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Sample records for african field conditions

  1. Establishment of a self-propagating population of the African malaria vector Anopheles arabiensis under semi-field conditions

    PubMed Central

    2010-01-01

    Background The successful control of insect disease vectors relies on a thorough understanding of their ecology and behaviour. However, knowledge of the ecology of many human disease vectors lags behind that of agricultural pests. This is partially due to the paucity of experimental tools for investigating their ecology under natural conditions without risk of exposure to disease. Assessment of vector life-history and demographic traits under natural conditions has also been hindered by the inherent difficulty of sampling these seasonally and temporally varying populations with the limited range of currently available tools. Consequently much of our knowledge of vector biology comes from studies of laboratory colonies, which may not accurately represent the genetic and behavioural diversity of natural populations. Contained semi-field systems (SFS) have been proposed as more appropriate tools for the study of vector ecology. SFS are relatively large, netting-enclosed, mesocosms in which vectors can fly freely, feed on natural plant and vertebrate host sources, and access realistic resting and oviposition sites. Methods A self-replicating population of the malaria vector Anopheles arabiensis was established within a large field cage (21 × 9.1 × 7.1 m) at the Ifakara Health Institute, Tanzania that mimics the natural habitat features of the rural village environments where these vectors naturally occur. Offspring from wild females were used to establish this population whose life-history, behaviour and demography under semi-field conditions was monitored over 24 generations. Results This study reports the first successful establishment and maintenance of an African malaria vector population under SFS conditions for multiple generations (> 24). The host-seeking behaviour, time from blood feeding to oviposition, larval development, adult resting and swarming behaviour exhibited by An. arabiensis under SFS conditions were similar to those seen in nature. Conclusions

  2. Development of a diagnostic gene expression assay for tuberculosis and its use under field conditions in African buffaloes (Syncerus caffer).

    PubMed

    Parsons, Sven D C; Menezes, Angela M; Cooper, David; Walzl, Gerhard; Warren, Robin M; van Helden, Paul D

    2012-08-15

    The development of diagnostic tests for tuberculosis (TB) in exotic species is constrained by host biology and the limited availability of suitable assay reagents. As such, we evaluated a gene expression assay (GEA) which is easily modified for novel species and allows for initial sample processing under field conditions. African buffaloes (Syncerus caffer) were categorized using the single comparative intradermal tuberculin test, and blood from test-positive and test-negative animals was incubated for 20 h in "Nil" tubes (containing saline) and "TB Antigen" tubes (containing Mycobacterium tuberculosis complex (MTC)-specific antigens) of a commercial human TB test, the QuantiFERON(®)-TB Gold (In-Tube) (QFT) assay. Blood samples were then stabilized in RNAlater(®) and transported to the laboratory for RNA extraction. A Custom TaqMan GEA was used to calculate the relative abundance of interferon-gamma (IFN-γ) mRNA in the TB Antigen tube compared to that in the Nil tube as a marker of immune activation in response to MTC antigen recognition. The GEA results from the two buffalo groups were compared and a cutoff value of 2.85 was calculated to differentiate between animals from these groups with a sensitivity of 80% (95% C.I.: 56-94%) and a specificity of 95% (95% C.I.: 75-100%). Further optimization of this assay could provide a highly useful tool for the diagnosis of MTC infection in exotic species.

  3. The Field of African Languages in the New Millennium.

    ERIC Educational Resources Information Center

    Moshi, Lioba

    2000-01-01

    Discusses the field of African languages as it enters the 21st century, focusing on its field base, the Language Learning Framework, and strategies planning. Suggests that the present as well as the future of African language instruction in the United States is very strong. (Author/VWL)

  4. The oral susceptibility of South African field populations of Culicoides to African horse sickness virus.

    PubMed

    Venter, G J; Wright, I M; Van Der Linde, T C; Paweska, J T

    2009-12-01

    Twenty-two isolates of African horse sickness virus (AHSV), representing its distinct serotypes, geographical and historical origins, were fed to three populations of South African livestock-associated Culicoides spp. (Diptera, Ceratopogonidae). Infective blood meals included 12 recent isolates, nine historical reference strains and one live attenuated vaccine strain serotype 7 (AHSV-7) of the virus. Field-collected midges were fed through a chicken-skin membrane on sheep blood spiked with one of the viruses, which concentrations ranged from 5.4 to 8.8 log(10)TCID(50)/mL of blood. After 10 days incubation at 23.5 degrees C, AHSV was isolated from 11 Culicoides species. Standard in vitro passaging of AHSV-7, used for the preparation of live attenuated vaccine, did not reduce its ability to infect Culicoides species. Virus recovery rates in orally infected Culicoides midges differed significantly between species and populations, serotypes, isolates and seasons. Significant variations in oral susceptibility recorded in this study emphasize a complex inter-relationship between virus and vector, which is further influenced by multiple intrinsic and extrinsic factors. As it is not possible to standardize all these factors under laboratory conditions, conclusive assessment of the role of field-collected Culicoides midges in the transmission of orbiviruses remains problematic. Nevertheless, results of this study suggest the potential for multi-vector transmission of AHSV virus in South Africa.

  5. Efficient robust conditional random fields.

    PubMed

    Song, Dongjin; Liu, Wei; Zhou, Tianyi; Tao, Dacheng; Meyer, David A

    2015-10-01

    Conditional random fields (CRFs) are a flexible yet powerful probabilistic approach and have shown advantages for popular applications in various areas, including text analysis, bioinformatics, and computer vision. Traditional CRF models, however, are incapable of selecting relevant features as well as suppressing noise from noisy original features. Moreover, conventional optimization methods often converge slowly in solving the training procedure of CRFs, and will degrade significantly for tasks with a large number of samples and features. In this paper, we propose robust CRFs (RCRFs) to simultaneously select relevant features. An optimal gradient method (OGM) is further designed to train RCRFs efficiently. Specifically, the proposed RCRFs employ the l1 norm of the model parameters to regularize the objective used by traditional CRFs, therefore enabling discovery of the relevant unary features and pairwise features of CRFs. In each iteration of OGM, the gradient direction is determined jointly by the current gradient together with the historical gradients, and the Lipschitz constant is leveraged to specify the proper step size. We show that an OGM can tackle the RCRF model training very efficiently, achieving the optimal convergence rate [Formula: see text] (where k is the number of iterations). This convergence rate is theoretically superior to the convergence rate O(1/k) of previous first-order optimization methods. Extensive experiments performed on three practical image segmentation tasks demonstrate the efficacy of OGM in training our proposed RCRFs.

  6. Transmission rate of African swine fever virus under experimental conditions.

    PubMed

    de Carvalho Ferreira, H C; Backer, J A; Weesendorp, E; Klinkenberg, D; Stegeman, J A; Loeffen, W L A

    2013-08-30

    African swine fever (ASF) is a highly lethal, viral disease of swine. No vaccine is available, so controlling an ASF outbreak is highly dependent on zoosanitary measures, such as stamping out infected herds and quarantining of affected areas. Information on ASF transmission parameters could allow for more efficient application of outbreak control measures. Three transmission experiments were carried out to estimate the transmission parameters of two ASF virus isolates: Malta'78 (in two doses) and Netherlands'86. Different criteria were used for onset of infectiousness of infected pigs and moment of infection of contact pigs. The transmission rate (β), estimated by a Generalized Linear Model, ranged from 0.45 to 3.63 per day. For the infectious period, a minimum as well as a maximum infectious period was determined, to account for uncertainties regarding infectiousness of persistently infected pigs. While the minimum infectious period ranged from 6 to 7 days, the average maximum infectious period ranged from approximately 20 to nearly 40 days. Estimates of the reproduction ratio (R) for the first generation of transmission ranged from 4.9 to 24.2 for the minimum infectious period and from 9.8 to 66.3 for the maximum infectious period, depending on the isolate. A first approximation of the basic reproduction ratio (R0) resulted in an estimate of 18.0 (6.90-46.9) for the Malta'78 isolate. This is the first R0 estimate of an ASFV isolate under experimental conditions. The estimates of the transmission parameters provide a quantitative insight into ASFV epidemiology and can be used for the design and evaluation of more efficient control measures.

  7. Comparative field evaluation of two rapid immunochromatographic tests for the diagnosis of bovine tuberculosis in African buffaloes (Syncerus caffer).

    PubMed

    Michel, A L; Simões, M

    2009-01-15

    Panels of sera from African buffalo with confirmed bovine tuberculosis and from known uninfected controls were used to evaluate the performance of two commercial rapid chromatographic immunoassays (A and B) for the detection of antibodies to Mycobacterium bovis. The sensitivity was 33% and 23%, respectively, while the specificity was determined at 90% and 94%, respectively. Overall the performance of both diagnostic tests under field conditions was not found sufficiently high to support their use in bovine tuberculosis management and control strategies in South African game reserves.

  8. The Southern African Regional Science Initiative (SAFARI 2000): Overview of the Dry Season Field Campaign

    NASA Technical Reports Server (NTRS)

    Swap, R. J.; Annegarn, H. J.; Suttles, J. T.; Haywood, J.; Helmlinger, M. C.; Hely, C.; Hobbs, P. V.; Holben, B. N.; Ji, J.; King, M. D.

    2002-01-01

    The Southern African Regional Science Initiative (SAFARI 2000) is an international project investigating the earth atmosphere -human system in southern Africa. The programme was conducted over a two year period from March 1999 to March 2001. The dry season field campaign (August-September 2000) was the most intensive activity involved over 200 scientist from eighteen countries. The main objectives were to characterize and quantify biogenic, pyrogenic and anthropogenic aerosol and trace gas emissions and their transport and transformations in the atmosphere and to validate NASA's Earth Observing System's Satellite Terra within a scientific context. Five aircraft-- two South African Weather Service Aeorcommanders, the University of Washington's CV-880, the U.K. Meteorological Office's C-130, and NASA's ER-2 --with different altitude capabilities, participated in the campaign. Additional airborne sampling of southern African air masses, that had moved downwind of the subcontinent, was conducted by the CSIRO over Australia. Multiple Observations were made in various geographical sections under different synoptic conditions. Airborne missions were designed to optimize the value of synchronous over-flights of the Terra Satellite platform, above regional ground validation and science targets. Numerous smaller scale ground validation activities took place throughout the subcontinent during the campaign period.

  9. The Underrepresentation of African American Female Students in STEM Fields: Implications for Classroom Teachers

    ERIC Educational Resources Information Center

    Farinde, Abiola A.; Lewis, Chance W.

    2012-01-01

    African American women are underrepresented in STEM (science, technology, engineering and math) fields (Catsambis, 1994). The socialization and "under-education" of African American female students engenders ideas of inferiority, while the presence of an inferior race, sex and class, in one body, may produce an ideology of mediocrity.…

  10. Reduced cannibalistic behavior of African catfish, Clarias gariepinus, larvae under dark and dim conditions.

    PubMed

    Mukai, Yukinori; Sanudin, Noorsyarinah; Firdaus, Rian Freddie; Saad, Shahbudin

    2013-06-01

    In general, African catfish shows higher survival rates in the dark conditions than in the light conditions. In this study, larval behavior of African catfish was observed under 0, 0.01, 0.1, 1, 10, and 100 lx using a CCD camera to investigate the reason why African catfish larvae show higher survival rates in dark conditions. The larvae showed significantly higher swimming activity under 0, 0.01, and 0.1 lx than that under 10 and 100 lx. The larvae also showed significantly increased aggressive behavior under 10 and 100 lx; the swimming larvae attacked resting individuals more frequently under 10 and 100 lx than under 0, 0.01, and 0.1 lx. The aggressive behavior and sharp teeth of the attacking larvae appeared to induce skin surface lesions on injured larvae. Chemical substances were then generated from the injured skin surface, and these chemical stimuli triggered cannibalistic behavior in other fish near the injured fish. The results of this study demonstrate that the higher survival rates of African catfish larvae under dark conditions are a result of inactivity and subsequent increase in chemical releasing stimuli concentrations around inactive individuals that triggers feeding behavior in nearby active catfish. Therefore, we recommend larval rearing of African catfish in dark or dim conditions, as it improves catfish survival rates.

  11. Mentorship: Strategically Leveling the Playing Field for African American Officers

    DTIC Science & Technology

    2009-02-10

    voice2001/010608/survey.htm (accessed December 18, 2008). 2 Molefi Kete Asante, 100 Greatest African Americans (Amherst, NY: Prometheus Books, 2002), 41-43. 3...Clinician-Scientist,” Clinical and Investigative Medicine 21, no. 6 (December 1998): 279-282, http://epe.lac-bac.gc.ca/100/201/300/cdn_medical_association/ cim/vol-21/issue-6/0279.htm (accessed December 29, 2008).

  12. The African Field Epidemiology Network--networking for effective field epidemiology capacity building and service delivery.

    PubMed

    Gitta, Sheba Nakacubo; Mukanga, David; Babirye, Rebecca; Dahlke, Melissa; Tshimanga, Mufuta; Nsubuga, Peter

    2011-01-01

    Networks are a catalyst for promoting common goals and objectives of their membership. Public Health networks in Africa are crucial, because of the severe resource limitations that nations face in dealing with priority public health problems. For a long time, networks have existed on the continent and globally, but many of these are disease-specific with a narrow scope. The African Field Epidemiology Network (AFENET) is a public health network established in 2005 as a non-profit networking alliance of Field Epidemiology and Laboratory Training Programs (FELTPs) and Field Epidemiology Training Programs (FETPs) in Africa. AFENET is dedicated to helping ministries of health in Africa build strong, effective and sustainable programs and capacity to improve public health systems by partnering with global public health experts. The Network's goal is to strengthen field epidemiology and public health laboratory capacity to contribute effectively to addressing epidemics and other major public health problems in Africa. AFENET currently networks 12 FELTPs and FETPs in sub-Saharan Africa with operations in 20 countries. AFENET has a unique tripartite working relationship with government technocrats from human health and animal sectors, academicians from partner universities, and development partners, presenting the Network with a distinct vantage point. Through the Network, African nations are making strides in strengthening their health systems. Members are able to: leverage resources to support field epidemiology and public health laboratory training and service delivery notably in the area of outbreak investigation and response as well as disease surveillance; by-pass government bureaucracies that often hinder and frustrate development partners; and consolidate efforts of different partners channelled through the FELTPs by networking graduates through alumni associations and calling on them to offer technical support in various public health capacities as the need arises

  13. Oceanographic Conditions Limit the Spread of a Marine Invader along Southern African Shores

    PubMed Central

    Nicastro, Katy R.; Zardi, Gerardo I.; McQuaid, Christopher D.; Serrão, Ester A.

    2015-01-01

    Invasive species can affect the function and structure of natural ecological communities, hence understanding and predicting their potential for spreading is a major ecological challenge. Once established in a new region, the spread of invasive species is largely controlled by their dispersal capacity, local environmental conditions and species interactions. The mussel Mytilus galloprovincialis is native to the Mediterranean and is the most successful marine invader in southern Africa. Its distribution there has expanded rapidly and extensively since the 1970s, however, over the last decade its spread has ceased. In this study, we coupled broad scale field surveys, Ecological Niche Modelling (ENM) and Lagrangian Particle Simulations (LPS) to assess the current invaded distribution of M. galloprovincialis in southern Africa and to evaluate what prevents further spread of this species. Results showed that all environmentally suitable habitats in southern Africa have been occupied by the species. This includes rocky shores between Rocky Point in Namibia and East London in South Africa (approx. 2800 km) and these limits coincide with the steep transitions between cool-temperate and subtropical-warmer climates, on both west and southeast African coasts. On the west coast, simulations of drifting larvae almost entirely followed the northward and offshore direction of the Benguela current, creating a clear dispersal barrier by advecting larvae away from the coast. On the southeast coast, nearshore currents give larvae the potential to move eastwards, against the prevalent Agulhas current and beyond the present distributional limit, however environmental conditions prevent the establishment of the species. The transition between the cooler and warmer water regimes is therefore the main factor limiting the northern spread on the southeast coast; however, biotic interactions with native fauna may also play an important role. PMID:26114766

  14. Teaching Giant African Pouched Rats to Find Landmines: Operant Conditioning With Real Consequences

    PubMed Central

    Poling, Alan; Weetjens, Bart J; Cox, Christophe; Beyene, Negussie; Bach, Håvard; Sully, Andrew

    2010-01-01

    Giant African pouched rats recently have been used as mine-detection animals in Mozambique. To provide an example of the wide range of problems to which operant conditioning procedures can be applied and to illustrate the common challenges often faced in applying those procedures, this manuscript briefly describes how the rats are trained and used operationally. To date, the rats have performed well and it appears they can play a valuable role in humanitarian demining. PMID:22532890

  15. Gradient Boosting for Conditional Random Fields

    DTIC Science & Technology

    2014-09-23

    Information Processing Systems 26 ( NIPS ’13), pages 647–655. 2013. [4] J. Friedman. Greedy function approximation: a gradient boosting machine. Annals of...and phrases and their compositionality. In Advances in Neural Information Processing Systems 26 ( NIPS ’13), pages 3111–3119. 2013. [15] A. Quattoni, M...Collins, and T. Darrell. Conditional random fields for object recognition. In Advances in Neural Information Processing Systems 17 ( NIPS ’04), pages

  16. Circular Conditional Autoregressive Modeling of Vector Fields.

    PubMed

    Modlin, Danny; Fuentes, Montse; Reich, Brian

    2012-02-01

    As hurricanes approach landfall, there are several hazards for which coastal populations must be prepared. Damaging winds, torrential rains, and tornadoes play havoc with both the coast and inland areas; but, the biggest seaside menace to life and property is the storm surge. Wind fields are used as the primary forcing for the numerical forecasts of the coastal ocean response to hurricane force winds, such as the height of the storm surge and the degree of coastal flooding. Unfortunately, developments in deterministic modeling of these forcings have been hindered by computational expenses. In this paper, we present a multivariate spatial model for vector fields, that we apply to hurricane winds. We parameterize the wind vector at each site in polar coordinates and specify a circular conditional autoregressive (CCAR) model for the vector direction, and a spatial CAR model for speed. We apply our framework for vector fields to hurricane surface wind fields for Hurricane Floyd of 1999 and compare our CCAR model to prior methods that decompose wind speed and direction into its N-S and W-E cardinal components.

  17. Circular Conditional Autoregressive Modeling of Vector Fields*

    PubMed Central

    Modlin, Danny; Fuentes, Montse; Reich, Brian

    2013-01-01

    As hurricanes approach landfall, there are several hazards for which coastal populations must be prepared. Damaging winds, torrential rains, and tornadoes play havoc with both the coast and inland areas; but, the biggest seaside menace to life and property is the storm surge. Wind fields are used as the primary forcing for the numerical forecasts of the coastal ocean response to hurricane force winds, such as the height of the storm surge and the degree of coastal flooding. Unfortunately, developments in deterministic modeling of these forcings have been hindered by computational expenses. In this paper, we present a multivariate spatial model for vector fields, that we apply to hurricane winds. We parameterize the wind vector at each site in polar coordinates and specify a circular conditional autoregressive (CCAR) model for the vector direction, and a spatial CAR model for speed. We apply our framework for vector fields to hurricane surface wind fields for Hurricane Floyd of 1999 and compare our CCAR model to prior methods that decompose wind speed and direction into its N-S and W-E cardinal components. PMID:24353452

  18. Biological entity recognition with conditional random fields.

    PubMed

    He, Ying; Kayaalp, Mehmet

    2008-11-06

    Due to the rapid evolution of molecular biology and the lack of naming standards, biological entity recognition (BER) remains a challenging task for information extraction and natural language understanding. In this study, we presented a statistical machine learning approach for extracting features, modeling, and predicting biological named entities. Our approach utilizes UMLS semantic types together with MetaMap, SemRep, and ABGene, as well as the conditional random fields (CRF) framework, and learns both the structure and parameters of a statistical model. Results of this study are competitive with the results of the state of the art tools in this field. Unlike competing similar approaches, the presented method is fully automatic, hence more generalizable and directly transferable to other named entity recognition (NER) problems in medical informatics.

  19. Strength and Conditioning Practices of University and High School Level Cricket Coaches: A South African Context.

    PubMed

    Pote, Lee; Christie, Candice J

    2016-12-01

    Pote, L and Christie, CJ. Strength and conditioning practices of University and high school level cricket coaches: a South African context. J Strength Cond Res 30(12): 3464-3470, 2016-Although the sport of cricket is well established, the strength and conditioning practices of cricket players are not well known. Therefore, the purpose of this study was to examine the current strength and conditioning practices that coaches implement for South African schoolboy and University level cricket players. An online survey, adapted from previous strength and conditioning questionnaires, was sent to 38 schoolboy and 12 University teams that participated in the top competitions in the country (n = 50). Of these, 24 replied indicating a response rate of 48%. Results indicated that although some forms of conditioning, workload monitoring and injury prevention were being implemented, the correct practices were not being administered. Furthermore, it was identified that most coaches had insufficient qualifications and experience to administer the correct training techniques. It was concluded that coaches require further education so that scientifically based training programs can be implemented. This was deemed particularly necessary for adolescent bowlers who are at an increased risk of injury, specifically in the lower back region.

  20. Field conditioning of sexual arousal in humans

    PubMed Central

    Hoffmann, Heather; Peterson, Kathryn; Garner, Hana

    2012-01-01

    Background Human sexual classical conditioning effects are less robust compared with those obtained in other animals. The artificiality of the laboratory environment and/or the unconditioned stimulus (US) used (e.g. watching erotic film clips as opposed to participating in sexual activity) may contribute to this discrepancy. The present experiment used a field study design to explore the conditioning of human sexual arousal. Method Seven heterosexual couples were instructed to include a novel, neutrally preferred scent as the conditioned stimulus (CS + ) during sexual interaction and another novel scent during non-sexual coupled-interaction (e.g. watching a movie, studying together). Seven control couples used both scents during non-sexual interaction. Conducted over a 2-week period, both experimental and control couples had three sexual interactions (oral sex and/or intercourse). In addition, experimental couples had three, while the controls had six, non-sexual interactions. Genital responding to and affective preference for the odors were assessed in the laboratory before and after the experience in the men. Results We observed significantly increased genital responding to the CS+ in the experimental relative to the control group; however, conditioned responses were not much stronger than those obtained during laboratory conditioning. Experimental males also showed a trend for decreased preference for the CS– odor. They may have learned that this odor predicted that sexual interaction with their partner would not occur. Conclusion The present study provides another demonstration of conditioned sexual arousal in men, specifically an instance of such learning that happened in a real-world setting. It also suggests that inhibitory learning may occur, at least with the affective measure. PMID:24693347

  1. Classical conditioning of proboscis extension in harnessed Africanized honey bee queens (Apis mellifera L.).

    PubMed

    Aquino, Italo S; Abramson, Charles I; Soares, Ademilson E E; Fernandes, Andrea Cardoso; Benbassat, Danny

    2004-06-01

    Experiments are reported on learning in virgin Africanized honey bee queens (Apis mellifera L.). Queens restrained in a "Pavlovian harness" received a pairing of hexanal odor with a 1.8-M feeding of sucrose solution. Compared to explicitly unpaired controls, acquisition was rapid in reaching about 90%. Acquisition was also rapid in queens receiving an unconditioned stimulus of "bee candy" or an unconditioned stimulus administered by worker bees. During extinction the conditioned response declines. The steepest decline was observed in queens receiving an unconditioned stimulus of bee candy. These findings extend previous work on learning of Afrianized honey bee workers to a population of queen bees.

  2. Conditional simulations for fields of extreme precipitation

    NASA Astrophysics Data System (ADS)

    Bechler, Aurélien; Vrac, Mathieu; Bel, Liliane

    2014-05-01

    Many environmental models, such as hydrological models, require input data, e.g. precipitation values, correctly simulated and distributed, even at locations where no observation is available. This is particularly true for extreme events that may be of high importance for impact studies. The last decade has seen max-stable processes emerge as a powerful tool for the statistical modeling of spatial extremes. Recently, such processes have been used in climate context to perform simulations at ungauged sites based on empirical distributions of a spatial field conditioned by observed values in some locations. In this work conditional simulations of extremal t process are investigated, taking benefits of its spectral construction. The methodology of conditional simulations proposed by Dombry et al. [2013] for Brown-Resnick and Schlather models is adapted for the extremal t process with some improvements which enlarge the possible number of conditional points. A simulation study enables to highlight the role of the different parameters of the model and to emphasize the importance of the steps of the algorithm. In this work, we focus on the French Mediterranean basin, which is a key spot of occurrences of meteorological extremes such as heavy precipitation. Indeed, major extreme precipitation are regularly observed in this region near the 'cévenol" mountains. The modeling and the understanding of these extreme precipitation - the so-called 'cévenol events" - are of major importance for hydrological studies in this complex terrain since they often trigger major floods in this region. The application of our methodology on real data in this region shows that the model and the algorithm perform well provided the stationary assumptions are fulfilled.

  3. Kitina: A West African intra-Albian field

    SciTech Connect

    Cornaggia, F.; Congo, S.A.; Agostino, M.

    1995-08-01

    Kitina field is located in Marine VII permit, offshore Congo. The field was discovered in 1991 by a joint venture composed of Agip Recherches Congo (operator), Hydrocongo and Chevron International Limited. The field is a structural four-way dip closure trap shaped as turtle-back. Halokinetic movements are responsible for the structuring. The seismic imaging of the reservoir is affected by strong lateral velocity variations caused by different sedimentation across the paleo-shelf edge in the post-Albian sequence. One pass 3D poststack depth migration, performed with a velocity field obtained by means of geostatistical integration of 2D seismic and wellbore velocities, achieved a good compromise between high dip reflector imaging and depths at well location. Three main reservoirs of lower Albian age exist between -2100 and -3100m. They are separated by tight mudstones which act as intraformational seal. Seismic trace inversion improved the resolution of petrophysical variations in some of the field reservoirs, which have the following characteristics (from top to bottom): reservoir 2A is composed of bioclastic and oolitic packstone-grainstone laid down during regional regressive phase in insulated offshore bars on the crest of structural high. Early diagenetic phenomena lead to the development of world class permeability framework. Reservoir 1A-1B are composed of sandstone bodies which were deposited as shoreface to offshore bars during short-term regressive pulse. The 1A-1B reservoir, are embedded in mudstones deposited during long lasting phases of relative high stand in relatively deep offshore setting characterised by high, halokinetic driven subsidence.

  4. Thermal field theories and shifted boundary conditions

    NASA Astrophysics Data System (ADS)

    Giusti, L.; Meyer, H.

    The analytic continuation to an imaginary velocity of the canonical partition function of a thermal system expressed in a moving frame has a natural implementation in the Euclidean path-integral formulation in terms of shifted boundary conditions. The Poincare' invariance underlying a relativistic theory implies a dependence of the free-energy on the compact length L_0 and the shift xi only through the combination beta=L_0(1+xi^2)^(1/2). This in turn implies that the energy and the momentum distributions of the thermal theory are related, a fact which is encoded in a set of Ward identities among the correlators of the energy-momentum tensor. The latter have interesting applications in lattice field theory: they offer novel ways to compute thermodynamic potentials, and a set of identities to renormalize non-perturbatively the energy-momentum tensor. At fixed bare parameters the shifted boundary conditions also provide a simple method to vary the temperature in much smaller steps than with the standard procedure.

  5. A knowledge gap analysis on multi-scale predictive ability for agriculturally derived sediments under South African conditions.

    PubMed

    van Zyl, A J

    2007-01-01

    Agriculture has been implicated as a major source of sediments in South Africa. The aim of the knowledge gap analysis was to understand the production and delivery components of agriculturally derived sediments under South African conditions and to assess the predictive ability to address the fate of these sediments from field to catchment scales. An overview is given of important erosion processes and erosion modelling applied in South Africa at the field and catchment scale. A limitation of the sediment models is that gully erosion is not simulated; therefore, the models should be complemented with gully erosion predictions if gullies are an important sediment source. Field-scale models inadequately predict sediment production localised at hydrologically sensitive areas as a result of saturation excess flow and/or throughflow. The discussion on erosion modelling reveals that more complex models have had limited application in South Africa because they require large and detailed data sets, and may have parameters that are difficult to measure or to estimate. A modelling framework is discussed which allows linking of sediment models requiring readily available data, gully erosion models/maps and the use of other techniques to assess the fate of agriculturally derived sediments from field to catchment scale.

  6. Psychiatric diagnosis of African Americans: diagnostic divergence in clinician-structured and semistructured interviewing conditions.

    PubMed Central

    Neighbors, H. W.; Trierweiler, S. J.; Munday, C.; Thompson, E. E.; Jackson, J. S.; Binion, V. J.; Gomez, J.

    1999-01-01

    This study is a primary data collection that varied patient race and diagnosis and used two diagnostic interviewing conditions: one clinician-structured (phase one) and the other a semi-structured diagnostic instrument (phase two). Four basic research questions are addressed: What is the relationship between race and the hospital diagnosis? How is race related to diagnosis in both research interviewing conditions? Why does diagnostic concordance between the hospital diagnosis and the research diagnosis vary by research interviewing condition? Is diagnostic concordance between the hospital and research diagnosis influenced by patient race? A total of 291 patients completed an interview during phase one, while 665 patients completed an interview during phase two. Blacks were more likely to receive a hospital diagnosis of schizophrenia and less likely to be diagnosed with mood disorder. Patient race was similarly related to the research diagnoses produced in the clinician-structured research condition (phase one). Although less pronounced, a higher percentage of African Americans than whites received a diagnosis of schizophrenia using the semi-structured DSM-III-R Symptom Checklist (phase two). The black-white distribution for mood disorders showed that whites were more likely than blacks to be diagnosed with mood disorder. PMID:10641496

  7. Human African trypanosomiasis: a latex agglutination field test for quantifying IgM in cerebrospinal fluid.

    PubMed Central

    Lejon, V.; Büscher, P.; Sema, N. H.; Magnus, E.; Van Meirvenne, N.

    1998-01-01

    LATEX/IgM, a rapid agglutination test for the semi-quantitative detection of IgM in cerebrospinal fluid of patients with African trypanosomiasis, is described in this article. The lyophilized reagent has been designed for field use and remains stable at 45 degrees C for one year. The test has been evaluated on cerebrospinal fluid samples from trypanosome-infected and non-infected patients, by comparison with commercial latex agglutination, radial immunodiffusion, and nephelometry. All test systems yielded similar results. PMID:10191550

  8. Four p67 alleles identified in South African Theileria parva field samples.

    PubMed

    Sibeko, Kgomotso P; Geysen, Dirk; Oosthuizen, Marinda C; Matthee, Conrad A; Troskie, Milana; Potgieter, Frederick T; Coetzer, Jacobus A W; Collins, Nicola E

    2010-02-10

    Previous studies characterizing the Theileria parva p67 gene in East Africa revealed two alleles. Cattle-derived isolates associated with East Coast fever (ECF) have a 129bp deletion in the central region of the p67 gene (allele 1), compared to buffalo-derived isolates with no deletion (allele 2). In South Africa, Corridor disease outbreaks occur if there is contact between infected buffalo and susceptible cattle in the presence of vector ticks. Although ECF was introduced into South Africa in the early 20th century, it has been eradicated and it is thought that there has been no cattle to cattle transmission of T. parva since. The variable region of the p67 gene was amplified and the gene sequences analyzed to characterize South African T. parva parasites that occur in buffalo, in cattle from farms where Corridor disease outbreaks were diagnosed and in experimentally infected cattle. Four p67 alleles were identified, including alleles 1 and 2 previously detected in East African cattle and buffalo, respectively, as well as two novel alleles, one with a different 174bp deletion (allele 3), the other with a similar sequence to allele 3 but with no deletion (allele 4). Sequence variants of allele 1 were obtained from field samples originating from both cattle and buffalo. Allele 1 was also obtained from a bovine that tested T. parva positive from a farm near Ladysmith in the KwaZulu-Natal Province. East Coast fever was not diagnosed on this farm, but the p67 sequence was identical to that of T. parva Muguga, an isolate that causes ECF in Kenya. Variants of allele 2 were obtained from all T. parva samples from both buffalo and cattle, except Lad 10 and Zam 5. Phylogenetic analysis revealed that alleles 3 and 4 are monophyletic and diverged early from the other alleles. These novel alleles were not identified from South African field samples collected from cattle; however allele 3, with a p67 sequence identical to those obtained in South African field samples from

  9. Modeling of ionospheric irregularities during geomagnetically disturbed conditions over African low-latitude region

    NASA Astrophysics Data System (ADS)

    Mungufeni, Patrick; Habarulema, John Bosco; Jurua, Edward

    2016-10-01

    In this study, station-specific models of ionospheric irregularities over low-latitude African region during geomagnetically disturbed days (Dst≤-50 nT) have been developed. Global Navigation Satellite Systems (GNSS)-derived ionospheric total electron content (TEC) data during 1998-2014 were used. Ionospheric irregularities were represented with the rate of change of TEC index (ROTI). The inputs for the models are the local time, solar flux index, day number of the year, auroral electrojet, and the disturbance storm time indices, while the output is the hourly median ROTI during these given conditions. To develop the models, the ROTI index values were binned based on the input parameters and cubic B splines were then fitted to the binned data. Developed models were validated with independent data over stations within 680 km radius. The models reproduced fairly well the inhibitions and the occurrences of ionospheric irregularities during geomagnetically disturbed days. The models even emulated these patterns in the various seasons, during medium and high solar activity conditions. During validations of the models, the percentages of the number of errors (difference between the observed and the modeled ROTI) <0.05 total electron content unit, 1TECU = 1016 el m-2 (TECU)/Min at all the stations were all >70% and the root-mean-square error were mostly < 0.1 TECU/Min. Furthermore, the correlation coefficients ranged from 0.47 to 0.76.

  10. Boundary conditions for the gravitational field

    NASA Astrophysics Data System (ADS)

    Winicour, Jeffrey

    2012-06-01

    A review of the treatment of boundaries in general relativity is presented with the emphasis on application to the formulations of Einstein's equations used in numerical relativity. At present, it is known how to treat boundaries in the harmonic formulation of Einstein's equations and a tetrad formulation of the Einstein-Bianchi system. However, a universal approach valid for other formulations is not in hand. In particular, there is no satisfactory boundary theory for the 3+1 formulations which have been highly successful in binary black hole simulation. I discuss the underlying problems that make the initial-boundary-value problem much more complicated than the Cauchy problem. I review the progress that has been made and the important open questions that remain. Science is a differential equation. Religion is a boundary condition. (Alan Turing, quoted in J D Barrow, ‘Theories of Everything’)

  11. Environmental conditions associated with repetitive behavior in a group of African elephants.

    PubMed

    Hasenjager, Matthew J; Bergl, Richard A

    2015-01-01

    Repetitive movement patterns are commonly observed in zoo elephants. The extent to which these behaviors constitute a welfare concern varies, as their expression ranges from stereotypies to potentially beneficial anticipatory behaviors. Nevertheless, their occurrence in zoo animals is often viewed negatively. To better identify conditions that prompt their performance, observations were conducted on six African elephants (Loxodonta africana) at the North Carolina Zoo. Individuals spent most of their time engaged in feeding, locomotion, resting, and repetitive behavior. Both generalized estimating equation and zero-inflated negative binomial models were used to identify factors associated with increased rates of repetitive behavior. Time of day in conjunction with location on- or off-exhibit best explained patterns of repetitive behavior. Repetitive behaviors occurred at a lower rate in the morning when on-exhibit, as compared to afternoons on-exhibit or at any time of day off-exhibit. Increased repetitive behavior rates observed on-exhibit in the afternoon prior to the evening transfer and feeding were possibly anticipatory responses towards those events. In contrast, consistently elevated frequencies of repetitive behavior off-exhibit at all times of day could be related to differences in exhibit complexity between off-exhibit and on-exhibit areas, as well as a lack of additional foraging opportunities. Our study contributes valuable information on captive elephant behavior and represents a good example of how behavioral research can be employed to improve management of zoo animals.

  12. The Frequency of "Brilliant" and "Genius" in Teaching Evaluations Predicts the Representation of Women and African Americans across Fields.

    PubMed

    Storage, Daniel; Horne, Zachary; Cimpian, Andrei; Leslie, Sarah-Jane

    2016-01-01

    Women and African Americans-groups targeted by negative stereotypes about their intellectual abilities-may be underrepresented in careers that prize brilliance and genius. A recent nationwide survey of academics provided initial support for this possibility. Fields whose practitioners believed that natural talent is crucial for success had fewer female and African American PhDs. The present study seeks to replicate this initial finding with a different, and arguably more naturalistic, measure of the extent to which brilliance and genius are prized within a field. Specifically, we measured field-by-field variability in the emphasis on these intellectual qualities by tallying-with the use of a recently released online tool-the frequency of the words "brilliant" and "genius" in over 14 million reviews on RateMyProfessors.com, a popular website where students can write anonymous evaluations of their instructors. This simple word count predicted both women's and African Americans' representation across the academic spectrum. That is, we found that fields in which the words "brilliant" and "genius" were used more frequently on RateMyProfessors.com also had fewer female and African American PhDs. Looking at an earlier stage in students' educational careers, we found that brilliance-focused fields also had fewer women and African Americans obtaining bachelor's degrees. These relationships held even when accounting for field-specific averages on standardized mathematics assessments, as well as several competing hypotheses concerning group differences in representation. The fact that this naturalistic measure of a field's focus on brilliance predicted the magnitude of its gender and race gaps speaks to the tight link between ability beliefs and diversity.

  13. Development of a Body Condition Scoring Index for Female African Elephants Validated by Ultrasound Measurements of Subcutaneous Fat

    PubMed Central

    Morfeld, Kari A.; Lehnhardt, John; Alligood, Christina; Bolling, Jeff; Brown, Janine L.

    2014-01-01

    Obesity-related health and reproductive problems may be contributing to non-sustainability of zoo African elephant (Loxodonta africana) populations. However, a major constraint in screening for obesity in elephants is lack of a practical method to accurately assess body fat. Body condition scoring (BCS) is the assessment of subcutaneous fat stores based on visual evaluation and provides an immediate appraisal of the degree of obesity of an individual. The objective of this study was to develop a visual BCS index for female African elephants and validate it using ultrasound measures of subcutaneous fat. To develop the index, standardized photographs were collected from zoo (n = 50) and free-ranging (n = 57) female African elephants for identifying key body regions and skeletal features, which were then used to visually determine body fat deposition patterns. This information was used to develop a visual BCS method consisting of a list of body regions and the physical criteria for assigning an overall score on a 5-point scale, with 1 representing the lowest and 5 representing the highest levels of body fat. Results showed that as BCS increased, ultrasound measures of subcutaneous fat thickness also increased (P<0.01), indicating the scores closely coincide with physical measures of fat reserves. The BCS index proved to be reliable and repeatable based on high intra- and inter-assessor agreement across three assessors. In comparing photographs of wild vs. captive African elephants, the median BCS in the free-ranging individuals (BCS = 3, range 1–5) was lower (P<0.001) than that of the zoo population (BCS = 4, range 2–5). In sum, we have developed the first validated BCS index for African elephants. This tool can be used to examine which factors impact body condition in zoo and free-ranging elephants, providing valuable information on how it affects health and reproductive potential of individual elephants. PMID:24718304

  14. High-Resolution Hα Velocity Fields of Nearby Spiral Galaxies with the Southern African Large Telescope

    NASA Astrophysics Data System (ADS)

    Mitchell, Carl; Williams, Ted; Spekkens, Kristine; Lee-Waddell, Karen; Kuzio de Naray, Rachel; Sellwood, Jerry

    2016-01-01

    In an effort to test ΛCDM predictions of galaxy mass distributions, we have obtained spectrophotometric observations of several nearby spiral galaxies with the Southern African Large Telescope (SALT) Fabry-Pérot (FP) interferometer as part of the RSS Imaging spectroscopy Nearby Galaxy Survey. Utilizing the SALT FP's 8 arcmin field of view and 2 arcsec angular resolution, we have derived 2D velocity fields of the Hα emission line to high spatial resolution at large radii. We have modeled these velocity fields with the DiskFit software package and found them to be in good agreement with lower-resolution velocity fields of the HI 21 cm line for the same galaxies. Here we present our Hα kinematic map of the barred spiral galaxy NGC 578. At the distance to this galaxy (22 Mpc), our kinematic data has a spatial resolution of 185 pc and extends to galactocentric radii of 13 kpc. The high spatial resolution of this data allows us to resolve the inner rising part of the rotation curves, which is compromised by beam smearing in lower-resolution observations. We are using these Hα kinematic data, combined with HI 21 cm kinematics and broadband photometric observations, to place constraints on NGC 578's mass distribution.

  15. Evidence for the emergence of new rice types of interspecific hybrid origin in West African farmers' fields.

    PubMed

    Nuijten, Edwin; van Treuren, Robbert; Struik, Paul C; Mokuwa, Alfred; Okry, Florent; Teeken, Béla; Richards, Paul

    2009-10-06

    In West Africa two rice species (Oryza glaberrima Steud. and Oryza sativa L.) co-exist. Although originally it was thought that interspecific hybridization is impossible without biotechnological methods, progenies of hybridization appear to occur in farmer fields. AFLP analysis was used to assess genetic diversity in West Africa (including the countries The Gambia, Senegal, Guinea Bissau, Guinea Conakry, Sierra Leone, Ghana and Togo) using 315 rice samples morphologically classified prior to analysis. We show evidence for farmer interspecific hybrids of African and Asian rice, resulting in a group of novel genotypes, and identify possible mechanisms for in-field hybridization. Spontaneous back-crossing events play a crucial role, resulting in different groups of genetic diversity in different regions developed by natural and cultural selection, often under adverse conditions. These new groups of genotypes may have potential relevance for exploitation by plant breeders. Future advances in crop development could be achieved through co-operation between scientists and marginalized farmer groups in order to address challenges of rapid adaptation in a world of increasing socio-political and climatic uncertainty.

  16. First report of the infection of insecticide-resistant malaria vector mosquitoes with an entomopathogenic fungus under field conditions

    PubMed Central

    2011-01-01

    Background Insecticide-resistant mosquitoes are compromising the ability of current mosquito control tools to control malaria vectors. A proposed new approach for mosquito control is to use entomopathogenic fungi. These fungi have been shown to be lethal to both insecticide-susceptible and insecticide-resistant mosquitoes under laboratory conditions. The goal of this study was to see whether entomopathogenic fungi could be used to infect insecticide-resistant malaria vectors under field conditions, and to see whether the virulence and viability of the fungal conidia decreased after exposure to ambient African field conditions. Methods This study used the fungus Beauveria bassiana to infect the insecticide-resistant malaria vector Anopheles gambiae s.s (Diptera: Culicidae) VKPER laboratory colony strain. Fungal conidia were applied to polyester netting and kept under West African field conditions for varying periods of time. The virulence of the fungal-treated netting was tested 1, 3 and 5 days after net application by exposing An. gambiae s.s. VKPER mosquitoes in WHO cone bioassays carried out under field conditions. In addition, the viability of B. bassiana conidia was measured after up to 20 days exposure to field conditions. Results The results show that B. bassiana infection caused significantly increased mortality with the daily risk of dying being increased by 2.5× for the fungus-exposed mosquitoes compared to the control mosquitoes. However, the virulence of the B. bassiana conidia decreased with increasing time spent exposed to the field conditions, the older the treatment on the net, the lower the fungus-induced mortality rate. This is likely to be due to the climate because laboratory trials found no such decline within the same trial time period. Conidial viability also decreased with increasing exposure to the net and natural abiotic environmental conditions. After 20 days field exposure the conidial viability was 30%, but the viability of control

  17. Effect of a Magnetic Field on Drosophila under Supercooled Conditions

    PubMed Central

    Mihara, Makoto; Terayama, Hayato; Hatayama, Naoyuki; Hayashi, Shogo; Matsushita, Masayuki; Itoh, Masahiro

    2012-01-01

    Under subzero degree conditions, free water contained in biological cells tends to freeze and then most living things die due to low temperatures. We examined the effect of a variable magnetic field on Drosophila under supercooled conditions (a state in which freezing is not caused even below the freezing point). Under such supercooled conditions with the magnetic field at 0°C for 72 hours, −4°C for 24 hours and −8°C for 1 hour, the Drosophila all survived, while all conversely died under the supercooled conditions without the magnetic field. This result indicates a possibility that the magnetic field can reduce cell damage caused due to low temperatures in living things. PMID:23284809

  18. Odor discrimination in classical conditioning of proboscis extension in two stingless bee species in comparison to Africanized honeybees.

    PubMed

    Mc Cabe, S I; Hartfelder, K; Santana, W C; Farina, W M

    2007-11-01

    Learning in insects has been extensively studied using different experimental approaches. One of them, the proboscis extension response (PER) paradigm, is particularly well suited for quantitative studies of cognitive abilities of honeybees under controlled conditions. The goal of this study was to analyze the capability of three eusocial bee species to be olfactory conditioned in the PER paradigm. We worked with two Brazilian stingless bees species, Melipona quadrifasciata and Scaptotrigona aff. depilis, and with the invasive Africanized honeybee, Apis mellifera. These three species present very different recruitment strategies, which could be related with different odor-learning abilities. We evaluated their gustatory responsiveness and learning capability to discriminate floral odors. Gustatory responsiveness was similar for the three species, although S. aff. depilis workers showed fluctuations along the experimental period. Results for the learning assays revealed that M. quadrifasciata workers can be conditioned to discriminate floral odors in a classical differential conditioning protocol and that this discrimination is maintained 15 min after training. During conditioning, Africanized honeybees presented the highest discrimination, for M. quadrifasciata it was intermediate, and S. aff. depilis bees presented no discrimination. The differences found are discussed considering the putative different learning abilities and procedure effect for each species.

  19. Stochastic Simulation of Microseisms Using Theory of Conditional Random Fields

    NASA Astrophysics Data System (ADS)

    Morikawa, H.; Akamatsu, J.; Nishimura, K.; Onoue, K.; Kameda, H.

    -We examine the applicability of conditional stochastic simulation to interpretation of microseisms observed on soft soil sediments at Kushiro, Hokkaido, Japan. The theory of conditional random fields developed by Kameda and Morikawa (1994) is used, which allows one to perform interpolation of a Gaussian stochastic time-space field that is conditioned by realized values of time functions specified at some discrete locations. The applicability is examined by a blind test, that is, by comparing a set of simulated seismograms and recorded ones obtained from three-point array observa tions. A test of fitness was performed by means of the sign test. It is concluded that the method is applicable to interpretation of microseisms, and that the wave field of microseisms can be treated as Gaussian random fields both in time and space.

  20. A Village without Borders: Umoja Programs Level the Playing Field for African-American Students

    ERIC Educational Resources Information Center

    Beebe, Anthony; Burgess, Terrence; Carroll, Constance; Charlens, Erin

    2009-01-01

    The San Diego Community College District (SDCCD) has implemented programs designed to help African-American students overcome the psychological and cultural obstacles to successful participation in formal learning environments. African-American students suffer low achievement rates in higher education compared with all racial or ethnic groups.…

  1. Establishment of a large semi-field system for experimental study of African malaria vector ecology and control in Tanzania

    PubMed Central

    Ferguson, Heather M; Ng'habi, Kija R; Walder, Thomas; Kadungula, Demetrius; Moore, Sarah J; Lyimo, Issa; Russell, Tanya L; Urassa, Honorathy; Mshinda, Hassan; Killeen, Gerry F; Knols, Bart GJ

    2008-01-01

    Background Medical entomologists increasingly recognize that the ability to make inferences between laboratory experiments of vector biology and epidemiological trends observed in the field is hindered by a conceptual and methodological gap occurring between these approaches which prevents hypothesis-driven empirical research from being conducted on relatively large and environmentally realistic scales. The development of Semi-Field Systems (SFS) has been proposed as the best mechanism for bridging this gap. Semi-field systems are defined as enclosed environments, ideally situated within the natural ecosystem of a target disease vector and exposed to ambient environmental conditions, in which all features necessary for its life cycle completion are present. Although the value of SFS as a research tool for malaria vector biology is gaining recognition, only a few such facilities exist worldwide and are relatively small in size (< 100 m2). Methods The establishment of a 625 m2 state-of-the-art SFS for large-scale experimentation on anopheline mosquito ecology and control within a rural area of southern Tanzania, where malaria transmission intensities are amongst the highest ever recorded, is described. Results A greenhouse frame with walls of mosquito netting and a polyethylene roof was mounted on a raised concrete platform at the Ifakara Health Institute. The interior of the SFS was divided into four separate work areas that have been set up for a variety of research activities including mass-rearing for African malaria vectors under natural conditions, high throughput evaluation of novel mosquito control and trapping techniques, short-term assays of host-seeking behaviour and olfaction, and longer-term experimental investigation of anopheline population dynamics and gene flow within a contained environment that simulates a local village domestic setting. Conclusion The SFS at Ifakara was completed and ready for use in under two years. Preliminary observations

  2. A new velocity field for Africa from combined GPS and DORIS space geodetic Solutions: Contribution to the definition of the African reference frame (AFREF)

    NASA Astrophysics Data System (ADS)

    Saria, E.; Calais, E.; Altamimi, Z.; Willis, P.; Farah, H.

    2013-04-01

    We analyzed 16 years of GPS and 17 years of Doppler orbitography and radiopositioning integrated by satellite (DORIS) data at continuously operating geodetic sites in Africa and surroundings to describe the present-day kinematics of the Nubian and Somalian plates and constrain relative motions across the East African Rift. The resulting velocity field describes horizontal and vertical motion at 133 GPS sites and 9 DORIS sites. Horizontal velocities at sites located on stable Nubia fit a single plate model with a weighted root mean square residual of 0.6 mm/yr (maximum residual 1 mm/yr), an upper bound for plate-wide motions and for regional-scale deformation in the seismically active southern Africa and Cameroon volcanic line. We confirm significant southward motion ( ˜ 1.5 mm/yr) in Morocco with respect to Nubia, consistent with earlier findings. We propose an updated angular velocity for the divergence between Nubia and Somalia, which provides the kinematic boundary conditions to rifting in East Africa. We update a plate motion model for the East African Rift and revise the counterclockwise rotation of the Victoria plate and clockwise rotation of the Rovuma plate with respect to Nubia. Vertical velocities range from - 2 to +2 mm/yr, close to their uncertainties, with no clear geographic pattern. This study provides the first continent-wide position/velocity solution for Africa, expressed in International Terrestrial Reference Frame (ITRF2008), a contribution to the upcoming African Reference Frame (AFREF). Except for a few regions, the African continent remains largely under-sampled by continuous space geodetic data. Efforts are needed to augment the geodetic infrastructure and openly share existing data sets so that the objectives of AFREF can be fully reached.

  3. Field resistance of transgenic plantain to nematodes has potential for future African food security.

    PubMed

    Tripathi, Leena; Babirye, Annet; Roderick, Hugh; Tripathi, Jaindra N; Changa, Charles; Urwin, Peter E; Tushemereirwe, Wilberforce K; Coyne, Danny; Atkinson, Howard J

    2015-01-30

    Plant parasitic nematodes impose losses of up to 70% on plantains and cooking bananas in Africa. Application of nematicides is inappropriate and resistant cultivars are unavailable. Where grown, demand for plantain is more than for other staple crops. Confined field testing demonstrated that transgenic expression of a biosafe, anti-feedant cysteine proteinase inhibitor and an anti-root invasion, non-lethal synthetic peptide confers resistance to plantain against the key nematode pests Radopholus similis and Helicotylenchus multicinctus. The best peptide transgenic line showed improved agronomic performance relative to non-transgenic controls and provided about 99% nematode resistance at harvest of the mother crop. Its yield was about 186% in comparison with the nematode challenged control non-transgenic plants based on larger bunches and diminished plant toppling in storms, due to less root damage. This is strong evidence for utilizing this resistance to support the future food security of 70 million, mainly poor Africans that depend upon plantain as a staple food.

  4. Field resistance of transgenic plantain to nematodes has potential for future African food security

    PubMed Central

    Tripathi, Leena; Babirye, Annet; Roderick, Hugh; Tripathi, Jaindra N.; Changa, Charles; Urwin, Peter E.; Tushemereirwe, Wilberforce K.; Coyne, Danny; Atkinson, Howard J.

    2015-01-01

    Plant parasitic nematodes impose losses of up to 70% on plantains and cooking bananas in Africa. Application of nematicides is inappropriate and resistant cultivars are unavailable. Where grown, demand for plantain is more than for other staple crops. Confined field testing demonstrated that transgenic expression of a biosafe, anti-feedant cysteine proteinase inhibitor and an anti-root invasion, non-lethal synthetic peptide confers resistance to plantain against the key nematode pests Radopholus similis and Helicotylenchus multicinctus. The best peptide transgenic line showed improved agronomic performance relative to non-transgenic controls and provided about 99% nematode resistance at harvest of the mother crop. Its yield was about 186% in comparison with the nematode challenged control non-transgenic plants based on larger bunches and diminished plant toppling in storms, due to less root damage. This is strong evidence for utilizing this resistance to support the future food security of 70 million, mainly poor Africans that depend upon plantain as a staple food. PMID:25634654

  5. Signature of ionospheric irregularities under different geophysical conditions on SBAS performance in the western African low-latitude region

    NASA Astrophysics Data System (ADS)

    Abe, Oladipo Emmanuel; Villamide, Xurxo Otero; Paparini, Claudia; Ngaya, Rodrigue Herbert; Radicella, Sandro M.; Nava, Bruno

    2017-01-01

    Rate of change of TEC (ROT) and its index (ROTI) are considered a good proxy to characterize the occurrence of ionospheric plasma irregularities like those observed after sunset at low latitudes. SBASs (satellite-based augmentation systems) are civil aviation systems that provide wide-area or regional improvement to single-frequency satellite navigation using GNSS (Global Navigation Satellite System) constellations. Plasma irregularities in the path of the GNSS signal after sunset cause severe phase fluctuations and loss of locks of the signals in GNSS receiver at low-latitude regions. ROTI is used in this paper to characterize plasma density ionospheric irregularities in central-western Africa under nominal and disturbed conditions and identified some days of irregularity inhibition. A specific low-latitude algorithm is used to emulate potential possible SBAS message using real GNSS data in the western African low-latitude region. The performance of a possible SBAS operation in the region under different ionospheric conditions is analysed. These conditions include effects of geomagnetic disturbed periods when SBAS performance appears to be enhanced due to ionospheric irregularity inhibition. The results of this paper could contribute to a feasibility assessment of a European Geostationary Navigation Overlay System-based SBAS in the sub-Saharan African region.

  6. The impact of IMF conditionality on government health expenditure: A cross-national analysis of 16 West African nations.

    PubMed

    Stubbs, Thomas; Kentikelenis, Alexander; Stuckler, David; McKee, Martin; King, Lawrence

    2017-02-01

    How do International Monetary Fund (IMF) policy reforms-so-called 'conditionalities'-affect government health expenditures? We collected archival documents on IMF programmes from 1995 to 2014 to identify the pathways and impact of conditionality on government health spending in 16 West African countries. Based on a qualitative analysis of the data, we find that IMF policy reforms reduce fiscal space for investment in health, limit staff expansion of doctors and nurses, and lead to budget execution challenges in health systems. Further, we use cross-national fixed effects models to evaluate the relationship between IMF-mandated policy reforms and government health spending, adjusting for confounding economic and demographic factors and for selection bias. Each additional binding IMF policy reform reduces government health expenditure per capita by 0.248 percent (95% CI -0.435 to -0.060). Overall, our findings suggest that IMF conditionality impedes progress toward the attainment of universal health coverage.

  7. Pinpointing error analysis of metal detectors under field conditions

    NASA Astrophysics Data System (ADS)

    Takahashi, Kazunori; Preetz, Holger

    2012-06-01

    Metal detectors are used not only to detect but also to locate targets. The location performance has been evaluated previously only in laboratory. The performance probably differs that in the field. In this paper, the evaluation of the location performance based on the analysis of pinpointing error is discussed. The data for the evaluation were collected in a blind test in the field. Therefore, the analyzed performance can be seen as the performance under field conditions. Further, the performance is discussed in relation to the search head and footprint dimensions.

  8. Characterization of a Pulse Neutron Source Yield under Field Conditions

    SciTech Connect

    Barzilov, Alexander; Novikov, Ivan; Womble, Phillip C.; Hopper, Lindsay

    2009-03-10

    Technique of rapid evaluation of a pulse neutron sources such as neutron generators under field conditions has been developed. The phoswich sensor and pulse-shape discrimination techniques have been used for the simultaneous measurements of fast neutrons, thermal neutrons, and photons. The sensor has been calibrated using activation neutron detectors and a pulse deuterium-tritium fusion neutron source.

  9. Existing Conditions Plan Fort Douglas, Stilwell Field, The portion ...

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

    Existing Conditions Plan - Fort Douglas, Stilwell Field, The portion of Fort Douglas bounded by De Trobriand Street on the north, Fort Douglas Boulevard on the east, Potter Street on the south, and Chase Street on the west. , Salt Lake City, Salt Lake County, UT

  10. Effect of weather conditions and presence of visitors on adrenocortical activity in captive African penguins (Spheniscus demersus).

    PubMed

    Ozella, L; Anfossi, L; Di Nardo, F; Pessani, D

    2017-02-01

    A number of potential stressors are present in captive environments and it is critically important to identify them in order to improve health and welfare in ex situ animal populations. In this study, we investigated the adrenocortical activity of a colony of African penguins hosted in an immersive zoo in Italy, with respect to the presence of visitors and local microclimatic conditions, using the non-invasive method of assessing faecal glucocorticoid metabolites (FGMs). The penguins' exhibit is a large naturalistic outdoor enclosure, which closely reproduces the natural habitat of this species. Data collection took place from the beginning of June to the end of August 2014, during the period of maximum flow of visitors. We carried out 12 sampling periods, each involving 2 consecutive days; during the first day we counted the visitors and we registered the meteorological data, and on the second day, we collected the faecal samples, which amounted to a total of 285 faecal samples. Our results showed that the number of visitors did not influence the adrenocortical activity of the African penguins. Conversely, the local microclimatic conditions did influence the physiological stress on these birds. We found that an increase of the daily mean temperature induced a significant increase in FGM concentrations, although humidity and wind speed had a moderating effect on temperature and reduced the heat-induced stress. Moreover, we calculated two climatic indices, commonly used to assess the thermal discomfort in animals, namely the THI (Temperature-Humidity Index) and WCI (Wind Chill Index), and we detected a positive relationship between their values and the FGM levels, demonstrating that these indices could be useful indicators of weather discomfort in African penguins. Our study shows that the simulating naturalistic conditions could have significant benefits for zoo animals, such as reducing the negative effect of visitors. Nevertheless, it should be taken into account

  11. Conditional random field-based gesture recognition with depth information

    NASA Astrophysics Data System (ADS)

    Chung, Hyunsook; Yang, Hee-Deok

    2013-01-01

    Gesture recognition is useful for human-computer interaction. The difficulty of gesture recognition is that instances of gestures vary both in motion and shape in three-dimensional (3-D) space. We use depth information generated using Microsoft's Kinect in order to detect 3-D human body components and apply a threshold model with a conditional random field in order to recognize meaningful gestures using continuous motion information. Body gesture recognition is achieved through a framework consisting of two steps. First, a human subject is described by a set of features, encoding the angular relationship between body components in 3-D space. Second, a feature vector is recognized using a threshold model with a conditional random field. In order to show the performance of the proposed method, we use a public data set, the Microsoft Research Cambridge-12 Kinect gesture database. The experimental results demonstrate that the proposed method can efficiently and effectively recognize body gestures automatically.

  12. Greenhouse window U-factors under field conditions

    SciTech Connect

    Klems, J.H.

    1997-06-01

    Field measurements of U-factor are reported for two projecting greenhouse windows, each paired with a picture window of comparable insulation level during testing. A well-known calorimetric field test facility was used to make the measurements. The time-varying U-factors obtained are related to measurements of exterior conditions. For one of the greenhouse windows, which was the subject of a published laboratory hotbox test and simulation study, the results are compared with published test and simulation data and found to be in disagreement. Data on interior and exterior film coefficients are presented, and it is shown that the greenhouse window has a significantly lower interior film coefficient than a conventional window under the same interior conditions. This is advanced as a possible explanation of the disagreement.

  13. Extension of laboratory-measured soil spectra to field conditions

    NASA Technical Reports Server (NTRS)

    Stoner, E. R.; Baumgardner, M. F.; Weismiller, R. A.; Biehl, L. L.; Robinson, B. F.

    1982-01-01

    Spectral responses of two glaciated soils, Chalmers silty clay loam and Fincastle silt loam, formed under prairie grass and forest vegetation, respectively, were measured in the laboratory under controlled moisture equilibria using an Exotech Model 20C spectroradiometer to obtain spectral data in the laboratory under artificial illumination. The same spectroradiometer was used outdoors under solar illumination to obtain spectral response from dry and moistened field plots with and without corn residue cover, representing the two different soils. Results indicate that laboratory-measured spectra of moist soil are directly proportional to the spectral response of that same field-measured moist bare soil over the 0.52 micrometer to 1.75 micrometer wavelength range. The magnitudes of difference in spectral response between identically treated Chalmers and Fincastle soils are greatest in the 0.6 micrometers to 0.8 micrometer transition region between the visible and near infrared, regardless of field condition or laboratory preparation studied.

  14. Spectator field dynamics in de Sitter and curvaton initial conditions

    SciTech Connect

    Enqvist, Kari; Lerner, Rose N.; Taanila, Olli; Tranberg, Anders E-mail: rose.lerner@helsinki.fi E-mail: antranbe@nbi.dk

    2012-10-01

    We investigate the stochastic behaviour of long wavelength modes of light spectator scalar fields during inflation. When starting from a classical field value, the probability distribution for the spectator both spreads out and moves towards an equilibrium distribution. We study the timescales for a mixed quadratic and quartic potential. The timescale of equilibration depends on the parameters of the model, and can be surprisingly large, more than thousands of e-folds for the majority of light spectators. These results imply that the initial conditions for spectator fields are not automatically erased during inflation. These general results can be used to determine the probability of the value of the zero-mode inside a Universe-sized patch, which is relevant for observations. As an example, we apply the results to the curvaton model to calculate the probability distribution of the curvature perturbation and discuss 'typical' Universes.

  15. Diel periodicity of Drosophila suzukii (Diptera: Drosophilidae) under field conditions

    PubMed Central

    Evans, Richard K.; Toews, Michael D.

    2017-01-01

    Drosophila suzukii Matsumura (Diptera: Drosophilidae), an economically important pest of blueberry and other thin-skinned fruits, persists and prolifically reproduces under seemingly lethal climatic conditions in the field. However, behavioral and physiological mechanisms employed by D. suzukii to tolerate such extreme climatic conditions in the field are unknown. The primary objective of this project was to investigate diel periodicity of D. suzukii and their reproductive success under field conditions as related by climatic factors such as temperature and relative humidity. Results show that D. suzukii reproductive success was significantly higher during the night (including dawn and dusk periods) than the day in terms of oviposition, pupation, adult eclosion, and the number of progeny per female. Female D. suzukii reproductive success was not significantly different between specific regions of a blueberry bush in relation to the amount of shade provided by the canopy. Our studies indicate that D. suzukii flight activity is crepuscular and is sensitive to fluctuations in temperature and relative humidity. Results also suggest that the majority of fly activity during peak hours is concentrated in areas around the border and within the center of blueberry orchards with little activity in the surrounding wooded areas. These findings suggest that D. suzukii prefers microclimate with mild temperatures and high humidity, and does not function well when exposed to direct sunlight with extreme heat. The authors propose that D. suzukii management strategies should be implemented during the early morning and immediately before darkness to maximize efficacy. PMID:28187140

  16. Phase-field elasticity model based on mechanical jump conditions

    NASA Astrophysics Data System (ADS)

    Schneider, Daniel; Tschukin, Oleg; Choudhury, Abhik; Selzer, Michael; Böhlke, Thomas; Nestler, Britta

    2015-05-01

    Computational models based on the phase-field method typically operate on a mesoscopic length scale and resolve structural changes of the material and furthermore provide valuable information about microstructure and mechanical property relations. An accurate calculation of the stresses and mechanical energy at the transition region is therefore indispensable. We derive a quantitative phase-field elasticity model based on force balance and Hadamard jump conditions at the interface. Comparing the simulated stress profiles calculated with Voigt/Taylor (Annalen der Physik 274(12):573, 1889), Reuss/Sachs (Z Angew Math Mech 9:49, 1929) and the proposed model with the theoretically predicted stress fields in a plate with a round inclusion under hydrostatic tension, we show the quantitative characteristics of the model. In order to validate the elastic contribution to the driving force for phase transition, we demonstrate the absence of excess energy, calculated by Durga et al. (Model Simul Mater Sci Eng 21(5):055018, 2013), in a one-dimensional equilibrium condition of serial and parallel material chains. To validate the driving force for systems with curved transition regions, we relate simulations to the Gibbs-Thompson equilibrium condition (Johnson and Alexander, J Appl Phys 59(8):2735, 1986).

  17. Assessment of Body Condition in African (Loxodonta africana) and Asian (Elephas maximus) Elephants in North American Zoos and Management Practices Associated with High Body Condition Scores

    PubMed Central

    Morfeld, Kari A.; Meehan, Cheryl L.; Hogan, Jennifer N.; Brown, Janine L.

    2016-01-01

    Obesity has a negative effect on health and welfare of many species, and has been speculated to be a problem for zoo elephants. To address this concern, we assessed the body condition of 240 elephants housed in North American zoos based on a set of standardized photographs using a 5-point Body Condition Score index (1 = thinnest; 5 = fattest). A multi-variable regression analysis was then used to determine how demographic, management, housing, and social factors were associated with an elevated body condition score in 132 African (Loxodonta africana) and 108 Asian (Elephas maximus) elephants. The highest BCS of 5, suggestive of obesity, was observed in 34% of zoo elephants. In both species, the majority of elephants had elevated BCS, with 74% in the BCS 4 (40%) and 5 (34%) categories. Only 22% of elephants had BCS 3, and less than 5% of the population was assigned the lowest BCS categories (BCS 1 and 2). The strongest multi-variable model demonstrated that staff-directed walking exercise of 14 hours or more per week and highly unpredictable feeding schedules were associated with decreased risk of BCS 4 or 5, while increased diversity in feeding methods and being female was associated with increased risk of BCS 4 or 5. Our data suggest that high body condition is prevalent among North American zoo elephants, and management strategies that help prevent and mitigate obesity may lead to improvements in welfare of zoo elephants. PMID:27415629

  18. Assessment of Body Condition in African (Loxodonta africana) and Asian (Elephas maximus) Elephants in North American Zoos and Management Practices Associated with High Body Condition Scores.

    PubMed

    Morfeld, Kari A; Meehan, Cheryl L; Hogan, Jennifer N; Brown, Janine L

    2016-01-01

    Obesity has a negative effect on health and welfare of many species, and has been speculated to be a problem for zoo elephants. To address this concern, we assessed the body condition of 240 elephants housed in North American zoos based on a set of standardized photographs using a 5-point Body Condition Score index (1 = thinnest; 5 = fattest). A multi-variable regression analysis was then used to determine how demographic, management, housing, and social factors were associated with an elevated body condition score in 132 African (Loxodonta africana) and 108 Asian (Elephas maximus) elephants. The highest BCS of 5, suggestive of obesity, was observed in 34% of zoo elephants. In both species, the majority of elephants had elevated BCS, with 74% in the BCS 4 (40%) and 5 (34%) categories. Only 22% of elephants had BCS 3, and less than 5% of the population was assigned the lowest BCS categories (BCS 1 and 2). The strongest multi-variable model demonstrated that staff-directed walking exercise of 14 hours or more per week and highly unpredictable feeding schedules were associated with decreased risk of BCS 4 or 5, while increased diversity in feeding methods and being female was associated with increased risk of BCS 4 or 5. Our data suggest that high body condition is prevalent among North American zoo elephants, and management strategies that help prevent and mitigate obesity may lead to improvements in welfare of zoo elephants.

  19. Behavior of the Reversed Field Pinch with Nonideal Boundary Conditions.

    NASA Astrophysics Data System (ADS)

    Ho, Yung-Lung

    The linear and nonlinear magnetohydrodynamic stability of current-driven modes is studied for a reversed field pinch with nonideal boundary conditions. The plasma is bounded by a thin resistive shell surrounded by a vacuum region out to a radius at which a perfectly conducting wall is situated. The distant wall and the thin shell problems are studied by removing either the resistive shell or the conducting wall. Linearly, growth rates of tearing modes and kink modes are calculated by analytical solutions based on the modified Bessel function model for the equilibrium. The effects of variation of the shell resistivity and wall proximity on the growth rates are investigated. The modes that may be important in different parameter regimes and with different boundary conditions are identified. These results then help to guide the nonlinear study, and also help to interpret the quasilinear aspect of the nonlinear results. The nonlinear behaviors are studied with a three -dimensional magnetohydrodynamics code. The fluctuations generally rise with increasing distance between the conducting wall and the plasma. The enhanced fluctuation induced v times b electric field primarily oppose toroidal current; hence, loop voltage must increase to sustain the constant. If the loop voltage is held constant, the current decreases and the plasma evolves toward a nonreversed tokamak-like state. Quasilinear interaction between modes typically associated with the dynamo action is identified as the most probable nonlinear destabilization mechanism. The helicity and energy balance properties of the simulation results are discussed. The interruption of current density along field lines intersecting the resistive shell is shown to lead to surface helicity leakage. This effect is intimately tied to stability, as fluctuation induced v times b electric field is necessary to transport the helicity to the surface. In this manner, all aspects of helicity balance, i.e., injection, transport, and

  20. Behavior of the reversed field pinch with nonideal boundary conditions

    NASA Astrophysics Data System (ADS)

    Ho, Yung-Lung

    1988-11-01

    The linear and nonlinear magnetohydrodynamic stability of current-driven modes are studied for a reversed field pinch with nonideal boundary conditions. The plasma is bounded by a thin resistive shell surrounded by a vacuum region out to a radius at which a perfectly conducting wall is situated. The distant wall and the thin shell problems are studied by removing either the resistive shell or the conducting wall. Linearly, growth rates of tearing modes and kink modes are calculated by analytical solutions based on the modified Bessel function model for the equilibrium. The effects of variation of the shell resistivity and wall proximity on the growth rates are investigated. The modes that may be important in different parameter regimes and with different boundary conditions are identified. The nonlinear behaviors are studied with a three-dimensional magnetohydrodynamics code. The fluctuations generally rise with increasing distance between the conducting wall and the plasma. The enhanced fluctuation induced v x b electric field primarily oppose toroidal current; hence, loop voltage must increase to sustain the constant. Quasilinear interaction between modes typically associated with the dynamo action is identified as the most probable nonlinear destabilization mechanism. The helicity and energy balance properties of the simulation results are discussed. The interruption of current density along field lines intersecting the resistive shell is shown to lead to surface helicity leakage. This effect is intimately tied to stability, as fluctuation induced v x b electric field is necessary to transport the helicity to the surface. In this manner, all aspects of helicity balance, i.e., injection, transport, and dissipation, are considered self-consistently. The importance of the helicity and energy dissipation by the mean components of the magnetic field and current density is discussed.

  1. Crop improvement using life cycle datasets acquired under field conditions

    PubMed Central

    Mochida, Keiichi; Saisho, Daisuke; Hirayama, Takashi

    2015-01-01

    Crops are exposed to various environmental stresses in the field throughout their life cycle. Modern plant science has provided remarkable insights into the molecular networks of plant stress responses in laboratory conditions, but the responses of different crops to environmental stresses in the field need to be elucidated. Recent advances in omics analytical techniques and information technology have enabled us to integrate data from a spectrum of physiological metrics of field crops. The interdisciplinary efforts of plant science and data science enable us to explore factors that affect crop productivity and identify stress tolerance-related genes and alleles. Here, we describe recent advances in technologies that are key components for data driven crop design, such as population genomics, chronological omics analyses, and computer-aided molecular network prediction. Integration of the outcomes from these technologies will accelerate our understanding of crop phenology under practical field situations and identify key characteristics to represent crop stress status. These elements would help us to genetically engineer “designed crops” to prevent yield shortfalls because of environmental fluctuations due to future climate change. PMID:26442053

  2. Introduction of periodic boundary conditions into UNRES force field.

    PubMed

    Sieradzan, Adam K

    2015-05-05

    In this article, implementation of periodic boundary conditions (PBC) into physics-based coarse-grained UNited RESidue (UNRES) force field is presented, which replaces droplet-like restraints previously used. Droplet-like restraints are necessary to keep multichain systems together and prevent them from dissolving to infinitely low concentration. As an alternative for droplet-like restrains cuboid PBCs with imaging of the molecules were introduced. Owing to this modification, artificial forces which arose from restraints keeping a droplet together were eliminated what leads to more realistic trajectories. Due to computational reasons cutoff and smoothing functions were introduced on the long range interactions. The UNRES force field with PBC was tested by performing microcanonical simulations. Moreover, to asses the behavior of the thermostat in PBCs Langevin and Berendsen thermostats were studied. The influence of PBCs on association pattern was compared with droplet-like restraints on the ββα hetero tetramer 1 protein system.

  3. Hidden Conditional Neural Fields for Continuous Phoneme Speech Recognition

    NASA Astrophysics Data System (ADS)

    Fujii, Yasuhisa; Yamamoto, Kazumasa; Nakagawa, Seiichi

    In this paper, we propose Hidden Conditional Neural Fields (HCNF) for continuous phoneme speech recognition, which are a combination of Hidden Conditional Random Fields (HCRF) and a Multi-Layer Perceptron (MLP), and inherit their merits, namely, the discriminative property for sequences from HCRF and the ability to extract non-linear features from an MLP. HCNF can incorporate many types of features from which non-linear features can be extracted, and is trained by sequential criteria. We first present the formulation of HCNF and then examine three methods to further improve automatic speech recognition using HCNF, which is an objective function that explicitly considers training errors, provides a hierarchical tandem-style feature and includes a deep non-linear feature extractor for the observation function. We show that HCNF can be trained realistically without any initial model and outperforms HCRF and the triphone hidden Markov model trained by the minimum phone error (MPE) manner using experimental results for continuous English phoneme recognition on the TIMIT core test set and Japanese phoneme recognition on the IPA 100 test set.

  4. Positive Energy Conditions in 4D Conformal Field Theory

    NASA Astrophysics Data System (ADS)

    Farnsworth, Kara; Luty, Markus; Prilepina, Valentina

    2016-03-01

    We argue that all consistent 4D quantum field theories obey a spacetime-averaged weak energy inequality avgT00 >= - C /L4 , where L is the size of the smearing region, and C is a positive constant that depends on the theory. If this condition is violated, the theory has states that are indistinguishable from states of negative total energy by any local measurement, and we expect instabilities or other inconsistencies. We apply this condition to 4D conformal field theories, and find that it places constraints on the OPE coefficients of the theory. The constraints we find are weaker than the ``conformal collider'' constraints of Hofman and Maldacena. We speculate that there may be theories that violate the Hofman-Maldacena bounds, but satisfy our bounds. In 3D CFTs, the only constraint we find is equivalent to the positivity of 2-point function of the energy-momentum tensor, which follows from unitarity. Our calculations are performed using momentum-space Wightman functions, which are remarkably simple functions of momenta, and may be of interest in their own right.

  5. Positive energy conditions in 4D conformal field theory

    NASA Astrophysics Data System (ADS)

    Farnsworth, Kara; Luty, Markus A.; Prilepina, Valentina

    2016-10-01

    We argue that all consistent 4D quantum field theories obey a spacetime-averaged weak energy inequality < T 00> ≥ - C/L 4, where L is the size of the smearing region, and C is a positive constant that depends on the theory. If this condition is violated, the theory has states that are indistinguishable from states of negative total energy by any local measurement, and we expect instabilities or other inconsistencies. We apply this condition to 4D conformal field theories, and find that it places constraints on the OPE coefficients of the theory. The constraints we find are weaker than the "conformal collider" constraints of Hofman and Maldacena. In 3D CFTs, the only constraint we find is equivalent to the positivity of 2-point function of the energy-momentum tensor, which follows from unitarity. Our calculations are performed using momentum-space Wightman functions, which are remarkably simple functions of momenta, and may be of interest in their own right.

  6. Servant Leadership, Africanization, and Disruptive Innovation as Conditions for Effective Leadership at UNISA

    ERIC Educational Resources Information Center

    Williams, Clayton; Gardner, J. Clark

    2012-01-01

    This article discusses effective leadership in educational environments and in particular focuses on the current situation at the University of South Africa (UNISA). The end of Apartheid in South Africa has brought many opportunities but also some challenges especially in education. Three conditions that contribute to ensuring strong distance…

  7. Intercomparison 2013 on measurements of the personal dose equivalent Hp(10) in photon fields in the African region.

    PubMed

    Arib, M; Herrati, A; Dari, F; Ma, J; Lounis-Mokrani, Z

    2015-02-01

    An intercomparison exercise on the measurement of personal dose equivalent Hp(10) was jointly organised by the International Atomic Energy Agency and the Nuclear Research Centre of Algiers through its Secondary Standard Dosimetry Laboratory in the African region. This intercomparison exercise was aimed at verifying the performance of the individual monitoring services of the participants in order to assess their capabilities to measure the quantity Hp(10) in photon (gamma and X ray) fields helping them to comply with dose limitation requirements. The scope of this intercomparison was aimed at passive dosemeters, which determine the personal dose equivalent in photon radiation fields, mainly for thermoluminescence and optically stimulated luminescence dosemeters. Twenty-seven countries from the Africa region and from outside Africa participated in this exercise. The intercomparison protocol, including the preparation of the dosemeters and the irradiation procedures, is described and the results are presented, analysed and discussed.

  8. Sensitivity of drainage efficiency of cranberry fields to edaphic conditions

    NASA Astrophysics Data System (ADS)

    Periard, Yann; José Gumiere, Silvio; Rousseau, Alain N.; Caron, Jean; Hallema, Dennis W.

    2014-05-01

    Water management on a cranberry farm requires intelligent irrigation and drainage strategies to sustain strong productivity and minimize environmental impact. For example, to avoid propagation of disease and meet evapotranspiration demand, it is imperative to maintain optimal moisture conditions in the root zone, which depends on an efficient drainage system. However, several drainage problems have been identified in cranberry fields. Most of these drainage problems are due to the presence of a restrictive layer in the soil profile (Gumiere et al., 2014). The objective of this work is to evaluate the effects of a restrictive layer on the drainage efficiency by the bias of a multi-local sensitivity analysis. We have tested the sensitivity of the drainage efficiency to different input parameters set of soil hydraulic properties, geometrical parameters and climatic conditions. Soil water flux dynamic for every input parameters set was simulated with finite element model Hydrus 1D (Simanek et al., 2008). Multi-local sensitivity was calculated with the Gâteaux directional derivatives with the procedure described by Cheviron et al. (2010). Results indicate that drainage efficiency is more sensitive to soil hydraulic properties than geometrical parameters and climatic conditions. Then, the geometrical parameters of the depth are more sensitive than the thickness. The drainage efficiency was very insensitive to the climatic conditions. Understanding the sensitivity of drainage efficiency according to soil hydraulic properties, geometrical and climatic conditions are essential for diagnosis drainage problems. However, it becomes important to identify the mechanisms involved in the genesis of anthropogenic soils cranberry to identify conditions that may lead to the formation of a restrictive layer. References: Cheviron, B., S.J. Gumiere, Y. Le Bissonnais, R. Moussa and D. Raclot. 2010. Sensitivity analysis of distributed erosion models: Framework. Water Resources Research

  9. Modeling effects of inter-annual variability in meteorological and land use conditions on coupled water and energy cycling in the cultivated African Sahel

    NASA Astrophysics Data System (ADS)

    Velluet, C.; Demarty, J.; Cappelaere, B.; Braud, I.; Boulain, N.; Favreau, G.; Charvet, G.; Ramier, D.; Issoufou, H.; Boucher, M.; Mainassara, I.; Chazarin, J.; Oï, M.; Yahou, H.; Benarrosh, N.; Ibrahim, M.

    2012-12-01

    In the dry tropics in general and in the African Sahel in particular, hydro-ecosystems are very sensitive to climate variability and land management. In the Niamey region of South-West Niger, a severe multi-decadal drought together with large-scale vegetation clearing coincided with an unexpected increase in surface and ground water resources. Such an apparent paradoxical situation illustrates the complex way in which climate and land cover interactions control the Sahelian water cycle dynamics. This stresses the importance of understanding and reliably modeling water/energy transfers in the local soil-plant-atmosphere system, under contrasted meteorological and surface conditions. This study investigates the effects of the inter-annual variability of meteorological and land use conditions on the coupled water and energy cycles in the cultivated Sahel over a 5-year period. This is based on a comprehensive multi-year field dataset acquired for a millet crop field and a fallow savannah, the two main land cover types of South-West Niger (Wankama catchment in the mesoscale AMMA-CATCH Niger observatory, part of the French-initiated RBV network). It includes atmospheric forcing, seasonal course of vegetation phenology, soil properties and model validation variables (net radiation, turbulent fluxes, soil heat/water profiles), for the two fields. The study area is typical of Central Sahel conditions, with 400-600 mm annual rainfall concentrated in the 4-5 month wet season. Soils are mainly sandy and prone to surface crusting, leading to a strong vertical contrast in hydrodynamic properties. The SiSPAT process-based model used solves the 1D mass and heat transfer system of equations in the soil, including vapor phase and coupled with a two-component (bare soil and vegetation) water and energy budget at the surface-atmosphere interface. The study explores whether such a model can be accurately calibrated and validated for the two sites using realistic-parameter values. The

  10. Generalized CMB initial conditions with pre-equality magnetic fields

    SciTech Connect

    Giovannini, Massimo; Kunze, Kerstin E.

    2008-06-15

    The most general initial conditions of cosmic microwave background anisotropies, compatible with the presence of pre-equality magnetic fields, are derived. When the plasma is composed of photons, baryons, electrons, cold dark matter particles and neutrinos, the initial data of the truncated Einstein-Boltzmann hierarchy contemplate one magnetized adiabatic mode and four (magnetized) nonadiabatic modes. After obtaining the analytical form of the various solutions, the Einstein-Boltzmann hierarchy is numerically integrated for the corresponding sets of initial data. The TT, TE and EE angular power spectra are illustrated and discussed for the magnetized generalization of the cold dark matter-radiation mode, of the baryon-radiation mode and of the nonadiabatic mode of the neutrino sector. Mixtures of initial conditions are examined by requiring that the magnetized adiabatic mode dominates over the remaining nonadiabatic contributions. In the latter case, possible degeneracies between complementary sets of initial data might be avoided through the combined analysis of the TT, TE and EE angular power spectra at high multipoles (i.e. l>1000)

  11. Conditional random fields for pattern recognition applied to structured data

    SciTech Connect

    Burr, Tom; Skurikhin, Alexei

    2015-07-14

    Pattern recognition uses measurements from an input domain, X, to predict their labels from an output domain, Y. Image analysis is one setting where one might want to infer whether a pixel patch contains an object that is “manmade” (such as a building) or “natural” (such as a tree). Suppose the label for a pixel patch is “manmade”; if the label for a nearby pixel patch is then more likely to be “manmade” there is structure in the output domain that can be exploited to improve pattern recognition performance. Modeling P(X) is difficult because features between parts of the model are often correlated. Therefore, conditional random fields (CRFs) model structured data using the conditional distribution P(Y|X = x), without specifying a model for P(X), and are well suited for applications with dependent features. This paper has two parts. First, we overview CRFs and their application to pattern recognition in structured problems. Our primary examples are image analysis applications in which there is dependence among samples (pixel patches) in the output domain. Second, we identify research topics and present numerical examples.

  12. Conditional random fields for pattern recognition applied to structured data

    DOE PAGES

    Burr, Tom; Skurikhin, Alexei

    2015-07-14

    Pattern recognition uses measurements from an input domain, X, to predict their labels from an output domain, Y. Image analysis is one setting where one might want to infer whether a pixel patch contains an object that is “manmade” (such as a building) or “natural” (such as a tree). Suppose the label for a pixel patch is “manmade”; if the label for a nearby pixel patch is then more likely to be “manmade” there is structure in the output domain that can be exploited to improve pattern recognition performance. Modeling P(X) is difficult because features between parts of the modelmore » are often correlated. Therefore, conditional random fields (CRFs) model structured data using the conditional distribution P(Y|X = x), without specifying a model for P(X), and are well suited for applications with dependent features. This paper has two parts. First, we overview CRFs and their application to pattern recognition in structured problems. Our primary examples are image analysis applications in which there is dependence among samples (pixel patches) in the output domain. Second, we identify research topics and present numerical examples.« less

  13. Considerations in detecting CDC select agents under field conditions

    NASA Astrophysics Data System (ADS)

    Spinelli, Charles; Soelberg, Scott; Swanson, Nathaneal; Furlong, Clement; Baker, Paul

    2008-04-01

    Surface Plasmon Resonance (SPR) has become a widely accepted technique for real-time detection of interactions between receptor molecules and ligands. Antibody may serve as receptor and can be attached to the gold surface of the SPR device, while candidate analyte fluids contact the detecting antibody. Minute, but detectable, changes in refractive indices (RI) indicate that analyte has bound to the antibody. A decade ago, an inexpensive, robust, miniature and fully integrated SPR chip, called SPREETA, was developed. University of Washington (UW) researchers subsequently developed a portable, temperature-regulated instrument, called SPIRIT, to simultaneously use eight of these three-channel SPREETA chips. A SPIRIT prototype instrument was tested in the field, coupled to a remote reporting system on a surrogate unmanned aerial vehicle (UAV). Two target protein analytes were released sequentially as aerosols with low analyte concentration during each of three flights and were successfully detected and verified. Laboratory experimentation with a more advanced SPIRIT instrument demonstrated detection of very low levels of several select biological agents that might be employed by bioterrorists. Agent detection under field-like conditions is more challenging, especially as analyte concentrations are reduced and complex matricies are introduced. Two different sample preconditioning protocols have been developed for select agents in complex matrices. Use of these preconditioning techniques has allowed laboratory detection in spiked heavy mud of Francisella tularensis at 10 3 CFU/ml, Bacillus anthracis spores at 10 3 CFU/ml, Staphylococcal enterotoxin B (SEB) at 1 ng/ml, and Vaccinia virus (a smallpox simulant) at 10 5 PFU/ml. Ongoing experiments are aimed at simultaneous detection of multiple agents in spiked heavy mud, using a multiplex preconditioning protocol.

  14. Gaussian conditional random fields for regression in remote sensing

    NASA Astrophysics Data System (ADS)

    Radosavljevic, Vladan

    In recent years many remote sensing instruments of various properties have been employed in an attempt to better characterize important geophysical phenomena. Satellite instruments provide an exceptional opportunity for global long-term observations of the land, the biosphere, the atmosphere, and the oceans. The collected data are used for estimation and better understanding of geophysical parameters such as land cover type, atmospheric properties, or ocean temperature. Achieving accurate estimations of such parameters is an important requirement for development of models able to predict global climate changes. One of the most challenging climate research problems is estimation of global composition, load, and variability of aerosols, small airborne particles that reflect and absorb incoming solar radiation. The existing algorithm for aerosol prediction from satellite observations is deterministic and manually tuned by domain scientist. In contrast to domain-driven method, we show that aerosol prediction is achievable by completely data-driven approaches. These statistical methods consist of learning of nonlinear regression models to predict aerosol load using the satellite observations as inputs. Measurements from unevenly distributed ground-based sites over the world are used as proxy to ground-truth outputs. Although statistical methods achieve better accuracy than deterministic method this setup is appropriate when data are independently and identically distributed (IID). The IID assumption is often violated in remote sensing where data exhibit temporal, spatial, or spatio-temporal dependencies. In such cases, the traditional supervised learning approaches could result in a model with degraded accuracy. Conditional random fields (CRF) are widely used for predicting output variables that have some internal structure. Most of the CRF research has been done on structured classification where the outputs are discrete. We propose a CRF model for continuous outputs

  15. The Frequency of “Brilliant” and “Genius” in Teaching Evaluations Predicts the Representation of Women and African Americans across Fields

    PubMed Central

    Storage, Daniel; Horne, Zachary; Cimpian, Andrei; Leslie, Sarah-Jane

    2016-01-01

    Women and African Americans—groups targeted by negative stereotypes about their intellectual abilities—may be underrepresented in careers that prize brilliance and genius. A recent nationwide survey of academics provided initial support for this possibility. Fields whose practitioners believed that natural talent is crucial for success had fewer female and African American PhDs. The present study seeks to replicate this initial finding with a different, and arguably more naturalistic, measure of the extent to which brilliance and genius are prized within a field. Specifically, we measured field-by-field variability in the emphasis on these intellectual qualities by tallying—with the use of a recently released online tool—the frequency of the words “brilliant” and “genius” in over 14 million reviews on RateMyProfessors.com, a popular website where students can write anonymous evaluations of their instructors. This simple word count predicted both women’s and African Americans’ representation across the academic spectrum. That is, we found that fields in which the words “brilliant” and “genius” were used more frequently on RateMyProfessors.com also had fewer female and African American PhDs. Looking at an earlier stage in students’ educational careers, we found that brilliance-focused fields also had fewer women and African Americans obtaining bachelor’s degrees. These relationships held even when accounting for field-specific averages on standardized mathematics assessments, as well as several competing hypotheses concerning group differences in representation. The fact that this naturalistic measure of a field’s focus on brilliance predicted the magnitude of its gender and race gaps speaks to the tight link between ability beliefs and diversity. PMID:26938242

  16. Predictive hydrogeochemical modelling of bauxite residue sand in field conditions.

    PubMed

    Wissmeier, Laurin; Barry, David A; Phillips, Ian R

    2011-07-15

    The suitability of residue sand (the coarse fraction remaining from Bayer's process of bauxite refining) for constructing the surface cover of closed bauxite residue storage areas was investigated. Specifically, its properties as a medium for plant growth are of interest to ensure residue sand can support a sustainable ecosystem following site closure. The geochemical evolution of the residue sand under field conditions, its plant nutrient status and soil moisture retention were studied by integrated modelling of geochemical and hydrological processes. For the parameterization of mineral reactions, amounts and reaction kinetics of the mineral phases natron, calcite, tricalcium aluminate, sodalite, muscovite and analcime were derived from measured acid neutralization curves. The effective exchange capacity for ion adsorption was measured using three independent exchange methods. The geochemical model, which accounts for mineral reactions, cation exchange and activity corrected solution speciation, was formulated in the geochemical modelling framework PHREEQC, and partially validated in a saturated-flow column experiment. For the integration of variably saturated flow with multi-component solute transport in heterogeneous 2D domains, a coupling of PHREEQC with the multi-purpose finite-element solver COMSOL was established. The integrated hydrogeochemical model was applied to predict water availability and quality in a vertical flow lysimeter and a cover design for a storage facility using measured time series of rainfall and evaporation from southwest Western Australia. In both scenarios the sand was fertigated and gypsum-amended. Results show poor long-term retention of fertilizer ions and buffering of the pH around 10 for more than 5 y of leaching. It was concluded that fertigation, gypsum amendment and rainfall leaching alone were insufficient to render the geochemical conditions of residue sand suitable for optimal plant growth within the given timeframe. The

  17. Odor Fear Conditioning Modifies Piriform Cortex Local Field Potentials Both during Conditioning and during Post-Conditioning Sleep

    PubMed Central

    Barnes, Dylan C.; Chapuis, Julie; Chaudhury, Dipesh; Wilson, Donald A.

    2011-01-01

    Background Sleep plays an active role in memory consolidation. Sleep structure (REM/Slow wave activity [SWS]) can be modified after learning, and in some cortical circuits, sleep is associated with replay of the learned experience. While the majority of this work has focused on neocortical and hippocampal circuits, the olfactory system may offer unique advantages as a model system for exploring sleep and memory, given the short, non-thalamic pathway from nose to primary olfactory (piriform cortex), and rapid cortex-dependent odor learning. Methodology/Principal Findings We examined piriform cortical odor responses using local field potentials (LFPs) from freely behaving Long-Evans hooded rats over the sleep-wake cycle, and the neuronal modifications that occurred within the piriform cortex both during and after odor-fear conditioning. We also recorded LFPs from naïve animals to characterize sleep activity in the piriform cortex and to analyze transient odor-evoked cortical responses during different sleep stages. Naïve rats in their home cages spent 40% of their time in SWS, during which the piriform cortex was significantly hypo-responsive to odor stimulation compared to awake and REM sleep states. Rats trained in the paired odor-shock conditioning paradigm developed enhanced conditioned odor evoked gamma frequency activity in the piriform cortex over the course of training compared to pseudo-conditioned rats. Furthermore, conditioned rats spent significantly more time in SWS immediately post-training both compared to pre-training days and compared to pseudo-conditioned rats. The increase in SWS immediately after training significantly correlated with the duration of odor-evoked freezing the following day. Conclusions/Significance The rat piriform cortex is hypo-responsive to odors during SWS which accounts for nearly 40% of each 24 hour period. The duration of slow-wave activity in the piriform cortex is enhanced immediately post-conditioning, and this increase

  18. Infinite hidden conditional random fields for human behavior analysis.

    PubMed

    Bousmalis, Konstantinos; Zafeiriou, Stefanos; Morency, Louis-Philippe; Pantic, Maja

    2013-01-01

    Hidden conditional random fields (HCRFs) are discriminative latent variable models that have been shown to successfully learn the hidden structure of a given classification problem (provided an appropriate validation of the number of hidden states). In this brief, we present the infinite HCRF (iHCRF), which is a nonparametric model based on hierarchical Dirichlet processes and is capable of automatically learning the optimal number of hidden states for a classification task. We show how we learn the model hyperparameters with an effective Markov-chain Monte Carlo sampling technique, and we explain the process that underlines our iHCRF model with the Restaurant Franchise Rating Agencies analogy. We show that the iHCRF is able to converge to a correct number of represented hidden states, and outperforms the best finite HCRFs--chosen via cross-validation--for the difficult tasks of recognizing instances of agreement, disagreement, and pain. Moreover, the iHCRF manages to achieve this performance in significantly less total training, validation, and testing time.

  19. Field performance of GCL under ion exchange conditions

    SciTech Connect

    James, A.N.; Fullerton, D.; Drake, R.

    1997-10-01

    Five Victorian reservoirs of brick pillar and arch construction were renovated using geosynthetic clay liners (also called bentonite/geosynthetic composites) (GCL) as roof sealing materials. The GCL was predominantly sodium bentonite and contained some 2% of calcite. GCLs were laid on leveled, original puddled clay packed between and above the brick arches. There was an overlying gravel layer connected to a drainage system that, in turn, was covered with soil and seeded with grass. Leaks through roofs into stored potable water were discovered. Excavation and exposure of the GCL showed that they were finely cracked in many places. Samples of the GCL bentonite from several locations at each of five sites had a high moisture content. Also, the GCL had a much reduced exchangeable sodium and increased exchangeable calcium content when compared to the dry unused GCL. Laboratory experiments, lasting for a limited period, were carried out to simulate operating conditions of the GCL whereby water falling on the ground and reaching the GCL flowed across the GCL in the overlying gravel layer to collector drains. Similar but less extensive ion exchange, calcium for sodium, was found here also. The evidence demonstrates that calcium from calcite, contained in the GCL bentonite, exchanged with sodium and, in so doing, contributed to shrinkage and cracking. Supplementary sources of calcium for ion exchange probably came from overlying calcareous soil and water from firehoses used to field test the integrity of the GCL.

  20. Accumulation of mercury in Typha domingensis under field conditions.

    PubMed

    Lominchar, M A; Sierra, M J; Millán, R

    2015-01-01

    Typha species is a common wetland plant used in the treatment of urban and industrial effluents. But, despite their widespread implementation, there are not many studies based on the behaviour of this plant growing in an areas affected by mercury. The present work investigates the ability of Typha domingensis to accumulate mercury under field conditions. The study area was along the Valdeazogues river which flows through the Almadén mining district (Ciudad Real, Spain) that is considered the largest mercury reservoir in the world. The mercury concentration in different plant fractions was measured as well as the available and total concentration in the bottom sediments. The results showed that the highest mercury concentrations were found in the belowground organs. T. domingensis had a high efficiency to accumulate mercury in their organs although available metal concentrations in the environment did not exceed 0.16 mg kg(-1). Bioaccumulation factors (BAF) ranged between 121 and 3168 in roots. Furthermore, significant correlations were found between mercury concentration in all plant organs and Hg in sediments (both total and available). These results demonstrated that T. domingensis could be used as a biomonitor as well as in phytoextraction technology in areas affected by mercury.

  1. Dissipation of Pendimethalin in Soybean Crop Under Field Conditions.

    PubMed

    Tandon, Shishir

    2016-05-01

    Persistence of pendimethalin was studied in soil, soybean pods, straw and water under field conditions. Pendimethalin was applied at 1 and 2 kg a.i. ha(-1). Residues in soil were detected up to 60 and 90 days at the recommended and double dose, respectively. Dissipation followed first order kinetics and was accounted for by a biphasic pattern. The half-life for the initial phase and later phase was 12.73 and 26.60 days, respectively, for recommended and 7.25 and 37.91 days, respectively, for double dose. The limit of quantification was 0.005 µg g(-1) of sample. Percent recovery from soil, oil, defatted cake, straw and water samples fortified with 0.01-1.0 mg kg(-1) varied from 84.5 %-89.6 %, 84.6 %-88.7 %, 79.4 %-86.0 %, 78.2 %-85.6 % and 90.2 %-93.0 %, respectively. At harvest, pendimethalin residue in soybean pods, straw, and soil were below detectable limits. No residues of pendimethalin were detected in ground water. Current application of pendimethalin in the environment is not expected to cause adverse health effects form the consumption of soybeans.

  2. An evidence for prompt electric field disturbance driven by changes in the solar wind density under northward IMF Bz condition

    NASA Astrophysics Data System (ADS)

    Rout, Diptiranjan; Chakrabarty, D.; Sekar, R.; Reeves, G. D.; Ruohoniemi, J. M.; Pant, Tarun K.; Veenadhari, B.; Shiokawa, K.

    2016-05-01

    Before the onset of a geomagnetic storm on 22 January 2012 (Ap = 24), an enhancement in solar wind number density from 10/cm3 to 22/cm3 during 0440-0510 UT under northward interplanetary magnetic field (IMF Bz) condition is shown to have enhanced the high-latitude ionospheric convection and also caused variations in the geomagnetic field globally. Conspicuous changes in ΔX are observed not only at longitudinally separated low-latitude stations over Indian (prenoon), South American (midnight), Japanese (afternoon), Pacific (afternoon) and African (morning) sectors but also at latitudinally separated stations located over high and middle latitudes. The latitudinal variation of the amplitude of the ΔX during 0440-0510 UT is shown to be consistent with the characteristics of prompt penetration electric field disturbances. Most importantly, the density pulse event caused enhancements in the equatorial electrojet strength and the peak height of the F layer (hmF2) over the Indian dip equatorial sector. Further, the concomitant enhancements in electrojet current and F layer movement over the dip equator observed during this space weather event suggest a common driver of prompt electric field disturbance at this time. Such simultaneous variations are found to be absent during magnetically quiet days. In absence of significant change in solar wind velocity and magnetospheric substorm activity, these observations point toward perceptible prompt electric field disturbance over the dip equator driven by the overcompression of the magnetosphere by solar wind density enhancement.

  3. Field Demonstration of Multi-Sensor Technology for Condition Assessment of Wastewater Collection Systems (Abstract)

    EPA Science Inventory

    The purpose of the field demonstration program is to gather technically reliable cost and performance information on selected condition assessment technologies under defined field conditions. The selected technologies include zoom camera, focused electrode leak location (FELL), ...

  4. Mobilizing a low-income African-American community around tobacco control: a force field analysis.

    PubMed

    Ellis, G A; Reed, D F; Scheider, H

    1995-11-01

    A statewide tobacco control campaign in California has been highly successful in reducing public exposure to the health hazards of secondhand smoke. Over 250 cities and counties in California have enacted local ordinances to regulate smoking in public places and workplaces. Although low-income people of color are disproportionately affected by the use of tobacco, the issue of regulating secondhand smoke tends to be a lower priority in communities that are confronted by other, more immediately pressing social justice issues, such as high rates of violence and lack of economic opportunity. This article describes the process undertaken by a county health department to mobilize a low-income African American community in a San Francisco Bay Area city to support a local ordinance mandating 100% smoke-free workplaces and restaurants. These efforts are more likely to succeed if health advocates (1) reframe issues in a context that acknowledges the political, economic, and social justice realities and strengths of the community; (2) organize within existing local networks and foster the integration of tobacco issues into the group's existing work; and (3) can defer their own agendas during times of community grieving and healing.

  5. Update on field use of the available drugs for the chemotherapy of human African trypanosomiasis.

    PubMed

    Simarro, P P; Franco, J; Diarra, A; Postigo, J A Ruiz; Jannin, J

    2012-06-01

    Despite the fact that eflornithine was considered as the safer drug to treat human African trypanosomiasis (HAT) and has been freely available since 2001, the difficulties in logistics and cost burden associated with this drug meant that the toxic melarsoprol remained the drug of choice. The World Health Organization responded to the situation by designing a medical kit containing all the materials needed to use eflornithine, and by implementing a training and drugs distribution programme which has allowed a transition to this much safer treatment. The introduction of the combination of nifurtimox and eflornithine (NECT) has accelerated the shift from melarsoprol to the best treatment available, due to reduced dosage and treatment time for eflornithine that has significantly lessened the cost and improved the burden of logistics encountered during treatment and distribution. The decrease in the use of more dangerous but cheaper melarsoprol has meant a rise in the per patient cost of treating HAT. Although NECT is cheaper than eflornithine monotherapy, an unexpected consequence has been a continuing rise in the per patient cost of treating HAT. The ethical decision of shifting to the best available treatment imposes a financial burden on HAT control programmes that might render long-term application unsustainable. These factors call for continuing research to provide new safer and more effective drugs that are simple to administer and cheaper when compared to current drugs.

  6. Experimental Infection of Domestic Pigs with African Swine Fever Virus Lithuania 2014 Genotype II Field Isolate.

    PubMed

    Gallardo, C; Soler, A; Nieto, R; Cano, C; Pelayo, V; Sánchez, M A; Pridotkas, G; Fernandez-Pinero, J; Briones, V; Arias, M

    2017-02-01

    An experimental infection was conducted to evaluate horizontal transmission, clinical, virological and humoral response induced in domestic pigs infected with African swine fever (ASF) genotype II virus circulating in 2014 into the European Union (EU). Ten naive pigs were placed in contact with eight pigs experimentally inoculated with the Lithuanian LT14/1490 ASF virus (ASFV) responsible for the first ASF case detected in wild boar in Lithuania in January 2014. Clinical examination and rectal temperature were recorded each day. Blood sampling from every animal was carried out twice weekly. Blood samples were examined for presence of ASF virus-specific antibodies and for determining the ASFV viral load. From the obtained results, it was concluded that the Lithuanian ASFV induced an acute disease which resulted in 94, 5% mortality. The disease was easily detected by real-time PCR prior to the onset of clinical signs and 33% of the animals seroconverted. All findings were in accordance with observations previously made in domestic pigs and wild boar when infected with ASF genotype II viruses characterized by a high virulence. One in-contact pig remained asymptomatic and survived the infection. The role of such animals in virus transmission would need further investigation.

  7. Management of School Infrastructure in the Context of a No-Fee Schools Policy in Rural South African Schools: Lessons from the Field

    ERIC Educational Resources Information Center

    Marishane, Ramodikoe Nylon

    2013-01-01

    This study examines the management of school infrastructure in the context of the "no-fee schools" policy introduced in the South African education delivery system. Focusing on four rural schools, the study applied a qualitative method, which involved observation of infrastructure conditions prevailing at four selected schools and…

  8. BVOC emission pattern from Quercus robur under field conditions

    NASA Astrophysics Data System (ADS)

    Pokorska, O.; Dewulf, J.; Joó; Šimpraga, M.; Steppe, K.; Amelynck, C.; Schoon, N.; Muller, J. J.; van Langenhove, H.

    2010-12-01

    Over the past decades biogenic volatile organic compounds (BVOC) have been widely studied not only for better understanding their functions, biosynthesis and regulation, but also because they have great impact on regional and global air quality [1]. Since all BVOCs react with hydroxyl radicals (OH●) and may also react with nitrate radicals (NO3●) and ozone (O3), they contribute to the formation of ozone and secondary organic aerosols. In this study we focus on Quercus robur which is a widely spread tree species in Europe and known as a strong isoprene emitter. We aimed to investigate seasonal patterns of BVOC emissions from Quercus robur under field conditions and to explore the intra-species variations within Quercus robur trees as both are of great importance for accurate modeling and regional inventories. Measurements were performed during a period from May till October 2009 at the campus of Ghent University (Belgium) using a dynamic branch enclosure system. Experiments were conducted on four potted Quercus robur trees with a varying 1-1.5 m height. Samples were collected on Tenax TA-Carbotrap adsorbent tubes and analyzed by TD-GC-MS. Isoprene was the predominant compound released by Quercus robur (QR1) with a pronounced seasonal emission. The normalized emission rates for isoprene calculated according to Guenther’s algorithm (standard conditions of temperature 30°C and PAR 1000 µmol m-2 s-1) varied from 29.89 µg h-1 g(DW)-1 in Spring (May) to 28.62 µg h-1 g(DW)-1 in Fall (October) reaching peak of 105.51 µg h-1 g(DW)-1 in August. Apart from isoprene, through the whole measurement period trans-β-ocimene and β-caryophyllene were the only BVOC emitted in detectable range (sum of the emissions varied between 0.15 µg h-1 g(DW)-1 in July and 0.24 µg h-1 g(DW)-1 in October). No clear seasonal pattern was observed for those compounds. In May when acorns where developing on enclosed branch, emissions of limonene and β-farnesene were also observed. The

  9. Inferring Lower Boundary Driving Conditions Using Vector Magnetic Field Observations

    NASA Technical Reports Server (NTRS)

    Schuck, Peter W.; Linton, Mark; Leake, James; MacNeice, Peter; Allred, Joel

    2012-01-01

    Low-beta coronal MHD simulations of realistic CME events require the detailed specification of the magnetic fields, velocities, densities, temperatures, etc., in the low corona. Presently, the most accurate estimates of solar vector magnetic fields are made in the high-beta photosphere. Several techniques have been developed that provide accurate estimates of the associated photospheric plasma velocities such as the Differential Affine Velocity Estimator for Vector Magnetograms and the Poloidal/Toroidal Decomposition. Nominally, these velocities are consistent with the evolution of the radial magnetic field. To evolve the tangential magnetic field radial gradients must be specified. In addition to estimating the photospheric vector magnetic and velocity fields, a further challenge involves incorporating these fields into an MHD simulation. The simulation boundary must be driven, consistent with the numerical boundary equations, with the goal of accurately reproducing the observed magnetic fields and estimated velocities at some height within the simulation. Even if this goal is achieved, many unanswered questions remain. How can the photospheric magnetic fields and velocities be propagated to the low corona through the transition region? At what cadence must we observe the photosphere to realistically simulate the corona? How do we model the magnetic fields and plasma velocities in the quiet Sun? How sensitive are the solutions to other unknowns that must be specified, such as the global solar magnetic field, and the photospheric temperature and density?

  10. Field Demonstration of Condition Assessment Technologies for Wastewater Collection Systems

    EPA Science Inventory

    Reliable information on pipe condition is needed to accurately estimate the remaining service life of wastewater collection system assets. Although inspections with conventional closed-circuit television (CCTV) have been the mainstay of pipeline condition assessment for decades,...

  11. Meat Quality Characteristics of Small East African Goats and Norwegian Crosses Finished under Small Scale Farming Conditions

    PubMed Central

    Hozza, W. A.; Mtenga, L. A.; Kifaro, G. C.; Shija, D. S. N.; Mushi, D. E.; Safari, J. G.; Shirima, E. J. M.

    2014-01-01

    The aim of the experiment was to study the effect of feeding system on meat quality characteristics of Small East African (SEA) goats and their crosses with Norwegian (SEA×N) goats finished under small scale farming conditions. Twenty four castrated goats at the age of 18 months with live body weight of 16.7±0.54 kg from each breed (SEA and SEA×N) were distributed in a completely randomized design in a 2×3 factorial arrangement (two breed, and three dietary treatments). The dietary treatments were; no access to concentrate (T0), 66% access to ad libitum concentrate allowance (T66) and 100% access to ad libitum concentrate allowance with 20% refusal (T100) and the experimental period was for 84 days. In addition, all goats were allowed to graze for 2 hours daily and later fed grass hay on ad libitum basis. Daily feed intakes were recorded for all 84-days of experiment after which the animals were slaughtered. Feed intake of T100 animals was 536 g/d, which was 183 g/d higher than that of T66 group. Supplemented goats had significantly (p<0.05) better feed conversion efficiency. The SEA had higher (p<0.05) hot carcass weight (8.2 vs 7.9 kg), true dressing percentage (54.5 vs 53.3) and commercial dressing percentage (43.3 vs 41.6) compared to SEA×N. There was no significant difference (p>0.05) for dressing percentage and carcass conformation among supplemented goats except fatness score, total fat depots and carcass fat which increased (p<0.05) with increasing concentrate levels in the diet. Increasing level of concentrate on offer increased meat dry matter with subsequent increase of fat in the meat. Muscle pH of goats fed concentrate declined rapidly and reached below 6 at 6 h post-mortem but temperature remained at 28°C. Cooking loss and meat tenderness improved (p<0.05) and thawing loss increased (p<0.05) with ageing period. Similarly, meat tenderness improved (p<0.05) with concentrate supplementation. Shear force of muscles varied from 36 to 66, the high

  12. Meat Quality Characteristics of Small East African Goats and Norwegian Crosses Finished under Small Scale Farming Conditions.

    PubMed

    Hozza, W A; Mtenga, L A; Kifaro, G C; Shija, D S N; Mushi, D E; Safari, J G; Shirima, E J M

    2014-12-01

    The aim of the experiment was to study the effect of feeding system on meat quality characteristics of Small East African (SEA) goats and their crosses with Norwegian (SEA×N) goats finished under small scale farming conditions. Twenty four castrated goats at the age of 18 months with live body weight of 16.7±0.54 kg from each breed (SEA and SEA×N) were distributed in a completely randomized design in a 2×3 factorial arrangement (two breed, and three dietary treatments). The dietary treatments were; no access to concentrate (T0), 66% access to ad libitum concentrate allowance (T66) and 100% access to ad libitum concentrate allowance with 20% refusal (T100) and the experimental period was for 84 days. In addition, all goats were allowed to graze for 2 hours daily and later fed grass hay on ad libitum basis. Daily feed intakes were recorded for all 84-days of experiment after which the animals were slaughtered. Feed intake of T100 animals was 536 g/d, which was 183 g/d higher than that of T66 group. Supplemented goats had significantly (p<0.05) better feed conversion efficiency. The SEA had higher (p<0.05) hot carcass weight (8.2 vs 7.9 kg), true dressing percentage (54.5 vs 53.3) and commercial dressing percentage (43.3 vs 41.6) compared to SEA×N. There was no significant difference (p>0.05) for dressing percentage and carcass conformation among supplemented goats except fatness score, total fat depots and carcass fat which increased (p<0.05) with increasing concentrate levels in the diet. Increasing level of concentrate on offer increased meat dry matter with subsequent increase of fat in the meat. Muscle pH of goats fed concentrate declined rapidly and reached below 6 at 6 h post-mortem but temperature remained at 28°C. Cooking loss and meat tenderness improved (p<0.05) and thawing loss increased (p<0.05) with ageing period. Similarly, meat tenderness improved (p<0.05) with concentrate supplementation. Shear force of muscles varied from 36 to 66, the high

  13. Field conditions at the Maricopa Agricultural Center, Maricopa County, Arizona, June 13, 1988

    USGS Publications Warehouse

    Owen-Joyce, Sandra J.

    1988-01-01

    Field conditions were documented during the Landsat satellite overpass of the Maricopa Agricultural Center, Maricopa County, Arizona, on June 13, 1988. Crop types were mapped and photographed for each demonstration farm field. Field conditions described include irrigation, cultivation, and orientation of rows. Field and photographic descriptions are presented in tabular form. (USGS)

  14. Field Studies Show That In Situ Greenhouse Gas Emission Factors for East African Agriculture Are Less Than IPCC Values

    NASA Astrophysics Data System (ADS)

    Pelster, D.; Butterbach-Bahl, K.; Rufino, M.; Rosenstock, T. S.; Wanyama, G.

    2015-12-01

    Greenhouse gas (GHG) emissions from African agricultural systems are thought to comprise a large portion of total emissions from the continent, however these estimates have been calculated using emission factors (EF) from other regions due to the lack of field studies in Africa, which results in large uncertainties for these estimates. Field measurements from western Kenya calculating emissions over a year in 59 different sites found that GHG emissions from typical smallholder farms ranged from 2.8 to 15.0 Mg CO2-C ha-1, -6.0 to 2.4 kg CH4-C ha-1 and -0.1 to 1.8 kg N2O-N ha-1, and were not affected by management intensity. The lack of a response in N2O emissions to N fertilization suggests that the EF currently used in national inventories overestimates N2O emissions from typical smallholder agriculture. Another study measuring N2O and CH4 emissions from manure deposited by grazing cattle found that the N2O EF ranged from 0.1 to 0.2%, while the CH4 EF ranged from 0.04 to 0.14 Kg CH4-C per 173 kg animal. These suggest that the current IPCC EF overestimate agricultural soil and manure GHG emissions for Kenya, and likely for much of East Africa.

  15. Detection of African Swine Fever Antibodies in Experimental and Field Samples from the Russian Federation: Implications for Control.

    PubMed

    Mur, L; Igolkin, A; Varentsova, A; Pershin, A; Remyga, S; Shevchenko, I; Zhukov, I; Sánchez-Vizcaíno, J M

    2016-10-01

    African swine fever (ASF) re-entered in Europe in 2007 by Georgia rapidly affecting neighbouring countries. Since then, ASF has caused severe problems to the Russian Federation (RF) and spread to Northern and Western regions, including Ukraine (2012 and 2014) and Belarus (2013). At the beginning of 2014, dead wild boars were found in Lithuania and Poland. Several outbreaks have been later notified in the European Union(EU), affecting domestic pigs and wild boar of Latvia, Lithuania and Poland, and also wild boar in Estonia, causing major problems for the EU pig sector. Some studies have been performed with this ASFV isolate, revealing that it belongs to genotype II and causes an acute form of the disease. However, few data are available about the presence of antibodies in field and experimental samples from the affected area. This study analysed samples from experimental infections with ASFV isolated from the RF in 2013 (74 sera and 3 tissue exudates), and field samples from the RF from 2013 to 2014 (266 samples, including 32 and 7 tissue exudates from domestic pigs and wild boar, respectively). All samples were tested by a commercial ELISA and, some of them (79), also by immunochromatographic tests. Positive and doubtful samples were confirmed by immunoblotting test. Positive results were found in experimental and field samples, which confirm the presence of antibodies against ASFV in the RF. Antibodies were detected in animals inoculated with three different ASFV isolates, with some differences found among them. Only a small percentage of field samples was positive for ASF antibodies (3.7%), in agreement with other observations that reported a high virulence for the ASFV isolates in the area. These results confirm the potential presence of survivor animals that should be considered in affected areas to help design effective control and eradication plans against ASF.

  16. [African silhouettes and field photography. M. Griaule's contribution to the Maussian "discovery" of body techniques].

    PubMed

    Despoix, Philippe

    2010-01-01

    This essay focuses on the interaction between the new reproduction media and corresponding reconfiguration of research fields in anthropology using the case of the "techniques of the body" - a concept developed by Marcel Mauss (1872-1950). For Mauss, the initiator of this discipline in France, body skills constituted the most important anthropological entity resulting from the confrontation of technical images and his interest in walking techniques. Three scenarios are especially significant for Mauss's formulation of "body techniques" as a genuine concept: the front during the World War I, a New Yorke hospital in 1926, and an ethnographical field study conducted in Africa during the ate 1920s. Both, the photographic media as well as the Abyssinian expedition of his student Marcel Griaule, whose research publication Mauss co-authored (Silhouettes et graffiti abyssins) n 1933, take centre stage here.

  17. Geology of oil fields and future exploration potential in west African Aptian Salt basin

    SciTech Connect

    Bignell, R.D.; Edwards, A.D.

    1987-05-01

    The Aptian Salt basin of west Africa, extends from Equatorial Guinea southward to Angola, contains recoverable reserves estimated at nearly 4 billion BOE, and is current producing 600,000 BOPD. The basin developed as a result of tensional forces between west Africa and South America initiated at the end of the Jurassic. The prospective sedimentary sequences ranged in age from Early Cretaceous (uppermost Jurassic in places) to Holocene and is divided by the Aptian transgressive sand and salt into a pre-salt, nonmarine, syn-rift sequence and a post-salt, marine, post-rift sequence. Both the pre- and post-salt sequences contain several successful exploration plays, the most prolific of which are the Early Cretaceous nonmarine sandstone fields in tilted fault blocks of Gabon and Cabinda; Early Cretaceous carbonate buildups on the margins of basement highs in Cabinda; Early Cretaceous transgressive marine sandstone fields in anticlines draped over basement highs in Gabon; Late Cretaceous shallow marine sandstone and carbonate fields in salt-related structures in the Congo, Zaire, Cabinda, and Angola; Late Cretaceous dolomites in structural/stratigraphic traps in Angola; Late Cretaceous/early Tertiary deltaic/estuarine sandstone traps formed by salt movement in Gabon, Cabinda, and angola; and Tertiary marine turbidite fields in Cabinda and Angola. Despite the exploration success in these trends, much of the basin is under or poorly explored. The major problems for exploration are the poor quality of seismic definition beneath the salt, which makes it difficult to predict pre-salt structure and stratigraphy, and the importance of a stratigraphic element in many of the post-salt traps, also difficult to detect on seismic.

  18. Sprint running performance: comparison between treadmill and field conditions.

    PubMed

    Morin, Jean-Benoît; Sève, Pierrick

    2011-08-01

    We investigated the differences in performance between 100-m sprints performed on a sprint treadmill recently validated versus on a standard track. To date, studies comparing overground and treadmill running have mainly focused on constant and not maximal "free" running speed, and compared running kinetics and kinematics over a limited number of steps, but not overall sprint performance. Eleven male physical education students including two sprinters performed one 100-m on the treadmill and one on a standard athletics track in a randomized order, separated by 30 min. Performance data were derived in both cases from speed-time relationships measured with a radar and with the instrumented sprint treadmill, which allowed subjects to run and produce speed "freely", i.e. with no predetermined belt speed imposed. Field and treadmill typical speed-distance curves and data of maximal and mean speed, 100-m time and acceleration/deceleration time constants were compared using t tests and field-treadmill correlations were tested. All the performance parameters but time to reach top speed and deceleration time constant differed significantly, by about 20% on average, between field and treadmill (e.g. top speed of 8.84 ± 0.51 vs. 6.90 ± 0.39 m s(-1)). However, significant correlations were found (r > 0.63; P < 0.05) for all the performance parameters except time to reach top speed. Treadmill and field 100-m sprint performances are different, despite the fact that subjects could freely accelerate the belt. However, the significant correlations found make it possible to investigate and interpret inter-individual differences in field performance from treadmill measurements.

  19. Lethal effects of experimental warming approximating a future climate scenario on southern African quartz-field succulents: a pilot study.

    PubMed

    Musil, Charles F; Schmiedel, Ute; Midgley, Guy F

    2005-02-01

    Here we examine the response of succulents in a global biodiversity hot spot to experimental warming consistent with a future African climate scenario. Passive daytime warming (averaging 5.5 degrees C above ambient) of the natural vegetation was achieved with 18 transparent hexagonal open-top chamber arrays randomized in three different quartz-field communities. After 4-months summer treatment, the specialized-dwarf and shrubby succulents displayed between 2.1 and 4.9 times greater plant and canopy mortalities in the open-top chambers than in the control plots. Those surviving in cooler ventilated areas and shaded refuges in the chambers had lower starch concentrations and water contents; the shrubby succulents also exhibited diminished chlorophyll concentrations. It is concluded that current thermal regimes are likely to be closely proximate to tolerable extremes for many endemic succulents in the region, and that anthropogenic warming could significantly exceed their thermal thresholds. Further investigation is required to elucidate the importance of associated moisture deficits in these warming experiments, a potential consequence of supplementary (fog and dew) precipitation interception by open-top chambers and higher evaporation therein, on plant mortalities.

  20. Response of grapevines to fluoride under field conditions

    SciTech Connect

    Murray, F.

    1983-07-01

    Grapevines (Vitis vinifera L. cv. Shiraz) were fumigated in open-top chambers with hydrogen fluoride for 64 days at mean atmospheric fluoride concentrations of 0.17 or 0.28 ..mu..gHFm/sup -3/. Other grapevines grown under ambient conditions in the vineyard or maintained in control chambers were exposed to 0.13 or 0.05 ..mu..gHFm/sup -3/, respectively. Leaves of grapevines exposed to 0.28, 0.17, 0.13, or 0.05 ..mu..gHFm/sup -3/ accumulated up to 85, 55, 20, or 11 ..mu..gFg/sup -1/, respectively. Foliar necrosis was observed on plants exposed to 0.28 ..mu..gHFm/sup -3/, but no injury symptoms were observed at 0.17 ..mu..gHFm/sup -3/ or in control plants. Grapevines growing under ambient conditions had significantly greater mean bunch weight, peduncle weight, number of grapes per bunch, and leaf protein levels than the fumigated treatments. However, these differences may be associated with a chamber effect rather than with an effect of fluoride on grapevines. No significant differences were found between treatments for grape potential alcohol content, fruit acids, number of bunches or grapes per vine, fresh weight of grapes, or leaf chlorophyll content, despite foliar fluoride concentrations in the highest fluoride fumigation level reaching 85 ..mu..gFg/sup -1/. No evidence was found of significant fluoride accumulation in berries or canes. 26 references, 4 tables.

  1. Nitrogen release from rock and soil under simulated field conditions

    USGS Publications Warehouse

    Holloway, J.M.; Dahlgren, R.A.; Casey, W.H.

    2001-01-01

    A laboratory study was performed to simulate field weathering and nitrogen release from bedrock in a setting where geologic nitrogen has been suspected to be a large local source of nitrate. Two rock types containing nitrogen, slate (1370 mg N kg-1) and greenstone (480 mg N kg-1), were used along with saprolite and BC horizon sand from soils derived from these rock types. The fresh rock and weathered material were used in batch reactors that were leached every 30 days over 6 months to simulate a single wet season. Nitrogen was released from rock and soil materials at rates between 10-20 and 10-19 mo1 N cm-2 s-1. Results from the laboratory dissolution experiments were compared to in situ soil solutions and available mineral nitrogen pools from the BC horizon of both soils. Concentrations of mineral nitrogen (NO3- + NH4+) in soil solutions reached the highest levels at the beginning of the rainy season and progressively decreased with increased leaching. This seasonal pattern was repeated for the available mineral nitrogen pool that was extracted using a KCl solution. Estimates based on these laboratory release rates bracket stream water NO3-N fluxes and changes in the available mineral nitrogen pool over the active leaching period. These results confirm that geologic nitrogen, when present, may be a large and reactive pool that may contribute as a non-point source of nitrate contamination to surface and ground waters. ?? 2001 Elsevier Science B.V. All rights reserved.

  2. Influence of Transportation Conditions and Postharvest Disinfection Treatments on Microbiological Quality of Fresh Market Tomatoes (cv. Nemo-Netta) in a South African Supply Chain.

    PubMed

    Sibomana, M S; Ziena, L W; Schmidt, S; Workneh, T S

    2017-02-01

    Postharvest microbial spoilage due to suboptimal transportation and packaging conditions is a key concern for the South African tomato industry. This study investigated the influence of washing with tap water or aqueous disinfectant solutions (chlorinated and anolyte water) on the microbiological quality of tomatoes during storage after transportation in nonrefrigerated trucks along two supply routes when packaged in crates and boxes. Route 1 was 1,093 km from field to storage site, while route 2 was 1,057 km. During transport, the temperature in the trucks fluctuated between 16 and 28°C and the relative humidity between 25 and 94% for route 1, while for route 2, the temperature was between 16 and 30°C and the relative humidity between 28 and 71%. Tomatoes at the pink maturity stage were sampled, treated, and stored for 28 days (11°C). The tomato firmness before treatment was 24.8 N (box samples) and 17.4 N (crate samples) for route 1, whereas it was 22.1 N (box samples) and 20.2 N (crate samples) for route 2. Temperature fluctuation during transportation led to water condensation on tomato surfaces. Tomatoes treated with anolyte water showed the lowest microbial surface burden during storage, with mean aerobic plate counts (APC) of 2.9 log CFU/cm(2), coliform counts (CC) of 1.1 log CFU/cm(2), and fungal counts (FC) of 2.3 log CFU/cm(2). Overall, of the total APC recorded during storage, anolyte-treated samples contributed 9% while chlorinated water-treated samples contributed 30%. Of the total CC, anolyte samples presented 3% while chlorinated water samples made up 12%, and of the total recorded FC, anolyte samples contributed 7% while chlorinated water samples made up 22%. Scanning electron microscopy imaging showed surface cracks, which enable microbial colonization in crate-transported tomatoes. A combination of anolyte treatment and box packaging during transport resulted in the best microbiological quality during storage. The findings of this investigation

  3. High opportunity for postcopulatory sexual selection under field conditions.

    PubMed

    Turnell, Biz R; Shaw, Kerry L

    2015-08-01

    In polygamous systems, male fitness is determined not only by mating success but also by fertilization success. Despite the growing interest over the past several decades in postcopulatory sexual selection, its relative importance compared to precopulatory sexual selection remains a subject of debate. Here, we use extensive behavioral observations of a seminatural population of Hawaiian swordtail crickets, Laupala cerasina, and molecular paternity assignment to measure the opportunities for pre- and postcopulatory selection. Because postcopulatory selection has the potential to operate at multiple stages, we also separately attribute its effects to factors specific to mating events versus factors specific to males. We find that variance in postcopulatory success is over four times as great as variance in precopulatory success, with most of it unexplained by male mating order or the number of nuptial gifts given. Surprisingly, we also find that male singing effort is under postcopulatory selection, suggesting that males who sing more frequently also have more competitive ejaculates. Our results are consistent with the hypothesis that high polyandry levels promote greater relative postcopulatory selection. They also highlight the need for detailed behavioral observations under conditions as natural as possible when measuring mating and reproductive success.

  4. Field Demonstration of Electro-Scan Defect Location Technology for Condition Assessment of Wastewater Collection Systems

    EPA Science Inventory

    The purpose of the field demonstration program is to gather technically reliable cost and performance information on selected condition assessment technologies under defined field conditions. The selected technologies include zoom camera, electro-scan (FELL-41), and a multi-sens...

  5. Quantifying the morphometric variability of monogenetic cones in volcanic fields: the Virunga Volcanic Province, East African Rift

    NASA Astrophysics Data System (ADS)

    Poppe, Sam; Grosse, Pablo; Barette, Florian; Smets, Benoît; Albino, Fabien; Kervyn, François; Kervyn, Matthieu

    2016-04-01

    Volcanic cone fields are generally made up of tens to hundreds of monogenetic cones, sometimes related to larger polygenetic edifices, which can exhibit a wide range of morphologies and degrees of preservation. The Virunga Volcanic Province (VVP) developed itself in a transfer zone which separates two rift segments (i.e. Edward and Kivu rift) within the western branch of the East-African Rift. As the result of volcanic activity related to this tectonic regime of continental extension, the VVP hosts eight large polygenetic volcanoes, surrounded by over 500 monogenetic cones and eruptive fissures, scattered over the vast VVP lava flow fields. Some cones lack any obvious geo-structural link to a specific Virunga volcano. Using recent high-resolution satellite images (SPOT, Pléiades) and a newly created 5-m-resolution digital elevation model (TanDEM-X), we have mapped and classified all monogenetic cones and eruptive fissures of the VVP. We analysed the orientation of all mapped eruptive fissures and, using the MORVOLC program, we calculated a set of morphometric parameters to highlight systematic spatial variations in size or morphometric ratios of the cones. Based upon morphological indicators, we classified the satellite cones into 4 categories: 1. Simple cones with one closed-rim crater; 2. Breached cones with one open-rim crater; 3. Complex cones with two or more interconnected craters and overlapping cones; 4. Other edifices without a distinguishable crater or cone shape (e.g. spatter mounds and levees along eruptive fissures). The results show that cones are distributed in clusters and along alignments, in some cases parallel with the regional tectonic orientations. Contrasts in the volumes of cones positioned on the rift shoulders compared to those located on the rift valley floor can possibly be attributed to contrasts in continental crust thickness. Furthermore, higher average cone slopes in the East-VVP (Bufumbira zone) and central-VVP cone clusters suggest

  6. Field conditions at the Maricopa Agricultural Center, Pinal County, Arizona, June 16, 1989

    USGS Publications Warehouse

    Owen-Joyce, Sandra J.

    1989-01-01

    Field conditions were documented during the SPOT satellite overpass of the Maricopa Agricultural Center, Pinal County, Arizona, on June 16, 1989. Crop types were mapped and photographed for each demonstration farm field, and irrigation, cultivation, and orientation of rows are described. Field and photographic descriptions are presented in tabular and graphic form. (USGS)

  7. Field conditions at the Maricopa Agricultural Center, Pinal County, Arizona, September 28, 1989

    USGS Publications Warehouse

    Owen-Joyce, Sandra J.

    1989-01-01

    Field conditions were documented during the Landsat and SPOT satellite overpasses of the Maricopa Agricultural Center, Pinal County, Arizona, on September 28, 1989. Crop types were mapped and photographed for each demonstration farm field, and irrigation, cultivation, and orientation of rows are described. Field and photographic descriptions are presented in tabular and graphic form. (USGS)

  8. Field conditions at the Maricopa Agricultural Center, Pinal County, Arizona, April 9, 1989

    USGS Publications Warehouse

    Owen-Joyce, Sandra J.

    1989-01-01

    Field conditions were documented during the SPOT satellite overpass of the Maricopa Agricultural Center, Pinal County, Arizona, on April 9, 1989. Crop types were mapped and photographed for each demonstration farm field, and irrigation, cultivation, and orientation of rows are described. Field and photographic descriptions are presented in tabular and graphic form. (USGS)

  9. Measuring health-related problem solving among African Americans with multiple chronic conditions: application of Rasch analysis.

    PubMed

    Fitzpatrick, Stephanie L; Hill-Briggs, Felicia

    2015-10-01

    Identification of patients with poor chronic disease self-management skills can facilitate treatment planning, determine effectiveness of interventions, and reduce disease complications. This paper describes the use of a Rasch model, the Rating Scale Model, to examine psychometric properties of the 50-item Health Problem-Solving Scale (HPSS) among 320 African American patients with high risk for cardiovascular disease. Items on the positive/effective HPSS subscales targeted patients at low, moderate, and high levels of positive/effective problem solving, whereas items on the negative/ineffective problem solving subscales mostly targeted those at moderate or high levels of ineffective problem solving. Validity was examined by correlating factor scores on the measure with clinical and behavioral measures. Items on the HPSS show promise in the ability to assess health-related problem solving among high risk patients. However, further revisions of the scale are needed to increase its usability and validity with large, diverse patient populations in the future.

  10. Geometric Representations of Condition Queries on Three-Dimensional Vector Fields

    NASA Technical Reports Server (NTRS)

    Henze, Chris

    1999-01-01

    Condition queries on distributed data ask where particular conditions are satisfied. It is possible to represent condition queries as geometric objects by plotting field data in various spaces derived from the data, and by selecting loci within these derived spaces which signify the desired conditions. Rather simple geometric partitions of derived spaces can represent complex condition queries because much complexity can be encapsulated in the derived space mapping itself A geometric view of condition queries provides a useful conceptual unification, allowing one to intuitively understand many existing vector field feature detection algorithms -- and to design new ones -- as variations on a common theme. A geometric representation of condition queries also provides a simple and coherent basis for computer implementation, reducing a wide variety of existing and potential vector field feature detection techniques to a few simple geometric operations.

  11. Olfactory Fear Conditioning Induces Field Potential Potentiation in Rat Olfactory Cortex and Amygdala

    ERIC Educational Resources Information Center

    Messaoudi, Belkacem; Granjon, Lionel; Mouly, Anne-Marie; Sevelinges, Yannick; Gervais, Remi

    2004-01-01

    The widely used Pavlovian fear-conditioning paradigms used for studying the neurobiology of learning and memory have mainly used auditory cues as conditioned stimuli (CS). The present work assessed the neural network involved in olfactory fear conditioning, using olfactory bulb stimulation-induced field potential signal (EFP) as a marker of…

  12. Energy conditions for the four dimensional cosmological model with nonminimal derivative coupling of scalar field

    NASA Astrophysics Data System (ADS)

    Suroso, Agus; Zen, Freddy P.; Hikmawan, Getbogi

    2015-09-01

    The energy conditions is a set of linear equations of energy density ρ and pressure p which ensure the the field(s) that we used in our model is physically "reasonable". We study the energy conditions for four dimensional nonminimal derivative coupling of scalar field and curvature tensor. Considering the scalar field as a perfect fluid, we find some constraint for the coupling constant ξ in order the energy conditions is satisfied or violated. We find that strong energy conditions (SEC) is violated if -1/9H2 ≤ ξ < 1/18H2. For de Sitter solution a ∝ eH0t for some constant H0, we find that while null, weak, and dominant energy conditions violated when ξ <-[12 H02(2 +9 H02) ] -1 . The accelerating universe is exist for the power law solution (a ∝ tp for constant p) if ξ < 0.

  13. Optimism and Education Buffer the Effects of Syndemic Conditions on HIV Status among African American Men who Have Sex with Men

    PubMed Central

    O’Leary, Ann; Jemmott, John B.; Stevens, Robin; Rutledge, Scott Edward; Icard, Larry D.

    2014-01-01

    The present study sought to replicate effects of the number of syndemic psychosocial health conditions on sexual risk behavior and HIV infection among a sample of high-risk African American men who have sex with men (MSM) and to identify resilience factors that may buffer these effects. We used baseline data from an HIV risk-reduction trial to examine whether a higher number of syndemic conditions was associated with higher rates of self-reported sexual risk behavior and HIV infection. Using logistic regression models, we tested for interactions between number of syndemic conditions and several potential resilience factors to identify buffering effects. Replicating previous studies, we found significant associations between numbers of syndemic conditions and higher rates of sexual risk behavior and HIV infection. Surprisingly, we also replicated a previous finding (Stall et al., 2003) that the effects of syndemic burden on HIV status fell off at the highest levels of syndemic conditions. Among a variety of potential resilience factors, two--optimism and education--buffered the syndemic effect on HIV prevalence. This is, to our knowledge, the first paper to identify resilience factors buffering against syndemic effects among MSM. It also constitutes a significant contribution to the literature regarding prevention among black MSM. These results point to the need to identify HIV-positive black MSM and provide effective treatment for them and to develop interventions addressing both syndemic and resilience factors. PMID:24705710

  14. Optimism and education buffer the effects of syndemic conditions on HIV status among African American men who have sex with men.

    PubMed

    O'Leary, Ann; Jemmott, John B; Stevens, Robin; Rutledge, Scott Edward; Icard, Larry D

    2014-11-01

    The present study sought to replicate effects of the number of syndemic psychosocial health conditions on sexual risk behavior and HIV infection among a sample of high-risk African American men who have sex with men (MSM) and to identify resilience factors that may buffer these effects. We used baseline data from an HIV risk-reduction trial to examine whether a higher number of syndemic conditions was associated with higher rates of self-reported sexual risk behavior and HIV infection. Using logistic regression models, we tested for interactions between number of syndemic conditions and several potential resilience factors to identify buffering effects. Replicating previous studies, we found significant associations between numbers of syndemic conditions and higher rates of sexual risk behavior and HIV infection. Surprisingly, we also replicated a previous finding (Stall et al., Am J Public Health, 93(6):939-942, 2003) that the effects of syndemic burden on HIV status fell off at the highest levels of syndemic conditions. Among a variety of potential resilience factors, two-optimism and education-buffered the syndemic effect on HIV prevalence. This is, to our knowledge, the first paper to identify resilience factors buffering against syndemic effects among MSM. It also constitutes a significant contribution to the literature regarding prevention among black MSM. These results point to the need to identify HIV-positive black MSM and provide effective treatment for them and to develop interventions addressing both syndemic and resilience factors.

  15. Trickle-down boundary conditions in aeolian dune-field pattern formation

    NASA Astrophysics Data System (ADS)

    Ewing, R. C.; Kocurek, G.

    2015-12-01

    One the one hand, wind-blown dune-field patterns emerge within the overarching boundary conditions of climate, tectonics and eustasy implying the presence of these signals in the aeolian geomorphic and stratigraphic record. On the other hand, dune-field patterns are a poster-child of self-organization, in which autogenic processes give rise to patterned landscapes despite remarkable differences in the geologic setting (i.e., Earth, Mars and Titan). How important are climate, tectonics and eustasy in aeolian dune field pattern formation? Here we develop the hypothesis that, in terms of pattern development, dune fields evolve largely independent of the direct influence of 'system-scale' boundary conditions, such as climate, tectonics and eustasy. Rather, these boundary conditions set the stage for smaller-scale, faster-evolving 'event-scale' boundary conditions. This 'trickle-down' effect, in which system-scale boundary conditions indirectly influence the event scale boundary conditions provides the uniqueness and richness of dune-field patterned landscapes. The trickle-down effect means that the architecture of the stratigraphic record of dune-field pattern formation archives boundary conditions, which are spatially and temporally removed from the overarching geologic setting. In contrast, the presence of an aeolian stratigraphic record itself, reflects changes in system-scale boundary conditions that drive accumulation and preservation of aeolian strata.

  16. Coupling Linearized Far-Field Boundary Conditions with Nonlinear Near-Field Solutions in Transonic Flow

    DTIC Science & Technology

    1988-02-29

    Plate and a NACA 64A010 Airfoil Section . 31 3. Spatial Variations of Velocity Potentials on a Flat Plate and MBB-A3 Airfoil Section ........ 32 4...39 14. Steady Flow Field Mach Number Variation for a NACA 64A010 Airfoil at a 10 Angle of Attack w ith M = 0.80...44 22. Steady Flow Field Mach Number Variation for a NACA 64A010 Airfoil at a 10 Angle of Attack 23. W ith M = 0.78

  17. Algorithms for contours depicting static electric fields during adverse weather conditions

    NASA Technical Reports Server (NTRS)

    Rompala, John T.

    1991-01-01

    A flexible and functional analytical tool is developed for the study of electric fields during adverse weather conditions. This tool is designed for use by members of the Atmospheric Science Group as part of their overall effort to appraise environmental conditions during these situations. It is also used to illustrate approaches open to those interested in the study of the physics of ambient electric field phenomena. Computer resources of KSC are coordinated with original software to produce contour interpretations of electric field data available from a grid of field mills spanning the region. Three model algorithms are presented and examples are given illustrating the system design, flexibility, and utility.

  18. Measuring conditions and trends in ecosystem services at multiple scales: the Southern African Millennium Ecosystem Assessment (SAfMA) experience

    PubMed Central

    van Jaarsveld, A.S; Biggs, R; Scholes, R.J; Bohensky, E; Reyers, B; Lynam, T; Musvoto, C; Fabricius, C

    2005-01-01

    The Southern African Millennium Ecosystem Assessment (SAfMA) evaluated the relationships between ecosystem services and human well-being at multiple scales, ranging from local through to sub-continental. Trends in ecosystem services (fresh water, food, fuel-wood, cultural and biodiversity) over the period 1990–2000 were mixed across scales. Freshwater resources appear strained across the continent with large numbers of people not securing adequate supplies, especially of good quality water. This translates to high infant mortality patterns across the region. In some areas, the use of water resources for irrigated agriculture and urban–industrial expansion is taking place at considerable cost to the quality and quantity of freshwater available to ecosystems and for domestic use. Staple cereal production across the region has increased but was outstripped by population growth while protein malnutrition is on the rise. The much-anticipated wood-fuel crisis on the subcontinent has not materialized but some areas are experiencing shortages while numerous others remain vulnerable. Cultural benefits of biodiversity are considerable, though hard to quantify or track over time. Biodiversity resources remain at reasonable levels, but are declining faster than reflected in species extinction rates and appear highly sensitive to land-use decisions. The SAfMA sub-global assessment provided an opportunity to experiment with innovative ways to assess ecosystem services including the use of supply–demand surfaces, service sources and sink areas, priority areas for service provision, service ‘hotspots’ and trade-off assessments. PMID:15814355

  19. Proceedings of the African Field Epidemiology Network (AFENET) Scientific Conference 17-22 November 2013 Addis Ababa, Ethiopia: plenaries and oral presentations

    PubMed Central

    Gitta, Sheba Nakacubo; Mwesiga, Allan; Kamadjeu, Raoul

    2015-01-01

    Biennially, trainees and graduates of Field Epidemiology and Laboratory Training Programs (FELTPs) are presented with a platform to share investigations and projects undertaken during their two-year training in Applied Epidemiology. The African Field Epidemiology Network (AFENET) Scientific Conference, is a perfect opportunity for public health professionals from various sectors and organizations to come together to discuss issues that impact on public health in Africa. This year's conference was organized by the Ethiopian Health and Nutrition Research Institute in collaboration with the Ethiopia Ministry of Health, Ethiopian Public Health Association (EPHA), Ethiopia Field Epidemiology Training Program (EFETP), Addis Ababa University (AAU), Training Programs in Epidemiology and Public Health Interventions Network (TEPHINET) and AFENET. Participants at this year's conference numbered 400 from over 20 countries including; Angola, Burkina Faso, Cameroon, Central African Republic, Democratic Republic of the Congo, Ethiopia, Ghana, Indonesia, Kenya, Mozambique, Namibia, Nigeria, Rwanda, South Africa, Sudan, Tanzania, Uganda, Yemen and Zimbabwe. The topics covered in the 144 oral presentations included: global health security, emergency response, public health informatics, vaccine preventable diseases, immunization, outbreak investigation, Millennium Development Goals, Non-Communicable Diseases, and public health surveillance. The theme for the 5th AFENET Scientific Conference was; “Addressing Public Health Priorities in Africa through FELTPs.” Previous AFENET Scientific conferences have been held in: Accra, Ghana (2005), Kampala, Uganda (2007), Mombasa, Kenya (2009) and Dar es Salaam, Tanzania (2011). PMID:26491534

  20. Regulation of osteogenic differentiation of human adipose-derived stem cells by controlling electromagnetic field conditions

    PubMed Central

    Kang, Kyung Shin; Hong, Jung Min; Kang, Jo A; Rhie, Jong-Won; Jeong, Young Hun; Cho, Dong-Woo

    2013-01-01

    Many studies have reported that an electromagnetic field can promote osteogenic differentiation of mesenchymal stem cells. However, experimental results have differed depending on the experimental and environmental conditions. Optimization of electromagnetic field conditions in a single, identified system can compensate for these differences. Here we demonstrated that specific electromagnetic field conditions (that is, frequency and magnetic flux density) significantly regulate osteogenic differentiation of adipose-derived stem cells (ASCs) in vitro. Before inducing osteogenic differentiation, we determined ASC stemness and confirmed that the electromagnetic field was uniform at the solenoid coil center. Then, we selected positive (30/45 Hz, 1 mT) and negative (7.5 Hz, 1 mT) osteogenic differentiation conditions by quantifying alkaline phosphate (ALP) mRNA expression. Osteogenic marker (for example, runt-related transcription factor 2) expression was higher in the 30/45 Hz condition and lower in the 7.5 Hz condition as compared with the nonstimulated group. Both positive and negative regulation of ALP activity and mineralized nodule formation supported these responses. Our data indicate that the effects of the electromagnetic fields on osteogenic differentiation differ depending on the electromagnetic field conditions. This study provides a framework for future work on controlling stem cell differentiation. PMID:23306704

  1. On the Ideal Boundary Condition in a General Toroidal Geometry for a Mixed Magnetic Field Representation

    SciTech Connect

    X. Z. Tang

    2000-12-18

    Subtleties of implementing the standard perfectly conducting wall boundary condition in a general toroidal geometry are clarified for a mixed scalar magnetic field representation. An iterative scheme based on Ohm's law is given.

  2. Reference dosimetry in the presence of magnetic fields: conditions to validate Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Bouchard, Hugo; de Pooter, Jacco; Bielajew, Alex; Duane, Simon

    2015-09-01

    With the advent of MRI-guided radiotherapy, reference dosimetry must be thoroughly addressed to account for the effects of the magnetic field on absorbed dose to water and on detector dose response. While Monte Carlo plays an essential role in reference dosimetry, it is also crucial for determining quality correction factors in these new conditions. The Fano cavity test is recognized as fundamental to validate Monte Carlo transport algorithms. In the presence of magnetic fields, it is necessary to define special conditions under which such a test can be performed. The present theoretical study proposes two conditions in which the validity of Fano’s theorem is demonstrated in the presence of a magnetic field and the analytic expression of energy deposition is verified. It is concluded that the proposed conditions form a valid basis for two types of Fano cavity tests in the presence of a magnetic field.

  3. Finite temperature Casimir effect for a massless fractional Klein-Gordon field with fractional Neumann conditions

    SciTech Connect

    Eab, C. H.; Lim, S. C.; Teo, L. P.

    2007-08-15

    This paper studies the Casimir effect due to fractional massless Klein-Gordon field confined to parallel plates. A new kind of boundary condition called fractional Neumann condition which involves vanishing fractional derivatives of the field is introduced. The fractional Neumann condition allows the interpolation of Dirichlet and Neumann conditions imposed on the two plates. There exists a transition value in the difference between the orders of the fractional Neumann conditions for which the Casimir force changes from attractive to repulsive. Low and high temperature limits of Casimir energy and pressure are obtained. For sufficiently high temperature, these quantities are dominated by terms independent of the boundary conditions. Finally, validity of the temperature inversion symmetry for various boundary conditions is discussed.

  4. A Portable Kit for Rapid Diagnosis of Infectious Diseases under Field Conditions

    DTIC Science & Technology

    1980-08-14

    A PORTABLE KIT FOR RAPID~ DIAGNOSIS OF INFECTIOUS DISEASES UNDER FIELD CONDITIONS W. R. SANBORN REPORT NO. 80-22 ELECT o JUL 198 ~SA NAV) AL HEALTH ...DIAGNOSIS of INFECTIOUS DISEASES under FIELD CONDITIONS I / Warren R. Sanborn Head, Microbiology Branch Biological Sciences Division Naval Health ...formation. Blood and stool examinations for parasites require a microscope, I as do examinations for certain superficial mycoses . The McArthur microscope

  5. Co-transmission of the non-transmissible South African Babesia bovis S24 vaccine strain during mixed infection with a field isolate.

    PubMed

    Combrink, M P; Troskie, P C; de Klerk, D G; Pienaar, R; Latif, A A; Mans, B J

    2015-03-01

    The South African Babesia bovis live blood vaccine, originating from a field isolate attenuated by 23 serial syringe passages in splenectomized calves, has lost the ability to infect the natural vector Rhipicephalus (Boophilus) microplus. In this study, infection with mixed parasites from the vaccine strain and a field isolate, resulted in transmission of both genotype populations. Comparing the field isolate and transmitted combination indicated no significant difference in their virulence, while challenge of vaccinated cattle with these isolates showed the ability of the vaccine to protect against both. Limiting dilution of the transmitted combination, followed by infection of splenectomized cattle (n=34) yielded no single infections for the vaccine strain genotype, seven clonal lines of the field isolate and one mixture of vaccine strain and field isolate. Only one of two field isolate clonal lines selected for vector transmission study was transmitted. Showing that B. bovis isolates can contain both tick transmissible and non-transmissible subpopulations. The findings of this study also indicate the probability of vaccine co-infection transmission occurring in the field, which may result in new genotype populations of B. bovis. However, the impact of this recombination with field isolates is considered negligible since a genotypically diverse population of B. bovis is already present in South Africa.

  6. African Swine Fever Diagnosis Adapted to Tropical Conditions by the Use of Dried-blood Filter Papers.

    PubMed

    Randriamparany, T; Kouakou, K V; Michaud, V; Fernández-Pinero, J; Gallardo, C; Le Potier, M-F; Rabenarivahiny, R; Couacy-Hymann, E; Raherimandimby, M; Albina, E

    2016-08-01

    The performance of Whatman 3-MM filter papers for the collection, drying, shipment and long-term storage of blood at ambient temperature, and for the detection of African swine fever virus and antibodies was assessed. Conventional and real-time PCR, viral isolation and antibody detection by ELISA were performed on paired samples (blood/tissue versus dried-blood 3-MM filter papers) collected from experimentally infected pigs and from farm pigs in Madagascar and Côte d'Ivoire. 3-MM filter papers were used directly in the conventional and real-time PCR without previous extraction of nucleic acids. Tests that performed better with 3-MM filter papers were in descending order: virus isolation, real-time UPL PCR and conventional PCR. The analytical sensitivity of real-time UPL PCR on filter papers was similar to conventional testing (virus isolation or conventional PCR) on organs or blood. In addition, blood-dried filter papers were tested in ELISA for antibody detection and the observed sensitivity was very close to conventional detection on serum samples and gave comparable results. Filter papers were stored up to 9 months at 20-25°C and for 2 months at 37°C without significant loss of sensitivity for virus genome detection. All tests on 3-MM filter papers had 100% specificity compared to the gold standards. Whatman 3-MM filter papers have the advantage of being cheap and of preserving virus viability for future virus isolation and characterization. In this study, Whatman 3-MM filter papers proved to be a suitable support for the collection, storage and use of blood in remote areas of tropical countries without the need for a cold chain and thus provide new possibilities for antibody testing and virus isolation.

  7. Stationary axisymmetric SU(2) Einstein-Yang-Mills fields with restricted circularity conditions are Abelian

    NASA Astrophysics Data System (ADS)

    Chinea, F. J.; Navarro-Lérida, F.

    2002-03-01

    In this paper we prove that in a stationary axisymmetric SU(2) Einstein-Yang-Mills theory the most reasonable circularity conditions that can be considered for the Yang-Mills fields imply in fact that the field is of embedded Abelian type, or else that the metric is not asymptotically flat.

  8. Influence of harvester and weather conditions on field loss and milling quality of rough rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A better understanding of factors affecting field losses and milling quality during harvest is needed to improve the economic value of rice. The main objective of this study was to evaluate the impact of harvester header, harvester type, and weather conditions on field loss and milling quality of ro...

  9. Conditions for the appearance of a stable microcrack in the elastic field of a screened disclination

    NASA Astrophysics Data System (ADS)

    Sarafanov, G. F.; Perevezentsev, V. N.

    2016-10-01

    The conditions of possible microcrack nucleation and stability in the elastic field of disclinations screened by a free surface, disclinations of the opposite sense, or a distributed ensemble of moving dislocations are considered. The plastic deformation screening the elastic field of a disclination is shown to effectively stabilize microcrack growth at a sufficiently large grain size.

  10. Ornithine-urea cycle and urea synthesis in African lungfishes, Protopterus aethiopicus and Protopterus annectens, exposed to terrestrial conditions for six days.

    PubMed

    Loong, Ai May; Hiong, Kum Chew; Lee, Serene Min Lin; Wong, Wai Peng; Chew, Shit Fun; Ip, Yuen Kwong

    2005-05-01

    reductions in ammonia production in P. aethiopicus (34%) and P. annectens (37%) than P. dolloi (28%) as previously reported. Thus, our results suggest that various species of African lungfishes respond to aerial exposure differently with respect to nitrogen metabolism and excretion, and it can be concluded that P. aethiopicus and P. annectens depended more on reductions in ammonia production than on increases in urea synthesis to ameliorate ammonia toxicity when exposed to terrestrial conditions.

  11. The Appointment and Conditions of Employment for African-American Law Faculty: Perspectives from inside America's Legal Academy

    ERIC Educational Resources Information Center

    Carson, Loftus C., II.

    2012-01-01

    African-Americans are underrepresented on the faculties of American law schools. Currently, it is estimated that while they make up 12.6% of the U.S. population, only approximately 4% of the tenured faculty members at historically white law schools are African American. Moreover, there is evidence that once appointed to a tenure-track law faculty…

  12. Redox conditions and the efficiency of chlorinated ethene biodegradation: Field studies

    USGS Publications Warehouse

    Chapelle, F.H.; Bradley, P.M.

    2000-01-01

    The effect of redox conditions on the efficiency of chlorinated ethene biodegradation was investigated at two field sites. One site (NAS Cecil Field, FL) is characterized by predominantly Fe(III)-reducing conditions in the contaminant source area, grading to predominantly sulfate- reducing conditions downgradient. This sequence of redox conditions led to relatively inefficient biodegradation of chlorinated ethenes, with high concentrations of trichloroethene extending more than 400 meters downgradient of the source area. In contrast, a second site (NBS Kings Bay, GA) characterized by predominantly sulfate-reducing conditions in the source area followed by Fe(III)-reducing conditions downgradient. In this system perchloroethene (PCE) and TCE were rapidly biodegraded and extended less than 100 meters downgradient. Rates of ground- water transport are similar at the two sites (???0.2 m/d) indicating that the succession of redox processes, rather than other hydrologic factors, is the principal control on biodegradation. In particular, redox conditions that favor the initial reduction of highly chlorinated ethenes (methanogenic or sulfate-reducing conditions) followed by more oxidizing conditions (Fe(III)- reducing or oxic conditions) favors efficient biodegradation. Thus, documenting the succession of redox processes is an important step in understanding the efficiency of chlorinated ethene biodegradation in ground-water systems.

  13. Scaling methane oxidation: from laboratory incubation experiments to landfill cover field conditions.

    PubMed

    Abichou, Tarek; Mahieu, Koenraad; Chanton, Jeff; Romdhane, Mehrez; Mansouri, Imane

    2011-05-01

    Evaluating field-scale methane oxidation in landfill cover soils using numerical models is gaining interest in the solid waste industry as research has made it clear that methane oxidation in the field is a complex function of climatic conditions, soil type, cover design, and incoming flux of landfill gas from the waste mass. Numerical models can account for these parameters as they change with time and space under field conditions. In this study, we developed temperature, and water content correction factors for methane oxidation parameters. We also introduced a possible correction to account for the different soil structure under field conditions. These parameters were defined in laboratory incubation experiments performed on homogenized soil specimens and were used to predict the actual methane oxidation rates to be expected under field conditions. Water content and temperature corrections factors were obtained for the methane oxidation rate parameter to be used when modeling methane oxidation in the field. To predict in situ measured rates of methane with the model it was necessary to set the half saturation constant of methane and oxygen, K(m), to 5%, approximately five times larger than laboratory measured values. We hypothesize that this discrepancy reflects differences in soil structure between homogenized soil conditions in the lab and actual aggregated soil structure in the field. When all of these correction factors were re-introduced into the oxidation module of our model, it was able to reproduce surface emissions (as measured by static flux chambers) and percent oxidation (as measured by stable isotope techniques) within the range measured in the field.

  14. Scaling methane oxidation: From laboratory incubation experiments to landfill cover field conditions

    SciTech Connect

    Abichou, Tarek; Mahieu, Koenraad; Chanton, Jeff; Romdhane, Mehrez; Mansouri, Imane

    2011-05-15

    Evaluating field-scale methane oxidation in landfill cover soils using numerical models is gaining interest in the solid waste industry as research has made it clear that methane oxidation in the field is a complex function of climatic conditions, soil type, cover design, and incoming flux of landfill gas from the waste mass. Numerical models can account for these parameters as they change with time and space under field conditions. In this study, we developed temperature, and water content correction factors for methane oxidation parameters. We also introduced a possible correction to account for the different soil structure under field conditions. These parameters were defined in laboratory incubation experiments performed on homogenized soil specimens and were used to predict the actual methane oxidation rates to be expected under field conditions. Water content and temperature corrections factors were obtained for the methane oxidation rate parameter to be used when modeling methane oxidation in the field. To predict in situ measured rates of methane with the model it was necessary to set the half saturation constant of methane and oxygen, K{sub m}, to 5%, approximately five times larger than laboratory measured values. We hypothesize that this discrepancy reflects differences in soil structure between homogenized soil conditions in the lab and actual aggregated soil structure in the field. When all of these correction factors were re-introduced into the oxidation module of our model, it was able to reproduce surface emissions (as measured by static flux chambers) and percent oxidation (as measured by stable isotope techniques) within the range measured in the field.

  15. From lab to field conditions: a pilot study on EEG methodology in applied sports sciences.

    PubMed

    Reinecke, Kirsten; Cordes, Marjolijn; Lerch, Christiane; Koutsandréou, Flora; Schubert, Michael; Weiss, Michael; Baumeister, Jochen

    2011-12-01

    Although neurophysiological aspects have become more important in sports and exercise sciences in the last years, it was not possible to measure cortical activity during performance outside a laboratory due to equipment limits or movement artifacts in particular. With this pilot study we want to investigate whether Electroencephalography (EEG) data obtained in a laboratory golf putting performance differ from a suitable putting task under field conditions. Therefore, parameters of the working memory (frontal Theta and parietal Alpha 2 power) were recorded during these two conditions. Statistical calculations demonstrated a significant difference only for Theta power at F4 regarding the two putting conditions "field" and "laboratory". These findings support the idea that brain activity patterns obtained under laboratory conditions are comparable but not equivalent to those obtained under field conditions. Additionally, we were able to show that the EEG methodology seems to be a reliable tool to observe brain activity under field conditions in a golf putting task. However, considering the still existing problems of movement artifacts during EEG measurements, eligible sports and exercises are limited to those being relatively motionless during execution. Further studies are needed to confirm these pilot results.

  16. African American Administrators and Staff

    ERIC Educational Resources Information Center

    Wright, Dianne; Taylor, Janice D.; Burrell, Charlotte; Stewart, Gregory

    2006-01-01

    This article explores the issues of African American participation in the administrative ranks of the academy. The authors find that African Americans tend to hold positions that are marginal in academic organizations, lacking power and influence, and that not much has changed over recent decades. Forces influencing this condition are explored,…

  17. Nonreflecting Far-Field Boundary Conditions for Unsteady Transonic Flow Computation

    NASA Technical Reports Server (NTRS)

    Kwak, D.

    1981-01-01

    The approximate nonreflecting far-field boundary condition, as proposed by Engquisi and Majda, is implemented In the computer code LTRAN2. This code solves the Implicit finite-difference representation of the small-disturbance equations for unsteady transonic flows about airfoils. The nonreflecting boundary condition and the description of the algorithm for Implementing these conditions In LTRAN2 tire discussed. Various cases re computed and compared with results from the older, more conventional procedures. One concludes that the nonreflecting far-field boundary approximation allows the far-field boundary to be located closer to the airfoil; this permits a decrease in the computer lime required to obtain the solution through the use of fewer mesh points.

  18. Development of a Visual Inspection Data Collection Tool for Evaluation of Fielded PV Module Condition

    SciTech Connect

    Packard, C. E.; Wohlgemuth, J. H.; Kurtz, S. R.

    2012-08-01

    A visual inspection data collection tool for the evaluation of fielded photovoltaic (PV) modules has been developed to facilitate describing the condition of PV modules with regard to field performance. The proposed data collection tool consists of 14 sections, each documenting the appearance or properties of a part of the module. This report instructs on how to use the collection tool and defines each attribute to ensure reliable and valid data collection. This tool has been evaluated through the inspection of over 60 PV modules produced by more than 20 manufacturers and fielded at two different sites for varying periods of time. Aggregated data from such a single data collection tool has the potential to enable longitudinal studies of module condition over time, technology evolution, and field location for the enhancement of module reliability models.

  19. African American Teaching and the Matriarchal Performance.

    ERIC Educational Resources Information Center

    Jeffries, Rhonda Baynes

    This paper discusses the role of matriarchs in African-American culture, explaining that traditionally, African-American matriarchs arise from a combination of African norms and American social positions that naturally forces them to assume leadership conditions. The roles these women assume are a response to the desire to survive in a society…

  20. Aphid Wing Induction and Ecological Costs of Alarm Pheromone Emission under Field Conditions

    PubMed Central

    Hatano, Eduardo; Kunert, Grit; Weisser, Wolfgang W.

    2010-01-01

    The pea aphid, Acyrthosiphon pisum Harris, (Homoptera: Aphididae) releases the volatile sesquiterpene (E)-β-farnesene (EBF) when attacked by a predator, triggering escape responses in the aphid colony. Recently, it was shown that this alarm pheromone also mediates the production of the winged dispersal morph under laboratory conditions. The present work tested the wing-inducing effect of EBF under field conditions. Aphid colonies were exposed to two treatments (control and EBF) and tested in two different environmental conditions (field and laboratory). As in previous experiments aphids produced higher proportion of winged morphs among their offspring when exposed to EBF in the laboratory but even under field conditions the proportion of winged offspring was higher after EBF application (6.84±0.98%) compared to the hexane control (1.54±0.25%). In the field, the proportion of adult aphids found on the plant at the end of the experiment was lower in the EBF treatment (58.1±5.5%) than in the control (66.9±4.6%), in contrast to the climate chamber test where the numbers of adult aphids found on the plant at the end of the experiment were, in both treatments, similar to the numbers put on the plant initially. Our results show that the role of EBF in aphid wing induction is also apparent under field conditions and they may indicate a potential cost of EBF emission. They also emphasize the importance of investigating the ecological role of induced defences under field conditions. PMID:20585639

  1. Object-based Conditional Random Fields for Road Extraction from Remote Sensing Image

    NASA Astrophysics Data System (ADS)

    Huang, Zhijian; Xu, Fanjiang; Lu, Lei; Nie, Hongshan

    2014-03-01

    To make full use of spatially contextual information and topological information in the procedure of Object-based Image Analysis (OBIA), an object-based conditional random field is proposed and used for road extraction. Objects are produced with an initial segmentation, then their neighbours are constructed. Each object is represented by three kinds of features, including the colour, the gradient of histogram and the texture. Formulating the road extraction as a binary classification problem, a Conditional Random Fields model learns and is used for inference. The experimental results demonstrate that the proposed method is effective.

  2. Electric Field Effects in Self-Propagating High-Temperature Synthesis under Microgravity Conditions

    NASA Technical Reports Server (NTRS)

    Unuvar, C.; Frederick, D. M.; Shaw, B. D.; Munir, Z. A.

    2003-01-01

    Self-propagating high-temperature synthesis (SHS) has been used to form many materials. SHS generally involves mixing reactants together (e.g., metal powders) and igniting the mixture such that a combustion (deflagration) wave passes though the mixture. The imposition of an electric field (AC or DC) across SHS reactants has been shown to have a marked effect on the dynamics of wave propagation and on the nature, composition, and homogeneity of the product . The use of an electric field with SHS has been termed "field-assisted SHS". Combustion wave velocities and temperatures are directly affected by the field, which is typically perpendicular to the average wave velocity. The degree of activation by the field (e.g., combustion rate) is related to the current density distribution within the sample, and is therefore related to the temperature-dependent spatial distribution of the effective electrical conductivity of reactants and products. Furthermore, the field can influence other important SHS-related phenomena including capillary flow, mass-transport in porous media, and Marangoni flows. These phenomena are influenced by gravity in conventional SHS processes (i.e., without electric fields). As a result the influence of the field on SHS under reduced gravity is expected to be different than under normal gravity. It is also known that heat loss rates from samples, which can depend significantly on gravity, can influence final products in SHS. This research program is focused on studying field-assisted SHS under reduced gravity conditions. The broad objective of this research program is to understand the role of an electric field in SHS reactions under conditions where gravity-related effects are suppressed. The research will allow increased understanding of fundamental aspects of field-assisted SHS processes as well as synthesis of materials that cannot be formed in normal gravity.

  3. Numerical simulation and experimental research on wake field of ships under off-design conditions

    NASA Astrophysics Data System (ADS)

    Guo, Chun-yu; Wu, Tie-cheng; Zhang, Qi; Gong, Jie

    2016-10-01

    Different operating conditions (e.g. design and off-design) may lead to a significant difference in the hydrodynamics performance of a ship, especially in the total resistance and wake field of ships. This work investigated the hydrodynamic performance of the well-known KRISO 3600 TEU Container Ship (KCS) under three different operating conditions by means of Particle Image Velocimetry (PIV) and Computational Fluid Dynamics (CFD). The comparison results show that the use of PIV to measure a ship's nominal wake field is an important method which has the advantages of being contactless and highly accurate. Acceptable agreements between the results obtained by the two different methods are achieved. Results indicate that the total resistances of the KCS model under two off-design conditions are 23.88% and 13.92% larger than that under the designed condition, respectively.

  4. Boundary conditions for Maxwell fields in Kerr-AdS spacetimes

    NASA Astrophysics Data System (ADS)

    Wang, Mengjie

    2016-05-01

    Perturbative methods are useful to study the interaction between black holes and test fields. The equation for a perturbation itself, however, is not complete to study such a composed system if we do not assign physically relevant boundary conditions. Recently we have proposed a new type of boundary conditions for Maxwell fields in Kerr-anti-de Sitter (Kerr-AdS) spacetimes, from the viewpoint that the AdS boundary may be regarded as a perfectly reflecting mirror, in the sense that energy flux vanishes asymptotically. In this paper, we prove explicitly that a vanishing energy flux leads to a vanishing angular momentum flux. Thus, these boundary conditions may be dubbed as vanishing flux boundary conditions.

  5. Condition and size of damselflies: a field study of food limitation.

    PubMed

    Baker, Robert L

    1989-10-01

    Based on evidence from field manipulations, several authors have recently suggested that interference competition among larval odonates reduces individual growth rates and biomass by reducing foraging rates. This study was designed to test the effects of food shortage on "condition" (relative mass per unit head width) of larval Ischnura verticalis (Odonata: Coenagrionidae) under laboratory conditions and to use these results to estimate the degree of food shortage of larvae under naturally occurring field conditions. In the laboratory, there were marked differences in condition of larvae fed diets ranging from ad libitum feeding with worms to ad libitum feeding with Daphnia 1 day out of every 8. Condition of larvae collected from May through October from 17 different sites in southern Ontario indicated that, for most of the year, larvae had conditions similar to those fed ad libitum with Daphnia in the laboratory. There was no evidence that larval condition was related to population density. Condition of larvae in most sites during July was similar to that of larvae fed poor diets in the laboratory. It is unlikely that the low conditions were due to competition as there were no correlations with density across sites and population densities during July were at their lowest. Adult head widths showed a seasonal decline from mid June to the end of the flight season. There was no evidence that head widths were related to population density although there was some evidence that head widths of males were positively related to larval condition. My results do not support the hypothesis that competition is important in affecting foraging rates and subsequent development of larvae. Contrasts between my results and other studies may stem from difficulties with the interpretation of field experiments, that densities in my study may have been low due to fish predation, and/or that I. verticalis larvae are slow moving relative to other larvae and thus less likely to interact.

  6. Far-Field Boundary Conditions in Numerical Solutions of the Navier-Stokes Equations.

    DTIC Science & Technology

    2014-09-26

    nonlinear system of mixed parabolic- hyperbolic type in two space dimensions and time, with four independent variables must be solved in an exterior...conditions. * III THE NAVIER-STOKES EQUATIONS AND CHARACTERISTIC VARIABLES : We now begin our discussion of the equations of gas dynamics. We will neglect...8217 Far-Field Boundary Conditions in Numerical Solutions of the Navier-Stokes Equations L°O * (. P.J. McKenna LA. DTIC * E.LECTE Final Report AFOSR Grant

  7. An outflow boundary condition and algorithm for incompressible two-phase flows with phase field approach

    NASA Astrophysics Data System (ADS)

    Dong, S.

    2014-06-01

    We present an effective outflow boundary condition, and an associated numerical algorithm, within the phase-field framework for dealing with two-phase outflows or open boundaries. The set of two-phase outflow boundary conditions for the phase-field and flow variables are designed to prevent the un-controlled growth in the total energy of the two-phase system, even in situations where strong backflows or vortices may be present at the outflow boundaries. We also present an additional boundary condition for the phase field function, which together with the usual Dirichlet condition can work effectively as the phase-field inflow conditions. The numerical algorithm for dealing with these boundary conditions is developed on top of a strategy for de-coupling the computations of all flow variables and for overcoming the performance bottleneck caused by variable coefficient matrices associated with variable density/viscosity. The algorithm contains special constructions, for treating the variable dynamic viscosity in the outflow boundary condition, and for preventing a numerical locking at the outflow boundaries for time-dependent problems. Extensive numerical tests with incompressible two-phase flows involving inflow and outflow boundaries demonstrate that, the two-phase outflow boundary conditions and the numerical algorithm developed herein allow for the fluid interface and the two-phase flow to pass through the outflow or open boundaries in a smooth and seamless fashion, and that our method produces stable simulations when large density ratios and large viscosity ratios are involved and when strong backflows are present at the outflow boundaries.

  8. The charged inflaton and its gauge fields: preheating and initial conditions for reheating

    SciTech Connect

    Lozanov, Kaloian D.; Amin, Mustafa A.

    2016-06-14

    We calculate particle production during inflation and in the early stages of reheating after inflation in models with a charged scalar field coupled to Abelian and non-Abelian gauge fields. A detailed analysis of the power spectra of primordial electric fields, magnetic fields and charge fluctuations at the end of inflation and preheating is provided. We carefully account for the Gauss constraints during inflation and preheating, and clarify the role of the longitudinal components of the electric field. We calculate the timescale for the back-reaction of the produced gauge fields on the inflaton condensate, marking the onset of non-linear evolution of the fields. We provide a prescription for initial conditions for lattice simulations necessary to capture the subsequent nonlinear dynamics. On the observational side, we find that the primordial magnetic fields generated are too small to explain the origin of magnetic fields on galactic scales and the charge fluctuations are well within observational bounds for the models considered in this paper.

  9. African Americans and Agriculture.

    ERIC Educational Resources Information Center

    Morgan, Joan

    2000-01-01

    Reviews the opportunities available in the field of agriculture for African American students and notes efforts of the 136 colleges of agriculture to publicize their offerings and recruit students. Profiles six black leaders in agriculture, highlighting their achievements in research and aid to developing countries. A table provides data on annual…

  10. Comparison of the sequence of the gene encoding African swine fever virus attachment protein p12 from field virus isolates and viruses passaged in tissue culture.

    PubMed Central

    Angulo, A; Viñuela, E; Alcamí, A

    1992-01-01

    Comparison of the amino acid sequence of the African swine fever virus attachment protein p12 from different field virus isolates, deduced from the nucleotide sequence of the gene, revealed a high degree of conservation. No mutations were found after adaptation to Vero cells, and a polypeptide with similar characteristics was present in an IBRS2-adapted virus. The sequence of the 5' flanking region was conserved among the isolates, whereas sequences downstream of the gene were highly variable in length and contained direct repeats in tandem that may account for the deletions found in different isolates. Protein p12 was synthesized in swine macrophages infected with all of the viruses tested. PMID:1583733

  11. Mapping the state of the field of social psychology in Africa and patterns of collaboration between African and international social psychologists.

    PubMed

    Quayle, Michael; Greer, Megan

    2014-12-01

    Patterns of collaboration in social psychology from 2000 to 2010 were mapped to analyse the position of African authors in the international co-authorship network using bibliographic records from the Thomson Reuters Web of Knowledge. There are very few social psychologists working in Africa, with the majority of these located in South Africa. Indeed, some small European countries boast more social psychologists than the entire continent of Africa. African authors published less than their non-African collaborators, but had comparable status on joint publications. Co-authorship relationships between African researchers from different African countries were generally mediated by partners from other continents, and direct collaboration between non-compatriot African authors was very rare. The small size, and extremely sparse connection of the African co-authorship network, is likely to be an obstacle both in the development of social psychology as a universally relevant discipline and in the penetration of social psychological knowledge in Africa.

  12. Monitoring diapause development in the Colorado potato beetle, Leptinotarsa decemlineata, under field conditions using molecular biomarkers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A multiplex PCR protocol was developed using five diapause-regulated genes to monitor diapause development of the Colorado potato beetle under field conditions. A total of 870 beetles from the Red River Valley of North Dakota and Minnesota, USA, were screened for three consecutive years. Out of the ...

  13. EPA FIELD DEMONSTRATION OF INNOVATIVE CONDITION ASSESSMENT TECHNOLOGIES FOR WATER MAINS AT LOUISVILLE, KY

    EPA Science Inventory

    This presentation will describe a series of field demonstrations of innovative leak detection/location and condition assessment technologies that was sponsored by the U.S. Environmental Protection Agency (EPA), conducted by EPA’s contractor (Battelle), and hosted by the Louisvil...

  14. EPA Field Demonstration of Innovative Condition Assessment Technologies for Water Mains at Louisville, KY - slides

    EPA Science Inventory

    This presentation will describe a series of field demonstrations of innovative leak detection/location and condition assessment technologies that was sponsored by the U.S. Environmental Protection Agency (EPA), conducted by EPA’s contractor (Battelle), and hosted by the Louisvill...

  15. Field Demonstration of Innovative Condition Assessment Technologies for Water Mains: Leak Detection and Location

    EPA Science Inventory

    Three leak detection/location technologies were demonstrated on a 76-year-old, 2,057-ft-long portion of a cement-lined, 24-in. cast iron water main in Louisville, KY. This activity was part of a series of field demonstrations of innovative leak detection/location and condition a...

  16. Bullying of Children and Adolescents with Autism Spectrum Conditions: A "State of the Field" Review

    ERIC Educational Resources Information Center

    Humphrey, Neil; Hebron, Judith

    2015-01-01

    A "state of the field" review of what is currently known about bullying of children and adolescents with autism spectrum conditions (ASC) is presented. We highlight compelling evidence that they are considerably more likely to be bullied than those with other or no special educational needs and disabilities. Although prevalence estimates…

  17. Drifts, boundary conditions and plasma convection on open magnetic field lines

    SciTech Connect

    Cohen, R. H.

    1998-11-20

    In a number of plasmas of practical interest, including the scrape-off layer of a tokamak with a divertor or toroidal limiter, some gas discharge devices, and in the vicinity of spacecraft, magnetic field lines intersect bounding surfaces at shallow angles. Under these circumstances a number of interesting and important effects arise. Drifts can compete with parallel flows in establishing the boundary conditions for plasma mass-flow and current (sheath current-voltage characteristics). We derive the mass-flow constraints including both poloidal and radial drifts, review the current boundary conditions, and survey the consequences, including along-field density and heat-flux asymmetries, convection created by a wavy surface, generation of electric fields and surface currents associated with shadows from surface structures, and modification of instability growth.

  18. The weight hierarchies and chain condition of a class of codes from varieties over finite fields

    NASA Technical Reports Server (NTRS)

    Wu, Xinen; Feng, Gui-Liang; Rao, T. R. N.

    1996-01-01

    The generalized Hamming weights of linear codes were first introduced by Wei. These are fundamental parameters related to the minimal overlap structures of the subcodes and very useful in several fields. It was found that the chain condition of a linear code is convenient in studying the generalized Hamming weights of the product codes. In this paper we consider a class of codes defined over some varieties in projective spaces over finite fields, whose generalized Hamming weights can be determined by studying the orbits of subspaces of the projective spaces under the actions of classical groups over finite fields, i.e., the symplectic groups, the unitary groups and orthogonal groups. We give the weight hierarchies and generalized weight spectra of the codes from Hermitian varieties and prove that the codes satisfy the chain condition.

  19. Non-Gaussianity in single field models without slow-roll conditions

    NASA Astrophysics Data System (ADS)

    Noller, Johannes; Magueijo, João

    2011-05-01

    We investigate non-Gaussianity in general single field models without assuming slow-roll conditions or the exact scale invariance of the scalar power spectrum. The models considered include general single field inflation (e.g. Dirac-Born-Infeld and canonical inflation) as well as bimetric models. We compute the full non-Gaussian amplitude A, its size fNL, its shape, and the running with scale nNG. In doing so we show that observational constraints allow significant violations of slow-roll conditions and we derive explicit bounds on slow-roll parameters for fast-roll single field scenarios. A variety of new observational signatures is found for models respecting these bounds. We also explicitly construct concrete model implementations giving rise to this new phenomenology.

  20. Temporal variability of soil water repellency in field conditions under humid Mediterranean climate (South of Spain)

    NASA Astrophysics Data System (ADS)

    Martinez-Murillo, Juan F.; Gabarron-Galeote, Miguel A.; Ruiz-Sinoga, Jose D.

    2013-04-01

    Soil water repellency (SWR) has become an important field of scientific study because of its effects on soil hydrological behavior, including reduced matrix infiltration, development of fingered flow in structural or textural preferential flow paths, irregular wetting fronts, and increased runoff generation and soil erosion. The aim of this study is to evaluate the temporal variability of SWR in Mediterranean rangeland under humid Mediterranean climatic conditions (Tª=14.5 °C; P=1,010 mm y-1) in South of Spain. Every month from September 2008 to May 2009 (rainy season), soil moisture and SWR was measured in field conditions by means of gravimetric method and Water Drop Penetration Test, respectively. The entire tests were performed in differente eco-geomorphological conditions in the experimental site: North and South aspect hillslopes and beneath shrub and bare soil in every of them. The results indicate that: i) climatic conditions seem to be more transcendent than the vegetal cover for explaining the temporal variability of SWR in field conditions; ii) thus, SWR appears to be controlled by the antecedent rainfall and soil moisture; iii) more severity SWR were observed in patches characterized by sandier soils and/or greater organic matter contents; and iv) the factor 'hillslope aspect' was not found very influential in the degree of SWR.

  1. Verification of the ISO calibration method for field pyranometers under tropical sky conditions

    NASA Astrophysics Data System (ADS)

    Janjai, Serm; Tohsing, Korntip; Pattarapanitchai, Somjet; Detkhon, Pasakorn

    2017-02-01

    Field pyranomters need to be annually calibrated and the International Organization for Standardization (ISO) has defined a standard method (ISO 9847) for calibrating these pyranometers. According to this standard method for outdoor calibration, the field pyranometers have to be compared to a reference pyranometer for the period of 2 to 14 days, depending on sky conditions. In this work, the ISO 9847 standard method was verified under tropical sky conditions. To verify the standard method, calibration of field pyranometers was conducted at a tropical site located in Nakhon Pathom (13.82o N, 100.04o E), Thailand under various sky conditions. The conditions of the sky were monitored by using a sky camera. The calibration results for different time periods used for the calibration under various sky conditions were analyzed. It was found that the calibration periods given by this standard method could be reduced without significant change in the final calibration result. In addition, recommendation and discussion on the use of this standard method in the tropics were also presented.

  2. Corrigendum to "The 3-D strain patterns in Turkey using geodetic velocity fields from the RTK-CORS (TR) network" [J. African Earth Sci. 115 (2016) 246-270

    NASA Astrophysics Data System (ADS)

    Kutoglu, Hakan Senol; Toker, Mustafa; Mekik, Cetin

    2016-12-01

    In the article titled "The 3-D Strain patterns in Turkey using Geodetic velocity fields from the RTK-CORS (TR) Network" published in Journal of African Earth Sciences Vol. 11, pp.246-270, the black arrows on the Figs. 10 and 12 are shifted due to printing error to undesired places. The correct form of Figs. 10 and 12 are given below:

  3. A single TLD dose algorithm to satisfy federal standards and typical field conditions

    SciTech Connect

    Stanford, N.; McCurdy, D.E. )

    1990-06-01

    Modern whole-body dosimeters are often required to accurately measure the absorbed dose in a wide range of radiation fields. While programs are commonly developed around the fields tested as part of the National Voluntary Accreditation Program (NVLAP), the actual fields of application may be significantly different. Dose algorithms designed to meet the NVLAP standard, which emphasizes photons and high-energy beta radiation, may not be capable of the beta-energy discrimination necessary for accurate assessment of absorbed dose in the work environment. To address this problem, some processors use one algorithm for NVLAP testing and one or more different algorithms for the work environments. After several years of experience with a multiple algorithm approach, the Dosimetry Services Group of Yankee Atomic Electric Company (YAEC) developed a one-algorithm system for use with a four-element TLD badge using Li2B4O7 and CaSO4 phosphors. The design of the dosimeter allows the measurement of the effective energies of both photon and beta components of the radiation field, resulting in excellent mixed-field capability. The algorithm was successfully tested in all of the NVLAP photon and beta fields, as well as several non-NVLAP fields representative of the work environment. The work environment fields, including low- and medium-energy beta radiation and mixed fields of low-energy photons and beta particles, are often more demanding than the NVLAP fields. This paper discusses the development of the algorithm as well as some results of the system testing including: mixed-field irradiations, angular response, and a unique test to demonstrate the stability of the algorithm. An analysis of the uncertainty of the reported doses under various irradiation conditions is also presented.

  4. A single TLD dose algorithm to satisfy federal standards and typical field conditions.

    PubMed

    Stanford, N; McCurdy, D E

    1990-06-01

    Modern whole-body dosimeters are often required to accurately measure the absorbed dose in a wide range of radiation fields. While programs are commonly developed around the fields tested as part of the National Voluntary Accreditation Program (NVLAP), the actual fields of application may be significantly different. Dose algorithms designed to meet the NVLAP standard, which emphasizes photons and high-energy beta radiation, may not be capable of the beta-energy discrimination necessary for accurate assessment of absorbed dose in the work environment. To address this problem, some processors use one algorithm for NVLAP testing and one or more different algorithms for the work environments. After several years of experience with a multiple algorithm approach, the Dosimetry Services Group of Yankee Atomic Electric Company (YAEC) developed a one-algorithm system for use with a four-element TLD badge using Li2B4O7 and CaSO4 phosphors. The design of the dosimeter allows the measurement of the effective energies of both photon and beta components of the radiation field, resulting in excellent mixed-field capability. The algorithm was successfully tested in all of the NVLAP photon and beta fields, as well as several non-NVLAP fields representative of the work environment. The work environment fields, including low- and medium-energy beta radiation and mixed fields of low-energy photons and beta particles, are often more demanding than the NVLAP fields. This paper discusses the development of the algorithm as well as some results of the system testing including: mixed-field irradiations, angular response, and a unique test to demonstrate the stability of the algorithm. An analysis of the uncertainty of the reported doses under various irradiation conditions is also presented.

  5. Comparison of the acceptability ratings of appetizers under laboratory, base level and high altitude field conditions.

    PubMed

    Premavalli, K S; Wadikar, D D; Nanjappa, C

    2009-08-01

    The relationship between laboratory and field ratings was investigated for six different appetizers, including four ready-to-reconstitute mixes and two ready-to-eat munches. Liking ratings on a 5-point hedonic scale were obtained from an Indian Army field study at base level as well as at an altitude of 11,500 ft above sea level and for the same appetizers in the laboratory. The field trials of the six products were conducted in two phases and results revealed that the products were more acceptable at altitude, with increased liking scores as compared to base level. Subjective ratings for hunger revealed that at altitude, appetizer consumption had stimulated the appetite of the soldiers. The ability of laboratory ratings to predict acceptability of foods consumed under realistic conditions appears to depend on the convenience of the appetizer as well as the environmental conditions and the psycho-physiological status of the participants. The appetizers received higher ratings at altitude because of the pungent and spicy nature of appetizer mixes as compared with base field and laboratory conditions. However, for all the appetizers the pungent and sweet taste of the appetizer munches was highly preferred.

  6. A new multistack radiation boundary condition for FDTD based on self-teleportation of fields

    SciTech Connect

    Diaz, Rodolfo E.; Scherbatko, Igor . E-mail: igor_s@asu.edu

    2005-02-10

    In [Electromagnetics 23 (2003) 187], a technique for injecting perfect plane waves into finite regions of space in FDTD was reported. The essence of the technique, called Field Teleportation, is to invoke the principle of equivalent sources using FDTDs discrete definition of the curl to copy any field propagating in one FDTD domain to a finite region of another domain. In this paper, we apply this technique of Field Teleportation to the original domain itself to create a transparent boundary across which any outward traveling FDTD field produces an exact negative copy of itself. When this copied field is teleported one cell ahead and one cell forward in time it causes significant self-cancelation of the original field. Illustrative experiments in two-dimensions show that a two-layer (10-cell thick) multi-stack Radiation Boundary Condition (RBC) with a simplest Huygens's termination readily yields reflection coefficients of the order of -80 dB up to grazing incidence for all the fields radiated by a harmonic point source ({lambda} = 30 cells) in free space located 20 cells away from the boundary. Similarly low levels of artificial reflection are demonstrated for a case in which the RBC cuts through five different magnetodielectric materials.

  7. Revisiting chameleon gravity: Thin-shell and no-shell fields with appropriate boundary conditions

    SciTech Connect

    Tamaki, Takashi; Tsujikawa, Shinji

    2008-10-15

    We derive analytic solutions of a chameleon scalar field {phi} that couples to a nonrelativistic matter in the weak gravitational background of a spherically symmetric body, paying particular attention to a field mass m{sub A} inside of the body. The standard thin-shell field profile is recovered by taking the limit m{sub A}r{sub c}{yields}{infinity}, where r{sub c} is a radius of the body. We show the existence of 'no-shell' solutions where the field is nearly frozen in the whole interior of the body, which does not necessarily correspond to the 'zero-shell' limit of thin-shell solutions. In the no-shell case, under the condition m{sub A}r{sub c}>>1, the effective coupling of {phi} with matter takes the same asymptotic form as that in the thin-shell case. We study experimental bounds coming from the violation of equivalence principle as well as solar-system tests for a number of models including f(R) gravity and find that the field is in either the thin-shell or the no-shell regime under such constraints, depending on the shape of scalar-field potentials. We also show that, for the consistency with local gravity constraints, the field at the center of the body needs to be extremely close to the value {phi}{sub A} at the extremum of an effective potential induced by the matter coupling.

  8. Examiner performance in calibration exercises compared with field conditions when scoring caries experience.

    PubMed

    Agbaje, Jimoh Olubanwo; Mutsvari, Timothy; Lesaffre, Emmanuel; Declerck, Dominique

    2012-04-01

    The objective of this study was to verify how valid misclassification measurements obtained from a 'pre-survey' calibration exercise are by comparing them to validation scores obtained in 'field' conditions. Validation data were collected from the 'Smile for Life' project, an oral health intervention study in Flemish children. A calibration exercise was organized under 'pre-survey' conditions (32 age-matched children examined by eight examiners and the benchmark scorer). In addition, using a pre-determined sampling scheme blinded to the examiners, the benchmark scorer re-examined between six and 11 children screened by each of the dentists during the survey. Factors influencing sensitivity and specificity for scoring caries experience (CE) were investigated, including examiner, tooth type, surface type, tooth position (upper/lower jaw, right/left side) and validation setting (pre-survey versus field). In order to account for the clustering effect in the data, a generalized estimating equations approach was applied. Sensitivity scores were influenced not only by the calibration setting (lower sensitivity in field conditions, p < 0.01), but also by examiner, tooth type (lower sensitivity in molar teeth, p < 0.01) and tooth position (lower sensitivity in the lower jaw, p < 0.01). Factors influencing specificity were examiner, tooth type (lower specificity in molar teeth, p < 0.01) and surface type (the occlusal surface with a lower specificity than other surfaces) but not the validation setting. Misclassification measurements for scoring CE are influenced by several factors. In this study, the validation setting influenced sensitivity, with lower scores obtained when measuring data validity in 'field' conditions. Results obtained in a pre-survey calibration setting need to be interpreted with caution and do not (always) reflect the actual performance of examiners during the field work.

  9. Detailed balance condition and ultraviolet stability of scalar field in Horava-Lifshitz gravity

    NASA Astrophysics Data System (ADS)

    Borzou, Ahmad; Lin, Kai; Wang, Anzhong

    2011-05-01

    Detailed balance and projectability conditions are two main assumptions when Horava recently formulated his theory of quantum gravity - the Horava-Lifshitz (HL) theory. While the latter represents an important ingredient, the former often believed needs to be abandoned, in order to obtain an ultraviolet stable scalar field, among other things. In this paper, because of several attractive features of this condition, we revisit it, and show that the scalar field can be stabilized, if the detailed balance condition is allowed to be softly broken. Although this is done explicitly in the non-relativistic general covariant setup of Horava-Melby-Thompson with an arbitrary coupling constant λ, generalized lately by da Silva, it is also true in other versions of the HL theory. With the detailed balance condition softly breaking, the number of independent coupling constants can be still significantly reduced. It is remarkable to note that, unlike other setups, in this da Silva generalization, there exists a master equation for the linear perturbations of the scalar field in the flat Friedmann-Robertson-Walker background.

  10. Biological control of bacterial speck of tomato under field conditions at several locations in north america.

    PubMed

    Wilson, M; Campbell, H L; Ji, P; Jones, J B; Cuppels, D A

    2002-12-01

    ABSTRACT Bacterial speck of tomato, caused by Pseudomonas syringae pv. tomato, continues to be a problem for tomato growers worldwide. A collection of nonpathogenic bacteria from tomato leaves plus P. syringae strains TLP2 and Cit7, P. fluorescens strain A506, and P. syringae pv. tomato DC3000 hrp mutants were examined in a greenhouse bioassay for the ability to reduce foliar bacterial speck disease severity. While several of these strains significantly reduced disease severity, P. syringae Cit7 was the most effective, providing a mean level of disease reduction of 78% under greenhouse conditions. The P. syringae pv. tomato DC3000 hrpA, hrpH, and hrpS mutants also significantly reduced speck severity under greenhouse conditions. The strains with the greatest efficacy under greenhouse conditions were tested for the ability to reduce bacterial speck under field conditions at locations in Alabama, Florida, and Ontario, Canada. P. syringae Cit7 was the most effective strain, providing a mean level of disease reduction of 28% over 10 different field experiments. P. fluorescens A506, which is commercially available as Blight-Ban A506, provided a mean level of disease reduction of 18% over nine different field experiments. While neither P. syringae Cit7 nor P. fluorescens A506 can be integrated with copper bactericides due to their copper sensitivity, there exist some potential for integrating these biological control agents with "plant activators", including Actigard. Of the P. syringae pv. tomato DC3000 hrp mutants tested, only the hrpS mutant reduced speck severity significantly under field conditions.

  11. On the far-field stream function condition for two-dimensional incompressible flows

    NASA Technical Reports Server (NTRS)

    Sa, Jong-Youb; Chang, Keun-Shik

    1990-01-01

    The present demonstration of the usefulness of the integral series expansion of the stream function as a far-field computational boundary condition shows the method to require only a 10-percent/time-step increase in computational effort over alternative boundary conditions, in the case of implementation of unsteady problems using a direct elliptic solver. So long as the vorticity was encompassed within the computational domain, the method proved sufficiently accurate to yield virtually identical results for two widely different domains. While the integral-series condition yielded the best results for periodic flow, the Neumann condition gave comparable accuracy with less computation time for the steady-flow case despite its inability to treat periodic flow with vortex shedding.

  12. Sakiadis flow of Maxwell fluid considering magnetic field and convective boundary conditions

    SciTech Connect

    Mustafa, M.; Khan, Junaid Ahmad; Hayat, T.; Alsaedi, A.

    2015-02-15

    In this paper we address the flow of Maxwell fluid due to constantly moving flat radiative surface with convective condition. The flow is under the influence of non-uniform transverse magnetic field. The velocity and temperature distributions have been evaluated numerically by shooting approach. The solution depends on various interesting parameters including local Deborah number De, magnetic field parameter M, Prandtl number Pr and Biot number Bi. We found that variation in velocity with an increase in local Deborah number De is non-monotonic. However temperature is a decreasing function of local Deborah number De.

  13. Effects of waste water irrigation on soil properties and soil fauna of spinach fields in a West African urban vegetable production system.

    PubMed

    Stenchly, Kathrin; Dao, Juliane; Lompo, Désiré Jean-Pascal; Buerkert, Andreas

    2017-03-01

    The usage of inadequately processed industrial waste water (WW) can lead to strong soil alkalinity and soil salinization of agricultural fields with negative consequences on soil properties and biota. Gypsum as a soil amendment to saline-sodic soils is widely used in agricultural fields to improve their soil physical, chemical and hence biological properties. This study aimed at analysing the effects of intensive WW irrigation on the structure and composition of soil-dwelling arthropods on spinach fields (Spinacia oleracea L.) in a West African urban vegetable production system. We used gypsum as a soil amendment with the potential to alleviate soil chemical stress resulting in a potentially positive impact on soil arthropods. A total of 32 plots were established that showed a gradient in soil pH ranging from slight to strong soil alkalinity and that were irrigated with WW (n = 12) or clean water (CW; n = 20), including eight plots into which gypsum was incorporated. Our study revealed a high tolerance of soil-dwelling arthropods for alkaline soils, but spinach fields with increased soil electrical conductivity (EC) showed a reduced abundance of Hymenoptera, Diptera and Auchenorrhyncha. Arthropod abundance was positively related to a dense spinach cover that in turn was not affected by WW irrigation or soil properties. Gypsum application reduced soil pH but increased soil EC. WW irrigation and related soil pH affected arthropod composition in the investigated spinach fields which may lead to negative effects on agronomical important arthropod groups such as pollinators and predators.

  14. Supersonic far-field boundary conditions for transonic small-disturbance theory

    NASA Technical Reports Server (NTRS)

    Gibbons, Michael D.; Batina, John T.

    1989-01-01

    Characteristic far-field boundary conditions for supersonic freestream flow have been developed and implemented within a transonic small-disturbance code. The boundary conditions have been implemented within the CAP-TSD code which has been developed recently for aeroelastic analysis of complete aircraft configurations. These boundary conditions improve the accuracy of the solutions for supersonic freestream applications. They also allow the extent of the grid to be much smaller, thus providing savings in the computational time required to obtain solutions. Comparisons are shown between surface pressures computed using large and small grid extents for the NACA 0012 airfoil and the F-5 wing at various Mach numbers and angles of attack. Both steady and unsteady results are presented and comparisons are made with Euler results and with experimental data to assess the accuracy of the new far-field boundary conditions. Comparisons of these results show that the supersonic boundary conditions allow a much smaller grid to be used without losing accuracy.

  15. Contrasting conditions of surface water balance in wet years and dry years as a possible land surface-atmosphere feedback mechanism in the West African Sahel

    NASA Technical Reports Server (NTRS)

    Lare, A. R.; Nicholson, S. E.

    1994-01-01

    The climate of West Africa, in particular the Sahel, is characterized by multiyear persistence of anomalously wet or dry conditions. Its Southern Hemisphere counterpart, the Kalahari, lacks the persistence that is evident in the Sahel even though both regions are subject to similar large-scale forcing. It has been suggested that land surface-atmosphere feedback contributes to this persistence and to the severity of drought. In this study, surface energy and water balance are quantified for nine stations along a latitudinal transect that extends from the Sahara to the Guinea coast. In the wetter regions of West Africa, the difference between wet and dry years is primarily reflected in the magnitude of runoff. For the Sahel and drier locations, evapotranspiration and soil moisture are more sensitive to rainfall anomalies. The increase in evapotranspiration, and hence latent heating, over the Sahel in wet years alters the thermal structure and gradients of the overlying atmosphere and thus the strength of the African easterly jet (AEJ) at 700 mb. The difference between dry and wet Augusts corresponds to a decrease in magnitude of the AEJ at 15 deg N on the order of 2.6 m/s, which is consistent with previous studies of observed winds. Spatial patterns were also developed for surface water balance parameters for both West Africa and southern Africa. Over southern Africa, the patterns are not as spatially homogeneous as those over West Africa and are lower in magnitude, thus supporting the suggestion that the persistence of rainfall anomalies in the Sahel might be due, at least in part, to land-atmosphere feedback, and that the absence of such persistence in the Kalahari is a consequence of less significant changes in surface water and energy balance.

  16. Dissipation and residue of 2,4-D in citrus under field condition.

    PubMed

    Chen, Weijun; Jiao, Bining; Su, Xuesu; Zhao, Qiyang; Sun, Dali

    2015-05-01

    The dissipation, residues, and risks of 2,4-dicholrophenoxyacetic acid (2,4-D) in citrus under field condition were investigated based on a simple ultra-performance LC (UPLC)-MS/MS method. The results indicated that the residue level of 2,4-D in citrus did not degrade gradually with sampling time under field condition. At pre-harvest intervals (PHI) of 20-40 days, 2,4-D residues were 0.021-0.269 mg/kg in citrus flesh, 0.028-0.337 mg/kg in whole citrus, and 0.028-0.376 mg/kg in citrus peel, all bellow the China maximum residue limit in citrus (1 mg/kg). Risks of 2,4-D were assessed by calculation of risk quotient, and the results revealed no significant health risks after consumption of citrus.

  17. Dissipation of pendimethalin in soil and its residues in chickpea (Cicer arietinum L.) under field conditions.

    PubMed

    Sondhia, Shobha

    2012-11-01

    Disappearance of pendimethalin in the soil of chickpea (Cicer arietinum L.) at 0-110 days, and terminal residues in plant samples have been studied under field conditions. Pendimethalin was applied as pre-emergence herbicide at 750, 350 and 180 g a.i. ha(-1) in winter, in chickpea crop. The dissipation of pendimethalin in the chickpea field soil conditions followed first order kinetics showing a half-life of 11.23 days averaged over all doses. Low pendimethalin residues were found in plant samples. 0.025, 0.015, <0.001 μg g(-1) residues of pendimethalin were found in grains at 750, 350 and 185 g a.i. ha(-1) treatments, respectively. Much lower pendimethalin residues were found in straw viz. 0.015 to <0.001 μg g(-1) at 750, 350 and 185 g a.i. ha(-1) treatments, respectively.

  18. Fuzzy-based latent-dynamic conditional random fields for continuous gesture recognition

    NASA Astrophysics Data System (ADS)

    Zhang, Shengjun; He, Xiaohai; Teng, Qizhi

    2012-06-01

    We show an original method for automatic hand gesture recognition that makes use of fuzzified latent-dynamic conditional random fields (LDCRF). In this method, fuzzy linguistic variables are used to model the features of hand gestures and then to modify the potential function in LDCRFs. By combining LDCRFs and fuzzy sets, these fuzzy-based LDCRFs (FLDCRF) have the advantages of LDCRFs in sequence labeling along with the advantage of retaining the imprecise character of gestures. The efficiency of the proposed method was tested with unsegmented gesture sequences in three different hand gesture data sets. The experimental results demonstrate that FLDCRFs compare favorably with support vector machines, hidden conditional random fields, and LDCRFs on hand gesture recognition tasks.

  19. Far Field Numerical Boundary Conditions for Internal and Cascade Flow Computations

    DTIC Science & Technology

    1988-11-01

    for the treatment of the fa field boundary conditions, Verhoff and O’Neil (1984), to more ,,eneral formulations of the Euler equations and to cascade...4eometries. linearized solutions ,-f the Euler equations are developed for the perturbations from the tiniform free stream, for ducts and cascades...Fourier expansion in the direction al on tlie inlet or exit boundaries. Resul obtained from an Euler code are shown ftor duCts and cascadels , rompa rin

  20. The effectiveness of jute and coir blankets for erosion control in different field and laboratory conditions

    NASA Astrophysics Data System (ADS)

    Kalibová, Jana; Jačka, Lukáš; Petrů, Jan

    2016-03-01

    Vegetation cover is found to be an ideal solution to most problems of erosion on steep slopes. Biodegradable geotextiles (GTXs) have been proved to provide sufficient protection against soil loss in the period before vegetation reaches maturity, so favouring soil formation processes. In this study, 500 g m-2 jute (J500), 400 g m-2 (C400), and 700 g m-2 coir (C700) GTXs were first installed on a 9° slope under "no-infiltration" laboratory conditions, then on a 27° slope under natural field conditions. The impact of GTXs on run-off and soil loss was investigated to compare the performance of GTXs under different conditions. Laboratory run-off ratio (percentage portion of control plot) equalled 78, 83, and 91 %, while peak discharge ratio equalled 83, 91, and 97 % for J500, C700, and C400 respectively. In the field, a run-off ratio of 31, 62, and 79 %, and peak discharge ratio of 37, 74, and 87 % were recorded for C700, J500, and C400 respectively. All tested GTXs significantly decreased soil erosion. The greatest soil loss reduction in the field was observed for J500 (by 99.4 %), followed by C700 (by 97.9 %) and C400 (by 93.8 %). Irrespective of slope gradient or experimental condition, C400 performed with lower run-off and peak discharge reduction than J500 and C700. The performance ranking of J500 and C700 in the laboratory differed from the field, which may be explained by different slope gradients, and also by the role of soil, which was not included in the laboratory experiment.

  1. A condition of equilibrium of a condensate membrane in an electric field

    NASA Astrophysics Data System (ADS)

    Korovkin, V. P.; Bologa, M. K.; Savin, I. K.

    1986-08-01

    The change in the conditions of the thermodynamical equilibruim liquid-vapor due to wave structure formation in a homogeneous electric field has been examined. The authors show the increasing of the surface tension related with superficial electric tensions , leading to non isothermicity of the curved membrane and to increasing of the temperature of the equilibruim coexistence of phases as compared with smooth separation surface at the same pressure.

  2. A Status Report on the Exploitation Conditions of the Ahuachapan Geothermal Field

    SciTech Connect

    Rivera-R., Jesus; Vides-R., Alberto; Cuellar, Gustavo; Samaniego-V., Fernando; Neri-I, Gustavo

    1983-12-15

    The present exploitation conditions of the Ahuachapan field are discussed. The high well density in a small area has resulted in a significant reservoir pressure decrease due to the inherent reservoir over-exploitation. The average pressure in the exploitation zone has decreased from the 1975 value of 34 kg/cm{sup 2} to the May 1983 value of 23 kg/cm{sup 2}. The production decline characteristics of the Ahuachapan wells were examined, concluding that all wells but Ah-22 show exponential decline. The cumulative production-reinjection for the field up to April 1983 is 159.090 x 10{sup 6} tons, and 37.592 x 10{sup 6} tons, respectively. The effect of reinjection upon field behavior is evident when observing the pressure decline characteristics of the field. It is seen that for indection fraction related to total mass extracted above 30 percent, the average decline pressure in the production area becomes approximately stabilized. If this condition is not met the reservoir pressure decreases sharply. From this finding it is concluded that a careful and properly planned reinjection program is a must for the field. The observed temperature reduction in some of the wells seems to be the result of two operating mechanisms. First, we have the pressure decline that produces water vaporization and the consequent temperature descend. Analysis of information available shows no clear indication of deleterious temperature effects on the producing wells due to injection. The only exception observed to date is well Ah-5 that because its close distance and its relative structural position and direct hydraulic connection to injector Ah-29, presented conditions for fast displacement of the thermal front, resulting in unsufficient contact area and residence time for reheating of the injected water.

  3. Evaluation of Cyantraniliprole and Other Commercial Fly Baits under Laboratory and Field Conditions

    PubMed Central

    Parker, Casey; Baldwin, Rebecca; Pereira, Roberto; Koehler, Philip

    2015-01-01

    Laboratory and field trials were performed to evaluate the attractiveness and efficacy of commercial baits (cyantraniliprole; methomyl + (Z)-9-tricosene; dinotefuran + (Z)-9-tricosene; imidacloprid granular + (Z)-9-tricosene; and imidacloprid liquid + (Z)-9-tricosene). In choice tests; flies were most attracted to cyantraniliprole bait > dinotefuran + (Z)-9 > methomyl + (Z)-9 bait > imidacloprid granular + (Z)-9 bait > imidacloprid liquid + (Z)-9 bait. Significant degradation in bait efficacy was observed after two weeks of aging excluding imidacloprid granular; which began to degrade in field conditions after one week. Cyantraniliprole; the new fly bait active ingredient in Zyrox®; had the longest time to knockdown in the laboratory tests; but on susceptible flies; achieved 95%–100% knockdown within an hour of exposure. Zyrox® was resistant to weathering for a week; and was more attractive to flies in the field when compared to methomyl + (Z)-9 bait. PMID:26610575

  4. Stability of vaccinia-vectored recombinant oral rabies vaccine under field conditions: a 3-year study.

    PubMed

    Hermann, Joseph R; Fry, Alethea M; Siev, David; Slate, Dennis; Lewis, Charles; Gatewood, Donna M

    2011-10-01

    Rabies is an incurable zoonotic disease caused by rabies virus, a member of the rhabdovirus family. It is transmitted through the bite of an infected animal. Control methods, including oral rabies vaccination (ORV) programs, have led to a reduction in the spread and prevalence of the disease in wildlife. This study evaluated the stability of RABORAL, a recombinant vaccinia virus vaccine that is used in oral rabies vaccination programs. The vaccine was studied in various field microenvironments in order to describe its viability and facilitate effective baiting strategies. Field microenvironments influenced the stability of this vaccine in this study. This study emphasizes the importance of understanding how vaccines perform under varying field conditions in order to plan effective baiting strategies.

  5. Physiological responses related to moderate mental load during car driving in field conditions.

    PubMed

    Wiberg, Henrik; Nilsson, Emma; Lindén, Per; Svanberg, Bo; Poom, Leo

    2015-05-01

    We measured physiological variables on nine car drivers to capture moderate magnitudes of mental load (ML) during driving in prolonged and repeated city and highway field conditions. Ecological validity was optimized by avoiding any artificial interference to manipulate drivers ML, drivers were alone in the car, they were free to choose their paths to the target, and the repeated drives familiarized drivers to the procedure. Our aim was to investigate if driver's physiological variables can be reliably measured and used as predictors of moderate individual levels of ML in naturally occurring unpredictably changing field conditions. Variables investigated were: heart-rate, skin conductance level, breath duration, blink frequency, blink duration, and eye fixation related potentials. After the drives, with support from video uptakes, a self-rating and a score made by external raters were used to distinguish moderately high and low ML segments. Variability was high but aggregated data could distinguish city from highway drives. Multivariate models could successfully classify high and low ML within highway and city drives using physiological variables as input. In summary, physiological variables have a potential to be used as indicators of moderate ML in unpredictably changing field conditions and to advance the evaluation and development of new active safety systems.

  6. Magnetic Field Perturbations from Currents in the Dark Polar Regions During Quiet Geomagnetic Conditions

    NASA Astrophysics Data System (ADS)

    Friis-Christensen, E.; Finlay, C. C.; Hesse, M.; Laundal, K. M.

    2017-03-01

    In the day-side sunlit polar ionosphere the varying and IMF dependent convection creates strong ionospheric currents even during quiet geomagnetic conditions. Observations during such times are often excluded when using satellite data to model the internal geomagnetic main field. Observations from the night-side or local winter during quiet conditions are, however, also influenced by variations in the IMF. In this paper we briefly review the large scale features of the ionospheric currents in the polar regions with emphasis on the current distribution during undisturbed conditions. We examine the distribution of scalar measurements of the magnetic field intensity minus predictions from a geomagnetic field model. These `residuals' fall into two main categories. One category is consistently distributed according to the well-known ionospheric plasma convection and its associated Birkeland currents. The other category represent contributions caused by geomagnetic activity related to the substorm current wedge around local magnetic midnight. A new observation is a strong IMF By control of the residuals in the midnight sector indicating larger ionospheric currents in the substorm current wedge in the northern polar region for By > 0 and correspondingly in the southern hemisphere for By < 0.

  7. Environmental Influences on the Release of Ophiosphaerella agrostis Ascospores Under Controlled and Field Conditions.

    PubMed

    Kaminski, John E; Dernoeden, Peter H; O'Neill, Nichole R

    2005-11-01

    ABSTRACT Ophiosphaerella agrostis, the causal agent of dead spot of creeping bentgrass (Agrostis stolonifera), can produce prodigious numbers of pseudothecia and ascospores throughout the summer. The environmental conditions and seasonal timings associated with O. agrostis ascospore release are unknown. The objectives of this research were to (i) determine the influence of light and relative humidity on ascospore release in a controlled environment, (ii) document the seasonal and daily discharge patterns of ascospores in the field, and (iii) elucidate environmental conditions that promote ascospore release under field conditions. In a growth chamber, a sharp decrease (100 to approximately 50%; 25 degrees C) in relative humidity resulted in a rapid (1- to 3-h) discharge of ascospores, regardless of whether pseudothecia were incubated in constant light or dark. In the field, daily ascospore release increased between 1900 and 2300 h and again between 0700 and 1000 h local time. The release of ascospores occurred primarily during the early morning hours when relative humidity was decreasing and the canopy began to dry, or during evening hours when relative humidity was low and dew began to form. Few ascospores were released between 1100 and 1800 h when the bentgrass canopy was dry. The release of ascospores also was triggered by precipitation. Of the ascospores collected during precipitation events, 87% occurred within 10 h of the beginning of each event.

  8. Magnetic Field Perturbations from Currents in the Dark Polar Regions During Quiet Geomagnetic Conditions

    NASA Astrophysics Data System (ADS)

    Friis-Christensen, E.; Finlay, C. C.; Hesse, M.; Laundal, K. M.

    2017-02-01

    In the day-side sunlit polar ionosphere the varying and IMF dependent convection creates strong ionospheric currents even during quiet geomagnetic conditions. Observations during such times are often excluded when using satellite data to model the internal geomagnetic main field. Observations from the night-side or local winter during quiet conditions are, however, also influenced by variations in the IMF. In this paper we briefly review the large scale features of the ionospheric currents in the polar regions with emphasis on the current distribution during undisturbed conditions. We examine the distribution of scalar measurements of the magnetic field intensity minus predictions from a geomagnetic field model. These `residuals' fall into two main categories. One category is consistently distributed according to the well-known ionospheric plasma convection and its associated Birkeland currents. The other category represent contributions caused by geomagnetic activity related to the substorm current wedge around local magnetic midnight. A new observation is a strong IMF By control of the residuals in the midnight sector indicating larger ionospheric currents in the substorm current wedge in the northern polar region for By > 0 and correspondingly in the southern hemisphere for By < 0.

  9. A boundary condition to the Khokhlov-Zabolotskaya equation for modeling strongly focused nonlinear ultrasound fields

    SciTech Connect

    Rosnitskiy, P. Yuldashev, P. Khokhlova, V.

    2015-10-28

    An equivalent source model was proposed as a boundary condition to the nonlinear parabolic Khokhlov-Zabolotskaya (KZ) equation to simulate high intensity focused ultrasound (HIFU) fields generated by medical ultrasound transducers with the shape of a spherical shell. The boundary condition was set in the initial plane; the aperture, the focal distance, and the initial pressure of the source were chosen based on the best match of the axial pressure amplitude and phase distributions in the Rayleigh integral analytic solution for a spherical transducer and the linear parabolic approximation solution for the equivalent source. Analytic expressions for the equivalent source parameters were derived. It was shown that the proposed approach allowed us to transfer the boundary condition from the spherical surface to the plane and to achieve a very good match between the linear field solutions of the parabolic and full diffraction models even for highly focused sources with F-number less than unity. The proposed method can be further used to expand the capabilities of the KZ nonlinear parabolic equation for efficient modeling of HIFU fields generated by strongly focused sources.

  10. Biological control and plant growth promoting capacity of rhizobacteria on pepper under greenhouse and field conditions.

    PubMed

    Hahm, Mi-Seon; Sumayo, Marilyn; Hwang, Ye-Ji; Jeon, Seon-Ae; Park, Sung-Jin; Lee, Jai Youl; Ahn, Joon-Hyung; Kim, Byung-Soo; Ryu, Choong-Min; Ghim, Sa-Youl

    2012-06-01

    Plant growth promoting rhizobacteria Ochrobactrum lupini KUDC1013 and Novosphingobium pentaromativorans KUDC1065 isolated from Dokdo Island, S. Korea are capable of eliciting induced systemic resistance (ISR) in pepper against bacterial spot disease. The present study aimed to determine whether plant growth-promoting rhizobacteria (PGPR) strains including strain KUDC1013, strain KUDC1065, and Paenibacillus polymyxa E681 either singly or in combinations were evaluated to have the capacity for potential biological control and plant growth promotion effect in the field trials. Under greenhouse conditions, the induced systemic resistance (ISR) effect of treatment with strains KUDC1013 and KUDC1065 differed according to pepper growth stages. Drenching of 3-week-old pepper seedlings with the KUDC-1013 strain significantly reduced the disease symptoms. In contrast, treatment with the KUDC1065 strain significantly protected 5-week-old pepper seedlings. Under field conditions, peppers treated with PGPR mixtures containing E681 and KUDC1013, either in a two-way combination, were showed greater effect on plant growth than those treated with an individual treatment. Collectively, the application of mixtures of PGPR strains on pepper might be considered as a potential biological control under greenhouse and field conditions.

  11. The under-representation of African American women in the STEM fields within the academy: A historical profile and current perceptions

    NASA Astrophysics Data System (ADS)

    Howard, Tenisha Senora

    This research project seeks to discover the reasons behind the underrepresentation of African American women (AAW) in higher education, particularly in the Science Technology Engineering and Mathematics fields. Why is there underrepresentation of AAW in the STEM fields? Research evidence has demonstrated that AAW face social disparities such as race, gender, and class in the academy. A lack of adequate mentoring and financial resources to support their research efforts are related to these disparities and present fundamental challenges for them. To conduct the inquiry about the barriers AAW have to overcome to achieve success in STEM disciplines, a qualitative research method was used to "attend to social, historical, and temporal context. The findings of these studies are tentatively applied; that is, they may be applicable in diverse situations based on comparability of other contexts" (Mariano, 1995, p. 464). The researcher collected data by conducting in-depth interviews with five participants, using an open-ended conversational format to facilitate the development of trust, rapport, and maximum elicitation of stories from the participants. The results suggest that AAW overcome barriers to successful STEM careers through their family and social ties, mentoring relationships as well as their religious practices.

  12. Dermal exposure of pesticide applicators as a measure of coverall performance under field conditions.

    PubMed

    Machera, K; Tsakirakis, A; Charistou, A; Anastasiadou, P; Glass, C R

    2009-08-01

    In this study, the field performance of two coverall designs used by pesticide applicators was determined. Two coverall types were selected based on data from previously conducted comfort testing under field conditions in southern Europe. Dermal exposure was measured during 22 applications conducted with 11 operators using similar hand-held spray guns in greenhouse pepper crops in the Ierapetra region of Crete, Greece. One of the coverall designs studied was made from a cotton/polyester material treated with a water-repellent Resist Spills(R) finish, which was compared in the field study to a coverall of similar design, but using a woven, untreated cotton material. An in-house analytical method was developed and validated for determining residues of the active substance (a.s.) malathion on the dosimeters. The derived levels of dermal exposure were used as a measure of the protection provided by the two types of coveralls. In addition, by comparing the total amount of the a.s. recovered from outer and inner dosimeters (potential dermal exposure = 238.8 mg kg(-1) a.s. for the cotton coverall and 160.44 mg kg(-1) a.s. for the Resist Spills coverall), a value could be determined for the degree of coverall penetration. The mean penetration (milligrams per kilogram a.s.) of the outer coveralls, calculated as a percentage of the total contamination, was 0.4% for the water-repellent coverall and 2.3% for the cotton coverall. The mean recovery from the laboratory and field-fortified samples was >91 and 74%, respectively and used as the main criterion for quality control of the analytical data. Under the field trial conditions evaluated, both the coverall designs gave better protection than the default values used in the most relevant predictive exposure model. Therefore, they could be considered as appropriate tools of personal protection when both comfort and field performance is taken into account under the specific application scenario.

  13. Characterization of extremely low frequency magnetic fields from diesel, gasoline and hybrid cars under controlled conditions.

    PubMed

    Hareuveny, Ronen; Sudan, Madhuri; Halgamuge, Malka N; Yaffe, Yoav; Tzabari, Yuval; Namir, Daniel; Kheifets, Leeka

    2015-01-30

    This study characterizes extremely low frequency (ELF) magnetic field (MF) levels in 10 car models. Extensive measurements were conducted in three diesel, four gasoline, and three hybrid cars, under similar controlled conditions and negligible background fields. Averaged over all four seats under various driving scenarios the fields were lowest in diesel cars (0.02 μT), higher for gasoline (0.04-0.05 μT) and highest in hybrids (0.06-0.09 μT), but all were in-line with daily exposures from other sources. Hybrid cars had the highest mean and 95th percentile MF levels, and an especially large percentage of measurements above 0.2 μT. These parameters were also higher for moving conditions compared to standing while idling or revving at 2500 RPM and higher still at 80 km/h compared to 40 km/h. Fields in non-hybrid cars were higher at the front seats, while in hybrid cars they were higher at the back seats, particularly the back right seat where 16%-69% of measurements were greater than 0.2 μT. As our results do not include low frequency fields (below 30 Hz) that might be generated by tire rotation, we suggest that net currents flowing through the cars' metallic chassis may be a possible source of MF. Larger surveys in standardized and well-described settings should be conducted with different types of vehicles and with spectral analysis of fields including lower frequencies due to magnetization of tires.

  14. Characterization of Extremely Low Frequency Magnetic Fields from Diesel, Gasoline and Hybrid Cars under Controlled Conditions

    PubMed Central

    Hareuveny, Ronen; Sudan, Madhuri; Halgamuge, Malka N.; Yaffe, Yoav; Tzabari, Yuval; Namir, Daniel; Kheifets, Leeka

    2015-01-01

    This study characterizes extremely low frequency (ELF) magnetic field (MF) levels in 10 car models. Extensive measurements were conducted in three diesel, four gasoline, and three hybrid cars, under similar controlled conditions and negligible background fields. Averaged over all four seats under various driving scenarios the fields were lowest in diesel cars (0.02 μT), higher for gasoline (0.04–0.05 μT) and highest in hybrids (0.06–0.09 μT), but all were in-line with daily exposures from other sources. Hybrid cars had the highest mean and 95th percentile MF levels, and an especially large percentage of measurements above 0.2 μT. These parameters were also higher for moving conditions compared to standing while idling or revving at 2500 RPM and higher still at 80 km/h compared to 40 km/h. Fields in non-hybrid cars were higher at the front seats, while in hybrid cars they were higher at the back seats, particularly the back right seat where 16%–69% of measurements were greater than 0.2 μT. As our results do not include low frequency fields (below 30 Hz) that might be generated by tire rotation, we suggest that net currents flowing through the cars’ metallic chassis may be a possible source of MF. Larger surveys in standardized and well-described settings should be conducted with different types of vehicles and with spectral analysis of fields including lower frequencies due to magnetization of tires. PMID:25647323

  15. Light masking in the field: an experiment with nocturnal and diurnal spiny mice under semi-natural field conditions.

    PubMed

    Rotics, Shay; Dayan, Tamar; Levy, Ofir; Kronfeld-Schor, Noga

    2011-02-01

    Light masking has been studied almost exclusively in the laboratory. The authors populated four field enclosures with locally coexisting nocturnal Acomys cahirinus and diurnal A. russatus, and monitored their body temperatures (T(b)) using implanted temperature-sensitive radio transmitters. A 3-h light pulse was initiated at the beginning of two consecutive nights; preceding nights were controls. A. cahirinus T(b) and calculated activity levels decreased significantly during the light pulse, demonstrating a negative light masking response (light effect on T(b): -0.32 °C ± 0.15 °C; average calculated activity records during the light pulse: 7 ± 1.53, control: 9.8 ± 1.62). Diurnal A. russatus did not respond to the light pulse. We conclude that light masking is not an artifact of laboratory conditions but represents a natural adaptive response in free-living populations.

  16. Ion Cyclotron Wall Conditioning Experiments on Tore Supra in Presence of the Toroidal Magnetic Field

    SciTech Connect

    Wauters, T.; Douai, D.; Bremond, S.; Lombard, G.; Pegourie, B.; Tsitrone, E.; de la Cal, E.; Lyssoivan, A.; Van Schoor, M.

    2009-11-26

    Wall conditioning techniques applicable in the presence of the high toroidal magnetic field will be required for the operation of ITER for tritium removal, isotopic ratio control and recovery to normal operation after disruptions. Recently ion cyclotron wall conditioning (ICWC) experiments have been carried out on Tore Supra in order to assess the efficiency of this technique in ITER relevant conditions. The ICRF discharges were operated in He/H{sub 2} mixtures at the Tore Supra nominal field (3.8 T) and a RF frequency of 48 MHz, i.e. within the ITER operational space. RF pulses of 60 s (max.) were applied using a standard Tore Supra two-strap resonant double loop antenna in ICWC mode, operated either in {pi} or 0-phasing with a noticeable improvement of the RF coupling in the latter case. In order to assess the efficiency of the technique for the control of isotopic ratio the wall was first preloaded using a D{sub 2} glow discharge. After 15 minutes of ICWC in He/H{sub 2} gas mixtures the isotopic ratio was altered from 4% to 50% at the price of an important H implantation into the walls. An overall analysis comparing plasma production and the conditioning efficiency as a function of discharge parameters is given.

  17. Ion Cyclotron Wall Conditioning Experiments on Tore Supra in Presence of the Toroidal Magnetic Field

    NASA Astrophysics Data System (ADS)

    Wauters, T.; Douai, D.; Brémond, S.; de la Cal, E.; Lombard, G.; Lyssoivan, A.; Pegourié, B.; Tsitrone, E.; Van Schoor, M.; Van Oost, G.

    2009-11-01

    Wall conditioning techniques applicable in the presence of the high toroidal magnetic field will be required for the operation of ITER for tritium removal, isotopic ratio control and recovery to normal operation after disruptions. Recently ion cyclotron wall conditioning (ICWC) experiments have been carried out on Tore Supra in order to assess the efficiency of this technique in ITER relevant conditions. The ICRF discharges were operated in He/H2 mixtures at the Tore Supra nominal field (3.8 T) and a RF frequency of 48 MHz, i.e. within the ITER operational space. RF pulses of 60 s (max.) were applied using a standard Tore Supra two-strap resonant double loop antenna in ICWC mode, operated either in π or 0-phasing with a noticeable improvement of the RF coupling in the latter case. In order to assess the efficiency of the technique for the control of isotopic ratio the wall was first preloaded using a D2 glow discharge. After 15 minutes of ICWC in He/H2 gas mixtures the isotopic ratio was altered from 4% to 50% at the price of an important H implantation into the walls. An overall analysis comparing plasma production and the conditioning efficiency as a function of discharge parameters is given.

  18. Antimony retention and release from drained and waterlogged shooting range soil under field conditions.

    PubMed

    Hockmann, Kerstin; Tandy, Susan; Lenz, Markus; Reiser, René; Conesa, Héctor M; Keller, Martin; Studer, Björn; Schulin, Rainer

    2015-09-01

    Many soils polluted by antimony (Sb) are subject to fluctuating waterlogging conditions; yet, little is known about how these affect the mobility of this toxic element under field conditions. Here, we compared Sb leaching from a calcareous shooting range soil under drained and waterlogged conditions using four large outdoor lysimeters. After monitoring the leachate samples taken at bi-weekly intervals for >1.5 years under drained conditions, two of the lysimeters were subjected to waterlogging with a water table fluctuating according to natural rainfall water infiltration. Antimony leachate concentrations under drained conditions showed a strong seasonal fluctuation between 110 μg L(-1) in summer and <40 μg L(-1) in winter, which closely correlated with fluctuations in dissolved organic carbon (DOC) concentrations. With the development of anaerobic conditions upon waterlogging, Sb in leachate decreased to 2-5 μg L(-1) Sb and remained stable at this level. Antimony speciation measurements in soil solution indicated that this decrease in Sb(V) concentrations was attributable to the reduction of Sb(V) to Sb(III) and the stronger sorption affinity of the latter to iron (Fe) (hydr)oxide phases. Our results demonstrate the importance of considering seasonal and waterlogging effects in the assessment of the risks from Sb-contaminated sites.

  19. Seismic Reverse Time Migration Using A New Wave-Field Extrapolator and a New Imaging Condition

    NASA Astrophysics Data System (ADS)

    Moradpouri, Farzad; Moradzadeh, Ali; Pestana, Reynam C.; Soleimani Monfared, Mehrdad

    2016-10-01

    Prestack reverse time migration (RTM), as a two way wave-field extrapolation method, can image steeply dipping structures without any dip limitation at the expense of potential increase in imaging artifacts. In this paper, an efficient symplectic scheme, called Leapfrog-Rapid Expansion Method (L-REM), is first introduced to extrapolate the wavefield and its derivative in the same time step with high accuracy and free numerical dispersion using a Ricker wavelet of a maximum frequency of 25 Hz. Afterwards, in order to suppress the artifacts as a characteristic of RTM, a new imaging condition based on Poynting vector and a type of weighting function is presented. The capability of the proposed new imaging condition is then tested on synthetic data. The obtained results indicate that the proposed imaging condition is able to suppress the RTM artifacts effectively. They also show the ability of the proposed approach for improving the amplitude and compensate for illumination.

  20. Accuracy of user-friendly blood typing kits tested under simulated military field conditions.

    PubMed

    Bienek, Diane R; Charlton, David G

    2011-04-01

    Rapid user-friendly ABO-Rh blood typing kits (Eldon Home Kit 2511, ABO-Rh Combination Blood Typing Experiment Kit) were evaluated to determine their accuracy when used under simulated military field conditions and after long-term storage at various temperatures and humidities. Rates of positive tests between control groups, experimental groups, and industry standards were measured and analyzed using the Fisher's exact chi-square method to identify significant differences (p < or = 0.05). When Eldon Home Kits 2511 were used in various operational conditions, the results were comparable to those obtained with the control group and with the industry standard. The performance of the ABO-Rh Combination Blood Typing Experiment Kit was adversely affected by prolonged storage in temperatures above 37 degrees C. The diagnostic performance of commercial blood typing kits varies according to product and environmental storage conditions.

  1. Boundary conditions for the Baumgarte-Shapiro-Shibata-Nakamura formulation of Einstein's field equations

    SciTech Connect

    Nunez, Dario; Sarbach, Olivier

    2010-02-15

    We discuss the initial-boundary value problem for the Baumgarte-Shapiro-Shibata-Nakamura evolution system of Einstein's field equations which has been used extensively in numerical simulations of binary black holes and neutron stars. We specify nine boundary conditions for this system with the following properties: (i) they impose the momentum constraint at the boundary, which is shown to preserve all the constraints throughout evolution; (ii) they approximately control the incoming gravitational degrees of freedom by specifying the Weyl scalar {Psi}{sub 0} at the boundary; (iii) they control the gauge freedom by requiring a Neumann boundary condition for the lapse, by setting the normal component of the shift to zero, and by imposing a Sommerfeld-like condition on the tangential components of the shift; and (iv) they are shown to yield a well-posed problem in the limit of weak gravity. Possible numerical applications of our results are also discussed briefly.

  2. Electric-field conditions for Landauer and Boltzmann-Drude conductance equations

    NASA Astrophysics Data System (ADS)

    Fenton, E. W.

    1992-08-01

    It is shown explicitly in a unified theory of conductance, for bulk metals and mesoscopic systems, that a Landauer type of conductance equation is compatible with a spatially localized continuous-q-spectrum electric field that is unidirectional, but not with a homogeneous q=0 field. The reverse field condition holds for the Boltzmann-Drude conductance equation for an inhomogeneous bulk metal that has no inelastic scattering. A Feynman-diagram form of Green-function theory shows explicitly the virtual processes and repeated quantum scattering from a single object that occur with Feynman path integrals. The distinction between repeated scattering of current and repeated one-electron scattering is important. For a mesoscopic system, infinite conduction would occur if scattering were to be exactly zero-there is no necessity for postulated contact potentials between lead wires and thermal reservoirs. This is because just in this translationally invariant case a q=0 electric field must occur, and for this the Landauer equation must be replaced by the Boltzmann-Drude equation with zero scattering. In contrast to the strong frequency dependence of the Boltzmann-Drude equation, it is shown that no frequency dependence of the conductance occurs in the Landauer type of equation for frequencies much smaller than the inverse of the electron transit time across the electric-field region.

  3. Multiple abiotic stimuli are integrated in the regulation of rice gene expression under field conditions

    PubMed Central

    Plessis, Anne; Hafemeister, Christoph; Wilkins, Olivia; Gonzaga, Zennia Jean; Meyer, Rachel Sarah; Pires, Inês; Müller, Christian; Septiningsih, Endang M; Bonneau, Richard; Purugganan, Michael

    2015-01-01

    Plants rely on transcriptional dynamics to respond to multiple climatic fluctuations and contexts in nature. We analyzed the genome-wide gene expression patterns of rice (Oryza sativa) growing in rainfed and irrigated fields during two distinct tropical seasons and determined simple linear models that relate transcriptomic variation to climatic fluctuations. These models combine multiple environmental parameters to account for patterns of expression in the field of co-expressed gene clusters. We examined the similarities of our environmental models between tropical and temperate field conditions, using previously published data. We found that field type and macroclimate had broad impacts on transcriptional responses to environmental fluctuations, especially for genes involved in photosynthesis and development. Nevertheless, variation in solar radiation and temperature at the timescale of hours had reproducible effects across environmental contexts. These results provide a basis for broad-based predictive modeling of plant gene expression in the field. DOI: http://dx.doi.org/10.7554/eLife.08411.001 PMID:26609814

  4. The impact of time and field conditions on brown bear (Ursus arctos) faecal DNA amplification

    USGS Publications Warehouse

    Murphy, M.A.; Kendall, K.C.; Robinson, A.; Waits, L.P.

    2007-01-01

    To establish longevity of faecal DNA samples under varying summer field conditions, we collected 53 faeces from captive brown bears (Ursus arctos) on a restricted vegetation diet. Each faeces was divided, and one half was placed on a warm, dry field site while the other half was placed on a cool, wet field site on Moscow Mountain, Idaho, USA. Temperature, relative humidity, and dew point data were collected on each site, and faeces were sampled for DNA extraction at <1, 3, 6, 14, 30, 45, and 60 days. Faecal DNA sample viability was assessed by attempting PCR amplification of a mitochondrial DNA (mtDNA) locus (???150 bp) and a nuclear DNA (nDNA) microsatellite locus (180-200 bp). Time in the field, temperature, and dew point impacted mtDNA and nDNA amplification success with the greatest drop in success rates occurring between 1 and 3 days. In addition, genotyping errors significantly increased over time at both field sites. Based on these results, we recommend collecting samples at frequent transect intervals and focusing sampling efforts during drier portions of the year when possible. ?? 2007 Springer Science+Business Media, Inc.

  5. Some Growth Points in African Child Development Research

    ERIC Educational Resources Information Center

    Serpell, Robert; Marfo, Kofi

    2014-01-01

    We reflect on ways in which research presented in earlier chapters responds to challenges of generating an African child development field and identify additional issues calling for the field's attention. The chapters collectively display a variety of African contexts and reflexive evidence of the authors' African cultural roots. Connecting…

  6. Evolving Complex Networks Analysis of Space-Time Multi-Scale Wavelike Fields: Application to African Rainfall Dynamics

    NASA Astrophysics Data System (ADS)

    Oluoch, Kevin; Marwan, Norbert; Trauth, Martin; Kurths, Juergen

    2013-04-01

    underlying dynamics. The similarities are then weighted by their recurrence rate to ensure that the similarities are not a one time noise but regular temporal occurrence. Finally, the evolving complex networks are constructed. These networks are envisioned to shade more light into the patterns of African rainfall dynamics and their possible underlying sources. Last but not least, the global measures from the network will give new time series to compare with external possible forcing in the global network and the the rainfall dynamics.

  7. Field application of immunoassays for the detection of Mycobacterium bovis infection in the African buffalo (Syncerus caffer).

    PubMed

    van der Heijden, E M D L; Jenkins, A O; Cooper, D V; Rutten, V P M G; Michel, A L

    2016-01-01

    The African buffalo (Syncerus caffer) is considered the most important maintenance host of bovine tuberculosis (BTB) in wildlife in Southern Africa. The diagnosis of Mycobacterium bovis infection in this species mostly relies on the single intradermal comparative tuberculin test (SICTT). As an alternative, the BOVIGAM® 1G, an interferon-gamma (IFN-γ) release assay, is frequently used. The test performance of cell-mediated immunity (CMI-) and humoral immunity (HI-) based assays for the detection of M. bovis infections in buffaloes was compared to identify the test or test combination that provided the highest sensitivity in the study. Buffaloes were sampled during the annual BTB SICTT testing in the Hluhluwe-iMfolozi-Park (KwaZulu-Natal, South Africa) during June 2013. A total of 35 animals were subjected to the SICTT, 13 of these tested positive and one showed an inconclusive reaction. CMI-based assays (BOVIGAM® 1G (B1G) and BOVIGAM® 2G (B2G)) as well as a serological assay (IDEXX TB ELISA) were used to further investigate and compare immune responsiveness. Thirteen SICTT positive buffaloes and one inconclusive reactor were slaughtered and a post-mortem (PM) examination was conducted to confirm BTB. Lesions characteristic of BTB were found in 8/14 animals (57.1%). Test results of individual assays were compared with serial and parallel test interpretation and the sensitivity was calculated as a percentage of test positives out of the number of SICTT positive animals with granulomatous lesions (relative sensitivity). The B1G assay showed the highest individual sensitivity (100%; 8/8) followed by the B2G assay (75%; 6/8) and the IDEXX TB ELISA (37.5%; 3/8). Therefore, using in parallel interpretation, any combination with the B1G showed a sensitivity of 100% (8/8), whereas combinations with the B2G showed a 75% sensitivity (6/8). Out of the 21 SICTT negative animals, 7 animals showed responsiveness in the B2G or IDEXX TB ELISA. In conclusion, this study has shown

  8. Soil application of Beauveria bassiana to control Ceratitis capitata in semi field conditions.

    PubMed

    Ali, Ali; Sermann, Helga; Lerche, Sandra; Büttner, Carmen

    2009-01-01

    The Mediterranean fruit fly Ceratitis capitata (Wiedemann) is a highly polyphagous pest of economic importance cultures in Syria, as in many other parts of the world. The potential of the entomopathogenic fungus Beauveria bassiona BALS (VUIL.) strain 412 against adults of Mediterranean fruit fly C. capitata was evaluated in semi field conditions during the summer. Soil (5-7 cm high) was filled into plastic container (27 cm x 32 cm). In one container 75 pupae, two days before emergency, were spread uniformly on the soil. Then the pupae were covered with soil (4-5 cm layer). After that, 30 ml suspension of fungal spores (4 x 10(8) spores/ml) was applied to the soil surface using a dash bottle. This corresponded to a spore density of 1.3 x 10(7) spores/cm2 on soil. Water and food (1:4 yeast, sucrose) were placed in the cages for the emerged flies. The semi-field evaluation of B. bassiana revealed a fly mortality of about 46% compared to 16% in the control. In addition 72% of dead flies were moulded in the treatment. These results indicated that the entomopathogenic fungus B. bassiana was pathogen against the adults of C. capitata not only in the laboratory condition but also under field condition. That means B. bassiana could decrease the offspring of C. capitata. Therefore B. bassiana could be an effective factor to control C. capitata in combination with other control methods, used in IPM program in the field.

  9. Molecular dynamics study of nanoconfined water flow driven by rotating electric fields under realistic experimental conditions.

    PubMed

    De Luca, Sergio; Todd, B D; Hansen, J S; Daivis, Peter J

    2014-03-25

    In our recent work, J. Chem. Phys. 2013, 138, 154712, we demonstrated the feasibility of unidirectional pumping of water, exploiting translational-rotational momentum coupling using nonequilibrium molecular dynamics simulations. Flow can be sustained when the fluid is driven out of equilibrium by an external spatially uniform rotating electric field and confined between two planar surfaces exposing different degrees of hydrophobicity. The permanent dipole moment of water follows the rotating field, thus inducing the molecules to spin, and the torque exerted by the field is continuously injected into the fluid, enabling a steady conversion of spin angular momentum into linear momentum. The translational-rotational coupling is a sensitive function of the rotating electric field parameters. In this work, we have found that there exists a small energy dissipation region attainable when the frequency of the rotating electric field matches the inverse of the dielectric relaxation time of water and when its amplitude lies in a range just before dielectric saturation effects take place. In this region, that is, when the frequency lies in a small window of the microwave region around ∼20 GHz and amplitude ∼0.03 V Å(-1), the translational-rotational coupling is most effective, yielding fluid velocities of magnitudes of ∼2 ms(-1) with only moderate fluid heating. In this work, we also confine water to a realistic nanochannel made of graphene giving a hydrophobic surface on one side and β-cristobalite giving a hydrophilic surface on the other, reproducing slip-and-stick velocity boundary conditions, respectively. This enables us to demonstrate that in a realistic environment, the coupling can be effectively exploited to achieve noncontact pumping of water at the nanoscale. A quantitative comparison between nonequilibrium molecular dynamics and analytical solutions of the extended Navier-Stokes equations, including an external rotating electric field has been performed

  10. Developing anatomical terms in an African language.

    PubMed

    Madzimbamuto, Farai Daniel

    2012-02-23

    Clinical and technical information imparted in most African languages involves inexact terminology and code switching, so it lacks the explanatory power characterised by the English language. African languages are absent in the tertiary science education environment and forums where African scientists could present scientific material in the medium of African languages. This limits the development of African languages in the scientific domain. There has recently been a trend in several African languages to develop and intellectualise them, especially in the field of medical sciences. The ChiShona language is used to explore the ability of an African language to develop new terminology, to name the vertebral skeleton and describe it scientifically. It uses word compounding to demonstrate terminology development. ChiShona has similarities with several hundred other Bantu languages in East, Central and Southern Africa. Advancing this language can promote similar developments in others, making them more explanatory for the lay public and health professionals.

  11. Alachlor transformation patterns in aquatic field mesocosms under variable oxygen and nutrient conditions

    USGS Publications Warehouse

    Graham, D.W.; Miley, M.K.; Denoyelles, F.; Smith, V.H.; Thurman, E.M.; Carter, R.

    2000-01-01

    Alachlor is one of the most commonly used herbicides in both Europe and North America. Because of its toxic properties, its fate and attenuation in natural waters is practically important. This paper assesses factors that affect alachlor decay rate in aquatic systems using field-scale experimental units. In particular, we used field mesocosms (11.3 m3 outdoor fiberglass tanks) to examine the affect of oxygen level and other factors on decay rate in water columns. This is one of the first studies ever performed where diverse water column conditions have been successfully simulated using common mesocosm-scale facilities. Four treatments were assessed, including aerobic systems (aerobic); low nutrient, oxygen-stratified systems (stratified-LN); moderate nutrient, oxygen-stratified systems (stratified-HN); and anaerobic systems (anaerobic). The lowest half-lives were observed in the anaerobic units (9.7 days) followed by the aerobic (21 days), stratified-HN (22 days), and stratified-LN (46 days) units. Our results indicate that alachlor is transformed most rapidly under anaerobic conditions, although the ambient phosphorus level also appears to influence decay rate. In this study, two common alachlor breakdown products, ethane sulfonic acid (ESA) and oxanilic acid, were also monitored. Oxanilic acid was produced in greater quantities than ESA under all treatments with the highest levels being produced in the stratified-HN units. In general, our results suggest that previous laboratory data, which indicated that high rates of alachlor decay can occur under oxygen-free methanogenic conditions, is translatable to field-scale applications. Copyright (C) 2000 Elsevier Science Ltd.Alachlor is one of the most commonly used herbicides in both Europe and North America. Because of its toxic properties, its fate and attenuation in natural waters is practically important. This paper assesses factors that affect alachlor decay rate in aquatic systems using field-scale experimental

  12. Exposure to tebuconazol in rice field and laboratory conditions induces oxidative stress in carp (Cyprinus carpio).

    PubMed

    Toni, Cândida; Loro, Vania Lucia; Santi, Adriana; de Menezes, Charlene Cavalheiro; Cattaneo, Roberta; Clasen, Bárbara Estevão; Zanella, Renato

    2011-01-01

    Pesticides can have an effect on the biochemical and physiological functions of living organisms. The changes seen in fish and their response to pesticides can be used as an example for vertebrate toxicity. In this study, carp fish (Cyprinus carpio) were exposed to different concentrations of tebuconazol fungicide, by rice field (31.95 μg/L) and laboratory (33.47 and 36.23 μg/L) conditional testing, during a 7 day period. Parameters such thiobarbituric acid-reactive substance levels (TBARS), protein carbonyl, catalase, glutathione S-transferase and acetylcholinesterase activities were studied, using the liver, brain and white muscle of the fish. The field experiment showed that the TBARS levels were increased in all the analyzed tissues. Similarly, the protein carbonyl of the liver and the brain AChE activity increased after 7 days. The laboratory experiment demonstrated that the TBARS levels in the liver were increased in both of the concentration tests. TBARS levels in the muscle increased only by the lowest test concentration. On the other hand, the protein carbonyl was increased only by the highest concentration. The results indicate that the tebuconazol exposure from the field and laboratory conditions directly affected the health of the fish, showing the occurrence of oxidative stress.

  13. Preservation of RNA and DNA from mammal samples under field conditions.

    PubMed

    Camacho-Sanchez, Miguel; Burraco, Pablo; Gomez-Mestre, Ivan; Leonard, Jennifer A

    2013-07-01

    Ecological and conservation genetics require sampling of organisms in the wild. Appropriate preservation of the collected samples, usually by cryostorage, is key to the quality of the genetic data obtained. Nevertheless, cryopreservation in the field to ensure RNA and DNA stability is not always possible. We compared several nucleic acid preservation solutions appropriate for field sampling and tested them on rat (Rattus rattus) blood, ear and tail tip, liver, brain and muscle. We compared the efficacy of a nucleic acid preservation (NAP) buffer for DNA preservation against 95% ethanol and Longmire buffer, and for RNA preservation against RNAlater (Qiagen) and Longmire buffer, under simulated field conditions. For DNA, the NAP buffer was slightly better than cryopreservation or 95% ethanol, but high molecular weight DNA was preserved in all conditions. The NAP buffer preserved RNA as well as RNAlater. Liver yielded the best RNA and DNA quantity and quality; thus, liver should be the tissue preferentially collected from euthanized animals. We also show that DNA persists in nonpreserved muscle tissue for at least 1 week at ambient temperature, although degradation is noticeable in a matter of hours. When cryopreservation is not possible, the NAP buffer is an economical alternative for RNA preservation at ambient temperature for at least 2 months and DNA preservation for at least 10 months.

  14. Enrofloxacin degradation in broiler chicken manure under field conditions and its residuals effects to the environment.

    PubMed

    Slana, M; Žigon, D; Sollner-Dolenc, M

    2017-04-11

    The rate of degradation of enrofloxacin in broiler chicken manure has been characterised. Its degradation was investigated in manure excreted by broiler chickens in an intensively reared chicken facility; further, the degradation also followed after transfer of the excreta into the natural environment occurred. The effect of enrofloxacin and its degradation products on cucumber and tomato was also investigated. Enrofloxacin degradation was shown to take place within the rearing facility and also continuing after the manure was transferred into the environment. The rates of enrofloxacin degradation and the degree of degradation product formation in the manure heap incubated in the environment were condition specific, both variables depending on the manure sampling depth. The degradation half-lives ranged from 12.7 to 38.1 days for enrofloxacin and from 1.2 to 8.2 days for the main metabolite ciprofloxacin. Only the cucumber showed signs of toxicity when incubated with the composted manure immediately after transfer into field occurred (t = 0). No toxic effects to plants were observed when manure from the last incubation day (60th) of the field study and manure from the last incubation day of the laboratory degradation study were applied. The degradation study under field conditions showed that enrofloxacin and its degradation products degrade fast in the environment. Additionally, the toxic effects to plants decrease with the incubation time of manure containing enrofloxacin residuals.

  15. Control of Root Rot and Wilt Diseases of Roselle under Field Conditions.

    PubMed

    Hassan, Naglaa; Elsharkawy, Mohsen Mohamed; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-12-01

    Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle.

  16. Monitoring diapause development in the Colorado potato beetle, Leptinotarsa decemlineata, under field conditions using molecular biomarkers.

    PubMed

    Yocum, George D; Rinehart, Joseph P; Larson, Marnie L

    2011-05-01

    A multiplex PCR protocol was developed using five diapause-regulated genes to monitor diapause development of the Colorado potato beetle under field conditions. A total of 870 beetles from the Red River valley of North Dakota and Minnesota, USA, were screened for three consecutive years. Out of the 32 possible expression profiles, eight could be arranged in chronological order of diapause development. These eight profiles account for over 92% of the beetles surveyed. Intra-population variation in diapause phenotypes was observed in the field. Some beetles were already in the diapause initiation phase in June when the day length was greater than 17 h. Inter-seasonal variation in the timing of diapause development was also noted. The greatest differences were before the day length decreased to less than 15 h. Anomalies in the results, e.g., the presence of the diapause maintenance phase profiles in beetles collected on the potato plants, argue that laboratory results are not always equivalent with what is observed under field conditions.

  17. Spatial-Temporal Conditional Random Fields Crop Classification from Terrasar-X Images

    NASA Astrophysics Data System (ADS)

    Kenduiywoa, B. K.; Bargiel, D.; Soergel, U.

    2015-03-01

    The rapid increase in population in the world has propelled pressure on arable land. Consequently, the food basket has continuously declined while global demand for food has grown twofold. There is need to monitor and update agriculture land-cover to support food security measures. This study develops a spatial-temporal approach using conditional random fields (CRF) to classify co-registered images acquired in two epochs. We adopt random forest (RF) as CRF association potential and introduce a temporal potential for mutual crop phenology information exchange between spatially corresponding sites in two epochs. An important component of temporal potential is a transitional matrix that bears intra- and inter-class changes between considered epochs. Conventionally, one matrix has been used in the entire image thereby enforcing stationary transition probabilities in all sites. We introduce a site dependent transition matrix to incorporate phenology information from images. In our study, images are acquired within a vegetation season, thus perceived spectral changes are due to crop phenology. To exploit this phenomena, we develop a novel approach to determine site-wise transition matrix using conditional probabilities computed from two corresponding temporal sites. Conditional probability determines transitions between classes in different epochs and thus we used it to propagate crop phenology information. Classification results show that our approach improved crop discrimination in all epochs compared to state-of-the-art mono-temporal approaches (RF and CRF monotemporal) and existing multi-temporal markov random fields approach by Liu et al. (2008).

  18. Comparative analysis of electric field influence on the quantum wells with different boundary conditions.

    PubMed Central

    Olendski, Oleg

    2015-01-01

    Analytical solutions of the Schrödinger equation for the one-dimensional quantum well with all possible permutations of the Dirichlet and Neumann boundary conditions (BCs) in perpendicular to the interfaces uniform electric field are used for the comparative investigation of their interaction and its influence on the properties of the system. Limiting cases of the weak and strong voltages allow an easy mathematical treatment and its clear physical explanation; in particular, for the small , the perturbation theory derives for all geometries a linear dependence of the polarization on the field with the BC-dependent proportionality coefficient being positive (negative) for the ground (excited) states. Simple two-level approximation elementary explains the negative polarizations as a result of the field-induced destructive interference of the unperturbed modes and shows that in this case the admixture of only the neighboring states plays a dominant role. Different magnitudes of the polarization for different BCs in this regime are explained physically and confirmed numerically. Hellmann-Feynman theorem reveals a fundamental relation between the polarization and the speed of the energy change with the field. It is proved that zero-voltage position entropies are BC independent and for all states but the ground Neumann level (which has ) are equal to while the momentum entropies depend on the edge requirements and the level. Varying electric field changes position and momentum entropies in the opposite directions such that the entropic uncertainty relation is satisfied. Other physical quantities such as the BC-dependent zero-energy and zero-polarization fields are also studied both numerically and analytically. Applications to different branches of physics, such as ocean fluid dynamics and atmospheric and metallic waveguide electrodynamics, are discussed. PMID:25914413

  19. Field Verification of Structural Performance of Thermoplastic Pipe Under Deep Backfill Conditions

    NASA Astrophysics Data System (ADS)

    Sargand, S.

    2002-05-01

    This report provides information regarding the structural performance of thermoplastic pipes under relatively deep soil cover conditions. The eighteen (12 HDPE, 6 PVC) thermoplastic pipes, with diameter ranging from 30 to 60 in., were instrumented with sensors, embedded with granular backfill in shallow trenches, and subjected to 20-ft or 40-ft high soil fill for about 10 months. Their installation plans involved two types of backfill soil, three relative compactions, and varying bedding thickness to study the effects of these installation parameters on the pipe performance. Once the field performance of each test pipe was presented and discussed, comparative cross examinations of the entire field data were made to identify the effects of various installation parameters on the pipe deformations/deflections and soil pressure against pipe. A comprehensive set of soil testing was performed in the laboratory to characterize each of the three soil types that existed in the field. Results from the shear strength tests were analyzed further to obtain hyperbolic model parameter values for these soils. Three analytical methods (modified Iowa formula, elastic solutions, and finite element) were applied to evaluate their abilities to predict the field performance of the thermoplastic pipes under relatively deep soil cover. In their applications, material properties measured in the laboratory were utilized as much as possible.

  20. Biochemical basis of drought tolerance in hybrid Populus grown under field production conditions. CRADA final report

    SciTech Connect

    Tschaplinski, T.J.; Tuskan, G.A.; Wierman, C.

    1997-04-01

    The purpose of this cooperative effort was to assess the use of osmotically active compounds as molecular selection criteria for drought tolerance in Populus in a large-scale field trial. It is known that some plant species, and individuals within a plant species, can tolerate increasing stress associated with reduced moisture availability by accumulating solutes. The biochemical matrix of such metabolites varies among species and among individuals. The ability of Populus clones to tolerate drought has equal value to other fiber producers, i.e., the wood products industry, where irrigation is used in combination with other cultural treatments to obtain high dry weight yields. The research initially involved an assessment of drought stress under field conditions and characterization of changes in osmotic constitution among the seven clones across the six moisture levels. The near-term goal was to provide a mechanistic basis for clonal differences in productivity under various irrigation treatments over time.

  1. Efficient Semantic Segmentation of Man-Made Scenes Using Fully-Connected Conditional Random Field

    NASA Astrophysics Data System (ADS)

    Li, Weihao; Yang, Michael Ying

    2016-06-01

    In this paper we explore semantic segmentation of man-made scenes using fully connected conditional random field (CRF). Images of man-made scenes display strong contextual dependencies in the spatial structures. Fully connected CRFs can model long-range connections within the image of man-made scenes and make use of contextual information of scene structures. The pairwise edge potentials of fully connected CRF models are defined by a linear combination of Gaussian kernels. Using filter-based mean field algorithm, the inference is very efficient. Our experimental results demonstrate that fully connected CRF performs better than previous state-of-the-art approaches on both eTRIMS dataset and LabelMeFacade dataset.

  2. African Aesthetics

    ERIC Educational Resources Information Center

    Abiodun, Rowland

    2001-01-01

    No single traditional discipline can adequately supply answers to the many unresolved questions in African art history. Because of the aesthetic, cultural, historical, and, not infrequently, political biases, already built into the conception and development of Western art history, the discipline of art history as defined and practiced in the West…

  3. African Pentecostalism

    ERIC Educational Resources Information Center

    Garrard, David J.

    2009-01-01

    The diversity of African Pentecostalism, its early colonial and missionary history and its current characteristics are described and analysed. Reference is made to methods of training and forms of leadership, and suggestions are made about the reasons for its growth and persistence. (Contains 19 notes.)

  4. Frequency decomposition of conditional Granger causality and application to multivariate neural field potential data.

    PubMed

    Chen, Yonghong; Bressler, Steven L; Ding, Mingzhou

    2006-01-30

    It is often useful in multivariate time series analysis to determine statistical causal relations between different time series. Granger causality is a fundamental measure for this purpose. Yet the traditional pairwise approach to Granger causality analysis may not clearly distinguish between direct causal influences from one time series to another and indirect ones acting through a third time series. In order to differentiate direct from indirect Granger causality, a conditional Granger causality measure in the frequency domain is derived based on a partition matrix technique. Simulations and an application to neural field potential time series are demonstrated to validate the method.

  5. Conditional Random Field-Based Offline Map Matching for Indoor Environments.

    PubMed

    Bataineh, Safaa; Bahillo, Alfonso; Díez, Luis Enrique; Onieva, Enrique; Bataineh, Ikram

    2016-08-16

    In this paper, we present an offline map matching technique designed for indoor localization systems based on conditional random fields (CRF). The proposed algorithm can refine the results of existing indoor localization systems and match them with the map, using loose coupling between the existing localization system and the proposed map matching technique. The purpose of this research is to investigate the efficiency of using the CRF technique in offline map matching problems for different scenarios and parameters. The algorithm was applied to several real and simulated trajectories of different lengths. The results were then refined and matched with the map using the CRF algorithm.

  6. Conditional Random Field-Based Offline Map Matching for Indoor Environments

    PubMed Central

    Bataineh, Safaa; Bahillo, Alfonso; Díez, Luis Enrique; Onieva, Enrique; Bataineh, Ikram

    2016-01-01

    In this paper, we present an offline map matching technique designed for indoor localization systems based on conditional random fields (CRF). The proposed algorithm can refine the results of existing indoor localization systems and match them with the map, using loose coupling between the existing localization system and the proposed map matching technique. The purpose of this research is to investigate the efficiency of using the CRF technique in offline map matching problems for different scenarios and parameters. The algorithm was applied to several real and simulated trajectories of different lengths. The results were then refined and matched with the map using the CRF algorithm. PMID:27537892

  7. Gradual conditioning of non-Gaussian transmissivity fields to flow and mass transport data: 1. Theory

    NASA Astrophysics Data System (ADS)

    Capilla, José E.; Llopis-Albert, Carlos

    2009-06-01

    SummaryThe paper presents a new stochastic inverse method for the simulation of transmissivity ( T) fields conditional to T measurements, secondary information obtained from expert judgement and geophysical surveys, transient piezometric and solute concentration measurements, and travel time data. The formulation of the method is simple and derived from the gradual deformation method. It basically consists of an iterative optimization procedure in which successive combinations of T fields, that honour T measurements and soft data (secondary data obtained from expert judgement and/or geophysical surveys), gradually lead to a simulated T field conditional to flow and mass transport data. Every combination of fields requires minimizing a penalty function that penalizes the difference between computed and measured conditioning data. This penalty function depends on only one parameter. Travel time conditioning data are considered by means of a backward-in-time probabilistic model, which extends the potential applications of the method to the characterization of groundwater contamination sources. In order to solve the mass transport equation, the method implements a Lagrangian approach that allows avoiding numerical problems usually found in Eulerian methods. Besides, to deal with highly heterogeneous and non-Gaussian media, being able to reproduce anomalous breakthrough curves, a dual-domain approach is implemented with a first-order mass transfer approach. To determine the particle distribution between the mobile domain and the immobile domain the method uses a Bernoulli trial on the appropriate phase transition probabilities, derived using the normalized zeroth spatial moments of the multirate transport equations. The presented method does not require assuming the classical multiGaussian hypothesis thus easing the reproduction of T spatial patterns where extreme values of T show high connectivity. This feature allows the reproduction of a property found in real

  8. Field emission electric propulsion power conditioning unit design concept, volume 1

    NASA Astrophysics Data System (ADS)

    Gasparini, A.; Devambez, F.; Valentian, D.

    The requirements for auxiliary and primary propulsion systems were investigated in order to define the requirements for the field emission electric propulsion power conditioning unit (PCU). Emphasis was placed on simplifying the PCU design and improving weight. The PCU consists of a central power and control module (CPCM) connected to several thruster dedicated power supply modules (TDPDM). The connections between the CPCM and the TDPDM the command and control philosophy, and the power components and power circuits are considered. The use of high inverter frequencies and optical fiber data transmission to aleviate high voltage insulation problems are addressed.

  9. Laboratory capacity building for the International Health Regulations (IHR[2005]) in resource-poor countries: the experience of the African Field Epidemiology Network (AFENET).

    PubMed

    Masanza, Monica Musenero; Nqobile, Ndlovu; Mukanga, David; Gitta, Sheba Nakacubo

    2010-12-03

    Laboratory is one of the core capacities that countries must develop for the implementation of the International Health Regulations (IHR[2005]) since laboratory services play a major role in all the key processes of detection, assessment, response, notification, and monitoring of events. While developed countries easily adapt their well-organized routine laboratory services, resource-limited countries need considerable capacity building as many gaps still exist. In this paper, we discuss some of the efforts made by the African Field Epidemiology Network (AFENET) in supporting laboratory capacity development in the Africa region. The efforts range from promoting graduate level training programs to building advanced technical, managerial and leadership skills to in-service short course training for peripheral laboratory staff. A number of specific projects focus on external quality assurance, basic laboratory information systems, strengthening laboratory management towards accreditation, equipment calibration, harmonization of training materials, networking and provision of pre-packaged laboratory kits to support outbreak investigation. Available evidence indicates a positive effect of these efforts on laboratory capacity in the region. However, many opportunities exist, especially to support the roll-out of these projects as well as attending to some additional critical areas such as biosafety and biosecuity. We conclude that AFENET's approach of strengthening national and sub-national systems provide a model that could be adopted in resource-limited settings such as sub-Saharan Africa.

  10. The dissipation of hexazinone in tropical soils under semi-controlled field conditions in Kenya.

    PubMed

    Lalah, Joseph O; Muendo, Bonface M; Getenga, Zachary M

    2009-09-01

    The dissipation of hexazinone (Velpar) in two tropical soil types in Kenya was studied under field and semi-controlled conditions for a period of 84 days. The dissipation was found to be very rapid and this could be attributed to adverse weather conditions including high initial rainfall as well as to low soil-organic-matter content, volatilization, surface run-off and biodegradation. The DT(50) values of dissipation obtained by first order kinetics were 20 days and 21.3 days in clay and loam soil types, respectively. The influence of bargasse compost (1000 microg/g dry soil) was also studied and was found to enhance dissipation to some extent, giving DT(50) values of 18 days and 18.3 days in clay and loam soil types, respectively.

  11. Differential preferences of oviposition by Aedes mosquitos in man-made containers under field conditions.

    PubMed

    Chua, Kaw Bing; Chua, I-Ly; Chua, I-Ee; Chua, Kerk Hsiang

    2004-09-01

    A study was made of the oviposit behavior of gravid female Aedes mosquitos in man-made habitats under field conditions. The study showed that the gravid female Aedes mosquitos preferred containers with relatively easy access but not too open to external environmental influence. The dark surface of the containers served as the initial and long-range attractant to the breeding sites. Volatile chemicals generated by the decaying vegetation in the container may serve as a close-range attractant. Finally, the water quality and the quantity of 'food' derived from decaying vegetative matter in the water determined the amount of eggs deposited in each container. The study confirmed previous findings that each gravid female Aedes mosquito had the tendency to lay her eggs in more than one container. However, the results of the study suggests that under favorable conditions, each gravid female Aedes mosquito could be encouraged to lay all her eggs in a single breeding site.

  12. Metabolite changes in nine different soybean varieties grown under field and greenhouse conditions.

    PubMed

    Maria John, K M; Natarajan, Savithiry; Luthria, Devanand L

    2016-11-15

    Global food security remains a worldwide concern due to changing climate, increasing population, and reduced agriculture acreages. Greenhouse cultivation increases productivity by extending growing seasons, reducing pest infestations and providing protection against short term drastic weather fluctuations like frost, heat, rain, and wind. In the present study, we examined and compared the metabolic responses of nine soybean varieties grown under field and greenhouse conditions. Extracts were assayed by GC-FID, GC-MS, and LC-MS for the identification of 10 primary (amino acids, organic acids, and sugars) and 10 secondary (isoflavones, fatty acid methyl esters) metabolites. Sugar molecules (glucose, sucrose, and pinitol) and isoflavone aglycons were increased but the isoflavones glucoside content decreased in the greenhouse cultivated soybeans. The amino acids and organic acids varied between the varieties. The results show that clustering (PCA and PLS-DA) patterns of soybean metabolites were significantly influenced by the genetic variation and growing conditions.

  13. Collision avoidance in persons with homonymous visual field defects under virtual reality conditions.

    PubMed

    Papageorgiou, Eleni; Hardiess, Gregor; Ackermann, Hermann; Wiethoelter, Horst; Dietz, Klaus; Mallot, Hanspeter A; Schiefer, Ulrich

    2012-01-01

    The aim of the present study was to examine the effect of homonymous visual field defects (HVFDs) on collision avoidance of dynamic obstacles at an intersection under virtual reality (VR) conditions. Overall performance was quantitatively assessed as the number of collisions at a virtual intersection at two difficulty levels. HVFDs were assessed by binocular semi-automated kinetic perimetry within the 90° visual field, stimulus III4e and the area of sparing within the affected hemifield (A-SPAR in deg(2)) was calculated. The effect of A-SPAR, age, gender, side of brain lesion, time since brain lesion and presence of macular sparing on the number of collisions, as well as performance over time were investigated. Thirty patients (10 female, 20 male, age range: 19-71 years) with HVFDs due to unilateral vascular brain lesions and 30 group-age-matched subjects with normal visual fields were examined. The mean number of collisions was higher for patients and in the more difficult level they experienced more collisions with vehicles approaching from the blind side than the seeing side. Lower A-SPAR and increasing age were associated with decreasing performance. However, in agreement with previous studies, wide variability in performance among patients with identical visual field defects was observed and performance of some patients was similar to that of normal subjects. Both patients and healthy subjects displayed equal improvement of performance over time in the more difficult level. In conclusion, our results suggest that visual-field related parameters per se are inadequate in predicting successful collision avoidance. Individualized approaches which also consider compensatory strategies by means of eye and head movements should be introduced.

  14. Detection and characterization of regulatory elements using probabilistic conditional random field and hidden Markov models.

    PubMed

    Wang, Hongyan; Zhou, Xiaobo

    2013-04-01

    By altering the electrostatic charge of histones or providing binding sites to protein recognition molecules, Chromatin marks have been proposed to regulate gene expression, a property that has motivated researchers to link these marks to cis-regulatory elements. With the help of next generation sequencing technologies, we can now correlate one specific chromatin mark with regulatory elements (e.g. enhancers or promoters) and also build tools, such as hidden Markov models, to gain insight into mark combinations. However, hidden Markov models have limitation for their character of generative models and assume that a current observation depends only on a current hidden state in the chain. Here, we employed two graphical probabilistic models, namely the linear conditional random field model and multivariate hidden Markov model, to mark gene regions with different states based on recurrent and spatially coherent character of these eight marks. Both models revealed chromatin states that may correspond to enhancers and promoters, transcribed regions, transcriptional elongation, and low-signal regions. We also found that the linear conditional random field model was more effective than the hidden Markov model in recognizing regulatory elements, such as promoter-, enhancer-, and transcriptional elongation-associated regions, which gives us a better choice.

  15. Treated wastewater irrigation: uptake of pharmaceutical and personal care products by common vegetables under field conditions.

    PubMed

    Wu, Xiaoqin; Conkle, Jeremy L; Ernst, Frederick; Gan, Jay

    2014-10-07

    Global water shortage is placing an unprecedented pressure on water supplies. Treated wastewater is a valuable water resource, but its reuse for agricultural irrigation faces a roadblock: the public concern over the potential accumulation of contaminants of emerging concern (CECs) into human diet. In the present study, we measured the levels of 19 commonly occurring pharmaceutical and personal care products (PPCPs) in 8 vegetables irrigated with treated wastewater under field conditions. Tertiary treated wastewater without or with a fortification of each PPCP at 250 ng/L, was used to irrigate crops until harvest. Plant samples at premature and mature stages were collected. Analysis of edible tissues showed a detection frequency of 64% and 91% in all vegetables from the treated wastewater and fortified water treatments, respectively. The edible samples from the two treatments contained the same PPCPs, including caffeine, meprobamate, primidone, DEET, carbamazepine, dilantin, naproxen, and triclosan. The total concentrations of PPCPs detected in edible tissues from the treated wastewater and fortified irrigation treatments were in the range of 0.01-3.87 and 0.15-7.3 ng/g (dry weight), respectively. Annual exposure of PPCPs from the consumption of mature vegetables irrigated with the fortified water was estimated to be only 3.69 μg per capita. Results from the present study showed that the accumulation of PPCPs in vegetables irrigated with treated wastewater was likely limited under field conditions.

  16. The infinite-order conditional random field model for sequential data modeling.

    PubMed

    Chatzis, Sotirios P; Demiris, Yiannis

    2013-06-01

    Sequential data labeling is a fundamental task in machine learning applications, with speech and natural language processing, activity recognition in video sequences, and biomedical data analysis being characteristic examples, to name just a few. The conditional random field (CRF), a log-linear model representing the conditional distribution of the observation labels, is one of the most successful approaches for sequential data labeling and classification, and has lately received significant attention in machine learning as it achieves superb prediction performance in a variety of scenarios. Nevertheless, existing CRF formulations can capture only one- or few-timestep interactions and neglect higher order dependences, which are potentially useful in many real-life sequential data modeling applications. To resolve these issues, in this paper we introduce a novel CRF formulation, based on the postulation of an energy function which entails infinitely long time-dependences between the modeled data. Building blocks of our novel approach are: 1) the sequence memoizer (SM), a recently proposed nonparametric Bayesian approach for modeling label sequences with infinitely long time dependences, and 2) a mean-field-like approximation of the model marginal likelihood, which allows for the derivation of computationally efficient inference algorithms for our model. The efficacy of the so-obtained infinite-order CRF (CRF(∞)) model is experimentally demonstrated.

  17. Non-destructive Phenotyping to Identify Brachiaria Hybrids Tolerant to Waterlogging Stress under Field Conditions.

    PubMed

    Jiménez, Juan de la Cruz; Cardoso, Juan A; Leiva, Luisa F; Gil, Juanita; Forero, Manuel G; Worthington, Margaret L; Miles, John W; Rao, Idupulapati M

    2017-01-01

    Brachiaria grasses are sown in tropical regions around the world, especially in the Neotropics, to improve livestock production. Waterlogging is a major constraint to the productivity and persistence of Brachiaria grasses during the rainy season. While some Brachiaria cultivars are moderately tolerant to seasonal waterlogging, none of the commercial cultivars combines superior yield potential and nutritional quality with a high level of waterlogging tolerance. The Brachiaria breeding program at the International Center for Tropical Agriculture, has been using recurrent selection for the past two decades to combine forage yield with resistance to biotic and abiotic stress factors. The main objective of this study was to test the suitability of normalized difference vegetation index (NDVI) and image-based phenotyping as non-destructive approaches to identify Brachiaria hybrids tolerant to waterlogging stress under field conditions. Nineteen promising hybrid selections from the breeding program and three commercial checks were evaluated for their tolerance to waterlogging under field conditions. The waterlogging treatment was imposed by applying and maintaining water to 3 cm above soil surface. Plant performance was determined non-destructively using proximal sensing and image-based phenotyping and also destructively via harvesting for comparison. Image analysis of projected green and dead areas, NDVI and shoot biomass were positively correlated (r ≥ 0.8). Our results indicate that image analysis and NDVI can serve as non-destructive screening approaches for the identification of Brachiaria hybrids tolerant to waterlogging stress.

  18. Scene-Layout Compatible Conditional Random Field for Classifying Terrestrial Laser Point Clouds

    NASA Astrophysics Data System (ADS)

    Luo, C.; Sohn, G.

    2014-08-01

    Terrestrial Laser Scanning (TLS) rapidly becomes a primary surveying tool due to its fast acquisition of highly dense threedimensional point clouds. For fully utilizing its benefits, developing a robust method to classify many objects of interests from huge amounts of laser point clouds is urgently required. Conditional Random Field (CRF) is a well-known discriminative classifier, which integrates local appearance of the observation (laser point) with spatial interactions among its neighbouring points in classification process. Typical CRFs employ generic label consistency using short-range dependency only, which often causes locality problem. In this paper, we present a multi-range and asymmetric Conditional Random Field (CRF) (maCRF), which adopts a priori information of scene-layout compatibility addressing long-range dependency. The proposed CRF constructs two graphical models, one for enhancing a local labelling smoothness within short-range (srCRF) and the other for favouring a global and asymmetric regularity of spatial arrangement between different object classes within long-range (lrCRF). This maCRF classifier assumes two graphical models (srCRF and lrCRF) are independent of each other. Final labelling decision was accomplished by probabilistically combining prediction results obtained from two CRF models. We validated maCRF's performance with TLS point clouds acquired from RIEGL LMS-Z390i scanner using cross validation. Experiment results demonstrate that synergetic classification improvement can be achievable by incorporating two CRF models.

  19. Non-destructive Phenotyping to Identify Brachiaria Hybrids Tolerant to Waterlogging Stress under Field Conditions

    PubMed Central

    Jiménez, Juan de la Cruz; Cardoso, Juan A.; Leiva, Luisa F.; Gil, Juanita; Forero, Manuel G.; Worthington, Margaret L.; Miles, John W.; Rao, Idupulapati M.

    2017-01-01

    Brachiaria grasses are sown in tropical regions around the world, especially in the Neotropics, to improve livestock production. Waterlogging is a major constraint to the productivity and persistence of Brachiaria grasses during the rainy season. While some Brachiaria cultivars are moderately tolerant to seasonal waterlogging, none of the commercial cultivars combines superior yield potential and nutritional quality with a high level of waterlogging tolerance. The Brachiaria breeding program at the International Center for Tropical Agriculture, has been using recurrent selection for the past two decades to combine forage yield with resistance to biotic and abiotic stress factors. The main objective of this study was to test the suitability of normalized difference vegetation index (NDVI) and image-based phenotyping as non-destructive approaches to identify Brachiaria hybrids tolerant to waterlogging stress under field conditions. Nineteen promising hybrid selections from the breeding program and three commercial checks were evaluated for their tolerance to waterlogging under field conditions. The waterlogging treatment was imposed by applying and maintaining water to 3 cm above soil surface. Plant performance was determined non-destructively using proximal sensing and image-based phenotyping and also destructively via harvesting for comparison. Image analysis of projected green and dead areas, NDVI and shoot biomass were positively correlated (r ≥ 0.8). Our results indicate that image analysis and NDVI can serve as non-destructive screening approaches for the identification of Brachiaria hybrids tolerant to waterlogging stress. PMID:28243249

  20. The flow field investigations of no load conditions in axial flow fixed-blade turbine

    NASA Astrophysics Data System (ADS)

    Yang, J.; Gao, L.; Wang, Z. W.; Zhou, X. Z.; Xu, H. X.

    2014-03-01

    During the start-up process, the strong instabilities happened at no load operation in a low head axial flow fixed-blade turbine, with strong pressure pulsation and vibration. The rated speed can not reach until guide vane opening to some extent, and stable operation could not be maintained under the rated speed at some head, which had a negative impact on the grid-connected operation of the unit. In order to find the reason of this phenomenon, the unsteady flow field of the whole flow passage at no load conditions was carried out to analyze the detailed fluid field characteristics including the pressure pulsation and force imposed on the runner under three typical heads. The main hydraulic cause of no load conditions instability was described. It is recommended that the power station should try to reduce the no-load running time and go into the high load operation as soon as possible when connected to grid at the rated head. Following the recommendations, the plant operation practice proved the unstable degree of the unit was reduced greatly during start up and connect to the power grid.

  1. Constraining Eruptive Conditions From Lava Flow Morphometry: A Case Study With Field Evidence

    NASA Astrophysics Data System (ADS)

    Bowles, Z. R.; Clarke, A.; Greeley, R.

    2007-12-01

    Volcanism is widely recognized as one of the primary factors affecting the surfaces of solid planets and satellites throughout the solar system. Basaltic lava is thought to be the most common composition based on observed features typical of basaltic eruptions found on Earth. Lava flows are one of the most easily recognizable landforms on planetary surfaces and their features may provide information about eruption dynamics, lava rheology, and potential hazards. More recently, researchers have taken a multi-faceted approach to combine remote sensing, field observations and quantitative modeling to constrain volcanic activity on Earth and other planets. Here we test a number of published models, including empirically derived relationships from Mt. Etna and Kilauea, models derived from laboratory experiments, and theoretical models previously applied to remote sensing of planetary surfaces, against well-documented eruptions from the literature and field observations. We find that the Graetz (Hulme and Felder, 1977, Phil.Trans., 285, 227 - 234) method for estimating effusion rates compares favorably with published eruption data, while, on the other hand, inverting lava flow length prediction models to estimate effusion rates leads to several orders of magnitude in error. The Graetz method also better constrains eruption duration. Simple radial spreading laws predict Hawaiian lava flow lengths quite well, as do using the thickness of the lava flow front and chilled crust. There was no observed difference between results from models thought to be exclusive to aa or pahoehoe flow fields. Interpreting historic conditions should therefore follow simple relationships to observable morphologies no matter the composition or surface texture. We have applied the most robust models to understand the eruptive conditions and lava rheology of the Batamote Mountains near Ajo, AZ, an eroded shield volcano in southern Arizona. We find effusion rates on the order of 100 - 200 cubic

  2. Thermodynamic potentials from shifted boundary conditions: the scalar-field theory case

    NASA Astrophysics Data System (ADS)

    Giusti, Leonardo; Meyer, Harvey B.

    2011-11-01

    In a thermal field theory, the cumulants of the momentum distribution can be extracted from the dependence of the Euclidean path integral on a shift in the fields built into the temporal boundary condition. When combined with the Ward identities associated with the invariance of the theory under the Poincaré group, thermodynamic potentials such as the entropy or the pressure can be directly inferred from the response of the system to the shift. Crucially the argument holds, up to harmless finite-size and discretization effects, even if translational and rotational invariance are broken to a discrete subgroup of finite shifts and rotations such as in a lattice box. The formulas are thus applicable at finite lattice spacing and volume provided the derivatives are replaced by their discrete counterpart, and no additive or multiplicative ultraviolet-divergent renormalizations are needed to take the continuum limit. In this paper we present a complete derivation of the relevant formulas in the scalar field theory, where several technical complications are avoided with respect to gauge theories. As a by-product we obtain a recursion relation among the cumulants of the momentum distribution, and formulæ for finite-volume corrections to several well-known thermodynamic identities.

  3. Velocity and magnetic field measurements of Taylor plumes in SSX under different boundary conditions

    NASA Astrophysics Data System (ADS)

    Kaur, Manjit; Brown, M. R.; Han, J.; Shrock, J. E.; Schaffner, D. A.

    2016-10-01

    The SSX device has been modified by the addition of a 1 m long glass extension for accommodating pulsed theta pinch coils. The Taylor plumes are launched from a magnetized plasma gun and flow to an expansion volume downstream. The time of flight (TOF) measurements of these plumes are carried out using a linear array of Ḃ probes (separated by 10cm). TOF of the plasma plumes from one probe location to the next is determined by direct comparison of the magnetic field structures as well as by carrying out a cross-correlation analysis. With the glass boundary, the typical velocity of the Taylor plumes is found to be 25km /s , accompanied by a fast plasma (>= 50km /s) at the leading edge. Magnetic field embedded in the Taylor plumes is measured in the expansion chamber using a three-dimensional array of Ḃ probes and is found to be 700G . Some flux conservation of the Taylor plumes is provided by using a resistive (soak time 3 μs) and a mesh (soak time 170 μs > discharge time) liner around the glass tube for improving the downstream Taylor state velocity as well as the magnetic field. The results from these different boundary conditions will be presented. Work supported by DOE OFES and ARPA-E ALPHA programs.

  4. Observing soil water dynamics under two field conditions by a novel sensor system

    NASA Astrophysics Data System (ADS)

    Sheng, W.; Sun, Y.; Schulze Lammers, P.; Schumann, H.; Berg, A.; Shi, C.; Wang, C.

    2011-10-01

    SummarySufficiently available soil water is a basic requirement in agricultural production. Monitoring soil water dynamics (SWD) in the root zone is an optimal approach for managing a crop's growth. This study presents a novel sensor system that simultaneously measures volumetric soil water content (VSWC), apparent electrical conductivity (EC a) and soil temperature at two different soil depths (shallow: 16 cm; deep: 36 cm). For testing its feasibility in the field, two prototypes were installed, one in bare soil and the other in a sugar beet ( Beta vulgaris L.) field in the summer of 2010. Following a sequence of rainfall events randomly distributed over the experimental period, we observed distinct responses from the sensors at each monitored depth in both field conditions. In addition to the multi-parameter measurements, the novel sensor design includes a series of technical advantages such as solar-powered operation, wireless communication, and being relatively easy to install/remove. Thus, the developed wireless sensor system is promising for networked applications in precision farming.

  5. Effects of variation in solar conditions and crustal sources' orientation on the Martian magnetic field topology

    NASA Astrophysics Data System (ADS)

    Ulusen, D.; Luhmann, J. G.; Ma, Y.; Brain, D. A.

    2013-12-01

    Strong crustal magnetic sources on the surface of Mars directly interact with the solar magnetic field and plasma, resulting a very dynamic environment near the planet. Effects of the orientation of these remnant magnetic sources with respect to the sun and variation of the solar conditions on the Martian plasma interaction have been investigated in a previous paper. In this previous study, magnetic topology maps obtained from ~7 years of Mars Global Surveyor (MGS) directional electron observations (obtained by Dave Brain) were compared with the topology maps obtained from a set of BATS-R-US MHD simulations for Mars. One conclusion from this study was that although the MHD model is consistent with the data and provides insight about the global magnetic field topology variation with changing crustal field orientation and solar parameters, detailed investigation of local effects is difficult due to MGS orbital bias. Moreover, proper comparison of the observations with the model requires more careful data selection rather than using 7 years time averages. In this paper, we readdress the study to tackle the problems of our previous work by performing more detailed data analysis and present the results of the updated model-data comparison.

  6. Table Extraction from Web Pages Using Conditional Random Fields to Extract Toponym Related Data

    NASA Astrophysics Data System (ADS)

    Luthfi Hanifah, Hayyu’; Akbar, Saiful

    2017-01-01

    Table is one of the ways to visualize information on web pages. The abundant number of web pages that compose the World Wide Web has been the motivation of information extraction and information retrieval research, including the research for table extraction. Besides, there is a need for a system which is designed to specifically handle location-related information. Based on this background, this research is conducted to provide a way to extract location-related data from web tables so that it can be used in the development of Geographic Information Retrieval (GIR) system. The location-related data will be identified by the toponym (location name). In this research, a rule-based approach with gazetteer is used to recognize toponym from web table. Meanwhile, to extract data from a table, a combination of rule-based approach and statistical-based approach is used. On the statistical-based approach, Conditional Random Fields (CRF) model is used to understand the schema of the table. The result of table extraction is presented on JSON format. If a web table contains toponym, a field will be added on the JSON document to store the toponym values. This field can be used to index the table data in accordance to the toponym, which then can be used in the development of GIR system.

  7. Automatic control of positioning along the joint during EBW in conditions of action of magnetic fields

    NASA Astrophysics Data System (ADS)

    Druzhinina, A. A.; Laptenok, V. D.; Murygin, A. V.; Laptenok, P. V.

    2016-11-01

    Positioning along the joint during the electron beam welding is a difficult scientific and technical problem to achieve the high quality of welds. The final solution of this problem is not found. This is caused by weak interference protection of sensors of the joint position directly in the welding process. