WorldWideScience

Sample records for ground stem locations

  1. Simple system for locating ground loops.

    Science.gov (United States)

    Bellan, P M

    2007-06-01

    A simple low-cost system for rapid identification of the cables causing ground loops in complex instrumentation configurations is described. The system consists of an exciter module that generates a 100 kHz ground loop current and a detector module that determines which cable conducts this test current. Both the exciter and detector are magnetically coupled to the ground circuit so there is no physical contact to the instrumentation system under test.

  2. New method for lightning location using optical ground wire

    Institute of Scientific and Technical Information of China (English)

    Zhaoyu Qin; Zhaogu Cheng; Zhiping Zhang; Jianqiang Zhu; Feng Li

    2006-01-01

    A new technology of lightning location is described, which is based on detecting the state of polarization(SOP) fluctuation of the laser light in the optic ground wire (OPGW). Compared with the conventional lightning location method, the new method is more accurate, more stable, and cheaper. Theories of Stokes generated by lightning strike can still be accurately identified by detecting the velocity of polarization motion. A new algorithm to quantify the velocity is also introduced.

  3. Stakeholder needs for ground penetrating radar utility location

    Science.gov (United States)

    Thomas, A. M.; Rogers, C. D. F.; Chapman, D. N.; Metje, N.; Castle, J.

    2009-04-01

    In the UK alone there are millions of miles of underground utilities with often inaccurate, incomplete, or non-existent location records that cause significant health and safety problems for maintenance personnel, together with the potential for large, unnecessary, social and financial costs for their upkeep and repair. This has led to increasing use of Ground Penetrating Radar (GPR) for utility location, but without detailed consideration of the degree of location accuracy required by stakeholders — i.e. all those directly involved in streetworks ranging from utility owners to contractors and surveyors and government departments. In order to ensure that stakeholder requirements are incorporated into a major new UK study, entitled Mapping the Underworld, a questionnaire has been used to determine the current and future utility location accuracy requirements. The resulting data indicate that stakeholders generally require location tolerances better than 100 mm at depths usually extending down to 3 m, and more occasionally to 5 m, below surface level, providing significant challenges to GPR if their needs are to be met in all ground conditions. As well as providing much useful data on stakeholder needs, these data are also providing a methodology for assessment of GPR utility location in terms of the factor most important to them — the degree to which the equipment provides location within their own accuracy requirements.

  4. New method for lightning location using optical ground wire

    Science.gov (United States)

    Qin, Zhaoyu; Cheng, Zhaogu; Zhang, Zhiping; Zhu, Jianqiang; Li, Feng

    2006-12-01

    A new technology of lightning location is described, which is based on detecting the state of polarization (SOP) fluctuation of the laser light in the optic ground wire (OPGW). Compared with the conventional lightning location method, the new method is more accurate, more stable, and cheaper. Theories of Stokes parameters and Poincare sphere are introduced to analyze the SOP at the lightning strike point. It can be concluded that although the initial points of SOP on the Poincare sphere are random, the SOP fluctuation generated by lightning strike can still be accurately identified by detecting the velocity of polarization motion. A new algorithm to quantify the velocity is also introduced.

  5. Adult neural stem cells stake their ground.

    Science.gov (United States)

    Lim, Daniel A; Alvarez-Buylla, Arturo

    2014-10-01

    The birth of new neurons in the walls of the adult brain lateral ventricles has captured the attention of many neuroscientists for over 2 decades, yielding key insights into the identity and regulation of neural stem cells (NSCs). In the adult ventricular-subventricular zone (V-SVZ), NSCs are a specialized form of astrocyte that generates several types of neurons for the olfactory bulb. In this review, we discuss recent findings regarding the unique organization of the V-SVZ NSC niche, the multiple regulatory controls of neuronal production, the distinct regional identities of adult NSCs, and the epigenetic mechanisms that maintain adult neurogenesis. Understanding how V-SVZ NSCs establish and maintain lifelong neurogenesis continues to provide surprising insights into the cellular and molecular regulation of neural development.

  6. Why (and how) they decide to leave: A grounded theory analysis of STEM attrition at a large public research university

    Science.gov (United States)

    Minutello, Michael F.

    A grounded theory investigation of STEM attrition was conducted that describes and explains why undergraduates at a large Mid-Atlantic research university decided to leave their initial STEM majors to pursue non-STEM courses of study. Participants ultimately decided to leave their initial STEM majors because they were able to locate preferable non-STEM courses of study that did not present the same kinds of obstacles they had encountered in their original STEM majors. Grounded theory data analysis revealed participants initially enrolled in STEM majors with tenuous motivation that did not withstand the various obstacles that were present in introductory STEM coursework. Obstacles that acted as demotivating influences and prompted participants to locate alternative academic pathways include the following: (1.) disengaging curricula; (2.) competitive culture; (3.) disappointing grades; (4.) demanding time commitments; and (5.) unappealing career options. Once discouraged from continuing along their initial STEM pathways, participants then employed various strategies to discover suitable non-STEM majors that would allow them to realize their intrinsic interests and extrinsic goals. Participants were largely satisfied with their decisions to leave STEM and have achieved measures of personal satisfaction and professional success.

  7. Influence of location of the lead wires on calculation results of grounding transient characteristics of a grounding rod

    Directory of Open Access Journals (Sweden)

    Kuklin D. V.

    2016-12-01

    Full Text Available For calculations and measurements of transient characteristics of groundings, the current and potential lead wires are frequently used accordingly to inject the current into the grounding and find the grounding potential rise (GPR. The results of the calculations and measurements can be dependent on the location of the current and potential lead wires due to mutual influence between them and the grounding wire. It is important to determine to what extent the location of the wires influences the calculation results for the grounding with a simple configuration. Notably, in contrast to the measurements, for the calculations it is possible to locate wires vertically, also the potential lead wire can be replaced by the integral of the electric field. For the calculations the finite difference time domain method (FDTD has been used in the work. In order to estimate to what extent the calculated GPR can be influenced by location of the wires, calculations with different wires locations have been carried out. An analysis of the calculation results has been made. There are calculation methods in which the injection of the current and calculation of the GPR are performed without the current and potential lead wires. The method based on the telegrapher's equations is one of such methods. In order to determine what location of the lead wires gives the same calculation results as those of the method that uses the telegrapher's equations, a comparison of calculation results of two methods has been made. Based on the calculation results it can be concluded that the calculated transient characteristics depend to a different extent on such factors as mutual location of the lead wires and the grounding wire, replacing the potential lead wire by the integral of the electric field, electrical parameters of the soil. Location of one of the lead wires above the grounding wire significantly reduces the calculated GPR. Calculation results for a perpendicular location

  8. Derivation of novel human ground state naive pluripotent stem cells.

    Science.gov (United States)

    Gafni, Ohad; Weinberger, Leehee; Mansour, Abed AlFatah; Manor, Yair S; Chomsky, Elad; Ben-Yosef, Dalit; Kalma, Yael; Viukov, Sergey; Maza, Itay; Zviran, Asaf; Rais, Yoach; Shipony, Zohar; Mukamel, Zohar; Krupalnik, Vladislav; Zerbib, Mirie; Geula, Shay; Caspi, Inbal; Schneir, Dan; Shwartz, Tamar; Gilad, Shlomit; Amann-Zalcenstein, Daniela; Benjamin, Sima; Amit, Ido; Tanay, Amos; Massarwa, Rada; Novershtern, Noa; Hanna, Jacob H

    2013-12-12

    Mouse embryonic stem (ES) cells are isolated from the inner cell mass of blastocysts, and can be preserved in vitro in a naive inner-cell-mass-like configuration by providing exogenous stimulation with leukaemia inhibitory factor (LIF) and small molecule inhibition of ERK1/ERK2 and GSK3β signalling (termed 2i/LIF conditions). Hallmarks of naive pluripotency include driving Oct4 (also known as Pou5f1) transcription by its distal enhancer, retaining a pre-inactivation X chromosome state, and global reduction in DNA methylation and in H3K27me3 repressive chromatin mark deposition on developmental regulatory gene promoters. Upon withdrawal of 2i/LIF, naive mouse ES cells can drift towards a primed pluripotent state resembling that of the post-implantation epiblast. Although human ES cells share several molecular features with naive mouse ES cells, they also share a variety of epigenetic properties with primed murine epiblast stem cells (EpiSCs). These include predominant use of the proximal enhancer element to maintain OCT4 expression, pronounced tendency for X chromosome inactivation in most female human ES cells, increase in DNA methylation and prominent deposition of H3K27me3 and bivalent domain acquisition on lineage regulatory genes. The feasibility of establishing human ground state naive pluripotency in vitro with equivalent molecular and functional features to those characterized in mouse ES cells remains to be defined. Here we establish defined conditions that facilitate the derivation of genetically unmodified human naive pluripotent stem cells from already established primed human ES cells, from somatic cells through induced pluripotent stem (iPS) cell reprogramming or directly from blastocysts. The novel naive pluripotent cells validated herein retain molecular characteristics and functional properties that are highly similar to mouse naive ES cells, and distinct from conventional primed human pluripotent cells. This includes competence in the generation

  9. Grounding the ungrounded : Estimating locations of unknown place names from linguistic associations and grounded representations

    NARCIS (Netherlands)

    Recchia, G.; Louwerse, M.M.

    2014-01-01

    Abstract Spatial locations can be extracted from language statistics, based on the idea that nearby locations are mentioned in similar linguistic contexts, akin to Tobler's first law of geography. However, the performance of language-based estimates is inferior to human estimates, raising questions

  10. Location of Agricultural Drainage Pipes and Assessment of Agricultural Drainage Pipe Conditions Using Ground Penetrating Radar

    Science.gov (United States)

    Methods are needed to not only locate buried agricultural drainage pipe, but to also determine if the pipes are functioning properly with respect to water delivery. The primary focus of this research project was to confirm the ability of ground penetrating radar (GPR) to locate buried drainage pipe ...

  11. Ground Zero in the Debate over Stem-Cell Research.

    Science.gov (United States)

    Southwick, Ron

    2001-01-01

    Describes how political, legal, and ethical battles over embryonic stem-cell research are focused on the University of Wisconsin at Madison, where the cells were first isolated. Addresses the issue of access to the university's stem cells and a recent presidential decision regarding funding for stem-cell research.(EV)

  12. Ground Zero in the Debate over Stem-Cell Research.

    Science.gov (United States)

    Southwick, Ron

    2001-01-01

    Describes how political, legal, and ethical battles over embryonic stem-cell research are focused on the University of Wisconsin at Madison, where the cells were first isolated. Addresses the issue of access to the university's stem cells and a recent presidential decision regarding funding for stem-cell research.(EV)

  13. Determining the location of buried plastic water pipes from measurements of ground surface vibration

    Science.gov (United States)

    Muggleton, J. M.; Brennan, M. J.; Gao, Y.

    2011-09-01

    ‘Mapping the Underworld' is a UK-based project, which aims to create a multi-sensor device that combines complementary technologies for remote buried utility service detection and location. One of the technologies to be incorporated in the device is low-frequency vibro-acoustics, and techniques for detecting buried infrastructure, in particular plastic water pipes, are being investigated. One of the proposed techniques involves excitation of the pipe at some known location with concurrent vibrational mapping of the ground surface in order to infer the location of the remainder of the pipe. In this paper, measurements made on a dedicated pipe rig are reported. Frequency response measurements relating vibrational velocity on the ground to the input excitation were acquired. Contour plots of the unwrapped phase revealed the location of the pipe to within 0.1-0.2 m. Magnitude contour plots revealed the excitation point and also the location of the pipe end. By examining the unwrapped phase gradients along a line above the pipe, it was possible to identify the wave-type within the pipe responsible for the ground surface vibration. Furthermore, changes in the ground surface phase speed computed using this method enabled the location of the end of the pipe to be confirmed.

  14. Development of access-based metrics for site location of ground segment in LEO missions

    Directory of Open Access Journals (Sweden)

    Hossein Bonyan Khamseh

    2010-09-01

    Full Text Available The classical metrics of ground segment site location do not take account of the pattern of ground segment access to the satellite. In this paper, based on the pattern of access between the ground segment and the satellite, two metrics for site location of ground segments in Low Earth Orbits (LEO missions were developed. The two developed access-based metrics are total accessibility duration and longest accessibility gap in a given period of time. It is shown that repeatability cycle is the minimum necessary time interval to study the steady behavior of the two proposed metrics. System and subsystem characteristics of the satellite represented by each of the metrics are discussed. Incorporation of the two proposed metrics, along with the classical ones, in the ground segment site location process results in financial saving in satellite development phase and reduces the minimum required level of in-orbit autonomy of the satellite. To show the effectiveness of the proposed metrics, simulation results are included for illustration.

  15. Ethanol production using Saccharomyces cerevisiae cells immobilised on corn stem ground tissue

    Directory of Open Access Journals (Sweden)

    Vučurović Vesna M.

    2009-01-01

    Full Text Available Cell immobilisation in alcoholic fermentation has been extensively studied during the past few decades because of its technical and economical advantages over those of free cell systems. A biocatalyst was prepared by immobilising a commercial Saccharomyces cerevisiae strain (baker yeast on corn stem ground tissue for use in alcoholic fermentation. For this purpose, the yeast cells were submitted to the batch tests 'in situ' adsorption onto pieces of the corn stem ground tissue. Cells immobilisation was analysed by optical microscopy. It was determined that the addition of the corn stem ground tissue led to an increase of the pH value, total dissolved salts content, and sugar content in fermentation medium. The addition of 5 and 10g of the corn stem ground tissue per liter of medium, increased ethanol yield, decreased amount of residual sugar and the cells immobilisation was effective. Corn stem is one of the abundant, available, inexpensive, stable, reusable, nontoxic celulosic biomaterial with high porosity, which facilitates the transmission of substrates and products between carrier and medium. The prepared immobilised biocatalyst showed higher fermentation activity than free cells. The results indicate that corn stem might be an interesting support for yeast cell immobilisation, and also a cheap alternative recourse of mineral components with possibility of application for improving ethanol productivities.

  16. Ground moving target geo-location from monocular camera mounted on a micro air vehicle

    Science.gov (United States)

    Guo, Li; Ang, Haisong; Zheng, Xiangming

    2011-08-01

    The usual approaches to unmanned air vehicle(UAV)-to-ground target geo-location impose some severe constraints to the system, such as stationary objects, accurate geo-reference terrain database, or ground plane assumption. Micro air vehicle(MAV) works with characteristics including low altitude flight, limited payload and onboard sensors' low accuracy. According to these characteristics, a method is developed to determine the location of ground moving target which imaged from the air using monocular camera equipped on MAV. This method eliminates the requirements for terrain database (elevation maps) and altimeters that can provide MAV's and target's altitude. Instead, the proposed method only requires MAV flight status provided by its inherent onboard navigation system which includes inertial measurement unit(IMU) and global position system(GPS). The key is to get accurate information on the altitude of the ground moving target. First, Optical flow method extracts background static feature points. Setting a local region around the target in the current image, The features which are on the same plane with the target in this region are extracted, and are retained as aided features. Then, inverse-velocity method calculates the location of these points by integrated with aircraft status. The altitude of object, which is calculated by using position information of these aided features, combining with aircraft status and image coordinates, geo-locate the target. Meanwhile, a framework with Bayesian estimator is employed to eliminate noise caused by camera, IMU and GPS. Firstly, an extended Kalman filter(EKF) provides a simultaneous localization and mapping solution for the estimation of aircraft states and aided features location which defines the moving target local environment. Secondly, an unscented transformation(UT) method determines the estimated mean and covariance of target location from aircraft states and aided features location, and then exports them for the

  17. Reducing multisensor monthly mean aerosol optical depth uncertainty: 2. Optimal locations for potential ground observation deployments

    Science.gov (United States)

    Li, Jing; Li, Xichen; Carlson, Barbara E.; Kahn, Ralph A.; Lacis, Andrew A.; Dubovik, Oleg; Nakajima, Teruyuki

    2017-04-01

    Surface remote sensing of aerosol properties provides "ground truth" for satellite and model validation and is an important component of aerosol observation system. Due to the different characteristics of background aerosol variability, information obtained at different locations usually has different spatial representativeness, implying that the location should be carefully chosen so that its measurement could be extended to a greater area. In this study, we present an objective observation array design technique that automatically determines the optimal locations with the highest spatial representativeness based on the Ensemble Kalman Filter (EnKF) theory. The ensemble is constructed using aerosol optical depth (AOD) products from five satellite sensors. The optimal locations are solved sequentially by minimizing the total analysis error variance, which means that observations at these locations will reduce the background error variance to the largest extent. The location determined by the algorithm is further verified to have larger spatial representativeness than some other arbitrary location. In addition to the existing active Aerosol Robotic Network (AERONET) sites, the 40 selected optimal locations are mostly concentrated on regions with both high AOD inhomogeneity and its spatial representativeness, namely, the Sahel, South Africa, East Asia, and North Pacific Islands. These places should be the focuses of establishing future AERONET sites in order to further reduce the uncertainty in the monthly mean AOD. Observations at these locations contribute to approximately 50% of the total background uncertainty reduction.

  18. USING GROUND PENETRATING RADAR TO DETERMINE THE TUNNEL LOCATION BURIED UNDER THE GLACIER

    Directory of Open Access Journals (Sweden)

    Deryuga Andrey Mikhaylovich

    2013-09-01

    Full Text Available The works were carried out with the help of ground penetrating radar “Grot-10”. Doublet broadband antennas with the central frequency of 100 MHz were used. Georadar measures the speed of EM waves v in ice-saturated soil and then the value ε′ is calculated. The radargrams received as a result of georadar survey, which represents stacked data (the two-way time is indicated on vertical scale, were transformed into depth sections, which reflect the space structure located below ground. The distance between the bottom landing and buried mountain road near the north tunnel portal is 78,5 m (profile # 1, and the distance from the upper landing is 84,5 m (profile no. 2. Later, in the April 2003 during the hole boring with the diameter 1,2 m the vertical distance between the upper landing, where ground penetrating works were carried out, and the carpet road of the tunnel was calculated. This distance appeared to be 83 m, that means, the discrepancy between boring and georadar data (84,5 m was only 1,5 m. Thus, the results of ground penetrating investigations helped the workers of glacier to make the correct conclusion on time about the location and burial depth of the tunnel.

  19. Wire position system to consistently measure and record the location change of girders following ground changes

    Science.gov (United States)

    Choi, H. J.; Lee, S. B.; Lee, H. G.; Y Back, S.; Kim, S. H.; Kang, H. S.

    2017-07-01

    Several parts that comprise the large scientific device should be installed and operated at the accurate three-dimensional location coordinates (X, Y, and Z) where they should be subjected to survey and alignment. The location of the aligned parts should not be changed in order to ensure that the electron beam parameters (Energy 10 GeV, Charge 200 pC, and Bunch Length 60 fs, Emittance X/Y 0.481 μm/0.256 μm) of PAL-XFEL (X-ray Free Electron Laser of the Pohang Accelerator Laboratory) remain stable and can be operated without any problems. As time goes by, however, the ground goes through uplift and subsidence, which consequently deforms building floors. The deformation of the ground and buildings changes the location of several devices including magnets and RF accelerator tubes, which eventually leads to alignment errors (∆X, ∆Y, and ∆Z). Once alignment errors occur with regard to these parts, the electron beam deviates from its course and beam parameters change accordingly. PAL-XFEL has installed the Hydrostatic Leveling System (HLS) to measure and record the vertical change of buildings and ground consistently and systematically and the Wire Position System (WPS) to measure the two dimensional changes of girders. This paper is designed to introduce the operating principle and design concept of WPS and discuss the current situation regarding installation and operation.

  20. Application of Fault Location Mode Based on Travelling Waves for Neutral Non-effective Grounding Systems

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>Fault location for distribution feeders short circuit especially single-phase grounding fault is an important task in distribution system with non-effectively grounded neutral.Fault location mode for distribution feeders using fault generated current and voltage transient traveling waves was investigated.The characteristics of transient traveling waves resulted from each short circuit fault and their transmission disciplinarian in distribution feeders are analyzed.This paper proposed that double end travelling waves theory which measures arriving time of fault initiated surge at both ends of the monitored line is fit for distribution feeders but single end traveling waves theory not.According to different distribution feeders,on the basis of analyzing original traveling waves reflection rule in line terminal, Current-voltage mode,voltage-voltage mode and current-current mode for fault location based on traveling waves are proposed and aerial mode component of original traveling waves is used to realize fault location.Experimental test verify the feasibility and correctness of the proposed method.

  1. The persistence of women in STEM: A constructivist grounded theory study

    Science.gov (United States)

    Gamm, Ryan

    Men and women have reached relative parity in most sectors of the United States workforce. Yet women remain underrepresented in science, technology, engineering, and mathematics (STEM) fields (AAUW, 2010). Underrepresentation persists despite several decades of research, legislation, and intervention focused on gender equality in STEM fields (Clewell, 2002). The underrepresentation or shortage of women in STEM fields is identifiable primarily in degree attainment, in workforce demographics, and in a gender wage gap. Situated in constructivist grounded theory, this study asks how do women in science, technology, engineering, and mathematics (STEM) fields, particularly those in established career positions, persist when encountering personal and institutional barriers, resistance, and hostility? I use an interpretive-constructivist lens to conduct a grounded theory study exploring the experiences of women who persist in STEM fields, their relation to extant literature on this topic, and the connections to K-12 education practices, specifically curriculum. To understand the connections to curriculum I employ Pinar's (2012) method of currere. Pinar (2012) contends currere "provides a strategy for students of curriculum to study the relations between academic knowledge and life history in the interests of self-understanding and social reconstruction" (p.44). This qualitative study explored nine female STEM workers stories of persistence as each respondent works in STEM fields were gender parity has yet to be established. This study presents a substantive theory: As women persist in STEM fields they reframe themselves to be situated in the overlapping intersection of the social processes that correspond to "engagement" and "persistence." This reframing is possible by interpreting one's present day circumstances by independently removing oneself from current circumstances to understand the cumulative effect of both past and present. The findings highlight the importance

  2. The educational journeys of first-generation college women in STEM: A grounded theory study

    Science.gov (United States)

    Geier, Susan

    The purpose of this study was to ascertain the various factors that influenced these first-generation college women as they chose a college and selected a STEM major and subsequently persisted to upper level (junior/senior) status. Twenty-five first-generation college women in STEM majors who attended a research-intensive university in the Midwest were interviewed. Approaching this study using constructivist grounded theory provided the opportunity for deeper insights by examining data at a conceptual level while preserving the voices of the women in this study. The women faced numerous challenges on their journeys, yet they persisted. As the women in this study selected and persisted in STEM, they demonstrated thoughtful determination, experienced shifting identities, established purposeful relationships and applied forward thinking, as they practiced high-stakes decision-making during their journeys. The experiences of these women, namely first-generation women in STEM fields, may inform students, parents, educators, researchers, and policymakers concerned with (a) inspiring students to consider STEM majors, (b) fostering student success in STEM throughout their academic journeys, and (c) ultimately increasing the number of underrepresented minorities and women in the STEM fields.

  3. Single Phase-to-Ground Fault Line Identification and Section Location Method for Non-Effectively Grounded Distribution Systems Based on Signal Injection

    Institute of Scientific and Technical Information of China (English)

    PAN Zhencun; WANG Chengshan; CONG Wei; ZHANG Fan

    2008-01-01

    A diagnostic signal current trace detecting based single phase-to-ground fault line identifica- tion and section location method for non-effectively grounded distribution systems is presented in thisi oaper. A special diagnostic signal current is injected into the fault distribution system, and then it is de- tected at the outlet terminals to identify the fault line and at the sectionalizing or branching point along the fault line to locate the fault section. The method has been put into application in actual distribution network and field experience shows that it can identify the fault line and locate the fault section correctly and effectively.

  4. Stem-loop structures of the repetitive DNA sequences located at human centromeres

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, G.; Garcia, A.E.; Ratliff, R.; Moyzis, R.K. [Los Alamos National Lab., NM (United States); Catasti, P.; Hong, Lin; Yau, P. [California Univ., Davis, CA (United States). Dept. of Biological Chemistry; Bradbury, E.M. [Los Alamos National Lab., NM (United States)]|[California Univ., Davis, CA (United States). Dept. of Biological Chemistry

    1993-09-01

    The presence of the highly conserved repetitive DNA sequences in the human centromeres argues for a special role of these sequences in their biological functions - most likely achieved by the formation of unusual structures. This prompted us to carry out quantitative one- and two-dimensional nuclear magnetic resonance (lD/2D NMR) spectroscopy to determine the structural properties of the human centromeric repeats, d(AATGG){sub n.d}(CCATT){sub n}. The studies on centromeric DNAs reveal that the complementary sequence, d(AATGG){sub n.d}(CCATT){sub n}, adopts the usual Watson-Crick B-DNA duplex and the pyrimidine-rich d(CCATT){sub n} strand is essentially a random coil. However, the purine-rich d(AATGG){sub n} strand is shown to adopt unusual stem-loop structures for repeat lengths, n=2,3,4, and 6. In addition to normal Watson-Crick A{center_dot}T pairs, the stem-loop structures are stabilized by mismatch A{center_dot}G and G{center_dot}G pairs in the stem and G-G-A stacking in the loop. Stem-loop structures of d(AATGG)n are independently verified by gel electrophoresis and nuclease digestion studies. Thermal melting studies show that the DNA repeats, d(AATGG){sub n}, are as stable as the corresponding Watson-Crick duplex d(AATGG){sub n.d}(CCATT){sub n}. Therefore, the sequence d(AATGG){sub n} can, indeed, nucleate a stem-loop structure at little free-energy cost and if, during mitosis, they are located on the chromosome surface they can provide specific recognition sites for kinetochore function.

  5. Tissue engineering potential of human dermis-isolated adult stem cells from multiple anatomical locations.

    Science.gov (United States)

    Kwon, Heenam; Haudenschild, Anne K; Brown, Wendy E; Vapniarsky, Natalia; Paschos, Nikolaos K; Arzi, Boaz; Hu, Jerry C; Athanasiou, Kyriacos A

    2017-01-01

    Abundance and accessibility render skin-derived stem cells an attractive cell source for tissue engineering applications. Toward assessing their utility, the variability of constructs engineered from human dermis-isolated adult stem (hDIAS) cells was examined with respect to different anatomical locations (foreskin, breast, and abdominal skin), both in vitro and in a subcutaneous, athymic mouse model. All anatomical locations yielded hDIAS cells with multi-lineage differentiation potentials, though adipogenesis was not seen for foreskin-derived hDIAS cells. Using engineered cartilage as a model, tissue engineered constructs from hDIAS cells were compared. Construct morphology differed by location. The mechanical properties of human foreskin- and abdominal skin-derived constructs were similar at implantation, remaining comparable after 4 additional weeks of culture in vivo. Breast skin-derived constructs were not mechanically testable. For all groups, no signs of abnormality were observed in the host. Addition of aggregate redifferentiation culture prior to construct formation improved chondrogenic differentiation of foreskin-derived hDIAS cells, as evident by increases in glycosaminoglycan and collagen contents. More robust Alcian blue staining and homogeneous cell populations were also observed compared to controls. Human DIAS cells elicited no adverse host responses, reacted positively to chondrogenic regimens, and possessed multi-lineage differentiation potential with the caveat that efficacy may differ by anatomical origin of the skin. Taken together, these results suggest that hDIAS cells hold promise as a potential cell source for a number of tissue engineering applications.

  6. Comparing distinct ground-based lightning location networks covering the Netherlands

    Science.gov (United States)

    de Vos, Lotte; Leijnse, Hidde; Schmeits, Maurice; Beekhuis, Hans; Poelman, Dieter; Evers, Läslo; Smets, Pieter

    2015-04-01

    Lightning can be detected using a ground-based sensor network. The Royal Netherlands Meteorological Institute (KNMI) monitors lightning activity in the Netherlands with the so-called FLITS-system; a network combining SAFIR-type sensors. This makes use of Very High Frequency (VHF) as well as Low Frequency (LF) sensors. KNMI has recently decided to replace FLITS by data from a sub-continental network operated by Météorage which makes use of LF sensors only (KNMI Lightning Detection Network, or KLDN). KLDN is compared to the FLITS system, as well as Met Office's long-range Arrival Time Difference (ATDnet), which measures Very Low Frequency (VLF). Special focus lies on the ability to detect Cloud to Ground (CG) and Cloud to Cloud (CC) lightning in the Netherlands. Relative detection efficiency of individual flashes and lightning activity in a more general sense are calculated over a period of almost 5 years. Additionally, the detection efficiency of each system is compared to a ground-truth that is constructed from flashes that are detected by both of the other datasets. Finally, infrasound data is used as a fourth lightning data source for several case studies. Relative performance is found to vary strongly with location and time. As expected, it is found that FLITS detects significantly more CC lightning (because of the strong aptitude of VHF antennas to detect CC), though KLDN and ATDnet detect more CG lightning. We analyze statistics computed over the entire 5-year period, where we look at CG as well as total lightning (CC and CG combined). Statistics that are considered are the Probability of Detection (POD) and the so-called Lightning Activity Detection (LAD). POD is defined as the percentage of reference flashes the system detects compared to the total detections in the reference. LAD is defined as the fraction of system recordings of one or more flashes in predefined area boxes over a certain time period given the fact that the reference detects at least one

  7. New fault location system for power transmission lines using composite fiber-optic overhead ground wire (OPGW)

    Energy Technology Data Exchange (ETDEWEB)

    Urasawa, K. (Tokyo Electric Power Co., Inc. (Japan)); Kanemaru, K.; Toyota, S.; Sugiyama, K. (Hitachi Cable, Ltd., Tokyo (Japan))

    1989-10-01

    A new fault location (FL) method using composite fiber-optic overhead ground wires (OPGWs) is developed to find out where electrical faults occur on overhead power transmission lines. This method locates the fault section by detecting the current induced in the ground wire (GW), i.e. OPGW in this system. Since detected fault information is essentially uncertain, the new FL method treats the fault information oas a current distribution pattern throughout the power line, and applies Fuzzy Theory to realize the human-like manner of fault location used by electrical power engineers. It was confirmed by computer simulations that the fault section can be accurately located using this method under various conditions. This FL system has already been applied to several commercial power transmission lines and successfully located the sections where electrical faults occurred on actual power transmission lines.

  8. Application of ground-penetrating radar technique to evaluate the waterfront location in hardened concrete

    Science.gov (United States)

    Rodríguez-Abad, Isabel; Klysz, Gilles; Martínez-Sala, Rosa; Balayssac, Jean Paul; Mené-Aparicio, Jesús

    2016-12-01

    The long-term performance of concrete structures is directly tied to two factors: concrete durability and strength. When assessing the durability of concrete structures, the study of the water penetration is paramount, because almost all reactions like corrosion, alkali-silica, sulfate, etc., which produce their deterioration, require the presence of water. Ground-penetrating radar (GPR) has shown to be very sensitive to water variations. On this basis, the objective of this experimental study is, firstly, to analyze the correlation between the water penetration depth in concrete samples and the GPR wave parameters. To do this, the samples were immersed into water for different time intervals and the wave parameters were obtained from signals registered when the antenna was placed on the immersed surface of the samples. Secondly, a procedure has been developed to be able to determine, from those signals, the reliability in the detection and location of waterfront depths. The results have revealed that GPR may have an enormous potential in this field, because excellent agreements were found between the correlated variables. In addition, when comparing the waterfront depths calculated from GPR measurements and those visually registered after breaking the samples, we observed that they totally agreed when the waterfront was more than 4 cm depth.

  9. Growth and differentiation of adult hippocampal arctic ground squirrel neural stem cells.

    Science.gov (United States)

    Drew, Kelly L; McGee, Rebecca C; Wells, Matthew S; Kelleher-Andersson, Judith A

    2011-01-07

    Arctic ground squirrels (Urocitellus parryii, AGS) are unique in their ability to hibernate with a core body temperature near or below freezing. These animals also resist ischemic injury to the brain in vivo and oxygen-glucose deprivation in vitro. These unique qualities provided the impetus to isolate AGS neurons to examine inherent neuronal characteristics that could account for the capacity of AGS neurons to resist injury and cell death caused by ischemia and extremely cold temperatures. Identifying proteins or gene targets that allow for the distinctive properties of these cells could aid in the discovery of effective therapies for a number of ischemic indications and for the study of cold tolerance. Adult AGS hippocampus contains neural stem cells that continue to proliferate, allowing for easy expansion of these stem cells in culture. We describe here methods by which researchers can utilize these stem cells and differentiated neurons for any number of purposes. By closely following these steps the AGS neural stem cells can be expanded through two passages or more and then differentiated to a culture high in TUJ1-positive neurons (~50%) without utilizing toxic chemicals to minimize the number of dividing cells. Ischemia induces neurogenesis and neurogenesis which proceeds via MEK/ERK and PI3K/Akt survival signaling pathways contributes to ischemia resistance in vivo and in vitro (Kelleher-Anderson, Drew et al., in preparation). Further characterization of these unique neural cells can advance on many fronts, using some or all of these methods.

  10. A New Method of Ground Fault Location in 2 × 25 kV Railway Power Supply Systems

    Directory of Open Access Journals (Sweden)

    Jesús Serrano

    2017-03-01

    Full Text Available Owing to the installation of autotransformers at regular intervals along the line, distance protection relays cannot be used with the aim of locating ground faults in 2 × 25 kV railway power supply systems. The reason is that the ratio between impedance and distance to the fault point is not linear in these electrification systems, unlike in 1 × 25 kV power systems. Therefore, the location of ground faults represents a complicated task in 2 × 25 kV railway power supply systems. Various methods have been used to localize the ground fault position in 2 × 25 kV systems. The method described here allows the location of a ground fault to be economically found in an accurate way in real time, using the modules of the circulating currents in different autotransformers when the ground fault occurs. This method first needs to know the subsection and the conductor (catenary or feeder with the defect, then localizes the ground fault’s position.

  11. Error Analysis of Fast Moving Target Geo-location in Wide Area Surveillance Ground Moving Target Indication Mode

    Directory of Open Access Journals (Sweden)

    Zheng Shi-chao

    2013-12-01

    Full Text Available As an important mode in airborne radar systems, Wide Area Surveillance Ground Moving Target Indication (WAS-GMTI mode has the ability of monitoring a large area in a short time, and then the detected moving targets can be located quickly. However, in real environment, many factors introduce considerable errors into the location of moving targets. In this paper, a fast location method based on the characteristics of the moving targets in WAS-GMTI mode is utilized. And in order to improve the location performance, those factors that introduce location errors are analyzed and moving targets are relocated. Finally, the analysis of those factors is proved to be reasonable by simulation and real data experiments.

  12. Detecting and locating light atoms from high-resolution STEM images: The quest for a single optimal design.

    Science.gov (United States)

    Gonnissen, J; De Backer, A; den Dekker, A J; Sijbers, J; Van Aert, S

    2016-11-01

    In the present paper, the optimal detector design is investigated for both detecting and locating light atoms from high resolution scanning transmission electron microscopy (HR STEM) images. The principles of detection theory are used to quantify the probability of error for the detection of light atoms from HR STEM images. To determine the optimal experiment design for locating light atoms, use is made of the so-called Cramér-Rao Lower Bound (CRLB). It is investigated if a single optimal design can be found for both the detection and location problem of light atoms. Furthermore, the incoming electron dose is optimised for both research goals and it is shown that picometre range precision is feasible for the estimation of the atom positions when using an appropriate incoming electron dose under the optimal detector settings to detect light atoms. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. NODAL Secures Pluripotency upon Embryonic Stem Cell Progression from the Ground State

    Directory of Open Access Journals (Sweden)

    Carla Mulas

    2017-07-01

    Full Text Available Naive mouse embryonic stem cells (ESCs can develop multiple fates, but the cellular and molecular processes that enable lineage competence are poorly characterized. Here, we investigated progression from the ESC ground state in defined culture. We utilized downregulation of Rex1::GFPd2 to track the loss of ESC identity. We found that cells that have newly downregulated this reporter have acquired capacity for germline induction. They can also be efficiently specified for different somatic lineages, responding more rapidly than naive cells to inductive cues. Inhibition of autocrine NODAL signaling did not alter kinetics of exit from the ESC state but compromised both germline and somatic lineage specification. Transient inhibition prior to loss of ESC identity was sufficient for this effect. Genetic ablation of Nodal reduced viability during early differentiation, consistent with defective lineage specification. These results suggest that NODAL promotes acquisition of multi-lineage competence in cells departing naive pluripotency.

  14. Estimation of source location and ground impedance using a hybrid multiple signal classification and Levenberg-Marquardt approach

    Science.gov (United States)

    Tam, Kai-Chung; Lau, Siu-Kit; Tang, Shiu-Keung

    2016-07-01

    A microphone array signal processing method for locating a stationary point source over a locally reactive ground and for estimating ground impedance is examined in detail in the present study. A non-linear least square approach using the Levenberg-Marquardt method is proposed to overcome the problem of unknown ground impedance. The multiple signal classification method (MUSIC) is used to give the initial estimation of the source location, while the technique of forward backward spatial smoothing is adopted as a pre-processer of the source localization to minimize the effects of source coherence. The accuracy and robustness of the proposed signal processing method are examined. Results show that source localization in the horizontal direction by MUSIC is satisfactory. However, source coherence reduces drastically the accuracy in estimating the source height. The further application of Levenberg-Marquardt method with the results from MUSIC as the initial inputs improves significantly the accuracy of source height estimation. The present proposed method provides effective and robust estimation of the ground surface impedance.

  15. Grid-Search Location Methods for Ground-Truth Collection from Local and Regional Seismic Networks

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, C A; Rodi, W; Myers, S C

    2003-07-24

    The objective of this project is to develop improved seismic event location techniques that can be used to generate more and better quality reference events using data from local and regional seismic networks. Their approach is to extend existing methods of multiple-event location with more general models of the errors affecting seismic arrival time data, including picking errors and errors in model-based travel-times (path corrections). Toward this end, they are integrating a grid-search based algorithm for multiple-event location (GMEL) with a new parameterization of travel-time corrections and new kriging method for estimating the correction parameters from observed travel-time residuals. Like several other multiple-event location algorithms, GMEL currently assumes event-independent path corrections and is thus restricted to small event clusters. The new parameterization assumes that travel-time corrections are a function of both the event and station location, and builds in source-receiver reciprocity and correlation between the corrections from proximate paths as constraints. The new kriging method simultaneously interpolates travel-time residuals from multiple stations and events to estimate the correction parameters as functions of position. They are currently developing the algorithmic extensions to GMEL needed to combine the new parameterization and kriging method with the simultaneous location of events. The result will be a multiple-event location method which is applicable to non-clustered, spatially well-distributed events. They are applying the existing components of the new multiple-event location method to a data set of regional and local arrival times from Nevada Test Site (NTS) explosions with known origin parameters. Preliminary results show the feasibility and potential benefits of combining the location and kriging techniques. They also show some preliminary work on generalizing of the error model used in GMEL with the use of mixture

  16. Maintenance of sweat glands by stem cells located in the acral epithelium

    Energy Technology Data Exchange (ETDEWEB)

    Ohe, Shuichi [Department of Stem Cell Pathology, Kansai Medical University, Osaka 573-1010 (Japan); Department of Dermatology, Kansai Medical University, Osaka 573-1010 (Japan); Tanaka, Toshihiro [Department of Stem Cell Pathology, Kansai Medical University, Osaka 573-1010 (Japan); Third Department of Internal Medicine, Kansai Medical University, Osaka 573-1010 (Japan); Yanai, Hirotsugu [Department of Stem Cell Pathology, Kansai Medical University, Osaka 573-1010 (Japan); Department of Surgery, Kansai Medical University, Osaka 573-1010 (Japan); Komai, Yoshihiro [Department of Stem Cell Pathology, Kansai Medical University, Osaka 573-1010 (Japan); Department of Urology and Andrology, Kansai Medical University, Osaka 573-1010 (Japan); Omachi, Taichi [Department of Stem Cell Pathology, Kansai Medical University, Osaka 573-1010 (Japan); Department of Pediatrics, Kansai Medical University, Osaka 573-1010 (Japan); Kanno, Shohei; Tanaka, Kiyomichi; Ishigaki, Kazuhiko; Saiga, Kazuho [Department of Stem Cell Pathology, Kansai Medical University, Osaka 573-1010 (Japan); Nakamura, Naohiro [Department of Stem Cell Pathology, Kansai Medical University, Osaka 573-1010 (Japan); Third Department of Internal Medicine, Kansai Medical University, Osaka 573-1010 (Japan); Ohsugi, Haruyuki [Department of Stem Cell Pathology, Kansai Medical University, Osaka 573-1010 (Japan); Department of Urology and Andrology, Kansai Medical University, Osaka 573-1010 (Japan); Tokuyama, Yoko; Atsumi, Naho; Hisha, Hiroko; Yoshida, Naoko; Kumano, Keiki [Department of Stem Cell Pathology, Kansai Medical University, Osaka 573-1010 (Japan); Yamazaki, Fumikazu; Okamoto, Hiroyuki [Department of Dermatology, Kansai Medical University, Osaka 573-1010 (Japan); Ueno, Hiroo, E-mail: hueno@hirakata.kmu.ac.jp [Department of Stem Cell Pathology, Kansai Medical University, Osaka 573-1010 (Japan)

    2015-10-23

    The skin is responsible for a variety of physiological functions and is critical for wound healing and repair. Therefore, the regenerative capacity of the skin is important. However, stem cells responsible for maintaining the acral epithelium had not previously been identified. In this study, we identified the specific stem cells in the acral epithelium that participate in the long-term maintenance of sweat glands, ducts, and interadnexal epidermis and that facilitate the regeneration of these structures following injury. Lgr6-positive cells and Bmi1-positive cells were found to function as long-term multipotent stem cells that maintained the entire eccrine unit and the interadnexal epidermis. However, while Lgr6-positive cells were rapidly cycled and constantly supplied differentiated cells, Bmi1-positive cells were slow to cycle and occasionally entered the cell cycle under physiological conditions. Upon irradiation-induced injury, Bmi1-positive cells rapidly proliferated and regenerated injured epithelial tissue. Therefore, Bmi1-positive stem cells served as reservoir stem cells. Lgr5-positive cells were rapidly cycled and maintained only sweat glands; therefore, we concluded that these cells functioned as lineage-restricted progenitors. Taken together, our data demonstrated the identification of stem cells that maintained the entire acral epithelium and supported the different roles of three cellular classes. - Highlights: • The acral epithelium have two types of stem cells. • Lgr6-positive cells are rapid-cycling, short-term stem cells. • Bmi1-positive cells are slow-cycling stem cells that act as reserver stem cells. • Lgr5 may be a useful sweat gland marker in mice.

  17. IMPROVED MULTIPLE EVENT LOCATION METHODS FOR GROUND TRUTH COLLECTION, Annual Report

    Science.gov (United States)

    2015-03-13

    Sambridge, and B.L.N. Kennett (1994), Errors in hypocenter location: picking, model and magnitude dependence, Bull. Seism . Soc. Am., 84, pp. 1978–1990...calibration, Bull. Seism . Soc. Am., 94, pp. 1528–1545 Bonda´r, I., E. Bergman, E.R. Engdahl, B. Kohl, Y-L Kung, and K. McLaughlin (2008), A hybrid...Sverdrup (1981), Teleseismic location techniques and their application to earthquake clusters in the south-central Pacific, Bull. Seism . Soc. Am

  18. Antenna structures and cloud-to-ground lightning location: 1995-2015

    Science.gov (United States)

    Kingfield, Darrel M.; Calhoun, Kristin M.; de Beurs, Kirsten M.

    2017-05-01

    Spatial analyses of cloud-to-ground (CG) lightning occurrence due to a rapid expansion in the number of antenna towers across the United States are explored by gridding 20 years of National Lightning Detection Network data at 500 m spatial resolution. The 99.8% of grid cells with ≥100 CGs were within 1 km of an antenna tower registered with the Federal Communications Commission. Tower height is positively correlated with CG occurrence; towers taller than 400 m above ground level experience a median increase of 150% in CG lightning density compared to a region 2 km to 5 km away. In the northern Great Plains, the cumulative CG lightning density near the tower was around 138% (117%) higher than a region 2 to 5 km away in the September-February (March-August) months. Higher CG frequencies typically also occur in the first full year following new tower construction, creating new lightning hot spots.

  19. Seasonal variations of infrasonic arrivals from long-term ground truth observations in Nevada and implication for event location

    Science.gov (United States)

    Negraru, Petru; Golden, Paul

    2017-04-01

    Long-term ground truth observations were collected at two infrasound arrays in Nevada to investigate how seasonal atmospheric variations affect the detection, traveltime and signal characteristics (azimuth, trace velocity, frequency content and amplitudes) of infrasonic arrivals at regional distances. The arrays were located in different azimuthal directions from a munition disposal facility in Nevada. FNIAR, located 154 km north of the source has a high detection rate throughout the year. Over 90 per cent of the detonations have traveltimes indicative of stratospheric arrivals, while tropospheric waveguides are observed from only 27 per cent of the detonations. The second array, DNIAR, located 293 km southeast of the source exhibits strong seasonal variations with high stratospheric detection rates in winter and the virtual absence of stratospheric arrivals in summer. Tropospheric waveguides and thermospheric arrivals are also observed for DNIAR. Modeling through the Naval Research Laboratory Ground to Space atmospheric sound speeds leads to mixed results: FNIAR arrivals are usually not predicted to be present at all (either stratospheric or tropospheric), while DNIAR arrivals are usually correctly predicted, but summer arrivals show a consistent traveltime bias. In the end, we show the possible improvement in location using empirically calibrated traveltime and azimuth observations. Using the Bayesian Infrasound Source Localization we show that we can decrease the area enclosed by the 90 per cent credibility contours by a factor of 2.5.

  20. Seasonal variations of infrasonic arrivals from long term ground truth observations in Nevada and implication for event location

    Science.gov (United States)

    Negraru, Petru; Golden, Paul

    2017-01-01

    SUMMARYLong term ground truth observations were collected at two infrasound arrays in Nevada to investigate how seasonal atmospheric variations affect the detection, travel time and signal characteristics (azimuth, trace velocity, frequency content and amplitudes) of infrasonic arrivals at regional distances. The arrays were located in different azimuthal directions from a munition disposal facility in Nevada. FNIAR, located 154 km north of the source has a high detection rate throughout the year. Over 90% of the detonations have travel times indicative of stratospheric arrivals, while tropospheric waveguides are observed from only 27% of the detonations. The second array, DNIAR, located 293 km southeast of the source exhibits strong seasonal variations with high stratospheric detection rates in winter and the virtual absence of stratospheric arrivals in summer. Tropospheric waveguides and thermospheric arrivals are also observed for DNIAR. Modelling through the Naval Research Laboratory Ground to Space (G2S) atmospheric sound speeds leads to mixed results: FNIAR arrivals are usually not predicted to be present at all (either stratospheric or tropospheric), while DNIAR arrivals are usually correctly predicted, but summer arrivals show a consistent travel time bias. In the end we show the possible improvement in location using empirically calibrated travel time and azimuth observations. Using the Bayesian Infrasound Source Localization we show that we can decrease the area enclosed by the 90% credibility contours by a factor of 2.5.

  1. Grid-Search Location Methods for Ground-Truth Collection From Local and Regional Seismic Networks

    Energy Technology Data Exchange (ETDEWEB)

    William Rodi; Craig A. Schultz; Gardar Johannesson; Stephen C. Myers

    2005-05-13

    This project investigated new techniques for improving seismic event locations derived from regional and local networks. The technqiues include a new approach to empirical travel-time calibration that simultaneously fits data from multiple stations and events, using a generalization of the kriging method, and predicts travel-time corrections for arbitrary event-station paths. We combined this calibration approach with grid-search event location to produce a prototype new multiple-event location method that allows the use of spatially well-distributed events and takes into account correlations between the travel-time corrections from proximate event-station paths. Preliminary tests with a high quality data set from Nevada Test Site explosions indicated that our new calibration/location method offers improvement over the conventional multiple-event location methods now in common use, and is applicable to more general event-station geometries than the conventional methods. The tests were limited, however, and further research is needed to fully evaluate, and improve, the approach. Our project also demonstrated the importance of using a realistic model for observational errors in an event location procedure. We took the initial steps in developing a new error model based on mixture-of-Gaussians probability distributions, which possess the properties necessary to characterize the complex arrival time error processes that can occur when picking low signal-to-noise arrivals. We investigated various inference methods for fitting these distributions to observed travel-time residuals, including a Markov Chain Monte Carlo technique for computing Bayesian estimates of the distribution parameters.

  2. Maintenance of sweat glands by stem cells located in the acral epithelium.

    Science.gov (United States)

    Ohe, Shuichi; Tanaka, Toshihiro; Yanai, Hirotsugu; Komai, Yoshihiro; Omachi, Taichi; Kanno, Shohei; Tanaka, Kiyomichi; Ishigaki, Kazuhiko; Saiga, Kazuho; Nakamura, Naohiro; Ohsugi, Haruyuki; Tokuyama, Yoko; Atsumi, Naho; Hisha, Hiroko; Yoshida, Naoko; Kumano, Keiki; Yamazaki, Fumikazu; Okamoto, Hiroyuki; Ueno, Hiroo

    2015-10-23

    The skin is responsible for a variety of physiological functions and is critical for wound healing and repair. Therefore, the regenerative capacity of the skin is important. However, stem cells responsible for maintaining the acral epithelium had not previously been identified. In this study, we identified the specific stem cells in the acral epithelium that participate in the long-term maintenance of sweat glands, ducts, and interadnexal epidermis and that facilitate the regeneration of these structures following injury. Lgr6-positive cells and Bmi1-positive cells were found to function as long-term multipotent stem cells that maintained the entire eccrine unit and the interadnexal epidermis. However, while Lgr6-positive cells were rapidly cycled and constantly supplied differentiated cells, Bmi1-positive cells were slow to cycle and occasionally entered the cell cycle under physiological conditions. Upon irradiation-induced injury, Bmi1-positive cells rapidly proliferated and regenerated injured epithelial tissue. Therefore, Bmi1-positive stem cells served as reservoir stem cells. Lgr5-positive cells were rapidly cycled and maintained only sweat glands; therefore, we concluded that these cells functioned as lineage-restricted progenitors. Taken together, our data demonstrated the identification of stem cells that maintained the entire acral epithelium and supported the different roles of three cellular classes.

  3. Ground Validation Locations (2012) in the U.S. Virgin Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This shapefile denotes the location of underwater photos and videos taken in Fish Bay and Coral Bay, St. John and the St. Thomas East End Reserve (STEER) in the U.S....

  4. Bi-objective approach for placing ground and air ambulance base and helipad locations in order to optimize EMS response.

    Science.gov (United States)

    Shahriari, Milad; Bozorgi-Amiri, Ali; Tavakoli, Shayan; Yousefi-Babadi, Abolghasem

    2017-06-15

    Shortening the travel time of patient transfer has clinical implications for many conditions such as cardiac arrest, trauma, stroke and STEMI. As resources are often limited precise calculations are needed. In this paper we consider the location problem for both ground and aerial emergency medical services. Given the uncertainty of when patients are in need of prompt medical attention we consider these demand points to be uncertain. We consider various ways in which ground and helicopter ambulances can work together to make the whole process go faster. We develop a mathematical model that minimizes travel time and maximizes service level. We use a compromising programming method to solve this bi-objective mathematical model. For numerical experiments we apply our model to a case study in Lorestan, Iran, using geographical and population data, and the location of the actual hospital based in the capital of the province. Results show that low-accessibility locations are the main focus of the proposed problem and with mathematical modeling access to a hospital is vastly improved. We also found out that once the budget reaches a certain point which suffices for building certain ambulance bases more investments does not necessarily result in less travel time. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. The effectiveness of ground-penetrating radar surveys in the location of unmarked burial sites in modern cemeteries

    Science.gov (United States)

    Fiedler, Sabine; Illich, Bernhard; Berger, Jochen; Graw, Matthias

    2009-07-01

    Ground-penetration radar (GPR) is a geophysical method that is commonly used in archaeological and forensic investigations, including the determination of the exact location of graves. Whilst the method is rapid and does not involve disturbance of the graves, the interpretation of GPR profiles is nevertheless difficult and often leads to incorrect results. Incorrect identifications could hinder criminal investigations and complicate burials in cemeteries that have no information on the location of previously existing graves. In order to increase the number of unmarked graves that are identified, the GPR results need to be verified by comparing them with the soil and vegetation properties of the sites examined. We used a modern cemetery to assess the results obtained with GPR which we then compared with previously obtained tachymetric data and with an excavation of the graves where doubt existed. Certain soil conditions tended to make the application of GPR difficult on occasions, but a rough estimation of the location of the graves was always possible. The two different methods, GPR survey and tachymetry, both proved suitable for correctly determining the exact location of the majority of graves. The present study thus shows that GPR is a reliable method for determining the exact location of unmarked graves in modern cemeteries. However, the method did not allow statements to be made on the stage of decay of the bodies. Such information would assist in deciding what should be done with graves where ineffective degradation creates a problem for reusing graves following the standard resting time of 25 years.

