this way. The degree of fractionation is controlled by the lithostatic pressure at the pore-closing front and so would have been roughly the same for all large planetesimals. The predicted degree of fractionation agrees well with that preserved in terrestrial and martian Xe. Relative to Xe, this source is strongly depleted in other noble gases. In contrast to the original Ozima and Nakazawa hypothesis, our hypothesis predicts the observed fractionation, and it allows planetary accretion to occur after the dissipation of the solar nebula. The required planetesimals are large, representing a class of object now extinct in the solar system.

  8. Absence of Maternal Methylation in Biparental Hydatidiform Moles from Women with NLRP7 Maternal-Effect Mutations Reveals Widespread Placenta-Specific Imprinting

    PubMed Central

    Sanchez-Delgado, Marta; Martin-Trujillo, Alejandro; Tayama, Chiharu; Vidal, Enrique; Esteller, Manel; Iglesias-Platas, Isabel; Deo, Nandita; Barney, Olivia; Maclean, Ken; Hata, Kenichiro; Nakabayashi, Kazuhiko; Fisher, Rosemary; Monk, David

    2015-01-01

    Familial recurrent hydatidiform mole (RHM) is a maternal-effect autosomal recessive disorder usually associated with mutations of the NLRP7 gene. It is characterized by HM with excessive trophoblastic proliferation, which mimics the appearance of androgenetic molar conceptuses despite their diploid biparental constitution. It has been proposed that the phenotypes of both types of mole are associated with aberrant genomic imprinting. However no systematic analyses for imprinting defects have been reported. Here, we present the genome-wide methylation profiles of both spontaneous androgenetic and biparental NLRP7 defective molar tissues. We observe total paternalization of all ubiquitous and placenta-specific differentially methylated regions (DMRs) in four androgenetic moles; namely gain of methylation at paternally methylated loci and absence of methylation at maternally methylated regions. The methylation defects observed in five RHM biopsies from NLRP7 defective patients are restricted to lack-of-methylation at maternal DMRs. Surprisingly RHMs from two sisters with the same missense mutations, as well as consecutive RHMs from one affected female show subtle allelic methylation differences, suggesting inter-RHM variation. These epigenotypes are consistent with NLRP7 being a maternal-effect gene and involved in imprint acquisition in the oocyte. In addition, bioinformatic screening of the resulting methylation datasets identified over sixty loci with methylation profiles consistent with imprinting in the placenta, of which we confirm 22 as novel maternally methylated loci. These observations strongly suggest that the molar phenotypes are due to defective placenta-specific imprinting and over-expression of paternally expressed transcripts, highlighting that maternal-effect mutations of NLRP7 are associated with the most severe form of multi-locus imprinting defects in humans. PMID:26544189

  9. Structural Changes and Lack of HCN1 Channels in the Binaural Auditory Brainstem of the Naked Mole-Rat (Heterocephalus glaber).

    PubMed

    Gessele, Nikodemus; Garcia-Pino, Elisabet; Omerbašić, Damir; Park, Thomas J; Koch, Ursula

    2016-01-01

    Naked mole-rats (Heterocephalus glaber) live in large eu-social, underground colonies in narrow burrows and are exposed to a large repertoire of communication signals but negligible binaural sound localization cues, such as interaural time and intensity differences. We therefore asked whether monaural and binaural auditory brainstem nuclei in the naked mole-rat are differentially adjusted to this acoustic environment. Using antibody stainings against excitatory and inhibitory presynaptic structures, namely the vesicular glutamate transporter VGluT1 and the glycine transporter GlyT2 we identified all major auditory brainstem nuclei except the superior paraolivary nucleus in these animals. Naked mole-rats possess a well structured medial superior olive, with a similar synaptic arrangement to interaural-time-difference encoding animals. The neighboring lateral superior olive, which analyzes interaural intensity differences, is large and elongated, whereas the medial nucleus of the trapezoid body, which provides the contralateral inhibitory input to these binaural nuclei, is reduced in size. In contrast, the cochlear nucleus, the nuclei of the lateral lemniscus and the inferior colliculus are not considerably different when compared to other rodent species. Most interestingly, binaural auditory brainstem nuclei lack the membrane-bound hyperpolarization-activated channel HCN1, a voltage-gated ion channel that greatly contributes to the fast integration times in binaural nuclei of the superior olivary complex in other species. This suggests substantially lengthened membrane time constants and thus prolonged temporal integration of inputs in binaural auditory brainstem neurons and might be linked to the severely degenerated sound localization abilities in these animals.

