Science.gov

Sample records for observations results showed

  1. Simple instruments used in monitoring ionospheric perturbations and some observational results showing the ionospheric responses to the perturbations mainly from the lower atmosphere

    NASA Astrophysics Data System (ADS)

    Xiao, Zuo; Hao, Yongqiang; Zhang, Donghe; Xiao, Sai-Guan; Huang, Weiquan

    Ionospheric disturbances such as SID and acoustic gravity waves in different scales are well known and commonly discussed topics. Some simple ground equipment was designed and used for monitoring continuously the effects of these disturbances, especially, SWF, SFD. Besides SIDs, They also reflect clearly the acoustic gravity waves in different scale and Spread-F and these data are important supplementary to the traditional ionosonde records. It is of signifi-cance in understanding physical essentials of the ionospheric disturbances and applications in SID warning. In this paper, the designing of the instruments is given and results are discussed in detail. Some case studies were introduced as example which showed very clearly not only immediate effects of solar flare, but also the phenomena of ionospheric responses to large scale gravity waves from lower atmosphere such as typhoon, great earthquake and volcano erup-tion. Particularlyresults showed that acoustic gravity waves play significant role in seeding ionospheric Spread-F. These examples give evidence that lower atmospheric activities strongly influence the ionosphere.

  2. Cassini UVIS Observations Show Active Saturn's Rings

    NASA Astrophysics Data System (ADS)

    Esposito, L.; Colwell, J. E.; UVIS Team

    2004-12-01

    The Cassini Ultraviolet Imaging Spectrograph (UVIS) is part of the remote sensing payload of the NASA/ESA Cassini spacecraft. This spectrograph includes channels for extreme UV and far UV spectroscopic imaging, high speed photometry of stellar occultations, solar EUV occultation, and a hydrogen/deuterium absorption cell. We report our initial results from UVIS observations of Saturn's rings. Dynamic interactions between neutrals, ions, rings, moons and meteoroids produce a highly structured and time variable Saturn system Oxygen in the Saturn system dominates the magnetosphere. Observed fluctuations indicate close interactions with plasma sources. Stochastic events in the E ring may be the ultimate source. The spectral signature of water ice is seen on Phoebe and in Saturn's rings. Water ice is mixed non-uniformly with darker constituents. The high structure of the UV ring reflectance argues that collisional transport dominates ballistic transport in darkening the rings. Our preliminary results support the idea that rings are recycled fragments of moons: the current processes are more important than history and initial conditions. The spectra along the UVIS SOI radial scan indicate varying amounts of water ice. In the A ring, the ice fraction increases outward to a maximum at the outer edge. This large-scale variation is consistent with initially pure ice that has suffered meteoritic bombardment over the age of the Solar system (Cuzzi and Estrada 1998). We also see variations over scales of 1000 - 3000 km, which cannot be explained by this mechanism. Ballistic transport of spectrally neutral extrinsic pollutants from meteoroids striking the rings has a typical throw distance of 6000 km (Durisen et al 1989), too long to explain this finer structure. We propose a class of smaller renewal events, in which a small moon residing within the rings is shattered by an external impactor (Colwell and Esposito 1993, Barbara and Esposito 2002, Esposito and Colwell 2003). The

  3. Observational astrochemistry: recent results.

    PubMed

    Irvine, W M

    1989-01-01

    More than 80 molecular species have now been observed by astronomers in the dense interstellar clouds where stars and planets form or in the envelopes expelled by evolved stars. Elemental constituents of these compounds include all of the "biogenic" elements, hydrogen, carbon, nitrogen, oxygen, sulfur, and (most recently) phosphorus. In addition, silicon is found in several molecules, and a series of metal halides have recently been detected in the outflowing envelope of a nearby carbon star. Additions to the list of known interstellar molecules since the last COSPAR meeting are discussed individually. Recent measurements of the hydrogen isotopic fractionation for the cyclic molecule C3H2 are described; values up to 10,000 times the cosmic deuterium-to-hydrogen ratio are found. Knowledge of the chemical reservoirs for the major volatile elements and a comparison between observed molecular abundances and theoretical models are both discussed. PMID:11537359

  4. Safety Observations Achieve Results

    Energy Science and Technology Software Center (ESTSC)

    2000-01-16

    The SOAR web application provides a multi-checklist capability where focused observations can be created to address risk-likely work environments, tasks, etc. The SOAR web application has numerous reports to sort the data by key word, multiple factors (i.e., location, team, behavior, checklist, work environment, etc.), and the highest frequency of behaviors and error-likely predecessors, etc. Other performance indicators are also provided.

  5. 17. Building 202, observation room for test cell, showing panel, ...

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

    17. Building 202, observation room for test cell, showing panel, abort button, phones, and observation window. View looking northwest. - Rocket Engine Testing Facility, GRC Building No. 202, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

  6. Battery Honeycutt Observation Station, closer view showing frame rain; view ...

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

    Battery Honeycutt Observation Station, closer view showing frame rain; view northeast - Fort McKinley, Battery Honeycutt Observation Station, East side of East Side Drive, approximately 225 feet south of Cove Side Drive, Great Diamond Island, Portland, Cumberland County, ME

  7. Battery Carpenter Observation Station, collapsed ruin showing south wall; view ...

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

    Battery Carpenter Observation Station, collapsed ruin showing south wall; view northeast - Fort McKinley, Battery Carpenter Observation Station, West side of East Side Drive, approximately 275 feet south of Weymouth Way, Great Diamond Island, Portland, Cumberland County, ME

  8. Interior of the mine observation tower building, showing the steel ...

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

    Interior of the mine observation tower building, showing the steel compass ring in the tower. View facing east - U.S. Naval Base, Pearl Harbor, Waipio Peninsula, Waipo Peninsula, Pearl City, Honolulu County, HI

  9. Ends of the mine observation tower and transformer buildings, showing ...

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

    Ends of the mine observation tower and transformer buildings, showing the separation between them. View facing east - U.S. Naval Base, Pearl Harbor, Waipio Peninsula, Waipo Peninsula, Pearl City, Honolulu County, HI

  10. 19. Detail of southeast corner of physical plant showing observation ...

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

    19. Detail of southeast corner of physical plant showing observation lookout (view is looking northwest) - Skinner Meat Packing Plant, Main Plant, 6006 South Twenty-seventh Street, Omaha, Douglas County, NE

  11. Battery Berry Observation Station, detail of west side showing former ...

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

    Battery Berry Observation Station, detail of west side showing former entry recess and typical sash window; view southeast - Fort McKinley, Battery Berry Observation Station, North side of Wood Side Drive approximately 80 feet east of Spring Cove Lane, Great Diamond Island, Portland, Cumberland County, ME

  12. 1. OVERVIEW SHOWING FIRING CONTROL BLOCKHOUSE 0502 AND ADJACENT OBSERVATION ...

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

    1. OVERVIEW SHOWING FIRING CONTROL BLOCKHOUSE 0502 AND ADJACENT OBSERVATION TOWER. WATER BRAKE TROUGH SEGMENT AT LOWER RIGHT. Looking north northeast. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  13. INTERIOR VIEW SHOWING FURNACE KEEPER OBSERVING FURNACE THROUGH BLUE GLASS ...

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

    INTERIOR VIEW SHOWING FURNACE KEEPER OBSERVING FURNACE THROUGH BLUE GLASS EVERY TWENTY MINUTES TO DETERMINE SIZE AND TEXTURE OF BATCH AND OTHER VARIABLES. FAN IN FRONT COOLS WORKERS AS THEY CONDUCT REPAIRS. FURNACE TEMPERATURE AT 1572 DEGREES FAHRENHEIT. - Chambers-McKee Window Glass Company, Furnace No. 2, Clay Avenue Extension, Jeannette, Westmoreland County, PA

  14. 13. DETAIL VIEW OF BUTTRESS 4 SHOWING THE RESULTS OF ...

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

    13. DETAIL VIEW OF BUTTRESS 4 SHOWING THE RESULTS OF POOR CONSTRUCTION WORK. THOUGH NOT A SERIOUS STRUCTURAL DEFICIENCY, THE 'HONEYCOMB' TEXTURE OF THE CONCRETE SURFACE WAS THE RESULT OF INADEQUATE TAMPING AT THE TIME OF THE INITIAL 'POUR'. - Hume Lake Dam, Sequioa National Forest, Hume, Fresno County, CA

  15. STS-55 Earth observation shows a sunset over South America

    NASA Technical Reports Server (NTRS)

    1993-01-01

    STS-55 Earth observation taken aboard Columbia, Orbiter Vehicle (OV) 102, shows a spectacular sunset view over South America and the cleanest atmosphere since before the volcanic eruptions of 1991, according to NASA scientists studying the STS-55 photography. A dark cloud layer is evident at an altitude of 7 to 9 kilometers. Five kilometers higher, a pink layer of sulfuric acid droplets and ammonium sulfate particles begins at the tropopause and extends upward into the stratosphere to 19 kilometers. Above that, blue scattering by the atmosphere diminishes until, at an altitude of 60 kilometers, the blackness of space is predominant.

  16. High-Resolution Observations of a Filament showing Activated Barb

    NASA Astrophysics Data System (ADS)

    Joshi, Anand; Martin, Sara F.; Mathew, Shibu; Srivastava, Nandita

    2012-07-01

    Analysis of a filament showing an activated barb using observations from the Dutch Open Telescope (DOT) on 2010 August 20 are presented. The DOT takes Doppler images in Hα, among other wavelengths, in a region about 110 × 110 arcsec^{2} in area, at a cadence of 30~seconds. The offline image restoration technique of speckle reconstruction is applied to obtain diffraction limited images. The filament developed a new barb in 10~minutes, which disappeared within the next 35~minutes. Such a rapid formation and disappearance of a filament barb is unusual, and has not been reported earlier. Line-of-sight velocity maps were constructed from the Doppler images of the target filament. We observe flows in the filament spine towards the barb location prior to its formation, and flows in the barb towards the spine during its disappearance. Photospheric magnetograms from Heliospheric Magnetic Imager on board the Solar Dynamics Observatory, at a cadence of 45~seconds, were used to determine the changes in magnetic flux in the region surrounding the barb location. The variation of magnetic flux in this duration supports the view that barbs are rooted in minor magnetic polarity. Our analysis shows that barbs can be short-lived and formation and disappearance of the barb was associated with cancellation of magnetic flux.

  17. Results of GEOS Observing Programs

    NASA Astrophysics Data System (ADS)

    Boninsegna, Roland

    The Groupe Européen d'Observations Stellaires (GEOS) program is described briefly, and ephemerides and light curves are given for the RRab star NSV 4285 Cnc and the eclipsing star BG Lyn (RRVI-51 Lyn).

  18. VERITAS Blazar Observations - Recent Results

    SciTech Connect

    Cogan, Peter

    2008-12-24

    We present the discovery of very high energy (VHE) gamma-ray emission from the high-frequency-peaked BL Lac object 1ES 0806+524 (z = 0.138) and the intermediate-frequency-peaked BL Lac object W Comae (z = 0.102) with VERITAS. VHE emission was discovered from these objects during the 2007/2008 observing campaign, with a strong outburst from W Comae detected in mid-March, lasting a few days. Quasi-simultaneous spectral energy distributions are presented, incorporating optical (AAVSO), and X-ray (Swift/RXTE) observations. We also present the energy spectrum of the distant BL Lac (z = 0.182) 1ES 1218+304 which was detected by VERITAS during the 2006/2007 observing campaign. The energy spectrum is discussed in the context of different models of absorption from the diffuse extragalactic background radiation. We present multiwavelength observations of the blazar Markarian 421 (z = 0.03), including a strong flare initially detected by the Whipple 10 m gamma-ray telescope. Finally we present a broadband spectral energy distribution for 1ES 2344+514 (z = 0.044) which is successfully fit using a one zone synchrotron self-Compton model.

  19. CASSINI VIMS OBSERVATIONS SHOW ETHANE IS PRESENT IN TITAN'S RAINFALL

    SciTech Connect

    Dalba, Paul A.; Buratti, Bonnie J.; Baines, Kevin H.; Sotin, Christophe; Lawrence, Kenneth J.; Brown, Robert H.; Barnes, Jason W.; Clark, Roger N.; Nicholson, Philip D.

    2012-12-20

    Observations obtained over two years by the Cassini Imaging Science Subsystem suggest that rain showers fall on the surface. Using measurements obtained by the Visual Infrared Mapping Spectrometer, we identify the main component of the rain to be ethane, with methane as an additional component. We observe five or six probable rainfall events, at least one of which follows a brief equatorial cloud appearance, suggesting that frequent rainstorms occur on Titan. The rainfall evaporates, sublimates, or infiltrates on timescales of months, and in some cases it is associated with fluvial features but not with their creation or alteration. Thus, Titan exhibits frequent 'gentle rainfall' instead of, or in addition to, more catastrophic events that cut rivers and lay down large fluvial deposits. Freezing rain may also be present, and the standing liquid may exist as puddles interspersed with patches of frost. The extensive dune deposits found in the equatorial regions of Titan imply multi-season arid conditions there, which are consistent with small, but possibly frequent, amounts of rain, in analogy to terrestrial deserts.

  20. Breast vibro-acoustography: initial results show promise

    PubMed Central

    2012-01-01

    Introduction Vibro-acoustography (VA) is a recently developed imaging modality that is sensitive to the dynamic characteristics of tissue. It detects low-frequency harmonic vibrations in tissue that are induced by the radiation force of ultrasound. Here, we have investigated applications of VA for in vivo breast imaging. Methods A recently developed combined mammography-VA system for in vivo breast imaging was tested on female volunteers, aged 25 years or older, with suspected breast lesions on their clinical examination. After mammography, a set of VA scans was acquired by the experimental device. In a masked assessment, VA images were evaluated independently by 3 reviewers who identified mass lesions and calcifications. The diagnostic accuracy of this imaging method was determined by comparing the reviewers' responses with clinical data. Results We collected images from 57 participants: 7 were used for training and 48 for evaluation of diagnostic accuracy (images from 2 participants were excluded because of unexpected imaging artifacts). In total, 16 malignant and 32 benign lesions were examined. Specificity for diagnostic accuracy was 94% or higher for all 3 reviewers, but sensitivity varied (69% to 100%). All reviewers were able to detect 97% of masses, but sensitivity for detection of calcification was lower (≤ 72% for all reviewers). Conclusions VA can be used to detect various breast abnormalities, including calcifications and benign and malignant masses, with relatively high specificity. VA technology may lead to a new clinical tool for breast imaging applications. PMID:23021305

  1. Resummed Results for Hadron Collider Observables

    NASA Astrophysics Data System (ADS)

    McAslan, Heather

    2016-07-01

    Event shapes are invaluable QCD tools for theoretical calculations and experimental measurements. We revise the definition of these observables in e+e- annihilation and in hadron collisions, and give a review of the state-of-the-art results for their resummation. Then we detail how recent work on the re-summation of event shapes in electron-positron annihilation can provide us with the tools to extend resummation of generic hadronic event shapes to NNLL accuracy. We match our findings to fixed-order results at NNLO accuracy, showing the sizeable effects of resummation in the relevant regions of phase space.

  2. Morphology Composition Isotopes: Recent Results from Observations

    NASA Astrophysics Data System (ADS)

    Schulz, R.

    2008-07-01

    This article presents some recent imaging and spectroscopic observations that led to results which are significant for understanding the properties of comet nuclei. The coma morphology and/or composition were investigated for 12 comets belonging to different dynamical classes. The data analysis showed that the coma morphology of three non-periodic comets is not consistent with the general assumption that dynamically new comets still have a relatively uniform nucleus surface and therefore do not exhibit gas and/or dust jets in their coma. The determination of carbon and nitrogen isotopic ratios revealed the same values for all comets investigated at various heliocentric distances. However, the relative abundance of the rare nitrogen isotope 15N is about twice as high as in the Earth’s atmosphere. Observations of comets at splitting events and during outbursts led to indications for differences between material from the nucleus surface and the interior. The monitoring of the induced outburst of 9P/Temple revealed that under non-steady state conditions the fast disintegration of species is detectable.

  3. Streaming Limit: New Observations and Model Results

    NASA Astrophysics Data System (ADS)

    Ng, C. K.; Reames, D. V.; Tylka, A. J.

    2010-12-01

    Solar energetic particle intensities at 1 AU often show an early temporal plateau where the intensity is limited. This early intensity limit may provide a valuable time window for astronauts to seek shelter before large shock-associated intensity increase (if any). The Ng and Reames (1994) time-dependent model of SEP transport through self-amplified Alfvén waves predicts a maximum proton intensity of ~ 250 particles /(cm^2 s str MeV) at ~ 1 MeV, in agreement within a factor of 2 with the observational survey by Reames and Ng (1998). In fact, streaming-limited intensity is implicit in the steady-state shock-acceleration solution of Bell (1978) and Lee (1983). Further studies on the effect of self-amplified waves on SEP intensity spectra have been made by Ng, Reames and Tylka (2003), Vanio (2003), and Lee (2005). Intensities exceeding the Ng and Reames (1994) limit have been reported (e.g., Lario et al. 2009). We present new observations of multi-species SEP spectra at the temporal intensity plateau. We also present new theoretical results on how the streaming limit depends on ion species and energy, ambient wave intensity spectrum, Alfvén speed, solar-wind speed, shock speed, and the presence of interplanetary shocks and interaction regions. Among the new interesting observations is the strong suppression of ion intensities near 1 MeV/amu in events that have high 10-100 MeV proton intensity. New modeling results confirm that this is due to these low-energy ions being strongly scattered at small pitch angles by waves amplified by 10-100 MeV protons at large pitch angles. As the high-energy protons travel upstream and scatter from small to large pitch-angles, they simultaneously amplify waves en route over a range of wavenumbers, including those that are resonant with low-energy protons. Thus, wave amplification by streaming protons and the pitch-angle dependence of the wave-particle resonance condition are essential factors in understanding the limiting behavior

  4. Results of Sustained Observations from SABSOON

    NASA Astrophysics Data System (ADS)

    Seim, H.; Nelson, J.

    2001-12-01

    A variety of meteorological and oceanographic data being collected on the continental shelf off Georgia by the South Atlantic Bight Synoptic Offshore Observational Network (SABSOON) permit an examination of episodic and seasonal phenomena operative on the shelf. Data are collected at offshore platforms and transmitted to shore in near-real time and made available on the project website. Examples of data collected since 1999 are presented that illustrate some of processes being addressed using the network. Maximum winds occur during remarkably energetic downbursts observed in spring and summer, associated with the passage of squalls over the coastal ocean. Peak wind speed at 50 m height exceed 40 ms and air temperature drops by 4 oC or more in less than 6 minutes, often accompanied by large changes in humidity and heavy rainfall, suggesting down draft of air from aloft. These events may play an important role in the offshore transport of continentally-derived material. Continuous ADCP measurements are being used to examine the seasonality of cross-shelf exchange and its relationship to the cross-shelf density gradient. The low-frequency cross-shelf circulation changes sign when the cross-shelf density gradient changes sign. Vertical stratification is surprisingly episodic, and maximum stratification has occurred in the winter and spring associated with appearance of long-salinity surface lens and may be associated with baroclinic instabilities. Strong stratification has also been observed in summer during Gulf Stream-derived intrusions onto the shelf, during which time the upper and lower layers become largely decoupled. Continuous optical measurements of above-water and in-water irradiance (PAR) show the mid-shelf surface sediments are often in the euphotic zone. Chlorophyll fluorescence (stimulated) shows strong light-dependent diurnal variability in near-surface waters and evidence of resuspension of benthic diatoms during storm events, particularly in the early

  5. Radio observations of asteroids: Results and prospects

    NASA Technical Reports Server (NTRS)

    Dickel, J. R.

    1978-01-01

    Radio observations of the asteroids can provide information on the thermal and dielectric properties of the surface materials and because the radio emission arises somewhat below the surface, the data give some indication of layering. Observational difficulty has limited the investigations to only 6 asteroids: 1 Ceres and 324 Bamberga appear to have a layer of dust covering a more compacted material; the data on 4 Vesta cannot be matched by any current models for the surface; and the results for 18 Melpomene, 31 Euphrosyne and 433 Eros are too incomplete for firm conclusions. Future possibilities include more accurate radiometry of a few selected asteroids of different taxonomic classes and actual resolution of some of the larger objects by aperture synthesis techniques.

  6. The Stellar Observations Network Group - first results

    NASA Astrophysics Data System (ADS)

    Antoci, Victoria; Grundahl, Frank; Christensen-Dalsgaard, Joergen; Kjeldsen, Hans

    2015-08-01

    SONG - the Stellar Observations Network Group is a Danish-led project set to design and build a global network of 1-m telescopes to carry out detailed studies of solar-like stars using asteroseismology and to discover and characterise exo-planets and their star system. Here we present more than 100 nights of high-precision radial velocity measurements from 2014 of the subgiant mu Herculis. Preliminary analyses of the largest ground-based data set ever obtained for such as star clearly show the detection of stochastically excited pressure modes. The high quality of our data allows unique extraction of individual modes over many orders in the frequency spectrum, leading to studies of rotation, convection, near-surface effects, core structure using mixed modes and stellar activity.

  7. Gun shows across a multistate American gun market: observational evidence of the effects of regulatory policies

    PubMed Central

    Wintemute, Garen J

    2007-01-01

    Objective To describe gun shows and assess the impact of increased regulation on characteristics linked to their importance as sources of guns used in crime. Design Cross‐sectional, observational. Subjects Data were collected at a structured sample of 28 gun shows in California, which regulates these events and prohibits undocumented private party gun sales; and in Arizona, Nevada, Texas and Florida—all leading sources of California's crime guns—where these restrictions do not exist. Main outcome measures Size of shows, measured by numbers of gun vendors and people in attendance; number and nature of guns for sale by gun vendors; measures of private party gun sales and illegal surrogate (“straw”) gun purchases. Results Shows in comparison states were larger, but the number of attendees per gun vendor was higher in California. None of these differences was statistically significant. Armed attendees were more common in other states (median 5.7%, interquartile range (IQR) 3.9–10.0%) than in California (median 1.1%, IQR 0.5–2.2%), p = 0.0007. Thirty percent of gun vendors both in California and elsewhere were identifiable as licensed firearm retailers. There were few differences in the types or numbers of guns offered for sale; vendors elsewhere were more likely to sell assault weapons (34.9% and 13.3%, respectively; p = 0.001). Straw purchases were more common in the comparison states (rate ratio 6.6 (95% CI 0.9 to 49.1), p = 0.06). Conclusions California's regulatory policies were associated with a decreased incidence of anonymous, undocumented gun sales and illegal straw purchases at gun shows. No significant adverse effects of these policies were observed. PMID:17567968

  8. Nanotribology Results Show that DNA Forms a Mechanically Resistant 2D Network in Metaphase Chromatin Plates

    PubMed Central

    Gállego, Isaac; Oncins, Gerard; Sisquella, Xavier; Fernàndez-Busquets, Xavier; Daban, Joan-Ramon

    2010-01-01

    In a previous study, we found that metaphase chromosomes are formed by thin plates, and here we have applied atomic force microscopy (AFM) and friction force measurements at the nanoscale (nanotribology) to analyze the properties of these planar structures in aqueous media at room temperature. Our results show that high concentrations of NaCl and EDTA and extensive digestion with protease and nuclease enzymes cause plate denaturation. Nanotribology studies show that native plates under structuring conditions (5 mM Mg2+) have a relatively high friction coefficient (μ ≈ 0.3), which is markedly reduced when high concentrations of NaCl or EDTA are added (μ ≈ 0.1). This lubricant effect can be interpreted considering the electrostatic repulsion between DNA phosphate groups and the AFM tip. Protease digestion increases the friction coefficient (μ ≈ 0.5), but the highest friction is observed when DNA is cleaved by micrococcal nuclease (μ ≈ 0.9), indicating that DNA is the main structural element of plates. Whereas nuclease-digested plates are irreversibly damaged after the friction measurement, native plates can absorb kinetic energy from the AFM tip without suffering any damage. These results suggest that plates are formed by a flexible and mechanically resistant two-dimensional network which allows the safe storage of DNA during mitosis. PMID:21156137

  9. SOAR remote observing: tactics and early results

    NASA Astrophysics Data System (ADS)

    Cecil, Gerald N.; Crain, J. Adam

    2004-09-01

    Travel from North America to the 4.1m SOAR telescope atop Cerro Pachon exceeds $1000, and takes >16 hours door to door (20+ hours typically). SOAR aims to exploit best seeing, requiring dynamic scheduling that is impossible to accomplish when catering to peripatetic astronomers. According to technical arguments at www.peakoil.org, we are near the peak rate of depleting world petroleum, so can expect travel costs to climb sharply. With the telecom bubble's glut of optical fiber, we can transmit data more efficiently than astronomers and "observe remotely". With data compression, less than half of the 6 Mbps bandwidth shared currently by SOAR and CTIO is enough to enable a high-fidelity observing presence for SOAR partners in North America, Brazil, and Chile. We discuss access from home by cable modem/DSL link.

  10. Meta-analysis of aspirin use and risk of lung cancer shows notable results.

    PubMed

    Hochmuth, Friederike; Jochem, Maximilian; Schlattmann, Peter

    2016-07-01

    Aspirin is a promising agent for chemoprevention of lung cancer. We assessed the association of aspirin use and the development of lung cancer, with a focus on heterogeneity between studies. Databases were searched for relevant studies until September 2014. Studies evaluating the relationship of aspirin use and incidence of lung cancer were considered. Relative risks (RR) were extracted and a pooled estimate was calculated. Heterogeneity was assessed by the I measure, random-effects models, and finite-mixture models. Sources of heterogeneity were investigated using a meta-regression. A decreased risk of lung cancer was found including 20 studies [RR=0.87, 95% confidence interval (CI): 0.79-0.95] on the basis of a random-effects model. Strong heterogeneity was observed (τ=0.0258, I=74.4%). As a result, two subpopulations of studies were identified on the basis of a mixture model. The first subpopulation (42%) has an average RR of 0.64. The remaining subpopulation (58%) shows an RR of 1.04. Different results were found for case-control (RR=0.74, 95% CI: 0.60-0.90) and cohort studies (RR=0.99, 95% CI: 0.93-1.06) in a stratified analysis. In a subgroup analysis, use of aspirin was associated with a decreased risk of non-small-cell lung cancer in case-control studies (RR=0.74; 95% CI: 0.58-0.94). At first glance, our meta-analysis shows an average protective effect. A second glance indicates that there is strong heterogeneity. This leads to a subpopulation with considerable benefit and another subpopulation with no benefit. For further investigations, it is important to identify populations that benefit from aspirin use. PMID:26067033

  11. STS-39 Earth observation of Earth's limb at sunset shows atmospheric layers

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-39 Earth observation taken aboard Discovery, Orbiter Vehicle (OV) 103, shows the Earth's limb at sunset with numerous atmospheric scattering layers highlighted. The layers consist of fine particles suspended in very stable layers of the atmosphere. The layers act as a prism for the sunlight.

  12. Comparison of some results of program SHOW with other solar hot water computer programs

    NASA Astrophysics Data System (ADS)

    Young, M. F.; Baughn, J. W.

    The SHOW (solar hot water) computer program is capable of simulating both one and two tank designs of thermosiphon and pumped solar domestic hot water systems. SHOW differs in a number of ways from other programs, the most notable of which is the emphasis on a thermal/hydraulic model of the stratified storage tank. The predicted performance for a typical two tank pumped system, computed by Program SHOW are compared, with results computed using F-CHART and TRNSYS. The results show fair to good agreement between the various computer programs when comparing the annual percent solar contributions. SHOW is also used to compute the expected performance of a two tank thermosiphon system and to compare its performance to the two tank pumped system.

  13. Gun Shows and Gun Violence: Fatally Flawed Study Yields Misleading Results

    PubMed Central

    Hemenway, David; Webster, Daniel; Pierce, Glenn; Braga, Anthony A.

    2010-01-01

    A widely publicized but unpublished study of the relationship between gun shows and gun violence is being cited in debates about the regulation of gun shows and gun commerce. We believe the study is fatally flawed. A working paper entitled “The Effect of Gun Shows on Gun-Related Deaths: Evidence from California and Texas” outlined this study, which found no association between gun shows and gun-related deaths. We believe the study reflects a limited understanding of gun shows and gun markets and is not statistically powered to detect even an implausibly large effect of gun shows on gun violence. In addition, the research contains serious ascertainment and classification errors, produces results that are sensitive to minor specification changes in key variables and in some cases have no face validity, and is contradicted by 1 of its own authors’ prior research. The study should not be used as evidence in formulating gun policy. PMID:20724672

  14. Gun shows and gun violence: fatally flawed study yields misleading results.

    PubMed

    Wintemute, Garen J; Hemenway, David; Webster, Daniel; Pierce, Glenn; Braga, Anthony A

    2010-10-01

    A widely publicized but unpublished study of the relationship between gun shows and gun violence is being cited in debates about the regulation of gun shows and gun commerce. We believe the study is fatally flawed. A working paper entitled "The Effect of Gun Shows on Gun-Related Deaths: Evidence from California and Texas" outlined this study, which found no association between gun shows and gun-related deaths. We believe the study reflects a limited understanding of gun shows and gun markets and is not statistically powered to detect even an implausibly large effect of gun shows on gun violence. In addition, the research contains serious ascertainment and classification errors, produces results that are sensitive to minor specification changes in key variables and in some cases have no face validity, and is contradicted by 1 of its own authors' prior research. The study should not be used as evidence in formulating gun policy. PMID:20724672

  15. Results From Mars Show Electrostatic Charging of the Mars Pathfinder Sojourner Rover

    NASA Technical Reports Server (NTRS)

    Kolecki, Joseph C.; Siebert, Mark W.

    1998-01-01

    Indirect evidence (dust accumulation) has been obtained indicating that the Mars Pathfinder rover, Sojourner, experienced electrostatic charging on Mars. Lander camera images of the Sojourner rover provide distinctive evidence of dust accumulation on rover wheels during traverses, turns, and crabbing maneuvers. The sol 22 (22nd Martian "day" after Pathfinder landed) end-of-day image clearly shows fine red dust concentrated around the wheel edges with additional accumulation in the wheel hubs. A sol 41 image of the rover near the rock "Wedge" (see the next image) shows a more uniform coating of dust on the wheel drive surfaces with accumulation in the hubs similar to that in the previous image. In the sol 41 image, note particularly the loss of black-white contrast on the Wheel Abrasion Experiment strips (center wheel). This loss of contrast was also seen when dust accumulated on test wheels in the laboratory. We believe that this accumulation occurred because the Martian surface dust consists of clay-sized particles, similar to those detected by Viking, which have become electrically charged. By adhering to the wheels, the charged dust carries a net nonzero charge to the rover, raising its electrical potential relative to its surroundings. Similar charging behavior was routinely observed in an experimental facility at the NASA Lewis Research Center, where a Sojourner wheel was driven in a simulated Martian surface environment. There, as the wheel moved and accumulated dust (see the following image), electrical potentials in excess of 100 V (relative to the chamber ground) were detected by a capacitively coupled electrostatic probe located 4 mm from the wheel surface. The measured wheel capacitance was approximately 80 picofarads (pF), and the calculated charge, 8 x 10(exp -9) coulombs (C). Voltage differences of 100 V and greater are believed sufficient to produce Paschen electrical discharge in the Martian atmosphere. With an accumulated net charge of 8 x 10(exp

  16. TES validation results from the Lake Tahoe special observations.

    NASA Astrophysics Data System (ADS)

    Trembaly, D.; Sund Kulawik, S.; Rider, D.; Hook, S. J.

    2006-12-01

    The Tropospheric Emission Spectrometer (TES) is a high-resolution infrared Fourier transform spectrometer on board the AURA spacecraft launched in 2004. As part of the science validation activities, four "Stare" special observations were acquired in August and September 2005 over Lake Tahoe located a the California-Nevada border in western US. Each "Stare" observation took 32 target observation scans each sharing almost the same footprint. The Tahoe site has several advantages for validation, namely it is at high altitude with negligible cloud cover, it has water as the surface with known spectral emissivity, and it has ground-based in-situ radiometric measurements. Statistics of the retrieved values of the target data set over water are compared with the observation error available in the TES product file. In most cases, the results show that the standard deviation of the volume mixing ratio (VMR 1 sigma) at a given pressure level is less that the observation error for H20, atmospheric temperature, and O3. VMR-sigma is higher than the observation error in the cases of H2O and atmospheric temperature for pressure levels very near the surface. The surface temperature retrieved by the TES algorithm agrees to less than 1K of the observed in-situ radiometeric measurements. This exercise has provided important validation of the TES reported errors and the TES on-board radiometric calibration source.

  17. Retrospective analysis showing the water method increased adenoma detection rate - a hypothesis generating observation.

    PubMed

    Leung, Joseph W; Do, Lynne D; Siao-Salera, Rodelei M; Ngo, Catherine; Parikh, Dhavan A; Mann, Surinder K; Leung, Felix W

    2011-01-01

    BACKGROUND: A water method developed to attenuate discomfort during colonoscopy enhanced cecal intubation in unsedated patients. Serendipitously a numerically increased adenoma detection rate (ADR) was noted. OBJECTIVE: To explore databases of sedated patients examined by the air and water methods to identify hypothesis-generating findings. DESIGN: Retrospective analysis. SETTING: VA endoscopy center. PATIENTS: creening colonoscopy. INTERVENTIONS: From 1/2000-6/2006 the air method was used - judicious air insufflation to permit visualization of the lumen to aid colonoscope insertion and water spray for washing mucosal surfaces. From 6/2006-11/2009 the water method was adopted - warm water infusion in lieu of air insufflation and suction removal of residual air to aid colonoscope insertion. During colonoscope withdrawal adequate air was insufflated to distend the colonic lumen for inspection, biopsy and polypectomy in a similar fashion in both periods. Main outcome measurements: ADR. RESULTS: The air (n=683) vs. water (n=495) method comparisons revealed significant differences in overall ADR 26.8% (183 of 683) vs. 34.9% (173 of 495) and ADR of adenomas >9 mm, 7.2% vs. 13.7%, respectively (both P<0.05, Fisher's exact test). LIMITATIONS: Non-randomized data susceptible to bias by unmeasured parameters unrelated to the methods. CONCLUSION: Confirmation of the serendipitous observation of an impact of the water method on ADR provides impetus to call for randomized controlled trials to test hypotheses related to the water method as an approach to improving adenoma detection. Because of recent concerns over missed lesions during colonoscopy, the provocative hypothesis-generating observations warrant presentation. PMID:21686105

  18. Aortic emboli show surprising size dependent predilection for cerebral arteries: Results from computational fluid dynamics

    NASA Astrophysics Data System (ADS)

    Carr, Ian; Schwartz, Robert; Shadden, Shawn

    2012-11-01

    Cardiac emboli can have devastating consequences if they enter the cerebral circulation, and are the most common cause of embolic stroke. Little is known about relationships of embolic origin/density/size to cerebral events; as these relationships are difficult to observe. To better understand stoke risk from cardiac and aortic emboli, we developed a computational model to track emboli from the heart to the brain. Patient-specific models of the human aorta and arteries to the brain were derived from CT angiography from 10 MHIF patients. Blood flow was modeled by the Navier-Stokes equations using pulsatile inflow at the aortic valve, and physiologic Windkessel models at the outlets. Particulate was injected at the aortic valve and tracked using modified Maxey-Riley equations with a wall collision model. Results demonstrate aortic emboli that entered the cerebral circulation through the carotid or vertebral arteries were localized to specific locations of the proximal aorta. The percentage of released particles embolic to the brain markedly increased with particle size from 0 to ~1-1.5 mm in all patients. Larger particulate became less likely to traverse the cerebral vessels. These findings are consistent with sparse literature based on transesophageal echo measurements. This work was supported in part by the National Science Foundation, award number 1157041.

  19. Evaluating the Impact of Database Heterogeneity on Observational Study Results

    PubMed Central

    Madigan, David; Ryan, Patrick B.; Schuemie, Martijn; Stang, Paul E.; Overhage, J. Marc; Hartzema, Abraham G.; Suchard, Marc A.; DuMouchel, William; Berlin, Jesse A.

    2013-01-01

    Clinical studies that use observational databases to evaluate the effects of medical products have become commonplace. Such studies begin by selecting a particular database, a decision that published papers invariably report but do not discuss. Studies of the same issue in different databases, however, can and do generate different results, sometimes with strikingly different clinical implications. In this paper, we systematically study heterogeneity among databases, holding other study methods constant, by exploring relative risk estimates for 53 drug-outcome pairs and 2 widely used study designs (cohort studies and self-controlled case series) across 10 observational databases. When holding the study design constant, our analysis shows that estimated relative risks range from a statistically significant decreased risk to a statistically significant increased risk in 11 of 53 (21%) of drug-outcome pairs that use a cohort design and 19 of 53 (36%) of drug-outcome pairs that use a self-controlled case series design. This exceeds the proportion of pairs that were consistent across databases in both direction and statistical significance, which was 9 of 53 (17%) for cohort studies and 5 of 53 (9%) for self-controlled case series. Our findings show that clinical studies that use observational databases can be sensitive to the choice of database. More attention is needed to consider how the choice of data source may be affecting results. PMID:23648805

  20. Mars Science Laboratory (MSL) - First Results of Pressure Observations

    NASA Astrophysics Data System (ADS)

    Harri, Ari-Matti; Kahanpää, Henrik; Kemppinen, Osku; Genzer, Maria; Gómez-Elvira, Javier; Haberle, Robert M.; Schmidt, Walter; Savijärvi, Hannu; Rodríquez-Manfredi, Jose Antonio; Rafkin, Scott; Polkko, Jouni; Richardson, Mark; Newman, Claire; de la Torre Juárez, Manuel; Martín-Torres, Javier; Paz Zorzano-Mier, Maria; Atlaskin, Evgeny; Kauhanen, Janne; Paton, Mark; Haukka, Harri

    2013-04-01

    The Mars Science laboratory (MSL) called Curiosity made a successful landing at Gale crater early August 2012. MSL has an environmental instrument package called the Rover Environmental Monitoring Station (REMS) as a part of its scientific payload. REMS comprises instrumentation for the observation of atmospheric pressure, temperature of the air, ground temperature, wind speed and direction, relative humidity, and UV measurements. The REMS instrument suite is described at length in [1]. We concentrate on describing the first results from the REMS pressure observations and comparison of the measurements with modeling results. The REMS pressure device is provided by the Finnish Meteorological Institute. It is based on silicon micro-machined capacitive pressure sensors developed by Vaisala Inc. The pressure device makes use of two transducer electronics sections placed on a single multi-layer PCB inside the REMS Instrument Control Unit (ICU) with a filter-protected ventilation inlet to the ambient atmosphere. The absolute accuracy of the pressure device (< 3 Pa) and zero-drift (< 1 Pa/year) enables the investigations of long term and seasonal cycles of the Martian atmosphere. The relative accuracy, or repeatability, in the diurnal time scale is < 1.5 Pa, less than 2 % of the observed diurnal pressure variation at the landing site. The pressure device has special sensors with very high precision (less than 0.2 Pa) that makes it a good tool to study short-term atmospheric phenomena, e.g., dust devils and other convective vortices. The observed MSL pressure data enable us to study both the long term and short-term phenomena of the Martian atmosphere. This would add knowledge of these phenomena to that gathered by earlier Mars missions and modeling experiments [2,3]. Pressure observations are revealing new information on the local atmosphere and climate at Gale crater, and will shed light on the mesoscale and micrometeorological phenomena. Pressure observations show also

  1. Long-Term Trial Results Show No Mortality Benefit from Annual Prostate Cancer Screening

    Cancer.gov

    Thirteen year follow-up data from the Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trial show higher incidence but similar mortality among men screened annually with the prostate-specific antigen (PSA) test and digital rectal examination

  2. Dysphoric students show higher use of the observer perspective in their retrieval of positive versus negative autobiographical memories

    PubMed Central

    Nelis, Sabine; Debeer, Elise; Holmes, Emily A.; Raes, Filip

    2013-01-01

    Autobiographical memories are retrieved as images from either a field perspective or an observer perspective. The observer perspective is thought to dull emotion. Positive affect is blunted in depressed mood. Consequently, are positive events recalled from an observer perspective in depressed mood? We investigated the relationship between memory vantage perspective and depressive symptoms in a student sample. Participants completed the Autobiographical Memory Test (AMT; Williams & Broadbent, 1986) and assessed the perspective accompanying each memory. The Beck Depression Inventory-II (BDI-II; Beck, Steer, & Brown, 1996) and the Responses to Positive Affect questionnaire (RPA; Feldman, Joormann, & Johnson, 2008) were administered. The results showed a small positive association between depressive symptoms and the use of an observer perspective for positive autobiographical memories, but not for negative memories. Furthermore, comparing a subgroup with clinically significant symptom levels (dysphoric students) with non-dysphoric individuals revealed that dysphoric students used an observer perspective more for positive memories compared with negative memories. This was not the case for non-dysphoric students. The observer perspective in dysphorics was associated with a dampening cognitive style in response to positive experiences. PMID:23083015

  3. Comparison of some results of program SHOW with other solar hot water computer programs

    NASA Astrophysics Data System (ADS)

    Young, M. F.; Baughn, J. W.