  6. Adult stem cells in the small intestine are intrinsically programmed with their location-specific function

    NARCIS (Netherlands)

    Middendorp, Sabine; Schneeberger, Kerstin; Wiegerinck, Caroline L; Mokry, Michal; Akkerman, Ronald D L; van Wijngaarden, Simone; Clevers, Hans; Nieuwenhuis, Edward E S

    Differentiation and specialization of epithelial cells in the small intestine are regulated in two ways. First, there is differentiation along the crypt-villus axis of the intestinal stem cells into absorptive enterocytes, Paneth, goblet, tuft, enteroendocrine, or M cells, which is mainly regulated

  7. Totipotent Embryonic Stem Cells Arise in Ground-State Culture Conditions

    Science.gov (United States)

    Morgani, Sophie M.; Canham, Maurice A.; Nichols, Jennifer; Sharov, Alexei A.; Migueles, Rosa Portero; Ko, Minoru S.H.; Brickman, Joshua M.

    2013-01-01

    Summary Embryonic stem cells (ESCs) are derived from mammalian embryos during the transition from totipotency, when individual blastomeres can make all lineages, to pluripotency, when they are competent to make only embryonic lineages. ESCs maintained with inhibitors of MEK and GSK3 (2i) are thought to represent an embryonically restricted ground state. However, we observed heterogeneous expression of the extraembryonic endoderm marker Hex in 2i-cultured embryos, suggesting that 2i blocked development prior to epiblast commitment. Similarly, 2i ESC cultures were heterogeneous and contained a Hex-positive fraction primed to differentiate into trophoblast and extraembryonic endoderm. Single Hex-positive ESCs coexpressed epiblast and extraembryonic genes and contributed to all lineages in chimeras. The cytokine LIF, necessary for ESC self-renewal, supported the expansion of this population but did not directly support Nanog-positive epiblast-like ESCs. Thus, 2i and LIF support a totipotent state comparable to early embryonic cells that coexpress embryonic and extraembryonic determinants. PMID:23746443

  8. Totipotent Embryonic Stem Cells Arise in Ground-State Culture Conditions

    Directory of Open Access Journals (Sweden)

    Sophie M. Morgani

    2013-06-01

    Full Text Available Embryonic stem cells (ESCs are derived from mammalian embryos during the transition from totipotency, when individual blastomeres can make all lineages, to pluripotency, when they are competent to make only embryonic lineages. ESCs maintained with inhibitors of MEK and GSK3 (2i are thought to represent an embryonically restricted ground state. However, we observed heterogeneous expression of the extraembryonic endoderm marker Hex in 2i-cultured embryos, suggesting that 2i blocked development prior to epiblast commitment. Similarly, 2i ESC cultures were heterogeneous and contained a Hex-positive fraction primed to differentiate into trophoblast and extraembryonic endoderm. Single Hex-positive ESCs coexpressed epiblast and extraembryonic genes and contributed to all lineages in chimeras. The cytokine LIF, necessary for ESC self-renewal, supported the expansion of this population but did not directly support Nanog-positive epiblast-like ESCs. Thus, 2i and LIF support a totipotent state comparable to early embryonic cells that coexpress embryonic and extraembryonic determinants.

  9. Fair Grounds, Located during MicroData field address collection 2004-2006. Kept in Spillman database for retrieval., Published in 2004, Vilas County Land Information/Mapping.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Fair Grounds dataset, was produced all or in part from Field Observation information as of 2004. It is described as 'Located during MicroData field address...

  10. Co-located ground-based remote sensing and in situ measurements at the tropical atmospheric observatory in Suriname

    Science.gov (United States)

    Warneke, T.; Petersen, K.; Gerbig, C.; Macatangay, R.; Koerner, S.; Jordan, A.; Rothe, M.; Notholt, J.; Schrems, O.

    2009-04-01

    The first ground-based remote sensing measurements of the column averaged volume mixing ratio of CO2 (XCO2) for the inner tropics have been obtained at Paramaribo, Suriname (5.8°N, 55.2°W). Due to the migration of the ITCZ over the measurement location the probed air masses belong to the northern or southern hemisphere depending on the time of the year. The XCO2 shows an average annual increase in the Southern Hemisphere of 2.2 ppm for the time period 2004 to 2007, which agrees within the error with model simulations. Co-located in-situ measurements are strongly influenced by a local source. From the isotopic composition of the air samples the local source component is suggested to be the terrestrial biosphere. Using d13C from the NOAA/ESRL stations Ascension Is. (ASC) and Ragged Point (RPB) the data has been corrected for the local source component. The corrected mixing ratios for the surface as well as the XCO2 qualitatively agree with model simulations.

  11. A Case of Primary Central Nervous System Lymphoma Located at Brain Stem in a Child

    Science.gov (United States)

    Kim, Jinho

    2016-01-01

    Primary central nervous system lymphoma (PCNSL) is an extranodal Non-Hodgkin's lymphoma that is confined to the brain, eyes, and/or leptomeninges without evidence of a systemic primary tumor. Although the tumor can affect all age groups, it is rare in childhood; thus, its incidence and prognosis in children have not been well defined and the best treatment strategy remains unclear. A nine-year old presented at our department with complaints of diplopia, dizziness, dysarthria, and right side hemiparesis. Magnetic resonance image suggested a diffuse brain stem glioma with infiltration into the right cerebellar peduncle. The patient was surgically treated by craniotomy and frameless stereotactic-guided biopsy, and unexpectedly, the histopathology of the mass was consistent with diffuse large B cell lymphoma, and immunohistochemical staining revealed positivity for CD20 and CD79a. Accordingly, we performed a staging work-up for systemic lymphoma, but no evidence of lymphoma elsewhere in the body was obtained. In addition, she had a negative serologic finding for human immunodeficient virus, which confirmed the histopathological diagnosis of PCNSL. She was treated by radiosurgery at 12 Gy and subsequent adjuvant combination chemotherapy based on high dose methotrexate. Unfortunately, 10 months after the tissue-based diagnosis, she succumbed due to an acute hydrocephalic crisis. PMID:27867930

  12. Mesenchymal stem cells that located in the electromagnetic fields improves rat model of Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Majid Jadidi

    2016-07-01

    Full Text Available Objective(s: The main characteristic of mesenchymal stem cells (MSCs is their ability to produce other cell types. Electromagnetic field (EMF stimulates differentiation of MSCs into other cells. In this study, we investigated whether EMF can effect on the differentiation of MSCs into dopaminergic (DA neurons. Materials and Methods: An EMF with a frequency of 50 Hz and two intensities of 40 and 400 µT 1hr/day was generated around the cells for a week. Afterwards, these cells were injected into the left ventricle of Parkinsonian rats. The rats survived for 2 weeks, and then sampling was performed. Results: The injected cells differentiated into DA neurons and sporadically settled in the substantia nigra pars compacta (SNpc. Transplanted rats exhibited significant partial correction apomorphine-induced rotational behavior compared to Parkinsonian rats (5.0±0.1 vs 7.57±0.08. Results demonstrated that endogenous serum and brain derived neurotrophic factor (BDNF were altered in all experimental groups. The greatest increase was in group of 400 µT EMF in comparison with Parkinsonian rats (398±15 vs. 312±11.79 pg ⁄ mg. Current study have shown that 6-Hydroxydopamine can cause severe loss of dopaminergic neurons (68±6.58, but injected MSCs that exposed to 40 and 400 µT EMF increased dopaminergic neurons in SNpc ( 108±2.33  & 126±3.89 (P

  13. Metrology of ground-based satellite validation: co-location mismatch and smoothing issues of total ozone comparisons

    Directory of Open Access Journals (Sweden)

    T. Verhoelst

    2015-12-01

    Full Text Available Comparisons with ground-based correlative measurements constitute a key component in the validation of satellite data on atmospheric composition. The error budget of these comparisons contains not only the measurement errors but also several terms related to differences in sampling and smoothing of the inhomogeneous and variable atmospheric field. A versatile system for Observing System Simulation Experiments (OSSEs, named OSSSMOSE, is used here to quantify these terms. Based on the application of pragmatic observation operators onto high-resolution atmospheric fields, it allows a simulation of each individual measurement, and consequently, also of the differences to be expected from spatial and temporal field variations between both measurements making up a comparison pair. As a topical case study, the system is used to evaluate the error budget of total ozone column (TOC comparisons between GOME-type direct fitting (GODFITv3 satellite retrievals from GOME/ERS2, SCIAMACHY/Envisat, and GOME-2/MetOp-A, and ground-based direct-sun and zenith–sky reference measurements such as those from Dobsons, Brewers, and zenith-scattered light (ZSL-DOAS instruments, respectively. In particular, the focus is placed on the GODFITv3 reprocessed GOME-2A data record vs. the ground-based instruments contributing to the Network for the Detection of Atmospheric Composition Change (NDACC. The simulations are found to reproduce the actual measurements almost to within the measurement uncertainties, confirming that the OSSE approach and its technical implementation are appropriate. This work reveals that many features of the comparison spread and median difference can be understood as due to metrological differences, even when using strict co-location criteria. In particular, sampling difference errors exceed measurement uncertainties regularly at most mid- and high-latitude stations, with values up to 10 % and more in extreme cases. Smoothing difference errors only

  14. Metrology of ground-based satellite validation: co-location mismatch and smoothing issues of total ozone comparisons

    Science.gov (United States)

    Verhoelst, T.; Granville, J.; Hendrick, F.; Köhler, U.; Lerot, C.; Pommereau, J.-P.; Redondas, A.; Van Roozendael, M.; Lambert, J.-C.

    2015-12-01

    Comparisons with ground-based correlative measurements constitute a key component in the validation of satellite data on atmospheric composition. The error budget of these comparisons contains not only the measurement errors but also several terms related to differences in sampling and smoothing of the inhomogeneous and variable atmospheric field. A versatile system for Observing System Simulation Experiments (OSSEs), named OSSSMOSE, is used here to quantify these terms. Based on the application of pragmatic observation operators onto high-resolution atmospheric fields, it allows a simulation of each individual measurement, and consequently, also of the differences to be expected from spatial and temporal field variations between both measurements making up a comparison pair. As a topical case study, the system is used to evaluate the error budget of total ozone column (TOC) comparisons between GOME-type direct fitting (GODFITv3) satellite retrievals from GOME/ERS2, SCIAMACHY/Envisat, and GOME-2/MetOp-A, and ground-based direct-sun and zenith-sky reference measurements such as those from Dobsons, Brewers, and zenith-scattered light (ZSL-)DOAS instruments, respectively. In particular, the focus is placed on the GODFITv3 reprocessed GOME-2A data record vs. the ground-based instruments contributing to the Network for the Detection of Atmospheric Composition Change (NDACC). The simulations are found to reproduce the actual measurements almost to within the measurement uncertainties, confirming that the OSSE approach and its technical implementation are appropriate. This work reveals that many features of the comparison spread and median difference can be understood as due to metrological differences, even when using strict co-location criteria. In particular, sampling difference errors exceed measurement uncertainties regularly at most mid- and high-latitude stations, with values up to 10 % and more in extreme cases. Smoothing difference errors only play a role in the

  15. Host microhabitat location by stem-borer parasitoidCotesia flavipes: the role of herbivore volatiles and locally and systemically induced plant volatiles.

    Science.gov (United States)

    Potting, R P; Vet, L E; Dicke, M

    1995-05-01

    The origin of olfactory stimuli involved in the host microhabitat location inCotesia flavipes, a parasitoid of stem-borer larvae, was investigated in a Y-tube olfactometer. The response of femaleC. flavipes towards different components of the plant-host complex, consisting of a maize plant infested with two or more larvae of the stem borerChilo partellus, was tested in dualchoice tests. The concealed lifestyle of the stem-borer larvae did not limit the emission of volatiles attractive to a parasitoid. A major source of the attractive volatiles from the plant-host complex was the stem-borer-injured stem, including the frass produced by the feeding larvae. Moreover, the production of volatiles attractive to a parasitoid was not restricted to the infested stem part but occurs systemically throughout the plant. The uninfested leaves of a stem-borer-infested plant were found to emit volatiles that attract femaleC. flavipes. We further demonstrate that an exogenous elicitor of this systemic plant response is situated in the regurgitate of a stem-borer larva. When a minor amount of regurgitate is inoculated into the stem of an uninfested plant, the leaves of the treated plant emit volatiles that attract femaleC. flavipes.

  16. LONG-TERM STABILITY OF THE LOCAL GROUND CONTROL NETWORK AT THE CO-LOCATION SITE OF MEDICINA

    Science.gov (United States)

    Abbondanza, C.; Sarti, P.; Legrand, J.

    2009-12-01

    ITRF combinations rely on the availability of accurate tie vectors linking reference points of space geodetic techniques. Co-located instruments are assumed to move consistently and no local relative motion is taken into account. Instabilities may degrade the quality of the co-location itself and perturb the result of ITRF combinations. This work aims to determine the stability of the local ground control network at Medicina (Italy) with independent surveying methods. The observatory hosts a co-location between a VLBI telescope and two GPS antennas, MEDI and MSEL. It is located in the Po Plain where thick layers of clays are the prevalent soil characteristics. Hence, provision of long term stability of geodetic monuments is a challenge and monitoring their stability is an issue. MEDI and the VLBI station regularly contribute to the determination of ITRF, while MSEL is part of the EUREF network. A set of five tie vectors observations linking the VLBI and MEDI reference points was acquired between 2001 and 2007. It is our main tool for performing local deformation analysis. Additionally, the GPS time series of MEDI and MSEL were used to cross check and confirm the local instability detected by terrestrial methods. To achieve a rigorous and reliable investigation of the local stability, multi-epoch terrestrial observations were homogeneously processed according to common parameterizations in a consistent reference frame. Similarly, continuous GPS observations from MEDI and MSEL were analysed according to the new EPN reprocessing strategy in order to monitor the short baseline between MEDI and MSEL; to spotlight any change in its length. Both approaches confirm differential motions at the site which can be related to monument instabilities originated by the particularly unfavourable local geological setting and the inapt design of the monuments foundation. The monuments move non homogeneously at rates reaching up to 1.6 mm/year, this value being comparable to intra

  17. Metrology of ground-based satellite validation: co-location mismatch and smoothing issues of total ozone comparisons

    Directory of Open Access Journals (Sweden)

    T. Verhoelst

    2015-08-01

    Full Text Available Comparisons with ground-based correlative measurements constitute a key component in the validation of satellite data on atmospheric composition. The error budget of these comparisons contains not only the measurement uncertainties but also several terms related to differences in sampling and smoothing of the inhomogeneous and variable atmospheric field. A versatile system for Observing System Simulation Experiments (OSSEs, named OSSSMOSE, is used here to quantify these terms. Based on the application of pragmatic observation operators onto high-resolution atmospheric fields, it allows a simulation of each individual measurement, and consequently also of the differences to be expected from spatial and temporal field variations between both measurements making up a comparison pair. As a topical case study, the system is used to evaluate the error budget of total ozone column (TOC comparisons between on the one hand GOME-type direct fitting (GODFITv3 satellite retrievals from GOME/ERS2, SCIAMACHY/Envisat, and GOME-2/MetOp-A, and on the other hand direct-sun and zenith-sky reference measurements such as from Dobsons, Brewers, and zenith scattered light (ZSL-DOAS instruments respectively. In particular, the focus is placed on the GODFITv3 reprocessed GOME-2A data record vs. the ground-based instruments contributing to the Network for the Detection of Atmospheric Composition Change (NDACC. The simulations are found to reproduce the actual measurements almost to within the measurement uncertainties, confirming that the OSSE approach and its technical implementation are appropriate. This work reveals that many features of the comparison spread and median difference can be understood as due to metrological differences, even when using strict co-location criteria. In particular, sampling difference errors exceed measurement uncertainties regularly at most mid- and high-latitude stations, with values up to 10 % and more in extreme cases. Smoothing

  18. Fair Grounds, Fair Ground point location in Iredell County, NC, Published in 2009, 1:2400 (1in=200ft) scale, Iredell County GIS.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Fair Grounds dataset, published at 1:2400 (1in=200ft) scale, was produced all or in part from Orthoimagery information as of 2009. It is described as 'Fair...

  19. Fair Grounds, Fair Grounds point locations in Critical Facilities data layer, Published in 2008, 1:4800 (1in=400ft) scale, Gove County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Fair Grounds dataset, published at 1:4800 (1in=400ft) scale, was produced all or in part from Field Survey/GPS information as of 2008. It is described as 'Fair...

  20. Membrane translocation of t-SNARE protein syntaxin-4 abrogates ground-state pluripotency in mouse embryonic stem cells

    Science.gov (United States)

    Hagiwara-Chatani, Natsumi; Shirai, Kota; Kido, Takumi; Horigome, Tomoatsu; Yasue, Akihiro; Adachi, Naoki; Hirai, Yohei

    2017-01-01

    Embryonic stem (ES) and induced pluripotent stem (iPS) cells are attractive tools for regenerative medicine therapies. However, aberrant cell populations that display flattened morphology and lose ground-state pluripotency often appear spontaneously, unless glycogen synthase kinase 3β (GSK3β) and mitogen-activated protein kinase kinase (MEK1/2) are inactivated. Here, we show that membrane translocation of the t-SNARE protein syntaxin-4 possibly is involved in this phenomenon. We found that mouse ES cells cultured without GSK3β/MEK1/2 inhibitors (2i) spontaneously extrude syntaxin-4 at the cell surface and that artificial expression of cell surface syntaxin-4 induces appreciable morphological changes and mesodermal differentiation through dephosphorylation of Akt. Transcriptome analyses revealed several candidate elements responsible for this, specifically, an E-to P-cadherin switch and a marked downregulation of Zscan4 proteins, which are DNA-binding proteins essential for ES cell pluripotency. Embryonic carcinoma cell lines F9 and P19CL6, which maintain undifferentiated states independently of Zscan4 proteins, exhibited similar cellular behaviors upon stimulation with cell surface syntaxin-4. The functional ablation of E-cadherin and overexpression of P-cadherin reproduced syntaxin-4-induced cell morphology, demonstrating that the E- to P-cadherin switch executes morphological signals from cell surface syntaxin-4. Thus, spontaneous membrane translocation of syntaxin-4 emerged as a critical element for maintenance of the stem-cell niche. PMID:28057922

  1. Location, location, location

    NARCIS (Netherlands)

    Anderson, S.P.; Goeree, J.K.; Ramer, R.

    1997-01-01

    We analyze the canonical location-then-price duopoly game with general log- concave consumer densities. A unique pure-strategy equilibrium to the two-stage game exists if the density is not "too asymmetric" and not "too concave." These criteria are satisfied by many commonly used densities. Equilibr

  2. Major gene for field stem rust resistance co-locates with resistance gene Sr12 in "Thatcher" wheat

    Science.gov (United States)

    Stem rust, caused by Puccinia graminis (Pgt), is a damaging disease of wheat that can be controlled by utilizing effecting stem rust resistance genes. "Thatcher" wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was ...

  3. Seismic Structural Considerations for the Stem and Base of Retaining Walls Subjected to Earthquake Ground Motions

    Science.gov (United States)

    2005-05-01

    and Morrison (1992). AKAE - (3/4) k k = 4 (AKAE) + 3 =4 (0.170) + 3 = 0.227 Observation: A constant horizontal acceleration khg equal to 0.227g will...1.93) Shear 0.375 p kh*g 1-1 1.00 p kh*g H3 0.400 p kh*g I’j 0.772 p khg W2 Moment 0.225 p kh*g • 0.63 p kh*g/3 0.130 p kh*g/H3 0.251 p kh*g H3 kh...ground acceleration, equal to khg a, Maximum vertical ground acceleration, equal to k~g A Area; Seismic coefficient representing the peak ground

  4. Terrain Classification and Identification of Tree Stems Using Ground-Based Lidar

    Science.gov (United States)

    2012-12-01

    enhance UGV localization (Vandapel et al., 2006; Carle et al., 2010). In the forestry domain, tree stem modeling can be used for estimating biomass ...Surface lidar remote sensing of basal area and biomass in deciduous forests of eastern Maryland, USA. Remote Sensing of Environment, 67, 83-98...Microsoft Research. Sharma, M., Parton, J. (2009). Modeling Stand Density Effects on Taper for Jack Pine and Black Spruce Plantations Using

  5. Totipotent Embryonic Stem Cells Arise in Ground-State Culture Conditions

    DEFF Research Database (Denmark)

    Morgani, Sophie M; Canham, Maurice A; Nichols, Jennifer

    2013-01-01

    Embryonic stem cells (ESCs) are derived from mammalian embryos during the transition from totipotency, when individual blastomeres can make all lineages, to pluripotency, when they are competent to make only embryonic lineages. ESCs maintained with inhibitors of MEK and GSK3 (2i) are thought...... not directly support Nanog-positive epiblast-like ESCs. Thus, 2i and LIF support a totipotent state comparable to early embryonic cells that coexpress embryonic and extraembryonic determinants....

  6. Medicare, Medicaid, and Children's Health Insurance Programs: Announcement of the Implementation and Extension of Temporary Moratoria on Enrollment of Part B Non-Emergency Ground Ambulance Suppliers and Home Health Agencies in Designated Geographic Locations and Lifting of the Temporary Moratoria on Enrollment of Part B Emergency Ground Ambulance Suppliers in All Geographic Locations. Extension, implementation, and lifting of temporary moratoria.

    Science.gov (United States)

    2016-08-03

    This document announces the extension of temporary moratoria on the enrollment of new Medicare Part B non-emergency ground ambulance suppliers and Medicare home health agencies (HHAs), subunits, and branch locations in specific locations within designated metropolitan areas in Florida, Illinois, Michigan, Texas, Pennsylvania, and New Jersey to prevent and combat fraud, waste, and abuse. It also announces the implementation of temporary moratoria on the enrollment of new Medicare Part B non-emergency ground ambulance suppliers and Medicare HHAs, subunits, and branch locations in Florida, Illinois, Michigan, Texas, Pennsylvania, and New Jersey on a statewide basis. In addition, it announces the lifting of the moratoria on all Part B emergency ground ambulance suppliers. These moratoria, and the changes described in this document, also apply to the enrollment of HHAs and non-emergency ground ambulance suppliers in Medicaid and the Children's Health Insurance Program.

  7. Ground Truth Location of Earthquakes by Use of Ambient Seismic Noise From a Sparse Seismic Network: A Case Study in Western Australia

    Science.gov (United States)

    Zeng, Xiangfang; Xie, Jun; Ni, Sidao

    2015-06-01

    The estimated Green's function (EGF) extracted from the ambient seismic noise cross-correlation function (NCF) enables valuable calibration of surface wave propagation along the path connecting seismic stations. Such calibration is adopted in a new method for ground truth location of earthquakes, achieved from the location relative to a seismic station. The surface wave group travel times were obtained from the NCFs between a station near the earthquake and remote stations. The differential travel times from the NCFs and the surface wave of the earthquake were used in a relative location procedure. When this method was applied to earthquake location with only six seismic stations in western Australia, the location of the Mw 4.1 Kalannie (September 21, 2005) earthquake was found to be accurate to within 2 km compared with the ground truth location with InSAR for which azimuth coverage of seismic stations is preferable. Synthetic tests suggest that the group travel time is slightly affected by focal mechanism and focal depth, thus unknown earthquake source parameters did not introduce substantial bias to earthquake location with the group travel time method.

  8. Locations, values, and uncertainties of hydraulic-head observations for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital geospatial data set contains the locations, values, and uncertainties of hydraulic-head observations used in the calibration of the transient model of...

  9. Locations, values, and uncertainties of hydraulic-head observations for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital geospatial data set contains the locations, values, and uncertainties of hydraulic-head observations used in the calibration of the transient model of...

  10. MONTE CARLO SIMULATION FOR MODELING THE EFFECT OF GROUND SEGMENT LOCATION ON IN-ORBIT RESPONSIVENESS OF LEO SUNSYNCHRONOUS SATELLITE S

    Institute of Scientific and Technical Information of China (English)

    M. Navabi; Hossein Bonyan Khamseh

    2011-01-01

    Responsiveness is a challenge for space systems to sustain competitive advantage over alternate non-spaceborne technologies.For a satellite in its operational orbit,in-orbit responsiveness is defined as the capability of the satellite to respond to a given demand in a timely manner.In this paper,it is shown that Average Wait Time (AWT) to pick up user demand from ground segment is the appropriate metric to evaluate the effect of ground segment location on in-orbit responsiveness of Low Earth Orbit (LEO) sunsynchronous satellites.This metric depends on pattern of ground segment access to satellite and distribution of user demands in time domain.A mathematical model is presented to determine pattern of ground segment access to satellite and concept of cumulative distribution function is used to simulate distribution of user demands for markets with different total demand scenarios.Monte Carlo simulations are employed to take account of uncertainty in distribution and total volume of user demands.Sampling error and standard deviation are used to ensure validity of AWT metric obtained from Monte Carlo simulations.Incorporation of the proposed metric in the ground segment site location process results in more responsive satellite systems which,in turn,lead to greater customer satisfaction levels and attractiveness of spaceborne systems for different applications.Finally,simulation results for a case study are presented.

  11. Ground-water use, locations of production wells, and areas irrigated using ground water in 1998, middle Humboldt River basin, north-central Nevada

    Science.gov (United States)

    Plume, Russell W.

    2003-01-01

    In 1998, ground water was being pumped from about 420 production wells in the middle Humboldt River Basin for a variety of uses. Principal uses were for agriculture, industry, mining, municipal, and power plant purposes. This report presents a compilation of the number and types of production wells, areas irrigated by ground water, and ground-water use in 14 hydrographic areas of the middle Humboldt River Basin in 1998. Annual pumping records for production wells usually are reported to the Nevada Division of Water Resources. However, operators of irrigation wells are not consistently required to report annual pumpage. Daily power-consumption and pump-discharge rates measured at 20 wells during the 1998 irrigation season and total power use at each well were used to estimate the amount of water, in feet of depth, applied to 20 alfalfa fields. These fields include about 10 percent of the total area, 36,700 acres, irrigated with ground water in the middle Humboldt River Basin. In 1998 an average of 2.0 feet of water was applied to 14 fields irrigated using center-pivot sprinkler systems, and an average of 2.6 feet of water was applied to 6 fields irrigated using wheel-line sprinkler systems. A similar approach was used to estimate the amount of water pumped at three wells using pumps powered by diesel engines. The two fields served by these three wells received 3.9 feet of water by flood irrigation during the 1998 irrigation season. The amount of water applied to the fields irrigated by center-pivot and wheel-line irrigation systems during the 1998 irrigation season was less than what would have been applied during a typical irrigation season because late winter and spring precipitation exceeded long-term monthly averages by as much as four times. As a result, the health of crops was affected by over-saturated soils, and most irrigation wells were only used sporadically in the first part of the irrigation season. Power consumption at 19 of the 20 wells in the 1994

  12. Association of short-term exposure to ground-level ozone and respiratory outpatient clinic visits in a rural location – Sublette County, Wyoming, 2008–2011

    Energy Technology Data Exchange (ETDEWEB)

    Pride, Kerry R., E-mail: hgp3@cdc.gov [Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, GA (United States); Wyoming Department of Health, 6101 Yellowstone Road, Suite 510, Cheyenne, WY 82002 (United States); Peel, Jennifer L. [Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523 (United States); Robinson, Byron F. [Scientific Education and Professional Development Program Office, Office of Surveillance, Epidemiology and Laboratory Services, Centers for Disease Control and Prevention, 1600 Clifton Rd, NE, E-92, Atlanta, GA 30333 (United States); Busacker, Ashley [Field Support Branch, Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Wyoming Department of Health, 6101 Yellowstone Road, Suite 510, Cheyenne, WY 82002 (United States); Grandpre, Joseph [Chronic Disease Epidemiologist, Wyoming Department of Health, 6101 Yellowstone Road, Suite 510, Cheyenne, WY 82002 (United States); Bisgard, Kristine M. [Scientific Education and Professional Development Program Office, Office of Surveillance, Epidemiology and Laboratory Services, Centers for Disease Control and Prevention, 600 Clifton Road, NE, E-92, Atlanta, GA 30333 (United States); Yip, Fuyuen Y. [Air Pollution and Respiratory Disease Branch, Centers for Disease Control and Prevention, 600 Clifton Rd, NE, E-92, Atlanta, GA 30333 (United States); Murphy, Tracy D. [Wyoming Department of Health, 101 Yellowstone Road, Suite 510, Cheyenne, WY 82002 (United States)

    2015-02-15

    -level ozone with an increase in clinic visits for adverse respiratory-related effects in the following day (lag day 1) in Sublette County; the magnitude was strongest during the winter months; this association during the winter months in a rural location warrants further investigation. - Highlights: • We assessed elevated ground-level ozone in frontier Sublette County, Wyoming. • Ground-level ozone concentrations were moderately to highly correlated between stations. • Adverse respiratory-related clinic visits occurred year round at lag 1. • Strongest association of clinic visits was in the coldest months at lag 1.

  13. Detection of arcing ground fault location on a distribution network connected PV system; Hikarihatsuden renkei haidensen ni okeru koko chiryaku kukan no kenshutsuho

    Energy Technology Data Exchange (ETDEWEB)

    Sato, M.; Iwaya, K.; Morooka, Y. [Hachinohe Institute of Technology, Aomori (Japan)

    1996-10-27

    In the near future, it is supposed that a great number of small-scale distributed power sources, such as photovoltaic power generation for general houses, will be interconnected with the ungrounded neutral distribution system in Japan. When ground fault of commercial frequency once occurs, great damage is easily guessed. This paper discusses the effect of the ground fault on the ground phase current using a 6.6 kV high-voltage model system by considering the non-linear self-inductance in the line, and by considering the non-linear relation of arcing ground fault current frequency. In the present method, the remarkable difference of series resonance frequency determined by the inductance and earth capacity between the source side and load side is utilized for the detection of high-voltage arcing ground fault location. In this method, there are some cases in which the non-linear effect obtained by measuring the inductance of sound phase including the secondary winding of transformer can not be neglected. Especially, for the actual high-voltage system, it was shown that the frequency characteristics of transformer inductance for distribution should be theoretically derived in the frequency range between 2 kHz and 6 kHz. 2 refs., 5 figs., 1 tab.

  14. Host location and host discrimination behavior of Telenomus isis, an egg parasitoid of the African cereal stem borer Sesamia calamistis.

    Science.gov (United States)

    Chabi-Olaye, A; Schulthess, F; Poehling, H M; Borgemeister, C

    2001-04-01

    In the Republic of Benin, the scelionid egg parasitoid Telenomus isis (Polaszek) is one of the most important control factors of the noctuid maize stem borer Sesamia calamistis. In the present study, the role of various sources of contact kairomones (male or virgin or mated female moths) and of the moth's oviposition substrate (leaf sheath versus filter paper: host plant species) in host location and oviposition behavior of T. isis was investigated in Munger cells, open arenas, and/or Petri dish assays. Furthermore, its ability to distinguish between unparasitized eggs and eggs parasitized by a conspecific female or by the trichogrammatid Lathromeris ovicida was studied. In the Munger cell experiment, T. isis spent more time in moths' odor fields than in the control. There was no difference between virgin and mated females. In the open arena assay, traces left by both the male and female moths acted as contact cues, which elicited an arrestment response in the parasitoid. The residence and patch retention time in the arena with virgin or mated females of S. calamistis was about 4.8 times as long as that with males. The presence of maize leaf sheaths stimulated the oviposition behavior of T. isis when compared to eggs offered on filter paper. During the first 6 hr, more eggs were parasitized on maize leaves, although there was no difference in the final number of offspring between the two substrates. In addition, if eggs of S. calamistis were offered together with different host plant species or alone, maize and sorghum were both more attractive than millet or the egg alone and equally attractive between themselves, indicating that the plant tissue influences host finding of T. isis. Both T. isis and L. ovicida recognized markings of conspecific females, and intraspecific superparasitism was therefore low. Interspecific superparasitism was more than three times higher for L. ovicida than for T. isis, indicating that only T. isis was able to recognize the marking of

  15. Improvements on GPS Location Cluster Analysis for the Prediction of Large Carnivore Feeding Activities: Ground-Truth Detection Probability and Inclusion of Activity Sensor Measures.

    Directory of Open Access Journals (Sweden)

    Kevin A Blecha

    Full Text Available Animal space use studies using GPS collar technology are increasingly incorporating behavior based analysis of spatio-temporal data in order to expand inferences of resource use. GPS location cluster analysis is one such technique applied to large carnivores to identify the timing and location of feeding events. For logistical and financial reasons, researchers often implement predictive models for identifying these events. We present two separate improvements for predictive models that future practitioners can implement. Thus far, feeding prediction models have incorporated a small range of covariates, usually limited to spatio-temporal characteristics of the GPS data. Using GPS collared cougar (Puma concolor we include activity sensor data as an additional covariate to increase prediction performance of feeding presence/absence. Integral to the predictive modeling of feeding events is a ground-truthing component, in which GPS location clusters are visited by human observers to confirm the presence or absence of feeding remains. Failing to account for sources of ground-truthing false-absences can bias the number of predicted feeding events to be low. Thus we account for some ground-truthing error sources directly in the model with covariates and when applying model predictions. Accounting for these errors resulted in a 10% increase in the number of clusters predicted to be feeding events. Using a double-observer design, we show that the ground-truthing false-absence rate is relatively low (4% using a search delay of 2-60 days. Overall, we provide two separate improvements to the GPS cluster analysis techniques that can be expanded upon and implemented in future studies interested in identifying feeding behaviors of large carnivores.

  16. Major Gene for Field Stem Rust Resistance Co-Locates with Resistance Gene Sr12 in 'Thatcher' Wheat.

    Science.gov (United States)

    Hiebert, Colin W; Kolmer, James A; McCartney, Curt A; Briggs, Jordan; Fetch, Tom; Bariana, Harbans; Choulet, Frederic; Rouse, Matthew N; Spielmeyer, Wolfgang

    2016-01-01

    Stem rust, caused by Puccinia graminis (Pgt), is a damaging disease of wheat that can be controlled by utilizing effective stem rust resistance genes. 'Thatcher' wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was to examine APR in 'Thatcher' and look for genetic interactions with Lr34. A RIL population was tested for stem rust resistance in field nurseries in Canada, USA, and Kenya. BSA was used to find SNP markers associated with reduced stem rust severity. A major QTL was identified on chromosome 3BL near the centromere in all environments. Seedling testing showed that Sr12 mapped to the same region as the QTL for APR. The SNP markers were physically mapped and the region carrying the resistance was searched for sequences with homology to members of the NB-LRR resistance gene family. SNP marker from one NB-LRR-like sequence, NB-LRR3 co-segregated with Sr12. Two additional populations, including one that lacked Lr34, were tested in field nurseries. NB-LRR3 mapped near the maximum LOD for reduction in stem rust severity in both populations. Lines from a population that segregated for Sr12 and Lr34 were tested for seedling Pgt biomass and infection type, as well as APR to field stem rust which showed an interaction between the genes. We concluded that Sr12, or a gene closely linked to Sr12, was responsible for 'Thatcher'-derived APR in several environments and this resistance was enhanced in the presence of Lr34.

  17. Major Gene for Field Stem Rust Resistance Co-Locates with Resistance Gene Sr12 in 'Thatcher' Wheat.

    Directory of Open Access Journals (Sweden)

    Colin W Hiebert

    Full Text Available Stem rust, caused by Puccinia graminis (Pgt, is a damaging disease of wheat that can be controlled by utilizing effective stem rust resistance genes. 'Thatcher' wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was to examine APR in 'Thatcher' and look for genetic interactions with Lr34. A RIL population was tested for stem rust resistance in field nurseries in Canada, USA, and Kenya. BSA was used to find SNP markers associated with reduced stem rust severity. A major QTL was identified on chromosome 3BL near the centromere in all environments. Seedling testing showed that Sr12 mapped to the same region as the QTL for APR. The SNP markers were physically mapped and the region carrying the resistance was searched for sequences with homology to members of the NB-LRR resistance gene family. SNP marker from one NB-LRR-like sequence, NB-LRR3 co-segregated with Sr12. Two additional populations, including one that lacked Lr34, were tested in field nurseries. NB-LRR3 mapped near the maximum LOD for reduction in stem rust severity in both populations. Lines from a population that segregated for Sr12 and Lr34 were tested for seedling Pgt biomass and infection type, as well as APR to field stem rust which showed an interaction between the genes. We concluded that Sr12, or a gene closely linked to Sr12, was responsible for 'Thatcher'-derived APR in several environments and this resistance was enhanced in the presence of Lr34.

  18. Major Gene for Field Stem Rust Resistance Co-Locates with Resistance Gene Sr12 in ‘Thatcher’ Wheat

    Science.gov (United States)

    Hiebert, Colin W.; Kolmer, James A.; McCartney, Curt A.; Briggs, Jordan; Fetch, Tom; Bariana, Harbans; Choulet, Frederic; Rouse, Matthew N.; Spielmeyer, Wolfgang

    2016-01-01

    Stem rust, caused by Puccinia graminis (Pgt), is a damaging disease of wheat that can be controlled by utilizing effective stem rust resistance genes. ‘Thatcher’ wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was to examine APR in ‘Thatcher’ and look for genetic interactions with Lr34. A RIL population was tested for stem rust resistance in field nurseries in Canada, USA, and Kenya. BSA was used to find SNP markers associated with reduced stem rust severity. A major QTL was identified on chromosome 3BL near the centromere in all environments. Seedling testing showed that Sr12 mapped to the same region as the QTL for APR. The SNP markers were physically mapped and the region carrying the resistance was searched for sequences with homology to members of the NB-LRR resistance gene family. SNP marker from one NB-LRR-like sequence, NB-LRR3 co-segregated with Sr12. Two additional populations, including one that lacked Lr34, were tested in field nurseries. NB-LRR3 mapped near the maximum LOD for reduction in stem rust severity in both populations. Lines from a population that segregated for Sr12 and Lr34 were tested for seedling Pgt biomass and infection type, as well as APR to field stem rust which showed an interaction between the genes. We concluded that Sr12, or a gene closely linked to Sr12, was responsible for ‘Thatcher’-derived APR in several environments and this resistance was enhanced in the presence of Lr34. PMID:27309724

  19. High ice nucleation activity located in blueberry stem bark is linked to primary freeze initiation and adaptive freezing behaviour of the bark.

    Science.gov (United States)

    Kishimoto, Tadashi; Yamazaki, Hideyuki; Saruwatari, Atsushi; Murakawa, Hiroki; Sekozawa, Yoshihiko; Kuchitsu, Kazuyuki; Price, William S; Ishikawa, Masaya

    2014-07-31

    Controlled ice nucleation is an important mechanism in cold-hardy plant tissues for avoiding excessive supercooling of the protoplasm, for inducing extracellular freezing and/or for accommodating ice crystals in specific tissues. To understand its nature, it is necessary to characterize the ice nucleation activity (INA), defined as the ability of a tissue to induce heterogeneous ice nucleation. Few studies have addressed the precise localization of INA in wintering plant tissues in respect of its function. For this purpose, we recently revised a test tube INA assay and examined INA in various tissues of over 600 species. Extremely high levels of INA (-1 to -4 °C) in two wintering blueberry cultivars of contrasting freezing tolerance were found. Their INA was much greater than in other cold-hardy species and was found to be evenly distributed along the stems of the current year's growth. Concentrations of active ice nuclei in the stem were estimated from quantitative analyses. Stem INA was localized mainly in the bark while the xylem and pith had much lower INA. Bark INA was located mostly in the cell wall fraction (cell walls and intercellular structural components). Intracellular fractions had much less INA. Some cultivar differences were identified. The results corresponded closely with the intrinsic freezing behaviour (extracellular freezing) of the bark, icicle accumulation in the bark and initial ice nucleation in the stem under dry surface conditions. Stem INA was resistant to various antimicrobial treatments. These properties and specific localization imply that high INA in blueberry stems is of intrinsic origin and contributes to the spontaneous initiation of freezing in extracellular spaces of the bark by acting as a subfreezing temperature sensor. Published by Oxford University Press on behalf of the Annals of Botany Company.

  20. Results of detailed ground geophysical surveys for locating and differentiating waste structures in waste management area 'A' at Chalk River Laboratories, Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Tomsons, D.K.; Street, P.J.; Lodha, G.S

    1999-07-01

    Waste Management Area 'A' (WMA 'A'), located in the outer area of the Chalk River Laboratories (CRL) was in use as a waste burial site from 1946 to 1955. Waste management structures include debris-filled trenches, concrete bunkers and miscellaneous contaminated solid materials, and ditches and pits used for liquid dispersal. In order to update historical records, it was proposed to conduct detailed ground geophysical surveys to define the locations of waste management structures in WMA 'A', assist in planning of the drilling and sampling program to provide ground truth for the geophysics investigation and to predict the nature and locations of unknown/undefined shallow structures. A detailed ground geophysical survey grid was established with a total of 127 grid lines, oriented NNE and spaced one metre apart. The geophysical surveys were carried out during August and September, 1996. The combination of geophysical tools used included the Geonics EM61 metal detector, the GSM-19 magnetometer/gradiometer and a RAMAC high frequency ground penetrating radar system. The geophysical surveys were successful in identifying waste management structures and in characterizing to some extent, the composition of the waste. The geophysical surveys are able to determine the presence of most of the known waste management structures, especially in the western and central portions of the grid which contain the majority of the metallic waste. The eastern portion of the grid has a completely different geophysical character. While historical records show that trenches were dug, they are far less evident in the geophysical record. There is clear evidence for a trench running between lines 30E and 63E at 70 m. There are indications from the radar survey of other trench-like structures in the eastern portion. EM61 data clearly show that there is far less metallic debris in the eastern portion. The geophysical surveys were also successful in identifying

  1. Impact of Biofuel Poplar Cultivation on Ground-Level Ozone and Premature Human Mortality Depends on Cultivar Selection and Planting Location.

    Science.gov (United States)

    Ashworth, Kirsti; Wild, Oliver; Eller, Allyson S D; Hewitt, C Nick

    2015-07-21

    Isoprene and other volatile organic compounds emitted from vegetation play a key role in governing the formation of ground-level ozone. Emission rates of such compounds depend critically on the plant species. The cultivation of biofuel feedstocks will contribute to future land use change, altering the distribution of plant species and hence the magnitude and distribution of emissions. Here we use relationships between biomass yield and isoprene emissions derived from experimental data for 29 commercially available poplar hybrids to assess the impact that the large-scale cultivation of poplar for use as a biofuel feedstock will have on air quality, specifically ground-level ozone concentrations, in Europe. We show that the increases in ground-level ozone across Europe will increase the number of premature deaths attributable to ozone pollution each year by up to 6%. Substantial crop losses (up to ∼9 Mt y(-1) of wheat and maize) are also projected. We further demonstrate that these impacts are strongly dependent on the location of the poplar plantations, due to the prevailing meteorology, the population density, and the dominant crop type of the region. Our findings indicate the need for a concerted and centralized decision-making process that considers all aspects of future land use change in Europe, and not just the effect on greenhouse gas emissions.

  2. The Location Method of Battlefield Targets Based on Ground Sensors%基于地面传感器的战场目标定位方法

    Institute of Scientific and Technical Information of China (English)

    鲍硕; 徐万里

    2016-01-01

    精确的网络节点定位是无线传感器网络各种应用和展开部署时自组网及网络管理的首要和基础条件,这就要求有很高的定位精度。战场侦察地面传感器系统中,大多使用声/震传感器结合时差定位法对地面目标进行定位,但其在近点定位效果较差,且若需在远点的测距精度达米级时,要求测时精度达纳秒级。无源红外传感器通过感知IR强度变化和方向对目标进行运动方向和数量的判别,它的测向误差在毫弧度级,理论上可采用多重采样相关定位法建立仿真模型,结果表明:基于红外传感器的地面目标定位算法对地面战场目标定位切实可行且定位精度较高。%Accurate network node localization is the most important and basic condition for the application and deployment of wireless sensor networks, which is the first and the basic condition of the network and the network management. Battlefield re-connaissance ground sensor system and are mainly used for acoustic/seismic sensors combined with TDOA location method to locate targets on the ground, but the in the near point positioning effect is poor, and if you need to in far ranging accuracy Damien level, measurement accuracy of Dana seconds level. Passive infrared sensor through perception about changes in the IR intensity and direction of target for discrimination of the direction and amount of the movement, the direction finding error in mrad level and theory using multiple sampling positioning method, the simulation model is established. The results show that:Based on infrared sensor ground target localization algorithm of ground battlefield target location is feasible and high positioning accuracy.

  3. Electrical Resistivity Tomography and Ground Penetrating Radar for locating buried petrified wood sites: a case study in the natural monument of the Petrified Forest of Evros, Greece

    Science.gov (United States)

    Vargemezis, George; Diamanti, Nectaria; Tsourlos, Panagiotis; Fikos, Ilias

    2014-05-01

    A geophysical survey was carried out in the Petrified Forest of Evros, the northernmost regional unit of Greece. This collection of petrified wood has an age of approximately 35 million years and it is the oldest in Greece (i.e., older than the well-known Petrified Forest of Lesvos island located in the North Aegean Sea and which is possibly the largest of the petrified forests worldwide). Protection, development and maintenance projects still need to be carried out at the area despite all fears regarding the forest's fate since many petrified logs remain exposed both in weather conditions - leading to erosion - and to the public. This survey was conducted as part of a more extensive framework regarding the development and protection of this natural monument. Geophysical surveying has been chosen as a non-destructive investigation method since the area of application is both a natural ecosystem and part of cultural heritage. Along with electrical resistivity tomography (ERT), ground penetrating radar (GPR) surveys have been carried out for investigating possible locations of buried fossilized tree trunks. The geoelectrical sections derived from ERT data in combination with the GPR profiles provided a broad view of the subsurface. Two and three dimensional subsurface geophysical images of the surveyed area have been constructed, pointing out probable locations of petrified logs. Regarding ERT, petrified trunks have been detected as high resistive bodies, while lower resistivity values were more related to the surrounding geological materials. GPR surveying has also indicated buried petrified log locations. As these two geophysical methods are affected in different ways by the subsurface conditions, the combined use of both techniques enhanced our ability to produce more reliable interpretations of the subsurface. After the completion of the geophysical investigations of this first stage, petrified trunks were revealed after a subsequent excavation at indicated

  4. Fine-scale delineation of the location of and relative ground shaking within the San Andreas Fault zone at San Andreas Lake, San Mateo County, California

    Science.gov (United States)

    Catchings, R.D.; Rymer, M.J.; Goldman, M.R.; Prentice, C.S.; Sickler, R.R.

    2013-01-01

    The San Francisco Public Utilities Commission is seismically retrofitting the water delivery system at San Andreas Lake, San Mateo County, California, where the reservoir intake system crosses the San Andreas Fault (SAF). The near-surface fault location and geometry are important considerations in the retrofit effort. Because the SAF trends through highly distorted Franciscan mélange and beneath much of the reservoir, the exact trace of the 1906 surface rupture is difficult to determine from surface mapping at San Andreas Lake. Based on surface mapping, it also is unclear if there are additional fault splays that extend northeast or southwest of the main surface rupture. To better understand the fault structure at San Andreas Lake, the U.S. Geological Survey acquired a series of seismic imaging profiles across the SAF at San Andreas Lake in 2008, 2009, and 2011, when the lake level was near historical lows and the surface traces of the SAF were exposed for the first time in decades. We used multiple seismic methods to locate the main 1906 rupture zone and fault splays within about 100 meters northeast of the main rupture zone. Our seismic observations are internally consistent, and our seismic indicators of faulting generally correlate with fault locations inferred from surface mapping. We also tested the accuracy of our seismic methods by comparing our seismically located faults with surface ruptures mapped by Schussler (1906) immediately after the April 18, 1906 San Francisco earthquake of approximate magnitude 7.9; our seismically determined fault locations were highly accurate. Near the reservoir intake facility at San Andreas Lake, our seismic data indicate the main 1906 surface rupture zone consists of at least three near-surface fault traces. Movement on multiple fault traces can have appreciable engineering significance because, unlike movement on a single strike-slip fault trace, differential movement on multiple fault traces may exert compressive and

  5. Low Temperature Affects Stem Cell Maintenance in Brassica oleracea Seedlings

    NARCIS (Netherlands)

    Jonge, de Jennifer; Kodde, Jan; Severing, Edouard I.; Bonnema, Guusje; Angenent, Gerco C.; Immink, Richard G.H.; Groot, Steven P.C.

    2016-01-01

    Most of the above ground tissues in higher plants originate from stem cells located in the shoot apical meristem (SAM). Several plant species can suffer from spontaneous stem cell arrest resulting in lack of further shoot development. In Brassica oleracea this SAM arrest is known as blindness and oc

  6. Ground control point locations associated with images collected during unmanned aerial systems (UAS) flights over Coast Guard Beach, Nauset Spit, Nauset Inlet, and Nauset Marsh, Cape Cod National Seashore, Eastham, Massachusetts on 1 March 2016 (Text file and photos)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset documents the locations of ground control points associated with images obtained from unmanned aerial systems (UAS) flown in the Cape Cod National...

  7. Ground control point locations associated with images collected during unmanned aerial systems (UAS) flights over Coast Guard Beach, Nauset Spit, Nauset Inlet, and Nauset Marsh, Cape Cod National Seashore, Eastham, Massachusetts on 1 March 2016 (Text file and photos)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset documents the locations of ground control points associated with images obtained from unmanned aerial systems (UAS) flown in the Cape Cod National...

  8. Search for an artificially buried karst cave entrance using ground penetrating radar: a successful case of locating the S-19 Cave in the Mt. Kanin massif (NW Slovenia

    Directory of Open Access Journals (Sweden)

    Andrej Gosar

    2016-05-01

    Full Text Available The S-19 Cave was with its explored depth of 177 m one of the most important caves of the Mt. Kanin massif, but after its discovery in 1974, a huge snow avalanche protection dyke was constructed across the cave entrance. To excavate the buried cave, the accurate location of the cave had to be determined first. Since the entrance coordinates were incorrect and no markers were available, application of geophysical techniques was necessary to do this. A Ground Penetrating Radar (GPR with special 50 MHz rough terrain antennas was selected as the single suitable geophysical method for the given conditions where thick debris overlay a rugged limestone surface. Nevertheless, it was not possible to directly detect the relatively narrow cave entrance itself due to data resolution limits. However, a historical photo of the area showed that the cave entrance was located in a local depression, which therefore represented the main target of the GPR survey. Seven GPR profiles were measured across the rough and steep surface causing difficulties in traversing the area with sensitive research equipment. In all recorded radargrams a small depression was clearly imaged under debris, and recognized as a topographic feature with the cave entrance. Based on the GPR data interpretation, the exact location for digging was determined and the thickness of debris assessed at 6.5–7 m. A massive excavation by a dredger resulted in a successful opening of the cave entrance, confirming both its geophysically determined location and its estimated depth. The application of an advanced geophysical method was therefore proven successful in providing a solution to this specific case in karst exploration and an important cave was saved.

  9. Properties of Arboreal Ant and Ground-Termite Nests in relation to Their Nesting Sites and Location in a Tropical-Derived Savanna

    Directory of Open Access Journals (Sweden)

    B. C. Echezona

    2012-01-01

    Full Text Available Ecosystem engineers such as ants and termites play an important role in the fertility of tropical soils. Physicochemical analyses were thus carried out on some arboreal ant nests collected from mango (Mangifera indica, bush mango (Irvingia gabonensis, kola (Cola nitida, newbouldia plant (Newbouldia laevis, and oil bean plant (Pentaclethra macrophylla and on ground nest of termite, Odontotermes sudanensis Sjost. (Isoptera: Termitidae in Nigeria. Arboreal nests, particularly those of M. indica, were significantly richer in the chemical constituents sampled, compared to those of ground-termite nests or adjacent unaffected soils. Available water capacity of nests from M. indica (60.0% was significantly higher than those of other sites or locations sampled. While biogenic structures were sandy-loamy in texture, their corresponding adjacent soils were either sandy or sandy-loamy. Soils worked by ants and termites had greater proportions of silt-sized (17.9 versus 9.7 and clay-sized (19.2 versus 9.3 to the detriment of coarse-sized particles (51.2 versus 60.9 and fine-sand-sized particles (11.7 versus 20.1 relative to the adjacent soils. Generally, biogenic structures were about 348% richer in P than their corresponding adjacent soils; an attribute, which holds a strong promise in bioremediation and biofortification of soils especially during amendment.