  10. Fractional characteristic times and dissipated energy in fractional linear viscoelasticity

    NASA Astrophysics Data System (ADS)

    Colinas-Armijo, Natalia; Di Paola, Mario; Pinnola, Francesco P.

    2016-08-01

    In fractional viscoelasticity the stress-strain relation is a differential equation with non-integer operators (derivative or integral). Such constitutive law is able to describe the mechanical behavior of several materials, but when fractional operators appear, the elastic and the viscous contribution are inseparable and the characteristic times (relaxation and retardation time) cannot be defined. This paper aims to provide an approach to separate the elastic and the viscous phase in the fractional stress-strain relation with the aid of an equivalent classical model (Kelvin-Voigt or Maxwell). For such equivalent model the parameters are selected by an optimization procedure. Once the parameters of the equivalent model are defined, characteristic times of fractional viscoelasticity are readily defined as ratio between viscosity and stiffness. In the numerical applications, three kinds of different excitations are considered, that is, harmonic, periodic, and pseudo-stochastic. It is shown that, for any periodic excitation, the equivalent models have some important features: (i) the dissipated energy per cycle at steady-state coincides with the Staverman-Schwarzl formulation of the fractional model, (ii) the elastic and the viscous coefficients of the equivalent model are strictly related to the storage and the loss modulus, respectively.

  11. Dependence of source gas mole ratio on crystalline quality of ZnSe layers grown on (100) ZnSe substrates by atmospheric pressure metalorganic vapor phase epitaxy

    NASA Astrophysics Data System (ADS)

    Yodo, T.; Koyama, T.; Yamashita, K.

    1988-10-01

    Single crystalline layers of undoped ZnSe have been grown on (100) ZnSe substrates at 250°C by atmospheric pressure metalorganic vapor phase epitaxy (MOVPE) using dimethylzinc (DMZ) and hydrogen selenide (H 2Se). The surface morphologies, observed by a Nomarski phase contrast interference microscope, depend on the growth conditions, particularly the source gas mole ratio η M ( ηM=[Se]/[Zn]). The surface morphologies of homoepilayers grown with η M of more than 15 are very rough like polycrystals. However, these layers have the best crystalline quality as determined by a double crystal X-ray diffraction spectrometer (the full width at half maximum (FWHM) of (400) diffraction is 33 arc sec). The surface morphologies of layers grown at values of η M between 3 and 15 are excellent as well as those of heteroepilayers (GaAs substrates are used). On the other hand, the crystalline quality becomes worse by reducing η M. The photoluminescence (PL) spectra at 4.2 K exhibit strong and well-resolved band-edge emissions from the donor bound exciton (hereafter called I x) and the free exciton (hereafter called E x) only for the low mole ratio (η M<10). The FWHM of I x is 0.8 meV which is sharper than that of heteroepilayers. However, the intensity of emissions from deep levels (deep emissions) of homoepilayers measured at 77 K is several times stronger than that of heteroepilayers. In the region of high mole ratio (η M>10), the PL spectra at 4.2 K show two broad lines: I x and the unknown I v (probably donor bound exciton). And the intensity of I x reduces two orders by decreasing the mole ratio from 20 to 3. This indicates that the concentration of donor decreases for the Se-rich condition. From the investigation of PL measurements, the origin of deep emissions is considered to be caused by complexes of Zn vacancies and impurities from the source gases. The dependences of η M on the quality of homoepilayers observed in this work are quite different from those in

  12. Air Apparent.

    ERIC Educational Resources Information Center

    Harbster, David A.

    1988-01-01

    Explains the principle upon which a barometer operates. Describes how to construct two barometric devices for use in the classroom that show air's changing pressure. Cites some conditions for predicting weather. (RT)

  13. Air Abrasion

    MedlinePlus

    ... information you need from the Academy of General Dentistry Sunday, April 9, 2017 About | Contact InfoBites Quick ... general dentist, who has been trained in restorative dentistry techniques, will perform any procedures that use air- ...