Superconducting gravimeters reveal unprecedented details of changes related to volcanic processes

NASA Astrophysics Data System (ADS)

Carbone, Daniele; Greco, Filippo; Cannavò, Flavio

2017-04-01

Continuous gravity measurements have been successfully carried out at a number of volcanoes around the world using spring gravimeters. Nevertheless, these instruments do not provide reliable measurements when used in continuous mode for weeks or more, because they are influenced by environmental factors and are subject to instrumental drift. Accordingly, most studies of continuous gravity at active volcanoes have focused on the analysis of changes over time-scales of minutes to a few days. An alternative to spring gravimeters for continuous measurements is given by superconducting gravimeters (SGs) that feature a much higher precision and stability than spring gravimeters. However, even the most portable SGs (e.g., the iGrav® by GWR) are not ideal for installation in the vicinity of active volcanic structures. Indeed, they require AC power at the installation site and some kind of hut or vault to house the instrumentation. At Mt. Etna, the installation of a mini-array of three SGs (distances of 3.5 to 15.5 km from the active craters) was begun in September 2014. To our knowledge, these are the first SGs ever installed on an active volcano. Signals from these instruments show hydrologically-induced components superimposed on small (a few microGal) gravity changes that are related to volcanic processes. Such changes, occurring over periods of minutes to weeks, would not be observable by spring gravimeters due to their intrinsic limitations regarding precision and long-term stability.

Final report on the Seventh International Comparison of Absolute Gravimeters (ICAG 2005)

USGS Publications Warehouse

Jiang, Z.; Francis, O.; Vitushkin, L.; Palinkas, V.; Germak, A.; Becker, M.; D'Agostino, G.; Amalvict, M.; Bayer, R.; Bilker-Koivula, M.; Desogus, S.; Faller, J.; Falk, R.; Hinderer, J.; Gagnon, C.; Jakob, T.; Kalish, E.; Kostelecky, J.; Lee, C.; Liard, J.; Lokshyn, Y.; Luck, B.; Makinen, J.; Mizushima, S.; Le, Moigne N.; Origlia, C.; Pujol, E.R.; Richard, P.; Robertsson, L.; Ruess, D.; Schmerge, D.; Stus, Y.; Svitlov, S.; Thies, S.; Ullrich, C.; Van Camp, M.; Vitushkin, A.; Ji, W.; Wilmes, H.

2011-01-01

The Bureau International des Poids et Mesures (BIPM), S??vres, France, hosted the 7th International Comparison of Absolute Gravimeters (ICAG) and the associated Relative Gravity Campaign (RGC) from August to September 2005. ICAG 2005 was prepared and performed as a metrological pilot study, which aimed: To determine the gravity comparison reference values; To determine the offsets of the absolute gravimeters; and As a pilot study to accumulate experience for the CIPM Key Comparisons. This document presents a complete and extensive review of the technical protocol and data processing procedures. The 1st ICAG-RGC comparison was held at the BIPM in 1980-1981 and since then meetings have been organized every 4 years. In this paper, we present an overview of how the meeting was organized, the conditions of BIPM gravimetric sites, technical specifications, data processing strategy and an analysis of the final results. This 7th ICAG final report supersedes all previously published reports. Readings were obtained from participating instruments, 19 absolute gravimeters and 15 relative gravimeters. Precise levelling measurements were carried out and all measurements were performed on the BIPM micro-gravity network which was specifically designed for the comparison. ?? 2011 BIPM & IOP Publishing Ltd.

Shift evaluation of the atomic gravimeter NIM-AGRb-1 and its comparison with FG5X

NASA Astrophysics Data System (ADS)

Wang, Shao-Kai; Zhao, Yang; Zhuang, Wei; Li, Tian-Chu; Wu, Shu-Qing; Feng, Jin-Yang; Li, Chun-Jian

2018-06-01

A mobile atomic absolute gravimeter NIM-AGRb-1 based on light-pulse atom interferometer has been built, evaluated by the National Institute of Metrology (NIM) China, and participated in the pilot study of the International Comparison of Absolute Gravimeters (CCM.G-K2.2017) held at NIM Changping Beijing in October 2017. The sensitivity of the gravimeter is 44 µGal Hz‑1/2 (1 µGal  =  10‑8 m s‑2  ≈  10‑9 g) and its instability reaches as small as 0.2 µGal when averaged over 30 000 s. The instrumental and environmental effects were evaluated and corrected with a total uncertainty of 5.2 µGal. The absolute g measured by NIM-AGRb-1 was compared to that of a commercial FG5X-249 optical gravimeter with the two devices operating side by side in the same laboratory and their results agree within  ‑0.2(6.3) µGal. NIM-AGRb-1 also demonstrated continuous operation over a period of more than 500 h.

Note: Effect of the parasitic forced vibration in an atom gravimeter

NASA Astrophysics Data System (ADS)

Chen, Le-Le; Luo, Qin; Zhang, Heng; Duan, Xiao-Chun; Zhou, Min-Kang; Hu, Zhong-Kun

2018-06-01

The vibration isolator usually plays an important role in atom interferometry gravimeters to improve their sensitivity. We show that the parasitic forced vibration of the Raman mirror, which is induced by external forces acting on the vibration isolator, can cause a bias in atom gravimeters. The mechanism of how this effect induces an additional phase shift in our interferometer is analyzed. Moreover, modulation experiments are performed to measure the dominant part of this effect, which is caused by the magnetic force between the passive vibration isolator and the coil of the magneto-optic trap. In our current apparatus, this forced vibration contributes a systematic error of -2.3(2) × 10-7 m/s2 when the vibration isolator works in the passive isolation mode. Even suppressed with an active vibration isolator, this effect can still contribute -6(1) × 10-8 m/s2; thus, it should be carefully considered in precision atom gravimeters.

An SINS/GNSS Ground Vehicle Gravimetry Test Based on SGA-WZ02.

PubMed

Yu, Ruihang; Cai, Shaokun; Wu, Meiping; Cao, Juliang; Zhang, Kaidong

2015-09-16

In March 2015, a ground vehicle gravimetry test was implemented in eastern Changsha to assess the repeatability and accuracy of ground vehicle SINS/GNSS gravimeter-SGA-WZ02. The gravity system developed by NUDT consisted of a Strapdown Inertial Navigation System (SINS), a Global Navigation Satellite System (GNSS) remote station on test vehicle, a GNSS static master station on the ground, and a data logging subsystem. A south-north profile of 35 km along the highway in eastern Changsha was chosen and four repeated available measure lines were obtained. The average speed of a vehicle is 40 km/h. To assess the external ground gravity disturbances, precise ground gravity data was built by CG-5 precise gravimeter as the reference. Under relative smooth conditions, internal accuracy among repeated lines shows an average agreement at the level of 1.86 mGal for half wavelengths about 1.1 km, and 1.22 mGal for 1.7 km. The root-mean-square (RMS) of difference between calculated gravity data and reference data is about 2.27 mGal/1.1 km, and 1.74 mGal/1.7 km. Not all of the noises caused by vehicle itself and experiments environments were eliminated in the primary results. By means of selecting reasonable filters and improving the GNSS observation conditions, further developments in ground vehicle gravimetry are promising.

Precision gravimetric survey at the conditions of urban agglomerations

NASA Astrophysics Data System (ADS)

Sokolova, Tatiana; Lygin, Ivan; Fadeev, Alexander

2014-05-01

Large cities growth and aging lead to the irreversible negative changes of underground. The study of these changes at the urban area mainly based on the shallow methods of Geophysics, which extensive usage restricted by technogenic noise. Among others, precision gravimetry is allocated as method with good resistance to the urban noises. The main the objects of urban gravimetric survey are the soil decompaction, leaded to the rocks strength violation and the karst formation. Their gravity effects are too small, therefore investigation requires the modern high-precision equipment and special methods of measurements. The Gravimetry division of Lomonosov Moscow State University examin of modern precision gravimeters Scintrex CG-5 Autograv since 2006. The main performance characteristics of over 20 precision gravimeters were examined in various operational modes. Stationary mode. Long-term gravimetric measurements were carried at a base station. It shows that records obtained differ by high-frequency and mid-frequency (period 5 - 12 hours) components. The high-frequency component, determined as a standard deviation of measurement, characterizes the level of the system sensitivity to external noise and varies for different devices from 2 to 5-7 μGals. Midrange component, which closely meet to the rest of nonlinearity gravimeter drifts, is partially compensated by the equipment. This factor is very important in the case of gravimetric monitoring or observations, when midrange anomalies are the target ones. For the examined gravimeters, amplitudes' deviations, associated with this parameter may reach 10 μGals. Various transportation modes - were performed by walking (softest mode), lift (vertical overload), vehicle (horizontal overloads), boat (vertical plus horizontal overloads) and helicopter. The survey quality was compared by the variance of the measurement results and internal convergence of series. The measurement results variance (from ±2 to ±4 μGals) and its internal convergence are independent on transportation mode. Actually, measurements differ just by the processing time and appropriate number of readings. Important, that the internal convergence is the individual attribute of particular device. For the investigated gravimeters it varies from ±3 up to ±8 μGals. Various stability of the gravimeters location base. The most stable basis (minimum microseisms) in this experiment was a concrete pedestal, the least stable - point on the 28th floor. There is no direct dependence of the measurement results variance at the external noise level. Moreover, the external dispersion between different gravimeters is minimal in the point of the highest microseisms. Conclusions. The quality of the modern high-precision gravimeters Scintrex CG-5 Autograv measurements is determined by stability of the particular device, its standard deviation value and the nonlinearity drift degree. Despite the fact, that mentioned parameters of the tested gravimeters, generally corresponded to the factory characters, for the surveys required accuracy ±2-5 μGals, the best gravimeters should be selected. Practical gravimetric survey with such accuracy allowed reliable determination of the position of technical communication boxes and underground walkway in the urban area, indicated by gravity minimums with the amplitudes from 6-8 μGals and 1 - 15 meters width. The holes' parameters, obtained as the result of interpretationare well aligned with priori data.

The Austrian absolute gravity base net: 27 years of spatial and temporal acquisition of gravity data

NASA Astrophysics Data System (ADS)

Ullrich, Christian; Ruess, Diethard

2014-05-01

Since 1987 the BEV (Federal Office of Metrology and Surveying) has been operating the absolute gravimeters JILAg-6 and FG5 which are used for basic measurements to determine or review fundamental gravity stations in Austria and abroad. Overall more than 70 absolute gravity stations were installed in Austria and neighbouring countries and some of them have been regularly monitored. A few stations are part of international projects like ECGN (European Combined Geodetic network) and UNIGRACE (Unification of Gravity System in Central and Eastern Europe). As a national metrology institute (NMI) the Metrology Service of the BEV maintains the national standards for the realisation of the legal units of measurement and ensures their international equivalence and recognition. Thus the BEV maintains the national standard for gravimetry in Austria, which is validated and confirmed by international comparisons. Since 1989 the Austrian absolute gravimeters participated seven times in the ICAG's (International Comparison of Absolute Gravimeters) at the BIPM in Paris and Luxemburg and as well participated three times at the ECAG (European Comparison of Absolute Gravimeters) in Luxemburg. The results of these ICAG's and especially the performance of the Austrian absolute gravimeter are reported in this presentation. We also present some examples and interpretation of long time monitoring stations of absolute gravity in several Austrian locations. Some stations are located in large cities like Vienna and Graz and some others are situated in mountainous regions. Mountain stations are at the Conrad Observatory where a SG (Superconducting Gravimeter) is permanently monitoring and in Obergurgl (Tyrolia) at an elevation of approx. 2000 m which is very strong influenced from the glacier retreat.

Lunar surface gravimeter experiment

NASA Technical Reports Server (NTRS)

Giganti, J. J.; Larson, J. V.; Richard, J. P.; Tobias, R. L.; Weber, J.

1977-01-01

The lunar surface gravimeter used the moon as an instrumented antenna to search for gravitational waves predicted by Einstein's general theory of relativity. Tidal deformation of the moon was measured. Gravitational radiation is a channel that is capable of giving information about the structure and evolution of the universe.

Superconducting-Gravimeter Tests of Local Lorentz Invariance

NASA Astrophysics Data System (ADS)

Flowers, Natasha A.; Goodge, Casey; Tasson, Jay D.

2017-11-01

Superconducting-gravimeter measurements are used to test the local Lorentz invariance of the gravitational interaction and of matter-gravity couplings. The best laboratory sensitivities to date are achieved via a maximum-reach analysis for 13 Lorentz-violating operators, with some improvements exceeding an order of magnitude.

Superconducting-Gravimeter Tests of Local Lorentz Invariance.

PubMed

Flowers, Natasha A; Goodge, Casey; Tasson, Jay D

2017-11-17

Superconducting-gravimeter measurements are used to test the local Lorentz invariance of the gravitational interaction and of matter-gravity couplings. The best laboratory sensitivities to date are achieved via a maximum-reach analysis for 13 Lorentz-violating operators, with some improvements exceeding an order of magnitude.

Microelectromechanical system gravimeters as a new tool for gravity imaging.

PubMed

Middlemiss, Richard P; Bramsiepe, Steven G; Douglas, Rebecca; Hild, Stefan; Hough, James; Paul, Douglas J; Samarelli, Antonio; Rowan, Sheila; Hammond, Giles D

2018-05-28

A microelectromechanical system (MEMS) gravimeter has been manufactured with a sensitivity of 40 ppb in an integration time of 1 s. This sensor has been used to measure the Earth tides: the elastic deformation of the globe due to tidal forces. No such measurement has been demonstrated before now with a MEMS gravimeter. Since this measurement, the gravimeter has been miniaturized and tested in the field. Measurements of the free-air and Bouguer effects have been demonstrated by monitoring the change in gravitational acceleration measured while going up and down a lift shaft of 20.7 m, and up and down a local hill of 275 m. These tests demonstrate that the device has the potential to be a useful field-portable instrument. The development of an even smaller device is underway, with a total package size similar to that of a smartphone.This article is part of a discussion meeting issue 'The promises of gravitational-wave astronomy'. © 2018 The Author(s).

Microelectromechanical system gravimeters as a new tool for gravity imaging

NASA Astrophysics Data System (ADS)

Middlemiss, Richard P.; Bramsiepe, Steven G.; Douglas, Rebecca; Hild, Stefan; Hough, James; Paul, Douglas J.; Samarelli, Antonio; Rowan, Sheila; Hammond, Giles D.

2018-05-01

A microelectromechanical system (MEMS) gravimeter has been manufactured with a sensitivity of 40 ppb in an integration time of 1 s. This sensor has been used to measure the Earth tides: the elastic deformation of the globe due to tidal forces. No such measurement has been demonstrated before now with a MEMS gravimeter. Since this measurement, the gravimeter has been miniaturized and tested in the field. Measurements of the free-air and Bouguer effects have been demonstrated by monitoring the change in gravitational acceleration measured while going up and down a lift shaft of 20.7 m, and up and down a local hill of 275 m. These tests demonstrate that the device has the potential to be a useful field-portable instrument. The development of an even smaller device is underway, with a total package size similar to that of a smartphone. This article is part of a discussion meeting issue `The promises of gravitational-wave astronomy'.

Educational Inductive Gravimeter

ERIC Educational Resources Information Center

Nunn, John

2014-01-01

A simple inductive gravimeter constructed from a rigid plastic pipe and insulated copper wire is described. When a magnet is dropped through the vertically mounted pipe it induces small alternating voltages. These small signals are fed to the microphone input of a typical computer and sampled at a typical rate of 44.1 kHz using a custom computer…

SGA-WZ: A New Strapdown Airborne Gravimeter

PubMed Central

Huang, Yangming; Olesen, Arne Vestergaard; Wu, Meiping; Zhang, Kaidong

2012-01-01

Inertial navigation systems and gravimeters are now routinely used to map the regional gravitational quantities from an aircraft with mGal accuracy and a spatial resolution of a few kilometers. However, airborne gravimeter of this kind is limited by the inaccuracy of the inertial sensor performance, the integrated navigation technique and the kinematic acceleration determination. As the GPS technique developed, the vehicle acceleration determination is no longer the limiting factor in airborne gravity due to the cancellation of the common mode acceleration in differential mode. A new airborne gravimeter taking full advantage of the inertial navigation system is described with improved mechanical design, high precision time synchronization, better thermal control and optimized sensor modeling. Apart from the general usage, the Global Positioning System (GPS) after differentiation is integrated to the inertial navigation system which provides not only more precise altitude information along with the navigation aiding, but also an effective way to calculate the vehicle acceleration. Design description and test results on the performance of the gyroscopes and accelerations will be emphasized. Analysis and discussion of the airborne field test results are also given. PMID:23012545

Linear ultrasonic motor for absolute gravimeter.

PubMed

Jian, Yue; Yao, Zhiyuan; Silberschmidt, Vadim V

2017-05-01

Thanks to their compactness and suitability for vacuum applications, linear ultrasonic motors are considered as substitutes for classical electromagnetic motors as driving elements in absolute gravimeters. Still, their application is prevented by relatively low power output. To overcome this limitation and provide better stability, a V-type linear ultrasonic motor with a new clamping method is proposed for a gravimeter. In this paper, a mechanical model of stators with flexible clamping components is suggested, according to a design criterion for clamps of linear ultrasonic motors. After that, an effect of tangential and normal rigidity of the clamping components on mechanical output is studied. It is followed by discussion of a new clamping method with sufficient tangential rigidity and a capability to facilitate pre-load. Additionally, a prototype of the motor with the proposed clamping method was fabricated and the performance tests in vertical direction were implemented. Experimental results show that the suggested motor has structural stability and high dynamic performance, such as no-load speed of 1.4m/s and maximal thrust of 43N, meeting the requirements for absolute gravimeters. Copyright © 2017 Elsevier B.V. All rights reserved.

Miniaturised Gravity Sensors for Remote Gravity Surveys.

NASA Astrophysics Data System (ADS)

Middlemiss, R. P.; Bramsiepe, S. G.; Hough, J.; Paul, D. J.; Rowan, S.; Samarelli, A.; Hammond, G.

2016-12-01

Gravimetry lets us see the world from a completely different perspective. The ability to measure tiny variations in gravitational acceleration (g), allows one to see not just the Earth's gravitational pull, but the influence of smaller objects. The more accurate the gravimeter, the smaller the objects one can see. Gravimetry has applications in many different fields: from tracking magma moving under volcanoes before eruptions; to locating hidden tunnels. The top commercial gravimeters weigh tens of kg and cost at least $100,000, limiting the situations in which they can be used. By contrast, smart phones use a MEMS (microelectromechanical system) accelerometer that can measure the orientation of the device. These are not nearly sensitive or stable enough to be used for the gravimetry but they are cheap, light-weight and mass-producible. At Glasgow University we have developed a MEMS device with both the stability and sensitivity for useful gravimetric measurements. This was demonstrated by a measurement of the Earth tides - the first time this has been achieved with a MEMS sensor. A gravimeter of this size opens up the possiblility for new gravity imaging modalities. Thousands of gravimeters could be networked over a survey site, storing data on an SD card or communicating wirelessly to a remote location. These devices could also be small enough to be carried by a UAVs: airborne gravity surveys could be carried out at low altitude by mulitple UAVs, or UAVs could be used to deliver ground based gravimeters to remote or inaccessible locations.

First Impressions of a Scintrex CG-6 Portable Gravimeter in an Extensive Field Campaign

NASA Astrophysics Data System (ADS)

van Westrum, D.; Kanney, J.

2017-12-01

First Impressions of a Scintrex CG-6 Portable Gravimeter in an Extensive Field Campaign AGU Fall Meeting 2017 Derek van Westrum and Jeff Kanney NOAA's National Geodetic Survey conducted its third and final Geoid Slope Validation Survey (GSVS) this past summer in the rugged mountains of southern Colorado. In addition to leveling, long period GPS, and defelction of vertical observations, absolute gravity and vertical gravity gradients were measured at 235 bench marks (approximately 1.5 km spacing) along US-160 between Durango and Walsenburg, Colorado. In previous surveys (Texas-2011 and Iowa-2014), an A10 absolute gravimeter was used to measure graivty at approximately 10-15% of the bench marks. The remaining marks were determined by using LaCoste & Romberg relative gravimeters. The same relative instruments were also used to measure two-tier (linear) vertical gravity gradients at the A10 sites. In the current work - becuase of the rapidly changing terrain in the Rocky Mountains - it was decided to employ the A10 at all 235 bench marks, and acquire three-tier (quadratic) gradients at every bench mark using the new Scintrex CG-6 Autograv relative gravimeter. Using these results, we will provide a real worldsummary of the CG-6's behavior by examining noise levels, repeatability, and acquisition rates. In addition, the coincident A10 absolute data set allows us to evaluate the CG-6's accuracy, and allows us to simulate and discuss various relative gravity survey designs.

Analyses of a 426-Day Record of Seafloor Gravity and Pressure Time Series in the North Sea

NASA Astrophysics Data System (ADS)

Rosat, S.; Escot, B.; Hinderer, J.; Boy, J.-P.

2017-04-01

Continuous gravity observations of ocean and solid tides are usually done with land-based gravimeters. In this study, we analyze a 426-day record of time-varying gravity acquired by an ocean-bottom Scintrex spring gravimeter between August 2005 and November 2006 at the Troll A site located in the North Sea at a depth of 303 m. Sea-bottom pressure changes were also recorded in parallel with a Paroscientific quartz pressure sensor. From these data, we show a comparison of the noise level of the seafloor gravimeter with respect to two standard land-based relative gravimeters: a Scintrex CG5 and a GWR Superconducting Gravimeter that were recording at the J9 gravimetric observatory of Strasbourg (France). We also compare the analyzed gravity records with the predicted solid and oceanic tides. The oceanic tides recorded by the seafloor barometer are also analyzed and compared to the predicted ones using FES2014b ocean model. Observed diurnal and semi-diurnal components are in good agreement with FES2014b predictions. Smallest constituents reflect some differences that may be attributed to non-linearity occurring at the Troll A site. Using the barotropic TUGO-m dynamic model of sea-level response to ECMWF atmospheric pressure and winds forcing, we show a good agreement with the detided ocean-bottom pressure residuals. About 4 hPa of standard deviation of remaining sea-bottom pressure are, however, not explained by the TUGO-m dynamic model.

Moving-mass gravimeter calibration in the Mátyáshegy Gravity and Geodynamical Observatory (Budapest)

NASA Astrophysics Data System (ADS)

Kis, Márta; Koppán, Andras; Kovács, Péter; Merényi, László

2014-05-01

A gravimeter calibration facility exists in the Mátyáshegy Gravity and Geodynamical Observatory of Geological and Geophysical Institute in Hungary. During the calibration a cylindrical ring of 3200 kg mass is vertically moving around the equipment, generating gravity variations. The effect of the moving mass can be precisely calculated from the known mass and geometrical parameters. The main target of the calibration device was to reach a relative accuracy of 0.1-0.2% for the calibration of Earth-tide registering gravimeters. The maximum theoretical gravity variation produced by the vertical movement of the mass is ab. 110 microGal, so it provides excellent possibility for the fine calibration of gravimeters in the tidal range. The instrument was out of order for many years and in 2012 and 2013 it was renovated and automatized. The calibration process is aided by intelligent controller electronics. A new PLC-based system has been developed to allow easy control of the movement of the calibrating mass and to measure the mass position. It enables also programmed steps of movements (waiting positions and waiting times) for refined gravity changes. All parameters (position of the mass, CPI data, X/Y leveling positions) are recorded with 1/sec. sampling rate. The system can be controlled remotely through the internet. As it is well known that variations of the magnetic field can influence the measurements of metal-spring gravimeters, authors carried out magnetic experiments on the pillar of the calibration device as well, in order to analyze the magnetic effect of the moving stainless steel-mass. During the movements of the mass, the observed magnetic field has been changed significantly. According to the magnetic measurements, a correction for the magnetic effect was applied on the measured gravimetric data series. In this presentation authors show the facility in details and the numerical results of tests carried out by applying LCR G gravimeters.

Time stability of spring and superconducting gravimeters through the analysis of very long gravity records

NASA Astrophysics Data System (ADS)

Calvo, Marta; Hinderer, Jacques; Rosat, Severine; Legros, Hilaire; Boy, Jean-Paul; Ducarme, Bernard; Zürn, Walter

2014-10-01

Long gravity records are of great interest when performing tidal analyses. Indeed, long series enable to separate contributions of near-frequency waves and also to detect low frequency signals (e.g. long period tides and polar motion). In addition to the length of the series, the quality of the data and the temporal stability of the noise are also very important. We study in detail some of the longest gravity records available in Europe: 3 data sets recorded with spring gravimeters in Black Forest Observatory (Germany, 1980-2012), Walferdange (Luxemburg, 1980-1995) and Potsdam (Germany, 1974-1998) and several superconducting gravimeters (SGs) data sets, with at least 9 years of continuous records, at different European GGP (Global Geodynamics Project) sites (Bad Homburg, Brussels, Medicina, Membach, Moxa, Vienna, Wettzell and Strasbourg). The stability of each instrument is investigated using the temporal variations of tidal parameters (amplitude factor and phase difference) for the main tidal waves (O1, K1, M2 and S2) as well as the M2/O1 factor ratio, the later being insensitive to the instrumental calibration. The long term stability of the tidal observations is also dependent on the stability of the scale factor of the relative gravimeters. Therefore we also check the time stability of the scale factor for the superconducting gravimeter C026 installed at the J9 Gravimetric Observatory of Strasbourg (France), using numerous calibration experiments carried out by co-located absolute gravimeter (AG) measurements during the last 15 years. The reproducibility of the scale factor and the achievable precision are investigated by comparing the results of different calibration campaigns. Finally we present a spectrum of the 25 years of SG records at J9 Observatory, with special attention to small amplitude tides in the semi-diurnal and diurnal bands, as well as to the low frequency part.

A historical review of gravimetric observations in Norway

NASA Astrophysics Data System (ADS)

Ragnvald Pettersen, Bjørn

2016-10-01

The first gravity determinations in Norway were made by Edward Sabine in 1823 with a pendulum instrument by Henry Kater. Seventy years later a Sterneck pendulum was acquired by the Norwegian Commission for the International Arc Measurements. It improved the precision and eventually reduced the bias of the absolute calibration from 85 to 15 mGal. The last pendulum observations in Norway were made in 1955 with an instrument from Cambridge University. At a precision of ±1 mGal, the purpose was to calibrate a section of the gravity line from Rome, Italy, to Hammerfest, Norway. Relative spring gravimeters were introduced in Norway in 1946 and were used to densify and expand the national gravity network. These data were used to produce regional geoids for Norway and adjacent ocean areas. Improved instrument precision allowed them to connect Norwegian and foreign fundamental stations as well. Extensive geophysical prospecting was made, as in other countries. The introduction of absolute gravimeters based on free-fall methods, especially after 2004, improved the calibration by 3 orders of magnitude and immediately revealed the secular changes of the gravity field in Norway. This was later confirmed by satellite gravimetry, which provides homogeneous data sets for global and regional gravity models. The first-ever determinations of gravity at sea were made by pendulum observations onboard the Norwegian polar vessel Fram during frozen-in conditions in the Arctic Ocean in 1893-1896. Simultaneously, an indirect method was developed at the University of Oslo for deducing gravity at sea with a hypsometer. The precision of both methods was greatly superseded by relative spring gravimeters 50 years later. They were employed extensively both at sea and on land. When GPS allowed precise positioning, relative gravimeters were mounted in airplanes to cover large areas of ocean faster than before. Gravimetry is currently being applied to study geodynamical phenomena relevant to climate change. The viscoelastic postglacial land uplift of Fennoscandia has been detected by terrestrial gravity time series as well as by satellite gravimetry. Corrections for local effects of snow load, hydrology, and ocean loading at coastal stations have been improved. The elastic adjustment of present-day melting of glaciers at Svalbard and in mainland Norway has been detected. Gravimetry is extensively employed at offshore oil facilities to monitor the subsidence of the ocean floor during oil and gas extraction.

Continuous gravimetric monitoring as an integrative tool for exploring hydrological processes in the Lomme Karst System (Belgium)

NASA Astrophysics Data System (ADS)

Watlet, A.; Van Camp, M. J.; Poulain, A.; Hallet, V.; Rochez, G.; Quinif, Y.; Meus, P.; Kaufmann, O.; Francis, O.

2016-12-01

Karst systems are highly heterogeneous which makes their hydrology difficult to understand. Geophysical techniques offer non-invasive and integrative methods that help interpreting such systems as a whole. Among these techniques, gravimetry has been increasingly used in the last decade to characterize the hydrological behavior of complex systems, e.g. karst environments or volcanoes. We present a continuous microgravimetric monitoring of 3 years in the karstic area of Rochefort (Belgium), that shows multiple occurrences of caves and karstic features. The gravity record includes measurements of a GWR superconducting gravimeter, a Micro-g LaCoste gPhone and an absolute FG5 gravimeter. Together with meteorological measurements and a surface/in-cave hydrogeological monitoring, we were able to improve the knowledge of hydrological processes. On the one hand, the data allowed identifying seasonal groundwater content changes in the unsaturated zone of the karst area, most likely to be linked to temporary groundwater storage occurring in the most karstified layers closed to the surface. Combined with additional geological information, modelling of the gravity signal based on the vertical potential of the gravitational attraction was then particularly useful to estimate the seasonal recharge leading to the temporary subsurface groundwater storage. On the other hand, the gravity monitoring of flash floods occurring in deeper layers after intense rainfall events informed on the effective porosity gradient of the limestones. Modelling was then helpful to identify the hydrogeological role played by the cave galleries with respect to the hosting limestones during flash floods. These results are also compared with measurements of an in-cave gravimetric monitoring performed with a gPhone spring gravimeter. An Electrical Resistivity Tomography monitoring is also conducted at site and brings additional information useful to verify the interpretation made with the gravimetric monitoring.

Corrigendum to ``Time stability of spring and superconducting gravimeters through the analysis of very long gravity record'' [J. Geodyn. 80, (2014) 20-33

NASA Astrophysics Data System (ADS)

Calvo, M.; Hinderer, J.; Rosat, S.; Legros, H.; Boy, J.-P.; Ducarme, B.; Zürn, W.

2017-05-01

In the paper ;Time stability of spring and superconducting gravimeters through the analysis of very long gravity record; by M. Calvo et al. (J. Geodyn. Vol. 80, pp. 20-33, doi:10.1016/j.jog.2014.04.009), Figs. 13 and 16 are incorrect.

Comment on ‘Relativistic theory of the falling retroreflector gravimeter’

NASA Astrophysics Data System (ADS)

Křen, Petr; Pálinkáš, Vojtech

2018-04-01

In the paper by Ashby (2018 Metrologia 55 1-10) the correction due to the time delay of light propagated through the prism retroreflector of absolute gravimeters is discussed. Accordingly, the correction of about  -6.8 µGal should be applied for a typical gravimeter such as the most precise FG5(X) gravimeter declaring standard uncertainty at the level of 2 µGal. In consequence, the present gravimetric results related to the Kibble balance or the global absolute gravity reference system should be significantly changed. However, such a change needs a deeper scientific consensus. In our comment, we would like to show that the proposed correction should not be applied since the author’s consideration is incorrect.

Linking Comparisons of Absolute Gravimeters: A Proof of Concept for a new Global Absolute Gravity Reference System.

NASA Astrophysics Data System (ADS)

Wziontek, H.; Palinkas, V.; Falk, R.; Vaľko, M.

2016-12-01

Since decades, absolute gravimeters are compared on a regular basis on an international level, starting at the International Bureau for Weights and Measures (BIPM) in 1981. Usually, these comparisons are based on constant reference values deduced from all accepted measurements acquired during the comparison period. Temporal changes between comparison epochs are usually not considered. Resolution No. 2, adopted by IAG during the IUGG General Assembly in Prague 2015, initiates the establishment of a Global Absolute Gravity Reference System based on key comparisons of absolute gravimeters (AG) under the International Committee for Weights and Measures (CIPM) in order to establish a common level in the microGal range. A stable and unique reference frame can only be achieved, if different AG are taking part in different kind of comparisons. Systematic deviations between the respective comparison reference values can be detected, if the AG can be considered stable over time. The continuous operation of superconducting gravimeters (SG) on selected stations further supports the temporal link of comparison reference values by establishing a reference function over time. By a homogenous reprocessing of different comparison epochs and including AG and SG time series at selected stations, links between several comparisons will be established and temporal comparison reference functions will be derived. By this, comparisons on a regional level can be traced to back to the level of key comparisons, providing a reference for other absolute gravimeters. It will be proved and discussed, how such a concept can be used to support the future absolute gravity reference system.

Field Tests of a Portable MEMS Gravimeter

PubMed Central

Bramsiepe, Steven G.; Douglas, Rebecca; Hough, James; Hammond, Giles D.

2017-01-01

Gravimeters are used to measure density anomalies under the ground. They are applied in many different fields from volcanology to oil and gas exploration, but present commercial systems are costly and massive. A new type of gravity sensor has been developed that utilises the same fabrication methods as those used to make mobile phone accelerometers. In this study, we describe the first results of a field-portable microelectromechanical system (MEMS) gravimeter. The stability of the gravimeter is demonstrated through undertaking a multi-day measurement with a standard deviation of 5.58×10−6 ms−2. It is then demonstrated that a change in gravitational acceleration of 4.5×10−5 ms−2 can be measured as the device is moved between the top and the bottom of a 20.7 m lift shaft with a signal-to-noise ratio (SNR) of 14.25. Finally, the device is demonstrated to be stable in a more harsh environment: a 4.5×10−4 ms−2 gravity variation is measured between the top and bottom of a 275-m hill with an SNR of 15.88. These initial field-tests are an important step towards a chip-sized gravity sensor. PMID:29117099

Field Tests of a Portable MEMS Gravimeter.

PubMed

Middlemiss, Richard P; Bramsiepe, Steven G; Douglas, Rebecca; Hough, James; Paul, Douglas J; Rowan, Sheila; Hammond, Giles D

2017-11-08

Gravimeters are used to measure density anomalies under the ground. They are applied in many different fields from volcanology to oil and gas exploration, but present commercial systems are costly and massive. A new type of gravity sensor has been developed that utilises the same fabrication methods as those used to make mobile phone accelerometers. In this study, we describe the first results of a field-portable microelectromechanical system (MEMS) gravimeter. The stability of the gravimeter is demonstrated through undertaking a multi-day measurement with a standard deviation of 5.58 × 10 - 6 ms - 2 . It is then demonstrated that a change in gravitational acceleration of 4.5 × 10 - 6 ms - 2 can be measured as the device is moved between the top and the bottom of a 20.7 m lift shaft with a signal-to-noise ratio (SNR) of 14.25. Finally, the device is demonstrated to be stable in a more harsh environment: a 4.5 × 10 - 4 ms - 2 gravity variation is measured between the top and bottom of a 275-m hill with an SNR of 15.88. These initial field-tests are an important step towards a chip-sized gravity sensor.

High precision tide spectroscopy. [using the superconducting gravimeter

NASA Technical Reports Server (NTRS)

Goodkind, J. M.

1978-01-01

Diurnal and long period earth tides were measured to high accuracy and precision with the superconducting gravimeter. The results provide new evidence on the geophysical questions which have been attacked through earth tide measurements in the past. In addition, they raise new questions of potential interest. Slow fluctuations in gravity of order 10 micron gal over periods of 3 to 5 months were observed and are discussed.

Data reduction and tying in regional gravity surveys—results from a new gravity base station network and the Bouguer gravity anomaly map for northeastern Mexico

NASA Astrophysics Data System (ADS)

Hurtado-Cardador, Manuel; Urrutia-Fucugauchi, Jaime

2006-12-01

Since 1947 Petroleos Mexicanos (Pemex) has conducted oil exploration projects using potential field methods. Geophysical exploration companies under contracts with Pemex carried out gravity anomaly surveys that were referred to different floating data. Each survey comprises observations of gravity stations along highways, roads and trails at intervals of about 500 m. At present, 265 separate gravimeter surveys that cover 60% of the Mexican territory (mainly in the oil producing regions of Mexico) are available. This gravity database represents the largest, highest spatial resolution information, and consequently has been used in the geophysical data compilations for the Mexico and North America gravity anomaly maps. Regional integration of gravimeter surveys generates gradients and spurious anomalies in the Bouguer anomaly maps at the boundaries of the connected surveys due to the different gravity base stations utilized. The main objective of this study is to refer all gravimeter surveys from Pemex to a single new first-order gravity base station network, in order to eliminate problems of gradients and spurious anomalies. A second objective is to establish a network of permanent gravity base stations (BGP), referred to a single base from the World Gravity System. Four regional loops of BGP covering eight States of Mexico were established to support the tie of local gravity base stations from each of the gravimeter surveys located in the vicinity of these loops. The third objective is to add the gravity constants, measured and calculated, for each of the 265 gravimeter surveys to their corresponding files in the Pemex and Instituto Mexicano del Petroleo database. The gravity base used as the common datum is the station SILAG 9135-49 (Latin American System of Gravity) located in the National Observatory of Tacubaya in Mexico City. We present the results of the installation of a new gravity base network in northeastern Mexico, reference of the 43 gravimeter surveys to the new network, the regional compilation of Bouguer gravity data and a new updated Bouguer gravity anomaly map for northeastern Mexico.

Effects of horizontal acceleration on the superconducting gravimeter CT #036 at Ishigakijima, Japan

NASA Astrophysics Data System (ADS)

Imanishi, Yuichi; Nawa, Kazunari; Tamura, Yoshiaki; Ikeda, Hiroshi

2018-01-01

In the gravity sensor of a superconducting gravimeter, a superconducting sphere as a test mass is levitated in a magnetic field. Such a sensor is susceptible to applied horizontal as well as vertical acceleration, because the translational degrees of freedom of the mass are not perfectly limited to the vertical direction. In the case of the superconducting gravimeter CT #036 installed at Ishigakijima, Japan, horizontal ground acceleration excited by the movements of a nearby VLBI antenna induces systematic step noise within the gravity recordings. We investigate this effect in terms of the static and dynamic properties of the gravity sensor using data from a collocated seismometer. It is shown that this effect can be effectively modeled by the coupling between the horizontal and vertical components in the gravity sensor. It is also found that the mechanical eigenfrequency for horizontal translation of the levitating sphere is approximately 3 Hz.[Figure not available: see fulltext.

Absolute marine gravimetry with matter-wave interferometry.

PubMed

Bidel, Y; Zahzam, N; Blanchard, C; Bonnin, A; Cadoret, M; Bresson, A; Rouxel, D; Lequentrec-Lalancette, M F

2018-02-12

Measuring gravity from an aircraft or a ship is essential in geodesy, geophysics, mineral and hydrocarbon exploration, and navigation. Today, only relative sensors are available for onboard gravimetry. This is a major drawback because of the calibration and drift estimation procedures which lead to important operational constraints. Atom interferometry is a promising technology to obtain onboard absolute gravimeter. But, despite high performances obtained in static condition, no precise measurements were reported in dynamic. Here, we present absolute gravity measurements from a ship with a sensor based on atom interferometry. Despite rough sea conditions, we obtained precision below 10 -5  m s -2 . The atom gravimeter was also compared with a commercial spring gravimeter and showed better performances. This demonstration opens the way to the next generation of inertial sensors (accelerometer, gyroscope) based on atom interferometry which should provide high-precision absolute measurements from a moving platform.

Mobile quantum gravity sensor with unprecedented stability

NASA Astrophysics Data System (ADS)

Freier, C.; Hauth, M.; Schkolnik, V.; Leykauf, B.; Schilling, M.; Wziontek, H.; Scherneck, H.-G.; Müller, J.; Peters, A.

2016-06-01

Changes of surface gravity on Earth are of great interest in geodesy, earth sciences and natural resource exploration. They are indicative of Earth system's mass redistributions and vertical surface motion, and are usually measured with falling corner-cube- and superconducting gravimeters (FCCG and SCG). Here we report on absolute gravity measurements with a mobile quantum gravimeter based on atom interferometry. The measurements were conducted in Germany and Sweden over periods of several days with simultaneous SCG and FCCG comparisons. They show the best-reported performance of mobile atomic gravimeters to date with an accuracy of 39nm/s2, long-term stability of 0.5nm/s2 and short-term noise of 96nm/s2/√Hz. These measurements highlight the unique properties of atomic sensors. The achieved level of performance in a transportable instrument enables new applications in geodesy and related fields, such as continuous absolute gravity monitoring with a single instrument under rough environmental conditions.

A network of superconducting gravimeters detects submicrogal coseismic gravity changes.

PubMed

Imanishi, Yuichi; Sato, Tadahiro; Higashi, Toshihiro; Sun, Wenke; Okubo, Shuhei

2004-10-15

With high-resolution continuous gravity recordings from a regional network of superconducting gravimeters, we have detected permanent changes in gravity acceleration associated with a recent large earthquake. Detected changes in gravity acceleration are smaller than 10(-8) meters seconds(-2) (1 micro-Galileo, about 10(-9) times the surface gravity acceleration) and agree with theoretical values calculated from a dislocation model. Superconducting gravimetry can contribute to the studies of secular gravity changes associated with tectonic processes.

New iGrav superconducting gravimeter: accuracy, drift and first results

NASA Astrophysics Data System (ADS)

Le Moigne, N.; Champollion, C.; Warburton, R. J.; Bayer, R.; Deville, S.; Doerflinger, E.; chery, J.; Vernant, P.; Boudin, F.; Collard, P.

2011-12-01

A GWR iGrav superconducting gravimeter has been installed in the Larzac karstic area (Southern France near the Mediterranean Sea, elevation 800m, karst thickness 200m). Continuous sub-μGal gravity measurements are needed to study water storage and transfer in the non-saturated zone of the karstic area. The GWR iGrav is a new generation of superconducting gravimeter of reduced size (Dewar 15L) with simplified installation. At first, the specifications of the iGrav site will be presented, then the drift behaviour and the data processing. The drift quickly decreases to less than 0.1 μGal per day and only a few offsets are observed in the data. In order to look at the stability of the iGrav over a wide time period, a FG5 gravimeter is used for bi-monthly absolute gravity measurements and for frequent calibrations. As a result of the installation, the iGrav allows sub-μGal gravity monitoring only a few weeks after the beginning of the installation. After having discussed the instrumental and data processing points of view, preliminary results on the local karstic water storage will be presented and interpreted by combining different geophysical data. Continuous gravity data allow to study processes at different timescale such as summer evapotranspiration or high precipitating event characteristic of the Mediterranean autumn.

The measurement of surface gravity.

PubMed

Crossley, David; Hinderer, Jacques; Riccardi, Umberto

2013-04-01

This review covers basic theory and techniques behind the use of ground-based gravimetry at the Earth's surface. The orientation is toward modern instrumentation, data processing and interpretation for observing surface, land-based, time-variable changes to the geopotential. The instrumentation side is covered in some detail, with specifications and performance of the most widely used models of the three main types: the absolute gravimeters (FG5, A10 from Micro-g LaCoste), superconducting gravimeters (OSG, iGrav from GWR instruments), and the new generation of spring instruments (Micro-g LaCoste gPhone, Scintrex CG5 and Burris ZLS). A wide range of applications is covered, with selected examples from tides and ocean loading, atmospheric effects on gravity, local and global hydrology, seismology and normal modes, long period and tectonics, volcanology, exploration gravimetry, and some examples of gravimetry connected to fundamental physics. We show that there are only a modest number of very large signals, i.e. hundreds of µGal (10(-8) m s(-2)), that are easy to see with all gravimeters (e.g. tides, volcanic eruptions, large earthquakes, seasonal hydrology). The majority of signals of interest are in the range 0.1-5.0 µGal and occur at a wide range of time scales (minutes to years) and spatial extent (a few meters to global). Here the competing effects require a careful combination of different gravimeter types and measurement strategies to efficiently characterize and distinguish the signals. Gravimeters are sophisticated instruments, with substantial up-front costs, and they place demands on the operators to maximize the results. Nevertheless their performance characteristics such as drift and precision have improved dramatically in recent years, and their data recording ability and ruggedness have seen similar advances. Many subtle signals are now routinely connected with known geophysical effects such as coseismic earthquake displacements, post-glacial rebound, local hydrological mass balances, and detection of non-steric sea level changes.

FFT swept filtering: a bias-free method for processing fringe signals in absolute gravimeters

NASA Astrophysics Data System (ADS)

Křen, Petr; Pálinkáš, Vojtech; Mašika, Pavel; Val'ko, Miloš

2018-05-01

Absolute gravimeters, based on laser interferometry, are widely used for many applications in geoscience and metrology. Although currently the most accurate FG5 and FG5X gravimeters declare standard uncertainties at the level of 2-3 μGal, their inherent systematic errors affect the gravity reference determined by international key comparisons based predominately on the use of FG5-type instruments. The measurement results for FG5-215 and FG5X-251 clearly showed that the measured g-values depend on the size of the fringe signal and that this effect might be approximated by a linear regression with a slope of up to 0.030 μGal/mV . However, these empirical results do not enable one to identify the source of the effect or to determine a reasonable reference fringe level for correcting g-values in an absolute sense. Therefore, both gravimeters were equipped with new measuring systems (according to Křen et al. in Metrologia 53:27-40, 2016. https://doi.org/10.1088/0026-1394/53/1/27 applied for FG5), running in parallel with the original systems. The new systems use an analogue-to-digital converter HS5 to digitize the fringe signal and a new method of fringe signal analysis based on FFT swept bandpass filtering. We demonstrate that the source of the fringe size effect is connected to a distortion of the fringe signal due to the electronic components used in the FG5(X) gravimeters. To obtain a bias-free g-value, the FFT swept method should be applied for the determination of zero-crossings. A comparison of g-values obtained from the new and the original systems clearly shows that the original system might be biased by approximately 3-5 μGal due to improperly distorted fringe signal processing.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Min-Kang; Xiong, Xin; Chen, Le-Le

An ultra-low frequency active vibration isolator, simultaneously suppressing three-dimensional vibration noise, is demonstrated experimentally. The equivalent natural period of the isolator is 100 s and 12 s for the vertical and horizontal direction, respectively. The vibration noise in the vertical direction is about 50 times reduced during 0.2 and 2 Hz, and 5 times reduced in the other two orthogonal directions in the same frequency range. This isolator is designed for atom gravimeters, especially suitable for the gravimeter whose sensitivity is limited by vibration couplings.

Superconducting gravimeter

NASA Technical Reports Server (NTRS)

Goodkind, J. M.

1982-01-01

The superconducting gravimeter was developed and applied to field measurements. The stability of the instrument yielded the highest precision measurements of the Earth tides ever attained. It revealed unprecedented details about the effect of the atmosphere on gravity. Secular variations in gravity and the stability of the instruments were measured by comparing records from co-located instruments. These efforts have resulted in substantial reductions in the noise level at very low frequencies so that the peak differences between two instruments at the same location can be reduced to 0.1 micron gal.

Atom chip gravimeter

NASA Astrophysics Data System (ADS)

Schubert, Christian; Abend, Sven; Gebbe, Martina; Gersemann, Matthias; Ahlers, Holger; Müntinga, Hauke; Matthias, Jonas; Sahelgozin, Maral; Herr, Waldemar; Lämmerzahl, Claus; Ertmer, Wolfgang; Rasel, Ernst

2016-04-01

Atom interferometry has developed into a tool for measuring rotations [1], accelerations [2], and testing fundamental physics [3]. Gravimeters based on laser cooled atoms demonstrated residual uncertainties of few microgal [2,4] and were simplified for field applications [5]. Atomic gravimeters rely on the interference of matter waves which are coherently manipulated by laser light fields. The latter can be interpreted as rulers to which the position of the atoms is compared. At three points in time separated by a free evolution, the light fields are pulsed onto the atoms. First, a coherent superposition of two momentum states is produced, then the momentum is inverted, and finally the two trajectories are recombined. Depending on the acceleration the atoms experienced, the number of atoms detected in the output ports will change. Consequently, the acceleration can be determined from the output signal. The laser cooled atoms with microkelvin temperatures used in state-of-the-art gravimeters impose limits on the accuracy [4]. Therefore, ultra-cold atoms generated by Bose-Einstein condensation and delta-kick collimation [6,7] are expected to be the key for further improvements. These sources suffered from a low flux implying an incompatible noise floor, but a competitive performance was demonstrated recently with atom chips [8]. In the compact and robust setup constructed for operation in the drop tower [6] we demonstrated all steps necessary for an atom chip gravimeter with Bose-Einstein condensates in a ground based operation. We will discuss the principle of operation, the current performance, and the perspectives to supersede the state of the art. The authors thank the QUANTUS cooperation for contributions to the drop tower project in the earlier stages. This work is supported by the German Space Agency (DLR) with funds provided by the Federal Ministry for Economic Affairs and Energy (BMWi) due to an enactment of the German Bundestag under grant numbers DLR 50WM1552-1557 (QUANTUS-IV-Fallturm) and by the Deutsche Forschungsgemeinschaft in the framework of the SFB 1128 geo-Q. [1] P. Berg et al., Composite-Light-Pulse Technique for High-Precision Atom Interferometry, Phys. Rev. Lett., 114, 063002, 2015. [2] A. Peters et al., Measurement of gravitational acceleration by dropping atoms, Nature 400, 849, 1999. [3] D. Schlippert et al., Quantum Test of the Universality of Free Fall, Phys. Rev. Lett., 112, 203002, 2014. [4] A. Louchet-Chauvet et al., The influence of transverse motion within an atomic gravimeter, New J. Phys. 13, 065026, 2011. [5] Q. Bodart et al., A cold atom pyramidal gravimeter with a single laser beam, Appl. Phys. Lett. 96, 134101, 2010. [6] H. Müntinga et al., Interferometry with Bose-Einstein Condensates in Microgravity, Phys. Rev. Lett., 110, 093602, 2013. [7] T. Kovachy et al., Matter Wave Lensing to Picokelvin Temperatures, Phys. Rev. Lett. 114, 143004, 2015. [8] J. Rudolph et al., A high-flux BEC source for mobile atom interferometers, New J. Phys. 17, 065001, 2015.

Somigliana-Pizzetti gravity: the international gravity formula accurate to the sub-nanoGal level

NASA Astrophysics Data System (ADS)

Ardalan, A. A.; Grafarend, E. W.

2001-09-01

The Somigliana-Pizzetti gravity field (the International gravity formula), namely the gravity field of the level ellipsoid (the International Reference Ellipsoid), is derived to the sub-nanoGal accuracy level in order to fulfil the demands of modern gravimetry (absolute gravimeters, super conducting gravimeters, atomic gravimeters). Equations (53), (54) and (59) summarise Somigliana-Pizzetti gravity o({,u) as a function of Jacobi spheroidal latitude { and height u to the order ™(10m10 Gal), and o(B,H) as a function of Gauss (surface normal) ellipsoidal latitude B and height H to the order ™(10m10 Gal) as determined by GPS (`global problem solver'). Within the test area of the state of Baden-Württemberg, Somigliana-Pizzetti gravity disturbances of an average of 25.452 mGal were produced. Computer programs for an operational application of the new international gravity formula with (L,B,H) or (u,{,u) coordinate inputs to a sub-nanoGal level of accuracy are available on the Internet.

Direct measurement of sub-surface mass change using the variable-baseline gravity gradient method

USGS Publications Warehouse

Kennedy, Jeffrey; Ferré, Ty P.A.; Güntner, Andreas; Abe, Maiko; Creutzfeldt, Benjamin

2014-01-01

Time-lapse gravity data provide a direct, non-destructive method to monitor mass changes at scales from cm to km. But, the effectively infinite spatial sensitivity of gravity measurements can make it difficult to isolate the signal of interest. The variable-baseline gravity gradient method, based on the difference of measurements between two gravimeters, is an alternative to the conventional approach of individually modeling all sources of mass and elevation change. This approach can improve the signal-to-noise ratio for many applications by removing the contributions of Earth tides, loading, and other signals that have the same effect on both gravimeters. At the same time, this approach can focus the support volume within a relatively small user-defined region of the subsurface. The method is demonstrated using paired superconducting gravimeters to make for the first time a large-scale, non-invasive measurement of infiltration wetting front velocity and change in water content above the wetting front.

Double diffraction in an atomic gravimeter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malossi, N.; Bodart, Q.; Merlet, S.

2010-01-15

We demonstrate the realization of a scheme for cold-atom gravimetry based on the recently demonstrated use of double-diffraction beam splitters [T. Leveque, A. Gauguet, F. Michaud, F. Pereira Dos Santos, and A. Landragin, Phys. Rev. Lett. 103, 080405 (2009)], where the use of two retro-reflected Raman beams allows symmetric diffraction in +-(Planck constant/2pi)k{sub eff} momenta. Although in principle restricted to the case of zero Doppler shift, for which the two pairs of Raman beams are simultaneously resonant, such diffraction pulses can remain efficient on atoms with nonzero velocity, such as in a gravimeter, when the frequency of one of themore » two Raman laser sources is modulated. Such pulses are used to realize an interferometer insensitive to laser phase noise and some of the dominant systematics. This approach reduces the technical requirements and would allow the realization of a simple atomic gravimeter. A sensitivity of 1.2x10{sup -7}g per shot is demonstrated.« less

Using an Optionally Piloted Aircraft for Airborne Gravity Observations with the NOAA GRAV-D Project

NASA Astrophysics Data System (ADS)

Youngman, M.; Johnson, J. A.; van Westrum, D.; Damiani, T.

2017-12-01

The U.S. National Geodetic Survey's (NGS) Gravity for the Redefintion of the American Vertical Datum (GRAV-D) project is collecting airborne gravity data to support a 1 cm geoid. Started in 2008, this project will collect airborne gravity data over the entire U.S. and territories by 2022. As of June 30, 2017, the project was almost 62% complete. With recent technological developments, NGS has been exploring using unmanned aircraft for airborne gravity measurements. This presentation will focus on results from two surveys over the U.S. Appalachian and Rocky Mountains using the Aurora Centaur Optionally Piloted Aircraft and the Micro-g Lacoste Turnkey Airborne Gravimeter System 7 (TAGS7). Collecting high quality data as well as dealing with remote locations has been a challenge for the GRAV-D project and the field of airborne gravity in general. Unmanned aircraft could potentially improve data quality, handle hard to reach locations, and reduce pilot fatigue. The optionally piloted Centaur aircraft is an attractive option because it is not restricted in U.S. airspace and delivers high quality gravity data. Specifically, the Centaur meets U.S. Federal Aviation Administration regulations for Unmanned Aircraft Systems (UAS) by using a safety pilot on board to maintain line of sight and the ability to take control in the event of an emergency. Even though this is a sizeable UAS, most traditional gravimeters are too large and heavy for the platform. With a smaller and lighter design, the TAGS7 was used for its ability to conform to the aircraft's size restrictions, with the added benefit of upgraded performance capabilities. Two surveys were performed with this aircraft and gravimeter, one in April and one in August to September of 2017. Initial results indicate that the high-gain, fast response of the Centaur autopilot (optimized for flights without passengers), coupled with the full-force feedback sensor of the TAGS7, provides superior performance in all conditions, and allows for acquisition in periods of higher turbulence that were inaccessible before. Based on these surveys this technology has the potential to improve data quality and decrease costs of airborne gravity surveying.

The Effects of Lever Arm (Instrument Offset) Error on GRAV-D Airborne Gravity Data

NASA Astrophysics Data System (ADS)

Johnson, J. A.; Youngman, M.; Damiani, T.

2017-12-01

High quality airborne gravity collection with a 2-axis, stabilized platform gravity instrument, such as with a Micro-g LaCoste Turnkey Airborne Gravity System (TAGS), is dependent on the aircraft's ability to maintain "straight and level" flight. However, during flight there is constant rotation about the aircraft's center of gravity. Standard practice is to install the scientific equipment close to the aircraft's estimated center of gravity to minimize the relative rotations with aircraft motion. However, there remain small offsets between the instruments. These distance offsets, the lever arm, are used to define the rigid-body, spatial relationship between the IMU, GPS antenna, and airborne gravimeter within the aircraft body frame. The Gravity for the Redefinition of the American Vertical Datum (GRAV-D) project, which is collecting airborne gravity data across the U.S., uses a commercial software package for coupled IMU-GNSS aircraft positioning. This software incorporates a lever arm correction to calculate a precise position for the airborne gravimeter. The positioning software must do a coordinate transformation to relate each epoch of the coupled GNSS-IMU derived position to the position of the gravimeter within the constantly-rotating aircraft. This transformation requires three inputs: accurate IMU-measured aircraft rotations, GNSS positions, and lever arm distances between instruments. Previous studies show that correcting for the lever arm distances improves gravity results, but no sensitivity tests have been done to investigate how error in the lever arm distances affects the final airborne gravity products. This research investigates the effects of lever arm measurement error on airborne gravity data. GRAV-D lever arms are nominally measured to the cm-level using surveying equipment. "Truth" data sets will be created by processing GRAV-D flight lines with both relatively small lever arms and large lever arms. Then negative and positive incremental errors will be introduced independently in the x, y, and z directions during GPS-IMU processing. Finally, the post-processed gravity data obtained using the erroneous lever arms will be compared to the post-processed truth sets to identify relationships between error in the lever arm measurement and the final gravity product.

Determination of beam-position dependent transfer functions of LCR-G gravimeters by means of moving mass calibration device in the Mátyáshegy Gravity and Geodynamical Observatory, Budapest

NASA Astrophysics Data System (ADS)

Koppán, András; Kis, Márta; Merényi, László; Papp, Gábor; Benedek, Judit; Meurers, Bruno

2017-04-01

In this presentation authors propose a method for the determination of transfer characteristics and fine calibration of LCR relative gravimeters used for earth-tide recordings, by means of the moving-mass gravimeter calibration device of Budapest-Mátyáshegy Gravity and Geodynamical Observatory. Beam-position dependent transfer functions of four relative LCR G type gravimeters were determined and compared. In order to make these instruments applicable for observatory tidal recordings, there is a need for examining the unique characteristics of equipments and adequately correcting these inherent distorting effects. Thus, the sensitivity for the tilting, temporal changes of scale factors and beam-position dependent transfer characteristics are necessary to be determined for observatory use of these instruments. During the calibration a cylindrical ring of 3200 kg mass is vertically moving around the equipment, generating gravity variations. The effect of the moving mass can be precisely calculated from the known mass and geometrical parameters. The maximum theoretical gravity variation produced by the vertical movement of the mass is ab. 110 microGal, so it provides excellent possibility for the fine calibration of gravimeters in the tidal range. Magnetic experiments were also carried out on the pillar of the calibration device as well, in order to analyse the magnetic effect of the moving stainless steel-mass. According to the magnetic measurements, a correction for the magnetic effect was applied on the measured gravimetric data series. The calibration process is aided by intelligent controller electronics. A PLC-based system has been developed to allow easy control of the movement of the calibrating mass and to measure the mass position. It enables also programmed steps of movements (waiting positions and waiting times) for refined gravity changes. All parameters (position of the mass, CPI data, X/Y leveling positions) are recorded with 1/sec. sampling rate. The system can be controlled remotely through the internet. Authors wish to express their thanks to OTKA (Hungarian Scientific Research Fund) for their support (OTKA-K101603, OTKA K109060).

A vibration correction method for free-fall absolute gravimeters

NASA Astrophysics Data System (ADS)

Qian, J.; Wang, G.; Wu, K.; Wang, L. J.

2018-02-01

An accurate determination of gravitational acceleration, usually approximated as 9.8 m s-2, has been playing an important role in the areas of metrology, geophysics, and geodetics. Absolute gravimetry has been experiencing rapid developments in recent years. Most absolute gravimeters today employ a free-fall method to measure gravitational acceleration. Noise from ground vibration has become one of the most serious factors limiting measurement precision. Compared to vibration isolators, the vibration correction method is a simple and feasible way to reduce the influence of ground vibrations. A modified vibration correction method is proposed and demonstrated. A two-dimensional golden section search algorithm is used to search for the best parameters of the hypothetical transfer function. Experiments using a T-1 absolute gravimeter are performed. It is verified that for an identical group of drop data, the modified method proposed in this paper can achieve better correction effects with much less computation than previous methods. Compared to vibration isolators, the correction method applies to more hostile environments and even dynamic platforms, and is expected to be used in a wider range of applications.

Mapping the absolute magnetic field and evaluating the quadratic Zeeman-effect-induced systematic error in an atom interferometer gravimeter

NASA Astrophysics Data System (ADS)

Hu, Qing-Qing; Freier, Christian; Leykauf, Bastian; Schkolnik, Vladimir; Yang, Jun; Krutzik, Markus; Peters, Achim

2017-09-01

Precisely evaluating the systematic error induced by the quadratic Zeeman effect is important for developing atom interferometer gravimeters aiming at an accuracy in the μ Gal regime (1 μ Gal =10-8m /s2 ≈10-9g ). This paper reports on the experimental investigation of Raman spectroscopy-based magnetic field measurements and the evaluation of the systematic error in the gravimetric atom interferometer (GAIN) due to quadratic Zeeman effect. We discuss Raman duration and frequency step-size-dependent magnetic field measurement uncertainty, present vector light shift and tensor light shift induced magnetic field measurement offset, and map the absolute magnetic field inside the interferometer chamber of GAIN with an uncertainty of 0.72 nT and a spatial resolution of 12.8 mm. We evaluate the quadratic Zeeman-effect-induced gravity measurement error in GAIN as 2.04 μ Gal . The methods shown in this paper are important for precisely mapping the absolute magnetic field in vacuum and reducing the quadratic Zeeman-effect-induced systematic error in Raman transition-based precision measurements, such as atomic interferometer gravimeters.

A High Stability Optical Shadow Sensor With Applications for Precision Accelerometers

NASA Astrophysics Data System (ADS)

Bramsiepe, Steven G.; Loomes, David; Middlemiss, Richard P.; Paul, Douglas J.; Hammond, Giles D.

2018-05-01

Gravimeters are devices which measure changes in the value of the gravitational acceleration, \\textit{g}. This information is used to infer changes in density under the ground allowing the detection of subsurface voids; mineral, oil and gas reserves; and even the detection of the precursors of volcanic eruptions. A micro-electro mechanical system (MEMS) gravimeter has been fabricated completely in silicon allowing the possibility of cost e-effective, lightweight and small gravimeters. To obtain a measurement of gravity, a highly stable displacement measurement of the MEMS is required. This requires the development of a portable electronics system that has a displacement sensitivity of $\\leq 2.5$ nm over a period of a day or more. The portable electronics system presented here has a displacement sensitivity $\\leq 10$ nm$/\\sqrt{\\textrm{Hz}}$ ($\\leq 0.6$ nm at $1000$ s). The battery power system used a modulated LED for measurements and required temperature control of the system to $\\pm$ 2 mK, monitoring of the tilt to $\\pm$ 2 $\\mu$radians, the storage of measured data and the transmission of the data to an external server.

Final report of the regional key comparison EURAMET.M.G-K1: European Comparison of Absolute Gravimeters ECAG-2011

NASA Astrophysics Data System (ADS)

Francis, Olivier; Klein, Gilbert; Baumann, Henri; Dando, Nicolas; Tracey, Ray; Ullrich, Christian; Castelein, Stefaan; Hua, Hu; Kang, Wu; Chongyang, Shen; Songbo, Xuan; Hongbo, Tan; Zhengyuan, Li; Pálinkás, Vojtech; Kostelecký, Jakub; Mäkinen, Jaakko; Näränen, Jyri; Merlet, Sébastien; Farah, Tristan; Guerlin, Christine; Pereira Dos Santos, Franck; Le Moigne, Nicolas; Champollion, Cédric; Deville, Sabrina; Timmen, Ludger; Falk, Reinhard; Wilmes, Herbert; Iacovone, Domenico; Baccaro, Francesco; Germak, Alessandro; Biolcati, Emanuele; Krynski, Jan; Sekowski, Marcin; Olszak, Tomasz; Pachuta, Andrzej; Agren, Jonas; Engfeldt, Andreas; Reudink, René; Inacio, Pedro; McLaughlin, Daniel; Shannon, Geoff; Eckl, Marc; Wilkins, Tim; van Westrum, Derek; Billson, Ryan

2012-01-01

During November 2011 a EURAMET key comparison of absolute gravimeters was organized in the Underground Laboratory for Geodynamics in Walferdange, Luxemburg. The comparison assembled 22 participants coming from 16 countries and four different continents. The comparison was divided into two parts: a key comparison that included six National Metrology Institutes or Designated Institutes, and a pilot study including all participants. The global result given by the pilot study confirms that all instruments are absolutely coherent with each other. The results obtained in the key comparison confirm a good agreement between the NMI instruments. Finally, a link to ICAG-2009 shows also that the NMI gravimeters are stable in time. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

A gyro-stabilized platform leveling loop for marine gravimeter.

PubMed

Wu, P F; Liu, L T; Wang, L; Wang, Y; Zhong, M; Zhou, Z B; Zou, Z

2017-06-01

An ultra-low-frequency platform leveling loop based on a mixed sensitivity H ∞ approach, which considers both the system bandwidth and response speed, was designed and applied to a prototype, two-axis gyro-stabilized platform marine gravimeter CHZ-II. The instrument was developed for regional surveys in deep ocean areas where high-resolution gravity measurements with accuracy 1 mGal are required. Horizontal accelerations in the surge and sway directions are suppressed about 60 dB in the frequency range 0.05 to 0.5 Hz. This typically improves the quality of the gravity data before any processing corrections. The time required for stabilizing the platform at the beginning of a survey line or course change is about 3 min, which improves the data collection efficiency. In May 2015, the first test was conducted in open sea conditions aboard the Chinese State Oceanic Administration's R/V Xiangyanghong 10. Sixteen traverses were run in the South China Sea to evaluate the loop performance. Platform motion tracks and gravity data from the survey were of satisfactory quality. According to analyses of 16 sets of calculated errors, the root mean square repeatability of the pitch and roll off-level angles were less than 10 and 20 arc sec, respectively, with a horizontal acceleration of about 50 Gal. Errors derived from the inability of the platform to maintain perfect sensor leveling during the survey cruise were less than 0.3 mGal.

Optimized Design of the SGA-WZ Strapdown Airborne Gravimeter Temperature Control System

PubMed Central

Cao, Juliang; Wang, Minghao; Cai, Shaokun; Zhang, Kaidong; Cong, Danni; Wu, Meiping

2015-01-01

The temperature control system is one of the most important subsystems of the strapdown airborne gravimeter. Because the quartz flexible accelerometer based on springy support technology is the core sensor in the strapdown airborne gravimeter and the magnet steel in the electromagnetic force equilibrium circuits of the quartz flexible accelerometer is greatly affected by temperature, in order to guarantee the temperature control precision and minimize the effect of temperature on the gravimeter, the SGA-WZ temperature control system adopts a three-level control method. Based on the design experience of the SGA-WZ-01, the SGA-WZ-02 temperature control system came out with a further optimized design. In 1st level temperature control, thermoelectric cooler is used to conquer temperature change caused by hot weather. The experiments show that the optimized stability of 1st level temperature control is about 0.1 °C and the max cool down capability is about 10 °C. The temperature field is analyzed in the 2nd and 3rd level temperature control using the finite element analysis software ANSYS. The 2nd and 3rd level temperature control optimization scheme is based on the foundation of heat analysis. The experimental results show that static accuracy of SGA-WZ-02 reaches 0.21 mGal/24 h, with internal accuracy being 0.743 mGal/4.8 km and external accuracy being 0.37 mGal/4.8 km compared with the result of the GT-2A, whose internal precision is superior to 1 mGal/4.8 km and all of them are better than those in SGA-WZ-01. PMID:26633407

Optimized Design of the SGA-WZ Strapdown Airborne Gravimeter Temperature Control System.

PubMed

Cao, Juliang; Wang, Minghao; Cai, Shaokun; Zhang, Kaidong; Cong, Danni; Wu, Meiping

2015-12-01

The temperature control system is one of the most important subsystems of the strapdown airborne gravimeter. Because the quartz flexible accelerometer based on springy support technology is the core sensor in the strapdown airborne gravimeter and the magnet steel in the electromagnetic force equilibrium circuits of the quartz flexible accelerometer is greatly affected by temperature, in order to guarantee the temperature control precision and minimize the effect of temperature on the gravimeter, the SGA-WZ temperature control system adopts a three-level control method. Based on the design experience of the SGA-WZ-01, the SGA-WZ-02 temperature control system came out with a further optimized design. In 1st level temperature control, thermoelectric cooler is used to conquer temperature change caused by hot weather. The experiments show that the optimized stability of 1st level temperature control is about 0.1 °C and the max cool down capability is about 10 °C. The temperature field is analyzed in the 2nd and 3rd level temperature control using the finite element analysis software ANSYS. The 2nd and 3rd level temperature control optimization scheme is based on the foundation of heat analysis. The experimental results show that static accuracy of SGA-WZ-02 reaches 0.21 mGal/24 h, with internal accuracy being 0.743 mGal/4.8 km and external accuracy being 0.37 mGal/4.8 km compared with the result of the GT-2A, whose internal precision is superior to 1 mGal/4.8 km and all of them are better than those in SGA-WZ-01.

Airborne Gravity Measurements using a Helicopter with Special Emphases on Delineating Local Gravity Anomalies Mainly for Detecting Active Seismic Faults (Invited)

NASA Astrophysics Data System (ADS)

Segawa, J.

2010-12-01

The first aerial gravity measurement in Japan started in 1998 using a Japanese airborne gravimeter ‘ Segawa-TKeiki airborne gravimeter Model FGA-1’. We lay emphasis on the measurement of detailed gravity structures at the land-to-sea border areas and mountainous areas. This is the reason why we use a helicopter and make surveys at low altitude and low speed. We have so far made measurement at twelve sites and the total flight amounts to 20,000km. The accuracy of measurement is 1.5 mgal and half-wavelength resolution is 1.5 km. The Japanese type gravimeter consists of a servo-accelerometer type gravity sensor, a horizontal platform controlled by an optical fiber gyro, GPS positioning system, and a data processing system. Helicopter movement has to be precisely monitored three-dimensionally to calculate the vehicle’s acceleration noises. The necessary accuracy of positioning of the vehicle must be better than 10 cm in positioning error. Our helicopter gravity measurement has a special target in Japan to investigate active seismic faults located across land-to-sea borderlines. In Japan, it is generally thought that gravity over most of the country has already been measured by the governmental surveys, leaving the land-sea border lines and mountainous zones unsurveyed as difficult-to-access areas. In addition the use of airplane or helicopter in Japan appeared disadvantageous because of the narrowness of the Japanese Islands. Under such situations the author thought there still remained a particular as well as unique need for aerial gravity measurement in Japan, i.e. the need for detailed and seamless knowledge of gravity structures across land-to-sea border lines to elucidate complicated crustal structures of the Japanese Islands as well as distribution of active seismic faults for disaster prevention. The results of gravity measurements we have conducted so far include those of 12 sites. In the following the brief logs of our measurements are listed. 1)April 2000. Saitama-Tsukuba-Kashima-Nada. Flight Length 1,300km. Discovery of inconsistency between land and marine gravity nearby. 2)July 2000. Suruga Bay. Flight Length 1,500km. Gravity was contoured in the Suruga Bay. 3)November 2000. Enshu-Nada Sea. Flight Length 1,700km. First measurement of land-sea border line of the Tokai area. 4)October 2001. Enshu-Nada Sea. Flight Length 1,500km. Revisit to Enshu Nada sea. 5)December 2001. Kohdu-shima and Miyake Jima. Flight Length 1,800km. Measurement of gravity over the basin between Miyake and Kohdu. 6)June 2002. Enshu-Nada Sea. Flight Length 2,200km. Measurement of gravity across the Tenryu-River active fault. 7)November 2004. Iyonada and Sata Peninsula. (Commercial works). 8)March 2006. Middle Noto Peninsula. (Commercial works). 9)November 2006. Wakasa Bay. (Commercial works). 10)October 2008. North Noto Peninsula. (Commercial works). 11)November 2008. West Seto Inland Sea. (Commercial works). 12)November 2009. Shimokita Peninsula and Seto Inland Sea.

Reply to ‘Comment on Relativistic theory of the falling cube gravimeter’

NASA Astrophysics Data System (ADS)

Ashby, Neil

2018-04-01

The comment (Křen and Pálinkás 2017 Metrologia 55 314-5) claims that the paper Relativistic theory of the falling cube gravimeter (Ashby 2017 Metrologia 55 1-10) is incorrect. The authors of this comment assert that optical paths in the two interferometer arms of an absolute gravimeter shift only the absolute phase difference between interferometer arms and therefore cannot affect the measured value of g, and that the only needed relativistic correction is the commonly applied ‘speed of light correction’. Neither claim stands up to scrutiny. Work of the U.S. government, not subject to copyright.

Gravity sensing using Very Long Baseline Atom Interferometry

NASA Astrophysics Data System (ADS)

Schlippert, D.; Wodey, E.; Meiners, C.; Tell, D.; Schubert, C.; Ertmer, W.; Rasel, E. M.