  10. 星地光通信的天气可用性与地面站选址研究%Satellite-to-ground optical communication's usability with different weathers and ground station location

    Institute of Scientific and Technical Information of China (English)

    姜晓峰; 赵尚弘; 李勇军; 王翔; 李瑞欣

    2012-01-01

    The attenuation of satellite-to-ground optical link in fog, rain, snow and cloud is calculated with empirical formulas. The result of simulation shows the longer the length of the light wave, the smaller the attenuation of the laser in the fog; the attenuation in the snow is 10 -100 times higher than that in the rain; when the optical depth of cloud is 4. 7, the laser attenuation is higher than 20 dB. Considering the geographic distribution, meteorological features and cloud cover statistics, it is suggested that the Tarim basin, the desert of western Inner Mongolia and the northwestern part of Loess Plateau in northwest of China should be favorable for satellite-to-ground optical communication ground station location.%利用经验公式计算了星地光链路在雾、雨、雪、云天气中的衰减,仿真结果表明:波长越长,雾对激光的衰减越小;雪对激光的衰减量高于雨对激光衰减量1~2个数量级;当光学厚度达到4.7时,云层对激光的衰减已达到20 dB以上.综合考虑我国的地理分布和气候特点以及云层覆盖情况,建议我国星地光通信地面站选址可以考虑西北地区的塔里木盆地-内蒙古西部戈壁沙漠-黄土高原西北部一带.

  11. Therapeutic Effect and Location of GFP-Labeled Placental Mesenchymal Stem Cells on Hepatic Fibrosis in Rats

    Directory of Open Access Journals (Sweden)

    Jiong Yu

    2017-01-01

    Full Text Available Background. Liver fibrosis is a chronic progressive liver disease, but no established effective treatment exists except for liver transplantation. The present study was designed to investigate the effect of human placenta mesenchymal stem cells (hPMSCs expressing green fluorescent protein (GFP on carbon tetrachloride- (CCl4- induced liver fibrosis in rats. Methods. Liver fibrosis was induced by subcutaneous injection with CCl4; hPMSCs were directly transplanted into rats through the caudal vein. The therapeutic efficacy of hPMSCs on liver fibrosis was measured by liver function tests, liver elastography, histopathology, Masson’s trichrome and Sirius red staining, and immunohistochemical studies. The expression levels of fibrotic markers, transforming growth factor β1 (TGF-β1 and α-smooth muscle actin (α-SMA, were assessed using real-time polymerase chain reaction. Results. We demonstrated that liver fibrosis was significantly dampened in the hPMSC transplantation group according to the Laennec fibrosis scoring system and histological data. The Sirius red-stained collagen area and the elastography score were significantly reduced in the hPMSC-treated group. Meanwhile, hPMSC administration significantly decreased TGF-β1 and α-SMA expression and enhanced liver functions in CCl4-induced fibrotic rats. Conclusion. This study indicates that transplantation of hPMSCs could repair liver fibrosis induced by CCl4 in rats, which may serve as a valuable therapeutic approach to treat liver diseases.

  12. Location of Caspase 3-like Protease in the Development of Sieve Element and Tracheary Element of Stem in Cucurbita moschata

    Institute of Scientific and Technical Information of China (English)

    Xia Hao; Jie Qian; Shan Xu; Xin Song; Jian Zhu

    2008-01-01

    The casepase is considered to regulate the process of programmed cell death in the development of organisms. In this study, caspase 3-like protease was detected by immunohistochemistry and immunoelectron microscopy during the development of sieve element and tracheary element of stem in Cucurbita moschata Duch. Antibody with brown color (under light microscopy) and gold particles (under transmission electron microscopy) for detecting caspase 3-like protease was mainly displayed in inner phloem, extemal phloem and xylem in the region close to procambium. From the results it was considered that caspase 3-like protease did exist in vascular elements and played different roles during the development of sieve and tracheary elements, and different types of programmed cell death might be carried out. The caspase 3-like protease mainly participated in making cytoplasmic streaming cease and in degrading P-protein bodies; however, it rarely participated in the function for signal transferring in the developmental sieve element. However, it might induce calcium accumulation for rupturing the tonoplast in the signal of PCD in the developmental tracheary element.

  13. Location of caspase 3-like protease in the development of sieve element and tracheary element of stem in Cucurbita moschata.

    Science.gov (United States)

    Hao, Xia; Qian, Jie; Xu, Shan; Song, Xin; Zhu, Jian

    2008-12-01

    The casepase is considered to regulate the process of programmed cell death in the development of organisms. In this study, caspase 3-like protease was detected by immunohistochemistry and immunoelectron microscopy during the development of sieve element and tracheary element of stem in Cucurbita moschata Duch. Antibody with brown color (under light microscopy) and gold particles (under transmission electron microscopy) for detecting caspase 3-like protease was mainly displayed in inner phloem, external phloem and xylem in the region close to procambium. From the results it was considered that caspase 3-like protease did exist in vascular elements and played different roles during the development of sieve and tracheary elements, and different types of programmed cell death might be carried out. The caspase 3-like protease mainly participated in making cytoplasmic streaming cease and in degrading P-protein bodies; however, it rarely participated in the function for signal transferring in the developmental sieve element. However, it might induce calcium accumulation for rupturing the tonoplast in the signal of PCD in the developmental tracheary element.

  14. Determining Earth's magnetic field strength during magnetically quiet and stormy times and predict the location of dancing Auroras using THEMIS Mission Educators ground based magnetometer data.

    Science.gov (United States)

    Craig, N.; Peticolas, L.; Trautman, V.

    2006-12-01

    The Education and Public Outreach program of the THEMIS Mission has deployed 10 ground-based observatories with science-grade magnetometers in schools in the Northern U.S. This network of schools, called Geomagnetic Event Observation Network by Students (GEONS), monitors local magnetic disturbances. The magnetometers are receiving local data; data are archived and available at the THEMIS E/PO Website. The E/PO program conducts teacher professional development workshops for the teachers of these schools. During the third year of the project, teachers from Alaska and Wisconsin started their classroom research using magnetometers that are installed in their classrooms. We will describe how with highly committed and enthusiastic teachers a research project developed to determine the strength of the local magnetic field in locations such as AK and WI and to compare these results with "companion schools" at lower latitudes. The GEONS teachers not only learned science and research tools, but they also conducted workshops in their own states, influenced the science curricula in their districts, and also started student research in their classrooms. We will discuss the challenges, give the results of their research, and encourage other teachers who wish to use real data in their classrooms to participate in this exciting project.

  15. Medicare, Medicaid, and Children's Health Insurance Programs: Announcement of the Extension of Temporary Moratoria on Enrollment of Part B Non-Emergency Ground Ambulance Suppliers and Home Health Agencies in Designated Geographic Locations. Extension of temporary moratoria.

    Science.gov (United States)

    2017-07-28

    This document announces the extension of statewide temporary moratoria on the enrollment of new Medicare Part B non-emergency ground ambulance providers and suppliers and Medicare home health agencies, subunits, and branch locations in Florida, Illinois, Michigan, Texas, Pennsylvania, and New Jersey, as applicable, to prevent and combat fraud, waste, and abuse. This extension also applies to the enrollment of new non-emergency ground ambulance suppliers and home health agencies, subunits, and branch locations in Medicaid and the Children's Health Insurance Program in those states.

  16. Cope and Grow: A Grounded Theory Approach to Early College Entrants' Lived Experiences and Changes in a STEM Program

    Science.gov (United States)

    Dai, David Yun; Steenbergen-Hu, Saiying; Zhou, Yehan

    2015-01-01

    In this grounded theory qualitative study, we interviewed 34 graduates from one cohort of 51 students from a prestigious early college entrance program in China. Based on the interview data, we identified distinct convergent and divergent patterns of lived experiences and changes. We found several dominant themes, including peers' mutual…

  17. Using the IRI, the MAGIC model, and the co-located ground-based GPS receivers to study ionospheric solar eclipse and storm signatures on July 22, 2009

    Science.gov (United States)

    Lin, Chi-Yen; Liu, Jann-Yenq; Lin, Chien-Hung; Sun, Yang-Yi; Araujo-Pradere, Eduardo A.; Kakinami, Yoshihiro

    2012-06-01

    The longest total solar eclipse in the 21st century occurred in Southeast Asia on 22 July 2009 from 00:55 to 04:15 UT, and was accompanied by a moderate magnetic storm starting at 03:00 UT with a D st reduction of -78 nT at 07:00 UT. In this study, we use the ionospheric reference model IRI, the data assimilation model MAGIC, and ground-based GPS receivers to simulate and examine the ionospheric solar eclipse and geomagnetic storm signatures in Taiwan and Japan. Cross-comparisons between the two model results and observations show that IRI fails to simulate the two signatures while MAGIC partially reproduces the storm features. It is essential to include ground-based GPS measurements to improve the IRI performance.

  18. The impact of biofuel poplar cultivation on ground-level ozone and premature human mortality depends on cultivar selection and planting location

    OpenAIRE

    Ashworth, Kirsti; Wild, Oliver; Eller, A. S. D.; Hewitt, C.N.

    2015-01-01

    Isoprene and other volatile organic compounds emitted from vegetation play a key role in governing the formation of ground-level ozone. Emission rates of such compounds depend critically on the plant species. Future land use change, driven by the cultivation of biofuel feedstocks, will change the distribution of plant species and hence the magnitude and distribution of emissions. Here we use relationships between biomass yield and isoprene emissions derived from experimental data for 29 comme...

  19. Locations, values, and uncertainties of hydraulic-head observations for the steady-state, prepumped period of the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital geospatial data set contains the locations, values, and uncertainties of 700 hydraulic-head observations used in the steady-state, prepumped period of...

  20. Analytical study on aseismic base isolation in new offshore location. For practical location for thermal power plants by soft-landing artificial ground construction method; Atarashii kaijo ricchi ni okeru menshinsei ni kansuru kaisekiteki kento. Nanchaku jinko jiban koho ni yoru karyoku hatsuden setsubi ricchi jitsuyoka ni mukete

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, T.; Sakakibara, T. [Tokyo Electric Power Co. Inc., Tokyo (Japan); Ishikawa, M. [Nikken Sekkei Ltd., Osaka (Japan)

    1996-09-05

    Assuming offshore location of thermal power plants by soft-landing artificial ground construction method, its effect on uneven settlement of facility unit group and its seismic behavior were studied. In soft-landing artificial ground, the total weight and buoyancy of a caisson body with interior space are balanced by controlling water level in a tank to reduce landing pressure. Artificial ground resists lateral seismic external force by friction with submarine bedrock. Settlement analysis and seismic behavior analysis were conducted by 2-D FEM. As a result, bottom RC honeycomb structure was sufficient to resist uneven settlement during construction even under fixed junction condition between units. In soft-landing artificial ground, the maximum acceleration was reduced to nearly 70% by aseismic base isolation as compared with conventional methods. In addition, its sliding manner in earthquake was different from that of rigid bodies, and the maximum stress acceleration transmitted to the bottom of artificial ground changed even under the same waveform. 4 refs., 13 figs., 4 tabs.

  1. Use of the BINP HLS to measure vertical changes in the locations of the building and ground at the PAL-XFEL

    Science.gov (United States)

    Choi, Hyo-Jin; Seo, Kwang-Won; Gil, Kye-Hwan; Kim, Seung-Hwan; Kang, Heung-Sik

    2016-09-01

    The Pohang Accelerator Laboratory's X-ray free-electron laser (PAL-XFEL), a 4 th generation light source, is currently being installed and will be completed by December 2015 so that users can be supported beginning in 2016. The PAL-XFEL equipment must continuously maintain the bunch-tobunch beam parameters (60 Hz, Energy: 10 GeV, Charge: 200 pC, Bunch Length: 60 fs, Emittance X/Y: 0.481/0.256 mm rad) in order to supply stable photons with the energy and flux appropriate for tests by beamline users. To this end, the PAL-XFEL equipment has to be kept precisely aligned (Linear Accelerator: +/- 100 μm, Undulator: +/- 50 μm). As a part of the process for installing the PAL-XFEL, a GPS-using surface geodetic network is being constructed for precise equipment measurement and alignment, and the installation of a tunnel measurement network inside the buildings is in the preparation stage; additionally, the fiducialization of major equipment is underway. After the PAL-XFEL equipment is optimized and aligned, if the ground and the buildings go through vertical changes during operation, misalignment (and tilt) of the equipment, including various magnets and RF structures, will cause errors in the electron beam's trajectory, which will lead to changes to the beam parameters. For continuous and systemic measurement of vertical changes in the buildings and monitoring of ground sinking and uplifting, the Budker Institute of Nuclear Physics (BINP) Ultrasonic-type Hydrostatic Levelling System (HLS) is to be installed and operated in all sections of the PAL-XFEL for the linear accelerator, the insertion device (undulator) and the beamline. This study will introduce the operation principle, design concept, and advantages (self-calibration) of the HLS and will outline its installation plan and operation plan.

  2. Collection, processing, and interpretation of ground-penetrating radar data to determine sediment thickness at selected locations in Deep Creek Lake, Garrett County, Maryland, 2007

    Science.gov (United States)

    Banks, William S.L.; Johnson, Carole D.

    2011-01-01

    The U.S. Geological Survey collected geophysical data in Deep Creek Lake in Garrett County, Maryland, between September 17 through October 4, 2007 to assist the Maryland Department of Natural Resources to better manage resources of the Lake. The objectives of the geophysical surveys were to provide estimates of sediment thickness in shallow areas around the Lake and to test the usefulness of three geophysical methods in this setting. Ground-penetrating radar (GPR), continuous seismic-reflection profiling (CSP), and continuous resistivity profiling (CRP) were attempted. Nearly 90 miles of GPR radar data and over 70 miles of CSP data were collected throughout the study area. During field deployment and testing, CRP was determined not to be practical and was not used on a large scale. Sediment accumulation generally could be observed in the radar profiles in the shallow coves. In some seismic profiles, a thin layer of sediment could be observed at the water bottom. The radar profiles appeared to be better than the seismic profiles for the determination of sediment thickness. Although only selected data profiles were processed, all data were archived for future interpretation.

  3. Estimation of shortwave direct aerosol radiative forcing at four locations on the Indo-Gangetic plains: Model results and ground measurement

    Science.gov (United States)

    Bibi, Humera; Alam, Khan; Bibi, Samina

    2017-08-01

    This study provides observational results of aerosol optical and radiative characteristics over four locations in IGP. Spectral variation of Aerosol Optical Depth (AOD), Single Scattering Albedo (SSA) and Asymmetry Parameter (AP) were analysed using AErosol RObotic NETwork (AERONET) data. The analysis revealed that coarse particles were dominant in summer and pre-monsoon, while fine particles were more pronounced in winter and post-monsoon. Furthermore, the spatio-temporal variations of Shortwave Direct Aerosol Radiative Forcing (SDARF) and Shortwave Direct Aerosol Radiative Forcing Efficiency (SDARFE) at the Top Of Atmosphere (TOA), SURface (SUR) and within ATMosphere (ATM) were calculated using SBDART model. The atmospheric Heating Rate (HR) associated with SDARFATM were also computed. It was observed that the monthly averaged SDARFTOA and SDARFSUR were found to be negative leading to positive SDARFATM during all the months over all sites. The increments in net atmospheric forcing lead to maximum HR in November-December and May. The seasonal analysis of SDARF revealed that SDARFTOA and SDARFSUR were negative during all seasons. The SW atmospheric absorption translates to highest atmospheric HR during summer over Karachi and during pre-monsoon over Lahore, Jaipur and Kanpur. Like SDARF, the monthly and seasonal variations of SDARFETOA and SDARFESUR were found to be negative, resulting in positive atmospheric forcing. Additionally, to compare the model estimated forcing against AERONET derived forcing, the regression analysis of AERONET-SBDART forcing were carried out. It was observed that SDARF at SUR and TOA showed relatively higher correlation over Lahore, moderate over Jaipur and Kanpur and lower over Karachi. Finally, the analysis of National Oceanic and Atmospheric Administration Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model revealed that air masses were arriving from multiple source locations.

  4. Atmospheric aerosol radiative forcing over a semi-continental location Tripura in North-East India: Model results and ground observations.

    Science.gov (United States)

    Dhar, Pranab; De, Barin Kumar; Banik, Trisanu; Gogoi, Mukunda M; Babu, S Suresh; Guha, Anirban

    2017-02-15

    Northeast India (NEI) is located within the boundary of the great Himalayas in the north and the Bay of Bengal (BoB) in the southwest, experiences the mixed influence of the westerly dust advection from the Indian desert, anthropogenic aerosols from the highly polluted Indo-Gangetic Plains (IGP) and marine aerosols from BoB. The present study deals with the estimation and characterization of aerosol radiative forcing over a semi-continental site Tripura, which is a strategic location in the western part of NEI having close proximity to the outflow of the IGP. Continuous long term measurements of aerosol black carbon (BC) mass concentrations and columnar aerosol optical depth (AOD) are used for the estimation of aerosol radiative forcing in each monthly time scale. The study revealed that the surface forcing due to aerosols was higher during both winter and pre-monsoon seasons, having comparable values of 32W/m(2) and 33.45W/m(2) respectively. The atmospheric forcing was also higher during these months due to increased columnar aerosol loadings (higher AOD ~0.71) shared by abundant BC concentrations (SSA ~0.7); while atmospheric forcing decreased in monsoon due to reduced magnitude of BC (SSA ~0.94 in July) as well as columnar AOD. The top of the atmosphere (TOA) forcing is positive in pre-monsoon and monsoon months with the highest positive value of 3.78W/m(2) in June 2012. The results are discussed in light of seasonal source impact and transport pathways from adjacent regions.

  5. Location-specific effect of microbiota and MyD88-dependent signaling on Wnt/β-catenin pathway and intestinal stem cells

    OpenAIRE

    Moossavi, Shirin

    2013-01-01

    Intestinal homeostasis depends on the proper activity of the intestinal stem cells (ISCs) and an appropriate host response to the normal resident microbiota. The question on the effect of microbiota on ISCs behavior has not been addressed yet. Canonical Wnt pathway and ISC gene expression signature was compared in germfree vs. conventional and MyD88−/− vs. Myd88+/+ mice based on publicly available gene expression data sets. Microbiota and MyD88-dependent signaling have distinct effects on the...

  6. Location-specific effect of microbiota and MyD88-dependent signaling on Wnt/β-catenin pathway and intestinal stem cells.

    Science.gov (United States)

    Moossavi, Shirin

    2014-01-01

    Intestinal homeostasis depends on the proper activity of the intestinal stem cells (ISCs) and an appropriate host response to the normal resident microbiota. The question on the effect of microbiota on ISCs behavior has not been addressed yet. Canonical Wnt pathway and ISC gene expression signature was compared in germfree vs. conventional and MyD88(-/-) vs. Myd88(+/+) mice based on publicly available gene expression data sets. Microbiota and MyD88-dependent signaling have distinct effects on the Wnt pathway and ISC at gene expression level. In addition, the effect of microbiota and MyD88-dependent signaling on Wnt pathway and ISCs show regional variation. The net effect of microbiota on Wnt pathway and ISCs cannot be inferred from the available data. Nonetheless, the data are suggestive of a potential regulatory mechanism of the Wnt pathway by the microbiota and plausibly by any alteration in the microbiota composition.

  7. Method Study Based on Ground Line Current Division Achieve Grounding Fault Location of DC Transmission Lines%基于地线分流实现直流输电线路接地故障区段定位的方法

    Institute of Scientific and Technical Information of China (English)

    王法; 曾东; 许金明; 张勇

    2012-01-01

    本文针对直流输电线路地线与杆塔非绝缘连接的特点,分析线路发生不同类型的接地故障时在各杆塔某一根地线上的故障电流分流特征。通过采集输电线路地线上故障电流的方向实现故障定位,从而为故障情况下不同的输电线路运维单位辅助决策服务。%In this article, according to DC transmission lines are non-isolated connected with tower, when different types of ground fault occur,we analyze the characteristics of fault current division through ground line of different towders. By collecting the direction of fault current in the ground line to achieve fault location. As a result, it supports decision service for the units of operation and maintenance of transmission lines when faults accur.

  8. Location Privacy

    Science.gov (United States)

    Meng, Xiaofeng; Chen, Jidong

    With rapid development of sensor and wireless mobile devices, it is easy to access mobile users' location information anytime and anywhere. On one hand, LBS is becoming more and more valuable and important. On the other hand, location privacy issues raised by such applications have also gained more attention. However, due to the specificity of location information, traditional privacy-preserving techniques in data publishing cannot be used. In this chapter, we will introduce location privacy, and analyze the challenges of location privacy-preserving, and give a survey of existing work including the system architecture, location anonymity and query processing.

  9. Stem Cells

    Science.gov (United States)

    Stem cells are cells with the potential to develop into many different types of cells in the body. ... the body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

  10. Epiblast ground state is controlled by canonical Wnt/β-catenin signaling in the postimplantation mouse embryo and epiblast stem cells.

    Directory of Open Access Journals (Sweden)

    Tomoyuki Sumi

    Full Text Available Epiblast stem cells (EpiSCs are primed pluripotent stem cells and can be derived from postimplantation mouse embryos. We now show that the absence of canonical Wnt/β-catenin signaling is essential for maintenance of the undifferentiated state in mouse EpiSCs and in the epiblast of mouse embryos. Attenuation of Wnt signaling with the small-molecule inhibitor XAV939 or deletion of the β-catenin gene blocked spontaneous differentiation of EpiSCs toward mesoderm and enhanced the expression of pluripotency factor genes, allowing propagation of EpiSCs as a homogeneous population. EpiSCs were efficiently established and propagated from single epiblast cells in the presence of both XAV939 and the Rho kinase (ROCK inhibitor Y27632. Cell transplantation revealed that EpiSCs were able to contribute to primordial germ cells and descendants of all three germ layers in a host embryo, suggesting that they maintained pluripotency, even after prolonged culture with XAV939. Such an improvement in the homogeneity of pluripotency achieved with the use of a Wnt inhibitor should prove advantageous for manipulation of primed pluripotent stem cells.

  11. Library Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Carnegie Library of Pittsburgh locations including address, coordinates, phone number, square footage, and standard operating hours.

  12. The Use of Grounded Theory to Investigate the Role of Teacher Education on STEM Teachers' Career Paths in High-Need Schools

    Science.gov (United States)

    Kirchhoff, Allison; Lawrenz, Frances

    2011-01-01

    An inductive grounded theory approach was used to investigate the role of teacher education on the career paths of 38 Noyce scholarship recipients ("scholars"), most of whom were teaching in high-need schools. The emergent research design was guided by the initial research question: "What are Noyce scholars' reasons for the decisions made on the…

  13. Synchronous Measurement Based Transient High Resistance Earth Fault Location in Resonant Grounding System%基于同步量测的谐振接地系统高阻接地故障区段暂态定位

    Institute of Scientific and Technical Information of China (English)

    陈筱薷; 薛永端; 王超; 徐丙垠; 黄仁乐; 程林

    2016-01-01

    谐振接地系统高阻接地故障发生概率较大,检测难度高,现有暂态分析及暂态区段定位方法不适合用于高阻接地故障。利用消弧线圈与系统对地电容间并联谐振的独特作用,分析了谐振接地系统高阻接地故障暂态零序电流与暂态零序电压的变化规律。研究发现,故障点下游各检测点暂态电流与暂态电压近似正交,而故障点上游检测点暂态电流还包含了与暂态电压成正比例的故障点暂态电流。利用同步量测单元采集的故障信息,计算各检测点暂态电流在暂态电压上的投影,若相邻检测点暂态电流投影分量之差超过一预设门槛,则该区段为故障区段,否则最末检测点下游区段为故障区段。所述方法完善了小电流接地故障暂态分析与暂态区段定位技术,数字仿真验证了该方法的可行性。%High resistant earth fault occurs frequently in resonant grounding systems,and is difficult to detect.The existing transient analysis and transient faulty section location method is not suitable for high resistance earth fault.The unique role of parallel resonance between Peterson coil and system capacitance to ground is used.The variation laws of zero-sequence current, zero-sequence voltage and their transient components are analyzed in under-damping and over-damping resonant processes.The facts can be observed in this study that the transient currents of downstream fault points of detecting point are approximately orthogonal to the transient zero-sequence voltage,and the transient currents of upstream fault points of detecting point include transient current at the fault point proportional to the magnitude of the transient voltage.The fault information collected by the synchronous measurement unit is used to calculate the proj ection components of transient current on transient voltage in every detecting point.If the difference in current proj ection magnitudes between

  14. Burial Ground Expansion Hydrogeologic Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Gaughan , T.F.

    1999-02-26

    Sirrine Environmental Consultants provided technical oversight of the installation of eighteen groundwater monitoring wells and six exploratory borings around the location of the Burial Ground Expansion.

  15. Estimation of whole-tree and stand-level methane emissions from the stems of Alnus japonica in a cool-temperate forested peatland

    Science.gov (United States)

    Terazawa, Kazuhiko; Yamada, Kenji; Sakata, Tadashi; Nakamura, Takatoshi; Ishizuka, Shigehiro

    2016-04-01

    We measured methane (CH4) fluxes at the stem surfaces of canopy trees in a forested peatland of northern Japan to estimate: 1) the CH4 emission rates from the stems of individual trees and 2) the stem CH4 emission rates at the stand level. The study site was located ca. 1 km south of Lake Tofutsu, a brackish lake in eastern Hokkaido. An experimental plot was established in an area dominated by Alnus japonica trees. For seven A. japonica, the stem CH4 fluxes were measured using a static closed-chamber method. Three of the sample trees were used to estimate the whole-tree stem CH4 emissions. The CH4 flux was measured at six heights (0.15 - 5.15 m above the ground at 1 m intervals) on the stem of each tree, using a scaffold constructed beside the tree. The stand-level stem CH4 emissions were estimated from the CH4 fluxes measured 0.15 m above the ground; the relationship between stem height and CH4 flux and the relationship between diameter at breast height and whole-tree CH4 emissions were determined. Stem CH4 emission rates were highest at the lowest measurement position on the stem (height 0.15 m), and decreased with stem height for all measurements. Nevertheless, significant CH4 emissions were detected 5.15 m above the ground. The relationship between stem height and CH4 emissions fit a power function. The estimated CH4 emission rate from the stem surface of an individual tree was 1.91 ± 1.24 and 0.68 ± 0.18 mg tree-1 h-1 for late-August and mid-September, respectively. The estimated stem CH4 emissions at the stand level varied seasonally, with the highest rate of 556 mg ha-1 h-1 in September.

  16. The origin of the ie endingless locative

    Directory of Open Access Journals (Sweden)

    Kenneth Shields

    1979-12-01

    Full Text Available In this paper is presented a new hypothesis regarding the development of the so-called "endingless locative" construction of Indo-European. It is argued that locative formations in -ē, and * ī came to appear in the , o-stem nouns through the monophthongization of word-final *-oi and *-ei before word-initial consonants. These formations were analogically extended to the other stem-classes, with the suffix*-ē, frequently hypercharacterized by the locative particles *-i or *-u, becoming the primary marker of the locative function in the i- and u-stems. On the basis of such apparently "endingless" locative constructions, old consonant-stem nominative (-accusative formations in were reinterpreted as locatives as well.

  17. Remedial Action Plan and Site Design for Stabilization of the Inactive Uranium Mill Tailings Site, Maybell, Colorado. Appendixes to Attachment 3: Appendix A, Hydrological services calculations: Appendix B, Ground water quality by location, Final report

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    This report contains chemical analysis data for ground water for the following: elements; cyanides; chlorides; dissolved organic carbon; fluorides; silica; sulfates; sulfides; dissolved solids; nitrates; and nitrites.

  18. Wnt-responsive cancer stem cells are located close to distorted blood vessels and not in hypoxic regions in a p53-null mouse model of human breast cancer.

    Science.gov (United States)

    Vadakkan, Tegy J; Landua, John D; Bu, Wen; Wei, Wei; Li, Fuhai; Wong, Stephen T C; Dickinson, Mary E; Rosen, Jeffrey M; Lewis, Michael T; Zhang, Mei

    2014-07-01

    Cancer stem cells (CSCs, or tumor-initiating cells) may be responsible for tumor formation in many types of cancer, including breast cancer. Using high-resolution imaging techniques, we analyzed the relationship between a Wnt-responsive, CSC-enriched population and the tumor vasculature using p53-null mouse mammary tumors transduced with a lentiviral Wnt signaling reporter. Consistent with their localization in the normal mammary gland, Wnt-responsive cells in tumors were enriched in the basal/myoepithelial population and generally located in close proximity to blood vessels. The Wnt-responsive CSCs did not colocalize with the hypoxia-inducible factor 1α-positive cells in these p53-null basal-like tumors. Average vessel diameter and vessel tortuosity were increased in p53-null mouse tumors, as well as in a human tumor xenograft as compared with the normal mammary gland. The combined strategy of monitoring the fluorescently labeled CSCs and vasculature using high-resolution imaging techniques provides a unique opportunity to study the CSC and its surrounding vasculature.

  19. Comparative Analysis of the Cloud-to-ground Lightning Data Between Two Lightning Location Systems%浙江省两套闪电定位系统地闪数据对比

    Institute of Scientific and Technical Information of China (English)

    赵伟; 姜瑜君; 童杭伟; 张斌

    2015-01-01

    Comparative analysis of the lightning location data from 2009 to 2013 is conducted by temporal and spatial distribution and detection efficiency,to explore the difference of data collected from two lightning location systems (LLS)of Zhejiang meteorological department and Zhejiang electric power department. Results show that the inter-annual cloud-to-ground (CG)lightning frequency observed by the LLS of Zhe-jiang meteorological department is stably lower than that observed by the LLS of Zhejiang electric power department.The number of positive CG lightning occupies 3.5% of total CG lightning observed by the LLS of Zhejiang meteorological department,which is also 2% less than that observed by the LLS of Zhe-jiang electric power department,and both of them are in a reasonable interval.From the viewpoint of spa-tial distribution,the CG lightning density of two datasets is nearly equal in coastal plain and the Jinhua-Quzhou Basin,but the CG lightning density obtained by Zhejiang electric power department is stably more than that of Zhejiang meteorological department in the other areas except in Chun’an which is located in the border of Hangzhou and Quzhou.It is also found that the occurrence of high CG lightning density re-gion in Chun’an observed by LLS of Zhejiang meteorological department is abnormal.Further analysis of the number of monthly mean thunderstorm days obtained by these two LLSs and manual observation indi-cates that the monthly mean thunderstorm days observed by the LLS of Zhejiang meteorological depart-ment is not more than that of manual observations except in summer,when the monthly mean thunder-storm days observed by LLS of Zhejiang electric power department is almost more than that of manual ob-servations every month.It suggests that the LLS of Zhejiang meteorological department does well in detec-ting strong thunderstorms while the weaker thunderstorms could be missed.Hence,the LLS detective a-bility of Zhejiang electric power department is

  20. Grounded theory.

    Science.gov (United States)

    Harris, Tina

    2015-04-29

    Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.

  1. Grounded cognition.

    Science.gov (United States)

    Barsalou, Lawrence W

    2008-01-01

    Grounded cognition rejects traditional views that cognition is computation on amodal symbols in a modular system, independent of the brain's modal systems for perception, action, and introspection. Instead, grounded cognition proposes that modal simulations, bodily states, and situated action underlie cognition. Accumulating behavioral and neural evidence supporting this view is reviewed from research on perception, memory, knowledge, language, thought, social cognition, and development. Theories of grounded cognition are also reviewed, as are origins of the area and common misperceptions of it. Theoretical, empirical, and methodological issues are raised whose future treatment is likely to affect the growth and impact of grounded cognition.

  2. Dosimetry of Rn-222 in the air in environments located above and below ground level; Dosimetria de Rn-222 no ar em ambientes localizados acima e abaixo do nivel do solo

    Energy Technology Data Exchange (ETDEWEB)

    Cazula, Camila Dias

    2015-07-01

    Exposure of the general population to ionizing radiation comes mainly from natural sources. The main contribution is due to inhalation of radon (Rn-222), a gas that occurs naturally (UNSCEAR, 2000). The Rn-222 concentration in the environment is controlled by factors such as soil permeability and water content, the weather variability, materials used in the foundation and the usual positive pressure differential between the soil and the internal environment. Studies indicate that the concentration of radon shows a wide variation in the basement, ground floor and upper floors of buildings. The objective of this study is to determine radon levels in basements, ground floor and floors above ground level, at a university in the city of Sao Paulo and in one residential building in the city of Peruibe. Rn-222 measurements were performed using the method with nuclear track of solid state detectors (CR-39). The studied environments present Rn-222 concentration well below the values recommended by the International Commission on Radiological Protection, published in the 2009 document, of 300 Bq/m{sup 3} for homes and 1000 Bq/m{sup 3} for the workplace. In the residential building, the concentration of Ra-266, Th-232 and K-40 in the materials used in the building construction was also analyzed, by gamma spectrometry. The effective total dose for the resident due to external exposure was 0.8 mSv y{sup -1}, lower than the annual dose limit for the general public of 1 mSv y{sup -1}. (author)

  3. Medicare, Medicaid, and Children's Health Insurance Programs: Announcement of the Provider Enrollment Moratoria Access Waiver Demonstration of Part B Non-Emergency Ground Ambulance Suppliers and Home Health Agencies in Moratoria-Designated Geographic Locations. Implementation of the waiver demonstration.

    Science.gov (United States)

    2016-08-03

    This notice announces the Provider Enrollment Moratoria Access Waiver Demonstration of Part B Non-Emergency Ground Ambulance Suppliers and Home Health Agencies in 6 states. The demonstration is being implemented in accordance with section 402 of the Social Security Amendments of 1967 and gives CMS the authority to grant waivers to the statewide enrollment moratoria on a case-by-case basis in response to access to care issues, and to subject providers and suppliers enrolling via such waivers to heightened screening, oversight, and investigations.

  4. Types of Stem Cells

    Science.gov (United States)

    ... Stem Cell Glossary Search Toggle Nav Types of Stem Cells Stem cells are the foundation from which all ... Learn About Stem Cells > Types of Stem Cells Stem cells Stem cells are the foundation for every organ ...

  5. Hydatid Disease Located in the Cerebellomedullary Cistern

    Directory of Open Access Journals (Sweden)

    Özgür Kızılca

    2014-01-01

    Full Text Available Hydatid disease is an endemic zoonotic disease in many areas of the world. Liver, followed by lung, is the most commonly affected organ and involvement of other organs is rare. When brain is involved, lesions are typically supratentorial, and infratentorial localisation is even rarer. We present a 45-year-old woman with hydatid disease located in premedullary location compressing the brain stem, an exceedingly rare location for cerebral echinococcosis. Relevant literature regarding typical properties of cerebral disease was reviewed.

  6. Ground Wars

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Kleis

    Political campaigns today are won or lost in the so-called ground war--the strategic deployment of teams of staffers, volunteers, and paid part-timers who work the phones and canvass block by block, house by house, voter by voter. Ground Wars provides an in-depth ethnographic portrait of two...... infrastructures that utilize large databases with detailed individual-level information for targeting voters, and armies of dedicated volunteers and paid part-timers. Nielsen challenges the notion that political communication in America must be tightly scripted, controlled, and conducted by a select coterie...... of professionals. Yet he also quashes the romantic idea that canvassing is a purer form of grassroots politics. In today's political ground wars, Nielsen demonstrates, even the most ordinary-seeming volunteer knocking at your door is backed up by high-tech targeting technologies and party expertise. Ground Wars...

  7. Final Harvest of Above-Ground Biomass and Allometric Analysis of the Aspen FACE Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mark E. Kubiske

    2013-04-15

    The Aspen FACE experiment, located at the US Forest Service Harshaw Research Facility in Oneida County, Wisconsin, exposes the intact canopies of model trembling aspen forests to increased concentrations of atmospheric CO2 and O3. The first full year of treatments was 1998 and final year of elevated CO2 and O3 treatments is scheduled for 2009. This proposal is to conduct an intensive, analytical harvest of the above-ground parts of 24 trees from each of the 12, 30 m diameter treatment plots (total of 288 trees) during June, July & August 2009. This above-ground harvest will be carefully coordinated with the below-ground harvest proposed by D.F. Karnosky et al. (2008 proposal to DOE). We propose to dissect harvested trees according to annual height growth increment and organ (main stem, branch orders, and leaves) for calculation of above-ground biomass production and allometric comparisons among aspen clones, species, and treatments. Additionally, we will collect fine root samples for DNA fingerprinting to quantify biomass production of individual aspen clones. This work will produce a thorough characterization of above-ground tree and stand growth and allocation above ground, and, in conjunction with the below ground harvest, total tree and stand biomass production, allocation, and allometry.

  8. Analyzing Forest Inventory Data from Geo-Located Photographs

    Science.gov (United States)

    Toivanen, Timo; Tergujeff, Renne; Andersson, Kaj; Molinier, Matthieu; Häme, Tuomas

    2015-04-01

    Forests are widely monitored using a variety of remote sensing data and techniques. Remote sensing offers benefits compared to traditional in-situ forest inventories made by experts. One of the main benefits is that the number of ground reference plots can be significantly reduced. Remote sensing of forests can provide reduced costs and time requirement compared to full forest inventories. The availability of ground reference data has been a bottleneck in remote sensing analysis over wide forested areas, as the acquisition of this data is an expensive and slow process. In this paper we present a tool for estimating forest inventory data from geo-located photographs. The tool can be used to estimate in-situ forest inventory data including estimated biomass, tree species, tree height and diameter. The collected in-situ forest measurements can be utilized as a ground reference material for spaceborne or airborne remote sensing data analysis. The GPS based location information with measured forest data makes it possible to introduce measurements easily as in-situ reference data. The central projection geometry of digital photographs allows the use of the relascope principle [1] to measure the basal area of stems per area unit, a variable very closely associated with tree biomass. Relascope is applied all over the world for forest inventory. Experiments with independent ground reference data have shown that in-situ data analysed from photographs can be utilised as reference data for satellite image analysis. The concept was validated by comparing mobile measurements with 54 independent ground reference plots from the Hyytiälä forest research station in Finland [2]. Citizen scientists could provide the manpower for analysing photographs from forests on a global level and support researchers working on tasks related to forests. This low-cost solution can also increase the coverage of forest management plans, particularly in regions where possibilities to invest on

  9. 用于草莓收获机器人的果实定位和果柄检测方法%Fruit location and stem detection method for strawberry harvesting robot

    Institute of Scientific and Technical Information of China (English)

    郭峰; 曹其新; 崔永杰; 永田雅辉

    2008-01-01

    A fruit localization and stem detection method for strawberry harvesting robot was introduced in this paper. OHTA color space based image segmentation algorithm was utilized to extract strawberry image from background; principal inertia axis of binary strawberry blob was calculated to define the pose of fruit. Strawberry was picked selectively according to its ripeness.Experimental results show that the average time of fruit localization is one second, the stem detection failure rate is 7% and fruit injury rate is 5%, which satisfy the speed and accuracy requirements of strawberry harvesting robot.%介绍了一种用于草莓收获机器人的果实定位和果柄检测方法.利用基于OHTA颜色空间的图像分割方法从背景中分割草莓;通过计算二值化草莓blob的惯性主轴来判断草莓的姿态,根据草莓的成熟度实现了果实的选择性采摘.试验证明这种方法的平均判别速度为1 s,果柄误判率为7%,在采摘过程中仅对5%的果实造成损伤,满足草莓机器人的收获速度和精度要求.

  10. Stem Cells

    Directory of Open Access Journals (Sweden)

    Madhukar Thakur

    2015-02-01

    Full Text Available Objective: The objective of this presentation is to create awareness of stem cell applications in the ISORBE community and to foster a strategy of how the ISORBE community can disseminate information and promote the use of radiolabeled stem cells in biomedical applications. Methods: The continued excitement in Stem Cells, in many branches of basic and applied biomedical science, stems from the remarkable ability of stem cells to divide and develop into different types of cells in the body. Often called as Magic Seeds, stem cells are produced in bone marrow and circulate in blood, albeit at a relatively low concentration. These virtues together with the ability of stem cells to grow in tissue culture have paved the way for their applications to generate new and healthy tissues and to replace diseased or injured human organs. Although possibilities of stem cell applications are many, much remains yet to be understood of these remarkable magic seeds. Conclusion: This presentation shall briefly cover the origin of stem cells, the pros and cons of their growth and division, their potential application, and shall outline some examples of the contributions of radiolabeled stem cells, in this rapidly growing branch of biomedical science

  11. The Development of Constructivist Grounded Theory

    Directory of Open Access Journals (Sweden)

    Jane Mills

    2006-03-01

    Full Text Available Constructivist grounded theory is a popular method for research studies primarily in the disciplines of psychology, education, and nursing. In this article, the authors aim to locate the roots of constructivist grounded theory and then trace its development. They examine key grounded theory texts to discern their ontological and epistemological orientation. They find Strauss and Corbin's texts on grounded theory to possess a discernable thread of constructivism in their approach to inquiry. They also discuss Charmaz's landmark work on constructivist grounded theory relative to her positioning of the researcher in relation to the participants, analysis of the data, and rendering of participants' experiences into grounded theory. Grounded theory can be seen as a methodological spiral that begins with Glaser and Strauss' original text and continues today. The variety of epistemological positions that grounded theorists adopt are located at various points on this spiral and are reflective of their underlying ontologies.

  12. Absolute localization of ground robots by matching LiDAR and image data in dense forested environments

    Science.gov (United States)

    Hussein, Marwan; Renner, Matthew; Iagnemma, Karl

    2014-06-01

    A method for the autonomous geolocation of ground vehicles in forest environments is discussed. The method provides an estimate of the global horizontal position of a vehicle strictly based on finding a geometric match between a map of observed tree stems, scanned in 3D by Light Detection and Ranging (LiDAR) sensors onboard the vehicle, to another stem map generated from the structure of tree crowns analyzed from high resolution aerial orthoimagery of the forest canopy. Extraction of stems from 3D data is achieved by using Support Vector Machine (SVM) classifiers and height above ground filters that separate ground points from vertical stem features. Identification of stems from overhead imagery is achieved by finding the centroids of tree crowns extracted using a watershed segmentation algorithm. Matching of the two maps is achieved by using a robust Iterative Closest Point (ICP) algorithm that determines the rotation and translation vectors to align the datasets. The alignment is used to calculate the absolute horizontal location of the vehicle. The method has been tested with real-world data and has been able to estimate vehicle geoposition with an average error of less than 2 m. It is noted that the algorithm's accuracy performance is currently limited by the accuracy and resolution of aerial orthoimagery used. The method can be used in real-time as a complement to the Global Positioning System (GPS) in areas where signal coverage is inadequate due to attenuation by the forest canopy, or due to intentional denied access. The method has two key properties that are significant: i) It does not require a priori knowledge of the area surrounding the robot. ii) Uses the geometry of detected tree stems as the only input to determine horizontal geoposition.

  13. Pressure Transducer Locations

    Data.gov (United States)

    National Aeronautics and Space Administration — Files are located here, defining the locations of the pressure transducers on the HIRENASD model. These locations also correspond to the locations that analysts...

  14. the automatic lightening location system and its implications for the ...

    African Journals Online (AJOL)

    ES Obe

    systems. The implications of the lightening location system for the Nigerian electric power system are also highlighted ... to be protected from the ground flash. ... measuring the lightening flash density ..... lightning location equipment in Norway,.

  15. Regional analysis of ground and above-ground climate

    Energy Technology Data Exchange (ETDEWEB)

    1981-12-01

    The regional suitability of underground construction as a climate control technique is discussed with reference to (1) a bioclimatic analysis of long-term weather data for 29 locations in the United States to determine appropriate above ground climate control techniques, (2) a data base of synthesized ground temperatures for the coterminous United States, and (3) monthly dew point ground temperature comparisons for identifying the relative likelihood of condensation from one region to another. It is concluded that the suitability of earth tempering as a practice and of specific earth-sheltered design stereotypes varies geographically; while the subsurface almost always provides a thermal advantage on its own terms when compared to above ground climatic data, it can, nonetheless, compromise the effectiveness of other, regionally more important climate control techniques. Also contained in the report are reviews of above and below ground climate mapping schemes related to human comfort and architectural design, and detailed description of a theoretical model of ground temperature, heat flow, and heat storage in the ground. Strategies of passive climate control are presented in a discussion of the building bioclimatic analysis procedure which has been applied in a computer analysis of 30 years of weather data for each of 29 locations in the United States.

  16. Locating the LCROSS Impact Craters

    CERN Document Server

    Marshall, William; Moratto, Zachary; Colaprete, Anthony; Neumann, Gregory; Smith, David; Hensley, Scott; Wilson, Barbara; Slade, Martin; Kennedy, Brian; Gurrola, Eric; Harcke, Leif; 10.1007/s11214-011-9765-0

    2011-01-01

    The Lunar CRater Observations and Sensing Satellite (LCROSS) mission impacted a spent Centaur rocket stage into a permanently shadowed region near the lunar south pole. The Sheperding Spacecraft (SSC) separated \\sim9 hours before impact and performed a small braking maneuver in order to observe the Centaur impact plume, looking for evidence of water and other volatiles, before impacting itself. This paper describes the registration of imagery of the LCROSS impact region from the mid- and near-infrared cameras onboard the SSC, as well as from the Goldstone radar. We compare the Centaur impact features, positively identified in the first two, and with a consistent feature in the third, which are interpreted as a 20 m diameter crater surrounded by a 160 m diameter ejecta region. The images are registered to Lunar Reconnaisance Orbiter (LRO) topographical data which allows determination of the impact location. This location is compared with the impact location derived from ground-based tracking and propagation of...

  17. STEM Education.

    Science.gov (United States)

    Xie, Yu; Fang, Michael; Shauman, Kimberlee

    2015-08-01

    Improving science, technology, engineering, and mathematics (STEM) education, especially for traditionally disadvantaged groups, is widely recognized as pivotal to the U.S.'s long-term economic growth and security. In this article, we review and discuss current research on STEM education in the U.S., drawing on recent research in sociology and related fields. The reviewed literature shows that different social factors affect the two major components of STEM education attainment: (1) attainment of education in general, and (2) attainment of STEM education relative to non-STEM education conditional on educational attainment. Cognitive and social psychological characteristics matter for both major components, as do structural influences at the neighborhood, school, and broader cultural levels. However, while commonly used measures of socioeconomic status (SES) predict the attainment of general education, social psychological factors are more important influences on participation and achievement in STEM versus non-STEM education. Domestically, disparities by family SES, race, and gender persist in STEM education. Internationally, American students lag behind those in some countries with less economic resources. Explanations for group disparities within the U.S. and the mediocre international ranking of US student performance require more research, a task that is best accomplished through interdisciplinary approaches.

  18. Stem Cells

    DEFF Research Database (Denmark)

    Sommerlund, Julie

    2004-01-01

    '. This paper is about tech-noscience, and about the proliferation of connections and interdependencies created by it.More specifically, the paper is about stem cells. Biotechnology in general has the power to capture the imagination. Within the field of biotechnology nothing seems more provocative...... and tantalizing than stem cells, in research, in medicine, or as products....

  19. STEM Education

    Science.gov (United States)

    Xie, Yu; Fang, Michael; Shauman, Kimberlee

    2015-01-01

    Improving science, technology, engineering, and mathematics (STEM) education, especially for traditionally disadvantaged groups, is widely recognized as pivotal to the U.S.’s long-term economic growth and security. In this article, we review and discuss current research on STEM education in the U.S., drawing on recent research in sociology and related fields. The reviewed literature shows that different social factors affect the two major components of STEM education attainment: (1) attainment of education in general, and (2) attainment of STEM education relative to non-STEM education conditional on educational attainment. Cognitive and social psychological characteristics matter for both major components, as do structural influences at the neighborhood, school, and broader cultural levels. However, while commonly used measures of socioeconomic status (SES) predict the attainment of general education, social psychological factors are more important influences on participation and achievement in STEM versus non-STEM education. Domestically, disparities by family SES, race, and gender persist in STEM education. Internationally, American students lag behind those in some countries with less economic resources. Explanations for group disparities within the U.S. and the mediocre international ranking of US student performance require more research, a task that is best accomplished through interdisciplinary approaches. PMID:26778893

  20. 'Grounded' Politics

    DEFF Research Database (Denmark)

    Schmidt, Garbi

    2012-01-01

    play within one particular neighbourhood: Nørrebro in the Danish capital, Copenhagen. The article introduces the concept of grounded politics to analyse how groups of Muslim immigrants in Nørrebro use the space, relationships and history of the neighbourhood for identity political statements....... The article further describes how national political debates over the Muslim presence in Denmark affect identity political manifestations within Nørrebro. By using Duncan Bell’s concept of mythscape (Bell, 2003), the article shows how some political actors idealize Nørrebro’s past to contest the present...

  1. Learn About Stem Cells

    Science.gov (United States)

    ... Patient Handbook Stem Cell Glossary Search Toggle Nav Stem Cell Basics Stem cells are the foundation from which ... original cell’s DNA, cytoplasm and cell membrane. About stem cells Stem cells are the foundation of development in ...

  2. Pattern and location of intracerebral hemorrhage in Enugu, South ...

    African Journals Online (AJOL)

    2015-10-16

    Oct 16, 2015 ... (ICH) is the second most common subtype of stroke with a worldwide ... hemorrhage (DCH) (including brain stem and cerebellar). Pattern and location .... hemoglobinopathies such as sickle cell disease which are common in ...

  3. Ground water in Oklahoma

    Science.gov (United States)

    Leonard, A.R.

    1960-01-01

    estimated that about one-third of the water used in the State in 1956, or 400,000 acre-feet, came from ground-water sources. In 1957, 71 percent of the irrigation water used in the State came from underground sources, and ground water was used for irrigation in 57 of the State's 77 counties. More than 300 of the towns and cities of the State obtain all their municipal water supplies from ground water. The major ground-water reservoirs, or aquifers, of Oklahoma may be classed in four general groups: (1) semiconsolidated sand and gravel underlying the High Plains, (2) unconsolidated alluvial deposits of sand and gravel along streams and adjacent to valleys, (3) sandstone aquifers, and (4) limestone aquifers, including, for the purpose of this generalized breakdown, dolomite and gypsum. The locations of these major aquifers are shown on figure 1. Areas on that map do not correspond exactly to outcrops, but are the areas where the formations contain significant quantities of potable water. Near their edges rock formations may be cut through by streams or they may be too thin to contain much water. On the other hand, some formations contain fresh ground water for many miles downdip from their outcrop areas, where wells must first penetrate overlying rocks to reach them. (available as photostat copy only)

  4. Nucleosome Organization in Human Embryonic Stem Cells.

    Directory of Open Access Journals (Sweden)

    Puya G Yazdi

    Full Text Available The fundamental repeating unit of eukaryotic chromatin is the nucleosome. Besides being involved in packaging DNA, nucleosome organization plays an important role in transcriptional regulation and cellular identity. Currently, there is much debate about the major determinants of the nucleosome architecture of a genome and its significance with little being known about its role in stem cells. To address these questions, we performed ultra-deep sequencing of nucleosomal DNA in two human embryonic stem cell lines and integrated our data with numerous epigenomic maps. Our analyses have revealed that the genome is a determinant of nucleosome organization with transcriptionally inactive regions characterized by a "ground state" of nucleosome profiles driven by underlying DNA sequences. DNA sequence preferences are associated with heterogeneous chromatin organization around transcription start sites. Transcription, histone modifications, and DNA methylation alter this "ground state" by having distinct effects on both nucleosome positioning and occupancy. As the transcriptional rate increases, nucleosomes become better positioned. Exons transcribed and included in the final spliced mRNA have distinct nucleosome profiles in comparison to exons not included at exon-exon junctions. Genes marked by the active modification H3K4m3 are characterized by lower nucleosome occupancy before the transcription start site compared to genes marked by the inactive modification H3K27m3, while bivalent domains, genes associated with both marks, lie exactly in the middle. Combinatorial patterns of epigenetic marks (chromatin states are associated with unique nucleosome profiles. Nucleosome organization varies around transcription factor binding in enhancers versus promoters. DNA methylation is associated with increasing nucleosome occupancy and different types of methylations have distinct location preferences within the nucleosome core particle. Finally, computational

  5. Nucleosome Organization in Human Embryonic Stem Cells.

    Science.gov (United States)

    Yazdi, Puya G; Pedersen, Brian A; Taylor, Jared F; Khattab, Omar S; Chen, Yu-Han; Chen, Yumay; Jacobsen, Steven E; Wang, Ping H

    2015-01-01

    The fundamental repeating unit of eukaryotic chromatin is the nucleosome. Besides being involved in packaging DNA, nucleosome organization plays an important role in transcriptional regulation and cellular identity. Currently, there is much debate about the major determinants of the nucleosome architecture of a genome and its significance with little being known about its role in stem cells. To address these questions, we performed ultra-deep sequencing of nucleosomal DNA in two human embryonic stem cell lines and integrated our data with numerous epigenomic maps. Our analyses have revealed that the genome is a determinant of nucleosome organization with transcriptionally inactive regions characterized by a "ground state" of nucleosome profiles driven by underlying DNA sequences. DNA sequence preferences are associated with heterogeneous chromatin organization around transcription start sites. Transcription, histone modifications, and DNA methylation alter this "ground state" by having distinct effects on both nucleosome positioning and occupancy. As the transcriptional rate increases, nucleosomes become better positioned. Exons transcribed and included in the final spliced mRNA have distinct nucleosome profiles in comparison to exons not included at exon-exon junctions. Genes marked by the active modification H3K4m3 are characterized by lower nucleosome occupancy before the transcription start site compared to genes marked by the inactive modification H3K27m3, while bivalent domains, genes associated with both marks, lie exactly in the middle. Combinatorial patterns of epigenetic marks (chromatin states) are associated with unique nucleosome profiles. Nucleosome organization varies around transcription factor binding in enhancers versus promoters. DNA methylation is associated with increasing nucleosome occupancy and different types of methylations have distinct location preferences within the nucleosome core particle. Finally, computational analysis of nucleosome

  6. A Location Privacy Aware Friend Locator

    DEFF Research Database (Denmark)

    Siksnys, Laurynas; Thomsen, Jeppe Rishede; Saltenis, Simonas

    2009-01-01

    to trade their location privacy for quality of service, limiting the attractiveness of the services. The challenge is to develop a communication-efficient solution such that (i) it detects proximity between a user and the user’s friends, (ii) any other party is not allowed to infer the location of the user...