    Subroutines and the driver program for the simulation code SHOW (solar hot water) for solar thermosyphon systems are discussed, and simulations are compared with predictions by the F-CHART and TRNSYS codes. SHOW has the driver program MAIN, which defines the system control logic for choosing the appropriate system subroutine for analysis. Ten subroutines are described, which account for the solar system physical parameters, the weather data, the manufacturer-supplied system specifications, mass flow rates, pumped systems, total transformed radiation, load use profiles, stratification in storage, an electric water heater, and economic analyses. The three programs are employed to analyze a thermosiphon installation in Sacramento with two storage tanks. TRNSYS and SHOW were in agreement and lower than F-CHARt for annual predictions, although significantly more computer time was necessary to make TRNSYS converge.

  4. Direct observation shows superposition and large scale flexibility within cytoplasmic dynein motors moving along microtubules

    PubMed Central

    Imai, Hiroshi; Shima, Tomohiro; Sutoh, Kazuo; Walker, Matthew L.; Knight, Peter J.; Kon, Takahide; Burgess, Stan A.

    2015-01-01

    Cytoplasmic dynein is a dimeric AAA+ motor protein that performs critical roles in eukaryotic cells by moving along microtubules using ATP. Here using cryo-electron microscopy we directly observe the structure of Dictyostelium discoideum dynein dimers on microtubules at near-physiological ATP concentrations. They display remarkable flexibility at a hinge close to the microtubule binding domain (the stalkhead) producing a wide range of head positions. About half the molecules have the two heads separated from one another, with both leading and trailing motors attached to the microtubule. The other half have the two heads and stalks closely superposed in a front-to-back arrangement of the AAA+ rings, suggesting specific contact between the heads. All stalks point towards the microtubule minus end. Mean stalk angles depend on the separation between their stalkheads, which allows estimation of inter-head tension. These findings provide a structural framework for understanding dynein's directionality and unusual stepping behaviour. PMID:26365535

  5. Direct observation shows superposition and large scale flexibility within cytoplasmic dynein motors moving along microtubules.

    PubMed

    Imai, Hiroshi; Shima, Tomohiro; Sutoh, Kazuo; Walker, Matthew L; Knight, Peter J; Kon, Takahide; Burgess, Stan A

    2015-01-01

    Cytoplasmic dynein is a dimeric AAA(+) motor protein that performs critical roles in eukaryotic cells by moving along microtubules using ATP. Here using cryo-electron microscopy we directly observe the structure of Dictyostelium discoideum dynein dimers on microtubules at near-physiological ATP concentrations. They display remarkable flexibility at a hinge close to the microtubule binding domain (the stalkhead) producing a wide range of head positions. About half the molecules have the two heads separated from one another, with both leading and trailing motors attached to the microtubule. The other half have the two heads and stalks closely superposed in a front-to-back arrangement of the AAA(+) rings, suggesting specific contact between the heads. All stalks point towards the microtubule minus end. Mean stalk angles depend on the separation between their stalkheads, which allows estimation of inter-head tension. These findings provide a structural framework for understanding dynein's directionality and unusual stepping behaviour. PMID:26365535

  6. Observations on a new family showing bisalbuminaemia of the slow type

    PubMed Central

    Mikulska, Teresa; Mikulski, Paweł; Rogulski, Jerzy

    1972-01-01

    A new family with an electrophoretically more slowly moving albumin variant is described. The pattern of variance was studied using three different electrophoretic techniques, and compared with certain other known fast and slow variants. Features of penicillin and bromphenol blue binding by normal and variant albumins were also studied. Both normal human albumin and the albumin variant treated with penicillin broadened and moved faster. Native albumin A, prestained with bromphenol blue, binds approximately twice as much of the dye as the slow-moving variant. On the other hand, staining of denatured proteins on paper showed that both bands take up equal amounts of dye. Images PMID:4119007

  7. Data for behavioral results and brain regions showing a time effect during pair-association retrieval.

    PubMed

    Jimura, Koji; Hirose, Satoshi; Wada, Hiroyuki; Yoshizawa, Yasunori; Imai, Yoshio; Akahane, Masaaki; Machida, Toru; Shirouzu, Ichiro; Koike, Yasuharu; Konishi, Seiki

    2016-09-01

    The current data article provides behavioral and neuroimaging data for the research article "Relatedness-dependent rapid development of brain activity in anterior temporal cortex during pair-association retrieval" (Jimura et al., 2016) [1]. Behavioral performance is provided in a table. Fig. 2 of the article is based on this table. Brain regions showing time effect are provided in a table. A statistical activation map for the time effect is shown in Fig. 3C of the article. PMID:27508239

  8. Preliminary Results from Coordinated UVCS-CDS-Ulysses Observations

    NASA Technical Reports Server (NTRS)

    Parenti, S.; Bromage, B. J.; Poletto, G.; Suess, S. T.; Raymond, J. C.; Noci, G.; Bromage, G. E.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    The June 2000 quadrature between the Sun, Earth, and Ulysses took place with Ulysses at a distance of 3.35 AU from the Sun and at heliocentric latitude 58.2 deg south, in the southeast quadrant. This provided an opportunity to observe the corona close to the Sun with Coronal Diagnostic Spectrometer (CDS) and Ultraviolet Coronograph Spectrometer (UVCS) and, subsequently, to sample the same plasma when it reached Ulysses. Here we focus on simultaneous observations of UVCS and CDS made on June 12, 13, 16 and 17. The UVCS data were acquired at heliocentric altitudes ranging from 1.6 to 2.2 solar radii, using different grating positions, in order to get a wide wavelength range. CDS data consisted of Normal Incidence Spectrometer (NIS) full wavelength rasters of 120" x 150" centered at altitudes up to 1.18 solar radii, together with Grazing Incidence Spectrometer (GIS) 4" x 4" rasters within the same field of view, out to 1.2 solar radii. The radial direction to Ulysses passed through a high latitude streamer, throughout the 4 days of observations, Analysis of the spectra taken by UVCS shows a variation of the element abundances in the streamer over our observing interval: however, because the observations were in slightly different parts of the streamer on different days, the variation could be ascribed either to a temporal or spatial effect. The oxygen abundance, however, seems to increase at the edge of the streamer, as indicated by previous analyses. This suggests the variation may be a function of position within the streamer, rather than a temporal effect. Oxygen abundances measured by SWICS on Ulysses are compared with the CDS and UVCS results to see whether changes measured in situ follow the same pattern.

  9. Children of Senegal River Basin show the highest prevalence of Blastocystis sp. ever observed worldwide

    PubMed Central

    2014-01-01

    Background Blastocystis sp. is currently the most common intestinal protist found in human feces and considered an emerging parasite with a worldwide distribution. Because of its potential impact in public health, we reinforced the picture of Blastocystis sp. prevalence and molecular subtype distribution in Africa by performing the first survey of this parasite in Senegal. Methods Stool samples from 93 symptomatic presenting with various gastrointestinal disorders or asymptomatic children living in three villages of the Senegal River Basin were tested for the presence of Blastocystis sp. by non-quantitative and quantitative PCR using primer pairs targeting the SSU rDNA gene. Positive samples were subtyped to investigate the frequency of Blastocystis sp. subtypes in our cohort and the distribution of subtypes in the symptomatic and asymptomatic groups of children. Results By the use of molecular tools, all 93 samples were found to be positive for Blastocystis sp. indicating a striking parasite prevalence of 100%. Mixed infections by two or three subtypes were identified in eight individuals. Among a total of 103 subtyped isolates, subtype 3 was most abundant (49.5%) followed by subtype 1 (28.2%), subtype 2 (20.4%) and subtype 4 (1.9%). Subtype 3 was dominant in the symptomatic group while subtypes 1 and 2 were detected with equal frequency in both symptomatic and asymptomatic groups. The distribution of subtypes was compared with those available in other African countries and worldwide. Comparison confirmed that subtype 4 is much less frequently detected or absent in Africa while it is commonly found in Europe. Potential sources of Blastocystis sp. infection including human-to-human, zoonotic, and waterborne transmissions were also discussed. Conclusions The prevalence of Blastocystis sp. in our Senegalese population was the highest prevalence ever recovered worldwide for this parasite by reaching 100%. All cases were caused by subtypes 1, 2, 3 and 4 with a

  10. Spectacular Results from Recent Spitzer Observations of Cassiopeia A

    NASA Astrophysics Data System (ADS)

    Delaney, Tracey

    2006-02-01

    I will present an overview of some of the exciting results from Spitzer observations of the young supernova remnant Cassiopeia A. The images from the MIPS instrument at 24 and 70 microns are dominated by thermal emission from dust within the remnant and clearly show the counterjet extending in the opposite direction from the well-known North-East jet. One of the most surprising results from the 24 micron observations is the presence of infrared light echoes in the vicinity of Cas A. These are thought to result from interstellar dust heated by the explosion and by flares from the compact central object. Images taken in the four IRAC bands show the presence of synchrotron emission. The spectral indices measured between 6cm and IRAC channel 1 at 3.6 micron are flatter than those measured between 6 cm and 20 cm indicating a curved synchrotron spectrum consistent with cosmic-ray-modified shocks. We have also used the IRS instrument in mapping mode to obtainlow-resolution spectra over nearly the entire extent of Cas A. This is the largest single spectral map yet constructed with Spitzer. The spectra, in conjunction with the IRAC images, show that different dust components are associated with different ejecta/circumstellar media components of the remnant. The distribution and composition of the inhomogeneous ejecta and the associated dust indicate that in each direction different nucleosynthetic layers have reached the reverse shock. We have identified diffuse Si and S emission near the center of the remnant that matches the morphology of the absorption seen in the radio at 74 MHz. This material is thought to be ejecta that has not yet encountered the reverse shock but has been photoionized by X-ray and ultraviolet radiation from the remnant. We are able to identify [Ni II] in the remnant. Since the half-life of 56Ni is only 6 days, this material may not be the remains of the Ni synthesized in the supernova explosion. Finally, we have identified strong Ne emission from

  11. Morphology-Composition-Isotopes: Recent Results from Observations

    NASA Astrophysics Data System (ADS)

    Schulz, R.

    This article presents some recent imaging and spectroscopic observations that led to results which are significant for understanding the properties of comet nuclei. The coma morphology and/or composition were investigated for 12 comets belonging to different dynamical classes. The data analysis showed that the coma morphology of three non-periodic comets is not consistent with the general assumption that dynamically new comets still have a relatively uniform nucleus surface and therefore do not exhibit gas and/or dust jets in their coma. The determination of carbon and nitrogen isotopic ratios revealed the same values for all comets investigated at various heliocentric distances. However, the relative abundance of the rare nitrogen isotope 15N is about twice as high as in the Earth's atmosphere. Observations of comets at splitting events and during outbursts led to indications for differences between material from the nucleus surface and the interior. The monitoring of the induced outburst of 9P/Temple revealed that under non-steady state conditions the fast disintegration of species is detectable.

  12. Scheduling Results for the THEMIS Observation Scheduling Tool

    NASA Technical Reports Server (NTRS)

    Mclaren, David; Rabideau, Gregg; Chien, Steve; Knight, Russell; Anwar, Sadaat; Mehall, Greg; Christensen, Philip

    2011-01-01

    We describe a scheduling system intended to assist in the development of instrument data acquisitions for the THEMIS instrument, onboard the Mars Odyssey spacecraft, and compare results from multiple scheduling algorithms. This tool creates observations of both (a) targeted geographical regions of interest and (b) general mapping observations, while respecting spacecraft constraints such as data volume, observation timing, visibility, lighting, season, and science priorities. This tool therefore must address both geometric and state/timing/resource constraints. We describe a tool that maps geometric polygon overlap constraints to set covering constraints using a grid-based approach. These set covering constraints are then incorporated into a greedy optimization scheduling algorithm incorporating operations constraints to generate feasible schedules. The resultant tool generates schedules of hundreds of observations per week out of potential thousands of observations. This tool is currently under evaluation by the THEMIS observation planning team at Arizona State University.

  13. Dark Clouds in the ISOGAL survey: Observational Results.

    NASA Astrophysics Data System (ADS)

    Teyssier, D.; Pérault, M.; Hennebelle, P.

    The ISOGAL survey was a galactic survey conducted in the mid-infrared with the ISO camera, under the leadership of A. Omont. Its purposes included the study of stellar populations and galactic structure (bulge and inner Galaxy up to longitudes of 60circ), as well as the emission and absorption due to the interstellar medium. Among the first results of this survey (Pérault et al., 1996) is the evidence of narrow (down to 10'' in size) absorbing filaments and globules which appear as dark features in the 7 or 15 microns images. We present here follow-up observations of the infrared dark features conducted at the IRAM 30-m telescope. The analysis of the CO isotope and continuum maps showed spectacular spatial correlation with the mid-IR absorption. These features are distributed as far as the prominent molecular ring area in the inner Galaxy (2-8 kpc), making them first detection of individual dark clouds away from the Solar Neighbourhood. The clouds exhibit shapes ranging from globules to thin filament down to 0.3 pc in size. The on-the-fly images obtained in C18O confirmed that the cores are dense, compact molecular emitters, significantly more massive than local dark clouds (more than 1000 Modot) and lie within low activity Giant Molecular Clouds (GMC's). Despite the high visual extinction values inferred in the mid-IR data (Av >= 25, Hennebelle et al, 2000), the CO isotope lines are surprisingly weak, indicating possible depletion onto grains. Complementary observations of temperature and density probes (mainly HC3N and CH3CCH) confirmed this trend and led to first estimates of kinetic temperature around 10 K or less and densities above 105 cm-3. Comparisons with similar observations done by the MSX project (Egan et al., 1998) are discussed.

  14. NEOWISE OBSERVATIONS OF NEAR-EARTH OBJECTS: PRELIMINARY RESULTS

    SciTech Connect

    Mainzer, A.; Bauer, J.; Masiero, J.; Eisenhardt, P.; Grav, T.; Mo, W.; McMillan, R. S.; Cutri, R. M.; Walker, R.; Wright, E.; Tholen, D. J.; Jedicke, R.; Denneau, L.; Spahr, T.; DeBaun, E.; Elsbury, D.; Gautier, T.; Gomillion, S.; Hand, E.; Watkins, J.; and others

    2011-12-20

    With the NEOWISE portion of the Wide-field Infrared Survey Explorer (WISE) project, we have carried out a highly uniform survey of the near-Earth object (NEO) population at thermal infrared wavelengths ranging from 3 to 22 {mu}m, allowing us to refine estimates of their numbers, sizes, and albedos. The NEOWISE survey detected NEOs the same way whether they were previously known or not, subject to the availability of ground-based follow-up observations, resulting in the discovery of more than 130 new NEOs. The survey's uniform sensitivity, observing cadence, and image quality have permitted extrapolation of the 428 near-Earth asteroids (NEAs) detected by NEOWISE during the fully cryogenic portion of the WISE mission to the larger population. We find that there are 981 {+-} 19 NEAs larger than 1 km and 20,500 {+-} 3000 NEAs larger than 100 m. We show that the Spaceguard goal of detecting 90% of all 1 km NEAs has been met, and that the cumulative size distribution is best represented by a broken power law with a slope of 1.32 {+-} 0.14 below 1.5 km. This power-law slope produces {approx}13, 200 {+-} 1900 NEAs with D > 140 m. Although previous studies predict another break in the cumulative size distribution below D {approx} 50-100 m, resulting in an increase in the number of NEOs in this size range and smaller, we did not detect enough objects to comment on this increase. The overall number for the NEA population between 100 and 1000 m is lower than previous estimates. The numbers of near-Earth comets and potentially hazardous NEOs will be the subject of future work.

  15. Radio emission from magnetic exoplanets: GMRT observations and results

    NASA Astrophysics Data System (ADS)

    Majid, W.; Winterhalter, D.; Kuiper, T.; Lazio, J.

    2011-10-01

    Massive extrasolar planets are expected to emit, in analogy with Jupiter and Saturn, detectable radio emission at low frequencies. We have carried out a series of observations of known extrasolar planetary systems at 150 MHz with the Giant Meterwave Radio Telescope (GMRT) in both interferometric and phased array modes. We will describe our observing campaign, target list, and preliminary results from studies of dynamic spectra. As low frequency observations are plagued with RFI, we will focus on observing strategies and analysis techniques to minimize, identify and remove RFI effects from dynamic spectra. We will also briefly discuss prospects for similar searches with future instruments such as LOFAR, the LWA, and the SKA instruments.

  16. First results of ISO-SWS observations of Jupiter.

    NASA Astrophysics Data System (ADS)

    Encrenaz, T.; de Graauw, T.; Schaeidt, S.; Lellouch, E.; Feuchtgruber, H.; Beintema, D. A.; Bezard, B.; Drossart, P.; Griffin, M.; Heras, A.; Kessler, M.; Leech, K.; Morris, P.; Roelfsema, P. R.; Roos-Serote, M.; Salama, A.; Vandenbussche, B.; Valentijn, E. A.; Davis, G. R.; Naylor, D. A.

    1996-11-01

    The spectrum of Jupiter has been recorded between 2.75 and 14.5μm with the grating mode of the Short-Wavelength Spectrometer (SWS) of ISO. The resolving power is 1500. The main preliminary results of this observation are (1) at 3μm, the first spectroscopic signature, probably associated with NH_3_ ice, of the Jovian cloud at 0.5 bar and (2) the first detection of a thermal emission at the center of the CH_4_-ν_3_ band at 3.3μm, showing evidence for a high temperature in the upper jovian stratosphere (T=800K at P=0.16 microbar). In addition, the R(2) HD line has been detected for the first time in Jupiter, using the Fabry-Perot (FP) mode of the SWS, with a resolving power of 31000. A preliminary analysis of the HD line indicates a D/H ratio of about 2.2x10^-5^.

  17. First Results of Venus Express Spacecraft Observations with Wettzell

    NASA Technical Reports Server (NTRS)

    Calves, Guifre Molera; Wagner, Jan; Neidhardt, Alexander; Kronschnabl, Gerhard; Ayucar, Miguel Perez; Cimo, Giuseppe; Pogrebenko, Sergei

    2010-01-01

    The ESA Venus Express spacecraft was observed at X-band with the Wettzell radio telescope in October-December 2009 in the framework of an assessment study of the possible contribution of the European VLBI Network to the upcoming ESA deep space missions. A major goal of these observations was to develop and test the scheduling, data capture, transfer, processing, and analysis pipeline. Recorded data were transferred from Wettzell to Metsahovi for processing, and the processed data were sent from Mets ahovi to JIVE for analysis. A turnover time of 24 hours from observations to analysis results was achieved. The high dynamic range of the detections allowed us to achieve a milliHz level of spectral resolution accuracy and to extract the phase of the spacecraft signal carrier line. Several physical parameters can be determined from these observational results with more observational data collected. Among other important results, the measured phase fluctuations of the carrier line at different time scales can be used to determine the influence of the solar wind plasma density fluctuations on the accuracy of the astrometric VLBI observations.

  18. Editorial: solar radiophysics — recent results on observations and theories

    NASA Astrophysics Data System (ADS)

    Nakariakov, Valery M.; Kashapova, Larisa K.; Yan, Yi-Hua

    2014-07-01

    Solar radiophysics is a rapidly developing branch of solar physics and plasma astrophysics. Solar radiophysics has the goal of analyzing observations of radio emissions from the Sun and understanding basic physical processes operating in quiet and active regions of the solar corona. In the near future, the commissioning of a new generation of solar radio observational facilities, which include the Chinese Spectral Radio Heliograph (CSRH) and the upgrade of the Siberian Solar Radio Telescope (SSRT), and the beginning of solar observations with the Atacama Large Millimeter/submillimeter Array (ALMA), is expected to bring us new breakthrough results of a transformative nature. The Marie-Curie International Research Staff Exchange (MC IRSES) “RadioSun” international network aims to create a solid foundation for the successful exploitation of upcoming solar radio observational facilities, as well as intensive use of the existing observational tools, advanced theoretical modeling of relevant physical processes and observables, and training a new generation of solar radio physicists. The RadioSun network links research teams from China, Czech Republic, Poland, Russia and the UK. This mini-volume presents research papers based on invited reviews and contributed talks at the 1st RadioSun workshop in China. These papers cover a broad range of research topics and include recent observational and theoretical advances in solar radiophysics, MHD seismology of the solar corona, physics of solar flares, generation of radio emission, numerical modeling of MHD and plasma physics processes, charged-particle acceleration and novel instrumentation.

  19. Sustained observations in the Weddell Sea spanning more than 20 years show gradual increase of the deep water heat content

    NASA Astrophysics Data System (ADS)

    Strass, Volker; Rohardt, Gerd; Hoppema, Mario

    2014-05-01

    Beginning in 1989, Eberhard Fahrbach established and maintained until his premature death an observational programme in the Weddell Sea, which outstandingly contributed to alleviate the grave problem of undersampling of the Southern Ocean. Continuation of his legacy by the Alfred-Wegener-Institut has yielded a time series that now extends into 2013, hence covers almost 24 years. Here we analyse this data set for long-term changes of the heat content in the deep Weddell Sea. We exclusively evaluate the calibrated temperature records obtained with ship-lowered CTD (conductivity-temperature-depth sonde) casts at repeated hydrographic stations and along repeated sections. Using this approach we avoid introducing potential temperature offsets that can result from combination of different measurement technologies and potential biases resultant from differences in geographic positions. Our results show that the deep water masses below 700 m gradually warmed over the past two decades by 0.001 - 0.004 K a-1. Superimposed inter-annual to multi-annual variations appear as largely uncorrelated horizontally across the Weddell Gyre. The long-term (21 - 24 years) trends of increasing temperatures in different depth layers below 700 m at all stations and sections can be approximated by linear regression that explains between 27 and 91 % of the variance, where the coefficients of correlation tend to increase with depth. No significant trends are found in the top 700 m. The heating rate of the water masses below 700 m is estimated to 0.79 ± 0.14 W m-2, which is more than twice as high as determined for the global deep ocean in general. Our results hence corroborate the view that Southern Ocean processes make an above-average contribution to the deep ocean warming, and so add to bring global estimates of the deep ocean heating rate and of the net energy flux into the Earth's climate system at the top of the atmosphere of 0.5 - 1 W m-2 closer in line with each other. Thus they help

  20. Mars Science Laboratory relative humidity observations: Initial results

    PubMed Central

    Harri, A-M; Genzer, M; Kemppinen, O; Gomez-Elvira, J; Haberle, R; Polkko, J; Savijärvi, H; Rennó, N; Rodriguez-Manfredi, JA; Schmidt, W; Richardson, M; Siili, T; Paton, M; Torre-Juarez, M De La; Mäkinen, T; Newman, C; Rafkin, S; Mischna, M; Merikallio, S; Haukka, H; Martin-Torres, J; Komu, M; Zorzano, M-P; Peinado, V; Vazquez, L; Urqui, R

    2014-01-01

    The Mars Science Laboratory (MSL) made a successful landing at Gale crater early August 2012. MSL has an environmental instrument package called the Rover Environmental Monitoring Station (REMS) as a part of its scientific payload. REMS comprises instrumentation for the observation of atmospheric pressure, temperature of the air, ground temperature, wind speed and direction, relative humidity (REMS-H), and UV measurements. We concentrate on describing the REMS-H measurement performance and initial observations during the first 100 MSL sols as well as constraining the REMS-H results by comparing them with earlier observations and modeling results. The REMS-H device is based on polymeric capacitive humidity sensors developed by Vaisala Inc., and it makes use of transducer electronics section placed in the vicinity of the three humidity sensor heads. The humidity device is mounted on the REMS boom providing ventilation with the ambient atmosphere through a filter protecting the device from airborne dust. The final relative humidity results appear to be convincing and are aligned with earlier indirect observations of the total atmospheric precipitable water content. The water mixing ratio in the atmospheric surface layer appears to vary between 30 and 75 ppm. When assuming uniform mixing, the precipitable water content of the atmosphere is ranging from a few to six precipitable micrometers. Key Points Atmospheric water mixing ratio at Gale crater varies from 30 to 140 ppm MSL relative humidity observation provides good data Highest detected relative humidity reading during first MSL 100 sols is RH75% PMID:26213667

  1. Initial Results Derived from JEM-GLIMS Observations

    NASA Astrophysics Data System (ADS)

    Sato, M.; Ushio, T.; Morimoto, T.; Kobayashi, N.; Takahashi, Y.; Suzuki, M.; Yamazaki, A.; Inan, U.; Linscott, I.; Hobara, Y.

    2012-12-01

    measured by two radio receivers. JEM-GIMS was successfully launched by H-IIB rocket at 02:06:18 UT on July 21, 2012 and transported to ISS by the HTV-3 cargo transfer spaceship. HTV-3 successfully arrived at ISS on July 27 and our JEM-GLIMS instruments will be installed at JEM-EF on August 9. For the period from September 15 to 21 we will carry out the initial checkout operation, and finally we will start continuous TLE observations from the middle of October. At the presentation we will show the test results obtained during the checkout operations and will present the initial results derived from JEM-GLIMS lightning/TLE observations.

  2. From the ashes: JVLA observations of water fountain nebula candidates show the rebirth of IRAS 18455+0448

    NASA Astrophysics Data System (ADS)

    Vlemmings, W. H. T.; Amiri, N.; van Langevelde, H. J.; Tafoya, D.

    2014-09-01

    Context. The class of water fountain nebulae is thought to represent the stage of the earliest onset of collimated bipolar outflows during the post-asymptotic giant branch phase. They thus play a crucial role in the study of the formation of bipolar planetary nebulae (PNe). To date, 14 water fountain nebulae have been identified. The identification of more sources in this unique stage of stellar evolution will enable us to study the origin of bipolar PNe morphologies in more detail. Aims: Water fountain candidates can be identified based on the often double peaked 22 GHz H2O maser spectrum with a large separation between the maser peaks (often >100 km s-1). However, even a fast bipolar outflow will only have a moderate velocity extent in its maser spectrum when located close to the plane of the sky. In this project we aim to enhance the water fountain sample by identifying objects whose jets are aligned close to the plane of the sky. Methods: We present the results of seven sources observed with the Jansky Very Large Array (JVLA) that were identified as water fountain candidates in an Effelsberg 100 m telescope survey of 74 AGB and early post-AGB stars. Results: We find that our sample of water fountain candidates displays strong variability in their 22 GHz H2O maser spectra. The JVLA observations show an extended bipolar H2O maser outflow for one source, the OH/IR star IRAS 18455+0448. This source was previously classified as a dying OH/IR star based on the exponential decrease of its 1612 MHz OH maser and the lack of H2O masers. We therefore also re-observed the 1612, 1665, and 1667 MHz OH masers. We confirm that the 1612 MHz masers have not reappeared and find that the1665/1667 MHz masers have decreased in strength by several orders of magnitude during the last decade. The JVLA observations also reveal a striking asymmetry in the red-shifted maser emission of IRAS 19422+3506. Conclusions: The OH/IR star IRAS 18455+0448 is confirmed to be a new addition to the

  3. Preliminary results of the amplitude retrieval from CHAMP observation data

    NASA Astrophysics Data System (ADS)

    Yan, H. J.; Zhang, G. X.; Guo, P.; Liu, M.; Hong, Z. J.

    2005-01-01

    Under the assumptions of geometric optics and thin phase screen the retrieval algorithms of amplitude in GPS/LEO occultation technique were listed in this paper. Geometric and physical decay sources producing observed signal amplitude variations were sorted according to their physical mechanisms. Using CHAMP observational data samples, the profiles of atmospheric bending, refractivity, pressure, and temperature were retrieved in tern by the series of signal noise ratio. The results were compared and discussed with that from phase process. The influences of both geometric and physical sources on the atmospheric retrievals were analyzed briefly.

  4. Basic results of the CORONAS-F solar observations

    NASA Astrophysics Data System (ADS)

    Kuznetsov, V. D.

    2006-08-01

    142190 Troitsk, Moscow Region, Russia V.D. Kuznetsov N.V.Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Troitsk, Russia The report contains a review of the basic results of the CORONAS-F solar observations during the period of orbital operation of the satellite (from July 31, 2001 to December 6, 2005). Basic results are related with helioseismic observations of the Sun, with localization and study of the morphology of numerous active phenomena in the Sun, including the outstanding events in the declining phase of the solar cycle; with spectroscopic diagnostics of the coronal and flare-generated plasma; with the study of the atomic and nuclear processes in solar flares; with detection of the fluxes of solar cosmic rays, gamma-rays, and neutrons from the major flares reaching the Earth's orbit.

  5. Results of Draconid 2011 observations from the BRAMS network

    NASA Astrophysics Data System (ADS)

    Calders, Stijn; Verbeeck, Cis; Lamy, Herve; Ranvier, Sylvain; Gamby, Emmanuel

    2013-01-01

    In this paper, the applicability of the Observability Function (OF) to the BRAMS network is pre- sented. Preliminary results are shown taking into account only geometry. Radiation patterns of the antennas are assumed to be isotropic. Manual counts for the Draconids outburst in 2011 obtained with the BRAMS network data are presented. The differences between the different stations are discussed in terms of the OFs and other parameters.

  6. Results from 2002 Leonid meteor storm TV observations in Kyiv

    NASA Astrophysics Data System (ADS)

    Kozak, P. M.; Rozhilo, O. O.; Kruchynenko, V. G.; Kazantsev, A. M.; Taranukha, Y. G.

    Results are presented from double-station TV observations of the 2002 Leonids meteor storm as seen from Kyiv (Ukraine). The observations were carried out from two observational stations 54 km apart. The total observation time was five hours: from 23:30 till 4:30 UT on 18/19 November, 2002. The total number of two-station meteors was 38, 28 of which allowed for precise processing. The trajectories of the meteors in Earth’s atmosphere, their radiant coordinates, heliocentric orbital elements, etc., were calculated. The highest beginning height observed was 151.53 ± 2.79 km, and distributions of beginning and end heights are presented. Leonids registered during the onset of the storm between 3:00 and 4:00 UT had geocentric radiants (J2000.0) concentrated into a compact group with mean RA = 154°.43 ± 0°.55 and Decl. = 21°.91 ± 0°.58. The corresponding mean inclination and argument of perihelion of the orbit are i = 162°.62 ± 0°.61 and ω = 175°.13 ± 1°.37, respectively. The initial masses of meteoroids were calculated from photometry, from which a mass distribution index s = 1.43 ± 0.02 was derived. We determined that the number of meteors brighter than 4m (1.54 × 10-4 g) that crossed a horizontal circular area of radius 100 km at an altitude of 100 km, for an assumed radiant in zenith, changed during the observations from 350/h to 1400/h. The corresponding spatial density of Leonid stream particles was 4.3 × 10-8 1.7 × 10-7 km-3.

  7. First Results from NuSTAR Observations of Mkn 421

    NASA Technical Reports Server (NTRS)

    Balokovic, M.; Ajello, M.; Blandford, R. D.; Boggs, S. E.; Borracci, F.; Chiang, J.; Christensen, F. E.; Craig, W. W.; Forster, K.; Furniss, A.; Furst, F.; Ghisellini, G.; Giebels, B.; Giommi, P.; Grefenstette, B. W.; Hailey, C. J.; Harrison, F. A.; Hayashida, M.; Humensky, B.; Inoue, Y.; Koglin, J. E.; Krawczynski, H.; Madejski, G. M.; Madsen, K. K.; Meier, D. L.; Zhang, W. W.

    2013-01-01

    Mkn 421 is a nearby active galactic nucleus dominated at all wavelengths by a very broad nonthermal continuum thought to arise from a relativistic jet seen at a small angle to the line of sight. Its spectral energy distribution peaks in the X-ray and TeV gamma-ray bands, where the energy output is dominated by cooling of high-energy electrons in the jet. In order to study the electron distribution and its evolution, we carried out a dedicated multi-wavelength campaign, including extensive observations by the recently launched highly sensitive hard X-ray telescope NuSTAR, between December 2012 and May 2013. Here we present some intial results based on NuSTAR data from January through March 2013, as well as calibration observations conducted in 2012. Although the observations cover some of the faintest hard X-ray flux states ever observed for Mkn 421, the sensitivity is high enough to resolve intra-day spectral variability. We find that in this low state the dominant f ux variations are smooth on timescales of hours, with typical intra-hour variations of approximately less than 5%. We do not find evidence for either a cutoff in the hard X-ray spectrum, or a rise towards a high-energy component, but rather that at low flux the spectrum assumes a power law shape with a photon index of approximately 3. The spectrum is found to harden with increasing brightness.

  8. Prognostic significance of intraoperative macroscopic serosal invasion finding when it shows a discrepancy in pathologic result gastric cancer

    PubMed Central

    Kang, Sang Yull; Park, Ho Sung

    2016-01-01

    Purpose Depth of wall invasion is an important prognostic factor in patients with gastric cancer, whereas the prognostic significance of intraoperative macroscopic serosal invasion (mSE) findings remain unclear when they show a discrepancy in pathologic findings. This study, therefore, assessed the prognostic significance of mSE. Methods Data from cohort of 2,835 patients with resectable gastric cancer who underwent surgery between 1990 and 2010 were retrospectively reviewed. Results The overall accuracy of mSE and pathologic results was 83.4%. The accuracy of mSE was 75.5% in pT2. On the other hand, the accuracy of pT3 dropped to 24.5%. According to mSE findings (+/–), the 5-year disease-specific survival (DSS) rate differed significantly in patients with pT2 (+; 74.2% vs. –; 92.0%), pT3 (+; 76.7% vs. –; 91.8%) and pT4a (+; 51.3% vs. –; 72.8%) (P < 0.001 each), but not in patients with T1 tumor. Multivariate analysis showed that mSE findings (hazard ratio [HR], 2.275; 95% confidence interval [CI], 1.148–4.509), tumor depth (HR, 6.894; 95% CI, 2.325–20.437), nodal status (HR, 5.206; 95% CI, 2.298–11.791), distant metastasis (HR, 2.881; 95% CI, 1.388–6.209), radical resection (HR, 2.002; 95% CI, 1.017–3.940), and lymphatic invasion (HR, 2.713; 95% CI, 1.424–5.167) were independent predictors of 5-year DSS rate. Conclusion We observed considerable discrepancies between macroscopic and pathologic diagnosis of serosal invasion. However, macroscopic diagnosis of serosal invasion was independently prognostic of 5-year DSS. It suggests that because the pathologic results could not be perfect and the local inflammatory change with mSE(+) could affect survival, a combination of mSE(+/–) and pathologic depth may be predictive of prognosis in patients with gastric cancer. PMID:27186569

  9. Mars Science Laboratory (MSL) - First Results of Relative Humidity Observations

    NASA Astrophysics Data System (ADS)

    Genzer, Maria; Harri, Ari-Matti; Kemppinen, Osku; Gómez-Elvira, Javier; Renno, Nilton; Savijärvi, Hannu; Schmidt, Walter; Polkko, Jouni; Rodríquez-Manfredi, Jose Antonio; de la Torre Juárez, Manuel; Mischna, Michael; Martín-Torres, Javier; Haukka, Harri; Paz Zorzano-Mier, Maria; Rafkin, Scott; Paton, Mark; MSL Science Team

    2013-04-01

    The Mars Science laboratory (MSL) called Curiosity made a successful landing at Gale crater early August 2012. MSL has an environmental instrument package called the Rover Environmental Monitoring Station (REMS) as a part of its scientific payload. REMS comprises instrumentation for the observation of atmospheric pressure, temperature of the air, ground temperature, wind speed and direction, relative humidity, and UV measurements. The REMS instrument suite is described at length in [1]. We concentrate on describing the first results from the REMS relative humidity observations and comparison of the measurements with modeling results. The REMS humidity device is provided by the Finnish Meteorological Institute. It is based on polymeric capacitive humidity sensors developed by Vaisala Inc. The humidity device makes use of one transducer electronics section placed in the vicinity of the three (3) humidity sensor heads. The humidity device is mounted on the REMS boom 2 providing ventilation with the ambient atmosphere through a filter protecting the device from airborne dust. The absolute accuracy of the humidity device is temperature dependent, and is of the order of 2% at the temperature range of -30 to -10 °C, and of the order of 10% at the temperature range of -80 to -60 °C. This enables the investigations of atmospheric humidity variations of both diurnal and seasonal scale. The humidity device measurements will have a lag, when a step-wise change in humidity is taking place. This lag effect is increasing with decreasing temperature, and it is of the order of a few hours at the temperature of -75 °C. To compensate for the lag effect we used an algorithm developed by Mäkinen [2]. The humidity observations were validated after tedious efforts. This was needed to compensate for the artifacts of the transducer electronics. The compensation process includes an assumption that the relative humidity at Mars in the temperature range of 0 to -30 °C is about zero. The

  10. Magnetic Field Observations near Mercury: Preliminary Results from Mariner 10.

    PubMed

    Ness, N F; Behannon, K W; Lepping, R P; Whang, Y C; Schatten, K H

    1974-07-12

    Results are presented from a preliminary analysis of data obtained near Mercury on 29 March 1974 by the NASA-GSFC magnetic field experiment on Mariner 10. Rather unexpectedly, a very well-developed, detached bow shock wave, which develops as the super-Alfvénic solar wind interacts with the planet, has been observed. In addition, a magnetosphere-like region, with maximum field strength of 98 gammas at closest approach (704 kilometers altitude), has been observed, contained within boundaries similar to the terrestrial magnetopause. The obstacle deflecting the solar wind flow is global in size, but the origin of the enhanced magnetic field has not yet been uniquely established. The field may be intrinsic to the planet and distorted by interaction with the solar wind. It may also be associated with a complex induction process whereby the planetary interior-atmosphere-ionosphere interacts with the solar wind flow to generate the observed field by a dynamo action. The complete body of data favors the preliminary conclusion that Mercury has an intrinsic magnetic field. If this is correct, it represents a major scientific discovery in planetary magnetism and will have considerable impact on studies of the origin of the solar system. PMID:17810508

  11. Electric earthquake precursors: from laboratory results to field observations

    NASA Astrophysics Data System (ADS)

    Vallianatos, Filippos; Triantis, Dimos; Tzanis, Andreas; Anastasiadis, Cimon; Stavrakas, Ilias

    The generation of transient electric potential prior to rupture has been demonstrated in a number of laboratory experiments involving both dry and wet rock specimens. Several different electrification effects are responsible for these observations, however, piezoelectricity cannot explain why quartz-free rocks can also generate precursory phenomena and electrokinetic phenomena are normally very weak to produce macro- and megascopic scale effects. Electrification is observed in dry, non-piezoelectric rocks meaning that additional, solid state mechanisms should be responsible. Herein we focus on a promising effect that is ubiquitous during brittle rock failure: the motion of charged edge dislocations (MCD) during crack opening and propagation (microfracturing). We report a series of laboratory experiments on dry marble samples and discuss their possible relationship to field observations of purported electric earthquake precursors (EEP). The experiments confirm the generation of pressure-stimulated currents (PSC) as expected by the MCD model. The PSC was linearly related to the stress rate, so long as the stressed material deformed elastically. Deviation from linearity arose when the applied stress drove the specimen into the plastic deformation range; this effect has been attributed to the dependence of the PSC on the stress rate and, ultimately, to the inverse of the changing (decreasing) Young's modulus. The emitted current appears very intense and non-linear just prior to failure, where massive crack propagation implies massive MCD processes. Repeated cycles of deformation are associated with progressively weaker current emission, indicating the strong dependence of electrification on the residual damage. Overall, the results are consistent with, and render support to the concept of electrification by MCD/microfracturing. Other mechanisms cannot be excluded of course but are rather considered to accompany and supplement the drastic MCD process. The experiments

  12. First results from the Comet ISON Observing Campaign (CIOC)

    NASA Astrophysics Data System (ADS)

    Lisse, C.