2017-12-01

Very Long Baseline Atom Interferometry (VLBAI) has applications in high-accuracy absolute gravimetry, gravity-gradiometry, and for tests of fundamental physics. Thanks to the quadratic scaling of the phase shift with increasing free evolution time, extending the baseline of atomic gravimeters from tens of centimeters to meters puts resolutions of 10-13g and beyond in reach.We present the design and progress of key elements of the VLBAI-test stand: a dual-species source of Rb and Yb, a high-performance two-layer magnetic shield, and an active vibration isolation system allowing for unprecedented stability of the mirror acting as an inertial reference. We envisage a vibration-limited short-term sensitivity to gravitational acceleration of 1x10-8 m/s-2Hz-1/2 and up to a factor of 25 improvement when including additional correlation with a broadband seismometer. Here, the supreme long-term stability of atomic gravity sensors opens the route towards competition with superconducting gravimeters. The operation of VLBAI as a differential dual-species gravimeter using ultracold mixtures of Yb and Rb atoms enables quantum tests of the universality of free fall (UFF) at an unprecedented level of <10-13, potentially surpassing the best experiments to date.

Gravity sensing using Very Long Baseline Atom Interferometry

NASA Astrophysics Data System (ADS)

Schlippert, Dennis; Wodey, Étienne; Meiners, Christian; Tell, Dorothee; Schubert, Christian; Ertmer, Wolfgang; Rasel, Ernst M.

2017-04-01

Very Long Baseline Atom Interferometry (VLBAI) has applications in high-accuracy absolute gravimetry, gravity-gradiometry, and for tests of fundamental physics. Thanks to the quadratic scaling of the phase shift with increasing free evolution time, extending the baseline of atomic gravimeters from tens of centimeters to meters puts resolutions of 10-13 g and beyond in reach. We present the design and progress of key elements of the VLBAI-test stand: a dual-species source of Rb and Yb, a high-performance two-layer magnetic shield, and an active vibration isolation system allowing for unprecedented stability of the mirror acting as an inertial reference. We envisage a vibration-limited short-term sensitivity to gravitational acceleration of 1 .10-8 m/s2 / Hz1/2 and up to a factor of 25 improvement when including additional correlation with a broadband seismometer. Here, the supreme long-term stability of atomic gravity sensors opens the route towards competition with superconducting gravimeters. The operation of VLBAI as a differential dual-species gravimeter using ultracold mixtures of Yb and Rb atoms enables quantum tests of the universality of free fall (UFF) at an unprecedented level of <=10-13 , potentially surpassing the best experiments to date.

Monitoring gravity and water storage changes in northern Benin

NASA Astrophysics Data System (ADS)

Hector, B.; Hinderer, J.; Boy, J.; Calvo, M.; Séguis, L.; Descloitres, M.; Cohard, J.; Rosat, S.; Riccardi, U.; Galle, S.

2013-12-01

The humid sudanian zone of West-Africa undergoes a monsoon climate, implying a strong seasonality in water storage changes (WSC). The GHYRAF (Gravity and Hydrology in Africa) project aims at monitoring both these local and non-local hydrological contributions with the main gravity sensors available today (FG5 absolute gravimeter, superconducting gravimeter -SG- and CG5 micro-gravimeter). The study area is located in hard-rock basement context in Djougou, northern Benin, and is also part of the long-term observing system AMMA-Catch, and thus under intense hydro-meteorological monitoring (rainfall, soil moisture, water table, evapotranspiration, ...). Gravity-derived WSC are compared to hydrological data and to physically-based or conceptual hydrological models calibrated on these data. This presentation shows the results and limitations of each gravimeter in the context of WSC retrieval. This site was first measured with a FG5 absolute gravimeter four times a year from 2008 to 2013. This can be considered as a high sampling rate, given the remote location and the complexity of FG5 carriage and installation. It allowed to derive an average specific yield for the local aquifer, and preliminary estimates of seasonal WSC (up to 120 nm/s2 - 270mm). Yet the lack of continuity in the data avoids further investigations. The SG-060 superconducting gravimeter has been installed in 2010 in order to monitor gravity response to WSC in a continuous way. A strong drift is present (230nm/s2/yr), and FG5 data together with a-priori information on WSC are needed for estimating its effect. Also, frequent power-failures lead to some significant gaps and offsets during which fast WSC may occur (e.g. rain), yielding to a challenging correction for these events. The retrieval of inter-annual WSC suffers from these strong and limiting instrumental effects. At higher frequencies, up to a few days, continuous gravity monitoring may help to quantify evapotranspiration (ET), a poorly-known variable of the hydrological cycle. In Djougou, favorable -flat- topographic conditions and significant ET (up to 5 mm/day) are present. However, the shelter size together with the low altitude of the SG sensor with respect to the ground yield to diminish the expected effect of ET. Also, atmospheric contribution at such frequencies in the equatorial band is governed by S1 and S2 pressure waves of planetary extension, with rather complicated behavior. Therefore, the retrieval of ET is limited by the SG environment (shelter and instrument height) and our ability to fully correct for atmospheric effects. The spatial variations of gravity changes on the local catchment are also investigated by CG5 micro-gravity surveys since July 2011 with weekly measurements in the wet season and monthly in the dry season, resulting in more than two years and 3 wet seasons coverage. This survey helped to identify preferential recharge areas and some specific water-redistribution processes at the catchment scale, driven by subsurface heterogeneities.

First Observations with the New Dual Sphere Superconducting Gravimeter Osg-073 at Metsähovi, Finland

NASA Astrophysics Data System (ADS)

Virtanen, H.; Raja-Halli, A.; Bilker-Koivula, M.; Naranen, J.; Ruotsalainen, H. E. O.

2014-12-01

The new dual sphere superconducting gravimeter (SG) OSG-073 was installed in the Metsähovi Geodetic Observatory in February 2014. Its two gravity sensors are side by side, not one on top of another as in most earlier dual sensor installations. One sensor is the standard iGrav™ SG, with a lightweight sphere (5 grams) which is nearly drift-free. The second sensor uses a heavy 20-gram sphere which gives ultra low noise and a much higher quality factor Q. We present time domain observations of the first months, and estimate drift rates after the initial exponential drift. We have determined the transfer functions. Calibration factors were obtained using parallel registrations with the FG5X-221 absolute gravimeter of the FGI. We show selected free oscillation spectra from the SG, and seismic data obtained at Metsähovi with the Nanometrics Trillium 120P broadband seismometer of the Institute of Seismology (University of Helsinki). The noise level of the data is then compared with the New Low Noise Model NLNM. The results with the dual sphere SG can be compared with parallel observations with the SG T020. This 20-year old instrument is situated in the same room at a distance of 2 metres from the dual-sphere SG.

Gsolve, a Python computer program with a graphical user interface to transform relative gravity survey measurements to absolute gravity values and gravity anomalies

NASA Astrophysics Data System (ADS)

McCubbine, Jack; Tontini, Fabio Caratori; Stagpoole, Vaughan; Smith, Euan; O'Brien, Grant

2018-01-01

A Python program (Gsolve) with a graphical user interface has been developed to assist with routine data processing of relative gravity measurements. Gsolve calculates the gravity at each measurement site of a relative gravity survey, which is referenced to at least one known gravity value. The tidal effects of the sun and moon, gravimeter drift and tares in the data are all accounted for during the processing of the survey measurements. The calculation is based on a least squares formulation where the difference between the absolute gravity at each surveyed location and parameters relating to the dynamics of the gravimeter are minimized with respect to the relative gravity observations, and some supplied gravity reference site values. The program additionally allows the user to compute free air gravity anomalies, with respect to the GRS80 and GRS67 reference ellipsoids, from the determined gravity values and calculate terrain corrections at each of the surveyed sites using a prism formula and a user supplied digital elevation model. This paper reviews the mathematical framework used to reduce relative gravimeter survey observations to gravity values. It then goes on to detail how the processing steps can be implemented using the software.

Joint analysis of deformation, gravity, and lava lake elevation reveals temporal variations in lava lake density at Kilauea Volcano, Hawaii

NASA Astrophysics Data System (ADS)

Carbone, Daniele; Poland, Michael; Patrick, Matthew

2015-04-01

We find a tight correlation between (i) changes in lava level within the summit eruptive vent at Kilauea Volcano, Hawaii, observed for at least 2 years since early 2011, and (ii) ground deformation in the vicinity of the vent. The observed correlation indicates that changing pressure within the shallow magma reservoir feeding the lava lake influences both deformation and lava level. However, those two parameters are related to chamber pressure through different properties, namely, the density of the lava filling the vent (for the lava level) and the size/position of the reservoir plus the elastic parameters of the host rock (for the deformation). Joint analyses in the time and frequency domains of lava level (determined from thermal camera imagery of the lava lake) and tilt measured on a borehole instrument (~2 km from the summit vent) reveal a good correlation throughout the studied period. The highest correlation occurs over periods ranging between 1 and 20 days. The ratio between lava level and tilt is not constant over time, however. Using data from a continuously recording gravimeter located near the rim of the summit eruptive vent, we demonstrate that the tilt-lava level ratio is controlled by the fluctuations in the density of the lava inside the vent (i.e., its degree of vesicularity). A second continuous gravimeter was installed near the summit eruptive vent in 2014, providing a new observation point for gravity change associated with summit lava lave activity to test models developed from the previously existing instrument. In addition, a continuous gravimeter was installed on the rim of the Puu Oo eruptive vent on Kilauea's East Rift Zone in 2013. Puu Oo is connected via the subvolcanic magma plumbing system to the summit eruptive vent and often deforms in concert with the summit. This growing network of continuously recording gravimeters at Kilauea can be used to examine correlations in gravity change associated with variations in eruptive activity across the volcano.

Karst system vadose zone hydrodynamics highlighted by an integrative geophysical and hydrogeological monitoring

NASA Astrophysics Data System (ADS)

Watlet, A.; Van Camp, M. J.; Francis, O.; Poulain, A.; Hallet, V.; Rochez, G.; Kaufmann, O.

2015-12-01

The vadose zone of karst systems plays an important role on the water dynamics. In particular, temporary perched aquifers can appear in the subsurface due to changes of climate conditions, diminished evapotranspiration and differences of porosity relative to deeper layers. It is therefore crucial, but challenging, to separate the hydrological signature of the vadose zone from the one of the saturated zone for understanding hydrological processes that occur in the vadose zone. Although many difficulties are usually encountered when studying karst environments due to their heterogeneities, cave systems offer an outstanding opportunity to investigate vadose zone from the inside with various techniques. We present results covering two years of hydrogeological and geophysical monitoring at the Rochefort Cave Laboratory (RCL), located in the Variscan fold-and-thrust belt (Belgium), a region that shows many karstic networks within Devonian limestone units. Hydrogeological data such as flows and levels monitoring or tracer tests performed in both vadose and saturated zones bring valuable information on the hydrological context of the studied area. Combining those results with geophysical measurements allows validating and imaging them with more integrative techniques. A microgravimetric monitoring involves a superconducting gravimeter continuously measuring at the surface of the RCL. Early in 2015, a second relative gravimeter was installed in the underlying cave system located 35 meters below the surface. This set up allows highlighting vadose gravity changes. These relative measurements are calibrated using an absolute gravimeter. 12 additional stations (7 at the surface, 5 in the cave) are monitored on a monthly basis by a spring gravimeter. To complete these gravimetric measurements, the site has been equipped with a permanent Electrical Resistivity Tomography (ERT) monitoring system comprising an uncommon array of surface, borehole and cave electrodes. Although such an unconventional ERT setup is challenging in terms of data processing and interpretation, it provides valuable data for inferring variations of the vadose zone saturation rate.

Surface and subsurface continuous gravimetric monitoring of groundwater recharge processes through the karst vadose zone at Rochefort Cave (Belgium)

NASA Astrophysics Data System (ADS)

Watlet, A.; Van Camp, M. J.; Francis, O.; Poulain, A.; Hallet, V.; Triantafyllou, A.; Delforge, D.; Quinif, Y.; Van Ruymbeke, M.; Kaufmann, O.

2017-12-01

Ground-based gravimetry is a non-invasive and integrated tool to characterize hydrological processes in complex environments such as karsts or volcanoes. A problem in ground-based gravity measurements however concerns the lack of sensitivity in the first meters below the topographical surface, added to limited infiltration below the gravimeter building (umbrella effect). Such limitations disappear when measuring underground. Coupling surface and subsurface gravity measurements therefore allow isolating hydrological signals occurring in the zone between the two gravimeters. We present a coupled surface/subsurface continuous gravimetric monitoring of 2 years at the Rochefort Cave Laboratory (Belgium). The gravity record includes surface measurements of a GWR superconducting gravimeter and subsurface measurements of a Micro-g LaCoste gPhone gravimeter, installed in a cave 35 m below the surface station. The recharge of karstic aquifers is extremely complex to model, mostly because karst hydrological systems are composed of strongly heterogeneous flows. Most of the problem comes from the inadequacy of conventional measuring tools to correctly sample such heterogeneous media, and particularly the existence of a duality of flow types infiltrating the vadose zone: from rapid flows via open conduits to slow seepage through porous matrix. Using the surface/subsurface gravity difference, we were able to identify a significant seasonal groundwater recharge within the karst vadose zone. Seasonal or perennial perched reservoirs have already been proven to exist in several karst areas due to the heterogeneity of the porosity and permeability gradient in karstified carbonated rocks. Our gravimetric experiment allows assessing more precisely the recharge processes of such reservoirs. The gravity variations were also compared with surface and in-cave hydrogeological monitoring (i.e. soil moisture, in-cave percolating water discharges, water levels of the saturated zone). Combined with additional geological information, modeling of the gravity signal based on the vertical component of the gravitational attraction was particularly useful to estimate the seasonal recharge leading to temporary groundwater storage in the vadose zone.

Apollo 17 traverse gravimeter experiment /Preliminary results/

NASA Technical Reports Server (NTRS)

Talwani, M.; Kahle, H.-G.

1976-01-01

Preliminary results of the traverse gravimeter experiment successfully performed during the Apollo 17 mission are discussed. An earth-moon gravity tie was established. On the basis of several readings, a gravity value of 162,695 + or - 5 mgal was obtained at the lunar-module landing site in the Taurus-Littrow valley. Free-air and Bouguer corrections were applied to the gravity data. The resultant Bouguer anomaly, analyzed with a two-dimensional approximation, shows a relative gravity maximum of about 25 to 30 mgal over the Taurus-Littrow valley. This maximum is interpreted in terms of a 1-km-thick block of basalt flow with a positive density contrast of 0.8 g/cu cm relative to the highland material on either side.

Method and apparatus for measuring gravitational acceleration utilizing a high temperature superconducting bearing

DOEpatents

Hull, John R.

2000-01-01

Gravitational acceleration is measured in all spatial dimensions with improved sensitivity by utilizing a high temperature superconducting (HTS) gravimeter. The HTS gravimeter is comprised of a permanent magnet suspended in a spaced relationship from a high temperature superconductor, and a cantilever having a mass at its free end is connected to the permanent magnet at its fixed end. The permanent magnet and superconductor combine to form a bearing platform with extremely low frictional losses, and the rotational displacement of the mass is measured to determine gravitational acceleration. Employing a high temperature superconductor component has the significant advantage of having an operating temperature at or below 77K, whereby cooling may be accomplished with liquid nitrogen.

A comparison of the performance of two types of inertial systems for strapdown airborne gravimetry

NASA Astrophysics Data System (ADS)

Deurloo, R. A.; Martin, J.; Bastos, M. L.; Becker, M. H.

2012-12-01

Over the past two decades so-called strapdown airborne gravimetry systems have proven to have the potential to compete with more traditional measurement systems such as modified spring gravimeters (e.g. LaCoste & Romberg Air-Sea gravimeters). Strapdown gravimetry systems rely on the integration of high-accuracy data from a GNSS (Global Navigation Satellite System) receiver and from a strapdown IMU (Inertial Measurement Unit). These GNSS/IMU integrated systems have the advantage of being less expensive and more compact, while being easier to use and install than spring gravimeters, which tend to be bulky and require specialized human resources for its operation. In the scope of a research project developed through the collaboration of the University of Porto and the Portuguese Air Force (PAF), an airborne survey was recently performed over the middle and southern area of Continental Portugal using a CASA C212 aircraft. The goal of this survey was to acquire data to assess the performance of different GNSS/IMU systems and associated processing approaches to determine the gravity field and evaluate their potential and effectiveness for airborne gravimetry using different types of airborne platforms, including UAVs (Unmanned Airborne Vehicles). Among the systems on board were a medium-quality (tactical grade) IMU with fiber-optic gyros (FOG), a Litton LN-200, and a high-quality (navigation grade) IMU with ring-laser gyros (RLG), an iMAR RHQ-1003, which are the focus of the present comparison. The advantage of using a strapdown airborne gravimetry system with high-quality inertial sensor is that it allows the complete gravity vector to be determined from the triads of accelerometers and gyros in the IMU (vector gravimetry). On the other hand a medium-quality inertial system is limited to determining only the magnitude of the gravity vector (scalar gravimetry). The limited quality of the gyros of the medium-quality inertial systems does not allow the horizontal components of the gravity vector to be determined. In spite of that, this type of system has been shown to still deliver very useful results in the range of a few mGal for resolutions below 10km. In this work we describe the setup used for our airborne test and we present a comparison and analysis of the performance of the medium- and high-quality inertial systems. This includes an analysis of the results of overlapping flight lines obtained with both systems. Considerations about the suitability of each of the systems for different types of applications are also discussed.

A highly accurate absolute gravimetric network for Albania, Kosovo and Montenegro

NASA Astrophysics Data System (ADS)

Ullrich, Christian; Ruess, Diethard; Butta, Hubert; Qirko, Kristaq; Pavicevic, Bozidar; Murat, Meha

2016-04-01

The objective of this project is to establish a basic gravity network in Albania, Kosovo and Montenegro to enable further investigations in geodetic and geophysical issues. Therefore the first time in history absolute gravity measurements were performed in these countries. The Norwegian mapping authority Kartverket is assisting the national mapping authorities in Kosovo (KCA) (Kosovo Cadastral Agency - Agjencia Kadastrale e Kosovës), Albania (ASIG) (Autoriteti Shtetëror i Informacionit Gjeohapësinor) and in Montenegro (REA) (Real Estate Administration of Montenegro - Uprava za nekretnine Crne Gore) in improving the geodetic frameworks. The gravity measurements are funded by Kartverket. The absolute gravimetric measurements were performed from BEV (Federal Office of Metrology and Surveying) with the absolute gravimeter FG5-242. As a national metrology institute (NMI) the Metrology Service of the BEV maintains the national standards for the realisation of the legal units of measurement and ensures their international equivalence and recognition. Laser and clock of the absolute gravimeter were calibrated before and after the measurements. The absolute gravimetric survey was carried out from September to October 2015. Finally all 8 scheduled stations were successfully measured: there are three stations located in Montenegro, two stations in Kosovo and three stations in Albania. The stations are distributed over the countries to establish a gravity network for each country. The vertical gradients were measured at all 8 stations with the relative gravimeter Scintrex CG5. The high class quality of some absolute gravity stations can be used for gravity monitoring activities in future. The measurement uncertainties of the absolute gravity measurements range around 2.5 micro Gal at all stations (1 microgal = 10-8 m/s2). In Montenegro the large gravity difference of 200 MilliGal between station Zabljak and Podgorica can be even used for calibration of relative gravimeters. The complete basic gravimetric network of these countries will be tied to these absolute stations. In this presentation all the stations and results will be presented in detail and some special results analysed.

Mobile quantum gravity sensor with unprecedented stability

NASA Astrophysics Data System (ADS)

Leykauf, Bastian; Freier, Christian; Schkolnik, Vladimir; Krutzik, Markus; Peters, Achim

2017-04-01

The gravimetric atom interferometer GAIN is based on interfering ensembles of laser-cooled 87Rb atoms in a fountain setup, using stimulated Raman transitions. GAIN's rugged design allows for transports to sites of geodetic and geophysical interest while maintaining a high accuracy compatible with the best classical instruments. We compared our instrument's performance with falling corner-cube and superconducting gravimeters in two measurement campaigns at geodetic observatories in Wettzell, Germany and Onsala, Sweden. Our instrument's long-term stability of 0.5 nm/s2 is the best value for absolute gravimeters reported to date [1]. Our measured gravity value agrees with other state-of-the-art gravimeters on the 10-9 level in g, demonstrating effective control over systematics including wavefront distortions of the Raman beams [2]. By using the juggling technique [3], we are able to perform gravity measurements on two atomic clouds simultaneously. Advantages include the suppression of common mode phase noise, enabling differential phase shift extraction without the need for vibration isolation. We will present the results of our first gravity gradient measurements. [1] Freier, Hauth, Schkolnik, Leykauf, Schilling, Wziontek, Scherneck, Müller and Peters (2016). Mobile quantum gravity sensor with unprecedented stability. Journal of Physics: Conference Series, 8th Symposium on Frequency Standards and Metrology 2015, 723, 12050. [2] Schkolnik, Leykauf, Hauth, Freier and Peters (2015). The effect of wavefront aberrations in atom interferometry. Applied Physics B, 120(2), 311 - 316. [3] Legere and Gibble (1998). Quantum Scattering in a Juggling Atomic Fountain. Physical Review Letters, 81(1), 5780 - 5783.

Comparisons of absolute gravimeters (COOMET.M.G-S1)

NASA Astrophysics Data System (ADS)

Vinnichenko, Mr Alexander; Germak, Alessandro, Dr

2017-01-01

This report describes the results of the RMO supplementary comparison COOMET.M.G-S1 (also known as bilateral comparison COOMET 634/UA/14). The comparison measurements between the two participants NSC 'IM' (pilot laboratory) and INRIM were started in December 2015 and finished in January 2016. Participants of comparisons were conducted at their national standards the measurements of the free fall acceleration in gravimetric point laboratory of absolute gravimetry of INRIM named INRiM.2. Absolute measurements of gravimetric acceleration were conducted by ballistic gravimeters. The agreement between the two participants is good. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Apollo scientific experiments data handbook

NASA Technical Reports Server (NTRS)

Eichelman, W. F. (Editor); Lauderdale, W. W. (Editor)

1974-01-01

A brief description of each of the Apollo scientific experiments was described, together with its operational history, the data content and formats, and the availability of the data. The lunar surface experiments described are the passive seismic, active seismic, lunar surface magnetometer, solar wind spectrometer, suprathermal ion detector, heat flow, charged particle, cold cathode gage, lunar geology, laser ranging retroreflector, cosmic ray detector, lunar portable magnetometer, traverse gravimeter, soil mechanics, far UV camera (lunar surface), lunar ejecta and meteorites, surface electrical properties, lunar atmospheric composition, lunar surface gravimeter, lunar seismic profiling, neutron flux, and dust detector. The orbital experiments described are the gamma-ray spectrometer, X-ray fluorescence, alpha-particle spectrometer, S-band transponder, mass spectrometer, far UV spectrometer, bistatic radar, IR scanning radiometer, particle shadows, magnetometer, lunar sounder, and laser altimeter. A brief listing of the mapping products available and information on the sample program were also included.

Prompt gravity signal induced by the 2011 Tohoku-Oki earthquake

PubMed Central

Montagner, Jean-Paul; Juhel, Kévin; Barsuglia, Matteo; Ampuero, Jean Paul; Chassande-Mottin, Eric; Harms, Jan; Whiting, Bernard; Bernard, Pascal; Clévédé, Eric; Lognonné, Philippe

2016-01-01

Transient gravity changes are expected to occur at all distances during an earthquake rupture, even before the arrival of seismic waves. Here we report on the search of such a prompt gravity signal in data recorded by a superconducting gravimeter and broadband seismometers during the 2011 Mw 9.0 Tohoku-Oki earthquake. During the earthquake rupture, a signal exceeding the background noise is observed with a statistical significance higher than 99% and an amplitude of a fraction of μGal, consistent in sign and order of magnitude with theoretical predictions from a first-order model. While prompt gravity signal detection with state-of-the-art gravimeters and seismometers is challenged by background seismic noise, its robust detection with gravity gradiometers under development could open new directions in earthquake seismology, and overcome fundamental limitations of current earthquake early-warning systems imposed by the propagation speed of seismic waves. PMID:27874858

Prompt gravity signal induced by the 2011 Tohoku-Oki earthquake.

PubMed

Montagner, Jean-Paul; Juhel, Kévin; Barsuglia, Matteo; Ampuero, Jean Paul; Chassande-Mottin, Eric; Harms, Jan; Whiting, Bernard; Bernard, Pascal; Clévédé, Eric; Lognonné, Philippe

2016-11-22

Transient gravity changes are expected to occur at all distances during an earthquake rupture, even before the arrival of seismic waves. Here we report on the search of such a prompt gravity signal in data recorded by a superconducting gravimeter and broadband seismometers during the 2011 Mw 9.0 Tohoku-Oki earthquake. During the earthquake rupture, a signal exceeding the background noise is observed with a statistical significance higher than 99% and an amplitude of a fraction of μGal, consistent in sign and order of magnitude with theoretical predictions from a first-order model. While prompt gravity signal detection with state-of-the-art gravimeters and seismometers is challenged by background seismic noise, its robust detection with gravity gradiometers under development could open new directions in earthquake seismology, and overcome fundamental limitations of current earthquake early-warning systems imposed by the propagation speed of seismic waves.

Prompt gravity anomaly induced to the 2011Tohoku-Oki earthquake

NASA Astrophysics Data System (ADS)

Montagner, Jean-Paul; Juhel, Kevin; Barsuglia, Matteo; Ampuero, Jean-Paul; Harms, Jan; Chassande-Mottin, Eric; Whiting, Bernard; Bernard, Pascal; Clévédé, Eric; Lognonné, Philippe

2017-04-01

Transient gravity changes are expected to occur at all distances during an earthquake rupture, even before the arrival of seismic waves. Here we report on the search of such a prompt gravity signal in data recorded by a superconducting gravimeter and broadband seismometers during the 2011 Mw 9.0 Tohoku-Oki earthquake. During the earthquake rupture, a signal exceeding the background noise is observed with a statistical significance higher than 99% and an amplitude of a fraction of μGal, consistent in sign and order-of-magnitude with theoretical predictions from a first-order model. While prompt gravity signal detection with state-of-the-art gravimeters and seismometers is challenged by background seismic noise, its robust detection with gravity gradiometers under development could open new directions in earthquake seismology, and overcome fundamental limitations of current earthquake early-warning systems (EEWS) imposed by the propagation speed of seismic waves.

Monitoring of water storage in karstic area (Larzac, France) with a iGrav continuous superconducting gravimeter

NASA Astrophysics Data System (ADS)

Le Moigne, N.; Champollion, C.; chery, J.; Deville, S.; Doerflinger, E.; Collard, P.; Flores, B.

2013-12-01

Quantitative knowledge of groundwater storage and transfer in karstic area is crucial for water resources management and protection. As the karst hydro-geological properties are highly heterogeneous and scale dependent, geophysical observations such as gravity are necessary to fill the gap between local (based on boreholes, moisture sensors, ...) and global (based on chemistry, river flow, ...) studies. Since almost 2 years, the iGrav #002 superconducting gravimeter is continuously operating in the French GEK (Géodésie des Eaux Karstiques) observatory in the Larzac karstic plateau (south of France). First the evaluation of the iGrav data (calibration, steps and drift) will be presented. Then a careful analyze of the topographic and building effects will be done. Finally the first interpretation of the hydrogeological signal and the integration an extensive observation dataset (borehole water level, evapotranspiration and electrical resistivity) are studied.

Hybrid gravity survey to search for submarine ore deposit

NASA Astrophysics Data System (ADS)

Araya, A.; Kanazawa, T.; Fujimoto, H.; Shinohara, M.; Yamada, T.; Mochizuki, K.; Iizasa, K.; Ishihara, T.; Omika, S.

2011-12-01

Along with seismic surveys, gravity survey is a useful method to profile the underground density structure. We propose a hybrid gravity survey using gravimeters and gravity gradiometers to detect submarine ore deposits as density anomalies by towing the instruments using an AUV (Autonomous Underwater Vehicle) or an ROV (Remotely Operated Vehicle). Gravimeters measure the regional density structure below the seafloor, whereas gravity gradiometers are sensitive to localized mass distribution. A gravity gradiometer comprises two accelerometers arranged with a vertical separation, and a gravity gradient can be obtained from the acceleration difference. Compared to gravimeters, gravity gradiometers are insensitive to common disturbances such as parallel acceleration, thermal drift, and apparent gravity effect (Eötvös effect). We made two accelerometers using astatic pendulums, and obtained common acceleration reduction more than two orders of magnitude. With these pendulums of 500-mm separation, resolution of 7E (=7x10^{-9}(1/s^2)), enough to detect a typical ore deposit buried 50m below the seafloor, was evaluated. During measurements using a submersible mobile object, instrument orientation is required to be controlled to keep verticality and to reduce centrifugal force associated with rotation of the instrument. Using a gyro and a tiltmeter, angular rotation was shown to be controlled within 0.001deg/s which corresponds to 0.3E in effective gravity gradient due to the centrifugal force. In this paper, target of this research, details of the instruments and their performance, and development for the submarine gravity survey using an AUV will be presented.

Laser interferometry method for absolute measurement of the acceleration of gravity

NASA Technical Reports Server (NTRS)

Hudson, O. K.

1971-01-01

Gravimeter permits more accurate and precise absolute measurement of g without reference to Potsdam values as absolute standards. Device is basically Michelson laser beam interferometer in which one arm is mass fitted with corner cube reflector.

Drift Rates of Three Micro-g LaCoste Turnkey Airborne Gravity Systems (TAGS) Used for the GRAV-D Project

NASA Astrophysics Data System (ADS)

Preaux, S. A.; Crump, B.; Damiani, T.

2015-12-01

The Gravity for the Redefinition of the American Vertical Datum (GRAV-D) project of NOAA's National Geodetic Survey has been collecting airborne gravity data since 2008 using 3 TAGS gravimeters, S-137, S-160 and S-161 (Table 1). The 38 surveys contain 1697 gravimeter calibration readings taken when the aircraft is parked on the ground before and after each flight, called still readings. This dataset is uniquely suited to examine the drift characteristics of these instruments. This study is broken into 3 parts: re-computation of individual still reading values; examination of drift rates during flights and surveys; and examination of long term drift rates. Re-computation of still readings was accomplished by isolating the least-noisy 10-minute segment of gravity data while the aircraft was parked and the beam unclamped. This automated method worked in most cases, but a small number of readings required further examination. This method improved the consistency of pre- and post-flight still readings as compared to those recorded in the field. Preliminary results indicate that the drift rate for these 3 instruments during a typical survey period is both small (95% smaller than 0.35 mGal/day) and linear. The average drift rate during a survey is -0.11 mGal/day with a standard deviation of 0.12 mGal/day (Figure 1). Still readings for most surveys were well represented by a linear trend, but a small number have curvature or discontinuities. The nature and cause of this non-linearity will be investigated. Early results show a long term linear drift rate for these 3 gravimeters between 0.01 and 0.04 mGal/day. There also appears to be significant non-linear variability. Comparing the 1.5-2 year time series of still readings from S-160 and S-161 with the 7.5 year time series for S-137, indicates that data from more than two years are needed to accurately characterize the long-term behavior. Instrumentation and processing causes for this non-linearity will be explored. Table1. Number of surveys and still reading and duration of use for each Gravimeter Meter # of surveys # still readings Duration of use S-137 27 1205 7.5 years S-160 4 288 1.5 years S-161 7 204 2 years

The Effect of Pitch, Roll, and Yaw on Airborne Gravity Observations of the NOAA GRAV-D Project

NASA Astrophysics Data System (ADS)

Childers, V. A.; Kanney, J.; Youngman, M.

2017-12-01

Aircraft turbulence can wreak havoc on the gravity measurementby beam-style gravimeters. Prior studies have confirmed the correlation of poor quality airborne gravity data collection to amplified aircraft motion. Motion in the aircraft is the combined effect of the airframe design, the autopilot and its performance, and the weather/wind regime. NOAA's National Geodetic Survey has launched the Gravity for the Redefinition of the American Vertical Datum project (GRAV-D) to provide the foundation for a new national vertical datum by 2022. This project requires collecting airborne gravity data covering the entire country and its holdings. The motion of the aircraft employed in this project is of prime importance because we use a beam-style gravimeter mounted on a gyro-stabilized platform to align the sensor to a time-averaged local vertical. Aircraft turbulence will tend to drive the platform off-level, allowing horizontal forces to map into the vertical gravity measurement. Recently, the GRAV-D project has experimented with two new factors in airborne gravity data collection. The first aspect is the use of the Aurora optionally piloted Centaur aircraft. This aircraft can be flown either with or without a pilot, but the autopilot is specifically designed to be very accurate. Incorporated into the much smaller frame of this aircraft is a new gravimeter developed by Micro-g LaCoste, called the Turnkey Airborne Gravimeter System 7 (TAGS7). This smaller, lighter instrument also has a new design whereby the beam is held fixed in an electromagnetic force field. The result of this new configuration is notably improved data quality in wind conditions higher than can be tolerated by our current system. So, which caused the improvement, the aircraft motion or the new meter? This study will start to tease apart these two effects with recently collected survey data. Specifically, we will compare the motion profile of the Centaur aircraft with other aircraft in the GRAV-D portfolio that we use successfully. In addition, we will investigate the relationship of aircraft motion, as measured by pitch, roll, and yaw, to airborne gravity quality in the Centaur operation as well as measurement aboard other aircraft with the beam-style sensor.

Nepal and Papua Airborne Gravity Surveys

NASA Astrophysics Data System (ADS)

Olesen, A. V.; Forsberg, R.; Kasenda, F.; Einarsson, I.; Manandhar, N.

2011-12-01

Airborne gravimetry offers a fast and economic way to cover vast areas and it allows access to otherwise difficult accessible areas like mountains, jungles and the near coastal zone. It has the potential to deliver high resolution and bias free data that may bridge the spectral gap between global satellite gravity models and the high resolution gravity information embedded in digital terrain models. DTU Space has for more than a decade done airborne gravity surveys in many parts of the world. Most surveys were done with a LaCoste & Romberg S-meter updated for airborne use. This instrument has proven to deliver near bias free data when properly processed. A Chekan AM gravimeter was recently added to the airborne gravity mapping system and will potentially enhance the spatial resolution and the robustness of the system. This paper will focus on results from two recent surveys over Nepal, flown in December 2010, and over Papua (eastern Indonesia), flown in May and June 2011. Both surveys were flown with the new double gravimeter setup and initial assessment of system performance indicates improved spatial resolution compared to the single gravimeter system. Comparison to EGM08 and to the most recent GOCE models highlights the impact of the new airborne gravity data in both cases. A newly computed geoid model for Nepal based on the airborne data allows for a more precise definition of the height of Mt. Everest in a global height system. This geoid model suggests that the height of Mt. Everest should be increased by approximately 1 meter. The paper will also briefly discuss system setup and will highlight a few essential processing steps that ensure that bias problems are minimized and spatial resolution enhanced.

Time Changes of the European Gravity Field from GRACE: A Comparison with Ground Measurements from Superconducting Gravimeters and with Hydrology Model Predictions

NASA Technical Reports Server (NTRS)

Hinderer, J.; Lemoine, Frank G.; Crossley, D.; Boy, J.-P.

2004-01-01

We investigate the time-variable gravity changes in Europe retrieved from the initial GRACE monthly solutions spanning a 18 month duration from April 2002 to October 2003. Gravity anomaly maps are retrieved in Central Europe from the monthly satellite solutions we compare the fields according to various truncation levels (typically between degree 10 and 20) of the initial fields (expressed in spherical harmonics to degree 120). For these different degrees, an empirical orthogonal function (EOF) decomposition of the time-variable gravity field leads us to its main spatial and temporal characteristics. We show that the dominant signal is found to be annual with an amplitude and a phase both in agreement with predictions in Europe modeled using snow and soil-moisture variations from recent hydrology models. We compare these GRACE gravity field changes to surface gravity observations from 6 superconducting gravimeters of the GGP (Global Geodynamics Project) European sub-network, with a special attention to loading corrections. Initial results suggest that all 3 data sets (GRACE, hydrology and GGP) are responding to annual changes in near-surface water in Europe of a few microGal (at length scales of approx.1000 km) that show a high value in winter and a summer minimum. We also point out that the GRACE gravity field evolution seems to indicate that there is a trend in gravity between summer 2002 and summer 2003 which can be related to the 2003 heatwave in Europe and its hydrological consequences (drought). Despite the limited time span of our analysis and the uncertainties in retrieving a regional solution from the network of gravimeters, the calibration and validation aspects of the GRACE data processing based on the annual hydrology cycle in Europe are in progress.

Apollo lunar surface experiments package. Apollo 17 ALSEP (array E) familiarization course handout

NASA Technical Reports Server (NTRS)

1972-01-01

The familiarization course for the Apollo 17 ALSEP (ARRAY E) is presented. The subjects discussed are: (1) power and data subsystems, (2) lunar surface gravimeter, (3) lunar mass spectrometer, (4) lunar seismic profiling experiment, and (5) heat flow experiment.

Design, Assembly, Integration, and Testing of a Power Processing Unit for a Cylindrical Hall Thruster, the NORSAT-2 Flatsat, and the Vector Gravimeter for Asteroids Instrument Computer

NASA Astrophysics Data System (ADS)

Svatos, Adam Ladislav

This thesis describes the author's contributions to three separate projects. The bus of the NORSAT-2 satellite was developed by the Space Flight Laboratory (SFL) for the Norwegian Space Centre (NSC) and Space Norway. The author's contributions to the mission were performing unit tests for the components of all the spacecraft subsystems as well as designing and assembling the flatsat from flight spares. Gedex's Vector Gravimeter for Asteroids (VEGA) is an accelerometer for spacecraft. The author's contributions to this payload were modifying the instrument computer board schematic, designing the printed circuit board, developing and applying test software, and performing thermal acceptance testing of two instrument computer boards. The SFL's cylindrical Hall effect thruster combines the cylindrical configuration for a Hall thruster and uses permanent magnets to achieve miniaturization and low power consumption, respectively. The author's contributions were to design, build, and test an engineering model power processing unit.

Using absolute gravimeter data to determine vertical gravity gradients

USGS Publications Warehouse

Robertson, D.S.

2001-01-01

The position versus time data from a free-fall absolute gravimeter can be used to estimate the vertical gravity gradient in addition to the gravity value itself. Hipkin has reported success in estimating the vertical gradient value using a data set of unusually good quality. This paper explores techniques that may be applicable to a broader class of data that may be contaminated with "system response" errors of larger magnitude than were evident in the data used by Hipkin. This system response function is usually modelled as a sum of exponentially decaying sinusoidal components. The technique employed here involves combining the x0, v0 and g parameters from all the drops made during a site occupation into a single least-squares solution, and including the value of the vertical gradient and the coefficients of system response function in the same solution. The resulting non-linear equations must be solved iteratively and convergence presents some difficulties. Sparse matrix techniques are used to make the least-squares problem computationally tractable.

Field test of the superconducting gravimeter as a hydrologic sensor.

PubMed

Wilson, Clark R; Scanlon, Bridget; Sharp, John; Longuevergne, Laurent; Wu, Hongqiu

2012-01-01

We report on a field test of a transportable version of a superconducting gravimeter (SG) intended for groundwater storage monitoring. The test was conducted over a 6-month period at a site adjacent to a well in the recharge zone of the karstic Edwards Aquifer, a major groundwater resource in central Texas. The purpose of the study was to assess requirements for unattended operation of the SG in a field setting and to obtain a gravimetric estimate of aquifer specific yield. The experiment confirmed successful operation of the SG, but water level changes were small (<0.3 m) leading to uncertainty in the estimate of specific yield. Barometric pressure changes were the dominant cause of both water level variations and non-tidal gravity changes. The specific yield estimate (0.26) is larger than most published values and dependent mainly on low frequency variations in residual gravity and water level time series. © 2011, The Author(s). Ground Water © 2011, National Ground Water Association.

Comparison of Superconducting and Spring Gravimeters at the Mizusawa VLBI Observatory of the National Astronomical Observatory of Japan

NASA Astrophysics Data System (ADS)

Miura, Satoshi; Ikeda, Hiroshi; Kim, Tae-Hee; Tamura, Yoshiaki

2017-04-01

Continuous microgravity monitoring is utilized to gain new insights into changes in the subsurface distribution of magma and/or fluid that commonly occur beneath active volcanoes. Rather new superconducting and spring gravimeters, iGrav#003 and gPhone#136 are collocated with a superconducting gravimeter, TT#70 at the Mizusawa VLBI Observatory of the National Astronomical Observatory of Japan, since the end of September, 2016 in order to evaluate those performances before field deployment planned in 2017. Calibration of iGrav#003 was carried out by collocation with an absolute gravimeter FG5 of the Earthquake Research Institute, University of Tokyo (Okubo, 2016, personal comm.) at a Fundamental Gravity Station in Sendai in July, 2016. Based on the scale factors of iGrav#003 obtained by the calibration and of gPhone#136 provided by the manufacturer (Micro-g LaCoste, Inc.), tidal analyses are performed by means of BAYTAP-G (Tamura et al., 1991, GJI). Amplitudes and phases of each major tidal constituent mutually agree well within ±4 % and ±3 degrees, respectively. The instrumental drift rate of iGrav#003 is very low, about 5 micro-Gal/month, whereas that of gPhone#136 is very high, about 500 micro-Gal/month. The high drift rate of gPhone#136, however, is well approximated by a quadratic function at present and can be removed. The detrended time series of gPhone#136 shows good agreement with iGrav#003 time series in the overall feature: gravity fluctuations with amplitudes of about a few micro-Gal and with durations of a few days, which may be due to variations in the moisture content of the topmost unsaturated sedimentary layer and the water table height. It suggests that both instruments may capture volcanic signals associated with pressure changes in magma chambers, dike intrusion/withdrawing, and so on. iGrav#003 will be installed in the Zao volcanological observatory of Tohoku University located at about 3 km from the summit crater, and gPhone#136 will be deployed in the Jododaira Astronomical Observatory located at about 0.5 km from Oana crater of Azumayama volcano in the spring of 2017. Both of the volcanoes, Zao and Azumayama show minor volcanic activity with frequent shallow earthquakes, changes in the total magnetic force, pressure changes at depth, and so on in 2014 and 2015.

Local and Catchment-Scale Water Storage Changes in Northern Benin Deduced from Gravity Monitoring at Various Time-Scales

NASA Astrophysics Data System (ADS)

Hinderer, J.; Hector, B.; Séguis, L.; Descloitres, M.; Cohard, J.; Boy, J.; Calvo, M.; Rosat, S.; Riccardi, U.; Galle, S.

2013-12-01

Water storage changes (WSC) are investigated by the mean of gravity monitoring in Djougou, northern Benin, in the frame of the GHYRAF (Gravity and Hydrology in Africa) project. In this area, WSC are 1) part of the control system for evapotranspiration (ET) processes, a key variable of the West-African monsoon cycle and 2) the state variable for resource management, a critical issue in storage-poor hard rock basement contexts such as in northern Benin. We show the advantages of gravity monitoring for analyzing different processes in the water cycle involved at various time and space scales, using the main gravity sensors available today (FG5 absolute gravimeter, superconducting gravimeter -SG- and CG5 micro-gravimeter). The study area is also part of the long-term observing system AMMA-Catch, and thus under intense hydro-meteorological monitoring (rain, soil moisture, water table level, ET ...). Gravity-derived WSC are compared at all frequencies to hydrological data and to hydrological models calibrated on these data. Discrepancies are analyzed to discuss the pros and cons of each approach. Fast gravity changes (a few hours) are significant when rain events occur, and involve different contributions: rainfall itself, runoff, fast subsurface water redistribution, screening effect of the gravimeter building and local topography. We investigate these effects and present the statistical results of a set of rain events recorded with the SG installed in Djougou since July 2010. The intermediate time scale of gravity changes (a few days) is caused by ET and both vertical and horizontal water redistribution. The integrative nature of gravity measurements does not allow to separate these different contributions, and the screening from the shelter reduces our ability to retrieve ET values. Also, atmospheric corrections are critical at such frequencies, and deserve some specific attention. However, a quick analysis of gravity changes following rain events shows that the values are in accordance with expected ET values (up to about 5mm/day). Seasonal WSC are analyzed since 2008 using FG5 absolute gravity measurements four times a year and since 2010 using the continuous SG time series. They can reach up to 12 microGal (≈270mm) and show a clear interannual variability, as can be expected from rainfall variability in the area. This data set allows some estimates of an average specific yield for the local aquifer, together with a scaling factor for Magnetic Resonance Soundings-derived water content.

Apollo lunar surface experiments package

NASA Technical Reports Server (NTRS)

1972-01-01

The ALSEP program status and monthly progress are reported. Environmental and quality control tests and test results are described. Details are given on the Apollo 17 Array E, and the lunar seismic profiling, ejecta and meteorites, mass spectrometer, surface gravimeter, and heat flow experiments. Monitoring of the four ALSEP systems on the moon is also described.

Macroscopic superpositions and gravimetry with quantum magnetomechanics.

PubMed

Johnsson, Mattias T; Brennen, Gavin K; Twamley, Jason

2016-11-21

Precision measurements of gravity can provide tests of fundamental physics and are of broad practical interest for metrology. We propose a scheme for absolute gravimetry using a quantum magnetomechanical system consisting of a magnetically trapped superconducting resonator whose motion is controlled and measured by a nearby RF-SQUID or flux qubit. By driving the mechanical massive resonator to be in a macroscopic superposition of two different heights our we predict that our interferometry protocol could, subject to systematic errors, achieve a gravimetric sensitivity of Δg/g ~ 2.2 × 10 -10  Hz -1/2 , with a spatial resolution of a few nanometres. This sensitivity and spatial resolution exceeds the precision of current state of the art atom-interferometric and corner-cube gravimeters by more than an order of magnitude, and unlike classical superconducting interferometers produces an absolute rather than relative measurement of gravity. In addition, our scheme takes measurements at ~10 kHz, a region where the ambient vibrational noise spectrum is heavily suppressed compared the ~10 Hz region relevant for current cold atom gravimeters.

Macroscopic superpositions and gravimetry with quantum magnetomechanics

PubMed Central

Johnsson, Mattias T.; Brennen, Gavin K.; Twamley, Jason

2016-01-01

Precision measurements of gravity can provide tests of fundamental physics and are of broad practical interest for metrology. We propose a scheme for absolute gravimetry using a quantum magnetomechanical system consisting of a magnetically trapped superconducting resonator whose motion is controlled and measured by a nearby RF-SQUID or flux qubit. By driving the mechanical massive resonator to be in a macroscopic superposition of two different heights our we predict that our interferometry protocol could, subject to systematic errors, achieve a gravimetric sensitivity of Δg/g ~ 2.2 × 10−10 Hz−1/2, with a spatial resolution of a few nanometres. This sensitivity and spatial resolution exceeds the precision of current state of the art atom-interferometric and corner-cube gravimeters by more than an order of magnitude, and unlike classical superconducting interferometers produces an absolute rather than relative measurement of gravity. In addition, our scheme takes measurements at ~10 kHz, a region where the ambient vibrational noise spectrum is heavily suppressed compared the ~10 Hz region relevant for current cold atom gravimeters. PMID:27869142

A comparison of the gravity field over Central Europe from superconducting gravimeters, GRACE and global hydrological models, using EOF analysis

NASA Astrophysics Data System (ADS)

Crossley, David; de Linage, Caroline; Hinderer, Jacques; Boy, Jean-Paul; Famiglietti, James

2012-05-01

We analyse data from seven superconducting gravimeter (SG) stations in Europe from 2002 to 2007 from the Global Geodynamics Project (GGP) and compare seasonal variations with data from GRACE and several global hydrological models - GLDAS, WGHM and ERA-Interim. Our technique is empirical orthogonal function (EOF) decomposition of the fields that allows for the inherent incompatibility of length scales between ground and satellite observations. GGP stations below the ground surface pose a problem because part of the attraction from soil moisture comes from above the gravimeter, and this gives rise to a complex (mixed) gravity response. The first principle component (PC) of the EOF decomposition is the main indicator for comparing the fields, although for some of the series it accounts for only about 50 per cent of the variance reduction. PCs for GRACE solutions RL04 from CSR and GFZ are filtered with a cosine taper (degrees 20-40) and a Gaussian window (350 km). Significant differences are evident between GRACE solutions from different groups and filters, though they all agree reasonably well with the global hydrological models for the predominantly seasonal signal. We estimate the first PC at 10-d sampling to be accurate to 1 μGal for GGP data, 1.5 μGal for GRACE data and 1 μGal between the three global hydrological models. Within these limits the CNES/GRGS solution and ground GGP data agree at the 79 per cent level, and better when the GGP solution is restricted to the three above-ground stations. The major limitation on the GGP side comes from the water mass distribution surrounding the underground instruments that leads to a complex gravity effect. To solve this we propose a method for correcting the SG residual gravity series for the effects of soil moisture above the station.

Multi-scale hydrogeological and hydrogeophysical approach to monitor vadose zone hydrodynamics of a karst system

NASA Astrophysics Data System (ADS)

Watlet, Arnaud; Poulain, Amaël; Van Camp, Michel; Francis, Olivier; Triantafyllou, Antoine; Rochez, Gaëtan; Hallet, Vincent; Kaufmann, Olivier

2016-04-01

The vadose zone of karst systems plays an important role on the water dynamics. In particular, temporary perched aquifers can appear in the subsurface due to changes of weather conditions, reduced evapotranspiration and the vertical gradients of porosity and permeability. Although many difficulties are usually encountered when studying karst environments due to their heterogeneities, cave systems offer an outstanding opportunity to investigate vadose zone from the inside. We present a multi-scale study covering two years of hydrogeological and geophysical monitoring of the Lomme Karst System (LKS) located in the Variscan fold-and-thrust belt (Belgium), a region (~ 3000 ha) that shows many karstic networks within Devonian limestone units. Hydrogeological data cover the whole LKS and involve e.g. flows and levels monitoring or tracer tests performed in both vadose and saturated zones. Such data bring valuable information on the hydrological context of the studied area at the catchment scale. Combining those results with geophysical measurements allows validating and imaging them at a smaller scale, with more integrative techniques. Hydrogeophysical measurements are focused on only one cave system of the LKS, at the Rochefort site (~ 40 ha), taking benefit of the Rochefort Cave Laboratory (RCL) infrastructures. In this study, a microgravimetric monitoring and an Electrical Resistivity Tomography (ERT) monitoring are involved. The microgravimetric monitoring consists in a superconducting gravimeter continuously measuring gravity changes at the surface of the RCL and an additional relative gravimeter installed in the underlying cave located 35 meters below the surface. While gravimeters are sensible to changes that occur in both the vadose zone and the saturated zone of the whole cave system, combining their recorded signals allows enhancing vadose zone's gravity changes. Finally, the surface ERT monitoring provide valuable information at the (sub)-meter scale on the hydrological processes that occur in the vadose zone. Seasonal water variations and preferential flow path are observed. This helps separating the hydrological signature of the vadose zone from that of the saturated zone.

Assessing the precision of the iGrav superconducting gravimeter for hydrological models and karstic hydrological process identification

NASA Astrophysics Data System (ADS)

Fores, B.; Champollion, C.; Le Moigne, N.; Bayer, R.; Chéry, J.

2017-01-01

In this paper we present the potential of a new compact superconducting gravimeter (GWR iGrav) designed for groundwater monitoring. At first, 3 yr of continuous gravity data are evaluated and the performance of the instrument is investigated. With repeated absolute gravity measurements using a Micro-g Lacoste FG5, the calibration factor (-894.8 nm s-2 V-1) and the long-term drift of this instrument (45 nm s-2 yr-1) are estimated for the first time with a high precision and found to be respectively constant and linear for this particular iGrav. The low noise level performance is found similar to those of previous superconducting gravimeters and leads to gravity residuals coherent with local hydrology. The iGrav is located in a fully instrumented hydrogeophysical observatory on the Durzon karstic basin (Larzac plateau, south of France). Rain gauges and a flux tower (evapo-transpiration measurements) are used to evaluate the groundwater mass balance at the local scale. Water mass balance demonstrates that the karst is only capacitive: all the rainwater is temporarily stored in the matrix and fast transfers to the spring through fractures are insignificant in this area. Moreover, the upper part of the karst around the observatory appears to be representative of slow transfer of the whole catchment. Indeed, slow transfer estimated on the site fully supports the low-flow discharge at the only spring which represents all groundwater outflows from the catchment. In the last part of the paper, reservoir models are used to characterize the water transfer and storage processes. Particular highlights are done on the advantages of continuous gravity data (compared to repeated campaigns) and on the importance of local accurate meteorological data to limit misinterpretation of the gravity observations. The results are complementary with previous studies at the basin scale and show a clear potential for continuous gravity time-series assimilation in hydrological simulations, even on heterogeneous karstic systems.

Indoor Micro-Gravity Survey: Using Massive Research Equipment for Geophysics Curriculum

NASA Astrophysics Data System (ADS)

Secco, R. A.; Sukara, R.

2016-12-01

There are many lab exercises for upper level school students and freshman undergraduates, especially in the physical sciences, to measure the value of the local acceleration due to gravity (g) near the Earth's surface. In physics courses where physical principles are applied to Earth problems however, the goal is usually to measure a change in a potential field, such as the Earth's gravitational field, in order to determine anomalous subsurface characteristics. We describe an indoor exercise carried out as part of an introductory course in our geophysics program to measure the local change in g resulting from a large anomalous mass inside the building. Our indoor survey was conducted on a length scale of 6 orders of magnitude smaller than the typical airborne gravity survey of 100's-1000's of line kms. We used a large high pressure apparatus as the anomalous object (mass = 30,600 kg) which is used to generate very high pressures for research investigations. Using a Worden gravimeter, we carried out surveys one floor above the press and directly above the press using a purpose-built cradle on a lab gantry crane. The results show clear anomalies caused by the press and in the survey on the floor above the press, also shows a signature of the steel I-beam in the floor. The mass of, and depth to, the press are calculated using well-known formulae in gravity exploration methods. Students are asked to speculate on the origin of the anomalous mass given its depth. While 30 ton pieces of equipment may not exist in most universities, the minimum anomalous mass detectable at the 0.05mgal level is 1000kg and localized masses of this magnitude are more readily available (egs. electron microprobe, mass spectrometer). We also show that large structural I-beams in the building are detectable in our micro-gravity survey. Since they are present in most buildings of modern construction, they can also serve as useful targets for suitably sensitive modern gravimeters to perform indoor micro-gravity surveys.

The seismotectonics of plate boundaries

NASA Technical Reports Server (NTRS)

Berger, J.; Brune, J. N.; Goodkind, J.; Wyatt, F.; Agnew, D. C.; Beaumont, C.

1981-01-01

Research on the seismotectonics of plate boundaries is summarized. Instrumental development and an observational program designed to study various aspects of the seismotectonics of southern California and the northern Gulf of California are described. A unique superconducting gravimeter was further developed and supported under this program for deployment and operation at several sites. Work on Earth tides is also discussed.

GTOOLS: an Interactive Computer Program to Process Gravity Data for High-Resolution Applications

NASA Astrophysics Data System (ADS)

Battaglia, M.; Poland, M. P.; Kauahikaua, J. P.

2012-12-01

An interactive computer program, GTOOLS, has been developed to process gravity data acquired by the Scintrex CG-5 and LaCoste & Romberg EG, G and D gravity meters. The aim of GTOOLS is to provide a validated methodology for computing relative gravity values in a consistent way accounting for as many environmental factors as possible (e.g., tides, ocean loading, solar constraints, etc.), as well as instrument drift. The program has a modular architecture. Each processing step is implemented in a tool (function) that can be either run independently or within an automated task. The tools allow the user to (a) read the gravity data acquired during field surveys completed using different types of gravity meters; (b) compute Earth tides using an improved version of Longman's (1959) model; (c) compute ocean loading using the HARDISP code by Petit and Luzum (2010) and ocean loading harmonics from the TPXO7.2 ocean tide model; (d) estimate the instrument drift using linear functions as appropriate; and (e) compute the weighted least-square-adjusted gravity values and their errors. The corrections are performed up to microGal ( μGal) precision, in accordance with the specifications of high-resolution surveys. The program has the ability to incorporate calibration factors that allow for surveys done using different gravimeters to be compared. Two additional tools (functions) allow the user to (1) estimate the instrument calibration factor by processing data collected by a gravimeter on a calibration range; (2) plot gravity time-series at a chosen benchmark. The interactive procedures and the program output (jpeg plots and text files) have been designed to ease data handling and archiving, to provide useful information for future data interpretation or modeling, and facilitate comparison of gravity surveys conducted at different times. All formulas have been checked for typographical errors in the original reference. GTOOLS, developed using Matlab, is open source and machine independent. We will demonstrate program use and utility with data from multiple microgravity surveys at Kilauea volcano, Hawai'i.

Relative gravimeter prototype based on micro electro mechanical system

NASA Astrophysics Data System (ADS)

Rozy, A. S. A.; Nugroho, H. A.; Yusuf, M.

2018-03-01

This research to make gravity measurement system by utilizing micro electro mechanical system based sensor in Gal order. System design consists of three parts, design of hardware, software, and interface. The design of the hardware include of designing the sensor design to measure the value of a stable gravity acceleration. The ADXL345 and ADXL335 sensors are tuned to obtain stable measurements. The design of the instrumentation system the next stage by creating a design to integrate between the sensor, microcontroller, and GPS. The design of programming algorithm is done with Arduino IDE software. The interface design uses a 20x4 LCD display to display the gravity acceleration value and store data on the storage media. The system uses a box made of iron and plate leveling to minimize measurement errors. The sensor test shows the ADXL345 sensor has a more stable value. The system is examined by comparing with gravity measurement of gravimeter A-10 results in Bandung observation post. The result of system test resulted the average of system correction value equal to 0.19 Gal. The system is expected to use for mineral exploration, water supply analyze, and earthquake precursor.

Towards Testing General Relativity with a dual species interferometer

NASA Astrophysics Data System (ADS)

Schlippert, Dennis; Hartwig, Jonas; Tiarks, Daniel; Velte, Ulrich; Ganske, Sven; Ertmer, Wolfgang; Rasel, Ernst M.

2012-06-01

We report on our work directed towards a dual species matter-wave interferometer for performing a differential measurement of the acceleration of free falling ^87Rb and ^39K atoms to test Einstein's equivalence principle (universality of free fall). Based on minimal Standard Model Extension calculations this combination of test masses is more sensitive to composition based equivalence principle violating effects than, e.g. ^85Rb-^87Rb. During free fall, a Mach-Zehnder type interferometry sequence employing stimulated Raman transitions is applied synchronously for both species, achieving high common noise rejection. With an expected single shot resolution of 5x10-8g the apparatus will allow for studying systematics at the 10-9g level after 100 s integration time. Post-correction methods for high vibrational noise environments are investigated. To assure well defined starting conditions the two species will be trapped in an optical dipole trap. The properties of this trap at 2 μm allow for fast and efficient laser cooling, use of evaporative and sympathetic cooling techniques is possible. We will show the enviromental noise limited performance of the single species Rb gravimeter and the progress of the implementation of the K gravimeter.

Relativistic theory of the falling retroreflector gravimeter

NASA Astrophysics Data System (ADS)

Ashby, Neil

2018-02-01

We develop a relativistic treatment of interference between light reflected from a falling cube retroreflector in the vertical arm of an interferometer, and light in a reference beam in the horizontal arm. Coordinates that are nearly Minkowskian, attached to the falling cube, are used to describe the propagation of light within the cube. Relativistic effects such as the dependence of the coordinate speed of light on gravitational potential, propagation of light along null geodesics, relativity of simultaneity, and Lorentz contraction of the moving cube, are accounted for. The calculation is carried to first order in the gradient of the acceleration of gravity. Analysis of data from a falling cube gravimeter shows that the propagation time of light within the cube itself causes a significant reduction in the value of the acceleration of gravity obtained from measurements, compared to assuming reflection occurs at the face. An expression for the correction to g is derived and found to agree with experiment. Depending on the instrument, the correction can be several microgals, comparable to commonly applied corrections such as those due to polar motion and earth tides. The controversial ‘speed of light’ correction is discussed. Work of the US government, not subject to copyright.

Direct Measurement of Daily Evapotranspiration From a Deciduous Forest Using a Superconducting Gravimeter

NASA Astrophysics Data System (ADS)

Van Camp, M. J.; de Viron, O.; Pajot-Métivier, G.; Cazenave, F.; Watlet, A.; Dassargues, A.; Vanclooster, M.

2015-12-01

The conversion of liquid water into water vapor strongly controls the energy transfer between the Earth and the atmosphere, and plays one of the most important roles in the hydrological cycle. This process, called evapotranspiration (ET), deeply constraints the amount of green water in the total global water balance. However, assessing the ET from terrestrial ecosystems remains a key challenge in hydrology. We show that the liquid water mass losses can be directly inferred from continuous gravity measurements: as water evaporates and transpires from terrestrial ecosystems, the mass distribution varies through the system, changing its gravity field. Using continuous superconducting gravity measurements, we were able to identify a daily changes in gravity at the level of, or smaller than 10-10 g per day. This corresponds to 2.0 mm of water over an area of 50 ha.The strength of this method is its ability to ensure a direct, traceable and continuous monitoring of actual ET for years at the mesoscale (~50 ha) with a precision of a few tenths of mm of water. This paves the way for the development of the method in different land-use, land-cover and geological contexts, using superconducting and coming quantum gravimeters.

Repeat Absolute and Relative Gravity Measurements for Geothermal Reservoir Monitoring in the Ogiri Geothermal Field, Southern Kyushu, Japan

NASA Astrophysics Data System (ADS)

Nishijima, J.; Umeda, C.; Fujimitsu, Y.; Takayama, J.; Hiraga, N.; Higuchi, S.

2016-09-01

Repeat hybrid microgravity measurements were conducted around the Ogiri Geothermal Field on the western slope of Kirishima volcano, southern Kyushu, Japan. This study was undertaken to detect the short-term gravity change caused by the temporary shutdown of production and reinjection wells for regular maintenance in 2011 and 2013. Repeat microgravity measurements were taken using an A-10 absolute gravimeter (Micro-g LaCoste) and CG-5 gravimeter (Scintrex) before and after regular maintenance. Both instruments had an accuracy of 10 μgal. The gravity stations were established at 27 stations (two stations for absolute measurements and 25 stations for relative measurements). After removal of noise effects (e.g., tidal movement, precipitation, shallow groundwater level changes), the residual gravity changes were subdivided into five types of response. We detected a gravity decrease (up to 20 μgal) in the reinjection area and a gravity increase (up to 30 μgal) in the production area 1 month after the temporary shutdown. Most of the gravity stations recovered after the maintenance. The temporal density changes in the geothermal reservoir were estimated based on these gravity changes.

Monitoring and modeling of water storage in karstic area (Larzac, France) with a continuous supraconducting gravimeter

NASA Astrophysics Data System (ADS)

Benjamin, Fores; Cédric, Champollion; Nicolas, Lemoigne; Jean, Chéry

2014-05-01

Quantitative knowledge of the groundwater storage and transfer in karstic area is crucial for water resources management and protection. As the karst hydro-geological properties are highly heterogeneous and scale dependent, geophysical observations such as time dependant gravity could be helpful to fill the gap between local (based on boreholes, moisture sensors, …) and global (based on chemistry, river flow, …) studies. Since more than 2 years, the iGrav #002 supraconducting gravimeter is continuously operating in the French GEK observatory(Géodésie de l'Environnement Karstique, OSU OREME, SNO H+) in the Larzac karstic plateau (south of France). The observatory is surrounding more than 250m karstified dolomite, with an unsaturated zone of ~150m thickness. First, the evaluation of the iGrav data (calibration, steps and drift) will be presented. Then a careful analysis of the global, topographic and building effects will be done to evaluate the local water storage only. The gravity data will be integrated with the water level data in nearby boreholes and petrophysical data from core samples. Finally, simple hydrological models will be presented to help the interpretation on the karst groundwater storage and transfer and to merge the whole dataset.

Reply to ‘No correction for the light propagation within the cube: Comment on Relativistic theory of the falling cube gravimeter’

NASA Astrophysics Data System (ADS)

Ashby, Neil

2018-06-01

The comment (Nagornyi 2018 Metrologia) claims that, notwithstanding the conclusions stated in the paper Relativistic theory of the falling cube gravimeter (Ashby 2008 Metrologia 55 1–10), there is no need to consider the dimensions or refractive index of the cube in fitting data from falling cube absolute gravimeters; additional questions are raised about matching quartic polynomials while determining only three quantities. The comment also suggests errors were made in Ashby (2008 Metrologia 55 1–10) while implementing the fitting routines on which the conclusions were based. The main contention of the comment is shown to be invalid because retarded time was not properly used in constructing a fictitious cube position. Such a fictitious position, fixed relative to the falling cube, is derived and shown to be dependent on cube dimensions and refractive index. An example is given showing how in the present context, polynomials of fourth order can be effectively matched by determining only three quantities, and a new compact characterization of the interference signal arriving at the detector is given. Work of the U.S. government, not subject to copyright.

Investigations on gravity data processing in airborne and shipborne gravimetry

NASA Astrophysics Data System (ADS)

Lu, Biao; Barthelmes, Franz; Petrovic, Svetozar; Förste, Christoph; Ince, Sinem; Flechtner, Frank

2017-04-01

Nowadays, airborne and shipborne gravimetry are very important methods to improve our knowledge about the Earth gravity field. The gravimeter Chekan-AM onboard the German High Altitude and Long Range (HALO) aircraft anables gravimetry at hardly accessible places like the polar regions of the Earth. One preparatory campaign on HALO has been carried out over Italy in 2012 to test the performance of the gravimeter Chekan-AM onboard such a jet aircraft. Specifically, the processing strategy of data achieved with this gravimeter has been studied. To investigate how future airborne gravity campaigns could be designed over regions like Antarctica, a dedicated flight track during the GEOHALO experiment had been run two times at different heights and velocities of the aircraft. These two flight paths are investigated and the results show that the equipment worked well also at higher altitude and speed. Comparisons with the global gravity field model EIGEN-6C4 and an analysis of the gravity differences at the crossover points show that the accuracy of this campaign is approximately 1 mGal. For geodetic purpose, a local geoid is computed by combining point mass modelling and the remove-compute-restore technique which is also taking into account the topography effect. Shipborne gravimetry can provide us high accurate and high resolution information of the Earth gravity field. Four campaigns of shipborne gravimetry by using the Chekan-AM on different research vessels have been conducted within the framework of the ongoing project "Finalising Surveys for the Baltic Motorways of the Sea" (FAMOS) since 2015. It turned out that problems due to influences of stormy sea and an abnormal drift behavior of the instrument at some parts of these campaigns need some additional investigations. The current processing of these gravity campaigns results in RMS of gravity differences at crossover points of about 0.5 mGal. Further investigations will continue to improve these results. Lastly, a high quality regional geoid will be built in the future based on the gravity data collected in this project and already existing gravity data.

Key technologies and applications of laser cooling and trapping {sup 87}Rb atomic system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ru, Ning, E-mail: runing@buaa.edu.cn; Zhang, Li, E-mail: mewan@buaa.edu.cn; Key Laboratory for Metrology, Changcheng Institute of Metrology and Measurement

2016-06-28

Atom Interferometry is proved to be a potential method for measuring the acceleration of atoms due to Gravity, we are now building a feasible system of cold atom gravimeter. In this paper development and the important applications of laser cooling and trapping atoms are introduced, some key techniques which are used to obtain {sup 87}Rb cold atoms in our experiments are also discussed.

Trans World Tidal Gravity Profile.

DTIC Science & Technology

1976-12-01

LABORATORY AIR FORCE SYSTEMS COMMAN D __ UNITEI) STATES AIR FO RC E HANSCOIVI AFB , MASSACHUSETTS 0173 1 ‘ S ~~~~~ V — (~~~) REPORT DOCUMENTATION PAGE...the fundamental station established at Canberra. Uniformity is maintained with the Brussels fundamental station. It is assessed that the...as well as Canberra and Alice Springs still operatin ~; in 1976. Four new stations are described here Kuala Lumpur (~ a1a’~sja) The gravimeter

Atom-chip-based interferometry with Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Gebbe, Martina; Abend, Sven; Gersemann, Matthias; Ahlers, Holger; Muentinga, Hauke; Herrmann, Sven; Laemmerzahl, Claus; Ertmer, Wolfgang; Rasel, Ernst M.; Quantus Collaboration

2017-04-01

Due to their small spatial and momentum width ultracold Bose-Einstein condensates (BEC) or even delta-kick collimated (DKC) atomic ensembles are very well suited for high precision atom interferometry and measure, for example, inertial forces with high accuracy. We generate such an ensemble in a miniaturized atom-chip setup, where BEC generation and DKC can be performed in a fast and reliable way. Using the chip as a retroreflector we have realized the first atom-chip-based gravimeter. All atom-optical operations including detection take place inside a volume of a one centimeter cube. In order to investigate new geometries we studied symmetric double Bragg diffraction as well as the coherent acceleration of atoms with Bloch oscillations. By combining both techniques we developed a novel relaunch mechanism, which we use to span a fountain geometry within our gravimeter. The relaunch increases the free fall time and, thus, enhances the device's sensitivity. Additionally, we employ these techniques to implement symmetric scalable large momentum beam splitters. This work is supported by the CRC 1128 geo-Q and the DLR with funds provided by the Federal Ministry of Economic Affairs and Energy (BMWi) due to an enactment of the German Bundestag under Grant No. DLR 50WM1552-1557 (QUANTUS-IV-Fallturm).

Ultra-low frequency vertical vibration isolator based on LaCoste spring linkage.

PubMed

Li, G; Hu, H; Wu, K; Wang, G; Wang, L J

2014-10-01

For the applications in precision measurement such as absolute gravimeter, we have designed and built an ultra-low frequency vertical vibration isolator based on LaCoste spring linkage. In the system, an arm with test mass is suspended by a mechanical extension spring, and one end of the arm is connected to the frame with flexible pivots. The displacement of the arm is detected by an optical reflection method. With the displacement signal, a feedback control force is exerted on the arm to keep it at the balance position. This method can also correct the systematic drift caused by temperature change. In order to study the vibration isolation performance of the system, we analyze the dynamic characteristics of the spring linkage in the general case, and present key methods to adjust the natural oscillating period of the system. With careful adjustment, the system can achieve a steady oscillation with a natural period up to 32 s. This isolator has been tested based on the T-1 absolute gravimeter. A statistical uncertainty of 2 μGal has been achieved within a typical 12 h measurement. The experimental results verify that the isolator has significant vibration isolation performance, and it is very suitable for applications in high precision absolute gravity measurement.

Gravity monitoring of Tatun Volcanic Group activities and inference for underground fluid circulations

NASA Astrophysics Data System (ADS)

Mouyen, Maxime; Chao, Benjamin Fong; Hwang, Cheinway; Hsieh, Wen-Chi

2016-12-01

The Tatun Volcano Group (TVG), located on the northern coast of Taiwan adjacent to the city of Taipei, experiences active hydrothermalism but has no historical record of volcanic eruption. Yet recent studies suggest that TVG is dormant-active rather than extinct. To monitor mass transfers and to gain further understanding of this volcanic area, gravity variations have been recorded continuously since 2012 using a superconducting gravimeter, and once every few months since 2005 using absolute gravimeters. We analyze the continuous gravity time series and propose a model that best explains the gravity variations due to local groundwater redistribution. By correcting these variations, we identify gravity changes as large as 35 μGal that occurred concomitantly to fluid pressure-induced earthquakes and changes in the gas composition at Dayoukeng, one of TVG's fumaroles, over 2005-2007. We examine several fluid movements that can match the gravity observations, yet too few additional constraints exist to favor any of them. In particular, no significant ground displacements are observed when these gravity variations occurred. On the other hand, the model of gravity changes due to local groundwater redistribution can be routinely computed and removed from the ongoing time gravity measurements in order to quickly identify any unusual mass transfer occurring beneath TVG.