  7. Improved Multiple Event Location Methods for Ground Truth Collection

    Science.gov (United States)

    2016-10-04

    likewise Gaussian with zero mean and variance matrix given by Γpri = ACAT . (24) The Rodi-Myers method specifies the model variance indirectly in terms of...respect to eij of the loga- rithm of the pick-error p.d.f. in (15). In the Gaussian case (p = 2) the weights are simply inverse variances: wij = σ −2 ij...data weights are set to reciprocal pick-error variances for any p, as they are in the Gaussian case. That is, the weights are set as wij = 1 σ2ij p 2/p

  8. Coordinated Optimization of Aircraft Routes and Locations of Ground Sensors

    Science.gov (United States)

    2014-09-17

    optimization approaches allowing minimization of the total cost subject to linear inequality constraints can be formulated in terms of the binary...the calculations are not trivial. ERDC/CRREL TR-14-20 9 3.1 Coverage matrix for aircraft Coverage matrix A enters the inequality coverage...of target (a person versus a car): 8 ± 2 px • Identification of the target (a woman versus a man, a specific car): 13 ± 3 px; These criteria

  9. Postmodernity Grounded

    Directory of Open Access Journals (Sweden)

    Stipe Grgas

    2011-06-01

    Full Text Available The following contribution to a discussion that purports to “rethink the humanities” stems from the field of American Studies which has, since its beginnings, challenged and put pressure on disciplinary borders and institutional structures of both the humanities and the social sciences. The approaches it has espoused has led observers to see it as a domain of inquiry where virtually anything goes. One of the explanations that has been put forth to account for the heterogeneity of both the research agendas and the multiplicity of methods within American Studies is the dynamics of demography within the United States and the way that this dynamic has impacted both the enrollment statistics at American universities and the diversifications of its teaching staff. According to this oft-repeated view, the research agenda of American Studies reflects the stages of empowerment of the different groups making up the United States polity. Although one would be hard put not to acknowledge these, distinctly American, developments, on the present occasion my point of departure is a more general rationale which American Studies, like other disciplines today, rely upon when setting their research agenda and deploying their methods: in simplest terms, they harbor a desire and feel a need for relevancy.

  10. Locating the LCROSS Impact Craters

    Science.gov (United States)

    Marshall, William; Shirley, Mark; Moratto, Zachary; Colaprete, Anthony; Neumann, Gregory A.; Smith, David E.; Hensley, Scott; Wilson, Barbara; Slade, Martin; Kennedy, Brian; hide

    2012-01-01

    The Lunar CRater Observations and Sensing Satellite (LCROSS) mission impacted a spent Centaur rocket stage into a permanently shadowed region near the lunar south pole. The Sheperding Spacecraft (SSC) separated approx. 9 hours before impact and performed a small braking maneuver in order to observe the Centaur impact plume, looking for evidence of water and other volatiles, before impacting itself. This paper describes the registration of imagery of the LCROSS impact region from the mid- and near-infrared cameras onboard the SSC, as well as from the Goldstone radar. We compare the Centaur impact features, positively identified in the first two, and with a consistent feature in the third, which are interpreted as a 20 m diameter crater surrounded by a 160 m diameter ejecta region. The images are registered to Lunar Reconnaisance Orbiter (LRO) topographical data which allows determination of the impact location. This location is compared with the impact location derived from ground-based tracking and propagation of the spacecraft's trajectory and with locations derived from two hybrid imagery/trajectory methods. The four methods give a weighted average Centaur impact location of -84.6796 deg, -48.7093 deg, with a 1s uncertainty of 115 m along latitude, and 44 m along longitude, just 146 m from the target impact site. Meanwhile, the trajectory-derived SSC impact location is -84.719 deg, -49.61 deg, with a 1 alpha uncertainty of 3 m along the Earth vector and 75 m orthogonal to that, 766 m from the target location and 2.803 km south-west of the Centaur impact. We also detail the Centaur impact angle and SSC instrument pointing errors. Six high-level LCROSS mission requirements are shown to be met by wide margins. We hope that these results facilitate further analyses of the LCROSS experiment data and follow-up observations of the impact region

  11. Locative Inversion in Cantonese.

    Science.gov (United States)

    Mok, Sui-Sang

    This study investigates the phenomenon of "Locative Inversion" in Cantonese. The term "Locative Inversion" indicates that the locative phrase (LP) syntactic process in Cantonese and the appears at the sentence-initial position and its logical subject occurs postverbally. It is demonstrated that this Locative Inversion is a…

  12. Becoming a Blood Stem Cell Donor

    Medline Plus

    Full Text Available ... 2:56 Stem cell donation from brother saves child from cancer - Duration: 3:22. CTV News 587 views 3:22 Bone Marrow Stem Cell Donation - Duration: 1:04. craigkeller1966 9,232 views 1:04 Loading more suggestions... Show more Language: English Content location: United States Restricted Mode: Off ...

  13. Development of Mine Explosion Ground Truth Smart Sensors

    Science.gov (United States)

    2011-09-01

    DEVELOPMENT OF MINE EXPLOSION GROUND TRUTH SMART SENSORS Steven R. Taylor1, Phillip E. Harben1, Steve Jarpe2, and David B. Harris3 Rocky...improved location is the compilation of ground truth data sets for which origin time and location are accurately known. Substantial effort by the...National Laboratories and seismic monitoring groups have been undertaken to acquire and develop ground truth catalogs that form the basis of location

  14. Law Enforcement Locations

    Data.gov (United States)

    Kansas Data Access and Support Center — Law Enforcement Locations in Kansas Any location where sworn officers of a law enforcement agency are regularly based or stationed. Law enforcement agencies "are...

  15. Hematopoietic Stem Cell Transplantation: Need for Research & Potential Applications. It’s status in India

    OpenAIRE

    Shripad D Banavali

    2009-01-01

    Stem cells are undifferentiated cells that through replications have the capabilities of both self-renewal and differentiation into mature specialized cells. Broadly, there are two types of stem cells, embryonic stem cells and adult stem cells. Embryonic stem cell biology has been associated with ethical controversy and also their growth is difficult to control. Adult stem cells are located in tissues throughout the body and function as a reservoir to replace damaged or aging cells. Embryonic...

  16. Onderzoek location based marketing: Mobile = location = effect

    NARCIS (Netherlands)

    Gisbergen, M.S. van; Huhn, A.E.; Khan, V.J.; Ketelaar, P.E.

    2011-01-01

    Onderzoekers van de NHTV (Internationaa Hoger Onderwijs Breda, Radboud Universiteit, DVJ Insights en Popai Benelux lieten consumenten in een virtuele supermarkt advertenties via de smartphone ontvangen wanneer men langs het geadverteerde product liep. De uitkomsten laten zien dat 'location based adv

  17. Onderzoek location based marketing: Mobile = location = effect

    OpenAIRE

    Gisbergen, M.S. van; Huhn, A.E.; Khan, V.J.; Ketelaar, P.E.

    2011-01-01

    Onderzoekers van de NHTV (Internationaa Hoger Onderwijs Breda, Radboud Universiteit, DVJ Insights en Popai Benelux lieten consumenten in een virtuele supermarkt advertenties via de smartphone ontvangen wanneer men langs het geadverteerde product liep. De uitkomsten laten zien dat 'location based advertising' effectief is.

  18. Locatives in Kpelle.

    Science.gov (United States)

    Kuha, Mai

    This paper examines the differences between locative expressions in Kpelle and English, based on the dialect of one native speaker of Kpelle. It discusses the crucial role of the reference object in defining the meaning of locatives in Kpelle, in contrast to English, where the characteristics of the object to be located are less important. An…

  19. The spermatogonial stem cell niche

    NARCIS (Netherlands)

    D.G. de Rooij

    2009-01-01

    Spermatogonial stem cells (SSCs; A(s) spermatogonia) and their direct descendants (A(pr) and A(al) spermatogonia) are preferentially located in those areas of the seminiferous tubules that border on the interstitial tissue. Fewer of these cells are present in tubule areas directly bordering on anoth

  20. Semantic Perspicuity and the Locative Hypothesis: Implications for Acquisition.

    Science.gov (United States)

    Gee, James Paul; Kegl, Judy Anne

    1982-01-01

    Describes American Sign Language (ASL) as "locative," because its grammatical/semantic structures derive from spatial notions; and "semantically perspicuous," because its phonetic and semantic structures are isomorphically related. Presents an ASL morphology showing how verbs are built from six basic locative/directional stems. Discusses…

  1. Noise Source Location Optimization

    Directory of Open Access Journals (Sweden)

    Ed O’Keefe

    1994-01-01

    Full Text Available This article describes a method to determine locations of noise sources that minimize modal coupling in complex acoustic volumes. Using the acoustic source scattering capabilities of the boundary element method, predictions are made of mode shape and pressure levels due to various source locations. Combining knowledge of the pressure field with a multivariable function minimization technique, the source location generating minimum pressure levels can be determined. The analysis also allows for an objective comparison of “best/worst” locations. The technique was implemented on a personal computer for the U.S. Space Station, predicting 5–10 dB noise reduction using optimum source locations.

  2. Smartphones as locative media

    CERN Document Server

    Frith, Jordan

    2015-01-01

    Smartphone adoption has surpassed 50% of the population in more than 15 countries, and there are now more than one million mobile applications people can download to their phones. Many of these applications take advantage of smartphones as locative media, which is what allows smartphones to be located in physical space. Applications that take advantage of people's location are called location-based services, and they are the focus of this book. Smartphones as locative media raise important questions about how we understand the complicated relationship between the Internet and physical space

  3. Place Based STEM: Leveraging Local Resources to Engage K-12 Teachers in Teaching Integrated STEM and for Addressing the Local STEM Pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Louis Nadelson; Anne Louise Seifert; Meagan McKinney

    2014-06-01

    Business, industry, parks, nature settings, government infrastructure, and people, can be invaluable resources for connecting STEM curriculum within context which results in conditions ideal for promoting purposeful learning of authentic STEM content. Thus, community-based STEM resources offer ideal context for teaching STEM content. A benefit of focusing teacher attention on these contextual, content aligned resources is that they are in every community; making place-based STEM education a possibility, regardless of the location of STEM teaching and learning. Further, associating STEM teaching and learning with local resources addresses workforce development and the STEM pipeline by exposing students to STEM careers and applications in their local communities. The desire to align STEM teaching and learning with local STEM related resources guided the design of our week-long integrated STEM K-12 teacher professional development (PD) program, i-STEM. We have completed four years of our i-STEM PD program and have made place-based STEM a major emphasis of our curriculum. This report focuses on the data collected in the fourth year of our program. Our week-long i-STEM PD served over 425 educators last summer (2013), providing them with in depth theme-based integrated STEM short courses which were limited to an average of 15 participants and whole group plenary sessions focused around placed based integrated STEM, inquiry, engineering design, standards and practices of Common Core and 21st Century skills. This state wide PD was distributed in five Idaho community colleges and took place over two weeks. The STEM short courses included topics on engineering for sustainability, using engineering to spark interest in STEM, municipal water systems, health, agriculture, food safety, mining, forestry, energy, and others. Integral to these short courses were field trips designed to connect the K-12 educators to the resources in their local communities that could be leveraged

  4. Hypoxia and Stem Cell-Based Engineering of Mesenchymal Tissues

    OpenAIRE

    Ma, Teng; Grayson, Warren L.; Fröhlich, Mirjam; Vunjak-Novakovic, Gordana

    2009-01-01

    Stem cells have the ability for prolonged self-renewal and differentiation into mature cells of various lineages, which makes them important cell sources for tissue engineering applications. Their remarkable ability to replenish and differentiate in vivo is regulated by both intrinsic and extrinsic cellular mechanisms. The anatomical location where the stem cells reside, known as the “stem cell niche or microenvironment,” provides signals conducive to the maintenance of definitive stem cell p...

  5. Why STEM?

    Science.gov (United States)

    Mitts, Charles R.

    2016-01-01

    The International Technology and Engineering Educators Association (ITEEA) defines STEM as a new transdisciplinary subject in schools that integrates the disciplines of science, technology, engineering, and mathematics into a single course of study. There are three major problems with this definition: There is no consensus in support of the ITEEA…

  6. Stem cells.

    Science.gov (United States)

    Redi, Carlo Alberto; Monti, Manuela; Merico, Valeria; Neri, Tui; Zanoni, Mario; Zuccotti, Maurizio; Garagna, Silvia

    2007-01-01

    The application of stem cells to regenerative medicine is one of the actual hot topics in biomedicine. This research could help the cure of a number of diseases that are affecting a large share of the population. Some good results in cell replacement have already been obtained (infarcted heart, diabetes, Parkinson disease), apart from those of more traditional applications like severe burns and blood tumors. We are now facing crucial questions in stem cell biology. One of the key questions is how a cell begins to proliferate or differentiate. Genome reprogramming, both following nuclear transfer and cytoplast action, will likely highlight some of the molecular mechanisms of cell differentiation and dedifferentiation. In turn, these clues should be useful to the production of populations of reprogrammed cells that could develop into tissues or, in the future, into proper organs. We will overview what stem cells are, what roles they play in normal developmental processes and how stem cells could have the potential to treat diseases.

  7. Of Microenvironments and Mammary Stem Cells

    Energy Technology Data Exchange (ETDEWEB)

    LaBarge, Mark A; Petersen, Ole W; Bissell, Mina J

    2007-06-01

    In most adult tissues there reside pools of stem and progenitor cells inside specialized microenvironments referred to as niches. The niche protects the stem cells from inappropriate expansion and directs their critical functions. Thus guided, stem cells are able to maintain tissue homeostasis throughout the ebb and flow of metabolic and physical demands encountered over a lifetime. Indeed, a pool of stem cells maintains mammary gland structure throughout development, and responds to the physiological demands associated with pregnancy. This review discusses how stem cells were identified in both human and mouse mammary glands; each requiring different techniques that were determined by differing biological needs and ethical constraints. These studies together create a robust portrait of mammary gland biology and identify the location of the stem cell niche, elucidate a developmental hierarchy, and suggest how the niche might be manipulated for therapeutic benefit.

  8. Evaluating transmission towers potentials during ground faults

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    During ground faults on transmission lines, a number of towers near the fault are likely to acquire high potentials to ground. These tower voltages, if excessive, may present a hazard to humans and animals. This paper presents analytical methods in order to determine the transmission towers potentials during ground faults, for long and short lines. The author developed a global systematic approach to calculate these voltages, which are dependent of a number of factors. Some of the most important factors are: magnitudes of fault currents, fault location with respect to the line terminals, conductor arrangement on the tower and the location of the faulted phase, the ground resistance of the faulted tower, soil resistivity, number, material and size of ground wires. The effects of these factors on the faulted tower voltages have been also examined for different types of power lines.

  9. Generic Network Location Service

    Directory of Open Access Journals (Sweden)

    Laban Mwansa

    2010-11-01

    Full Text Available This work presents the Generic Network Location Service based on the Chord implementation utilizing data structures called distributed hash tables (DHT or structured overlay networks, which are used to build scalable self-managing distributed systems. The provided algorithms guarantee resilience in the presence of dynamism: they guarantee consistent lookup results in the presence of nodes failing and leaving. Generic Network Location Service provides a Location Service system based on DHT technology, which is storing device location records in nodes within a Chord DHT. Location records are consisting of network device identification keys as attributes, which are used to create replicas of additional location records through established Chord hashing mechanisms. Storing device location records, in places address-able (using the DHT lookup by individual location record keys provides a simple way of implementing transla¬tion functions similar to well¬ known network services (e.g. ARP, DNS, ENUM. The generic network location ser¬vice presented in the paper is not supposed to be a substitu¬tion of the existing translation techniques (e.g. ARP, DNS, ENUM, but it is considered as an overlay service that uses data available in existing systems and provides some translations currently unavailable.

  10. Smart Location Database - Download

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Smart Location Database (SLD) summarizes over 80 demographic, built environment, transit service, and destination accessibility attributes for every census block...

  11. Smart Location Database - Service

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Smart Location Database (SLD) summarizes over 80 demographic, built environment, transit service, and destination accessibility attributes for every census block...

  12. Project-Based Learning Not Just for STEM Anymore

    Science.gov (United States)

    Duke, Nell K.; Halvorsen, Anne-Lise; Strachan, Stephanie L.

    2016-01-01

    The popularity of project-based learning has been driven in part by a growing number of STEM schools and programs. But STEM subjects are not the only fertile ground for project-based learning (PBL). Social studies and literacy content, too, can be adapted into PBL units to benefit teaching and learning, the authors argue. They review key studies…

  13. Locating Cosmopolitanism Within Academic Mobility

    Directory of Open Access Journals (Sweden)

    Liudmila Kirpitchenko

    2014-02-01

    Full Text Available Intensified academic mobility is an enticing platform for examining the emerging manifestations of cosmopolitanism in expanding intercultural encounters. Cosmopolitanism calls for a dialogue between cultures and for reciprocal appropriation and internalization of cultures within one’s own culture. This paper endeavors to locate empirical evidence on evolving cosmopolitanism in everyday intercultural interactions and academic experiences. It is guided by the methodological applications of cosmopolitanism and the way cosmopolitanism is redefining the sociological frame of reference. This paper presents discussion and empirical testing of three defining features of cosmopolitanism according to Beck (2002: globality, plurality and civility. Mirroring these guiding principles, this research attempted to identify and analyze cosmopolitan values and dispositions in everyday intercultural encounters, discourses, situations and experiences. This paper presented an argument that cosmopolitan values and dispositions tend to create mutually beneficial conditions for intercultural inclusion and academic mobility provides a fertile ground for their current and future exploration.

  14. A family business: stem cell progeny join the niche to regulate homeostasis.

    Science.gov (United States)

    Hsu, Ya-Chieh; Fuchs, Elaine

    2012-01-23

    Stem cell niches, the discrete microenvironments in which the stem cells reside, play a dominant part in regulating stem cell activity and behaviours. Recent studies suggest that committed stem cell progeny become indispensable components of the niche in a wide range of stem cell systems. These unexpected niche inhabitants provide versatile feedback signals to their stem cell parents. Together with other heterologous cell types that constitute the niche, they contribute to the dynamics of the microenvironment. As progeny are often located in close proximity to stem cell niches, similar feedback regulations may be the underlying principles shared by different stem cell systems.

  15. Manhole cover point locations across Guam's developed areas

    Data.gov (United States)

    U.S. Environmental Protection Agency — This is a point feature dataset with points across Guam's developed areas. The points represent manhole cover locations, ground elevation and manhole access depth.

  16. Industrial location and competitiveness

    NARCIS (Netherlands)

    S. Brakman (Steven); J.H. Garretsen (Harry); J.G.M. van Marrewijk (Charles)

    2006-01-01

    textabstractThe interaction between the extent of location advantages and the intensity of firm competition relative to the size of the market jointly determines the location of industrial activity. Technology, factor endowments, geography, and scale economies are influential for determining locatio

  17. Appraising manufacturing location

    NARCIS (Netherlands)

    Steenhuis, Harm-Jan; Bruijn, de Erik J.

    2002-01-01

    International location of manufacturing activities is an issue for managers of manufacturing companies as well as public policy makers. For managers, the issue is relevant because international locations offer opportunities for lowering costs due to productivity improvements. For governments the iss

  18. Assessing manufacturing location

    NARCIS (Netherlands)

    Steenhuis, Harm-Jan; Bruijn, de Erik J.

    2004-01-01

    International location of manufacturing activities is an issue for managers of manufacturing companies as well as public policy-makers. For managers, the issue is relevant because international locations offer opportunities for lowering costs due to productivity improvements. For governments the iss

  19. The Influence of Proactive Personality and Coping on Commitment to STEM Majors

    Science.gov (United States)

    Major, Debra A.; Holland, Jonathan M.; Oborn, Kurt L.

    2012-01-01

    Despite increasing demand for workers in fields that are grounded in science, technology, engineering, and math (STEM), retention rates are low among relevant college majors. Using Web-based survey data from 290 STEM majors, the authors investigated links among personality, coping strategies, and STEM major commitment. Proactive personality was…

  20. 30 CFR 75.700-1 - Approved methods of grounding.

    Science.gov (United States)

    2010-07-01

    ... conductors are a part of the system will be approved if a solid connection is made to the neutral conductor... low resistance to earth; (c) A solid connection to a grounding conductor, other than the neutral conductor of a resistance grounded system, extending to a low resistance ground field located on the...

  1. Pressurizing the STEM Pipeline: an Expectancy-Value Theory Analysis of Youths' STEM Attitudes

    Science.gov (United States)

    Ball, Christopher; Huang, Kuo-Ting; Cotten, Shelia R.; Rikard, R. V.

    2017-08-01

    Over the past decade, there has been a strong national push to increase minority students' positive attitudes towards STEM-related careers. However, despite this focus, minority students have remained underrepresented in these fields. Some researchers have directed their attention towards improving the STEM pipeline which carries students through our educational system and into STEM careers. Previous research has shown that expectancy-value theory (EVT) is useful for examining the short-term as well as long-term academic motivations and intentions of elementary age minority students. These findings provide insights into ways we may be able to potentially "patch" particular STEM pipeline leaks. In the current study, we advance this research by using EVT as a framework to examine the STEM attitudes of young students directly. We hypothesize that students' academic-related expectancies for success and subjective task values will be associated with an increase in STEM attitudes. Data for this study was gathered over the course of a large-scale computing intervention which sought to increase students' STEM interest. This computing intervention took place in an urban elementary school district located within the southeastern USA. Results from this study indicate that both intrinsic values and utility values predict students' STEM attitudes but they influence attitudes related to the various dimensions of STEM differently. These findings demonstrate that EVT provides a useful framework, which can be integrated into future computing interventions, to help encourage positive STEM attitudes in young children, thus increasing the internal pressure (or flow) within the STEM pipeline.

  2. Pressurizing the STEM Pipeline: an Expectancy-Value Theory Analysis of Youths' STEM Attitudes

    Science.gov (United States)

    Ball, Christopher; Huang, Kuo-Ting; Cotten, Shelia R.; Rikard, R. V.

    2017-01-01

    Over the past decade, there has been a strong national push to increase minority students' positive attitudes towards STEM-related careers. However, despite this focus, minority students have remained underrepresented in these fields. Some researchers have directed their attention towards improving the STEM pipeline which carries students through our educational system and into STEM careers. Previous research has shown that expectancy-value theory (EVT) is useful for examining the short-term as well as long-term academic motivations and intentions of elementary age minority students. These findings provide insights into ways we may be able to potentially "patch" particular STEM pipeline leaks. In the current study, we advance this research by using EVT as a framework to examine the STEM attitudes of young students directly. We hypothesize that students' academic-related expectancies for success and subjective task values will be associated with an increase in STEM attitudes. Data for this study was gathered over the course of a large-scale computing intervention which sought to increase students' STEM interest. This computing intervention took place in an urban elementary school district located within the southeastern USA. Results from this study indicate that both intrinsic values and utility values predict students' STEM attitudes but they influence attitudes related to the various dimensions of STEM differently. These findings demonstrate that EVT provides a useful framework, which can be integrated into future computing interventions, to help encourage positive STEM attitudes in young children, thus increasing the internal pressure (or flow) within the STEM pipeline.

  3. Ground water and energy

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    This national workshop on ground water and energy was conceived by the US Department of Energy's Office of Environmental Assessments. Generally, OEA needed to know what data are available on ground water, what information is still needed, and how DOE can best utilize what has already been learned. The workshop focussed on three areas: (1) ground water supply; (2) conflicts and barriers to ground water use; and (3) alternatives or solutions to the various issues relating to ground water. (ACR)

  4. Smart Location Mapping

    Science.gov (United States)

    The Smart Location Database, Access to Jobs and Workers via Transit, and National Walkability Index tools can help assess indicators related to the built environment, transit accessibility, and walkability.

  5. Waste Recovery Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Locations where City residents are encouraged to drop off and dispose or recycle of unwanted materials. Information provided is subject to change. Please call ahead...

  6. Electronic apex locators.

    Science.gov (United States)

    Gordon, M P J; Chandler, N P

    2004-07-01

    Prior to root canal treatment at least one undistorted radiograph is required to assess canal morphology. The apical extent of instrumentation and the final root filling have a role in treatment success, and are primarily determined radiographically. Electronic apex locators reduce the number of radiographs required and assist where radiographic methods create difficulty. They may also indicate cases where the apical foramen is some distance from the radiographic apex. Other roles include the detection of root canal perforation. A review of the literature focussed first on the subject of electronic apex location. A second review used the names of apex location devices. From the combined searches, 113 pertinent articles in English were found. This paper reviews the development, action, use and types of electronic apex locators.

  7. Allegheny County Dam Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset shows the point locations of dams in Allegheny County. If viewing this description on the Western Pennsylvania Regional Data Center’s open data portal...

  8. VT Hospital Site Locations

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) This data layer contains point locations of all major community, regional, comprehensive health, and healthcare provider hospitals in the state of...

  9. IHS Facility Locator

    Data.gov (United States)

    U.S. Department of Health & Human Services — This map can be used to find an Indian Health Service, Tribal or Urban Indian Health Program facility. This map can be used to: Zoom in to a general location to...

  10. USAID Activity Locations

    Data.gov (United States)

    US Agency for International Development — The USAID Activities dataset is a snapshot of activities supported by USAID including their geographical locations within countries at the time of the snapshot. The...

  11. Eldercare Locator Database

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Eldercare Locator is a searchable database that allows a user to search via zip code or city/ state for agencies at the State and local levels that provide...

  12. Uranium Location Database

    Data.gov (United States)

    U.S. Environmental Protection Agency — A GIS compiled locational database in Microsoft Access of ~15,000 mines with uranium occurrence or production, primarily in the western United States. The metadata...

  13. Global Volcano Locations Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC maintains a database of over 1,500 volcano locations obtained from the Smithsonian Institution Global Volcanism Program, Volcanoes of the World publication. The...

  14. Location and logistics

    OpenAIRE

    Alumura, Sibel A.; Karab, Bahar Y.; Melo, M. Teresa

    2013-01-01

    Facility location decisions play a critical role in designing logistics networks. This article provides some guidelines on how location decisions and logistics functions can be integrated into a single mathematical model to optimize the configuration of a logistics network. This will be illustrated by two generic models, one supporting the design of a forward logistics network and the other addressing the specific requirements of a reverse logistics network. Several special cases and extensio...

  15. Location and logistics

    OpenAIRE

    Alumura, Sibel A.; Karab, Bahar Y.; Melo, M. Teresa

    2013-01-01

    Facility location decisions play a critical role in designing logistics networks. This article provides some guidelines on how location decisions and logistics functions can be integrated into a single mathematical model to optimize the configuration of a logistics network. This will be illustrated by two generic models, one supporting the design of a forward logistics network and the other addressing the specific requirements of a reverse logistics network. Several special cases and extensio...

  16. US EPA OPTIMAL WELL LOCATOR (OWL): A SCREENING TOOL FOR EVALUATING LOCATIONS OF MONITORING WELLS

    Science.gov (United States)

    The Optimal Well Locator (OWL): uses linear regression to fit a plane to the elevation of the water table in monitoring wells in each round of sampling. The slope of the plane fit to the water table is used to predict the direction and gradient of ground water flow. Along with ...

  17. Nonclinical safety strategies for stem cell therapies

    Energy Technology Data Exchange (ETDEWEB)

    Sharpe, Michaela E., E-mail: michaela_sharpe@yahoo.com [Investigative Toxicology, Drug Safety Research and Development, Pfizer Ltd, Ramsgate Road, Sandwich, CT13 9NJ (United Kingdom); Morton, Daniel [Exploratory Drug Safety, Drug Safety Research and Development, Pfizer Inc, Cambridge, 02140 (United States); Rossi, Annamaria [Investigative Toxicology, Drug Safety Research and Development, Pfizer Ltd, Ramsgate Road, Sandwich, CT13 9NJ (United Kingdom)

    2012-08-01

    Recent breakthroughs in stem cell biology, especially the development of the induced pluripotent stem cell techniques, have generated tremendous enthusiasm and efforts to explore the therapeutic potential of stem cells in regenerative medicine. Stem cell therapies are being considered for the treatment of degenerative diseases, inflammatory conditions, cancer and repair of damaged tissue. The safety of a stem cell therapy depends on many factors including the type of cell therapy, the differentiation status and proliferation capacity of the cells, the route of administration, the intended clinical location, long term survival of the product and/or engraftment, the need for repeated administration, the disease to be treated and the age of the population. Understanding the product profile of the intended therapy is crucial to the development of the nonclinical safety study design.

  18. Skin Stem Cells in Skin Cell Therapy

    Directory of Open Access Journals (Sweden)

    Mollapour Sisakht

    2015-12-01

    Full Text Available Context Preclinical and clinical research has shown that stem cell therapy is a promising therapeutic option for many diseases. This article describes skin stem cells sources and their therapeutic applications. Evidence Acquisition Compared with conventional methods, cell therapy reduces the surgical burden for patients because it is simple and less time-consuming. Skin cell therapy has been developed for variety of diseases. By isolation of the skin stem cell from the niche, in vitro expansion and transplantation of cells offers a surprising healing capacity profile. Results Stem cells located in skin cells have shown interesting properties such as plasticity, transdifferentiation, and specificity. Mesenchymal cells of the dermis, hypodermis, and other sources are currently being investigated to promote regeneration. Conclusions Because skin stem cells are highly accessible from autologous sources and their immunological profile is unique, they are ideal for therapeutic approaches. Optimization of administrative routes requires more investigation own to the lack of a standard protocol.

  19. Advances in studies on hepatic stem cells

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The question whether hepatic stem cells exist or not has been debated for several decades. Current researches confirm that there are hepatic stem cells in the liver. Oval cells, putative bipotential hepatic stem cells, are probably located within canals of Hering, portal tracts or branches of biliary trees. Bone marrow is a potential source of oval cells, indicating that there exists a close relationship between liver and hematopoiesis in adulthood. Hepatic stem cells are able to proliferate in vitro and can be induced to differentiate into hepatocytes. This will provide a promising approach of cell transplantation, tissue engineering and gene therapy for liver diseases. In this review, the evidence of their presence, origin, identification, proliferation in vitro, differentiation by induction, application prospects of hepatic stem cells and future directions for the field are discussed.

  20. Grounding-Induced Sectional Forces and Residual Strength of Grounded Ship Hulls

    DEFF Research Database (Denmark)

    Paik, Jeom Kee; Pedersen, Preben Terndrup

    1996-01-01

    The aim of the present study is to determine the sectional forces induced by ship grounding and also to assess the residual strength of groundedship hulls. An analytical approach is used to estimate the grounding-induced sectional forces of ships. The extent and location of structural damage due...... to grounding is defined based on the ABS Safe Hull guide. The residual strength of damaged hulls is calculated by using a simple analytical formula. The method is applied to residual strength assessment of a damaged double hull tanker of 38,400 dwt due to grounding....

  1. Geostar - Navigation location system

    Science.gov (United States)

    Keyser, Donald A.

    The author describes the Radiodetermination Satellite Service (RDSS). The initial phase of the RDSS provides for a unique service enabling central offices and headquarters to obtain position-location information and receive short digital messages from mobile user terminals throughout the contiguous United States, southern Canada, and northern Mexico. The system employs a spread-spectrum, CDMA modulation technique allowing multiple customers to use the system simultaneously, without preassigned coordination with fellow users. Position location is currently determined by employing an existing radio determination receiver, such as Loran-C, GPS, or Transit, in the mobile user terminal. In the early 1990s position location will be determined at a central earth station by time-differential ranging of the user terminals via two or more geostationary satellites. A brief overview of the RDSS system architecture is presented with emphasis on the user terminal and its diverse applications.

  2. Semantics versus Statistics in the Retreat from Locative Overgeneralization Errors

    Science.gov (United States)

    Ambridge, Ben; Pine, Julian M.; Rowland, Caroline F.

    2012-01-01

    The present study investigated how children learn that some verbs may appear in the figure-locative but not the ground-locative construction (e.g., "Lisa poured water into the cup"; "*Lisa poured the cup with water"), with some showing the opposite pattern (e.g., "*Bart filled water into the cup"; "Bart filled the cup with water"), and others…

  3. Lost in Location

    DEFF Research Database (Denmark)

    Hansen, Lone Koefoed

    2009-01-01

    The article investigates how users of personal satellite navigation devices (often referred to as sat-nav) are sometimes lost and led astray and argues that the satnav's aim to remove every insecurity about the correct route seems to remove the individual's conscious perception of the space...... performance, the article examines how the growing locative media industry can learn from the location-aware performative strategies employed by artists who create situated and urban performances for the curious participant. The academic frames employed in the analysis draw on psychogeography, site...

  4. Stem photosynthesis and hydraulics are coordinated in desert plant species.

    Science.gov (United States)

    Ávila-Lovera, Eleinis; Zerpa, Antonio J; Santiago, Louis S

    2017-08-21

    Coordination between stem photosynthesis and hydraulics in green-stemmed desert plants is important for understanding the physiology of stem photosynthesis and possible drought responses. Plants with photosynthetic stems have extra carbon gain that can help cope with the detrimental effects of drought. We studied photosynthetic, hydraulic and functional traits of 11 plant species with photosynthetic stems from three California desert locations. We compared relationships among traits between wet and dry seasons to test the effect of seasonality on these relationships. Finally, we compared stem trait relationships with analogous relationships in the leaf economics spectrum. We found that photosynthetic and hydraulic traits are coordinated in photosynthetic stems. The slope or intercept of all trait relationships was mediated by seasonality. The relationship between mass-based stem photosynthetic CO2 assimilation rate (Amass ) and specific stem area (SSA; stem surface area to dry mass ratio) was statistically indistinguishable from the leaf economics spectrum. Our results indicate that photosynthetic stems behave like leaves in the coordination of multiple traits related to carbon gain, water movement and water loss. Because of the similarity of the stem Amass -SSA relationship to the leaf Amass -specific leaf area relationship, we suggest the existence of a photosynthetic stem economic spectrum. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  5. Building Grounded Theory in Entrepreneurship Research

    DEFF Research Database (Denmark)

    Mäkelä, Markus; Turcan, Romeo V.

    2007-01-01

    In this chapter we describe the process of building of theory from data (Glaser and Strauss 1967; Strauss and Corbin 1998). We discuss current grounded theory in relation to research in entrepreneurship and point out directions and potential improvements for further research in this field...... our approach to grounded theory, we acknowledge the existence of other approaches and try to locate our approach in relation to them. As an important part of this discussion, we take a stand on how to usefully define ‘grounded theory’ and ‘case study research’. Second, we seek to firmly link our....... The chapter has two goals. First, we wish to provide an explicit paradigmatic positioning of the grounded theory methodology, discussing the most relevant views of ontology and epistemology that can be used as alternative starting points for conducting grounded theory research. While the chapter introduces...

  6. Building Grounded Theory in Entrepreneurship Research

    DEFF Research Database (Denmark)

    Mäkelä, Markus; Turcan, Romeo V.

    2007-01-01

    our approach to grounded theory, we acknowledge the existence of other approaches and try to locate our approach in relation to them. As an important part of this discussion, we take a stand on how to usefully define ‘grounded theory’ and ‘case study research’. Second, we seek to firmly link our......In this chapter we describe the process of building of theory from data (Glaser and Strauss 1967; Strauss and Corbin 1998). We discuss current grounded theory in relation to research in entrepreneurship and point out directions and potential improvements for further research in this field...... discussion to the potential value of grounded theory research to the field of entrepreneurship and thus the need in this field of further grounded theory....

  7. Location-routing problems

    Energy Technology Data Exchange (ETDEWEB)

    Laporte, G.

    1987-01-01

    Location-routing problems involve simultaneously locating a number of facilities among candidate sites and establishing delivery routes to a set of users in such a way that the total system cost is minimized. This paper presents a survey of such problems. It includes some applications and examples of location-routing problems, a description of the main heuristics that have been developed for such problems, and reviews of various formulations and algorithms used in solving these problems. A more detailed review is given of exact algorithms for the vehicle routing problem, three-index vehicle flow formulations, and two-index vehicle flow formulations and algorithms for symmetrical and non-symmetrical problems. It is concluded that location-routing problem research is a fast-growing area, with most developments occurring over the past few years; however, research is relatively fragmented, often addresses problems which are too specific and contains several voids which have yet to be filled. A number of promising research areas are identified. 137 refs., 3 figs.

  8. The Czech Locative Chameleon

    Directory of Open Access Journals (Sweden)

    Tarald Taraldsen

    2007-12-01

    Full Text Available We show that under certain circumstances, the Czech locative prepositions (LOC show up as directional prepositions (DIR and vice versa, (under different circumstances the Czech DIR PPs show up as LOC. We argue that such a chameleon life of the PPs is structurally dependent.

  9. The Czech Locative Chameleon

    OpenAIRE

    Tarald Taraldsen; Lucie Medová

    2007-01-01

    We show that under certain circumstances, the Czech locative prepositions (LOC) show up as directional prepositions (DIR) and vice versa, (under different circumstances) the Czech DIR PPs show up as LOC. We argue that such a chameleon life of the PPs is structurally dependent.

  10. Locative Inversion in English

    NARCIS (Netherlands)

    Broekhuis, H.

    2005-01-01

    This article aims at reformulating in more current terms Hoekstra and Mulder’s (1990) analysis of the Locative Inversion (LI) construction. The new proposal is crucially based on the assumption that Small Clause (SC) predicates agree with their external argument in phi-features, which may be morphol

  11. Location-based games

    DEFF Research Database (Denmark)

    Ejsing-Duun, Stine

    In this dissertation, it is explored which prerequisites are necessary in location-based games (LBGs) to make meaningful the meeting between players and spatiality with an emphasis on physical locations. Throughout the dissertation, it has been shown that LBGs affect players’ perception of and be......In this dissertation, it is explored which prerequisites are necessary in location-based games (LBGs) to make meaningful the meeting between players and spatiality with an emphasis on physical locations. Throughout the dissertation, it has been shown that LBGs affect players’ perception...... of and behavior in everyday spaces, as the games reside on the boundaries between the continuums of play and ordinary, authentic and fictional, and as they merge physical and digital media. These are termed the six dimensions of LBGs. LBGs let the player explore the boundaries between these dimensions...... experiences of being in the world and the creation of meaning. The theory on motivation defines what motivation consists of and how it relates to our actions. This theory has been combined with theories concerning play and play culture, digital media, (digital) games, (optimal) experiences, landscape...

  12. RFID Location Algorithm

    Directory of Open Access Journals (Sweden)

    Wang Zi Min

    2016-01-01

    Full Text Available With the development of social services, people’s living standards improve further requirements, there is an urgent need for a way to adapt to the complex situation of the new positioning technology. In recent years, RFID technology have a wide range of applications in all aspects of life and production, such as logistics tracking, car alarm, security and other items. The use of RFID technology to locate, it is a new direction in the eyes of the various research institutions and scholars. RFID positioning technology system stability, the error is small and low-cost advantages of its location algorithm is the focus of this study.This article analyzes the layers of RFID technology targeting methods and algorithms. First, RFID common several basic methods are introduced; Secondly, higher accuracy to political network location method; Finally, LANDMARC algorithm will be described. Through this it can be seen that advanced and efficient algorithms play an important role in increasing RFID positioning accuracy aspects.Finally, the algorithm of RFID location technology are summarized, pointing out the deficiencies in the algorithm, and put forward a follow-up study of the requirements, the vision of a better future RFID positioning technology.

  13. Crime Location Choice

    NARCIS (Netherlands)

    Bernasco, Wim; Ruiter, Stijn

    2014-01-01

    Most behavior of interest to social scientists is choice behavior: actions people commit while they could also have done something else. In geographical and environmental criminology, a new framework has emerged for analyzing individual crime location choice. It is based on the principle of random u

  14. Plant stem cells as innovation in cosmetics.

    Science.gov (United States)

    Moruś, Martyna; Baran, Monika; Rost-Roszkowska, Magdalena; Skotnicka-Graca, Urszula

    2014-01-01

    The stem cells thanks to their ability of unlimited division number or transformation into different cell types creating organs, are responsible for regeneration processes. Depending on the organism in which the stem cells exists, they divide to the plant or animal ones. The later group includes the stem cells existing in both embryo's and adult human's organs. It includes, among others, epidermal stem cells, located in the hair follicle relieves and also in its basal layers, and responsible for permanent regeneration of the epidermis. Temporary science looks for method suitable for stimulation of the epidermis stem cells, amongst the other by delivery of e.g., growth factors for proliferation that decrease with the age. One of the methods is the use of the plant cell culture technology, including a number of methods that should ensure growth of plant cells, issues or organs in the environment with the microorganism-free medium. It uses abilities of the different plant cells to dedifferentiation into stem cells and coming back to the pluripotent status. The extracts obtained this way from the plant stem cells are currently used for production of both common or professional care cosmetics. This work describes exactly impact of the plant stem cell extract, coming from one type of the common apple tree (Uttwiler Spätlauber) to human skin as one of the first plant sorts, which are used in cosmetology and esthetic dermatology.

  15. Simulation of Ground Winds Time Series

    Science.gov (United States)

    Adelfang, S. I.

    2008-01-01

    A simulation process has been developed for generation of the longitudinal and lateral components of ground wind atmospheric turbulence as a function of mean wind speed, elevation, temporal frequency range and distance between locations. The distance between locations influences the spectral coherence between the simulated series at adjacent locations. Short distances reduce correlation only at high frequencies; as distances increase correlation is reduced over a wider range of frequencies. The choice of values for the constants d1 and d3 in the PSD model is the subject of work in progress. An improved knowledge of the values for zO as a function of wind direction at the ARES-1 launch pads is necessary for definition of d1. Results of other studies at other locations may be helpful as summarized in Fichtl's recent correspondence. Ideally, further research is needed based on measurements of ground wind turbulence with high resolution anemometers at a number of altitudes at a new KSC tower located closer to the ARES-1 launch pad .The proposed research would be based on turbulence measurements that may be influenced by surface terrain roughness that may be significantly different from roughness prior to 1970 in Fichtl's measurements. Significant improvements in instrumentation, data storage end processing will greatly enhance the capability to model ground wind profiles and ground wind turbulence.

  16. Magnetometry and Ground-Penetrating Radar Studies in the Sihuas Valley, Peru

    Science.gov (United States)

    Wisnicki, E.; Papadimitrios, K.; Bank, C.

    2013-12-01

    The Quillcapampa la Antigua site in Peru's Sihuas Valley is a settlement from Peru's Middle Horizon (600-100 A.D.). Archaeological interest in the area stems from the question of whether ancient civilizations were able to have extensive state control of distant groups, or whether state influence occurred through less direct ties (e.g., marriage, religion, or trade). Our geophysical surveys are preliminary to archaeological digging in the area. Ground-penetrating radar and magnetometry attempt to locate areas of interest for focused archaeological excavation, characterize the design of architectural remains and burial mounds in the area, and allow archaeologists to interpret the amount of influence the Wari civilization had on the local residents.

  17. Electric current locator

    Science.gov (United States)

    King, Paul E [Corvallis, OR; Woodside, Charles Rigel [Corvallis, OR

    2012-02-07

    The disclosure herein provides an apparatus for location of a quantity of current vectors in an electrical device, where the current vector has a known direction and a known relative magnitude to an input current supplied to the electrical device. Mathematical constants used in Biot-Savart superposition equations are determined for the electrical device, the orientation of the apparatus, and relative magnitude of the current vector and the input current, and the apparatus utilizes magnetic field sensors oriented to a sensing plane to provide current vector location based on the solution of the Biot-Savart superposition equations. Description of required orientations between the apparatus and the electrical device are disclosed and various methods of determining the mathematical constants are presented.

  18. Comparison of algorithms for finding the air-ground interface in ground penetrating radar signals

    Science.gov (United States)

    Wood, Joshua; Bolton, Jeremy; Casella, George; Collins, Leslie; Gader, Paul; Glenn, Taylor; Ho, Jeffery; Lee, Wen; Mueller, Richard; Smock, Brandon; Torrione, Peter; Watford, Ken; Wilson, Joseph

    2011-06-01

    In using GPR images for landmine detection it is often useful to identify the air-ground interface in the GPR signal for alignment purposes. A number of algorithms have been proposed to solve the air-ground interface detection problem, including some which use only A-scan data, and others which track the ground in B-scans or C-scans. Here we develop a framework for comparing these algorithms relative to one another and we examine the results. The evaluations are performed on data that have been categorized in terms of features that make the air-ground interface difficult to find or track. The data also have associated human selected ground locations, from multiple evaluators, that can be used for determining correctness. A distribution is placed over each of the human selected ground locations, with the sum of these distributions at the algorithm selected location used as a measure of its correctness. Algorithms are also evaluated in terms of how they affect the false alarm and true positive rates of mine detection algorithms that use ground aligned data.

  19. Real-time Gaussian Markov random-field-based ground tracking for ground penetrating radar data

    Science.gov (United States)

    Bradbury, Kyle; Torrione, Peter A.; Collins, Leslie

    2009-05-01

    Current ground penetrating radar algorithms for landmine detection require accurate estimates of the location of the air/ground interface to maintain high levels of performance. However, the presence of surface clutter, natural soil roughness, and antenna motion lead to uncertainty in these estimates. Previous work on improving estimates of the location of the air/ground interface have focused on one-dimensional filtering techniques to localize the air/ground interface. In this work, we propose an algorithm for interface localization using a 2- D Gaussian Markov random field (GMRF). The GMRF provides a statistical model of the surface structure, which enables the application of statistical optimization techniques. In this work, the ground location is inferred using iterated conditional modes (ICM) optimization which maximizes the conditional pseudo-likelihood of the GMRF at a point, conditioned on its neighbors. To illustrate the efficacy of the proposed interface localization approach, pre-screener performance with and without the proposed ground localization algorithm is compared. We show that accurate localization of the air/ground interface provides the potential for future performance improvements.

  20. Social class and the STEM career pipeline an ethnographic investigation of opportunity structures in a high-poverty versus affluent high school

    Science.gov (United States)

    Nikischer, Andrea B.

    This research investigates science, technology, engineering and mathematics (STEM) high school opportunity structures, including student experiences with math and science course sequences and progress, college guidance and counseling, and STEM extracurricular activities (Weis and Eisenhart, 2009), specifically related to STEM fields and career and college choice, for top-performing math and science students. Differences in these structures and processes as they play out in two representative high schools that vary by social class and racial/ethnic makeup are examined. This comparative ethnography includes 36 school and classroom observations, 56 semi-structured individual interviews, and a review of relevant documents, all gathered during the focal students' junior year of high school. Three data chapters are presented, discussing three distinct, yet interconnected themes. In the first, I examine the ways in which chronic attendance problems and classroom distractions negatively impact math and science instruction time and lead to an instruction (time) deficit. In the second, I compare the math and science course and extra-curricular offerings at each school, and discuss the significant differences between sites regarding available STEM exposure and experience, also known as "STEM educational dose" (Wai, et al., 2010). In the third, I investigate available guidance counseling services and STEM and college-linking at each site. Perceived failures in the counseling services available are discussed. This dissertation is grounded in the literature on differences in academic achievement based on school setting, the nature/distribution of knowledge based on social class, and STEM opportunity structures. The concepts of "social capital" and "STEM capital" are engaged throughout. Ultimately, I argue through this dissertation that segregation by race, and most importantly social class, both between and within districts, damages the STEM pipeline for high-performing math and

  1. Ground level cosmic ray observations

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, S.A. [Tata Institute of Fundamental Research, Bombay (International Commission on Radiation Units and Measurements); Grimani, C.; Brunetti, M.T.; Codino, A. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); Papini, P.; Massimo Brancaccio, F.; Piccardi, S. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Basini, G.; Bongiorno, F. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Hof, M. [Siegen Univ. (Germany). Fachbereich Physik

    1995-09-01

    Cosmic rays at ground level have been collected using the NMSU/Wizard - MASS2 instrument. The 17-hr observation run was made on September 9. 1991 in Fort Sumner, New Mexico, Usa. Fort Sumner is located at 1270 meters a.s.l., corresponding to an atmospheric depth of about 887 g/cm{sup 2}. The geomagnetic cutoff is 4.5 GV/c. The charge ratio of positive and negative muons and the proton to muon ratio have been determined. These observations will also be compared with data collected at a higher latitude using the same basic apparatus.

  2. Elements of the niche for adult stem cell expansion.

    Science.gov (United States)

    Redondo, Patricia A; Pavlou, Marina; Loizidou, Marilena; Cheema, Umber

    2017-01-01

    Adult stem cells are crucial for tissue homeostasis. These cells reside within exclusive locations in tissues, termed niches, which protect adult stem cell fidelity and regulate their many functions through biophysical-, biochemical- and cellular-mediated mechanisms. There is a growing understanding of how these mechanisms and their components contribute towards maintaining stem cell quiescence, self-renewal, expansion and differentiation patterns. In vitro expansion of adult stem cells is a powerful tool for understanding stem cell biology, and for tissue engineering and regenerative medicine applications. However, it is technically challenging, since adult stem cell removal from their native microenvironment has negative repercussions on their sustainability. In this review, we overview specific elements of the biomimetic niche and how recreating such elements can help in vitro propagation of adult stem cells.

  3. Immigrants' location preferences

    DEFF Research Database (Denmark)

    Damm, Anna Piil

    This paper exploits a spatial dispersal policy for refugee immigrants to estimate the importance of local and regional factors for refugees' location preferences. The main results of a mixed proportional hazard competing risks model are that placed refugees react to high regional unemployment...... and lack of a local immigrant population by migrating to large municipalities. Lack of local fellow countrymen, however, increases the exit rate to medium-sized as well as large municipalities. This finding is likely to be a result of the dispersal policy. Finally, refugees react strongly to assignment...

  4. The experiences of Panamanian Afro-Caribbean women in STEM: Voices to inform work with Black females in STEM education

    Science.gov (United States)

    Miller, Beverly A. King

    This grounded theory case study examines the experiences of Panamanian Afro-Caribbean women and their membership in STEM (Science, Technology, Engineering and Mathematics) training and careers. The shortage of Science and Math teachers in 48 of 50 States heightens the need for those trained in STEM. Females of African phenotype have persistently been underrepresented in STEM. However, this trend does not appear to have held for Panamanian Afro-Caribbean women. The current study explores issues related to STEM participation for these women by addressing the overarching question: What key factors from the lived experiences of Panamanian Afro-Caribbean women in STEM careers can be used to inform work with females of African phenotype in their pursuit of STEM education and STEM careers? Five women were identified for inclusion in the study's purposive sample. The study draws upon assertions and implications about the relevance of self-identity and collective-identity for membership in STEM. Data for the study was gathered through qualitative interviews, surveys, and observations. The grounded theory approach was used to analyze emergent themes related to participants' responses to the research questions. Two models, the STEM Attainment Model (SAM) and the Ecological Model of Self-Confidence and Bi-Directional Effect, are proposed from evaluation of the identified information. Socio-cultural values and learned strategies were determined to influence self-confidence which is identified as important for persistence in STEM training and careers for females of African phenotype. Evidence supports that the influences of parents, country of origin, neighborhood communities, schools and teachers are factors for persistence. Through the voices of these women, recommendations are offered to the gatekeepers of STEM academic pathways and ultimately STEM careers.

  5. [Therapeutic use of stem cells].

    Science.gov (United States)

    Uzan, Georges

    2004-09-15

    Stem cells display important capacities of self renewing, proliferation and differentiation. Because those present in the embryo have the more remarkable properties, their potential use in the therapy of until now incurable degenerative diseases have been envisioned. Embryonic stem (ES) cells are located in the inner mass of the balstocyst at early stages of the development. Even in long-term cultures they still retain their undifferentiated features. Under specific culture conditions, ES cells can be committed into a variety of differentiation pathways, giving rise to large amounts of cells corresponding to different tissues (neurones, cardiomyocytes, skeletal muscle, etc.). However, producing these tissues from already established ES cell lines would lead to immune rejection when transplanted to patients. To prevent this pitfall and using the expertise accumulated by animal cloning by nucleus transfer, it has been proposed to adapt this technique to human ES cells. The therapeutic cloning consists in transferring the nucleus of somatic stem cells isolated from the patient into an enucleated oocyte, to allow blastocyst development from which ES cells will be derived. From these stem cells, compatible tissues will be then produced. The problem is that it is in theoretically possible to reimplant the cloned blastocyst into a surrogate mother for obtaining a baby genetically identical to the donor. This is called reproductive cloning. This worrying risk raises important ethic and legal questions.

  6. General minisum circle location

    DEFF Research Database (Denmark)

    Körner, Mark; Brimberg, Jack; Juel, Henrik

    2009-01-01

    In our paper we approximate a set of given points by a general circle. More precisely, we consider the problem of locating and scaling the unit ball of some given norm k1 with respect to xed points on the plane such that the sum of weighted distances between the circle and the xed points is minim......In our paper we approximate a set of given points by a general circle. More precisely, we consider the problem of locating and scaling the unit ball of some given norm k1 with respect to xed points on the plane such that the sum of weighted distances between the circle and the xed points...... is minimized, where the distance is measured by a norm k2. We present results for the general case. In the case that k1 and k2 are both block norms, we are able to identify a nite dominating set in R3 for the problem, which can be obtained as the intersection of cones....

  7. Indoor Location Technologies

    CERN Document Server

    Goswami, Subrata

    2013-01-01

    Focusing on the special challenges posed by accurately pinpointing a location indoors, this volume reflects the distance we have come in the handful of decades since the germination of GPS technology. Not only can we locate a signal to within a meter’s accuracy, but we now have this technology in the most basic mobile phone. Tracing recent practical developments in positioning technology and in the market it supplies, the author examines the contributions of the varied research—in silicon, signal and image processing, radio communications and software—to a fast-evolving field. The book looks forward to a time when, in addition to directing your road journey, positioning systems can peer indoors and guide you to an available photocopier in your office building. Featuring standalone chapters each dealing with a specific aspect of the subject, including treatments of systems such as Zebra, Awarepoint, Aeroscout, IEEE 802.11, etc. This study has all the detail needed to get up to speed on a key modern techn...

  8. Location and distribution of bone marrow mesenchymal stem cells in the kidney of IgA nephropathy rats%骨髓间充质干细胞在IgA肾病大鼠肾脏中的定位与分布

    Institute of Scientific and Technical Information of China (English)

    彭伟; 刘郑荣

    2011-01-01

    背景:由于骨髓间充质干细胞缺乏特异性表面抗原,常根据其贴壁生长、成骨成脂分化等生物学特点来鉴定.目的:观察骨髓间充质干细胞在IgA肾病大鼠肾脏中的定位与分布情况.方法:以牛血清白蛋白+葡萄球菌肠毒素B+皮下注射四氯化碳的改良法建立SD大鼠IgA肾病模型.造模成功分别经尾静脉移植大鼠骨髓间充质干细胞或生理盐水,并设立不造模的正常对照组.移植后1,4周观察各组大鼠的尿蛋白、肾功能、肾脏病理变化、IgA荧光沉积变化,并通过免疫组织化学观察BrdU标记的骨髓间充质干细胞在肾组织中的分布情况.结果与结论:移植后1周,骨髓间充质干细胞组尿蛋白、血肌酐明显低于生理盐水组;移植后4周,骨髓间充质干细胞组肾脏病理变化、IgA荧光沉积与生理盐水组比较差异有显著性意义.提示骨髓间充质干细胞输注可促进大鼠IgA肾病的修复,并可定位于肾小球系膜区及少数肾小管间质区,但随时间延长,BrdU标记的髓间充质干细胞在肾组织中分布却逐渐减少.%BACKGROUND: Bone marrow mesenchymal stem cells (BMSCs) without specific surface antigens are often identified according to adhesive growth, osteogenic differentiation, adipogenic differentiation and other biological characteristics. OBJECTIVE: to observe the location and distribution of BMSCs in IgA nephropathy rats.METHODS: Sprague-Dawley rats were randomly divided into three groups: BMSCs group, saline group and control group. IgA nephropathy model was established by the improving method with bovine serum albumin+staphylococcal enterotoxin B+subcutaneous injection of carbon tetrachloride in the former two groups. At the 1st and 4th weeks after BMSCs injection, the changes of urine protein, renal function, histopathology and IgA immunofluorescence were observed. BrdU-labeled BMSCs were detected by immunohistochemistry to observe the disposition in the kidney

  9. Airport Ground Staff Scheduling

    DEFF Research Database (Denmark)

    Clausen, Tommy

    travels safely and efficiently through the airport. When an aircraft lands, a significant number of tasks must be performed by different groups of ground crew, such as fueling, baggage handling and cleaning. These tasks must be complete before the aircraft is able to depart, as well as check......-in and security services. These tasks are collectively known as ground handling, and are the major source of activity with airports. The business environments of modern airports are becoming increasingly competitive, as both airports themselves and their ground handling operations are changing to private...... ownership. As airports are in competition to attract airline routes, efficient and reliable ground handling operations are imperative for the viability and continued growth of both airports and airlines. The increasing liberalization of the ground handling market prompts ground handling operators...

  10. [Introduction to grounded theory].

    Science.gov (United States)

    Wang, Shou-Yu; Windsor, Carol; Yates, Patsy

    2012-02-01

    Grounded theory, first developed by Glaser and Strauss in the 1960s, was introduced into nursing education as a distinct research methodology in the 1970s. The theory is grounded in a critique of the dominant contemporary approach to social inquiry, which imposed "enduring" theoretical propositions onto study data. Rather than starting from a set theoretical framework, grounded theory relies on researchers distinguishing meaningful constructs from generated data and then identifying an appropriate theory. Grounded theory is thus particularly useful in investigating complex issues and behaviours not previously addressed and concepts and relationships in particular populations or places that are still undeveloped or weakly connected. Grounded theory data analysis processes include open, axial and selective coding levels. The purpose of this article was to explore the grounded theory research process and provide an initial understanding of this methodology.

  11. Ground Vehicle Robotics

    Science.gov (United States)

    2013-08-20

    Ground Vehicle Robotics Jim Parker Associate Director, Ground Vehicle Robotics UNCLASSIFIED: Distribution Statement A. Approved for public...DATE 20 AUG 2013 2. REPORT TYPE Briefing Charts 3. DATES COVERED 09-05-2013 to 15-08-2013 4. TITLE AND SUBTITLE Ground Vehicle Robotics 5a...Willing to take Risk on technology -User Evaluated -Contested Environments -Operational Data Applied Robotics for Installation & Base Ops -Low Risk

  12. The Grounded Theory Bookshelf

    Directory of Open Access Journals (Sweden)

    Vivian B. Martin, Ph.D.

    2005-03-01

    Full Text Available Bookshelf will provide critical reviews and perspectives on books on theory and methodology of interest to grounded theory. This issue includes a review of Heaton’s Reworking Qualitative Data, of special interest for some of its references to grounded theory as a secondary analysis tool; and Goulding’s Grounded Theory: A practical guide for management, business, and market researchers, a book that attempts to explicate the method and presents a grounded theory study that falls a little short of the mark of a fully elaborated theory.Reworking Qualitative Data, Janet Heaton (Sage, 2004. Paperback, 176 pages, $29.95. Hardcover also available.

  13. Locating Nordic Noir

    DEFF Research Database (Denmark)

    Hansen, Kim Toft; Waade, Anne Marit

    This book is a comprehensive study of Nordic Noir television drama from the 1990’s until today. The authors introduce the history of contemporary Nordic Noir from the perspective of place, production and location studies. The chapters include readings of well-known television crime dramas...... production in Sweden, Denmark, Norway and Iceland. Consequently, Nordic Noir is read as both a transnational financial and creative phenomenon and as a local possibility for community building. The book is aimed at readers with an interest in crime drama as well as television scholars and students...... of television drama, and it offers a comprehensible, scholarly and methodologically original approach to the popularity of Nordic television crime dramas....

  14. Quantum Image Location

    Science.gov (United States)

    Jiang, Nan; Dang, Yijie; Zhao, Na

    2016-10-01

    Quantum image processing has been a hot topic as a consequence of the development of quantum computation. Many quantum image processing algorithms have been proposed, whose efficiency are theoretically higher than their corresponding classical algorithms. However, most of the quantum schemes do not consider the problem of measurement. If users want to get the results, they must measure the final state many times to get all the pixels' values. Moreover, executing the algorithm one time, users can only measure the final state one time. In order to measure it many times, users must execute the algorithms many times. If the measurement process is taken into account, whether or not the algorithms are really efficient needs to be reconsidered. In this paper, we try to solve the problem of measurement and give a quantum image location algorithm. This scheme modifies the probability of pixels to make the target pixel to be measured with higher probability. Furthermore, it only has linear complexity.

  15. Hepatic stem cells: existence and origin

    Institute of Scientific and Technical Information of China (English)

    Ying Zhang; Xue-Fan Bai; Chang-Xing Huang

    2003-01-01

    Stem cells are not only units of biological organization,responsible for the development and the regeneration oftissue and organ systems, but also are units in evolution bynatural selection. It is accepted that there is stem cellpotential in the liver. Like most organs in a healthy adult,the liver maintains a perfect balance between cell gain andloss. It has three levels of cells that can respond to loss ofhepatocytes: (1) Mature hepatocytes, which proliferate afternormal liver tissue renewal, less severe liver damage, etc;they are numerous, unipotent, "committed" and respondrapidly to liver injury. (2) Oval cells, which are activated toproliferate when the liver damage is extensive and chronic,or if proliferation of hepatocytes is inhibited; they lie withinor immediately adjacent tothe canal of Hering (CoH); theyare less numerous, bipotent and respond by longer, but stilllimited proliferation. (3) Exogenous liver stem cells, whichmay derive from circulating hematopoietic stem cells (HSCs)or bone marrow stem cells; they respond to allyl alcoholinjury or hepatocarcinogenesis; they are multipotent, rare,but have a very long proliferation potential. They make amore significant contribution to regeneration, and evencompletely restore normal function in a murine model ofhereditary tyrosinaemia. How these three stem cellpopulations integrate to achieve a homeostatic balanceremains enigmatic. This review focuses on the location,activation, markers of the three candidates of liver stemcell, and the most importantly, therapeutic potential ofhepatic stem cells.

  16. Hanford site ground water protection management plan

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    Ground water protection at the Hanford Site consists of preventative and remedial measures that are implemented in compliance with a variety of environmental regulations at local, state, and federal levels. These measures seek to ensure that the resource can sustain a broad range of beneficial uses. To effectively coordinate and ensure compliance with applicable regulations, the U.S. Department of Energy has issued DOE Order 5400.1 (DOE 1988a). This order requires all U.S. Department of Energy facilities to prepare separate ground water protection program descriptions and plans. This document describes the Ground Water Protection Management Plan (GPMP) for the Hanford Site located in the state of Washington. DOE Order 5400.1 specifies that the GPMP covers the following general topical areas: (1) documentation of the ground water regime; (2) design and implementation of a ground water monitoring program to support resource management and comply with applicable laws and regulations; (3) a management program for ground water protection and remediation; (4) a summary and identification of areas that may be contaminated with hazardous waste; (5) strategies for controlling hazardous waste sources; (6) a remedial action program; and (7) decontamination, decommissioning, and related remedial action requirements. Many of the above elements are currently covered by existing programs at the Hanford Site; thus, one of the primary purposes of this document is to provide a framework for coordination of existing ground water protection activities. The GPMP provides the ground water protection policy and strategies for ground water protection/management at the Hanford Site, as well as an implementation plan to improve coordination of site ground water activities.

  17. DETECTION OF SINGLE TREE STEMS IN FORESTED AREAS FROM HIGH DENSITY ALS POINT CLOUDS USING 3D SHAPE DESCRIPTORS

    Directory of Open Access Journals (Sweden)

    N. Amiri

    2017-09-01

    Full Text Available Airborne Laser Scanning (ALS is a widespread method for forest mapping and management purposes. While common ALS techniques provide valuable information about the forest canopy and intermediate layers, the point density near the ground may be poor due to dense overstory conditions. The current study highlights a new method for detecting stems of single trees in 3D point clouds obtained from high density ALS with a density of 300 points/m2. Compared to standard ALS data, due to lower flight height (150–200 m this elevated point density leads to more laser reflections from tree stems. In this work, we propose a three-tiered method which works on the point, segment and object levels. First, for each point we calculate the likelihood that it belongs to a tree stem, derived from the radiometric and geometric features of its neighboring points. In the next step, we construct short stem segments based on high-probability stem points, and classify the segments by considering the distribution of points around them as well as their spatial orientation, which encodes the prior knowledge that trees are mainly vertically aligned due to gravity. Finally, we apply hierarchical clustering on the positively classified segments to obtain point sets corresponding to single stems, and perform ℓ1-based orthogonal distance regression to robustly fit lines through each stem point set. The ℓ1-based method is less sensitive to outliers compared to the least square approaches. From the fitted lines, the planimetric tree positions can then be derived. Experiments were performed on two plots from the Hochficht forest in Oberösterreich region located in Austria.We marked a total of 196 reference stems in the point clouds of both plots by visual interpretation. The evaluation of the automatically detected stems showed a classification precision of 0.86 and 0.85, respectively for Plot 1 and 2, with recall values of 0.7 and 0.67.

  18. Adaptive Magnetorheological Isolator for Ground Support Equipment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The minimization of vibration-induced damage has become a critical issue for rocket launch ground support electronics (GSE). GSE located near a major rocket launch...

  19. Pesticides in Ground Water

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup

    1996-01-01

    Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588.......Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588....

  20. Pesticides in Ground Water

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup

    1996-01-01

    Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588.......Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588....

  1. Performance of stem flow gauges in greenhouse and desert environments

    Energy Technology Data Exchange (ETDEWEB)

    Levitt, D.G. [Reynolds Electrical and Engineering Co., Inc., Las Vegas, NV (United States); Simpson, J.R. [California Univ., Davis, CA (United States). Dept. of Environmental Horticulture; Tipton, J.L. [Arizona Univ., Tucson, AZ (United States). Dept. of Plant Sciences

    1995-06-01

    This study was conducted to evaluate the accuracy and general performance of a heat balance method for estimating transpirational sap flow through plant stems on two tree species in greenhouse and field experiments in Tucson, Arizona. Sap flow through 20-mm diameter stems of oak (Quercus virginiana `Heritage`) and mesquite (Prosopis alba `Colorado`.) trees in containers was measured using stem flow gauges and a precision balance, from January to October, 1991. Overall gauge accuracy, and the effects of gauge location on the tree stem, gauge ventilation, gauge insulation, sheath conductance factor (Ksh) selection method, and increased numbers of vertical thermocouple pairs on gauge performance were evaluated.

  2. Tracking adult stem cells.

    Science.gov (United States)

    Snippert, Hugo J; Clevers, Hans

    2011-02-01

    The maintenance of stem-cell-driven tissue homeostasis requires a balance between the generation and loss of cell mass. Adult stem cells have a close relationship with the surrounding tissue--known as their niche--and thus, stem-cell studies should preferably be performed in a physiological context, rather than outside their natural environment. The mouse is an attractive model in which to study adult mammalian stem cells, as numerous experimental systems and genetic tools are available. In this review, we describe strategies commonly used to identify and functionally characterize adult stem cells in mice and discuss their potential, limitations and interpretations, as well as how they have informed our understanding of adult stem-cell biology. An accurate interpretation of physiologically relevant stem-cell assays is crucial to identify adult stem cells and elucidate how they self-renew and give rise to differentiated progeny.

  3. Stem Cell Information: Glossary

    Science.gov (United States)

    ... Tips Info Center Research Topics Federal Policy Glossary Stem Cell Information General Information Clinical Trials Funding Information Current ... here Home » Glossary Back to top Glossary Adult stem cell Astrocyte Blastocoel Blastocyst Bone marrow stromal cells Bone ...

  4. Stem Cell Transplant

    Science.gov (United States)

    ... transplant is a procedure that infuses healthy blood stem cells into your body to replace your damaged or ... A bone marrow transplant is also called a stem cell transplant. A bone marrow transplant may be necessary ...

  5. Geophysical methods for locating abandoned wells

    Science.gov (United States)

    Frischknecht, Frank C.; Muth, L.; Grette, R.; Buckley, T.; Kornegay, B.

    1983-01-01

    A preliminary study of the feasibility of using geophysical exploration methods to locate abandoned wells containing steel casing indicated that magnetic methods promise to be effective and that some electrical techniques might be useful as auxiliary methods. Ground magnetic measurements made in the vicinity of several known cased wells yielded total field anomalies with peak values ranging from about 1,500 to 6,000 gammas. The anomalies measured on the ground are very narrow and, considering noise due to other cultural and geologic sources, a line spacing on the order of 50 feet (15.2 m) would be necessary to locate all casings in the test area. The mathematical model used to represent a casing was a set of magnetic pole pairs. By use of a non-linear least squares curve fitting (inversion) program, model parameters which characterize each test casing were determined. The position and strength of the uppermost pole was usually well resolved. The parameters of lower poles were not as well resolved but it appears that the results are adequate for predicting the anomalies which would be observed at aircraft altitudes. Modeling based on the parameters determined from the ground data indicates that all of the test casings could be detected by airborne measurements made at heights of 150 to 200 feet (45.7-61.0 m) above the ground, provided lines spaced as closely as 330 feet (100 m) were used and provided noise due to other cultural and geologic sources is not very large. Given the noise levels of currently available equipment and assuming very low magnetic gradients due to geologic sources, the detection range for total field measurements is greater than that for measurements of the horizontal or vertical gradient of the total intensity. Electrical self-potential anomalies were found to be associated with most of the casings where measurements were made. However, the anomalies tend to be very narrow and, in several cases, they are comparable in magnitude to other small

  6. Communication, concepts and grounding.

    Science.gov (United States)

    van der Velde, Frank

    2015-02-01

    This article discusses the relation between communication and conceptual grounding. In the brain, neurons, circuits and brain areas are involved in the representation of a concept, grounding it in perception and action. In terms of grounding we can distinguish between communication within the brain and communication between humans or between humans and machines. In the first form of communication, a concept is activated by sensory input. Due to grounding, the information provided by this communication is not just determined by the sensory input but also by the outgoing connection structure of the conceptual representation, which is based on previous experiences and actions. The second form of communication, that between humans or between humans and machines, is influenced by the first form. In particular, a more successful interpersonal communication might require forms of situated cognition and interaction in which the entire representations of grounded concepts are involved.

  7. Stochastic ground motion simulation

    Science.gov (United States)

    Rezaeian, Sanaz; Xiaodan, Sun; Beer, Michael; Kougioumtzoglou, Ioannis A.; Patelli, Edoardo; Siu-Kui Au, Ivan

    2014-01-01

    Strong earthquake ground motion records are fundamental in engineering applications. Ground motion time series are used in response-history dynamic analysis of structural or geotechnical systems. In such analysis, the validity of predicted responses depends on the validity of the input excitations. Ground motion records are also used to develop ground motion prediction equations(GMPEs) for intensity measures such as spectral accelerations that are used in response-spectrum dynamic analysis. Despite the thousands of available strong ground motion records, there remains a shortage of records for large-magnitude earthquakes at short distances or in specific regions, as well as records that sample specific combinations of source, path, and site characteristics.

  8. Ground energy coupling

    Science.gov (United States)

    Metz, P. D.

    The feasibility of ground coupling for various heat pump systems was investigated. Analytical heat flow models were developed to approximate design ground coupling devices for use in solar heat pump space conditioning systems. A digital computer program called GROCS (GRound Coupled Systems) was written to model 3-dimensional underground heat flow in order to simulate the behavior of ground coupling experiments and to provide performance predictions which have been compared to experimental results. GROCS also has been integrated with TRNSYS. Soil thermal property and ground coupling device experiments are described. Buried tanks, serpentine earth coils in various configurations, lengths and depths, and sealed vertical wells are being investigated. An earth coil used to heat a house without use of resistance heating is described.

  9. On location at CERN

    CERN Multimedia

    Joannah Caborn Wengler

    2012-01-01

    CERN continues to be a very popular candidate for film locations at the moment. Not only has it inspired a German author and a film-maker interested in the more exotic interpretations of the science being worked on at the Organization, but even the recent puppet animation film by the legendary Muppets featured some CERN scenes.   Dr Bunsen Honeydew (far left) and his friends at ATLAS. Beaker, Bunsen's assistant, has just been sucked up the vacuum tube top left... Image courtesy Walt Disney Studios. In “The Muppet Movie”, released in November 2011 in North America and world-wide in January and February this year, Kermit is reuniting his friends who have ended up in some far-flung places since they last worked together 10 years ago. CERN caught the imagination of the film-makers as the perfect place for the Muppet scientists, Dr. Honeydew Bunsen and his hapless assistant Beaker. After a brief scene filmed in front of a backdrop of the ATLAS detector, the rest of the ...

  10. Costly location in Hotelling duopoly

    NARCIS (Netherlands)

    Hinloopen, J.; Martin, S.

    2013-01-01

    We introduce a cost of location into Hotelling’s (1929) spatial duopoly. We derive the general conditions on the cost-of-location function under which a pure strategy price-location Nash equilibrium exists. With linear transportation cost and a suitably specified cost of location that rises toward

  11. Ground Loop Impedance of Long EHV Cable Lines

    DEFF Research Database (Denmark)

    Ohno, Teruo; Bak, Claus Leth; Sørensen, Thomas K.

    2012-01-01

    The distance protection scheme without communication is often applied to the backup protection of EHV cable lines. For a reliable operation of a ground distance relay, the ground loop impedance of EHV cable lines needs to have a linear relationship to the distance from the relay location to the f...

  12. Tracking adult stem cells

    NARCIS (Netherlands)

    Snippert, H.J.G.; Clevers, H.

    2011-01-01

    The maintenance of stem-cell-driven tissue homeostasis requires a balance between the generation and loss of cell mass. Adult stem cells have a close relationship with the surrounding tissue--known as their niche--and thus, stem-cell studies should preferably be performed in a physiological context,

  13. Stereotaxic gamma knife surgery in treatment of critically located pilocytic astrocytoma: preliminary result

    Directory of Open Access Journals (Sweden)

    Hafez Raef FA

    2007-03-01

    Full Text Available Abstract Background Low-grade gliomas are uncommon primary brain tumors, located more often in the posterior fossa, optic pathway, and brain stem and less commonly in the cerebral hemispheres. Case presentations Two patients with diagnosed recurrent cystic pilocytic astrocytoma critically located within the brain (thalamic and brain stem were treated with gamma knife surgery. Gamma knife surgery (GKS did improve the patient's clinical condition very much which remained stable later on. Progressive reduction on the magnetic resonance imaging (MRI studies of the solid part of the tumor and almost disappearance of the cystic component was achieved within the follow-up period of 36 months in the first case with the (thalamic located lesion and 22 months in the second case with the (brain stem located lesion. Conclusion Gamma knife surgery represents an alternate tool in the treatment of recurrent and/or small postoperative residual pilocytic astrocytoma especially if they are critically located

  14. Stereotaxic gamma knife surgery in treatment of critically located pilocytic astrocytoma: preliminary result

    Science.gov (United States)

    Hafez, Raef FA

    2007-01-01

    Background Low-grade gliomas are uncommon primary brain tumors, located more often in the posterior fossa, optic pathway, and brain stem and less commonly in the cerebral hemispheres. Case presentations Two patients with diagnosed recurrent cystic pilocytic astrocytoma critically located within the brain (thalamic and brain stem) were treated with gamma knife surgery. Gamma knife surgery (GKS) did improve the patient's clinical condition very much which remained stable later on. Progressive reduction on the magnetic resonance imaging (MRI) studies of the solid part of the tumor and almost disappearance of the cystic component was achieved within the follow-up period of 36 months in the first case with the (thalamic located lesion) and 22 months in the second case with the (brain stem located lesion). Conclusion Gamma knife surgery represents an alternate tool in the treatment of recurrent and/or small postoperative residual pilocytic astrocytoma especially if they are critically located PMID:17394660

  15. Plant and animal stem cells: similar yet different.

    Science.gov (United States)

    Heidstra, Renze; Sabatini, Sabrina

    2014-05-01

    The astonishingly long lives of plants and their regeneration capacity depend on the activity of plant stem cells. As in animals, stem cells reside in stem cell niches, which produce signals that regulate the balance between self-renewal and the generation of daughter cells that differentiate into new tissues. Plant stem cell niches are located within the meristems, which are organized structures that are responsible for most post-embryonic development. The continuous organ production that is characteristic of plant growth requires a robust regulatory network to keep the balance between pluripotent stem cells and differentiating progeny. Components of this network have now been elucidated and provide a unique opportunity for comparing strategies that were developed in the animal and plant kingdoms, which underlie the logic of stem cell behaviour.

  16. Fault location method for transmission line based on traveling waves

    Institute of Scientific and Technical Information of China (English)

    ZHENG Na; ZHAO Yulin

    2007-01-01

    The single phase grounding fault location is the focus which researchers pay attention to and study in power system. The accurate fault location can lighten the patrolling burden, and enhance the reliability of the power network. It adopts A/D which has high speed, and uses TMS320VC5402 DSP chip as the system core. This paper presented theory of operation based on traveling waves and achieved software and hardware in detail.

  17. Locating industrial VOC sources with aircraft observations

    Energy Technology Data Exchange (ETDEWEB)

    Toscano, P., E-mail: p.toscano@ibimet.cnr.it [Institute for Biometeorology (IBIMET - CNR), Via G. Caproni 8, 50145 Firenze (Italy); Gioli, B. [Institute for Biometeorology (IBIMET - CNR), Via G. Caproni 8, 50145 Firenze (Italy); Dugheri, S. [Careggi Hospital-University of Florence, Occupational Health Division, Largo Palagi 1, 50100 Florence (Italy); Salvini, A. [Department of Organic Chemistry, University of Florence, Via della Lastruccia 13, 50019 Sesto Fiorentino, Florence (Italy); Matese, A. [Institute for Biometeorology (IBIMET - CNR), Via G. Caproni 8, 50145 Firenze (Italy); Bonacchi, A. [Careggi Hospital-University of Florence, Occupational Health Division, Largo Palagi 1, 50100 Florence (Italy); Zaldei, A. [Institute for Biometeorology (IBIMET - CNR), Via G. Caproni 8, 50145 Firenze (Italy); Cupelli, V. [Careggi Hospital-University of Florence, Occupational Health Division, Largo Palagi 1, 50100 Florence (Italy); Miglietta, F. [Institute for Biometeorology (IBIMET - CNR), Via G. Caproni 8, 50145 Firenze (Italy); Fondazione Edmund Mach, Via Mach 1, San Michele all' Adige, Trento (Italy)

    2011-05-15

    Observation and characterization of environmental pollution, focussing on Volatile Organic Compounds (VOCs), in a high-risk industrial area, are particularly important in order to provide indications on a safe level of exposure, indicate eventual priorities and advise on policy interventions. The aim of this study is to use the Solid Phase Micro Extraction (SPME) method to measure VOCs, directly coupled with atmospheric measurements taken on a small aircraft environmental platform, to evaluate and locate the presence of VOC emission sources in the Marghera industrial area. Lab analysis of collected SPME fibres and subsequent analysis of mass spectrum and chromatograms in Scan Mode allowed the detection of a wide range of VOCs. The combination of this information during the monitoring campaign allowed a model (Gaussian Plume) to be implemented that estimates the localization of emission sources on the ground. - Highlights: > Flight plan aimed at sampling industrial area at various altitudes and locations. > SPME sampling strategy was based on plume detection by means of CO{sub 2}. > Concentrations obtained were lower than the limit values or below the detection limit. > Scan mode highlighted presence of {gamma}-butyrolactone (GBL) compound. > Gaussian dispersion modelling was used to estimate GBL source location and strength. - An integrated strategy based on atmospheric aircraft observations and dispersion modelling was developed, aimed at estimating spatial location and strength of VOC point source emissions in industrial areas.

  18. Lung Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Sharon R. Pine

    2008-01-01

    Full Text Available Lung cancer remains a major cause of cancer-related lethality because of high incidence and recurrence in spite of significant advances in staging and therapies. Recent data indicates that stem cells situated throughout the airways may initiate cancer formation. These putative stem cells maintain protumorigenic characteristics including high proliferative capacity, multipotent differentiation, drug resistance and long lifespan relative to other cells. Stem cell signaling and differentiation pathways are maintained within distinct cancer types, and destabilization of this machinery may participate in maintenance of cancer stem cells. Characterization of lung cancer stem cells is an area of active research and is critical for developing novel therapies. This review summarizes the current knowledge on stem cell signaling pathways and cell markers used to identify the lung cancer stem cells.

  19. Plant stem cell niches.

    Science.gov (United States)

    Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas

    2012-01-01

    Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis.

  20. Search for naive human pluripotent stem cells

    Institute of Scientific and Technical Information of China (English)

    Simone Aparecida Siqueira Fonseca; Roberta Montero Costas; Lygia Veiga Pereira

    2015-01-01

    Normal mouse pluripotent stem cells were originallyderived from the inner cell mass (ICM) of blastocystsand shown to be the in vitro equivalent of those preimplantationembryonic cells, and thus were calledembryonic stem cells (ESCs). More than a decade later,pluripotent cells were isolated from the ICM of humanblastocysts. Despite being called human ESCs, thesecells differ significantly from mouse ESCs, includingdifferent morphology and mechanisms of control ofpluripotency, suggesting distinct embryonic originsof ESCs from the two species. Subsequently, mousepluripotent stem cells were established from the ICMderivedepiblast of post-implantation embryos. Thesemouse epiblast stem cells (EpiSCs) are morphologicaland epigenetically more similar to human ESCs. Thisraised the question of whether cells from the humanICM are in a more advanced differentiation stage thantheir murine counterpart, or whether the availableculture conditions were not adequate to maintain thosehuman cells in their in vivo state, leading to a transitioninto EpiSC-like cells in vitro . More recently, novel cultureconditions allowed the conversion of human ESCs intomouse ESC-like cells called naive (or ground state)human ESCs, and the derivation of naive human ESCsfrom blastocysts. Here we will review the characteristicsof each type of pluripotent stem cells, how (andwhether) these relate to different stages of embryonicdevelopment, and discuss the potential implications ofnaive human ESCs in research and therapy.

  1. Ground State Spin Logic

    CERN Document Server

    Whitfield, J D; Biamonte, J D

    2012-01-01

    Designing and optimizing cost functions and energy landscapes is a problem encountered in many fields of science and engineering. These landscapes and cost functions can be embedded and annealed in experimentally controllable spin Hamiltonians. Using an approach based on group theory and symmetries, we examine the embedding of Boolean logic gates into the ground state subspace of such spin systems. We describe parameterized families of diagonal Hamiltonians and symmetry operations which preserve the ground state subspace encoding the truth tables of Boolean formulas. The ground state embeddings of adder circuits are used to illustrate how gates are combined and simplified using symmetry. Our work is relevant for experimental demonstrations of ground state embeddings found in both classical optimization as well as adiabatic quantum optimization.

  2. Plant stem cell maintenance involves direct transcriptional repression of differentiation program

    OpenAIRE

    Yadav, Ram Kishor; Perales, Mariano; Gruel, Jérémy; Ohno, Carolyn; Heisler, Marcus; Girke, Thomas; Jönsson, Henrik; Reddy, G. Venugopala

    2013-01-01

    In animal systems, master regulatory transcription factors (TFs) mediate stem cell maintenance through a direct transcriptional repression of differentiation promoting TFs. Whether similar mechanisms operate in plants is not known. In plants, shoot apical meristems serve as reservoirs of stem cells that provide cells for all above ground organs. WUSCHEL, a homeodomain TF produced in cells of the niche, migrates into adjacent cells where it specifies stem cells. Through high-resolution genomic...

  3. Estimating ground water discharge by hydrograph separation.

    Science.gov (United States)

    Hannula, Steven R; Esposito, Kenneth J; Chermak, John A; Runnells, Donald D; Keith, David C; Hall, Larry E

    2003-01-01

    Iron Mountain is located in the West Shasta Mining District in California. An investigation of the generation of acid rock drainage and metals loading to Boulder Creek at Iron Mountain was conducted. As part of that investigation, a hydrograph separation technique was used to determine the contribution of ground water to total flow in Boulder Creek. During high-flow storm events in the winter months, peak flow in Boulder Creek can exceed 22.7 m3/sec, and comprises surface runoff, interflow, and ground water discharge. A hydrograph separation technique was used to estimate ground water discharge into Boulder Creek during high-flow conditions. Total ground water discharge to the creek approaches 0.31 m3/sec during the high-flow season. The hydrograph separation technique combined with an extensive field data set provided reasonable estimates of ground water discharge. These estimates are useful for other investigations, such as determining a corresponding metals load from the metal-rich ground water found at Iron Mountain and thus contributing to remedial alternatives.

  4. Ground Vehicle Robotics Presentation

    Science.gov (United States)

    2012-08-14

    Mr. Jim Parker Associate Director Ground Vehicle Robotics Distribution Statement A. Approved for public release Report Documentation Page...Briefing 3. DATES COVERED 01-07-2012 to 01-08-2012 4. TITLE AND SUBTITLE Ground Vehicle Robotics Presentation 5a. CONTRACT NUMBER 5b. GRANT...ABSTRACT Provide Transition-Ready, Cost-Effective, and Innovative Robotics and Control System Solutions for Manned, Optionally-Manned, and Unmanned

  5. Stem cell genome-to-systems biology.

    Science.gov (United States)

    Chia, Na-Yu; Ng, Huck-Hui

    2012-01-01

    Stem cells are capable of extended proliferation and concomitantly differentiating into a plethora of specialized cell types that render them apropos for their usage as a form of regenerative medicine for cell replacement therapies. The molecular processes that underlie the ability for stem cells to self-renew and differentiate have been intriguing, and elucidating the intricacies within the genome is pertinent to enhance our understanding of stem cells. Systems biology is emerging as a crucial field in the study of the sophisticated nature of stem cells, through the adoption of multidisciplinary approaches which couple high-throughput experimental techniques with computational and mathematical analysis. This allows for the determination of the molecular constituents that govern stem cell characteristics and conjointly with functional validations via genetic perturbation and protein location binding analysis necessitate the construction of the complex transcriptional regulatory network. With the elucidation of protein-protein interaction, protein-DNA regulation, microRNA involvement as well as the epigenetic modifications, it is possible to comprehend the defining features of stem cells at the system level. Copyright © 2011 John Wiley & Sons, Inc.

  6. ICE Online Detainee Locator System

    Data.gov (United States)

    Department of Homeland Security — The Online Detainee Locator datasets provide the location of a detainee who is currently in ICE custody, or who was release from ICE custody for any reason with the...

  7. Duality in constrained location problems

    DEFF Research Database (Denmark)

    Juel, Henrik; Love, Robert F.

    1987-01-01

    The dual of a facility location problem with general norms, distance constraints, and linear constraints is formulated.......The dual of a facility location problem with general norms, distance constraints, and linear constraints is formulated....

  8. Duality in constrained location problems

    DEFF Research Database (Denmark)

    Juel, Henrik; Love, Robert F.

    1987-01-01

    The dual of a facility location problem with general norms, distance constraints, and linear constraints is formulated.......The dual of a facility location problem with general norms, distance constraints, and linear constraints is formulated....

  9. Cleanup Verification Package for the 118-F-1 Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    E. J. Farris and H. M. Sulloway

    2008-01-10

    This cleanup verification package documents completion of remedial action for the 118-F-1 Burial Ground on the Hanford Site. This burial ground is a combination of two locations formerly called Minor Construction Burial Ground No. 2 and Solid Waste Burial Ground No. 2. This waste site received radioactive equipment and other miscellaneous waste from 105-F Reactor operations, including dummy elements and irradiated process tubing; gun barrel tips, steel sleeves, and metal chips removed from the reactor; filter boxes containing reactor graphite chips; and miscellaneous construction solid waste.

  10. The grounding of temporal metaphors

    Science.gov (United States)

    Lai, Vicky T.; Desai, Rutvik H.

    2016-01-01

    Grounded cognition suggests that the processing of conceptual knowledge cued by language relies on the sensory-motor regions. Does temporal language similarly engage brain areas involved in time perception? Participants read sentences that describe the temporal extent of events with motion verbs (Her seminar stretches across the afternoon) and their static controls. Comparison conditions were fictive motion (Her backyard stretches across the desert) and literal motion (Her arm stretches across the table), along with their static controls. Several time sensitive locations, identified using a meta-analysis, showed activation specific to temporal metaphors, including in the left insula, right claustrum, and bilateral posterior superior temporal sulci. Fictive and literal motion contrasts did not show this difference. Fictive motion contrast showed activation in a conceptual motion sensitive area of the left posterior inferior temporal sulcus. These data suggest that language of time is at least partially grounded in experiential time. In addition, motion semantics has different consequences for events and objects: temporal events become animate, while static entities become motional. PMID:26854961

  11. Grounding word learning in space.

    Directory of Open Access Journals (Sweden)

    Larissa K Samuelson

    Full Text Available Humans and objects, and thus social interactions about objects, exist within space. Words direct listeners' attention to specific regions of space. Thus, a strong correspondence exists between where one looks, one's bodily orientation, and what one sees. This leads to further correspondence with what one remembers. Here, we present data suggesting that children use associations between space and objects and space and words to link words and objects--space binds labels to their referents. We tested this claim in four experiments, showing that the spatial consistency of where objects are presented affects children's word learning. Next, we demonstrate that a process model that grounds word learning in the known neural dynamics of spatial attention, spatial memory, and associative learning can capture the suite of results reported here. This model also predicts that space is special, a prediction supported in a fifth experiment that shows children do not use color as a cue to bind words and objects. In a final experiment, we ask whether spatial consistency affects word learning in naturalistic word learning contexts. Children of parents who spontaneously keep objects in a consistent spatial location during naming interactions learn words more effectively. Together, the model and data show that space is a powerful tool that can effectively ground word learning in social contexts.

  12. FLAVOUR - Friendly Location-aware Conference Aid with PriVacy Observant ArchitectURe

    NARCIS (Netherlands)

    Muthukrishnan, Kavitha; Meratnia, Nirvana; Lijding, Maria

    2005-01-01

    Context-aware applications are emerging on the daily basis and location information proves to be one of the key components to develop context-aware applications upon. This stems from the fact that location information enables and facilitates reasoning about what users are doing (user's behavioural p

  13. A high-resolution aeromagnetic field test in Friuli: towards developing remote location of buried ferro-metallic bodies

    Directory of Open Access Journals (Sweden)

    E. Armadillo

    2002-06-01

    Full Text Available High Resolution AeroMagnetic surveys (HRAM are a novel tool experimented in several countries for volcano and earthquake hazard re-assessment, ground water exploration and mitigation, hazardous waste site characterization and accurate location of buried ferrous objects (drums, UXO, pipelines. The improvements achieved by HRAM stem from lower terrain clearance coupled with accurately positioned, real-time differential navigation on closely spaced flight grids. In field cultural noise filtering, advanced data processing, imaging and improved interpretation techniques enhance data information content. Development of HRAM approaches might also contribute to mitigate environmental hazards present throughout the Italian territory. Hence an HRAM field test was performed in July 2000 in Friuli, North-Eastern Italy to assess the capabilities and limitations of HRAM over a buried pipeline and a domestic waste site. A Cesium magnetometer in towed bird configuration was used on two separate grids. Profile line spacing was 50-100 m and bird nominal ground clearance was set to 50 m. Microlevelled total field magnetic anomaly data forms the basis for subsequent advanced processing products including 3D analytic signal, maximum horizontal gradient of pseudo-gravity and 3D Euler Deconvolution. The magnetic signatures we detected and enhanced over the environmental test site area in Friuli are also compared with similar but more extensive HRAM signatures recently observed in other countries.

  14. Ground Enterprise Management System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Emergent Space Technologies Inc. proposes to develop the Ground Enterprise Management System (GEMS) for spacecraft ground systems. GEMS will provide situational...

  15. Location theory a unified approach

    CERN Document Server

    Nickel, Stefan

    2006-01-01

    Although modern location theory is now more than 90 years old, the focus of researchers in this area has been mainly problem oriented. However, a common theory, which keeps the essential characteristics of classical location models, is still missing.This monograph addresses this issue. A flexible location problem called the Ordered Median Problem (OMP) is introduced. For all three main subareas of location theory (continuous, network and discrete location) structural properties of the OMP are presented and solution approaches provided. Numerous illustrations and examples help the reader to bec

  16. U.S. EPA OPTIMAL WELL LOCATOR (OWL): A SCREENING TOOL FOR EVALUATING LOCATIONS OF MONITORING WELLS (ROCKY GAP, MD)

    Science.gov (United States)

    The Optimal Well Locator (OWL): uses linear regression to fit a plane to the elevation of the water table in monitoring wells in each round of sampling. The slope of the plane fit to the water table is used to predict the direction and gradient of ground water flow. Along with ...

  17. Ground-water quality atlas of Wisconsin

    Science.gov (United States)

    Kammerer, Phil A.

    1981-01-01

    This report summarizes data on ground-water quality stored in the U.S. Geological Survey's computer system (WATSTORE). The summary includes water quality data for 2,443 single-aquifer wells, which tap one of the State's three major aquifers (sand and gravel, Silurian dolomite, and sandstone). Data for dissolved solids, hardness, alkalinity, calcium, magnesium, sodium, potassium, iron, manganese, sulfate, chloride, fluoride, and nitrate are summarized by aquifer and by county, and locations of wells for which data are available 1 are shown for each aquifer. Calcium, magnesium, and bicarbonate (the principal component of alkalinity) are the major dissolved constituents in Wisconsin's ground water. High iron concentrations and hardness cause ground-water quality problems in much of the State. Statewide ,summaries of trace constituent (selected trace metals; arsenic, boron, and organic carbon) concentrations show that these constituents impair water quality in only a few isolated wells.

  18. Location-based Web Search

    Science.gov (United States)

    Ahlers, Dirk; Boll, Susanne

    In recent years, the relation of Web information to a physical location has gained much attention. However, Web content today often carries only an implicit relation to a location. In this chapter, we present a novel location-based search engine that automatically derives spatial context from unstructured Web resources and allows for location-based search: our focused crawler applies heuristics to crawl and analyze Web pages that have a high probability of carrying a spatial relation to a certain region or place; the location extractor identifies the actual location information from the pages; our indexer assigns a geo-context to the pages and makes them available for a later spatial Web search. We illustrate the usage of our spatial Web search for location-based applications that provide information not only right-in-time but also right-on-the-spot.

  19. Spatial distribution of near-fault ground motion

    Institute of Scientific and Technical Information of China (English)

    刘启方; 袁一凡; 金星

    2004-01-01

    Near-fault strong ground motion of strike-slip and dip-slip of vertical and inclined rectangular fault in half-space and layered half-space is analyzed by dislocation source model. The Fourier spectra ratio of ground motion is adopted to study the characteristics of near-fault ground motion. For both slip models, near-fault strong ground motion with high amplitude is located in a narrow belt area along the projection of the fault on the ground and mainly controlled by the sub-faults nearby. Directivity of strike-slip fault is more dominant in long period for components perpendicular to the fault, and more dominant in long period for components parallel to the fault for dip-slip fault. The deeper the location of the source is, the more slowly the amplitude of ground motion attenuates.There is obvious hanging wall effect in ground motion of inclined fault, and the spatial distribution of ground motion is asymmetric which coincides with observational data. Finally, a fitting function of spatial distribution for near-fault ground motion is proposed and compared with near source factors of the 1997 Uniform Building Code of USA.

  20. Location of Urban Logistic Terminals as Hub Location Problem

    Directory of Open Access Journals (Sweden)

    Jasmina Pašagić Škrinjar

    2012-09-01

    Full Text Available In this paper the problems of locating urban logistic terminals are studied as hub location problems that due to a large number of potential nodes in big cities belong to hard non-polynomial problems, the so-called NP-problems. The hub location problems have found wide application in physical planning of transport and telecommunication systems, especially systems of fast delivery, networks of logistic and distribution centres and cargo traffic terminals of the big cities, etc. The paper defines single and multiple allocations and studies the numerical examples. The capacitated single allocation hub location problems have been studied, with the provision of a mathematical model of selecting the location for the hubs on the network. The paper also presents the differences in the possibilities of implementing the exact and heuristic methods to solve the actual location problems of big dimensions i.e. hub problems of the big cities.

  1. The Ibibio Locative Copular Constructions

    Directory of Open Access Journals (Sweden)

    Ogbonna Anyanwu

    2010-10-01

    Full Text Available The Ibibio language, a member of the Lower Cross group of languages is predominantly spoken in Akwa Ibom State, Nigeria. Ibibio has two types of copular construction. One is locative while the other is predicative. Using a purely descriptive approach/method, this paper provides a descriptive account of the copular locative constructions in Ibibio. This study is based on a database collected from adult speakers of Ibibio by the author using an elicitation list. The database includes both actual and potential words/sentences, which standard Ibibio speakers found to be in consistent with their language rules.The paper has observed that Ibibio copular locatives make use of locative copular verbs which have semantic content, but are however, with indeterminate locative precision except when they co- occur with an appropriate locative complement. It has further observed that in Ibibio, the location of a subject entity can be marked with locative elements in two ways. In the first instance, a locative copular verb which can be dórò, ‘be on’ síne ‘be in’ bà ‘be at’ obligatorily co-occurs with a deitic locative complement or a locative prepositional phrase (PP complement headed by a multipurpose preposition (P, ké. The P is semantically, interpreted as either on, in, at or under depending on the particular locative copular verb that it co-occurs with. In the second instance, in addition to the locative copular verb and the locative PP complement headed by the P ké, there is also within the PP complement (headed by the P ké , a locative relational noun modifier which, modifies the head noun, a complement to the locative P ké. Based on Ameka andOgbonna Anyanwu71Levinson’s (2007 cross-linguistic classification of positional and locative verbs, the paper concludes that Ibibio belongs to the multi-verb type of languages with inherently locative copular verbs which are used to express the spatial locative orientation of subject

  2. Many facets of stem cells

    Institute of Scientific and Technical Information of China (English)

    Jiarui Wu

    2011-01-01

    @@ Research area on stem cells is one of frontiers in biology.The collection of five research articles in this issue aims to cover timely developments in stem cell biology, ranging from generating and identifying stem cell line to manipulating stem cells, and from basic mechanism analysis to applied medical potential.These papers reflect the various research tasks in stem cell biology.

  3. Global Collaborative STEM Education

    Science.gov (United States)

    Meabh Kelly, Susan; Smith, Walter

    2016-04-01

    Global Collaborative STEM Education, as the name suggests, simultaneously supports two sets of knowledge and skills. The first set is STEM -- science, technology, engineering and math. The other set of content knowledge and skills is that of global collaboration. Successful global partnerships require awareness of one's own culture, the biases embedded within that culture, as well as developing awareness of the collaborators' culture. Workforce skills fostered include open-mindedness, perseverance when faced with obstacles, and resourceful use of technological "bridges" to facilitate and sustain communication. In respect for the 2016 GIFT Workshop focus, Global Collaborative STEM Education projects dedicated to astronomy research will be presented. The projects represent different benchmarks within the Global Collaborative STEM Education continuum, culminating in an astronomy research experience that fully reflects how the global STEM workforce collaborates. To facilitate wider engagement in Global Collaborative STEM Education, project summaries, classroom resources and contact information for established international collaborative astronomy research projects will be disseminated.

  4. Reinventing Grounded Theory: Some Questions about Theory, Ground and Discovery

    Science.gov (United States)

    Thomas, Gary; James, David

    2006-01-01

    Grounded theory's popularity persists after three decades of broad-ranging critique. In this article three problematic notions are discussed--"theory," "ground" and "discovery"--which linger in the continuing use and development of grounded theory procedures. It is argued that far from providing the epistemic security promised by grounded theory,…

  5. Location Systems An Introduction to the Technology Behind Location Awareness

    CERN Document Server

    LaMarca, Anthony

    2008-01-01

    Advances in electronic location technology and the coming of age of mobile computing have opened the door for location-aware applications to permeate all aspects of everyday life. Location is at the core of a large number of high-value applications ranging from the life-and-death context of emergency response to serendipitous social meet-ups. For example, the market for GPS products and services alone is expected to grow to US200 billion by 2015. Unfortunately, there is no single location technology that is good for every situation and exhibits high accuracy, low cost, and universal coverage.

  6. The Influence of Ground Water on Stream Restoration Following Dam Removal

    Science.gov (United States)

    Constantz, J.; Essaid, H.

    2003-12-01

    With the exception of ground-water seepage beneath dams and the resulting impact on structural failure, there is a void of work directly examining the downstream impacts of dams from the perspective of ground-water/surface-water interaction. This work considers alterations in an alluvial basin caused by: (1) erection of a dam upstream, (2) followed by ground-water pumping in the basin, and (3) dam removal. Theoretical results predict that when dams are removed in developed ground-water basins, downstream baseflows may be greatly reduced relative to natural baseflows, as a result of lower water table elevations in the developed basin relative to the natural setting. Without the dam as a `safety valve' providing extra streamflow during low-flow seasons, there is a real potential for ephemeral conditions downstream of the previous location of the dam as the dry season progresses. MODFLOW simulations are used to test these theoretical results, by quantifying the impact of dam removal on downstream surface water and ground water. The simulations incorporate an improved stream-aquifer interaction and streamflow routing package to represent movement of water in the vadose zone between the stream and a lowered water table. An idealized MODFLOW model with the new stream package has been constructed, which extends from the upland bedrock headwaters of a stream to the downstream sediment-filled basin. The model domain is 180 km long, 15 km wide, and 2.2 km deep, including a stream with a potential length of 180 km. In the upper reaches, the stream is divided into a north, south, and main stem with their confluence upstream of a dam situated in the domain above the bedrock/basin contact. Horizontal discretization is 1000 m in the direction parallel to the stream, 200 to 600 m perpendicular to the stream, and vertical discretization is 100 m. This modeling framework affords the opportunity to examine a variety of cases with and without the presence of an upstream dam. Initial

  7. STEM CELLS AND PROTEOMICS

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yong-ming; GUO Tian-nan; HUANG Shi-ang

    2006-01-01

    The distinctive features of proteomics are large-scale and high throughput. The key techniques of proteomics are two-dimensional gel electrophoresis, mass spectrometry and bioinformatics. Stem cell can differentiate into all kinds of cells, tissues and organs. There are many proteins and cytokines involved in the process of differentiation. Applying proteomics techniques to the research of the complex process of stem cell differentiation is of great importance to study the mechanism and applications of stem cell differentiation.

  8. Surface Geophysical Measurements for Locating and Mapping Ice-Wedges

    DEFF Research Database (Denmark)

    Ingeman-Nielsen, Thomas; Tomaskovicova, Sonia; Larsen, S.H.

    2012-01-01

    With the presently observed trend of permafrost warming and degradation, the development and availability of effective tools to locate and map ice-rich soils and massive ground ice is of increasing importance. This paper presents a geophysical study of an area with polygonal landforms in order...... to test the applicability of DC electrical resistivity tomography (ERT) and Ground Penetrating Radar (GPR) to identifying and mapping ice-wedge occurrences. The site is located in Central West Greenland, and the ice-wedges are found in a permafrozen peat soil with an active layer of about 30 cm. ERT...... and GPR measurements give a coherent interpretation of possible ice-wedge locations, and active layer probing show a tendency for larger thaw depth in the major trench systems consistent with a significant temperature (at 10 cm depth) increase in these trenches identified by thermal profiling. Three...

  9. Cancer stem cell metabolism

    National Research Council Canada - National Science Library

    Peiris-Pagès, Maria; Martinez-Outschoorn, Ubaldo E; Pestell, Richard G; Sotgia, Federica; Lisanti, Michael P

    2016-01-01

    .... Cancer stem cells also seem to adapt their metabolism to microenvironmental changes by conveniently shifting energy production from one pathway to another, or by acquiring intermediate metabolic phenotypes...

  10. The roots of diversity: below ground species richness and rooting distributions in a tropical forest revealed by DNA barcodes and inverse modeling.

    Directory of Open Access Journals (Sweden)

    F Andrew Jones

    Full Text Available BACKGROUND: Plants interact with each other, nutrients, and microbial communities in soils through extensive root networks. Understanding these below ground interactions has been difficult in natural systems, particularly those with high plant species diversity where morphological identification of fine roots is difficult. We combine DNA-based root identification with a DNA barcode database and above ground stem locations in a floristically diverse lowland tropical wet forest on Barro Colorado Island, Panama, where all trees and lianas >1 cm diameter have been mapped to investigate richness patterns below ground and model rooting distributions. METHODOLOGY/PRINCIPAL FINDINGS: DNA barcode loci, particularly the cpDNA locus trnH-psba, can be used to identify fine and small coarse roots to species. We recovered 33 species of roots from 117 fragments sequenced from 12 soil cores. Despite limited sampling, we recovered a high proportion of the known species in the focal hectare, representing approximately 14% of the measured woody plant richness. This high value is emphasized by the fact that we would need to sample on average 13 m(2 at the seedling layer and 45 m(2 for woody plants >1 cm diameter to obtain the same number of species above ground. Results from inverse models parameterized with the locations and sizes of adults and the species identifications of roots and sampling locations indicates a high potential for distal underground interactions among plants. CONCLUSIONS: DNA barcoding techniques coupled with modeling approaches should be broadly applicable to studying root distributions in any mapped vegetation plot. We discuss the implications of our results and outline how second-generation sequencing technology and environmental sampling can be combined to increase our understanding of how root distributions influence the potential for plant interactions in natural ecosystems.