    2014-07-01

    Comet ISON came fresh from the Oort Cloud as predicted, coming within 0.07 au of Mars, 0.24 au of Mercury, and 10^{6} km of the solar photospheric surface. It did not become the ''Comet of the Century'' in terms of its brightness in the Earth's night-time sky as predicted, but instead became one of the rare dynamically new Oort Cloud comets to graze the Sun's corona (these occur every few decades; the last one observed was C/Ikeya-Seki 1965). For an initially bright comet detected as far out as the orbit of Saturn in Sept 2011, the comet worried us all quite a bit with its flat-lining activity from 4 to 0.8 au (March to Oct 2013). It thus put on a somewhat disappointing showing at Mars in early October, but then defied predictions of its demise and a government shutdown, ramping up instead to become a beautiful early morning green ''lollipop'' as it passed Mercury in mid-November (Figure). ISON ultimately peaked at maximum Q_{gas} = 2 × 10^{30} mol/s of water [1] within the last few days before perihelion, then seemed to have almost no gas output the day of perihelion, 28 Nov 2013 [2] before spectacularly disrupting under the watchful eyes of the SOHO and STEREO spacecraft (Figure), after which its debris fan was tracked for days until it finally disappeared [3,4]. Over 19 NASA and ESA spacecraft ultimately pointed at the comet, with at least 14 reporting detections of it ranging from the X-rays through the infrared. More than 30 ground-based observatories observed ISON from at UV to radio wavelengths. Important findings concerning the comet's size, rotation state, dust to gas ratio, composition, and coma and tail structure were made during ISON'S apparition. Numerous observing groups produced evidence for a small and CO poor (but rich in solid carbon and CO_2) nucleus that was rapidly evolving. Throughout this time, parallels to the behavior of other dynamically new comets, like C/1973 E (Kohoutek), were readily apparent. In this talk I present an overview of the

  13. DUst around NEarby Stars. The Survey Observational Results

    NASA Technical Reports Server (NTRS)

    Eiroa, C.; Marshall, J. P.; Mora, A.; Montesinos, B.; Absil, O.; Augereau, J. Ch.; Bayo, A.; Bryden, G.; Danchi, W.; delBurgo, C.; Ertel, S..; Fridlund, M.; Heras, A. M.; Krivov, A. V.; Launhardt, R.; Liseau, R.; Lohne, T.; Maldonado, J.; Pilbratt, G. L.; Roberge, A.; Rodman, J.; Sanz-Forcada, J.; Stapelfeldt, K.; Ardila, D.; Beichmann, C.

    2013-01-01

    Context. Debris discs are a consequence of the planet formation process and constitute the fingerprints of planetesimal systems. Their solar system counterparts are the asteroid and Edgeworth-Kuiper belts.Aims. The DUNES survey aims at detecting extra-solar analogues to the Edgeworth-Kuiper belt around solar-type stars, putting in this way the solar system into context. The survey allows us to address some questions related to the prevalence and properties of planetesimal systems.Methods. We used Herschel PACS to observe a sample of nearby FGK stars. Data at 100 and 160 micron were obtained, complemented in some cases with observations at 70 micron, and at 250, 350 and 500 micron using SPIRE. The observing strategy was to integrate as deep as possible at 100 micron to detect the stellar photosphere. Results. Debris discs have been detected at a fractional luminosity level down to several times that of the Edgeworth-Kuiper belt. The incidence rate of discs around the DUNES stars is increased from a rate of approx. 12.1% +/- 5% before Herschel to approx 20.2 % +/- % 2. A significant fraction (approx. 52%) of the discs are resolved, which represents an enormous step ahead from the previously known resolved discs. Some stars are associated with faint far-IR excesses attributed to a new class of cold discs. Although it cannot be excluded that these excesses are produced by coincidental alignment of background galaxies, statistical arguments suggest that at least some of them are true debris discs. Some discs display peculiar SEDs with spectral indexes in the 70-160 micron range steeper than the Rayleigh-Jeans one. An analysis of the debris disc parameters suggests that a decrease might exist of the mean black body radius from the F-type to the K-type stars. In addition, a weak trend is suggested for a correlation of disc sizes and an anticorrelation of disc temperatures with the stellar age.

  14. Spacelab Science Results Study. Volume 1; External Observations

    NASA Technical Reports Server (NTRS)

    Naumann, Robert J. (Compiler)

    1999-01-01

    Some of the 36 Spacelab missions were more or less dedicated to specific scientific disciplines, while other carried a eclectic mixture of experiments ranging from astrophysics to life sciences. However, the experiments can be logically classified into two general categories; those that make use of the Shuttle as an observing platform for external phenomena (including those which use the Shuttle in an interactive mode) and those which use the Shuttle as a microgravity laboratory. This first volume of this Spacelab Science Results study will be devoted to experiments of the first category. The disciplines included are Astrophysics, Solar Physics, Space Plasma Physics, Atmospheric Sciences, and Earth Sciences. Because of the large number of microgravity investigations, Volume 2 will be devoted to Microgravity Sciences, which includes Fluid Physics, Combustion Science, Materials Science, and Biotechnology, and Volume 3 will be devoted to Space Life Sciences, which studies the response and adaptability of living organisms to the microgravity environment.

  15. Tajikistan fireball network and results of photographic observations

    NASA Astrophysics Data System (ADS)

    Kokhirova, G. I.; Babadzhanov, P. B.; Khamroev, U. Kh.

    2015-07-01

    The fireball network was created in Tajikistan with the aim of obtaining new data on the near-Earth meteoroid environment concerning large bodies, entering in the Earth's atmosphere and producing fireballs, as well as new observational data on the activity of known meteor/fireball showers. The network consists of five observational stations equipped with the photographic fireball and digital all-sky cameras. Distances between the stations are from 53 to 184 km and the area covered by monitoring is around 11000 km2. For astrometric reduction of fireball photographs, a technique has been developed that allows positions of object details to be determined at an accuracy of about 1', which is a sufficiently good result for negatives of this scale. In the method of photometric reduction, a dependence of measured widths of diurnal star trails on their magnitudes is used. As a result of processing of multi-station photographs of more than 200 fireballs, photographed by the fireball network for 2006-2013, the data on their atmospheric trajectories, coordinates of radiants, velocities, decelerations, orbits in the interplanetary space, light curves, photometric masses, and densities, as well as on the nature of origin of meteoroids which produced the fireballs are obtained; membership of the fireballs to the known fireball/meteor showers is determined. A brightness of the majority of fireballs is within the maximum absolute magnitude range from -5 to -8. It is shown that 62% of fireball-producing meteoroids have a cometary origin and the remaining 38% are of an asteroidal nature. The greater part of the photographed fireballs belongs to the known meteor/fireball showers, while the lesser part (almost 30%) relates to the sporadic background. The obtained results will noticeably replenish the world database with new information on fireballs and are required for solving contemporary astronomy problems associated with studying meteoroid environment in the near-Earth space and

  16. All-sky observations with HAWC: latest results

    NASA Astrophysics Data System (ADS)

    Arteaga-Velázquez, J. C.; HAWC Collaboration

    2015-08-01

    The High Altitude Water Cherenkov (HAWC) observatory is a ground-based air- shower detector designed to study cosmic rays and gamma rays with energies from 100 GeV up to 100 TeV. HAWC simultaneously surveys 2sr of the northern sky with a high duty cycle > 90% in search for photons from point and extended sources, diffuse emission, transient events and other astrophysical phenomena at multi-TeV scales against the background of cosmic rays. In fact, the study of this background will open also the possibility of doing cosmic ray physics in the GeV — TeV regime and even to perform solar studies at HAWC. The observatory will consist of a densely packed array of 300 water Cherenkov tanks (4.5 m tall and 7.3 m diameter with 4 photomultipliers each) distributed on a 22 000 m2 surface. Deployment started in March 2012 on a plateau situated on the Sierra Negra Volcano in the state of Puebla, Mexico, at an altitude of 4100 m. Construction is expected to be finished by the first months of 2015. In the mean time, HAWC has been taking data with a partial array and preliminary results have been already obtained. In this contribution, the results from the latest HAWC observations will be presented.

  17. Earth observations and photography experiment: Summary of significant results

    NASA Technical Reports Server (NTRS)

    El-Baz, F.

    1978-01-01

    Observation and photographic data from the Apollo Soyuz Test Project are analyzed. The discussion is structured according to the fields of investigation including: geology, desert studies, oceanography, hydrology, and meteorology. The data were obtained by: (1) visual observations of selected Earth features, (2) hand-held camera photography to document observations, and (3) stereo mapping photography of areas of significant scientific interest.

  18. First results of the earth observation Water Cycle Multi-mission Observation Strategy (WACMOS)

    NASA Astrophysics Data System (ADS)

    Su, Z.; Fernández-Prieto, D.; Timmermans, J.; Chen, X.; Hungershoefer, K.; Roebeling, R.; Schröder, M.; Schulz, J.; Stammes, P.; Wang, P.; Wolters, E.

    2014-02-01

    Observing and monitoring the different components of the global water cycle and their dynamics are essential steps to understand the climate of the Earth, forecast the weather, predict natural disasters like floods and droughts, and improve water resources management. Earth observation technology is a unique tool to provide a global understanding of many of the essential variables governing the water cycle and monitor their evolution from global to basin scales. In the coming years, an increasing number of Earth observation missions will provide an unprecedented capacity to quantify several of these variables on a routine basis. However, this growing observational capacity is also increasing the need for dedicated research efforts aimed at exploring the potential offered by the synergies among different and complementary EO data records. In this context, the European Space Agency (ESA) launched the Water Cycle Multi-mission Observation Strategy (WACMOS) in 2009 aiming at enhancing, developing and validating a novel set of multi-mission based methods and algorithms to retrieve a number of key variables relevant to the water cycle. In particular the project addressed four major scientific challenges associated to a number of key variables governing the water cycle: evapotranspiration, soil moisture, cloud properties related to surface solar irradiance and precipitation, and water vapour. This paper provides an overview of the scientific results and findings with the ultimate goal of demonstrating the potential of strategies based on utilizing multi-mission observations in maximizing the synergistic use of the different types of information provided by the currently available observation systems and establish the basis for further work.

  19. International program of observations of selected minor planets: first results

    NASA Astrophysics Data System (ADS)

    Chernetenko, Yulia A.

    2001-07-01

    International programs of observations of selected minor planets have lasted about 50 years and the last one comes to the end in 2000. The main aim of these observational programs consists in obtaining the orientation of the stellar reference frame with respect to the dynamical one using observations of the bright minor planets. The observations are also useful for the orbital improvements of the asteroids themselves. They are available from the author via e-mail at the address . During the above mentioned period more than 23 000 observations of minor planets, referred to different reference star catalogues, have been obtained. The reduction procedure of observations to the PPM star catalogue is described. The orientation parameters are given and discussed.

  20. Overview of TIMED CEDAR observations showing the MLTI system response to changing drivers from solar maximum to solar minimum

    NASA Astrophysics Data System (ADS)

    Kozyra, J. U.; Crowley, G.; Doe, R. A.; Mlynczak, M. G.; Paxton, L. J.; Skinner, W. R.; Solomon, S. C.; Talaat, E.; Woods, T. N.; Wu, Q.; Yee, J.

    2007-12-01

    TIMED CEDAR observations have spanned a large range of solar activity conditions from just past solar maximum during which active region eruptions dominate, through the descending phase during which corotating interaction regions reach a maximum, and now fast approaching a 22-year minimum in magnetic activity during which inputs from below become increasingly prominent against a magnetically quieting state. During this interval, TIMED observed the response of the MLTI to a large number of powerful X-class flares, severe solar proton events, 7 superstorms, newly identified sawtooth events, high dynamic pressure during both southward and northward IMF, and to the strongest CIR-driven magnetic activity of the last 4 solar cycles. We will summarize new knowledge about the response of the MLTI to the very different characteristic inputs from this range of drivers and explore resulting insights into the behavior of the geospace system. As the ascending phase of solar cycle 24 begins, TIMED will observe the response of the MLTI to a new regime in the balance between solar irradiance and magnetic activity, specifically to rising F10.7 in the presence of low magnetic activity. An developing list of unanswered questions related to the MLTI state under these driving conditions will be presented in preparation for continuing community interactions in support of TIMED CEDAR MLTI science.

  1. New results of the spectral observations of CP stars

    NASA Astrophysics Data System (ADS)

    Polosukhina, N. S.; Shavrina, A. V.; Drake, N. A.; Kudryavtsev, D. O.; Smirnova, M. A.

    2010-04-01

    The lithium problem in Ap-CP stars has been, for a long time, a subject of debate. Individual characteristics of CP stars, such as high abundance of the rare-earth elements presence of magnetic fields, complicate structure of the surface distribution of chemical elements, rapid oscillations of some CP-stars, make the detection of the lithium lines and the determination of the lithium abundance, a difficult task. During the International Meeting in Slovakia in 1996, the lithium problem in Ap-CP stars was discussed. The results of the Li study carried out in CrAO Polosukhina (1973-1976), the works of Hack & Faraggiana (1963), Wallerstein & Hack (1964), Faraggiana et al. (1992-1996) formed the basis of the International project ‘Lithium in the cool CP-stars with magnetic fields’. The main goal of the project was, using systematical observations of Ap-CP stars with phase rotation in the spectral regions of the resonance doublet Li I 6708 Å and subordinate 6104 Å lithium lines with different telescopes, to create a database, which will permit to explain the physical origin of anomalous Li abundance in the atmospheres of these stars.

  2. Results of forward-scatter radio echo observations in 2000

    NASA Astrophysics Data System (ADS)

    Ueda, Masayoshi; Maegawa, Kimio

    2001-11-01

    We had been performing a forward scatter radio observation of meteor since 1996. The transmitting station was at Fukui (Japan), and the frequency is 53.750 MHz and the power is 50W. The receiving station is Osaka (Japan) and base line has 160 km distance and NE-SW direction. 504,588 meteor echoes have been observed from January to December 2000. Total of radio observation was 8,238 hours. We made the activities of these showers (June), δ Aquarids (July), Perseids (August), Leonids (November), Geminids (December) and Ursids (December). Moreover, we reported the daily variation of mean meteor rates and the annual variation of mean meteor rates.

  3. Initial Results from the Circumarctic Lakes Observation Network (CALON) Project

    NASA Astrophysics Data System (ADS)

    Hinkel, K. M.; Lenters, J. D.; Grosse, G.; Arp, C. D.; Jones, B.; Beck, R. A.; Eisner, W. R.; Frey, K. E.; Liu, H.; Kim, C.; Townsend-Small, A.

    2011-12-01

    About half of the Arctic Coastal Plain (ACP) of northern Alaska is covered with thermokarst lakes and drained lake basins, making lakes a dominant landscape element and a crucial component of the Arctic permafrost system. However, to date there has been no systematic collection of key lake parameters or baseline data with which to make spatial and temporal comparisons to assess the impact of warmer temperatures, changing cloud cover and precipitation patterns, permafrost degradation, and direct human impacts on lakes. As separate groups, we have been working on lakes in arctic Alaska for the past decade and are currently monitoring some lakes. This effort has recently been organized into the Circumarctic Lakes Observation Network (CALON) with funding from NSF's Arctic Observing Network (AON) program. The objective of CALON is to expand and integrate our existing lake monitoring network across arctic Alaska to provide data for key indices using in situ measurements, field surveys, interviews with members of the indigenous community, and remote sensing/GIS technologies. In 2012, we will enhance the existing in situ network by developing lake monitoring sites to collect year-round baseline data and assess physical, chemical, and biological lake characteristics across environmental gradients. This will be accomplished by implementing a multiscale (hierarchical) lake instrumentation scheme such that basic data are collected from 51 lakes, while a subset of 16 lakes is more intensively instrumented. Regional scaling and extrapolation of key metrics is accomplished through validation of satellite imagery with ground measurements, and standardized protocols will be developed to enable inter-site comparison and to prepare for expansion towards a pan-Arctic network. Initial results are available from lake water profile temperature measurements made in summer 2010 along a 130-km transect extending from Barrow southward toward the interior. Ice-out occurs about 2-4 weeks later

  4. Cloud radar deployment for Indian Monsoon observations: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Chakravarty, K.; Kalapureddy, M.; Pa, M.; Deshpandy, S.; Das, S.; Pandithurai, G.; Prabhakaran, T.; Chandrasekar, C. V.; Goswami, B.

    2013-12-01

    .04290 N, 73.86890 E, 1.35 km AMSL) from a scanning mobile platform since May, 2013. The initial results of the above cloud radar observations on Indian monsoon will be discussed.

  5. Plasma observations near Neptune: Initial results for Voyager 2

    SciTech Connect

    Belcher, J.W.; Bridge, H.S.; Coppi, B.; Gordon, G.S. Jr.; Lazarus, A.J.; McNutt, R.L. Jr.; Richardson, J.D.; Steinberg, J.T.; Sullivan, A.; Szabo, A.; Villanueva, L.; Zhang, M. ); Bagenal, F. ); Divers, O. ); Ogilvie, K.W.; Sittler, E.C. Jr. ); Siscoe, G.L. ); Eviatar, A. ); Vasyliunas, V.M. )

    1989-12-15

    The plasma science experiment on Voyager 2 made observations of the plasma environment in Neptune's magnetosphere and in the surrounding solar wind. Because of the large tilt of the magnetic dipole and fortuitous timing, Voyager entered Neptune's magnetosphere through the cusp region, the first cusp observations at an outer planet. Thus the transition from the magnetosheath to the magnetosphere observed by Voyager 2 was not sharp but rather appeared as a gradual decrease in plasma density and temperature. The maximum plasma density observed in the magnetosphere is inferred to be 1.4 per cubic centimeter (the exact value depends on the composition), the smallest observed by Voyager in any magnetosphere. The plasma has at least two components; light ions (mass, 1 to 5) and heavy ions (mass, 10 to 40), but more precise species identification is not yet available. Most of the plasma is concentrated in a plasma sheet or plasma torus and near closest approach to the planet. A likely source of the heavy ions is Triton's atmosphere or ionosphere, whereas the light ions probably escape from Neptune. The large tilt of Neptune's magnetic dipole produces a dynamic magnetosphere that changes configuration every 16 hours as the planet rotates.

  6. Plasma observations near neptune: initial results from voyager 2.

    PubMed

    Belcher, J W; Bridge, H S; Bagenal, F; Coppi, B; Divers, O; Eviatar, A; Gordon, G S; Lazarus, A J; McNutt, R L; Ogilvie, K W; Richardson, J D; Siscoe, G L; Sittler, E C; Steinberg, J T; Sullivan, J D; Szabo, A; Villanueva, L; Vasyliunas, V M; Zhang, M

    1989-12-15

    The plasma science experiment on Voyager 2 made observations of the plasma environment in Neptune's magnetosphere and in the surrounding solar wind. Because of the large tilt of the magnetic dipole and fortuitous timing, Voyager entered Neptune's magnetosphere through the cusp region, the first cusp observations at an outer planet. Thus the transition from the magnetosheath to the magnetosphere observed by Voyager 2 was not sharp but rather appeared as a gradual decrease in plasma density and temperature. The maximum plasma density observed in the magnetosphere is inferred to be 1.4 per cubic centimeter (the exact value depends on the composition), the smallest observed by Voyager in any magnetosphere. The plasma has at least two components; light ions (mass, 1 to 5) and heavy ions (mass, 10 to 40), but more precise species identification is not yet available. Most of the plasma is concentrated in a plasma sheet or plasma torus and near closest approach to the planet. A likely source of the heavy ions is Triton's atmosphere or ionosphere, whereas the light ions probably escape from Neptune. The large tilt of Neptune's magnetic dipole produces a dynamic magnetosphere that changes configuration every 16 hours as the planet rotates. PMID:17756003

  7. Infrasound/seismic observation of the Hayabusa reentry: Observations and preliminary results

    NASA Astrophysics Data System (ADS)

    Ishihara, Yoshiaki; Hiramatsu, Yoshihiro; Yamamoto, Masa-yuki; Furumoto, Muneyoshi; Fujita, Kazuhisa

    2012-07-01

    The Hayabusa, the world's first sample-return minor body explorer, returned to the Earth, and reentered the Earth's atmosphere on June 13, 2010. Multi-site ground observations of the Hayabusa reentry were carried out in the Woomera Prohibited Area (WPA), Australia. The ground observations were configured with optical imaging with still and video recordings, spectroscopies, and shockwave detection with infrasound and seismic sensors. At three main stations, we installed small aperture infrasound/seismic arrays, as well as three single component seismic sub stations. The infrasound and seismic sensors clearly recorded sonic-boom-type shockwaves from the Hayabusa Sample Return Capsule (H-SRC) and the disrupted fragments of the Hayabusa Spacecraft (H-S/C) itself. Positive overpressure values of shockwaves (corresponding to the H-SRC) recorded at the three main stations were 1.3 Pa, 1.0 Pa, and 0.7 Pa with slant distances of 36.9 km, 54.9 km, and 67.8 km, respectively. Incident vectors of the shockwave from the H-SRC at all three arrays are estimated by an F-K spectrum and agree well with those predicted. Particle motions of ground motions excited by the shockwave show characteristics of a typical Rayleigh wave.

  8. Cassini Observations of Saturn's Magnetotail Region: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Sittler, E. C.; Arridge, C.; Rymer, A.; Coates, A.; Krupp, N.; Blanc, M.; Richardson, J.; Andre, N.; Thomsen, M.; Tokar, R. L.; McAndrews, H. J.; Henderson, Mike; Cooper, J. F.; Burger, M.; Simpson, D.; Khurana, K. K.; Russell, C.; Dougherty, M.; Young, D. T.

    2007-01-01

    Using Cassini thermal plasma, hot plasma and magnetic field observations for several intervals between the dawn meridian of Saturn's outer magnetosphere and Saturn's magnetotail region, we investigate the structure of the magnetotail, plasma and magnetic field properties within tail-like current sheet regions and ion flows within the magnetotail regions. We use Cassini Plasma Spectrometer (CAPS) Ion Mass Spectrometer (IMS), Electron Plasma Spectrometer (ELS) observations, MIMI LEMMS ion and electron observations and Cassini magnetometer data (MAG) to characterize the plasma environment. IMS observations are used to measure plasma flow velocities from which one can infer rotation versus convective flows. IMS composition measurements are used to trace the source of plasma from the inner magnetosphere (protons, H2+ and water group ions) versus an external solar wind source (protons and e +i+on s). A critical parameter for both models is the strength of the convection electric field with respect to the rotational electric field for the large scale magnetosphere. For example, are there significant return flows (i.e., negative radial velocities, VR < 0) and/or plasmoids (V(sub R) > 0) within the magnetotail region? Initial preliminary evidence of such out flows and return flows was presented by Sittler et al. This talk complements the more global analysis by McAndrews et al.

  9. Sensor Web Interoperability Testbed Results Incorporating Earth Observation Satellites

    NASA Technical Reports Server (NTRS)

    Frye, Stuart; Mandl, Daniel J.; Alameh, Nadine; Bambacus, Myra; Cappelaere, Pat; Falke, Stefan; Derezinski, Linda; Zhao, Piesheng

    2007-01-01

    This paper describes an Earth Observation Sensor Web scenario based on the Open Geospatial Consortium s Sensor Web Enablement and Web Services interoperability standards. The scenario demonstrates the application of standards in describing, discovering, accessing and tasking satellites and groundbased sensor installations in a sequence of analysis activities that deliver information required by decision makers in response to national, regional or local emergencies.

  10. Cassini Observations of Saturn's Dawn-Magnetotail Region: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Sittler, Edward C.

    2007-01-01

    Using Cassini thermal plasma, hot plasma and magnetic field observations for several intervals between the dawn meridian of Saturn's outer magnetosphere and Saturn's magnetotail region, we investigate the structure of the magnetotail, plasma and magnetic field properties within tail-like current sheet regions and ion flows within the dawn to magnetotail regions. We use Cassini Plasma Spectrometer (CAPS) Ion Mass Spectrometer (IMS) and Electron Plasma Spectrometer (ELS) observations and MIMI LEMMS ion and electron observations to characterize the plasma environment. LMS observations are used to measure plasma flow velocities from which one can infer rotation versus convective flows. IMS composition measurements are used to trace the, source of plasma from the inner magnetosphere (protons, H(2+) and water group ions) versus an external solar wind source (protons and He++ ions). A critical parameter for both models is the strength of the convection electric field with respect to the rotational electric field for the large scale magnetosphere. For example, are there significant return flows (i.e., negative radial velocities, V(sub R) < 0) and/or plasmoids (V(sub R) > 0) within the magnetotail region?

  11. Europa's Opposition Spike: Preliminary Results from Galileo E14 Observations

    NASA Technical Reports Server (NTRS)

    Kreslavsky, M. A.; Helfenstein, P.; Shkuratov, Yu. G.

    2000-01-01

    The phase function at 0-0.3deg phase angle is studied using high-resolution SSI images. The opposition spike is very sharp, especially for dark material. Some stratigraphically young terrains show anomalously weak opposition spike.

  12. First Results on Observation of New Shape Isomers

    NASA Astrophysics Data System (ADS)

    Pyatkov, Yu. V.; Kamanin, D. V.; Alexandrov, A. A.; Alexandrova, I. A.; Kuznetsova, E. A.; Lavrova, Yu. E.; Strekalovsky, A. O.; Strekalovsky, O. V.; Zhuchko, V. E.

    In our previous publications devoted to the collinear cluster tri-partition (CCT) of the low excited nuclei [1,2] we have discussed the role of scattering medium in the registration of the CCT products. This decay mode has been called by us "collinear cluster tri-partition" (CCT) in view of the observed features of the effect, that the decay partners fly apart almost collinearly and at least one of them has magic nucleon composition. Briefly, even if initially two CCT partners fly in the same direction perfectly collinearly they get some angular divergence after passing the scattering medium on the flight pass due to the multiple scattering. Thanks to such effect they can be registered independently in the "stop" mosaic detector. Actually even thin backing of the radioactive source provides the observable effect.

  13. Crustal dynamics project observations: 1982 results and plans for 1983

    NASA Technical Reports Server (NTRS)

    Frey, H.

    1983-01-01

    The 1982 Crustal Dynamics Project observations by fixed and mobile SLR and VLBI systems are reviewed. Plate motion measurements between North America and Europe were conducted by both techniques and SLR measurements were also made between North America, the Pacific, Australia and South American plates. Regional deformation measurements by VLBI and SLR systems were restricted to the western United States in 1982, including a number of important intercomparison baseline measured by both techniques. In 1983 the observing program grows significantly, with new SLR systems in Mexico, Easter Island, the Pacific and Italy. New VLBI systems will include a dedicated VLBI site at Weltzell, in Germany. Two highly mobile SLR and two highly mobile VLBI systems will greatly increase the regional deformation measurements in California and through the Basin and Range, where more than 25 sites will be occupied in 1983.

  14. Voyager spacecraft radio observations of Jupiter: Initial cruise results

    NASA Technical Reports Server (NTRS)

    Kaiser, M. L.; Desch, M. D.; Riddle, A. C.; Lecacheux, A.; Pearce, J. B.; Alexander, J. K.; Warwick, J. W.; Thieman, J. R.

    1979-01-01

    Jupiter's low-frequency radio emission were detected by the planetary radio astronomy instruments onboard the two Voyager spacecraft. The emission is surprisingly similar in morphology but opposite in polarization to the high-frequency Jovian radio noise that were observed with ground-based telescopes for more than two decades. Several possible explanations for the behavior of the low-frequency emission are examined, but none of them is completely satisfactory.

  15. Earth's colour unchanged since 1967: results from earthshine observations

    NASA Astrophysics Data System (ADS)

    Thejll, Peter; Flynn, Chris; Gleisner, Hans; Schwarz, Henriette

    2014-05-01

    The colour of Earthlight is a function of atmospheric, surface and ocean conditions because each scatters light in a characteristic way. The colour of Earth can in principle be determined and monitored from satellites - but geostationary satellites do not observe in multiple visual bands, and low Earth orbit platforms do not provide instantaneous colour pictures of the terrestrial disc. Observations of the dark side of the Moon - illuminated by earthlight - can be used to determine the terrestrial colour, and was done accurately in 1967 with astronomical photometric techniques. Until now, such techniques have not been re-applied. We report on multi-band visual photometry of the earthshine in 2011/2012. Scattered light in the atmosphere and the equipment is a difficult issue to circumvent - but for a unique pair of observations in the Johnson B and V bands we have a situation where scattered light cancels closely and thus we can estimate the Johnson B-V colours of the earthshine itself. By arguing on the basis of changes in reflected sunlight we can estimate the colour of the earthlight striking the Moon - and hence the colour of the Earth at that particular time. We find good agreement with the a measurement performed 47 years previously, and broad agreement with historic measurements from the 1920s and 30s. This similarity has fundamental consequences for the climate system feedback mechanisms, discussed in this poster.

  16. WISE/NEOWISE OBSERVATIONS OF THE HILDA POPULATION: PRELIMINARY RESULTS

    SciTech Connect

    Grav, T.; Mainzer, A. K.; Bauer, J.; Masiero, J.; Eisenhardt, P. R.; Blauvelt, E.; DeBaun, E.; Elsbury, D.; Gautier, T.; Gomillion, S.; Hand, E.; Wilkins, A.; Spahr, T.; McMillan, R. S.; Walker, R.; Cutri, R.; Wright, E.

    2012-01-10

    We present the preliminary analysis of 1023 known asteroids in the Hilda region of the solar system observed by the NEOWISE component of the Wide-field Infrared Survey Explorer (WISE). The sizes of the Hildas observed range from {approx}3 to 200 km. We find no size-albedo dependency as reported by other projects. The albedos of our sample are low, with a weighted mean value of p{sub V} = 0.055 {+-} 0.018, for all sizes sampled by the NEOWISE survey. We observed a significant fraction of the objects in the two known collisional families in the Hilda population. It is found that the Hilda collisional family is brighter, with a weighted mean albedo of p{sub V} = 0.061 {+-} 0.011, than the general population and dominated by D-type asteroids, while the Schubart collisional family is darker, with a weighted mean albedo of p{sub V} = 0.039 {+-} 0.013. Using the reflected sunlight in the two shortest WISE bandpasses, we are able to derive a method for taxonomic classification of {approx}10% of the Hildas detected in the NEOWISE survey. For the Hildas with diameter larger than 30 km, there are 67{sup +7}{sub -15}% D-type asteroids and 26{sup +17}{sub -5%} C-/P-type asteroids (with the majority of these being P-types).

  17. Mechanical thinning pillar peach trees - second year results and observations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Columnar (pillar) form peach trees were mechanically thinned at 50 days after full bloom during the pit hardening stage of development. A spike-drum mechanical shaker, which showed promise for peach fruit thinning, during preliminary tests in 2005 was used to remove the young fruits. The shaker wa...

  18. Some results of regular observations of the twilight bolides

    NASA Astrophysics Data System (ADS)

    Churyumov, K. I.; Steklov, A. F.; Vidmachenko, A. P.; Steklov, E. A.

    2014-09-01

    Over the observational period from March 2013 to September 2014 we have registered fall in at least a dozen fragments of cometary nuclei, more than five of sufficiently large, and tens of small fragments of meteoroids. Following the example of most Europe and America countries, Ukraine needs to create a network of small base observatory of aerospace monitoring, equipped with a simple wide-angle camera for the registration of these phenomena and recording them to a personal computer. By such simple inexpensive hardware complexes should be equipped as a professional observatory, and basic university, school and amateur observatories

  19. Recent fluffy dust observations by Rosetta / GIADA and OSIRIS results

    NASA Astrophysics Data System (ADS)

    Fulle, Marco; Rotundi, Alessandra; Sierks, Holger; Guettler, Carsten; Della corte, Vincenzo

    2016-07-01

    During the 18 months of ongoing operations of ESA Rosetta Mission at comet 67P, the GIADA dust detector on-board the Rosetta orbiter has observed tens of showers of hundreds of mm-sized particles lasting a few seconds each. These particles had always a momentum below the detection threshold and speeds below 0.1 m/s. During campaigns investigating the source of false stars affecting the performance of Rosetta star-trackers, the OSIRIS Wide-Angle Camera has as well detected showers of mm-sized dust floating close to the spacecraft at speeds of a few cm/s. The observed low speeds, much lower than the escaping velocity from 67P nucleus, imply a strong dust deceleration at the spacecraft, possibly by its negative potential, which charges and fragments cm-sized fluffy parents of very low density (possibly close to 1 kg per cubic meter). The spacecraft electric field decelerates the approaching charged fragments, which are then accelerated away from the spacecraft in all the directions. This continuously replenished cloud of fluffy fragments, much denser than the surrounding dust coma, may be the source of Rosetta star-tracker issues, and should drive the software of star-trackers of future cometary missions. The presence of extremely fluffy particles in 67P nucleus puts strong constraints on the accretion history of the nuclei of the Jupiter Family Comets.

  20. Palomar 5 and its tidal tails: New observational results

    SciTech Connect

    M. Odenkirchen et al.

    2003-02-06

    Sloan Digital Sky Survey data for the field of the cluster Pal 5 reveal the existence of a long massive stream of tidal debris spanning an arc of 10{sup o} on the sky. Pal 5 thus provides an outstanding example for tidal disruption of globular clusters in the Milky Way. Radial velocities from VLT spectra show that Pal 5 has an extremely low velocity dispersion, in accordance with the very low mass derived from its total luminosity.

  1. Not all Surface Waters show a Strong Relation between DOC and Hg Species: Results from an Adirondack Mountain Watershed

    NASA Astrophysics Data System (ADS)

    Burns, D. A.; Schelker, J.; Murray, K. R.; Brigham, M. E.; Aiken, G.

    2009-12-01

    in ponded areas, and (3) the effects of the widely varying seasonal temperature and snow cover on the rates of microbial processes such as the decomposition of soil organic matter and methylation of Hg. These results emphasize that not all watersheds show simple linear relations between DOC and Hg species on an annual basis, and provide a caution that measurements such as the optical properties of waters are not always a strong surrogate for Hg.

  2. Strong Motion Observations In India-synthesis of Results

    NASA Astrophysics Data System (ADS)

    Bansal, B. K.; Gupta, G. D.; Srivastava, H. N.

    During the last two decades strong motion arrays have been installed in the various parts of Himalaya including N-E India through the Department of Science &Technology. Several moderate earthquakes have been recorded by these networks, which have brought out interesting results about the pattern of attenuation of ground acceleration in these regions. The networks are being strengthened further covering the entire Indian region. Significant improvement in the strong motion data have been made possible with the installation of digital accelerographs with GPS timing systems. The paper presents the strong motion results of Bhuj (2001) and other earthquakes recorded at Delhi, Ahmedabad, Koyna region, besides Himalaya and NE India. The most interesting results pertain to the distinct difference in the attenuation characteristics in the Himalayan region vis-à-vis NE India. The paper also summarizes the methods used to synthesize expected ground motions by random summation of the Empirical Green's Function and the stochastic methods for different site conditions in Delhi due to a possible great earthquake (M=8.0) in the central Himalayas. It is concluded that for reliable assessment of strong ground acceleration, the network of stations needs further improvement.

  3. Results of Lunar Impact Observations During Geminid Meteor Shower Events

    NASA Technical Reports Server (NTRS)

    Suggs, R. J.; Suggs, R. M.

    2015-01-01

    the lunar environment associated with larger lunar impactors, but also provides statistical data for verification and improving meteoroid prediction models. Current meteoroid models indicate that the Moon is struck by a sporadic meteoroid with a mass greater than 1 kg over 260 times per year. This number is very uncertain since observations for objects in this mass range are few. Factors of several times, higher or lower, are easily possible. Meteor showers are also present to varying degrees at certain times of the year. The Earth experiences meteor showers when encountering the debris left behind by comets, which is also the case with 2 the Moon. During such times, the rate of shower meteoroids can greatly exceed that of the sporadic background rate for larger meteoroids. Looking for meteor shower impacts on the Moon at about the same time as they occur on Earth will yield important data that can be fed into meteor shower forecasting models, which can then be used to predict times of greater meteoroid hazard on the Moon. The Geminids are one such meteor shower of interest. The Geminids are a major meteor shower that occur in December with a peak intensity occurring usually during the 13th and 14th of the month and appearing to come from a radiant in the constellation Gemini. The Geminids are interesting in that the parent body of the debris stream is an asteroid, which along with the Quadrantids, are the only major meteor showers not originating from a comet. The Geminids parent body, 3200 Phaethon, is about 5 km in diameter and has an orbit that has a 22deg inclination which intersects the main asteroid belt and has a perihelion less than half of Mercury's perihelion distance. Thus, its orbit crosses those of Mars, Earth, Venus, and Mercury. The Geminid debris stream is by far the most massive as compared to the others. When the Earth passes through the stream in mid-December, a peak intensity of approx. equal 120 meteors per hour can be seen. Because of the

  4. A processing method and results of meteor shower radar observations

    NASA Technical Reports Server (NTRS)

    Belkovich, O. I.; Suleimanov, N. I.; Tokhtasjev, V. S.

    1987-01-01

    Studies of meteor showers permit the solving of some principal problems of meteor astronomy: to obtain the structure of a stream in cross section and along its orbits; to retrace the evolution of particle orbits of the stream taking into account gravitational and nongravitational forces and to discover the orbital elements of its parent body; to find out the total mass of solid particles ejected from the parent body taking into account physical and chemical evolution of meteor bodies; and to use meteor streams as natural probes for investigation of the average characteristics of the meteor complex in the solar system. A simple and effective method of determining the flux density and mass exponent parameter was worked out. This method and its results are discussed.

  5. Swift/UVOT Observations show SN2016ccj to be UV-blue for a SN Ia

    NASA Astrophysics Data System (ADS)

    Brown, Peter J.; Milne, P.

    2016-05-01

    Following the classification of SN2016ccj (ASASSN-16ex; Kiyota et al. 2016 ATEL#9020) as a Type Ia supernova similar to super-Chandrasekhar mass SNe 2006gz and 2009dc (Piascik & Steele 2016 ATEL#9023; Tomasella et al. 2016 ATEL#9024), we requested observations with Swift's Ultraviolet/Optical Telescope (UVOT; Gehrels et al. 2004, Roming et al. 2005).

  6. Genomic and Enzymatic Results Show Bacillus cellulosilyticus Uses a Novel Set of LPXTA Carbohydrases to Hydrolyze Polysaccharides

    PubMed Central

    Mead, David; Drinkwater, Colleen; Brumm, Phillip J.