Gravity monitoring of Tatun Volcanic Group activities and inference for underground fluid circulations

NASA Astrophysics Data System (ADS)

Mouyen, Maxime; Chao, Benjamin; Hwang, Cheinway; Hsieh, Wen-Chi

2017-04-01

The Tatun Volcano Group (TVG), located on the northern coast of Taiwan adjacent to the city of Taipei, experiences active hydrothermalism but has no historical record of volcanic eruption. Yet recent studies suggest that TVG is dormant-active rather than extinct. To monitor mass transfers and to gain further understanding of this volcanic area, gravity variations have been recorded continuously since 2012 using a superconducting gravimeter, and once every few months since 2005 using absolute gravimeters. We analyze the continuous gravity time series and propose a model that best explain the gravity variations due to local groundwater redistribution. By correcting these variations, we identify gravity changes as large as 35 µGal that occurred concomitantly to fluid pressure-induced earthquakes and changes in the gas composition at Dayoukeng, one of TVG's fumaroles, over 2005-2007. We examine several fluid movements that can match the gravity observations, yet too few additional constraints exist to favor any of them. In particular, no significant ground displacements are observed when these gravity variations occurred. On the other hand, the model of gravity changes due to local groundwater redistribution can be routinely computed and removed from the ongoing time gravity measurements in order to quickly identify any unusual mass transfer occurring beneath TVG.

Ultra-low frequency vertical vibration isolator based on LaCoste spring linkage

NASA Astrophysics Data System (ADS)

Li, G.; Hu, H.; Wu, K.; Wang, G.; Wang, L. J.

2014-10-01

For the applications in precision measurement such as absolute gravimeter, we have designed and built an ultra-low frequency vertical vibration isolator based on LaCoste spring linkage. In the system, an arm with test mass is suspended by a mechanical extension spring, and one end of the arm is connected to the frame with flexible pivots. The displacement of the arm is detected by an optical reflection method. With the displacement signal, a feedback control force is exerted on the arm to keep it at the balance position. This method can also correct the systematic drift caused by temperature change. In order to study the vibration isolation performance of the system, we analyze the dynamic characteristics of the spring linkage in the general case, and present key methods to adjust the natural oscillating period of the system. With careful adjustment, the system can achieve a steady oscillation with a natural period up to 32 s. This isolator has been tested based on the T-1 absolute gravimeter. A statistical uncertainty of 2 μGal has been achieved within a typical 12 h measurement. The experimental results verify that the isolator has significant vibration isolation performance, and it is very suitable for applications in high precision absolute gravity measurement.

New gravity control in Poland - needs, the concept and the design

NASA Astrophysics Data System (ADS)

Krynski, Jan; Olszak, Tomasz; Barlik, Marcin; Dykowski, Przemyslaw

2013-06-01

The existing Polish gravity control (POGK) established in the last few years of 20th century according to the international standards is spanned on 12 absolute gravity stations surveyed with four different types of absolute gravimeters. Relative measurements performed by various groups on nearly 350 points of POGK with the use of LaCoste&Romberg (LCR) gravimeters were linked to those 12 stations. The construction of the network, in particular the limited number of non homogeneously distributed absolute gravity stations with gravity determined with different instruments in different epochs is responsible for systematic errors in g on POGK stations. The estimate of those errors with the use of gravity measurements performed in 2007-2008 is given and their possible sources are discussed. The development of absolute gravity measurement technologies, in particular instruments for precise field absolute gravity measurements, provides an opportunity to establish new type of gravity control consisting of stations surveyed with absolute gravimeters. New gravity control planned to be established in 2012-2014 will consist of 28 fundamental points (surveyed with the FG5 - gravimeter), and 169 base points (surveyed with the A10 gravimeter). It will fulfill recent requirements of geodesy and geodynamics and it will provide good link to the existing POGK. A number of stations of the new gravity control with precisely determined position and height will form the national combined geodetic network. Methodology and measurement schemes for both absolute gravimeters as well as the technology for vertical gravity gradient determinations in the new gravity control were developed and tested. The way to assure proper gravity reference level with relation to ICAG and ECAG campaigns as well as local absolute gravimeter comparisons are described highlighting the role of metrology in the project. Integral part of the project are proposals of re-computation of old gravity data and their transformation to a new system (as 2nd order network) as well as a definition of gravity system as "zero-tide" system. Seasonal variability of gravity has been discussed indicating that the effects of environmental changes when establishing modern gravity control with absolute gravity survey cannot be totally neglected. Założona w Polsce w ostatniej dekadzie XX wieku zgodnie z obowiązującymi standardami międzynarodowymi Podstawowa Osnowa Grawimetryczna Kraju (POGK), składająca się z około 350 punktów, została oparta na 12 absolutnych punktach grawimetrycznych, na których przyspieszenie siły ciężkości wyznaczono przy użyciu czterech różnych typów grawimetrów absolutnych. Względne pomiary grawimetryczne na punktach tej osnowy, z jednoczesnym dowiązaniem jej do przyspieszenia siły ciężkości na 12 absolutnych punktach grawimetrycznych, wykonały różne grupy pomiarowe przy wykorzystaniu grawimetrów LaCoste&Romberg (LCR). Konstrukcja powstałej sieci grawimetrycznej, w szczególności ograniczona liczba nierównomiernie rozłożonych punktów absolutnych na terenie kraju, na których w dodatku przyspieszenie siły ciężkości wyznaczono różnymi instrumentami w różnych epokach, spowodowały wystąpienie błędów systematycznych w wartościach g na punktach POGK. W niniejszej pracy, przy wykorzystaniu pomiarów grawimetrycznych wykonanych w latach 2007-2008 dokonano oceny tych błędów oraz przeprowadzono dyskusję ich możliwych źródeł. Rozwój technologii absolutnych pomiarów grawimetrycznych, w szczególności instrumentów przeznaczonych do precyzyjnych absolutnych pomiarów grawimetrycznych w warunkach polowych, stwarza możliwość założenia nowego typu osnowy grawimetrycznej, składającej się ze stacji, na których przyspieszenie siły ciężkości jest pomierzone grawimetrami absolutnymi. Nowa osnowa grawimetryczna Polski, która będzie zakładana w latach 2012-2014, będzie się składała z 28 punktów fundamentalnych (mierzonych grawimetrem FG5) i 169 punktów bazowych (mierzonych grawimetrem A10). Będzie ona spełniała wymagania współczesnej geodezji i geodynamiki oraz zapewniała dobre powiązanie z istniejącą osnową POGK. Znaczna liczba punktów nowej osnowy grawimetrycznej, o precyzyjnie wyznaczonej pozycji wysokości utworzy krajową zintegrowaną osnowę geodezyjną. Opracowano i przetestowano metodologie i procedury pomiarowe na punktach nowej osnowy grawimetrycznej dla obu grawimetrów absolutnych (FG5, A10) oraz technologie wyznaczania gradientu pionowego przyspieszenia siły ciężkości na tych punktach. Określono metody zapewnienia odpowiedniego poziomu grawimetrycznego osnowy poprzez udział grawimetrów FG5 i A10 w międzynarodowej (ICAG) i europejskiej (ECAG), a także lokalnych kampaniach porównawczych grawimetrów absolutnych podkreślając jednocześnie rolę metrologii w projekcie. Integralnymi częściami projektu są zamierzenia przeliczenia archiwalnych danych grawimetrycznych wykorzystywanych przy tworzeniu POGK i ich przetransformowania do nowego systemu (jako sieć 2 rzędu) oraz zdefiniowania nowego systemu grawimetrycznego jako systemu "zero-tide". Przeprowadzono również dyskusję zmienności sezonowej przyspieszenia siły ciężkości wskazując, że przy wyznaczaniu przyspieszenia siły ciężkości na punktach nowoczesnej osnowy grawimetrycznej wpływ zmian środowiskowych nie może być traktowany jako w pełni zaniedbywalny.

Absolute gravimetry as an operational tool for geodynamics research

NASA Astrophysics Data System (ADS)

Torge, W.

Relative gravimetric techniques have been used for nearly 30 years for measuring non-tidal gravity variations with time, and thus have contributed to geodynamics research by monitoring vertical crustal movements and internal mass shifts. With today's accuracy of about ± 0.05µms-2 (or 5µGal), significant results have been obtained in numerous control nets of local extension, especially in connection with seismic and volcanic events. Nevertheless, the main drawbacks of relative gravimetry, which are deficiencies in absolute datum and calibration, set a limit for its application, especially with respect to large-scale networks and long-term investigations. These problems can now be successfully attacked by absolute gravimetry, with transportable gravimeters available since about 20 years. While the absolute technique during the first two centuries of gravimetry's history was based on the pendulum method, the free-fall method can now be employed taking advantage of laser-interferometry, electronic timing, vacuum and shock absorbing techniques, and on-line computer-control. The accuracy inherent in advanced instruments is about ± 0.05 µms-2. In field work, generally an accuracy of ±0.1 µms-2 may be expected, strongly depending on local environmental conditions.

Stabilized Laser Gravimeter

DTIC Science & Technology

1976-11-01

For the creep to be important, temperatures on the order of one- half the melting temperature and stresses that are a significant per- centage of the ...temperature will be less than 35C while one- half the melting temperature is approximately 7500C. Therefore, no experimental creep tests were...and its align- ment in a gravity fie.d. Trace B is the beam response to a low level base input (perpendicular to the plane of the beam) with no

Low-frequency centroid-moment-tensor inversion from superconducting-gravimeter data: The effect of seismic attenuation

NASA Astrophysics Data System (ADS)

Zábranová, Eliška; Matyska, Ctirad

2014-10-01

After the 2010 Maule and 2011 Tohoku earthquakes the spheroidal modes up to 1 mHz were clearly registered by the Global Geodynamic Project (GGP) network of superconducting gravimeters (SG). Fundamental parameters in synthetic calculations of the signals are the quality factors of the modes. We study the role of their uncertainties in the centroid-moment-tensor (CMT) inversions. First, we have inverted the SG data from selected GGP stations to jointly determine the quality factors of these normal modes and the three low-frequency CMT components, Mrr,(Mϑϑ-Mφφ)/2 and Mϑφ, that generate the observed SG signal. We have used several-days-long records to minimize the trade-off between the quality factors and the CMT but it was not eliminated completely. We have also inverted each record separately to get error estimates of the obtained parameters. Consequently, we have employed the GGP records of 60-h lengths for several published modal-quality-factor sets and inverted only the same three CMT components. The obtained CMT tensors are close to the solution from the joint Q-CMT inversion of longer records and resulting variability of the CMT components is smaller than differences among routine agency solutions. Reliable low-frequency CMT components can thus be obtained for any quality factors from the studied sets.

Integrative monitoring of water storage variations at the landscape-scale with an iGrav superconducting gravimeter in a field enclosure

NASA Astrophysics Data System (ADS)

Guntner, A.; Reich, M.; Mikolaj, M.; Creutzfeldt, B.; Schroeder, S.; Wziontek, H.

2017-12-01

In spite of the fundamental role of the landscape water balance for the Earth's water and energy cycles, monitoring the water balance and related storage dynamics beyond the point scale is notoriously difficult due to the multitude of flow and storage processes and their spatial heterogeneity. We present the first outdoor deployment of an iGrav superconducting gravimeter (SG) in a minimized field enclosure on a wet-temperate grassland site for integrative monitoring of water storage changes. It is shown that the system performs similarly precise as SGs that have hitherto been deployed in observatory buildings, but with higher sensitivity to hydrological variations in the surroundings of the instrument. Gravity variations observed by the field setup are almost independent of the depth below the terrain surface where water storage changes occur, and thus the field SG system directly observes the total water storage change in an integrative way. We provide a framework to single out the water balance components actual evapotranspiration and lateral subsurface discharge from the gravity time series on annual to daily time scales. With about 99% and 85% of the gravity signal originating within a radius of 4000 and 200 meter around the instrument, respectively, the setup paves the road towards gravimetry as a continuous hydrological field monitoring technique for water storage dynamics at the landscape scale.

Location Accuracy of INS/Gravity-Integrated Navigation System on the Basis of Ocean Experiment and Simulation

PubMed Central

Wang, Hubiao; Chai, Hua; Bao, Lifeng; Wang, Yong

2017-01-01

An experiment comparing the location accuracy of gravity matching-aided navigation in the ocean and simulation is very important to evaluate the feasibility and the performance of an INS/gravity-integrated navigation system (IGNS) in underwater navigation. Based on a 1′ × 1′ marine gravity anomaly reference map and multi-model adaptive Kalman filtering algorithm, a matching location experiment of IGNS was conducted using data obtained using marine gravimeter. The location accuracy under actual ocean conditions was 2.83 nautical miles (n miles). Several groups of simulated data of marine gravity anomalies were obtained by establishing normally distributed random error N(u,σ2) with varying mean u and noise variance σ2. Thereafter, the matching location of IGNS was simulated. The results show that the changes in u had little effect on the location accuracy. However, an increase in σ2 resulted in a significant decrease in the location accuracy. A comparison between the actual ocean experiment and the simulation along the same route demonstrated the effectiveness of the proposed simulation method and quantitative analysis results. In addition, given the gravimeter (1–2 mGal accuracy) and the reference map (resolution 1′ × 1′; accuracy 3–8 mGal), location accuracy of IGNS was up to reach ~1.0–3.0 n miles in the South China Sea. PMID:29261136

Location Accuracy of INS/Gravity-Integrated Navigation System on the Basis of Ocean Experiment and Simulation.

PubMed

Wang, Hubiao; Wu, Lin; Chai, Hua; Bao, Lifeng; Wang, Yong

2017-12-20

An experiment comparing the location accuracy of gravity matching-aided navigation in the ocean and simulation is very important to evaluate the feasibility and the performance of an INS/gravity-integrated navigation system (IGNS) in underwater navigation. Based on a 1' × 1' marine gravity anomaly reference map and multi-model adaptive Kalman filtering algorithm, a matching location experiment of IGNS was conducted using data obtained using marine gravimeter. The location accuracy under actual ocean conditions was 2.83 nautical miles (n miles). Several groups of simulated data of marine gravity anomalies were obtained by establishing normally distributed random error N ( u , σ 2 ) with varying mean u and noise variance σ 2 . Thereafter, the matching location of IGNS was simulated. The results show that the changes in u had little effect on the location accuracy. However, an increase in σ 2 resulted in a significant decrease in the location accuracy. A comparison between the actual ocean experiment and the simulation along the same route demonstrated the effectiveness of the proposed simulation method and quantitative analysis results. In addition, given the gravimeter (1-2 mGal accuracy) and the reference map (resolution 1' × 1'; accuracy 3-8 mGal), location accuracy of IGNS was up to reach ~1.0-3.0 n miles in the South China Sea.

Techniques, analysis, and noise in a Salt Lake Valley 4D gravity experiment

USGS Publications Warehouse

Gettings, P.; Chapman, D.S.; Allis, R.

2008-01-01

Repeated high-precision gravity measurements using an automated gravimeter and analysis of time series of 1-Hz samples allowed gravity measurements to be made with an accuracy of 5 ??Gal or better. Nonlinear instrument drift was removed using a new empirical staircase function built from multiple station loops. The new technique was developed between March 1999 and September 2000 in a pilot study conducted in the southern Salt Lake Valley along an east-west profile of eight stations from the Wasatch Mountains to the Jordan River. Gravity changes at eight profile stations were referenced to a set of five stations in the northern Salt Lake Valley, which showed residual signals of <10 ??Gal in amplitude, assuming a reference station near the Great Salt Lake to be stable. Referenced changes showed maximum amplitudes of -40 through +40 ??Gal at profile stations, with minima in summer 1999, maxima in winter 1999-2000, and some decrease through summer 2000. Gravity signals were likely a composite of production-induced changes monitored by well-water levels, elevation changes, precipitation-induced vadose-zone changes, and local irrigation effects for which magnitudes were estimated quantitatively. ?? 2008 Society of Exploration Geophysicists. All rights reserved.

Vertical and horizontal seismometric observations of tides

NASA Astrophysics Data System (ADS)

Lambotte, S.; Rivera, L.; Hinderer, J.

2006-01-01

Tidal signals have been largely studied with gravimeters, strainmeters and tiltmeters, but can also be retrieved from digital records of the output of long-period seismometers, such as STS-1, particularly if they are properly isolated. Horizontal components are often noisier than the vertical ones, due to sensitivity to tilt at long periods. Hence, horizontal components are often disturbed by local effects such as topography, geology and cavity effects, which imply a strain-tilt coupling. We use series of data (duration larger than 1 month) from several permanent broadband seismological stations to examine these disturbances. We search a minimal set of observable signals (tilts, horizontal and vertical displacements, strains, gravity) necessary to reconstruct the seismological record. Such analysis gives a set of coefficients (per component for each studied station), which are stable over years and then can be used systematically to correct data from these disturbances without needing heavy numerical computation. A special attention is devoted to ocean loading for stations close to oceans (e.g. Matsushiro station in Japon (MAJO)), and to pressure correction when barometric data are available. Interesting observations are made for vertical seismometric components; in particular, we found a pressure admittance between pressure and data 10 times larger than for gravimeters for periods larger than 1 day, while this admittance reaches the usual value of -3.5 nm/s 2/mbar for periods below 3 h. This observation may be due to instrumental noise, but the exact mechanism is not yet understood.

Hydrology in Central Europe - a Comparison Between Data from the GRACE Satellite Mission and Ground Superconducting Gravimeters

NASA Astrophysics Data System (ADS)

Crossley, D.; de Linage, C.; Boy, J.-P.; Hinderer, J.

2009-04-01

The surface gravity field is subject to many influences of mass redistribution within the Earth system, operating at the microgal (10-8 m s-2) level and at timescales from minutes to years. We include deformation within the Earth (tides, polar motion), motions within the atmosphere (local, regional, and global loading; also mass attractions), the oceans (non-tidal currents), and near-surface hydrology derived from rainfall (local, regional, and global contributions). In central Europe a network of 7 superconducting gravimeters (the only instrument with the required resolution for this type of work) has been operating for many years, recording variations at the sub-microgal level. Hydrology is the largest component in the un-modelled residual signal, most of which comes from an area within a few hundred m of the instrument. We use data from 2002-2007 to construct a regionalized ground gravity data set that is analyzed by Principal Component (EOF) analysis to extract the predominantly seasonal signal common to all stations. This we compare with the GRACE-derived field using solutions from GFZ Potsdam, CSR Texas, and GRGS Toulouse. There is very good agreement on the phase of the two different types of data, but the amplitude of the ground signal is complicated by the local hydrology around several of the stations, which is both above and below the instrument. We show our most recent analysis and compare the results with the GLDAS global hydrology model from NASA.

Radio-Frequency Illuminated Superconductive Disks: Reverse Josephson Effects and Implications for Precise Measuring of Proposed Gravity Effects

NASA Technical Reports Server (NTRS)

Noever, David A.; Koczor, Ronald J.

1998-01-01

We have previously reported results using a high precision gravimeter to probe local gravity changes in the neighborhood of large bulk-processed high-temperature superconductors. It have been indicated three essential components to achieve anomalous gravity effects, namely large, two-layer high-temperature YBCO superconductors, magnetic levitation and AC input in the form of radio-frequency (RF) electromagnetic fields. We report experiments on RF-illuminated (1-15 MHz) superconducting disks with corresponding gravity readings indicating an apparent increase in observed gravity of approximately 3-5 x l0(exp -5)cm/sq s, above and to the side of the superconductor. In this preliminary study, RF- illumination is achieved using a series of large radius (15 cm) spiral antenna with RF power inputs equal to or greater than 90 W. The observed gravitational modification range is significantly lower than the 2.1% gravity modification. The error analyses of thermal and electromagnetic interference in a magnetically shielded gravimeter with vacuum enclosures, Faraday cages and shielded instrument leads, are outlined both experimentally and theoretically. The nearly exact correspondence between the peak gravity effects reported and the well-known peak in AC resistance in superconductors (2-7 MHz, owing to reverse Josephson quantum effects) suggests that electrical resistance will arise in this frequency range and subsequently any trapped magnetic fields in the superconductor may disperse partially into the measuring instrument's local environment. Implications for propulsion initiatives and RF-heating in superconductors will be discussed.

Total water storage dynamics derived from tree-ring records and terrestrial gravity observations

NASA Astrophysics Data System (ADS)

Creutzfeldt, Benjamin; Heinrich, Ingo; Merz, Bruno

2015-10-01

For both societal and ecological reasons, it is important to understand past and future subsurface water dynamics but estimating subsurface water storage is notoriously difficult. In this pilot study, we suggest the reconstruction of subsurface water dynamics by a multi-disciplinary approach combining hydrology, dendrochronology and geodesy. In a first step, nine complete years of high-precision gravimeter observations are used to estimate water storage changes in the subsurface at the Geodetic Observatory Wettzell in the Bavarian Forest, Germany. The record is extended to 63 years by calibrating a hydrological model against the 9 years of gravimeter observations. The relationship between tree-ring growth and water storage changes is evaluated as well as that between tree-ring growth and supplementary hydro-meteorological data. Results suggest that tree-ring growth is influenced primarily by subsurface water storage. Other variables related to the overall moisture status (e.g., Standardized Precipitation Index, Palmer Drought Severity Index, streamflow) are also strongly correlated with tree-ring width. While these indices are all indicators of water stored in the landscape, water storage changes of the subsurface estimated by depth-integral measurements give us the unique opportunity to directly reconstruct subsurface water storage dynamics from records of tree-ring width. Such long reconstructions will improve our knowledge of past water storage variations and our ability to predict future developments. Finally, knowing the relationship between subsurface storage dynamics and tree-ring growth improves the understanding of the different signal components contained in tree-ring chronologies.

Ultra-low-frequency vertical vibration isolator based on a two-stage beam structure for absolute gravimetry.

PubMed

Wang, G; Wu, K; Hu, H; Li, G; Wang, L J

2016-10-01

To reduce seismic and environmental vibration noise, ultra-low-frequency vertical vibration isolation systems play an important role in absolute gravimetry. For this purpose, an isolator based on a two-stage beam structure is proposed and demonstrated. The isolator has a simpler and more robust structure than the present ultra-low-frequency vertical active vibration isolators. In the system, two beams are connected to a frame using flexural pivots. The upper beam is suspended from the frame with a normal hex spring and the lower beam is suspended from the upper one using a zero-length spring. The pivot of the upper beam is not vertically above the pivot of the lower beam. With this special design, the attachment points of the zero-length spring to the beams can be moved to adjust the effective stiffness. A photoelectric detector is used to detect the angle between the two beams, and a voice coil actuator attached to the upper beam is controlled by a feedback circuit to keep the angle at a fixed value. The system can achieve a natural period of 100 s by carefully moving the attachment points of the zero-length spring to the beams and tuning the feedback parameters. The system has been used as an inertial reference in the T-1 absolute gravimeter. The experiment results demonstrate that the system has significant vibration isolation performance that holds promise in applications such as absolute gravimeters.

Ultra-low-frequency vertical vibration isolator based on a two-stage beam structure for absolute gravimetry

NASA Astrophysics Data System (ADS)

Wang, G.; Wu, K.; Hu, H.; Li, G.; Wang, L. J.

2016-10-01

To reduce seismic and environmental vibration noise, ultra-low-frequency vertical vibration isolation systems play an important role in absolute gravimetry. For this purpose, an isolator based on a two-stage beam structure is proposed and demonstrated. The isolator has a simpler and more robust structure than the present ultra-low-frequency vertical active vibration isolators. In the system, two beams are connected to a frame using flexural pivots. The upper beam is suspended from the frame with a normal hex spring and the lower beam is suspended from the upper one using a zero-length spring. The pivot of the upper beam is not vertically above the pivot of the lower beam. With this special design, the attachment points of the zero-length spring to the beams can be moved to adjust the effective stiffness. A photoelectric detector is used to detect the angle between the two beams, and a voice coil actuator attached to the upper beam is controlled by a feedback circuit to keep the angle at a fixed value. The system can achieve a natural period of 100 s by carefully moving the attachment points of the zero-length spring to the beams and tuning the feedback parameters. The system has been used as an inertial reference in the T-1 absolute gravimeter. The experiment results demonstrate that the system has significant vibration isolation performance that holds promise in applications such as absolute gravimeters.

Superconductor-Mediated Modification of Gravity? AC Motor Experiments with Bulk YBCO Disks in Rotating Magnetic Fields

NASA Technical Reports Server (NTRS)

Noever, David A.; Koczor, Ronald J.; Roberson, Rick

1998-01-01

We have previously reported results using a high precision gravimeter to probe local gravity changes in the neighborhood of large bulk-processed high-temperature superconductors. Podkietnov, et al (Podkietnov, E. and Nieminen, R. (1992) A Possibility of Gravitational Force Shielding by Bulk YBa2 Cu3 O7-x Superconductor, Physica C, C203:441-444.) have indicated that rotating AC fields play an essential role in their observed distortion of combined gravity and barometric pressure readings. We report experiments on large (15 cm diameter) bulk YBCO ceramic superconductors placed in the core of a three-phase, AC motor stator. The applied rotating field produces up to a 12,000 revolutions per minute magnetic field. The field intensity decays rapidly from the maximum at the outer diameter of the superconducting disk (less than 60 Gauss) to the center (less than 10 Gauss). This configuration was applied with and without a permanent DC magnetic field levitating the superconducting disk, with corresponding gravity readings indicating an apparent increase in observed gravity of less than 1 x 10(exp -6)/sq cm, measured above the superconductor. No effect of the rotating magnetic field or thermal environment on the gravimeter readings or on rotating the superconducting disk was noted within the high precision of the observation. Implications for propulsion initiatives and power storage flywheel technologies for high temperature superconductors will be discussed for various spacecraft and satellite applications.

Earth's core and inner-core resonances from analysis of VLBI nutation and superconducting gravimeter data

NASA Astrophysics Data System (ADS)

Rosat, S.; Lambert, S. B.; Gattano, C.; Calvo, M.

2017-01-01

Geophysical parameters of the deep Earth's interior can be evaluated through the resonance effects associated with the core and inner-core wobbles on the forced nutations of the Earth's figure axis, as observed by very long baseline interferometry (VLBI), or on the diurnal tidal waves, retrieved from the time-varying surface gravity recorded by superconducting gravimeters (SGs). In this paper, we inverse for the rotational mode parameters from both techniques to retrieve geophysical parameters of the deep Earth. We analyse surface gravity data from 15 SG stations and VLBI delays accumulated over the last 35 yr. We show existing correlations between several basic Earth parameters and then decide to inverse for the rotational modes parameters. We employ a Bayesian inversion based on the Metropolis-Hastings algorithm with a Markov-chain Monte Carlo method. We obtain estimates of the free core nutation resonant period and quality factor that are consistent for both techniques. We also attempt an inversion for the free inner-core nutation (FICN) resonant period from gravity data. The most probable solution gives a period close to the annual prograde term (or S1 tide). However the 95 per cent confidence interval extends the possible values between roughly 28 and 725 d for gravity, and from 362 to 414 d from nutation data, depending on the prior bounds. The precisions of the estimated long-period nutation and respective small diurnal tidal constituents are hence not accurate enough for a correct determination of the FICN complex frequency.

Gravity Survey of the Carson Sink - Data and Maps

DOE Data Explorer

Faulds, James E.

2013-12-31

A detailed gravity survey was carried out for the entire Carson Sink in western Nevada (Figure 1) through a subcontract to Zonge Engineering, Inc. The Carson Sink is a large composite basin containing three known, blind high-temperature geothermal systems (Fallon Airbase, Stillwater, and Soda Lake). This area was chosen for a detailed gravity survey in order to characterize the gravity signature of the known geothermal systems and to identify other potential blind systems based on the structural setting indicated by the gravity data. Data: Data were acquired at approximately 400, 800, and 1600 meter intervals for a total of 1,243 stations. The project location and station location points are presented in Figure 14. The station distribution for this survey was designed to complete regional gravity coverage in the Carson Sink area without duplication of available public and private gravity coverage. Gravity data were acquired using a Scintrex CG-5 gravimeter and a LaCoste and Romberg (L&R) Model-G gravimeter. The CG-5 gravity meter has a reading resolution of 0.001 milligals and a typical repeatability of less than 0.005 milligals. The L&R gravity meter has a reading resolution of 0.01 milligals and a typical repeatability of 0.02 milligals. The basic processing of gravimeter readings to calculate through to the Complete Bouguer Anomaly was made using the Gravity and Terrain Correction software version 7.1 for Oasis Montaj by Geosoft LTD. Results: The gravity survey of the Carson Sink yielded the following products. Project location and station location map (Figure 14). Complete Bouguer Anomaly @ 2.67 gm/cc reduction density. Gravity Complete Bouguer Anomaly at 2.50 g/cc Contour Map (Figure 15). Gravity Horizontal Gradient Magnitude Shaded Color Contour Map. Gravity 1st Vertical Derivative Color Contour Map. Interpreted Depth to Mesozoic Basement (Figure 16), incorporating drill-hole intercept values. Preliminary Interpretation of Results: The Carson Sink is a complex composite basin with several major depocenters (Figures 15 and 16). Major depocenters are present in the south-central, east-central, and northeastern parts of the basin. The distribution of gravity anomalies suggests a complex pattern of faulting in the subsurface of the basin, with many fault terminations, step-overs, and accommodation zones. The pattern of faulting implies that other, previously undiscovered blind geothermal systems are likely in the Carson Sink. The gravity survey was completed near the end of this project. Thus, more thorough analysis of the data and potential locations of blind geothermal systems is planned for future work.

Water, gravity and trees: Relationship of tree-ring widths and total water storage dynamics

NASA Astrophysics Data System (ADS)

Creutzfeldt, B.; Heinrich, I.; Merz, B.; Blume, T.; Güntner, A.

2012-04-01

Water stored in the subsurface as groundwater or soil moisture is the main fresh water source not only for drinking water and food production but also for the natural vegetation. In a changing environment water availability becomes a critical issue in many different regions. Long-term observations of the past are needed to improve the understanding of the hydrological system and the prediction of future developments. Tree ring data have repeatedly proved to be valuable sources for reconstructing long-term climate dynamics, e.g. temperature, precipitation and different hydrological variables. In water-limited environments, tree growth is primarily influenced by total water stored in the subsurface and hence, tree-ring records usually contain information about subsurface water storage. The challenge is to retrieve the information on total water storage from tree rings, because a training dataset of water stored in the sub-surface is required for calibration against the tree-ring series. However, measuring water stored in the subsurface is notoriously difficult. We here present high-precision temporal gravimeter measurements which allow for the depth-integrated quantification of total water storage dynamics at the field scale. In this study, we evaluate the relationship of total water storage change and tree ring growth also in the context of the complex interactions of other meteorological forcing factors. A tree-ring chronology was derived from a Norway spruce stand in the Bavarian Forest, Germany. Total water storage dynamics were measured directly by the superconducting gravimeter of the Geodetic Observatory Wettzell for a 9-years period. Time series were extended to 63-years period by a hydrological model using gravity data as the only calibration constrain. Finally, water storage changes were reconstructed based on the relationship between the hydrological model and the tree-ring chronology. Measurement results indicate that tree-ring growth is primarily controlled by total water storage in the subsurface. But high uncertainties intervals of the correlation coefficient urges for the extension of the measurement period. This multi-disciplinary study, combining hydrology, dendrochronology and geodesy shows that temporal gravimeter measurements may give us the unique opportunity to retrieve the information of total water storage contained in tree-ring records to reconstruct total water storage dynamics. Knowing the relationship of water storage and tree-ring growth can also support the reconstruction of other climate records based on tree-ring series, help with hydrological model testing and can improve our knowledge of long-term variations of water storage in the past.

Establishment of National Gravity Base Network of Iran

NASA Astrophysics Data System (ADS)

Hatam Chavari, Y.; Bayer, R.; Hinderer, J.; Ghazavi, K.; Sedighi, M.; Luck, B.; Djamour, Y.; Le Moign, N.; Saadat, R.; Cheraghi, H.

2009-04-01

A gravity base network is supposed to be a set of benchmarks uniformly distributed across the country and the absolute gravity values at the benchmarks are known to the best accessible accuracy. The gravity at the benchmark stations are either measured directly with absolute devices or transferred by gravity difference measurements by gravimeters from known stations. To decrease the accumulation of random measuring errors arising from these transfers, the number of base stations distributed across the country should be as small as possible. This is feasible if the stations are selected near to the national airports long distances apart but faster accessible and measurable by a gravimeter carried in an airplane between the stations. To realize the importance of such a network, various applications of a gravity base network are firstly reviewed. A gravity base network is the required reference frame for establishing 1st , 2nd and 3rd order gravity networks. Such a gravity network is used for the following purposes: a. Mapping of the structure of upper crust in geology maps. The required accuracy for the measured gravity values is about 0.2 to 0.4 mGal. b. Oil and mineral explorations. The required accuracy for the measured gravity values is about 5 µGal. c. Geotechnical studies in mining areas for exploring the underground cavities as well as archeological studies. The required accuracy is about 5 µGal and better. d. Subsurface water resource explorations and mapping crustal layers which absorb it. An accuracy of the same level of previous applications is required here too. e. Studying the tectonics of the Earth's crust. Repeated precise gravity measurements at the gravity network stations can assist us in identifying systematic height changes. The accuracy of the order of 5 µGal and more is required. f. Studying volcanoes and their evolution. Repeated precise gravity measurements at the gravity network stations can provide valuable information on the gradual upward movement of lava. g. Producing precise mean gravity anomaly for precise geoid determination. Replacing precise spirit leveling by the GPS leveling using precise geoid model is one of the forth coming application of the precise geoid. A gravity base network of 28 stations established over Iran. The stations were built mainly at bedrocks. All stations were measured by an FG5 absolute gravimeter, at least 12 hours at each station, to obtain an accuracy of a few micro gals. Several stations were repeated several times during recent years to estimate the gravity changes.

A new airborne geophysical platform and its application in the Princess Elizabeth Land during CHINARE 32 and 33 in East Antarctica

NASA Astrophysics Data System (ADS)

Cui, Xiangbin; Sun, Bo; Guo, Jingxue; Tang, Xueyuan; Greenbaum, Jamin; Lindzey, Laura; Habbal, Feras; Young, Duncan

2017-04-01

The ice thickness, subglacial topography and bedrock conditions of Princess Elizabeth Land (PEL) in central East Antarctic Ice Sheet (EAIS) are still unknown due to lack of direct geophysical measurements. This prevents our understanding of the ice sheet dynamics, subglacial morphology and climate evolution in the region. According to recent results from remote sensing results, it's very likely that there's a large, previously undiscovered subglacial lake and subglacial drainage networks existing beneath the ice sheet in PEL with possible subglacial canyons extend over a distance of 1100 km from inland to coast. But there's no direct measurements to identify them yet. China deployed its first fixed-wing airplane named Snow Eagle 601 and implemented airborne geophysical investigation in PEL during the 32nd and 33rd Chinese National Antarctic Research Expeditions (CHINARE 32 and 33, 2015/16 and 2016/17). The HiCARS deep ice-penetrating radar system and other instruments including GT-2A gravimeter, CS-3 magnetometer, laser altimeter, GPS and camera, were installed in the airplane to measure the ice sheet and subglacial conditions, as well as bedrock geology and tectonic. The field campaign was built beside Russian airfield (ZGN) near Zhongshan Station. During CHINARE 32, the airborne surveying grid was designed as radial lines from ZGN so as to investigate the region as large as possible, and total flight lines are 32 000 km. During the CHINARE 33, airborne survey will pay attention to the subglacial lake and subglacal canyons. Here, we introduce the Snow Eagle airborne geophysical platform firstly. Then, we present some preliminary results from CHINARE 32 and CHINARE 33.

Chinese Digital Zenith Telescope (DZT) used for Astro-geodetic Deflection of the Vertical Determination

NASA Astrophysics Data System (ADS)

Tian, L.; Wang, B.; Wang, Z.; Yin, Z.; Hu, H.; Wang, H.; Han, Y.

2015-12-01

Classical optical astrometry can be used to measure and study variations of plumb line. For the earth gravity filed related researches, it is irreplaceable by technologies like GNSS、VLBI、SLR, etc. However, classical astrometric instruments have some major drawback, such as low efficiency, low automation, more operating observers, and individual error in some visual instruments. In 2011, The National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) successfully developed the new digital zenith telescope prototype (DZT-1), which has the ability of highly automatic observation and data processing, even allowing unattended observation by remote control. By utilizing CCD camera as imaging terminal and high-accuracy tiltmeter to replace mercurial plate, observation efficiency of DZT is improved greatly. According to the results of data obtained from test observations, single-observation accuracy of DZT-1 is 0.15-0.3″ and one night observation accuracy up to 0.07-0.08″, which is better than the observation accuracy of classical astrometric instruments. The observations of DZT can be used to obtain the plumb line variations and the vertical deflections, which can be used for carrying out seismic, geodetic and other related geo-scientific researches. Especially the collocated observations with gravimeters and the conjoint analysis of the observation data will be helpful to recognize the anomalous motion and variation of underground mass over time, and maybe provide significant information for estimating the scale of underground anomalous mass. The information is valuable for determining the three key factors of earthquake possibly. Moreover, the project team is carrying out the development of new DZT with better performance and studying the key techniques for new instrument to make DZT play a more significant role in the astronomy and geoscience fields.

Episodic strain accumulation in southern california.

PubMed

Thatcher, W

1976-11-12

Reexamination of horizontal geodetic data in the region of recently discovered aseismic uplift has demonstrated that equally unusual horizontal crustal deformation accompanied the development of the uplift. During this time interval compressive strains were oriented roughly normal to the San Andreas fault, suggesting that the uplift produced little shear strain accumulation across this fault. On the other hand, the orientation of the anomalous shear straining is consistent with strain accumulation across northdipping range-front thrusts like the San Fernando fault. Accordingly, the horizontal and vertical crustal deformation disclosed by geodetic observation is interpreted as a short epoch of rapid strain accumulation on these frontal faults. If this interpretation is correct, thrust-type earthquakes will eventually release the accumulated strains, but the geodetic data examined here cannot be used to estimate when these events might occur. However, observation of an unusual sequence of tilts prior to 1971 on a level line lying to the north of the magnitude 6.4 San Fernando earthquake offers some promise for precursor monitoring. The data are adequately explained by a simple model of up-dip aseismic slip propagation toward the 1971 epicentral region. These observations and the simple model that accounts for them suggest a conceptually straightforward monitoring scheme to search for similar uplift and tilt precursors within the uplifted region. Such premonitory effects could be detected by a combination of frequenlty repeated short (30 to 70 km in length) level line measurements, precise gravity traverses, and continuously recording gravimeters sited to the north of the active frontal thrust faults. Once identified, such precursors could be closely followed in space and time, and might then provide effective warnings of impending potentially destructive earth-quakes.

Multiple-hypothesis multiple-model line tracking

NASA Astrophysics Data System (ADS)

Pace, Donald W.; Owen, Mark W.; Cox, Henry

2000-07-01

Passive sonar signal processing generally includes tracking of narrowband and/or broadband signature components observed on a Lofargram or on a Bearing-Time-Record (BTR) display. Fielded line tracking approaches to date have been recursive and single-hypthesis-oriented Kalman- or alpha-beta filters, with no mechanism for considering tracking alternatives beyond the most recent scan of measurements. While adaptivity is often built into the filter to handle changing track dynamics, these approaches are still extensions of single target tracking solutions to multiple target tracking environment. This paper describes an application of multiple-hypothesis, multiple target tracking technology to the sonar line tracking problem. A Multiple Hypothesis Line Tracker (MHLT) is developed which retains the recursive minimum-mean-square-error tracking behavior of a Kalman Filter in a maximum-a-posteriori delayed-decision multiple hypothesis context. Multiple line track filter states are developed and maintained using the interacting multiple model (IMM) state representation. Further, the data association and assignment problem is enhanced by considering line attribute information (line bandwidth and SNR) in addition to beam/bearing and frequency fit. MHLT results on real sonar data are presented to demonstrate the benefits of the multiple hypothesis approach. The utility of the system in cluttered environments and particularly in crossing line situations is shown.

Apollo-Soyuz pamphlet no. 4: Gravitational field. [experimental design

NASA Technical Reports Server (NTRS)

Page, L. W.; From, T. P.

1977-01-01

Two Apollo Soyuz experiments designed to detect gravity anomalies from spacecraft motion are described. The geodynamics experiment (MA-128) measured large-scale gravity anomalies by detecting small accelerations of Apollo in the 222 km orbit, using Doppler tracking from the ATS-6 satellite. Experiment MA-089 measured 300 km anomalies on the earth's surface by detecting minute changes in the separation between Apollo and the docking module. Topics discussed in relation to these experiments include the Doppler effect, gravimeters, and the discovery of mascons on the moon.

Principal facts for a gravity survey of the Double Hot Springs Known Geothermal Resource Area, Humboldt County, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, D.L.; Kaufmann, H.E.

1978-01-01

During July 1977, forty-nine gravity stations were obtained in the Double Hot Springs Known Geothermal Resource Area and vicinity, northwestern Nevada. The gravity observations were made with a Worden gravimeter having a scale factor of about 0.5 milligal per division. No terrain corrections have been applied to these data. The earth tide correction was not used in drift reduction. The Geodetic Reference System 1967 formula (International Association of Geodesy, 1967) was used to compute theoretical gravity.

Landscape-scale water balance monitoring with an iGrav superconducting gravimeter in a field enclosure

NASA Astrophysics Data System (ADS)

Güntner, Andreas; Reich, Marvin; Mikolaj, Michal; Creutzfeldt, Benjamin; Schroeder, Stephan; Wziontek, Hartmut

2017-04-01

In spite of the fundamental role of the landscape water balance for the Earth's water and energy cycles, monitoring the water balance and its components beyond the point scale is notoriously difficult due to the multitude of flow and storage processes and their spatial heterogeneity. Here, we present the first deployment of an iGrav superconducting gravimeter (SG) in a minimized field enclosure on a grassland site for integrative monitoring of water storage changes. Results of the field SG were compared to data provided by a nearby SG located in the controlled environment of an observatory building. For wet-temperate climate conditions, the system proves to provide gravity time series that are similarly precise as those of the observatory SG. At the same time, the field SG is more sensitive to hydrological variations than the observatory SG. We demonstrate that the gravity variations observed by the field setup are almost independent of the depth below the terrain surface where water storage changes occur (contrary to SGs in buildings), and thus the field SG system directly observes the total water storage change, i.e., the water balance, in its surroundings in an integrative way. We provide a framework to single out the water balance components actual evapotranspiration and lateral subsurface discharge from the gravity time series on annual to daily time scales. With about 99% and 85% of the gravity signal originating within a radius of 4000 and 200 meter around the instrument, respectively, this setup paves the road towards gravimetry as a continuous hydrological field monitoring technique at the landscape scale.

New Geodetic Infrastructure for Australia: The NCRIS / AuScope Geospatial Component

NASA Astrophysics Data System (ADS)

Tregoning, P.; Watson, C. S.; Coleman, R.; Johnston, G.; Lovell, J.; Dickey, J.; Featherstone, W. E.; Rizos, C.; Higgins, M.; Priebbenow, R.

2009-12-01

In November 2006, the Australian Federal Government announced AUS15.8M in funding for geospatial research infrastructure through the National Collaborative Research Infrastructure Strategy (NCRIS). Funded within a broader capability area titled ‘Structure and Evolution of the Australian Continent’, NCRIS has provided a significant investment across Earth imaging, geochemistry, numerical simulation and modelling, the development of a virtual core library, and geospatial infrastructure. Known collectively as AuScope (www.auscope.org.au), this capability area has brought together Australian’s leading Earth scientists to decide upon the most pressing scientific issues and infrastructure needs for studying Earth systems and their impact on the Australian continent. Importantly and at the same time, the investment in geospatial infrastructure offers the opportunity to raise Australian geodetic science capability to the highest international level into the future. The geospatial component of AuScope builds onto the AUS15.8M of direct funding through the NCRIS process with significant in-kind and co-investment from universities and State/Territory and Federal government departments. The infrastructure to be acquired includes an FG5 absolute gravimeter, three gPhone relative gravimeters, three 12.1 m radio telescopes for geodetic VLBI, a continent-wide network of continuously operating geodetic quality GNSS receivers, a trial of a mobile SLR system and access to updated cluster computing facilities. We present an overview of the AuScope geospatial capability, review the current status of the infrastructure procurement and discuss some examples of the scientific research that will utilise the new geospatial infrastructure.

Determining the 3D Subsurface Density Structure of Taurus Littrow Valley Using Apollo 17 Gravity Data

NASA Technical Reports Server (NTRS)

Urbancic, N.; Ghent, R.; Stanley, S,; Johnson, C. L.; Carroll, K. A.; Hatch, D.; Williamson, M. C.; Garry, W. B.; Talwani, M.

2016-01-01

Surface gravity surveys can detect subsurface density variations that can reveal subsurface geologic features. In 1972, the Apollo 17 (A17) mission conducted the Traverse Gravimeter Experiment (TGE) using a gravimeter that measured the local gravity field near Taurus Littrow Valley (TLV), located on the south-eastern rim of the Serenitatis basin. TLV is hypothesized to be a basaltfilled radial graben resulting from the impact that formed Mare Serenitatis. It is bounded by both the North and South Massifs (NM and SM) as well as other smaller mountains to the East that are thought to be mainly composed of brecciated highland material. The TGE is the first and only successful gravity survey on the surface of the Moon. Other more recent satellite surveys, such as NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission (2011- 2012), have produced the best global gravity field to date (approx. 13km resolution). However, these satellite surveys are not sensitive enough to detect fine-scale (<1km) lunar subsurface structures. This underscores the value of the data collected at the surface by A17. In the original analysis of the data a 2D forward-modelling approach was used to derive a thickness of the subsurface basalt layer of 1.0 km by assuming a simple flat-faced rectangular geometry and using densities derived from Apollo lunar samples. We are investigating whether modern 3D modelling techniques in combination with high-resolution topographical and image datasets can reveal additional fine-scale subsurface structure in TLV.

Multiple-Line Inference of Selection on Quantitative Traits

PubMed Central

Riedel, Nico; Khatri, Bhavin S.; Lässig, Michael; Berg, Johannes

2015-01-01

Trait differences between species may be attributable to natural selection. However, quantifying the strength of evidence for selection acting on a particular trait is a difficult task. Here we develop a population genetics test for selection acting on a quantitative trait that is based on multiple-line crosses. We show that using multiple lines increases both the power and the scope of selection inferences. First, a test based on three or more lines detects selection with strongly increased statistical significance, and we show explicitly how the sensitivity of the test depends on the number of lines. Second, a multiple-line test can distinguish between different lineage-specific selection scenarios. Our analytical results are complemented by extensive numerical simulations. We then apply the multiple-line test to QTL data on floral character traits in plant species of the Mimulus genus and on photoperiodic traits in different maize strains, where we find a signature of lineage-specific selection not seen in two-line tests. PMID:26139839

Present status of marine gravity

NASA Technical Reports Server (NTRS)

Watts, A. B.

1978-01-01

The technique of measuring gravity at sea was greatly improved by the development of spring-type surface-ship gravimeters which can be operated in a wide variety of sea conditions. A brief review of the most recent developments in marine gravity is presented. The extent of marine gravity data coverage is illustrated in a compilation map of the world's free-air gravity anomaly maps of the world's oceans. A brief discussion of some of the main results in the interpretation of marine gravity is given. Some comments made on recent determinations of the gravity field in oceanic regions using satellite radar altimeters are also presented.

Atom Interferometry with the Sr Optical Clock Transition.

PubMed

Hu, Liang; Poli, Nicola; Salvi, Leonardo; Tino, Guglielmo M

2017-12-29

We report on the realization of a matter-wave interferometer based on single-photon interaction on the ultranarrow optical clock transition of strontium atoms. We experimentally demonstrate its operation as a gravimeter and as a gravity gradiometer. No reduction of interferometric contrast was observed for a total interferometer time up to ∼10  ms, limited by geometric constraints of the apparatus. Single-photon interferometers represent a new class of high-precision sensors that could be used for the detection of gravitational waves in so far unexplored frequency ranges and to enlighten the boundary between quantum mechanics and general relativity.

Measuring the Newtonian constant of gravitation with a differential free-fall gradiometer: A feasibility study

NASA Astrophysics Data System (ADS)

Rothleitner, Christian; Francis, Olivier

2014-04-01

An original setup is presented to measure the Newtonian Constant of Gravitation G. It is based on the same principle as used in ballistic absolute gravimeters. The differential acceleration of three simultaneously freely falling test masses is measured in order to determine G. In this paper, a description of the experimental setup is presented. A detailed uncertainty budget estimates the relative uncertainty to be of the order of 5.3 × 10-4, however with some improvements a relative uncertainty in G of one part in 104 could be feasible.

Data User's Note: Apollo seismological investigations

NASA Technical Reports Server (NTRS)

Vostreys, R. W.

1980-01-01

Seismological objectives and equipment used in the passive seismic, active seismic, lunar seismic profiling, and the lunar gravimeter experiments conducted during Apollo 11, 12, 14, 15, 16, and 17 missions are described. The various formats in which the data form these investigations can be obtained are listed an an index showing the NSSDC identification number is provided. Tables show manned lunar landing missions, lunar seismic network statistics, lunar impact coordinate statistics, detonation masses and times of EP's, the ALSEP (Apollo 14) operational history; compressed scale playout tape availability, LSPE coverage for one lunation, and experimenter interpreted events types.

The Data Base of the International Geodynamics and Earth Tide Service (IGETS)

NASA Astrophysics Data System (ADS)

Voigt, Christian; Förste, Christoph; Wziontek, Hartmut; Crossley, David; Meurers, Bruno; Pálinkáš, Vojtech; Hinderer, Jacques; Boy, Jean-Paul; Barriot, Jean-Pierre; Sun, Heping

2017-04-01

The International Geodynamics and Earth Tide Service (IGETS) was established in 2015 by the International Association of Geodesy (IAG). IGETS continues the activities of the Global Geodynamics Project (GGP, 1997-2015) to provide support to geodetic and geophysical research activities using superconducting gravimeter data within the context of an international network. The primary objective of IGETS is to provide a service for continuous ground based measurements to monitor temporal variations of the Earth's gravity field and deformation of the Earth's surface by long term records from ground gravimeters, tiltmeters, strainmeters and other geodynamic sensors. IGETS also continues the activities of the International Center for Earth Tides (ICET), in particular, in collecting, archiving and distributing Earth tide records from long series of the various geodynamic sensors. This presentation introduces the IGETS data base hosted by GFZ and accessible via http://igets.gfz-potsdam.de to the geodetic and geodynamics community as well as to all other interested data producers and users. At present, records from superconducting gravimeters at 34 stations worldwide are available. Level 1 products are raw gravity and local pressure records decimated at 1 minute samples. As a new feature, records with 1 or 2 seconds samples are already provided for a few stations. Level 2 products consist of gravity and pressure data corrected for instrumental perturbations and ready for tidal analysis, which are derived from Level 1 datasets and computed by the University of French Polynesia (Tahiti, French Polynesia). Gravity residuals after particular geophysical corrections (including solid Earth tides, polar motion, tidal and non-tidal loading effects) considered as Level 3 products are derived from Level 2 datasets and computed by EOST (Ecole et Observatoire des Sciences de la Terre, Strasbourg, France). The IGETS data sets are stored by GFZ on a FTP server and are freely available after a compulsory user registration. A major benefit of IGETS is the provision of digital object identifiers (DOI) by the research repository of GFZ Data Services for the data sets of every station. This ensures a long term storage and an increased visibility as part of an international network but also a proper data citation. At present, the IGETS data base is supported by 24 data producers providing records to almost 100 registered users. All relevant information on the data base, i.e., data availability and access, stations and sensors, conventional data formats, etc. are compiled in a specific scientific technical report (see http://doi.org/10.2312/GFZ.b103-16087). As IGETS is seeking for providing all kinds of long-term geodynamic time series, interested station operators are cordially invited to provide their data sets to the IGETS data base and, in return, benefit from being part of the IAG service IGETS.

Geophysical Characterization of Groundwater-Fault Dynamics at San Andreas Oasis

NASA Astrophysics Data System (ADS)

Faherty, D.; Polet, J.; Osborn, S. G.

2017-12-01

The San Andreas Oasis has historically provided a reliable source of fresh water near the northeast margin of the Salton Sea, although since the recent completion of the Coachella Canal Lining Project and persistent drought in California, surface water at the site has begun to disappear. This may be an effect of the canal lining, however, the controls on groundwater are complicated by the presence of the Hidden Springs Fault (HSF), a northeast dipping normal fault that trends near the San Andreas Oasis. Its surface expression is apparent as a lineation against which all plant growth terminates, suggesting that it may form a partial barrier to subsurface groundwater flow. Numerous environmental studies have detailed the chemical evolution of waters resources at San Andreas Spring, although there remains a knowledge gap on the HSF and its relation to groundwater at the site. To better constrain flow paths and characterize groundwater-fault interactions, we have employed resistivity surveys near the surface trace of the HSF to generate profiles of lateral and depth-dependent variations in resistivity. The survey design is comprised of lines installed in Wenner Arrays, using an IRIS Syscal Kid, with 24 electrodes, at a maximum electrode spacing of 5 meters. In addition, we have gathered constraints on the geometry of the HSF using a combination of ground-based magnetic and gravity profiles, conducted with a GEM walking Proton Precession magnetometer and a Lacoste & Romberg gravimeter. Seventeen gravity measurements were acquired across the surface trace of the fault. Preliminary resistivity results depict a shallow conductor localized at the oasis and discontinuous across the HSF. Magnetic data reveal a large contrast in subsurface magnetic susceptibility that appears coincident with the surface trace and trend of the HSF, while gravity data suggests a shallow, relatively high density anomaly centered near the oasis. These data also hint at a second, previously undocumented fault bounding the opposite margin of the oasis and trending subparallel to the HSF. We thus speculate that the Hidden Springs Fault and this possible secondary fault act as partial barriers to lateral subsurface flow and form a structural wedge, localizing groundwater beneath the oasis.

Landscape-scale water balance monitoring with an iGrav superconducting gravimeter in a field enclosure

NASA Astrophysics Data System (ADS)

Güntner, Andreas; Reich, Marvin; Mikolaj, Michal; Creutzfeldt, Benjamin; Schroeder, Stephan; Wziontek, Hartmut

2017-06-01

In spite of the fundamental role of the landscape water balance for the Earth's water and energy cycles, monitoring the water balance and its components beyond the point scale is notoriously difficult due to the multitude of flow and storage processes and their spatial heterogeneity. Here, we present the first field deployment of an iGrav superconducting gravimeter (SG) in a minimized enclosure for long-term integrative monitoring of water storage changes. Results of the field SG on a grassland site under wet-temperate climate conditions were compared to data provided by a nearby SG located in the controlled environment of an observatory building. The field system proves to provide gravity time series that are similarly precise as those of the observatory SG. At the same time, the field SG is more sensitive to hydrological variations than the observatory SG. We demonstrate that the gravity variations observed by the field setup are almost independent of the depth below the terrain surface where water storage changes occur (contrary to SGs in buildings), and thus the field SG system directly observes the total water storage change, i.e., the water balance, in its surroundings in an integrative way. We provide a framework to single out the water balance components actual evapotranspiration and lateral subsurface discharge from the gravity time series on annual to daily timescales. With about 99 and 85 % of the gravity signal due to local water storage changes originating within a radius of 4000 and 200 m around the instrument, respectively, this setup paves the road towards gravimetry as a continuous hydrological field-monitoring technique at the landscape scale.

Non-Tidal Ocean Loading Correction for the Argentinean-German Geodetic Observatory Using an Empirical Model of Storm Surge for the Río de la Plata

NASA Astrophysics Data System (ADS)

Oreiro, F. A.; Wziontek, H.; Fiore, M. M. E.; D'Onofrio, E. E.; Brunini, C.

2018-05-01

The Argentinean-German Geodetic Observatory is located 13 km from the Río de la Plata, in an area that is frequently affected by storm surges that can vary the level of the river over ±3 m. Water-level information from seven tide gauge stations located in the Río de la Plata are used to calculate every hour an empirical model of water heights (tidal + non-tidal component) and an empirical model of storm surge (non-tidal component) for the period 01/2016-12/2016. Using the SPOTL software, the gravimetric response of the models and the tidal response are calculated, obtaining that for the observatory location, the range of the tidal component (3.6 nm/s2) is only 12% of the range of the non-tidal component (29.4 nm/s2). The gravimetric response of the storm surge model is subtracted from the superconducting gravimeter observations, after applying the traditional corrections, and a reduction of 7% of the RMS is obtained. The wavelet transform is applied to the same series, before and after the non-tidal correction, and a clear decrease in the spectral energy in the periods between 2 and 12 days is identify between the series. Using the same software East, North and Up displacements are calculated, and a range of 3, 2, and 11 mm is obtained, respectively. The residuals obtained after applying the non-tidal correction allow to clearly identify the influence of rain events in the superconducting gravimeter observations, indicating the need of the analysis of this, and others, hydrological and geophysical effects.

Combining sprinkling experiments and superconducting gravimetry in the field: a qualitative approach to identify dominant infiltration patterns

NASA Astrophysics Data System (ADS)

Reich, Marvin; Mikolaj, Michal; Blume, Theresa; Güntner, Andreas

2017-04-01

Hydrological process research at the plot to catchment scale commonly involves invasive field methods, leading to a large amount of point data. A promising alternative, which gained increasing interest in the hydrological community over the last years, is gravimetry. The combination of its non-invasive and integrative nature opens up new possibilities to approach hydrological process research. In this study we combine a field-scale sprinkling experiment with continuous superconducting gravity (SG) measurements. The experimental design consists of 8 sprinkler units, arranged symmetrically within a radius of about ten meters around an iGrav (SG) in a field enclosure. The gravity signal of the infiltrating sprinkling water is analyzed using a simple 3D water mass distribution model. We first conducted a number of virtual sprinkling experiments resulting in different idealized infiltration patterns and determined the pattern specific gravity response. In a next step we determined which combination of idealized infiltration patterns was able to reproduce the gravity response of our real-world experiment at the Wettzell Observatory (Germany). This process hypothesis is then evaluated with measured point-scale soil moisture responses and the results of the time-lapse electric resistivity survey which was carried out during the sprinkling experiment. This study demonstrates that a controlled sprinkling experiment around a gravimeter in combination with a simple infiltration model is sufficient to identify subsurface flow patterns and thus the dominant infiltration processes. As gravimeters become more portable and can actually be deployed in the field, their combination with sprinkling experiments as shown here constitutes a promising possibility to investigate hydrological processes in a non-invasive way.

3D joint inversion of gravity-gradient and borehole gravity data

NASA Astrophysics Data System (ADS)

Geng, Meixia; Yang, Qingjie; Huang, Danian

2017-12-01

Borehole gravity is increasingly used in mineral exploration due to the advent of slim-hole gravimeters. Given the full-tensor gradiometry data available nowadays, joint inversion of surface and borehole data is a logical next step. Here, we base our inversions on cokriging, which is a geostatistical method of estimation where the error variance is minimised by applying cross-correlation between several variables. In this study, the density estimates are derived using gravity-gradient data, borehole gravity and known densities along the borehole as a secondary variable and the density as the primary variable. Cokriging is non-iterative and therefore is computationally efficient. In addition, cokriging inversion provides estimates of the error variance for each model, which allows direct assessment of the inverse model. Examples are shown involving data from a single borehole, from multiple boreholes, and combinations of borehole gravity and gravity-gradient data. The results clearly show that the depth resolution of gravity-gradient inversion can be improved significantly by including borehole data in addition to gravity-gradient data. However, the resolution of borehole data falls off rapidly as the distance between the borehole and the feature of interest increases. In the case where the borehole is far away from the target of interest, the inverted result can be improved by incorporating gravity-gradient data, especially all five independent components for inversion.

Improving absolute gravity estimates by the L p -norm approximation of the ballistic trajectory

NASA Astrophysics Data System (ADS)

Nagornyi, V. D.; Svitlov, S.; Araya, A.

2016-04-01

Iteratively re-weighted least squares (IRLS) were used to simulate the L p -norm approximation of the ballistic trajectory in absolute gravimeters. Two iterations of the IRLS delivered sufficient accuracy of the approximation without a significant bias. The simulations were performed on different samplings and perturbations of the trajectory. For the platykurtic distributions of the perturbations, the L p -approximation with 3  <  p  <  4 was found to yield several times more precise gravity estimates compared to the standard least-squares. The simulation results were confirmed by processing real gravity observations performed at the excessive noise conditions.

COMMENT: Comment on 'Evaluation of the local value of the Earth gravity field in the context of the new definition of the kilogram'

NASA Astrophysics Data System (ADS)

Svitlov, S. M.

2010-06-01

A recent paper (Baumann et al 2009 Metrologia 46 178-86) presents a method to evaluate the free-fall acceleration at a desired point in space, as required for the watt balance experiment. The claimed uncertainty of their absolute gravity measurements is supported by two bilateral comparisons using two absolute gravimeters of the same type. This comment discusses the case where absolute gravity measurements are traceable to a key comparison reference value. Such an approach produces a more complete uncertainty budget and reduces the risk of the results of different watt balance experiments not being compatible.

Hydro-gravimetry in West-Africa: First results from the Djougou (Benin) superconducting gravimeter

NASA Astrophysics Data System (ADS)

Hector, Basile; Hinderer, Jacques; Séguis, Luc; Boy, Jean-Paul; Calvo, Marta; Descloitres, Marc; Rosat, Séverine; Galle, Sylvie; Riccardi, Umberto

2014-10-01

The increasing number of hydro-gravimetry studies proves the rising interest of the hydrology community toward this monitoring method. The accuracy of superconducting gravimeters (SG) potentially allows the retrieval of small water storage changes (WSC) down to a few millimeters of equivalent water thickness. However, the importance of corrections applied to SG data to achieve such a precision in gravity residuals should be recalled. The Djougou permanent gravity station presented in this paper and located in northern Benin, West-Africa, provides a good opportunity to review these considerations. This station is equipped since July 2010 with the superconducting gravimeter SG-060 aimed at deriving WSC at different time-scales, daily to inter-annual. In this area, WSC are (1) part of the control system for evapotranspiration (ET) process, a key variable of the West-African monsoon cycle and (2) the state variable for resource management, a critical issue in storage-poor hard rock basement contexts such as in northern Benin. The potential for deriving WSC from time-lapse gravity data partly depends on environmental features such as topography and the instrument shelter. Therefore, this issue is addressed first, with the background idea that such sensitivity analysis should be undertaken before setting up any new instrument. In Djougou, local topography is quite flat leading to a theoretical straightforward relationship between gravity changes and WSC, close to the standard Bouguer value. However, the shelter plays a significant masking role, which is the principal limitation to the retrieval of fast hydrological processes such as ET following a rain event. Several issues concerning classical gravity corrections are also addressed in the paper. These include gap-filling procedures during rain-events and drift estimates for short time series. Special attention is provided to atmospheric corrections, and different approaches are tested: a simple scalar admittance, a filtered scalar admittance, a frequency-dependent admittance and direct atmospheric loading calculations. It is shown that the physically based approach of direct loading calculations performs better in both residual minimization and ET retrieval. Moreover, non-local hydrological effects are investigated and account for about 20% of the gravity residuals. Finally, gravity residuals are briefly analyzed at two distinct time scales: rapid (up to a few days) and seasonal. At the rapid time-scale, it is shown that ET retrieval is hardly achievable given shelter size and state-of-the-art atmospheric corrections. Still, mean values retrieved from this study are in accordance with known values of potential ET and lateral flow. Direct comparison of gravity changes with hydrological data (neutron probe monitoring and water table levels) show some discrepancies, particularly for the hydrological year of 2011, for which all hydrological data show a deficit, but SG and FG5 data do not. This preliminary analysis both provides a basis and call for further hydro-gravity modeling, to comprehensively investigate the water-cycle at the Djougou station.

New insights into ocean tide loading corrections on tidal gravity data in Canary Islands

NASA Astrophysics Data System (ADS)

Arnoso, J.; Benavent, M.; Bos, M. S.; Montesinos, F. G.

2009-04-01

The Canary Islands are an interesting area to investigate ocean tides loading effects due to the complex coastline of the islands and the varying bathymetry. We present here the quality of five recent global oceanic tidal models, GOT00.2, GOT4.7, FES2004, TPXO.7.1 and AG2006, by comparing their predicted ocean tide loading values with results from tidal gravity observations made on three islands, Lanzarote, Tenerife and El Hierro, for the four harmonic constituents O1, K1, M2 and S2. In order to improve the accuracy of the loading corrections on the gravity tide measurements, we have used the high resolution regional oceanic model CIAM2 to supplement the global models considered here. This regional model has been obtained by assimilating TOPEX/Poseidon altimetry at crossovers and along-track points and tide gauge observations into a hydrodynamic model. The model has a 5'Ã-5' resolution and covers the area between the coordinates 26°.5N to 30°.0N and 19°.0W to 12°.5W. The gravity tide observing sites have been occupied by three different LaCoste&Romberg (LCR) spring gravimeters during different periods of observation. We considered here the most recent gravity tide observations made with LCR Graviton-EG1194 in El Hierro Island, for a period of 6 months during 2008. In the case of Tenerife and Lanzarote sites we have used observation periods of 6 months and 8 years with LCR-G665 and LCR-G434 gravimeters, respectively. The last two sites have been revisited in order to improve the previous tidal analysis results. Thus, the gravity ocean tide loading corrections, based on the five global ocean tide models supplemented with the regional model CIAM2 allowed us to review the normalization factors (scale factor and phase lag) of both two gravimeters. Also, we investigated the discrepancies of the corrected gravimetric factors with the DDW elastic and inelastic non hydrostatic body tide model (Dehant et al., 1999). The lowest values are found for inelastic model in the case of M2 and O1 waves at three sites. However, the scatter between oceanic models seen at final residual vectors does not indicate clearly if tidal observations are close to elastic or inelastic body tide model. Finally, after computing misfits of gravity tide observations and ocean tide loading calculations the level of agreement between the five global oceanic models is below 0.2 Gal (1 Gal=10-8ms-2), except for the solar harmonic K1, which reaches a large value that reflects the thermal instability at three sites because the period of K1 is very close to that of S1. None of the five global models seems to give results that are clearly better than the other models.

New determinations of Q quality factors and eigenfrequencies for the whole set of singlets of the Earth's normal modes 0S 0, 0S 2, 0S 3 and 2S 1 using superconducting gravimeter data from the GGP network

NASA Astrophysics Data System (ADS)

Roult, Geneviève; Rosat, Séverine; Clévédé, Eric; Millot-Langet, Raphaële; Hinderer, Jacques

2006-01-01

We present new modal Q measurements of the 0S 0 and 0S 2 modes, and first modal frequencies and Q measurements of 2S 1 and 0S 3 modes. The high quality of the GGP (Global Geodynamics Project) superconducting gravimeters (SGs) contributes to the clear observation of seismic normal modes at frequencies lower than 1 mHz and offers a good opportunity for studying the behaviour of these modes. The interest of scientists in the gravest normal modes is due to the fact that they do contribute to a better knowledge of the density profile in the Earth, helping to constrain Earth's models. These modes have been clearly identified after some large recent events recorded with superconducting gravimeters, particularly well-suited for low-frequency investigations. The Ms = 8.1 (Mw = 8.4) Peruvian earthquake of June 2001 and the Ms = 9.0 (Mw = 9.3) Sumatra-Andaman earthquake of December 2004 provide us with individual spectra which exhibit a clear splitting of the spheroidal modes 0S 2, 0S 3 and 2S 1, and a clear identification of each of the individual singlets, with a resolution never obtained from broad-band seismometers records. The Q quality factors have been determined from the apparent decrease of the amplitude of each singlet with time, according to a well-suited technique [Roult, G., Clévédé, E., 2000. New refinements in attenuation measurements from free-oscillation and surface-wave observations. Phys. Earth Planet. Inter. 121, 1-37]. The results are compared to the theoretical frequencies and Q quality factors computed for the PREM and 1066A models, taking into account both rotation and ellipticity effects of the Earth. The two observed datasets (frequencies and Q quality factors) exhibit a splitting on the observed values different from the predicted one. That seems to point out that some parameters as density or attenuation values used in the theoretical models do not explain the observations. A new dataset of frequencies and Q quality factors of the whole set of singlets of the gravest spheroidal modes is thus under construction. That dataset includes the five individual singlets of the 0S 2 mode clearly identified on the SG records, the three singlets of the 2S 1 mode recently observed for the first time by [Rosat, S., Hinderer, J., Rivera, L., 2003b. First observation of 2S 1 and study of the splitting of the football mode 0S 2 after the June 2001 Peru earthquake of magnitude 8.4. Geophys. Res. Lett. 30, 21211, doi:10-1029/2003L018304], the 0S 0 radial mode, and the seven individual singlets of the 0S 3 mode.

Natural killer cell lines preferentially kill clonogenic multiple myeloma cells and decrease myeloma engraftment in a bioluminescent xenograft mouse model.

PubMed

Swift, Brenna E; Williams, Brent A; Kosaka, Yoko; Wang, Xing-Hua; Medin, Jeffrey A; Viswanathan, Sowmya; Martinez-Lopez, Joaquin; Keating, Armand

2012-07-01

Novel therapies capable of targeting drug resistant clonogenic MM cells are required for more effective treatment of multiple myeloma. This study investigates the cytotoxicity of natural killer cell lines against bulk and clonogenic multiple myeloma and evaluates the tumor burden after NK cell therapy in a bioluminescent xenograft mouse model. The cytotoxicity of natural killer cell lines was evaluated against bulk multiple myeloma cell lines using chromium release and flow cytometry cytotoxicity assays. Selected activating receptors on natural killer cells were blocked to determine their role in multiple myeloma recognition. Growth inhibition of clonogenic multiple myeloma cells was assessed in a methylcellulose clonogenic assay in combination with secondary replating to evaluate the self-renewal of residual progenitors after natural killer cell treatment. A bioluminescent mouse model was developed using the human U266 cell line transduced to express green fluorescent protein and luciferase (U266eGFPluc) to monitor disease progression in vivo and assess bone marrow engraftment after intravenous NK-92 cell therapy. Three multiple myeloma cell lines were sensitive to NK-92 and KHYG-1 cytotoxicity mediated by NKp30, NKp46, NKG2D and DNAM-1 activating receptors. NK-92 and KHYG-1 demonstrated 2- to 3-fold greater inhibition of clonogenic multiple myeloma growth, compared with killing of the bulk tumor population. In addition, the residual colonies after treatment formed significantly fewer colonies compared to the control in a secondary replating for a cumulative clonogenic inhibition of 89-99% at the 20:1 effector to target ratio. Multiple myeloma tumor burden was reduced by NK-92 in a xenograft mouse model as measured by bioluminescence imaging and reduction in bone marrow engraftment of U266eGFPluc cells by flow cytometry. This study demonstrates that NK-92 and KHYG-1 are capable of killing clonogenic and bulk multiple myeloma cells. In addition, multiple myeloma tumor burden in a xenograft mouse model was reduced by intravenous NK-92 cell therapy. Since multiple myeloma colony frequency correlates with survival, our observations have important clinical implications and suggest that clinical studies of NK cell lines to treat MM are warranted.

Measuring the effect of multiple eye fixations on memory for visual attributes.

PubMed

Palmer, J; Ames, C T

1992-09-01

Because of limited peripheral vision, many visual tasks depend on multiple eye fixations. Good performance in such tasks demonstrates that some memory must survive from one fixation to the next. One factor that must influence performance is the degree to which multiple eye fixations interfere with the critical memories. In the present study, the amount of interference was measured by comparing visual discriminations based on multiple fixations to visual discriminations based on a single fixation. The procedure resembled partial report, but used a discrimination measure. In the prototype study, two lines were presented, followed by a single line and a cue. The cue pointed toward one of the positions of the first two lines. Observers were required to judge if the single line in the second display was longer or shorter than the cued line of the first display. These judgments were used to estimate a length threshold. The critical manipulation was to instruct observers either to maintain fixation between the lines of the first display or to fixate each line in sequence. The results showed an advantage for multiple fixations despite the intervening eye movements. In fact, thresholds for the multiple-fixation condition were nearly as good as those in a control condition where the lines were foveally viewed without eye movements. Thus, eye movements had little or no interfering effect in this task. Additional studies generalized the procedure and the stimuli. In conclusion, information about a variety of size and shape attributes was remembered with essentially no interference across eye fixations.

Principal facts for gravity stations in Dixie; Fairview, and Stingaree valleys, Churchill and Pershing counties, Nevada

USGS Publications Warehouse

Schaefer, D.H.; Thomas, J.M.; Duffrin, B.G.

1984-01-01

During March through July 1979, gravity measurements were made at 300 stations in Dixie Valley, Nevada. In December 1981, 45 additional stations were added--7 in Dixie Valley, 23 in Fairview Valley, and 15 in Stingaree Valley. Most altitudes were determined by using altimeters or topographic maps. The gravity observations were made with a Worden temperature-controlled gravimeter with an initial scale factor of 0.0965 milliGal/scale division. Principal facts for each of the 345 stations are tabulated; they consist of latitude, longitude, altitude, observed gravity, free-air anomaly, terrain correction, and Bouguer anomaly values at a bedrock density of 2.67 grams/cu cm. (Lantz-PTT)

APOLLO 17 - INFLIGHT Experiment Equipment

NASA Image and Video Library

1972-11-28

S72-53952 (November 1972) --- The Traverse Gravimeter Experiment (S-199), with cover removed, which will be used by the Apollo 17 crewmen at the Taurus-Littrow landing site. The purposes of this experiment are to make a high accuracy relative survey of the lunar gravitational field in the lunar landing area and to make an Earth-moon gravity tie. Specific experiment objectives related to these purposes are to: (1) measure the value of gravity, relative to the value at a lunar base station, at selected known locations along the lunar traverse; (2) measure the value of gravity at a known point on the lunar surface (base station) relative to the value of gravity at a known point on Earth.