  11. Detection of ground ice using ground penetrating radar method

    Institute of Scientific and Technical Information of China (English)

    Gennady M. Stoyanovich; Viktor V. Pupatenko; Yury A. Sukhobok

    2015-01-01

    The paper presents the results of a ground penetrating radar (GPR) application for the detection of ground ice. We com-bined a reflection traveltime curves analysis with a frequency spectrogram analysis. We found special anomalies at specific traces in the traveltime curves and ground boundaries analysis, and obtained a ground model for subsurface structure which allows the ground ice layer to be identified and delineated.

  12. Collison and Grounding

    DEFF Research Database (Denmark)

    Wang, G.; Ji, C.; Kuhala, P.;

    2006-01-01

    COMMITTEE MANDATE Concern for structural arrangements on ships and floating structures with regard to their integrity and adequacy in the events of collision and grounding, with the view towards risk assessment and management. Consideration shall be given to the frequency of occurrence, the proba......COMMITTEE MANDATE Concern for structural arrangements on ships and floating structures with regard to their integrity and adequacy in the events of collision and grounding, with the view towards risk assessment and management. Consideration shall be given to the frequency of occurrence...

  13. Coding Issues in Grounded Theory

    Science.gov (United States)

    Moghaddam, Alireza

    2006-01-01

    This paper discusses grounded theory as one of the qualitative research designs. It describes how grounded theory generates from data. Three phases of grounded theory--open coding, axial coding, and selective coding--are discussed, along with some of the issues which are the source of debate among grounded theorists, especially between its…

  14. Coding Issues in Grounded Theory

    Science.gov (United States)

    Moghaddam, Alireza

    2006-01-01

    This paper discusses grounded theory as one of the qualitative research designs. It describes how grounded theory generates from data. Three phases of grounded theory--open coding, axial coding, and selective coding--are discussed, along with some of the issues which are the source of debate among grounded theorists, especially between its…

  15. WHERE2 Location Aided Communications

    DEFF Research Database (Denmark)

    Dammann, Armin; Agapiou, George; Brunel, Loïc

    2013-01-01

    This paper presents an overview of preliminary results of investigations within the WHERE2 Project on identifying promising avenues for location aided enhancements to wireless communication systems. The wide ranging contributions are organized according to the following targeted systems: cellular......(s). And this at a reasonable cost given the ubiquitous availability of location information in recent wireless standards or smart phones. Location tracking furthermore opens the new perspective of slow fading prediction....

  16. Development of mine explosion ground truth smart sensors

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Steven R. [Rocky Mountain Geophysics, Inc., Los Alamos, NM (United States); Harben, Phillip E. [Rocky Mountain Geophysics, Inc., Los Alamos, NM (United States); Jarpe, Steve [Jarpe Data Solutions, Prescott, AZ (United States); Harris, David B. [Deschutes Signal Processing, Maupin, OR (United States)

    2015-09-14

    Accurate seismo-acoustic source location is one of the fundamental aspects of nuclear explosion monitoring. Critical to improved location is the compilation of ground truth data sets for which origin time and location are accurately known. Substantial effort by the National Laboratories and other seismic monitoring groups have been undertaken to acquire and develop ground truth catalogs that form the basis of location efforts (e.g. Sweeney, 1998; Bergmann et al., 2009; Waldhauser and Richards, 2004). In particular, more GT1 (Ground Truth 1 km) events are required to improve three-dimensional velocity models that are currently under development. Mine seismicity can form the basis of accurate ground truth datasets. Although the location of mining explosions can often be accurately determined using array methods (e.g. Harris, 1991) and from overhead observations (e.g. MacCarthy et al., 2008), accurate origin time estimation can be difficult. Occasionally, mine operators will share shot time, location, explosion size and even shot configuration, but this is rarely done, especially in foreign countries. Additionally, shot times provided by mine operators are often inaccurate. An inexpensive, ground truth event detector that could be mailed to a contact, placed in close proximity (< 5 km) to mining regions or earthquake aftershock regions that automatically transmits back ground-truth parameters, would greatly aid in development of ground truth datasets that could be used to improve nuclear explosion monitoring capabilities. We are developing an inexpensive, compact, lightweight smart sensor unit (or units) that could be used in the development of ground truth datasets for the purpose of improving nuclear explosion monitoring capabilities. The units must be easy to deploy, be able to operate autonomously for a significant period of time (> 6 months) and inexpensive enough to be discarded after useful operations have expired (although this may not be part of our business

  17. Stem Cell Transplants (For Teens)

    Science.gov (United States)

    ... Can I Help Someone Who's Being Bullied? Volunteering Stem Cell Transplants KidsHealth > For Teens > Stem Cell Transplants Print ... Does it Take to Recover? Coping What Are Stem Cells? As you probably remember from biology class, every ...

  18. Features of the Deployed NPOESS Ground System

    Science.gov (United States)

    Smith, D.; Grant, K. D.; Route, G.; Heckmann, G.

    2009-12-01

    NOAA, DoD, and NASA are jointly acquiring the National Polar-orbiting Operational Environmental Satellite System (NPOESS) replacing the current NOAA Polar-orbiting Operational Environmental Satellites (POES) and the DoD's Defense Meteorological Satellite Program (DMSP). The NPOESS satellites will carry a suite of sensors to collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere and space. The ground data processing segment is the Interface Data Processing Segment (IDPS), developed by Raytheon Intelligence & Information Systems (IIS). The IDPS processes NPOESS satellite data to provide environmental data products (aka, Environmental Data Records or EDRs) to US NOAA and DoD processing centers. The IDPS will process EDRs beginning with the NPOESS Preparatory Project (NPP) and through the lifetime of the NPOESS system. The command and telemetry segment is the Command, Control and Communications Segment (C3S), also developed by Raytheon IIS. C3S is responsible for managing the overall NPOESS mission from control and status of the space and ground assets to ensuring delivery of timely, high quality data from the Space Segment (SS) to IDPS for processing. In addition, the C3S provides the globally distributed ground assets necessary to collect and transport mission, telemetry, and command data between the satellites and the processing locations. The C3S provides all functions required for day-to-day commanding and state-of-health monitoring of the NPP and NPOESS satellites, and delivery of SMD to each Central IDP for data products development and transfer to System subscribers. The C3S also monitors and reports system-wide health, status and data communications with external systems and between the NPOESS segments. The NPOESS C3S and IDPS ground segments have been delivered and transitioned to operations for NPP. C3S was transitioned to operations at the NOAA Satellite Operations Facility in Suitland MD in August

  19. Proteomic analysis as a means to approach limbal stem cell biology in a search for stem cell markers.

    Science.gov (United States)

    Honoré, Bent; Vorum, Henrik

    2014-04-01

    The cornea consists of three main layers: an outer surface epithelium, the stroma, and the endothelium. A clear cornea is necessary for optimal vision and is maintained and repaired from limbal epithelial stem cells located in the limbus between the cornea and the sclera. Diseases and injury may result in deficiency of the stem cells impairing their ability to renew the corneal epithelium. Patients with limbal stem cell deficiency experience chronic pain and ultimately blindness. Attempts to treat the disease are based on replacement of the stem cells by transplantation or by culturing the stem cells. We here review the proteomic techniques that so far have been used to approach characterization of limbal stem cells and markers to identify them. It is apparent that the field is in a rather inchoate state due to the scarcity and relative inaccessibility of the stem cells. However, the importance of revealing limbal stem cell biology and identifying stem cell biomarkers calls for greater use of emerging methodology. Strategies for future studies are discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Locating industrial VOC sources with aircraft observations.

    Science.gov (United States)

    Toscano, P; Gioli, B; Dugheri, S; Salvini, A; Matese, A; Bonacchi, A; Zaldei, A; Cupelli, V; Miglietta, F

    2011-05-01

    Observation and characterization of environmental pollution, focussing on Volatile Organic Compounds (VOCs), in a high-risk industrial area, are particularly important in order to provide indications on a safe level of exposure, indicate eventual priorities and advise on policy interventions. The aim of this study is to use the Solid Phase Micro Extraction (SPME) method to measure VOCs, directly coupled with atmospheric measurements taken on a small aircraft environmental platform, to evaluate and locate the presence of VOC emission sources in the Marghera industrial area. Lab analysis of collected SPME fibres and subsequent analysis of mass spectrum and chromatograms in Scan Mode allowed the detection of a wide range of VOCs. The combination of this information during the monitoring campaign allowed a model (Gaussian Plume) to be implemented that estimates the localization of emission sources on the ground.

  1. Mechanics of Ship Grounding

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup

    1996-01-01

    In these notes first a simplified mathematical model is presented for analysis of ship hull loading due to grounding on relatively hard and plane sand, clay or rock sea bottoms. In a second section a more rational calculation model is described for the sea bed soil reaction forces on the sea bottom...

  2. Grounding Anger Management

    Directory of Open Access Journals (Sweden)

    Odis E. Simmons, PhD

    2017-06-01

    Full Text Available One of the things that drew me to grounded theory from the beginning was Glaser and Strauss’ assertion in The Discovery of Grounded Theory that it was useful as a “theoretical foothold” for practical applications (p. 268. From this, when I was a Ph.D student studying under Glaser and Strauss in the early 1970s, I devised a GT based approach to action I later came to call “grounded action.” In this short paper I’ll present a very brief sketch of an anger management program I developed in 1992, using grounded action. I began my research by attending a two-day anger management training workshop designed for training professionals in the most commonly used anger management model. Like other intervention programs I had seen, this model took a psychologizing and pathologizing approach to the issue. Following this, I sat through the full course of an anger management program that used this model, observing the reactions of the participants and the approach of the facilitator. Following each session I conducted open-ended interviews with most of the participants, either individually or in groups of two or three. I had also done previous research in counseling and social work contexts that turned out to be very relevant to an anger management program design.

  3. Grounding in Instant Messaging

    Science.gov (United States)

    Fox Tree, Jean E.; Mayer, Sarah A.; Betts, Teresa E.

    2011-01-01

    In two experiments, we investigated predictions of the "collaborative theory of language use" (Clark, 1996) as applied to instant messaging (IM). This theory describes how the presence and absence of different grounding constraints causes people to interact differently across different communicative media (Clark & Brennan, 1991). In Study 1, we…

  4. Informed Grounded Theory

    Science.gov (United States)

    Thornberg, Robert

    2012-01-01

    There is a widespread idea that in grounded theory (GT) research, the researcher has to delay the literature review until the end of the analysis to avoid contamination--a dictum that might turn educational researchers away from GT. Nevertheless, in this article the author (a) problematizes the dictum of delaying a literature review in classic…

  5. TARDEC Ground Vehicle Robotics

    Science.gov (United States)

    2013-05-30

    UNCLASSIFIED UNCLASSIFIED 10 Optionally Manned Vehicles OMV can be driven by a soldier; OMV can drive a soldier; OMV can be remotely operated; OMV can be...all missions for OMV (i.e. shared driving) (i.e. remotely operated) 2 m od al iti es Mission Payloads UNCLASSIFIED UNCLASSIFIED 11 Ground

  6. Northeast Tennessee Educators' Perception of STEM Education Implementation

    Science.gov (United States)

    Turner, Kristin Beard

    A quantitative nonexperimental survey study was developed to investigate Northeast Tennessee K-8 educators' perceptions of STEM education. This study was an examination of current perceptions of STEM education. Perceived need, current implementation practices, access to STEM resources, definition of STEM, and the current condition of STEM in Northeast Tennessee were also examined. The participating school districts are located in the Northeast Region of Tennessee: Bristol City Schools, Hamblen County Schools, Johnson City Schools, Johnson County Schools, Kingsport City Schools, Sullivan County Schools, and Washington County Schools. Educational professionals including both administrators and teachers in the elementary and/or middle school setting were surveyed. The closed and open form survey consisted of 20 research items grouped by 5 core research questions. Quantitative data were analyzed using single sample t tests. A 4 point Likert scale was used to measure responses with a 2.5 point of neutrality rating. The open-ended question was summarized and recorded for frequency. Research indicated that Northeast Tennessee K-8 educators perceive a need for STEM education to a significant extent. However, many do not feel prepared for implementation. Lack of professional development opportunities and STEM assets were reported as areas of need. Teachers reported implementation of inquiry-based, problem solving activities in their classrooms. The majority of participants reported that the current condition of STEM education in Northeast Tennessee is not meeting the needs of 21st century learners. Challenges facing STEM instruction include: funding designated for STEM is too low, professional development for STEM teacher is insufficient, and STEM Education in K-8 is lacking or inadequate.

  7. Recent ground fissures in the Hetao basin, Inner Mongolia, China

    Science.gov (United States)

    He, Zhongtai; Ma, Baoqi; Long, Jianyu; Zhang, Hao; Liang, Kuan; Jiang, Dawei

    2017-10-01

    Ground fissures are a geological hazard with complex formation mechanisms. Increasing amounts of human activity have created more ground fissures, which can destroy buildings and threaten human security. Some ground fissures indicate potentially devastating earthquakes, so we must pay attention to these hazards. This paper documents recently discovered ground fissures in the Hetao basin. These ground fissures are located along the frontal margins of the terraces of the Sertengshan piedmont fault. These fissures are 600-1600 m long, 5-50 cm wide, and at most 1 m deep. These ground fissures emerged after 2010 and ruptured newly constructed roads and field ridges. The deep geodynamic mechanisms within this extensional environment, which is dominated by NE-SW principal compressive shear, involve N-S tensile stress, which has produced continuous subsidence in the Hetao basin and continuous activity along the Sertengshan piedmont fault since the late Quaternary. Trenches across the ground fissures reveal that the fissures are the latest manifestation of the activity of preexisting faults and are the result of creep-slip movement along the faults. The groundwater level in the Hetao basin has been dropping since the 1960s because of overexploitation, resulting in subsidence. When the tensile stress exceeds the ultimate tensile strength of the strata, the strata rupture along preexisting faults, producing ground fissures. Thus, the Sertengshan piedmont fault planes are the structural foundation of the ground fissures, and groundwater extraction induces the development of ground fissures.

  8. Linking Symbolic Interactionism and Grounded Theory Methods in a Research Design

    Directory of Open Access Journals (Sweden)

    Jennifer Chamberlain-Salaun

    2013-09-01

    Full Text Available This article focuses on Corbin and Strauss’ evolved version of grounded theory. In the third edition of their seminal text, Basics of Qualitative Research: Techniques and Procedures for Developing Grounded Theory, the authors present 16 assumptions that underpin their conception of grounded theory methodology. The assumptions stem from a symbolic interactionism perspective of social life, including the themes of meaning, action and interaction, self and perspectives. As research design incorporates both methodology and methods, the authors aim to expose the linkages between the 16 assumptions and essential grounded theory methods, highlighting the application of the latter in light of the former. Analyzing the links between symbolic interactionism and essential grounded theory methods provides novice researchers and researchers new to grounded theory with a foundation from which to design an evolved grounded theory research study.

  9. On the quantitativeness of EDS STEM

    Energy Technology Data Exchange (ETDEWEB)

    Lugg, N.R. [Institute of Engineering Innovation, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan); Kothleitner, G. [Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz (Austria); Centre for Electron Microscopy, Steyrergasse 17, 8010 Graz (Austria); Shibata, N.; Ikuhara, Y. [Institute of Engineering Innovation, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2015-04-15

    Chemical mapping using energy dispersive X-ray spectroscopy (EDS) in scanning transmission electron microscopy (STEM) has recently shown to be a powerful technique in analyzing the elemental identity and location of atomic columns in materials at atomic resolution. However, most applications of EDS STEM have been used only to qualitatively map whether elements are present at specific sites. Obtaining calibrated EDS STEM maps so that they are on an absolute scale is a difficult task and even if one achieves this, extracting quantitative information about the specimen – such as the number or density of atoms under the probe – adds yet another layer of complexity to the analysis due to the multiple elastic and inelastic scattering of the electron probe. Quantitative information may be obtained by comparing calibrated EDS STEM with theoretical simulations, but in this case a model of the structure must be assumed a priori. Here we first theoretically explore how exactly elastic and thermal scattering of the probe confounds the quantitative information one is able to extract about the specimen from an EDS STEM map. We then show using simulation how tilting the specimen (or incident probe) can reduce the effects of scattering and how it can provide quantitative information about the specimen. We then discuss drawbacks of this method – such as the loss of atomic resolution along the tilt direction – but follow this with a possible remedy: precession averaged EDS STEM mapping. - Highlights: • Signal obtained in EDS STEM maps (of STO) compared to non-channelling signal. • Deviation from non-channelling signal occurs in on-axis experiments. • Tilting specimen: signal close to non-channelling case but atomic resolution is lost. • Tilt-precession series: non-channelling signal and atomic-resolution features obtained. • Associated issues are discussed.

  10. Investigating Preservice STEM Teacher Conceptions of STEM Education

    Science.gov (United States)

    Radloff, Jeff; Guzey, Selcen

    2016-10-01

    Surrounding the national emphasis on improving STEM education, effective STEM educators are required. Connected, yet often overlooked, is the need for effective preservice STEM teaching instruction for incoming educators. At a basic level, preservice STEM teacher education should include STEM content, pedagogy, and conceptualization. However, the literature suggests no leading conception of STEM education, and little is known about how preservice STEM teachers are conceptualizing STEM education. In order to explore preservice STEM teacher conceptions of STEM education, preservice teachers at a large, Midwestern research university were given an open-ended survey eliciting both textual and visual responses. Here, we report and discuss the results of employing this instrument in relation with the current STEM conceptualization literature.

  11. Immunology of Stem Cells and Cancer Stem Cells

    Institute of Scientific and Technical Information of China (English)

    Xiao-Feng Yang

    2007-01-01

    The capacity of pluri-potent stem cells to repair the tissues in which stem cells reside holds great promise in development of novel cell replacement therapeutics for treating chronic and degenerative diseases. However,numerous reports show that stem cell therapy, even in an autologous setting, triggers lymphocyte infiltration and inflammation. Therefore, an important question to be answered is how the host immune system responds to engrafted autologous stem cells or allogeneous stem cells. In this brief review, we summarize the progress in several related areas in this field, including some of our data, in four sections: (1) immunogenicity of stem cells; (2)strategies to inhibit immune rejection to allograft stem cells; (3) immune responses to cancer stem cells; and (4)mesenchymal stem cells in immune regulation. Improvement of our understanding on these and other aspects of immune system-stem cell interplay would greatly facilitate the development of stem cell-based therapeutics for regenerative purposes.

  12. Some applications of nanotechnologies in stem cells research

    Energy Technology Data Exchange (ETDEWEB)

    Belicchi, M. [Fondazione IRCCS Ospedale Policlinico di Milano, Via Francesco Sforza, Milano 20122 (Italy); Cancedda, R. [Istituto Nazionale per la Ricerca sul Cancro and Dipartimento di Oncologia Biologia e Genetica - Universita di Genova, Largo R. Benzi 10, Genova 16132 (Italy); Cedola, A. [Istituto di Fotonica e Nanotecnologie - CNR, Via Cinto Romano 42, Roma 00156 (Italy); Fiori, F. [Dipartimento S.A.I.F.E.T. Sezione di Scienze Fisiche - Universita' Politecnica delle Marche, Via Brecce Bianche, Ancona 60131 (Italy); INBB - Istituto Nazionale Biostrutture e Biosistemi (Italy); CNISM - Matec (Ancona) (Italy); Gavina, M. [Fondazione IRCCS Ospedale Policlinico di Milano, Via Francesco Sforza, Milano 20122 (Italy); Giuliani, A. [Dipartimento S.A.I.F.E.T. Sezione di Scienze Fisiche - Universita' Politecnica delle Marche, Via Brecce Bianche, Ancona 60131 (Italy); CNISM - Matec (Ancona) (Italy); Komlev, V.S. [Dipartimento S.A.I.F.E.T. Sezione di Scienze Fisiche - Universita' Politecnica delle Marche, Via Brecce Bianche, Ancona 60131 (Italy); Institute for Physical Chemistry of Ceramics, Russian Academy of Sciences, Ozernaya 48, 119361 Moscow (Russian Federation); Lagomarsino, S. [Istituto di Fotonica e Nanotecnologie - CNR, Via Cinto Romano 42, Roma 00156 (Italy); Mastrogiacomo, M. [Istituto Nazionale per la Ricerca sul Cancro and Dipartimento di Oncologia Biologia e Genetica - Universita di Genova, Largo R. Benzi 10, Genova 16132 (Italy); Renghini, C. [Dipartimento S.A.I.F.E.T. Sezione di Scienze Fisiche - Universita' Politecnica delle Marche, Via Brecce Bianche, Ancona 60131 (Italy); INBB - Istituto Nazionale Biostrutture e Biosistemi (Italy); CNISM - Matec (Ancona) (Italy); Rustichelli, F., E-mail: f.rustichelli@univpm.i [Dipartimento S.A.I.F.E.T. Sezione di Scienze Fisiche - Universita' Politecnica delle Marche, Via Brecce Bianche, Ancona 60131 (Italy); INBB - Istituto Nazionale Biostrutture e Biosistemi (Italy); CNISM - Matec (Ancona) (Italy)

    2009-12-15

    Stem cell based tissue engineering therapies involve the administration of ex vivo manipulated stem cell populations with the purpose of repairing and regenerating damaged or diseased tissue. Currently available methods of monitoring transplanted cells are quite limited. To monitor the outcomes of stem cell therapy longitudinally requires the development of non-destructive strategies that are capable of identifying the location, magnitude, and duration of cellular survival and fate. The recent development of imaging techniques offers great potential to address these critical issues by non-invasively tracking the fate of the transplanted cells. This review offers a focused presentation of some examples of the use of imaging techniques connected to the nanotechnological world in research areas related to stem cells. In particular investigations will be considered concerning tissue-engineered bone, treatment of intervertebral disc degeneration, treatment by human stem cells of muscular dystrophy of Duchenne in small animal models and the repair of spinal cord injuries.

  13. Using Pokéman GO to Teach Integrative STEM

    Science.gov (United States)

    Bartholomew, Scott R.

    2017-01-01

    Pokémon GO ranks as one of the most downloaded apps of all time. The app works by utilizing the GPS embedded in a user's phone to locate real-world locations. The phone screen shows the user's real-world location, and when moving about, he or she will encounter Pokémon that can be caught with a Pokéball (Pokémon, 2016). What does STEM Education…

  14. Stem cells in urology.

    Science.gov (United States)

    Aboushwareb, Tamer; Atala, Anthony

    2008-11-01

    The shortage of donors for organ transplantation has stimulated research on stem cells as a potential resource for cell-based therapy in all human tissues. Stem cells have been used for regenerative medicine applications in many organ systems, including the genitourinary system. The potential applications for stem cell therapy have, however, been restricted by the ethical issues associated with embryonic stem cell research. Instead, scientists have explored other cell sources, including progenitor and stem cells derived from adult tissues and stem cells derived from the amniotic fluid and placenta. In addition, novel techniques for generating stem cells in the laboratory are being developed. These techniques include somatic cell nuclear transfer, in which the nucleus of an adult somatic cell is placed into an oocyte, and reprogramming of adult cells to induce stem-cell-like behavior. Such techniques are now being used in tissue engineering applications, and some of the most successful experiments have been in the field of urology. Techniques to regenerate bladder tissue have reached the clinic, and exciting progress is being made in other areas, such as regeneration of the kidney and urethra. Cell therapy as a treatment for incontinence and infertility might soon become a reality. Physicians should be optimistic that regenerative medicine and tissue engineering will one day provide mainstream treatment options for urologic disorders.

  15. Making STEM Connections

    Science.gov (United States)

    Stump, Sheryl L.; Bryan, Joel A.; McConnell, Tom J.

    2016-01-01

    Integrated approaches to education in science, technology, engineering, and mathematics (STEM), especially those set in the context of real-world situations, can motivate and deepen students' learning of the STEM subjects (National Academy of Engineering and National Research Council 2014). This article describes two integrated investigations used…

  16. Teaching STEM by Design

    Science.gov (United States)

    Billiar, Kristen; Hubelbank, Jeanne; Oliva, Thomas; Camesano, Terri

    2014-01-01

    Developing innovative science, technology, engineering and mathematics (STEM) curricula that elicit student excitement for learning is a continuous challenge for K-12 STEM teachers. Generating these lessons while meeting conflicting pedagogical objectives and constraints of time, content, and cost from various parties is truly a challenging task…

  17. Stem cells in dermatology.

    Science.gov (United States)

    Ogliari, Karolyn Sassi; Marinowic, Daniel; Brum, Dario Eduardo; Loth, Fabrizio

    2014-01-01

    Preclinical and clinical research have shown that stem cell therapy could be a promising therapeutic option for many diseases in which current medical treatments do not achieve satisfying results or cure. This article describes stem cells sources and their therapeutic applications in dermatology today.

  18. Dazlin' pluripotent stem cells

    NARCIS (Netherlands)

    Welling, M.A.

    2014-01-01

    Pluripotent embryonic stem cells (ESCs) can be isolated from the inner cell mass (ICM) of blastocyst embryos and differentiate into all three germ layers in vitro. However, despite their similar origin, mouse embryonic stem cells represent a more naïve ICM-like pluripotent state whereas human embryo

  19. Aneuploidy in stem cells

    NARCIS (Netherlands)

    Garcia-Martinez, Jorge; Bakker, Bjorn; Schukken, Klaske M; Simon, Judith E; Foijer, Floris

    2016-01-01

    Stem cells hold enormous promise for regenerative medicine as well as for engineering of model systems to study diseases and develop new drugs. The discovery of protocols that allow for generating induced pluripotent stem cells (IPSCs) from somatic cells has brought this promise steps closer to real

  20. Further obsrvations on a newly located prawn fishery off Saurashtra coast

    Digital Repository Service at National Institute of Oceanography (India)

    Gopalan, U.K.

    The abundance of prawns in a newly located ground off Saurashtra has been described Catch omposition showed that Metapenaeus affinis formed the bulk of the catches Previously this species was thought to be of not much commercial importance...

  1. Family ties and residential locations

    NARCIS (Netherlands)

    Mulder, C.H.; Cooke, T.J.

    2009-01-01

    In this paper, and in the Special Issue it introduces, the focus is on the role of family ties in residential location choice and, conversely, the role of residential locations in maintaining family ties. Not only do events in the nuclear family trigger residential relocations, but nearby family mem

  2. Improved Dynamic Planar Point Location

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Arge, Lars; Georgiadis, Loukas

    2006-01-01

    We develop the first linear-space data structures for dynamic planar point location in general subdivisions that achieve logarithmic query time and poly-logarithmic update time.......We develop the first linear-space data structures for dynamic planar point location in general subdivisions that achieve logarithmic query time and poly-logarithmic update time....

  3. Pan-information Location Map

    Science.gov (United States)

    Zhu, X. Y.; Guo, W.; Huang, L.; Hu, T.; Gao, W. X.

    2013-11-01

    A huge amount of information, including geographic, environmental, socio-economic, personal and social network information, has been generated from diverse sources. Most of this information exists separately and is disorderly even if some of it is about the same person, feature, phenomenon or event. Users generally need to collect related information from different sources and then utilize them in applications. An automatic mechanism, therefore, for establishing a connection between potentially-related information will profoundly expand the usefulness of this huge body of information. A connection tie is semantic location describing semantically concepts and attributes of locations as well as relationships between locations, since 80% of information contains some kind of geographic reference but not all of geographic reference has explicit geographic coordinates. Semantic location is an orthogonal form of location representation which can be represented as domain ontology or UML format. Semantic location associates various kinds of information about a same object to provide timely information services according to users' demands, habits, preferences and applications. Based on this idea, a Pan-Information Location Map (PILM) is proposed as a new-style 4D map to associates semantic location-based information dynamically to organize and consolidate the locality and characteristics of corresponding features and events, and delivers on-demand information with a User-Adaptive Smart Display (UASD).

  4. RESEARCH METHODS OF LOCATIVE ELEMENT

    Directory of Open Access Journals (Sweden)

    SULAYMANOVA N.J.

    2012-01-01

    Full Text Available The article is devoted to the methods of investigation of locative elements. Sentence analysis with locative elements is taken according to the results of component analysis in the system of contradicting – opposition. More over the article is full of examples related to the description of various syntactic units.

  5. Neural correlates of locative prepositions

    NARCIS (Netherlands)

    Noordzij, Matthijs L.; Neggers, Sebastiaan F.W.; Ramsey, Nick F.; Postma, Albert

    2008-01-01

    Locative prepositions might be special linguistic modifiers because they form a natural link between verbal and visual-spatial information. In the present fMRI study we found evidence that understanding categorical spatial relations expressed in language with locative prepositions such as “to the le

  6. Locative Terms and Warlpiri Acquisition.

    Science.gov (United States)

    Bavin, Edith L.

    1990-01-01

    Focuses on the influence of language specific properties in the acquisition of locative expressions. Some of the claims from literature on the acquisition of locative expressions are discussed and data from the acquisition of Warlpiri are presented and discussed in terms of these claims. (Author/CB)

  7. Neural correlates of locative prepositions

    NARCIS (Netherlands)

    Noordzij, Matthijs Leendert; Neggers, Sebastiaan F.W.; Ramsey, Nick F.; Postma, Albert

    2008-01-01

    Locative prepositions might be special linguistic modifiers because they form a natural link between verbal and visual-spatial information. In the present fMRI study we found evidence that understanding categorical spatial relations expressed in language with locative prepositions such as “to the

  8. Mobile Alternative Fueling Station Locator

    Energy Technology Data Exchange (ETDEWEB)

    2009-04-01

    The Department of Energy's Alternative Fueling Station Locator is available on-the-go via cell phones, BlackBerrys, or other personal handheld devices. The mobile locator allows users to find the five closest biodiesel, electricity, E85, hydrogen, natural gas, and propane fueling sites using Google technology.

  9. Redox Regulation in Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Shijie Ding

    2015-01-01

    Full Text Available Reactive oxygen species (ROS and ROS-dependent (redox regulation signaling pathways and transcriptional activities are thought to be critical in stem cell self-renewal and differentiation during growth and organogenesis. Aberrant ROS burst and dysregulation of those ROS-dependent cellular processes are strongly associated with human diseases including many cancers. ROS levels are elevated in cancer cells partially due to their higher metabolism rate. In the past 15 years, the concept of cancer stem cells (CSCs has been gaining ground as the subpopulation of cancer cells with stem cell-like properties and characteristics have been identified in various cancers. CSCs possess low levels of ROS and are responsible for cancer recurrence after chemotherapy or radiotherapy. Unfortunately, how CSCs control ROS production and scavenging and how ROS-dependent signaling pathways contribute to CSCs function remain poorly understood. This review focuses on the role of redox balance, especially in ROS-dependent cellular processes in cancer stem cells (CSCs. We updated recent advances in our understanding of ROS generation and elimination in CSCs and their effects on CSC self-renewal and differentiation through modulating signaling pathways and transcriptional activities. The review concludes that targeting CSCs by manipulating ROS metabolism/dependent pathways may be an effective approach for improving cancer treatment.

  10. A COLLABORATIVE LOCATION MODEL FOR CELLULAR MOBILE POSITION LOCATION

    Institute of Scientific and Technical Information of China (English)

    Deng Ping; Liu Lin; Fan Pingzhi

    2004-01-01

    In cellular network, several Time Difference Of Arrival (TDOA) location algorithms can be applied to mobile position estimation. However, each algorithm has its own limitations and none of them is proved to be the most reliable one in different channel environments. In this paper Kleine-Ostmann's data fusion model is modified and a collaborative location model which incorporates position estimate of two TDOA location algorithms is proposed.Analysis and simulation show that more reliable and accurate mobile position estimation can be achieved based on this model.

  11. Expanding STEM Education | Poster

    Science.gov (United States)

    Editor’s note: This article is written as a reflection on experiential STEM education by a student who completed her Werner H. Kirsten internship in June 2015. Here, she advocates for incorporating hands-on experience into STEM curricula. If the only way for high school students to learn science, technology, engineering, and mathematics (STEM) is through textbooks, then count me out. But how then do you get students to learn STEM outside of the classroom? The focus of this article is to advocate for high school STEM education through experiential learning. Tom Freston, one of the founders and the chief executive officer (CEO) of MTV Productions, said in an interview in Men’s Journal that “innovation is taking two things that already exist and...

  12. Modeling discrete competitive facility location

    CERN Document Server

    Karakitsiou, Athanasia

    2015-01-01

    This book presents an up-to-date review of modeling and optimization approaches for location problems along with a new bi-level programming methodology which captures the effect of competition of both producers and customers on facility location decisions. While many optimization approaches simplify location problems by assuming decision making in isolation, this monograph focuses on models which take into account the competitive environment in which such decisions are made. New insights in modeling, algorithmic and theoretical possibilities are opened by this approach and new applications are possible. Competition on equal term plus competition between market leader and followers are considered in this study, consequently bi-level optimization methodology is emphasized and further developed. This book provides insights regarding modeling complexity and algorithmic approaches to discrete competitive location problems. In traditional location modeling, assignment of customer demands to supply sources are made ...

  13. Uncapacitated facility location problems: contributions

    Directory of Open Access Journals (Sweden)

    Galvão Roberto Diéguez

    2004-01-01

    Full Text Available The objective of the present paper is to review my personal contributions in the field of uncapacitated facility location problems. These contributions took place throughout my academic career, from the time I was a Ph.D. student at Imperial College to the present day. They cover approximately 30 years, from 1973 to 2003; they address: algorithms developed for the p-median problem and for a general formulation of uncapacitated location problems; the study of dynamic location models; covering and hierarchical location problems; queuing-based probabilistic location models. The contributions encompass theoretical developments, computational algorithms and practical applications. All work took place in an academic environment, with the invaluable collaboration of colleagues (both in Brazil and abroad and research students at COPPE. Each section in the paper is dedicated to a topic that involves a personal contribution. Every one of them is placed within the context of the existing literature.

  14. The Acquisition and Interpretation of English Locative Constructions by Native Speakers of Korean.

    Science.gov (United States)

    Bley-Vroman, Robert; Joo, Hye-Ri

    2001-01-01

    Investigates whether native speakers of Korean learning English develop Knowledge of the holism effect in the English locative and knowledge of the narrow constraints. Results suggest that when given a ground-object structure, both learners and English native speakers preferentially chose a ground-holism picture. (Author/VWL)

  15. Light location influences the perceived locations of internal sounds.

    Science.gov (United States)

    Dellorso, Scott; Schirillo, James

    2010-01-01

    Numerous studies have shown that visual stimuli can bias the perceived location of auditory stimuli. Here, we sought to determine if a visual stimulus can also bias the perceived location of multiple internal auditory stimuli. Fifty subjects were presented with a train of eight binaural click-pairs over headphones while a single flash of light was presented either to the left or to the right side of a central fixation point on an otherwise black CRT screen. A no-flash baseline was also implemented, as was a no-fixation control. The subjects used a rating scale to indicate the perceived location of each of the eight click-pairs within their heads. The results showed that the flash of light significantly influenced the perceived location of the click-pairs, biasing them in the same direction as the flash of light. This suggests that, even without perceptual correspondence, cross-modal interactions can occur.

  16. Infrasonic induced ground motions

    Science.gov (United States)

    Lin, Ting-Li

    On January 28, 2004, the CERI seismic network recorded seismic signals generated by an unknown source. Our conclusion is that the acoustic waves were initiated by an explosive source near the ground surface. The meteorological temperature and effective sound speed profiles suggested existence of an efficient near-surface waveguide that allowed the acoustic disturbance to propagate to large distances. An explosion occurring in an area of forest and farms would have limited the number of eyewitnesses. Resolution of the source might be possible by experiment or by detailed analysis of the ground motion data. A seismo-acoustic array was built to investigate thunder-induced ground motions. Two thunder events with similar N-wave waveforms but different horizontal slownesses are chosen to evaluate the credibility of using thunder as a seismic source. These impulsive acoustic waves excited P and S reverberations in the near surface that depend on both the incident wave horizontal slowness and the velocity structure in the upper 30 meters. Nineteen thunder events were chosen to further investigate the seismo-acoustic coupling. The consistent incident slowness differences between acoustic pressure and ground motions suggest that ground reverberations were first initiated somewhat away from the array. Acoustic and seismic signals were used to generate the time-domain transfer function through the deconvolution technique. Possible non-linear interaction for acoustic propagation into the soil at the surface was observed. The reverse radial initial motions suggest a low Poisson's ratio for the near-surface layer. The acoustic-to-seismic transfer functions show a consistent reverberation series of the Rayleigh wave type, which has a systematic dispersion relation to incident slownesses inferred from the seismic ground velocity. Air-coupled Rayleigh wave dispersion was used to quantitatively constrain the near-surface site structure with constraints afforded by near-surface body

  17. Using Seismic Tomography and Holography Ground Imaging to Investigate Ground Conditions

    Institute of Scientific and Technical Information of China (English)

    Ed Kase; Tim Ross

    2004-01-01

    Unforeseen, variable subsurface ground conditions present the greatest challenge to the heavy construction and civil engineering industry in the design, construction, and maintenance of large projects. A detailed, accurate site investigation will reduce project risk, improve construction performance and safety, prolong the life of the tunnel or structure,and prevent waste in over - design. Presently, site characterization and geotechnical engineering are limited by the inability to adequately describe these subsurface ground conditions.NSA Geotechnical Services has successfully applied seismic tomography and holography ground imaging technologies on tunneling and heavy civil excavations worldwide. Seismic signal waveforms traveling through a complex medium consist of various arrivals from refractions, reflections, scattering, and dispersion. Tomography and holography are proven inversion technologies for estimating location and extent of material property variations causing changes in signal waveforms.ent attenuation rates and velocities. Seismic waves will travel faster through competent material and be generally less attenuated than through broken/fractured ground or voids.encounters an interface between ground zones possessing different seismic properties. Most geologic structures, anomalies,and changes in lithology provide detectable seismic reflections if they are within a reasonable distance of the seismic source.This paper will present various applications of these technologies, illustrating how seismic imaging can provide accurate information regarding ground conditions associated with tunneling projects. With this information, engineers can complete projects safely, within time and budget constraints.

  18. STEM learning activity among home-educating families

    Science.gov (United States)

    Bachman, Jennifer

    2011-12-01

    Science, technology, engineering, and mathematics (STEM) learning was studied among families in a group of home-educators in the Pacific Northwest. Ethnographic methods recorded learning activity (video, audio, fieldnotes, and artifacts) which was analyzed using a unique combination of Cultural-Historical Activity Theory (CHAT) and Mediated Action (MA), enabling analysis of activity at multiple levels. Findings indicate that STEM learning activity is family-led, guided by parents' values and goals for learning, and negotiated with children to account for learner interests and differences, and available resources. Families' STEM education practice is dynamic, evolves, and influenced by larger societal STEM learning activity. Parents actively seek support and resources for STEM learning within their home-school community, working individually and collectively to share their funds of knowledge. Home-schoolers also access a wide variety of free-choice learning resources: web-based materials, museums, libraries, and community education opportunities (e.g. afterschool, weekend and summer programs, science clubs and classes, etc.). A lesson-heuristic, grounded in Mediated Action, represents and analyzes home STEM learning activity in terms of tensions between parental goals, roles, and lesson structure. One tension observed was between 'academic' goals or school-like activity and 'lifelong' goals or everyday learning activity. Theoretical and experiential learning was found in both activity, though parents with academic goals tended to focus more on theoretical learning and those with lifelong learning goals tended to be more experiential. Examples of the National Research Council's science learning strands (NRC, 2009) were observed in the STEM practices of all these families. Findings contribute to the small but growing body of empirical CHAT research in science education, specifically to the empirical base of family STEM learning practices at home. It also fills a

  19. Ground Water SPA

    Data.gov (United States)

    Vermont Center for Geographic Information — Groundwater SPA. This GIS layer consists of the geographic location of the Source Protection Areas for active and inactive Public Community and Non-Transient...

  20. Crypt region localization of intestinal stem cells in adults

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The intestinal epithelial lining plays a central role in the digestion and absorption of nutrients, but exists in a harsh luminal environment that necessitates continual renewal. This renewal process involves epithelial cell proliferation in the crypt base and later cell migration from the crypt base to the luminal surface. This process is dependent on multi-potent progenitor cells, or stem cells, located in each crypt. There are about 4 to 6 stem cells per crypt, and these stem cells are believed to generate distinct end-differentiated epithelial cell types, including absorptive cells, goblet cells, enteroendocrine cells and Paneth cells, while also maintaining their own progenitor cell state. Earlier studies suggested that intestinal stem cells were located either in the crypt base interspersed between the Paneth cells [i.e. Crypt base columnar (CBC) cell model] or at an average position of 4 cells from the crypt base [I.e. Label-retaining cells (LRC +4) model]. Recent studies have employed biomarkers in the in vivo mammalian state to more precisely evaluate the location of these progenitor cells in the intestinal crypt. Most notable of these novel markers are Lgr5, a gene that encodes a G-protein-coupled receptor with expression restricted to CBC cells, and Bmi 1, which encodes a chromatin remodeling protein expressed by LRC. These studies raise the possibility that there may be separate stem cell lines or different states of stem cell activation involved in the renewal of normal mammalian intestinal tract.

  1. Screening Marker Components Of Tyrosinase Inhibitor From Xylocarpus Granatum Stem

    Directory of Open Access Journals (Sweden)

    Latifah K Darusman

    2017-03-01

    Full Text Available The aim of our research was to screen the marker components of tyrosinase inhibitor from Xylocarpus granatum stem collected from Pulau Sebuku, South Kalimantan, Indonesia.  The screening method started from selection of part of X. granatum, stem or stem bark.  Stem and stem bark of X. granatum were dried and grounded before submitted to methanol.  The stem extracts is more potent as tyrosinase inhibitor (IC50 for monophenolase is 45.12 μg/ml and diphenolase is 31.59μg/ml compared to the bark extracts. The IC50 values of kojic acid as positive control are 17.43μg/ml for monophenolase and 20.69 μg/ml for diphenolase. The stem extract then separated with silica gel column chromatography and preparative thin layer chromatography.  The results showed that component with Rf 0,25 and 0.63 (TLC analysis with stationary phase silica gel GF254 and mobile phase ethyl acetic: methanol (8:2 are the marker components as tyrosinase inhibitor for X. granatum.

  2. [On plant stem cells and animal stem cells].

    Science.gov (United States)

    You, Yun; Jiang, Chao; Huang, Lu-Qi

    2014-01-01

    A comparison of plant and animal stem cells can highlight core aspects of stem-cell biology. In both kingdoms, stem cells are defined by their clonogenic properties and are maintained by intercellular signals. The signaling molecules are different in plants and animals stem cell niches, but the roles of argonaute and polycomb group proteins suggest that there are some molecular similarities.

  3. Decentralized Ground Staff Scheduling

    DEFF Research Database (Denmark)

    Sørensen, M. D.; Clausen, Jens

    2002-01-01

    Typically, ground staff scheduling is centrally planned for each terminal in an airport. The advantage of this is that the staff is efficiently utilized, but a disadvantage is that staff spends considerable time walking between stands. In this paper a decentralized approach for ground staff...... scheduling is investigated. The airport terminal is divided into zones, where each zone consists of a set of stands geographically next to each other. Staff is assigned to work in only one zone and the staff scheduling is planned decentralized for each zone. The advantage of this approach is that the staff...... work in a smaller area of the terminal and thus spends less time walking between stands. When planning decentralized the allocation of stands to flights influences the staff scheduling since the workload in a zone depends on which flights are allocated to stands in the zone. Hence solving the problem...

  4. Ibis ground calibration

    Energy Technology Data Exchange (ETDEWEB)

    Bird, A.J.; Barlow, E.J.; Tikkanen, T. [Southampton Univ., School of Physics and Astronomy (United Kingdom); Bazzano, A.; Del Santo, M.; Ubertini, P. [Istituto di Astrofisica Spaziale e Fisica Cosmica - IASF/CNR, Roma (Italy); Blondel, C.; Laurent, P.; Lebrun, F. [CEA Saclay - Sap, 91 - Gif sur Yvette (France); Di Cocco, G.; Malaguti, E. [Istituto di Astrofisica Spaziale e Fisica-Bologna - IASF/CNR (Italy); Gabriele, M.; La Rosa, G.; Segreto, A. [Istituto di Astrofisica Spaziale e Fisica- IASF/CNR, Palermo (Italy); Quadrini, E. [Istituto di Astrofisica Spaziale e Fisica-Cosmica, EASF/CNR, Milano (Italy); Volkmer, R. [Institut fur Astronomie und Astrophysik, Tubingen (Germany)

    2003-11-01

    We present an overview of results obtained from IBIS ground calibrations. The spectral and spatial characteristics of the detector planes and surrounding passive materials have been determined through a series of calibration campaigns. Measurements of pixel gain, energy resolution, detection uniformity, efficiency and imaging capability are presented. The key results obtained from the ground calibration have been: - optimization of the instrument tunable parameters, - determination of energy linearity for all detection modes, - determination of energy resolution as a function of energy through the range 20 keV - 3 MeV, - demonstration of imaging capability in each mode, - measurement of intrinsic detector non-uniformity and understanding of the effects of passive materials surrounding the detector plane, and - discovery (and closure) of various leakage paths through the passive shielding system.

  5. Locations in television drama series

    DEFF Research Database (Denmark)

    Waade, Anne Marit

    , and reflect the growing academic and business interests, respectively, on places in a global media and consumption culture (Falkheimer & Jansson, 2006). Based on empirical location studies of three crime series, Wallander (Yellow Bird, 2008-2012), The Bridge (SVT1 & DR1, 2011-2013) and Dicte (Misofilm/TV2...... in the extra bonus material (Gray, 2010; Waade, 2013), and film tours and film apps become part of the television series’ trans-media franchise (Reijnders, 2011; Thompson, 2007). Location has so far been a practical term describing the place where the series is shot. Ellis (1992) used to see location...

  6. Location Based Services and Applications

    Directory of Open Access Journals (Sweden)

    Elenis Gorrita Michel

    2012-05-01

    Full Text Available Location Based Services (LBS continue to grow in popularity, effectiveness and reliability, to the extent that applications are designed and implemented taking into account the facilities of the user location information. In this work, some of the main applications are addressed, in order to make an assessment of the current importance of the LBS, as a branch of technology in full swing. In addition, the main techniques for location estimation are studied, essential information to the LBS. Because of this it is a highly topical issue, the ongoing works and researches are also discussed.

  7. Mechanics of Ship Grounding

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup

    1996-01-01

    In these notes first a simplified mathematical model is presented for analysis of ship hull loading due to grounding on relatively hard and plane sand, clay or rock sea bottoms. In a second section a more rational calculation model is described for the sea bed soil reaction forces on the sea bottom....... Finally, overall hull failure is considered first applying a quasistatic analysis model and thereafter a full dynamic model....

  8. Outdoor ground impedance models.

    Science.gov (United States)

    Attenborough, Keith; Bashir, Imran; Taherzadeh, Shahram

    2011-05-01

    Many models for the acoustical properties of rigid-porous media require knowledge of parameter values that are not available for outdoor ground surfaces. The relationship used between tortuosity and porosity for stacked spheres results in five characteristic impedance models that require not more than two adjustable parameters. These models and hard-backed-layer versions are considered further through numerical fitting of 42 short range level difference spectra measured over various ground surfaces. For all but eight sites, slit-pore, phenomenological and variable porosity models yield lower fitting errors than those given by the widely used one-parameter semi-empirical model. Data for 12 of 26 grassland sites and for three beech wood sites are fitted better by hard-backed-layer models. Parameter values obtained by fitting slit-pore and phenomenological models to data for relatively low flow resistivity grounds, such as forest floors, porous asphalt, and gravel, are consistent with values that have been obtained non-acoustically. Three impedance models yield reasonable fits to a narrow band excess attenuation spectrum measured at short range over railway ballast but, if extended reaction is taken into account, the hard-backed-layer version of the slit-pore model gives the most reasonable parameter values.

  9. Gradual translocation of spatial correlates of neuronal firing in the hippocampus toward prospective reward locations.

    Science.gov (United States)

    Lee, Inah; Griffin, Amy L; Zilli, Eric A; Eichenbaum, Howard; Hasselmo, Michael E

    2006-09-07

    In a continuous T-maze alternation task, CA1 complex-spike neurons in the hippocampus differentially fire as the rat traverses overlapping segments of the maze (i.e., the stem) repeatedly via alternate routes. The temporal dynamics of this phenomenon were further investigated in the current study. Rats learned the alternation task from the first day of acquisition and the differential firing pattern in the stem was observed accordingly. More importantly, we report a phenomenon in which spatial correlates of CA1 neuronal ensembles gradually changed from their original firing locations, shifting toward prospective goal locations in the continuous T-maze alternation task. The relative locations of simultaneously recorded firing fields, however, were preserved within the ensemble spatial representation during this shifting. The within-session shifts in preferred firing locations in the absence of any changes in the environment suggest that certain cognitive factors can significantly alter the location-bound coding scheme of hippocampal neurons.

  10. Theory of ground state factorization in quantum cooperative systems.

    Science.gov (United States)

    Giampaolo, Salvatore M; Adesso, Gerardo; Illuminati, Fabrizio

    2008-05-16

    We introduce a general analytic approach to the study of factorization points and factorized ground states in quantum cooperative systems. The method allows us to determine rigorously the existence, location, and exact form of separable ground states in a large variety of, generally nonexactly solvable, spin models belonging to different universality classes. The theory applies to translationally invariant systems, irrespective of spatial dimensionality, and for spin-spin interactions of arbitrary range.

  11. Fish stem cell cultures.

    Science.gov (United States)

    Hong, Ni; Li, Zhendong; Hong, Yunhan

    2011-04-13

    Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES) cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is the second organism that generated ES cells and the first that gave rise to a spermatogonial stem cell line capable of test-tube sperm production. Most recently, the first haploid stem cells capable of producing whole animals have also been generated from medaka. ES-like cells have been reported also in zebrafish and several marine species. Attempts for germline transmission of ES cell cultures and gene targeting have been reported in zebrafish. Recent years have witnessed the progress in markers and procedures for ES cell characterization. These include the identification of fish homologs/paralogs of mammalian pluripotency genes and parameters for optimal chimera formation. In addition, fish germ cell cultures and transplantation have attracted considerable interest for germline transmission and surrogate production. Haploid ES cell nuclear transfer has proven in medaka the feasibility of semi-cloning as a novel assisted reproductive technology. In this special issue on "Fish Stem Cells and Nuclear Transfer", we will focus our review on medaka to illustrate the current status and perspective of fish stem cells in research and application. We will also mention semi-cloning as a new development to conventional nuclear transfer.

  12. Fish Stem Cell Cultures

    Directory of Open Access Journals (Sweden)

    Ni Hong, Zhendong Li, Yunhan Hong

    2011-01-01

    Full Text Available Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is the second organism that generated ES cells and the first that gave rise to a spermatogonial stem cell line capable of test-tube sperm production. Most recently, the first haploid stem cells capable of producing whole animals have also been generated from medaka. ES-like cells have been reported also in zebrafish and several marine species. Attempts for germline transmission of ES cell cultures and gene targeting have been reported in zebrafish. Recent years have witnessed the progress in markers and procedures for ES cell characterization. These include the identification of fish homologs/paralogs of mammalian pluripotency genes and parameters for optimal chimera formation. In addition, fish germ cell cultures and transplantation have attracted considerable interest for germline transmission and surrogate production. Haploid ES cell nuclear transfer has proven in medaka the feasibility of semi-cloning as a novel assisted reproductive technology. In this special issue on “Fish Stem Cells and Nuclear Transfer”, we will focus our review on medaka to illustrate the current status and perspective of fish stem cells in research and application. We will also mention semi-cloning as a new development to conventional nuclear transfer.

  13. CBP List of Preclearance Locations

    Data.gov (United States)

    Department of Homeland Security — CBP Preclearance provides for the U.S. border inspection and clearance of commercial air passengers and their goods at (15) locations in (6) foreign countries. CBP...

  14. Mental Health Treatement Facilities Locator

    Data.gov (United States)

    U.S. Department of Health & Human Services — An online resource for locating mental health treatment facilities and programs supported by the Substance Abuse and Mental Health Services Administration (SAMHSA)....

  15. Allegheny County WIC Vendor Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset contains the locations of Women, Infants, and Children (WIC) program vendors. If viewing this description on the Western Pennsylvania Regional Data...

  16. Allegheny County Blazed Trails Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Shows the location of blazed trails in all Allegheny County parks. This is the same data used in the Allegheny County Parks Trails Mobile App, available for Apple...

  17. NIGERIA - A TROPICAL COASTAL LOCATION

    African Journals Online (AJOL)

    2008-02-21

    Feb 21, 2008 ... “Department of Physics, University of Calabar, Calabar, Nigeria ... The characteristic pattern of rainfall in Calabar, a coastal - tropical location ... percentiles over most of Australia for ... meteorological records of the Margaret.

  18. VT School Locations - K-12

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) FacilitiesSchools_PTSCHOOL is designed to provide point locations of every Vermont School along with the established school ID (PSID) for...

  19. Locative inferences in medical texts.

    Science.gov (United States)

    Mayer, P S; Bailey, G H; Mayer, R J; Hillis, A; Dvoracek, J E

    1987-06-01

    Medical research relies on epidemiological studies conducted on a large set of clinical records that have been collected from physicians recording individual patient observations. These clinical records are recorded for the purpose of individual care of the patient with little consideration for their use by a biostatistician interested in studying a disease over a large population. Natural language processing of clinical records for epidemiological studies must deal with temporal, locative, and conceptual issues. This makes text understanding and data extraction of clinical records an excellent area for applied research. While much has been done in making temporal or conceptual inferences in medical texts, parallel work in locative inferences has not been done. This paper examines the locative inferences as well as the integration of temporal, locative, and conceptual issues in the clinical record understanding domain by presenting an application that utilizes two key concepts in its parsing strategy--a knowledge-based parsing strategy and a minimal lexicon.

  20. Neural correlates of locative prepositions.

    Science.gov (United States)

    Noordzij, Matthijs L; Neggers, Sebastiaan F W; Ramsey, Nick F; Postma, Albert

    2008-04-01

    Locative prepositions might be special linguistic modifiers because they form a natural link between verbal and visual-spatial information. In the present fMRI study we found evidence that understanding categorical spatial relations expressed in language with locative prepositions such as "to the left of" and "to the right of" were reliably associated with cerebral activity in the supramarginal gyrus (SMG) located in the left inferior parietal lobe. The higher activity associated with spatial as compared to non-spatial sentences in this region was not dependent on the context (verbal or visual-spatial) in which the sentence was read. Therefore, the function of this activity appears to be to create a general, amodal representation of locative prepositions that allow for flexible comparisons to either verbal or visual-spatial material.

  1. Allegheny County Public Building Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset contains the locations of municipal facilities in Allegheny County. If viewing this description on the Western Pennsylvania Regional Data Center’s...

  2. Allegheny County Public Building Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset contains the locations of municipal facilities in Allegheny County. If viewing this description on the Western Pennsylvania Regional Data Center’s open...

  3. Substance Abuse Treatment Facilities Locator

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Substance Abuse and Mental Health Services Administration (SAMHSA) provides on-line resource for locating drug and alcohol abuse treatment programs. The...

  4. Allegheny County WIC Vendor Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset contains the locations of Women, Infants, and Children (WIC) program vendors. If viewing this description on the Western Pennsylvania Regional Data...

  5. Allegheny County Blazed Trails Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Shows the location of blazed trails in all Allegheny County parks. This is the same data used in the Allegheny County Parks Trails Mobile App, available for Apple...

  6. Stem Cells in Tooth Development, Growth, Repair, and Regeneration.

    Science.gov (United States)

    Yu, Tian; Volponi, Ana Angelova; Babb, Rebecca; An, Zhengwen; Sharpe, Paul T

    2015-01-01

    Human teeth contain stem cells in all their mesenchymal-derived tissues, which include the pulp, periodontal ligament, and developing roots, in addition to the support tissues such as the alveolar bone. The precise roles of these cells remain poorly understood and most likely involve tissue repair mechanisms but their relative ease of harvesting makes teeth a valuable potential source of mesenchymal stem cells (MSCs) for therapeutic use. These dental MSC populations all appear to have the same developmental origins, being derived from cranial neural crest cells, a population of embryonic stem cells with multipotential properties. In rodents, the incisor teeth grow continuously throughout life, a feature that requires populations of continuously active mesenchymal and epithelial stem cells. The discrete locations of these stem cells in the incisor have rendered them amenable for study and much is being learnt about the general properties of these stem cells for the incisor as a model system. The incisor MSCs appear to be a heterogeneous population consisting of cells from different neural crest-derived tissues. The epithelial stem cells can be traced directly back in development to a Sox10(+) population present at the time of tooth initiation. In this review, we describe the basic biology of dental stem cells, their functions, and potential clinical uses.

  7. Hull properties in location problems

    DEFF Research Database (Denmark)

    Juel, Henrik; Love, Robert F.

    1983-01-01

    Some properties of the solution set for single and multifacility continuous location problems with lp distances are given. A set reduction algorithm is developed for problems in k-dimensional space having rectangular distances.......Some properties of the solution set for single and multifacility continuous location problems with lp distances are given. A set reduction algorithm is developed for problems in k-dimensional space having rectangular distances....

  8. WHERE2 Location Aided Communications

    DEFF Research Database (Denmark)

    Dammann, Armin; Agapiou, George; Brunel, Loïc

    2013-01-01

    networks, mobile ad hoc networks (MANETs) and cognitive radio. Location based approaches are found to allevi- ate significant signaling overhead in various forms of modern communication paradigms that are very information hungry in terms of channel state information at the transmitter......This paper presents an overview of preliminary results of investigations within the WHERE2 Project on identifying promising avenues for location aided enhancements to wireless communication systems. The wide ranging contributions are organized according to the following targeted systems: cellular...

  9. Dental pulp stem cells

    DEFF Research Database (Denmark)

    Ashri, N. Y.; Ajlan, S. A.; Aldahmash, Abdullah M.

    2015-01-01

    Inflammatory periodontal disease is a major cause of loss of tooth-supporting structures. Novel approaches for regeneration of periodontal apparatus is an area of intensive research. Periodontal tissue engineering implies the use of appropriate regenerative cells, delivered through a suitable...... scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal) stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from...... an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors....

  10. Cardiac stem cell niches

    Directory of Open Access Journals (Sweden)

    Annarosa Leri

    2014-11-01

    Full Text Available The critical role that stem cell niches have in cardiac homeostasis and myocardial repair following injury is the focus of this review. Cardiac niches represent specialized microdomains where the quiescent and activated state of resident stem cells is regulated. Alterations in niche function with aging and cardiac diseases result in abnormal sites of cardiomyogenesis and inadequate myocyte formation. The relevance of Notch1 signaling, gap-junction formation, HIF-1α and metabolic state in the regulation of stem cell growth and differentiation within the cardiac niches are discussed.

  11. A Calculus of Located Entities

    Directory of Open Access Journals (Sweden)

    Adriana Compagnoni

    2014-03-01

    Full Text Available We define BioScapeL, a stochastic pi-calculus in 3D-space. A novel aspect of BioScapeL is that entities have programmable locations. The programmer can specify a particular location where to place an entity, or a location relative to the current location of the entity. The motivation for the extension comes from the need to describe the evolution of populations of biochemical species in space, while keeping a sufficiently high level description, so that phenomena like diffusion, collision, and confinement can remain part of the semantics of the calculus. Combined with the random diffusion movement inherited from BioScape, programmable locations allow us to capture the assemblies of configurations of polymers, oligomers, and complexes such as microtubules or actin filaments. Further new aspects of BioScapeL include random translation and scaling. Random translation is instrumental in describing the location of new entities relative to the old ones. For example, when a cell secretes a hydronium ion, the ion should be placed at a given distance from the originating cell, but in a random direction. Additionally, scaling allows us to capture at a high level events such as division and growth; for example, daughter cells after mitosis have half the size of the mother cell.

  12. Testing the stem dominance hypothesis: meaning analysis of inflected words and prepositional phrases.

    Directory of Open Access Journals (Sweden)

    Minna Lehtonen

    Full Text Available We tested the hypothesis that lexical-semantic access of inflected words is governed by the word stem. Object drawings overlaid with a dot/arrow marking position/movement were matched with corresponding linguistic expressions like "from the house". To test whether the stem dominates lexical-semantic access irrespective of its position, we used Swedish prepositional phrases (locative information via preposition immediately preceding the stem or Finnish case-inflected words (locative information via suffix immediately following the stem. Both in monolingual Swedish and in bilingual Finnish-Swedish speakers, correct stems with incorrect prepositions/case-endings were hardest to reject. This finding supports the view that the stem is indeed the dominant unit in meaning access of inflected words.

  13. Testing the stem dominance hypothesis: meaning analysis of inflected words and prepositional phrases.

    Science.gov (United States)

    Lehtonen, Minna; Harrer, Gabor; Wande, Erling; Laine, Matti

    2014-01-01

    We tested the hypothesis that lexical-semantic access of inflected words is governed by the word stem. Object drawings overlaid with a dot/arrow marking position/movement were matched with corresponding linguistic expressions like "from the house". To test whether the stem dominates lexical-semantic access irrespective of its position, we used Swedish prepositional phrases (locative information via preposition immediately preceding the stem) or Finnish case-inflected words (locative information via suffix immediately following the stem). Both in monolingual Swedish and in bilingual Finnish-Swedish speakers, correct stems with incorrect prepositions/case-endings were hardest to reject. This finding supports the view that the stem is indeed the dominant unit in meaning access of inflected words.

  14. COMPARISON OF TDOA LOCATION ALGORITHMS WITH DIRECT SOLUTION METHOD

    Institute of Scientific and Technical Information of China (English)

    Li Chun; Liu Congfeng; Liao Guisheng

    2011-01-01

    For Time Difference Of Arrival (TDOA) location based on multi-ground stations scene,two direct solution methods are proposed to solve the target position in TDOA location.Therein,the solving methods are realized in the rectangular and polar coordinates.On the condition of rectangular coordinates,first of all,it solves the radial range between the target and reference station,then calculates the location of the target.In the case of polar coordinates,the azimuth between the target and reference station is solved first,then the radial range between the target and reference station is figured out,finally the location of the target is obtained.Simultaneously,the simulation and comparison analysis are given in detail,and show that the polar solving method has the better fuzzy performance than that of rectangular coordinate.

  15. The ATLAS SCT grounding and shielding concept and implementation

    CERN Document Server

    Bates, RL; Bernabeu, J; Bizzell, J; Bohm, J; Brenner, R; Bruckman de Renstrom, P A; Catinaccio, A; Cindro, V; Ciocio, A; Civera, J V; Chouridou, S; Dervan, P; Dick, B; Dolezal, Z; Eklund, L; Feld, L; Ferrere, D; Gadomski, S; Gonzalez, F; Gornicki, E; Greenhall, A; Grillo, A A; Grosse-Knetter, J; Gruwe, M; Haywood, S; Hessey, N P; Ikegami, Y; Jones, T J; Kaplon, J; Kodys, P; Kohriki, T; Kondo, T; Koperny, S; Lacasta, C; Lozano Bahilo, J; Malecki, P; Martinez-McKinney, F; McMahon, S J; McPherson, A; Mikulec, B; Mikus, M; Moorhead, G F; Morrissey, M C; Nagai, K; Nichols, A; O'Shea, V; Pater, J R; Peeters, S J M; Pernegger, H; Perrin, E; Phillips, P W; Pieron, J P; Roe, S; Sanchez, J; Spencer, E; Stastny, J; Tarrant, J; Terada, S; Tyndel, M; Unno, Y; Wallny, R; Weber, M; Weidberg, A R; Wells, P S; Werneke, P; Wilmut, I

    2012-01-01

    This paper describes the design and implementation of the grounding and shielding system for the ATLAS SemiConductor Tracker (SCT). The mitigation of electromagnetic interference and noise pickup through power lines is the critical design goal as they have the potential to jeopardize the electrical performance. We accomplish this by adhering to the ATLAS grounding rules, by avoiding ground loops and isolating the different subdetectors. Noise sources are identified and design rules to protect the SCT against them are described. A rigorous implementation of the design was crucial to achieve the required performance. This paper highlights the location, connection and assembly of the different components that affect the grounding and shielding system: cables, filters, cooling pipes, shielding enclosure, power supplies and others. Special care is taken with the electrical properties of materials and joints. The monitoring of the grounding system during the installation period is also discussed. Finally, after con...

  16. Semantics versus statistics in the retreat from locative overgeneralization errors.

    Science.gov (United States)

    Ambridge, Ben; Pine, Julian M; Rowland, Caroline F

    2012-05-01

    The present study investigated how children learn that some verbs may appear in the figure-locative but not the ground-locative construction (e.g., Lisa poured water into the cup; *Lisa poured the cup with water), with some showing the opposite pattern (e.g., *Bart filled water into the cup; Bart filled the cup with water), and others appearing in both (Lisa sprayed water onto the flowers; Lisa sprayed the flowers with water). Grammatical acceptability judgments were obtained for the use of each of 142 locative verbs (60 for children) in each sentence type. Overall, and for each age group individually, the judgment data were best explained by a model that included ratings of the extent to which each verb exhibits both the broad- and narrow-range semantic properties of the figure- and ground-locative constructions (relating mainly to manner and end-state respectively; Pinker, 1989) and the statistical-learning measure of overall verb frequency (entrenchment; Braine & Brooks, 1995). A second statistical-learning measure, frequency in each of the two locative constructions (pre-emption; Goldberg, 1995), was found to have no additional dissociable effect. We conclude by drawing together various theoretical proposals to arrive at a possible account of how semantics and statistics interact in the retreat from overgeneralization.

  17. On Constrained Facility Location Problems

    Institute of Scientific and Technical Information of China (English)

    Wei-Lin Li; Peng Zhang; Da-Ming Zhu

    2008-01-01

    Given m facilities each with an opening cost, n demands, and distance between every demand and facility,the Facility Location problem finds a solution which opens some facilities to connect every demand to an opened facility such that the total cost of the solution is minimized. The k-Facility Location problem further requires that the number of opened facilities is at most k, where k is a parameter given in the instance of the problem. We consider the Facility Location problems satisfying that for every demand the ratio of the longest distance to facilities and the shortest distance to facilities is at most w, where w is a predefined constant. Using the local search approach with scaling technique and error control technique, for any arbitrarily small constant ∈ > 0, we give a polynomial-time approximation algorithm for the ω-constrained Facility Location problem with approximation ratio 1 + √ω + 1 + ∈, which significantly improves the previous best known ratio (ω + 1)/α for some 1 ≤α≤ 2, and a polynomial-time approximation algorithm for the ω-constrained κ-Facility Location problem with approximation ratio ω + 1 + ∈. On the aspect of approximation hardness, we prove that unless NP (C) DTIME(nO(loglogn)), the ω-constrained Facility Location problem cannot be approximated within 1 + √ω-1,which slightly improves the previous best known hardness result 1.243 + 0.316 ln(ω - 1). The experimental results on the standard test instances of Facility Location problem show that our algorithm also has good performance in practice.

  18. Inferring Stop-Locations from WiFi

    DEFF Research Database (Denmark)

    Wind, David Kofoed; Sapiezynski, Piotr; Furman, Magdalena Anna

    2016-01-01

    Human mobility patterns are inherently complex. In terms of understanding these patterns, the process of converting raw data into series of stop-locations and transitions is an important first step which greatly reduces the volume of data, thus simplifying the subsequent analyses. Previous resear...... the most important routers and one which uses a density-based clustering algorithm to detect router fingerprints. We validate our results using participants' GPS data as well as ground truth data collected during a two month period....

  19. Plant Stem Cells

    National Research Council Canada - National Science Library

    Greb, Thomas; Lohmann, Jan U

    2016-01-01

    .... While the promise of organ regeneration and the end of cancer have captured our imagination, it has gone almost unnoticed that plant stem cells represent the ultimate origin of much of the food we...

  20. Innovation and STEM Schools

    Science.gov (United States)

    Roberts, Julia Link

    2015-01-01

    How do schools with a focus on science, technology, engineering, and mathematics (STEM) fit in with state goals to increase innovation and to boost the economy? This article briefly discusses how educators can encourage creativity and innovation.

  1. Stem Cell Basics

    Science.gov (United States)

    ... why are they important? Stem cells have the remarkable potential to develop into many different cell types ... of Health, U.S. Department of Health and Human Services, 2016 [cited October 9, 2017 ] Available at < //stemcells. ...

  2. Engineering Stem Cell Organoids

    National Research Council Canada - National Science Library

    Yin, Xiaolei; Mead, Benjamin E; Safaee, Helia; Langer, Robert; Karp, Jeffrey M; Levy, Oren

    2016-01-01

    .... Herein, we discuss basic approaches to generate stem cell-based organoids, their advantages and limitations, and how bioengineering strategies can be used to steer the cell composition and their 3D...

  3. Induced pluripotent stem cells

    Institute of Scientific and Technical Information of China (English)

    Siddhartha Bhowmik; LI Yong

    2011-01-01

    Induced pluripotent stem (iPS) cells are a recent development which has brought a promise of great therapeutic values. The previous technique of somatic cell nuclear transfer (SCNT) has been ineffective in humans. Recent discoveries show that human fibroblasts can be reprogrammed by a transient over expression of a small number of genes; they can undergo induced pluripotency. iPS were first produced in 2006. By 2008, work was underway to remove the potential oncogenes from their structure. In 2009, protein iPS (piPS) cells were discovered. Surface markers and reporter genes play an important role in stem cell research. Clinical applications include generation of self renewing stem cells, tissue replacement and many more. Stem cell therapy has the ability to dramatically change the treatment of human diseases.

  4. Regenerative Applications Using Tooth Derived Stem Cells in Other Than Tooth Regeneration: A Literature Review

    OpenAIRE

    2016-01-01

    Tooth derived stem cells or dental stem cells are categorized according to the location from which they are isolated and represent a promising source of cells for regenerative medicine. Originally, as one kind of mesenchymal stem cells, they are considered an alternative of bone marrow stromal cells. They share many commonalties but maintain differences. Considering their original function in development and the homeostasis of tooth structures, many applications of these cells in dentistry ha...

  5. What are Stem Cells?

    Directory of Open Access Journals (Sweden)

    Ahmadshah Farhat

    2014-05-01

    Full Text Available   Stem cells are undifferentiated self regenerating multi potential cells. There are three types of stem cells categories by the ability to form after cells and correlated with the body’s development process. Totipotent: these stem cells can form an entire organism such as fertilized egg. Ploripotent: ploripotent cells are those that can form any cell in the body but cannot form an entire organism such as developing embryo’s totipotent cells become ploripotent  Multipotent: Multi potent stem cells are those that can only form specific cells in the body such as blood cells based. Based on the sources of stem cells we have three types of these cells: Autologous: Sources of the patient own cells are (Autologous either the cells from patient own body or his or her cord blood. For this type of transplant the physician now usually collects the periphery rather than morrow because the procedure is easier on like a bane morrow harvest it take place outside of an operating room, and the patient does not to be under general unsetting . Allogenic: Sources of stem cells from another donore are primarily relatives (familial allogenic or completely unrelated donors. Xenogenic: In these stem cells from different species are transplanted e .g striatal porcine fetal mesan cephalic (FVM xenotransplants for Parkinson’s disease. On sites of isolation such as embryo, umbilical cord and other body tissues stem cells are named embnyonic, cord blood, and adult stem cells. The scope of results and clinical application of stem cells are such as: Neurodegenerative conditions (MS,ALS, Parkinson’s, Stroke, Ocular disorders- Glaucoma, retinitis Pigmentosa (RP, Auto Immune Conditions (Lupus, MS,R. arthritis, Diabetes, etc, Viral Conditions (Hepatitis C and AIDS, Heart Disease, Adrenal Disorders, Injury(Nerve, Brain, etc, Anti aging (hair, skin, weight control, overall well being/preventive, Emotional disorders, Organ / Tissue Cancers, Blood cancers, Blood diseases

  6. Infrasound from ground to space

    Science.gov (United States)

    Bowman, Daniel Charles

    Acoustic detector networks are usually located on the Earth's surface. However, these networks suffer from shortcomings such as poor detection range and pervasive wind noise. An alternative is to deploy acoustic sensors on high altitude balloons. In theory, such platforms can resolve signals arriving from great distances, acquire others that never reach the surface at all, and avoid wind noise entirely. This dissertation focuses on scientific advances, instrumentation, and analytical techniques resulting from the development of such sensor arrays. Results from infrasound microphones deployed on balloon flights in the middle stratosphere are described, and acoustic sources such as the ocean microbarom and building ventilation systems are discussed. Electromagnetic noise originating from the balloon, flight system, and other payloads is shown to be a pervasive issue. An experiment investigating acoustic sensor calibration at low pressures is presented, and implications for high altitude recording are considered. Outstanding challenges and opportunities in sound measurement using sensors embedded in the free atmosphere are outlined. Acoustic signals from field scale explosions designed to emulate volcanic eruptions are described, and their generation mechanisms modeled. Wave forms recorded on sensors suspended from tethered helium balloons are compared with those detected on ground stations during the experiment. Finally, the Hilbert-Huang transform, a high time resolution spectral analysis method for nonstationary and nonlinear time series, is presented.

  7. Models of knot and stem development in black spruce trees indicate a shift in allocation priority to branches when growth is limited

    Directory of Open Access Journals (Sweden)

    Emmanuel Duchateau

    2015-04-01

    Full Text Available The branch autonomy principle, which states that the growth of individual branches can be predicted from their morphology and position in the forest canopy irrespective of the characteristics of the tree, has been used to simplify models of branch growth in trees. However, observed changes in allocation priority within trees towards branches growing in light-favoured conditions, referred to as ‘Milton’s Law of resource availability and allocation,’ have raised questions about the applicability of the branch autonomy principle. We present models linking knot ontogeny to the secondary growth of the main stem in black spruce (Picea mariana (Mill. B.S.P., which were used to assess the patterns of assimilate allocation over time, both within and between trees. Data describing the annual radial growth of 445 stem rings and the three-dimensional shape of 5,377 knots were extracted from optical scans and X-ray computed tomography images taken along the stems of 10 trees. Total knot to stem area increment ratios (KSR were calculated for each year of growth, and statistical models were developed to describe the annual development of knot diameter and curvature as a function of stem radial increment, total tree height, stem diameter, and the position of knots along an annual growth unit. KSR varied as a function of tree age and of the height to diameter ratio of the stem, a variable indicative of the competitive status of the tree. Simulations of the development of an individual knot showed that an increase in the stem radial growth rate was associated with an increase in the initial growth of the knot, but also with a shorter lifespan. Our results provide support for ‘Milton’s Law,’ since they indicate that allocation priority is given to locations where the potential return is the highest. The developed models provided realistic simulations of knot morphology within trees, which could be integrated into a functional-structural model of tree

  8. Skeletal (stromal) stem cells

    DEFF Research Database (Denmark)

    Abdallah, Basem M; Kermani, Abbas Jafari; Zaher, Walid

    2015-01-01

    Skeletal (marrow stromal) stem cells (BMSCs) are a group of multipotent cells that reside in the bone marrow stroma and can differentiate into osteoblasts, chondrocytes and adipocytes. Studying signaling pathways that regulate BMSC differentiation into osteoblastic cells is a strategy....../preadipocyte factor 1 (Dlk1/Pref-1), the Wnt co-receptor Lrp5 and intracellular kinases. This article is part of a Special Issue entitled: Stem Cells and Bone....

  9. Sensitivities and uncertainties of modeled ground temperatures in mountain environments

    Directory of Open Access Journals (Sweden)

    S. Gubler

    2013-08-01

    Full Text Available Model evaluation is often performed at few locations due to the lack of spatially distributed data. Since the quantification of model sensitivities and uncertainties can be performed independently from ground truth measurements, these analyses are suitable to test the influence of environmental variability on model evaluation. In this study, the sensitivities and uncertainties of a physically based mountain permafrost model are quantified within an artificial topography. The setting consists of different elevations and exposures combined with six ground types characterized by porosity and hydraulic properties. The analyses are performed for a combination of all factors, that allows for quantification of the variability of model sensitivities and uncertainties within a whole modeling domain. We found that model sensitivities and uncertainties vary strongly depending on different input factors such as topography or different soil types. The analysis shows that model evaluation performed at single locations may not be representative for the whole modeling domain. For example, the sensitivity of modeled mean annual ground temperature to ground albedo ranges between 0.5 and 4 °C depending on elevation, aspect and the ground type. South-exposed inclined locations are more sensitive to changes in ground albedo than north-exposed slopes since they receive more solar radiation. The sensitivity to ground albedo increases with decreasing elevation due to shorter duration of the snow cover. The sensitivity in the hydraulic properties changes considerably for different ground types: rock or clay, for instance, are not sensitive to uncertainties in the hydraulic properties, while for gravel or peat, accurate estimates of the hydraulic properties significantly improve modeled ground temperatures. The discretization of ground, snow and time have an impact on modeled mean annual ground temperature (MAGT that cannot be neglected (more than 1 °C for several

  10. Common Ground and Delegation

    DEFF Research Database (Denmark)

    Dobrajska, Magdalena; Foss, Nicolai Juul; Lyngsie, Jacob

    Much recent research suggests that firms need to increase their level of delegation to better cope with, for example, the challenges introduced by dynamic rapid environments and the need to engage more with external knowledge sources. However, there is less insight into the organizational...... preconditions of increasing delegation. We argue that key HR practices?namely, hiring, training and job-rotation?are associated with delegation of decision-making authority. These practices assist in the creation of shared knowledge conditions between managers and employees. In turn, such a ?common ground...

  11. Ground penetrating radar

    CERN Document Server

    Daniels, David J

    2004-01-01

    Ground-penetrating radar has come to public attention in recent criminal investigations, but has actually been a developing and maturing remote sensing field for some time. In the light of recent expansion of the technique to a wide range of applications, the need for an up-to-date reference has become pressing. This fully revised and expanded edition of the best-selling Surface-Penetrating Radar (IEE, 1996) presents, for the non-specialist user or engineer, all the key elements of this technique, which span several disciplines including electromagnetics, geophysics and signal processing. The

  12. Singlet Ground State Magnetism:

    DEFF Research Database (Denmark)

    Loidl, A.; Knorr, K.; Kjems, Jørgen;

    1979-01-01

    The magneticGamma 1 –Gamma 4 exciton of the singlet ground state system TbP has been studied by inelastic neutron scattering above the antiferromagnetic ordering temperature. Considerable dispersion and a pronounced splitting was found in the [100] and [110] directions. Both the band width...... and the splitting increased rapidly as the transition temperature was approached in accordance with the predictions of the RPA-theory. The dispersion is analysed in terms of a phenomenological model using interactions up to the fourth nearest neighbour....

  13. The LOFT Ground Segment

    DEFF Research Database (Denmark)

    Bozzo, E.; Antonelli, A.; Argan, A.;

    2014-01-01

    targets per orbit (~90 minutes), providing roughly ~80 GB of proprietary data per day (the proprietary period will be 12 months). The WFM continuously monitors about 1/3 of the sky at a time and provides data for about ~100 sources a day, resulting in a total of ~20 GB of additional telemetry. The LOFT...... we summarize the planned organization of the LOFT ground segment (GS), as established in the mission Yellow Book 1 . We describe the expected GS contributions from ESA and the LOFT consortium. A review is provided of the planned LOFT data products and the details of the data flow, archiving...

  14. Comparing methods for Earthquake Location

    Science.gov (United States)

    Turkaya, Semih; Bodin, Thomas; Sylvander, Matthieu; Parroucau, Pierre; Manchuel, Kevin

    2017-04-01

    There are plenty of methods available for locating small magnitude point source earthquakes. However, it is known that these different approaches produce different results. For each approach, results also depend on a number of parameters which can be separated into two main branches: (1) parameters related to observations (number and distribution of for example) and (2) parameters related to the inversion process (velocity model, weighting parameters, initial location etc.). Currently, the results obtained from most of the location methods do not systematically include quantitative uncertainties. The effect of the selected parameters on location uncertainties is also poorly known. Understanding the importance of these different parameters and their effect on uncertainties is clearly required to better constrained knowledge on fault geometry, seismotectonic processes and at the end to improve seismic hazard assessment. In this work, realized in the frame of the SINAPS@ research program (http://www.institut-seism.fr/projets/sinaps/), we analyse the effect of different parameters on earthquakes location (e.g. type of phase, max. hypocentral separation etc.). We compare several codes available (Hypo71, HypoDD, NonLinLoc etc.) and determine their strengths and weaknesses in different cases by means of synthetic tests. The work, performed for the moment on synthetic data, is planned to be applied, in a second step, on data collected by the Midi-Pyrénées Observatory (OMP).

  15. Processing locational and orientational information.

    Science.gov (United States)

    Maki, R H; Maki, W S; Marsh, L G

    1977-09-01

    In choice reaction time (RT) tasks, college students verified the truth of displays expressing spatial relations between two objects. The relations werelocational (A is left of B) ororientational (A and B are horizontal). The objects were names of states in the United States, symbols, or letter arrays. The objects were memorized prior to the display (states and letters) or were presented as part of the display (symbols and letters). In the location tasks with both states and symbols, locatives were spatial (right, left, above, below) or compass (north, south, east, west). Distance between states was also varied. When location was judged, horizontally aligned stimuli resulted in slower responses than vertically aligned stimuli, independently of materials and locative set. Reaction time was inversely related to distance. When orientation was judged, responses to horizontal pairs of states were slower than responses to vertical pairs of states, responses to horizontal pairs of letters were faster than responses to vertical pairs, and RT did not depend upon the orientation of symbols. This pattern of results suggests that orientational judgments are influenced by type of materials and the entext to which the material has been encoded (i.e., memorized). Locational judgments reflect a potent source of difficulty not present in orientation tasks, namely, telling left from right. Alternative explanations of the right-left effect are discussed.

  16. Space and Ground-Based Infrastructures

    Science.gov (United States)

    Weems, Jon; Zell, Martin

    This chapter deals first with the main characteristics of the space environment, outside and inside a spacecraft. Then the space and space-related (ground-based) infrastructures are described. The most important infrastructure is the International Space Station, which holds many European facilities (for instance the European Columbus Laboratory). Some of them, such as the Columbus External Payload Facility, are located outside the ISS to benefit from external space conditions. There is only one other example of orbital platforms, the Russian Foton/Bion Recoverable Orbital Capsule. In contrast, non-orbital weightless research platforms, although limited in experimental time, are more numerous: sounding rockets, parabolic flight aircraft, drop towers and high-altitude balloons. In addition to these facilities, there are a number of ground-based facilities and space simulators, for both life sciences (for instance: bed rest, clinostats) and physical sciences (for instance: magnetic compensation of gravity). Hypergravity can also be provided by human and non-human centrifuges.

  17. Embryonic death and the creation of human embryonic stem cells

    OpenAIRE

    Landry, Donald W.; Zucker, Howard A.

    2004-01-01

    The creation of human embryonic stem cells through the destruction of a human embryo pits the value of a potential therapeutic tool against that of an early human life. This contest of values has resulted in a polarized debate that neglects areas of common interest and perspective. We suggest that a common ground for pursuing research on human embryonic stem cells can be found by reconsidering the death of the human embryo and by applying to this research the ethical norms of essential organ ...

  18. Embryonic death and the creation of human embryonic stem cells.

    Science.gov (United States)

    Landry, Donald W; Zucker, Howard A

    2004-11-01

    The creation of human embryonic stem cells through the destruction of a human embryo pits the value of a potential therapeutic tool against that of an early human life. This contest of values has resulted in a polarized debate that neglects areas of common interest and perspective. We suggest that a common ground for pursuing research on human embryonic stem cells can be found by reconsidering the death of the human embryo and by applying to this research the ethical norms of essential organ donation.

  19. Location and activity specific site-management for military locations

    NARCIS (Netherlands)

    Maring, L.; Hulst, M. van; Meuken, D.

    2009-01-01

    pace is limited in the Netherlands and military activities, that may cause nuisance or environmental hazards, should therefore be considered and evaluated during the use of military locations. The last few years TNO and Deltares have worked on a research program on environmental effects due to milit

  20. Hematopoietic stem cells are coordinated by the molecular cues of the endosteal niche.

    NARCIS (Netherlands)

    Huurne, M.C. ter; Figdor, C.G.; Torensma, R.

    2010-01-01

    Hematopoietic stem cells (HSCs) accomplish a complex task. On a daily base billions of the 8 different mature cells are delivered in the right proportions. HSCs are located in niches located at several locations in the body. Communication between these spatially separated niches is accomplished by s

  1. On what grounds?

    DEFF Research Database (Denmark)

    Markussen, Thomas; Krogh, Peter Gall; Bang, Anne Louise

    2015-01-01

    Research through design is a murky field and there is an increasing interest in understanding its varied practices and methodology. In the research literature that is initially reviewed in this paper two positions are located as the most dominant representing opposite opinions concerning the natu...

  2. Neuroanatomical correlates of locative prepositions.

    Science.gov (United States)

    Tranel, Daniel; Kemmerer, David

    2004-10-01

    Very little research has explored which neural systems may be important for retrieving the meanings of locative prepositions (e.g., in, on, around). To begin to address this knowledge gap, we conducted a lesion study in which we tested the hypothesis that processing the meanings of locative prepositions depends on neural structures in the left inferior prefrontal cortex and left inferior parietal cortex. Seventy-eight subjects with focal, stable lesions to various parts of the telencephalon and a comparison group of 60 normal participants were studied with tasks that require production, comprehension, and semantic analysis of locative prepositions. In support of our hypothesis, we found that in subjects with impaired knowledge of locative prepositions, the highest region of lesion overlap was in the left frontal operculum and the left supramarginal gyrus, and in the white matter subjacent to these two areas. In a second study, focused on six subjects who had pervasive defects for locative preposition knowledge, we confirmed that such defects were associated specifically with damage to the posterior left frontal operculum, white matter subjacent to this region, and white matter underneath the inferior parietal operculum. These subjects did not have basic impairments in spatial processing or working memory, and they had relatively well-preserved processing of conceptual knowledge for actions and various categories of concrete entities (e.g., persons, animals, tools). All six subjects, however, had defects in naming actions, and some of them also had defective naming of some categories of concrete entities. Overall, the findings converge nicely with recent results from functional imaging approaches, and with classic studies from the aphasia-based literature, and suggest that the left inferior prefrontal and left inferior parietal regions have crucial-albeit not exclusive-roles in processing knowledge associated with locative prepositions.

  3. Locating ATMs in Urban Areas

    Directory of Open Access Journals (Sweden)

    Mehdi MoradiTabar

    2013-08-01

    Full Text Available In recent years, the banks and financial institutions have considerably attempted to provide better and more varied services to the customers. These varied services may satisfy needs of differentgroup of customers. In this regard, the location of these services as well as their level of accessibility (access to these services is greatly important. The importance of these issues is well recognized by responsible managers of the financial firms. In other words, the managers accept the importance of these services and they know that the quality and location of these services significantly affect their success in the business. Therefore, bank managers sought scientific methods, which may facilitate the locating process for their services. How to select the most effective methods and how to use these methods in this regard depend on following factors: the customers' demands, local capacities and fair distribution of theservices, etc. The effective impact of these factors as well as the interactive relationship between them should also be noted in the application. This study is a descriptive kind of research, which is applicable in various areas. Library and environmental studies were used to conduct the study. Considering the parameters that considerably affect the level of acceptability of ATMs services and analyzing the importance of these parameters according to this criterion, the researchers tried to use multiple attribute decision-making model. a heuristic algorithm was used in the context of this approach. Then, the most appropriate locations around the optimal locations were introduced based on fuzzy concept as well as quantitative and qualitative factors, including the minimum cost and maximum coverage according to the customers’ demands. The case study was located in the 13th district of Tehran city.

  4. Identification of Damage in IR-Structures from Earthquake Records - Optimal Location of Sensors

    DEFF Research Database (Denmark)

    Nielsen, Søren R.K.; Skjærbæk, P. S.; Cakmak, A. S.

    of the optimal location of measurements sensors, i.e. at which locations along the structure the most information about the damage distribution is gained. In all cases it is assumed that measurements are performed at top storey and ground surface, and the investigations are concentrated on putting one or two...

  5. Benefits of Location-Based Access Control:A Literature Study

    NARCIS (Netherlands)

    Cleeff, van André; Pieters, Wolter; Wieringa, Roel

    2010-01-01

    Location-based access control (LBAC) has been suggested as a means to improve IT security. By 'grounding' users and systems to a particular location, attackers supposedly have more difficulty in compromising a system. However, the motivation behind LBAC and its potential benefits have not been inve

  6. The LOFT Ground Segment

    CERN Document Server

    Bozzo, E; Argan, A; Barret, D; Binko, P; Brandt, S; Cavazzuti, E; Courvoisier, T; Herder, J W den; Feroci, M; Ferrigno, C; Giommi, P; Götz, D; Guy, L; Hernanz, M; Zand, J J M in't; Klochkov, D; Kuulkers, E; Motch, C; Lumb, D; Papitto, A; Pittori, C; Rohlfs, R; Santangelo, A; Schmid, C; Schwope, A D; Smith, P J; Webb, N A; Wilms, J; Zane, S

    2014-01-01

    LOFT, the Large Observatory For X-ray Timing, was one of the ESA M3 mission candidates that completed their assessment phase at the end of 2013. LOFT is equipped with two instruments, the Large Area Detector (LAD) and the Wide Field Monitor (WFM). The LAD performs pointed observations of several targets per orbit (~90 minutes), providing roughly ~80 GB of proprietary data per day (the proprietary period will be 12 months). The WFM continuously monitors about 1/3 of the sky at a time and provides data for about ~100 sources a day, resulting in a total of ~20 GB of additional telemetry. The LOFT Burst alert System additionally identifies on-board bright impulsive events (e.g., Gamma-ray Bursts, GRBs) and broadcasts the corresponding position and trigger time to the ground using a dedicated system of ~15 VHF receivers. All WFM data are planned to be made public immediately. In this contribution we summarize the planned organization of the LOFT ground segment (GS), as established in the mission Yellow Book 1 . We...

  7. Mesenchymal stem cells in human placental chorionic villi reside in a vascular Niche

    NARCIS (Netherlands)

    Castrechini, N. M.; Murthi, P.; Gude, N. M.; Erwich, J. J. H. M.; Gronthos, S.; Zannettino, A.; Brennecke, S. R.; Kalionis, B.; Brennecke, S.P.

    2010-01-01

    The chorionic villi of human term placentae are a rich source of mesenchymal stem cells (PMSCs) The stem cell "niche" within the chorionic villi regulates how PMSCs participate in placental tissue generation, maintenance and repair, but the anatomic location of the niche has not been defined A numbe

  8. STEM Aspiration: The Influence of Social Capital and Chilly Climate on Female Community College Students

    Science.gov (United States)

    Jorstad, John; Starobin, Soko S.; Chen, Yu; Kollasch, Aurelia

    2017-01-01

    This quantitative study examined the predictive impact of a series of factors on female community college students' intention to transfer in science, technology, engineering, and mathematics (STEM). The STEM Student Success Literacy survey (SSSL) was utilized to collect data from a large, diverse community college located in Florida. After the…

  9. Paneth cells constitute the niche for Lgr5 stem cells in intestinal crypts

    NARCIS (Netherlands)

    Sato, T.; van Es, J.H.; Snippert, H.J.G.; Stange, D.E.; Vries, R.G.J.; van den Born, M.M.W.; Barker, N.; Shroyer, N.F.; van de Wetering, M.L.; Clevers, H.

    2010-01-01

    Homeostasis of self-renewing small intestinal crypts results from neutral competition between Lgr5 stem cells, which are small cycling cells located at crypt bottoms. Lgr5 stem cells are interspersed between terminally differentiated Paneth cells that are known to produce bactericidal products such

  10. Intestinal crypt homeostasis revealed at single-stem-cell level by in vivo live imaging

    Science.gov (United States)

    Ritsma, Laila; Ellenbroek, Saskia I. J.; Zomer, Anoek; Snippert, Hugo J.; de Sauvage, Frederic J.; Simons, Benjamin D.; Clevers, Hans; van Rheenen, Jacco

    2014-03-01

    The rapid turnover of the mammalian intestinal epithelium is supported by stem cells located around the base of the crypt. In addition to the Lgr5 marker, intestinal stem cells have been associated with other markers that are expressed heterogeneously within the crypt base region. Previous quantitative clonal fate analyses have led to the proposal that homeostasis occurs as the consequence of neutral competition between dividing stem cells. However, the short-term behaviour of individual Lgr5+ cells positioned at different locations within the crypt base compartment has not been resolved. Here we establish the short-term dynamics of intestinal stem cells using the novel approach of continuous intravital imaging of Lgr5-Confetti mice. We find that Lgr5+ cells in the upper part of the niche (termed `border cells') can be passively displaced into the transit-amplifying domain, after the division of proximate cells, implying that the determination of stem-cell fate can be uncoupled from division. Through quantitative analysis of individual clonal lineages, we show that stem cells at the crypt base, termed `central cells', experience a survival advantage over border stem cells. However, through the transfer of stem cells between the border and central regions, all Lgr5+ cells are endowed with long-term self-renewal potential. These findings establish a novel paradigm for stem-cell maintenance in which a dynamically heterogeneous cell population is able to function long term as a single stem-cell pool.

  11. Valve stem and packing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wordin, J.J.

    1990-12-31

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele`s pivot. The Schiele`s pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele`s pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele`s pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

  12. WHO Standard Acupuncture Point Locations

    Directory of Open Access Journals (Sweden)

    Sabina Lim

    2010-01-01

    Full Text Available ‘WHO Standard Acupuncture Point Locations in the Western Pacific Region (WHO Standard was released in 2008. Initially, there were 92/361 controversial acupuncture points (acupoints. Through seven informal consultations and four task force team meetings, 86 points were agreed upon among the 92 controversial acupoints, leaving 6 remaining controversial acupoints, demanding active research in the future. This will enhance the reproducibility and validity of acupuncture studies. It will also lead to a better understanding of acupuncture mechanisms in order to optimize its clinical efficacy for a range of diseases and syndromes. This book has two parts: General Guidelines for Acupuncture Point Locations and WHO Standard Acupuncture Point Locations. First of all, familiarity with the General Guidelines for Acupuncture Point Locations in this book can help the reader to understand and use the contents of this book in depth. I would like to thank all of the participating experts and scholars for this great work, who have overcome the limits of previous acupuncture references. I also appreciate the dedicated effort and harmonious leadership of Dr Choi Seung-hoon, former Regional Adviser in Traditional Medicine of Western Pacific Office, WHO.

  13. Potential Crash Location (PCL) Model

    Science.gov (United States)

    2014-02-05

    LCA ) model provides a method for calculating how large the actual lethal area at the site of impact would be. The LCA model is described in a...helicopter failures. The crash location calculations are just one portion of the TLS tool, the other portion is LCA . Although the LCA is not

  14. LOCATING LEAKS WITH ACOUSTIC TECHNOLOGY

    Science.gov (United States)

    Many water distribution systems in this country are almost 100 years old. About 26 percent of piping in these systems is made of unlined cast iron or steel and is in poor condition. Many methods that locate leaks in these pipes are time-consuming, costly, disruptive to operations...

  15. Competition in spatial location models

    NARCIS (Netherlands)

    Webers, H.M.

    1996-01-01

    Models of spatial competition are designed and analyzed to describe the fact that space, by its very nature, is a source of market power. This field of research, lying at the interface of game theory and economics, has attracted much interest because location problems are related to many aspects of

  16. Locating a buried earth penetrator

    Energy Technology Data Exchange (ETDEWEB)

    Caffey, T.W.H.

    1977-11-01

    The purpose of this work was to assist the recovery of a buried earth penetrator by locating the vertical projection of the penetator upon the surface within a horizontal radius error of one meter. The penetrator will carry a small coil which is driven by an alternating current to form a magnetic dipole. Five measurements of the magnetic field vector upon the surface of the earth are shown to be sufficient for determining not only the xyz-coordinates of the dipole, but also the orientation of the dipole axis. The theory, computation process, and field tests are comprehensively described. Results of 26 field tests with the dipole at 9 different combinations of location and orientation are given. Average radial and vertical location errors are 0.27 m and -0.05 m, respectively, while the mean errors in the tilt and orientation angles of the dipole axis are 3 degrees and 8 degrees, respectively. The results are applied to the design of a locating system for a Pershing II penetrator which contains a recessed, rear-mounted coil.

  17. Competition in spatial location models

    NARCIS (Netherlands)

    Webers, H.M.

    1996-01-01

    Models of spatial competition are designed and analyzed to describe the fact that space, by its very nature, is a source of market power. This field of research, lying at the interface of game theory and economics, has attracted much interest because location problems are related to many aspects of

  18. A detection-level hazardous waste ground-water monitoring compliance plan for the 200 areas low-level burial grounds and retrievable storage units

    Energy Technology Data Exchange (ETDEWEB)

    1987-02-01

    This plan defines the actions needed to achieve detection-level monitoring compliance at the Hanford Site 200 Areas Low-Level Burial Grounds (LLBG) in accordance with the Resource Conservation and Recovery Act (RCRA). Compliance will be achieved through characterization of the hydrogeology and monitoring of the ground water beneath the LLBG located in the Hanford Site 200 Areas. 13 refs., 20 figs.

  19. Limbal stem cell transplantation: current perspectives

    Directory of Open Access Journals (Sweden)

    Atallah MR

    2016-04-01

    Full Text Available Marwan Raymond Atallah, Sotiria Palioura, Victor L Perez, Guillermo Amescua Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA Abstract: Regeneration of the corneal surface after an epithelial insult involves division, migration, and maturation of a specialized group of stem cells located in the limbus. Several insults, both intrinsic and extrinsic, can precipitate destruction of the delicate microenvironment of these cells, resulting in limbal stem cell deficiency (LSCD. In such cases, reepithelialization fails and conjunctival epithelium extends across the limbus, leading to vascularization, persistent epithelial defects, and chronic inflammation. In partial LSCD, conjunctival epitheliectomy, coupled with amniotic membrane transplantation, could be sufficient to restore a healthy surface. In more severe cases and in total LSCD, stem cell transplantation is currently the best curative option. Before any attempts are considered to perform a limbal stem cell transplantation procedure, the ocular surface must be optimized by controlling causative factors and comorbid conditions. These factors include adequate eyelid function or exposure, control of the ocular surface inflammatory status, and a well-lubricated ocular surface. In cases of unilateral LSCD, stem cells can be obtained from the contralateral eye. Newer techniques aim at expanding cells in vitro or in vivo in order to decrease the need for large limbal resection that may jeopardize the “healthy” eye. Patients with bilateral disease can be treated using allogeneic tissue in combination with systemic immunosuppressive therapy. Another emerging option for this subset of patients is the use of noncorneal cells such as mucosal grafts. Finally, the use of keratoprosthesis is reserved for patients who are not candidates for any of the aforementioned options, wherein the choice of the type of keratoprosthesis depends on

  20. Designing as middle ground

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian Mossfeldt; Binder, Thomas

    2010-01-01

    The theoretical background in this chapter is science and technology studies and actor network theory, enabling investigation of heterogeneity, agency and perfor-mative effects through ‘symmetric’ analysis. The concept of design is defined as being imaginative and mindful to a number of actors...... in a network of humans and non-humans, highlighting that design objects and the designer as an authority are constructed throughout this endeavour. The illustrative case example is drawn from product development in a rubber valve factory in Jutland in Denmark. The key contribution to a general core of design...... research is an articulation of design activity taking place as a middle ground and as an intermixture between a ‘scientific’ regime of knowledge transfer and a capital ‘D’ ‘Designerly’ regime of authoring....

  1. Wind-induced ground motion

    Science.gov (United States)

    Naderyan, Vahid; Hickey, Craig J.; Raspet, Richard

    2016-02-01

    Wind noise is a problem in seismic surveys and can mask the seismic signals at low frequency. This research investigates ground motions caused by wind pressure and shear stress perturbations on the ground surface. A prediction of the ground displacement spectra using the measured ground properties and predicted pressure and shear stress at the ground surface is developed. Field measurements are conducted at a site having a flat terrain and low ambient seismic noise. Triaxial geophones are deployed at different depths to study the wind-induced ground vibrations as a function of depth and wind velocity. Comparison of the predicted to the measured wind-induced ground displacement spectra shows good agreement for the vertical component but significant underprediction for the horizontal components. To validate the theoretical model, a test experiment is designed to exert controlled normal pressure and shear stress on the ground using a vertical and a horizontal mass-spring apparatus. This experiment verifies the linear elastic rheology and the quasi-static displacements assumptions of the model. The results indicate that the existing surface shear stress models significantly underestimate the wind shear stress at the ground surface and the amplitude of the fluctuation shear stress must be of the same order of magnitude as the normal pressure. Measurement results show that mounting the geophones flush with the ground provides a significant reduction in wind noise on all three components of the geophone. Further reduction in wind noise with depth of burial is small for depths up to 40 cm.

  2. Usp16: key controller of stem cells in Down syndrome

    Science.gov (United States)

    Xu, Jin-chong; Dawson, Valina L; Dawson, Ted M

    2013-01-01

    Nature 501: 380–384 Somatic stem cell activity is critical for tissue homeostasis. Defects in stem cells are thought to be involved in many diseases, including inherited disorders and aging (He et al, 2009). In a recent paper published in Nature, Adorno et al (2013) demonstrate that there is a general somatic stem cell defect in Down syndrome (DS), a congenital disorder with triplication of human chromosome 21 (HSA21; Roper and Reeves, 2006; Mégarbané et al, 2009). They report that the deubiquitinase Usp16 gene located on HSA21 is a key epigenetic switch that regulates stem cell self-renewal and senescence in DS, and suggest that inhibiting or reducing HSA21 may be beneficial in treating the sequelae of DS. PMID:24076652

  3. Clarification of the Blurred Boundaries between Grounded Theory and Ethnography: Differences and Similarities

    Science.gov (United States)

    Aldiabat, Khaldoun; Le Navenec, Carol-Lynne

    2011-01-01

    There is confusion among graduate students about how to select the qualitative methodology that best fits their research question. Often this confusion arises in regard to making a choice between a grounded theory methodology and an ethnographic methodology. This difficulty may stem from the fact that these students do not have a clear…

  4. Location, Location, Location: How Would a High-Performing Charter School Network Fare in Different States?

    Science.gov (United States)

    Lozier, Chris; Rotherham, Andrew J.

    2011-01-01

    In this paper the authors do not examine different operating strategies for charter schools or analyze the impact of their often educationally intensive models on finance. Instead, because public charter schools are funded predominantly by public dollars, they simply ask what impact location--and its associated variances in public funding and the…

  5. PTEN, Stem Cells, and Cancer Stem Cells*S⃞

    OpenAIRE

    Hill, Reginald; Wu, Hong

    2009-01-01

    Like normal stem cells, “cancer stem cells” have the capacity for indefinite proliferation and generation of new cancerous tissues through self-renewal and differentiation. Among the major intracellular signaling pathways, WNT, SHH, and NOTCH are known to be important in regulating normal stem cell activities, and their alterations are associated with tumorigenesis. It has become clear recently that PTEN (phosphatase and tensin homologue) is also critical for stem cell...

  6. Location predicting methods for UAVs

    Science.gov (United States)

    Peng, Xiaodong; Zhang, Yu

    2017-08-01

    Location prediction of unmanned aerial vehicle (UAV) is important for fighting with its enemy and ensuring its normal operation. This paper presents the motion model of UAVs and reduces the state space into 7 dimensions. The Bayesian Network, Markov Chain, Curve Fitting and Neural Network are introduced for designing predicting methods. Then Curve Fitting Predicting method, Markov Chain Predicting method, Bayesian Network Predicting method and Neural Network Predicting method are designed for UAVs. The simulation result shows that 1) Neural Network Predicting method has highest predicting accuracy; 2) Markov Chain Predicting method and Bayesian Network Predicting method methods have similar performance and both are better than Bayesian Network Predicting method methods; 3) Neural Network Predicting method is the first choice when predicting the locations of UAVs.

  7. Location Privacy in RFID Applications

    Science.gov (United States)

    Sadeghi, Ahmad-Reza; Visconti, Ivan; Wachsmann, Christian

    RFID-enabled systems allow fully automatic wireless identification of objects and are rapidly becoming a pervasive technology with various applications. However, despite their benefits, RFID-based systems also pose challenging risks, in particular concerning user privacy. Indeed, improvident use of RFID can disclose sensitive information about users and their locations allowing detailed user profiles. Hence, it is crucial to identify and to enforce appropriate security and privacy requirements of RFID applications (that are also compliant to legislation). This chapter first discusses security and privacy requirements for RFID-enabled systems, focusing in particular on location privacy issues. Then it explores the advances in RFID applications, stressing the security and privacy shortcomings of existing proposals. Finally, it presents new promising directions for privacy-preserving RFID systems, where as a case study we focus electronic tickets (e-tickets) for public transportation.

  8. Orthogonal coding of object location.

    Science.gov (United States)

    Knutsen, Per Magne; Ahissar, Ehud

    2009-02-01

    It has been argued whether internal representations are encoded using a universal ('the neural code') or multiple codes. Here, we review a series of experiments that demonstrate that tactile encoding of object location via whisking employs an orthogonal, triple-code scheme. Rats, and other rodents, actively move the whiskers back and forth to localize and identify objects. Neural recordings from primary sensory afferents, along with behavioral observations, demonstrate that vertical coordinates of contacted objects are encoded by the identity of activated afferents, horizontal coordinates by the timing of activation and radial coordinates by the intensity of activation. Because these codes are mutually independent, the three-dimensional location of an object could, in principle, be encoded by individual afferents during single whisker-object contacts. One advantage of such a same-neuron-different-codes scheme over the traditionally assumed same-code-different-neurons scheme is a reduction of code ambiguity that, in turn, simplifies decoding circuits.