    2013-01-01

    Background Alkaliphilic Bacillus species are intrinsically interesting due to the bioenergetic problems posed by growth at high pH and high salt. Three alkaline cellulases have been cloned, sequenced and expressed from Bacillus cellulosilyticus N-4 (Bcell) making it an excellent target for genomic sequencing and mining of biomass-degrading enzymes. Methodology/Principal Findings The genome of Bcell is a single chromosome of 4.7 Mb with no plasmids present and three large phage insertions. The most unusual feature of the genome is the presence of 23 LPXTA membrane anchor proteins; 17 of these are annotated as involved in polysaccharide degradation. These two values are significantly higher than seen in any other Bacillus species. This high number of membrane anchor proteins is seen only in pathogenic Gram-positive organisms such as Listeria monocytogenes or Staphylococcus aureus. Bcell also possesses four sortase D subfamily 4 enzymes that incorporate LPXTA-bearing proteins into the cell wall; three of these are closely related to each other and unique to Bcell. Cell fractionation and enzymatic assay of Bcell cultures show that the majority of polysaccharide degradation is associated with the cell wall LPXTA-enzymes, an unusual feature in Gram-positive aerobes. Genomic analysis and growth studies both strongly argue against Bcell being a truly cellulolytic organism, in spite of its name. Preliminary results suggest that fungal mycelia may be the natural substrate for this organism. Conclusions/Significance Bacillus cellulosilyticus N-4, in spite of its name, does not possess any of the genes necessary for crystalline cellulose degradation, demonstrating the risk of classifying microorganisms without the benefit of genomic analysis. Bcell is the first Gram-positive aerobic organism shown to use predominantly cell-bound, non-cellulosomal enzymes for polysaccharide degradation. The LPXTA-sortase system utilized by Bcell may have applications both in anchoring

  7. Distributed Permafrost Observation Network in Western Alaska: the First Results

    NASA Astrophysics Data System (ADS)

    Romanovsky, V. E.; Cable, W.; Marchenko, S. S.; Panda, S. K.

    2014-12-01

    The area of Western Alaska including the Selawik National Wildlife Refuge (SNWR) is generally underrepresented in terms of permafrost thermal monitoring. Thus, the main objective of this study was to establish a permafrost monitoring network in Western Alaska in order to understand the spatial variability in permafrost thermal regime in the area and to have a baseline in order to detect future change. Present and future thawing of permafrost in the region will have a dramatic effect on the ecosystems and infrastructure because the permafrost here generally has a high ice content, as a result of preservation of old ground ice in these relatively cold regions even during the warmer time intervals of the Holocene. Over the summers of 2011 and 2012 a total of 26 automated monitoring stations were established to collect temperature data from the active layer and near-surface permafrost. While most of these stations were basic and only measured the temperature down to 1.5 m at 4 depths, three of the stations had higher vertical temperature resolution down to 3 m. The sites were selected using an ecotype (basic vegetation groups) map of very high resolution (30 m) that had been created for the area in 2009. We found the Upland Dwarf Birch-Tussock Shrub ecotype to be the coldest with a mean annual ground temperature at 1 meter (MAGT1.0) of -3.9 °C during the August 1st, 2012 to July 31st, 2013 measurement period. This is also the most widespread ecotype in the SNWR, covering approximately 28.4% by area. The next widespread ecotype in the SNWR is the Lowland and Upland Birch-Ericaceous Low Shrub. This ecotype had higher ground temperatures with an average MAGT1.0 of -2.4 °C during the same measurement period. We also found that within some ecotypes (White Spruce and Alder-Willow Shrub) the presence or absence of moss on the surface seems to indicate the presence or absence of near surface permafrost. In general, we found good agreement between ecotype classes and

  8. Final Results From the Circumarctic Lakes Observation Network (CALON) Project

    NASA Astrophysics Data System (ADS)

    Hinkel, K. M.; Arp, C. D.; Eisner, W. R.; Frey, K. E.; Grosse, G.; Jones, B. M.; Kim, C.; Lenters, J. D.; Liu, H.; Townsend-Small, A.

    2015-12-01

    Since 2012, the physical and biogeochemical properties of ~60 lakes in northern Alaska have been investigated under CALON, a project to document landscape-scale variability of Arctic lakes in permafrost terrain. The network has ten nodes along two latitudinal transects extending inland 200 km from the Arctic Ocean. A meteorological station is deployed at each node and six representative lakes instrumented and continuously monitored, with winter and summer visits for synoptic assessment of lake conditions. Over the 4-year period, winter and summer climatology varied to create a rich range of lake responses over a short period. For example, winter 2012-13 was very cold with a thin snowpack producing thick ice across the region. Subsequent years had relatively warm winters, yet regionally variable snow resulted in differing gradients of ice thickness. Ice-out timing was unusually late in 2014 and unusually early in 2015. Lakes are typically well-mixed and largely isothermal, with minor thermal stratification occurring in deeper lakes during calm, sunny periods in summer. Lake water temperature records and morphometric data were used to estimate the ground thermal condition beneath 28 lakes. Application of a thermal equilibrium steady-state model suggests a talik penetrating the permafrost under many larger lakes, but lake geochemical data do not indicate a significant contribution of subpermafrost groundwater. Biogeochemical data reveal distinct spatial and seasonal variability in chlorophyll biomass, chromophoric dissolved organic carbon (CDOM), and major cations/anions. Generally, waters sampled beneath ice in April had distinctly higher concentrations of inorganic solutes and methane compared with August. Chlorophyll concentrations and CDOM absorption were higher in April, suggesting significant biological/biogeochemical activity under lake ice. Lakes are a positive source of methane in summer, and some also emit nitrous oxide and carbon dioxide. As part of the

  9. Cyclophilin D Knock-Out Mice Show Enhanced Resistance to Osteoporosis and to Metabolic Changes Observed in Aging Bone

    PubMed Central

    White, Noelle S; Nadtochiy, Sergiy M.; Bentley, Karen L. de Mesy; Brookes, Paul S; Jonason, Jennifer H.; Eliseev, Roman A.

    2016-01-01

    Pathogenic factors associated with aging, such as oxidative stress and hormone depletion converge on mitochondria and impair their function via opening of the mitochondrial permeability transition pore (MPTP). The MPTP is a large non-selective pore regulated by cyclophilin D (CypD) that disrupts mitochondrial membrane integrity. MPTP involvement has been firmly established in degenerative processes in heart, brain, and muscle. Bone has high energy demands and is therefore expected to be highly sensitive to mitochondrial dysfunction. Despite this, the role of mitochondria and the MPTP in bone maintenance and bone pathology has not been elucidated. Our goal was to determine whether mitochondria are impaired in aging bone and to see if protecting mitochondria from MPTP opening via CypD deletion protects against bone loss. We found that bone mass, strength, and formation progressively decline over the course of 18 months in C57BL/6J mice. Using metabolomics and electron microscopy, we determined that oxidative metabolism is impaired in aging bone leading to a glycolytic shift, imbalance in nucleotides, and decreased NAD+/NADH ratio. Mitochondria in osteocytes appear swollen which is a major marker of MPTP opening. CypD deletion by CypD knockout mouse model (CypD KO) protects against bone loss in 13- and 18-month-old mice and prevents decline in bone formation and mitochondrial changes observed in wild type C57BL/6J mice. Together, these data demonstrate that mitochondria are impaired in aging bone and that CypD deletion protects against this impairment to prevent bone loss. This implicates CypD-regulated MPTP and mitochondrial dysfunction in the impairment of bone cells and in aging-related bone loss. Our findings suggest mitochondrial metabolism as a new target for bone therapeutics and inhibition of CypD as a novel strategy against bone loss. PMID:27183225

  10. Observations of net soil exchange of CO2 in a dryland show experimental warming increases carbon losses in biocrust soils

    USGS Publications Warehouse

    Darrouzet-Nardi, Anthony N.; Reed, Sasha C.; Grote, Ed; Belnap, Jayne

    2015-01-01

    Many arid and semiarid ecosystems have soils covered with well-developed biological soil crust communities (biocrusts) made up of mosses, lichens, cyanobacteria, and heterotrophs living at the soil surface. These communities are a fundamental component of dryland ecosystems, and are critical to dryland carbon (C) cycling. To examine the effects of warming temperatures on soil C balance in a dryland ecosystem, we used infrared heaters to warm biocrust-dominated soils to 2 °C above control conditions at a field site on the Colorado Plateau, USA. We monitored net soil exchange (NSE) of CO2 every hour for 21 months using automated flux chambers (5 control and 5 warmed chambers), which included the CO2 fluxes of the biocrusts and the soil beneath them. We observed measurable photosynthesis in biocrust soils on 12 % of measurement days, which correlated well with precipitation events and soil wet-up. These days included several snow events, providing what we believe to be the first evidence of substantial photosynthesis underneath snow by biocrust organisms in drylands. Overall, biocrust soils in both control and warmed plots were net CO2 sources to the atmosphere, with control plots losing 62 ± 8 g C m−2 (mean ± SE) over the first year of measurement and warmed plots losing 74 ± 9 g C m−2. Between control and warmed plots, the difference in soil C loss was uncertain over the course of the entire year due to large and variable rates in spring, but on days during which soils were wet and crusts were actively photosynthesizing, biocrusts that were warmed by 2 °C had a substantially more negative C balance (i.e., biocrust soils took up less C and/or lost more C in warmed plots). Taken together, our data suggest a substantial risk of increased C loss from biocrust soils with higher future temperatures, and highlight a robust capacity to predict CO2 exchange in biocrust soils using easily measured environmental parameters.

  11. Evaluation of observation-fused regional air quality model results for population air pollution exposure estimation.

    PubMed

    Chen, Gang; Li, Jingyi; Ying, Qi; Sherman, Seth; Perkins, Neil; Rajeshwari, Sundaram; Mendola, Pauline

    2014-07-01

    In this study, Community Multiscale Air Quality (CMAQ) model was applied to predict ambient gaseous and particulate concentrations during 2001 to 2010 in 15 hospital referral regions (HRRs) using a 36-km horizontal resolution domain. An inverse distance weighting based method was applied to produce exposure estimates based on observation-fused regional pollutant concentration fields using the differences between observations and predictions at grid cells where air quality monitors were located. Although the raw CMAQ model is capable of producing satisfying results for O3 and PM2.5 based on EPA guidelines, using the observation data fusing technique to correct CMAQ predictions leads to significant improvement of model performance for all gaseous and particulate pollutants. Regional average concentrations were calculated using five different methods: 1) inverse distance weighting of observation data alone, 2) raw CMAQ results, 3) observation-fused CMAQ results, 4) population-averaged raw CMAQ results and 5) population-averaged fused CMAQ results. It shows that while O3 (as well as NOx) monitoring networks in the HRRs are dense enough to provide consistent regional average exposure estimation based on monitoring data alone, PM2.5 observation sites (as well as monitors for CO, SO2, PM10 and PM2.5 components) are usually sparse and the difference between the average concentrations estimated by the inverse distance interpolated observations, raw CMAQ and fused CMAQ results can be significantly different. Population-weighted average should be used to account for spatial variation in pollutant concentration and population density. Using raw CMAQ results or observations alone might lead to significant biases in health outcome analyses. PMID:24747248

  12. Evaluation of Observation-Fused Regional Air Quality Model Results for Population Air Pollution Exposure Estimation

    PubMed Central

    Chen, Gang; Li, Jingyi; Ying, Qi; Sherman, Seth; Perkins, Neil; Rajeshwari, Sundaram; Mendola, Pauline

    2014-01-01

    In this study, Community Multiscale Air Quality (CMAQ) model was applied to predict ambient gaseous and particulate concentrations during 2001 to 2010 in 15 hospital referral regions (HRRs) using a 36-km horizontal resolution domain. An inverse distance weighting based method was applied to produce exposure estimates based on observation-fused regional pollutant concentration fields using the differences between observations and predictions at grid cells where air quality monitors were located. Although the raw CMAQ model is capable of producing satisfying results for O3 and PM2.5 based on EPA guidelines, using the observation data fusing technique to correct CMAQ predictions leads to significant improvement of model performance for all gaseous and particulate pollutants. Regional average concentrations were calculated using five different methods: 1) inverse distance weighting of observation data alone, 2) raw CMAQ results, 3) observation-fused CMAQ results, 4) population-averaged raw CMAQ results and 5) population-averaged fused CMAQ results. It shows that while O3 (as well as NOx) monitoring networks in the HRR regions are dense enough to provide consistent regional average exposure estimation based on monitoring data alone, PM2.5 observation sites (as well as monitors for CO, SO2, PM10 and PM2.5 components) are usually sparse and the difference between the average concentrations estimated by the inverse distance interpolated observations, raw CMAQ and fused CMAQ results can be significantly different. Population-weighted average should be used to account spatial variation in pollutant concentration and population density. Using raw CMAQ results or observations alone might lead to significant biases in health outcome analyses. PMID:24747248

  13. Presentation Showing Results of a Hydrogeochemical Investigation of the Standard Mine Vicinity, Upper Elk Creek Basin, Colorado

    USGS Publications Warehouse

    Manning, Andrew H.; Verplanck, Philip L.; Mast, M. Alisa; Wanty, Richard B.

    2008-01-01

    PREFACE This Open-File Report consists of a presentation given in Crested Butte, Colorado on December 13, 2007 to the Standard Mine Advisory Group. The presentation was paired with another presentation given by the Colorado Division of Reclamation, Mining, and Safety on the physical features and geology of the Standard Mine. The presentation in this Open-File Report summarizes the results and conclusions of a hydrogeochemical investigation of the Standard Mine performed by the U.S. Geological Survey (Manning and others, in press). The purpose of the investigation was to aid the U.S. Environmental Protection Agency in evaluating remediation options for the Standard Mine site. Additional details and supporting data related to the information in this presentation can be found in Manning and others (in press).

  14. Betaine and Trimethylamine-N-Oxide as Predictors of Cardiovascular Outcomes Show Different Patterns in Diabetes Mellitus: An Observational Study

    PubMed Central

    Lever, Michael; George, Peter M.; Slow, Sandy; Bellamy, David; Young, Joanna M.; Ho, Markus; McEntyre, Christopher J.; Elmslie, Jane L.; Atkinson, Wendy; Molyneux, Sarah L.; Troughton, Richard W.; Frampton, Christopher M.; Richards, A. Mark; Chambers, Stephen T.

    2014-01-01

    Background Betaine is a major osmolyte, also important in methyl group metabolism. Concentrations of betaine, its metabolite dimethylglycine and analog trimethylamine-N-oxide (TMAO) in blood are cardiovascular risk markers. Diabetes disturbs betaine: does diabetes alter associations between betaine-related measures and cardiovascular risk? Methods Plasma samples were collected from 475 subjects four months after discharge following an acute coronary admission. Death (n = 81), secondary acute MI (n = 87), admission for heart failure (n = 85), unstable angina (n = 72) and all cardiovascular events (n = 283) were recorded (median follow-up: 1804 days). Results High and low metabolite concentrations were defined as top or bottom quintile of the total cohort. In subjects with diabetes (n = 79), high plasma betaine was associated with increased frequencies of events; significantly for heart failure, hazard ratio 3.1 (1.2–8.2) and all cardiovascular events, HR 2.8 (1.4–5.5). In subjects without diabetes (n = 396), low plasma betaine was associated with events; significantly for secondary myocardial infarction, HR 2.1 (1.2–3.6), unstable angina, HR 2.3 (1.3–4.0), and all cardiovascular events, HR 1.4 (1.0–1.9). In diabetes, high TMAO was a marker of all outcomes, HR 2.7 (1.1–7.1) for death, 4.0 (1.6–9.8) for myocardial infarction, 4.6 (2.0–10.7) for heart failure, 9.1 (2.8–29.7) for unstable angina and 2.0 (1.1–3.6) for all cardiovascular events. In subjects without diabetes TMAO was only significant for death, HR 2.7 (1.6–4.8) and heart failure, HR 1.9 (1.1–3.4). Adding the estimated glomerular filtration rate to Cox regression models tended to increase the apparent risks associated with low betaine. Conclusions Elevated plasma betaine concentration is a marker of cardiovascular risk in diabetes; conversely low plasma betaine concentrations indicate increased risk in the absence of diabetes. We speculate that the

  15. Selection Indices and Multivariate Analysis Show Similar Results in the Evaluation of Growth and Carcass Traits in Beef Cattle.

    PubMed

    Brito Lopes, Fernando; da Silva, Marcelo Corrêa; Magnabosco, Cláudio Ulhôa; Goncalves Narciso, Marcelo; Sainz, Roberto Daniel

    2016-01-01

    This research evaluated a multivariate approach as an alternative tool for the purpose of selection regarding expected progeny differences (EPDs). Data were fitted using a multi-trait model and consisted of growth traits (birth weight and weights at 120, 210, 365 and 450 days of age) and carcass traits (longissimus muscle area (LMA), back-fat thickness (BF), and rump fat thickness (RF)), registered over 21 years in extensive breeding systems of Polled Nellore cattle in Brazil. Multivariate analyses were performed using standardized (zero mean and unit variance) EPDs. The k mean method revealed that the best fit of data occurred using three clusters (k = 3) (P < 0.001). Estimates of genetic correlation among growth and carcass traits and the estimates of heritability were moderate to high, suggesting that a correlated response approach is suitable for practical decision making. Estimates of correlation between selection indices and the multivariate index (LD1) were moderate to high, ranging from 0.48 to 0.97. This reveals that both types of indices give similar results and that the multivariate approach is reliable for the purpose of selection. The alternative tool seems very handy when economic weights are not available or in cases where more rapid identification of the best animals is desired. Interestingly, multivariate analysis allowed forecasting information based on the relationships among breeding values (EPDs). Also, it enabled fine discrimination, rapid data summarization after genetic evaluation, and permitted accounting for maternal ability and the genetic direct potential of the animals. In addition, we recommend the use of longissimus muscle area and subcutaneous fat thickness as selection criteria, to allow estimation of breeding values before the first mating season in order to accelerate the response to individual selection. PMID:26789008

  16. Selection Indices and Multivariate Analysis Show Similar Results in the Evaluation of Growth and Carcass Traits in Beef Cattle

    PubMed Central

    Brito Lopes, Fernando; da Silva, Marcelo Corrêa; Magnabosco, Cláudio Ulhôa; Goncalves Narciso, Marcelo; Sainz, Roberto Daniel

    2016-01-01

    This research evaluated a multivariate approach as an alternative tool for the purpose of selection regarding expected progeny differences (EPDs). Data were fitted using a multi-trait model and consisted of growth traits (birth weight and weights at 120, 210, 365 and 450 days of age) and carcass traits (longissimus muscle area (LMA), back-fat thickness (BF), and rump fat thickness (RF)), registered over 21 years in extensive breeding systems of Polled Nellore cattle in Brazil. Multivariate analyses were performed using standardized (zero mean and unit variance) EPDs. The k mean method revealed that the best fit of data occurred using three clusters (k = 3) (P < 0.001). Estimates of genetic correlation among growth and carcass traits and the estimates of heritability were moderate to high, suggesting that a correlated response approach is suitable for practical decision making. Estimates of correlation between selection indices and the multivariate index (LD1) were moderate to high, ranging from 0.48 to 0.97. This reveals that both types of indices give similar results and that the multivariate approach is reliable for the purpose of selection. The alternative tool seems very handy when economic weights are not available or in cases where more rapid identification of the best animals is desired. Interestingly, multivariate analysis allowed forecasting information based on the relationships among breeding values (EPDs). Also, it enabled fine discrimination, rapid data summarization after genetic evaluation, and permitted accounting for maternal ability and the genetic direct potential of the animals. In addition, we recommend the use of longissimus muscle area and subcutaneous fat thickness as selection criteria, to allow estimation of breeding values before the first mating season in order to accelerate the response to individual selection. PMID:26789008

  17. AIRWATCH from SPACE: preliminary results from lab. measurements and from balloon background observations.

    NASA Astrophysics Data System (ADS)

    Giarrusso, S.; Catalano, O.; La Rosa, G.; Linsley, J.; Maccarone, M. C.; Sacco, B.; Scarsi, L.; AIRWATCH Collaboration

    1998-12-01

    In the framework of the AIRWATCH from SPACE mission, measurements of efficiency of UV yield, in air and in Nitrogen, have been performed using X-ray photons of 22 keV at the LAX X-Ray Beam Facility in Palermo. Results are reported and discussed. The nightglow has been observed with the instrument dubbed BABY (BAckground BYpass) from an altitude of 26 Km during a balloon flight from the Trapani-Milo Base in Sicily. Data profile are presented, showing the difference between over-land and over-sea detector exposition in the range of 300-400 nanometers.

  18. A Portrait of the Centaur 2060 Chiron: new results from groundbased and Herschel observations

    NASA Astrophysics Data System (ADS)

    Fornasier, S.; Lellouch, E.; Müller, T.; Panuzzo, P.; Kiss, C.; Lim, T.; Mommert, M.; Bockelée-Morvan, D.; Vilenius, E.; Tozzi, G. P.; Mottola, S.; Duffard, R.; Barucci, M. A.

    2013-09-01

    The Herschel Open Time Key Program entitled "TNOs are Cool: A survey of the trans-Neptunian region" has been awarded 373 hours to investigate the albedo, size distribution and thermal properties of TNOs and Centaurs [1]. In this work we present the results of the combined SPIRE and PACS instruments observations over 6 bands of the Centaur 2060 Chiron, together with groundbased observations used to constrain its absolute magnitude, to investigate possible cometary activity and its surface composition. The estimated nuclear HV magnitude during the Herschel observations is 5.81±0.08, indicating a high flux from the Centaur comparable to that of its activity peak during 1989. Using this HV value, our Chiron's best size estimation, from NEATM and TPM modelling, is 218±20 km, with an albedo of 16±3 %, a value higher than previous Chiron's albedo estimation. Chiron shows the strongest decrease in the emissivity versus wavelength in the TNOs and Centaurs sample investigated with the PACS and SPIRE instruments. The results on the cometary activity analysis both in the visual and far infrared images will also be presented.

  19. Solar Irradiance observation from Fengyun3 meteorological satellites: recent results and future plan

    NASA Astrophysics Data System (ADS)

    Qi, Jin; Zhang, Peng; Qiu, Hong; Fang, Wei

    2016-04-01

    The Solar Irradiance Monitors (SIM) on-board Fengyun3 (FY3) satellites have been observing Total Solar Irradiance since June 2008. With the lessons from the first two satellites, the SIM on FY3C has two significant improvements by adding sun tracing system and temperature control system, which is named after SIM-II. The SIM-II measurements are first really traceable to World Radiometric Reference and building an on-orbit aging model. TSI from FY3C/SIM-II has been evaluated by comparing with SORCE/TIM and RMIB composite data. The result shows a good consistency. Monitoring of strong solar activity during Oct. 2014, FY3C/SIM-II and SORCE/TIM showed the similar result about solar energy change. For the future plan, we would like to have cooperation with RMIB and PMOD on TSI observation from FY3 early-morning orbit satellite which is designed to launch in 2018. We also plan to develop a new ability to capture daily variance in solar spectral irradiance on the early-morning orbit.

  20. Upper Stratospheric Temperature Climatology Derived from SAGE II Observations: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Wang, P.-H.; Cunnold, D. M.; Wang, H. J.; Chu, W. P.; Thomason, L. W.

    2002-01-01

    This study shows that the temperature information in the upper stratosphere can be derived from the SAGE II 385-mn observations. The preliminary results indicate that the zonal mean temperature increases with altitude below 50 km and decreases above 50 km. At 50 km, a regional maximum of 263 K is located in the tropics, and a minimum of 261 K occurs in the subtropics in both hemispheres. The derived long-term temperature changes from 1985 to 1997 reveal a statistically significant negative trend of -2 to -2.5 K/decade in the tropical upper stratosphere and about -2 K/decade in the subtropics near the stratopause. At latitudes poleward of 50, the results show a statistically significant positive trend of about 1 K/decade in the upper stratosphere. The preliminary results also show large annual temperature oscillations in the extratropics with a maximum amplitude of approx. 8 K located at about 44 km near 50 in both hemispheres during local summer. In addition, the semiannual oscillation is found to be a maximum in the tropics with a peak amplitude of approx. 3.3 K located at about 42 km during the equinox.

  1. Spectral heterogeneity on Phobos and Deimos: HiRISE observations and comparisons to Mars Pathfinder results

    NASA Astrophysics Data System (ADS)

    Thomas, N.; Stelter, R.; Ivanov, A.; Bridges, N. T.; Herkenhoff, K. E.; McEwen, A. S.

    2011-10-01

    The High-Resolution Imaging Science Experiment (HiRISE) onboard Mars Reconnaissance Orbiter (MRO) has been used to observe Phobos and Deimos at spatial scales of around 6 and 20 m/px, respectively. HiRISE (McEwen et al., JGR, 112, CiteID E05S02, DOI: 10.1029/2005JE002605, 2007) has provided, for the first time, high-resolution colour images of the surfaces of the Martian moons. When processed, by the production of colour ratio images for example, the data show considerable small-scale heterogeneity, which might be attributable to fresh impacts exposing different materials otherwise largely hidden by a homogenous regolith. The bluer material that is draped over the south-eastern rim of the largest crater on Phobos, Stickney, has been perforated by an impact to reveal redder material and must therefore be relatively thin. A fresh impact with dark crater rays has been identified. Previously identified mass-wasting features in Stickney and Limtoc craters stand out strongly in colour. The interior deposits in Stickney appear more inhomogeneous than previously suspected. Several other local colour variations are also evident. Deimos is more uniform in colour but does show some small-scale inhomogeneity. The bright “streamers” (Thomas et al., Icarus, 123, 536-556,1996) are relatively blue. One crater to the south-west of Voltaire and its surroundings appear quite strongly reddened with respect to the rest of the surface. The reddening of the surroundings may be the result of ejecta from this impact. The spectral gradients at optical wavelengths observed for both Phobos and Deimos are quantitatively in good agreement with those found by unresolved photometric observations made by the Imager for Mars Pathfinder (IMP; Thomas et al., JGR, 104, 9055-9068, 1999). The spectral gradients of the blue and red units on Phobos bracket the results from IMP.

  2. Spectral heterogeneity on Phobos and Deimos: HiRISE observations and comparisons to Mars Pathfinder results

    USGS Publications Warehouse

    Thomas, N.; Stelter, R.; Ivanov, A.; Bridges, N.T.; Herkenhoff, K. E.; McEwen, A.S.

    2011-01-01

    The High-Resolution Imaging Science Experiment (HiRISE) onboard Mars Reconnaissance Orbiter (MRO) has been used to observe Phobos and Deimos at spatial scales of around 6 and 20 m/px, respectively. HiRISE (McEwen et al.; JGR, 112, CiteID E05S02, DOI: 10.1029/2005JE002605, 2007) has provided, for the first time, high-resolution colour images of the surfaces of the Martian moons. When processed, by the production of colour ratio images for example, the data show considerable small-scale heterogeneity, which might be attributable to fresh impacts exposing different materials otherwise largely hidden by a homogenous regolith. The bluer material that is draped over the south-eastern rim of the largest crater on Phobos, Stickney, has been perforated by an impact to reveal redder material and must therefore be relatively thin. A fresh impact with dark crater rays has been identified. Previously identified mass-wasting features in Stickney and Limtoc craters stand out strongly in colour. The interior deposits in Stickney appear more inhomogeneous than previously suspected. Several other local colour variations are also evident. Deimos is more uniform in colour but does show some small-scale inhomogeneity. The bright streamers (Thomas et al.; Icarus, 123, 536556,1996) are relatively blue. One crater to the south-west of Voltaire and its surroundings appear quite strongly reddened with respect to the rest of the surface. The reddening of the surroundings may be the result of ejecta from this impact. The spectral gradients at optical wavelengths observed for both Phobos and Deimos are quantitatively in good agreement with those found by unresolved photometric observations made by the Imager for Mars Pathfinder (IMP; Thomas et al.; JGR, 104, 90559068, 1999). The spectral gradients of the blue and red units on Phobos bracket the results from IMP. ?? 2010 Elsevier Ltd. All rights reserved.

  3. NuSTAR Results and Future Plans for Magnetar and Rotation-Powered Pulsar Observations

    NASA Technical Reports Server (NTRS)

    An, H.; Kaspi, V. M.; Archibald, R.; Bachetti, M.; Bhalerao, V.; Bellm, E. C.; Beloborodov, A. M.; Boggs, S. E.; Chakrabarty, D.; Christensen, F. E.; Craig, W. W.; Dufour, F.; Forster, K.; Gotthelf, B. W.; Grefenstette, B. W.; Hailey, C. J.; Harrison, F. A.; Hascoet, R.; Kitaguchi, T.; Kouveliotou, Ch.; Madsen, K. K.; Mori, K.; Pivovaroff, M. J.; Rana, V. R.; Stern, D.; Tendulkar, S.; Tomsick, J. A.; Vogel, J. K.; Zhang, William W.

    2014-01-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR) is the first focusing hard X-ray mission in orbit and operates in the 3-79 keV range. NuSTAR's sensitivity is roughly two orders of magnitude better than previous missions in this energy band thanks to its superb angular resolution. Since its launch in 2012 June, NuSTAR has performed excellently and observed many interesting sources including four magnetars, two rotation-powered pulsars and the cataclysmic variable AE Aquarii. NuSTAR also discovered 3.76-s pulsations from the transient source SGR J1745-29 recently found by Swift very close to the Galactic center, clearly identifying the source as a transient magnetar. For magnetar 1E 1841-045, we show that the spectrum is well fit by an absorbed blackbody plus broken power-law model with a hard power-law photon index of approximately 1.3. This is consistent with previous results by INTEGRAL and RXTE. We also find an interesting double-peaked pulse profile in the 25-35 keV band. For AE Aquarii, we show that the spectrum can be described by a multi-temperature thermal model or a thermal plus non-thermal model; a multi-temperature thermal model without a non-thermal component cannot be ruled out. Furthermore, we do not see a spiky pulse profile in the hard X-ray band, as previously reported based on Suzaku observations. For other magnetars and rotation-powered pulsars observed with NuSTAR, data analysis results will be soon available.

  4. Long Term Seismic Observation in Mariana by OBSs : Results of the DD inversion

    NASA Astrophysics Data System (ADS)

    Shiobara, H.; Sugioka, H.; Mochizuki, K.; Oki, S.; Kanazawa, T.; Fukao, Y.; Suyehiro, K.

    2004-12-01

    In order to obtain the deep arc structural image of Mariana, a large-scale seismic observation by using 58 long-term ocean bottom seismometers (LTOBS) had been performed from June 2003 until April 2004, which is a part of the MARGINS program funded by the NSF. Prior to this observation, a pilot long-term seismic array observation was conducted in the same area by using 10 LTOBSs from Oct. 2001 until Feb. 2003. By using seven LTOBS's data, those are about 11 months long, hypocenter determination was performed at first and more than 3000 local events were found, although the PDE list contains only 59. A 1D velocity structure based on the iasp91 model was used, and a systematic shift of epicenters between the PDE list and this study was seen. To investigate the detail of hypocenter distribution and the 3D velocity structure, the DD inversion (tomoDD: Zhang and Thurber, 2003) was applied for this data set with a 1D structure initial model except for the crust, which has been surveyed by using a dense airgun-OBS system (Takahashi et al., 2003). The result of relocated hypocenters shows double seismic zones until about 200km depth and a lined focuses along the current ridge axis in the back-arc basin, and the result of the tomographic inversion shows a image of subducting slab and a low-Vs region below the Pagan island erupted in 1981 at 80km depth. The mantle structure beneath the back-arc basin was not clearly resolved due to the inadequate source-receiver coverage, which is cleared in the recent experiment.

  5. Results of observations of the dust distribution in the F-corona of the sun

    NASA Astrophysics Data System (ADS)

    Shestakova, L. I.; Demchenko, B. I.

    2016-03-01

    The results of modeling of the distribution of dust in the circumsolar zone are presented. The dust distribution was retrieved from observations of the line-of-sight velocities in the F-corona to the distances of 7-11 solar radii during the total eclipses of the Sun in different years: on July 31, 1981; August 11, 1991; March 29, 2006; and August 1, 2008. Comparison of the results has shown that the dust composition varies from year to year and the dust is dynamically nonuniform. In addition to the dust related to the zodiacal cloud and concentrating to the ecliptic plane, the dust of retrograde motion and the ejections and accretion in the polar regions are observed. From the results of observations of eclipses on July 31, 1981, August 11, 1991, and August 1, 2008, the east-west asymmetry in a sign of the line-of-sight velocities was detected: they are negative to the east of the Sun and positive to the west. Such distribution of the velocities is indicative of the nearecliptic orbital dust motion, whose direction coincides with that of the motion of the planets. In the course of the eclipse of March 29, 2006, almost no dynamical connection with the zodiacal cloud was found. At the same time, the direction, where the observed velocities are largest in value and opposite in sign on opposite sides of the Sun, was determined, which provides evidence of the orbital motion deviating from the ecliptic plane. The results of observations in 2006 reveal a clear genetic connection of the observed orbital motion of dust with the parent comets of the Kreutz family found near the Sun close to the eclipse date. The velocities observed near the symmetry line in the plane of the sky grow by absolute value with increasing the elongation, which may take place, if the line of sight croßses an empty zone that is free of dust. The modeling of the data of observations near the symmetry plane allowed the parameters of the dust distribution near the sublimation zone to be obtained. In

  6. Strategy and results of East Asian GRB FOllow-up Network (EAFON) follow-up observations

    NASA Astrophysics Data System (ADS)

    Urata, Y.; Eafon Team

    We have established Japan-Taiwan-China collaboration on GRBs study in the East-Asian region since 2004 This serves as valuable additions to the world-wide optical and infrared follow-up network because the East-Asia region is otherwise blank for the network We have been carrying out imaging and spectroscopic follow-up observations by Lulin Taiwan Kiso Japan WIDGET Japan and Xinglong China Using Xinglong and Kiso we can locate candidates and obtain early time spectra of afterglows While WIDGET provides early time observations before the burst the high-time resolution for multi-band light curves will be obtained by Lulin With the data from these sites we will obtain detailed information of light curve and redshift of GRBs which are important to understand the mechanism of afterglows Utilizing East Asian GRB Follow-up Observation Network EAFON we have observed 56 GRB optical afterglows and detected 15 early optical afterglow behavior including two short GRBs in multi-bands Based on these observations we have obtained 3 major results 1 first long term monitoring of short GRB afterglow from sim 0 1 days after the burst 2 two components in early optical afterglow 3 catch about 30 high redshift GRB candidates In this meeting we will present mainly report early a common feature of long GRB early afterglow We have found a common feature in long GRB early afterglow light curves These early light curves show re-brightening and or plateau phase around 0 1 days 2 4hours after bursts Combined with other prompt

  7. Transport Timescales in the Lowermost Stratosphere: Observations and Results from ECHAM5/MESSy

    NASA Astrophysics Data System (ADS)

    Hoor, P.; Fischer, H.; Joeckel, P.; Lelieveld, J.; Brenninkmeijer, C.; Gurk, C.; Hegglin, M. I.; Brunner, D.; Krebsbach, M.; Schiller, C.; Bruehl, C.; Steil, B.

    2006-12-01

    We present a comparison of high resolution in-situ measurements in the lowermost stratosphere over Europe and model results obtained with the new chemistry circulation model ECHAM5/MESSy. Model calculations were performed using T42 spectral resolution and 90 vertical levels from the surface up to 80 km providing a vertical resolution of about 600 m in the extratropical lowermost stratosphere. The model was nudged in the troposphere up to 200 hPa using operational ECMWF data. We compare in particular CO, CO2, N2O and O3 data with in-situ observations from SPURT between 2001 and 2003 with corresponding model data interpolated in time and space. Trace gas profiles and correlations of in-situ observations and modelled data show a remarkable agreement. To deduce transport time scales we compare probability density functions of trace gases in different layers relative to the dynamical tropopause and on N2O-isopleths. To extend the data to a global scale and investigate transport time scales we will use NMVOC data from CARIBIC and compare them with model derived data. The CO2 seasonal cycle and its propagation in the stratosphere provides further information on transport timescales from the tropopause to the lowermost stratosphere. The good agreement between the model and the SPURT observations allows to investigate transport timescales in the UTLS region on global scales.

  8. Multilayer Perceptron Model for Nowcasting Visibility from Surface Observations: Results and Sensitivity to Dissimilar Station Altitudes

    NASA Astrophysics Data System (ADS)

    Chaudhuri, Sutapa; Das, Debanjana; Sarkar, Ishita; Goswami, Sayantika

    2015-10-01

    The reduction in the visibility during fog significantly influences surface as well as air transport operations. The prediction of fog remains difficult despite improvements in numerical weather prediction models. The present study aims at identifying a suitable neural network model with proper architecture to provide precise nowcast of the horizontal visibility during fog over the airports of three significantly affected metropolises of India, namely: Kolkata (22°32'N; 88°20'E), Delhi (28°38'N; 77°12'E) and Bengaluru (12°95'N; 77°72'E). The investigation shows that the multilayer perceptron (MLP) model provides considerably less error in nowcasting the visibility during fog over the said metropolises than radial basis function network, generalized regression neural network or linear neural network. The MLP models of different architectures are trained with the data and records from 2000 to 2010. The model results are validated with observations from 2011 to 2014. Our results reveal that MLP models with different configurations (1) four input layers, three hidden layers with three hidden nodes in each layer and a single output; (2) four input layers with two hidden layers having one hidden node in the first hidden layer and two hidden nodes in the second hidden layer, and a single output layer; and (3) four input layers with two hidden layers having two hidden nodes in each hidden layer and a single output layer] provide minimum error in nowcasting the visibility during fog over the airports of Kolkata, Delhi and Bengaluru, respectively. The results show that the MLP model is well suited for nowcasting visibility during fog with 6 h lead time, however, the study reveals that the MLP model sensitive to dissimilar station altitudes in nowcasting visibility, as the minimum prediction error for the three metropolises having dissimilar mean sea level altitudes is observed through different configurations of the model.

  9. Results of MODIS Band-to-Band Registration Characterization Using On-Orbit Lunar Observations

    NASA Technical Reports Server (NTRS)

    Xiong, Xiaoxiong; Sun, Junqiang; Angal,Amit

    2011-01-01

    Since launch, lunar observations have been made regularly by both Terra and Aqua MODIS and used for a number of sensor calibration and characterization related applications, including radiometric stability monitoring, spatial characterization, optical leak and electronic cross-talk characterization, and calibration inter-comparison. MODIS has 36 spectral bands with a total of 490 individual detectors. They are located on four focal plane assemblies (FPA). This paper focuses on the use of MODIS lunar observations to characterize its band-to-band registration (BBR). In addition to BBR, the approach developed by the MODIS Characterization Support Team (MCST) can be used to characterize MODIS detector-to-detector registration (DDR). Long-term BBR results developed from this approach are presented and compared with that derived from a unique on-board calibrator (OBC). Results show that on-orbit changes of BBR have been very small for both Terra and Aqua MODIS and this approach can be applied to other remote sensing instruments.