Natural killer cell lines preferentially kill clonogenic multiple myeloma cells and decrease myeloma engraftment in a bioluminescent xenograft mouse model

PubMed Central

Swift, Brenna E.; Williams, Brent A.; Kosaka, Yoko; Wang, Xing-Hua; Medin, Jeffrey A.; Viswanathan, Sowmya; Martinez-Lopez, Joaquin; Keating, Armand

2012-01-01

Background Novel therapies capable of targeting drug resistant clonogenic MM cells are required for more effective treatment of multiple myeloma. This study investigates the cytotoxicity of natural killer cell lines against bulk and clonogenic multiple myeloma and evaluates the tumor burden after NK cell therapy in a bioluminescent xenograft mouse model. Design and Methods The cytotoxicity of natural killer cell lines was evaluated against bulk multiple myeloma cell lines using chromium release and flow cytometry cytotoxicity assays. Selected activating receptors on natural killer cells were blocked to determine their role in multiple myeloma recognition. Growth inhibition of clonogenic multiple myeloma cells was assessed in a methylcellulose clonogenic assay in combination with secondary replating to evaluate the self-renewal of residual progenitors after natural killer cell treatment. A bioluminescent mouse model was developed using the human U266 cell line transduced to express green fluorescent protein and luciferase (U266eGFPluc) to monitor disease progression in vivo and assess bone marrow engraftment after intravenous NK-92 cell therapy. Results Three multiple myeloma cell lines were sensitive to NK-92 and KHYG-1 cytotoxicity mediated by NKp30, NKp46, NKG2D and DNAM-1 activating receptors. NK-92 and KHYG-1 demonstrated 2- to 3-fold greater inhibition of clonogenic multiple myeloma growth, compared with killing of the bulk tumor population. In addition, the residual colonies after treatment formed significantly fewer colonies compared to the control in a secondary replating for a cumulative clonogenic inhibition of 89–99% at the 20:1 effector to target ratio. Multiple myeloma tumor burden was reduced by NK-92 in a xenograft mouse model as measured by bioluminescence imaging and reduction in bone marrow engraftment of U266eGFPluc cells by flow cytometry. Conclusions This study demonstrates that NK-92 and KHYG-1 are capable of killing clonogenic and bulk multiple myeloma cells. In addition, multiple myeloma tumor burden in a xenograft mouse model was reduced by intravenous NK-92 cell therapy. Since multiple myeloma colony frequency correlates with survival, our observations have important clinical implications and suggest that clinical studies of NK cell lines to treat MM are warranted. PMID:22271890

A Comparison of Off-Level Correction Techniques for Airborne Gravity using GRAV-D Re-Flights

NASA Astrophysics Data System (ADS)

Preaux, S. A.; Melachroinos, S.; Diehl, T. M.

2011-12-01

The airborne gravity data collected for the GRAV-D project contain a number of tracks which have been flown multiple times, either by design or due to data collection issues. Where viable data can be retrieved, these re-flights are a valuable resource not only for assessing the quality of the data but also for evaluating the relative effectiveness of various processing techniques. Correcting for the instantaneous misalignment of the gravimeter sensitive axis with local vertical has been a long standing challenge for stable platform airborne gravimetry. GRAV-D re-flights are used to compare the effectiveness of existing methods of computing this off-level correction (Valliant 1991, Peters and Brozena 1995, Swain 1996, etc.) and to assess the impact of possible modifications to these methods including pre-filtering accelerations, use of IMU horizontal accelerations in place of those derived from GPS positions and accurately compensating for GPS lever-arm and attitude effects prior to computing accelerations from the GPS positions (Melachroinos et al. 2010, B. de Saint-Jean, et al. 2005). The resulting corrected gravity profiles are compared to each other and to EGM08 in order to assess the accuracy and precision of each method. Preliminary results indicate that the methods presented in Peters & Brozena 1995 and Valliant 1991 completely correct the off-level error some of the time but only partially correct it others, while introducing an overall bias to the data of -0.5 to -2 mGal.

Too Fast to Measure: Network Adjustment of Rapidly Changing Gravity Fields

NASA Astrophysics Data System (ADS)

Kennedy, J.; Ferre, T. P. A.

2014-12-01

Measurements of spatially-variable gravity at the field scale are difficult; measurements of the time-varying field even more so. Every previous gravity survey using relative gravimeters—still the workhorse of gravity studies, despite their nearly 80 year history—has assumed a static gravity field during the course of a survey, which may last days to weeks. With recently-improved instrumentation, however, measurements of fields changing on the order of tens of nm/sec2 per day are now possible. In particular, the A-10 portable absolute gravimeter provides not only absolute control, but also the change in that control during the course of a survey. Using digitally-recording spring-based relative gravimeters (namely, the ZLS Burris meter and the Scintrex CG-5), with their more efficient data collection and lower drift than previous generations, many more data are collected in a day. We demonstrate a method for incorporating in the least-squares network adjustment of relative gravity data a relation between the rate of change of gravity, dg, and distance from an infiltration source, x. This relation accounts for the fact that gravity at stations adjacent to the infiltration source changes more rapidly than stations further away; if all measurements collected over several days are to be included in a single network-adjustment, consideration of this change is required. Two methods are used to simulate the dg(x) relation: a simple model where dg is a linear function of x, and a coupled-hydrogeophysical method where a groundwater flow model predicts the nonlinear spatial variation of dg. Then, the change in gravity between different, independently adjusted surveys is used to parameterize the groundwater model. Data from two recent field examples, an artificial recharge facility near Tucson, Arizona, USA, and from the 2014 Lower Colorado River pulse flow experiment, clearly show the need to account for gravity change during a survey; maximum rates of change for the two studies were up to 30 and 50 nm/sec2 per day, respectively.

Applications of atom interferometry - from ground to space

NASA Astrophysics Data System (ADS)

Schubert, Christian; Rasel, Ernst Maria; Gaaloul, Naceur; Ertmer, Wolfgang

2016-07-01

Atom interferometry is utilized for the measurement of rotations [1], accelerations [2] and for tests of fundamental physics [3]. In these devices, three laser light pulses separated by a free evolution time coherently manipulate the matter waves which resembles the Mach-Zehnder geometry in optics. Atom gravimeters demonstrated an accuracy of few microgal [2,4], and atom gradiometers showed a noise floor of 30 E Hz^{-1/2} [5]. Further enhancements of atom interferometers are anticipated by the integration of novel source concepts providing ultracold atoms, extending the free fall time of the atoms, and enhanced techniques for coherent manipulation. Sources providing Bose-Einstein condensates recently demontrated a flux compatible with precision experiments [6]. All of these aspects are studied in the transportable quantum gravimeter QG-1 and the very long baseline atom interferometry teststand in Hannover [7] with the goal of surpassing the microgal regime. Going beyond ground based setups, the QUANTUS collaboration exploits the unique features of a microgravity environment in drop tower experiments [8] and in a sounding rocket mission. The payloads are compact and robust atom optics experiments based on atom chips [6], enabling technology for transportable sensors on ground as a byproduct. More prominently, they are pathfinders for proposed satellite missions as tests of the universality of free fall [9] and gradiometry based on atom interferometers [10]. This work is supported by the German Space Agency (DLR) with funds provided by the Federal Ministry for Economic Affairs and Energy (BMWi) due to an enactment of the German Bundestag under grant numbers DLR 50WM1552-1557 (QUANTUS-IV-Fallturm) and by the Deutsche Forschungsgemeinschaft in the framework of the SFB 1128 geo-Q. [1] PRL 114 063002 2015 [2] Nature 400 849 1999 [3] PRL 112 203002 2014 [4] NJP 13 065026 2011 [5] PRA 65 033608 2002 [6] NJP 17 065001 2015 [7] NJP 17 035011 2015 [8] PRL 110 093602 2013 [9] CQG 31 115010 2014 [10] MST 26 139 2014.

Refining the effects of aircraft motion on an airborne beam-type gravimeter

NASA Astrophysics Data System (ADS)

Childers, V. A.; Weil, C.

2016-12-01

A challenge of modern airborne gravimetry is identifying an aircraft/autopilot combination that will allow for high quality data collection. The natural motion of the aircraft coupled with the autopilot's reaction to changing winds and turbulence can result in a successful data collection effort when the motion is benign or in total failure when the motion is at its worst. Aircraft motion plays such an important role in airborne gravimetry for several reasons, but most importantly to this study it affects the behavior of the gravimeter's gyro-stabilized platform. The gyro-stabilized platform keeps the sensor aligned with a time-averaged local vertical to produce a scalar measurement along the plumb direction. However, turbulence can cause the sensor to align temporarily with aircraft horizontal accelerations that can both decrease the measured gravity (because the sensor is no longer aligned with the gravity field) and increase the measured gravity (because horizontal accelerations are coupling into the measurement). NOAA's Gravity for the Redefinition of the American Vertical Datum (GRAV-D) project has collected airborne gravity data using a Micro-g LaCoste TAGS (Turnkey Airborne Gravity System) beam-type meter on a variety of mostly turboprop aircraft with a wide range of outcomes, some different than one would predict. Some aircraft that seem the smoothest to the operator in flight do not produce as high quality a measurement as one would expect. Alternatively, some aircraft that have significant motion produce very high quality data. Due to the extensive nature of the GRAV-D survey, significant quantities of data exist on our various successful aircraft. In addition, we have numerous flights, although fewer, that were not successful for a number of reasons. In this study, we use spectral analysis to evaluate the aircraft motion for our various successful aircraft and compare with the problem flights in our effort to identify the signature motions indicative of aircraft that could be successful or not successful for airborne gravity collection with a beam-type sensor.

Providing long-term trend and gravimetric factor at Chandler period from superconducting gravimeter records by using Singular Spectrum Analysis along with its multivariate extension

NASA Astrophysics Data System (ADS)

Gruszczynska, M.; Rosat, S.; Klos, A.; Bogusz, J.

2017-12-01

In this study, Singular Spectrum Analysis (SSA) along with its multivariate extension MSSA (Multichannel SSA) were used to estimate long-term trend and gravimetric factor at the Chandler wobble frequency from superconducting gravimeter (SG) records. We have used data from seven stations located worldwide and contributing to the International Geodynamics and Earth Tides Service (IGETS). The timespan ranged from 15 to 19 years. Before applying SSA and MSSA, we had removed local tides, atmospheric (ECMWF data), hydrological (MERRA2 products) loadings and non-tidal ocean loading (ECCO2 products) effects. In the first part of analysis, we used the SSA approach in order to estimate the long-term trends from SG observations. We use the technique based on the classical Karhunen-Loève spectral decomposition of time series into long-term trend, oscillations and noise. In the second part, we present the determination of common time-varying pole tide (annual and Chandler wobble) to estimate gravimetric factor from SG time series using the MSSA approach. The presented method takes advantage over traditional methods like Least Squares Estimation by determining common modes of variability which reflect common geophysical field. We adopted a 6-year lag-window as the optimal length to extract common seasonal signals and the Chandler components of the Earth polar motion. The signals characterized by annual and Chandler wobble account for approximately 62% of the total variance of residual SG data. Then, we estimated the amplitude factors and phase lags of Chandler wobble with respect to the IERS (International Earth Rotation and Reference Systems Service) polar motion observations. The resulting gravimetric factors at the Chandler Wobble period are finally compared with previously estimates. A robust estimate of the gravimetric Earth response to the Chandlerian component of the polar motion is required to better constrain the mantle anelasticity at this frequency and hence the attenuation models of the Earth interior.

Tunable valley polarization by a gate voltage when an electron tunnels through multiple line defects in graphene.

PubMed

Liu, Zhe; Jiang, Liwei; Zheng, Yisong

2015-02-04

By means of an appropriate wave function connection condition, we study the electronic structure of a line defect superlattice of graphene with the Dirac equation method. We obtain the analytical dispersion relation, which can simulate well the tight-binding numerical result about the band structure of the superlattice. Then, we generalize this theoretical method to study the electronic transmission through a potential barrier where multiple line defects are periodically patterned. We find that there exists a critical incident angle which restricts the electronic transmission through multiple line defects within a specific incident angle range. The critical angle depends sensitively on the potential barrier height, which can be modulated by a gate voltage. As a result, non-trivial transmissions of K and K' valley electrons are restricted, respectively, in two distinct ranges of the incident angle. Our theoretical result demonstrates that a gate voltage can act as a feasible measure to tune the valley polarization when electrons tunnel through multiple line defects.

Optimization of a Time-Lapse Gravity Network for Carbon Sequestration

NASA Astrophysics Data System (ADS)

Appriou, D.; Strickland, C. E.; Ruprecht Yonkofski, C. M.

2017-12-01

The objective of this study is to evaluate what could be a comprehensive and optimal state of the art gravity monitoring network that would meet the UIC class VI regulation and insure that 90% of the CO2 injected remain underground. Time-lapse gravity surveys have a long history of effective applications of monitoring temporal density changes in the subsurface. For decades, gravity measurements have been used for a wide range of applications. The interest of time-lapse gravity surveys for monitoring carbon sequestration sites started recently. The success of their deployment in such sites depends upon a combination of favorable conditions, such as the reservoir geometry, depth, thickness, density change over time induced by the CO2 injection and the location of the instrument. In most cases, the density changes induced by the CO2 plume in the subsurface are not detectable from the surface but the use of borehole gravimeters can provide excellent results. In the framework of the National Assessment and Risk Partnership (NRAP) funded by the Department of Energy, the evaluation of the effectiveness of the gravity monitoring of a CO2 storage site has been assessed using multiple synthetic scenarios implemented on a community model developed for the Kimberlina site (e.g., fault leakage scenarios, borehole leakage). The Kimberlina carbon sequestration project was a pilot project located in southern San Joaquin Valley, California, aimed to safely inject 250,000 t CO2/yr for four years. Although the project was cancelled in 2012, the site characterization efforts resulted in the development of a geologic model. In this study, we present the results of the time-lapse gravity monitoring applied on different multiphase flow and reactive transport models developed by Lawrence Berkeley National Laboratory (i.e., no leakage, permeable fault zone, wellbore leakage). Our monitoring approach considers an ideal network, consisting of multiple vertical and horizontal instrumented boreholes that could be used to track the CO2 plume and potential leaks. A preliminary cost estimate will also be provided.

HIV integration sites in latently infected cell lines: evidence of ongoing replication.

PubMed

Symons, Jori; Chopra, Abha; Malatinkova, Eva; De Spiegelaere, Ward; Leary, Shay; Cooper, Don; Abana, Chike O; Rhodes, Ajantha; Rezaei, Simin D; Vandekerckhove, Linos; Mallal, Simon; Lewin, Sharon R; Cameron, Paul U

2017-01-13

Assessing the location and frequency of HIV integration sites in latently infected cells can potentially inform our understanding of how HIV persists during combination antiretroviral therapy. We developed a novel high throughput sequencing method to evaluate HIV integration sites in latently infected cell lines to determine whether there was virus replication or clonal expansion in these cell lines observed as multiple integration events at the same position. We modified a previously reported method using random DNA shearing and PCR to allow for high throughput robotic processing to identify the site and frequency of HIV integration in latently infected cell lines. Latently infected cell lines infected with intact virus demonstrated multiple distinct HIV integration sites (28 different sites in U1, 110 in ACH-2 and 117 in J1.1 per 150,000 cells). In contrast, cell lines infected with replication-incompetent viruses (J-Lat cells) demonstrated single integration sites. Following in vitro passaging of the ACH-2 cell line, we observed a significant increase in the frequency of unique HIV integration sites and there were multiple mutations and large deletions in the proviral DNA. When the ACH-2 cell line was cultured with the integrase inhibitor raltegravir, there was a significant decrease in the number of unique HIV integration sites and a transient increase in the frequency of 2-LTR circles consistent with virus replication in these cells. Cell lines latently infected with intact HIV demonstrated multiple unique HIV integration sites indicating that these cell lines are not clonal and in the ACH-2 cell line there was evidence of low level virus replication. These findings have implications for the use of latently infected cell lines as models of HIV latency and for the use of these cells as standards.

In line monitoring of the preparation of water-in-oil-in-water (W/O/W) type multiple emulsions via dielectric spectroscopy.

PubMed

Beer, Sebastian; Dobler, Dorota; Gross, Alexander; Ost, Martin; Elseberg, Christiane; Maeder, Ulf; Schmidts, Thomas Michael; Keusgen, Michael; Fiebich, Martin; Runkel, Frank

2013-01-30

Multiple emulsions offer various applications in a wide range of fields such as pharmaceutical, cosmetics and food technology. Two features are known to yield a great influence on multiple emulsion quality and utility as encapsulation efficiency and prolonged stability. To achieve a prolonged stability, the production of the emulsions has to be observed and controlled, preferably in line. In line measurements provide available parameters in a short time frame without the need for the sample to be removed from the process stream, thereby enabling continuous process control. In this study, information about the physical state of multiple emulsions obtained from dielectric spectroscopy (DS) is evaluated for this purpose. Results from dielectric measurements performed in line during the production cycle are compared to theoretically expected results and to well established off line measurements. Thus, a first step to include the production of multiple emulsions into the process analytical technology (PAT) guidelines of the Food and Drug Administration (FDA) is achieved. DS proved to be beneficial in determining the crucial stopping criterion, which is essential in the production of multiple emulsions. The stopping of the process at a less-than-ideal point can severely lower the encapsulation efficiency and the stability, thereby lowering the quality of the emulsion. DS is also expected to provide further information about the multiple emulsion like encapsulation efficiency. Copyright © 2012 Elsevier B.V. All rights reserved.

Toward a standard line for use in multibeam echo sounder calibration

NASA Astrophysics Data System (ADS)

Weber, Thomas C.; Rice, Glen; Smith, Michael

2018-06-01

A procedure is suggested in which a relative calibration for the intensity output of a multibeam echo sounder (MBES) can be performed. This procedure identifies a common survey line (i.e., a standard line), over which acoustic backscatter from the seafloor is collected with multiple MBES systems or by the same system multiple times. A location on the standard line which exhibits temporal stability in its seafloor backscatter response is used to bring the intensity output of the multiple MBES systems to a common reference. This relative calibration procedure has utility for MBES users wishing to generate an aggregate seafloor backscatter mosaic using multiple systems, revisiting an area to detect changes in substrate type, and comparing substrate types in the same general area but with different systems or different system settings. The calibration procedure is demonstrated using three different MBES systems over 3 different years in New Castle, NH, USA.

Patterned growth of individual and multiple vertically aligned carbon nanofibers

NASA Astrophysics Data System (ADS)

Merkulov, V. I.; Lowndes, D. H.; Wei, Y. Y.; Eres, G.; Voelkl, E.

2000-06-01

The results of studies of patterned growth of vertically aligned carbon nanofibers (VACNFs) prepared by plasma-enhanced chemical vapor deposition are reported. Nickel (Ni) dots of various diameters and Ni lines with variable widths and shapes were fabricated using electron beam lithography and evaporation, and served for catalytic growth of VACNFs whose structure was determined by high resolution transmission electron microscopy. It is found that upon plasma pre-etching and heating up to 600-700 °C, thin films of Ni break into droplets which initiate the growth of VACNFs. Above a critical dot size multiple droplets are formed, and consequently multiple VACNFs grow from a single evaporated dot. For dot sizes smaller than the critical size only one droplet is formed, resulting in a single VACNF. In the case of a patterned line, the growth mechanism is similar to that from a dot. VACNFs grow along the line, and above a critical linewidth multiple VACNFs are produced across the line. The mechanism of the formation of single and multiple catalyst droplets and subsequently of VACNFs is discussed.

New Crustal Boundary Revealed Beneath the Ross Ice Shelf, Antarctica, through ROSETTA-Ice Integrated Aerogeophysics, Geology, and Ocean Research

NASA Astrophysics Data System (ADS)

Tinto, K. J.; Siddoway, C. S.; Bell, R. E.; Lockett, A.; Wilner, J.

2017-12-01

Now submerged within marine plateaus and rises bordering Antarctica, Australia and Zealandia, the East Gondwana accretionary margin was a belt of terranes and stitched by magmatic arcs, later stretched into continental ribbons separated by narrow elongate rifts. This crustal architecture is known from marine geophysical exploration and ocean drilling of the mid-latitude coastal plateaus and rises. A concealed sector of the former East Gondwana margin that underlies the Ross Ice Shelf (RIS), Antarctica, is the focus of ROSETTA-ICE, a new airborne data acquisition campaign that explores the crustal makeup, tectonic boundaries and seafloor bathymetry beneath RIS. Gravimeters and a magnetometer are deployed by LC130 aircraft surveying along E-W lines spaced at 10 km, and N-S tie lines at 55 km, connect 1970s points (RIGGS) for controls on ocean depth and gravity. The ROSETTA-ICE survey, 2/3 completed thus far, provides magnetic anomalies, Werner depth-to-basement solutions, a new gravity-based bathymetric model at 20-km resolution, and a new crustal density map tied to the 1970s data. Surprisingly, the data reveal that the major lithospheric boundary separating East and West Antarctica lies 300 km east of the Transantarctic Mountains, beneath the floating RIS. The East and West regions have contrasting geophysical characteristics and bathymetry, with relatively dense lithosphere, low amplitude magnetic anomalies, and deep bathymetry on the East Antarctica side, and high amplitude magnetic anomalies, lower overall density and shallower water depths on the West Antarctic side. The Central High, a basement structure cored at DSDP Site 270 and seismically imaged in the Ross Sea, continues beneath RIS as a faulted but coherent crustal ribbon coincident with the tectonic boundary. The continuity of Gondwana margin crustal architecture discovered beneath the West Antarctic Ice Sheet requires a revision of the existing tectonic framework. The sub-RIS narrow rift basins and transfer zones, and the crustal boundary that is well-separated from the Transantarctic Mountains front, control the bathymetry, impart the large-scale patterning within and upon the base of the ice sheet, influence oceanographic circulation, and therefore are of import for Ross Ice Shelf stability.

Comparative analysis on flexibility requirements of typical Cryogenic Transfer lines

NASA Astrophysics Data System (ADS)

Jadon, Mohit; Kumar, Uday; Choukekar, Ketan; Shah, Nitin; Sarkar, Biswanath

2017-04-01

The cryogenic systems and their applications; primarily in large Fusion devices, utilize multiple cryogen transfer lines of various sizes and complexities to transfer cryogenic fluids from plant to the various user/ applications. These transfer lines are composed of various critical sections i.e. tee section, elbows, flexible components etc. The mechanical sustainability (under failure circumstances) of these transfer lines are primary requirement for safe operation of the system and applications. The transfer lines need to be designed for multiple design constraints conditions like line layout, support locations and space restrictions. The transfer lines are subjected to single load and multiple load combinations, such as operational loads, seismic loads, leak in insulation vacuum loads etc. [1]. The analytical calculations and flexibility analysis using professional software are performed for the typical transfer lines without any flexible component, the results were analysed for functional and mechanical load conditions. The failure modes were identified along the critical sections. The same transfer line was then refurbished with the flexible components and analysed for failure modes. The flexible components provide additional flexibility to the transfer line system and make it safe. The results obtained from the analytical calculations were compared with those obtained from the flexibility analysis software calculations. The optimization of the flexible component’s size and selection was performed and components were selected to meet the design requirements as per code.

Note: Directly measuring the direct digital synthesizer frequency chirp-rate for an atom interferometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tao, Juan-Juan; Zhou, Min-Kang, E-mail: zkhu@hust.edu.cn, E-mail: zmk@hust.edu.cn; Zhang, Qiao-Zhen

2015-09-15

During gravity measurements with Raman type atom interferometry, the frequency of the laser used to drive Raman transition is scanned by chirping the frequency of a direct digital synthesizer (DDS), and the local gravity is determined by precisely measuring the chip rate α of DDS. We present an effective method that can directly evaluate the frequency chirp rate stability of our DDS. By mixing a pair of synchronous linear sweeping signals, the chirp rate fluctuation is precisely measured with a frequency counter. The measurement result shows that the relative α instability can reach 5.7 × 10{sup −11} in 1 s,more » which is neglectable in a 10{sup −9} g level atom interferometry gravimeter.« less

Processing of Bulk YBa2Cu3O(7-x) High Temperature Superconductor Materials for Gravity Modification Experiments and Performance Under AC Levitation

NASA Technical Reports Server (NTRS)

Koczor, Ronald; Noever, David; Hiser, Robert

1999-01-01

We have previously reported results using a high precision gravimeter to probe local gravity changes in the neighborhood of bulk-processed high temperature superconductor disks. Others have indicated that large annular disks (on the order of 25cm diameter) and AC levitation fields play an essential role in their observed experiments. We report experiments in processing such large bulk superconductors. Successful results depend on material mechanical characteristics, and pressure and heat treat protocols. Annular disks having rough dimensions of 30cm O.D., 7cm I.D. and 1 cm thickness have been routinely fabricated and tested under AC levitation fields ranging from 45 to 300OHz. Implications for space transportation initiatives and power storage flywheel technology will be discussed.

Principal facts for a gravity survey of the Gerlach Extension Known Geothermal Resource Area, Pershing County, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, D.L.; Kaufmann, H.E.

1978-01-01

During July 1977, fifty-one gravity stations were obtained in the Gerlach Extension Known Geothermal Resource Area and vicinity, northwestern Nevada. The gravity observations were made with a Worden gravimeter having a scale factor of about 0.5 milligal per division. No terrain corrections have been applied to these data. The earth tide correction was not used in drift reduction. The Geodetic Reference System 1967 formula (International Association of Geodesy, 1967) was used to compute theoretical gravity. Observed gravity is referenced to a base station in Gerlach, Nevada, having a value based on the Potsdam System of 1930. A density of 2.67more » g per cm/sup 3/ was used in computing the Bouguer anomaly.« less

Principal facts for a gravity survey of the Fly Ranch Extension Known Geothermal Resource Area, Pershing County, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, D.L.; Kaufmann, H.E.

1978-01-01

During July 1977, forty-four gravity stations were obtained in the Fly Ranch Extension Known Geothermal Resource Area and vicinity, northwestern Nevada. The gravity observations were made with a Worden gravimeter having a scale factor of about 0.5 milligal per division. No terrain corrections have been applied to these data. The earth tide correction was not used in drift reduction. The Geodetic Reference System 1967 formula (International Association of Geodesy, 1967) was used to compute theoretical gravity. Observed gravity is referenced to a base station in Gerlach, Nevada, having a value based on the Potsdam System of 1930 (fig. 1). Amore » density of 2.67 g per cm/sup 3/ was used in computing the Bouguer anomaly.« less

Growing barium hexaferrite (BaFe{sub 12}O{sub 19}) thin films using chemical solution deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Budiawanti, Sri, E-mail: awanty77@yahoo.com; Faculty of Teacher Training and Education, Sebelas Maret University; Soegijono, Bambang

Barium hexaferrite (BaFe{sub 12}O{sub 19}, or simply known as BaM) thin films has been recognized as a potential candidate for microwave-based devices, magnetic recording media and data storage. To grow BaM thin films, chemical solution deposition is conducted using the aqueous solution of metal nitrates, which involves spin coatings on Si substrates. Furthermore, Thermal Gravimeter Analysis (TGA), X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM) are applied to evaluate the decomposition behavior, structure, morphology, and magnetic properties of BaM thin films. Additionally, the effects of number of layers variation are also investigated. Finally, magnetic properties analysismore » indicates the isotropic nature of the films.« less

A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Webb, Carol F., E-mail: carol-webb@omrf.org; Immunobiology and Cancer Research, Oklahoma Medical Research Foundation, Oklahoma City, OK; Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK

Despite exciting new possibilities for regenerative therapy posed by the ability to induce pluripotent stem cells, recapitulation of three-dimensional kidneys for repair or replacement has not been possible. ARID3a-deficient mouse tissues generated multipotent, developmentally plastic cells. Therefore, we assessed the adult mouse ARID3a−/− kidney cell line, KKPS5, which expresses renal progenitor surface markers as an alternative cell source for modeling kidney development. Remarkably, these cells spontaneously developed into multicellular nephron-like structures in vitro, and engrafted into immunocompromised medaka mesonephros, where they formed mouse nephron structures. These data implicate KKPS5 cells as a new model system for studying kidney development. - Highlights:more » • An ARID3a-deficient mouse kidney cell line expresses multiple progenitor markers. • This cell line spontaneously forms multiple nephron-like structures in vitro. • This cell line formed mouse kidney structures in immunocompromised medaka fish kidneys. • Our data identify a novel model system for studying kidney development.« less

Temporal sea-surface gravity changes observed near the source area prior to the 2011 Tohoku earthquake

NASA Astrophysics Data System (ADS)

Nakamura, T.; Tsuboi, S.

2013-12-01

Recent seismological studies suggested subsurface activities preceding the 2011 Tohoku earthquake; the occurrence of migration of seismicity (Kato et al., 2012) and slow slip events (Ito et al., 2013) in and around the source area one month before the mainshock. In this study, we investigated sea-surface gravity changes observed by the shipboard gravimeter mounted on research vessels before the mainshock. The vessels incidentally passed through the source area along almost the same cruise track twice, four months before and one month before the mainshock. Comparing the sea surface gravity in the former track with that in the latter after Bouguer correction, we find the gravity changes of approximately 7 mGal in coseismic slip areas near the trench axis during the three months. We find these gravity changes even in the crossing areas of the cruise tracks where seafloor topographies have no differences between the tracks. We also find that the topographic differences show positive changes but the gravity changes negative ones in other areas, which is a negative correlation inconsistent with the theoretical relationship between the topographic difference and the gravity change. These mean that the differences of seafloor topographies due to differences between the two cruise tracks are not main causes of the observed gravity changes there. The changes cannot also be explained by drifts of the gravimeter and geostrophic currents. Although we have not had any clear evidences, we speculate that the possible cause may be density increases around the seismogenic zone or uplifts of seafloor in order to explain the changes of this size. We estimate the density increases of 1.0 g/cm**3 in a disk with a radius of 40 km and a width of 200 m or the uplifts of several tens of meters in seafloor areas for the observed gravity changes. Our results indicate that sea-surface gravity observations may be one of valid approaches to monitor the approximate location of a possible great earthquake in offshore areas.

Determining the Ability of Terrestrial Time-Lapse Microgravity Surveying on a Glacier to Find Summer Mass Balance Using Gravitational Modeling

NASA Astrophysics Data System (ADS)

Young, Emma V.

Mass loss of alpine glaciers presently account for about half of the cryospheric contribution to the global sea-level rise. Mass balance of alpine glaciers has predominantly been monitored by; (1) glaciological and hydrological methods, and (2) satellite gravimetric methods using data from NASA's Gravity Recovery and Climate Experiment (GRACE) satellite mission. However, the former can be logistically costly and have large extrapolation errors: measurements taken at monthly temporal scales are expensive and have a spatial resolution of roughly one kilometer. The latter provides monthly mass-balance estimates of aggregates of alpine glaciers, although the spatial resolution ( 300 km) is far too coarse for assessing individual glaciers' mass balance. Ground-based, time-lapse microgravity measurements can potentially overcome some of the disadvantages of the glaciological, hydrological, and satellite gravitational methods for assessing mass changes and their spatial distribution on a single glacier. Gravity models were utilized to predict the gravity signals of the summer-time mass balance, changes in the seasonal snow cover outside of the glacier, and the vertical gravity gradient (VGG) needed for the free-air correction on Wolverine Glacier, AK. The modeled gravity signal of the summer-time mass balance (average of -0.237 mGal) is more than an order of magnitude larger than the uncertainty of conventional relative gravimeters (+/- 0.007 mGal). Therefore, modeling predict that the time-lapse gravitational method could detect the summer-time mass balance on Wolverine Glacier. The seasonal snow effect was shown to have the greatest influence ( -0.15 mGal) on the outer 100 m boundary of the glacier and minimal effect ( -0.02 mGal) towards the center, both larger than the uncertainty of relative gravimeters. The VGG has a positive deviation, about -0.1 to -0.2 mGal/m, from the normal VGG (-0.309 mGal/m). Thus, seasonal snow effect and VGG need to be correctly accounted for when processing gravity measurements to derive the residual gravity signal of the glacier mass balance. Accurate measurements of elevation changes, seasonal snow depth, and the VGG should be performed in future gravity surveys of glaciers.

The 2017 solar eclipse and Majorana & Allais gravity anomalies

NASA Astrophysics Data System (ADS)

Munera, Hector A.

2017-01-01

Two little known anomalies hint to phenomena beyond current theory. Majorana effect: around 1920 in a series of well-designed experiments with a chemical laboratory balance, Quirino Majorana found in Italy that mercury (Hg) and lead (Pb) might shield terrestrial gravity. Majorana experiments were never repeated by the international scientific community. Instead his results were dismissed on theoretical claims: a) unobserved heating of earth by absorption of gravity, and b) unobserved cyclic lunar perturbation of solar gravity at earth’s surface. However, Majorana critics missed the crucial fact that shielding is not mere absorption, but also scattering, and that atomic number Z of matter in the moon is much lower than Z=80 (Hg) and Z=82 (Pb). From the June 30/1954 solar eclipse onwards, high-quality mechanical gravimeters were used to search for Majorana shielding by the moon. Results are positive, provided that shielding is interpreted as scattering rather than absorption of gravity by moon (H. A. Munera, Physics Essays 24, 428-434, 2011). Allais effect: during the same 1954 eclipse (partial in Paris) Maurice Allais had in operation a sensitive paraconical pendulum for a very different purpose. Surprisingly, the pendulum was perturbed by the eclipse, condition repeated once again in a 1959 solar eclipse, also partial in Paris. During the past sixty years, paraconical, torsion and Foucault pendula, and other mechanical devices, have been used to (dis)confirm Allais effect, but the results are not conclusive thus far. A book edited by this author (Should the laws of gravitation be revised? Apeiron 2011) describes some of those observations. Various unexpected effects, some of them torsional, appear both near the optical shadow, and far away. The Sun-Moon-Earth alignment in a solar eclipse allows detection on the terrestrial surface of the dark matter flow scattered on moon’s surface (flow not hitting earth in other geometries). Rotation of moon may induce torsional effects on scattered dark matter. Scattered gravity may be detected with mechanical gravimeters and torsinds located inside and outside the optical shadow path in USA, Canada and Mexico.

A regional-scale network for geoid monitoring and satellite gravimetry validation

NASA Astrophysics Data System (ADS)

Winester, D.; Pool, D.; Kennedy, J.

2010-12-01

In the past two decades, improved measurements of acceleration due to gravity have allowed for accurate detection of temporal gravity change. Terrestrial absolute gravimeters (for example, Micro-g LaCoste FG5 or A-10) can sense changes of gravity induced by elevation or mass changes, including local effects that may bias regional studies. Satellite instrumentation (e.g. GRACE) can detect large scale mass changes on a regular basis. However, the Nyquist wave number for satellite observations is often much too small for the size of regional studies. Also, satellites are limited by their life of deployment. Both techniques are used to (in)validate change models generated from other geophysical observations including water storage(underground and glacial), geoid definition, isostatic adjustments and tectonic(magmatic and faulting)activity. The gap between terrestrial and satellite gravity observations (and between satellite missions) might be bridged by developing a terrestrial network of sites of various observation techniques that define a representative sample of a given, regional study area. This information could then be statistically extrapolated to the extent of the region. The Southern High Plains Aquifer is such a region, since it has widespread relatively uniform geology, has relatively flat topography, and is well monitored for groundwater levels and soil moisture. Each site would have extensive instrumentation for monitoring, at a minimum, gravity (periodic and continuous) using absolute and tidal gravimeters, soil moisture, precipitation, depths to water in wells, evapotranspiration, air pressure, and land surface (GPS). Where possible, the network would build upon existing, data collection infrastructure. Preferably, the region would also have seismic tomography or crustal seismic reflection observations to characterize Moho-depth mass changes and have regional Bouguer anomaly mapping. In addition to information on local hydrology and geology, data collection would allow for characterization of local seasonal corrections, earth tides, atmospheric loading and episodic slip. No test network has yet been funded, but cost and man-power can be estimated. Such a network would rely on co-operation between various federal, state, local and university groups.

Regeneration of multiple shoots from transgenic potato events facilitates the recovery of phenotypically normal lines: assessing a cry9Aa2 gene conferring insect resistance

PubMed Central

2011-01-01

Background The recovery of high performing transgenic lines in clonal crops is limited by the occurrence of somaclonal variation during the tissue culture phase of transformation. This is usually circumvented by developing large populations of transgenic lines, each derived from the first shoot to regenerate from each transformation event. This study investigates a new strategy of assessing multiple shoots independently regenerated from different transformed cell colonies of potato (Solanum tuberosum L.). Results A modified cry9Aa2 gene, under the transcriptional control of the CaMV 35S promoter, was transformed into four potato cultivars using Agrobacterium-mediated gene transfer using a nptII gene conferring kanamycin resistance as a selectable marker gene. Following gene transfer, 291 transgenic lines were grown in greenhouse experiments to assess somaclonal variation and resistance to potato tuber moth (PTM), Phthorimaea operculella (Zeller). Independently regenerated lines were recovered from many transformed cell colonies and Southern analysis confirmed whether they were derived from the same transformed cell. Multiple lines regenerated from the same transformed cell exhibited a similar response to PTM, but frequently exhibited a markedly different spectrum of somaclonal variation. Conclusions A new strategy for the genetic improvement of clonal crops involves the regeneration and evaluation of multiple shoots from each transformation event to facilitate the recovery of phenotypically normal transgenic lines. Most importantly, regenerated lines exhibiting the phenotypic appearance most similar to the parental cultivar are not necessarily derived from the first shoot regenerated from a transformed cell colony, but can frequently be a later regeneration event. PMID:21995716

Simulations of buoyancy-generated horizontal roll vortices over multiple heating lines

Treesearch

W.E. Heilman

1994-01-01

A two-dimensional nonhydrostatic atmospheric model is used to simulate the boundary-layer circulations that develop from multiple lines of extremely high surface temperatures. Numerical simulations are carried out to investigate the role of buoyancy and ambient crossflow effects in generating horizontal roll vortices in the vicinity of adjacent wildland fire perimeters...

Long interspersed nuclear elements (LINEs) show tissue-specific, mosaic genome and methylation-unrestricted, widespread expression of noncoding RNAs in somatic tissues of the rat

PubMed Central

Singh, Deepak K.; Rath, Pramod C.

2012-01-01

We report strong somatic and germ line expression of LINE RNAs in eight different tissues of rat by using a novel ~2.8 kb genomic PstI-LINE DNA (P1-LINE) isolated from the rat brain. P1-LINE is present in a 93 kb LINE-SINE-cluster in sub-telomeric region of chromosome 12 (12p12) and as multiple truncated copies interspersed in all rat chromosomes. P1-LINEs occur as inverted repeats at multiple genomic loci in tissue-specific and mosaic patterns. P1-LINE RNAs are strongly expressed in brain, liver, lungs, heart, kidney, testes, spleen and thymus into large to small heterogeneous RNAs (~5.0 to 0.2 kb) in tissue-specific and dynamic patterns in individual rats. P1-LINE DNA is strongly methylated at CpG-dinucleotides in most genomic copies in all the tissues and weakly hypomethylated in few copies in some tissues. Small (700–75 nt) P1-LINE RNAs expressed in all tissues may be possible precursors for small regulatory RNAs (PIWI-interacting/piRNAs) bioinformatically derived from P1-LINE. The strong and dynamic expression of LINE RNAs from multiple chromosomal loci and the putative piRNAs in somatic tissues of rat under normal physiological conditions may define functional chromosomal domains marked by LINE RNAs as long noncoding RNAs (lncRNAs) unrestricted by DNA methylation. The tissue-specific, dynamic RNA expression and mosaic genomic distribution of LINEs representing a steady-state genomic flux of retrotransposon RNAs suggest for biological role of LINE RNAs as long ncRNAs and small piRNAs in mammalian tissues independent of their cellular fate for translation, reverse-transcription and retrotransposition. This may provide evolutionary advantages to LINEs and mammalian genomes. PMID:23064113

49 CFR 236.754 - Line, open wire.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Line, open wire. 236.754 Section 236.754 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Line, open wire. An overhead wire line consisting of single conductors as opposed to multiple-conductor...

49 CFR 236.754 - Line, open wire.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Line, open wire. 236.754 Section 236.754 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Line, open wire. An overhead wire line consisting of single conductors as opposed to multiple-conductor...

49 CFR 236.754 - Line, open wire.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Line, open wire. 236.754 Section 236.754 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Line, open wire. An overhead wire line consisting of single conductors as opposed to multiple-conductor...

49 CFR 236.754 - Line, open wire.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Line, open wire. 236.754 Section 236.754 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Line, open wire. An overhead wire line consisting of single conductors as opposed to multiple-conductor...

49 CFR 236.754 - Line, open wire.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Line, open wire. 236.754 Section 236.754 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Line, open wire. An overhead wire line consisting of single conductors as opposed to multiple-conductor...

Integrated QSAR study for inhibitors of hedgehog signal pathway against multiple cell lines:a collaborative filtering method

PubMed Central

2012-01-01

Background The Hedgehog Signaling Pathway is one of signaling pathways that are very important to embryonic development. The participation of inhibitors in the Hedgehog Signal Pathway can control cell growth and death, and searching novel inhibitors to the functioning of the pathway are in a great demand. As the matter of fact, effective inhibitors could provide efficient therapies for a wide range of malignancies, and targeting such pathway in cells represents a promising new paradigm for cell growth and death control. Current research mainly focuses on the syntheses of the inhibitors of cyclopamine derivatives, which bind specifically to the Smo protein, and can be used for cancer therapy. While quantitatively structure-activity relationship (QSAR) studies have been performed for these compounds among different cell lines, none of them have achieved acceptable results in the prediction of activity values of new compounds. In this study, we proposed a novel collaborative QSAR model for inhibitors of the Hedgehog Signaling Pathway by integration the information from multiple cell lines. Such a model is expected to substantially improve the QSAR ability from single cell lines, and provide useful clues in developing clinically effective inhibitors and modifications of parent lead compounds for target on the Hedgehog Signaling Pathway. Results In this study, we have presented: (1) a collaborative QSAR model, which is used to integrate information among multiple cell lines to boost the QSAR results, rather than only a single cell line QSAR modeling. Our experiments have shown that the performance of our model is significantly better than single cell line QSAR methods; and (2) an efficient feature selection strategy under such collaborative environment, which can derive the commonly important features related to the entire given cell lines, while simultaneously showing their specific contributions to a specific cell-line. Based on feature selection results, we have proposed several possible chemical modifications to improve the inhibitor affinity towards multiple targets in the Hedgehog Signaling Pathway. Conclusions Our model with the feature selection strategy presented here is efficient, robust, and flexible, and can be easily extended to model large-scale multiple cell line/QSAR data. The data and scripts for collaborative QSAR modeling are available in the Additional file 1. PMID:22849868

Integrated QSAR study for inhibitors of Hedgehog Signal Pathway against multiple cell lines:a collaborative filtering method.

PubMed

Gao, Jun; Che, Dongsheng; Zheng, Vincent W; Zhu, Ruixin; Liu, Qi

2012-07-31

The Hedgehog Signaling Pathway is one of signaling pathways that are very important to embryonic development. The participation of inhibitors in the Hedgehog Signal Pathway can control cell growth and death, and searching novel inhibitors to the functioning of the pathway are in a great demand. As the matter of fact, effective inhibitors could provide efficient therapies for a wide range of malignancies, and targeting such pathway in cells represents a promising new paradigm for cell growth and death control. Current research mainly focuses on the syntheses of the inhibitors of cyclopamine derivatives, which bind specifically to the Smo protein, and can be used for cancer therapy. While quantitatively structure-activity relationship (QSAR) studies have been performed for these compounds among different cell lines, none of them have achieved acceptable results in the prediction of activity values of new compounds. In this study, we proposed a novel collaborative QSAR model for inhibitors of the Hedgehog Signaling Pathway by integration the information from multiple cell lines. Such a model is expected to substantially improve the QSAR ability from single cell lines, and provide useful clues in developing clinically effective inhibitors and modifications of parent lead compounds for target on the Hedgehog Signaling Pathway. In this study, we have presented: (1) a collaborative QSAR model, which is used to integrate information among multiple cell lines to boost the QSAR results, rather than only a single cell line QSAR modeling. Our experiments have shown that the performance of our model is significantly better than single cell line QSAR methods; and (2) an efficient feature selection strategy under such collaborative environment, which can derive the commonly important features related to the entire given cell lines, while simultaneously showing their specific contributions to a specific cell-line. Based on feature selection results, we have proposed several possible chemical modifications to improve the inhibitor affinity towards multiple targets in the Hedgehog Signaling Pathway. Our model with the feature selection strategy presented here is efficient, robust, and flexible, and can be easily extended to model large-scale multiple cell line/QSAR data. The data and scripts for collaborative QSAR modeling are available in the Additional file 1.

Artificial Neural Network Based Fault Diagnostics of Rotating Machinery Using Wavelet Transforms as a Preprocessor

NASA Astrophysics Data System (ADS)

Paya, B. A.; Esat, I. I.; Badi, M. N. M.

1997-09-01

The purpose of condition monitoring and fault diagnostics are to detect and distinguish faults occurring in machinery, in order to provide a significant improvement in plant economy, reduce operational and maintenance costs and improve the level of safety. The condition of a model drive-line, consisting of various interconnected rotating parts, including an actual vehicle gearbox, two bearing housings, and an electric motor, all connected via flexible couplings and loaded by a disc brake, was investigated. This model drive-line was run in its normal condition, and then single and multiple faults were introduced intentionally to the gearbox, and to the one of the bearing housings. These single and multiple faults studied on the drive-line were typical bearing and gear faults which may develop during normal and continuous operation of this kind of rotating machinery. This paper presents the investigation carried out in order to study both bearing and gear faults introduced first separately as a single fault and then together as multiple faults to the drive-line. The real time domain vibration signals obtained for the drive-line were preprocessed by wavelet transforms for the neural network to perform fault detection and identify the exact kinds of fault occurring in the model drive-line. It is shown that by using multilayer artificial neural networks on the sets of preprocessed data by wavelet transforms, single and multiple faults were successfully detected and classified into distinct groups.

The Aeromagnetic Survey of the North Polar Region in 2009

NASA Astrophysics Data System (ADS)

Matzka, Juergen; Olesen, Arne V.; Rasmussen, Thorkild M.; Forsberg, Rene; Halpenny, John

2010-05-01

As part of its "LOMGRAV 09 Geophysical Survey", DTU Space and National Resources Canada made in spring 2009 a survey of the region between North of Greenland and the North pole. The survey was done using a DC-3 airplane equipped with gravimeter and, in addition, a scalar magnetometer (Geometrics G-283 cesium magnetometer) operating at 10 Hz sampling rate at the tip of a 5 m long tail boom. In total 54.000 profile km at an altitude of 600 m were flown, covering a region of 550.000 km2. The survey area is within the polar cap region, and geomagnetic data from the observatory Qaanaaq (THL) and the variometer station Station Nord (NRD) in Greenland are available for temporal reduction of the aeromagnetic observations. Here we present the survey and a preliminary analysis of the data.

GPS-aided gravimetry at 30 km altitude from a balloon-borne platform

NASA Technical Reports Server (NTRS)

Lazarewicz, Andrew R.; Evans, Alan G.

1989-01-01

A balloon-borne experiment, flown at 30 km altitude over New Mexico, was used to test dynamic differential Global Positioning System (GPS) tracking in support of gravimetry at high-altitudes. The experiment package contained a gravimeter (Vibrating String Accelerometer), a full complement of inertial instruments, a TI-4100 GPS receiver and a radar transponder. The flight was supported by two GPS receivers on the ground near the flight path. From the 8 hour flight, about a forty minute period was selected for analysis. Differential GPS phase measurements were used to estimate changes in position over the sample time interval, or average velocity. In addition to average velocity, differential positions and numerical averages of acceleration were obtained in three components. Gravitational acceleration was estimated by correcting for accelerations due to translational motion, ignoring all rotational effects.

IN SITU AND LABORATORY GEOTECHNICAL TESTS OF THE PIERRE SHALE NEAR HAYES, SOUTH DAKOTA - A CHARACTERIZATION OF ENGINEERING BEHAVIOR.

USGS Publications Warehouse

Nichols, Thomas C.; Collins, Donley S.; Davidson, Richard R.

1986-01-01

A geotechnical investigation of the Pierre Shale near Hayes, South Dakota, was conducted by the U. S. Geological Survey as a basis for evaluating problems in deep excavations into that formation. The physical and mechanical properties of the shale were determined through use of core holes drilled to a maximum depth of 184 m. In situ borehole determinations included a gravimeter survey, pressuremeter testing, thermal profile measurements, and borehole velocity measurements. Onsite and offsite laboratory measurements included rebound measurements, sonic velocity measurements of shear and primary waves, X-ray mineralogy and major element determinations, size analyses, fracture analyses, fabric analyses, and determination of thermal properties. The properties of the clay shale indicate problems that may be encountered in excavation and use of deep underground facilities.

Compact Laser System for Field Deployable Ultracold Atom Sensors

NASA Astrophysics Data System (ADS)

Pino, Juan; Luey, Ben; Anderson, Mike

2013-05-01

As ultracold atom sensors begin to see their way to the field, there is a growing need for small, accurate, and robust laser systems to cool and manipulate atoms for sensing applications such as magnetometers, gravimeters, atomic clocks and inertial sensing. In this poster we present a laser system for Rb, roughly the size of a paperback novel, capable of generating and controlling light sufficient for the most complicated of cold atom sensors. The system includes >100dB of non-mechanical, optical shuttering, the ability to create short, microsecond pulses, a Demux stage to port light onto different optical paths, and an atomically referenced, frequency agile laser source. We will present data to support the system, its Size Weight and Power (SWaP) requirements, as well as laser stability and performance. funded under DARPA

Gravity measurement, processing and evaluation: Test cases de Peel and South Limburg

NASA Astrophysics Data System (ADS)

Nohlmans, Ron

1990-05-01

A general overview of the process of the measurement and the adjustment of a gravity network and the computation of some output parameters of gravimetry, gravity values, gravity anomalies and mean block anomalies, is given. An overview of developments in gravimetry, globally and in the Netherlands, until now is given. The basic theory of relative gravity measurements is studied and a description of the most commonly used instrument, the LaCoste and Romberg gravimeter is given. The surveys done in the scope of this study are descibed. A more detailed impression of the adjustment procedure and the results of the adjustment are given. A closer look is taken at the more geophysical side of gravimetry: gravity reduction, the computation of anomalies and the correlation with elevation. The interpolation of gravity and the covariance of gravity anomalies are addressed.

[Multiplication of Brucella abortus and production of nitric oxide in two macrophage cell lines of different origin].

PubMed

Serafino, J; Conde, S; Zabal, O; Samartino, L

2007-01-01

Brucella abortus is a bacterium which causes abortions and infertility in cattle and undulant fever in humans. It multiplies intracellularly, evading the mechanisms of cellular death. Nitric oxide (NO) is important in the regulation of the immune response. In the present work, we studied the ability of three B. abortus strains to survive intracellularly in two macrophage cell lines. The bacterial multiplication in both cell lines was determined at two different times in UFC/ ml units. Moreover the inoculated cells were also observed under light-field and fluorescence microscopy stained with Giemsa and acridine orange, respectively. The stain of both cellular lines showed similar results with respect to the UFC/ml determination. The presence of B. abortus was confirmed by electronic microscopy. In both macrophage cell lines inoculated with the rough strain RB51, the multiplication diminished and the level of NO was higher, compared with cells inoculated with smooth strains (S19 and 2308). These results suggest that the absence of O-chain of LPS probably affects the intracellular growth of B. abortus.

Multi-line triggering and interdigitated electrode structure for photoconductive semiconductor switches

DOEpatents

Mar, Alan [Albuquerque, NM; Zutavern, Fred J [Albuquerque, NM; Loubriel, Guillermo [Albuquerque, NM

2007-02-06

An improved photoconductive semiconductor switch comprises multiple-line optical triggering of multiple, high-current parallel filaments between the switch electrodes. The switch can also have a multi-gap, interdigitated electrode for the generation of additional parallel filaments. Multi-line triggering can increase the switch lifetime at high currents by increasing the number of current filaments and reducing the current density at the contact electrodes in a controlled manner. Furthermore, the improved switch can mitigate the degradation of switching conditions with increased number of firings of the switch.

48 CFR 32.604 - Demand for payment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... distribution of the principal amount of the debt by line(s) of accounting subject to the following: (i) If the debt affects multiple lines of accounting, the contracting officer shall, to the maximum extent practicable, identify all affected lines of accounting. If it is not practicable to identify all affected...

The electric field change caused by a ground flash with multiple channels

NASA Technical Reports Server (NTRS)

Nakano, Minoru; Takagi, Nobuyuki; Arima, Izumi; Kawasaki, Zen-Ichiro; Takeuti, Tosio

1991-01-01

The electric field and the magnetic flux changes caused by a ground flash with multiple channels are measured near the electric power transmission lines during winter thunderstorms. Triggered lightning strokes and the following associated strokes to the transmission line towers produce characteristic waveforms of the field changes. A few examples of the waveforms and a brief discussion are given.

Comprehensive analysis of line-edge and line-width roughness for EUV lithography

NASA Astrophysics Data System (ADS)

Bonam, Ravi; Liu, Chi-Chun; Breton, Mary; Sieg, Stuart; Seshadri, Indira; Saulnier, Nicole; Shearer, Jeffrey; Muthinti, Raja; Patlolla, Raghuveer; Huang, Huai

2017-03-01

Pattern transfer fidelity is always a major challenge for any lithography process and needs continuous improvement. Lithographic processes in semiconductor industry are primarily driven by optical imaging on photosensitive polymeric material (resists). Quality of pattern transfer can be assessed by quantifying multiple parameters such as, feature size uniformity (CD), placement, roughness, sidewall angles etc. Roughness in features primarily corresponds to variation of line edge or line width and has gained considerable significance, particularly due to shrinking feature sizes and variations of features in the same order. This has caused downstream processes (Etch (RIE), Chemical Mechanical Polish (CMP) etc.) to reconsider respective tolerance levels. A very important aspect of this work is relevance of roughness metrology from pattern formation at resist to subsequent processes, particularly electrical validity. A major drawback of current LER/LWR metric (sigma) is its lack of relevance across multiple downstream processes which effects material selection at various unit processes. In this work we present a comprehensive assessment of Line Edge and Line Width Roughness at multiple lithographic transfer processes. To simulate effect of roughness a pattern was designed with periodic jogs on the edges of lines with varying amplitudes and frequencies. There are numerous methodologies proposed to analyze roughness and in this work we apply them to programmed roughness structures to assess each technique's sensitivity. This work also aims to identify a relevant methodology to quantify roughness with relevance across downstream processes.

Sensor And Method For Detecting A Superstrate

NASA Technical Reports Server (NTRS)

Arndt, G. Dickey (Inventor); Cari, James R. (Inventor); Ngo, Phong H. (Inventor); Fink, Patrick W. (Inventor); Siekierski, James D. (Inventor)

2006-01-01

Method and apparatus are provided for determining a superstrate on or near a sensor, e.g., for detecting the presence of an ice superstrate on an airplane wing or a road. In one preferred embodiment, multiple measurement cells are disposed along a transmission line. While the present invention is operable with different types of transmission lines, construction details for a presently preferred coplanar waveguide and a microstrip waveguide are disclosed. A computer simulation is provided as part of the invention for predicting results of a simulated superstrate detector system. The measurement cells may be physically partitioned, nonphysically partitioned with software or firmware, or include a combination of different types of partitions. In one embodiment, a plurality of transmission lines are utilized wherein each transmission line includes a plurality of measurement cells. The plurality of transmission lines may be multiplexed with the signal from each transmission line being applied to the same phase detector. In one embodiment, an inverse problem method is applied to determine the superstrate dielectric for a transmission line with multiple measurement cells.

Dynamic electrical impedance imaging with the interacting multiple model scheme.

PubMed

Kim, Kyung Youn; Kim, Bong Seok; Kim, Min Chan; Kim, Sin; Isaacson, David; Newell, Jonathan C

2005-04-01

In this paper, an effective dynamical EIT imaging scheme is presented for on-line monitoring of the abruptly changing resistivity distribution inside the object, based on the interacting multiple model (IMM) algorithm. The inverse problem is treated as a stochastic nonlinear state estimation problem with the time-varying resistivity (state) being estimated on-line with the aid of the IMM algorithm. In the design of the IMM algorithm multiple models with different process noise covariance are incorporated to reduce the modeling uncertainty. Simulations and phantom experiments are provided to illustrate the proposed algorithm.

Analysis of Brassica oleracea early stage abiotic stress responses reveals tolerance in multiple crop types and for multiple sources of stress.

PubMed

Beacham, Andrew M; Hand, Paul; Pink, David Ac; Monaghan, James M

2017-12-01

Brassica oleracea includes a number of important crop types such as cabbage, cauliflower, broccoli and kale. Current climate conditions and weather patterns are causing significant losses in these crops, meaning that new cultivars with improved tolerance of one or more abiotic stress types must be sought. In this study, genetically fixed B. oleracea lines belonging to a Diversity Fixed Foundation Set (DFFS) were assayed for their response to seedling stage-imposed drought, flood, salinity, heat and cold stress. Significant (P ≤ 0.05) variation in stress tolerance response was found for each stress, for each of four measured variables (relative fresh weight, relative dry weight, relative leaf number and relative plant height). Lines tolerant to multiple stresses were found to belong to several different crop types. There was no overall correlation between the responses to the different stresses. Abiotic stress tolerance was identified in multiple B. oleracea crop types, with some lines exhibiting resistance to multiple stresses. For each stress, no one crop type appeared significantly more or less tolerant than others. The results are promising for the development of more environmentally robust lines of different B. oleracea crops by identifying tolerant material and highlighting the relationship between responses to different stresses. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Stochastic nature of Landsat MSS data

NASA Technical Reports Server (NTRS)

Labovitz, M. L.; Masuoka, E. J.

1987-01-01

A multiple series generalization of the ARIMA models is used to model Landsat MSS scan lines as sequences of vectors, each vector having four elements (bands). The purpose of this work is to investigate if Landsat scan lines can be described by a general multiple series linear stochastic model and if the coefficients of such a model vary as a function of satellite system and target attributes. To accomplish this objective, an exploratory experimental design was set up incorporating six factors, four representing target attributes - location, cloud cover, row (within location), and column (within location) - and two factors representing system attributes - satellite number and detector bank. Each factor was included in the design at two levels and, with two replicates per treatment, 128 scan lines were analyzed. The results of the analysis suggests that a multiple AR(4) model is an adequate representation across all scan lines. Furthermore, the coefficients of the AR(4) model vary with location, particularly changes in physiography (slope regimes), and with percent cloud cover, but are insensitive to changes in system attributes.

High resolution crustal image of South California Continental Borderland: Reverse time imaging including multiples

NASA Astrophysics Data System (ADS)

Bian, A.; Gantela, C.

2014-12-01

Strong multiples were observed in marine seismic data of Los Angeles Regional Seismic Experiment (LARSE).It is crucial to eliminate these multiples in conventional ray-based or one-way wave-equation based depth image methods. As long as multiples contain information of target zone along travelling path, it's possible to use them as signal, to improve the illumination coverage thus enhance the image quality of structural boundaries. Reverse time migration including multiples is a two-way wave-equation based prestack depth image method that uses both primaries and multiples to map structural boundaries. Several factors, including source wavelet, velocity model, back ground noise, data acquisition geometry and preprocessing workflow may influence the quality of image. The source wavelet is estimated from direct arrival of marine seismic data. Migration velocity model is derived from integrated model building workflow, and the sharp velocity interfaces near sea bottom needs to be preserved in order to generate multiples in the forward and backward propagation steps. The strong amplitude, low frequency marine back ground noise needs to be removed before the final imaging process. High resolution reverse time image sections of LARSE Lines 1 and Line 2 show five interfaces: depth of sea-bottom, base of sedimentary basins, top of Catalina Schist, a deep layer and a possible pluton boundary. Catalina Schist shows highs in the San Clemente ridge, Emery Knoll, Catalina Ridge, under Catalina Basin on both the lines, and a minor high under Avalon Knoll. The high of anticlinal fold in Line 1 is under the north edge of Emery Knoll and under the San Clemente fault zone. An area devoid of any reflection features are interpreted as sides of an igneous plume.

ACHP | News | ACHP Issue Spotlight: Transmission Lines in the West

Science.gov Websites

effects. Some historic properties are affected by several of these lines, and some lines have multiple parts of Idaho and Montana. There are potential effects to a number of important historic properties impact, visual effects of this transmission line, will be approximated through "backsighted analysis

CO J = 2-1 LINE EMISSION IN CLUSTER GALAXIES AT z {approx} 1: FUELING STAR FORMATION IN DENSE ENVIRONMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wagg, Jeff; Pope, Alexandra; Alberts, Stacey

We present observations of CO J = 2-1 line emission in infrared-luminous cluster galaxies at z {approx} 1 using the IRAM Plateau de Bure Interferometer. Our two primary targets are optically faint, dust-obscured galaxies (DOGs) found to lie within 2 Mpc of the centers of two massive (>10{sup 14} M{sub Sun }) galaxy clusters. CO line emission is not detected in either DOG. We calculate 3{sigma} upper limits to the CO J = 2-1 line luminosities, L'{sub CO} < 6.08 Multiplication-Sign 10{sup 9} and <6.63 Multiplication-Sign 10{sup 9} K km s{sup -1} pc{sup 2}. Assuming a CO-to-H{sub 2} conversion factormore » derived for ultraluminous infrared galaxies in the local universe, this translates to limits on the cold molecular gas mass of M{sub H{sub 2}}< 4.86 Multiplication-Sign 10{sup 9} M{sub Sun} and M{sub H{sub 2}}< 5.30 Multiplication-Sign 10{sup 9} M{sub Sun }. Both DOGs exhibit mid-infrared continuum emission that follows a power law, suggesting that an active galactic nucleus (AGN) contributes to the dust heating. As such, estimates of the star formation efficiencies in these DOGs are uncertain. A third cluster member with an infrared luminosity, L{sub IR} < 7.4 Multiplication-Sign 10{sup 11} L{sub Sun }, is serendipitously detected in CO J = 2-1 line emission in the field of one of the DOGs located roughly two virial radii away from the cluster center. The optical spectrum of this object suggests that it is likely an obscured AGN, and the measured CO line luminosity is L'{sub CO} = (1.94 {+-} 0.35) Multiplication-Sign 10{sup 10} K km s{sup -1} pc{sup 2}, which leads to an estimated cold molecular gas mass M{sub H{sub 2}}= (1.55{+-}0.28) Multiplication-Sign 10{sup 10} M{sub Sun }. A significant reservoir of molecular gas in a z {approx} 1 galaxy located away from the cluster center demonstrates that the fuel can exist to drive an increase in star formation and AGN activity at the outskirts of high-redshift clusters.« less

Study of Double-Weighted Graph Model and Optimal Path Planning for Tourist Scenic Area Oriented Intelligent Tour Guide

NASA Astrophysics Data System (ADS)

Shi, Y.; Long, Y.; Wi, X. L.

2014-04-01

When tourists visiting multiple tourist scenic spots, the travel line is usually the most effective road network according to the actual tour process, and maybe the travel line is different from planned travel line. For in the field of navigation, a proposed travel line is normally generated automatically by path planning algorithm, considering the scenic spots' positions and road networks. But when a scenic spot have a certain area and have multiple entrances or exits, the traditional described mechanism of single point coordinates is difficult to reflect these own structural features. In order to solve this problem, this paper focuses on the influence on the process of path planning caused by scenic spots' own structural features such as multiple entrances or exits, and then proposes a doubleweighted Graph Model, for the weight of both vertexes and edges of proposed Model can be selected dynamically. And then discusses the model building method, and the optimal path planning algorithm based on Dijkstra algorithm and Prim algorithm. Experimental results show that the optimal planned travel line derived from the proposed model and algorithm is more reasonable, and the travelling order and distance would be further optimized.

Production of Multiple Growth Factors by a Newly Established Human Thyroid Carcinoma Cell Line

PubMed Central

Yoshida, Yataro; Ohashi, Kensaku; Sano, Emiko; Kobayashi, Hisataka; Endo, Keigo; Naruto, Masanobu; Nakamura, Toru

1992-01-01

A multiple growth factor‐producing tumor cell line (NIM‐1) was newly established from a patient with thyroid cancer and remarkable neutrophilia. NIM‐1 cells also caused severe neutrophilia in nude mice bearing tumors. NIM‐1‐conditioned medium (NIM‐1CM) contained activities that supported not only granulocyte, macrophage and eosinophil colony formation of human bone marrow cells but also the growth of colony‐stimulating factor (CSF)‐dependent cell lines, NFS60‐KX and TF‐1. Northern blot hybridization analysis revealed the constitutive expression of granulocyte‐CSF (G‐CSF), granulocyte/macrophage‐CSF (GM‐CSF) and interleukin(IL)‐6 mRNAs in NIM‐1 cells. Enzyme‐linked immunosorbent assays (ELISA) using NIM‐1CM also confirmed the production of IL‐la and a small amount of IL‐1β besides G‐CSF, GM‐CSF and IL‐6 in NIM‐1 cells. In addition, unexpected production of IL‐11 in NIM‐1 cells was detected by northern blot hybridization analysis and by bioassay using an IL‐11‐dependent cell line. Therefore, NIM‐1 cell line is shown to produce multiple cytokines including potentially megakaryopoietic growth factors such as GM‐CSF, IL‐6 and IL‐11. PMID:1372885

[The results of a randomized open multicenter comparative study on the tolerability and safety of gilenya (fingolimod) in patients with remitting multiple sclerosis].

PubMed

Popova, E V; Boyko, A N; Boyko, O V

2015-01-01

At the present time, disease modifying drugs (DMD) for treatment of patients with multiple sclerosis are used to reduce the risk of exacerbations and, consequently, slowing the progression of disability in accordance to treatment standards. However, the application of the first line of this therapy is not always successful. In these situations, patients receive second-line DMD. Fingolimod is one of the second-line drugs in Russia. To gain experience in using fingolimod in routine neurological practice, we have conducted a post-marketing research - GIMN.

Generation of six multiple sclerosis patient-derived induced pluripotent stem cell lines.

PubMed

Miquel-Serra, L; Duarri, A; Muñoz, Y; Kuebler, B; Aran, B; Costa, C; Martí, M; Comabella, M; Malhotra, S; Montalban, X; Veiga, A; Raya, A

2017-10-01

Multiple sclerosis (MS) is considered a chronic autoimmune disease of the central nervous system that leads to gliosis, demyelination, axonal damage and neuronal death. The MS disease aetiology is unknown, though a polymorphism of the TNFRSF1A gene, rs1800693, is known to confer an increased risk for MS. Using retroviral delivery of reprogramming transgenes, we generated six MS patient-specific iPSC lines with two distinct genotypes, CC or TT, of the polymorphism rs1800693. iPSC lines had normal karyotype, expressed pluripotency genes and differentiated into the three germ layers. These lines offer a good tool to study MS pathomechanisms and for drug testing. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Multiple point mutations in a shuttle vector propagated in human cells: evidence for an error-prone DNA polymerase activity.

PubMed

Seidman, M M; Bredberg, A; Seetharam, S; Kraemer, K H

1987-07-01

Mutagenesis was studied at the DNA-sequence level in human fibroblast and lymphoid cells by use of a shuttle vector plasmid, pZ189, containing a suppressor tRNA marker gene. In a series of experiments, 62 plasmids were recovered that had two to six base substitutions in the 160-base-pair marker gene. Approximately 20-30% of the mutant plasmids that were recovered after passing ultraviolet-treated pZ189 through a repair-proficient human fibroblast line contained these multiple mutations. In contrast, passage of ultraviolet-treated pZ189 through an excision-repair-deficient (xeroderma pigmentosum) line yielded only 2% multiple base substitution mutants. Introducing a single-strand nick in otherwise unmodified pZ189 adjacent to the marker, followed by passage through the xeroderma pigmentosum cells, resulted in about 66% multiple base substitution mutants. The multiple mutations were found in a 160-base-pair region containing the marker gene but were rarely found in an adjacent 170-base-pair region. Passing ultraviolet-treated or nicked pZ189 through a repair-proficient human B-cell line also yielded multiple base substitution mutations in 20-33% of the mutant plasmids. An explanation for these multiple mutations is that they were generated by an error-prone polymerase while filling gaps. These mutations share many of the properties displayed by mutations in the immunoglobulin hypervariable regions.

Method of analyzing multiple sample simultaneously by detecting absorption and systems for use in such a method

DOEpatents

Yeung, Edward S.; Gong, Xiaoyi

2004-09-07

The present invention provides a method of analyzing multiple samples simultaneously by absorption detection. The method comprises: (i) providing a planar array of multiple containers, each of which contains a sample comprising at least one absorbing species, (ii) irradiating the planar array of multiple containers with a light source and (iii) detecting absorption of light with a detetion means that is in line with the light source at a distance of at leaat about 10 times a cross-sectional distance of a container in the planar array of multiple containers. The absorption of light by a sample indicates the presence of an absorbing species in it. The method can further comprise: (iv) measuring the amount of absorption of light detected in (iii) indicating the amount of the absorbing species in the sample. Also provided by the present invention is a system for use in the abov metho.The system comprises; (i) a light source comrnpising or consisting essentially of at leaat one wavelength of light, the absorption of which is to be detected, (ii) a planar array of multiple containers, and (iii) a detection means that is in line with the light source and is positioned in line with and parallel to the planar array of multiple contiainers at a distance of at least about 10 times a cross-sectional distance of a container.

Precise Orbit Determination for LEO Spacecraft Using GNSS Tracking Data from Multiple Antennas

NASA Technical Reports Server (NTRS)

Kuang, Da; Bertiger, William; Desai, Shailen; Haines, Bruce

2010-01-01

To support various applications, certain Earth-orbiting spacecrafts (e.g., SRTM, COSMIC) use multiple GNSS antennas to provide tracking data for precise orbit determination (POD). POD using GNSS tracking data from multiple antennas poses some special technical issues compared to the typical single-antenna approach. In this paper, we investigate some of these issues using both real and simulated data. Recommendations are provided for POD with multiple GNSS antennas and for antenna configuration design. The observability of satellite position with multiple antennas data is compared against single antenna case. The impact of differential clock (line biases) and line-of-sight (up, along-track, and cross-track) on kinematic and reduced-dynamic POD is evaluated. The accuracy of monitoring the stability of the spacecraft structure by simultaneously performing POD of the spacecraft and relative positioning of the multiple antennas is also investigated.

Absolute gravimetry for monitoring geodynamics in Greenland.

NASA Astrophysics Data System (ADS)

Nielsen, E.; Strykowski, G.; Forsberg, R.

2015-12-01

Here are presented the preliminary results of the absolute gravity measurements done in Greenland by DTU Space with their A10 absolute gravimeter (the A10-019). The purpose, besides establishing and maintaining a national gravity network, is to study geodynamics.The absolute gravity measurements are juxtaposed with the permanent GNET GNSS stations. The first measurements were conducted in 2009 and a few sites have been re-visited. As of present is there a gravity value at 18 GNET sites.There are challenges in interpreting the measurements from Greenland and several signals has to be taken into account, besides the geodynamical signals originating from the changing load of the ice, there is also a clear signal of direct attraction from different masses. Here are presented the preliminary results of our measurements in Greenland and attempts explain them through modelling of the geodynamical signals and the direct attraction from the ocean and ice.

Observations with FG5 and A10 absolute gravimeters on Ross Island and in Terra Nova Bay in November-December 2011

NASA Astrophysics Data System (ADS)

Rogister, Yves; Hothem, Larry; Nielsen, J. Emil; Bernard, Jean-Daniel; Hinderer, Jacques; Forsberg, René; Wilson, Terry; Capra, Alessandro; Zanutta, Antonio; Winefield, Rachelle; Collett, Dave

2013-04-01

A campaign of absolute gravity (AG) measurements was conducted with both FG5 and A10 meters on Ross Island and in Terra Nova Bay in November and December 2011. It resulted from a collaboration between Danish, French, Italian, New Zealand and US agencies and institutes, under the POLENET program. For the second time in 2 years, AG was measured at McMurdo Station and Scott Base. For the fifth time in 21 years, it was measured at Mario Zucchelli Station. Moreover, AG field observations were initiated at various GPS stations of the A-NET network. We will report on the very last campaign, show the gravity trends at McMurdo Station, Scott Base and Mario Zucchelli Station, and describe how they compare to estimates of the gravity variation derived from space measurements by the GRACE twin satellites.

Tidal Amplitude Delta Factors and Phase Shifts for an Oceanic Earth

NASA Astrophysics Data System (ADS)

Spiridonov, E. A.

2017-12-01

M.S. Molodenskiy's problem, which describes the state of an elastic self-gravitating compressible sphere, is generalized to the case of a biaxial hydrostatically equilibrium rotating elliptical inelastic shell. The system of sixth-order equations is supplemented with corrections due to the relative and Coriolis accelerations. The ordinary and load Love numbers of degree 2 are calculated with allowance for their latitude dependence and dissipation for different models of the Earth's structure (the AK135, IASP91, and PREM models). The problem is solved by Love's method. The theoretical amplitude delta factors and phase shifts of second-order tidal waves for an oceanic Earth are compared with their most recent empirical counterparts obtained by the GGP network superconducting gravimeters. In particular, it is shown that a good matching (up to the fourth decimal place) of the theoretical and observed amplitude factors of semidiurnal tides does not require the application of the nonhydrostatic theory.

Assessing the likely value of gravity and drawdown measurements to constrain estimates of hydraulic conductivity and specific yield during unconfined aquifer testing

USGS Publications Warehouse

Blainey, Joan B.; Ferré, Ty P.A.; Cordova, Jeffrey T.

2007-01-01

Pumping of an unconfined aquifer can cause local desaturation detectable with high‐resolution gravimetry. A previous study showed that signal‐to‐noise ratios could be predicted for gravity measurements based on a hydrologic model. We show that although changes should be detectable with gravimeters, estimations of hydraulic conductivity and specific yield based on gravity data alone are likely to be unacceptably inaccurate and imprecise. In contrast, a transect of low‐quality drawdown data alone resulted in accurate estimates of hydraulic conductivity and inaccurate and imprecise estimates of specific yield. Combined use of drawdown and gravity data, or use of high‐quality drawdown data alone, resulted in unbiased and precise estimates of both parameters. This study is an example of the value of a staged assessment regarding the likely significance of a new measurement method or monitoring scenario before collecting field data.

Development of a network RTK positioning and gravity-surveying application with gravity correction using a smartphone.

PubMed

Kim, Jinsoo; Lee, Youngcheol; Cha, Sungyeoul; Choi, Chuluong; Lee, Seongkyu

2013-07-12

This paper proposes a smartphone-based network real-time kinematic (RTK) positioning and gravity-surveying application (app) that allows semi-real-time measurements using the built-in Bluetooth features of the smartphone and a third-generation or long-term evolution wireless device. The app was implemented on a single smartphone by integrating a global navigation satellite system (GNSS) controller, a laptop, and a field-note writing tool. The observation devices (i.e., a GNSS receiver and relative gravimeter) functioned independently of this system. The app included a gravity module, which converted the measured relative gravity reading into an absolute gravity value according to tides; meter height; instrument drift correction; and network adjustments. The semi-real-time features of this app allowed data to be shared easily with other researchers. Moreover, the proposed smartphone-based gravity-survey app was easily adaptable to various locations and rough terrain due to its compact size.

On-line Differential Thermal Isotope Analysis: A New Method for Measuring Oxygen and Hydrogen Isotopes of Hydration Water in Minerals

NASA Astrophysics Data System (ADS)

Bauska, T.; Hodell, D. A.; Walters, G.

2016-12-01

Oxygen (16O,17O,18O) and hydrogen (H,D) isotopes of hydration water in minerals provide a rich source of information about the conditions under which hydrated minerals form on Earth and other planetary bodies (e.g. Mars). We have developed a new method for measuring different types of bonded water (e.g., molecular, hydroxyl) contained in hydrated minerals by coupling a thermal gravimeter (TG) and a cavity ringdown laser spectrometer (CRDS). The method involves step heating a mineral sample, precisely measuring the weight loss and enthalpy as the sample undergoes dehydration and dehydroxylation, whilst simultaneously determining the oxygen and hydrogen isotopes of the water vapor evolved from the mineral sample by cavity ring-down laser spectroscopy (CRDS). Nitrogen carrier gas is used to transfer the sample from the TG to the CRDS via a heated line and interface box. The interface includes the capability of (i) cryogenic trapping discrete types of water for samples containing small amounts of water; (ii) injecting small quantities of water of known isotopic value for calibration; and (iii) converting volatile organic compounds to nascent amounts of water using a catalyst. The CRDS continually measures water vapor concentration in the optical cavity and hydrogen and oxygen isotope ratios. Isotopic values are calculated by integrating the product of the water amount and its isotopic value for the separated peaks after correcting for background. Precision of the method was estimated by comparing isotope results of total water for gypsum measured by DTIA with our conventional method of extraction and analysis (Gázquez et al., 2015. Rapid Communications in Mass Spectrometry, 29, 1997-2006). Errors for the isotopic values of total hydration water vary between ±0.08 and ±0.34 ‰ for δ18O and between ±0.16 and ±0.86 ‰ for δD. We demonstrate the application of the DTIA method to a variety of hydrous minerals and mineraloids including gypsum, clays, and amorphous silica (opal, glass, chert). The DTIA method has wide ranging application for addressing fundamental problems across many disciplines in Earth and Planetary Sciences, including: paleoclimatology, sedimentology, volcanology, water exchange between the solid earth and hydrosphere, and water on Mars and other planetary bodies.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ochiai, Yoshihiro

Heat-conduction analysis under steady state without heat generation can easily be treated by the boundary element method. However, in the case with heat conduction with heat generation can approximately be solved without a domain integral by an improved multiple-reciprocity boundary element method. The convention multiple-reciprocity boundary element method is not suitable for complicated heat generation. In the improved multiple-reciprocity boundary element method, on the other hand, the domain integral in each step is divided into point, line, and area integrals. In order to solve the problem, the contour lines of heat generation, which approximate the actual heat generation, are used.

Real-time multiple-look synthetic aperture radar processor for spacecraft applications

NASA Technical Reports Server (NTRS)

Wu, C.; Tyree, V. C. (Inventor)

1981-01-01

A spaceborne synthetic aperture radar (SAR) having pipeline multiple-look data processing is described which makes use of excessive azimuth bandwidth in radar echo signals to produce multiple-looking images. Time multiplexed single-look image lines from an azimuth correlator go through an energy analyzer which analyzes the mean energy in each separate look to determine the radar antenna electric boresight for use in generating the correct reference functions for the production of high quality SAR images. The multiplexed single look image lines also go through a registration delay to produce multi-look images.

[Lentivirus-mediated shRNA silencing of LAMP2A inhibits the proliferation of multiple myeloma cells].

PubMed

Li, Lixuan; Li, Jia

2015-05-01

To study the effects of lentivirus-mediated short hairpin RNA (shRNA) silencing of lysosome-associated membrane protein type 2A (LAMP2A) expression on the proliferation of multiple myeloma cells. The constructed shRNA lentiviral vector was applied to infect human multiple myeloma cell line MM.1S, and stable expression cell line was obtained by puromycin screening. Western blotting was used to verify the inhibitory effect on LAMP2A protein expression. MTT assay was conducted to detect the effect of knocked-down LAMP2A on MM.1S cell proliferation, and the anti-tumor potency of suberoylanilide hydroxamic acid (SAHA) against the obtained MM.1S LAMP2A(shRNA) stable cell line. Lactate assay was performed to observe the impact of low LAMP2A expression on cell glycolysis. The stable cell line with low LAMP2A expression were obtained with the constructed human LAMP2A-shRNA lentiviral vector. Down-regulation of LAMP2A expression significantly inhibited MM.1S cell proliferation and enhanced the anti-tumor activity of SAHA. Interestingly, decreased LAMP2A expression also inhibited MM.1S cell lactic acid secretion. Down-regulation of LAMP2A expression could inhibit cell proliferation in multiple myeloma cells.

Summary from Working Group on Multiple Beams and Funneling

NASA Technical Reports Server (NTRS)

Wangler, T. P.

1985-01-01

The working group on Multiple Beams and Funneling discussed various topics related to multiple beams and funneling, including (1) design considerations for multiple-beam accelerators; (2) scaling of current, emittance, and brightness for multiple-beam systems; (3) funneling lines using either discrete components or a radiofrequency quadrupole (RFQ) funneling structure; and (4) alternatives to funneling.

Single transmission line interrogated multiple channel data acquisition system

DOEpatents

Fasching, George E.; Keech, Jr., Thomas W.

1980-01-01

A single transmission line interrogated multiple channel data acquisition system is provided in which a plurality of remote station/sensor circuits each monitors a specific process variable and each transmits measurement values over a single transmission line to a master interrogating station when addressed by said master interrogating station. Typically, as many as 330 remote stations may be parallel connected to the transmission line which may exceed 7,000 feet. The interrogation rate is typically 330 stations/second. The master interrogating station samples each station according to a shared, charging transmit-receive cycle. All remote station address signals, all data signals from the remote stations/sensors and all power for all of the remote station/sensors are transmitted via a single continuous terminated coaxial cable. A means is provided for periodically and remotely calibrating all remote sensors for zero and span. A provision is available to remotely disconnect any selected sensor station from the main transmission line.

High peak current operation of x-ray free-electron laser multiple beam lines by suppressing coherent synchrotron radiation effects

NASA Astrophysics Data System (ADS)

Hara, Toru; Kondo, Chikara; Inagaki, Takahiro; Togawa, Kazuaki; Fukami, Kenji; Nakazawa, Shingo; Hasegawa, Taichi; Morimoto, Osamu; Yoshioka, Masamichi; Maesaka, Hirokazu; Otake, Yuji; Tanaka, Hitoshi

2018-04-01

The parallel operation of multiple beam lines is an important means to expand the opportunity of user experiments at x-ray free-electron laser (XFEL) facilities. At SPring-8 Angstrom free-electron laser (SACLA), the multi-beam-line operation had been tested using two beam lines, but transverse coherent synchrotron radiation (CSR) effects at a dogleg beam transport severely limited the laser performance. To suppress the CSR effects, a new beam optics based on two double bend achromat (DBA) structures was introduced for the dogleg. After the replacement of the beam optics, high peak current bunches of more than 10 kA are now stably transported through the dogleg and the laser pulse output is increased by a factor of 2-3. In the multi-beam-line operation of SACLA, the electron beam parameters, such as the beam energy and peak current, can be adjusted independently for each beam line. Thus the laser output can be optimized and wide spectral tunability is ensured for all beam lines.

Fire Hose Instability in the Multiple Magnetic Reconnection

NASA Astrophysics Data System (ADS)

Alexandrova, A.; Retino, A.; Divin, A. V.; Le Contel, O.; Matteini, L.; Breuillard, H.; Deca, J.; Catapano, F.; Cozzani, G.; Nakamura, R.; Panov, E. V.; Voros, Z.

2017-12-01

We present observations of multiple reconnection in the Earth's magnetotail. In particular, we observe an ion temperature anisotropy characterized by large temperature along the magnetic field, between the two active X-lines. The anisotropy is associated with right-hand polarized waves at frequencies lower than the ion cyclotron frequency and propagating obliquely to the background magnetic field. We show that the observed anisotropy and the wave properties are consistent with linear kinetic theory of fire hose instability. The observations are in agreement with the particle-in-cell simulations of multiple reconnection. The results suggest that the fire hose instability can develop during multiple reconnection as a consequence of the ion parallel anisotropy that is produced by counter-streaming ions trapped between the X-lines.

Technology Management within Product Lines in High Technology Markets

ERIC Educational Resources Information Center

Sarangee, Kumar R.

2009-01-01

Understanding the nuances of product line management has been of great interest to business scholars and practitioners. This assumes greater significance for firms conducting business in technologically dynamic industries, where they face certain challenges regarding the management of multiple, overlapping technologies within their product lines.…

Patterns of relapse and outcome of elderly multiple myeloma patients treated as front-line therapy with novel agents combinations☆

PubMed Central

Lopez, Aurelio; Mateos, Maria-Victoria; Oriol, Albert; Valero, Marta; Martínez, Joaquín; Lorenzo, Jose Ignacio; Perez, Montserrat; Martinez, Rafael; de Paz, Raquel; Granell, Miguel; De Arriba, Felipe; Blanchard, M. Jesús; Peñalver, Francisco Javier; Bello, Jose Luis; Martin, Maria Luisa; Bargay, Joan; Blade, Joan; Lahuerta, Juan Jose; San Miguel, Jesús F.; de la Rubia, Javier

2015-01-01

We report the characteristics of relapse, treatment response, and outcomes of 145 elderly patients with multiple myeloma in first relapse after front-line treatment with VMP or VTP. Reappearance of CRAB symptoms (113 patients) and more aggressive forms of disease (32 patients) were the most common patterns of relapse. After second-line therapy, 75 (51.7%) patients achieved at partial response and 16 (11%) complete response (CR). Overall survival was longer among patients receiving VMP as front-line induction (21.4 vs. 14.4 months, P=0.037), in patients achieving CR (28.3 vs. 14.8 months; P=0.04), and in patients without aggressive relapse (28.6 vs. 7.6 months; P=0.0007). PMID:26500850

Genetic Algorithm for Multiple Bus Line Coordination on Urban Arterial

PubMed Central

Yang, Zhen; Wang, Wei; Chen, Shuyan; Ding, Haoyang; Li, Xiaowei

2015-01-01

Bus travel time on road section is defined and analyzed with the effect of multiple bus lines. An analytical model is formulated to calculate the total red time a bus encounters when travelling along the arterial. Genetic algorithm is used to optimize the offset scheme of traffic signals to minimize the total red time that all bus lines encounter in two directions of the arterial. The model and algorithm are applied to the major part of Zhongshan North Street in the city of Nanjing. The results show that the methods in this paper can reduce total red time of all the bus lines by 31.9% on the object arterial and thus improve the traffic efficiency of the whole arterial and promote public transport priority. PMID:25663837

Scheduling optimization of design stream line for production research and development projects

NASA Astrophysics Data System (ADS)

Liu, Qinming; Geng, Xiuli; Dong, Ming; Lv, Wenyuan; Ye, Chunming

2017-05-01

In a development project, efficient design stream line scheduling is difficult and important owing to large design imprecision and the differences in the skills and skill levels of employees. The relative skill levels of employees are denoted as fuzzy numbers. Multiple execution modes are generated by scheduling different employees for design tasks. An optimization model of a design stream line scheduling problem is proposed with the constraints of multiple executive modes, multi-skilled employees and precedence. The model considers the parallel design of multiple projects, different skills of employees, flexible multi-skilled employees and resource constraints. The objective function is to minimize the duration and tardiness of the project. Moreover, a two-dimensional particle swarm algorithm is used to find the optimal solution. To illustrate the validity of the proposed method, a case is examined in this article, and the results support the feasibility and effectiveness of the proposed model and algorithm.

Controlling the motion of multiple objects on a Chladni plate

NASA Astrophysics Data System (ADS)

Zhou, Quan; Sariola, Veikko; Latifi, Kourosh; Liimatainen, Ville

2016-09-01

The origin of the idea of moving objects by acoustic vibration can be traced back to 1787, when Ernst Chladni reported the first detailed studies on the aggregation of sand onto nodal lines of a vibrating plate. Since then and to this date, the prevailing view has been that the particle motion out of nodal lines is random, implying uncontrollability. But how random really is the out-of-nodal-lines motion on a Chladni plate? Here we show that the motion is sufficiently regular to be statistically modelled, predicted and controlled. By playing carefully selected musical notes, we can control the position of multiple objects simultaneously and independently using a single acoustic actuator. Our method allows independent trajectory following, pattern transformation and sorting of multiple miniature objects in a wide range of materials, including electronic components, water droplets loaded on solid carriers, plant seeds, candy balls and metal parts.

More Thoughts on AG-SG Comparisons and SG Scale Factor Determinations

NASA Astrophysics Data System (ADS)

Crossley, David; Calvo, Marta; Rosat, Severine; Hinderer, Jacques

2018-05-01

We revisit a number of details that arise when doing joint AG-SG (absolute gravimeter-superconducting gravimeter) calibrations, focusing on the scale factor determination and the AG mean value that derives from the offset. When fitting SG data to AG data, the choice of which time span to use for the SG data can make a difference, as well as the inclusion of a trend that might be present in the fitting. The SG time delay has only a small effect. We review a number of options discussed recently in the literature on whether drops or sets provide the most accurate scale factor, and how to reject drops and sets to get the most consistent result. Two effects are clearly indicated by our tests, one being to smooth the raw SG 1 s (or similar sampling interval) data for times that coincide with AG drops, the other being a second pass in processing to reject residual outliers after the initial fit. Although drops can usefully provide smaller SG calibration errors compared to using set data, set values are more robust to data problems but one has to use the standard error to avoid large uncertainties. When combining scale factor determinations for the same SG at the same station, the expected gradual reduction of the error with each new experiment is consistent with the method of conflation. This is valid even when the SG data acquisition system is changed, or different AG's are used. We also find a relationship between the AG mean values obtained from SG to AG fits with the traditional short-term AG (`site') measurements usually done with shorter datasets. This involves different zero levels and corrections in the AG versus SG processing. Without using the Micro-g FG5 software it is possible to use the SG-derived corrections for tides, barometric pressure, and polar motion to convert an AG-SG calibration experiment into a site measurement (and vice versa). Finally, we provide a simple method for AG users who do not have the FG5-software to find an internal FG5 parameter that allows us to convert AG values between different transfer heights when there is a change in gradient.

A New Moonquake Catalog from Apollo 17 Seismic Data II: Lunar Surface Gravimeter: Implications of Expanding the Passive Seismic Array

NASA Astrophysics Data System (ADS)

Phillips, D.; Dimech, J. L.; Weber, R. C.

2017-12-01

Apollo 17's Lunar Surface Gravimeter (LSG) was deployed on the Moon in 1972, and was originally intended to detect gravitational waves as a confirmation of Einstein's general theory of relativity. Due to a design problem, the instrument did not function as intended. However, remotely-issued reconfiguration commands permitted the instrument to act effectively as a passive seismometer. LSG recorded continuously until Sept. 1977, when all surface data recording was terminated. Because the instrument did not meet its primary science objective, little effort was made to archive the data. Most of it was eventually lost, with the exception of data spanning the period March 1976 until Sept. 1977, and a recent investigation demonstrated that LSG data do contain moonquake signals (Kawamura et al., 2015). The addition of useable seismic data at the Apollo 17 site has important implications for event location schemes, which improve with increasing data coverage. All previous seismic event location attempts were limited to the four stations deployed at the Apollo 12, 14, 15, and 16 sites. Apollo 17 extends the functional aperture of the seismic array significantly to the east, permitting more accurate moonquake locations and improved probing of the lunar interior. Using the standard location technique of linearized arrival time inversion through a known velocity model, Kawamura et al. (2015) used moonquake signals detected in the LSG data to refine location estimates for 49 deep moonquake clusters, and constrained new locations for five previously un-located clusters. Recent efforts of the Apollo Lunar Surface Experiments Package Data Recovery Focus Group have recovered some of the previously lost LSG data, spanning the time period April 2, 1975 to June 30, 1975. In this study, we expand Kawamura's analysis to the newly recovered data, which contain over 200 known seismic signals, including deep moonquakes, shallow moonquakes, and meteorite impacts. We have completed initial data processing and verified the presence of deep moonquake signals in the recovered data. This positions us well for the application of automated event-detection techniques that have been successfully applied to the Apollo 16 Passive Seismic Experiment data as well as the Apollo 17 Lunar Seismic Profiling Experiment data.

More Thoughts on AG-SG Comparisons and SG Scale Factor Determinations

NASA Astrophysics Data System (ADS)

Crossley, David; Calvo, Marta; Rosat, Severine; Hinderer, Jacques

2018-03-01

We revisit a number of details that arise when doing joint AG-SG (absolute gravimeter-superconducting gravimeter) calibrations, focusing on the scale factor determination and the AG mean value that derives from the offset. When fitting SG data to AG data, the choice of which time span to use for the SG data can make a difference, as well as the inclusion of a trend that might be present in the fitting. The SG time delay has only a small effect. We review a number of options discussed recently in the literature on whether drops or sets provide the most accurate scale factor, and how to reject drops and sets to get the most consistent result. Two effects are clearly indicated by our tests, one being to smooth the raw SG 1 s (or similar sampling interval) data for times that coincide with AG drops, the other being a second pass in processing to reject residual outliers after the initial fit. Although drops can usefully provide smaller SG calibration errors compared to using set data, set values are more robust to data problems but one has to use the standard error to avoid large uncertainties. When combining scale factor determinations for the same SG at the same station, the expected gradual reduction of the error with each new experiment is consistent with the method of conflation. This is valid even when the SG data acquisition system is changed, or different AG's are used. We also find a relationship between the AG mean values obtained from SG to AG fits with the traditional short-term AG (`site') measurements usually done with shorter datasets. This involves different zero levels and corrections in the AG versus SG processing. Without using the Micro-g FG5 software it is possible to use the SG-derived corrections for tides, barometric pressure, and polar motion to convert an AG-SG calibration experiment into a site measurement (and vice versa). Finally, we provide a simple method for AG users who do not have the FG5-software to find an internal FG5 parameter that allows us to convert AG values between different transfer heights when there is a change in gradient.

Accounting for time- and space-varying changes in the gravity field to improve the network adjustment of relative-gravity data

USGS Publications Warehouse

Kennedy, Jeffrey R.; Ferre, Ty P.A.

2015-01-01

The relative gravimeter is the primary terrestrial instrument for measuring spatially and temporally varying gravitational fields. The background noise of the instrument—that is, non-linear drift and random tares—typically requires some form of least-squares network adjustment to integrate data collected during a campaign that may take several days to weeks. Here, we present an approach to remove the change in the observed relative-gravity differences caused by hydrologic or other transient processes during a single campaign, so that the adjusted gravity values can be referenced to a single epoch. The conceptual approach is an example of coupled hydrogeophysical inversion, by which a hydrologic model is used to inform and constrain the geophysical forward model. The hydrologic model simulates the spatial variation of the rate of change of gravity as either a linear function of distance from an infiltration source, or using a 3-D numerical groundwater model. The linear function can be included in and solved for as part of the network adjustment. Alternatively, the groundwater model is used to predict the change of gravity at each station through time, from which the accumulated gravity change is calculated and removed from the data prior to the network adjustment. Data from a field experiment conducted at an artificial-recharge facility are used to verify our approach. Maximum gravity change due to hydrology (observed using a superconducting gravimeter) during the relative-gravity field campaigns was up to 2.6 μGal d−1, each campaign was between 4 and 6 d and one month elapsed between campaigns. The maximum absolute difference in the estimated gravity change between two campaigns, two months apart, using the standard network adjustment method and the new approach, was 5.5 μGal. The maximum gravity change between the same two campaigns was 148 μGal, and spatial variation in gravity change revealed zones of preferential infiltration and areas of relatively high groundwater storage. The accommodation for spatially varying gravity change would be most important for long-duration campaigns, campaigns with very rapid changes in gravity and (or) campaigns where especially precise observed relative-gravity differences are used in the network adjustment.

Large Interstellar Polarisation Survey. II. UV/optical study of cloud-to-cloud variations of dust in the diffuse ISM

NASA Astrophysics Data System (ADS)

Siebenmorgen, R.; Voshchinnikov, N. V.; Bagnulo, S.; Cox, N. L. J.; Cami, J.; Peest, C.

2018-03-01

It is well known that the dust properties of the diffuse interstellar medium exhibit variations towards different sight-lines on a large scale. We have investigated the variability of the dust characteristics on a small scale, and from cloud-to-cloud. We use low-resolution spectro-polarimetric data obtained in the context of the Large Interstellar Polarisation Survey (LIPS) towards 59 sight-lines in the Southern Hemisphere, and we fit these data using a dust model composed of silicate and carbon particles with sizes from the molecular to the sub-micrometre domain. Large (≥6 nm) silicates of prolate shape account for the observed polarisation. For 32 sight-lines we complement our data set with UVES archive high-resolution spectra, which enable us to establish the presence of single-cloud or multiple-clouds towards individual sight-lines. We find that the majority of these 35 sight-lines intersect two or more clouds, while eight of them are dominated by a single absorbing cloud. We confirm several correlations between extinction and parameters of the Serkowski law with dust parameters, but we also find previously undetected correlations between these parameters that are valid only in single-cloud sight-lines. We find that interstellar polarisation from multiple-clouds is smaller than from single-cloud sight-lines, showing that the presence of a second or more clouds depolarises the incoming radiation. We find large variations of the dust characteristics from cloud-to-cloud. However, when we average a sufficiently large number of clouds in single-cloud or multiple-cloud sight-lines, we always retrieve similar mean dust parameters. The typical dust abundances of the single-cloud cases are [C]/[H] = 92 ppm and [Si]/[H] = 20 ppm.

DISSECTING THE HIGH- z INTERSTELLAR MEDIUM THROUGH INTENSITY MAPPING CROSS-CORRELATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serra, Paolo; Doré, Olivier; Lagache, Guilaine, E-mail: Paolo.Serra@jpl.nasa.gov

We explore the detection, with upcoming spectroscopic surveys, of three-dimensional power spectra of emission line fluctuations produced in different phases of the interstellar medium (ISM) by forbidden transitions of ionized carbon [C ii] (157.7 μ m), ionized nitrogen [N ii] (121.9 and 205.2 μ m), and neutral oxygen [O i] (145.5 μ m) at redshift z  > 4. These lines are important coolants of both the neutral and the ionized medium, and probe multiple phases of the ISM. In the framework of the halo model, we compute predictions of the three-dimensional power spectra for two different surveys, showing that they havemore » the required sensitivity to detect cross-power spectra between the [C ii] line and both the [O i] line and the [N ii] lines with sufficient signal-to-noise ratio. The importance of cross-correlating multiple lines with the intensity mapping technique is twofold. On the one hand, we will have multiple probes of the different phases of the ISM, which is key to understanding the interplay between energetic sources, and the gas and dust at high redshift. This kind of study will be useful for a next-generation space observatory such as the NASA Far-IR Surveyor, which will probe the global star formation and the ISM of galaxies from the peak of star formation to the epoch of reionization. On the other hand, emission lines from external galaxies are an important foreground when measuring spectral distortions of the cosmic microwave background spectrum with future space-based experiments like PIXIE; measuring fluctuations in the intensity mapping regime will help constrain the mean amplitude of these lines, and will allow us to better handle this important foreground.« less

Cytogenetic and molecular identification of a wheat-Leymus mollis alien multiple substitution line from octoploid Tritileymus x Triticum durum.

PubMed

Pang, Y H; Zhao, J X; Du, W L; Li, Y L; Wang, J; Wang, L M; Wu, J; Cheng, X N; Yang, Q H; Chen, X H

2014-05-23

Leymus mollis (Trin.) Pilger (NsNsXmXm, 2n = 28), a wild relative of common wheat, possesses many traits that are potentially valuable for wheat improvement. In order to exploit and utilize the useful genes of L. mollis, we developed a multiple alien substitution line, 10DM50, from the progenies of octoploid Tritileymus M842-16 x Triticum durum cv. D4286. Genomic in situ hybridization analysis of mitosis and meiosis (metaphase I), using labeled total DNA of Psathyrostachys huashanica as probe, showed that the substitution line 10DM50 was a cytogenetically stable alien substitution line with 36 chromosomes from wheat and three pairs of Ns genome chromosomes from L. mollis. Simple sequence repeat analysis showed that the chromosomes 3D, 6D, and 7D were absent in 10DM50. Expressed sequence tag-sequence tagged sites analysis showed that new chromatin from 3Ns, 6Ns, and 7Ns of L. mollis were detected in 10DM50. We deduced that the substitution line 10DM50 was a multiple alien substitution line with the 3D, 6D, and 7D chromosomes replaced by 3Ns, 6Ns, and 7Ns from L. mollis. 10DM50 showed high resistance to leaf rust and significantly improved spike length, spikes per plant, and kernels per spike, which are correlated with higher wheat yield. These results suggest that line 10DM50 could be used as intermediate material for transferring desirable traits from L. mollis into common wheat in breeding programs.

Multiple markers and multiple individuals refine true seal phylogeny and bring molecules and morphology back in line.

PubMed

Fulton, Tara Lynn; Strobeck, Curtis

2010-04-07

Despite decades of study, some aspects of Phocidae (Pinnipedia, Carnivora) phylogeny still remain unresolved. Using the largest novel dataset to date, including all extant phocids and comprising 15 nuclear and 13 mitochondrial genes, we illustrate the utility of including multiple individuals per species in resolving rapid radiations, and provide new insight into phocid phylogeny. In line with longstanding morphological views, Pusa is recovered as monophyletic for the first time with genetic data. The data are also used to explore the relationship between genetic distance and taxonomic rank. Intraspecific sampling also highlights the discrepancy between molecular and morphological rates of evolution within Phocidae.

Appearance of low signal intensity lines in MRI of silicone breast implants.

PubMed

Stroman, P W; Rolland, C; Dufour, M; Grondin, P; Guidoin, R G

1996-05-01

Magnetic resonance (MR) images of five explanted mammary prostheses were obtained with a 1.5 T GE Signa system using a conventional spin-echo pulse sequence, in order to investigate the low-intensity curvilinear lines which may be observed in MR images of silicone gel-filled breast implants under pressure from fibrous capsules. MR images showed ellipsoid prostheses, often containing multiple low-intensity curvilinear lines which in some cases presented an appearance very similar to that of the linguine sign. Upon opening the fibrous capsules, however, all of the prostheses were found to be completely intact demonstrating that the appearance of multiple low signal intensity curvilinear lines in MR images of silicone gel-filled prostheses is not necessarily a sign of prosthesis rupture. The MR image features which are specific to the linguine sign must be more precisely defined.

19 CFR 142.42 - Application for Line Release processing.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 2 2010-04-01 2010-04-01 false Application for Line Release processing. 142.42... processing. In order to obtain approval for processing import transactions through Line Release, a broker or... level for particular product or range of HTSUS numbers at sub-heading levels for multiple products for...

Line intersect sampling: Ell-shaped transects and multiple intersections

Treesearch

Timothy G. Gregoire; Harry T. Valentine

2003-01-01

The probability of selecting a population element under line intersect sampling depends on the width of the particle in the direction perpendicular to the transect, as is well known. The consequence of this when using ell-shaped transects rather than straight-line transects are explicated, and modifications that preserve design-unbiasedness of Kaiser's (1983)...

Line Intercept (LI)

Treesearch

John F. Caratti

2006-01-01

The FIREMON Line Intercept (LI) method is used to assess changes in plant species cover for a macroplot. This method uses multiple line transects to sample within plot variation and quantify statistically valid changes in plant species cover and height over time. This method is suited for most forest and rangeland communities, but is especially useful for sampling...

Sequential Test Strategies for Multiple Fault Isolation

NASA Technical Reports Server (NTRS)

Shakeri, M.; Pattipati, Krishna R.; Raghavan, V.; Patterson-Hine, Ann; Kell, T.

1997-01-01

In this paper, we consider the problem of constructing near optimal test sequencing algorithms for diagnosing multiple faults in redundant (fault-tolerant) systems. The computational complexity of solving the optimal multiple-fault isolation problem is super-exponential, that is, it is much more difficult than the single-fault isolation problem, which, by itself, is NP-hard. By employing concepts from information theory and Lagrangian relaxation, we present several static and dynamic (on-line or interactive) test sequencing algorithms for the multiple fault isolation problem that provide a trade-off between the degree of suboptimality and computational complexity. Furthermore, we present novel diagnostic strategies that generate a static diagnostic directed graph (digraph), instead of a static diagnostic tree, for multiple fault diagnosis. Using this approach, the storage complexity of the overall diagnostic strategy reduces substantially. Computational results based on real-world systems indicate that the size of a static multiple fault strategy is strictly related to the structure of the system, and that the use of an on-line multiple fault strategy can diagnose faults in systems with as many as 10,000 failure sources.

service line analytics in the new era.

PubMed

Spence, Jay; Seargeant, Dan

2015-08-01

To succeed under the value-based business model, hospitals and health systems require effective service line analytics that combine inpatient and outpatient data and that incorporate quality metrics for evaluating clinical operations. When developing a framework for collection, analysis, and dissemination of service line data, healthcare organizations should focus on five key aspects of effective service line analytics: Updated service line definitions. Ability to analyze and trend service line net patient revenues by payment source. Access to accurate service line cost information across multiple dimensions with drill-through capabilities. Ability to redesign key reports based on changing requirements. Clear assignment of accountability.

Single cell multiplexed assay for proteolytic activity using droplet microfluidics.

PubMed

Ng, Ee Xien; Miller, Miles A; Jing, Tengyang; Chen, Chia-Hung

2016-07-15

Cellular enzymes interact in a post-translationally regulated fashion to govern individual cell behaviors, yet current platform technologies are limited in their ability to measure multiple enzyme activities simultaneously in single cells. Here, we developed multi-color Förster resonance energy transfer (FRET)-based enzymatic substrates and use them in a microfluidics platform to simultaneously measure multiple specific protease activities from water-in-oil droplets that contain single cells. By integrating the microfluidic platform with a computational analytical method, Proteolytic Activity Matrix Analysis (PrAMA), we are able to infer six different protease activity signals from individual cells in a high throughput manner (~100 cells/experimental run). We characterized protease activity profiles at single cell resolution for several cancer cell lines including breast cancer cell line MDA-MB-231, lung cancer cell line PC-9, and leukemia cell line K-562 using both live-cell and in-situ cell lysis assay formats, with special focus on metalloproteinases important in metastasis. The ability to measure multiple proteases secreted from or expressed in individual cells allows us to characterize cell heterogeneity and has potential applications including systems biology, pharmacology, cancer diagnosis and stem cell biology. Copyright © 2016 Elsevier B.V. All rights reserved.

"Always looking for a new balance": toward an understanding of what it takes to continue working while being diagnosed with relapsing-remitting multiple sclerosis.

PubMed

Meide, Hanneke van der; Gorp, Dennis van; van der Hiele, Karin; Visser, Leo

2017-06-22

The aim of this study was to gain insight into the meaning of work in the everyday lives of people with relapsing-remitting multiple sclerosis, and the barriers and facilitators to staying in work. Nineteen employed adults diagnosed with relapsing-remitting multiple sclerosis participated in narrative interviews. All interviews were transcribed and coded for thematic analysis. For people with relapsing-remitting multiple sclerosis, continuing to work was a precarious balancing act. Five themes influenced this balance: becoming familiar with the disease, adjusting expectations, having an understanding and realistic line manager, seeing work as meaningful life activity and strategic considerations. People receiving a diagnosis of relapsing-remitting multiple sclerosis have to refamiliarize themselves with their own body in a meaningful way to be able to continue their work. Rehabilitation professionals can support them herein by taking into account not merely functional capabilities but also identity aspects of the body. Medication that stabilizes symptoms supports making the necessary adjustments. A trusting relationship with the line manager is vital for this adaptation process. Additionally, a match between being adequately challenged by work, while still having the capacity to meet those work demands, is needed, as is long-term financial stability. Implications for rehabilitation Rehabilitation professionals can support employees with relapsing-remitting multiple sclerosis by taking into account not merely functional capabilities but also identity aspects of the body. A trusting relationship with the line manager, including a timely disclosure of the diagnosis, is vital for people with relapsing-remitting multiple sclerosis to remain at work. For people with relapsing-remitting multiple sclerosis, there is a delicate balance between being adequately challenged by work while still having the capacity to meet work demands.

Heterodyne detection using spectral line pairing for spectral phase encoding optical code division multiple access and dynamic dispersion compensation.

PubMed

Yang, Yi; Foster, Mark; Khurgin, Jacob B; Cooper, A Brinton

2012-07-30

A novel coherent optical code-division multiple access (OCDMA) scheme is proposed that uses spectral line pairing to generate signals suitable for heterodyne decoding. Both signal and local reference are transmitted via a single optical fiber and a simple balanced receiver performs sourceless heterodyne detection, canceling speckle noise and multiple-access interference (MAI). To validate the idea, a 16 user fully loaded phase encoded system is simulated. Effects of fiber dispersion on system performance are studied as well. Both second and third order dispersion management is achieved by using a spectral phase encoder to adjust phase shifts of spectral components at the optical network unit (ONU).

On Local Ionization Equilibrium and Disk Winds in QSOs

NASA Astrophysics Data System (ADS)

Pereyra, Nicolas A.

2014-11-01

We present theoretical C IV λλ1548,1550 absorption line profiles for QSOs calculated assuming the accretion disk wind (ADW) scenario. The results suggest that the multiple absorption troughs seen in many QSOs may be due to the discontinuities in the ion balance of the wind (caused by X-rays), rather than discontinuities in the density/velocity structure. The profiles are calculated from a 2.5-dimensional time-dependent hydrodynamic simulation of a line-driven disk wind for a typical QSO black hole mass, a typical QSO luminosity, and for a standard Shakura-Sunyaev disk. We include the effects of ionizing X-rays originating from within the inner disk radius by assuming that the wind is shielded from the X-rays from a certain viewing angle up to 90° ("edge on"). In the shielded region, we assume constant ionization equilibrium, and thus constant line-force parameters. In the non-shielded region, we assume that both the line-force and the C IV populations are nonexistent. The model can account for P-Cygni absorption troughs (produced at edge on viewing angles), multiple absorption troughs (produced at viewing angles close to the angle that separates the shielded region and the non-shielded region), and for detached absorption troughs (produced at an angle in between the first two absorption line types); that is, the model can account for the general types of broad absorption lines seen in QSOs as a viewing angle effect. The steady nature of ADWs, in turn, may account for the steady nature of the absorption structure observed in multiple-trough broad absorption line QSOs. The model parameters are M bh = 109 M ⊙ and L disk = 1047 erg s-1.

On-Line Multi-Damage Scanning Spatial-Wavenumber Filter Based Imaging Method for Aircraft Composite Structure.

PubMed

Ren, Yuanqiang; Qiu, Lei; Yuan, Shenfang; Bao, Qiao

2017-05-11

Structural health monitoring (SHM) of aircraft composite structure is helpful to increase reliability and reduce maintenance costs. Due to the great effectiveness in distinguishing particular guided wave modes and identifying the propagation direction, the spatial-wavenumber filter technique has emerged as an interesting SHM topic. In this paper, a new scanning spatial-wavenumber filter (SSWF) based imaging method for multiple damages is proposed to conduct on-line monitoring of aircraft composite structures. Firstly, an on-line multi-damage SSWF is established, including the fundamental principle of SSWF for multiple damages based on a linear piezoelectric (PZT) sensor array, and a corresponding wavenumber-time imaging mechanism by using the multi-damage scattering signal. Secondly, through combining the on-line multi-damage SSWF and a PZT 2D cross-shaped array, an image-mapping method is proposed to conduct wavenumber synthesis and convert the two wavenumber-time images obtained by the PZT 2D cross-shaped array to an angle-distance image, from which the multiple damages can be directly recognized and located. In the experimental validation, both simulated multi-damage and real multi-damage introduced by repeated impacts are performed on a composite plate structure. The maximum localization error is less than 2 cm, which shows good performance of the multi-damage imaging method. Compared with the existing spatial-wavenumber filter based damage evaluation methods, the proposed method requires no more than the multi-damage scattering signal and can be performed without depending on any wavenumber modeling or measuring. Besides, this method locates multiple damages by imaging instead of the geometric method, which helps to improve the signal-to-noise ratio. Thus, it can be easily applied to on-line multi-damage monitoring of aircraft composite structures.

On-Line Multi-Damage Scanning Spatial-Wavenumber Filter Based Imaging Method for Aircraft Composite Structure

PubMed Central

Ren, Yuanqiang; Qiu, Lei; Yuan, Shenfang; Bao, Qiao

2017-01-01

Structural health monitoring (SHM) of aircraft composite structure is helpful to increase reliability and reduce maintenance costs. Due to the great effectiveness in distinguishing particular guided wave modes and identifying the propagation direction, the spatial-wavenumber filter technique has emerged as an interesting SHM topic. In this paper, a new scanning spatial-wavenumber filter (SSWF) based imaging method for multiple damages is proposed to conduct on-line monitoring of aircraft composite structures. Firstly, an on-line multi-damage SSWF is established, including the fundamental principle of SSWF for multiple damages based on a linear piezoelectric (PZT) sensor array, and a corresponding wavenumber-time imaging mechanism by using the multi-damage scattering signal. Secondly, through combining the on-line multi-damage SSWF and a PZT 2D cross-shaped array, an image-mapping method is proposed to conduct wavenumber synthesis and convert the two wavenumber-time images obtained by the PZT 2D cross-shaped array to an angle-distance image, from which the multiple damages can be directly recognized and located. In the experimental validation, both simulated multi-damage and real multi-damage introduced by repeated impacts are performed on a composite plate structure. The maximum localization error is less than 2 cm, which shows good performance of the multi-damage imaging method. Compared with the existing spatial-wavenumber filter based damage evaluation methods, the proposed method requires no more than the multi-damage scattering signal and can be performed without depending on any wavenumber modeling or measuring. Besides, this method locates multiple damages by imaging instead of the geometric method, which helps to improve the signal-to-noise ratio. Thus, it can be easily applied to on-line multi-damage monitoring of aircraft composite structures. PMID:28772879

Overexpressing the Multiple-Stress Responsive Gene At1g74450 Reduces Plant Height and Male Fertility in Arabidopsis thaliana

PubMed Central

Visscher, Anne M.; Belfield, Eric J.; Vlad, Daniela; Irani, Niloufer; Moore, Ian; Harberd, Nicholas P.

2015-01-01

A subset of genes in Arabidopsis thaliana is known to be up-regulated in response to a wide range of different environmental stress factors. However, not all of these genes are characterized as yet with respect to their functions. In this study, we used transgenic knockout, overexpression and reporter gene approaches to try to elucidate the biological roles of five unknown multiple-stress responsive genes in Arabidopsis. The selected genes have the following locus identifiers: At1g18740, At1g74450, At4g27652, At4g29780 and At5g12010. Firstly, T-DNA insertion knockout lines were identified for each locus and screened for altered phenotypes. None of the lines were found to be visually different from wildtype Col-0. Secondly, 35S-driven overexpression lines were generated for each open reading frame. Analysis of these transgenic lines showed altered phenotypes for lines overexpressing the At1g74450 ORF. Plants overexpressing the multiple-stress responsive gene At1g74450 are stunted in height and have reduced male fertility. Alexander staining of anthers from flowers at developmental stage 12–13 showed either an absence or a reduction in viable pollen compared to wildtype Col-0 and At1g74450 knockout lines. Interestingly, the effects of stress on crop productivity are most severe at developmental stages such as male gametophyte development. However, the molecular factors and regulatory networks underlying environmental stress-induced male gametophytic alterations are still largely unknown. Our results indicate that the At1g74450 gene provides a potential link between multiple environmental stresses, plant height and pollen development. In addition, ruthenium red staining analysis showed that At1g74450 may affect the composition of the inner seed coat mucilage layer. Finally, C-terminal GFP fusion proteins for At1g74450 were shown to localise to the cytosol. PMID:26485022

40 CFR 1060.102 - What permeation emission control requirements apply for fuel lines?

Code of Federal Regulations, 2011 CFR

2011-07-01

... assemblies as aggregated systems that include multiple sections of fuel line with connectors and fittings. For example, you may certify fuel lines for portable marine fuel tanks as assemblies of fuel hose, primer bulbs, and self-sealing end connections. The length of such an assembly must not be longer than a...

40 CFR 1060.102 - What permeation emission control requirements apply for fuel lines?

Code of Federal Regulations, 2010 CFR

2010-07-01

... assemblies as aggregated systems that include multiple sections of fuel line with connectors and fittings. For example, you may certify fuel lines for portable marine fuel tanks as assemblies of fuel hose, primer bulbs, and self-sealing end connections. The length of such an assembly must not be longer than a...

Passing in Command Line Arguments and Parallel Cluster/Multicore Batching in R with batch.

PubMed

Hoffmann, Thomas J

2011-03-01

It is often useful to rerun a command line R script with some slight change in the parameters used to run it - a new set of parameters for a simulation, a different dataset to process, etc. The R package batch provides a means to pass in multiple command line options, including vectors of values in the usual R format, easily into R. The same script can be setup to run things in parallel via different command line arguments. The R package batch also provides a means to simplify this parallel batching by allowing one to use R and an R-like syntax for arguments to spread a script across a cluster or local multicore/multiprocessor computer, with automated syntax for several popular cluster types. Finally it provides a means to aggregate the results together of multiple processes run on a cluster.

Nas transgenic mouse line allows visualization of Notch pathway activity in vivo.

PubMed

Souilhol, Céline; Cormier, Sarah; Monet, Marie; Vandormael-Pournin, Sandrine; Joutel, Anne; Babinet, Charles; Cohen-Tannoudji, Michel

2006-06-01

The Notch signaling pathway plays multiple and important roles in mammals. However, several aspects of its action, in particular, the precise mapping of its sites of activity, remain unclear. To address this issue, we generated a transgenic line carrying a construct consisting of a nls-lacZ reporter gene under the control of a minimal promoter and multiple RBP-Jkappa binding sites. Here we show that this transgenic line, which we termed NAS (for Notch Activity Sensor), displays an expression profile that is consistent with current knowledge on Notch activity sites in mice, even though it may not report on all these sites. Moreover, we observe that NAS transgene expression is abolished in a RBP-Jkappa-deficient background, indicating that it indeed requires Notch/RBP-Jkappa signaling pathway activity. Thus, the NAS transgenic line constitutes a valuable and versatile tool to gain further insights into the complex and various functions of the Notch signaling pathway.

Fast-tracking determination of homozygous transgenic lines and transgene stacking using a reliable quantitative real-time PCR assay.

PubMed

Wang, Xianghong; Jiang, Daiming; Yang, Daichang

2015-01-01

The selection of homozygous lines is a crucial step in the characterization of newly generated transgenic plants. This is particularly time- and labor-consuming when transgenic stacking is required. Here, we report a fast and accurate method based on quantitative real-time PCR with a rice gene RBE4 as a reference gene for selection of homozygous lines when using multiple transgenic stacking in rice. Use of this method allowed can be used to determine the stacking of up to three transgenes within four generations. Selection accuracy reached 100 % for a single locus and 92.3 % for two loci. This method confers distinct advantages over current transgenic research methodologies, as it is more accurate, rapid, and reliable. Therefore, this protocol could be used to efficiently select homozygous plants and to expedite time- and labor-consuming processes normally required for multiple transgene stacking. This protocol was standardized for determination of multiple gene stacking in molecular breeding via marker-assisted selection.

Inhibiting the Aurora B Kinase Potently Suppresses Repopulation During Fractionated Irradiation of Human Lung Cancer Cell Lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sak, Ali, E-mail: ali.sak@uni-due.de; Stuschke, Martin; Groneberg, Michael

2012-10-01

Purpose: The use of molecular-targeted agents during radiotherapy of non-small-cell lung cancer (NSCLC) is a promising strategy to inhibit repopulation, thereby improving therapeutic outcome. We assessed the combined effectiveness of inhibiting Aurora B kinase and irradiation on human NSCLC cell lines in vitro. Methods and Materials: NSCLC cell lines were exposed to concentrations of AZD1152-hydroxyquinazoline pyrazol anilide (AZD1152-HQPA) inhibiting colony formation by 50% (IC50{sub clone}) in combination with single dose irradiation or different fractionation schedules using multiple 2-Gy fractions per day up to total doses of 4-40 Gy. The total irradiation dose required to control growth of 50% of themore » plaque monolayers (TCD50) was determined. Apoptosis, G2/M progression, and polyploidization were also analyzed. Results: TCD50 values after single dose irradiation were similar for the H460 and H661 cell lines with 11.4 {+-} 0.2 Gy and 10.7 {+-} 0.3 Gy, respectively. Fractionated irradiation using 3 Multiplication-Sign 2 Gy/day, 2 Multiplication-Sign 2 Gy/day, and 1 Multiplication-Sign 2 Gy/day schedules significantly increased TCD50 values for both cell lines grown as plaque monolayers with increasing radiation treatment time. This could be explained by a repopulation effect per day that counteracts 75 {+-} 8% and 27 {+-} 6% of the effect of a 2-Gy fraction in H460 and H661 cells, respectively. AZD1152-HQPA treatment concomitant to radiotherapy significantly decreased the daily repopulation effect (H460: 28 {+-} 5%, H661: 10 {+-} 4% of a 2-Gy fraction per day). Treatment with IC50{sub clone} AZD1152-HPQA did not induce apoptosis, prolong radiation-induced G2 arrest, or delay cell cycle progression before the spindle check point. However, polyploidization was detected, especially in cell lines without functional p53. Conclusions: Inhibition of Aurora B kinase with low AZD1152-HQPA concentrations during irradiation of NSCLC cell lines affects repopulation during radiotherapy. Thus, concomitant Aurora B kinase inhibition and irradiation may be a promising strategy for fast repopulating tumors, which are difficult to cure by dose escalation based on conventional fractionation.« less

Multiwavelength generation in a random distributed feedback fiber laser using an all fiber Lyot filter.

PubMed

Sugavanam, S; Yan, Z; Kamynin, V; Kurkov, A S; Zhang, L; Churkin, D V

2014-02-10

Multiwavelength lasing in the random distributed feedback fiber laser is demonstrated by employing an all fiber Lyot filter. Stable multiwavelength generation is obtained, with each line exhibiting sub-nanometer line-widths. A flat power distribution over multiple lines is obtained, which indicates that the power between lines is redistributed in nonlinear mixing processes. The multiwavelength generation is observed both in first and second Stokes waves.

SDSS-IV MaNGA: the spectroscopic discovery of strongly lensed galaxies

NASA Astrophysics Data System (ADS)

Talbot, Michael S.; Brownstein, Joel R.; Bolton, Adam S.; Bundy, Kevin; Andrews, Brett H.; Cherinka, Brian; Collett, Thomas E.; More, Anupreeta; More, Surhud; Sonnenfeld, Alessandro; Vegetti, Simona; Wake, David A.; Weijmans, Anne-Marie; Westfall, Kyle B.

2018-06-01

We present a catalogue of 38 spectroscopically detected strong galaxy-galaxy gravitational lens candidates identified in the Sloan Digital Sky Survey IV (SDSS-IV). We were able to simulate narrow-band images for eight of them demonstrating evidence of multiple images. Two of our systems are compound lens candidates, each with two background source-planes. One of these compound systems shows clear lensing features in the narrow-band image. Our sample is based on 2812 galaxies observed by the Mapping Nearby Galaxies at APO (MaNGA) integral field unit (IFU). This Spectroscopic Identification of Lensing Objects (SILO) survey extends the methodology of the Sloan Lens ACS Survey (SLACS) and BOSS Emission-Line Survey (BELLS) to lower redshift and multiple IFU spectra. We searched ˜1.5 million spectra, of which 3065 contained multiple high signal-to-noise ratio background emission-lines or a resolved [O II] doublet, that are included in this catalogue. Upon manual inspection, we discovered regions with multiple spectra containing background emission-lines at the same redshift, providing evidence of a common source-plane geometry which was not possible in previous SLACS and BELLS discovery programs. We estimate more than half of our candidates have an Einstein radius ≳ 1.7 arcsec, which is significantly greater than seen in SLACS and BELLS. These larger Einstein radii produce more extended images of the background galaxy increasing the probability that a background emission-line will enter one of the IFU spectroscopic fibres, making detection more likely.

Multiple primary tumors of the upper aerodigestive tract: is there a role for constitutional mutations in the p53 gene?

PubMed

Gallo, O; Sardi, I; Pepe, G; Franchi, A; Attanasio, M; Giusti, B; Bocciolini, C; Abbate, R

1999-07-19

Head-and-neck cancer (HNC) patients have a high risk of developing second primary tumors of the upper aerodigestive tract, the main cause of death. Although the roles of tobacco and diet in multiple head-and-neck carcinogenesis have been thoroughly investigated, little is known about individual genetic susceptibility factors involved in this process. Genomic instability, reflecting the propensity and the susceptibility of the genome to acquire multiple alterations, could be considered a driving force behind multiple carcinogenesis. Mutation of the p53 tumor-suppressor gene has been proposed to play an important role in this process. Therefore, we evaluated the incidence of inherited p53 germ-line alteration(s) in a population of 24 consecutive HNC patients and their first-degree relatives affected by multiple malignancies as well as the occurrence of p53 somatic acquired mutation(s) in 16 cancers, including first and second primaries from 5 HNCs of the same group. Mutations in exons 4-11 of the p53 gene were investigated using SSCP-PCR analysis and DNA sequencing. Analysis was extended to the peripheral blood and cancer biopsies available from first-degree relatives of cancer-prone families with p53 germ-line mutations. p53 germ-line mutations were identified in the peripheral blood and corresponding cancers of 3 HNC patients who had multiple malignancies. The only missense mutation detected was mapped in exon 6; it is a GTG to GAG substitution with an amino acid change from Val to Glu at codon 197. The remaining 2 p53 germ-line mutations were single-nucleotide substitutions without amino acid change in exon 6 (codon 213, CGA to CGG) and in exon 8 (codon 295, CCT to CCC), respectively. These mutations were found in HNC patients with a family history of cancer. Abnormal expression of wild-type p53 protein in normal and pathological tissues from patients with the same sense single-nucleotide substitutions was detected by immuno-histochemistry.

RETRAN analysis of multiple steam generator blow down caused by an auxiliary feedwater steam-line break

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feltus, M.A.

1987-01-01

Analysis results for multiple steam generator blow down caused by an auxiliary feedwater steam-line break performed with the RETRAN-02 MOD 003 computer code are presented to demonstrate the capabilities of the RETRAN code to predict system transient response for verifying changes in operational procedures and supporting plant equipment modifications. A typical four-loop Westinghouse pressurized water reactor was modeled using best-estimate versus worst case licensing assumptions. This paper presents analyses performed to evaluate the necessity of implementing an auxiliary feedwater steam-line isolation modification. RETRAN transient analysis can be used to determine core cooling capability response, departure from nucleate boiling ratio (DNBR)more » status, and reactor trip signal actuation times.« less

Efficacy and safety of bortezomib-based retreatment at the first relapse in multiple myeloma patients: A retrospective study.

PubMed

Oriol, Albert; Giraldo, Pilar; Kotsianidis, Ioannis; Couturier, Catherine; Olie, Robert; Angermund, Ralf; Corso, Alessandro

2015-08-01

Multiple myeloma remains incurable and retreatment with available therapies is of substantial interest. This retrospective observational study included data from 35 patients treated initially and at the first relapse with bortezomib-containing regimens. Bortezomib retreatment provided a similar depth and time to response as first-line therapy; however, as could be expected, the duration of response was shorter with retreatment. The tolerability profile was similar with bortezomib as the first- and second-line therapy, with no evidence of cumulative toxicity. These findings support bortezomib retreatment after a treatment-free interval of ≥6 months in patients who achieved at least a partial response to the first-line bortezomib-based therapy.

Methods for constraining fine structure constant evolution with OH microwave transitions.

PubMed

Darling, Jeremy

2003-07-04

We investigate the constraints that OH microwave transitions in megamasers and molecular absorbers at cosmological distances may place on the evolution of the fine structure constant alpha=e(2)/ variant Planck's over 2pi c. The centimeter OH transitions are a combination of hyperfine splitting and lambda doubling that can constrain the cosmic evolution of alpha from a single species, avoiding systematic errors in alpha measurements from multiple species which may have relative velocity offsets. The most promising method compares the 18 and 6 cm OH lines, includes a calibration of systematic errors, and offers multiple determinations of alpha in a single object. Comparisons of OH lines to the HI 21 cm line and CO rotational transitions also show promise.

Immortalized Human Schwann Cell Lines Derived From Tumors of Schwannomatosis Patients.

PubMed

Ostrow, Kimberly Laskie; Donaldson, Katelyn; Blakeley, Jaishri; Belzberg, Allan; Hoke, Ahmet

2015-01-01

Schwannomatosis, a rare form of neurofibromatosis, is characterized predominantly by multiple, often painful, schwannomas throughout the peripheral nervous system. The current standard of care for schwannomatosis is surgical resection. A major obstacle to schwannomatosis research is the lack of robust tumor cell lines. There is a great need for mechanistic and drug discovery studies of schwannomatosis, yet appropriate tools are not currently available. Schwannomatosis tumors are difficult to grow in culture as they survive only a few passages before senescence. Our lab has extensive experience in establishing primary and immortalized human Schwann cell cultures from normal tissue that retain their phenotypes after immortalization. Therefore we took on the challenge of creating immortalized human Schwann cell lines derived from tumors from schwannomatosis patients. We have established and fully characterized 2 schwannomatosis cell lines from 2 separate patients using SV40 virus large T antigen. One patient reported pain and the other did not. The schwannomatosis cell lines were stained with S100B antibodies to confirm Schwann cell identity. The schwannomatosis cells also expressed the Schwann cell markers, p75NTR, S100B, and NGF after multiple passages. Cell morphology was retained following multiple passaging and freeze/ thaw cycles. Gene expression microarray analysis was used to compare the cell lines with their respective parent tumors. No differences in key genes were detected, with the exception that several cell cycle regulators were upregulated in the schwannomatosis cell lines when compared to their parent tumors. This upregulation was apparently a product of cell culturing, as the schwannomatosis cells exhibited the same expression pattern of cell cycle regulatory genes as normal primary human Schwann cells. Cell growth was also similar between normal primary and immortalized tumor cells in culture. Accurate cell lines derived directly from human tumors will serve as invaluable tools for advancing schwannomatosis research, including drug screening.

Immortalized Human Schwann Cell Lines Derived From Tumors of Schwannomatosis Patients

PubMed Central

Ostrow, Kimberly Laskie; Donaldson, Katelyn; Blakeley, Jaishri; Belzberg, Allan; Hoke, Ahmet

2015-01-01

Schwannomatosis, a rare form of neurofibromatosis, is characterized predominantly by multiple, often painful, schwannomas throughout the peripheral nervous system. The current standard of care for schwannomatosis is surgical resection. A major obstacle to schwannomatosis research is the lack of robust tumor cell lines. There is a great need for mechanistic and drug discovery studies of schwannomatosis, yet appropriate tools are not currently available. Schwannomatosis tumors are difficult to grow in culture as they survive only a few passages before senescence. Our lab has extensive experience in establishing primary and immortalized human Schwann cell cultures from normal tissue that retain their phenotypes after immortalization. Therefore we took on the challenge of creating immortalized human Schwann cell lines derived from tumors from schwannomatosis patients. We have established and fully characterized 2 schwannomatosis cell lines from 2 separate patients using SV40 virus large T antigen. One patient reported pain and the other did not. The schwannomatosis cell lines were stained with S100B antibodies to confirm Schwann cell identity. The schwannomatosis cells also expressed the Schwann cell markers, p75NTR, S100B, and NGF after multiple passages. Cell morphology was retained following multiple passaging and freeze/ thaw cycles. Gene expression microarray analysis was used to compare the cell lines with their respective parent tumors. No differences in key genes were detected, with the exception that several cell cycle regulators were upregulated in the schwannomatosis cell lines when compared to their parent tumors. This upregulation was apparently a product of cell culturing, as the schwannomatosis cells exhibited the same expression pattern of cell cycle regulatory genes as normal primary human Schwann cells. Cell growth was also similar between normal primary and immortalized tumor cells in culture. Accurate cell lines derived directly from human tumors will serve as invaluable tools for advancing schwannomatosis research, including drug screening. PMID:26657314

Widom Lines in Binary Mixtures of Supercritical Fluids.

PubMed

Raju, Muralikrishna; Banuti, Daniel T; Ma, Peter C; Ihme, Matthias

2017-06-08

Recent experiments on pure fluids have identified distinct liquid-like and gas-like regimes even under supercritical conditions. The supercritical liquid-gas transition is marked by maxima in response functions that define a line emanating from the critical point, referred to as Widom line. However, the structure of analogous state transitions in mixtures of supercritical fluids has not been determined, and it is not clear whether a Widom line can be identified for binary mixtures. Here, we present first evidence for the existence of multiple Widom lines in binary mixtures from molecular dynamics simulations. By considering mixtures of noble gases, we show that, depending on the phase behavior, mixtures transition from a liquid-like to a gas-like regime via distinctly different pathways, leading to phase relationships of surprising complexity and variety. Specifically, we show that miscible binary mixtures have behavior analogous to a pure fluid and the supercritical state space is characterized by a single liquid-gas transition. In contrast, immiscible binary mixture undergo a phase separation in which the clusters transition separately at different temperatures, resulting in multiple distinct Widom lines. The presence of this unique transition behavior emphasizes the complexity of the supercritical state to be expected in high-order mixtures of practical relevance.

The art and science of straight lines in radiology.

PubMed

Day, Cynthia M; Sodickson, Aaron

2011-02-01

The purpose of this article is to review the physical basis for straight radiographic lines, identify the possible components that may form a straight line interface in the body, provide illustrative examples across multiple organ systems and modalities, and explore how the detection of these interfaces can support specific diagnoses. Detection of a straight line interface can help the radiologist recognize otherwise difficult or subtle pathologic processes, and identification of its components can provide valuable clues to diagnosis.

mtDNA lineage analysis of mouse L-cell lines reveals the accumulation of multiple mtDNA mutants and intermolecular recombination

PubMed Central

Fan, Weiwei; Lin, Chun Shi; Potluri, Prasanth; Procaccio, Vincent; Wallace, Douglas C.

2012-01-01

The role of mitochondrial DNA (mtDNA) mutations and mtDNA recombination in cancer cell proliferation and developmental biology remains controversial. While analyzing the mtDNAs of several mouse L cell lines, we discovered that every cell line harbored multiple mtDNA mutants. These included four missense mutations, two frameshift mutations, and one tRNA homopolymer expansion. The LA9 cell lines lacked wild-type mtDNAs but harbored a heteroplasmic mixture of mtDNAs, each with a different combination of these variants. We isolated each of the mtDNAs in a separate cybrid cell line. This permitted determination of the linkage phase of each mtDNA and its physiological characteristics. All of the polypeptide mutations inhibited their oxidative phosphorylation (OXPHOS) complexes. However, they also increased mitochondrial reactive oxygen species (ROS) production, and the level of ROS production was proportional to the cellular proliferation rate. By comparing the mtDNA haplotypes of the different cell lines, we were able to reconstruct the mtDNA mutational history of the L–L929 cell line. This revealed that every heteroplasmic L-cell line harbored a mtDNA that had been generated by intracellular mtDNA homologous recombination. Therefore, deleterious mtDNA mutations that increase ROS production can provide a proliferative advantage to cancer or stem cells, and optimal combinations of mutant loci can be generated through recombination. PMID:22345519

A time-lapse gravity survey of the Coso geothermal field, China Lake Naval Air Weapons Station, California

USGS Publications Warehouse

Phelps, Geoffrey; Cronkite-Ratcliff, Collin; Blake, Kelly

2018-04-19

We have conducted a gravity survey of the Coso geothermal field to continue the time-lapse gravity study of the area initiated in 1991. In this report, we outline a method of processing the gravity data that minimizes the random errors and instrument bias introduced into the data by the Scintrex CG-5 relative gravimeters that were used. After processing, the standard deviation of the data was estimated to be ±13 microGals. These data reveal that the negative gravity anomaly over the Coso geothermal field, centered on gravity station CER1, is continuing to increase in magnitude over time. Preliminary modeling indicates that water-table drawdown at the location of CER1 is between 65 and 326 meters over the last two decades. We note, however, that several assumptions on which the model results depend, such as constant elevation and free-water level over the study period, still require verification.

Gravity and crustal movements: The canadian experience

NASA Astrophysics Data System (ADS)

Tanner, J. G.; Lambert, A.

1987-07-01

Repeated high precision gravity measurement have already played an important role in the detection of crustal deformation in Canada and elsewhere, but even more useful results can be expected through more widespread use of gravity in combination with other techniques. The crucial element in the process is the development of a good physical model on which the experiment can be based. Otherwise, considerable time and effort can be spent on determining the most appropriate field strategy. New technical developments on the horizon appear to offer enhanced opportunities for gravity studies of crustal processes. The coming availability of the Global Positioning System and transportable absolute gravimeters will open up the possibility of regional studies (i.e., areas of the order of 100 km or perhaps greater) of crustal movements at reasonable cost. Within Africa the development of an African Gravity Standardization Net will be a major first step in any program to provide a better understanding of the neo-tectonic framework of this vast continent.

A new generation of high-performance operational quantum sensors (Conference Presentation)

NASA Astrophysics Data System (ADS)

Lautier-Gaud, Jean; Desruelle, Bruno; Ménoret, Vincent; Schaff, Jean-François; Stern, Guillaume; Vermeulen, Pierre

2016-04-01

After 30 years of academic research in cold atom sciences, intensive developments are being conducted to improve the compactness and the reliability of experimental set-ups in order to transfer such devices from laboratory-based research to an operational utilization outside of the laboratory. We will present the long-lasting developments that we have been carrying to provide the first industrial cold-atom absolute gravimeter and the first industrial cold-atom atomic clock. We will present in detail the principles of operation and the main features of our instruments. Their performances in terms of sensitivity, stability and accuracy and the latest results they achieved will be reviewed. We will then discuss their use to support other research activities. One of the key technology elements of such instruments that need to be addressed is the laser system used to cool down and manipulate the atoms. A specific focus on our latest developments in this area in terms of performances will be proposed.

Gravimetric effects of petroleum accumulations--A preliminary summary

USGS Publications Warehouse

McCulloh, Thane Hubert

1966-01-01

Negative gravity anomalies of very local extent and with amplitudes of 1.2 milligals or less have been observed over some known petroleum and natural gas fields in southern California and South Dagestan, U.S.S.R. Field evidence, laboratory measurements, and theory indicate that these anomalies are mainly the result of hydrocarbon pore fluids of densities significantly lower than that of water. Gravity meters already available have the precision necessary to detect some of these anomalies from surface measurements. In addition, a high-precision borehole gravity meter has been developed, by the industrial firm of LaCoste and Romberg, Inc., that can be used in wells with a casing 7 inches or more in diameter and at temperatures below 100?C. Field tests indicate that the prototype attains a precision in wells of ? 0.015 milligal for a single measurement. These observations and the new gravimeter should aid in the search for new petroleum fields and for new reservoirs in known fields that are incompletely explored.

The quest for the perfect gravity anomaly: Part 2 - Mass effects and anomaly inversion

USGS Publications Warehouse

Keller, Gordon R.; Hildenbrand, T.G.; Hinze, W. J.; Li, X.; Ravat, D.; Webring, M.

2006-01-01

Gravity anomalies have become an important tool for geologic studies since the widespread use of high-precision gravimeters after the Second World War. More recently the development of instrumentation for airborne gravity observations, procedures for acquiring data from satellite platforms, the readily available Global Positioning System for precise vertical and horizontal control, improved global data bases, and enhancement of computational hardware and software have accelerated the use of the gravity method. As a result, efforts are being made to improve the gravity databases that are made available to the geoscience community by broadening their observational holdings and increasing the accuracy and precision of the included data. Currently the North American Gravity Database as well as the individual databases of Canada, Mexico, and the United States of America are being revised using new formats and standards. The objective of this paper is to describe the use of the revised standards for gravity data processing and modeling and there impact on geological interpretations. ?? 2005 Society of Exploration Geophysicists.

Static Test for a Gravitational Force Coupled to Type 2 YBCO Superconductors

NASA Technical Reports Server (NTRS)

Li, Ning; Noever, David; Robertson, Tony; Koczor, Ron; Brantley, Whitt

1997-01-01

As a Bose condensate, superconductors provide novel conditions for revisiting previously proposed couplings between electromagnetism and gravity. Strong variations in Cooper pair density, large conductivity and low magnetic permeability define superconductive and degenerate condensates without the traditional density limits imposed by the Fermi energy (approx. 10(exp -6) g cc. Recent experiments have reported anomalous weight loss for a test mass suspended above a rotating type II, YBCO superconductor, with the percentage change (0.05 - 2.1 %) independent of the test mass' chemical composition and diamagnetic properties. A variation of 5 parts per 10' was reported above a stationary (non-rotating) superconductor. In experiments using a sensitive gravimeter, bulk YBCO superconductors were stably levitated in a DC magnetic field. Changes in acceleration were measured to be less than 2 parts in 108 of the normal gravitational acceleration. This result puts new limits on the strength and range of the proposed coupling between static superconductors and gravity.

Oxygen potential of (U 0.88Pu 0.12)O 2±x and (U 0.7Pu 0.3)O 2±x at high temperatures of 1673-1873 K

NASA Astrophysics Data System (ADS)

Kato, M.; Takeuchi, K.; Uchida, T.; Sunaoshi, T.; Konashi, K.

2011-07-01

The oxygen potential of (U 0.88Pu 0.12)O 2±x (-0.0119 < x < 0.0408) and (U 0.7Pu 0.3)O 2±x (-0.0363 < x < 0.0288) was measured at high temperatures of 1673-1873 K using gas equilibrium method with thermo gravimeter. The measured data were analyzed by a defect chemistry model. Expressions were derived to represent the oxygen potential based on defect chemistry as functions of temperature and oxygen-to-metal ratio. The thermodynamic data, ΔG, ΔH and ΔS, at stoichiometric composition were obtained. The expressions can be used for in situ determination of the oxygen-to-metal ratio by the gas-equilibration method. The calculation results were consistent with measured data. It was estimated that addition of 1 wt.% Pu content increased oxygen potential of uranium and plutonium mixed oxide by 2-5 kJ/mol.

Frequency characteristics and far-field effect of gravity perturbation before earthquake

NASA Astrophysics Data System (ADS)

Qiang, Jian-Ke; Lu, Kai; Zhang, Qian-Jiang; Man, Kai-Feng; Li, Jun-Ying; Mao, Xian-Cheng; Lai, Jian-Qing

2017-03-01

We used high-pass filtering and the Fourier transform to analyze tidal gravity data prior to five earthquakes from four superconducting gravity stations around the world. A stable gravitational perturbation signal is received within a few days before the earthquakes. The gravitational perturbation signal before the Wenchuan earthquake on May 12, 2008 has main frequency of 0.1-0.3 Hz, and the other four have frequency bands of 0.12-0.17 Hz and 0.06-0.085 Hz. For earthquakes in continental and oceanic plate fault zones, gravity anomalies often appear on the superconducting gravimeters away from the epicenter, whereas the stations near the epicenter record small or no anomalies. The results suggest that this kind of gravitational perturbation signals correlate with earthquake occurrence, making them potentially useful earthquake predictors. The far-field effect of the gravitational perturbation signals may reveal the interaction mechanisms of the Earth's tectonic plates. However, owing to the uneven distribution of gravity tide stations, the results need to be further confirmed in the future.

Development of a Network RTK Positioning and Gravity-Surveying Application with Gravity Correction Using a Smartphone

PubMed Central

Kim, Jinsoo; Lee, Youngcheol; Cha, Sungyeoul; Choi, Chuluong; Lee, Seongkyu

2013-01-01

This paper proposes a smartphone-based network real-time kinematic (RTK) positioning and gravity-surveying application (app) that allows semi-real-time measurements using the built-in Bluetooth features of the smartphone and a third-generation or long-term evolution wireless device. The app was implemented on a single smartphone by integrating a global navigation satellite system (GNSS) controller, a laptop, and a field-note writing tool. The observation devices (i.e., a GNSS receiver and relative gravimeter) functioned independently of this system. The app included a gravity module, which converted the measured relative gravity reading into an absolute gravity value according to tides; meter height; instrument drift correction; and network adjustments. The semi-real-time features of this app allowed data to be shared easily with other researchers. Moreover, the proposed smartphone-based gravity-survey app was easily adaptable to various locations and rough terrain due to its compact size. PMID:23857258

Gravity effects obtained from global hydrology models in comparison with high precision gravimetric time series

NASA Astrophysics Data System (ADS)

Wziontek, Hartmut; Wilmes, Herbert; Güntner, Andreas; Creutzfeldt, Benjamin

2010-05-01

Water mass changes are a major source of variations in residual gravimetric time series obtained from the combination of observations with superconducting and absolute gravimeters. Changes in the local water storage are the main influence, but global variations contribute to the signal significantly. For three European gravity stations, Bad Homburg, Wettzell and Medicina, different global hydrology models are compared. The influence of topographic effects is discussed and due to the long-term stability of the combined gravity time series, inter-annual signals in model data and gravimetric observations are compared. Two sources of influence are discriminated, i.e., the effect of a local zone with an extent of a few kilometers around the gravimetric station and the global contribution beyond 50km. Considering their coarse resolution and uncertainties, local effects calculated from global hydrological models are compared with the in-situ gravity observations and, for the station Wettzell, with local hydrological monitoring data.

Line-drawing algorithms for parallel machines

NASA Technical Reports Server (NTRS)

Pang, Alex T.

1990-01-01

The fact that conventional line-drawing algorithms, when applied directly on parallel machines, can lead to very inefficient codes is addressed. It is suggested that instead of modifying an existing algorithm for a parallel machine, a more efficient implementation can be produced by going back to the invariants in the definition. Popular line-drawing algorithms are compared with two alternatives; distance to a line (a point is on the line if sufficiently close to it) and intersection with a line (a point on the line if an intersection point). For massively parallel single-instruction-multiple-data (SIMD) machines (with thousands of processors and up), the alternatives provide viable line-drawing algorithms. Because of the pixel-per-processor mapping, their performance is independent of the line length and orientation.

Genetic variation in heat tolerance-related traits in a population of wheat multiple synthetic derivatives

PubMed Central

Elbashir, Awad A. E.; Gorafi, Yasir S. A.; Tahir, Izzat S. A.; Elhashimi, Ashraf. M. A.; Abdalla, Modather G. A.; Tsujimoto, Hisashi

2017-01-01

In wheat (Triticum aestivum L.) high temperature (≥30°C) during grain filling leads to considerable reduction in grain yield. We studied 400 multiple synthetic derivatives (MSD) lines to examine the genetic variability of heat stress–adaptive traits and to identify new sources of heat tolerance to be used in wheat breeding programs. The experiment was arranged in an augmented randomized complete block design in four environments in Sudan. A wide range of genetic variability was found in most of the traits in all environments. For all traits examined, we found MSD lines that showed better performance than their parent ‘Norin 61’ and two adapted Sudanese cultivars. Using the heat tolerance efficiency, we identified 13 highly heat-tolerant lines and several lines with intermediate heat tolerance and good yield potential. We also identified lines with alleles that can be used to increase wheat yield potential. Our study revealed that the use of the MSD population is an efficient way to explore the genetic variation in Ae. tauschii for wheat breeding and improvement. PMID:29398942

In vitro Development of Chemotherapy and Targeted Therapy Drug-Resistant Cancer Cell Lines: A Practical Guide with Case Studies

PubMed Central

McDermott, Martina; Eustace, Alex J.; Busschots, Steven; Breen, Laura; Crown, John; Clynes, Martin; O’Donovan, Norma; Stordal, Britta

2014-01-01

The development of a drug-resistant cell line can take from 3 to 18 months. However, little is published on the methodology of this development process. This article will discuss key decisions to be made prior to starting resistant cell line development; the choice of parent cell line, dose of selecting agent, treatment interval, and optimizing the dose of drug for the parent cell line. Clinically relevant drug-resistant cell lines are developed by mimicking the conditions cancer patients experience during chemotherapy and cell lines display between two- and eight-fold resistance compared to their parental cell line. Doses of drug administered are low, and a pulsed treatment strategy is often used where the cells recover in drug-free media. High-level laboratory models are developed with the aim of understanding potential mechanisms of resistance to chemotherapy agents. Doses of drug are higher and escalated over time. It is common to have difficulty developing stable clinically relevant drug-resistant cell lines. A comparative selection strategy of multiple cell lines or multiple chemotherapeutic agents mitigates this risk and gives insight into which agents or type of cell line develops resistance easily. Successful selection strategies from our research are presented. Pulsed-selection produced platinum or taxane-resistant large cell lung cancer (H1299 and H460) and temozolomide-resistant melanoma (Malme-3M and HT144) cell lines. Continuous selection produced a lapatinib-resistant breast cancer cell line (HCC1954). Techniques for maintaining drug-resistant cell lines are outlined including; maintaining cells with chemotherapy, pulse treating with chemotherapy, or returning to master drug-resistant stocks. The heterogeneity of drug-resistant models produced from the same parent cell line with the same chemotherapy agent is explored with reference to P-glycoprotein. Heterogeneity in drug-resistant cell lines reflects the heterogeneity that can occur in clinical drug resistance. PMID:24639951

Coolant monitoring apparatus for nuclear reactors

DOEpatents

Tokarz, Richard D.

1983-01-01

A system for monitoring coolant conditions within a pressurized vessel. A length of tubing extends outward from the vessel from an open end containing a first line restriction at the location to be monitored. The flowing fluid is cooled and condensed before passing through a second line restriction. Measurement of pressure drop at the second line restriction gives an indication of fluid condition at the first line restriction. Multiple lengths of tubing with open ends at incremental elevations can measure coolant level within the vessel.

OPCML is a broad tumor suppressor for multiple carcinomas and lymphomas with frequently epigenetic inactivation.

PubMed

Cui, Yan; Ying, Ying; van Hasselt, Andrew; Ng, Ka Man; Yu, Jun; Zhang, Qian; Jin, Jie; Liu, Dingxie; Rhim, Johng S; Rha, Sun Young; Loyo, Myriam; Chan, Anthony T C; Srivastava, Gopesh; Tsao, George S W; Sellar, Grant C; Sung, Joseph J Y; Sidransky, David; Tao, Qian

2008-08-20

Identification of tumor suppressor genes (TSGs) silenced by CpG methylation uncovers the molecular mechanism of tumorigenesis and potential tumor biomarkers. Loss of heterozygosity at 11q25 is common in multiple tumors including nasopharyngeal carcinoma (NPC). OPCML, located at 11q25, is one of the downregulated genes we identified through digital expression subtraction. Semi-quantitative RT-PCR showed frequent OPCML silencing in NPC and other common tumors, with no homozygous deletion detected by multiplex differential DNA-PCR. Instead, promoter methylation of OPCML was frequently detected in multiple carcinoma cell lines (nasopharyngeal, esophageal, lung, gastric, colon, liver, breast, cervix, prostate), lymphoma cell lines (non-Hodgkin and Hodgkin lymphoma, nasal NK/T-cell lymphoma) and primary tumors, but not in any non-tumor cell line and seldom weakly methylated in normal epithelial tissues. Pharmacological and genetic demethylation restored OPCML expression, indicating a direct epigenetic silencing. We further found that OPCML is stress-responsive, but this response is epigenetically impaired when its promoter becomes methylated. Ecotopic expression of OPCML led to significant inhibition of both anchorage-dependent and -independent growth of carcinoma cells with endogenous silencing. Thus, through functional epigenetics, we identified OPCML as a broad tumor suppressor, which is frequently inactivated by methylation in multiple malignancies.

Variability of ultraviolet emission in the carbon star TX Piscium

NASA Technical Reports Server (NTRS)

Johnson, Hollis R.; Baumert, John H.; Querci, Francois; Querci, Monique

1986-01-01

Multiple low-resolution IUE observations of the cool carbon star TX Psc (N0; C6, 2) permit an analysis of the variations in strength of the strongest emission lines - the Mg II line at 2800 A, the C II line at 2330 A, and certain Fe II lines. The integrated flux of the Mg II line varied by at least a factor of eight, while that of the C II line varies by at least a factor of five. The variations in Fe II may be considerably larger. The lines appear to vary together. The continuous flux in the best observed range from 2800 to 3200 A does not vary noticeably.

Double-observer line transect surveys with Markov-modulated Poisson process models for animal availability.

PubMed

Borchers, D L; Langrock, R

2015-12-01

We develop maximum likelihood methods for line transect surveys in which animals go undetected at distance zero, either because they are stochastically unavailable while within view or because they are missed when they are available. These incorporate a Markov-modulated Poisson process model for animal availability, allowing more clustered availability events than is possible with Poisson availability models. They include a mark-recapture component arising from the independent-observer survey, leading to more accurate estimation of detection probability given availability. We develop models for situations in which (a) multiple detections of the same individual are possible and (b) some or all of the availability process parameters are estimated from the line transect survey itself, rather than from independent data. We investigate estimator performance by simulation, and compare the multiple-detection estimators with estimators that use only initial detections of individuals, and with a single-observer estimator. Simultaneous estimation of detection function parameters and availability model parameters is shown to be feasible from the line transect survey alone with multiple detections and double-observer data but not with single-observer data. Recording multiple detections of individuals improves estimator precision substantially when estimating the availability model parameters from survey data, and we recommend that these data be gathered. We apply the methods to estimate detection probability from a double-observer survey of North Atlantic minke whales, and find that double-observer data greatly improve estimator precision here too. © 2015 The Authors Biometrics published by Wiley Periodicals, Inc. on behalf of International Biometric Society.

A geophysical investigation of the northeastern rim of the St. Martin impact structure, Manitoba, Canada

NASA Astrophysics Data System (ADS)

Zivkovic, Vladimir B.

The St. Martin impact structure is a 40 Km diameter structure located in Manitoba, Canada lies in featureless, glaciated terrain lacking any surface expression of an impact structure. The age of the structure has been re-determined to range between 224.3 Ma to 241.4 Ma which nullified a previous hypothesis suggesting this impact was part of a multiple impact event. Within the proposed structural boundary two outcrops of Archean granite are present. The first outcrop is located in what has been identified as the central peak of the impact structure. The second outcrop lies along the northeastern boundary and is known locally as Big Rock. The purpose of this investigation was to determine the relationship of Big Rock, if any, to the impact event and to constrain a more accurate diameter of the structure. To accomplish this I conducted two geophysical surveys and used selected data from a previous survey. The two methods I conducted were: a magnetic survey and seismic reflection profiling. Selected data from a previous gravity survey was used to supplement survey results. The magnetic survey was conducted using the total field G-856 Memory-Mag proton precession magnetometer which measures local or regional field strength. The seismic reflection survey was conducted using three Geometrics Geode exploration seismographs. Due to the complexity of seismic data processing I retained an outside seismic data processing company. Previous gravity anomaly data were acquired using a LaCoste and Romberg Model G gravimeter. The results of this geophysical investigation reveal a shallowing of granitic basement rock with exposure near Big Rock. However, a suggested listric fault near Big Rock was not identified via seismic reflection profiling, but was suggested by both the gravity and magnetic surveys. Listric faults that are genetically related to impact structures are also indicative of the structure's outer boundary and therefore can confirm that the St. Martin impact structure is indeed 40 Km in diameter.

GRAV-D for Puerto Rico and the U.S. Virgin Islands

NASA Astrophysics Data System (ADS)

Roman, D. R.; Li, X.; Smith, D. A.; Geoid; GRAV-D Teams

2013-05-01

NOAA's National Geodetic Survey began the Gravity for the Redefinition of the American Vertical Datum (GRAV-D) program in an effort to modernize and unify vertical datums in all states and territories. As a part of this program, NGS collected aerogravity profiles over the islands of Puerto Rico and the U.S. Virgin Islands in January 2009. A Citation II aircraft was equipped with an airborne gravimeter, GPS receiver, and a GPS/Inertial unit. Absolute gravity and GPS ties were made to multiple ground sites to ensure consistency in the results. The main survey covered a region of approximately 400 km by 500 km with flight altitudes of 10,668 m (35,000ft) and with 10 km track spacing. Cross-track profiles at 40 km spacing were also collected to establish an accuracy of 1.34 mGals RMSE. In addition to the high altitude flights, two more flights were made primarily over terrestrial areas at 1,524 m (5,000 ft) to obtain higher resolution information in these regions. There were no cross-ties established for these lower altitude flights. Additionally, terrestrial surveys were also conducted to better tie ground sites and to serve as control for later analysis for available but older terrestrial and marine gravity data in the region already held by NGS. The aerogravity data were analyzed and at least internally compared to obtain the optimal results before being published on the web. In this study, the aerogravity data were compared to available global gravity models derived from satellite missions (GRACE & GOCE) to evaluate their long wavelength character (e.g., potential biases and trends). The vetted satellite-aerogravity data were then combined and used to evaluate surface data (terrestrial and marine) in the region to remove any potential systematic effects. Finally, all these data were combined into a gravimetric geoid height model and evaluated with an eye to eventual use as a GNSS-accessed vertical datum.

Innate responses to gene knockouts impact overlapping gene networks and vary with respect to resistance to viral infection.

PubMed

Liu, Yonghong; Liu, Yuanyuan; Wu, Jiaming; Roizman, Bernard; Zhou, Grace Guoying

2018-04-03

Analyses of the levels of mRNAs encoding IFIT1, IFI16, RIG-1, MDA5, CXCL10, LGP2, PUM1, LSD1, STING, and IFNβ in cell lines from which the gene encoding LGP2, LSD1, PML, HDAC4, IFI16, PUM1, STING, MDA5, IRF3, or HDAC 1 had been knocked out, as well as the ability of these cell lines to support the replication of HSV-1, revealed the following: ( i ) Cell lines lacking the gene encoding LGP2, PML, or HDAC4 (cluster 1) exhibited increased levels of expression of partially overlapping gene networks. Concurrently, these cell lines produced from 5 fold to 12 fold lower yields of HSV-1 than the parental cells. ( ii ) Cell lines lacking the genes encoding STING, LSD1, MDA5, IRF3, or HDAC 1 (cluster 2) exhibited decreased levels of mRNAs of partially overlapping gene networks. Concurrently, these cell lines produced virus yields that did not differ from those produced by the parental cell line. The genes up-regulated in cell lines forming cluster 1, overlapped in part with genes down-regulated in cluster 2. The key conclusions are that gene knockouts and subsequent selection for growth causes changes in expression of multiple genes, and hence the phenotype of the cell lines cannot be ascribed to a single gene; the patterns of gene expression may be shared by multiple knockouts; and the enhanced immunity to viral replication by cluster 1 knockout cell lines but not by cluster 2 cell lines suggests that in parental cells, the expression of innate resistance to infection is specifically repressed.

Nas transgenic mouse line allows visualization of Notch pathway activity in vivo

PubMed Central

Souilhol, Céline; Cormier, Sarah; Monet, Marie; Vandormael-Pournin, Sandrine; Joutel, Anne; Babinet, Charles; Cohen-Tannoudji, Michel

2006-01-01

The Notch signalling pathway plays multiple and important roles in mammals. However, several aspects of its action, in particular the precise mapping of its sites of activity, remain unclear. To address this issue, we have generated a transgenic line carrying a construct consisting of a nls-lacZ reporter gene under the control of a minimal promoter and multiple RBP-Jκ binding sites. Here we show that this transgenic line, we named NAS for Notch Activity Sensor, displays an expression profile that is consistent with current knowledge on Notch activity sites in mice, even though it may not report on all these sites. Moreover, we observe that NAS transgene expression is abolished in a RBP-Jκ deficient background indicating that it indeed requires Notch/RBP-Jκ signalling pathway activity. Thus, the NAS transgenic line constitutes a valuable and versatile tool to gain further insights into the complex and various functions of the Notch signalling pathway. PMID:16708386

Rationally optimized cryopreservation of multiple mouse embryonic stem cell lines: I--Comparative fundamental cryobiology of multiple mouse embryonic stem cell lines and the implications for embryonic stem cell cryopreservation protocols.

PubMed

Kashuba, Corinna M; Benson, James D; Critser, John K

2014-04-01

The post-thaw recovery of mouse embryonic stem cells (mESCs) is often assumed to be adequate with current methods. However as this publication will show, this recovery of viable cells actually varies significantly by genetic background. Therefore there is a need to improve the efficiency and reduce the variability of current mESC cryopreservation methods. To address this need, we employed the principles of fundamental cryobiology to improve the cryopreservation protocol of four mESC lines from different genetic backgrounds (BALB/c, CBA, FVB, and 129R1 mESCs) through a comparative study characterizing the membrane permeability characteristics and membrane integrity osmotic tolerance limits of each cell line. In the companion paper, these values were used to predict optimal cryoprotectants, cooling rates, warming rates, and plunge temperatures, and then these predicted optimal protocols were validated against standard freezing protocols. Copyright © 2014 Elsevier Inc. All rights reserved.

Flight Test Evaluation of an Unmanned Aircraft System Traffic Management (UTM) Concept for Multiple Beyond-Visual-Line-of-Sight (BVLOS) Operations

NASA Technical Reports Server (NTRS)

Johnson, Marcus; Jung, Jaewoo; Rios, Joseph; Mercer, Joey; Homola, Jeffrey; Prevot, Thomas; Mulfinger, Daniel; Kopardekar, Parimal

2017-01-01

This study evaluates a traffic management concept designed to enable simultaneous operations of multiple small unmanned aircraft systems (UAS) in the national airspace system (NAS). A five-day flight-test activity is described that examined the feasibility of operating multiple UAS beyond visual line of sight (BVLOS) of their respective operators in the same airspace. Over the five-day campaign, three groups of five flight crews operated a total of eleven different aircraft. Each group participated in four flight scenarios involving five simultaneous missions. Each vehicle was operated BVLOS up to 1.5 miles from the pilot in command. Findings and recommendations are presented to support the feasibility and safety of routine BVLOS operations for small UAS.

Flight Test Evaluation of an Unmanned Aircraft System Traffic Management (UTM) Concept for Multiple Beyond-Visual-Line-of-Sight Operations

NASA Technical Reports Server (NTRS)

Johnson, Marcus; Jung, Jaewoo; Rios, Joseph; Mercer, Joey; Homola, Jeffrey; Prevot, Thomas; Mulfinger, Daniel; Kopardekar, Parimal

2017-01-01

This study evaluates a traffic management concept designed to enable simultaneous operations of multiple small unmanned aircraft systems (UAS) in the national airspace system (NAS). A five-day flight-test activity is described that examined the feasibility of operating multiple UAS beyond visual line of sight (BVLOS) of their respective operators in the same airspace. Over the five-day campaign, three groups of five flight crews operated a total of eleven different aircraft. Each group participated in four flight scenarios involving five simultaneous missions. Each vehicle was operated BVLOS up to 1.5 miles from the pilot in command. Findings and recommendations are presented to support the feasibility and safety of routine BVLOS operations for small UAS.

A common deletion in two gamma ray induced rat pulmonary tumor cell lines.

PubMed

Van Klaveren, P; De Bruijne, J; Van der Winden, H; Kal, H B; Bentvelzen, P

1994-01-01

Subtraction hybridization was performed on normal WAG/Rij rat DNA with DNA from a syngeneic Ir-192 induced pulmonary tumor cell line L37. The residual DNA was amplified by means of sequence-independent PCR. This procedure yielded a sequence, of which multiple copies are present in normal rat DNA. In the tumor line L37 two restriction fragments hybridizing with this repeat sequence are lacking. In another Ir-192 induced pulmonary tumor line, L33, one of these fragments was also lacking. This indicates a common deletion in the two tumor lines.

A cell clone strain from Mythimna separata (Lepidoptera: Noctuidae) highly susceptible to Autographa californica multiple nucleopolyhedrovirus (AcMNPV) and M. separata NPV (MsNPV).

PubMed

Meng, Xiang-Qian; Zheng, Gui-Ling; Zhao, Chuan-De; Wan, Fang-Hao; Li, Chang-You

2017-08-01

In this study, we describe a cell line, Ms-10C, cloned from the line QAU-Ms-E-10 (simplified Ms-10), an embryonic line from Mythimna separata. The cloned cell line was significantly more sensitive to nucleopolyhedrovirus (NPV). Ms-10C cells were mainly spherical with a diameter of 14.42 ± 2.23 μm. DNA amplification fingerprinting (DAF) confirmed the profile of PCR-amplified bands of the cloned cell line was consistent with those of the parental cell line, Ms-10. The sequencing result of the mitochondrial cytochrome c oxidase I (mtCO I) fragment confirmed that the amplified 636-bps mtCOI fragment was 100% identical to that of M. separata. Its chromosomes exhibited the typical characters of lepidopteran cell lines. Its population doubling time was 42.2 h at 27°C. Ms-10C was more sensitive than Ms-10 to both Autographa californica multiple nucleopolyhedrovirus (AcMNPV) and M. separata nucleopolyhedrovirus (MsNPV). At 4 d post infection, the infection rates of two viruses reached 94.2 and 92.3%, respectively. The availability of this cell clone strain will provide a useful tool for the basic research on nucleopolyhedrovirus and for potential application in expression of recombinant proteins with baculovirus expression vector system.

A Phthalimide Derivative That Inhibits Centrosomal Clustering Is Effective on Multiple Myeloma

PubMed Central

Shiheido, Hirokazu; Terada, Fukiko; Tabata, Noriko; Hayakawa, Ichigo; Matsumura, Nobutaka; Takashima, Hideaki; Ogawa, Yoko; Du, Wenlin; Yamada, Taketo; Shoji, Mitsuru; Sugai, Takeshi; Doi, Nobuhide; Iijima, Shiro; Hattori, Yutaka; Yanagawa, Hiroshi

2012-01-01

Despite the introduction of newly developed drugs such as lenalidomide and bortezomib, patients with multiple myeloma are still difficult to treat and have a poor prognosis. In order to find novel drugs that are effective for multiple myeloma, we tested the antitumor activity of 29 phthalimide derivatives against several multiple myeloma cell lines. Among these derivatives, 2-(2,6-diisopropylphenyl)-5-amino-1H-isoindole-1,3- dione (TC11) was found to be a potent inhibitor of tumor cell proliferation and an inducer of apoptosis via activation of caspase-3, 8 and 9. This compound also showed in vivo activity against multiple myeloma cell line KMS34 tumor xenografts in ICR/SCID mice. By means of mRNA display selection on a microfluidic chip, the target protein of TC11 was identified as nucleophosmin 1 (NPM). Binding of TC11 and NPM monomer was confirmed by surface plasmon resonance. Immunofluorescence and NPM knockdown studies in HeLa cells suggested that TC11 inhibits centrosomal clustering by inhibiting the centrosomal-regulatory function of NPM, thereby inducing multipolar mitotic cells, which undergo apoptosis. NPM may become a novel target for development of antitumor drugs active against multiple myeloma. PMID:22761710

Palmprint authentication using multiple classifiers

NASA Astrophysics Data System (ADS)

Kumar, Ajay; Zhang, David

2004-08-01

This paper investigates the performance improvement for palmprint authentication using multiple classifiers. The proposed methods on personal authentication using palmprints can be divided into three categories; appearance- , line -, and texture-based. A combination of these approaches can be used to achieve higher performance. We propose to simultaneously extract palmprint features from PCA, Line detectors and Gabor-filters and combine their corresponding matching scores. This paper also investigates the comparative performance of simple combination rules and the hybrid fusion strategy to achieve performance improvement. Our experimental results on the database of 100 users demonstrate the usefulness of such approach over those based on individual classifiers.

Ultra-relativistic Au+Au and d+Au collisions:

NASA Astrophysics Data System (ADS)

Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Hauer, M.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Seals, H.; Sedykh, I.; Skulski, W.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

In this talk I will review PHOBOS data on charged particle multiplicities, obtained in Au+Au and d+Au collisions at RHIC. The general features of the Au+Au pseudorapidity distributions results will be discussed and compared to those of /line{p}p collisions. The total charged particle multiplicity, scaled by the number of participant pairs, is observed to be about 40% higher in Au+Au collisions than in /line{p}p and d+Au systems, but, surprisingly at the same level of e+e- collisions. Limiting fragmentation scaling is seen to be obeyed in Au+Au collisions.

Current approaches for the treatment of multiple myeloma.

PubMed

Watanabe, Reiko; Tokuhira, Michihide; Kizaki, Masahiro

2013-03-01

The development of novel therapeutic agents over the past decade, including the proteasome inhibitor, bortezomib, and the immunomodulatory drugs, lenalidomide and thalidomide, has resulted in improved outcomes for patients with multiple myeloma. However, there is still considerable controversy as to which regimen should be used as first-line therapy, which patients should be considered for autologous or allogeneic transplantation, and how consolidation or maintenance therapy is used in patients that have a good response to first-line therapy. The present paper will review clinical evidence from previous and ongoing studies to explore issues related to these questions.

Left-handed compact MIMO antenna array based on wire spiral resonator for 5-GHz wireless applications

NASA Astrophysics Data System (ADS)

Alqadami, Abdulrahman Shueai Mohsen; Jamlos, Mohd Faizal; Soh, Ping Jack; Rahim, Sharul Kamal Abdul; Narbudowicz, Adam

2017-01-01

A compact coplanar waveguide-fed multiple-input multiple-output antenna array based on the left-handed wire loaded spiral resonators (SR) is presented. The proposed antenna consists of a 2 × 2 wire SR with two symmetrical microstrip feed lines, each line exciting a 1 × 2 wire SR. Left-handed metamaterial unit cells are placed on its reverse side and arranged in a 2 × 3 array. A reflection coefficient of less than -16 dB and mutual coupling of less than -28 dB are achieved at 5.15 GHz WLAN band.

Audiences for the Theory of Multiple Intelligences

ERIC Educational Resources Information Center

Gardner, Howard

2004-01-01

In his closing comments, Howard Gardner discusses the various audiences that have emerged over the years for the theory of multiple intelligences. Under that rubric, he places the various papers in this issue and speculates about future lines of work on MI theory.

Effects Of Frame Rates In Video Displays

NASA Technical Reports Server (NTRS)

Kellogg, Gary V.; Wagner, Charles A.

1991-01-01

Report describes experiment on subjective effects of rates at which display on cathode-ray tube in flight simulator updated and refreshed. Conducted to learn more about jumping, blurring, flickering, and multiple lines that observer perceives when line moves at high speed across screen of a calligraphic CRT.

Hair follicle nevus in a distribution following Blaskho's lines.

PubMed

Germain, Marguerite; Smith, Kathleen J

2002-05-01

We present a case of a rare follicular hamartoma, a hair follicle nevus. Although most previous reports have been solitary lesions, the case we are reporting had multiple papules and nodules following Blaskho's lines. There have been no reports of malignancies arising in these hamartomas.

Momentum deposition on Wolf-Rayet winds: Nonisotropic diffusion with effective gray opacity

NASA Technical Reports Server (NTRS)

Gayley, Kenneth G.; Owocki, Stanley P.; Cranmer, Steven R.

1995-01-01

We derive the velocity and mass-loss rate of a steady state Wolf-Rayet (WR) wind, using a nonisotropic diffusion approximation applied to the transfer between strongly overlapping spectral lines. Following the approach of Friend & Castor (1983), the line list is assumed to approximate a statistically parameterized Poisson distribution in frequency, so that photon transport is controlled by an angle-dependent, effectively gray opacity. We show the nonisotropic diffusion approximation yields good agreement with more accurate numerical treatments of the radiative transfer, while providing analytic insight into wind driving by multiple scattering. We illustrate, in particular, that multiple radiative momentum deposition does not require that potons be repeatedly reflected across substantial distances within the spherical envelope, but indeed is greatest when photons undergo a nearly local diffusion, e.g., through scattering by many lines closely spaced in frequency. Our results reiterate the view that the so-called 'momentum problem' of Wolf-Rayet winds is better characterized as an 'opacity problem' of simply identfying enough lines. One way of increasing the number of thick lines in Wolf-Rayet winds is to transfer opacity from saturated to unsaturated lines, yielding a steeper opacity distribution than that found in OB winds. We discuss the implications of this perspective for extending our approach to W-R wind models that incorporate a more fundamental treatment of the ionization and excitation processes that determine the line opacity. In particular, we argue that developing statistical descriptions of the lines to allow an improved effective opacity for the line ensemble would offer several advantages for deriving such more fundamental W-R wind models.

Momentum deposition on Wolf-Rayet winds: Nonisotropic diffusion with effective gray opacity

NASA Astrophysics Data System (ADS)

Gayley, Kenneth G.; Owocki, Stanley P.; Cranmer, Steven R.

1995-03-01

We derive the velocity and mass-loss rate of a steady state Wolf-Rayet (WR) wind, using a nonisotropic diffusion approximation applied to the transfer between strongly overlapping spectral lines. Following the approach of Friend & Castor (1983), the line list is assumed to approximate a statistically parameterized Poisson distribution in frequency, so that photon transport is controlled by an angle-dependent, effectively gray opacity. We show the nonisotropic diffusion approximation yields good agreement with more accurate numerical treatments of the radiative transfer, while providing analytic insight into wind driving by multiple scattering. We illustrate, in particular, that multiple radiative momentum deposition does not require that photons be repeatedly reflected across substantial distances within the spherical envelope, but indeed is greatest when photons undergo a nearly local diffusion, e.g., through scattering by many lines closely spaced in frequency. Our results reiterate the view that the so-called 'momentum problem' of Wolf-Rayet winds is better characterized as an 'opacity problem' of simply identifying enough lines. One way of increasing the number of thick lines in Wolf-Rayet winds is to transfer opacity from saturated to unsaturated lines, yielding a steeper opacity distribution than that found in OB winds. We discuss the implications of this perspective for extending our approach to W-R wind models that incorporate a more fundamental treatment of the ionization and excitation processes that determine the line opacity. In particular, we argue that developing statistical descriptions of the lines to allow an improved effective opacity for the line ensemble would offer several advantages for deriving such more fundamental W-R wind models.

What is the benefit of treatment with multiple lines of chemotherapy for patients with metastatic breast cancer? A retrospective cohort study.

PubMed

Bakker, J L; Wever, K; van Waesberghe, J H; Beeker, A; Meijers-Heijboer, H; Konings, I R; Verheul, H M W

2015-12-01

Despite the extensive clinical experience, it is still under debate to what extent patients with metastatic breast cancer (MBC) benefit from multiple lines of chemotherapy beyond standard first or second line treatment. Selection of patients with MBC who will benefit from treatment is crucial to improve outcome and reduce unnecessary toxicity. In this retrospective study, systemic treatment outcome for patients with metastatic MBC is being evaluated. We evaluated to what extent the clinical benefit of prior chemotherapy can predict the success of a subsequent treatment line. Ninety-one patients treated with chemotherapy for MBC between January 2005 and January 2009 were included in this study. Clinical characteristics of patients, choices of chemotherapy and response at first evaluation of every treatment line was evaluated based on radiologic and clinical data. Patients received multiple systemic cytotoxic and biological (combination) therapies. 30% of these patients received more than five consecutive systemic (combination) treatments. First line chemotherapy was mostly anthracycline-based, followed by taxanes, capecitabine and vinorelbine. The response rate (RR, complete response plus partial response according to RECIST 1.1) decreased from 20% (95% CI 11-28%) upon first line of treatment to 0% upon the fourth line. The clinical benefit rate (combining RR and stable disease) decreased from 85% (95% CI 78-93%) in the first to 54% (95% CI 26-67) upon the fourth line. 24% of the patients with clinical benefit at first evaluation did not receive a subsequent line of treatment when progressive disease occurred, while sixty-one percent of the patients with progressive disease at first evaluation of a treatment did not receive a subsequent line of chemotherapy. When applied, the efficacy of a subsequent line of treatment was similar for patients independent of previous treatment benefit. The clinical benefit at first evaluation from systemic treatment in MBC does not predict for subsequent treatment benefit in this retrospective analysis. The fact that 61% of patients did not receive subsequent treatment after previous treatment failure suggests that either clinical judgement is of critical value in selection of patients to prevent them from unnecessary toxicity or, alternatively indicates that based on the assumption that prior treatment failure predicts for lack of benefit undertreatment of patients occurs. Therefore, a more adequate clinical judgement tool or predictive biomarkers for response are urgently needed to improve treatment outcome. Copyright © 2015. Published by Elsevier Ltd.

Integrative Exploratory Analysis of Two or More Genomic Datasets.

PubMed

Meng, Chen; Culhane, Aedin

2016-01-01

Exploratory analysis is an essential step in the analysis of high throughput data. Multivariate approaches such as correspondence analysis (CA), principal component analysis, and multidimensional scaling are widely used in the exploratory analysis of single dataset. Modern biological studies often assay multiple types of biological molecules (e.g., mRNA, protein, phosphoproteins) on a same set of biological samples, thereby creating multiple different types of omics data or multiassay data. Integrative exploratory analysis of these multiple omics data is required to leverage the potential of multiple omics studies. In this chapter, we describe the application of co-inertia analysis (CIA; for analyzing two datasets) and multiple co-inertia analysis (MCIA; for three or more datasets) to address this problem. These methods are powerful yet simple multivariate approaches that represent samples using a lower number of variables, allowing a more easily identification of the correlated structure in and between multiple high dimensional datasets. Graphical representations can be employed to this purpose. In addition, the methods simultaneously project samples and variables (genes, proteins) onto the same lower dimensional space, so the most variant variables from each dataset can be selected and associated with samples, which can be further used to facilitate biological interpretation and pathway analysis. We applied CIA to explore the concordance between mRNA and protein expression in a panel of 60 tumor cell lines from the National Cancer Institute. In the same 60 cell lines, we used MCIA to perform a cross-platform comparison of mRNA gene expression profiles obtained on four different microarray platforms. Last, as an example of integrative analysis of multiassay or multi-omics data we analyzed transcriptomic, proteomic, and phosphoproteomic data from pluripotent (iPS) and embryonic stem (ES) cell lines.

Introduction of new genetic markers on human chromosomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Satoh, Hitoshi; Barrett, J.C.; Oshimura, Mitsuo

1991-03-01

The purpose of this study was to use DNA transfection and microcell chromosome transfer techniques to engineer a human chromosome containing multiple biochemical markers for which selectable growth conditions exist. The starting chromosome was a t(X;3)(3pter{yields}3p12::Xq26{yields}Xpter) chromosome from a reciprocal translocation in the normal human fibroblast cell line GM0439. This chromosome was transferred to a HPRT (hypoxanthine phosphoribosyltransferase)-deficient mouse A9 cell line by microcell fusion and selected under growth conditions for the HPRT gene on the human t(X;3) chromosome. A resultant HAT-resistant cell line (A9(GM0439)-1) contained a single human t(X;3) chromosome. These results demonstrate that microcell chromosome transfer can bemore » used to select chromosomes containing multiple markers.« less

Single transmission line data acquisition system

DOEpatents

Fasching, George E.

1984-01-01

A single transmission line interrogated multiple channel data acquisition system is provided in which a plurality of remote station/sensors monitor specific process variables and transmit measurement values over the single transmission line to a master station when addressed by the master station. Power for all remote stations (up to 980) is provided by driving the line with constant voltage supplied from the master station and automatically maintained independent of the number of remote stations directly connected to the line. The transmission line can be an RG-62 coaxial cable with lengths up to about 10,000 feet with branches up to 500 feet. The remote stations can be attached randomly along the line. The remote stations can be scanned at rates up to 980 channels/second.

1D design style implications for mask making and CEBL

NASA Astrophysics Data System (ADS)

Smayling, Michael C.

2013-09-01

At advanced nodes, CMOS logic is being designed in a highly regular design style because of the resolution limitations of optical lithography equipment. Logic and memory layouts using 1D Gridded Design Rules (GDR) have been demonstrated to nodes beyond 12nm.[1-4] Smaller nodes will require the same regular layout style but with multiple patterning for critical layers. One of the significant advantages of 1D GDR is the ease of splitting layouts into lines and cuts. A lines and cuts approach has been used to achieve good pattern fidelity and process margin to below 12nm.[4] Line scaling with excellent line-edge roughness (LER) has been demonstrated with self-aligned spacer processing.[5] This change in design style has important implications for mask making: • The complexity of the masks will be greatly reduced from what would be required for 2D designs with very complex OPC or inverse lithography corrections. • The number of masks will initially increase, as for conventional multiple patterning. But in the case of 1D design, there are future options for mask count reduction. • The line masks will remain simple, with little or no OPC, at pitches (1x) above 80nm. This provides an excellent opportunity for continual improvement of line CD and LER. The line pattern will be processed through a self-aligned pitch division sequence to divide pitch by 2 or by 4. • The cut masks can be done with "simple OPC" as demonstrated to beyond 12nm.[6] Multiple simple cut masks may be required at advanced nodes. "Coloring" has been demonstrated to below 12nm for two colors and to 8nm for three colors. • Cut/hole masks will eventually be replaced by e-beam direct write using complementary e-beam lithography (CEBL).[7-11] This transition is gated by the availability of multiple column e-beam systems with throughput adequate for high- volume manufacturing. A brief description of 1D and 2D design styles will be presented, followed by examples of 1D layouts. Mask complexity for 1D layouts patterned directly will be compared to mask complexity for lines and cuts at nodes larger than 20nm. No such comparison is possible below 20nm since single-patterning does not work below ~80nm pitch using optical exposure tools. Also discussed will be recently published wafer results for line patterns with pitch division by-2 and by-4 at sub-12nm nodes, plus examples of post-etch results for 1D patterns done with cut masks and compared to cuts exposed by a single-column e-beam direct write system.

Molecular characterization of neoplastic and normal "sister" lymphoblastoid B-cell lines from chronic lymphocytic leukemia.

PubMed

Lanemo Myhrinder, Anna; Hellqvist, Eva; Bergh, Ann-Charlotte; Jansson, Mattias; Nilsson, Kenneth; Hultman, Per; Jonasson, Jon; Buhl, Anne Mette; Bredo Pedersen, Lone; Jurlander, Jesper; Klein, Eva; Weit, Nicole; Herling, Marco; Rosenquist, Richard; Rosén, Anders

2013-08-01

Chronic lymphocytic leukemia (CLL) B-cells resemble self-renewing CD5 + B-cells carrying auto/xeno-antigen-reactive B-cell receptors (BCRs) and multiple innate pattern-recognition receptors, such as Toll-like receptors and scavenger receptors. Integration of signals from BCRs with multiple surface membrane receptors determines whether the cells will be proliferating, anergic or apoptotic. To better understand the role of antigen in leukemogenesis, CLL cell lines producing monoclonal antibodies (mAbs) will facilitate structural analysis of antigens and supply DNA for genetic studies. We present here a comprehensive genotypic and phenotypic characterization of available CLL and normal B-cell-derived lymphoblastoid cell lines (LCLs) from the same individuals (n = 17). Authenticity and verification studies of CLL-patient origin were done by IGHV sequencing, fluorescence in situ hybridization (FISH) and DNA/short tandem repeat (STR) fingerprinting. Innate B-cell features, i.e. natural Ab production and CD5 receptors, were present in most CLL cell lines, but in none of the normal LCLs. This panel of immortalized CLL-derived cell lines is a valuable reference representing a renewable source of authentic Abs and DNA.

12. TYPICAL CONCRETELINED CANAL/FLUME TRANSITION (LOCATED JUST WEST OF HIGHWAY ...

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

12. TYPICAL CONCRETE-LINED CANAL/FLUME TRANSITION (LOCATED JUST WEST OF HIGHWAY 190 CROSSOVER). WATER CONVEYANCE SYSTEM IS COMPRISED OF MULTIPLE INTERSET CONCRETE-LINED CANAL AND FLUME SECTIONS. VIEW TO WEST. - Tule River Hydroelectric Project, Water Conveyance System, Middle Fork Tule River, Springville, Tulare County, CA

Edge Effects in Line Intersect Sampling With

Treesearch

David L. R. Affleck; Timothy G. Gregoire; Harry T. Valentine

2005-01-01

Transects consisting of multiple, connected segments with a prescribed configuration are commonly used in ecological applications of line intersect sampling. The transect configuration has implications for the probability with which population elements are selected and for how the selection probabilities can be modified by the boundary of the tract being sampled. As...

CTF User's Manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Avramova, Maria; Blyth, Taylor S.; Salko, Robert K.

This document describes how to make a CTF input deck. A CTF input deck is organized into Card Groups and Cards. A Card Group is a collection of Cards. A Card is defined as a line of input. Each Card may contain multiple data. A Card is terminated by making a new line.

Design unbiased estimation in line intersect sampling using segmented transects

Treesearch

David L.R. Affleck; Timothy G. Gregoire; Harry T. Valentine; Harry T. Valentine

2005-01-01

In many applications of line intersect sampling. transects consist of multiple, connected segments in a prescribed configuration. The relationship between the transect configuration and the selection probability of a population element is illustrated and a consistent sampling protocol, applicable to populations composed of arbitrarily shaped elements, is proposed. It...

Building with a Line

ERIC Educational Resources Information Center

Hubbert, Beth

2011-01-01

Architecture is a versatile, multifaceted area to study in the artroom with multiple age levels. It can easily stimulate a study of basic line, shape, and various other art elements and principles. It can then be extended into a more extensive study of architectural elements, styles, specific architects, architecture of different cultures, and…

WATER VAPOR IN NEARBY INFRARED GALAXIES AS PROBED BY HERSCHEL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang Chentao; Gao Yu; Liu Daizhong

2013-07-10

We report the first systematic study of the submillimeter water vapor rotational emission lines in infrared (IR) galaxies based on the Fourier Transform Spectrometer (FTS) data of Herschel SPIRE. Among the 176 galaxies with publicly available FTS data, 45 have at least one H{sub 2}O emission line detected. The H{sub 2}O line luminosities range from {approx}1 Multiplication-Sign 10{sup 5} L{sub Sun} to {approx}5 Multiplication-Sign 10{sup 7} L{sub Sun} while the total IR luminosities (L{sub IR}) have a similar spread ({approx}1-300 Multiplication-Sign 10{sup 10} L{sub Sun }). In addition, emission lines of H{sub 2}O{sup +} and H{sub 2}{sup 18}O are alsomore » detected. H{sub 2}O is found, for most galaxies, to be the strongest molecular emitter after CO in FTS spectra. The luminosity of the five most important H{sub 2}O lines is near-linearly correlated with L{sub IR}, regardless of whether or not strong active galactic nucleus signature is present. However, the luminosity of H{sub 2}O(2{sub 11}-2{sub 02}) and H{sub 2}O(2{sub 20}-2{sub 11}) appears to increase slightly faster than linear with L{sub IR}. Although the slope turns out to be slightly steeper when z {approx} 2-4 ULIRGs are included, the correlation is still closely linear. We find that L{sub H{sub 2O}}/L{sub IR} decreases with increasing f{sub 25}/f{sub 60}, but see no dependence on f{sub 60}/f{sub 100}, possibly indicating that very warm dust contributes little to the excitation of the submillimeter H{sub 2}O lines. The average spectral line energy distribution (SLED) of the entire sample is consistent with individual SLEDs and the IR pumping plus collisional excitation model, showing that the strongest lines are H{sub 2}O(2{sub 02}-1{sub 11}) and H{sub 2}O(3{sub 21}-3{sub 12}).« less

Radial velocities of southern visual multiple stars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tokovinin, Andrei; Pribulla, Theodor; Fischer, Debra, E-mail: atokovinin@ctio.noao.edu, E-mail: pribulla@ta3.sk, E-mail: debra.fischer@gmail.com

2015-01-01

High-resolution spectra of visual multiple stars were taken in 2008–2009 to detect or confirm spectroscopic subsystems and to determine their orbits. Radial velocities of 93 late-type stars belonging to visual multiple systems were measured by numerical cross-correlation. We provide the individual velocities, the width, and the amplitude of the Gaussians that approximate the correlations. The new information on the multiple systems resulting from these data is discussed. We discovered double-lined binaries in HD 41742B, HD 56593C, and HD 122613AB, confirmed several other known subsystems, and constrained the existence of subsystems in some visual binaries where both components turned out tomore » have similar velocities. The orbits of double-lined subsystems with periods of 148 and 13 days are computed for HD 104471 Aa,Ab and HD 210349 Aa,Ab, respectively. We estimate individual magnitudes and masses of the components in these triple systems and update the outer orbit of HD 104471 AB.« less

Geometric descriptions of entangled states by auxiliary varieties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holweck, Frederic; Luque, Jean-Gabriel; Thibon, Jean-Yves

2012-10-15

The aim of the paper is to propose geometric descriptions of multipartite entangled states using algebraic geometry. In the context of this paper, geometric means each stratum of the Hilbert space, corresponding to an entangled state, is an open subset of an algebraic variety built by classical geometric constructions (tangent lines, secant lines) from the set of separable states. In this setting, we describe well-known classifications of multipartite entanglement such as 2 Multiplication-Sign 2 Multiplication-Sign (n+ 1), for n Greater-Than-Or-Slanted-Equal-To 1, quantum systems and a new description with the 2 Multiplication-Sign 3 Multiplication-Sign 3 quantum system. Our results complete themore » approach of Miyake and make stronger connections with recent work of algebraic geometers. Moreover, for the quantum systems detailed in this paper, we propose an algorithm, based on the classical theory of invariants, to decide to which subvariety of the Hilbert space a given state belongs.« less

The Grism Lens-amplified Survey from Space (GLASS). IV. Mass Reconstruction of the Lensing Cluster Abell 2744 from Frontier Field Imaging and GLASS Spectroscopy

NASA Astrophysics Data System (ADS)

Wang, X.; Hoag, A.; Huang, K.-H.; Treu, T.; Bradač, M.; Schmidt, K. B.; Brammer, G. B.; Vulcani, B.; Jones, T. A.; Ryan, R. E., Jr.; Amorín, R.; Castellano, M.; Fontana, A.; Merlin, E.; Trenti, M.

2015-09-01

We present a strong and weak lensing reconstruction of the massive cluster Abell 2744, the first cluster for which deep Hubble Frontier Fields (HFF) images and spectroscopy from the Grism Lens-Amplified Survey from Space (GLASS) are available. By performing a targeted search for emission lines in multiply imaged sources using the GLASS spectra, we obtain five high-confidence spectroscopic redshifts and two tentative ones. We confirm one strongly lensed system by detecting the same emission lines in all three multiple images. We also search for additional line emitters blindly and use the full GLASS spectroscopic catalog to test reliability of photometric redshifts for faint line emitters. We see a reasonable agreement between our photometric and spectroscopic redshift measurements, when including nebular emission in photometric redshift estimations. We introduce a stringent procedure to identify only secure multiple image sets based on colors, morphology, and spectroscopy. By combining 7 multiple image systems with secure spectroscopic redshifts (at 5 distinct redshift planes) with 18 multiple image systems with secure photometric redshifts, we reconstruct the gravitational potential of the cluster pixellated on an adaptive grid, using a total of 72 images. The resulting mass map is compared with a stellar mass map obtained from the deep Spitzer Frontier Fields data to study the relative distribution of stars and dark matter in the cluster. We find that the stellar to total mass ratio varies substantially across the cluster field, suggesting that stars do not trace exactly the total mass in this interacting system. The maps of convergence, shear, and magnification are made available in the standard HFF format.

Experiences in anti-tuberculosis treatment in patients with multiple previous treatments and its impact on drug resistant tuberculosis epidemics

PubMed Central

Xu, Biao; Zhao, Qi; Hu, Yi; Shi, Ying; Wang, Weibing; Diwan, Vinod K.

2014-01-01

Background Tuberculosis (TB) patients with a history of multiple anti-TB treatments are the ‘neglected’ group to the free anti-TB treatment policy in China. Objective To understand the experiences of TB patients with multiple previous treatments with regard to bacteriological diagnosis and treatment regimens, especially for second-line anti-TB drugs, and how this might influence the risks of multidrug and extensively drug-resistant TB (M/XDR-TB). Design A cross-sectional study was conducted in 10 county/district TB clinics in five provinces of China. The study participants were TB patients that had at least two previous treatment episodes that lasted longer than 1 month each. Face-to-face interviews and drug susceptibility testing (DST) were conducted with the consenting participants. Results A total of 328 TB patients were recruited. The proportion of multidrug-resistant tuberculosis (MDR-TB) was 58.2% in the 287 DST-confirmed patients. Forty-two percent of the patients did not complete their first treatment course. About 23.8% of the participants had a history of taking second-line drugs, and more than 77.8% of them were treated in county TB dispensaries where only sputum microscopy was applied. Multivariate analysis found that the use of second-line drugs was significantly associated with frequency of previous treatments (p<0.01), but not with drug resistance profiles of patients. Conclusions Patients with multiple previous treatments are at extremely high risk of MDR-TB in China. The unregulated use of second-line drugs bring about the threat of XDR-TB epidemic. DST-guided treatment and strict regulations of anti-TB treatment should be assured for the high-risk TB patients for the prevention and control of M/XDR-TB. PMID:25138531

Adhesive interactions of human multiple myeloma cell lines with different extracellular matrix molecules.

PubMed

Kibler, C; Schermutzki, F; Waller, H D; Timpl, R; Müller, C A; Klein, G

1998-06-01

Multiple myeloma represents a human B cell malignancy which is characterized by a predominant localization of the malignant cell clone within the bone marrow. With the exception of the terminal stage of the disease the myeloma tumor cells do not circulate in the peripheral blood. The bone marrow microenvironment is believed to play an important role in homing, proliferation and terminal differentiation of myeloma cells. Here we have studied the expression of several extracellular matrix (ECM) molecules in the bone marrow of multiple myeloma patients and analyzed their adhesive capacities with four different human myeloma-derived cell lines. All ECM molecules analyzed (tenascin, laminin, fibronectin, collagen types I, III, V and VI) could be detected in bone marrow cryostat sections of multiple myeloma patients. Adhesion assays showed that only laminin, the microfibrillar collagen type VI and fibronectin were strong adhesive components for the myeloma cell lines U266, IM-9, OPM-2 and NCI-H929. Tenascin and collagen type I were only weak adhesive substrates for these myeloma cells. Adhesion to laminin and fibronectin was beta 1-integrin-mediated since addition of anti-beta 1-integrin antibodies could inhibit the binding of the four different cell types to both matrix molecules. In contrast, integrins do not seem to be involved in binding of the myeloma cells to collagen type VI. Instead, inhibition of binding by heparin suggested that membrane-bound heparan sulfate proteoglycans are responsible ligands for binding to collagen type VI. Adhesion assays with several B-cell lines resembling earlier differentiation stages revealed only weak interactions with tenascin and no interactions with collagen type VI, laminin or fibronectin. In summary, the interactions of human myeloma cells with the extracellular matrix may explain the specific retention of the plasma cells within the bone marrow.

Image synchronization for 3D application using the NanEye sensor

NASA Astrophysics Data System (ADS)

Sousa, Ricardo M.; Wäny, Martin; Santos, Pedro; Dias, Morgado

2015-03-01

Based on Awaiba's NanEye CMOS image sensor family and a FPGA platform with USB3 interface, the aim of this paper is to demonstrate a novel technique to perfectly synchronize up to 8 individual self-timed cameras. Minimal form factor self-timed camera modules of 1 mm x 1 mm or smaller do not generally allow external synchronization. However, for stereo vision or 3D reconstruction with multiple cameras as well as for applications requiring pulsed illumination it is required to synchronize multiple cameras. In this work, the challenge to synchronize multiple self-timed cameras with only 4 wire interface has been solved by adaptively regulating the power supply for each of the cameras to synchronize their frame rate and frame phase. To that effect, a control core was created to constantly monitor the operating frequency of each camera by measuring the line period in each frame based on a well-defined sampling signal. The frequency is adjusted by varying the voltage level applied to the sensor based on the error between the measured line period and the desired line period. To ensure phase synchronization between frames of multiple cameras, a Master-Slave interface was implemented. A single camera is defined as the Master entity, with its operating frequency being controlled directly through a PC based interface. The remaining cameras are setup in Slave mode and are interfaced directly with the Master camera control module. This enables the remaining cameras to monitor its line and frame period and adjust their own to achieve phase and frequency synchronization. The result of this work will allow the realization of smaller than 3mm diameter 3D stereo vision equipment in medical endoscopic context, such as endoscopic surgical robotic or micro invasive surgery.

THE GRISM LENS-AMPLIFIED SURVEY FROM SPACE (GLASS). IV. MASS RECONSTRUCTION OF THE LENSING CLUSTER ABELL 2744 FROM FRONTIER FIELD IMAGING AND GLASS SPECTROSCOPY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, X.; Schmidt, K. B.; Jones, T. A.

2015-09-20

We present a strong and weak lensing reconstruction of the massive cluster Abell 2744, the first cluster for which deep Hubble Frontier Fields (HFF) images and spectroscopy from the Grism Lens-Amplified Survey from Space (GLASS) are available. By performing a targeted search for emission lines in multiply imaged sources using the GLASS spectra, we obtain five high-confidence spectroscopic redshifts and two tentative ones. We confirm one strongly lensed system by detecting the same emission lines in all three multiple images. We also search for additional line emitters blindly and use the full GLASS spectroscopic catalog to test reliability of photometricmore » redshifts for faint line emitters. We see a reasonable agreement between our photometric and spectroscopic redshift measurements, when including nebular emission in photometric redshift estimations. We introduce a stringent procedure to identify only secure multiple image sets based on colors, morphology, and spectroscopy. By combining 7 multiple image systems with secure spectroscopic redshifts (at 5 distinct redshift planes) with 18 multiple image systems with secure photometric redshifts, we reconstruct the gravitational potential of the cluster pixellated on an adaptive grid, using a total of 72 images. The resulting mass map is compared with a stellar mass map obtained from the deep Spitzer Frontier Fields data to study the relative distribution of stars and dark matter in the cluster. We find that the stellar to total mass ratio varies substantially across the cluster field, suggesting that stars do not trace exactly the total mass in this interacting system. The maps of convergence, shear, and magnification are made available in the standard HFF format.« less

The firehose instability during multiple reconnection in the Earth's magnetotail

NASA Astrophysics Data System (ADS)

Alexandrova, Alexandra; Divin, Andrey; Retino, Alessandro; Deca, Jan; Catapano, Filomena; Cozzani, Giulia

2017-04-01

We found unique events in the Cluster spacecraft observations of the Earth's magnetotail which correspond to the case of multiple reconnection sites. The ion temperature anisotropy of more energized ions in the direction parallel to the magnetic field, rather than in the perpendicular direction, is observed in the region of dynamical interaction between two active X-lines. The magnetic field and plasma parameters associated with the anisotropy correspond to the firehose instability conditions. We discuss possible scenarios of development of the firehose instability in multiple reconnection by comparing the observations with numerical simulations. Conventional Particle-in-Cell simulations of 2D magnetic reconnection starting from Harris equilibria are performed using implicit PIC code iPIC3D [Markidis, 2010]. At earlier stages the evolution creates fronts which push the weakly magnetized current sheet plasma away from the X-line. Fronts accelerate and reflect particles, producing parallel ion beams and increasing parallel ion temperature ahead of the front. If multiple X-lines are present, then the counterstreaming ion beams appear inside the original current sheet between colliding reconnection jet fronts. For large enough parallel ion pressure anisotropy, the firehose-like mode is excited inside the original current sheet with a flapping-like appearance along the X GSM direction but not Y GSM (current) direction. One should note that our simulations do not include the Bz magnetic field component (normal to the current sheet), hence ion beams cannot escape into the lobes and the whole region between two colliding fronts is unstable to firehose-like instability. In the Earth's magnetotail such configuration likely occurs when two active X-lines are close enough to each other, similar to a few cases we found in the Cluster observations.

Achievement of First-, Second-, and Third-Grade Students on Multiplication and Division Word Problems in Two Different Solution Environments.

ERIC Educational Resources Information Center

O'Brien, Aileen; Cabral, Sheryl Ann

This is a project in an emerging line of research investigating children's informed knowledge of mathematics questions. The purpose of this study was to analyze the ability of students who had not received multiplication or division instruction to solve multiplication and division word problems. The study consisted of videotaped interviews with 89…

Real-world Outcomes of Multiple Myeloma: Retrospective Analysis of the Czech Registry of Monoclonal Gammopathies.

PubMed

Hájek, Roman; Jarkovsky, Jiri; Maisnar, Vladimír; Pour, Ludek; Špička, Ivan; Minařík, Jiri; Gregora, Evžen; Kessler, Petr; Sýkora, Michal; Fraňková, Hana; Campioni, Marco; DeCosta, Lucy; Treur, Maarten; Gonzalez-McQuire, Sebastian; Bouwmeester, Walter

2018-06-01

Real-world data on patient outcomes and treatment patterns in multiple myeloma (MM) are limited. The present noninterventional, observational, retrospective analysis of prospectively collected Czech patient medical record data from the Registry of Monoclonal Gammopathies estimated real-world outcomes in adults with a diagnosis of symptomatic MM made between May 2007 and June 2014. In total, 2446 patients had initiated first-line treatment. The median overall survival since the diagnosis (primary endpoint) was 50.3 months (95% confidence interval, 46.1-54.5 months) and decreased with each successive treatment line. A similar trend was observed for progression-free survival and the depth of response. In line with European guidelines and clinical practice, bortezomib-, thalidomide-, and lenalidomide-based regimens were most commonly used across all treatment lines (42.3%, 28.9%, and 18.4%, respectively). In the first line, bortezomib and thalidomide were used most often, with lenalidomide the most commonly used agent in the relapse setting (second to fourth lines). Exploratory analyses revealed that younger age (≤ 65 years), lower international staging system stage, and previous stem cell transplantation were associated with significant improvements in overall and progression-free survival, especially in the early treatment lines. The present study is the first analysis of Czech data from the Registry of Monoclonal Gammopathies, and it provides important insights into the real-world management of MM for physicians and healthcare providers. Copyright © 2018 Elsevier Inc. All rights reserved.

Detection of genomic signatures of recent selection in commercial broiler chickens.

PubMed

Fu, Weixuan; Lee, William R; Abasht, Behnam

2016-08-26

Identification of the genomic signatures of recent selection may help uncover causal polymorphisms controlling traits relevant to recent decades of selective breeding in livestock. In this study, we aimed at detecting signatures of recent selection in commercial broiler chickens using genotype information from single nucleotide polymorphisms (SNPs). A total of 565 chickens from five commercial purebred lines, including three broiler sire (male) lines and two broiler dam (female) lines, were genotyped using the 60K SNP Illumina iSelect chicken array. To detect genomic signatures of recent selection, we applied two methods based on population comparison, cross-population extended haplotype homozygosity (XP-EHH) and cross-population composite likelihood ratio (XP-CLR), and further analyzed the results to find genomic regions under recent selection in multiple purebred lines. A total of 321 candidate selection regions spanning approximately 1.45 % of the chicken genome in each line were detected by consensus of results of both XP-EHH and XP-CLR methods. To minimize false discovery due to genetic drift, only 42 of the candidate selection regions that were shared by 2 or more purebred lines were considered as high-confidence selection regions in the study. Of these 42 regions, 20 were 50 kb or less while 4 regions were larger than 0.5 Mb. In total, 91 genes could be found in the 42 regions, among which 19 regions contained only 1 or 2 genes, and 9 regions were located at gene deserts. Our results provide a genome-wide scan of recent selection signatures in five purebred lines of commercial broiler chickens. We found several candidate genes for recent selection in multiple lines, such as SOX6 (Sex Determining Region Y-Box 6) and cTR (Thyroid hormone receptor beta). These genes may have been under recent selection due to their essential roles in growth, development and reproduction in chickens. Furthermore, our results suggest that in some candidate regions, the same or opposite alleles have been under recent selection in multiple lines. Most of the candidate genes in the selection regions are novel, and as such they should be of great interest for future research into the genetic architecture of traits relevant to modern broiler breeding.

Safety and Efficacy of Fingolimod and Natalizumab in Multiple Sclerosis After the Failure of First-Line Therapy: Single Center Experience Based on the Treatment of Forty-Four Patients.

PubMed

Puz, Przemysław; Lasek-Bal, Anetta

2016-11-10

BACKGROUND In Poland, natalizumab or fingolimod treatment can be delivered as a second-line therapy to those patients with relapsing-remitting multiple sclerosis (RRMS) who demonstrated no response to interferon or glatiramer acetate treatment for a minimum of one year. MATERIAL AND METHODS Analysis covered 44 RRMS patients switched from first- to second-line therapy. The annualized relapse rate, disability progression (assessed with Expanded Disability Status Scale, EDSS) and MRI results (new or enlarged T2 lesions and new Gd-positive lesions) before and after switching were compared. The occurrence of adverse events was also assessed. RESULTS The annualized relapse rate for second-line therapy was significantly lower than for first-line therapy (0.35±0.74 vs. 2.13±0.87, p=0.00005). Median of EDSS progression with first-line therapy was significantly higher than that with natalizumab or fingolimod treatment (p=0.00002). The mean number of new or enlarged T2 and Gd+ lesions in MRI after one-year second-line treatment was significantly lower in comparison to lesions in MRI performed at the end of the first-line therapy (for T2: 0.61 vs. 4.56, p=0.0004; for Gd+: 0.13 vs. 1.98, p=0.0009). No significant differences in the clinical data, MRI results, and side effects between fingolimod and natalizumab patients have been observed. CONCLUSIONS Treatment with natalizumab or fingolimod as a second-line therapy in RRMS patients is safe and effective. Less restrictive criteria for switching should be considered.

Genomic vulnerability to LINE-1 hypomethylation is a potential determinant of the clinicogenetic features of multiple myeloma

PubMed Central

2012-01-01

Background The aim of this study was to clarify the role of global hypomethylation of repetitive elements in determining the genetic and clinical features of multiple myeloma (MM). Methods We assessed global methylation levels using four repetitive elements (long interspersed nuclear element-1 (LINE-1), Alu Ya5, Alu Yb8, and Satellite-α) in clinical samples comprising 74 MM samples and 11 benign control samples (7 cases of monoclonal gammopathy of undetermined significance (MGUS) and 4 samples of normal plasma cells (NPC)). We also evaluated copy-number alterations using array-based comparative genomic hybridization, and performed methyl-CpG binding domain sequencing (MBD-seq). Results Global levels of the repetitive-element methylation declined with the degree of malignancy of plasma cells (NPC>MGUS>MM), and there was a significant inverse correlation between the degree of genomic loss and the LINE-1 methylation levels. We identified 80 genomic loci as common breakpoints (CBPs) around commonly lost regions, which were significantly associated with increased LINE-1 densities. MBD-seq analysis revealed that average DNA-methylation levels at the CBP loci and relative methylation levels in regions with higher LINE-1 densities also declined during the development of MM. We confirmed that levels of methylation of the 5' untranslated region of respective LINE-1 loci correlated strongly with global LINE-1 methylation levels. Finally, there was a significant association between LINE-1 hypomethylation and poorer overall survival (hazard ratio 2.8, P = 0.015). Conclusion Global hypomethylation of LINE-1 is associated with the progression of and poorer prognosis for MM, possibly due to frequent copy-number loss. PMID:23259664

A new cognitive rehabilitation programme for patients with multiple sclerosis: the 'MS-line! Project'.

PubMed

Gich, Jordi; Freixenet, Jordi; Garcia, Rafael; Vilanova, Joan Carles; Genís, David; Silva, Yolanda; Montalban, Xavier; Ramió-Torrentà, Lluís

2015-09-01

Cognitive rehabilitation is often delayed in multiple sclerosis (MS). To develop a free and specific cognitive rehabilitation programme for MS patients to be used from early stages that does not interfere with daily living activities. MS-line!, cognitive rehabilitation materials consisting of written, manipulative and computer-based materials with difficulty levels developed by a multidisciplinary team. Mathematical, problem-solving and word-based exercises were designed. Physical materials included spatial, coordination and reasoning games. Computer-based material included logic and reasoning, working memory and processing speed games. Cognitive rehabilitation exercises that are specific for MS patients have been successfully developed. © The Author(s), 2014.

Line spring model and its applications to part-through crack problems in plates and shells

NASA Technical Reports Server (NTRS)

Erdogan, Fazil; Aksel, Bulent

1988-01-01

The line spring model is described and extended to cover the problem of interaction of multiple internal and surface cracks in plates and shells. The shape functions for various related crack geometries obtained from the plane strain solution and the results of some multiple crack problems are presented. The problems considered include coplanar surface cracks on the same or opposite sides of a plate, nonsymmetrically located coplanar internal elliptic cracks, and in a very limited way the surface and corner cracks in a plate of finite width and a surface crack in a cylindrical shell with fixed end.

Line Spring Model and Its Applications to Part-Through Crack Problems in Plates and Shells

NASA Technical Reports Server (NTRS)

Erdogan, F.; Aksel, B.

1986-01-01

The line spring model is described and extended to cover the problem of interaction of multiple internal and surface cracks in plates and shells. The shape functions for various related crack geometries obtained from the plane strain solution and the results of some multiple crack problems are presented. The problems considered include coplanar surface cracks on the same or opposite sides of a plate, nonsymmetrically located coplanar internal elliptic cracks, and in a very limited way the surface and corner cracks in a plate of finite width and a surface crack in a cylindrical shell with fixed end.

The ac power line protection for an IEEE 587 Class B environment

NASA Technical Reports Server (NTRS)

Roehr, W. D.; Clark, O. M.

1984-01-01

The 587B series of protectors are unique, low clamping voltage transient suppressors to protect ac-powered equipment from the 6000V peak open-circuit voltage and 3000A short circuit current as defined in IEEE standard 587 for Category B transients. The devices, which incorporate multiple-stage solid-state protector components, were specifically designed to operate under multiple exposures to maximum threat levels in this severe environment. The output voltage peaks are limited to 350V under maximum threat conditions for a 120V ac power line, thus providing adequate protection to vulnerable electronic equipment. The principle of operation and test performance data is discussed.

Partial Validation of Multibody Program to Optimize Simulated Trajectories II (POST II) Parachute Simulation With Interacting Forces

NASA Technical Reports Server (NTRS)

Raiszadeh, Ben; Queen, Eric M.

2002-01-01

A capability to simulate trajectories Of Multiple interacting rigid bodies has been developed. This capability uses the Program to Optimize Simulated Trajectories II (POST II). Previously, POST II had the ability to simulate multiple bodies without interacting forces. The current implementation is used for the Simulation of parachute trajectories, in which the parachute and suspended bodies can be treated as rigid bodies. An arbitrary set of connecting lines can be included in the model and are treated as massless spring-dampers. This paper discusses details of the connection line modeling and results of several test cases used to validate the capability.

Differential BPFs with Multiple Transmission Zeros Based on Terminated Coupled Lines

NASA Astrophysics Data System (ADS)

Niu, Yiming; Yang, Guo; Wu, Wen

2018-04-01

Differential bandpass filters (BPFs) named Filter A and Filter B based on Terminated Coupled Lines (TCLs) are proposed in this letter. The TCLs contributes to not only three poles in differential-mode (DM) for wideband filtering response but also multiple zeros in both DM and common-mode (CM) offering wide DM out-of-band rejection and good CM suppression. Fabricated filters centred at 3.5 GHz with wide DM passband and wideband CM suppression have been designed and measured. The filters improved the noise suppression capability of the communication and radiometer systems. The simulated and measured results are in good agreement.

On Multiple Reconnection X-lines and Tripolar Perturbations of Strong Guide Magnetic Fields

NASA Astrophysics Data System (ADS)

Eriksson, S.; Lapenta, G.; Newman, D. L.; Phan, T. D.; Gosling, J. T.; Lavraud, B.; Khotyaintsev, Yu. V.; Carr, C. M.; Markidis, S.; Goldman, M. V.

2015-05-01

We report new multi-spacecraft Cluster observations of tripolar guide magnetic field perturbations at a solar wind reconnection exhaust in the presence of a guide field BM which is almost four times as strong as the reversing field BL. The novel tripolar field consists of two narrow regions of depressed BM, with an observed 7%-14% ΔBM magnitude relative to the external field, which are found adjacent to a wide region of enhanced BM within the exhaust. A stronger reversing field is associated with each BM depression. A kinetic reconnection simulation for realistic solar wind conditions and the observed strong guide field reveals that tripolar magnetic fields preferentially form across current sheets in the presence of multiple X-lines as magnetic islands approach one another and merge into fewer and larger islands. The simulated ΔBM/ΔXN over the normal width ΔXN between a BM minimum and the edge of the external region agree with the normalized values observed by Cluster. We propose that a tripolar guide field perturbation may be used to identify candidate regions containing multiple X-lines and interacting magnetic islands at individual solar wind current sheets with a strong guide field.

Heat pump system with selective space cooling

DOEpatents

Pendergrass, J.C.

1997-05-13

A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve. 4 figs.

Heat pump system with selective space cooling

DOEpatents

Pendergrass, Joseph C.

1997-01-01

A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve.

Raman spectroscopy differentiates between sensitive and resistant multiple myeloma cell lines

NASA Astrophysics Data System (ADS)

Franco, Domenico; Trusso, Sebastiano; Fazio, Enza; Allegra, Alessandro; Musolino, Caterina; Speciale, Antonio; Cimino, Francesco; Saija, Antonella; Neri, Fortunato; Nicolò, Marco S.; Guglielmino, Salvatore P. P.

2017-12-01

Current methods for identifying neoplastic cells and discerning them from their normal counterparts are often nonspecific and biologically perturbing. Here, we show that single-cell micro-Raman spectroscopy can be used to discriminate between resistant and sensitive multiple myeloma cell lines based on their highly reproducible biomolecular spectral signatures. In order to demonstrate robustness of the proposed approach, we used two different cell lines of multiple myeloma, namely MM.1S and U266B1, and their counterparts MM.1R and U266/BTZ-R subtypes, resistant to dexamethasone and bortezomib, respectively. Then, micro-Raman spectroscopy provides an easily accurate and noninvasive method for cancer detection for both research and clinical environments. Characteristic peaks, mostly due to different DNA/RNA ratio, nucleic acids, lipids and protein concentrations, allow for discerning the sensitive and resistant subtypes. We also explored principal component analysis (PCA) for resistant cell identification and classification. Sensitive and resistant cells form distinct clusters that can be defined using just two principal components. The identification of drug-resistant cells by confocal micro-Raman spectroscopy is thus proposed as a clinical tool to assess the development of resistance to glucocorticoids and proteasome inhibitors in myeloma cells.

Detection of environmental impacts of shrimp farming through multiple lines of evidence.

PubMed

Hatje, Vanessa; de Souza, Manuel M; Ribeiro, Luisa F; Eça, Gilmara F; Barros, Francisco

2016-12-01

In order to evaluate the impact of semi-intensive shrimp farming, comparisons between Control and Impact areas were made based on multiple lines of evidence using an asymmetrical design. Water and sediment samples were collected in four shrimp farms located in Todos os Santos Bay, Bahia, Brazil. Nutrients, trace elements and macrobenthic assemblages were evaluated using uni- and multivariate analyzes. Significant differences were observed between Impact and Control areas for the water column dataset (i.e., ancillary variables, SPM, dissolved nutrients and major and trace elements in SPM), whereas no significant differences were observed for the chemistry of sediments. Macrobenthic assemblages were negatively affected by shrimp farm activities. Impacted sites presented the lowest abundance, richness and different structure of macrofaunal benthic assemblages. Farms clearly produced negative impacts in the Todos os Santos Bay. This conclusion was only possible to be reached through the use of multiple lines of evidence. Chemistry and benthic assemblages data combined produced a better description of the quality and impacts of the evaluated environments. Different conclusions would have been reached if chemistry and ecology results were studied separately vs. together. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimize of shrink process with X-Y CD bias on hole pattern

NASA Astrophysics Data System (ADS)

Koike, Kyohei; Hara, Arisa; Natori, Sakurako; Yamauchi, Shohei; Yamato, Masatoshi; Oyama, Kenichi; Yaegashi, Hidetami

2017-03-01

Gridded design rules[1] is major process in configuring logic circuit used 193-immersion lithography. In the scaling of grid patterning, we can make 10nm order line and space pattern by using multiple patterning techniques such as self-aligned multiple patterning (SAMP) and litho-etch- litho-etch (LELE)[2][3][4] . On the other hand, Line cut process has some error parameters such as pattern defect, placement error, roughness and X-Y CD bias with the decreasing scale. We tried to cure hole pattern roughness to use additional process such as Line smoothing[5] . Each smoothing process showed different effect. As the result, CDx shrink amount is smaller than CDy without one additional process. In this paper, we will report the pattern controllability comparison of EUV and 193-immersion. And we will discuss optimum method about CD bias on hole pattern.

Characteristics of a cell line established from a patient with multiple osteosarcoma, appearing 13 years after treatment for bilateral retinoblastoma.

PubMed

Fodstad, O; Brøgger, A; Bruland, O; Solheim, O P; Nesland, J M; Pihl, A

1986-07-15

An osteosarcoma cell line, OHS, was established from a patient with multiple skeletal manifestations of osteosarcoma, developing after bilateral retinoblastoma. The tumor cells expressed sarcoma-associated antigens and showed rapid growth in monolayers and as multicellular spheroids. They formed distinct colonies in soft agar, and subcutaneous tumors in nude mice. Morphological studies indicated that OHS cells had retained important characteristics of the cells of origin. No deletion of the retinoblastoma genes on chromosome 13q14 could be demonstrated with the banding techniques used. However, cytogenetic studies revealed double minute chromosomes, as evidence of gene amplification, as well as translocations involving chromosomes 1,6,11 and 13. The OHS line can be used to study the genetic basis of tumor initiation and growth, and to elucidate factors predisposing for second primary cancers in retinoblastoma patients.

Phenylpropanoids from Phragmipedium calurum and their antiproliferative activity

PubMed Central

Starks, Courtney M.; Williams, Russell B.; Norman, Vanessa L.; Lawrence, Julie A.; O’Neil-Johnson, Mark; Eldridge, Gary R.

2012-01-01

Two new and five known stilbenes and one new alkylresorcinol were isolated from the orchid Phragmipedium calurum during a screen for new anticancer compounds. The compounds were evaluated for antiproliferative activity against multiple human cancer cell lines. Two of the compounds (1 and 7) displayed moderate activity against several cell lines. PMID:22805176

Role of Mitochondrial Inheritance on Prostate Cancer Outcome in African-American Men

DTIC Science & Technology

2014-10-01

prostate cancer cell line cybrids was not effective and we have instead decided to use the Rhodamine -6-G procedure. Thus far PNT1A cybrid cell lines...the original protocol. To overcome these difficulties, we tested multiple alternative approaches including rhodamine -6G (R6G) mediated short-term

Role of Mitochondrial Inheritance on Prostate Cancer Outcome in African American Men

DTIC Science & Technology

2015-12-01

for generating prostate cancer cell line cybrids was not effective and we have instead used a Rhodamine -6-G procedure. PNT1A cybrid cell lines have...difficulties, we tested multiple alternative approaches including rhodamine -6G (R6G) mediated short-term mitochondrial dysfunction in generating rho zero cells

47 CFR 68.213 - Installation of other than “fully protected” non-system simple customer premises wiring.

Code of Federal Regulations, 2010 CFR

2010-10-01

... only to “unprotected” premises wiring used with simple installations of wiring for up to four line residential and business telephone service. More complex installations of wiring for multiple line services... requirements, for installation and maintenance of wiring on the subscriber's side of the demarcation point...

Foliar resistance to fall armyworm in corn germplasm lines that confer resistance to root- and ear-feeding insects

USDA-ARS?s Scientific Manuscript database

A holistic approach to developing new corn germplasm that confers multiple insect resistance in various plant tissues at different growth stages was examined. Eight corn germplasm lines were examined for their foliage resistance to fall armyworm [Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noc...

Comprehensive field screenings for whorl- and ear-feeding insect resistance in corn germplasm lines

USDA-ARS?s Scientific Manuscript database

A holistic approach to developing new corn germplasm that confers multiple insect resistance in various plant tissues at different growth stages was examined in two separate studies. The first study was the screening of eight corn germplasm lines for resistance whorl damage to fall armyworm [Spodop...

Background controlled QTL mapping in pure-line genetic populations derived from four-way crosses

PubMed Central

Zhang, S; Meng, L; Wang, J; Zhang, L

2017-01-01

Pure lines derived from multiple parents are becoming more important because of the increased genetic diversity, the possibility to conduct replicated phenotyping trials in multiple environments and potentially high mapping resolution of quantitative trait loci (QTL). In this study, we proposed a new mapping method for QTL detection in pure-line populations derived from four-way crosses, which is able to control the background genetic variation through a two-stage mapping strategy. First, orthogonal variables were created for each marker and used in an inclusive linear model, so as to completely absorb the genetic variation in the mapping population. Second, inclusive composite interval mapping approach was implemented for one-dimensional scanning, during which the inclusive linear model was employed to control the background variation. Simulation studies using different genetic models demonstrated that the new method is efficient when considering high detection power, low false discovery rate and high accuracy in estimating quantitative trait loci locations and effects. For illustration, the proposed method was applied in a reported wheat four-way recombinant inbred line population. PMID:28722705

Background controlled QTL mapping in pure-line genetic populations derived from four-way crosses.

PubMed

Zhang, S; Meng, L; Wang, J; Zhang, L

2017-10-01

Pure lines derived from multiple parents are becoming more important because of the increased genetic diversity, the possibility to conduct replicated phenotyping trials in multiple environments and potentially high mapping resolution of quantitative trait loci (QTL). In this study, we proposed a new mapping method for QTL detection in pure-line populations derived from four-way crosses, which is able to control the background genetic variation through a two-stage mapping strategy. First, orthogonal variables were created for each marker and used in an inclusive linear model, so as to completely absorb the genetic variation in the mapping population. Second, inclusive composite interval mapping approach was implemented for one-dimensional scanning, during which the inclusive linear model was employed to control the background variation. Simulation studies using different genetic models demonstrated that the new method is efficient when considering high detection power, low false discovery rate and high accuracy in estimating quantitative trait loci locations and effects. For illustration, the proposed method was applied in a reported wheat four-way recombinant inbred line population.

Hierarchy for targeting prosurvival BCL2 family proteins in multiple myeloma: pivotal role of MCL1.

PubMed

Gong, Jia-Nan; Khong, Tiffany; Segal, David; Yao, Yuan; Riffkin, Chris D; Garnier, Jean-Marc; Khaw, Seong Lin; Lessene, Guillaume; Spencer, Andrew; Herold, Marco J; Roberts, Andrew W; Huang, David C S

2016-10-06

New therapeutic targets are needed to address the poor prognosis of patients with high-risk multiple myeloma. Myeloma cells usually express a range of the prosurvival BCL2 proteins. To define the hierarchy of their relative importance for maintaining the survival of myeloma cells, we targeted each of them in a large panel of cell lines, using pharmacological inhibitors or gene editing or by peptide-based approaches, alone or in combination. The majority of well-established immortalized cell lines (17/25) or low-passage myeloma cell lines (5/7) are readily killed when MCL1 is targeted, even including those cell lines sensitive to BCL2 inhibition. Targeting MCL1 also constrained the growth of myeloma in vivo. We also identified a previously unrecognized subset of myeloma that is highly BCLXL-dependent, and has the potential for cotargeting MCL1 and BCLXL. As MCL1 is pivotal for maintaining survival of most myelomas, it should be prioritized for targeting in the clinic once high-quality, validated inhibitors become available. © 2016 by The American Society of Hematology.

Aberrant Cortical Activity in Multiple GCaMP6-Expressing Transgenic Mouse Lines

PubMed Central

Buetfering, Christina; Groblewski, Peter A.; Manavi, Sahar; Miles, Jesse; White, Casey; Griffin, Fiona; Roll, Kate; Cross, Sissy; Nguyen, Thuyanh V.; Larsen, Rachael; Daigle, Tanya; Thompson, Carol L.; Olsen, Shawn; Hausser, Michael

2017-01-01

Abstract Transgenic mouse lines are invaluable tools for neuroscience but, as with any technique, care must be taken to ensure that the tool itself does not unduly affect the system under study. Here we report aberrant electrical activity, similar to interictal spikes, and accompanying fluorescence events in some genotypes of transgenic mice expressing GCaMP6 genetically encoded calcium sensors. These epileptiform events have been observed particularly, but not exclusively, in mice with Emx1-Cre and Ai93 transgenes, of either sex, across multiple laboratories. The events occur at >0.1 Hz, are very large in amplitude (>1.0 mV local field potentials, >10% df/f widefield imaging signals), and typically cover large regions of cortex. Many properties of neuronal responses and behavior seem normal despite these events, although rare subjects exhibit overt generalized seizures. The underlying mechanisms of this phenomenon remain unclear, but we speculate about possible causes on the basis of diverse observations. We encourage researchers to be aware of these activity patterns while interpreting neuronal recordings from affected mouse lines and when considering which lines to study. PMID:28932809

PWM-switching pattern-based diagnosis scheme for single and multiple open-switch damages in VSI-fed induction motor drives.

PubMed

Trabelsi, Mohamed; Boussak, Mohamed; Gossa, Moncef

2012-03-01

This paper deals with a fault detection technique for insulated-gate bipolar transistors (IGBTs) open-circuit faults in voltage source inverter (VSI)-fed induction motor drives. The novelty of this idea consists in analyzing the pulse-width modulation (PWM) switching signals and the line-to-line voltage levels during the switching times, under both healthy and faulty operating conditions. The proposed method requires line-to-line voltage measurement, which provides information about switching states and is not affected by the load. The fault diagnosis scheme is achieved using simple hardware and can be included in the existing inverter system without any difficulty. In addition, it allows not only accurate single and multiple faults diagnosis but also minimization of the fault detection time to a maximum of one switching period (T(c)). Simulated and experimental results on a 3-kW squirrel-cage induction motor drive are displayed to validate the feasibility and the effectiveness of the proposed strategy. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

A Novel Method for Reconstructing Broken Contour Lines Extracted from Scanned Topographic Maps

NASA Astrophysics Data System (ADS)

Wang, Feng; Liu, Pingzhi; Yang, Yun; Wei, Haiping; An, Xiaoya

2018-05-01

It is known that after segmentation and morphological operations on scanned topographic maps, gaps occur in contour lines. It is also well known that filling these gaps and reconstruction of contour lines with high accuracy and completeness is not an easy problem. In this paper, a novel method is proposed dedicated in automatic or semiautomatic filling up caps and reconstructing broken contour lines in binary images. The key part of end points' auto-matching and reconnecting is deeply discussed after introducing the procedure of reconstruction, in which some key algorithms and mechanisms are presented and realized, including multiple incremental backing trace to get weighted average direction angle of end points, the max constraint angle control mechanism based on the multiple gradient ranks, combination of weighted Euclidean distance and deviation angle to determine the optimum matching end point, bidirectional parabola control, etc. Lastly, experimental comparisons based on typically samples are complemented between proposed method and the other representative method, the results indicate that the former holds higher accuracy and completeness, better stability and applicability.

Reconfigurable multiport EPON repeater

NASA Astrophysics Data System (ADS)

Oishi, Masayuki; Inohara, Ryo; Agata, Akira; Horiuchi, Yukio

2009-11-01

An extended reach EPON repeater is one of the solutions to effectively expand FTTH service areas. In this paper, we propose a reconfigurable multi-port EPON repeater for effective accommodation of multiple ODNs with a single OLT line card. The proposed repeater, which has multi-ports in both OLT and ODN sides, consists of TRs, BTRs with the CDR function and a reconfigurable electrical matrix switch, can accommodate multiple ODNs to a single OLT line card by controlling the connection of the matrix switch. Although conventional EPON repeaters require full OLT line cards to accommodate subscribers from the initial installation stage, the proposed repeater can dramatically reduce the number of required line cards especially when the number of subscribers is less than a half of the maximum registerable users per OLT. Numerical calculation results show that the extended reach EPON system with the proposed EPON repeater can save 17.5% of the initial installation cost compared with a conventional repeater, and can be less expensive than conventional systems up to the maximum subscribers especially when the percentage of ODNs in lightly-populated areas is higher.

Multiple disease resistance to fungal and oomycete pathogens using a recombinant inbred line population in pepper

USDA-ARS?s Scientific Manuscript database

Incorporating disease resistance into cultivars is a primary focus of modern breeding programs. Resistance to pathogens is often introgressed from landrace or wild individuals with poor fruit quality into commercial-quality cultivars. Sites of multiple disease resistance (MDR) are regions or “hotspo...

Real-World Use of 3rd Line Therapy for Multiple Myeloma in Austria: An Austrian Myeloma Registry (AMR) Analysis of the Therapeutic Landscape and Clinical Outcomes prior to the Use of Next Generation Myeloma Therapeutics.

PubMed

Willenbacher, Ella; Weger, Roman; Rochau, Ursula; Siebert, Uwe; Willenbacher, Wolfgang

2016-01-01

Clinical trials demonstrate improving survival in patients with multiple myeloma (MM) after treatment. However, it is unclear whether increased survival translates to a similar benefit in a real world setting. We analyzed the overall survival of 347 multiple myeloma patients in Austria by means of a national registry (AMR), focused on results from 3rd and later lines of therapy. This benchmark was chosen to define a baseline prior to the broad application of upcoming 2nd generation drugs (carfilzomib, pomalidomide). Projected 10 years survival for patients with MM in Austria is estimated to be 56% in patients diagnosed in between the years 2011-2014, 21% in patients with a diagnosis made between 2000-2005, and 39% in those with a diagnosis made between 2006-2010). For the same intervals a significant increase in the use of both bortezomib, lenalidomide and thalidomide-so called IMiDs (from 2005 onwards) and their simultaneous use in combination therapies (from 2010 onwards) could be shown. The use of autologous transplantation (ASCT) remained more or less constant at ~ 35% of patients in the 1st line setting over the whole period, comparing well to international practice patterns, while the use of 2nd line ASCT increased from 5.5% to 18.7% of patients. Patients in 3rd or later line treatment (n = 105), showed that even in relapsed and refractory disease median survival was 27 months with a considerable proportion of long-term survivors (~20%). With the expected emergence of additional active anti-myeloma compounds, we aim to assess survival in patients with relapsed and refractory MM.

Users manual for program ADMIT: Admittance and pressure transfer function developed for use on a PC computer

NASA Technical Reports Server (NTRS)

Armstrong, Wilbur C.

1992-01-01

The piping in a liquid rocket can assume complex configurations due to multiple tanks, multiple engines, and structures that must be piped around. The capability to handle some of these complex configurations have been incorporated into the ADMIT code. The capability to modify the input on line has been implemented. The configurations allowed include multiple tanks, multiple engines, the splitting of a pipe into unequal segments going to different (or the same) engines. This program will handle the following type elements: straight pipes, bends, inline accumulators, tuned stub accumulators, Helmholtz resonators, parallel resonators, pumps, split pipes, multiple tanks, and multiple engines.

Users manual for program SSFREQ intermediate mode stability curves: Developed for use on a PC computer

NASA Technical Reports Server (NTRS)

Armstrong, Wilbur C.

1992-01-01

The piping in a liquid rocket can assume complex configurations due to multiple tanks, multiple engines, and structures that must be piped around. The capability to handle some of these complex configurations have been incorporated into the SSFREQ code. The capability to modify the input on line has been implemented. The configurations allowed include multiple tanks, multiple engines, the splitting of a pipe into equal segments going to different (or the same) engines. This program will handle the following type elements: straight pipes, bends, inline accumulators, tuned stub accumulators, Helmholtz resonators, parallel resonators, pumps, split pipes, multiple tanks, and multiple engines.

ALMA Multiple-transition Observations of High-density Molecular Tracers in Ultraluminous Infrared Galaxies

NASA Astrophysics Data System (ADS)

Imanishi, Masatoshi; Nakanishi, Kouichiro; Izumi, Takuma

2018-04-01

We present the results of our ALMA observations of 11 (ultra)luminous infrared galaxies ((U)LIRGs) at J = 4–3 of HCN, HCO+, and HNC and J = 3–2 of HNC. This is an extension of our previously published HCN and HCO+ J = 3–2 observations to multiple rotational J-transitions of multiple molecules, to investigate how molecular emission line flux ratios vary at different J-transitions. We confirm that ultraluminous infrared galaxies (ULIRGs) that contain or may contain luminous obscured active galactic nuclei (AGNs) tend to show higher HCN-to-HCO+ flux ratios than starburst galaxies, both at J = 4–3 and J = 3–2. For selected HCN-flux-enhanced AGN-important ULIRGs, our isotopologue H13CN, H13CO+, and HN13C J = 3–2 line observations suggest a higher abundance of HCN than HCO+ and HNC, which is interpreted to be primarily responsible for the elevated HCN flux in AGN-important galaxies. For such sources, the intrinsic HCN-to-HCO+ flux ratios after line opacity correction will be higher than the observed ratios, making the separation between AGNs and starbursts even larger. The signature of the vibrationally excited (v 2 = 1f) HCN J = 4–3 emission line is seen in one ULIRG, IRAS 12112‑0305 NE. P Cygni profiles are detected in the HCO+ J = 4–3 and J = 3–2 lines toward IRAS 15250+3609, with an estimated molecular outflow rate of ∼250–750 M ⊙ yr‑1. The SiO J = 6–5 line also exhibits a P Cygni profile in IRAS 12112+0305 NE, suggesting the presence of shocked outflow activity. Shock tracers are detected in many sources, suggesting ubiquitous shock activity in the nearby ULIRG population.

Multiplex Superconducting Transmission Line for green power consolidation on a Smart Grid

NASA Astrophysics Data System (ADS)

McIntyre, P.; Gerity, J.; Kellams, J.; Sattarov, A.

2017-12-01

A multiplex superconducting transmission line (MSTL) is being developed for applications requiring interconnection of multi-MW electric power generation among a number of locations. MSTL consists of a cluster of many 2- or 3-conductor transmission lines within a coaxial cryostat envelope. Each line operates autonomously, so that the interconnection of multiple power loads can be done in a failure-tolerant network. Specifics of the electrical, mechanical, and cryogenic design are presented. The consolidation of transformation and conditioning and the failure-tolerant interconnects have the potential to offer important benefit for the green energy components of a Smart Grid.

Optical properties of an inhomogeneously broadened ΛV-system with multiple excited states

NASA Astrophysics Data System (ADS)

Kaur, Paramjit; Bharti, Vineet; Wasan, Ajay

2014-09-01

We present a theoretical model using a density matrix approach to show the influence of multiple excited states on the optical properties of an inhomogeneously broadened ?V-system of the ?Rb D2 line. These closely spaced multiple excited states cause asymmetry in absorption and dispersion profiles. We observe the reduced absorption profiles, due to dressed state interactions of the applied electromagnetic fields, which results the Mollow sideband-like transparency windows. In a room temperature vapor, we obtain a narrow enhanced absorption and steep positive dispersion at the line center when the strengths of control and pump fields are equal. Here, we show how the probe transmittance varies when it passes through the atomic medium. We also discuss the transient behavior of our system which agrees well with the corresponding absorption and dispersion profiles. This study has potential applications in controllability of group velocity, and for optical and quantum information processing.

Shielding effectiveness of multiple-shield cables with arbitrary terminations via transmission line analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campione, Salvatore; Basilio, Lorena I.; Warne, Larry Kevin

Our paper reports on a transmission-line model for calculating the shielding effectiveness of multiple-shield cables with arbitrary terminations. Since the shields are not perfect conductors and apertures in the shields permit external magnetic and electric fields to penetrate into the interior regions of the cable, we use this model to estimate the effects of the outer shield current and voltage (associated with the external excitation and boundary conditions associated with the external conductor) on the inner conductor current and voltage. It is commonly believed that increasing the number of shields of a cable will improve the shielding performance. But thismore » is not always the case, and a cable with multiple shields may perform similar to or worse than a cable with a single shield. Furthermore, we want to shed more light on these situations, which represent the main focus of this paper.« less

Multiplexed Liquid Chromatography-Multiple Reaction Monitoring Mass Spectrometry Quantification of Cancer Signaling Proteins

PubMed Central

Chen, Yi; Fisher, Kate J.; Lloyd, Mark; Wood, Elizabeth R.; Coppola, Domenico; Siegel, Erin; Shibata, David; Chen, Yian A.; Koomen, John M.

2017-01-01

Quantitative evaluation of protein expression across multiple cancer-related signaling pathways (e.g. Wnt/β-catenin, TGF-β, receptor tyrosine kinases (RTK), MAP kinases, NF-κB, and apoptosis) in tumor tissues may enable the development of a molecular profile for each individual tumor that can aid in the selection of appropriate targeted cancer therapies. Here, we describe the development of a broadly applicable protocol to develop and implement quantitative mass spectrometry assays using cell line models and frozen tissue specimens from colon cancer patients. Cell lines are used to develop peptide-based assays for protein quantification, which are incorporated into a method based on SDS-PAGE protein fractionation, in-gel digestion, and liquid chromatography-multiple reaction monitoring mass spectrometry (LC-MRM/MS). This analytical platform is then applied to frozen tumor tissues. This protocol can be broadly applied to the study of human disease using multiplexed LC-MRM assays. PMID:28808993

Shielding effectiveness of multiple-shield cables with arbitrary terminations via transmission line analysis

DOE PAGES

Campione, Salvatore; Basilio, Lorena I.; Warne, Larry Kevin; ...

2016-06-25

Our paper reports on a transmission-line model for calculating the shielding effectiveness of multiple-shield cables with arbitrary terminations. Since the shields are not perfect conductors and apertures in the shields permit external magnetic and electric fields to penetrate into the interior regions of the cable, we use this model to estimate the effects of the outer shield current and voltage (associated with the external excitation and boundary conditions associated with the external conductor) on the inner conductor current and voltage. It is commonly believed that increasing the number of shields of a cable will improve the shielding performance. But thismore » is not always the case, and a cable with multiple shields may perform similar to or worse than a cable with a single shield. Furthermore, we want to shed more light on these situations, which represent the main focus of this paper.« less

Modeling contact angle hysteresis of a liquid droplet sitting on a cosine wave-like pattern surface.

PubMed

Promraksa, Arwut; Chen, Li-Jen

2012-10-15

A liquid droplet sitting on a hydrophobic surface with a cosine wave-like square-array pattern in the Wenzel state is simulated by using the Surface Evolver to determine the contact angle. For a fixed drop volume, multiple metastable states are obtained at two different surface roughnesses. Unusual and non-circular shape of the three-phase contact line of a liquid droplet sitting on the model surface is observed due to corrugation and distortion of the contact line by structure of the roughness. The contact angle varies along the contact line for each metastable state. The maximum and minimum contact angles among the multiple metastable states at a fixed viewing angle correspond to the advancing and the receding contact angles, respectively. It is interesting to observe that the advancing/receding contact angles (and contact angle hysteresis) are a function of viewing angle. In addition, the receding (or advancing) contact angles at different viewing angles are determined at different metastable states. The contact angle of minimum energy among the multiple metastable states is defined as the most stable (equilibrium) contact angle. The Wenzel model is not able to describe the contact angle along the three-phase contact line. The contact angle hysteresis at different drop volumes is determined. The number of the metastable states increases with increasing drop volume. Drop volume effect on the contact angles is also discussed. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

Wheat multiple synthetic derivatives: a new source for heat stress tolerance adaptive traits

PubMed Central

Elbashir, Awad Ahmed Elawad; Gorafi, Yasir Serag Alnor; Tahir, Izzat Sidahmed Ali; Kim, June-Sik; Tsujimoto, Hisashi

2017-01-01

Heat stress is detrimental to wheat (Triticum aestivum L.) productivity. In this study, we aimed to select heat-tolerant plants from a multiple synthetic derivatives (MSD) population and evaluate their agronomic and physiological traits. We selected six tolerant plants from the population with the background of the cultivar ‘Norin 61’ (N61) and established six MNH (MSD population of N61 selected as heat stress-tolerant) lines. We grew these lines with N61 in the field and growth chamber. In the field, we used optimum and late sowings to ensure plant exposure to heat. In the growth chamber, in addition to N61, we used the heat-tolerant cultivars ‘Gelenson’ and ‘Bacanora’. We confirmed that MNH2 and MNH5 lines acquired heat tolerance. These lines had higher photosynthesis and stomata conductance and exhibited no reduction in grain yield and biomass under heat stress compared to N61. We noticed that N61 had relatively good adaptability to heat stress. Our results indicate that the MSD population includes the diversity of Aegilops tauschii and is a promising resource to uncover useful quantitative traits derived from this wild species. Selected lines could be useful for heat stress tolerance breeding. PMID:28744178

Electroreflectance spectra from multiple InGaN/GaN quantum wells in the nonuniform electric field of a p–n junction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Avakyants, L. P.; Aslanyan, A. E.; Bokov, P. Yu., E-mail: pavel-bokov@physics.msu.ru

A line at E = 2.77 eV (with a width of Γ = 88 meV) related to interband transitions in the region of multiple quantum wells in the active region is detected in the electroreflectance spectra of the GaN/InGaN/AlGaN heterostructure. As the modulation bias is reduced from 2.9 to 0.4 V, the above line is split into two lines with energies of E{sub 1} = 2.55 eV and E{sub 2} = 2.75 eV and widths of Γ{sub 1} = 66 meV and Γ{sub 2} = 74 meV, respectively. The smaller widths of separate lines indicate that these lines are causedmore » by interband transitions in particular quantum wells within the active region. The difference between the interband transition energies E{sub 1} and E{sub 2} in identical quantum wells in the active region is related to the fact that the quantum wells are in an inhomogeneous electric field of the p–n junction. The magnitudes of the electric-field strengths in particular quantum wells in the active region of the heterostructure are estimated to be 1.6 and 2.2 MV/cm.« less

Geophysics From Terrestrial Time-Variable Gravity Measurements

NASA Astrophysics Data System (ADS)

Van Camp, Michel; de Viron, Olivier; Watlet, Arnaud; Meurers, Bruno; Francis, Olivier; Caudron, Corentin

2017-12-01

In a context of global change and increasing anthropic pressure on the environment, monitoring the Earth system and its evolution has become one of the key missions of geosciences. Geodesy is the geoscience that measures the geometric shape of the Earth, its orientation in space, and gravity field. Time-variable gravity, because of its high accuracy, can be used to build an enhanced picture and understanding of the changing Earth. Ground-based gravimetry can determine the change in gravity related to the Earth rotation fluctuation, to celestial body and Earth attractions, to the mass in the direct vicinity of the instruments, and to vertical displacement of the instrument itself on the ground. In this paper, we review the geophysical questions that can be addressed by ground gravimeters used to monitor time-variable gravity. This is done in relation to the instrumental characteristics, noise sources, and good practices. We also discuss the next challenges to be met by ground gravimetry, the place that terrestrial gravimetry should hold in the Earth observation system, and perspectives and recommendations about the future of ground gravity instrumentation.

Specific Yields Estimated from Gravity Change during Pumping Test

NASA Astrophysics Data System (ADS)

Chen, K. H.; Hwang, C.; Chang, L. C.

2017-12-01

Specific yield (Sy) is the most important parameter to describe available groundwater capacity in an unconfined aquifer. When estimating Sy by a field pumping test, aquifer heterogeneity and well performers will cause a large uncertainty. In this study, we use a gravity-based method to estimate Sy. At the time of pumping test, amounts of mass (groundwater) are forced to be taken out. If drawdown corn is big and close enough to high precision gravimeter, the gravity change can be detected. The gravity-based method use gravity observations that are independent from traditional flow computation. Only the drawdown corn should be modeled with observed head and hydrogeology data. The gravity method can be used in most groundwater field tests, such as locally pumping/injection tests initiated by active man-made or annual variations due to natural sources. We apply our gravity method at few sites in Taiwan situated over different unconfined aquifer. Here pumping tests for Sy determinations were also carried out. We will discuss why the gravity method produces different results from traditional pumping test, field designs and limitations of the gravity method.

Evaluation of global satellite gravity models using terrestrial gravity observations over the Kingdom of Saudi Arabia A. Alothman and B. Elsaka

NASA Astrophysics Data System (ADS)

Alothman, Abdulaziz; Elsaka, Basem

The gravity field models from the GRACE and GOCE missions have increased the knowledge of the earth’s global gravity field. The latter GOCE mission has provided accuracies of about 1-2 cm and 1milli-Gal level in the global geoid and gravity anomaly, respectively. However, determining all wavelength ranges of the gravity field spectrum cannot be only achieved from satellite gravimetry but from the allowed terrestrial gravity data. In this contribution, we use a gravity network of 42 first-order absolute gravity stations, observed by LaCosta Romberg gravimeter during the period 1967-1969 by Ministry of Petroleum and Mineral Resources, to validate the GOCE gravity models in order to gain more detailed regional gravity information. The network stations are randomly distributed all over the country with a spacing of about 200 km apart. The results show that the geoid height and gravity anomaly determined from terrestrial gravity data agree with the GOCE based models and give additional information to the satellite gravity solutions.

NGS' GRAV-D Project Brings Advances in Aerogravimetry

NASA Astrophysics Data System (ADS)

Childers, V. A.; Preaux, S. A.; Diehl, T. M.; Li, X.; Weil, C.

2011-12-01

NOAA's National Geodetic Survey has undertaken an extensive airborne gravity campaign to help replace the nation's vertical datum by 2022. After receiving Congressional funding in FY10 &11, the GRAV-D project has now surveyed 13.45% of the total area (as of abstract submittal time). The survey has now worked on a number of aircraft, both jets and turboprops. Early work was performed at 35,000 ft and 280 kts. Since summer of 2009, the survey altitude has been lowered to 20,000 ft to enhance signal recovery and to reduce the amplitude enhancement of noise in the downward continuation needed for gravity field blending. The high altitude and speed of the survey has forced a re-evaluation of all aspects of the airborne gravity processing methodology. This presentation will update the community on the progress of the project, summarize the various processing improvements implemented, and discuss the magnitude of their effects. Improvements and research include: a new in-house gravity processing software package called "Newton", kinematic GPS processing variables and their impacts on final gravity products, and evaluation of gravimeter off-level corrections, among other topics.

Granular Superconductors and Gravity

NASA Technical Reports Server (NTRS)

Noever, David; Koczor, Ron

1999-01-01

As a Bose condensate, superconductors provide novel conditions for revisiting previously proposed couplings between electromagnetism and gravity. Strong variations in Cooper pair density, large conductivity and low magnetic permeability define superconductive and degenerate condensates without the traditional density limits imposed by the Fermi energy (approx. 10(exp -6) g cu cm). Recent experiments have reported anomalous weight loss for a test mass suspended above a rotating Type II, YBCO superconductor, with a relatively high percentage change (0.05-2.1%) independent of the test mass' chemical composition and diamagnetic properties. A variation of 5 parts per 104 was reported above a stationary (non-rotating) superconductor. In experiments using a sensitive gravimeter, bulk YBCO superconductors were stably levitated in a DC magnetic field and exposed without levitation to low-field strength AC magnetic fields. Changes in observed gravity signals were measured to be less than 2 parts in 108 of the normal gravitational acceleration. Given the high sensitivity of the test, future work will examine variants on the basic magnetic behavior of granular superconductors, with particular focus on quantifying their proposed importance to gravity.

On Physical Interpretation of the In-Site Measurement of Earth Rotation by Ring Laser Gyrometers

NASA Technical Reports Server (NTRS)

Chao, B. F.

2004-01-01

Large ring laser gyrometers under development have demonstrated the capability of detecting minute ground motions and deformations on a wide range of timescales. The next challenge and goal is to measure the Earth's rotation variations to a precision that rivals that of the present space-geodesy techniques, thus providing an in-situ (and cost effective alternatives of Earth rotation measurement for geophysical research and geodetic applications. Aside from thermal and mechanical instabilities, "undesirable" ground motion and tilt that appear in the signal will need to be removed before any variation in Earth rotation can be detected. Removal of these signals, some of them are larger than the sought rotation signals, has been a typical procedure in many precise geophysical instruments, such as gravimeters, seismometers, and tiltmeters. The remaining Earth rotation signal resides in both the spin around the axis and in the orientation of the axis. In the case of the latter, the in-situ measurement is complementary to the space-geodetic observables in terms of polar motion and nutation, a fact to be exploited.

The Improved Hydrological Gravity Model for Moxa Observatory, Germany

NASA Astrophysics Data System (ADS)

Weise, A.; Jahr, Th.

2017-04-01

The gravity variations observed by the superconducting gravimeter (SG) CD-034 at Moxa Geodynamic Observatory/Germany were compared with the GRACE results some years ago. The combination of a local hydrological model of a catchment area with a 3D-gravimetric model had been applied successfully for correcting the SG record of Moxa which is especially necessary due to the strong topography nearest to the SG location. Now, the models have been corrected and improved considerably by inserting several details in the very near surrounding. Mainly these are: the observatory building is inserted with the roof covered by a soil layer above the gravity sensor where humidity is varying, snow is placed on top of the roof and on topography (steep slope), and ground water is taken into account, additionally. The result is that the comparison of the corrected gravity residuals with gravity variations of the satellite mission GRACE, now using RL5 data, shows higher agreement, not only in amplitude but also the formerly apparent phase shift is obviously not realistic. The agreement between terrestrial gravity variations (SG) and the GRACE data is improved considerably which is discussed widely.

The Improved Hydrological Gravity Model for Moxa Observatory, Germany

NASA Astrophysics Data System (ADS)

Weise, A.; Jahr, Th.

2018-05-01

The gravity variations observed by the superconducting gravimeter (SG) CD-034 at Moxa Geodynamic Observatory/Germany were compared with the GRACE results some years ago. The combination of a local hydrological model of a catchment area with a 3D-gravimetric model had been applied successfully for correcting the SG record of Moxa which is especially necessary due to the strong topography nearest to the SG location. Now, the models have been corrected and improved considerably by inserting several details in the very near surrounding. Mainly these are: the observatory building is inserted with the roof covered by a soil layer above the gravity sensor where humidity is varying, snow is placed on top of the roof and on topography (steep slope), and ground water is taken into account, additionally. The result is that the comparison of the corrected gravity residuals with gravity variations of the satellite mission GRACE, now using RL5 data, shows higher agreement, not only in amplitude but also the formerly apparent phase shift is obviously not realistic. The agreement between terrestrial gravity variations (SG) and the GRACE data is improved considerably which is discussed widely.

Mapping Quantitative Trait Loci in Crosses between Outbred Lines Using Least Squares

PubMed Central

Haley, C. S.; Knott, S. A.; Elsen, J. M.

1994-01-01

The use of genetic maps based upon molecular markers has allowed the dissection of some of the factors underlying quantitative variation in crosses between inbred lines. For many species crossing inbred lines is not a practical proposition, although crosses between genetically very different outbred lines are possible. Here we develop a least squares method for the analysis of crosses between outbred lines which simultaneously uses information from multiple linked markers. The method is suitable for crosses where the lines may be segregating at marker loci but can be assumed to be fixed for alternative alleles at the major quantitative trait loci (QTLs) affecting the traits under analysis (e.g., crosses between divergent selection lines or breeds with different selection histories). The simultaneous use of multiple markers from a linkage group increases the sensitivity of the test statistic, and thus the power for the detection of QTLs, compared to the use of single markers or markers flanking an interval. The gain is greater for more closely spaced markers and for markers of lower information content. Use of multiple markers can also remove the bias in the estimated position and effect of a QTL which may result when different markers in a linkage group vary in their heterozygosity in the F(1) (and thus in their information content) and are considered only singly or a pair at a time. The method is relatively simple to apply so that more complex models can be fitted than is currently possible by maximum likelihood. Thus fixed effects and effects of background genotype can be fitted simultaneously with the exploration of a single linkage group which will increase the power to detect QTLs by reducing the residual variance. More complex models with several QTLs in the same linkage group and two-locus interactions between QTLs can similarly be examined. Thus least squares provides a powerful tool to extend the range of crosses from which QTLs can be dissected whilst at the same time allowing flexible and realistic models to be explored. PMID:8005424

Lung Cancer Cell Lines as Tools for Biomedical Discovery and Research

PubMed Central

Girard, Luc; Lockwood, William W.; Lam, Wan L.; Minna, John D.

2010-01-01

Lung cancer cell lines have made a substantial contribution to lung cancer translational research and biomedical discovery. A systematic approach to initiating and characterizing cell lines from small cell and non–small cell lung carcinomas has led to the current collection of more than 200 lung cancer cell lines, a number that exceeds those for other common epithelial cancers combined. The ready availability and widespread dissemination of the lines to investigators worldwide have resulted in more than 9000 citations, including multiple examples of important biomedical discoveries. The high (but not perfect) genomic similarities between lung cancer cell lines and the lung tumor type from which they were derived provide evidence of the relevance of their use. However, major problems including misidentification or cell line contamination remain. Ongoing studies and new approaches are expected to reveal the full potential of the lung cancer cell line panel. PMID:20679594

Pyramiding transgenes for multiple resistance in rice against bacterial blight, yellow stem borer and sheath blight.

PubMed

Datta, K; Baisakh, N; Thet, K Maung; Tu, J; Datta, S K

2002-12-01

Here we describe the development of transgene-pyramided stable elite rice lines resistant to disease and insect pests by conventional crossing of two transgenic parental lines transformed independently with different genes. The Xa21 gene (resistance to bacterial blight), the Bt fusion gene (for insect resistance) and the chitinase gene (for tolerance of sheath blight) were combined in a single rice line by reciprocal crossing of two transgenic homozygous IR72 lines. F4 plant lines carrying all the genes of interest stably were identified using molecular methods. The identified lines, when exposed to infection caused by Xanthomonas oryzae pv oryzae, showed resistance to bacterial blight. Neonate larval mortality rates of yellow stem borer ( Scirpophaga incertulas) in an insect bioassay of the same identified lines were 100%. The identified line pyramided with different genes to protect against yield loss showed high tolerance of sheath blight disease caused by Rhizoctonia solani.

Iron K lines from low-mass X-ray binaries

NASA Technical Reports Server (NTRS)

Kallman, T.; White, N. E.

1989-01-01

Models are presented for the 6-7 keV iron line emission from low-mass X-ray binaries. A simplified model for an accretion disk corona is used to examine the dependence of the observable line properties, line width and mean energy, on the radial distance of the emission region from the X-ray source, and on the fraction of the X-rays from the source which reach the disk surface. The effects of blending of multiple line components and of Comptonization of the line profile are included in numerical calculations of the emitted profile shape. The results of these calculations, when compared with the line properties observed from several low-mass X-ray binaries, suggest that the broadening is dominated either by rotation or by Compton scattering through a greater optical depth than is expected from an accretion disk corona.

SOLAR MULTIPLE ERUPTIONS FROM A CONFINED MAGNETIC STRUCTURE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jeongwoo; Chae, Jongchul; Liu, Chang

2016-09-20

How eruption can recur from a confined magnetic structure is discussed based on the Solar Dynamics Observatory observations of the NOAA active region 11444, which produced three eruptions within 1.5 hr on 2012 March 27. The active region (AR) had the positive-polarity magnetic fields in the center surrounded by the negative-polarity fields around. Since such a distribution of magnetic polarity tends to form a dome-like magnetic fan structure confined over the AR, the multiple eruptions were puzzling. Our investigation reveals that this event exhibits several properties distinct from other eruptions associated with magnetic fan structures: (i) a long filament encirclingmore » the AR was present before the eruptions; (ii) expansion of the open–closed boundary (OCB) of the field lines after each eruption was suggestive of the growing fan-dome structure, and (iii) the ribbons inside the closed magnetic polarity inversion line evolved in response to the expanding OCB. It thus appears that in spite of multiple eruptions the fan-dome structure remained undamaged, and the closing back field lines after each eruption rather reinforced the fan-dome structure. We argue that the multiple eruptions could occur in this AR in spite of its confined magnetic structure because the filament encircling the AR was adequate for slipping through the magnetic separatrix to minimize the damage to its overlying fan-dome structure. The result of this study provides a new insight into the productivity of eruptions from a confined magnetic structure.« less

Reduction of IgE binding and nonpromotion of Aspergillus flavus fungal growth by simultaneously silencing Ara h 2 and Ara h 6 in peanut.

USDA-ARS?s Scientific Manuscript database

The most potent peanut allergens, Ara h 2 and 6, were silenced in transgenic plants by RNA interference. Three independent transgenic lines were recovered after microprojectile bombardment, of which two contained single, integrated copies of the transgene. The third line contained multiple copies ...

Registration of PR0806-80 and PR0806-81 white bean germplasm lines with resistance to BGYMV, BCMV, BCMNV and rust

USDA-ARS?s Scientific Manuscript database

PR0806-80 (Reg. No. GP-___, PI ______) and PR0806-81 (Reg. No. GP-___, PI ______) are multiple disease resistant dry bean (Phaseolus vulgaris L.) germplasm lines, adapted to the humid tropics, that were developed and released cooperatively by the University of Puerto Rico Agricultural Experiment Sta...

Peak Lead Levels and Diagnostics in Lead Service Lines Dominated by PbO2 - abstract

EPA Science Inventory

Multiple studies have presented “profiles” of water lead levels from tap to main through lead service lines (LSLs), in systems where the LSLs were coated with common Pb(II) corrosion solids. These Pb(II) solids were either actual Pb(II) minerals or Pb(II) sorbed onto other pipe ...

Advanced Spectral Modeling Development

DTIC Science & Technology

1992-09-14

above, the AFGL line-by-line code already possesses many of the attributes desired of a generally applicable transmittance/radiance simulation code, it...transmittance calculations, (b) perform generalized multiple scattering calculations, (c) calculate both heating and dissociative fluxes, (d) provide...This report is subdivided into task specific subsections. The following section describes our general approach to address these technical issues (Section

On-Line Synthesis and Analysis by Mass Spectrometry

ERIC Educational Resources Information Center

Bain, Ryan M.; Pulliam, Christopher J.; Raab, Shannon A.; Cooks, R. Graham

2015-01-01

In this laboratory experiment, students learn how to use ESI to accelerate chemical synthesis and to couple it with on-line mass spectrometry for structural analysis. The Hantzsch synthesis of symmetric 1,4-dihydropyridines is a classic example of a one-pot reaction in which multiple intermediates can serve to indicate the progress of the reaction…

Mitigating "Milliken"? School District Boundary Lines and Desegregation Policy in Four Southern Metropolitan Areas, 1990-2010

ERIC Educational Resources Information Center

Siegel-Hawley, Genevieve

2014-01-01

Over the past half century, law and policy have helped cement tremendous inequities into the structure of our cities. District boundary lines separating multiple, unequal school systems within a single metropolitan (metro) area play a central role in structuring racial and economic isolation. Using data from the National Center for Education…

Time dependent emission line profiles in the radially streaming particle model of Seyfert galaxy nuclei and quasi-stellar objects

NASA Technical Reports Server (NTRS)

Hubbard, R.

1974-01-01

The radially-streaming particle model for broad quasar and Seyfert galaxy emission features is modified to include sources of time dependence. The results are suggestive of reported observations of multiple components, variability, and transient features in the wings of Seyfert and quasi-stellar emission lines.

Group selection for adaptation to multiple-hen cages: humoral immune response.

PubMed

Hester, P Y; Muir, W M; Craig, J V

1996-11-01

A selected line of White Leghorns, which has shown improved survivability and reduced feather loss in large multiple-hen cages, was evaluated for humoral immune response to SRBC under both stressed and unstressed conditions. Three lines of chickens (selected, control, and commercial) were housed in either single- (1 hen) or multiple-hen cages (12 hens, social competition) and subjected to a cold ambient temperature (0 C) at 33 wk of age and to two heating episodes (38 C) at 44 wk of age. Each hen was challenged intravenously with 1 mL of a 7% saline suspension of SRBC at the time that cold exposure was initiated. Hens subjected to high ambient temperatures had been exposed previously to a cold temperature, but were not challenged with SRBC until 16 to 18 h following the end of the second heating episode. Exposure to cold caused immunosuppression in single-caged hens, but not in hens in colony cages. Single- vs colony-caged hens of the control environment challenged with SRBC at 33 wk of age had similar primary hemagglutinin responses to SRBC. Hens subjected to heat experienced immunosuppression at 9 and 12 d following challenge to SRBC when compared to the controls. Hens of multiple-bird cages challenged with antigen at 44 wk of age had a significantly lower hemagglutinin response to SRBC than those reared in single-bird cages. The three lines of genetic stock had similar primary hemagglutinin responses to SRBC; the interactions of genetic stock with cage size or environmental temperature were not significant. It was concluded that genetically selecting hens for survival in multiple-hen cages did not affect their humoral immune response to SRBC.

Aminoglycoside-Resistant Aeromonas hydrophila as Part of a Polymicrobial Infection following a Traumatic Fall into Freshwater▿

PubMed Central

Shak, Joshua R.; Whitaker, Jennifer A.; Ribner, Bruce S.; Burd, Eileen M.

2011-01-01

Amikacin is a first-line treatment for Aeromonas infection due to high efficacy. There are few reports of aminoglycoside-resistant Aeromonas spp. We report a soft tissue infection containing multiple pathogens, including a strain of Aeromonas hydrophila resistant to amikacin, tobramycin, and multiple cephalosporins. PMID:21209173

Aminoglycoside-resistant Aeromonas hydrophila as part of a polymicrobial infection following a traumatic fall into freshwater.

PubMed

Shak, Joshua R; Whitaker, Jennifer A; Ribner, Bruce S; Burd, Eileen M

2011-03-01

Amikacin is a first-line treatment for Aeromonas infection due to high efficacy. There are few reports of aminoglycoside-resistant Aeromonas spp. We report a soft tissue infection containing multiple pathogens, including a strain of Aeromonas hydrophila resistant to amikacin, tobramycin, and multiple cephalosporins.

Reversibility of Thought: An Instance in Multiplicative Tasks

ERIC Educational Resources Information Center

Ramful, Ajay; Olive, John

2008-01-01

In line with current efforts to understand the piece-by-piece structure and articulation of children's mathematical concepts, this case study compares the reversibility schemes of two eighth-grade students. The aim of the study was to identify the mechanism through which students reverse their thought processes in a multiplicative situation. Data…

Homography-based multiple-camera person-tracking

NASA Astrophysics Data System (ADS)

Turk, Matthew R.

2009-01-01

Multiple video cameras are cheaply installed overlooking an area of interest. While computerized single-camera tracking is well-developed, multiple-camera tracking is a relatively new problem. The main multi-camera problem is to give the same tracking label to all projections of a real-world target. This is called the consistent labelling problem. Khan and Shah (2003) introduced a method to use field of view lines to perform multiple-camera tracking. The method creates inter-camera meta-target associations when objects enter at the scene edges. They also said that a plane-induced homography could be used for tracking, but this method was not well described. Their homography-based system would not work if targets use only one side of a camera to enter the scene. This paper overcomes this limitation and fully describes a practical homography-based tracker. A new method to find the feet feature is introduced. The method works especially well if the camera is tilted, when using the bottom centre of the target's bounding-box would produce inaccurate results. The new method is more accurate than the bounding-box method even when the camera is not tilted. Next, a method is presented that uses a series of corresponding point pairs "dropped" by oblivious, live human targets to find a plane-induced homography. The point pairs are created by tracking the feet locations of moving targets that were associated using the field of view line method. Finally, a homography-based multiple-camera tracking algorithm is introduced. Rules governing when to create the homography are specified. The algorithm ensures that homography-based tracking only starts after a non-degenerate homography is found. The method works when not all four field of view lines are discoverable; only one line needs to be found to use the algorithm. To initialize the system, the operator must specify pairs of overlapping cameras. Aside from that, the algorithm is fully automatic and uses the natural movement of live targets for training. No calibration is required. Testing shows that the algorithm performs very well in real-world sequences. The consistent labelling problem is solved, even for targets that appear via in-scene entrances. Full occlusions are handled. Although implemented in Matlab, the multiple-camera tracking system runs at eight frames per second. A faster implementation would be suitable for real-world use at typical video frame rates.

EVIDENCE FOR CO SHOCK EXCITATION IN NGC 6240 FROM HERSCHEL SPIRE SPECTROSCOPY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meijerink, R.; Spaans, M.; Kristensen, L. E.

2013-01-10

We present Herschel SPIRE FTS spectroscopy of the nearby luminous infrared galaxy NGC 6240. In total 20 lines are detected, including CO J = 4 - 3 through J = 13 - 12, 6 H{sub 2}O rotational lines, and [C I] and [N II] fine-structure lines. The CO to continuum luminosity ratio is 10 times higher in NGC 6240 than Mrk 231. Although the CO ladders of NGC 6240 and Mrk 231 are very similar, UV and/or X-ray irradiation are unlikely to be responsible for the excitation of the gas in NGC 6240. We applied both C and J shockmore » models to the H{sub 2} v = 1-0 S(1) and v = 2-1 S(1) lines and the CO rotational ladder. The CO ladder is best reproduced by a model with shock velocity v{sub s} = 10 km s{sup -1} and a pre-shock density n{sub H} = 5 Multiplication-Sign 10{sup 4} cm{sup -3}. We find that the solution best fitting the H{sub 2} lines is degenerate. The shock velocities and number densities range between v{sub s} = 17-47 km s{sup -1} and n{sub H} = 10{sup 7}-5 Multiplication-Sign 10{sup 4} cm{sup -3}, respectively. The H{sub 2} lines thus need a much more powerful shock than the CO lines. We deduce that most of the gas is currently moderately stirred up by slow (10 km s{sup -1}) shocks while only a small fraction ({approx}< 1%) of the interstellar medium is exposed to the high-velocity shocks. This implies that the gas is rapidly losing its highly turbulent motions. We argue that a high CO line-to-continuum ratio is a key diagnostic for the presence of shocks.« less

Focused shock spark discharge drill using multiple electrodes

DOEpatents

Moeny, William M.; Small, James G.

1988-01-01

A spark discharge focused drill provided with one pulse forming line or a number of pulse forming lines. The pulse forming line is connected to an array of electrodes which would form a spark array. One of the electrodes of each of the array is connected to the high voltage side of the pulse forming line and the other electrodes are at ground potential. When discharged in a liquid, these electrodes produce intense focused shock waves that can pulverize or fracture rock. By delaying the firing of each group of electrodes, the drill can be steered within the earth. Power can be fed to the pulse forming line either downhole or from the surface area. A high voltage source, such as a Marx generator, is suitable for pulse charging the lines.

Clinical service lines in integrated delivery systems: an initial framework and exploration.

PubMed

Parker, V A; Charns, M P; Young, G J

2001-01-01

The increasing pressures on integrated healthcare delivery systems (IDSs) to provide coordinated and cost-effective care focuses attention on the question of how to best integrate across multiple sites of care. One increasingly common approach to this issue is the development of clinical service lines that integrate specific bundles of services across the operating units of a system. This article presents a conceptual model of service lines and reports results from a descriptive investigation of service line development among members of the Industry Advisory Board--a research consortium comprising IDSs. The experiences of these IDSs (1) provide valuable insights into the range of organizational arrangements and implementation issues that are associated with service line management in healthcare systems and (2) suggest aspects of service line management worthy of further inquiry.

Identification of multiple ear-colonizing insect and disease resistance in CIMMYT maize inbred lines with varying levels of silk maysin.

PubMed

Ni, Xinzhi; Krakowsky, Matthew D; Buntin, G David; Rector, Brian G; Guo, Baozhu; Snook, Maurice E

2008-08-01

Ninety four corn inbred lines selected from International Center for the Improvement of Maize and Wheat (CIMMYT) in Mexico were evaluated for levels of silk maysin in 2001 and 2002. Damage by major ear-feeding insects [i.e., corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae); maize weevil, Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae); brown stink bug, Euschistus servus (Say); southern green stink bugs, Nezara viridula (L.) (Heteroptera: Pentatomidae)], and common smut [Ustilago maydis DC (Corda)] infection on these inbred lines were evaluated in 2005 and 2006 under subtropical conditions at Tifton, GA. Ten inbred lines possessing good agronomic traits were also resistant to the corn earworm. The correlation between ear-feeding insect damage or smut infection and three phenotypic traits (silk maysin level, husk extension, and husk tightness of corn ears) was also examined. Corn earworm and stink bug damage was negatively correlated to husk extension, but not to either silk maysin levels or husk tightness. In combination with the best agronomic trait ratings that show the least corn earworm and stink bug damage, lowest smut infection rate, and good insect-resistant phenotypic traits (i.e., high maysin and good husk coverage and husk tightness), 10 best inbred lines (CML90, CML92, CML94, CML99, CML104, CML108, CML114, CML128, CML137, and CML373) were identified from the 94 lines examined. These selected inbred lines will be used for further examination of their resistance mechanisms and development of new corn germplasm that confers multiple ear-colonizing pest resistance.

Characterization and differentiation of human embryonic stem cells.

PubMed

Carpenter, M K; Rosler, E; Rao, M S

2003-01-01

Cell replacement therapies have been limited by the availability of sufficient quantities of cells for transplantation. Human ES (hES) cell lines have recently been generated by several laboratories. When maintained for over 1 year in vitro, they remain karyotypically and phenotypically stable and may therefore provide an excellent source material for cell therapies. Currently, data is available for 26 hES cell lines. Although limited characterization has been performed on most of these lines, there are remarkable similarities in expression of markers. hES cell lines derived in different laboratories show similar expression profiles of surface markers, including SSEA-4, Tra-1-60, and Tra-1-81. In addition, markers associated with pluripotent cells such as OCT-4 are expressed at in all cell lines tested. These cells express high levels of telomerase and appear to have indefinite growth potential. The generation of the large quantities of cells necessary for cell replacement therapies will require a cell population which is stable over long term culture. We have characterized the properties of multiple hES cell lines that have been maintained in culture for extended periods. Quantitative analyses demonstrate that all of the cell lines examined show consistent marker expression and retain a normal karyotype after long-term culture. hES cells have been differentiated into the derivatives of all three germ layers. Specifically this includes cardiomyocytes, neural cells, hepatocyte-like cells, endothelial cells and hematopoietic progenitor cells. These data demonstrating the karyotypic and phenotypic stability of hES cells and their extensive differentiative capacity indicate that they may be an appropriate source of cells for multiple regenerative medicine applications.

A single CD4 test with 250 cells/mm3 threshold predicts viral suppression in HIV-infected adults failing first-line therapy by clinical criteria.

PubMed

Gilks, Charles F; Walker, A Sarah; Munderi, Paula; Kityo, Cissy; Reid, Andrew; Katabira, Elly; Goodall, Ruth L; Grosskurth, Heiner; Mugyenyi, Peter; Hakim, James; Gibb, Diana M

2013-01-01

In low-income countries, viral load (VL) monitoring of antiretroviral therapy (ART) is rarely available in the public sector for HIV-infected adults or children. Using clinical failure alone to identify first-line ART failure and trigger regimen switch may result in unnecessary use of costly second-line therapy. Our objective was to identify CD4 threshold values to confirm clinically-determined ART failure when VL is unavailable. 3316 HIV-infected Ugandan/Zimbabwean adults were randomised to first-line ART with Clinically-Driven (CDM, CD4s measured but blinded) or routine Laboratory and Clinical Monitoring (LCM, 12-weekly CD4s) in the DART trial. CD4 at switch and ART failure criteria (new/recurrent WHO 4, single/multiple WHO 3 event; LCM: CD4<100 cells/mm(3)) were reviewed in 361 LCM, 314 CDM participants who switched over median 5 years follow-up. Retrospective VLs were available in 368 (55%) participants. Overall, 265/361 (73%) LCM participants failed with CD4<100 cells/mm(3); only 7 (2%) switched with CD4≥250 cells/mm(3), four switches triggered by WHO events. Without CD4 monitoring, 207/314 (66%) CDM participants failed with WHO 4 events, and 77(25%)/30(10%) with single/multiple WHO 3 events. Failure/switching with single WHO 3 events was more likely with CD4≥250 cells/mm(3) (28/77; 36%) (p = 0.0002). CD4 monitoring reduced switching with viral suppression: 23/187 (12%) LCM versus 49/181 (27%) CDM had VL<400 copies/ml at failure/switch (p<0.0001). Amongst CDM participants with CD4<250 cells/mm(3) only 11/133 (8%) had VL<400 copies/ml, compared with 38/48 (79%) with CD4≥250 cells/mm(3) (p<0.0001). Multiple, but not single, WHO 3 events predicted first-line ART failure. A CD4 threshold 'tiebreaker' of ≥250 cells/mm(3) for clinically-monitored patients failing first-line could identify ∼80% with VL<400 copies/ml, who are unlikely to benefit from second-line. Targeting CD4s to single WHO stage 3 'clinical failures' would particularly avoid premature, costly switch to second-line ART.

A Single CD4 Test with 250 Cells/Mm3 Threshold Predicts Viral Suppression in HIV-Infected Adults Failing First-Line Therapy by Clinical Criteria

PubMed Central

Munderi, Paula; Kityo, Cissy; Reid, Andrew; Katabira, Elly; Goodall, Ruth L.; Grosskurth, Heiner; Mugyenyi, Peter; Hakim, James; Gibb, Diana M.

2013-01-01

Background In low-income countries, viral load (VL) monitoring of antiretroviral therapy (ART) is rarely available in the public sector for HIV-infected adults or children. Using clinical failure alone to identify first-line ART failure and trigger regimen switch may result in unnecessary use of costly second-line therapy. Our objective was to identify CD4 threshold values to confirm clinically-determined ART failure when VL is unavailable. Methods 3316 HIV-infected Ugandan/Zimbabwean adults were randomised to first-line ART with Clinically-Driven (CDM, CD4s measured but blinded) or routine Laboratory and Clinical Monitoring (LCM, 12-weekly CD4s) in the DART trial. CD4 at switch and ART failure criteria (new/recurrent WHO 4, single/multiple WHO 3 event; LCM: CD4<100 cells/mm3) were reviewed in 361 LCM, 314 CDM participants who switched over median 5 years follow-up. Retrospective VLs were available in 368 (55%) participants. Results Overall, 265/361 (73%) LCM participants failed with CD4<100 cells/mm3; only 7 (2%) switched with CD4≥250 cells/mm3, four switches triggered by WHO events. Without CD4 monitoring, 207/314 (66%) CDM participants failed with WHO 4 events, and 77(25%)/30(10%) with single/multiple WHO 3 events. Failure/switching with single WHO 3 events was more likely with CD4≥250 cells/mm3 (28/77; 36%) (p = 0.0002). CD4 monitoring reduced switching with viral suppression: 23/187 (12%) LCM versus 49/181 (27%) CDM had VL<400 copies/ml at failure/switch (p<0.0001). Amongst CDM participants with CD4<250 cells/mm3 only 11/133 (8%) had VL<400copies/ml, compared with 38/48 (79%) with CD4≥250 cells/mm3 (p<0.0001). Conclusion Multiple, but not single, WHO 3 events predicted first-line ART failure. A CD4 threshold ‘tiebreaker’ of ≥250 cells/mm3 for clinically-monitored patients failing first-line could identify ∼80% with VL<400 copies/ml, who are unlikely to benefit from second-line. Targeting CD4s to single WHO stage 3 ‘clinical failures’ would particularly avoid premature, costly switch to second-line ART. PMID:23437399

Highly stable multi-wavelength erbium-doped fiber linear laser based on modal interference

NASA Astrophysics Data System (ADS)

Herrera-Piad, L. A.; Jauregui-Vazquez, D.; Lopez-Dieguez, Y.; Estudillo-Ayala, J. M.; Hernandez-Garcia, J. C.; Sierra-Hernandez, J. M.; Bianchetti, M.; Rojas-Laguna, R.

2018-03-01

We report a linear fiber laser cavity based on an all-fiber Fabry-Perot interferometer and bi-tapered optical fiber for multi-wavelength emission generation. Curvature and strain are used to operate the laser system and the number of lines as well, the emission regions are stronger related to the physical effect applied, due to the phase alteration between the multiple fiber optic modes involved. The original laser emissions present zero wavelength variations, minimal power fluctuations and small spacing mode (1 nm). Additionally, a nonlinear fiber was employed trying to improve the performance of the multiple lasing lines. This system offers a low implementation cost, compactness and good laser parameters.

DISCOVERY OF THE TRANSITION OF A MINI-BROAD ABSORPTION LINE INTO A BROAD ABSORPTION LINE IN THE SDSS QUASAR J115122.14+020426.3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hidalgo, Paola Rodriguez; Eracleous, Michael; Charlton, Jane

We present the detection of a rare case of dramatic strengthening in the UV absorption profiles in the spectrum of the quasar J115122.14+020426.3 between observations {approx}2.86 yr apart in the quasar rest frame. A spectrum obtained in 2001 by the Sloan Digital Sky Survey shows a C IV ''mini-broad'' absorption line (FWHM = 1220 km s{sup -1}) with a maximum blueshift velocity of {approx}9520 km s{sup -1}, while a later spectrum from the Very Large Telescope shows a significantly broader and stronger absorption line, with a maximum blueshift velocity of {approx}12, 240 km s{sup -1} that qualifies as a broadmore » absorption line. A similar variability pattern is observed in two additional systems at lower blueshifted velocities and in the Ly{alpha} and N V transitions as well. One of the absorption systems appears to be resolved and shows evidence for partial covering of the quasar continuum source (C{sub f} {approx} 0.65), indicating a transverse absorber size of, at least, {approx}6 Multiplication-Sign 10{sup 16} cm. In contrast, a cluster of narrower C IV lines appears to originate in gas that fully covers the continuum and broad emission line sources. There is no evidence for changes in the centroid velocity of the absorption troughs. This case suggests that at least some of the absorbers that produce ''mini-broad'' and broad absorption lines in quasar spectra do not belong to intrinsically separate classes. Here, the ''mini-broad'' absorption line is most likely interpreted as an intermediate phase before the appearance of a broad absorption line due to their similar velocities. While the current observations do not provide enough constraints to discern among the possible causes for this variability, future monitoring of multiple transitions at high resolution will help achieve this goal.« less

The use of anthracycline at first-line compared to alkylating agents or nucleoside analogs improves the outcome of salvage treatments after relapse in follicular lymphoma The REFOLL study by the Fondazione Italiana Linfomi.

PubMed

Rossi, Giuseppe; Marcheselli, Luigi; Dondi, Alessandra; Bottelli, Chiara; Tucci, Alessandra; Luminari, Stefano; Arcaini, Luca; Merli, Michele; Pulsoni, Alessandro; Boccomini, Carola; Puccini, Benedetta; Micheletti, Moira; Martinelli, Giovanni; Rossi, Andrea; Zilioli, Vittorio Ruggero; Bozzoli, Valentina; Balzarotti, Monica; Bolis, Silvia; Cabras, Maria Giuseppina; Federico, Massimo

2015-01-01

Follicular lymphoma (FL) patients experience multiple remissions and relapses and commonly receive multiple treatment lines. A crucial question is whether anthracyclines should be used at first-line or whether they would be better "reserved" for relapse and whether FL outcome can be optimized by definite sequences of treatments. Randomized trials can be hardly designed to address this question. In this retrospective multi-institutional study, time-to-next-treatment after first relapse was analyzed in 510 patients who had received either alkylating agents- or anthracycline- or nucleoside analogs-based chemotherapy with/without rituximab at first-line and different second-line therapies. After a median of 42 months, median time-to-next-treatment after relapse was 41 months (CI95%:34-47 months). After adjustment for covariates, first-line anthracycline-based chemotherapy with/without rituximab was associated with better time-to-next-treatment after any salvage than alkylating agents-based chemotherapy with/without rituximab or nucleoside analogs-based chemotherapy with/without rituximab (HR:0.74, P = 0.027). The addition of rituximab to first-line chemotherapy had no significant impact (HR:1.22, P = 0.140). Autologs stem cell transplantation performed better than any other salvage treatment (HR:0.53, P < 0.001). First-line anthracycline-based chemotherapy significantly improved time-to-next-treatment even in patients receiving salvage autologs stem cell transplantation (P = 0.041). This study supports the concept that in FL previous treatments significantly impact on the outcome of subsequent therapies. The outcome of second-line treatments, either with salvage chemoimmunotherapy or with autologs stem cell transplantation, was better when an anthracycline-containing regimen was used at first-line. © 2014 Wiley Periodicals, Inc.

The Kinematics of Multiple-peaked Lyα Emission in Star-forming Galaxies at z ~ 2-3

NASA Astrophysics Data System (ADS)

Kulas, Kristin R.; Shapley, Alice E.; Kollmeier, Juna A.; Zheng, Zheng; Steidel, Charles C.; Hainline, Kevin N.

2012-01-01

We present new results on the Lyα emission-line kinematics of 18 z ~ 2-3 star-forming galaxies with multiple-peaked Lyα profiles. With our large spectroscopic database of UV-selected star-forming galaxies at these redshifts, we have determined that ~30% of such objects with detectable Lyα emission display multiple-peaked emission profiles. These profiles provide additional constraints on the escape of Lyα photons due to the rich velocity structure in the emergent line. Despite recent advances in modeling the escape of Lyα from star-forming galaxies at high redshifts, comparisons between models and data are often missing crucial observational information. Using Keck II NIRSPEC spectra of Hα (z ~ 2) and [O III]λ5007 (z ~ 3), we have measured accurate systemic redshifts, rest-frame optical nebular velocity dispersions, and emission-line fluxes for the objects in the sample. In addition, rest-frame UV luminosities and colors provide estimates of star formation rates and the degree of dust extinction. In concert with the profile sub-structure, these measurements provide critical constraints on the geometry and kinematics of interstellar gas in high-redshift galaxies. Accurate systemic redshifts allow us to translate the multiple-peaked Lyα profiles into velocity space, revealing that the majority (11/18) display double-peaked emission straddling the velocity-field zero point with stronger red-side emission. Interstellar absorption-line kinematics suggest the presence of large-scale outflows for the majority of objects in our sample, with an average measured interstellar absorption velocity offset of langΔv absrang = -230 km s-1. A comparison of the interstellar absorption kinematics for objects with multiple- and single-peaked Lyα profiles indicate that the multiple-peaked objects are characterized by significantly narrower absorption line widths. We compare our data with the predictions of simple models for outflowing and infalling gas distributions around high-redshift galaxies. While popular "shell" models provide a qualitative match with many of the observations of Lyα emission, we find that in detail there are important discrepancies between the models and data, as well as problems with applying the framework of an expanding thin shell of gas to explain high-redshift galaxy spectra. Our data highlight these inconsistencies, as well as illuminating critical elements for success in future models of outflow and infall in high-redshift galaxies. Based, in part, on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.

Two-dimensional simulation and modeling in scanning electron microscope imaging and metrology research.

PubMed

Postek, Michael T; Vladár, András E; Lowney, Jeremiah R; Keery, William J

2002-01-01

Traditional Monte Carlo modeling of the electron beam-specimen interactions in a scanning electron microscope (SEM) produces information about electron beam penetration and output signal generation at either a single beam-landing location, or multiple landing positions. If the multiple landings lie on a line, the results can be graphed in a line scan-like format. Monte Carlo results formatted as line scans have proven useful in providing one-dimensional information about the sample (e.g., linewidth). When used this way, this process is called forward line scan modeling. In the present work, the concept of image simulation (or the first step in the inverse modeling of images) is introduced where the forward-modeled line scan data are carried one step further to construct theoretical two-dimensional (2-D) micrographs (i.e., theoretical SEM images) for comparison with similar experimentally obtained micrographs. This provides an ability to mimic and closely match theory and experiment using SEM images. Calculated and/or measured libraries of simulated images can be developed with this technique. The library concept will prove to be very useful in the determination of dimensional and other properties of simple structures, such as integrated circuit parts, where the shape of the features is preferably measured from a single top-down image or a line scan. This paper presents one approach to the generation of 2-D simulated images and presents some suggestions as to their application to critical dimension metrology.

Intercomparison of shortwave radiative transfer schemes in global aerosol modeling: results from the AeroCom Radiative Transfer Experiment

NASA Astrophysics Data System (ADS)

Randles, C. A.; Kinne, S.; Myhre, G.; Schulz, M.; Stier, P.; Fischer, J.; Doppler, L.; Highwood, E.; Ryder, C.; Harris, B.; Huttunen, J.; Ma, Y.; Pinker, R. T.; Mayer, B.; Neubauer, D.; Hitzenberger, R.; Oreopoulos, L.; Lee, D.; Pitari, G.; Di Genova, G.; Quaas, J.; Rose, Fred G.; Kato, S.; Rumbold, S. T.; Vardavas, I.; Hatzianastassiou, N.; Matsoukas, C.; Yu, H.; Zhang, F.; Zhang, H.; Lu, P.

2012-12-01

In this study we examine the performance of 31 global model radiative transfer schemes in cloud-free conditions with prescribed gaseous absorbers and no aerosols (Rayleigh atmosphere), with prescribed scattering-only aerosols, and with more absorbing aerosols. Results are compared to benchmark results from high-resolution, multi-angular line-by-line radiation models. For purely scattering aerosols, model bias relative to the line-by-line models in the top-of-the atmosphere aerosol radiative forcing ranges from roughly -10 to 20%, with over- and underestimates of radiative cooling at higher and lower sun elevation, respectively. Inter-model diversity (relative standard deviation) increases from ~10 to 15% as sun elevation increases. Inter-model diversity in atmospheric and surface forcing decreases with increased aerosol absorption, indicating that the treatment of multiple-scattering is more variable than aerosol absorption in the models considered. Aerosol radiative forcing results from multi-stream models are generally in better agreement with the line-by-line results than the simpler two-stream schemes. Considering radiative fluxes, model performance is generally the same or slightly better than results from previous radiation scheme intercomparisons. However, the inter-model diversity in aerosol radiative forcing remains large, primarily as a result of the treatment of multiple-scattering. Results indicate that global models that estimate aerosol radiative forcing with two-stream radiation schemes may be subject to persistent biases introduced by these schemes, particularly for regional aerosol forcing.

Intercomparison of shortwave radiative transfer schemes in global aerosol modeling: results from the AeroCom Radiative Transfer Experiment

NASA Astrophysics Data System (ADS)

Randles, C. A.; Kinne, S.; Myhre, G.; Schulz, M.; Stier, P.; Fischer, J.; Doppler, L.; Highwood, E.; Ryder, C.; Harris, B.; Huttunen, J.; Ma, Y.; Pinker, R. T.; Mayer, B.; Neubauer, D.; Hitzenberger, R.; Oreopoulos, L.; Lee, D.; Pitari, G.; Di Genova, G.; Quaas, J.; Rose, F. G.; Kato, S.; Rumbold, S. T.; Vardavas, I.; Hatzianastassiou, N.; Matsoukas, C.; Yu, H.; Zhang, F.; Zhang, H.; Lu, P.

2013-03-01

In this study we examine the performance of 31 global model radiative transfer schemes in cloud-free conditions with prescribed gaseous absorbers and no aerosols (Rayleigh atmosphere), with prescribed scattering-only aerosols, and with more absorbing aerosols. Results are compared to benchmark results from high-resolution, multi-angular line-by-line radiation models. For purely scattering aerosols, model bias relative to the line-by-line models in the top-of-the atmosphere aerosol radiative forcing ranges from roughly -10 to 20%, with over- and underestimates of radiative cooling at lower and higher solar zenith angle, respectively. Inter-model diversity (relative standard deviation) increases from ~10 to 15% as solar zenith angle decreases. Inter-model diversity in atmospheric and surface forcing decreases with increased aerosol absorption, indicating that the treatment of multiple-scattering is more variable than aerosol absorption in the models considered. Aerosol radiative forcing results from multi-stream models are generally in better agreement with the line-by-line results than the simpler two-stream schemes. Considering radiative fluxes, model performance is generally the same or slightly better than results from previous radiation scheme intercomparisons. However, the inter-model diversity in aerosol radiative forcing remains large, primarily as a result of the treatment of multiple-scattering. Results indicate that global models that estimate aerosol radiative forcing with two-stream radiation schemes may be subject to persistent biases introduced by these schemes, particularly for regional aerosol forcing.

Dislocation Multiplication in the Early Stage of Deformation in Mo Single Crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsiung, L.; Lassila, D.H.

Initial dislocation structure in annealed high-purity Mo single crystals and deformation substructure in a crystal subjected to 1% compression have been examined and studied using transmission electron microscopy (TEM) techniques in order to investigate dislocation multiplication mechanisms in the early stage of plastic deformation. The initial dislocation density is in a range of 10{sup 6} {approx} 10{sup 7} cm{sup -2}, and the dislocation structure is found to contain many grown-in superjogs along dislocation lines. The dislocation density increases to a range of 10{sup 8} {approx} 10{sup 9} cm{sup -2}, and the average jog height is also found to increase aftermore » compressing for a total strain of 1%. It is proposed that the preexisting jogged screw dislocations can act as (multiple) dislocation multiplication sources when deformed under quasi-static conditions. The jog height can increase by stress-induced jog coalescence, which takes place via the lateral migration (drift) of superjogs driven by unbalanced line-tension partials acting on link segments of unequal lengths. The coalescence of superjogs results in an increase of both link length and jog height. Applied shear stress begins to push each link segment to precede dislocation multiplication when link length and jog height are greater than critical lengths. This ''dynamic'' dislocation multiplication source is suggested to be crucial for the dislocation multiplication in the early stage of plastic deformation in Mo.« less

The oscillation model of hydrothermal dynamics beneath Aso volcano, southwest Japan after small eruption on May 2011: A new understanding model using repeated absolute and relative gravity measurement

NASA Astrophysics Data System (ADS)

Sofyan, Yayan; Nishijima, Jun; Fujimitsu, Yasuhiro; Yoshikawa, Shin; Kagiyama, Tsuneomi; Ohkura, Takahiro

2016-01-01

At the end of 2010, the seismic activity in Aso volcano intensely increased and water level in the Nakadake crater decreased until early in 2011, then was followed by a small eruption in May 2011. After the eruption and heavy rain, the volcanic activity subsided to calm period, crater bottom was refilled with water, and water level increased in the Nakadake crater. The next tremor reappeared in 2014 and tracked to eruption in November 2014. This eruptive pattern and water level variation in the crater repeatedly appeared on the surface, and it should be related to the hydrothermal dynamics beneath Aso volcano. We initiated the gravity measurements in relation to hydrothermal dynamics in the subsurface of Aso volcano using Scintrex CG-5 (549) and LaCoste Romberg type G-1016 relative gravimeter at 28 benchmarks in April 2011, one month before the eruption. The repeated gravity measurements continue to monitor Aso volcano with a series of the measurement after the eruption in every three months to a half year. We analyze the gravity variation from 2011 to 2014 between the time of the phreatic and strombolian eruption. The measurements covered the area more than 60 km2 in the west side of Aso caldera. A new gravity network was also installed in May 2010 at seven benchmarks using A10-017 absolute gravimeter, which re-occupied in October 2010, June 2011 and two benchmarks in June 2014. As a result, the gravity changes distinguish hydrothermal dynamic in the subsurface, which has a direct correlation to water level fluctuation in the crater, after the first eruption and before the second discharge. The monitoring data notice large gravity changes between the surveys at benchmarks around Nakadake crater and Kusasenri area. The simple 3D inversion models of the 4-D gravity data deduce the density contrast distribution beneath Aso volcano. The inversion and mass change result generate the oscillation typical as a new understanding model. The variation of the mass shows a similar trend with the hydrothermal input rate to the crater of past research. The third year monitoring from April 2013 displays a large gravity and mass variation, while precipitation data in this period is smaller than the previous season. The largest increased mass about 43 million tons by Gaussian method occurred between May 2013 and September 2013. According to the three year gravity monitoring, the calm period in Aso volcano happens after May 2011 eruption until September 2013, which is followed by the active period, before the November 2014 eruption. This result will contribute to understand the process of eruption.

A Foamy Lava Lake at Kilauea Volcano, Hawai`i

NASA Astrophysics Data System (ADS)

Poland, M. P.; Carbone, D.

2012-12-01

Kilauea Volcano, in Hawai`i, is currently erupting from two locations simultaneously: along the east rift zone and at the summit. The east rift zone eruption began in 1983 and is characterized by lava effusion from the Pu`u `O`o and nearby vents, while the summit eruptive vent, which opened in 2008, persistently emits gas and small amounts of ash while hosting a lava lake. On March 5, 2011, a dike initiated from the east rift zone magma conduit and reached the surface, resulting in the 4.5-day-long Kamoamoa fissure eruption just uprift of Pu`u `O`o. The eruption was accompanied by summit deflation as magma withdrew from subsurface reservoirs to feed the fissure eruption. The level of the summit lava lake dropped as the summit deflated. A continuously recording gravimeter located at Kilauea's summit (about 150 m east of the center of the summit eruptive vent, 80 m above the vent rim, and about 140 m above the highest level reached by the lava lake) measured a gravity decrease of about 150 μGal during the lava level drop, after taking into account corrections for the solid Earth tide. The gravity signal is caused by a combination of three processes. First, subsidence of 15 cm due to summit deflation moved the gravimeter closer to the center of the Earth, resulting in a gravity increase. Second, mass removal from the subsurface magma reservoir at a depth of 1.4 km (based on a model from GPS and InSAR data) caused a gravity decrease. Third, the drop in the level of the lava lake, which reached a maximum of about 150 m, led to a gravity decrease. Assuming a simple point source of pressure change and a typical density for basaltic magma (2.3-2.7 g/cm3), the first two processes can only explain a small percent of the observed gravity decrease, which must therefore be mainly due to the drop in the level of the lava lake. We developed a numerical model of the summit eruptive vent that takes into account its complex geometry (as deduced from geological observations). Using the change in lava level over time (data courtesy of Matt Patrick), we estimated that a lava density of about 0.8 g/cm3 is required to fit the gravity time series. Gravity results, therefore, argue that the upper part of the vent is occupied by a low-density lava foam (in agreement with models of Kilauea's summit eruption from seismic, gas, and geologic data by Tim Orr and Matt Patrick) and provide the only means of quantifying the lava lake density.

tRNA and Its Activation Targets as Biomarkers and Regulators of Breast Cancer

DTIC Science & Technology

2013-09-01

linked tRNA misregulation to cancer. We have previously reported that tRNA levels are significantly elevated in breast cancer and multiple myeloma ...significantly elevated in breast cancer and multiple myeloma cells. To further investigate the cellular and physiological effects of tRNA overexpression, we...tRNA levels are elevated in breast cancer and multiple myeloma cell lines (Pavon-Eternod et al. 2009; Zhou et al. 2009). Though abnormal RNA polymerase

Initial dislocation structure and dynamic dislocation multiplication in Mo single crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsiung, L M; Lassila, D H

Initial dislocation structure in annealed high-purity Mo single crystals and deformation substructure in a crystal subjected to 1% compression have been examined and studied in order to investigate dislocation multiplication mechanisms in the early stages of plastic deformation. The initial dislocation density is in a range of 10{sup 6} {approx} 10{sup 7} cm{sup -2}, and the dislocation structure is found to contain many grown-in superjogs along dislocation lines. The dislocation density increases to a range of 10{sup 8} {approx} 10{sup 9} cm{sup -2}, and the average jog height is also found to increase after compressing for a total strain ofmore » 1%. It is proposed that the preexisting jogged screw dislocations can act as (multiple) dislocation multiplication sources when deformed under quasi-static conditions. Both the jog height and length of link segment (between jogs) can increase by stress-induced jog coalescence, which takes place via the lateral migration (drift) of superjogs driven by unbalanced line-tension partials acting on link segments of unequal lengths. Applied shear stress begins to push each link segment to precede dislocation multiplication when link length and jog height are greater than critical lengths. This dynamic dislocation multiplication source is subsequently verified by direct simulations of dislocation dynamics under stress to be crucial in the early stages of plastic deformation in Mo single crystals.« less

[Stimulation of mouse encephalomyocarditis virus reproduction by non-multiplying poliomyelitis virus in several transplantable tissue culture lines].

PubMed

Maslova, S V; Shirman, G A; Gavrilovskaia, I N

1977-01-01

Reproduction of mouse encephalomyocarditis virus (EMC) was studied in 5 continuous primate cell lines: HeLa, Fl, Detroit-6, P/7, and MIO inoculated with guanidine-dependent variant of poliomyelitis virus in the absence of guanidine. Poliomyelitis virus stimulated EMC virus reproduction in all cell lines under study. This stimulation effect was studied at length in HeLa and MIO cells. In HeLa cells, stimulation was observed at a low and moderate multiplicity of infection of EMC virus but not at a high (100 PEU/cell) multiplicity. Also, when EMC virus reproduction was stimulated, a shortening of the latent period of its multiplication cycle, an increase in the number of antigen-containing cells and the number of infectious centers were observed. In MIO cells, stimulation was found to occur both with low and high doses of EMC virus but not to be accompanied by a shortening in the latent period of EMC reproduction cycle, or any increase in the antigen-containing cells or number of infectious centers. In both cell types upon mixed infection the synthesis of virus-specific RNA's of EMC virus was enhanced. It is suggested that the stimulating effect of poliomyelitis virus is realized in HeLa and MIO cells at different stages of EMC virus reproduction.

A Passive Method for Detecting Vegetation Stress from Orbit: Chlorophyll Fluorescence Spectra from Fraunhofer Lines

NASA Technical Reports Server (NTRS)

Theisen, Arnold F.

2000-01-01

Solar-stimulated chlorophyll fluorescence measured with the Fraunhofer line depth method has correlated well with vegetation stress in previous studies. However, the instruments used in those studies were limited to a single solar absorption line (e.g. 656.3 nm), obviating the red/far-red ratio (R/FR) method. Optics and detector technology have reached the level whereby multiple, very narrow Fraunhofer lines are resolvable. Thirteen such lines span the visible spectrum in the red to far-red region where chlorophyll fluorescence occurs. Fluorescence intensities at the 13 Fraunhofer line wavelengths were used to model emission spectra. The source data were collected for summer and fall bean crops (Phaseolus vulgaris L.) subjected to various levels of nitrogen fertilization. The intensities were adjusted to account for Fraunhofer line depth and atmospheric transmittance. Multiple R/FR fluorescence ratios, calculated from the modeled fluorescence spectra, correlated strongly with leaf chlorophyll concentration and well with applied nitrogen. The ratio yielding the best correlation with chlorophyll utilized red fluorescence at the 694.5 nm Fraunhofer line and farred fluorescence at the 755.6 nm Fraunhofer line. Twenty R/FR ratios, each evaluated for the maximum differential between low and high (optimal) nitrogen treatments, ranked higher in some cases and lower in others, possibly related to the time of year the crops were grown and the stage of growth of the crops. Ratios with 728.9 nm and 738.9 nm in the denominator consistently ranked in the lowest and next lowest quartile, respectively. Ratios of the 656.3 nm Fraunhofer line and the 755.6 nm line consistently ranked highest for the summer crop. Ratios with 755.6 nm in the denominator ranked in the upper quartile for 10 out of 12 measurement dates. Differences in ratio ranking indicate that physiological conditions may be estimated using selected ratios of Fraunhofer lines within the context of R/FR analysis. A passive instrument designed to monitor R/FR chlorophyll fluorescence (i.e. vegetation stress) from orbit could be built today.

Logo recognition in video by line profile classification

NASA Astrophysics Data System (ADS)

den Hollander, Richard J. M.; Hanjalic, Alan

2003-12-01

We present an extension to earlier work on recognizing logos in video stills. The logo instances considered here are rigid planar objects observed at a distance in the scene, so the possible perspective transformation can be approximated by an affine transformation. For this reason we can classify the logos by matching (invariant) line profiles. We enhance our previous method by considering multiple line profiles instead of a single profile of the logo. The positions of the lines are based on maxima in the Hough transform space of the segmented logo foreground image. Experiments are performed on MPEG1 sport video sequences to show the performance of the proposed method.

Genomic prediction based on data from three layer lines using non-linear regression models.

PubMed

Huang, Heyun; Windig, Jack J; Vereijken, Addie; Calus, Mario P L

2014-11-06

Most studies on genomic prediction with reference populations that include multiple lines or breeds have used linear models. Data heterogeneity due to using multiple populations may conflict with model assumptions used in linear regression methods. In an attempt to alleviate potential discrepancies between assumptions of linear models and multi-population data, two types of alternative models were used: (1) a multi-trait genomic best linear unbiased prediction (GBLUP) model that modelled trait by line combinations as separate but correlated traits and (2) non-linear models based on kernel learning. These models were compared to conventional linear models for genomic prediction for two lines of brown layer hens (B1 and B2) and one line of white hens (W1). The three lines each had 1004 to 1023 training and 238 to 240 validation animals. Prediction accuracy was evaluated by estimating the correlation between observed phenotypes and predicted breeding values. When the training dataset included only data from the evaluated line, non-linear models yielded at best a similar accuracy as linear models. In some cases, when adding a distantly related line, the linear models showed a slight decrease in performance, while non-linear models generally showed no change in accuracy. When only information from a closely related line was used for training, linear models and non-linear radial basis function (RBF) kernel models performed similarly. The multi-trait GBLUP model took advantage of the estimated genetic correlations between the lines. Combining linear and non-linear models improved the accuracy of multi-line genomic prediction. Linear models and non-linear RBF models performed very similarly for genomic prediction, despite the expectation that non-linear models could deal better with the heterogeneous multi-population data. This heterogeneity of the data can be overcome by modelling trait by line combinations as separate but correlated traits, which avoids the occasional occurrence of large negative accuracies when the evaluated line was not included in the training dataset. Furthermore, when using a multi-line training dataset, non-linear models provided information on the genotype data that was complementary to the linear models, which indicates that the underlying data distributions of the three studied lines were indeed heterogeneous.

Study of the Effect of a Closed-End Side Branch on Sinusoidally Perturbed Flow of Liquid in a Line

NASA Technical Reports Server (NTRS)

Lewis, William; Blade, Robert J.; Dorsch, Robert G.

1963-01-01

Classical undamped acoustic-wave theory was used to determine analytical relations among sinusoidal perturbations of pressure and flow at the ends of a hydraulic-transmission line having a closed-end branch of arbitrary length attached at an arbitrary point. Experimental data were obtained for the equilateral case (a branch half as long as the main line connected to the main line at the midpoint) at mean flow speeds of 5 to 10 feet per second. Measured pressure-perturbation ratios agreed closely with analytical predictions. As frequencies for which the branch length was an odd multiple of 1/4 wavelength, waves in the main line were almost completely reflected at the junction point.

Unidentified line in x-ray spectra of the Andromeda galaxy and Perseus galaxy cluster.

PubMed

Boyarsky, A; Ruchayskiy, O; Iakubovskyi, D; Franse, J

2014-12-19

We report a weak line at 3.52±0.02  keV in x-ray spectra of the Andromeda galaxy and the Perseus galaxy cluster observed by the metal-oxide-silicon (MOS) and p-n (PN) CCD cameras of the XMM-Newton telescope. This line is not known as an atomic line in the spectra of galaxies or clusters. It becomes stronger towards the centers of the objects; is stronger for Perseus than for M31; is absent in the spectrum of a deep "blank sky" data set. Although for each object it is hard to exclude that the feature is due to an instrumental effect or an atomic line, it is consistent with the behavior of a dark matter decay line. Future (non-)detections of this line in multiple objects may help to reveal its nature.

Transmission line design for a power distribution system at 20 kHz for aircraft

NASA Technical Reports Server (NTRS)

Zelby, L. W.; Mathes, J. B.; Shawver, J. W.

1986-01-01

A low inductance, low characteristic impedance transmission line was designed for a 20 kHz power distribution system. Several different conductor configurations were considered: strip lines, interdigitated metal ribbons, and standard insulated wires in multiwire configurations (circular and rectangular cylindrical arrangements). The final design was a rectangular arrangement of multiple wires of the same gauge with alternating polarities from wire to wire. This offered the lowest inductance per unit length (on the order of several nanohenries/meter) and the lowest characteristic impedance (on the order of one Ohm). Standard multipin connectors with gold-plated elements were recommended with this transmission line, the junction boxes to be internally connected with flat metal ribbons for low inductance, and the line to be constructed in sections of suitable length. Computer programs for the calculation of inductance of multiwire lines and of capacitances of strip lines were developed.

Building Facade Modeling Under Line Feature Constraint Based on Close-Range Images

NASA Astrophysics Data System (ADS)

Liang, Y.; Sheng, Y. H.

2018-04-01

To solve existing problems in modeling facade of building merely with point feature based on close-range images , a new method for modeling building facade under line feature constraint is proposed in this paper. Firstly, Camera parameters and sparse spatial point clouds data were restored using the SFM , and 3D dense point clouds were generated with MVS; Secondly, the line features were detected based on the gradient direction , those detected line features were fit considering directions and lengths , then line features were matched under multiple types of constraints and extracted from multi-image sequence. At last, final facade mesh of a building was triangulated with point cloud and line features. The experiment shows that this method can effectively reconstruct the geometric facade of buildings using the advantages of combining point and line features of the close - range image sequence, especially in restoring the contour information of the facade of buildings.

Mission Critical Computer Resources Management Guide

DTIC Science & Technology

1988-09-01

Support Analyzers, Management, Generators Environments Word Workbench Processors Showroom System Structure HO Compilers IMath 1OperatingI Functions I...Simulated Automated, On-Line Generators Support Exercises Catalog, Function Environments Formal Spec Libraries Showroom System Structure I ADA Trackers I...shown in Figure 13-2. In this model, showrooms of larger more capable piecesare developed off-line for later integration and use in multiple systems

Line Up, Line Up: Using Technology to Align and Enhance Peer Learning and Assessment in a Student Centred Foundation Organic Chemistry Module

ERIC Educational Resources Information Center

Ryan, Barry J.

2013-01-01

This paper describes how three technologies were utilised in combination to align student learning and assessment as part of a case study. Multiple choice questions (MCQs) were central to all these technologies. The peer learning technologies; Personal Response Devices (a.k.a. "Clickers") and "PeerWise"…

Simple, Efficient, and Rapid Methods to Determine the Potential for Vapor Intrusion into the Home: Temporal Trends, Vapor Intrusion Forecasting, Sampling Strategies, and Contaminant Migration Routes

EPA Science Inventory

Current practice for evaluating the vapor intrusion pathway involves a multiple line of evidence approach based on direct measurements of volatile organic compound (VOC) concentrations in groundwater, external soil gas, subslab soil gas, and/or indoor air. No single line of evide...

The correlated k-distribution technique as applied to the AVHRR channels

NASA Technical Reports Server (NTRS)

Kratz, David P.

1995-01-01

Correlated k-distributions have been created to account for the molecular absorption found in the spectral ranges of the five Advanced Very High Resolution Radiometer (AVHRR) satellite channels. The production of the k-distributions was based upon an exponential-sum fitting of transmissions (ESFT) technique which was applied to reference line-by-line absorptance calculations. To account for the overlap of spectral features from different molecular species, the present routines made use of the multiplication transmissivity property which allows for considerable flexibility, especially when altering relative mixing ratios of the various molecular species. To determine the accuracy of the correlated k-distribution technique as compared to the line-by-line procedure, atmospheric flux and heating rate calculations were run for a wide variety of atmospheric conditions. For the atmospheric conditions taken into consideration, the correlated k-distribution technique has yielded results within about 0.5% for both the cases where the satellite spectral response functions were applied and where they were not. The correlated k-distribution's principal advantages is that it can be incorporated directly into multiple scattering routines that consider scattering as well as absorption by clouds and aerosol particles.

From webs to polylogarithms

NASA Astrophysics Data System (ADS)

Gardi, Einan

2014-04-01

We compute a class of diagrams contributing to the multi-leg soft anomalous dimension through three loops, by renormalizing a product of semi-infinite non-lightlike Wilson lines in dimensional regularization. Using non-Abelian exponentiation we directly compute contributions to the exponent in terms of webs. We develop a general strategy to compute webs with multiple gluon exchanges between Wilson lines in configuration space, and explore their analytic structure in terms of α ij , the exponential of the Minkowski cusp angle formed between the lines i and j. We show that beyond the obvious inversion symmetry α ij → 1 /α ij , at the level of the symbol the result also admits a crossing symmetry α ij → - α ij , relating spacelike and timelike kinematics, and hence argue that in this class of webs the symbol alphabet is restricted to α ij and . We carry out the calculation up to three gluons connecting four Wilson lines, finding that the contributions to the soft anomalous dimension are remarkably simple: they involve pure functions of uniform weight, which are written as a sum of products of polylogarithms, each depending on a single cusp angle. We conjecture that this type of factorization extends to all multiple-gluon-exchange contributions to the anomalous dimension.

Replication of Syngrapha falcifera Multiple-Nuclear Polyhedrosis Virus-D in Different Insect Cells

NASA Astrophysics Data System (ADS)

Khalid Nessr Alhag, Sadeq; Xin, Peng Jian

Six insect cell lines were tested for susceptibility to Syngrapha falcifera multiple nucleocapsid nucleopolyhedrovirus-D (SfaMNPV-D) infection by use of a typical endpoint assay procedure. Cell lines from Trichoplusia ni (Tn5B1-4), (L105-clone), Spodoptera litura (SL-ZSU-1), Spodoptera frugiperda (IPLB-SF-21), Pieris rapaeb (Pr-E-HNU9) and Helicoverpa zea (BCIRL-HZ-AM1) in 96-well tissue culture plates were infected with dilutions of extra cellular virus suspensions of (SfaMNPV-D). Each cell/virus combination was incubated at temperatures 27°C and wells were scored for positive infection at 2 to 4 day intervals. The resulting data were analyzed by Reed and Muench method, providing virus titers for each combination of virus, cell line. The results were categorized by accuracy and by rapidity of maximum titer. Virus titer of Tn5B-4 was higher than other cell lines TCID50 8.7x108, the lowest level detected in infected was in (Pr-E-HNU9) cells TCID50 2.4x108. No Virions or polyhedral inclusion bodies were detected in infected SL-ZSU-1 cells.

Top 10 Research Questions Related to Physical Activity and Multiple Sclerosis

ERIC Educational Resources Information Center

Motl, Robert W.; Learmonth, Yvonne C.; Pilutti, Lara A.; Gappmaier, Eduard; Coote, Susan

2015-01-01

An estimated 2.5 million people worldwide are living with multiple sclerosis (MS), and this disease may be increasing in prevalence. MS is a disease of the central nervous system that is associated with heterogeneous symptoms and functional consequences, and the current first-line disease-modifying therapies often become ineffective later in the…

Quantitative Trait Loci for Resistance to Aspergillus Ear Rot: Analysis by Linkage Mapping, Characterization of Near-Isogenic Lines and Meta-Analysis

USDA-ARS?s Scientific Manuscript database

High levels of aflatoxin contamination of maize can be deadly for exposed human populations. Resistance to aflatoxin accumulation in maize has been reported in multiple studies and acts at multiple steps where there is fungal-plant interaction. In this study, we report the identification and mapping...

EFL Learners' Multiple Documents Literacy: Effects of a Strategy-Directed Intervention Program

ERIC Educational Resources Information Center

Karimi, Mohammad Nabi

2015-01-01

There is a substantial body of L2 research documenting the central role of strategy instruction in reading comprehension. However, this line of research has been conducted mostly within the single text paradigm of reading research. With reading literacy undergoing a marked shift from single source reading to multiple documents literacy, little is…

IGRINS NEAR-IR HIGH-RESOLUTION SPECTROSCOPY OF MULTIPLE JETS AROUND LkHα 234

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oh, Heeyoung; Yuk, In-Soo; Park, Byeong-Gon

2016-02-01

We present the results of high-resolution near-IR spectroscopy toward the multiple outflows around the Herbig Be star LkHα 234 using the Immersion Grating Infrared Spectrograph. Previous studies indicate that the region around LkHα 234 is complex, with several embedded young stellar objects and the outflows associated with them. In simultaneous H- and K-band spectra from HH 167, we detected 5 [Fe ii] and 14 H{sub 2} emission lines. We revealed a new [Fe ii] jet driven by radio continuum source VLA 3B. Position–velocity diagrams of the H{sub 2} 1−0 S(1) λ2.122 μm line show multiple velocity peaks. The kinematics maymore » be explained by a geometrical bow shock model. We detected a component of H{sub 2} emission at the systemic velocity (V{sub LSR} = −10.2 km s{sup −1}) along the whole slit in all slit positions, which may arise from the ambient photodissociation region. Low-velocity gas dominates the molecular hydrogen emission from knots A and B in HH 167, which is close to the systemic velocity; [Fe ii] emission lines are detected farther from the systemic velocity, at V{sub LSR} = −100–−130 km s{sup −1}. We infer that the H{sub 2} emission arises from shocked gas entrained by a high-velocity outflow. Population diagrams of H{sub 2} lines imply that the gas is thermalized at a temperature of 2500–3000 K and the emission results from shock excitation.« less

Employing X-ray absorption technique for better detector resolution and measurement of low cross-section events

NASA Astrophysics Data System (ADS)

Sharma, Gaurav; Puri, Nitin K.; Kumar, Pravin; Nandi, T.

2018-03-01

The versatility of X-ray absorption technique is experimentally employed for enhancing the detector resolution and to rejuvenate the low probable transitions obscured in the pile-up region, during a beam-foil spectroscopy experiment. The multiple aluminum absorber layers (10 μm each) are used to suppress the pile-up contribution drastically and to restore a weak transition which is about 1.38 × 104 times weaker than a one-electron-one-photon transitions viz. Kα and Khα. The weak line is possibly originating from a two-electron-one-photon transition in He-like Ti. Further, the transitions, which were obscured in the spectra due to high intensity ratio, are revived by dissimilar line intensity attenuation using this technique. The measured lifetimes of Kα line with and without intensity attenuation match well within error bar. The present technique finds potential implications in understanding the structure of multiple-core-vacant ions and other low cross section processes in ion-solid collisions.

Nonlinear predictive control of a boiler-turbine unit: A state-space approach with successive on-line model linearisation and quadratic optimisation.

PubMed

Ławryńczuk, Maciej

2017-03-01

This paper details development of a Model Predictive Control (MPC) algorithm for a boiler-turbine unit, which is a nonlinear multiple-input multiple-output process. The control objective is to follow set-point changes imposed on two state (output) variables and to satisfy constraints imposed on three inputs and one output. In order to obtain a computationally efficient control scheme, the state-space model is successively linearised on-line for the current operating point and used for prediction. In consequence, the future control policy is easily calculated from a quadratic optimisation problem. For state estimation the extended Kalman filter is used. It is demonstrated that the MPC strategy based on constant linear models does not work satisfactorily for the boiler-turbine unit whereas the discussed algorithm with on-line successive model linearisation gives practically the same trajectories as the truly nonlinear MPC controller with nonlinear optimisation repeated at each sampling instant. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

A survey of ultraviolet interstellar absorption lines

NASA Technical Reports Server (NTRS)

Bohlin, R. C.; Jenkins, E. B.; Spitzer, L., Jr.; York, D. G.; Hill, J. K.; Savage, B. D.; Snow, T. P., Jr.

1983-01-01

A telescope-spectrometer on the Copernicus spacecraft made possible the measurement of many ultraviolet absorption lines produced by the interstellar gas. The present survey provides data on ultraviolet absorption lines in the spectra of 88 early-type stars. The stars observed are divided into four classes, including reddened stars, unreddened bright stars, moderately reddened bright stars, and unreddened and moderately reddened faint stars. Data are presented for equivalent width, W, radial velocity V, and rms line width, D, taking into account some 10 to 20 lines of N I, O I, Si II, P II, S II, Cl I, Cl II, Mn II, Fe II, Ni II, Cu II, and H2. The data are based on multiple scans for each line. Attention is given to details of observations, the data reduction procedure, and the computation of equivalent width, mean velocity, and velocity dispersion.

Packings of a charged line on a sphere.

PubMed

Alben, Silas

2008-12-01

We find equilibrium configurations of open and closed lines of charge on a sphere, and track them with respect to varying sphere radius. Closed lines transition from a circle to a spiral-like shape through two low-wave-number bifurcations-"baseball seam" and "twist"-which minimize Coulomb energy. The spiral shape is the unique stable equilibrium of the closed line. Other unstable equilibria arise through tip-splitting events. An open line transitions smoothly from an arc of a great circle to a spiral as the sphere radius decreases. Under repulsive potentials with faster-than-Coulomb power-law decay, the spiral is tighter in initial stages of sphere shrinkage, but at later stages of shrinkage the equilibria for all repulsive potentials converge on a spiral with uniform spacing between turns. Multiple stable equilibria of the open line are observed.

Establishment of two new cell lines derived from human breast carcinomas with HER-2/neu amplification.

PubMed Central

Meltzer, P.; Leibovitz, A.; Dalton, W.; Villar, H.; Kute, T.; Davis, J.; Nagle, R.; Trent, J.

1991-01-01

Two human cell lines (UACC-812 and 893), both containing significant amplification of the HER-2/neu gene, were established from biopsy specimens of breast carcinomas. One patient had Stage II breast carcinoma; the other had metastatic disease. Characterisation of these lines has revealed that both are highly aneuploid containing multiple clonal chromosome alterations, have doubling times near 100 h, and are oestrogen and progesterone receptor negative. Electron microscopy demonstrates that both lines contain numerous microvilli, cytoplasmic filaments, multivesicular bodies, and desmosomes. Immunoblot analysis for P-glycoprotein using the monoclonal antibody C219 was negative for both patient cell lines. These relatively rare cell lines may represent a useful model to investigate human breast carcinomas. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:1674877

Velocity profiles of high-excitation molecular hydrogen lines

NASA Technical Reports Server (NTRS)

Moorhouse, A.; Brand, P. W. J. L.; Geballe, T. R.; Burton, M. G.

1990-01-01

Profiles of three lines of molecular hydrogen near 2.2 microns, originating from widely spaced energy levels, have been measured at a resolution of 32 km/s at Peak 1 in the Orion molecular outflow. The three lines, 1 - 0 S(1), 2 - 1 S(1), and 3 - 2 S(3), are found to have identical profiles. This result rules out any significant contribution to the population of the higher energy levels of molecular hydrogen at Peak 1 by fluorescence, and is generally consistent with emission from multiple J-type shocks.

Time-domain multiple-quantum NMR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weitekamp, Daniel P.

1982-11-01

The development of time-domain multiple-quantum nuclear magnetic resonance is reviewed through mid 1982 and some prospects for future development are indicated. Particular attention is given to the problem of obtaining resolved, interpretable, many-quantum spectra for anisotropic magnetically isolated systems of coupled spins. New results are presented on a number of topics including the optimization of multiple-quantum-line intensities, analysis of noise in two-dimensional spectroscopy, and the use of order-selective excitation for cross polarization between nuclear-spin species.

Systems and Methods for Imaging of Falling Objects

NASA Technical Reports Server (NTRS)

Fallgatter, Cale (Inventor); Garrett, Tim (Inventor)

2014-01-01

Imaging of falling objects is described. Multiple images of a falling object can be captured substantially simultaneously using multiple cameras located at multiple angles around the falling object. An epipolar geometry of the captured images can be determined. The images can be rectified to parallelize epipolar lines of the epipolar geometry. Correspondence points between the images can be identified. At least a portion of the falling object can be digitally reconstructed using the identified correspondence points to create a digital reconstruction.

Preserved learning of novel information in amnesia: evidence for multiple memory systems.

PubMed

Gordon, B

1988-06-01

Four of five patients with marked global amnesia, and others with new learning impairments, showed normal processing facilitation for novel stimuli (nonwords) and/or for familiar stimuli (words) on a word/nonword (lexical) decision task. The data are interpreted as a reflection of the learning capabilities of in-line neural processing stages with multiple, distinct, informational codes. These in-line learning processes are separate from the recognition/recall memory impaired by amygdalohippocampal/dosomedial thalamic damage, but probably supplement such memory in some tasks in normal individuals. Preserved learning of novel information seems incompatible with explanations of spared learning in amnesia that are based on the episodic/semantic or memory/habit distinctions, but is consistent with the procedural/declarative hypothesis.

A Fiber Interferometer for the Magnetized Shock Experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoo, Christian

2012-08-30

The Magnetized Shock Experiment (MSX) at Los Alamos National Laboratory requires remote diagnostics of plasma density. Laser interferometry can be used to determine the line-integrated density of the plasma. A multi-chord heterodyne fiber optic Mach-Zehnder interferometer is being assembled and integrated into the experiment. The advantage of the fiber coupling is that many different view chords can be easily obtained by simply moving transmit and receive fiber couplers. Several such fiber sets will be implemented to provide a time history of line-averaged density for several chords at once. The multiple chord data can then be Abel inverted to provide radiallymore » resolved spatial profiles of density. We describe the design and execution of this multiple fiber interferometer.« less

A Fiber Interferometer for the Magnetized Shock Experiment

NASA Astrophysics Data System (ADS)

Yoo, C. B.; Gao, K. W.; Weber, T. E.; Intrator, T. P.

2012-10-01

The Magnetized Shock Experiment (MSX) at Los Alamos National Laboratory requires remote diagnostics of plasma density. Laser interferometry can be used to determine the line-integrated density of the plasma. A multi-chord heterodyne fiber optic Mach-Zehnder interferometer is being assembled and integrated into the experiment. The advantage of the fiber coupling is that many different view chords can be easily obtained by simply moving transmit and receive fiber couplers. Several such fiber sets will be implemented to provide a time history of line-averaged density for several chords at once. The multiple chord data can then be Abel inverted to provide radially resolved spatial profiles of density. We describe the design and execution of this multiple fiber interferometer.

3D Power Line Extraction from Multiple Aerial Images.

PubMed

Oh, Jaehong; Lee, Changno

2017-09-29

Power lines are cables that carry electrical power from a power plant to an electrical substation. They must be connected between the tower structures in such a way that ensures minimum tension and sufficient clearance from the ground. Power lines can stretch and sag with the changing weather, eventually exceeding the planned tolerances. The excessive sags can then cause serious accidents, while hindering the durability of the power lines. We used photogrammetric techniques with a low-cost drone to achieve efficient 3D mapping of power lines that are often difficult to approach. Unlike the conventional image-to-object space approach, we used the object-to-image space approach using cubic grid points. We processed four strips of aerial images to automatically extract the power line points in the object space. Experimental results showed that the approach could successfully extract the positions of the power line points for power line generation and sag measurement with the elevation accuracy of a few centimeters.

3D Power Line Extraction from Multiple Aerial Images

PubMed Central

Lee, Changno

2017-01-01

Power lines are cables that carry electrical power from a power plant to an electrical substation. They must be connected between the tower structures in such a way that ensures minimum tension and sufficient clearance from the ground. Power lines can stretch and sag with the changing weather, eventually exceeding the planned tolerances. The excessive sags can then cause serious accidents, while hindering the durability of the power lines. We used photogrammetric techniques with a low-cost drone to achieve efficient 3D mapping of power lines that are often difficult to approach. Unlike the conventional image-to-object space approach, we used the object-to-image space approach using cubic grid points. We processed four strips of aerial images to automatically extract the power line points in the object space. Experimental results showed that the approach could successfully extract the positions of the power line points for power line generation and sag measurement with the elevation accuracy of a few centimeters. PMID:28961204

Patient population with multiple myeloma and transitions across different lines of therapy in the USA: an epidemiologic model.

PubMed

Cid Ruzafa, Javier; Merinopoulou, Evie; Baggaley, Rebecca F; Leighton, Pamela; Werther, Winifred; Felici, Diana; Cox, Andrew

2016-08-01

Multiple myeloma (MM) is a progressive, malignant neoplasia with a worldwide, age-standardized annual incidence of 1.5 per 100 000 individuals and 5-year prevalence around 230 000 patients. Main favorable prognostic factors are younger age, low/standard cytogenetic risk, and undergoing stem cell transplantation. Our aim was to estimate the size of the patient population with MM eligible to receive a new MM therapy at different lines of therapy in the USA. We constructed a compartmental, differential equation model representing the flow of MM patients from diagnosis to death, via two possible treatment pathways and distinguished in four groups based on prognostic factors. Parameters were obtained from published references, available statistics, and assumptions. The model was used to estimate number of diagnosed MM patients and number of patient transitions from one line of therapy to the next over 1 year. Model output included 95% credible intervals from probabilistic sensitivity analyses. The base-case estimates were 80 219 patients living with MM, including 70 375 on treatment, 780 symptomatic untreated patients, and 9064 asymptomatic untreated patients. Over a 1-year period, the number of MM patients on treatment line 1 was estimated at 23 629 (credible intervals 22 236-25 029), and the number of transitions from treatment line 1 to treatment line 2 was estimated at 14 423. The size of the patient population with MM on different lines of therapy and in patient subgroups of interest estimated from this epidemiologic model can be used to assess the number of patients who could benefit from new MM therapies and their corresponding budgetary impact. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Sample Acquisition and Handling System from a Remote Platform

NASA Technical Reports Server (NTRS)

Badescu, Mircea; Sherrit, Stewart; Jones, Jack A.

2011-01-01

A system has been developed to acquire and handle samples from a suspended remote platform. The system includes a penetrator, a penetrator deployment mechanism, and a sample handler. A gravity-driven harpoon sampler was used for the system, but other solutions can be used to supply the penetration energy, such as pyrotechnic, pressurized gas, or springs. The deployment mechanism includes a line that is attached to the penetrator, a spool for reeling in the line, and a line engagement control mechanism. The penetrator has removable tips that can collect liquid, ice, or solid samples. The handling mechanism consists of a carousel that can store a series of identical or different tips, assist in penetrator reconfiguration for multiple sample acquisition, and deliver the sample to a series of instruments for analysis. The carousel sample handling system was combined with a brassboard reeling mechanism and a penetrator with removable tips. It can attach the removable tip to the penetrator, release and retrieve the penetrator, remove the tip, and present it to multiple instrument stations. The penetrator can be remotely deployed from an aerobot, penetrate and collect the sample, and be retrieved with the sample to the aerobot. The penetrator with removable tips includes sample interrogation windows and a sample retainment spring for unconsolidated samples. The line engagement motor can be used to control the penetrator release and reeling engagement, and to evenly distribute the line on the spool by rocking between left and right ends of the spool. When the arm with the guiding ring is aligned with the spool axis, the line is free to unwind from the spool without rotating the spool. When the arm is perpendicular to the spool axis, the line can move only if the spool rotates.

Digital sun sensor multi-spot operation.

PubMed

Rufino, Giancarlo; Grassi, Michele

2012-11-28

The operation and test of a multi-spot digital sun sensor for precise sun-line determination is described. The image forming system consists of an opaque mask with multiple pinhole apertures producing multiple, simultaneous, spot-like images of the sun on the focal plane. The sun-line precision can be improved by averaging multiple simultaneous measures. Nevertheless, the sensor operation on a wide field of view requires acquiring and processing images in which the number of sun spots and the related intensity level are largely variable. To this end, a reliable and robust image acquisition procedure based on a variable shutter time has been considered as well as a calibration function exploiting also the knowledge of the sun-spot array size. Main focus of the present paper is the experimental validation of the wide field of view operation of the sensor by using a sensor prototype and a laboratory test facility. Results demonstrate that it is possible to keep high measurement precision also for large off-boresight angles.

75 FR 38066 - Airworthiness Directives; The Boeing Company Model 727, 727C, 727-100, 727-100C, 727-200, and 727...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-01

... 0.75 inch to 11.8 inches in length at the buttock line 61, between water line (WL) 220 and WL 228..., and between 10,685 total flight cycles and 29,357 total flight cycles. The cracking is attributed to..., in addition to normal pressurization cycles. Material analysis revealed multiple crack initiation...

In vitro and in vivo activity of melflufen (J1)in lymphoma.

PubMed

Delforoush, Maryam; Strese, Sara; Wickström, Malin; Larsson, Rolf; Enblad, Gunilla; Gullbo, Joachim

2016-04-04

Melphalan has been used in the treatment of various hematologic malignancies for almost 60 years. Today it is part of standard therapy for multiple myeloma and also as part of myeloablative regimens in association with autologous allogenic stem cell transplantation. Melflufen (melphalan flufenamide ethyl ester, previously called J1) is an optimized derivative of melphalan providing targeted delivery of active metabolites to cells expressing aminopeptidases. The activity of melflufen has compared favorably with that of melphalan in a series of in vitro and in vivo experiments performed preferentially on different solid tumor models and multiple myeloma. Melflufen is currently being evaluated in a clinical phase I/II trial in relapsed or relapsed and refractory multiple myeloma. Cytotoxicity of melflufen was assayed in lymphoma cell lines and in primary tumor cells with the Fluorometric Microculture Cytotoxicity Assay and cell cycle analyses was performed in two of the cell lines. Melflufen was also investigated in a xenograft model with subcutaneous lymphoma cells inoculated in mice. Melflufen showed activity with cytotoxic IC50-values in the submicromolar range (0.011-0.92 μM) in the cell lines, corresponding to a mean of 49-fold superiority (p < 0.001) in potency vs. melphalan. In the primary cultures melflufen yielded slightly lower IC50-values (2.7 nM to 0.55 μM) and an increased ratio vs. melphalan (range 13-455, average 108, p < 0.001). Treated cell lines exhibited a clear accumulation in the G2/M-phase of the cell cycle. Melflufen also showed significant activity and no, or minimal side effects in the xenografted animals. This study confirms previous reports of a targeting related potency superiority of melflufen compared to that of melphalan. Melflufen was active in cell lines and primary cultures of lymphoma cells, as well as in a xenograft model in mice and appears to be a candidate for further evaluation in the treatment of this group of malignant diseases.

Coordinating Known and Unknown Quantities in a Multiplicative Context: Problem Conceptualization, Affordances and Constraints

ERIC Educational Resources Information Center

Ramful, Ajay

2012-01-01

In line with continuing efforts to explain the demanding nature of multiplicative reasoning among middle-school students, this study explores the fine-grained knowledge elements that two pairs of 7th and 8th graders deployed in their attempt to coordinate the known and unknown quantities in the gear-wheel problem. Failure to conceptualize the…

System and Method for Detecting Unauthorized Device Access by Comparing Multiple Independent Spatial-Time Data Sets from Other Devices

NASA Technical Reports Server (NTRS)

Westmeyer, Paul A. (Inventor); Wertenberg, Russell F. (Inventor); Krage, Frederick J. (Inventor); Riegel, Jack F. (Inventor)

2017-01-01

An authentication procedure utilizes multiple independent sources of data to determine whether usage of a device, such as a desktop computer, is authorized. When a comparison indicates an anomaly from the base-line usage data, the system, provides a notice that access of the first device is not authorized.

The Effects of Multiple Exemplar Training on a Working Memory Task Involving Sequential Responding in Children with Autism

ERIC Educational Resources Information Center

Baltruschat, Lisa; Hasselhorn, Marcus; Tarbox, Jonathan; Dixon, Dennis R.; Najdowski, Adel; Mullins, Ryan David; Gould, Evelyn

2012-01-01

This study is part of a programmatic line of research into the use of basic positive reinforcement procedures for improving working memory in children with autism spectrum disorders. The authors evaluated the effects of multiple exemplar training, utilizing positive reinforcement, on performance of a "digit span backwards" task--a test of working…

From Addition to Multiplication ... and Back: The Development of Students' Additive and Multiplicative Reasoning Skills

ERIC Educational Resources Information Center

Van Dooren, Wim; De Bock, Dirk; Verschaffel, Lieven

2010-01-01

This study builds on two lines of research that have so far developed largely separately: the use of additive methods to solve proportional word problems and the use of proportional methods to solve additive word problems. We investigated the development with age of both kinds of erroneous solution methods. We gave a test containing missing-value…

Taguchi's off line method and Multivariate loss function approach for quality management and optimization of process parameters -A review

NASA Astrophysics Data System (ADS)

Bharti, P. K.; Khan, M. I.; Singh, Harbinder

2010-10-01

Off-line quality control is considered to be an effective approach to improve product quality at a relatively low cost. The Taguchi method is one of the conventional approaches for this purpose. Through this approach, engineers can determine a feasible combination of design parameters such that the variability of a product's response can be reduced and the mean is close to the desired target. The traditional Taguchi method was focused on ensuring good performance at the parameter design stage with one quality characteristic, but most products and processes have multiple quality characteristics. The optimal parameter design minimizes the total quality loss for multiple quality characteristics. Several studies have presented approaches addressing multiple quality characteristics. Most of these papers were concerned with maximizing the parameter combination of signal to noise (SN) ratios. The results reveal the advantages of this approach are that the optimal parameter design is the same as the traditional Taguchi method for the single quality characteristic; the optimal design maximizes the amount of reduction of total quality loss for multiple quality characteristics. This paper presents a literature review on solving multi-response problems in the Taguchi method and its successful implementation in various industries.

Rolled-up transmission line structure for a radiofrequency integrated circuit (RFIC)

DOEpatents

Li, Xiuling; Huang, Wen

2015-04-28

A rolled-up transmission line structure for a radiofrequency integrated circuit (RFIC) comprises a multilayer sheet in a rolled configuration comprising multiple turns about a longitudinal axis, where the multilayer sheet comprises a conductive pattern layer on a strain-relieved layer. The conductive pattern layer comprises a first conductive film and a second conductive film separated from the first conductive film in a rolling direction. In the rolled configuration, the first conductive film surrounds the longitudinal axis, and the second conductive film surrounds the first conductive film. The first conductive film serves as a signal line and the second conductive film serves as a conductive shield for the rolled-up transmission line structure.

Attenuation of multiples in image space

NASA Astrophysics Data System (ADS)

Alvarez, Gabriel F.

In complex subsurface areas, attenuation of 3D specular and diffracted multiples in data space is difficult and inaccurate. In those areas, image space is an attractive alternative. There are several reasons: (1) migration increases the signal-to-noise ratio of the data; (2) primaries are mapped to coherent events in Subsurface Offset Domain Common Image Gathers (SODCIGs) or Angle Domain Common Image Gathers (ADCIGs); (3) image space is regular and smaller; (4) attenuating the multiples in data space leaves holes in the frequency-Wavenumber space that generate artifacts after migration. I develop a new equation for the residual moveout of specular multiples in ADCIGs and use it for the kernel of an apex-shifted Radon transform to focus and separate the primaries from specular and diffracted multiples. Because of small amplitude, phase and kinematic errors in the multiple estimate, we need adaptive matching and subtraction to estimate the primaries. I pose this problem as an iterative least-squares inversion that simultaneously matches the estimates of primaries and multiples to the data. Standard methods match only the estimate of the multiples. I demonstrate with real and synthetic data that the method produces primaries and multiples with little cross-talk. In 3D, the multiples exhibit residual moveout in SODCIGs in in-line and cross-line offsets. They map away from zero subsurface offsets when migrated with the faster velocity of the primaries. In ADCIGs the residual moveout of the primaries as a function of the aperture angle, for a given azimuth, is flat for those angles that illuminate the reflector. The multiples have residual moveout towards increasing depth for increasing aperture angles at all azimuths. As a function of azimuth, the primaries have better azimuth resolution than the multiples at larger aperture angles. I show, with a real 3D dataset, that even below salt, where illumination is poor, the multiples are well attenuated in ADCIGs with the new Radon transform in planes of azimuth-stacked ADCIGs. The angle stacks of the estimated primaries show little residual multiple energy.

Collaborative Aerial-Drawing System for Supporting Co-Creative Communication

NASA Astrophysics Data System (ADS)

Osaki, Akihiro; Taniguchi, Hiroyuki; Miwa, Yoshiyuki

This paper describes the collaborative augmented reality (AR) system with which multiple users can handwrite 3D lines in the air simultaneously and manipulate the lines directly in the real world. In addition, we propose a new technique for co-creative communication utilizing the 3D drawing activity. Up to now, the various 3D user interfaces have been proposed. Although most of them aim to solve the specific problems in the virtual environments, the possibility of the 3D drawing expression has not been explored yet. Accordingly, we paid special attention to the interaction with the real objects in daily life, and considered to manipulate real objects and 3D lines without any distinctions by the same action. The developed AR system consists of a stereoscopic head-mounted display, a drawing tool, 6DOF sensors measuring three-dimensional position and Euler angles, and the 3D user interface, which enables to push, grasp and pitch 3D lines directly by use of the drawing tool. Additionally users can pick up desired color from either a landscape or a virtual line through the direct interaction with this tool. For sharing 3D lines among multiple users at the same place, the distributed-type AR system has been developed that mutually sends and receives drawn data between systems. With the developed system, users can proceed to design jointly in the real space through arranging each 3D drawing by direct manipulation. Moreover, a new application to the entertainment has become possible to play sports like catch, fencing match, or the like.

Multiple sensory modalities used by squid in successful predator evasion throughout ontogeny.

PubMed

York, Carly A; Bartol, Ian K; Krueger, Paul S

2016-09-15

Squid rely on multiple sensory systems for predator detection. In this study we examine the role of two sensory systems, the lateral line analogue and vision, in successful predator evasion throughout ontogeny. Squid Doryteuthis pealeii and Lolliguncula brevis were recorded using high-speed videography in the presence of natural predators under light and dark conditions with their lateral line analogue intact or ablated via a pharmacological technique. Paralarval squid showed reduced escape responses when ablated; however, no differences were found between light and dark conditions in non-ablated paralarvae, as was previously shown in juveniles and adults, indicating that the lateral line analogue is integral for predator detection early in life. However, vision does play a role in survival because ablated squid in dark conditions had lower levels of survival than all other treatments. Throughout ontogeny, squid oriented themselves anteriorly towards the oncoming predator, maximizing sensory input to the lateral line analogue system and providing better positioning for tail-first escape jetting, the preferred escape mode. Ablated juveniles and adults had lower response times, escape velocities and peak acceleration than non-ablated individuals, indicating that the lateral line analogue enables squid to respond quicker and with more powerful jets to a predator and maximize escape success. Our findings reveal that the lateral line analogue plays a role in predator detection and successful escape response at the earliest life stages, and continues to contribute to successful evasion by aiding visual cues in juvenile and adult squid. © 2016. Published by The Company of Biologists Ltd.

Lentiviral and targeted cellular barcoding reveals ongoing clonal dynamics of cell lines in vitro and in vivo

PubMed Central

2014-01-01

Background Cell lines are often regarded as clonal, even though this simplifies what is known about mutagenesis, transformation and other processes that destabilize them over time. Monitoring these clonal dynamics is important for multiple areas of biomedical research, including stem cell and cancer biology. Tracking the contributions of individual cells to large populations, however, has been constrained by limitations in sensitivity and complexity. Results We utilize cellular barcoding methods to simultaneously track the clonal contributions of tens of thousands of cells. We demonstrate that even with optimal culturing conditions, common cell lines including HeLa, K562 and HEK-293 T exhibit ongoing clonal dynamics. Starting a population with a single clone diminishes but does not eradicate this phenomenon. Next, we compare lentiviral and zinc-finger nuclease barcode insertion approaches, finding that the zinc-finger nuclease protocol surprisingly results in reduced clonal diversity. We also document the expected reduction in clonal complexity when cells are challenged with genotoxic stress. Finally, we demonstrate that xenografts maintain clonal diversity to a greater extent than in vitro culturing of the human non-small-cell lung cancer cell line HCC827. Conclusions We demonstrate the feasibility of tracking and quantifying the clonal dynamics of entire cell populations within multiple cultured cell lines. Our results suggest that cell heterogeneity should be considered in the design and interpretation of in vitro culture experiments. Aside from clonal cell lines, we propose that cellular barcoding could prove valuable in modeling the clonal behavior of heterogeneous cell populations over time, including tumor populations treated with chemotherapeutic agents. PMID:24886633

Sea Level, Tectonics, Environmental Monitoring and Altimeter Calibration in Eastern Mediterranean

NASA Astrophysics Data System (ADS)

Pavlis, E. C.; Mertikas, S. P.; Evans, K.

2003-12-01

The Eastern Mediterranean area is one of great interest for its intense tectonic activity as well as for its regional oceanography. Recent observations convincingly demonstrated the importance of the area for regional meteorological and climatologic changes. Monitoring tide-gauge locations with continuous GPS on the other hand removes the uncertainties introduced by local tectonics that contaminate the observed sea level variations. Such a global tide-gauge network with long historical records is already used to calibrate satellite altimeters (e.g. on TOPEX/POSEIDON, GFO, JASON-1, ENVISAT, etc.), at present, a common IOC-GLOSS-IGS effort --TIGA. Crete hosts two of the oldest tide-gauges in the regional network, at Souda Bay and Heraklion. We recently completed the instrumentation of a third, state-of-the-art mean sea level (MSL) monitoring facility in southwestern Crete, on the isle of Gavdos, the southernmost European parcel of land. Our project (GAVDOS) further expands the regional tide gauge network to the south, and contributes to TIGA and MedGLOSS. The presentation will focus on the altimeter calibration aspect of the facility, in particular, its application to the JASON-1 mission. Another component of the "GAVDOS" project is the repeated occupation of the older tide-gauges at Souda Bay and Heraklion, and their tie to the new facility. We will present results from positioning of these sites and some of the available tidal records. The Gavdos facility is situated under a ground-track crossing point of the original T/P and present JASON-1 orbits, allowing two calibration observations per cycle. It is an ideal site if the tectonic motions are monitored precisely and continuously. The facility hosts in addition to two tide gauges, multiple GPS receivers, a DORIS beacon for positioning and orbit control, a transponder for direct calibration, and is visited periodically by water vapor radiometers and solar spectrometers, GPS-laden buoys, and airborne surveys with gravimeters and laser profiling lidars. The French transportable laser ranging system (FTLRS) completed recently a co-location campaign at Chania, Crete, for improved orbit control over the site, and to ensure the best possible and most reliable results.

First Gravity Traverse on the Martian Surface from the Curiosity Rover

NASA Astrophysics Data System (ADS)

Lewis, K. W.; Peters, S. F.; Gonter, K. A.; Vasavada, A. R.

2016-12-01

Orbital gravity surveys have been a key tool in understanding planetary interiors and shallow crustal structure, exemplified by recent missions such as GRAIL and Juno. However, due to the loss of spatial resolution with altitude, airborne and ground-based survey methods are typically employed on the Earth. Previously, the Lunar Traverse Gravimeter experiment on the Apollo 17 mission has been the only attempt to collect surface gravity measurements on another planetary body. We will describe the results of the first gravity survey on the Martian surface, using data from the Curiosity rover over its >10 km traverse across the floor of Gale crater and lower slopes of Mount Sharp. These results enable us to estimate bulk rock density, and to search for potential subsurface density anomalies. To measure local gravitational acceleration, we use one of the two onboard Rover Inertial Measurement Units (RIMU-A), designed for rover position and fine attitude determination. The IMU contains three-axis micro-electromechanical (MEMS) accelerometers and fiber-optic gyros, and is used for gyrocompassing by integrating data for several minutes on sols with no drive or arm motions (roughly 50% of sols to date). Raw acceleration data are calibrated for biases induced by temperature effects and rover orientation, along with rover elevation over the course of the mission using multiple regression. We use the best fit linear relationship between topographic height and gravitational acceleration to estimate a Bouguer correction for the observed change in magnitude over the mission as the rover has ascended over 100 meters up the lower slopes of Mount Sharp. We find a relatively low best-fit density of 1600 +/- 500 kg/m^3 for the rocks of Mount Sharp, consistent with rover-based measurements of thermal inertial, and potentially indicating pervasive fracturing, high porosity and/or low compaction within the original sediments at least to depths of order 100 meters. Future measurements will further refine this estimate as Curiosity continues to gain elevation. Although not originally intended as a science instrument, these results highlight the scientific potential of surface gravity and topography surveys for future planetary exploration missions.

ON MULTIPLE RECONNECTION X-LINES AND TRIPOLAR PERTURBATIONS OF STRONG GUIDE MAGNETIC FIELDS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eriksson, S.; Gosling, J. T.; Lapenta, G.

We report new multi-spacecraft Cluster observations of tripolar guide magnetic field perturbations at a solar wind reconnection exhaust in the presence of a guide field B{sub M} {sub  }which is almost four times as strong as the reversing field B{sub L}. The novel tripolar field consists of two narrow regions of depressed B{sub M}, with an observed 7%–14% ΔB{sub M} magnitude relative to the external field, which are found adjacent to a wide region of enhanced B{sub M} within the exhaust. A stronger reversing field is associated with each B{sub M} depression. A kinetic reconnection simulation for realistic solar windmore » conditions and the observed strong guide field reveals that tripolar magnetic fields preferentially form across current sheets in the presence of multiple X-lines as magnetic islands approach one another and merge into fewer and larger islands. The simulated ΔB{sub M}/ΔX{sub N} over the normal width ΔX{sub N} between a B{sub M} minimum and the edge of the external region agree with the normalized values observed by Cluster. We propose that a tripolar guide field perturbation may be used to identify candidate regions containing multiple X-lines and interacting magnetic islands at individual solar wind current sheets with a strong guide field.« less

Human metastatic melanoma cell lines express high levels of growth hormone receptor and respond to GH treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sustarsic, Elahu G.; Department of Biological Sciences, Ohio University, Athens, OH; Junnila, Riia K.

2013-11-08

Highlights: •Most cancer types of the NCI60 have sub-sets of cell lines with high GHR expression. •GHR is highly expressed in melanoma cell lines. •GHR is elevated in advanced stage IV metastatic tumors vs. stage III. •GH treatment of metastatic melanoma cell lines alters growth and cell signaling. -- Abstract: Accumulating evidence implicates the growth hormone receptor (GHR) in carcinogenesis. While multiple studies show evidence for expression of growth hormone (GH) and GHR mRNA in human cancer tissue, there is a lack of quantification and only a few cancer types have been investigated. The National Cancer Institute’s NCI60 panel includesmore » 60 cancer cell lines from nine types of human cancer: breast, CNS, colon, leukemia, melanoma, non-small cell lung, ovarian, prostate and renal. We utilized this panel to quantify expression of GHR, GH, prolactin receptor (PRLR) and prolactin (PRL) mRNA with real-time RT qPCR. Both GHR and PRLR show a broad range of expression within and among most cancer types. Strikingly, GHR expression is nearly 50-fold higher in melanoma than in the panel as a whole. Analysis of human metastatic melanoma biopsies confirmed GHR gene expression in melanoma tissue. In these human biopsies, the level of GHR mRNA is elevated in advanced stage IV tumor samples compared to stage III. Due to the novel finding of high GHR in melanoma, we examined the effect of GH treatment on three NCI60 melanoma lines (MDA-MB-435, UACC-62 and SK-MEL-5). GH increased proliferation in two out of three cell lines tested. Further analysis revealed GH-induced activation of STAT5 and mTOR in a cell line dependent manner. In conclusion, we have identified cell lines and cancer types that are ideal to study the role of GH and PRL in cancer, yet have been largely overlooked. Furthermore, we found that human metastatic melanoma tumors express GHR and cell lines possess active GHRs that can modulate multiple signaling pathways and alter cell proliferation. Based on this data, GH could be a new therapeutic target in melanoma.« less

Heterogeneic dynamics of the structures of multiple gene clusters in two pathogenetically different lines originating from the same phytoplasma.

PubMed

Arashida, Ryo; Kakizawa, Shigeyuki; Hoshi, Ayaka; Ishii, Yoshiko; Jung, Hee-Young; Kagiwada, Satoshi; Yamaji, Yasuyuki; Oshima, Kenro; Namba, Shigetou

2008-04-01

Phytoplasmas are phloem-limited plant pathogens that are transmitted by insect vectors and are associated with diseases in hundreds of plant species. Despite their small sizes, phytoplasma genomes have repeat-rich sequences, which are due to several genes that are encoded as multiple copies. These multiple genes exist in a gene cluster, the potential mobile unit (PMU). PMUs are present at several distinct regions in the phytoplasma genome. The multicopy genes encoded by PMUs (herein named mobile unit genes [MUGs]) and similar genes elsewhere in the genome (herein named fundamental genes [FUGs]) are likely to have the same function based on their annotations. In this manuscript we show evidence that MUGs and FUGs do not cluster together within the same clade. Each MUG is in a cluster with a short branch length, suggesting that MUGs are recently diverged paralogs, whereas the origin of FUGs is different from that of MUGs. We also compared the genome structures around the lplA gene in two derivative lines of the 'Candidatus Phytoplasma asteris' OY strain, the severe-symptom line W (OY-W) and the mild-symptom line M (OY-M). The gene organizations of the nucleotide sequences upstream of the lplA genes of OY-W and OY-M were dramatically different. The tra5 insertion sequence, an element of PMUs, was found only in this region in OY-W. These results suggest that transposition of entire PMUs and PMU sections has occurred frequently in the OY phytoplasma genome. The difference in the pathogenicities of OY-W and OY-M might be caused by the duplication and transposition of PMUs, followed by genome rearrangement.

Multi-camera synchronization core implemented on USB3 based FPGA platform

NASA Astrophysics Data System (ADS)

Sousa, Ricardo M.; Wäny, Martin; Santos, Pedro; Dias, Morgado

2015-03-01

Centered on Awaiba's NanEye CMOS image sensor family and a FPGA platform with USB3 interface, the aim of this paper is to demonstrate a new technique to synchronize up to 8 individual self-timed cameras with minimal error. Small form factor self-timed camera modules of 1 mm x 1 mm or smaller do not normally allow external synchronization. However, for stereo vision or 3D reconstruction with multiple cameras as well as for applications requiring pulsed illumination it is required to synchronize multiple cameras. In this work, the challenge of synchronizing multiple selftimed cameras with only 4 wire interface has been solved by adaptively regulating the power supply for each of the cameras. To that effect, a control core was created to constantly monitor the operating frequency of each camera by measuring the line period in each frame based on a well-defined sampling signal. The frequency is adjusted by varying the voltage level applied to the sensor based on the error between the measured line period and the desired line period. To ensure phase synchronization between frames, a Master-Slave interface was implemented. A single camera is defined as the Master, with its operating frequency being controlled directly through a PC based interface. The remaining cameras are setup in Slave mode and are interfaced directly with the Master camera control module. This enables the remaining cameras to monitor its line and frame period and adjust their own to achieve phase and frequency synchronization. The result of this work will allow the implementation of smaller than 3mm diameter 3D stereo vision equipment in medical endoscopic context, such as endoscopic surgical robotic or micro invasive surgery.

A Multistrain Mathematical Model To Investigate the Role of Pyrazinamide in the Emergence of Extensively Drug-Resistant Tuberculosis

PubMed Central

Shrestha, Sourya; Knight, Gwenan M.; Cohen, Ted; White, Richard G.; Cobelens, Frank

2016-01-01

ABSTRACT Several infectious diseases of global importance—e.g., HIV infection and tuberculosis (TB)—require prolonged treatment with combination antimicrobial regimens typically involving high-potency core agents coupled with additional companion drugs that protect against the de novo emergence of mutations conferring resistance to the core agents. Often, the most effective (or least toxic) companion agents are reused in sequential (first-line, second-line, etc.) regimens. We used a multistrain model of Mycobacterium tuberculosis transmission in Southeast Asia to investigate how this practice might facilitate the emergence of extensive drug resistance, i.e., resistance to multiple core agents. We calibrated this model to regional TB and drug resistance data using an approximate Bayesian computational approach. We report the proportion of data-consistent simulations in which the prevalence of pre-extensively drug-resistant (pre-XDR) TB—defined as resistance to both first-line and second-line core agents (rifampin and fluoroquinolones)—exceeds predefined acceptability thresholds (1 to 2 cases per 100,000 population by 2035). The use of pyrazinamide (the most effective companion agent) in both first-line and second-line regimens increased the proportion of simulations in which the prevalence exceeded the pre-XDR acceptability threshold by 7-fold compared to a scenario in which patients with pyrazinamide-resistant TB received an alternative drug. Model parameters related to the emergence and transmission of pyrazinamide-resistant TB and resistance amplification were among those that were the most strongly correlated with the projected pre-XDR prevalence, indicating that pyrazinamide resistance acquired during first-line treatment subsequently promotes amplification to pre-XDR TB under pyrazinamide-containing second-line treatment. These findings suggest that the appropriate use of companion drugs may be critical to preventing the emergence of strains resistant to multiple core agents. PMID:27956422

Identifying microRNAs that Regulate Neuroblastoma Cell Differentiation

DTIC Science & Technology

2015-10-01

Award Number: W81XWH-13-1-0241 TITLE: Identifying that Regulate Neuroblastoma Cell Differentiation PRINCIPAL INVESTIGATOR: Dr. Liqin Du...inducing miRNA, miR- 449a. We examined the differentiation-inducing function of miR-449a in multiple neuroblastoma cell lines. We have demonstrated that...miR-449a functions as an inducer of cell differentiation in neuroblastoma cell lines with distinct genetic backgrounds, including the MYCN

Transient Signal Distortion and Coupling in Multilayer Multiconductor MIC Microstrips

DTIC Science & Technology

1990-05-22

cess.ar1 and identify by block number) I FIELD GROUP I $..)3-{; ’\\0-:: Transient signals, distortion, dispersion, microstrip J 1 i nes , multi...printed circuit design; complex microstrip structures {multiple lines and/or dielectric layers), coupling between lines, distortion of non -periodic...signals on complex structures, and a new method to control coupling on multilayer structures, as well as presenting numerical results for each of these

Statistical Fine Structure in Inhomogeneously Broadened Absorption Lines in Solids.

DTIC Science & Technology

1987-12-22

the inhomogeneously broadened zero-phonon SijSo (0-0) absorption of pentacene molecules in crystals of p-terphenyl at liquid helium temperatures. SFS...structure (SFS) in the inhomogeneously broadened zero-phonon S, +- So (0-0) absorption of pentacene molecules in crystals of p-terphenyl at liquid helium...tile large multiplicity of local environments. Inhomogeneously broadened absorption lines are usually treated as smooth, Gaussian profiles. In recent

On an image reconstruction method for ECT

NASA Astrophysics Data System (ADS)

Sasamoto, Akira; Suzuki, Takayuki; Nishimura, Yoshihiro

2007-04-01

An image by Eddy Current Testing(ECT) is a blurred image to original flaw shape. In order to reconstruct fine flaw image, a new image reconstruction method has been proposed. This method is based on an assumption that a very simple relationship between measured data and source were described by a convolution of response function and flaw shape. This assumption leads to a simple inverse analysis method with deconvolution.In this method, Point Spread Function (PSF) and Line Spread Function(LSF) play a key role in deconvolution processing. This study proposes a simple data processing to determine PSF and LSF from ECT data of machined hole and line flaw. In order to verify its validity, ECT data for SUS316 plate(200x200x10mm) with artificial machined hole and notch flaw had been acquired by differential coil type sensors(produced by ZETEC Inc). Those data were analyzed by the proposed method. The proposed method restored sharp discrete multiple hole image from interfered data by multiple holes. Also the estimated width of line flaw has been much improved compared with original experimental data. Although proposed inverse analysis strategy is simple and easy to implement, its validity to holes and line flaw have been shown by many results that much finer image than original image have been reconstructed.

SPECTROSCOPY ALONG MULTIPLE, LENSED SIGHT LINES THROUGH OUTFLOWING WINDS IN THE QUASAR SDSS J1029+2623

DOE Office of Scientific and Technical Information (OSTI.GOV)

Misawa, Toru; Inada, Naohisa; Ohsuga, Ken

2013-02-01

We study the origin of absorption features on the blue side of the C IV broad emission line of the large-separation lensed quasar SDSS J1029+2623 at z{sub em} {approx} 2.197. The quasar images, produced by a foreground cluster of galaxies, have a maximum separation angle of {theta} {approx} 22.''5. The large angular separation suggests that the sight lines to the quasar central source can go through different regions of outflowing winds from the accretion disk of the quasar, providing a unique opportunity to study the structure of outflows from the accretion disk, a key ingredient for the evolution of quasarsmore » as well as for galaxy formation and evolution. Based on medium- and high-resolution spectroscopy of the two brightest images conducted at the Subaru telescope, we find that each image has different intrinsic levels of absorptions, which can be attributed either to variability of absorption features over the time delay between the lensed images, {Delta}t {approx} 744 days, or to the fine structure of quasar outflows probed by the multiple sight lines toward the quasar. While both these scenarios are consistent with the current data, we argue that they can be distinguished with additional spectroscopic monitoring observations.« less

Visual detection of multiple genetically modified organisms in a capillary array.

PubMed

Shao, Ning; Chen, Jianwei; Hu, Jiaying; Li, Rong; Zhang, Dabing; Guo, Shujuan; Hui, Junhou; Liu, Peng; Yang, Litao; Tao, Sheng-Ce

2017-01-31

There is an urgent need for rapid, low-cost multiplex methodologies for the monitoring of genetically modified organisms (GMOs). Here, we report a C[combining low line]apillary A[combining low line]rray-based L[combining low line]oop-mediated isothermal amplification for M[combining low line]ultiplex visual detection of nucleic acids (CALM) platform for the simple and rapid monitoring of GMOs. In CALM, loop-mediated isothermal amplification (LAMP) primer sets are pre-fixed to the inner surface of capillaries. The surface of the capillary array is hydrophobic while the capillaries are hydrophilic, enabling the simultaneous loading and separation of the LAMP reaction mixtures into each capillary by capillary forces. LAMP reactions in the capillaries are then performed in parallel, and the results are visually detected by illumination with a hand-held UV device. Using CALM, we successfully detected seven frequently used transgenic genes/elements and five plant endogenous reference genes with high specificity and sensitivity. Moreover, we found that measurements of real-world blind samples by CALM are consistent with results obtained by independent real-time PCRs. Thus, with an ability to detect multiple nucleic acids in a single easy-to-operate test, we believe that CALM will become a widely applied technology in GMO monitoring.

Abnormality in catalase import into peroxisomes leads to severe neurological disorder

PubMed Central

Sheikh, Faruk G.; Pahan, Kalipada; Khan, Mushfiquddin; Barbosa, Ernest; Singh, Inderjit

1998-01-01

Peroxisomal disorders are lethal inherited diseases caused by either defects in peroxisome assembly or dysfunction of single or multiple enzymatic function(s). The peroxisomal matrix proteins are targeted to peroxisomes via the interaction of peroxisomal targeting signal sequences 1 and 2 (PTS1 or PTS2) with their respective cytosolic receptors. We have studied human skin fibroblast cell lines that have multiple peroxisomal dysfunctions with normal packaging of PTS1 and PTS2 signal-containing proteins but lack catalase in peroxisomes. To understand the defect in targeting of catalase to peroxisomes and the loss of multiple enzyme activities, we transfected the mutant cells with normal catalase modified to contain either PTS1 or PTS2 signal sequence. We demonstrate the integrity of these pathways by targeting catalase into peroxisomes via PTS1 or PTS2 pathways. Furthermore, restoration of peroxisomal functions by targeting catalase-SKL protein (a catalase fused to the PTS1 sequence) to peroxisomes indicates that loss of multiple functions may be due to their inactivation by H2O2 or other oxygen species in these catalase-negative peroxisomes. In addition to enzyme activities, targeting of catalase-SKL chimera to peroxisomes also corrected the in situ levels of fatty acids and plasmalogens in these mutant cell lines. In normal fibroblasts treated with aminotriazole to inhibit catalase, we found that peroxisomal functions were inhibited to the level found in mutant cells, an observation that supports the conclusion that multiple peroxisomal enzyme defects in these patients are caused by H2O2 toxicity in catalase-negative peroxisomes. Moreover, targeting of catalase to peroxisomes via PTS1 and PTS2 pathways in these mutant cell lines suggests that there is another pathway for catalase import into peroxisomes and that an abnormality in this pathway manifests as a peroxisomal disease. PMID:9501198

Imaging of enzyme activity using bio-LSI system enables simultaneous immunosensing of different analytes in multiple specimens.

PubMed

Hokuto, Toshiki; Yasukawa, Tomoyuki; Kunikata, Ryota; Suda, Atsushi; Inoue, Kumi Y; Ino, Kosuke; Matsue, Tomokazu; Mizutani, Fumio

2016-06-01

Electrochemical imaging is an excellent technique to characterize an activity of biomaterials, such as enzymes and cells. Large scale integration-based amperometric sensor (Bio-LSI) has been developed for the simultaneous and continuous detection of the concentration distribution of redox species generated by reactions of biomolecules. In this study, the Bio-LSI system was demonstrated to be applicable for simultaneous detection of different anaytes in multiple specimens. The multiple specimens containing human immunoglobulin G (hIgG) and mouse IgG (mIgG) were introduced into each channel of the upper substrate across the antibody lines for hIgG and mIgG on the lower substrate. Hydrogen peroxide generated by the enzyme reaction of glucose oxidase captured at intersections was simultaneously detected by 400 microelectrodes of Bio-LSI chip. The oxidation current increased with increasing the concentrations of hIgG, which can be detected in the range of 0.01-1.0 µg mL(-1) . Simultaneous detection of hIgG and mIgG in multiple specimens was achieved by using line pattern of both antibodies. Therefore, the presence of different target molecules in the multiple samples would be quantitatively and simultaneously visualized as a current image by the Bio-LSI system. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An Interferometric 270--355 GHz Spectral Line Survey of the Red Supergiant VY CMa

NASA Astrophysics Data System (ADS)

Menten, K. M.; Young, K. H.; Patel, N. A.; Gottlieb, C. A.; Thaddeus, P.; McCarthy, M. C.; Gurwell, M. A.; Belloche, A.; Kaminski, T.; Verheyen, L.; Decin, L.; Brunken, S.; Holger, S. P. M.

2011-05-01

We have used the Submillimeter Array to image the molecular line emission in the circumstellar envelope of the peculiar red supergiant star VY Canis Majoris over the whole 870 μm atmospheric window. Employing adaptive calibration using the object's continuum emission we achieve high quality one arcsecond resolution imaging of the whole 280--355 GHz range within which we find 211 distinct spectral lines from 33 molecules (including isotopologues) plus 40 unidentified lines. From the distribution of molecules we are obtaining their abundances and isotopologic abundance ratios. Using data for multiple transitions in a number of molecules we are deriving the physical conditions in the circumstellar envelope to reach a picture of the star's chemistry that can be compared with models. Our legacy survey is accompanied by a strong laboratory effort that helps with the identification of possibly newly found molecules traced by unidentified lines. We shall create a publicly accessible database of spectral-line channel-maps of the emission from all the lines detected in the survey.

Magnetic flux ropes at the high-latitude magnetopause

NASA Technical Reports Server (NTRS)

Berchem, Jean; Raeder, Joachim; Ashour-Abdalla, Maha

1995-01-01

We examine the consequences of magnetic reconnection at the high-latitude magnetopause using a three-dimensional global magnetohydrodynamic simulation of the solar wind interaction with the Earth's magnetosphere. Magnetic field lines from the simulation reveal the formation of magnetic flux ropes during periods with northward interplanetary magnetic field. These flux ropes result from multiple reconnection processes between the lobes field lines and draped magnetosheath field lines that are convected around the flank of the magnetosphere. The flux ropes identified in the simulation are consistent with features observed in the magnetic field measured by Hawkeye-1 during some high-latitude magnetopause crossings.

An efficient implementation of Forward-Backward Least-Mean-Square Adaptive Line Enhancers

NASA Technical Reports Server (NTRS)

Yeh, H.-G.; Nguyen, T. M.

1995-01-01

An efficient implementation of the forward-backward least-mean-square (FBLMS) adaptive line enhancer is presented in this article. Without changing the characteristics of the FBLMS adaptive line enhancer, the proposed implementation technique reduces multiplications by 25% and additions by 12.5% in two successive time samples in comparison with those operations of direct implementation in both prediction and weight control. The proposed FBLMS architecture and algorithm can be applied to digital receivers for enhancing signal-to-noise ratio to allow fast carrier acquisition and tracking in both stationary and nonstationary environments.