  9. Unexpected location of pilonidal sinuses.

    Science.gov (United States)

    Sion-Vardy, N; Osyntsov, L; Cagnano, E; Osyntsov, A; Vardy, D; Benharroch, D

    2009-12-01

    Pilonidal sinuses usually occur in the sacrococcygeal area in young men, and occasionally can be found in other ectopic sites. We present a retrospective case review on unusual locations of pilonidal sinuses in the past 4 years. The lesion sites were as follows: one on the penis, two on the scalp, two on the abdomen, one on the neck, two in the groin and two in the axilla. Abdominal and penile lesions are uncommon, but the other locations reported are unusually rare. To our knowledge, the groin has not been reported previously as a site of a pilonidal sinus, although the histological appearance of hidradenitis suppurativa may well resemble it. When trying to clarify the pathogenesis of these occurrences, we found that recurrent hair removal was a common characteristic of the patients we contacted, and this may have been the initiating trauma.

  10. Local above-ground persistence of vascular plants : Life-history trade-offs and environmental constraints

    NARCIS (Netherlands)

    Ozinga, Wim A.; Hennekens, Stephan M.; Schaminee, Joop H. J.; Smits, Nina A. C.; Bekker, Renee M.; Roemermann, Christine; Klimes, Leos; Bakker, Jan P.; van Groenendael, Jan M.

    2007-01-01

    Questions: 1. Which plant traits and habitat characteristics best explain local above-ground persistence of vascular plant species and 2. Is there a trade-off between local above-ground persistence and the ability for seed dispersal and below-ground persistence in the soil seed bank? Locations: 845

  11. Local above-ground persistence of vascular plants: life-history trade-offs and environmental constraints

    NARCIS (Netherlands)

    Ozinga, W.A.; Hennekens, S.M.; Schaminée, J.H.J.; Smits, N.A.C.; Bekker, R.M.; Römermann, C.; Bakker, J.P.; Groenendael, van J.M.

    2007-01-01

    Questions: 1. Which plant traits and habitat characteristics best explain local above-ground persistence of vascular plant species and 2. Is there a trade-off between local above-ground persistence and the ability for seed dispersal and below-ground persistence in the soil seed bank? Locations: 845

  12. MNEs as border-crossing multi-location enterprises : The role of discontinuities in geographic space

    NARCIS (Netherlands)

    Beugelsdijk, Sjoerd; Mudambi, Ram

    2013-01-01

    Spurred by the classic work of Dunning, MNE location has become the focus of a growing body of research in the field. In this paper we argue that international business (IB) research examining the spatial dimension has serious weaknesses, stemming from its traditional assumption of the country as

  13. Clowning, Location, and Mediterranean Drama

    OpenAIRE

    Publicover, Laurence

    2015-01-01

    This essay explores the ways in which early modern clowns disturb both spatial and generic decorum within early modern drama, and examines the ideological implications of these disturbances. With a particular focus on plays set in the Mediterranean, it demonstrates how clown-figures, through a variety of techniques, refocus attention on the performance space even at moments when plays seem most concerned with the real geographical locations they present. The essay ends by considering the impa...

  14. Computer Model Locates Environmental Hazards

    Science.gov (United States)

    2008-01-01

    Catherine Huybrechts Burton founded San Francisco-based Endpoint Environmental (2E) LLC in 2005 while she was a student intern and project manager at Ames Research Center with NASA's DEVELOP program. The 2E team created the Tire Identification from Reflectance model, which algorithmically processes satellite images using turnkey technology to retain only the darkest parts of an image. This model allows 2E to locate piles of rubber tires, which often are stockpiled illegally and cause hazardous environmental conditions and fires.

  15. Rare locations of calcifying tendinitis

    Energy Technology Data Exchange (ETDEWEB)

    Nidecker, A.; Hartweg, H.

    1983-12-01

    5 case-reports illustrate 2 rare locations of calcifying peritendinitis: The insertion of the deltoid tendon in the proximal humreus and the insertion of the gluteus maximus tendon in the femur. Knowledge of these insertion sites on one hand and the possibility of calcifying tendinitis at these sites on the other hand may allow proper diagnosis of certain shoulder- and hip joint pain syndromes and subsequent correct therapy.

  16. Underwater Acoustic Beacon Location System

    Science.gov (United States)

    2016-12-23

    transpose operator is a standard operator in linear or matrix algebra . The transpose operator converts the row vector   T aaaa z,y,x=P to a column...February 2017 The below identified patent application is available for licensing. Requests for information should be addressed to...300087 1 of 31 UNDERWATER ACOUSTIC BEACON LOCATION SYSTEM [0001] The present application claims the benefit of United States Provisional

  17. Uranium Critical Point Location Problem

    CERN Document Server

    Iosilevskiy, Igor

    2013-01-01

    Significant uncertainty of our present knowledge for uranium critical point parameters is under consideration. Present paper is devoted to comparative analysis of possible resolutions for the problem of uranium critical point location, as well as to discussion of plausible scheme of decisive experiment, which could resolve existing uncertainty. New calculations of gas-liquid coexistence in uranium by modern thermodynamic code are included in the analysis.

  18. Location Estimation using Delayed Measurements

    DEFF Research Database (Denmark)

    Bak, Martin; Larsen, Thomas Dall; Nørgård, Peter Magnus

    1998-01-01

    When combining data from various sensors it is vital to acknowledge possible measurement delays. Furthermore, the sensor fusion algorithm, often a Kalman filter, should be modified in order to handle the delay. The paper examines different possibilities for handling delays and applies a new techn...... technique to a sensor fusion system for estimating the location of an autonomous guided vehicle. The system fuses encoder and vision measurements in an extended Kalman filter. Results from experiments in a real environment are reported...

  19. Electronic warfare target location methods

    CERN Document Server

    Poisel, Richard

    2012-01-01

    Describing the mathematical development underlying current and classical methods of geolocating electronic systems that are emitting, this newly revised and greatly expanded edition of a classic Artech House book offers practical guidance in electronic warfare target location. The Second Edition features a wealth of additional material including new chapters on time delay estimation, direction finding techniques, and the MUSIC algorithm. This practical resource provides you with critical design information on geolocation algorithms, and establishes the fundamentals of existing algorithms as a

  20. Geocoding location expressions in Twitter messages: A preference learning method

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2014-12-01

    Full Text Available Resolving location expressions in text to the correct physical location, also known as geocoding or grounding, is complicated by the fact that so many places around the world share the same name. Correct resolution is made even more difficult when there is little context to determine which place is intended, as in a 140-character Twitter message, or when location cues from different sources conflict, as may be the case among different metadata fields of a Twitter message. We used supervised machine learning to weigh the different fields of the Twitter message and the features of a world gazetteer to create a model that will prefer the correct gazetteer candidate to resolve the extracted expression. We evaluated our model using the F1 measure and compared it to similar algorithms. Our method achieved results higher than state-of-the-art competitors.

  1. Melanoma stem cells.

    Science.gov (United States)

    Roesch, Alexander

    2015-02-01

    The cancer stem cell concept significantly broadens our understanding of melanoma biology. However, this concept should be regarded as an integral part of a holistic cancer model that also includes the genetic evolution of tumor cells and the variability of cell phenotypes within a dynamic tumor microenvironment. The biologic complexity and methodological difficulties in identifying cancer stem cells and their biomarkers are currently impeding the direct translation of experimental findings into clinical practice. Nevertheless, it is these methodological shortcomings that provide a new perspective on the phenotypic heterogeneity and plasticity of melanoma with important consequences for future therapies. The development of new combination treatment strategies, particularly with regard to overcoming treatment resistance, could significantly benefit from targeted elimination of cell subpopulations with cancer stem cell properties. © 2015 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

  2. Aneuploidy in stem cells

    Institute of Scientific and Technical Information of China (English)

    Jorge; Garcia-Martinez; Bjorn; Bakker; Klaske; M; Schukken; Judith; E; Simon; Floris; Foijer

    2016-01-01

    Stem cells hold enormous promise for regenerative medicine as well as for engineering of model systems to study diseases and develop new drugs. The discovery of protocols that allow for generating induced pluripotent stem cells(IPSCs) from somatic cells has brought this promise steps closer to reality. However,as somatic cells might have accumulated various chromosomal abnormalities,including aneuploidies throughout their lives,the resulting IPSCs might no longer carry the perfect blueprint for the tissue to be generated,or worse,become at risk of adopting a malignant fate. In this review,we discuss the contribution of aneuploidy to healthy tissues and how aneuploidy can lead to disease. Furthermore,we review the differences between how somatic cells and stem cells respond to aneuploidy.

  3. Stem Properties of Autobacteria

    Directory of Open Access Journals (Sweden)

    Boris A. Berdichevskyy

    2014-03-01

    Full Text Available This paper discusses the stem properties of the autobacteria as part of the activation syndrome and persistence of the endogenous microflora in the adaptation process of the macroorganism to stress, as well as the ability of the bacteria to stimulate the cells of the macroorganism to manifest stem properties. The essence of this syndrome involves testing the tissue with the autobacteria of their "host" body to identify the foci of cellular insolvency with the subsequent inclusion of the autostrains in the implementation phase of the catabolic and anabolic inflammations. Considering the genetic tropism of the microbes to the organ-specific tissue of the area affected, the existence of the stem properties of the autobacteria is assumed to be realized in the process of reparative regeneration. The great clinical significance of further study of this phenomenon is not excluded.

  4. Location, Location: Jurisdiction & Conflicts in Transborder Contract Litigation

    DEFF Research Database (Denmark)

    Lookofsky, Joseph

    In transborder contract litigation place-based factors are often decisive, both as regards jurisdiction to adjudicate as well as the rules which determine the applicable substantive law. Relevant locations include the place where the contract was made, where the parties reside, transact business...... or own property, the place of delivery, payment or other performance etc. Using concrete case-based examples, Professor Lookofsky explains how rules of jurisdiction and contract conflicts in Europe are tied to rigidly defined, single-place-based factors. In the United States, by contrast...

  5. Uranium in US surface, ground, and domestic waters. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Drury, J.S.; Reynolds, S.; Owen, P.T.; Ross, R.H.; Ensminger, J.T.

    1981-04-01

    The report Uranium in US Surface, Ground, and Domestic Waters comprises four volumes. Volumes 2, 3, and 4 contain data characterizing the location, sampling date, type, use, and uranium conentrations of 89,994 individual samples presented in tabular form. The tabular data in volumes 2, 3, and 4 are summarized in volume 1 in narrative form and with maps and histograms.

  6. Peat Deposits Of Light Ground Pocosin, Pamlico County, North Carolina

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Light Ground Pocosin peat deposit is located in south central Pamlico County, 13 miles east of New Bern. Except for a narrow channel 8 to 12 feet deep, and two...

  7. Cleanup Verification Package for the 118-F-6 Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    H. M. Sulloway

    2008-10-02

    This cleanup verification package documents completion of remedial action for the 118-F-6 Burial Ground located in the 100-FR-2 Operable Unit of the 100-F Area on the Hanford Site. The trenches received waste from the 100-F Experimental Animal Farm, including animal manure, animal carcasses, laboratory waste, plastic, cardboard, metal, and concrete debris as well as a railroad tank car.

  8. Localizing Ground-Penetrating Radar

    Science.gov (United States)

    2014-11-01

    ing Ground-Penetrating Radar (LGPR) uses very high frequency (VHF) radar reflections of underground features to generate base- line maps and then...Innovative ground- penetrating radar that maps underground geological features provides autonomous vehicles with real-time localization. Localizing...NOV 2014 2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Localizing Ground-Penetrating Radar 5a. CONTRACT NUMBER

  9. Stem cell therapy for diabetes

    Directory of Open Access Journals (Sweden)

    K O Lee

    2012-01-01

    Full Text Available Stem cell therapy holds immense promise for the treatment of patients with diabetes mellitus. Research on the ability of human embryonic stem cells to differentiate into islet cells has defined the developmental stages and transcription factors involved in this process. However, the clinical applications of human embryonic stem cells are limited by ethical concerns, as well as the potential for teratoma formation. As a consequence, alternative forms of stem cell therapies, such as induced pluripotent stem cells, umbilical cord stem cells and bone marrow-derived mesenchymal stem cells, have become an area of intense study. Recent advances in stem cell therapy may turn this into a realistic treatment for diabetes in the near future.

  10. Stem cells and healthy aging.

    Science.gov (United States)

    Goodell, Margaret A; Rando, Thomas A

    2015-12-04

    Research into stem cells and aging aims to understand how stem cells maintain tissue health, what mechanisms ultimately lead to decline in stem cell function with age, and how the regenerative capacity of somatic stem cells can be enhanced to promote healthy aging. Here, we explore the effects of aging on stem cells in different tissues. Recent research has focused on the ways that genetic mutations, epigenetic changes, and the extrinsic environmental milieu influence stem cell functionality over time. We describe each of these three factors, the ways in which they interact, and how these interactions decrease stem cell health over time. We are optimistic that a better understanding of these changes will uncover potential strategies to enhance stem cell function and increase tissue resiliency into old age.

  11. The Stem Cell Conundrum

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ At the beginning of this year, Kelly Reynolds,a US-national diagnosed with amyotrophic lateral sclerosis (ALS), became the one of the latest overseas patient to undergo stem cell treatment at the Nanshan Hospital in Shenzhen.Confined to a wheelchair and with limited use of his hands,the 39-year old received four fetal stem cell injections over a three-week period. So far,the results have been positive and Reynolds, acording to his personal blog page, is upbeat about the long-term benefits.

  12. Human mesenchymal stem cells

    DEFF Research Database (Denmark)

    Abdallah, Basem; Kassem, Moustapha

    2008-01-01

    Mesenchymal stem cells (MSC) are a group of clonogenic cells present among the bone marrow stroma and capable of multilineage differentiation into mesoderm-type cells such as osteoblasts, adipocytes and chondrocytes. Due to their ease of isolation and their differentiation potential, MSC are being...... introduced into clinical medicine in variety of applications and through different ways of administration. Here, we discuss approaches for isolation, characterization and directing differentiation of human mesenchymal stem cells (hMSC). An update of the current clinical use of the cells is also provided....

  13. STEM on the radio

    Science.gov (United States)

    Showstack, Randy

    2011-10-01

    Looking for an Internet radio station focusing on programing about science, technology, engineering, and math (STEM)? The U.S. National Science Foundation (NSF) announced on 26 September the launch of Science360 Radio, which it says is the first Internet radio stream dedicated to STEM programing. Science360 includes more than 100 radio shows and podcasts that are available on the Web as well as on iPhone and Android devices. The shows originate from a variety of sources, including NSF, other U.S. government agencies, science organizations, universities, and media outlets. For more information, see http://science360.gov/files/.

  14. Stem Cell Organoid Engineering

    Science.gov (United States)

    Yin, Xiaolei; Mead, Benjamin E.; Safaee, Helia; Langer, Robert; Karp, Jeffrey M.; Levy, Oren

    2016-01-01

    Organoid systems leverage the self-organizing properties of stem cells to create diverse multi-cellular tissue proxies. Most organoid models only represent single or partial components of a tissue, and it is often difficult to control the cell type, organization, and cell-cell/cell-matrix interactions within these systems. Herein, we discuss basic approaches to generate stem cell-based organoids, their advantages and limitations, and how bioengineering strategies can be used to steer the cell composition and their 3D organization within organoids to further enhance their utility in research and therapies. PMID:26748754

  15. System for tracking transplanted limbal epithelial stem cells in the treatment of corneal stem cell deficiency (Conference Presentation)

    Science.gov (United States)

    Boadi, Joseph; Matcher, Stephen; MacNeil, Sheila; Sangwan, Virender S.

    2016-04-01

    The prevailing hypothesis for the existence and healing of the avascular corneal epithelium is that this layer of cells are continually produced by stem cells in the limbus and transported onto the cornea to mature into corneal epithelium. In the event that the cornea is damaged and the limbal stem cell population is severely reduced, this condition known as Limbal Stem Cell Deficiency and can lead to blindness. There are numerous treatments but most have high long term failure rates. Most treatment methods include the transplantation of limbal stem cells into damaged limbus with hope of repopulating the region and regenerating at healthy corneal epithelium. Optical Coherence Tomography (OCT) is well known for its high resolution in vivo images. A bespoke OCT has been built to investigate the trajectories of these limbal stem cells after transplantation to see whether if they do repopulate the damaged limbus or not. In the experimentation magneto-labelling was used to track the limbal stem cells. For the magneto-labelling a mixture of limbal stem cells and cornea epithelium are cultured with super paramagnetic iron (Fe3O4) nanoparticles (20-30nm in size) for 24hours, to allow for uptake. The cells are then transplanted onto the denuded cornea. The transplanted cell mixture with the encapsulated magnetic nanoparticles is actuated with an external magnetic field 0.08T leading to a phase modulation on the signal. A Phase sensitive Magneto-motive OCT is used to locate the transplanted cells. The location of the cells with embed SPIOs were located both in 2D and 3D.

  16. Modeling and locating underground water pipe leak with microseismic data

    Science.gov (United States)

    Wang, Jing; Liu, Jiangping; Liu, Hao; Tian, Zhijian; Cheng, Fei

    2017-01-01

    for locating underground pipelines leak from an array located on the ground surface.

  17. Improved location procedures at the International Seismological Centre

    Science.gov (United States)

    Bondár, István; Storchak, Dmitry

    2011-09-01

    The International Seismological Centre (ISC) is a non-governmental, non-profit organization with the primary mission of producing the definitive account of the Earth's seismicity. The ISC Bulletin covers some 50 yr (1960-2011) of seismicity. The recent years have seen a dramatic increase both in the number of reported events and especially in the number of reported phases, owing to the ever-increasing number of stations worldwide. Similar ray paths will produce correlated traveltime prediction errors due to unmodelled heterogeneities in the Earth, resulting in underestimated location uncertainties, and for unfavourable network geometries, location bias. Hence, the denser and more unbalanced the global seismic station coverage becomes, the less defensible is the assumption (that is the observations are independent), which is made by most location algorithms. To address this challenge we have developed a new location algorithm for the ISC that accounts for correlated error structure, and uses all IASPEI standard phases with a valid ak135 traveltime prediction to obtain more accurate event locations. In this paper we describe the new ISC locator, and present validation tests by relocating the ground truth events in the IASPEI Reference Event List, as well as by relocating the entire ISC Bulletin. We show that the new ISC location algorithm provides small, but consistent location improvements, considerable improvements in depth determination and significantly more accurate formal uncertainty estimates. We demonstrate that the new algorithm, through the use of later phases and testing for depth resolution, considerably clusters event locations more tightly, thus providing an improved view of the seismicity of the Earth.

  18. Ground test for vibration control demonstrator

    Science.gov (United States)

    Meyer, C.; Prodigue, J.; Broux, G.; Cantinaud, O.; Poussot-Vassal, C.

    2016-09-01

    In the objective of maximizing comfort in Falcon jets, Dassault Aviation is developing an innovative vibration control technology. Vibrations of the structure are measured at several locations and sent to a dedicated high performance vibration control computer. Control laws are implemented in this computer to analyse the vibrations in real time, and then elaborate orders sent to the existing control surfaces to counteract vibrations. After detailing the technology principles, this paper focuses on the vibration control ground demonstration that was performed by Dassault Aviation in May 2015 on Falcon 7X business jet. The goal of this test was to attenuate vibrations resulting from fixed forced excitation delivered by shakers. The ground test demonstrated the capability to implement an efficient closed-loop vibration control with a significant vibration level reduction and validated the vibration control law design methodology. This successful ground test was a prerequisite before the flight test demonstration that is now being prepared. This study has been partly supported by the JTI CleanSky SFWA-ITD.

  19. Derivation of tree stem structural parameters from static terrestrial laser scanning data

    Science.gov (United States)

    Tian, Wei; Lin, Yi; Liu, Yajing; Niu, Zheng

    2014-11-01

    Accurate tree-level characteristic information is increasingly demanded for forest management and environment protection. The cutting-edge remote sensing technique of terrestrial laser scanning (TLS) shows the potential of filling this gap. This study focuses on exploring the methods for deriving various tree stem structural parameters, such as stem position, diameter at breast height (DBH), the degree of stem shrinkage, and the elevation angle and azimuth angle of stem inclination. The data for test was collected with a Leica HDS6100 TLS system in Seurasaari, Southern Finland in September 2010. In the field, the reference positions and DBHs of 100 trees were measured manually. The isolation of individual trees is based on interactive segmentation of point clouds. The estimation of stem position and DBH is based on the schematic of layering and then least-square-based circle fitting in each layer. The slope of robust fit line between the height of each layer and DBH is used to characterize the stem shrinkage. The elevation angle of stem inclination is described by the angle between the ground plane and the fitted stem axis. The angle between the north direction and the fitted stem axis gives the azimuth angle of stem inclination. The estimation of the DBHs performed with R square (R2) of 0.93 and root mean square error (RMSE) of 0.038m.The average angle corresponding to stem shrinkage is -1.86°. The elevation angles of stem inclinations are ranged from 31° to 88.3°. The results have basically validated TLS for deriving multiple structural parameters of stem, which help better grasp tree specialties.

  20. 46 CFR 120.376 - Grounded distribution systems (Neutral grounded).

    Science.gov (United States)

    2010-10-01

    ... ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 120.376 Grounded distribution systems... distribution system having a neutral bus or conductor must have the neutral grounded. (c) The neutral or each... generator is connected to the bus, except the neutral of an emergency power generation system must...

  1. Laser biomodulation on stem cells

    Science.gov (United States)

    Liu, Timon C.; Duan, Rui; Li, Yan; Li, Xue-Feng; Tan, Li-Ling; Liu, Songhao

    2001-08-01

    Stem cells are views from the perspectives of their function, evolution, development, and cause. Counterintuitively, most stem cells may arise late in development, to act principally in tissue renewal, thus ensuring an organisms long-term survival. Surprisingly, recent reports suggest that tissue-specific adult stem cells have the potential to contribute to replenishment of multiple adult tissues. Stem cells are currently in the news for two reasons: the successful cultivation of human embryonic stem cell lines and reports that adult stem cells can differentiate into developmentally unrelated cell types, such as nerve cells into blood cells. The spotlight on stem cells has revealed gaps in our knowledge that must be filled if we are to take advantage of their full potential for treating devastating degenerative diseases such as Parkinsons's disease and muscular dystrophy. We need to know more about the intrinsic controls that keep stem cells as stem cells or direct them along particular differentiation pathways. Such intrinsic regulators are, in turn, sensitive to the influences of the microenvironment, or niche, where stem cells normally reside. Both intrinsic and extrinsic signals regular stem cell fate and some of these signals have now been identified. Vacek et al and Wang et al have studied the effect of low intensity laser on the haemopoietic stem cells in vitro. There experiments show there is indeed the effect of low intensity laser on the haemopoietic stem cells in vitro, and the present effect is the promotion of haemopoietic stem cells proliferation. In other words, low intensity laser irradiation can act as an extrinsic signal regulating stem cell fate. In this paper, we study how low intensity laser can be used to regulate stem cell fate from the viewpoint of collective phototransduction.

  2. Influence of Microgravity Environment on Root Growth, Soluble Sugars, and Starch Concentration of Sweetpotato Stem Cuttings

    Science.gov (United States)

    Mortley, Desmond G.; Bonsi, Conrad K.; Hill, Walter A.; Morris, Carlton E.; Williams, Carol S.; Davis, Ceyla F.; Williams, John W.; Levine, Lanfang H.; Petersen, Barbara V.; Wheeler, Raymond M.

    2009-01-01

    Because sweetpotato [Ipomoea batatas (L.) Lam.] stem cuttings regenerate very easily and quickly, a study of their early growth and development in microgravity could be useful to an understanding of morphological changes that might occur under such conditions for crops that are propagated vegetatively. An experiment was conducted aboard a U.S. Space Shuttle to investigate the impact of microgravity on root growth, distribution of amyloplasts in the root cells, and on the concentration of soluble sugars and starch in the stems of sweetpotatoes. Twelve stem cuttings of ‘Whatley/Loretan’ sweetpotato (5 cm long) with three to four nodes were grown in each of two plant growth units filled with a nutrient agarose medium impregnated with a half-strength Hoagland solution. One plant growth unit was flown on Space Shuttle Colombia for 5 days, whereas the other remained on the ground as a control. The cuttings were received within 2 h postflight and, along with ground controls, processed in ≈45 min. Adventitious roots were counted, measured, and fixed for electron microscopy and stems frozen for starch and sugar assays. Air samples were collected from the headspace of each plant growth unit for postflight determination of carbon dioxide, oxygen, and ethylene levels. All stem cuttings produced adventitious roots and growth was quite vigorous in both ground-based and flight samples and, except for a slight browning of some root tips in the flight samples, all stem cuttings appeared normal. The roots on the flight cuttings tended to grow in random directions. Also, stem cuttings grown in microgravity had more roots and greater total root length than ground-based controls. Amyloplasts in root cap cells of ground-based controls were evenly sedimented toward one end compared with a more random distribution in the flight samples. The concentration of soluble sugars, glucose, fructose, and sucrose and total starch concentration were all substantially greater in the stems of

  3. Ground Penetrating Radar (GPR) Trackline Locations Collected from Dauphin Island, Alabama in April 2013

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — From April 13-20, 2013, scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center (USGS-SPCMSC) conducted geophysical surveys and...

  4. Stress Changes and Deformation Monitoring of Longwall Coal Pillars Located in Weak Ground

    Science.gov (United States)

    Yu, Bin; Zhang, Zhenyu; Kuang, Tiejun; Liu, Jinrong

    2016-08-01

    Coal pillar stability is strongly influenced by the site-specific geological and geotechnical conditions. Many geological structures such as faults, joints, or rock intrusions can be detrimental to mining operations. In order to evaluate the performance of coal pillars under weak roof degraded by igneous rock intrusion, stress and deformation monitoring was conducted in the affected tailgate areas of Nos. 8208 and 8210 longwalls in Tashan coal mine, Shanxi Province, China. The measurements in the 8208 longwall tailgate showed that the mining-induced stresses in 38-m-wide coal chain pillars under the overburden depth of 300-500 m started to increase at about 100 m ahead of the 8208 longwall working face and reached its peak level at approximately 50 m ahead of the longwall face. The peak stress of 9.16 MPa occurred at the depth of 8-9 m into the pillar from the tailgate side wall. In comparison, disturbance of the headgate block pillar area was negligible, indicating the difference of abutment pressure distribution between the tailgate and headgate sites where the adjacent unmined longwall block carried most of the overburden load. However, when the longwall face passed the headgate monitoring site by 360-379 m, the pillar stress increased to a peak value of 21.4 MPa at the pillar depth of 13 m from the gob side mainly due to stress redistribution in the chain pillar. In contrast to the headgate, at the tailgate side, the adjacent goaf was the dominant triggering factor for high stress concentrations in the chain pillar. Convergence measurements in the tailgate during longwall mining further indicated the evolution characteristics of coal pillar deformation, clearly showing that the gateroad deformation is mainly induced by the longwall extraction it serves. When predicting the future pillar loads from the monitored data, two stress peaks appeared across the 38-m-wide tailgate coal pillar, which are separated by the lower stress area within the pillar center. This 10-m-wide elastic pillar core area indicates that the coal pillar may be narrowed to 30 m to improve coal recovery. The measurements further indicate that, if the headgate of the next panel can be developed after the adjacent gob becomes stable, the coal pillar width may be further reduced to 20 m. This study is applicable for the chain pillar design, the gateroad secondary support design ahead of the longwall mining face, and the gateroad preparation of the next longwall panel under similar geological and geotechnical conditions.

  5. Radiotelemetry locates wintering grounds of DDE-contaminated black-crowned night-herons

    Science.gov (United States)

    Henny, C.J.; Blus, L.J.

    1986-01-01

    This study was designed to determine if night-herons nesting at Ruby Lake, Nevada, shared a common wintering area with lesser contaminated night-herons nesting farther north in Oregon and Idaho. Radiotelemetry (29 transmitters) and banding studies indicated that the lesser-contaminated Oregon-Idaho night-herons wintered primarily in coastal Mexico (mean 22-23'N latitude), while the Ruby Lake night-herons wintered in the southwestern United States with some in the interior of northern Mexico (mean 29-30?N latitude). We believe the nearly disjunct wintering areas for the populations, and the apparent differing pollutant loads on the wintering areas accounted for the 3-fold higher DDE egg residues at Ruby Lake. Findings from this study emphasize the influence migration patterns can have on pollutants accumulated by populations of migratory birds nesting in relatively unpolluted areas and at relatively short distances apart (400 km).

  6. Shallow-Water Benthic Habitats of Southwest Puerto Rico: Ground Validation Site Locations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Shallow-water (<30m) benthic habitat maps of the nearshore marine environment of two areas in Southwest Puerto Rico (PR), including the Guanica Bay/La Parguera...

  7. VT Potential Solar PV SHW and Ground Mount Resources - location points

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  8. Contamination of Ground Water Due To Landfill Leachate

    Directory of Open Access Journals (Sweden)

    M. V. S. Raju

    2012-12-01

    Full Text Available The present site under investigation at Ajitsingh Nagar in Vijayawada of Andhra Pradesh is initially a low lying area and used for disposing the urban solid waste for the last few years, through open dumping with out taking any measures to protect the Ground water against pollution. The present study has been taken up to measure the degree of pollution of ground water due to leachate produced in the landfill site. Bore holes were made at eight random locations to measure the depth and characteristics of solid waste. Four sampling wells were made for the collection of ground water samples and they were analyzed for various parameters. All parameters were measured based on Standard methods. It is found that the ground water is contaminated due leachates of Landfill to the large extent and is not suitable for Drinking, Domestic and Irrigation purposes.

  9. Getting grounded: using Glaserian grounded theory to conduct nursing research.

    Science.gov (United States)

    Hernandez, Cheri Ann

    2010-03-01

    Glaserian grounded theory is a powerful research methodology for understanding client behaviour in a particular area. It is therefore especially relevant for nurse researchers. Nurse researchers use grounded theory more frequently than other qualitative analysis research methods because of its ability to provide insight into clients' experiences and to make a positive impact. However, there is much confusion about the use of grounded theory.The author delineates key components of grounded theory methodology, areas of concern, and the resulting implications for nursing knowledge development. Knowledge gained from Glaserian grounded theory research can be used to institute measures for enhancing client-nurse relationships, improving quality of care, and ultimately improving client quality of life. In addition, it can serve to expand disciplinary knowledge in nursing because the resulting substantive theory is a middle-range theory that can be subjected to later quantitative testing.

  10. Spacelab Ground Processing

    Science.gov (United States)

    Scully, Edward J.; Gaskins, Roger B.

    1982-02-01

    Spacelab (SL) ground processing is active at the Kennedy Space Center (KSC). The palletized payload for the second Shuttle launch is staged and integrated with interface verification active. The SL Engineering Model is being assembled for subsequent test and checkout activities. After delivery of SL flight elements from Europe, prelaunch operations for the first SL flight start with receipt of the flight experiment packages and staging of the SL hardware. Experiment operations consist of integrating the various experiment elements into the SL racks, floors and pallets. Rack and floor assemblies with the experiments installed, are integrated into the flight module. Aft end-cone installation, pallet connections, and SL subsystems interface verifications are accomplished, and SL-Orbiter interfaces verified. The Spacelab cargo is then transferred to the Orbiter Processing Facility (OPF) in a controlled environment using a canister/transporter. After the SL is installed into the Orbiter payload bay, physical and functional integrity of all payload-to-Orbiter interfaces are verified and final close-out operations conducted. Spacelab payload activities at the launch pad are minimal with the payload bay doors remaining closed. Limited access is available to the module through the Spacelab Transfer Tunnel. After mission completion, the SL is removed from the Orbiter in the OPF and returned to the SL processing facility for experiment equipment removal and reconfiguration for the subsequent mission.

  11. PALSAR ground data processing

    Science.gov (United States)

    Frick, Heinrich; Palsetia, Marzban; Carande, Richard; Curlander, James C.

    2002-02-01

    The upcoming launches of new satellites like ALOS, Envisat, Radarsat2 and ECHO will pose a significant challenge for many ground stations, namely to integrate new SAR processing software into their existing systems. Vexcel Corporation in Boulder, Colorado, has built a SAR processing system, named APEX -Suite, for spaceborne SAR satellites that can easily be expanded for the next generation of SAR satellites. APEX-Suite includes an auto-satellite-detecting Level 0 Processor that includes bit-error correction, data quality characterization, and as a unique feature, a sophisticated and very accurate Doppler centroid estimator. The Level 1 processing is divided into the strip mode processor FOCUST, based on the well-proven range-Doppler algorithm, and the SWATHT ScanSAR processor that uses the Chirp Z Trans-form algorithm. A high-accuracy ortho-rectification processor produces systematic and precision corrected Level 2 SAR image pro ducts. The PALSAR instrument is an L-band SAR with multiple fine and standard resolution beams in strip mode, and several wide-swath ScanSAR modes. We will address the adaptation process of Vexcel's APEX-Suite processing system for the PALSAR sensor and discuss image quality characteristics based on processed simulated point target phase history data.

  12. STEM--Beyond the Acronym

    Science.gov (United States)

    Vasquez, Jo Anne

    2015-01-01

    When most educators think of STEM education, they think of fully integrated projects seamlessly combining all four disciplines--science, technology, engineering, and mathematics. Although such transdisciplinary STEM units are ideal, writes Vasquez, they are not the only way to give students valuable STEM experiences. She gives examples of two…

  13. Stem cells and genetic diseases

    Directory of Open Access Journals (Sweden)

    Irshad S.

    2012-09-01

    Full Text Available In this review, we have discussed a role of stem cells in the treatment of genetic diseases including cochlear and retinal regeneration. The most perceptive use of stem cells at the genetic diseases is cellular repair of tissues affected by a genetic mutation when stem cells without such mutation are transplanted to restore normal tissue function.

  14. Stem cell organization in Arabidopsis

    NARCIS (Netherlands)

    Wendrich, J.R.

    2016-01-01

    Growth of plant tissues and organs depends on continuous production of new cells, by niches of stem cells. Stem cells typically divide to give rise to one differentiating daughter and one non-differentiating daughter. This constant process of self-renewal ensures that the niches of stem cells or mer

  15. Stem Cell Transplants (For Parents)

    Science.gov (United States)

    ... Teaching Kids to Be Smart About Social Media Stem Cell Transplants KidsHealth > For Parents > Stem Cell Transplants Print A A A What's in this ... Recovery Coping en español Trasplantes de células madre Stem cells are cells in the body that have the ...

  16. Information on Stem Cell Research

    Science.gov (United States)

    ... Home » Current Research » Focus on Research Focus on Stem Cell Research Stem cells possess the unique ability to differentiate into many ... they also retain the ability to produce more stem cells, a process termed self-renewal. There are multiple ...

  17. Electrical Property Characterization of Neural Stem Cells in Differentiation.

    Directory of Open Access Journals (Sweden)

    Yang Zhao

    Full Text Available Electrical property characterization of stem cells could be utilized as a potential label-free biophysical approach to evaluate the differentiation process. However, there has been a lack of technology or tools that can quantify the intrinsic cellular electrical markers (e.g., specific membrane capacitance (Cspecific membrane and cytoplasm conductivity (σcytoplasm for a large amount of stem cells or differentiated cells. In this paper, a microfluidic platform enabling the high-throughput quantification of Cspecific membrane and σcytoplasm from hundreds of single neural stem cells undergoing differentiation was developed to explore the feasibility to characterize the neural stem cell differentiation process without biochemical staining. Experimental quantification using biochemical markers (e.g., Nestin, Tubulin and GFAP of neural stem cells confirmed the initiation of the differentiation process featured with gradual loss in cellular stemness and increased cell markers for neurons and glial cells. The recorded electrical properties of neural stem cells undergoing differentiation showed distinctive and unique patterns: 1 in the suspension culture before inducing differentiation, a large distribution and difference in σcytoplasm among individual neural stem cells was noticed, which indicated heterogeneity that may result from the nature of suspension culture of neurospheres; and 2 during the differentiation in adhering monolayer culture, significant changes and a large difference in Cspecific membrane were located indicating different expressions of membrane proteins during the differentiation process, and a small distribution difference in σcytoplasm was less significant that indicated the relatively consistent properties of cytoplasm during the culture. In summary, significant differences in Cspecific membrane and σcytoplasm were observed during the neural stem cell differentiation process, which may potentially be used as label

  18. New Location Improves Efficiency | Poster

    Science.gov (United States)

    By Nancy Parrish, Staff Writer The physical proximity of the SAIC-Frederick Intellectual Property (IP) Office to the NCI Technology Transfer Center (NCI-TTC) is one of the many benefits of being at the Advanced Technology Research Facility (ATRF), according to Courtney Silverthorn, Ph.D. Being in one location “has increased the effectiveness of both informal communication and formal meetings. We have already brainstormed solutions for several issues in the hallway during an informal chat,” said Silverthorn, an SAIC-Frederick IP specialist.

  19. Studying the Formation Mechanism of New Ground Strike Points in Natural Negative Cloud-to-Ground Lightning

    Science.gov (United States)

    Campos, L. Z. D. S.; Cummins, K. L.; Pinto, O., Jr.

    2015-12-01

    Data from three-dimensional VHF mapping, high-speed video and slow electric field antenna of multiple ground contact flashes (MGCFs) have been analyzed in an attempt to characterize the process through which new ground terminations in natural lightning are formed. The three-dimensional VHF mapping data (obtained by a Lightning Mapping Array, LMA) provided valuable information on the processes that occurred inside the cloud during the interval between strokes. Detailed case studies of over 30 MGCFs observed in the vicinity of a wind farm in Kansas, USA, have allowed the identification and qualitative description of three mechanisms through which a given flash may touch ground at different locations. In events of Type I, the dart leader that initiates the subsequent stroke starts in the original channel and then diverges from the original path of the first stroke, ionizing a new channel and reaching ground at a different location. In high-speed video records, these events eventually have their "diverging" point visible below cloud base and their strike locations are separated by a few hundreds of meters. Type II, on the other hand, comprises flashes in which the subsequent stroke is initiated in an in-cloud branch that is farther from the inception region of the first return stroke, moving in another direction and touching ground at farther distances (up to more than 10 km from the initial strike location). Finally, Type III flashes typically gave rise to several return strokes, each with different ground strike points. Stepped leaders initiated in the same general region in the cloud give rise to these strokes with typical interstroke intervals below 100 milliseconds but no common channel branches among them could be conclusively identified. Representative events of each type are discussed in detail.

  20. An evaluation of location management procedures

    NARCIS (Netherlands)

    Baumann, Frank V.; Niemegeers, Ignas G.

    1994-01-01

    This paper gives a comparative description of two scenarios for location management in a mobile telecommunications system. The first scenario uses fixed location and paging areas. Mobiles perform a location update as they enter a new location area. The second scenario uses a time-out based location

  1. Using laser to measure stem thickness and cut weed stems

    DEFF Research Database (Denmark)

    Heisel, T.; Schou, Jørgen; Andreasen, C.

    2002-01-01

    Stem thickness of the weed Solanum nigrum and the crop sugarbeet was determined with a He-Ne laser using a novel non-destructive technique measuring stem shadow. Thereafter, the stems were cut close to the soil surface with a CO2 laser. Treatments were carried out on pot plants, grown...... in the greenhouse, at two different growth stages, and plant dry matter was measured 2-5 weeks after treatment. The relationship between plant dry weight and laser energy was analysed using two different non-linear dose-response regression models; one model included stem thickness as a variable, the other did not....... A binary model was also tested. The non-linear model incorporating stem thickness described the data best, indicating that it would be possible to optimize laser cutting by measuring stem thickness before cutting. The general tendency was that more energy was needed the thicker the stem. Energy uses...

  2. A Problem with STEM

    Science.gov (United States)

    Marder, Michael

    2013-01-01

    Striking differences between physics and biology have important implications for interdisciplinary science, technology, engineering, and mathematics (STEM) education. The author is a physicist with interdisciplinary connections. The research group in which he works, the Center for Nonlinear Dynamics at the University of Texas at Austin, is…

  3. Stem cell heterogeneity revealed

    DEFF Research Database (Denmark)

    Andersen, Marianne S; Jensen, Kim B

    2016-01-01

    The skin forms a protective, water-impermeable barrier consisting of heavily crosslinked epithelial cells. However, the specific role of stem cells in sustaining this barrier remains a contentious issue. A detailed analysis of the interfollicular epidermis now proposes a model for how a composite...... of cells with different properties are involved in its maintenance....

  4. Porcine embryonic stem cells

    DEFF Research Database (Denmark)

    Hall, Vanessa Jane

    2008-01-01

    The development of porcine embryonic stem cell lines (pESC) has received renewed interest given the advances being made in the production of immunocompatible transgenic pigs. However, difficulties are evident in the production of pESCs in-vitro. This may largely be attributable to differences...

  5. STEM Sense and Nonsense

    Science.gov (United States)

    Charette, Robert N.

    2015-01-01

    If you can believe the daily flood of mass media stories, journal articles, and white papers, the United States is facing a STEM worker crisis. Business leaders and politicians warn that the nation is falling hopelessly behind in the global economic race because our students are unprepared for and uninterested in science, technology, engineering,…

  6. Advancing Diversity in STEM

    Science.gov (United States)

    Hill, Paul L.; Shaw, Rose A.; Taylor, Jan R.; Hallar, Brittan L.

    2011-01-01

    Although progress has been made, greater efforts are needed to promote faculty diversity at the college and university levels, especially in STEM fields. Thus, it is important to elucidate best practices both for increasing awareness of diversity issues pertaining to higher education and for implementing change. This article focuses on the…

  7. Integrated STEM Assessment Model

    Science.gov (United States)

    Bicer, Ali; Capraro, Robert M.; Capraro, Mary M.

    2017-01-01

    Previous research identified a strong correlation between mathematics and science performance albeit for small samples of students. Even though there was a high correlation between mathematics and science performance, researchers examining students' STEM achievement investigated mathematics and science achievement separately. The present study…

  8. Ground-water flow and the possible effects of remedial actions at J-Field, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Hughes, W.B.

    1995-01-01

    J-Field, located in the Edgewood Area of Aberdeen Proving Ground, Md, has been used since World War II to test and dispose of explosives, chemical warfare agents, and industrial chemicals resulting in ground-water, surface-water, and soil contami- nation. The U.S. Geological Survey finite-difference model was used to better understand ground-water flow at the site and to simulate the effects of remedial actions. A surficial aquifer and a confined aquifer were simulated with the model. A confining unit separates these units and is represented by leakance between the layers. The area modeled is 3.65 mi2; the model was constructed with a variably spaced 40 X 38 grid. The horizontal and lower boundaries of the model are all no-flow boundaries. Steady-state conditions were used. Ground water at the areas under investigation flows from disposal pit areas toward discharge areas in adjacent estuaries or wetlands. Simulations indicate that capping disposal areas with an impermeable cover effectively slows advective ground water flow by 0.7 to 0.5 times. Barriers to lateral ground-water flow were simulated and effectively prevented the movement of ground water toward discharge areas. Extraction wells were simulated as a way to contain ground-water contamination and to extract ground water for treatment. Two wells pumping 5 gallons per minute each at the toxic-materials disposal area and a single well pumping 2.5 gallons per minute at the riot-control-agent disposal area effectively contained contamination at these sites. A combi- nation of barriers to horizontal flow east and south of the toxic-materials disposal area, and a single extraction well pumping at 5 gallons per minute can extract contaminated ground water and prevent pumpage of marsh water.

  9. 30 CFR 77.807-1 - High-voltage powerlines; clearances above ground.

    Science.gov (United States)

    2010-07-01

    ... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.807-1 High-voltage powerlines; clearances above ground. High-voltage powerlines located above driveways, haulageways, and railroad tracks...

  10. Global mapping of transposon location.

    Directory of Open Access Journals (Sweden)

    Abram Gabriel

    2006-12-01

    Full Text Available Transposable genetic elements are ubiquitous, yet their presence or absence at any given position within a genome can vary between individual cells, tissues, or strains. Transposable elements have profound impacts on host genomes by altering gene expression, assisting in genomic rearrangements, causing insertional mutations, and serving as sources of phenotypic variation. Characterizing a genome's full complement of transposons requires whole genome sequencing, precluding simple studies of the impact of transposition on interindividual variation. Here, we describe a global mapping approach for identifying transposon locations in any genome, using a combination of transposon-specific DNA extraction and microarray-based comparative hybridization analysis. We use this approach to map the repertoire of endogenous transposons in different laboratory strains of Saccharomyces cerevisiae and demonstrate that transposons are a source of extensive genomic variation. We also apply this method to mapping bacterial transposon insertion sites in a yeast genomic library. This unique whole genome view of transposon location will facilitate our exploration of transposon dynamics, as well as defining bases for individual differences and adaptive potential.

  11. The Aware Cricket Ground

    CERN Document Server

    Khan, Wazir Zada; Arshad, Quratul Ain

    2011-01-01

    The most profound technologies are those that disappear. They weave themselves into fabrics of everyday life until they are indistinguishable from it [1]. This research work is a mere effort for automated decision making during sports of most common interest leveraging ubiquitous computing. Primarily cricket has been selected for the first implementation of the idea. A positioning system is used for locating the objects moving in the field. Main objectives of the research are to help achieve the following goals. 1) Make Decisions where human eye can make error due to human limitations. 2) Simulate the Match activity during and after the game in a 3D computerized Graphics system. 3) Make various types of game and performance analysis of a certain team or a player.

  12. Epstein on Anchors and Grounds

    Directory of Open Access Journals (Sweden)

    Guala Francesco

    2016-03-01

    Full Text Available The distinction between anchors and grounds is one of the most innovative contributions of The Ant Trap. In this commentary I will argue that the distinction suffers from an ambiguity between tokens and types. This leads Epstein to endorse pluralism about anchors and grounds, a position that is not justified in the book and to which there are plausible alternatives.

  13. Ground water and climate change

    NARCIS (Netherlands)

    Taylor, R.G.; Scanlon, B.; Döll, P.; Rodell, M.; Beek, R. van; Wada, Y.; Longuevergne, L.; Leblanc, M.; Famiglietti, J.S.; Edmunds, M.; Konikow, L.; Green, T.R.; Chen, J.; Taniguchi, M.; Bierkens, M.F.P.; MacDonald, A.; Fan, Y.; Maxwell, R.M.; Yechieli, Y.; Gurdak, J.J.; Allen, D.M.; Shamsudduha, M.; Hiscock, K.; Yeh, Pat J.-F.; Holman, Ian; Treidel, Holger

    2012-01-01

    As the world’s largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate chang

  14. Ground Attenuation of Railroad Noise

    DEFF Research Database (Denmark)

    Makarewicz, R.; Rasmussen, Karsten Bo; Kokowski, P.

    1996-01-01

    The influence of ground effect on railroad noise is described using the concept of the peak A-weighted sound exposure level, and A-weighted sound exposure level. The train is modelled by a continuous line of incoherent point sources that have a cosine directivity. The ground effect is included by...

  15. Ground water and climate change

    NARCIS (Netherlands)

    Taylor, R.G.; Scanlon, B.; Döll, P.; Rodell, M.; Beek, R. van; Wada, Y.; Longuevergne, L.; Leblanc, M.; Famiglietti, J.S.; Edmunds, M.; Konikow, L.; Green, T.R.; Chen, J.; Taniguchi, M.; Bierkens, M.F.P.; MacDonald, A.; Fan, Y.; Maxwell, R.M.; Yechieli, Y.; Gurdak, J.J.; Allen, D.M.; Shamsudduha, M.; Hiscock, K.; Yeh, Pat J.-F.; Holman, Ian; Treidel, Holger

    2012-01-01

    As the world’s largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate

  16. Grounding Damage to Conventional Vessels

    DEFF Research Database (Denmark)

    Lützen, Marie; Simonsen, Bo Cerup

    2003-01-01

    The present paper is concerned with rational design of conventional vessels with regard to bottom damage generated in grounding accidents. The aim of the work described here is to improve the design basis, primarily through analysis of new statistical data for grounding damage. The current...

  17. Grounded action: Achieving optimal and sustainable change

    Directory of Open Access Journals (Sweden)

    Odis E. Simmons, Ph.D.

    2004-11-01

    Full Text Available Grounded action is the application and extension of grounded theory for the purpose of designing and implementing practical actions such as interventions, program designs, action models, social and organizational policies, and change initiatives. Grounded action is grounded theory with an added action component in which actions are systematically derived from a systematically derived explanatory grounded theory. Actions are grounded in the grounded theory in the same way that grounded theories are grounded in data. Grounded actionwas designed by the authors to address complex, multi-dimensionalorganizational and social problems and issues.

  18. Biomass Estimation of Individual Trees Using STEM and Crown Diameter Tls Measurements

    Science.gov (United States)

    Holopainen, M.; Vastaranta, M.; Kankare, V.; Räty, M.; Vaaja, M.; Liang, X.; Yu, X.; Hyyppä, J.; Hyyppä, H.; Viitala, R.; Kaasalainen, S.

    2011-09-01

    The objective of this study was to make preliminary investigations between accurately measured field biomasses and terrestrial laser scanning (TLS) measurements including tree crown and stem diameters. Stem and crown biomass were determined based on detailed field measurements of the individual tree stem, bark, branch and needles. At the tree level, field measurements were intensive and thus material consisted of only 20 trees located at 11 stands. Stem and crown diameters were extracted manually from TLS point clouds and used as predictors for total biomass. Correlations from 0.96 to 0.99 between predicted and field measured biomass estimates were obtained. Examination of stem form predictions showed that various diameters measured by TLS could enhance the tree level stem curve predictions. Results are rather promising, but more field data is needed for developing practical modelling means. Our further studies will concentrate on automation of TLS data processing and use the of TLS features in the biomass estimation.

  19. Effects of foggy conditions on the measurement of stem respiration in a cloud forest in Taiwan

    Science.gov (United States)

    Chang, S.-C.; Wang, H.-K.; Lin, Y.-C.; Hsia, Y.-J.

    2010-07-01

    Stem CO2 efflux of a Chamaecyparis obtusa var. formosana forest ecosystem was measured at the Chi-Lan Mountain (CLM) site in northern Taiwan. The site is located at an altitude of 1650 m and is subjected to frequent fog coverage around the year. Stem CO2 efflux was measured continuously at 1 m height by horizontally mounting an automatic soil respiration chamber system (LI-8100 Survey Chamber, LI-COR) on the stem surface. Every 10 min, the chamber was closed for 2 min for the measurement of CO2 concentration within the closed system. Stem temperature beside the chamber was monitored by a thermistor inserted 3 cm into the stem. Sapflow velocity was recorded using thermal dissipation probes installed on five nearby Chamaecyparis obtusa var. formosana trees. The data from May 2009 was used in the current analysis. Under clear weather, e. g. on May 8, 2009, the diurnal stem CO2 efflux rate vs. stem temperature showed a clear hysteresis loop. The daytime stem CO2 efflux rates were lower than the potential values, which were predicted by the nighttime stem temperature-stem CO2 efflux relation. The magnitude of the daytime depression of the stem CO2 efflux was positively correlated with the sapflow velocity. On the contrary, when the site was submerged in fog during the daytime, the hysteresis did not take place and the very low sapflow velocities caused only minor decrease in the daytime stem CO2 efflux compared to those in nighttime. In May 2009, the daily accumulated daytime depression of stem CO2 efflux ranged from 0.54 to 7.70 mmol m-2. The daily daytime foggy time had a negative linear correlation with the amount of daily depression. The effects of foggy conditions on the stem CO2 efflux measurement might have some ecological implications. The frequent occurrence of fog in the cloud forests, where the transpiration rates are low, might guarantee a less biased estimation of stem respiration by the chamber method. The measured stem CO2 efflux might significantly

  20. Inflammation and cancer stem cells.

    Science.gov (United States)

    Shigdar, Sarah; Li, Yong; Bhattacharya, Santanu; O'Connor, Michael; Pu, Chunwen; Lin, Jia; Wang, Tao; Xiang, Dongxi; Kong, Lingxue; Wei, Ming Q; Zhu, Yimin; Zhou, Shufeng; Duan, Wei

    2014-04-10

    Cancer stem cells are becoming recognised as being responsible for metastasis and treatment resistance. The complex cellular and molecular network that regulates cancer stem cells and the role that inflammation plays in cancer progression are slowly being elucidated. Cytokines, secreted by tumour associated immune cells, activate the necessary pathways required by cancer stem cells to facilitate cancer stem cells progressing through the epithelial-mesenchymal transition and migrating to distant sites. Once in situ, these cancer stem cells can secrete their own attractants, thus providing an environment whereby these cells can continue to propagate the tumour in a secondary niche.