  10. Observation results by the TAMA300 detector on gravitational wave bursts from stellar-core collapses

    SciTech Connect

    Ando, Masaki; Aso, Youichi; Iida, Yukiyoshi; Nishi, Yuhiko; Otsuka, Shigemi; Seki, Hidetsugu; Soida, Kenji; Taniguchi, Shinsuke; Tochikubo, Kuniharu; Tsubono, Kimio; Yoda, Tatsuo; Arai, Koji; Beyersdorf, Peter; Kawamura, Seiji; Sato, Shuichi; Takahashi, Ryutaro; Tatsumi, Daisuke; Tsunesada, Yoshiki; Zhu, Zong-Hong; Fujimoto, Masa-Katsu

    2005-04-15

    We present data-analysis schemes and results of observations with the TAMA300 gravitational wave detector, targeting burst signals from stellar-core collapse events. In analyses for burst gravitational waves, the detection and fake-reduction schemes are different from well-investigated ones for a chirp wave analysis, because precise waveform templates are not available. We used an excess -power filter for the extraction of gravitational wave candidates, and developed two methods for the reduction of fake events caused by nonstationary noises of the detector. These analysis schemes were applied to real data from the TAMA300 interferometric gravitational wave detector. As a result, fake events were reduced by a factor of about 1000 in the best cases. In addition, in order to interpret the event candidates from an astronomical viewpoint, we performed a Monte-Carlo simulation with an assumed Galactic event distribution model and with burst waveforms obtained from numerical simulations of stellar-core collapses. We set an upper limit of 5.0x10{sup 3} events/sec on the burst gravitational wave event rate in our Galaxy with a confidence level of 90%. This work shows prospects on the search for burst gravitational waves, by establishing an analysis scheme for the observation data from an interferometric gravitational wave detector.

  11. Preliminary results of V440 Per and α UMi observations with the Poznan Spectroscopic Telescope

    NASA Astrophysics Data System (ADS)

    Fagas, M.; Baranowski, R.; Bartczak, P.; Borczyk, W.; Dimitrow, W.; Kaminski, K.; Kwiatkowski, T.; Ratajczak, R.; Rozek, A.; Schwarzenberg-Czerny, A.

    2009-03-01

    Presented herein are preliminary radial velocity results for two classical Cepheids: V440 Per and α UMi (Polaris). Both stars have been observed with the Poznan Spectroscopic Telescope (PST), operational since Aug 2007 at the Borowiec Station of Poznań Astronomical Observatory in Poland. Data obtained for V440 Per suggest the presence of a low-amplitude secondary mode of pulsations. Results of α UMi observations confirm further pulsation amplitude growth, as observed during the last decades.

  12. Lya intensity mapping: current observational results from SDSS/BOSS and its future potential.

    NASA Astrophysics Data System (ADS)

    Croft, Rupert A.; Miralda-Escudé, Jordi; Zheng, Zheng

    2016-01-01

    Over the past 10 years, widefield optical survey telescopes have taken several million fiber spectra of objects in the night sky. This enormous dataset can be used to carry out optical intensity mapping measurements right now, as well as informing and motivating future dedicated instruments. Using cross-correlation techniques have made measurements of the large-scale structure of the Universe in the hydrogen Lyman-alpha line from SDSS/BOSS fiber spectra. We compare our results to the structure expected in the LambdaCDM cosmological model, and make the first global estimate of the Lyman-alpha luminosity density of the Universe. We discuss how lessons learned during our analysis can be applied to future experiments, and which observational tracers will be useful for further applications of these techniques. We also show how intensity mapping could dramatically enhance our ability to make measurements of new effects in galaxy clustering, such as general and special relativistic distortions.

  13. New Results from Space and Field Observations on the Aerosol Direct and Indirect Radiative Forcing

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram J.; Remer, Lorraine; Tanre, Didier; Boucher, Olivier; Chin, Mian; Dubovik, Oleg; Holben, Brent

    2002-01-01

    New space observations from the MODIS instrument on board the Terra satellite and analysis of POLDER data flown on the ADEOS satellite, show in great details the spatial and seasonal variability of the global aerosol system. These spaceborne instruments distinguish fine aerosol from man-made regional pollution and biomass burning from mostly natural coarse dust and sea salt aerosol. E.g. fine regional pollution in and around the Indian sub-continent, Europe and North America; smoke from biomass burning in Southern Africa and Southern America; coarse dust from West Africa and mixed dust pollution and smoke from West and central Africa and East Asia. These regions were also studied extensively in focused field experiments and by the distributed AERONET network. The results generate the first climatologies of the aerosol system, are used to derive the aerosol radiative effects and to estimate the anthropogenic component. The measurements are also used to evaluate each other and constrain aerosol transport models.

  14. Optimal estimation of tropospheric delay corrections to INSAR results from GPS observations based on SVM

    NASA Astrophysics Data System (ADS)

    Song, Xiaogang; Li, Derena; Liao, Mingsheng; Cheng, Liang

    2007-06-01

    Interferometric synthetic aperture radar (InSAR) has been demonstrated useful for topographic mapping and surface deformation measurement. However, the atmospheric disturbance, especially the tropospheric heterogeneity, represents a major limitation to accuracy. It is usually difficult to accurately model and correct the atmospheric effects. Consequently, significant errors are often resulted in misinterpretation of InSAR results. The purpose of this paper is to seek to reduce the atmospheric effects on repeat-pass InSAR using independent datasets, viz. Global Positioning System (GPS). A between-site and between-epoch double-differencing algorithm for the generation of tropospheric corrections to InSAR results based on GPS observations is applied. In order to correct the radar results on a pixel-by-pixel basis, the Support Vector Machine (SVM) with adaptive parameters is introduced to regressively estimate tropospheric corrections over unknown points using the sparse GPS-derived corrections. The feasibility of applying SVM in troposphetic corrections estimation is examined by using data from the Southern California Integrated GPS Network (SCIGN). Cross-validation tests show that SVM method is more suitable than the conventional inverse distance weighted (IDW) method; it accounts for not only topography-dependent but also topography-independent atmospheric effects, so it seems optimal to estimate the tropospheric delay corrections of unknown pixels from GPS data.

  15. Planck intermediate results. XXIX. All-sky dust modelling with Planck, IRAS, and WISE observations

    NASA Astrophysics Data System (ADS)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Alves, M. I. R.; Aniano, G.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Chamballu, A.; Chiang, H. C.; Christensen, P. R.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Couchot, F.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Draine, B. T.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Falgarone, E.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Ghosh, T.; Giard, M.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gregorio, A.; Gruppuso, A.; Guillet, V.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Holmes, W. A.; Hovest, W.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leonardi, R.; Levrier, F.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maffei, B.; Maino, D.; Mandolesi, N.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; Mazzotta, P.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Natoli, P.; Nørgaard-Nielsen, H. U.; Novikov, D.; Novikov, I.; Oxborrow, C. A.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Pasian, F.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Pratt, G. W.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ristorcelli, I.; Rocha, G.; Roudier, G.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Scott, D.; Spencer, L. D.; Stolyarov, V.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; Ysard, N.; Yvon, D.; Zacchei, A.; Zonca, A.

    2016-02-01

    We present all-sky modelling of the high resolution Planck, IRAS, and WISE infrared (IR) observations using the physical dust model presented by Draine & Li in 2007 (DL, ApJ, 657, 810). We study the performance and results of this model, and discuss implications for future dust modelling. The present work extends the DL dust modelling carried out on nearby galaxies using Herschel and Spitzer data to Galactic dust emission. We employ the DL dust model to generate maps of the dust mass surface density ΣMd, the dust optical extinction AV, and the starlight intensity heating the bulk of the dust, parametrized by Umin. The DL model reproduces the observed spectral energy distribution (SED) satisfactorily over most of the sky, with small deviations in the inner Galactic disk and in low ecliptic latitude areas, presumably due to zodiacal light contamination. In the Andromeda galaxy (M31), the present dust mass estimates agree remarkably well (within 10%) with DL estimates based on independent Spitzer and Herschel data. We compare the DL optical extinction AV for the diffuse interstellar medium (ISM) with optical estimates for approximately 2 × 105 quasi-stellar objects (QSOs) observed inthe Sloan Digital Sky Survey (SDSS). The DL AV estimates are larger than those determined towards QSOs by a factor of about 2, which depends on Umin. The DL fitting parameter Umin, effectively determined by the wavelength where the SED peaks, appears to trace variations in the far-IR opacity of the dust grains per unit AV, and not only in the starlight intensity. These results show that some of the physical assumptions of the DL model will need to be revised. To circumvent the model deficiency, we propose an empirical renormalization of the DL AV estimate, dependent of Umin, which compensates for the systematic differences found with QSO observations. This renormalization, made to match the AV estimates towards QSOs, also brings into agreement the DL AV estimates with those derived for

  16. The ILAN sprite campaigns in Israel: results from 7 years of observations

    NASA Astrophysics Data System (ADS)

    Yair, Yoav; Rubanenko, Lior; Katzenelson, Dor; Rosenthal, Neta; Mezuman, Keren; Price, Colin

    2014-05-01

    The ILAN (Imaging of Lightning And Nocturnal flashes, http://ilanteam.com/) campaigns have been conducted since 2004 from Israel, observing winter thunderstorms in the eastern Mediterranean. We searched for transient luminous events using the standard commercial CCD cameras (Watec N100, 902H2 Ultimate) and the UFO-capture software for event detection, commonly used by other TLE- research groups in Europe and Japan. Winter thunderstorms mostly occur in conjunction with the passage of cold fronts in Cyprus lows, and thus TLEs are best observed when the storms are 200-300 km west of the Israeli coastline, above the Mediterranean Sea. We present statistical analysis of 505 sprites observed in 7 winter campaigns from 2006/7-2012/13. Results show a clear peak in the frequency of sprite detections, with maximum values (above 40% of events) between 00:30-02:50 LST (Local Standard Time, UT+2). This distribution is very different from that of lightning in the region, which peaks ~ 05:00 LST over the sea (Altaratz et al., 2001), hinting at the different temporal behavior of +CG flashes, known to be the major producers of sprites. The morphological distribution of 339 sprites is dominated by column sprites (49.3%) with angels (33.0%) and carrots (25.7%) being less frequent. This is similar to reports of winter sprites over the Sea of Japan (Matsudo et al., 2007). Other shapes (trees, wishbones, etc.; Bór, 2013) appear quite rarely. Single element events constitute 16.8% of observations, with 83.2% containing 2 elements or more. Clusters of homogenous types are slightly more frequent than mixed ones (55%). In some rare cases we observed 12-23 elements in a single sprite. The number of elements and the temporal distribution of different sprite types will be presented and compared with the properties of the parent thunderstorms. Altaratz, O., Levin Z. and Y. Yair, 2001: Winter thunderstorms in Israel - a study with lightning location systems and weather radar. Month. Weath. Rev

  17. Some 5-13 micrometer airborne observations of Comet Wilson 1986l: Preliminary results

    NASA Technical Reports Server (NTRS)

    Lynch, David K.; Russell, Ray W.; Witteborn, F. C.; Bregman, Jesse D.; Rank, D. M.; Cohen, M. C; Campins, Humberto C.

    1988-01-01

    Comet Wilson was observed from the Kuiper Airborne Observatory approximately 23.6 and 25.7 Apr. 1987, UT (approx. 3 to 5 days after perihelion) using the NASA-Ames Faint Object Grating Spectrometer. Spectrophotometric data were observed with a 21 inch aperture between 5 and 13 micrometer and with a spectral resolution of 50 to 100. Spectra of the inner coma and nucleus reveal a fairly smooth continuum with little evidence of silicate emission. The 5 to 8 micrometer color temperature of the comet was 300 + or - 15 K, approx. 15 percent higher than the equilibrium blackbody temperature. All three spectra of the nucleus show a new emission feature at approx. 12.25 micrometer approx. two channels (.22 micrometer) wide. Visual and photographic observations made during the time of these observations showed a broad faint, possible two component tail. No outburst activity was observed.

  18. "The Show"

    ERIC Educational Resources Information Center

    Gehring, John

    2004-01-01

    For the past 16 years, the blue-collar city of Huntington, West Virginia, has rolled out the red carpet to welcome young wrestlers and their families as old friends. They have come to town chasing the same dream for a spot in what many of them call "The Show". For three days, under the lights of an arena packed with 5,000 fans, the state's best…

  19. Battery Performance of ADEOS (Advanced Earth Observing Satellite) and Ground Simulation Test Results

    NASA Technical Reports Server (NTRS)

    Koga, K.; Suzuki, Y.; Kuwajima, S.; Kusawake, H.

    1997-01-01

    The Advanced Earth Observing Satellite (ADEOS) is developed with the aim of establishment of platform technology for future spacecraft and inter-orbit communication technology for the transmission of earth observation data. ADEOS uses 5 batteries, consists of two packs. This paper describes, using graphs and tables, the ground simulation tests and results that are carried to determine the performance of the ADEOS batteries.

  20. Lunar impact flashes: Results from 56 hours of video survey data observed by using one telescope

    NASA Astrophysics Data System (ADS)

    Ait Moulay Larbi, M.; Benkhaldoun, Z.; Baratoux, D.; Daassou, A.; Bouley, S.

    2015-10-01

    Primarily observations are performed during 2013 and 2014 at AGM observatory of Marrakech by using one SC telescope in the aim of observing sporadic meteoroids impacting the lunar dark side. Here,we report results from 56 hours of video survey.

  1. Observational results of a multi-telescope campaign in search of interstellar urea [(NH{sub 2}){sub 2}CO

    SciTech Connect

    Remijan, Anthony J.; Snyder, Lewis E.; Kuo, Hsin-Lun; Looney, Leslie W.; Friedel, Douglas N.; McGuire, Brett A.; Golubiatnikov, G. Yu; Lovas, Frank J.; Ilyushin, V. V.; Alekseev, E. A.; Dyubko, S. F.; McCall, Benjamin J.; Hollis, Jan M.

    2014-03-10

    In this paper, we present the results of an observational search for gas phase urea [(NH{sub 2}){sub 2}CO] observed toward the Sgr B2(N-LMH) region. We show data covering urea transitions from ∼100 GHz to 250 GHz from five different observational facilities: the Berkeley-Illinois-Maryland-Association (BIMA) Array, the Combined Array for Research in Millimeter-wave Astronomy (CARMA), the NRAO 12 m telescope, the IRAM 30 m telescope, and the Swedish-ESO Submillimeter Telescope (SEST). The results show that the features ascribed to urea can be reproduced across the entire observed bandwidth and all facilities by best-fit column density, temperature, and source size parameters which vary by less than a factor of two between observations merely by adjusting for telescope-specific parameters. Interferometric observations show that the emission arising from these transitions is cospatial and compact, consistent with the derived source sizes and emission from a single species. Despite this evidence, the spectral complexity of both (NH{sub 2}){sub 2}CO and of Sgr B2(N) makes the definitive identification of this molecule challenging. We present observational spectra, laboratory data, and models, and discuss our results in the context of a possible molecular detection of urea.

  2. Modeling upward brine migration through faults as a result of CO2 storage in the Northeast German Basin shows negligible salinization in shallow aquifers

    NASA Astrophysics Data System (ADS)

    Kuehn, M.; Tillner, E.; Kempka, T.; Nakaten, B.

    2012-12-01

    The geological storage of CO2 in deep saline formations may cause salinization of shallower freshwater resources by upward flow of displaced brine from the storage formation into potable groundwater. In this regard, permeable faults or fractures can serve as potential leakage pathways for upward brine migration. The present study uses a regional-scale 3D model based on real structural data of a prospective CO2 storage site in Northeastern Germany to determine the impact of compartmentalization and fault permeability on upward brine migration as a result of pressure elevation by CO2 injection. To evaluate the degree of salinization in the shallower aquifers, different fault leakage scenarios were carried out using a newly developed workflow in which the model grid from the software package Petrel applied for pre-processing is transferred to the reservoir simulator TOUGH2-MP/ECO2N. A discrete fault description is achieved by using virtual elements. A static 3D geological model of the CO2 storage site with an a real size of 40 km x 40 km and a thickness of 766 m was implemented. Subsequently, large-scale numerical multi-phase multi-component (CO2, NaCl, H2O) flow simulations were carried out on a high performance computing system. The prospective storage site, located in the Northeast German Basin is part of an anticline structure characterized by a saline multi-layer aquifer system. The NE and SW boundaries of the study area are confined by the Fuerstenwalde Gubener and the Lausitzer Abbruch fault zones represented by four discrete faults in the model. Two formations of the Middle Bunter were chosen to assess brine migration through faults triggered by an annual injection rate of 1.7 Mt CO2 into the lowermost formation over a time span of 20 years. In addition to varying fault permeabilities, different boundary conditions were applied to evaluate the effects of reservoir compartmentalization. Simulation results show that the highest pressurization within the storage

  3. Globular-cluster stars - Results of theoretical evolution and pulsation studies compared with the observations.

    NASA Technical Reports Server (NTRS)

    Iben, I., Jr.

    1971-01-01

    Survey of recently published studies on globular clusters, and comparison of stellar evolution and pulsation theory with reported observations. The theory of stellar evolution is shown to be capable of describing, in principle, the behavior of a star through all quasi-static stages. Yet, as might be expected, estimates of bulk properties obtained by comparing observations with results of pulsation and stellar atmosphere theory differ somewhat from estimates of these same properties obtained by comparing observations with results of evolution theory. A description is given of how such estimates are obtained, and suggestions are offered as to where the weak points in each theory may lie.

  4. Polarimetric Radar Observations of Arctic Clouds: Signal Processing and First Results from the may 2013 Iop

    NASA Astrophysics Data System (ADS)

    Galletti, M.; Oue, M.; Verlinde, J.

    2013-12-01

    The ARM Climate Research Facility site at the North Slope of Alaska in Barrow provides polarimetric radar observations of Arctic clouds at X, Ka and W bands. During the May 2013 Scanning radar Intensive Observation Period, raw I and Q data were acquired with the X-SAPR and the Ka-W SACR for the purpose of validating existing, and testing new signal processing procedures specifically tailored for Arctic observations. The raw I and Q datasets were collected on May 3rd 2013 for the case of low-level boundary layer mixed-phase arctic clouds and on May 6th 2013 for the case of a synoptic low moving in from the west. http://www.arm.gov/campaigns/nsa2013nsasr The present paper describes the impact of signal processing procedures on the data, and establishes dual-polarization radar as a valuable tool for the microphysical characterization of ice clouds. In particular, the X-SAPR operates at STSR mode, making available differential reflectivity ZDR, copolar correlation coefficient ρhv, specific differential phase KDP and Degree of Polarization at Simultaneous Transmit DOPS. Low-level boundary layer mixed-phase Arctic clouds are characterized by layers of supercooled liquid water aloft, which present a stark polarimetric contrast with respect to the associated ice precipitation fallout. The ice particles falling from boundary layer Arctic clouds on May 2nd, 3rd and 4th 2013 (winds were very weak or absent) showed the remarkable property of being composed exclusively by large dendrites - fern-like, stellars, twelve-branched - indicating deposition as the main accretion mechanism. http://www.flickr.com/photos/michele_galletti/sets/72157633422079814/ Boundary Layer mixed-phase Arctic clouds provide an exceptional natural laboratory for the exploration of polarimetric signatures in presence of dendritic ice particles. The first-ever X-band analysis of differential reflectivity ZDR of mixed-phase Arctic clouds is presented in [1]. For the May 6th case, ice particle populations

  5. Distinct characteristics of asymmetric magnetic reconnections: Observational results from the exhaust region at the dayside magnetopause

    NASA Astrophysics Data System (ADS)

    Zhang, Y. C.

    2016-06-01

    Magnetic reconnection plays a key role in the conversion of magnetic energy into the thermal and kinetic energy of plasma. On either side of the diffusion region in space plasma, the conditions for the occurrence of reconnections are usually not symmetric. Previous theoretical studies have predicted that reconnections under asymmetric conditions will bear different features compared with those of symmetric reconnections, and numerical simulations have verified these distinct features. However, to date, the features of asymmetric reconnections have not been thoroughly investigated using in situ observations; thus, some results from theoretical studies and simulations have not been tested with observations sufficiently well. Here, spacecraft observations are used in a statistical investigation of asymmetric magnetic reconnection exhaust at the dayside magnetopause. The resulting observational features are consistent with the theoretical predictions. The results presented here advance our understanding of the development of reconnections under asymmetric conditions.

  6. Distinct characteristics of asymmetric magnetic reconnections: Observational results from the exhaust region at the dayside magnetopause.

    PubMed

    Zhang, Y C

    2016-01-01

    Magnetic reconnection plays a key role in the conversion of magnetic energy into the thermal and kinetic energy of plasma. On either side of the diffusion region in space plasma, the conditions for the occurrence of reconnections are usually not symmetric. Previous theoretical studies have predicted that reconnections under asymmetric conditions will bear different features compared with those of symmetric reconnections, and numerical simulations have verified these distinct features. However, to date, the features of asymmetric reconnections have not been thoroughly investigated using in situ observations; thus, some results from theoretical studies and simulations have not been tested with observations sufficiently well. Here, spacecraft observations are used in a statistical investigation of asymmetric magnetic reconnection exhaust at the dayside magnetopause. The resulting observational features are consistent with the theoretical predictions. The results presented here advance our understanding of the development of reconnections under asymmetric conditions. PMID:27270685

  7. Distinct characteristics of asymmetric magnetic reconnections: Observational results from the exhaust region at the dayside magnetopause

    PubMed Central

    Zhang, Y. C.

    2016-01-01

    Magnetic reconnection plays a key role in the conversion of magnetic energy into the thermal and kinetic energy of plasma. On either side of the diffusion region in space plasma, the conditions for the occurrence of reconnections are usually not symmetric. Previous theoretical studies have predicted that reconnections under asymmetric conditions will bear different features compared with those of symmetric reconnections, and numerical simulations have verified these distinct features. However, to date, the features of asymmetric reconnections have not been thoroughly investigated using in situ observations; thus, some results from theoretical studies and simulations have not been tested with observations sufficiently well. Here, spacecraft observations are used in a statistical investigation of asymmetric magnetic reconnection exhaust at the dayside magnetopause. The resulting observational features are consistent with the theoretical predictions. The results presented here advance our understanding of the development of reconnections under asymmetric conditions. PMID:27270685

  8. Summer-Fall Seasonal Ices at the Mars Phoenix Landing Site: Results from CRISM Observations

    NASA Astrophysics Data System (ADS)

    Cull, S.; Arvidson, R. E.; Morris, R. V.; Wolff, M. J.; Mellon, M. T.; Lemmon, M. T.

    2009-12-01

    We combine ground observations from the Mars Phoenix lander with orbital data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) to chart the onset of seasonal ice at the landing site from late spring (solar longitude [Ls] ~ 84) to late summer (Ls] ~ 117) . We use 25 CRISM observations acquired directly over the landing site and 13 acquired near the landing site. We find that summer ice-free spectra at the Phoenix landing site are approximated by scattering properties similar to Gusev Crater soils. Summer spectra have the strong water absorption at 3 μm, indicating a low level of hydration or adsorption of water, an effect previously observed throughout the northern hemisphere. Patches of permanent water ice appear on the shadowed sides of Heimdal Crater and on the shadowed sides of large mountains to the northeast. These patches were monitored throughout the summer and did not appear to grow or shrink; however, the ice patches darken between Ls~119 and Ls~160, possibly due to the sublimation or sintering of fine-grained ices cold-trapped onto the ice deposits during the spring defrost period. Mobile patches of summertime ice were observed to follow the shadow of a crater wall on an ~85-m crater located ~6.5 km northeast of the landing site. Widespread surface ice was first observed at the Phoenix landing site during the night (3 a.m. Local True Solar Time [LTST]) at Ls~104, and water ice was first observed in the afternoon (3 p.m. LTST) at Ls~154. CRISM observations show the first afternoon water ice clouds at Ls~157. Phoenix Surface Stereo Imager (SSI) images first show evidence of afternoon (1 p.m. LTST) water ice in the shadows of large rocks on operations sol 80 (Ls~112), but did not observe widespread afternoon ice during the mission, which ended at Ls~149.

  9. The NIKA 2013-2014 observation campaigns: control of systematic effects and results

    NASA Astrophysics Data System (ADS)

    Catalano, A.; Adam, R.; Adane, A.; Ade, P.; André, P.; Beelen, A.; Belier, B.; Benoît, A.; Bideaud, A.; Billot, N.; Boudou, N.; Bourrion, O.; Calvo, M.; Coiffard, G.; Comis, B.; D'Addabbo, A.; Désert, F.-X.; Doyle, S.; Goupy, J.; Kramer, C.; Leclercq, S.; Macías-Pérez, J.-F.; Martino, J.; Mauskopf, P.; Mayet, F.; Monfardini, A.; Pajot, F.; Pascale, E.; Perotto, L.; Pointecouteau, E.; Ponthieu, N.; Revéret, V.; Ritacco, A.; Rodriguez, L.; Savini, G.; Schuster, K.; Sievers, A.; Tucker, C.; Zylka, R.

    2014-07-01

    The New IRAM KID Array (NIKA) is a dual-band camera operating with frequency multiplexed arrays of Lumped Element Kinetic Inductance Detectors (LEKIDs) cooled to 100 mK. NIKA is designed to observe the intensity and polarisation of the sky at 1.25 and 2.14 mm from the IRAM 30 m telescope. We present the improvements on the control of systematic effects and astrophysical results made during the last observation campaigns between 2012 and 2014.

  10. Evaluation of observation-driven evaporation algorithms: results of the WACMOS-ET project

    NASA Astrophysics Data System (ADS)

    Miralles, Diego G.; Jimenez, Carlos; Ershadi, Ali; McCabe, Matthew F.; Michel, Dominik; Hirschi, Martin; Seneviratne, Sonia I.; Jung, Martin; Wood, Eric F.; (Bob) Su, Z.; Timmermans, Joris; Chen, Xuelong; Fisher, Joshua B.; Mu, Quiaozen; Fernandez, Diego

    2015-04-01

    Terrestrial evaporation (ET) links the continental water, energy and carbon cycles. Understanding the magnitude and variability of ET at the global scale is an essential step towards reducing uncertainties in our projections of climatic conditions and water availability for the future. However, the requirement of global observational data of ET can neither be satisfied with our sparse global in-situ networks, nor with the existing satellite sensors (which cannot measure evaporation directly from space). This situation has led to the recent rise of several algorithms dedicated to deriving ET fields from satellite data indirectly, based on the combination of ET-drivers that can be observed from space (e.g. radiation, temperature, phenological variability, water content, etc.). These algorithms can either be based on physics (e.g. Priestley and Taylor or Penman-Monteith approaches) or be purely statistical (e.g., machine learning). However, and despite the efforts from different initiatives like GEWEX LandFlux (Jimenez et al., 2011; Mueller et al., 2013), the uncertainties inherent in the resulting global ET datasets remain largely unexplored, partly due to a lack of inter-product consistency in forcing data. In response to this need, the ESA WACMOS-ET project started in 2012 with the main objectives of (a) developing a Reference Input Data Set to derive and validate ET estimates, and (b) performing a cross-comparison, error characterization and validation exercise of a group of selected ET algorithms driven by this Reference Input Data Set and by in-situ forcing data. The algorithms tested are SEBS (Su et al., 2002), the Penman- Monteith approach from MODIS (Mu et al., 2011), the Priestley and Taylor JPL model (Fisher et al., 2008), the MPI-MTE model (Jung et al., 2010) and GLEAM (Miralles et al., 2011). In this presentation we will show the first results from the ESA WACMOS-ET project. The performance of the different algorithms at multiple spatial and temporal

  11. GUVI observations of the airglow response to solar flares: Results from the CAWSES campaign period

    NASA Astrophysics Data System (ADS)

    Wolven, B. C.; Paxton, L. J.; Morrison, D.

    2006-05-01

    GUVI limb and disk observations of oxygen and nitrogen airglow emissions show strong variability during solar events; both the intensity and the altitude of peak limb emission vary in response to the brightened and hardened solar spectrum. We present the observed response, and compare it to model predictions generated using a flare-type solar input spectrum. We examine the difference in atmospheric response to consecutive flare events, owing to the modification of thermospheric density and composition by the initial flare and subsequent geomagnetic disturbances.

  12. Solar irradiance observed on the FY-3 satellites - instrument overview and primary observation results of in-orbit experiments

    NASA Astrophysics Data System (ADS)

    Wang, H.; Fang, W.; Li, H.

    2015-12-01

    instrument system overview and observation results of space experiments in this abstract.

  13. Kinematic Characteristics of Meteor Showers by Results of the Combined Radio-Television Observations

    NASA Astrophysics Data System (ADS)

    Narziev, Mirhusen

    2016-07-01

    One of the most important tasks of meteor astronomy is the study of the distribution of meteoroid matter in the solar system. The most important component to address this issue presents the results of measurements of the velocities, radiants, and orbits of both showers and sporadic meteors. Radiant's and orbits of meteors for different sets of data obtained as a result of photographic, television, electro-optical, video, Fireball Network and radar observations have been measured repeatedly. However, radiants, velocities and orbits of shower meteors based on the results of combined radar-optical observations have not been sufficiently studied. In this paper, we present a methods for computing the radiants, velocities, and orbits of the combined radar-TV meteor observations carried out at HisAO in 1978-1980. As a result of the two-year cycle of simultaneous TV-radar observations 57 simultaneous meteors have been identified. Analysis of the TV images has shown that some meteor trails appeared as dashed lines. Among the simultaneous meteors of d-Aquariids 10 produced such dashed images, and among the Perseids there were only 7. Using a known method, for such fragmented images of simultaneous meteors - together with the measured radar distance, trace length, and time interval between the segments - allowed to determine meteor velocity using combined method. In addition, velocity of the same meteors was measured using diffraction and radar range-time methods based on the results of radar observation. It has been determined that the mean values of meteoroid velocity based on the combined radar-TV observations are greater in 1 ÷ 3 km / c than the averaged velocity values measured using only radar methods. Orbits of the simultaneously observed meteors with segmented photographic images were calculated on the basis of the average velocity observed using the combined radar-TV method. The measured results of radiants velocities and orbital elements of individual meteors

  14. TV Observations of Meteors in INASAN: Equipment, Methods and First Results

    NASA Astrophysics Data System (ADS)

    Kartashova, Anna P.; Bagrov, A. V.; Leonov, V. A.

    2007-08-01

    For the analysis the risk from particles of meteor streams, we must have proved information about masses and densities of meteors. The prime task is to select minor streams from sporadic meteors. Very few astronomers tried to do it, when others only mark observed meteor “Sporadic” without registering its track. So very few previous observations cannot be used for streams detection, and we had to do it from special observations. As a width of meteoroid stream may be very narrow, the Earth will cross it in few hours and it is necessary to observe meteor events 24 hour a day. This is why we provide meteor monitoring and catch every ray of light in night skies and ask other observers to join our program. The current goal of our investigation is continuous monitoring of meteor events by two ways: from nearby sites (about 20-60 km distance) for triangle observations and simultaneously from some observation sites separated by approximately thousand kilometers for detection of minor streams. The last one will reveal spatial heterogeneity's of strong meteor showers also. Since July 2002 at the Arkhyz Space Tracking Station (North Caucasus) and near Moscow hybrid TV-cameras with CCD (“PatrolCa”) are used for meteor observations. Limiting magnitude of the first camera is about +5 magn in the 52-degrees field under frame rate 25 f/sec, the second camera has limiting magnitude 11,5m in field 18x22 degrees with rate 7,5 f/sec. Since June 2006 four extra PatrolCa begin stereo (basis) TV-observation near Moscow with the aims of determination of individual orbits of observed meteors and their physical densities. Observed by meteor monitoring data show that at least 40% of sporadic meteors may be referred to catalogued weak meteor streams. In this paper we present the method of definition of celestial coordinates of objects in the single frame of the wide-angle system. The method allows definition of celestial coordinates of a meteor at the restrictions of absents of enough

  15. Observational results from cooling neutron stars in X-ray binaries

    NASA Astrophysics Data System (ADS)

    Degenaar, Nathalie

    2016-07-01

    The composition and structure of the ~1 km thick, solid crust of neutron stars is responsible for many of their observable properties, and plays a fundamental role in the emission of gravitational waves and the evolution of their magnetic field. When residing in an X-ray binary, a neutron star accretes gas from a companion star. As matter accumulates on the neutron star surface, the underlying crust is compressed and heated due to nuclear reactions induced by this compression. Once accretion switches off, sensitive X-ray satellites can be employed to observe how the heated crust cools. Comparing these observations with theoretical simulations provides very valuable insight into the structure and composition of the crusts of neutron stars. I will present the latest observational results and challenges in this research field.

  16. A remote sensing applications update: Results of interviews with Earth Observations Commercialization Program (EOCAP) participants

    NASA Technical Reports Server (NTRS)

    Mcvey, Sally

    1991-01-01

    Earth remote sensing is a uniquely valuable tool for large-scale resource management, a task whose importance will likely increase world-wide through the foreseeable future. NASA research and engineering have virtually created the existing U.S. system, and will continue to push the frontiers, primarily through Earth Observing System (EOS) instruments, research, and data and information systems. It is the researchers' view that the near-term health of remote sensing applications also deserves attention; it seems important not to abandon the system or its clients. The researchers suggest that, like its Landsat predecessor, a successful Earth Observing System program is likely to reinforce pressure to 'manage' natural resources, and consequently, to create more pressure for Earth Observations Commercialization (EOCAP) type applications. The current applications programs, though small, are valuable because of their technical and commercial results, and also because they support a community whose contributions will increase along with our ability to observe the Earth from space.

  17. New results from old data - Lunar photometric anomalies in Wildey and Pohn's 1962 observations

    NASA Technical Reports Server (NTRS)

    Cameron, W. S.

    1980-01-01

    The anomalies in V magnitude in photometric data on lunar features obtained by Wildey and Pohn (1964) are analyzed in the three colors of their UBV observations. The data have been averaged with respect to phase and graphed, and deviations from the average have been tabulated for each color. Sigma equal to or exceeding 3 for V, B-V, and U-B measures are shown on table. These variations are found to be similar to the much larger body of observations of lunar transient phenomena (LTP). The data for 25 features with 25 observations each show that in terms of individual measures the frequency of anomalies is approximately 3%, similar to frequencies obtained in other analyses of LTP data.

  18. New Theoretical Results on Channelized Hotelling Observer Performance Estimation with Known Difference of Class Means.

    PubMed

    Wunderlich, Adam; Noo, Frédéric

    2013-01-11

    Task-based assessments of image quality constitute a rigorous, principled approach to the evaluation of imaging system performance. To conduct such assessments, it has been recognized that mathematical model observers are very useful, particularly for purposes of imaging system development and optimization. One type of model observer that has been widely applied in the medical imaging community is the channelized Hotelling observer (CHO). Since estimates of CHO performance typically include statistical variability, it is important to control and limit this variability to maximize the statistical power of image-quality studies. In a previous paper, we demonstrated that by including prior knowledge of the image class means, a large decrease in the bias and variance of CHO performance estimates can be realized. The purpose of the present work is to present refinements and extensions of the estimation theory given in our previous paper, which was limited to point estimation with equal numbers of images from each class. Specifically, we present and characterize minimum-variance unbiased point estimators for observer signal-to-noise ratio (SNR) that allow for unequal numbers of lesion-absent and lesion-present images. Building on this SNR point estimation theory, we then show that confidence intervals with exactly-known coverage probabilities can be constructed for commonly-used CHO performance measures. Moreover, we propose simple, approximate confidence intervals for CHO performance, and we show that they are well-behaved in most scenarios of interest. PMID:24436497

  19. Results of Instrument Observations and Adaptive Prediction of Thermoabrasion of Banks of the Vilyui Reservoir

    SciTech Connect

    Velikin, S. A.; Sobol', I. S.; Sobol', S. V.; Khokhlov, D. N.

    2013-11-15

    Quantitative data derived from observations of reformation of the thermoabrasive banks of the Viliyui Reservoir in Yakutia during the service period from 1972 through 2011, and results of analytical prediction of bank formations over the next 20 years for purposes of monitoring the ecological safety of this water body are presented.

  20. Revisiting Spitzer Transit Observations with Independent Component Analysis: New Results for Exoplanetary Systems

    NASA Astrophysics Data System (ADS)

    Morello, G.; Waldmann, I. P.; Tinetti, G.; Howarth, I. D.; Micela, G.

    2015-10-01

    Blind source separation techniques are used to reanalyse several exoplanetary transit lightcurves of a few exoplanets recorded with the infrared camera IRAC on board the Spitzer Space Telescope during the "cold" era. These observations, together with observations at other IR wavelengths, are crucial to characterise the atmospheres of the planets. Previous analyses of the same datasets reported discrepant results, hence the necessity of the reanalyses. The method we used here is based on the Independent Component Analysis (ICA) statistical technique, which ensures a high degree of objectivity. The use of ICA to detrend single photometric observations in a self-consistent way is novel in the literature. The advantage of our reanalyses over previous work is that we do not have to make any assumptions on the structure of the unknown instrumental systematics. We obtained for the first time coherent and repeatable results over different epochs for the exoplanets HD189733b and GJ436b[Morello et al.(2014), Morello et al.(2015)]. The technique has been also tested on simulated datasets with different instrument properties, proving its validity in a more general context [Morello et al.(2015b)]. We will present here the technique, and the results of its application to different observations, in addition to the already published ones. A uniform re-analysis of other archive data with this technique will provide improved parameters for a list of exoplanets, and in particular some other results debated in the literature.

  1. Experimental results concerning global observables from the CERN SPS heavy ion program

    SciTech Connect

    Young, G.R.

    1990-06-01

    A brief overview is given of experimental results obtained during the initial operation of the heavy-ion program at the CERN SPS during the period 1986--1988. This paper confines itself to a presentation of results on so-called global observables, such as energy flow and multiplicity distributions, and on information extracted from them. Of particular interest among the latter are an estimate of the magnitude and spatial distribution of the energy density attained. 3 refs., 27 figs.

  2. A numerical modeling study of a Montana thunderstorm: 1. Model results versus observations involving nonelectrical aspects

    NASA Astrophysics Data System (ADS)

    Helsdon, John H.; Farley, Richard D.

    1987-05-01

    A recently developed Storm Electrification Model (SEM) has been used to simulate the July 19, 1981, Cooperative Convective Precipitation Experiment (CCOPE) case study cloud. This part of the investigation examines the comparison between the model results and the observations of the actual cloud with respect to its nonelectrical aspects. A timing equivalence is established between the simulation and observations based on an explosive growth phase which was both observed and modeled. This timing equivalence is used as a basis upon which the comparisons are made. The model appears to do a good job of reproducing (in both space and time) many of the observed characteristics of the cloud. These include: (1) the general cloud appearance; (2) cloud size; (3) cloud top rise rate; (4) rapid growth phase; (5) updraft structure; (6) first graupel appearance; (7) first radar echo; (8) qualitative radar range-height indicator evolution; (9) cloud decay; and (10) the location of hydrometers with respect to the updraft/-downdraft structure. Some features that are not accurately modeled are the cloud base height, the maximum liquid water content, and the time from first formation of precipitation until it reaches the ground. While the simulation is not perfect, the faithfulness of the model results to the observations is sufficient to give us confidence that the microphysical processes active in this storm are adequately represented in the model physics. Areas where model improvement is indicated are also discussed.

  3. Analysis of conservative tracer measurement results using the Frechet distribution at planted horizontal subsurface flow constructed wetlands filled with coarse gravel and showing the effect of clogging processes.

    PubMed

    Dittrich, Ernő; Klincsik, Mihály

    2015-11-01

    A mathematical process, developed in Maple environment, has been successful in decreasing the error of measurement results and in the precise calculation of the moments of corrected tracer functions. It was proved that with this process, the measured tracer results of horizontal subsurface flow constructed wetlands filled with coarse gravel (HSFCW-C) can be fitted more accurately than with the conventionally used distribution functions (Gaussian, Lognormal, Fick (Inverse Gaussian) and Gamma). This statement is true only for the planted HSFCW-Cs. The analysis of unplanted HSFCW-Cs needs more research. The result of the analysis shows that the conventional solutions (completely stirred series tank reactor (CSTR) model and convection-dispersion transport (CDT) model) cannot describe these types of transport processes with sufficient accuracy. These outcomes can help in developing better process descriptions of very difficult transport processes in HSFCW-Cs. Furthermore, a new mathematical process can be developed for the calculation of real hydraulic residence time (HRT) and dispersion coefficient values. The presented method can be generalized to other kinds of hydraulic environments. PMID:26126688

  4. Photographic zenith tube of the Zvenigorod INASAN Observatory - Processing method and observation results

    NASA Astrophysics Data System (ADS)

    Yurov, E. A.

    1992-10-01

    A method for the reduction of PZT plates which has been used at the Zvenigorod INASAN Observatory since 1986 is described. The formulas used for computing the coordinates of the stellar image in the focal plane at the midpoint of the exposure are correct to 0.0024 arcsec. Observations from February 1986 to October 1988 are compared with data of BIH and IERS, and the results of the comparison are used to compute the amplitudes of the annual terms of nonpolar variations in the observed latitudes and Delta(UTI).

  5. Satellite laser ranging station "Holosiiv-Kyiv". Technical characteristics and results of 2001 observations

    NASA Astrophysics Data System (ADS)

    Bolotina, O. V.; Gluschenko, Yu. M.; Medvedskij, M. M.; Peretyatko, N. N.; Suberlyak, V. R.; Yatskiv, D. Ya.

    2001-12-01

    Basic characteristics of the satellite laser ranging station "Holosiiv-Kyiv" (SLR) are presented. The principle of operation and the field system software of the station are described. Some peculiarities of the satellite tracking system and the calibration of measurements are discussed. The results and the analysis of observations and accuracy estimations of distance measurements are given. The coordinates of the SLR station reference point are improved on the basis of LAGEOS-1 and LAGEOS-2 observations over the period 24.01.01--17.06.01. The coordinates obtained with the SLR method and calculated on the basis of geodetic measurements are compared, and their differences were analyzed.

  6. Observation VLBI Session RAPL02. the Results of the Data Processing

    NASA Astrophysics Data System (ADS)

    Chuprikov, A. A.

    Results of processing of data of a VLBI experiment titled RAPL02 are presented. These observations were made in 2011 February with 5 antennas. All 3 antennas of Petersberg's Institute of Applied Astronomy (IAA) were used in this session. These were antennae in Svetloe, in Zelenchuck, and in Badary. Additionally, a 22-m antenna in Puschino as well as a 32-m antenna in Medicina (Italy) were also included into observations. The raw data correlation was made at the software correlator of Astro Space Center. The secondary data processing was made for 3 quasars, 3C273, 3C279, and 3C286.

  7. Early Results on Energetic Particle Precipitation Observed by the ABOVE Instrument Array

    NASA Astrophysics Data System (ADS)

    Cully, C. M.; Chaddock, D.; Daniel, C.; Davis, E.; Galts, D.; McGuffin, N.; Quinn, C.; Sheldon, A.; Wilson, C.

    2014-12-01

    ABOVE, the Array for Broadband Observations of VLF/ELF Emissions, is a network of radio instruments located across western Canada. The instruments monitor natural and artificial electromagnetic radiation in the frequency range from 200 Hz to 75 kHz. The primary scientific focus is on energetic particle precipitation: we infer precipitation into the atmosphere based on the observed amplitude and phase of remotely transmitted artificial signals, and simultanesouly monitor natural whistler-mode waves (chorus and hiss) that drive the precipitation. Instrument deployment began during the summer of 2014. We report here on the instrument design and the first results.

  8. Array for Microwave Background Anisotropy: Observations, Data Analysis, and Results for Sunyaev-Zel'Dovich Effects

    NASA Astrophysics Data System (ADS)

    Wu, Jiun-Huei Proty; Ho, Paul T. P.; Huang, Chih-Wei Locutus; Koch, Patrick M.; Liao, Yu-Wei; Lin, Kai-Yang; Liu, Guo-Chin; Molnar, Sandor M.; Nishioka, Hiroaki; Umetsu, Keiichi; Wang, Fu-Cheng; Altamirano, Pablo; Birkinshaw, Mark; Chang, Chia-Hao; Chang, Shu-Hao; Chang, Su-Wei; Chen, Ming-Tang; Chiueh, Tzihong; Han, Chih-Chiang; Huang, Yau-De; Hwang, Yuh-Jing; Jiang, Homin; Kesteven, Michael; Kubo, Derek Y.; Lancaster, Katy; Li, Chao-Te; Martin-Cocher, Pierre; Oshiro, Peter; Raffin, Philippe; Wei, Tashun; Wilson, Warwick

    2009-04-01

    We present observations, analysis, and results for the first-year operation of Array for Microwave Background Anisotropy (AMiBA), an interferometric experiment designed to study cosmology via the measurement of cosmic microwave background (CMB). AMiBA is the first CMB interferometer operating at 3 mm to have reported successful results, currently with seven close-packed antennas of 60 cm diameter giving a synthesized resolution of around 6'. During 2007, AMiBA detected the Sunyaev-Zel'dovich effects (SZEs) of six galaxy clusters at redshift 0.091 <= z <= 0.322. An observing strategy with on-off-source switching is used to minimize the effects from electronic offset and ground pickup. Planets were used to test the observational capability of AMiBA and to calibrate the conversion from correlator time-lag data to visibilities. The detailed formalism for data analysis is given. We summarize our early tests including observations of planets and quasars, and present images, visibility profiles, the estimated central coordinates, sizes, and SZE amplitudes of the galaxy clusters. Scientific implications are summarized. We also discuss possible systematic effects in the results.

  9. The effect of observing session duration on OPUS-RS results

    NASA Astrophysics Data System (ADS)

    Dincer Dogru, A.; Ugur Sanli, D.; Hayal, Adem G.; Berber, Mustafa

    2016-04-01

    Online GPS positioning software has now a widespread interest among practitioners and researchers. Researchers rescently use online software to monitor natural hazards such as landslides. The fact that this software usually employs continuously operating GPS stations of the International GNSS Service (IGS) as reference stations in the processing, the community of world-wide users is growing day by day. In the monitoring of landslides, rapid static mode of a GPS surveying is usually preferred because it is possible to have wider field coverage with only a few minutes of data and low cost ground markers. Results comparable to static positioning can be obtained with careful network design and processing strategies. Some online software such as OPUS-RS developed by the National Geodetic Survey (NGS) of the USA provides rapid static positioning engine that processes GPS data from sessions of only a few minutes. 15-minute is the recommended/standard observing session duration for OPUS-RS processing. In this study, using the CORS data operating in the US, we carried out some tests in which the observing session duration is changed from 8 through 118 minutes, and observed the accuracy change on the OPUS-RS solutions. Then we compared the results with the accuracy levels given for 15-min solutions by the NGS. We determined that there is the effect of changing observing session duration on the obtained results, and we report them in this study.

  10. Boundary Layer Vertical Exchange Processes and the Mass Budget of Ozone: Observations and Model Results

    SciTech Connect

    Berkowitz, Carl M.; Fast, Jerome D.; Easter, Richard C.

    2000-06-16

    An Eulerian chemical model is used to assess the relative importance of a variety of processes associated with producing high surface ozone episodes during selected periods of the NARSTO 1995 field campaign over the northeastern United States. A comparison of the observed and predicted hourly surface ozone mixing ratios showed that the model qualitatively reproduced the observed ozone trends over the northeastern U.S. The model, however, over-predicted the surface concentrations by 10 to 15 ppb. The simulated mass budget tendency terms are compared for days with low ozone values immediately followed by days with high values. The later days showed observed and simulated ozone mixing ratios aloft to be of order twice that found on preceding days, although the associated chemical mix appeared to have relatively little potential for the subsequent generation of "new" ozone. Under conditions of shallow mixing over urban regions, simulated surface ozone production rates were negative (a net loss) throughout much of the day with convective mixing bringing newly produced ozone from aloft to the surface. It is noted that surface ozone levels appeared to be relatively insensitive to mixing layer growth rates.

  11. Dynamics of Tachyon Fields and Inflation - Comparison of Analytical and Numerical Results with Observation

    NASA Astrophysics Data System (ADS)

    Milošević, M.; Dimitrijević, D. D.; Djordjević, G. S.; Stojanović, M. D.

    2016-06-01

    The role tachyon fields may play in evolution of early universe is discussed in this paper. We consider the evolution of a flat and homogeneous universe governed by a tachyon scalar field with the DBI-type action and calculate the slow-roll parameters of inflation, scalar spectral index (n), and tensor-scalar ratio (r) for the given potentials. We pay special attention to the inverse power potential, first of all to V(x)˜ x^{-4}, and compare the available results obtained by analytical and numerical methods with those obtained by observation. It is shown that the computed values of the observational parameters and the observed ones are in a good agreement for the high values of the constant X_0. The possibility that influence of the radion field can extend a range of the acceptable values of the constant X_0 to the string theory motivated sector of its values is briefly considered.

  12. PHOTOMETRY OF VARIABLE STARS FROM DOME A, ANTARCTICA: RESULTS FROM THE 2010 OBSERVING SEASON

    SciTech Connect

    Wang, Lingzhi; Zhu, Zonghong; Macri, Lucas M.; Wang, Lifan; Ashley, Michael C. B.; Lawrence, Jon S.; Luong-Van, Daniel; Storey, John W. V.; Cui, Xiangqun; Feng, Long-Long; Gong, Xuefei; Liu, Qiang; Shang, Zhaohui; Yang, Huigen; Yang, Ji; Yuan, Xiangyan; Zhou, Xu; Zhu, Zhenxi; Pennypacker, Carl R.; York, Donald G.

    2013-12-01

    We present results from a season of observations with the Chinese Small Telescope ARray, obtained over 183 days of the 2010 Antarctic winter. We carried out high-cadence time-series aperture photometry of 9125 stars with i ∼< 15.3 mag located in a 23 deg{sup 2} region centered on the south celestial pole. We identified 188 variable stars, including 67 new objects relative to our 2008 observations, thanks to broader synoptic coverage, a deeper magnitude limit, and a larger field of view. We used the photometric data set to derive site statistics from Dome A. Based on two years of observations, we find that extinction due to clouds at this site is less than 0.1 and 0.4 mag during 45% and 75% of the dark time, respectively.

  13. Very-long-baseline radio interferometry (VLBI) observations of gamma-ray blazars: results from millimeter-VLBI observations.

    PubMed Central

    Krichbaum, T P; Britzen, S; Standke, K J; Witzel, A; Schalinski, C J; Zensus, J A

    1995-01-01

    VLBI observations of the extremely gamma-bright blazar PKS 0528+134 at 8, 22, 43, and 86 GHz reveal a strongly bent one-sided-core jet structure with at least three moving and two apparently stationary jet components. At the highest observing frequencies the brightest and most compact jet component (the VLBI core) is unresolved with an upper limit to its size of approximately 50 microarcsec corresponding to approximately 0.2 parsec [H0 = 100 km.s-1.Mpc-1 (megaparsec-1), q0 = 0.5, where H0 is Hubble constant and q0 is the deceleration parameter]. Two 86-GHz VLBI observations performed in 1993.3 and 1994.0 reveal a new jet component emerging with superluminal speed from the core. Linear back-extrapolation of its motion yields strong evidence that the ejection of this component is related to an outburst in the millimeter regime and a preceding intense flare of the gamma-flux density observed in early 1993. This and the radio/optical "light curves" and VLBI data for two other sources (S5 0836+710 and 3C 454.3) suggest that the observed gamma-radiation might be Doppler-boosted and perhaps is closely related to the physical processes acting near the "base" of the highly relativistic jets observed in quasars. PMID:11607602

  14. Very-long-baseline radio interferometry (VLBI) observations of gamma-ray blazars: results from millimeter-VLBI observations.

    PubMed

    Krichbaum, T P; Britzen, S; Standke, K J; Witzel, A; Schalinski, C J; Zensus, J A

    1995-12-01

    VLBI observations of the extremely gamma-bright blazar PKS 0528+134 at 8, 22, 43, and 86 GHz reveal a strongly bent one-sided-core jet structure with at least three moving and two apparently stationary jet components. At the highest observing frequencies the brightest and most compact jet component (the VLBI core) is unresolved with an upper limit to its size of approximately 50 microarcsec corresponding to approximately 0.2 parsec [H0 = 100 km.s-1.Mpc-1 (megaparsec-1), q0 = 0.5, where H0 is Hubble constant and q0 is the deceleration parameter]. Two 86-GHz VLBI observations performed in 1993.3 and 1994.0 reveal a new jet component emerging with superluminal speed from the core. Linear back-extrapolation of its motion yields strong evidence that the ejection of this component is related to an outburst in the millimeter regime and a preceding intense flare of the gamma-flux density observed in early 1993. This and the radio/optical "light curves" and VLBI data for two other sources (S5 0836+710 and 3C 454.3) suggest that the observed gamma-radiation might be Doppler-boosted and perhaps is closely related to the physical processes acting near the "base" of the highly relativistic jets observed in quasars. PMID:11607602

  15. Astrometric results of observations of mutual occultations and eclipses of the Saturnian satellites in 2009

    NASA Astrophysics Data System (ADS)

    Arlot, J.-E.; Emelyanov, N. V.; Lainey, V.; Andreev, M.; Assafin, M.; Braga-Ribas, F.; Camargo, J. I. B.; Casas, R.; Christou, A.; Colas, F.; Da Silva Neto, D. N.; Dechambre, O.; Dias-Oliveira, A.; Dourneau, G.; Farmakopoulos, A.; Gault, D.; George, T.; Gorshanov, D. L.; Herald, D.; Kozlov, V.; Kurenya, A.; Le Campion, J. F.; Lecacheux, J.; Loader, B.; Massallé, A.; Mc Brien, M.; Murphy, A.; Parakhin, N.; Roman-Lopes, A.; Schnabel, C.; Sergeev, A.; Tsamis, V.; Valdés Sada, P.; Vieira-Martins, R.; Zhang, X.

    2012-08-01

    Context. The photometry of mutual occultations and eclipses of natural planetary satellites can be used to infer very accurate astrometric data. This can be achieved by processing the light curves of the satellites observed during international campaigns of photometric observations of these mutual events. Aims: This work focuses on processing the complete database of photometric observations of the mutual occultations and eclipses of the Saturnian satellites made during the international campaign in 2009. The final goal is to derive new accurate astrometric data. Methods: We develop an accurate photometric model of mutual event observations of sufficiently high accuracy. Our original method is applied to derive astrometric data from photometric observations of the mutual occultations and eclipses of the Saturnian satellites. Results: We process the 26 light curves obtained during the international campaign of photometric observations of the Saturnian satellites in 2009. Compared with the theory TASS 1.7 by Vienne and Duriez, we find that the root mean square of the "O-C" residuals for the 23 highest quality observations are equal to 48.5 and 21.7 mas in right ascension and declination, respectively, we obtain 16.4 and 20.7 mas with the new theory by Lainey and collaborators and 17.3 and 21.6 mas with JPL SAT351 ephemerides. Topocentric or heliocentric angular differences for satellites pairs are obtained for 16 time instants during the time period from December 19, 2008 to July 16, 2009. Light curves are available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/544/A29

  16. Spinning particles in Saturn's C ring from mid-infrared observations: Pre-Cassini mission results

    NASA Astrophysics Data System (ADS)

    Leyrat, Cédric; Ferrari, Cécile; Charnoz, Sébastien; Decriem, Judicael; Spilker, Linda J.; Pilorz, Stuart

    2008-08-01

    Saturn's C ring thermal emission has been observed in mid-infrared wavelengths, at three different epochs and solar phase angles, using ground based instruments (CFHT in 1999 and VLT/ESO in 2005) and the Infrared Radiometer Instrument Spectrometer (IRIS) onboard the Voyager 1 spacecraft in 1980. Azimuthal variations of temperature in the C ring's inner region, observed at several phase angles, have been analyzed using our new standard thermal model [Ferrari, C., Leyrat, C., 2006. Astron. Astrophys. 447, 745-760]. This model provides predicted ring temperatures for a monolayer ring composed of spinning icy spherical particles. We confirm the very low thermal inertia (on the order of 10 JmKs) found previously by Ferrari et al. [Ferrari, C., Galdemard, P., Lagage, P.O., Pantin E., Quoirin, C., 2005. Astron. Astrophys. 441, 379-389] that reveals the very porous regolith at the surface of ring particles. We are able to explain both azimuthal variations of temperature and the strong asymmetry of the emission function between low and high phase angles. We show that large particles spinning almost synchronously might be present in the C ring to explain differences of temperature observed between low and high phase angle. Their cross section might represent about 45% of the total cross section. However, their numerical fraction is estimated to only ˜0.1% of all particles. Thermal behavior of other particles can be modeled as isothermal behavior. This work provides an indirect estimation of the particle's rotation rate in Saturn's rings from observations.

  17. Results of Space Debris Survey Observations on Highly-Eccentric MEO Orbits

    NASA Astrophysics Data System (ADS)

    Hinze, Andreas; Schildknecht, T.; Flohrer, T.; Krag, H.

    2013-08-01

    Optical surveys for space debris in high-altitude orbits have been conducted since more than ten years. First observation strategies and processing techniques were successfully developed for the geostationary ring (GEO). The observations scenarios were adjusted for observations in the geostationary transfer orbit (GTO) and in the medium Earth orbit (MEO). After the already investigated circular MEO orbits of the GPS and GLONASS constellations the Astronomical Institute of the University of Bern (AIUB) developed survey and follow-up strategies for the systematically search of space debris in highly-eccentric orbits in the MEO region, in particular in Molniya-type orbits. Several breakup events and deliberate fragmentations are known to have taken place in such orbits. The AIUB performed several survey campaigns between January 2013 and April 2013 to search for debris objects in this MEO region. The optical observations were conducted in the framework of an ESA study using ESA's Space Debris Telescope (ESASDT) the 1-m Zeiss telescope located at the Optical Ground Station (OGS) at the Teide Observatory at Tenerife, Spain. The results from the different observation campaigns will be presented.

  18. Transgene silencing of the Hutchinson-Gilford progeria syndrome mutation results in a reversible bone phenotype, whereas resveratrol treatment does not show overall beneficial effects.

    PubMed

    Strandgren, Charlotte; Nasser, Hasina Abdul; McKenna, Tomás; Koskela, Antti; Tuukkanen, Juha; Ohlsson, Claes; Rozell, Björn; Eriksson, Maria

    2015-08-01

    Hutchinson-Gilford progeria syndrome (HGPS) is a rare premature aging disorder that is most commonly caused by a de novo point mutation in exon 11 of the LMNA gene, c.1824C>T, which results in an increased production of a truncated form of lamin A known as progerin. In this study, we used a mouse model to study the possibility of recovering from HGPS bone disease upon silencing of the HGPS mutation, and the potential benefits from treatment with resveratrol. We show that complete silencing of the transgenic expression of progerin normalized bone morphology and mineralization already after 7 weeks. The improvements included lower frequencies of rib fractures and callus formation, an increased number of osteocytes in remodeled bone, and normalized dentinogenesis. The beneficial effects from resveratrol treatment were less significant and to a large extent similar to mice treated with sucrose alone. However, the reversal of the dental phenotype of overgrown and laterally displaced lower incisors in HGPS mice could be attributed to resveratrol. Our results indicate that the HGPS bone defects were reversible upon suppressed transgenic expression and suggest that treatments targeting aberrant progerin splicing give hope to patients who are affected by HGPS. PMID:25877214

  19. Magnetic Sphincter Augmentation for Gastroesophageal Reflux at 5 Years: Final Results of a Pilot Study Show Long-Term Acid Reduction and Symptom Improvement

    PubMed Central

    Saino, Greta; Bonavina, Luigi; Lipham, John C.; Dunn, Daniel

    2015-01-01

    Abstract Background: As previously reported, the magnetic sphincter augmentation device (MSAD) preserves gastric anatomy and results in less severe side effects than traditional antireflux surgery. The final 5-year results of a pilot study are reported here. Patients and Methods: A prospective, multicenter study evaluated safety and efficacy of the MSAD for 5 years. Prior to MSAD placement, patients had abnormal esophageal acid and symptoms poorly controlled by proton pump inhibitors (PPIs). Patients served as their own control, which allowed comparison between baseline and postoperative measurements to determine individual treatment effect. At 5 years, gastroesophageal reflux disease (GERD)-Health Related Quality of Life (HRQL) questionnaire score, esophageal pH, PPI use, and complications were evaluated. Results: Between February 2007 and October 2008, 44 patients (26 males) had an MSAD implanted by laparoscopy, and 33 patients were followed up at 5 years. Mean total percentage of time with pH <4 was 11.9% at baseline and 4.6% at 5 years (P < .001), with 85% of patients achieving pH normalization or at least a 50% reduction. Mean total GERD-HRQL score improved significantly from 25.7 to 2.9 (P < .001) when comparing baseline and 5 years, and 93.9% of patients had at least a 50% reduction in total score compared with baseline. Complete discontinuation of PPIs was achieved by 87.8% of patients. No complications occurred in the long term, including no device erosions or migrations at any point. Conclusions: Based on long-term reduction in esophageal acid, symptom improvement, and no late complications, this study shows the relative safety and efficacy of magnetic sphincter augmentation for GERD. PMID:26437027

  20. MAX-DOAS observations of trace gases over Mainz: preliminary results

    NASA Astrophysics Data System (ADS)

    Alberti, Carlos; Gu, Myojeong; Remmers, Julia; Wagner, Thomas

    2014-05-01

    In this work we report on levels of trace gases in ambient atmosphere in Mainz, Germany. We measured the differential Slant Column Density (dSCD) of NO2, HCHO and O4 in the ultraviolet region of the electromagnetic spectrum using a Mini-MAX-DOAS instrument. The MAX-DOAS observations were taken at Max Planck Institute for Chemistry in Mainz, from January to March 2014, at different elevation angles. The main aim of the study is to compare the results of the Mini-MAX-DOAS instrument with those from a 'scientific' MAX-DOAS instrument operated simultaneously at the same location. We quantify systematic differences and random and errors of both data sets for different measurement conditions. The preliminary results of this MAX DOAS observations and the diurnal variation of the retrieved trace gas DSCDs will be discussed in this work.

  1. NEOWISE: Recent Results and Observations of Tiny Near-Earth Objects

    NASA Astrophysics Data System (ADS)

    Mainzer, Amanda K.; Bauer, J.; Grav, T.; Masiero, J.; Nugent, C.; Cutri, R.; Wright, E. L.; NEOWISE Team

    2013-10-01

    The minor planet-hunting portion of the Wide-field Infrared Survey Explorer mission (Wright et al. 2010), known as NEOWISE, has resulted in the creation of an archive of single exposure images and extracted sources collected by this infrared all-sky survey (Mainzer et al. 2011). All data products have now been publicly released through NASA's Infrared Science Archive (Cutri et al. 2012). Along with the single exposure images and source databases, the NEOWISE project supported the development of tools for solar system-friendly queries of the data. We have used these tools to extract mid-infrared observations of near-Earth objects that make extremely close approaches to the Earth. Using these observations, we have computed physical properties for these objects. An overview of these derived properties as well as other recent results and status from the project will be presented.

  2. Recent results of X-ray observations from OSO-7 and SAS-3

    NASA Technical Reports Server (NTRS)

    Clark, G. W.

    1978-01-01

    Recent observations bearing on the nature of compact X-ray sources obtained from the MIT instruments aboard OSO-7 and SAS-3 are discussed. Results on the X-ray sky survey, new ultralow-energy X-ray sources, X-ray sources in globular clusters, slow X-ray pulsars, and variability and position of compact X-ray sources in Cen A are discussed. Descriptions of the satellite-borne X-ray instruments are provided.

  3. Results of observations of the Eta Aquarid and Orionid meteor showers in 1980-1984

    NASA Technical Reports Server (NTRS)

    Hajduk, A.

    1987-01-01

    The main characteristics of meteor showers associated with Comet Halley were derived from the most recent radar observations carried out at the Ondrejov Astronomical Observatory during the periods of May 1 to 10 and October 15 to 30. The activity variations, the positions of activity maxima, the size distribution of particles, the particle flux variation within the stream and other characteristics were determined and compared with other results.

  4. Test-observation well near Odessa, Washington: description and preliminary results

    USGS Publications Warehouse

    Walters, Kenneth L.; Cline, D.R.; Luzier, J.E.

    1972-01-01

    The test-observation well drilled near Odessa, Wash., provides information on the area's aquifer characteristics which is not otherwise available from existing deep irrigation wells. The information is of value to the State of Washington Department of Ecology in its management decisions in this area where heavy ground-water withdrawals have resulted in increasing annual water-level declines. The 10-inch well is 750 feet deep and penetrates six aquifer zones (A through F) in basalt. The upper 60 feet of the well is cased while the remainder of the hole is open in the basalt. The well was test pumped during drilling and showed specific capacities of (1) 0.65 gpm (gallon per minute) per foot of drawdown when at the 258-foot depth and open to aquifers A and B. (2) 0.62 gpm per foot of drawdown when at the 540-foot depth and open to aquifers A through D, and (3) 22 gpm foot of drawdown when at full 750-foot depth and open to all six aquifers. To supplement the driller's log of the well, borehole geophysical logging provided information on natural gamma radiation, water temperature and resistivity, downhole movement (via flowmeter) of the water, and borehole diameter (via caliper log). Upon completion of the well each aquifer zone was isolated from the others by cement seals, and piezometer pipes were installed to each zone to allow definition of the vertical hydraulic gradient and an estimate of the vertical ground-water movement in the area, along with chemical-quality sampling of the various zones and monitoring of any changes in water quality with time. The initial measurements of water levels showed that the levels generally decrease with aquifer depth, with about 200 feet of head difference existing between the uppermost and lowermost aquifer zones. Another pipe, installed for providing thermometer access, permits recording the geothermal gradient with depth in the well, and provides another basis for estimating vertical ground-water movement in the area. Prior to

  5. Observed galaxy number counts on the lightcone up to second order: I. Main result

    SciTech Connect

    Bertacca, Daniele; Maartens, Roy; Clarkson, Chris E-mail: roy.maartens@gmail.com

    2014-09-01

    We present the galaxy number overdensity up to second order in redshift space on cosmological scales for a concordance model. The result contains all general relativistic effects up to second order that arise from observing on the past light cone, including all redshift effects, lensing distortions from convergence and shear, and contributions from velocities, Sachs-Wolfe, integrated SW and time-delay terms. This result will be important for accurate calculation of the bias on estimates of non-Gaussianity and on precision parameter estimates, introduced by nonlinear projection effects.

  6. Third-Year Results from the Circumarctic Lakes Observation Network (CALON) Project

    NASA Astrophysics Data System (ADS)

    Hinkel, K. M.; Arp, C. D.; Beck, R. A.; Eisner, W. R.; Frey, K. E.; Grosse, G.; Jones, B. M.; Kim, C.; Lenters, J. D.; Liu, H.; Townsend-Small, A.

    2014-12-01

    Since 2012, 60 lakes in northern Alaska have been instrumented under the auspices of CALON, a project designed to document landscape-scale variability in physical and biogeochemical processes of Arctic lakes in permafrost terrain. The network has ten observation nodes along two latitudinal transects extending from the Arctic Ocean inland some 200 km to the Brooks Range foothills. At each node, a meteorological station is deployed, and six representative lakes of differing area and depth are instrumented and sampled at different intensity levels to collect basic field measurements. In April, sensors measuring water temperature and depth are deployed through the ice in each lake, ice and snow thickness recorded, and water samples are collected. Data are downloaded, lakes re-sampled, and bathymetric surveys are conducted in August. In 2014, the snow cover on inland lakes was thinner than in previous years but thicker on lakes located near the coast. Lake ice was generally thinner near the coast, but the difference diminished inland. Winters (Oct-March) have been progressively warmer over the 3-year period, which partially explains the thinner lake ice that formed in 2013-14. Lakes are typically well-mixed and largely isothermal, with minor thermal stratification occurring in deeper lakes during calm, sunny periods. These regional lake and meteorological data sets, used in conjunction with satellite imagery, supports the wind-driven lake circulation model for the origin of thermokarst lakes. Results of biogeochemical analyses of lake waters generally show notably higher concentrations of cations/anions, chromophoric dissolved organic matter, and chlorophyll-a during April as compared with August. Dissolved methane concentrations are also much higher under ice than in open water during summer, although all lakes are a source of atmospheric methane. Interviews with indigenous elders in Anaktuvuk Pass indicate that mountain lakes are drying up. During the 2014 breakup

  7. Interannual sedimentary effluxes of alkalinity in the southern North Sea: Model results compared with summer observations.

    NASA Astrophysics Data System (ADS)

    Paetsch, Johannes; Kuehn, Wilfried; Six, Katharina

    2016-04-01

    Alkalinity generation in the sediment of the southern North Sea is the focus of several recent studies. One motivation for these efforts is the potentially enhanced buffering capacity of anthropogenic CO2 invasion into the corresponding pelagic system. An adaptation of a global multilayer sediment model (Heinze et al., 1999) in combination with a pelagic ecosystem model for shelf sea dynamics was used to study the benthic reactions on very different annual cycles (2001 - 2009) including the River Elbe summer flooding in 2002. The focus of this study is the efflux of alkalinity, their different contributors (aerobic respiration, denitrification, net sulfate reduction, calcite dissolution, nitrification) and their seasonal and interannual cycles. Similar to the observations covering the southern North Sea (Brenner et al., 2015) the model results show large horizontal gradients from the near-shore high productive areas with benthic remineralization up to Rmin = 10.6 mol C m‑2 yr‑1 and TA generation RTA = 2 mol C m‑2 yr‑1 to off-shore moderate productive areas with mean Rmin = 2.5 mol C m‑2 yr‑1 and mean TA generation RTA = 0.4 mol C m‑2 yr‑1. Beside calcite dissolution, aerobic respiration (producing ammonium) and denitrification are the largest contributors to alkalinity generation. Nitrification is reducing alkalinity in the sediment. Due to low regenerated primary production in summer, the year 2001 exhibits the lowest input of particulate organic matter into the sediment (POCexp=2.3 mol C m‑2 yr‑1), while the year 2003 exhibits the highest export production (POCexp=2.6 mol C m‑2 yr‑1). The biogeochemical reactions and the effluxes from the sediment follow these pelagic amplitudes with a time lag of about one year with damped amplitudes. References Brenner, H., Braeckman, U., Le Guitton, M., Meysman, F.J.R., 2015. The impact of sedimentary alkalinity release on the water column CO2 system in the North Sea. Biogeosiences Discussion, 12

  8. Early results on 67P/Churyumov-Gerasimenko observed by Rosetta/OSIRIS

    NASA Astrophysics Data System (ADS)

    Sierks, H.; Tubiana, C.; Snodgrass, C.; Agarwal, J.; Güttler, C.; Oklay, N.; Vincent, J.; Küppers, M.; Barbieri, C.; Lamy, P.; Rickman, H.; Rodrigo, R.; Koschny, D.; Hviid, S.; Mottola, S.; Osiris Team

    2014-07-01

    67P/Churyumov-Gerasimenko (67P) is the target comet of the ESA Rosetta mission. Launched in 2004, the Rosetta spacecraft woke up on the 20th of January 2014. After 36 months of deep space hibernation, Rosetta is now traveling to rendezvous with the comet at 4.1 au from the Sun, and it will follow 67P along its orbit, investigating how the comet changes and evolves while approaching the Sun. The Optical, Spectroscopic, and Infrared Remote Imaging System OSIRIS (Keller et al., 2007) is the scientific imaging system onboard Rosetta. It comprises the Narrow Angle Camera (NAC) with wavelength range 250--1000 nm and the Wide Angle Camera (WAC) with wavelength range 240--720 nm. The NAC (FOV = 2.20×2.22 deg) is a system with high spatial resolution that allows an initial detection of the nucleus, studies its structure and rotation from relatively great distances, investigates the mineralogy of the surface, and studies the dust ejection processes. The WAC has much lower spatial resolution but, accordingly, a much wider field of view (about 11.35×12.11 deg). This allows observations of the 3-dimensional flow field of dust and gas near the nucleus and, in addition, provides a synoptic view of the whole nucleus. In summary, the WAC would provide long-term monitoring of the entire nucleus from close distances, while the NAC studies the details. The two camera units have been designed as a complementary pair, which, on one hand, addresses the study of the nucleus surface, and on the other hand, investigates the dynamics of the sublimation process. After commissioning in March 2014, OSIRIS took first images of comet 67P and its dust environment. Ground-based observations performed in 2007/08 when 67P was in the same orbital arc as it will be in March/April 2014, show that the comet was already active at 4.3 au inbound and that its behavior was repetitive during the last three apparitions (Snodgrass et al. 2013). We therefore expect to detect early comet activity by OSIRIS in

  9. Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Data Processing, Sky Maps, and Basic Results

    NASA Technical Reports Server (NTRS)

    Weiland, J.L.; Hill, R.S.; Odegard, 3.; Larson, D.; Bennett, C.L.; Dunkley, J.; Jarosik, N.; Page, L.; Spergel, D.N.; Halpern, M.; Meyer, S.S.; Tucker, G.S.; Wright, E.L.

    2008-01-01

    The Wilkinson Microwave Anisotropy Probe (WMAP) is a Medium-Class Explorer (MIDEX) satellite aimed at elucidating cosmology through full-sky observations of the cosmic microwave background (CMB). The WMAP full-sky maps of the temperature and polarization anisotropy in five frequency bands provide our most accurate view to date of conditions in the early universe. The multi-frequency data facilitate the separation of the CMB signal from foreground emission arising both from our Galaxy and from extragalactic sources. The CMB angular power spectrum derived from these maps exhibits a highly coherent acoustic peak structure which makes it possible to extract a wealth of information about the composition and history of the universe. as well as the processes that seeded the fluctuations. WMAP data have played a key role in establishing ACDM as the new standard model of cosmology (Bennett et al. 2003: Spergel et al. 2003; Hinshaw et al. 2007: Spergel et al. 2007): a flat universe dominated by dark energy, supplemented by dark matter and atoms with density fluctuations seeded by a Gaussian, adiabatic, nearly scale invariant process. The basic properties of this universe are determined by five numbers: the density of matter, the density of atoms. the age of the universe (or equivalently, the Hubble constant today), the amplitude of the initial fluctuations, and their scale dependence. By accurately measuring the first few peaks in the angular power spectrum, WMAP data have enabled the following accomplishments: Showing the dark matter must be non-baryonic and interact only weakly with atoms and radiation. The WMAP measurement of the dark matter density puts important constraints on supersymmetric dark matter models and on the properties of other dark matter candidates. With five years of data and a better determination of our beam response, this measurement has been significantly improved. Precise determination of the density of atoms in the universe. The agreement between

  10. Results of a Deep Chandra Observation of the Crab Nebula and Pulsar

    NASA Technical Reports Server (NTRS)

    Weisskopf, M. C.; Becker, W.; Elsner, R.; Kahn, S.; Kolodziejczak, J.; Murray, S.; ODell, S.; Paerels, F.; Shibazaki, N.; Swartz, D.

    2000-01-01

    The Crab Nebula and pulsar were observed for a total of 150 ksec with the LETG/HRC-S combination aboard the Chandra X-Ray Observatory in 2000, January. One of the principal aims of the experiment was to study the emission of from the pulsar as a function of pulse phase. Neutron stars are believed to be formed with core temperatures of T(sub c) approx. 10(sup 11) K. As the pulsar is the youngest known neutron star with an age of only 940 yrs, it should be possible to observe thermal emission from the hot stellar surface which in turn constrains equations of state. The pulsar, on the other hand, is a powerful non-thermal emitter, powering an X-ray bright synchrotron nebula which, in Einstein and ROSAT observations, overshadowed the fainter thermal surface emission. Making use of the high angular resolution provided by Chandra we were able to detect X-rays from the Crab-pulsar at all pulse phases. We discuss whether this detection is indeed of thermal emission or of a faint synchrotron component of the pulsed emission from the magnetosphere. We further report on dynamical effects observed in the pulsar-wind outflow and the analysis of the LETG spectral data, especially near the oxygen edge. The results of the spectral analysis has interesting implications for the composition of the interstellar medium.(c) 2000.: American Astronomical Society. All rights reserved

  11. Results of a Deep Chandra Observation of the Crab Nebula and Pulsar

    NASA Technical Reports Server (NTRS)

    Weisskopf, M. C.; Becker, W.; Elsner, R.; Kahn, S.; Kolodziejczak, J.; Murray, S.; ODell, S.; Paerels, F.; Shibazaki, N.; Swartz, D.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    The Crab Nebula and pulsar were observed for a total of 150 ksec with the LETG/HRC-S combination aboard the Chandra X-Ray Observatory in 2000, January. One of the principal aims of the experiment was to study the emission of from the pulsar as a function of pulse phase. Neutron stars are believed to be formed with core temperatures of 10(exp 11). As the pulsar is the youngest known neutron star with an age of only 940 yrs, it should be possible to observe thermal emission from the hot stellar surface which in turn constrains equations of state. The pulsar, on the other hand, is a powerful non-thermal emitter, powering an X-ray bright synchrotron nebula which, in Einstein and ROSAT observations, overshadowed the fainter thermal surface emission. Making use of the high angular resolution provided by Chandra we were able to detect X-rays from the Crab-pulsar at all pulse phases. We discuss whether this detection is indeed of thermal emission or of a faint synchrotron component of the pulsed emission from the magnetosphere. We further report on dynamical effects observed in the pulsar-wind outflow and the analysis of the LETG spectral data, especially near the oxygen edge. The results of the spectral analysis has interesting implications for the composition of the interstellar medium.

  12. Magnetic reconnection signatures in the solar atmosphere: results from multi-wavelength observations

    NASA Astrophysics Data System (ADS)

    Zuccarello, F.; Guglielmino, S. L.; Romano, P.

    In the solar atmosphere magnetic reconnection is invoked as the main mechanism causing very energetic events (1028 - 1032 erg), like flares and coronal mass ejections, as well as other less energetic phenomena, like microflares, X-ray jets and chromospheric surges. In the last decade, thanks to high spatial resolution, multi-wavelength observations carried out by both ground-based telescopes (THEMIS, SST, VTT, DST) and space-born satellites (SOHO, TRACE, RHESSI, HINODE), it has been possible to study these phenomena and several signatures of the occurrence of magnetic reconnection have been singled out. In this paper, we describe some results obtained from the analysis of multi-wavelength observations carried out in the last years, with special emphasis on those events that were characterized by plasma outflows from the reconnection site. The events here discussed are relevant to some active regions observed on the Sun, characterized by the interaction of different bundles of magnetic flux tubes, as a consequence of phenomena of emergence of new magnetic flux from the subphotospheric layers and/or of cancellation of magnetic fragments. We report on these phenomena in order to give a contribution to the possibility to find a similarity with jets observed in AGNs.

  13. Mineral and nitrogen balance study - Results of metabolic observations on Skylab II 28-day orbital mission

    NASA Technical Reports Server (NTRS)

    Whedon, G. D.; Lutwak, L.; Reid, J.; Rambaut, P.; Whittle, M.; Smith, M.; Leach, C.

    1975-01-01

    The prediction that various stresses of flight, particularly weightlessness, would bring about significant derangements in the metabolism of the musculoskeletal system has been based on various balance-study observations of long-term immobilized or inactive bed rest. The three astronauts of Skylab II consumed a planned dietary intake of major metabolic elements in mixed foods and beverages and provided virtually complete collections of excreta for 31 days preflight, 28 days inflight, and 17 days postflight. Analyses showed that, in varying degree among the crewmen, urinary calcium increased gradually during flight in a pattern similar to that observed in bed-rest studies. Fecal calcium excretion did not change significantly, but calcium balance, owing to the urinary calcium rise, became either negative or less positive than in preflight measurement. Increased excretion and negative nitrogen and phosphorus balances inflight indicated appreciable loss of muscle tissue in all three crewmen. Significant losses also occurred inflight in potassium, sodium, and magnesium. Based on the similarity in pattern and degree between these observations of calcium, phosphorus, and nitrogen loss, musculoskeletal integrity would not be threatened in space flights of up to at least 3 months. However, if similar changes occur in the planed Skylab flights for considerably more than 28 days, concern for capable musculoskeletal function should be serious for flights of very many months' duration.

  14. Hubble Tarantula Treasury Project: Unraveling Tarantula's Web. I. Observational Overview and First Results

    NASA Astrophysics Data System (ADS)

    Sabbi, E.; Anderson, J.; Lennon, D. J.; van der Marel, R. P.; Aloisi, A.; Boyer, M. L.; Cignoni, M.; de Marchi, G.; de Mink, S. E.; Evans, C. J.; Gallagher, J. S., III; Gordon, K.; Gouliermis, D. A.; Grebel, E. K.; Koekemoer, A. M.; Larsen, S. S.; Panagia, N.; Ryon, J. E.; Smith, L. J.; Tosi, M.; Zaritsky, D.

    2013-09-01

    The Hubble Tarantula Treasury Project (HTTP) is an ongoing panchromatic imaging survey of stellar populations in the Tarantula Nebula in the Large Magellanic Cloud that reaches into the sub-solar mass regime (<0.5 M ⊙). HTTP utilizes the capability of the Hubble Space Telescope to operate the Advanced Camera for Surveys and the Wide Field Camera 3 in parallel to study this remarkable region in the near-ultraviolet, optical, and near-infrared spectral regions, including narrow-band Hα images. The combination of all these bands provides a unique multi-band view. The resulting maps of the stellar content of the Tarantula Nebula within its main body provide the basis for investigations of star formation in an environment resembling the extreme conditions found in starburst galaxies and in the early universe. Access to detailed properties of individual stars allows us to begin to reconstruct the temporal and spatial evolution of the stellar skeleton of the Tarantula Nebula over space and time on a sub-parsec scale. In this first paper we describe the observing strategy, the photometric techniques, and the upcoming data products from this survey and present preliminary results obtained from the analysis of the initial set of near-infrared observations. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA Inc., under NASA contract NAS 5-26555.

  15. Anomalous results observed in magnetization of bulk high temperature superconductors—A windfall for applications

    NASA Astrophysics Data System (ADS)

    Weinstein, Roy; Parks, Drew; Sawh, Ravi-Persad; Carpenter, Keith; Davey, Kent

    2016-04-01

    Recent experiments on pulsed-zero field cool magnetization of bulk high Jc YBCO (YBa2Cu3O7-δ) have shown unexpected results. For example, reproducible, non-destructive, rapid, giant field leaps (GFLs) to higher penetrated field are observed. The observations are inconsistent with the critical state model (CSM), in several aspects. Additional experiments have been pursued in an attempt to clarify the physics involved in the observed anomalies. Here, we present experimental results for the Jc dependence of the anomalous features. It is found that the sudden field increase in the GFL is a monotonically increasing function of Jc. The ratio of required pulsed field amplitude, BA,max, to obtain maximum trappable field, BT,max, which CSM predicts to be ≥2.0, gradually approaches 1.0 at high Jc. Tests using values of pulsed, applied field BA,max just below the GFL exhibit two additional anomalies: (i) At high Jc, the highest trapped field is up to ˜6 times lower than predicted by CSM, and (ii) the measured Lorentz force as a function of Jc deviates sharply from CSM predictions. The data rule out heating effects and pinning center geometry as possible physical causes of these anomalies. A speculative cause is considered.

  16. Optical spectroscopic observations of γ-ray blazar candidates. I. Preliminary results

    SciTech Connect

    Paggi, A.; Milisavljevic, D.; D'Abrusco, R.; Smith, H. A.; Margutti, R.; Martínez-Galarza, J. R.; Landoni, M.; Grindlay, J. E.; Masetti, N.; Giroletti, M.; Jiménez-Bailón, E.; Otí-Floranes, H.; Chavushyan, V.; Massaro, F.; Funk, S.; Tosti, G.

    2014-05-01

    A significant fraction (∼30%) of the γ-ray sources listed in the second Fermi/LAT (2FGL) catalog is still of unknown origin, being not yet associated with counterparts at lower energies. Using the available information at lower energies and optical spectroscopy on the selected counterparts of these γ-ray objects, we can pinpoint their exact nature. Here, we present a pilot project pointing to assess the effectiveness of the several classification methods developed to select γ-ray blazar candidates. To this end, we report optical spectroscopic observations of a sample of five γ-ray blazar candidates selected on the basis of their infrared Wide-field Infrared Survey Explorer (WISE) colors or of their low-frequency radio properties. Blazars come in two main classes, BL Lac objects and FSRQs, showing similar optical spectra except for the stronger emission lines of the latter. For three of our sources, the almost featureless optical spectra obtained confirm their BL Lac nature, while for the source WISEJ022051.24+250927.6 we observe emission lines with equivalent width EW ∼ 31 Å, identifying it as a FSRQ with z = 0.48. The source WISEJ064459.38+603131.7, although not featuring a clear radio counterpart, shows a blazar-like spectrum with weak emission lines with EW ∼ 7 Å, yielding a redshift estimate of z = 0.36. In addition, we report optical spectroscopic observations of four WISE sources associated with known γ-ray blazars without a firm classification or redshift estimate. For the latter sources, we confirm a BL Lac classification, with a tentative redshift estimate for the source WISEJ100800.81+062121.2 of z = 0.65.

  17. A three-dimensional variational data assimilation system for the South China Sea: preliminary results from observing system simulation experiments

    NASA Astrophysics Data System (ADS)

    Peng, Shiqiu; Zeng, Xuezhi; Li, Zhijin

    2016-03-01

    A three-dimensional variational data assimilation (3DVAR) system based on the Regional Ocean Modeling System (ROMS) is established for the South China Sea (SCS). A set of Observing System Simulation Experiments (OSSEs) are performed to evaluate the performance of this data assimilation system and investigate the impacts of different types of observations on representation of three-dimensional large-scale circulations and meso-scale eddies in the SCS. The pseudo-observations that are examined include sea surface temperatures (SSTs), sea surface heights (SSHs), sparse temperature/salinity (T/S) profiles, sea surface velocities (SSVs), and sea surface salinities (SSSs). The results show that SSHs can extend their impacts into the subsurface or even the deep ocean while other surface observations only have impacts within surface mixed layer. SSVs have similar impacts though confined to their spatial coverage, suggesting that SSVs could be a substitute of SSHs nearshore where SSHs are of poor quality. Despite their sparseness, the T/S profiles improve the representation of the temperature and salinity structures below the mixed layer, and a combination of T/S profiles with surface observations leads to a better representation of the meso-scale eddies. Based on the OSSE results, an affordable observing network for the SCS in the near future is proposed.

  18. A three-dimensional variational data assimilation system for the South China Sea: preliminary results from observing system simulation experiments

    NASA Astrophysics Data System (ADS)

    Peng, Shiqiu; Zeng, Xuezhi; Li, Zhijin

    2016-05-01

    A three-dimensional variational data assimilation (3DVAR) system based on the Regional Ocean Modeling System (ROMS) is established for the South China Sea (SCS). A set of Observing System Simulation Experiments (OSSEs) are performed to evaluate the performance of this data assimilation system and investigate the impacts of different types of observations on representation of three-dimensional large-scale circulations and meso-scale eddies in the SCS. The pseudo-observations that are examined include sea surface temperatures (SSTs), sea surface heights (SSHs), sparse temperature/salinity (T/S) profiles, sea surface velocities (SSVs), and sea surface salinities (SSSs). The results show that SSHs can extend their impacts into the subsurface or even the deep ocean while other surface observations only have impacts within surface mixed layer. SSVs have similar impacts though confined to their spatial coverage, suggesting that SSVs could be a substitute of SSHs nearshore where SSHs are of poor quality. Despite their sparseness, the T/S profiles improve the representation of the temperature and salinity structures below the mixed layer, and a combination of T/S profiles with surface observations leads to a better representation of the meso-scale eddies. Based on the OSSE results, an affordable observing network for the SCS in the near future is proposed.

  19. Lung cancer detection with digital chest tomosynthesis: first round results from the SOS observational study

    PubMed Central

    Viti, Andrea; Tavella, Chiara; Priotto, Roberto; Ghirardo, Donatella; Grosso, Maurizio; Terzi, Alberto

    2015-01-01

    Objective Baseline results of the Studio OSservazionale (SOS), observational study, a single-arm observational study of digital chest tomosynthesis for lung cancer detection in an at-risk population demonstrated a detection rate of lung cancer comparable to that of studies that used low dose CT scan (LDCT). We present the results of the first round. Methods Totally 1,703 out of 1,843 (92%) subjects who had a baseline digital chest tomosynthesis underwent a first round reevaluation after 1 year. Results At first round chest digital tomosynthesis, 13 (0.7%) subjects had an indeterminate nodule larger than 5 mm and underwent low-dose CT scan for nodule confirmation. PET/CT study was obtained in 10 (0.5%) subjects and 2 subjects had a low-dose CT follow up. Surgery, either video-assisted thoracoscopic or open surgery for indeterminate pulmonary nodules was performed in 10 (0.2%) subjects. A lung cancer was diagnosed and resected in five patients. The lung cancer detection rate at first round was 0.3% (5/1,703). Conclusions The detection rate of lung cancer at first round for tomosynthesis is comparable to rates reported for CT. In addition, results of first round digital chest tomosynthesis confirm chest tomosynthesis as a possible first-line lung cancer-screening tool. PMID:25992366

  20. Second-Year Results from the Circumarctic Lakes Observation Network (CALON) Project

    NASA Astrophysics Data System (ADS)

    Hinkel, K. M.; Arp, C. D.; Beck, R. A.; Eisner, W. R.; Frey, K. E.; Gaglioti, B.; Grosse, G.; Jones, B. M.; Kim, C.; Lenters, J. D.; Liu, H.; Townsend-Small, A.

    2013-12-01

    Beginning in April 2012, over 55 lakes in northern Alaska were instrumented as the initial phase of CALON, a project designed to document landscape-scale variability in physical and biogeochemical processes of Arctic lakes developed atop permafrost. The current network has nine observation nodes along two latitudinal transects that extend from the Arctic Ocean south 200 km to the foothills of the Brooks Range. At each node, six representative lakes of differing area and depth were instrumented at different intensity levels, and a suite of instruments were deployed to collect field measurements on lake physiochemistry, lake-surface and terrestrial climatology, and lake bed and permafrost temperature. Each April, sensors measuring water temperature and water depth are deployed through the ice and water samples are collected. Sensors are downloaded from lakes and meteorological stations in August, recording a timeline of lake regimes and events from ice decay to the summertime energy and water balance. In general, lake ice thickness increased with latitude. In 2012, ice on deeper (>2 m) lakes was about 1.4 m thick in the Arctic Foothills and 1.7 m thick near the Arctic Ocean coast. Lake ice thickness was about 20 cm thicker in winter 2013 although winter temperatures were several degrees warmer than the previous year; this is likely due to a thinner snow cover in 2013. Lake ice elevations agree with this general trend, showing higher absolute elevation in April 2013 compared to 2012 for most of the surveyed lakes. Regionally, ice-off occurs 2-4 weeks later on lakes near the coast, although there is significant inter-lake variability related to lake depth. Following ice-off, rapid lake warming occurs and water temperature varies synchronously in response to synoptic weather variations and associated changes in net radiation and turbulent heat fluxes. Average mid-summer (July) lake temperatures spanned a relatively wide range in 2012 from 7°C to 18°C, with higher

  1. The evolution of nonlinear internal waves in Massachusetts Bay: observations and model results.

    NASA Astrophysics Data System (ADS)

    Scotti, A. D.

    2004-05-01

    Nonlinear internal waves are a common feature in many coastal areas. In Massachusetts Bay, trains of high-frequency and short-wavelength internal waves are generated by the semidiurnal barotropic tide flowing over Stellwagen Bank, and propagate shoreward. In this talk, we present observational and modeling results that have been accumulated over the past 6 years. We will consider in particular the strongly nonlinear interaction with the bottom that occurs when the waves propagate along the incline leading to the shallow (25 m) area just off the coast south of Boston. Contrary to what was previously thought, only part of the baroclinic energy is dissipated locally. The remaining energy propagates in the shallow area to the west of the incline, creating highly nonlinear and very steep waves of elevation that we were able to observe in great detail. The evidence accumulated so far suggest that these waves depart strongly from the hydrostatic equilibrium. The consequences for modeling will be discussed.

  2. Hi-C Observations of Penumbral Bright Dots: Comparison with the IRIS Results

    NASA Technical Reports Server (NTRS)

    Alpert, S. E.; Tiwari, S. K.; Moore, R. L.; Savage, S. L.; Winebarger, A. R.

    2014-01-01

    We observed bright dots (BDs) in a sunspot penumbra by using data acquired by the High Resolution Coronal Imager (Hi-C). The sizes of these BDs are on the order of 1 arcsecond (1') and are therefore hard to identify using the Atmospheric Imaging Assembly's (AIA) 0.6' pixel -1 resolution. These BDs become readily apparent with Hi-C's 0.1' pixel -1 resolution. Tian et al. (2014) found penumbral BDs in the transition region (TR) by using the Interface Region Imaging Spectrograph (IRIS). However, only a few of their dots could be associated with any enhanced brightness in AIA channels. In this work, we examine the characteristics of the penumbral BDs observed by Hi-C in a sunspot penumbra, including their sizes, lifetimes, speeds, and intensity. We also attempt to relate these BDs to the IRIS BDs. There are fewer Hi-C BDs in the penumbra than seen by IRIS, though different sunspots were studied and Hi-C had a short observation time. We use 193 A Hi-C data from July 11, 2012 which observed from 18:52:00 UT{18:56:00 UT and supplement it with data from AIA's 193 A passband to see the complete lifetime of the dots that were born before and/or lasted longer than Hi-C's 5-minute observation period. We use additional AIA passbands and compare the light curves of the BDs at different temperatures to test whether the Hi-C BDs are TR BDs. We find that most Hi-C BDs show clear movement, and of those that do, they move in a radial direction, toward or away from the sunspot umbra, sometimes doing both. BDs interact with other BDs, combining to fade away or brighten. The BDs that do not interact with other BDs tend to move less and last longer. We examine the properties of the Hi-C BDs and compare them with the IRIS BDs. Our BDs are similar to the exceptional values of the IRIS BDs: they move slower on average and their sizes and lifetimes are on the higher end of the distributions of IRIS BDs. We infer that our penumbral BDs are some of the larger BDs observed by IRIS.

  3. More screen operation than calling: the results of observing cyclists' behaviour while using mobile phones.

    PubMed

    de Waard, Dick; Westerhuis, Frank; Lewis-Evans, Ben

    2015-03-01

    Operating a mobile telephone while riding a bicycle is fairly common practice in the Netherlands, yet it is unknown if this use is stable or increasing. As such, whether the prevalence of mobile phone use while cycling has changed over the past five years was studied via on-road observation. In addition the impact of mobile phone use on lateral position, i.e. distance from the front wheel to the curb, was also examined to see if it compared to the results seen in previous experimental studies. Bicyclists were observed at six different locations and their behaviour was scored. It was found that compared to five years ago the use of mobile phones while cycling has changed, not in frequency, but in how cyclists were operating their phones. As found in 2008, three percent of the bicyclists were observed to be operating a phone, but a shift from calling (0.7% of cyclists observed) to operating (typing, texting, 2.3% of cyclists) was found. In 2008 nearly the complete opposite usage was observed: 2.2% of the cyclists were calling and 0.6% was texting. Another finding was that effects on lateral position were similar to those seen in experimental studies in that cyclists using a phone maintained a cycling position which was further away from the curb. It was also found that when at an intersection, cyclist's operating their phone made less head movements to the right than cyclists who were just cycling. This shift from calling to screen operation, when combined with the finding related to reduced head movements at intersections, is worrying and potentially dangerous. PMID:25590920

  4. Greenhouse gases observation from space -initial operation and calibration results of TANSO on GOSAT- (Invited)

    NASA Astrophysics Data System (ADS)

    Kuze, A.; Shiomi, K.; Suto, H.; Nakajima, M.

    2009-12-01

    The Greenhouse gases Observing SATellite (GOSAT) observes carbon dioxide (CO2) and methane (CH4) globally from space. It is a joint project of Japan Aerospace Exploration Agency (JAXA), Ministry of the Environment (MOE) and National Institute for Environmental Studies (NIES). GOSAT was launched on January 23, 2009 from Tanegashima Space Center and placed in a 666 km sun-synchronous orbit of 12:48 local time, with an inclination angle of 98 deg. There are two instruments: the Thermal And Near infrared Sensor for carbon Observation Fourier-Transform Spectrometer (TANSO-FTS) detects gas absorption spectra of Short Wave InfraRed (SWIR) reflected on the earth's surface as well as of Thermal InfraRed (TIR) radiated from the ground and the atmosphere. TANSO-FTS is capable of detecting wide spectral coverage; three narrow bands (0.76, 1.6, and 2μm) and a wide band (5.5-14.3 μm) with 0.27 cm-1 spectral resolution. The TANSO Cloud and Aerosol Imager (TANSO-CAI) is a radiometer of ultraviolet (UV), visible, and SWIR to detect cloud and aerosol interference. TANSO-FTS and CAI acquire global data every three days. For the first six months after the launch, on-orbit function, performance, calibration, and validation have been checked-out. The presentation includes instrument design, pre-launch test results, observation plan, onboard calibration schemes, and the initial on-orbit results of radiometric, geometric and spectroscopic performances. The data processing on the ground is also presented.

  5. Comparison of Thermal Structure Results from Venus Express and Ground Based Observations since Vira

    NASA Astrophysics Data System (ADS)

    Limaye, Sanjay

    2016-07-01

    An international team was formed in 2013 through the International Space Studies Institute (Bern, Switzerland) to compare recent results of the Venus atmospheric thermal structure from spacecraft and ground based observations made since the Venus International Reference Atmosphere (VIRA) was developed (Kliore et al., 1985, Keating et al., 1985). Five experiments on European Space Agency's Venus Express orbiter mission have yielded results on the atmospheric structure during is operational life (April 2006 - November 2014). Three of these were from occultation methods: at near infrared wavelengths from solar occultations, (SOIR, 70 - 170 km), at ultraviolet wavelengths from stellar occultations (SPICAV, 90-140 km), and occultation of the VEx-Earth radio signal (VeRa, 40-90 km). In-situ drag measurements from three different techniques (accelerometry, torque, and radio tracking, 130 - 200 km) were also obtained using the spacecraft itself while passive infrared remote sensing was used by the VIRTIS experiment (70 - 120 km). The only new data in the -40-70 km altitude range are from radio occultation, as no new profiles of the deep atmosphere have been obtained since the VeGa 2 lander measurements in 1985 (not included in VIRA). Some selected ground based results available to the team were also considered by team in the inter comparisons. The temperature structure in the lower thermosphere from disk resolved ground based observations (except for one ground based investigation), is generally consistent with the Venus Express results. These experiments sampled at different periods, at different locations and at different local times and have different vertical and horizontal resolution and coverage. The data were therefore binned in latitude and local time bins and compared, ignoring temporal variations over the life time of the Venus Express mission and assumed north-south symmetry. Alternating warm and cooler layers are present in the 120-160 altitude range in results

  6. Revisiting Spitzer Transit Observations with Independent Component Analysis: New Results for the GJ 436 System

    NASA Astrophysics Data System (ADS)

    Morello, G.; Waldmann, I. P.; Tinetti, G.; Howarth, I. D.; Micela, G.; Allard, F.

    2015-04-01

    We analyzed four Spitzer/IRAC observations at 3.6 and 4.5 μm of the primary transit of the exoplanet GJ 436b, by using blind source separation techniques. These observations are important for investigating the atmospheric composition of the planet GJ 436b. Previous analyses claimed strong inter-epoch variations of the transit parameters due to stellar variability, casting doubts on the possibility of conclusively extracting an atmospheric signal. Those analyses also reported discrepant results, hence the necessity of this reanalysis. The method we used has been proposed in Morello et al. to analyze 3.6 μm transit light curves of the hot Jupiter HD 189733b. It performes an Independent Component Analysis on a set of pixel light curves, i.e., time series read by individual pixels, from the same photometric observation. Our method only assumes the independence of instrumental and astrophysical signals, and therefore guarantees a higher degree of objectivity compared to parametric detrending techniques published in the literature. The data sets we analyzed in this paper represent a more challenging test than the previous ones. Contrary to previous results reported in the literature, our results (1) do not support any detectable inter-epoch variations of orbital and stellar parameters, (2) are photometrically stable at the level ˜10-4 in the IR, and (3) the transit depth measurements at the two wavelengths are consistent within 1σ. We also (4) detect a possible transit duration variation of ˜80 s (2σ significance level) that has not been pointed out in the literature, and (5) confirm no transit timing variations ≳30 s.

  7. Barometric and magnetic observations of vertical acoustic resonance and resultant generation of field-aligned current associated with earthquakes

    NASA Astrophysics Data System (ADS)

    Iyemori, Toshihiko; Tanaka, Yoshikazu; Odagi, Yoko; Sano, Yasuharu; Takeda, Masahiko; Nose, Masahito; Utsugi, Mitsuru; Rosales, Domingo; Choque, Edwin; Ishitsuka, Jose; Yamanaka, Sadato; Nakanishi, Kunihito; Matsumura, Mitsuru; Shinagawa, Hiroyuki

    2013-08-01

    Three rare occasions are introduced, where the excitation of vertical acoustic resonance between the ground and the ionosphere, and the resultant generation of a field-aligned current, just after earthquakes are observationally confirmed. In the case of two inland earthquakes, barometric observations very close to the epicenters (i.e., only 30 km apart) were available, and they showed a sharp spectral peak which appeared within one hour after the origin time and lasted a few hours. The observed periods of the spectral peaks around 260 seconds are close to the period of the theoretically-expected fundamental mode of the resonance. On the other hand, magnetic observations on the ground showed a dominant period at 220-230 seconds which corresponds to the first overtone among theoretically-expected major resonance peaks. In the third case, i.e., during the 2010 Chile earthquake, a long-period magnetic oscillation in the east-west direction, which has two major resonance periods at 265 and 190-195 seconds, was observed on the night-side magnetic dip equator in Peru, where the distance is more than 2600 km from the epicenter, under a very quiet geomagnetic condition. The oscillation was interpreted as the effect of field-aligned current generated through a dynamo process in the ionosphere over the epicenter caused by the resonance.

  8. Worldwide variations in atmospheric transmission. I - Baseline results from Smithsonian observations.

    NASA Technical Reports Server (NTRS)

    Roosen, R. G.; Klemcke, C. H.; Angione, R. J.

    1973-01-01

    The spectrobolometer used in the studies is discussed, giving attention to instrument design, the method of recording, and the spectral resolution. The atmospheric transmission for each wavelength was determined by making observations over a range of air masses. The precipitable water vapor values were found from the spectrobolograms by measurement of the depths of water vapor bands at 0.935, 1.13, and 1.47 microns. The results of the studies are discussed together with seasonal variations, long term trends, and the nature of the aerosols.

  9. Collisional evolution in the Eos and Koronis asteroid families - Observational and numerical results

    NASA Technical Reports Server (NTRS)

    Binzel, Richard P.

    1988-01-01

    The origin and evolution of the Eos and Koronis families are addressed by an analysis of Binzel's (1987) observational results. The Maxwellian distribution of the Eos family's rotation rates implies a collisionally-evolved population; these rates are also faster than those of the Koronis family and nonfamily asteroids. While the age of the Eos family may be comparable to the solar system's, that of the Koronis family could be considerably younger. Greater shape irregularity may account for the Koronis family's higher mean lightcurve amplitude.

  10. Very high energy observations of the Galactic Centre: recent results and perspectives with CTA

    NASA Astrophysics Data System (ADS)

    Terrier, Regis

    2016-07-01

    The central 300 pc of our Galaxy are a major laboratory for high energy astrophysics. They harbor the closest supermassive black hole (SMBH) and are the site of a sustained star formation activity. The energy released by the supernovae on the ambient medium must be very strong. Similarly, albeit extremely faint nowadays, the SMBH must have experienced episodes of intense activity in the past which can influence significantly the central regions and beyond, e.g. powering the Fermi bubbles. I review observational results at very high energies from the central region and discuss their implications and the questions they leave open. I discuss the perspectives CTA offers for Galactic Centre astrophysics.

  11. MHD Model Results of Solar Wind Plasma Interaction with Mars and Comparison with MAVEN Observations

    NASA Technical Reports Server (NTRS)

    Ma, Y. J.; Russell, C. T.; Nagy, A. F.; Toth, G.; Halekas, J. S.; Connerney, J. E. P.; Espley, J. R.; Mahaffy, P. R.

    2015-01-01

    The crustal remnant field on Mars rotates constantly with the planet, varying the magnetic field configuration interacting with the solar wind. It has been found that ion loss rates slowly vary with the subsolar longitude, anticorrelating with the intensity of the dayside crustal field source, with some time delay, using a time-dependent multispecies MHD model. In this study, we investigate in detail how plasma properties are influenced locally by the crustal field and its rotation. Model results will be compared in detail with plasma observations from MAVEN.

  12. Polarization observations and results of the 1998 February 26th solar corona

    NASA Astrophysics Data System (ADS)

    Gabryl, J.-R.; Cugnon, P.; Clette, F.

    1999-03-01

    In the frame of the long-term study program of the solar corona, we have organized an expedition in Curacao (Dutch Antillas) to observe the total solar eclipse of February 26th, 1998. As the totality duration was quite short, we had to improve again the CCD experiment layout in order to record a sample of images as wide as possible in both polarization and brightness ranges. This was made possible by the acquisition of a new PC with fast hard disc and data transfer port. We managed then to record 7 series of different exposures, each containing polarization measurements of 24 images (thus 8 times oversampled). The data processing led to accurate brightness and polarization maps as well as electron density models. The shape of the corona is highly flattened with large polar holes filled by numerous wide plumes. Large streamers are also observed and are essentially aligned along the solar equatorial plane. Moreover, the polarization indicates that these structures are located in the vicinity of the plane of the sky. Unfortunately, the unusually high sky brightness hid the faintest coronal structures and limited the visibility up to 3 solar radii implying a similar limitation in our modelling. We present here these results and give a brief comparison with our previous eclipse observation.

  13. Results of IPS Observations in the Period Near Solar Activity Minimum

    NASA Astrophysics Data System (ADS)

    Chashei, I. V.; Shishov, V. I.; Tyul'bashev, S. A.; Subaev, I. A.; Oreshko, V. V.

    2013-07-01

    IPS observations with the Big Scanning Array of Lebedev Physical Institute (BSA LPI) radio telescope at the frequency 111 MHz have been monitored since 2006. All the sources, about several hundred daily, with a scintillating flux greater than 0.2 Jy are recorded for 24 hours in the 16 beams of the radio telescope covering a sky strip of 8∘ declination width. We present some results of IPS observations for the recent period of low solar activity considering a statistical ensemble of scintillating radio sources. The dependences of the averaged over ensemble scintillation index on heliocentric distance are considerably weaker than the dependence expected for a spherically symmetric geometry. The difference is especially pronounced in the year 2008 during the very deep solar activity minimum period. These features are explained by the influence of the heliospheric current sheet that is seen as a strong concentration of turbulent solar wind plasma aligned with the solar equatorial plane. A local maximum of the scintillation index is found in the anti-solar direction. Future prospects of IPS observations using BSA LPI are briefly discussed.

  14. Planet-Induced Emission Enhancements in HD 179949: Results from McDonald Observations

    NASA Astrophysics Data System (ADS)

    Gurdemir, L.; Redfield, S.; Cuntz, M.

    2012-04-01

    We monitored the Ca II H and K lines of HD 179949, a notable star in the southern hemisphere, to observe and confirm previously identified planet induced emission (PIE) as an effect of star-planet interaction. We obtained high resolution spectra (R~53000) with a signal-to-noise ratio S/N >~50 in the Ca II H and K cores during 10 nights of observation at the McDonald Observatory. Wide-band echelle spectra were taken using the 2.7-m telescope. Detailed statistical analysis of Ca II K revealed fluctuations in the Ca II K core attributable to planet induced chromospheric emission. This result is consistent with previous studies by Shkolnik et al. (2003). Additionally, we were able to confirm the reality and temporal evolution of the phase shift of the maximum of star-planet interaction previously found. However, no identifiable fluctuations were detected in the Ca II H core. The Al I λ3944Å line was also monitored to gauge if the expected activity enhancements are confined to the chromospheric layer. Our observations revealed some variability, which is apparently unassociated with planet-induced activity.

  15. First Results of Coordinated Observations from IRIS and New Solar Telescope

    NASA Astrophysics Data System (ADS)

    Kosovichev, A. G.; Cao, W.; Goode, P. R.; Gorceix, N.; Kleint, L.; Plymate, C.; Varsik, J. R.; Shumko, S.; Yurchyshyn, V.

    2013-12-01

    Most of the chromospheric structuring and dynamics is controlled by the underlying photospheric processes, associated with turbulent magnetoconvection, ubiquitous magnetic flux emergence, small-scale eruptions and acoustic events. The 1.6 m New Solar Telescope (NST) of Big Bear Solar Observatory offers a substantial improvement in ground-based high-resolution capabilities, and provides important support for the IRIS mission. The primary goal of the coordinated IRIS-NST observations is to obtain complementary data for investigations of photosphere-chromosphere links and drivers of the chromospheric dynamics. The coordinated NST observations are performed using the second-generation adaptive optics system AO-308, and three instruments: Broadband Filter Imagers (G-band and TiO), Visible Imaging Spectrometer (H-alpha), and Near InfraRed Imaging Spectropolarimeter (NIRIS). NIRIS provides high-cadence data in Fe I 1565 nm doublet which is the most Zeeman sensitive probe of magnetic fields in the deep photosphere, and in the He I 1083 nm multiplet for diagnostics of the upper chromosphere. We present initial results of the coordinated observations, and discuss properties of small-scale ejections in fibril magnetic structures, obtained from analysis of IRIS and NST data.

  16. Highlights of recent results from the VERITAS Active Galactic Nuclei Observing Program

    NASA Astrophysics Data System (ADS)

    Abeysekara, Udara; VERITAS Collaboration

    2016-03-01

    Active Galactic Nuclei (AGN) are the dominant class of the Very High Energy (VHE) gamma-ray sources. The VERITAS Observatory dedicates about 430 hr/year of dark time and 200 hr/year of observations under moonlight, on the AGN observing program. VERITAS is located at the Fred Lawrence Whipple Observatory near Tucson, Arizona, and is sensitive to gamma rays with energies between of 85 GeV and 30 TeV. VERITAS became fully operational in 2007, and has since then detected 34 very high energy (VHE) AGN. The majority of the detected galaxies are blazars, in addition to a few radio galaxies. The VHE emission mechanism, and the location of the VHE emission zone of AGN are still poorly understood. Detailed observations of VHE AGN are necessary for understanding these uncertainties. AGN are plausible source candidates for ultra-high-energy cosmic rays and astrophysical neutrinos. VHE gamma-rays from AGN can also be used as probes to place limits on extragalactic background light density. This presentation will report the most recent results from the VERITAS AGN program including newly discovered AGN, and VHE flares of known TeV AGN. Udara Abeysekara for the VERITAS Collaboration.

  17. First results of mapping sporadic E with a passive observing network

    NASA Astrophysics Data System (ADS)

    Rice, D. D.; Sojka, J. J.; Eccles, J. V.; Raitt, J. W.; Brady, J. J.; Hunsucker, R. D.

    2011-12-01

    Sporadic E (Es) can have dramatic effects on communications in the HF and low VHF range, producing over-the-horizon propagation for signals normally restricted to line-of-sight, and sometimes blocking F region propagation of signals in the lower HF range. Measuring the E region winds believed to produce Es is difficult, and no practical means of predicting Es occurrence currently exists other than statistical models. We describe a low-cost observing network based on software-controlled receivers that continuously watches for Es in near-real time using oblique HF propagation from existing transmitters. Results from an 11-day pilot campaign in July 2008 demonstrated that even a limited number of receivers in the network can readily determine the presence and extent of Es patches. These observations indicate that Es often develops quickly over regions of several hundred kilometers rather than gradually drifting across an area. These widespread Es “blooms” have been observed near winter solstice and occasionally at other times of the year; their lifetime depends on the season but can be several hours during the summer. The current network allows the extent of Es in portions of North America to be evaluated: the geographical distribution of Es and bounds on the density of the layer are inferred from its effects on the ionospheric maximum usable frequency (MUF). This study demonstrates quantitatively that Es mapping can provide information about Es layer geographical growth and decay. The observed sudden widespread Es blooms are space weather events that can have significant impact on HF/lower VHF communications and propagation model predictions.

  18. The Hubble Space Telescope quasar absorption line key project. III - First observational results on Milky Way gas

    NASA Technical Reports Server (NTRS)

    Savage, Blair D.; Lu, Limin; Bahcall, John N.; Bergeron, Jacqueline; Boksenberg, Alec; Hartig, George F.; Jannuzi, Buell T.; Kirhakos, Sofia; Lockman, Felix J.; Sargent, W. L. W.

    1993-01-01

    Absorption lines found near zero redshift due to Milky Way disk and halo gas in the spectra of 15 quasars observed with the Faint Object Spectrograph (FOS) of the HST at a resolution of about 230 km/s are reported. Results show that Milky Way absorption lines comprise about 44 percent of all absorption lines seen in the first group of Key Project FOS spectra. Milky Way lines were observed for 3C 273 and H1821 + 643. Limits to the Mg-to-H abundance ratio obtained for very high velocity Mg II absorption detections imply gas-phase Mg abundances for the very high velocity gas ranging from more than 0.059 to more than 0.32 times the solar abundance. In all cases where high-velocity H I emission is seen, corresponding high-velocity metal-line absorption is observed.

  19. First multipoint in situ observations of electron microbursts: Initial results from the NSF FIREBIRD II mission

    NASA Astrophysics Data System (ADS)

    Crew, Alexander B.; Spence, Harlan E.; Blake, J. Bernard; Klumpar, David M.; Larsen, Brian A.; O'Brien, T. Paul; Driscoll, Shane; Handley, Matthew; Legere, Jason; Longworth, Stephen; Mashburn, Keith; Mosleh, Ehson; Ryhajlo, Nicholas; Smith, Sonya; Springer, Larry; Widholm, Mark

    2016-06-01

    We present initial dual spacecraft observations that for the first time both constrain the spatial scale size and provide spectral properties at medium energies of electron microbursts. We explore individual microburst events that occurred on 2 February 2015 using simultaneous observations made by the twin CubeSats which comprise the National Science Foundation (NSF) Focused Investigations of Relativistic Electron Bursts: Intensity, Range, and Dynamics (FIREBIRD II). During these microburst events, the two identically instrumented FIREBIRD II CubeSats were separated by as little as 11 km while traversing electron precipitation regions in low-Earth orbit. These coincident microburst events map to size scales >120 km at the equator. Given the prevalence of coincident and noncoincident events we conclude that this is of the same order of magnitude as that of the spatial scale size of electron microburst, an unknown property that is critical for quantifying their overall role in radiation belt dynamics. Finally, we present measurements of electron microbursts showing that precipitation often occurs simultaneously across a broad energy range spanning 200 keV to 1 MeV, a new form of empirical evidence that provides additional insights into the physics of microburst generation mechanisms.

  20. The Evolution of Stellar Coronae: Initial Results from a ROSAT PSPC Observation of IC 2391

    NASA Technical Reports Server (NTRS)

    Patten, Brian M.; Simon, Theodore

    1993-01-01

    A 23 ks ROSAT PSPC image of the young star cluster, IC 2391, reveals 76 soft x-ray sources with L(sub x)(0.2-2.0 keV) greater than or equal to 2 x 10(exp 28) ergs/s in the direction of the cluster center. Nineteen of these sources are associated with known cluster members. We find that x-ray emission from the IC 2391 B stars deviates widely from the L(sub x)/L(sub bol) = 10(exp -7) relation based on Einstein observations of O and early B stars. Instead, we observe a wide range in L(sub x) with an order of magnitude spread at any given mass and no apparent dependence on spectral type. A comparison of the spread of L(sub x) as a function of B-V for low-mass stars between IC 2391 and the much older Hyades cluster shows that despite the factor of approx. 10 difference in their ages, these two clusters exhibit very similar dispersions in levels of stellar activity. We conclude that the low-mass stars in IC 2391 have arrived on the ZAMS with a wide range of coronal activity levels, from very strong to very weak, and that existing empirical activity-age scaling laws therefore cannot be valid.

  1. Results of NASA's First Autonomous Formation Flying Experiment: Earth Observing-1 (EO-1)

    NASA Technical Reports Server (NTRS)

    Folta, David C.; Hawkins, Albin; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    NASA's first autonomous formation flying mission completed its primary goal of demonstrating an advanced technology called enhanced formation flying. To enable this technology, the Guidance, Navigation, and Control center at the Goddard Space Flight Center (GSFC) implemented a universal 3-axis formation flying algorithm in an autonomous executive flight code onboard the New Millennium Program's (NMP) Earth Observing-1 (EO-1) spacecraft. This paper describes the mathematical background of the autonomous formation flying algorithm and the onboard flight design and presents the validation results of this unique system. Results from functionality assessment through fully autonomous maneuver control are presented as comparisons between the onboard EO-1 operational autonomous control system called AutoCon(tm), its ground-based predecessor, and a standalone algorithm.

  2. Preliminary Results of NASA's First Autonomous Formation Flying Experiment: Earth Observing-1 (EO-1)

    NASA Technical Reports Server (NTRS)

    Folta, David; Hawkins, Albin

    2001-01-01

    NASA's first autonomous formation flying mission is completing a primary goal of demonstrating an advanced technology called enhanced formation flying. To enable this technology, the Guidance, Navigation, and Control center at the Goddard Space Flight Center has implemented an autonomous universal three-axis formation flying algorithm in executive flight code onboard the New Millennium Program's (NMP) Earth Observing-1 (EO-1) spacecraft. This paper describes the mathematical background of the autonomous formation flying algorithm and the onboard design and presents the preliminary validation results of this unique system. Results from functionality assessment and autonomous maneuver control are presented as comparisons between the onboard EO-1 operational autonomous control system called AutoCon(tm), its ground-based predecessor, and a stand-alone algorithm.

  3. Results of NASA's First Autonomous Formation Flying Experiment: Earth Observing-1 (EO-1)

    NASA Technical Reports Server (NTRS)

    Folta, David; Hawkins, Albin; Bauer, Frank (Technical Monitor)

    2002-01-01

    NASA's first autonomous formation flying mission completed its primary goal of demonstrating an advanced technology called enhanced formation flying. To enable this technology, the Flight Dynamics Analysis Branch at the Goddard Space Flight Center implemented a universal 3-axis formation flying algorithm in an autonomous executive flight code onboard the New Millennium Program's (NMP) Earth Observing-1 (EO-1) spacecraft. This paper describes the mathematical background of the autonomous formation flying algorithm, the onboard flight design and the validation results of this unique system. Results from fully autonomous maneuver control are presented as comparisons between the onboard EO-1 operational autonomous control system called AutoCon, its ground-based predecessor used in operations, and the original standalone algorithm. Maneuvers discussed encompass reactionary, routine formation maintenance, and inclination control. Orbital data is also examined to verify that all formation flying requirements were met.

  4. Results Of NASA's First Autonomous Formation Flying Experiment: Earth Observing-1 (EO-1)

    NASA Technical Reports Server (NTRS)

    Folta, David; Hawkins, Albin

    2002-01-01

    NASA's first autonomous formation flying mission completed its primary goal of demonstrating an advanced technology called Enhanced Formation Flying. To enable this technology, a team at the Goddard Space Flight Center implemented a universal 3-axis formation flying algorithm in an autonomous executive flight code onboard the New Millennium Program's (NMP) Earth Observing-1 (EO-1) spacecraft. This paper describes the mathematical background of the autonomous formation flying algorithm, the onboard flight design and the validation results of this unique system. Results from fully autonomous maneuver control are presented as comparisons between the onboard EO-1 operational autonomous control system called AutoCon(trademark), its ground-based predecessor used in operations, and the original standalone algorithm. Maneuvers discussed encompass reactionary, routine formation maintenance, and inclination control. Orbital data is also examined to verify that all formation flying requirements were met.

  5. Ethical challenges in preclinical Alzheimer's disease observational studies and trials: Results of the Barcelona summit.

    PubMed

    Molinuevo, José L; Cami, Jordi; Carné, Xavier; Carrillo, Maria C; Georges, Jean; Isaac, Maria B; Khachaturian, Zaven; Kim, Scott Y H; Morris, John C; Pasquier, Florence; Ritchie, Craig; Sperling, Reisa; Karlawish, Jason

    2016-05-01

    Alzheimer's disease (AD) is among the most significant health care burdens. Disappointing results from clinical trials in late-stage AD persons combined with hopeful results from trials in persons with early-stage suggest that research in the preclinical stage of AD is necessary to define an optimal therapeutic success window. We review the justification for conducting trials in the preclinical stage and highlight novel ethical challenges that arise and are related to determining appropriate risk-benefit ratios and disclosing individuals' biomarker status. We propose that to conduct clinical trials with these participants, we need to improve public understanding of AD using unified vocabulary, resolve the acceptable risk-benefit ratio in asymptomatic participants, and disclose or not biomarker status with attention to study type (observational studies vs clinical trials). Overcoming these challenges will justify clinical trials in preclinical AD at the societal level and aid to the development of societal and legal support for trial participants. PMID:26988427

  6. Surface electromagnetic impedance and geomagnetic activity: results of long term observation

    NASA Astrophysics Data System (ADS)

    Lemperger, István; Menvielle, Menvielle; Wesztergom, Viktor; Bencze, Pál; Szendrői, Judit; Novák, Attila; Kis, Árpád; Szalai, Sándor

    2014-05-01

    The magnetotelluric (MT) method is one of the most useful geophysical tool to discover even the deep subsurface structures. The target function of the MT data processing is the surface electromagnetic (EM) impedance. In case of practical MT exploration the surface EM impedance is computed based on a simplification related to the nature of the ionospheric source of the surface EM signals. Assuming that the ionospheric current systems result in homogeneous surface electromagnetic variations, the uncertainty of the computed surface electromagnetic impedance tensor depends only the duration of the EM observation. However the surface EM field can only be approached by plane waves in certain time periods and besides given uncertainty. The EM impedance may be sensitive to magnetospheric and -indirectly- interplanetary circumstances and solar activity. Four years continuous observation of telluric and surface geomagnetic components allowed to perform a representative survey to discover if geomagnetic activity has any effect on observed EM impedance tensor. Geomagnetic indices (Dst, ULF-index, ASY-H, SYM-H) have been used to classify dates according to geomagnetic activity. Processing to estimate the mean surface EM impedance tensor has been performed in each dataset, each class separately. The sensitivity and the characteristics of the answer of the EM impedance tensor to the geomagnetic disturbances seems to be definite. This presentation aims to briefly summarize the preliminary results of our study based on the unique dataset of the Széchenyi István Geophysical Obsevatory (Intermagnet code:NCK). In addition, pointing out the limitations of the routine way of practical MT data processing and interpretation is an important duty of this study. This study was supported by the TAMOP-4.2.2.C-11/1/KONV-2012-0015 (Earth-system) project sponsored by the EU and European Social Foundation.

  7. HUBBLE TARANTULA TREASURY PROJECT: UNRAVELING TARANTULA'S WEB. I. OBSERVATIONAL OVERVIEW AND FIRST RESULTS

    SciTech Connect

    Sabbi, E.; Anderson, J.; Van der Marel, R. P.; Aloisi, A.; De Mink, S. E.; Gordon, K.; Koekemoer, A. M.; Panagia, N.; Lennon, D. J.; Boyer, M. L.; Cignoni, M.; De Marchi, G.; Evans, C. J.; Gallagher, J. S. III; Ryon, J. E.; Gouliermis, D. A.; Grebel, E. K.; Larsen, S. S.; and others

    2013-09-15

    The Hubble Tarantula Treasury Project (HTTP) is an ongoing panchromatic imaging survey of stellar populations in the Tarantula Nebula in the Large Magellanic Cloud that reaches into the sub-solar mass regime (<0.5 M{sub Sun }). HTTP utilizes the capability of the Hubble Space Telescope to operate the Advanced Camera for Surveys and the Wide Field Camera 3 in parallel to study this remarkable region in the near-ultraviolet, optical, and near-infrared spectral regions, including narrow-band H{alpha} images. The combination of all these bands provides a unique multi-band view. The resulting maps of the stellar content of the Tarantula Nebula within its main body provide the basis for investigations of star formation in an environment resembling the extreme conditions found in starburst galaxies and in the early universe. Access to detailed properties of individual stars allows us to begin to reconstruct the temporal and spatial evolution of the stellar skeleton of the Tarantula Nebula over space and time on a sub-parsec scale. In this first paper we describe the observing strategy, the photometric techniques, and the upcoming data products from this survey and present preliminary results obtained from the analysis of the initial set of near-infrared observations.

  8. Hubble Tarantula Treasury Project: Unraveling Tarantula's Web. I. Observational Overview and First Results

    NASA Technical Reports Server (NTRS)

    Sabbi, E.; Anderson, J.; Lennon, D. J.; van der Marel, R. P.; Aloisi, A.; Boyer, Martha L.; Cignoni, M.; De Marchi, G.; De Mink, S. E.; Evans, C. J.; Gallagher, J. S., III; Gordon, K.; Gouliermis, D. A.; Grebel, E. K.; Koekemoer, A. M.; Larsen, S. S.; Panagia, N.; Ryon, J. E.; Smith, L. J.; Tosi, M.; Zaritsky, D.

    2013-01-01

    The Hubble Tarantula Treasury Project (HTTP) is an ongoing panchromatic imaging survey of stellar populations in the Tarantula Nebula in the Large Magellanic Cloud that reaches into the sub-solar mass regime (<0.5 Stellar Mass). HTTP utilizes the capability of the Hubble Space Telescope to operate the Advanced Camera for Surveys and the Wide Field Camera 3 in parallel to study this remarkable region in the near-ultraviolet, optical, and near-infrared spectral regions, including narrow-band H(alpha) images. The combination of all these bands provides a unique multi-band view. The resulting maps of the stellar content of the Tarantula Nebula within its main body provide the basis for investigations of star formation in an environment resembling the extreme conditions found in starburst galaxies and in the early universe. Access to detailed properties of individual stars allows us to begin to reconstruct the temporal and spatial evolution of the stellar skeleton of the Tarantula Nebula over space and time on a sub-parsec scale. In this first paper we describe the observing strategy, the photometric techniques, and the upcoming data products from this survey and present preliminary results obtained from the analysis of the initial set of near-infrared observations.

  9. DETERMINING INCLINATIONS OF ACTIVE GALACTIC NUCLEI VIA THEIR NARROW-LINE REGION KINEMATICS. I. OBSERVATIONAL RESULTS

    SciTech Connect

    Fischer, T. C.; Crenshaw, D. M.; Kraemer, S. B.; Schmitt, H. R.

    2013-11-01

    Active galactic nuclei (AGNs) are axisymmetric systems to first order; their observed properties are likely strong functions of inclination with respect to our line of sight (LOS). However, except for a few special cases, the specific inclinations of individual AGNs are unknown. We have developed a promising technique for determining the inclinations of nearby AGNs by mapping the kinematics of their narrow-line regions (NLRs), which are often easily resolved with Hubble Space Telescope [O III] imaging and long-slit spectra from the Space Telescope Imaging Spectrograph. Our studies indicate that NLR kinematics dominated by radial outflow can be fit with simple biconical outflow models that can be used to determine the inclination of the bicone axis, and hence the obscuring torus, with respect to our LOS. We present NLR analysis of 53 Seyfert galaxies and the resulting inclinations from models of 17 individual AGNs with clear signatures of biconical outflows. Our model results agree with the unified model in that Seyfert 1 AGNs have NLRs inclined further toward our LOS than Seyfert 2 AGNs. Knowing the inclinations of these AGN NLRs, and thus their accretion disk and/or torus axes, will allow us to determine how their observed properties vary as a function of polar angle. We find no correlation between the inclinations of the AGN NLRs and the disks of their host galaxies, indicating that the orientation of the gas in the torus is independent of that of the host disk.

  10. FIRST, a fibered aperture masking instrument: Results of the Lick observing campaign

    NASA Astrophysics Data System (ADS)

    Bordwell, Baylee; Duchene, Gaspard; Huby, Elsa; Goebel, Sean; Marchis, Franck; Perrin, Guy; Lacour, Sylvestre; Kotani, Takayuki; Gates, Elinor L.; Choquet, Elodie

    2015-01-01

    FIRST is a prototype instrument aimed at achieving high dynamic range and angular resolution in ground-based images at visible wavelengths near the diffraction limit. FIRST utilizes an aperture masking-like technique that makes use of single-mode fibers and pupil remapping to maximize the area of the telescope mirror in use. While located at Lick observatory in 2011 and 2012, FIRST observed 25 binary systems with the Shane 3m telescope, with separations ranging from 20 to 200 mas, comparable to the 50 mas diffraction limit for our central wavelength. Huby et al. (2013) has reported results for the Capella system that established the utility of FIRST for characterizing stellar binaries using the directly measured spectral flux ratio. Using an improved data analysis pipeline, we obtained closure phase measurements for a majority of the targets observed at Lick, and derived angular separations and spectral flux ratios. From the spectral flux ratios we obtained spectra for the companions over at least 600-850 nm with R~300. Finally, by obtaining results for many binary systems we have better constrained the current performance of FIRST, which has an exciting future ahead at its current location behind SCExAO at the Subaru 8.2 m telescope, where it will eventually become available for general use by the astronomical community.

  11. Recent Observational Results of Seafloor Crustal Deformation Along the Suruga-Nankai Trough, Japan

    NASA Astrophysics Data System (ADS)

    Tadokoro, K.; Sugimoto, S.; Watanabe, T.; Muto, D.; Kimoto, A.; Okuda, T.; Ikuta, R.; Sayanagi, K.; Kuno, M.

    2008-12-01

    The Suruga-Nankai Trough is one of the active plate boundaries in the world. The Philippine Sea plate is subducting beneath the Amurian (Eurasian) plate along the tough, and major subduction earthquakes, Nankai and Tonankai earthquakes, have repeatedly occurred with intervals of about 100-150 years. The 1944 Tonankai and 1946 Nankai earthquakes are the most recent significant earthquakes along the trough. Therefore, the 50-years probabilities of the next major earthquakes are estimated at 80-90% by Headquarters for Earthquake Research Promotion, Japanese Government. It is, therefore, necessary to start monitoring crustal deformation above the source regions of the major earthquakes where in the ocean area. We developed a new system composed of the precise acoustic ranging and kinematic GPS positioning techniques for monitoring of seafloor crustal deformation [Tadokoro et al., 2006, GRL; Ikuta et al., 2008, JGR]. We had installed seven seafloor benchmarks for acoustic ranging at the Suruga-Nankai Trough region between 2002 and 2004. The water depths at the benchmarks are about 800 to 2000 m. We installed a new seafloor benchmark at the eastern margin of the Kumano Basin on June 23, 2008. Three seafloor benchmarks had been aligned perpendicular to the trough axis. In contrast, the new benchmark was installed eastward relative to the pre-installed benchmarks, and we can monitor lateral variations in crustal deformation at the region. We started the repeated measurements at four benchmarkes (two at the Kumano Basin named KMN and KMS, and the other two at the Suruga Bay named SNW and SNE) in 2005. The number of times we have measured are seven, eleven, three and nine times at KMN, KMS, SNW and SNE, respectively. Recent results of the repeated measurements show the following horizontal velocities with relative to the Amurian Plate: 6.4 cm/yr, N86W at KMN; 5.3 cm/yr, N71W at KMS; 3.3 cm/yr, N57W at SNE. The errors of the horizontal velocities are 1-3 cm/yr. Unfortunately

  12. Recent Results from Follow-up Astrometric Observations of KBOs and NEOs

    NASA Astrophysics Data System (ADS)

    Tholen, D. J.; Connelley, M. S.

    2001-11-01

    , 2000 UR13 (we repaired an erroneous orbit that resulted from a bad identification), and 2000 VN2 (an object that had been prematurely numbered, based on erroneous single-night precovery observations). This work has been supported by NASA Grant No. NAG5-4524.

  13. Validation of first chemistry mode retrieval results from new limb-imaging FTS GLORIA with correlative MIPAS-STR observations

    NASA Astrophysics Data System (ADS)

    Woiwode, W.; Suminska-Ebersoldt, O.; Oelhaf, H.; Höpfner, M.; Belyaev, G. V.; Ebersoldt, A.; Friedl-Vallon, F.; Grooß, J.-U.; Gulde, T.; Kaufmann, M.; Kleinert, A.; Krämer, M.; Kretschmer, E.; Kulessa, T.; Maucher, G.; Neubert, T.; Piesch, C.; Preusse, P.; Riese, M.; Rongen, H.; Sartorius, C.; Schardt, G.; Schönfeld, A.; Schuettemeyer, D.; Sha, M. K.; Stroh, F.; Ungermann, J.; Volk, C. M.; Orphal, J.

    2014-12-01

    We report first chemistry mode retrieval results from the new airborne limb-imaging infrared FTS (Fourier transform spectrometer) GLORIA and comparisons with observations by the conventional airborne limb-scanning infrared FTS MIPAS-STR. For GLORIA, the flights aboard the high-altitude research aircraft M55 Geophysica during the ESSenCe campaign (ESa Sounder Campaign 2011) were the very first in field deployment after several years of development. The simultaneous observations of GLORIA and MIPAS-STR during the flight on 16 December 2011 inside the polar vortex and under the conditions of optically partially transparent polar stratospheric clouds (PSCs) provided us the unique opportunity to compare the observations by two different infrared FTS generations directly. The retrieval results of temperature, HNO3, O3, H2O, CFC-11 and CFC-12 show reasonable agreement of GLORIA with MIPAS-STR and collocated in-situ observations. For the horizontally binned hyperspectral limb-images, the GLORIA sampling outnumbered the horizontal cross-track sampling of MIPAS-STR by up to one order of magnitude. Depending on the target parameter, typical vertical resolutions of 0.5 to 2.0 km were obtained for GLORIA and are typically by factors of 2 to 4 better compared to MIPAS-STR. While the improvement of the performance, characterisation and data processing of GLORIA are subject of ongoing work, the presented first results already demonstrate the considerable gain in sampling and vertical resolution achieved with GLORIA.

  14. Results of the Baikal Experiment on Observations of Macroscopic Nonlocal Correlations in Reverse Time

    NASA Astrophysics Data System (ADS)

    Korotaev, S. M.; Serdyuk, V. O.; Kiktenko, E. O.; Budnev, N. M.; Gorohov, J. V.

    Although the general theory macroscopic quantum entanglement of is still in its infancy, consideration of the matter in the framework of action-at-a distance electrodynamics predicts for the random dissipative processes observability of the advanced nonlocal correlations (time reversal causality). These correlations were really revealed in our previous experiments with some large-scale heliogeophysical processes as the source ones and the lab detectors as the probe ones. Recently a new experiment has been performing on the base of Baikal Deep Water Neutrino Observatory. The thick water layer is an excellent shield against any local impacts on the detectors. The first annual series 2012/2013 has demonstrated that detector signals respond to the heliogeophysical (external) processes and causal connection of the signals directed downwards: from the Earth surface to the Baikal floor. But this nonlocal connection proved to be in reverse time. In addition advanced nonlocal correlation of the detector signal with the regional source-process: the random component of hydrological activity in the upper layer was revealed and the possibility of its forecast on nonlocal correlations was demonstrated. But the strongest macroscopic nonlocal correlations are observed at extremely low frequencies, that is at periods of several months. Therefore the above results should be verified in a longer experiment. We verify them by data of the second annual series 2013/2014 of the Baikal experiment. All the results have been confirmed, although some quantitative parameters of correlations and time reversal causal links turned out different due to nonstationarity of the source-processes. A new result is displaying of the advanced response of nonlocal correlation detector to the earthquake. This opens up the prospect of the earthquake forecast on the new physical principle, although further confirmation in the next events is certainly needed. The continuation of the Baikal experiment with

  15. Results of the Baikal Experiment on Observations of oscopic Nonlocal Correlations in Reverse Time

    NASA Astrophysics Data System (ADS)

    Korotaev, S. M.; Serdyuk, V. O.; Kiktenko, E. O.; Budnev, N. M.; Gorohov, J. V.

    Although the general theory oscopic quantum entanglement of is still in its infancy, consideration of the matter in the framework of action-at-a distance electrodynamics predicts for the random dissipative processes observability of the advanced nonlocal correlations (time reversal causality). These correlations were really revealed in our previous experiments with some large-scale heliogeophysical processes as the source ones and the lab detectors as the probe ones. Recently a new experiment has been performing on the base of Baikal Deep Water Neutrino Observatory. The thick water layer is an excellent shield against any local impacts on the detectors. The first annual series 2012/2013 has demonstrated that detector signals respond to the heliogeophysical (external) processes and causal connection of the signals directed downwards: from the Earth surface to the Baikal floor. But this nonlocal connection proved to be in reverse time. In addition advanced nonlocal correlation of the detector signal with the regional source-process: the random component of hydrological activity in the upper layer was revealed and the possibility of its forecast on nonlocal correlations was demonstrated. But the strongest oscopic nonlocal correlations are observed at extremely low frequencies, that is at periods of several months. Therefore the above results should be verified in a longer experiment. We verify them by data of the second annual series 2013/2014 of the Baikal experiment. All the results have been confirmed, although some quantitative parameters of correlations and time reversal causal links turned out different due to nonstationarity of the source-processes. A new result is displaying of the advanced response of nonlocal correlation detector to the earthquake. This opens up the prospect of the earthquake forecast on the new physical principle, although further confirmation in the next events is certainly needed. The continuation of the Baikal experiment with expanded

  16. Storytelling Slide Shows to Improve Diabetes and High Blood Pressure Knowledge and Self-Efficacy: Three-Year Results among Community Dwelling Older African Americans

    ERIC Educational Resources Information Center

    Bertera, Elizabeth M.

    2014-01-01

    This study combined the African American tradition of oral storytelling with the Hispanic medium of "Fotonovelas." A staggered pretest posttest control group design was used to evaluate four Storytelling Slide Shows on health that featured community members. A total of 212 participants were recruited for the intervention and 217 for the…

  17. Seasonal and diurnal variations in AMPERE observations of the Birkeland currents compared to modeled results

    NASA Astrophysics Data System (ADS)

    Coxon, J. C.; Milan, S. E.; Carter, J. A.; Clausen, L. B. N.; Anderson, B. J.; Korth, H.

    2016-05-01

    We reduce measurements made by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) to give the total Birkeland (field-aligned) current flowing in both hemispheres in monthly and hourly bins. We analyze these totals using 6 years of data (2010-2015) to examine solar zenith angle-driven variations in the total Birkeland current flowing in both hemispheres, simultaneously, for the first time. A diurnal variation is identified in the total Birkeland current flowing, consistent with variations in the solar zenith angle. A seasonal variation is also identified, with more current flowing in the Northern (Southern) Hemisphere during Bartels rotations in northern (southern) summer. For months close to equinox, more current is found to flow in the Northern Hemisphere, contrary to our expectations. We also conduct the first test of the Milan (2013) model for estimating Birkeland current magnitudes, with modifications made to account for solar contributions to ionospheric conductance based on the observed variation of the Birkeland currents with season and time of day. The modified model, using the value of ΦD averaged by Bartels rotation (scaled by 1.7), is found to agree with the observed AMPERE currents, with a correlation of 0.87 in the Northern Hemisphere and 0.86 in the Southern Hemisphere. The improvement over the correlation with dayside reconnection rate is demonstrated to be a significant improvement to the model. The correlation of the residuals is found to be consistent with more current flowing in the Northern Hemisphere. This new observation of systematically larger current flowing in the Northern Hemisphere is discussed in the context of previous results which suggest that the Northern Hemisphere may react more strongly to dayside reconnection than the Southern Hemisphere.

  18. Review on optical constants of Titan aerosols: Experimental results and modeling/observational data

    NASA Astrophysics Data System (ADS)

    Brassé, Coralie; Muñoz, Olga; Coll, Patrice; Raulin, François

    2014-05-01

    During the last years many studies have been performed to improve the experimental database of optical constants of Titan aerosols. Indeed, the determination of the optical constants of these particles is essential to quantify their capacity to absorb and to scatter solar radiation, and thus to evaluate their role on Titan's radiative balance and climate. The study of optical properties is also crucial to analyze and to better interpret many of Titan's observational data, in particular those acquired during the Cassini-Huygens mission. One way to determine Titan aerosols optical constant is to measure the optical constants of analogues of Titan complex organic material synthesized in the laboratory, usually named Titan's tholins (Sagan and Khare, 1979). But the optical constants depend on the chemical composition, the size and the shape of particles (Raulin et al., 2012). Those three parameters result from the experimental conditions such as energy source, gas mixing ratio, gas pressure, flow rate and irradiation time (Cable et al., 2012). Besides the determination of the refractive index in the laboratory, there are others methods using theoretical models or observational data. Nevertheless, theoretical models are based on laboratory data or/and observational data. The visible - near infrared spectral region of optical constants has been widely studied with laboratory analogues. Comparison of the obtained results suggest that tholins synthesized by Tran et al. (2003) and Majhoub et al. (2012) are the best representative of Titan aerosols with regards to their refractive indexes in this spectral region. The mid-infrared spectral range has been studied only by Imanaka et al. (2012) and slightly by Tran et al. (2003). In that spectral range, Titan tholins do not exhibit the features displayed by Kim and Courtin (2013) from Titan's observations. For spectral region of wavelengths smaller than 0.20µm or higher than 25µm, only the data from Khare et al. (1984) are

  19. Improving Wind Energy Forecasts through Assimilation of New Meteorological Observations: Results from the Wind Forecast Improvement Project (WFIP)

    NASA Astrophysics Data System (ADS)

    Bianco, L.; Wilczak, J. M.; Djalalova, I. V.; Olson, J. B.; Benjamin, S.; Finley, C. A.; Freedman, J. M.; DiMego, G.; Carley, J. R.; Orwig, K.; Cline, J.; Marquis, M.

    2013-12-01

    The U.S. Department of Energy sponsored a joint research project with NOAA and private industry to improve wind energy forecasts, called the Wind Forecast Improvement Project. The key elements of this program have been 1) a one-year deployment of extensive meteorological observing systems in two regions with significant wind energy production, from August 2011-September 2012; 2) assimilation of these observations into the hourly-updated NOAA Rapid Refresh (RAP), run nationwide each hour at 13 km resolution; and 3) evaluation of the benefits of these improved wind forecasts on electrical utility operations, especially for ramp-events in the 0-6 h forecast time-frame. The special observation data sets assimilated are concentrated over the two selected regions of the U.S. and include: 12 wind profiling radars, 12 sodars, 185 instrumented tall towers (40-200m tall), and 400 nacelle anemometers. In this presentation we will describe results from data denial experiments that have been run for limited periods within the WFIP project. The goal of the data denial experiments is to quantitatively document the precise impact that assimilation of the special WFIP data had on model accuracy, by comparing simulations from identical models run with and without the new data. Standard statistical measures show a significant improvement from the assimilation of the new data, and metrics for wind ramp events (including magnitude and phase of the ramps) show an even larger impact of the observations.

  20. A Compact Infrared Space Telescope MIRIS and its Preliminary Observational Results

    NASA Astrophysics Data System (ADS)

    Han, Wonyong; Pyo, Jeonghyun; Kim, Il-Joong; Lee, Dae-Hee; Jeong, Woong-Seob; Moon, Bongkon; Park, Youngsik; Park, Sung-Joon; Lee, Dukhang; Park, Won-Kee; Ko, Kyeongyeon; Kim, Min Gyu; Nam, Uk-Won; Park, Hong-Young; Lee, Hyung Mok; Matsumoto, Toshio

    2015-08-01

    The first Korean infrared space telescope MIRIS (Milti-purpose InfraRed Imaging System) was successfully launched in November 2013, as the main payload of Korean STSAT-3 (Science and Technology Satellite-3). After the initial on-orbit operation for verification, the observations are made with MIRIS for the fluctuation of Cosmic Infrared Background (CIB) and the Galactic Plane survey. For the study of near-infrared background, MIRIS surveyed large areas (> 10° x 10°) around the pole regions: the north ecliptic pole (NEP), the north and south Galactic poles (NGP, SGP), while the NEP region is continually monitored for the instrumental calibration and the zodiacal light study. In addition, the Paschen-α Galactic plane survey has been made with two narrow-band filters (at 1.88 μm and 1.84+1.92 μm) for the study of warm interstellar medium. We plan to continue surveying the entire galactic plane with the latitude of ±3°, and expect to be completed by 2015. The data are still under the stage of reduction and analysis, and guest observations are on-going. We present some of the preliminary results.

  1. Polarization observations and results of the 1998 February 26th solar eclipse

    NASA Astrophysics Data System (ADS)

    Gabryl, J.-R.; Cugnon, P.; Clette, F.

    1999-06-01

    Following our long-term solar corona study program, we organized an expedition to the Curacao island (Dutch Antillas) to observe the total solar eclipse of February 26th, 1998. As the duration of this totality was quite short, our polarized white-light CCD imaging experiment was redesigned in order to increase the number of recorded images, thereby increasing the number of sampled polarization angles and exposures. This was made possible by upgrading to a new PC system, with fast hard disc and data transfer port. This allowed us to finally record 7 series of different exposures, each containing 24 images taken at 12 polarization angles, i.e. with 8-time oversampling. The data were processed to derive global maps of brightness and polarization, and from these, to build electron density models. In those maps, the shape of the corona is highly flattened, with extended polar holes filled with numerous wide plumes. All large streamers are essentially aligned along the solar equatorial plane. Moreover, the measured degree of polarization indicates that these structures are located in the vicinity of the plane of the sky. Unfortunately, the unusually high sky brightness hid the faint extensions of coronal structures. This limited their visibility to less than 3 solar radii, implying a corresponding limitation in the radial extent of our global model. The results presented here are also briefly compared with our earlier eclipse observations.

  2. Efficacy and safety of natalizumab in multiple sclerosis: interim observational programme results

    PubMed Central

    Butzkueven, Helmut; Kappos, Ludwig; Pellegrini, Fabio; Trojano, Maria; Wiendl, Heinz; Patel, Radhika N; Zhang, Annie; Hotermans, Christophe; Belachew, Shibeshih

    2014-01-01

    Background Clinical trials established the efficacy and safety of natalizumab. Data are needed over longer periods of time and in the clinical practice setting. Objective To evaluate long-term safety of natalizumab and its impact on annualised relapse rate and Expanded Disability Status Scale (EDSS) progression in patients with relapsing-remitting multiple sclerosis (RRMS). Methods The Tysabri (natalizumab) Observational Program (TOP) is an open-label, multinational, 10-year prospective study in clinical practice settings. Results In this 5-year interim analysis, 4821 patients were enrolled. Follow-up for at least 4 years from natalizumab commencement in 468 patients and at least 2 years in 2496 patients revealed no new safety signals. There were 18 cases of progressive multifocal leucoencephalopathy reported, following 11–44 natalizumab infusions. Mean annualised relapse rate decreased from 1.99 in the 12 months prior to baseline to 0.31 on natalizumab therapy (p<0.0001), remaining low at 5 years. Lower annualised relapse rates were observed in patients who used natalizumab as first MS therapy, in patients with lower baseline EDSS scores, and in patients with lower prenatalizumab relapse rates. Mean EDSS scores remained unchanged up to 5 years. Conclusions Interim TOP data confirm natalizumab's overall safety profile and the low relapse rate and stabilised disability levels in natalizumab-treated patients with RRMS in clinical practice. Trial registration number NCT00493298. PMID:24532785

  3. The Australian bush fires of February 2009: MIPAS observations and GEM-AQ model results

    NASA Astrophysics Data System (ADS)

    Glatthor, N.; Höpfner, M.; Semeniuk, K.; Lupu, A.; Palmer, P. I.; McConnell, J. C.; Kaminski, J. W.; von Clarmann, T.; Stiller, G. P.; Funke, B.; Kellmann, S.; Linden, A.; Wiegele, A.

    2012-06-01

    On 7 February 2009, and the following days Southeast Australia was devastated by large bush fires, which burned an area of about 3000 km2. This event was extraordinary, because a large number of combustion products was transported into the uppermost troposphere and lower stratosphere within a few days. Various biomass burning products released by the fire were observed by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on the ENVISAT satellite. We track the plume using MIPAS C2H2, HCN and HCOOH single-scan measurements on a day-to-day basis. The measurements are compared with a high-resolution model run of the Global Environmental Multiscale-Air Quality (GEM-AQ) model. Generally there is very good agreement between the spatial distribution of measured and modelled pollutants during the first two weeks after the outbreak of the fire even over intercontinental distances. Both MIPAS and GEM-AQ show a fast south-eastward transport of the pollutants to New Zealand within one day. During the following 3-4 days the plume was located north and eastward of New Zealand and centered at altitudes of 15 to 18 km. Thereafter its eastern part was transported eastward at altitudes of 15-16 km, followed by westward transport of its western part at somewhat higher altitudes. On 17 February the eastern part had reached Southern South America and on 20 February the South African west coast. On the latter day a second relic of the plume was observed moving eastward above the Southern Pacific, whereas the westward transported pollutants were located above Australia at altitudes of 18-20 km. First evidence for entry of the pollutants into the stratosphere was found in MIPAS data of 11 February, followed by larger amounts on 17 February and the days thereafter. Between 20 February and the first week of March the stratospheric pollutants above Australia were transported further westward over the Indian Ocean towards Southern Africa.

  4. Optical constants of Titan aerosols and their tholins analogs: Experimental results and modeling/observational data

    NASA Astrophysics Data System (ADS)

    Brassé, Coralie; Muñoz, Olga; Coll, Patrice; Raulin, François

    2015-05-01

    Since Bishun Khare's pioneer works on Titan tholins, many studies have been performed to improve the experimental database of the optical constants of Titan tholins. The determination of the optical constants of Titan aerosols is indeed essential to quantify their capacity to absorb and scatter solar radiation, and thus to evaluate their role on Titan's radiative balance and climate. The study of the optical properties is also crucial to analyze and better interpret many of Titan's observational data, in particular those acquired during the Cassini-Huygens mission. This review paper critically summarizes these new results and presents constraints on Titan's aerosols optical constants. Finally, the information lacking in this field is highlighted as well as some possible investigations that could be carried out to fill these gaps.

  5. Results of instrumental observations of tidal wave propagation in the atmosphere

    NASA Astrophysics Data System (ADS)

    Adushkin, V. V.; Spivak, A. A.; Kharlamov, V. A.

    2016-07-01

    This paper presents the results of processing and analysis of acoustic waves in the surface layer of the atmosphere, registered at the Mikhnevo Geophysical Observatory, Institute of Geosphere Dynamics, Russian Academy of Sciences (IGD RAS). Using the autoregression model of digital series, the spectrum of acoustic oscillations was evaluated and the tidal waves in the envelopes of acoustic oscillations were distinguished. The tidal components with similar periods were separated using the method of extraction of harmonic components by using adaptive notch filters. The observed features of the spectrum of acoustic oscillations open up new opportunities for instrumental control over meteorological conditions and the establishment of general regularities controlling the regimes of energy-exchange processes in the Earth's atmosphere.

  6. Conversations between community-based neurologists and patients with epilepsy: results of an observational linguistic study.

    PubMed

    Gilliam, Frank; Penovich, Patricia E; Eagan, Corey A; Stern, John M; Labiner, David M; Onofrey, Meaghan; Holmes, Gregory L; Mathis, Eileen; Cramer, Joyce

    2009-10-01

    An in-office linguistic study was conducted to assess neurologist-patient discussions of epilepsy. Naturally occurring interactions among 20 neurologists and 60 of their patients with epilepsy were recorded. Participants were interviewed separately postvisit. Transcripts were analyzed using sociolinguistic techniques. Of 59 patients taking antiepileptic drugs previsit, 44 (75%) discussed side effects with their neurologist. Side effect discussions were most often neurologist initiated. Postvisit, patients and neurologists often disagreed about which side effects were experienced. The presence of a caregiver (e.g., spouse) usually resulted in lengthier, more detailed discussions of side effects, without drastically increasing overall visit length. Discussions of mood- and behavior-related comorbidities occurred infrequently (14 of 60 visits); postvisit, neurologists stated that they felt that management of these conditions was outside their area of expertise. Communication gaps observed in discussions of epilepsy and its treatment warrant further exploration. Additional research is currently underway to assess the efficacy of a previsit assessment tool. PMID:19720567

  7. Initiation of insulin aspart to Indian subjects on OADs show significant improvement in glycaemic outcomes: the A1chieve observational study.

    PubMed

    Rao, P V; Bhattacharyya, A; Sahay, R K

    2013-01-01

    The prevalence of diabetes is increasing worldwide and India stands second next only to china. The management of diabetes in real life settings needs to be evaluated for deriving better management practices. A1chieve observational study evaluated the use of modern insulin in real life settings. This was a 24-week, international, prospective, multicenter, non-interventional, observational study of people with type 2 diabetes. India recruited with 20,554 subjects and a total of 1815 patients were enrolled to receive insulin aspart as bolus insulin therapy of whom 1450 (79.9%) were insulin naïve and 365 (20.1%) were insulin users. At the end of 24 weeks, only one SAE was reported in this study and overall hypoglycemia events per patient year decreased from 2.49 (348 episodes) to 0.17 (20 episodes). There were no major hypoglycemic episodes reported in either insulin naive or insulin treated subjects. There was a significant improvement in the HbA(1c) values from the baseline in both insulin naive and insulin users. The mean HbA(1c) value was reduced from 9.5 to 7.4 (p < 0.001) for insulin naïve subjects and from 9.2 to 7.7 (p < 0.001) in insulin experienced subjects. Fasting plasma glucose values decreased by 70 mg/dL and 50 mg/dL in insulin naive and insulin experienced, respectively and the difference from baseline was statistically significant (P < 0.001). The post prandial glucose value was also significantly (p < 0.001) reduced by 105 mg/dL for insulin naïve subjects and 55 mg/dL for insulin experienced subjects. The composite end point was achieved by 46.6% of insulin naive and 38.1% of insulin-experienced subjects. The study concluded with good HbA(1c) reduction along with lower incidence of hypoglycemia and better health related quality of life outcomes in both in insulin naive and insulin experienced subjects who used insulin aspart as bolus insulin treatment. PMID:24482983

  8. Linear and circular polarimetry of recent comets: Observational results for eight comets

    NASA Astrophysics Data System (ADS)

    Rosenbush, V.; Ivanova, A.; Kiselev, N.; Afanasiev, V.; Kolesnikov, S.; Shakhovskoy, D.

    2014-07-01

    We present the results of polarimetric observations for a number of recent comets carried out at the 6-m telescope of the Special Astrophysical Observatory (Russia) and the 2.6-m telescope of the Crimean Astrophysical Observatory (Ukraine) during 2011--2013. Comets 103P/Hartley 2, C/2009 P1 (Garradd), C/2011 L4 (PANSTARRS), C/2012 S1 (ISON), C/2013 R1 (Lovejoy), 29P/Schwassmann-Wachmann 1, C/2010 S1 (LINEAR), and C/2011 R1 (McNaught) were observed at different distances from the Sun (0.9--6.3 au) and at different phase angles (6.2--83.5 deg). The results obtained are compared with the phase-angle dependencies of linear polarization typical for the high-polarization and low-polarization comets. The linear polarization of comet S1 (LINEAR) and Schwassmann-Wachmann 1 are the first ever measured at the heliocentric distances larger than 6 au. The maps of circular polarization over the coma and its variations with the distance from the nucleus of comets P1 (Garradd), L4 (PANSTARRS), R1 (McNaught), and Schwassmann-Wachmann 1 are obtained. In all cases, left-handed circular polarization is detected and its value is within the range from -0.04 % up to -0.3 %. Detection of left-handed circular polarization in these comets has confirmed our previous conclusion that circular polarization of comets is predominantly left-handed. We will discuss the possible reasons for the diversity and similarity of linear and circular polarization in comets.

  9. Global ozone observations from the UARS MLS: An overview of zonal-mean results

    NASA Technical Reports Server (NTRS)

    Froidevaux, Lucien; Waters, Joe W.; Read, William G.; Elson, Lee S.; Flower, Dennis A.; Jarnot, Robert F.

    1994-01-01

    Global ozone observations from the Microwave Limb Sounder (MLS) aboard the Upper Atmosphere Research Satellite (UARS) are presented, in both vertically resolved and column abundance formats. The authors review the zonal-mean ozone variations measured over the two and a half years since launch in September 1991. Well-known features such as the annual and semiannual variations are ubiquitous. In the equatorial regions, longer-term changes are believed to be related to the quasi-biennial oscillation (QBO), with a strong semiannual signal above 20 hPa. Ozone values near 50 hPa exhibit an equatorial low from October 1991 to June 1992, after which the low ozone pattern splits into two subtropical lows (possibly in connection with residual circulation changes tied to the QBO) and returns to an equatorial low in September 1993. The ozone hole development at high southern latitudes is apparent in MLS column data integrated down to 100 hPa, the MLS data reinforce current knowledge of this lower-stratospheric phenomenon by providing a height-dependent view of the variations. The region from 30 deg S to 30 deg N (an area equal to half the global area) shows very little change in the ozone column from year to year and within each year. The most striking ozone changes have occurred at northern midlatitudes, with the October 1992 to July 1993 column values significantly lower than during the prior year. The zonal-mean changes manifest themselves as a slower rate of increase during the 1992/93 winter, and there is some evidence for a lower fall minimum. A recovery occurs during late summer of 1993; early 1994 values are significantly larger than during the two previous winters. The timing and latitudinal extent of the northern midlatitude decreases appear to rule out observed ClO enhancements in the Arctic vortex, with related chemical processing and ozone dilution effects, as a unique cause. Local depletion from ClO-related chemical mechanisms alone is also not sufficient, based

  10. Carbon and Water Flux Observations from AmeriFlux and Fluxnet: Some Early Results

    NASA Astrophysics Data System (ADS)

    Law, B. E.

    2001-12-01

    Flux networks provide a means for scientists to make common measurements of carbon, water, and energy exchange, to share advancements in methods, and synthesize results across the network. AmeriFlux objectives are to: Determine how environmental factors and climate regulate ecosystem CO2 and H2O exchange over the short- and long-term, evaluate impacts of anthropogenic factors, and provide data and new understanding for incorporation into models. AmeriFlux is part of the larger international network, Fluxnet. Among Fluxnet sites, we investigated seasonal and annual CO2 and water vapor exchange, and relations with environmental variables to elucidate generalities within and among biomes. The data showed a strong linkage between carbon gain and water loss, with the highest water-use efficiency values for grasslands, and lowest values for tundra. Ecosystem respiration was only weakly correlated with mean annual temperature across biomes, in spite of sensitivity within site over shorter temporal scales. Mean annual temperature and site water balanced explained much of the variation in gross photosynthesis, whereby water availability limits LAI over the long-term, and inter-annual climate variability limits carbon uptake below the potential of the leaf area available for photosynthesis. We compared BIOME-BGC model results among AmeriFlux coniferous forests, and the model showed that variation in net ecosystem carbon exchange (NEE) is mostly a function of disturbance history, with important secondary effects from site climate, ecophysiology, and changing atmospheric CO2 and nitrogen deposition.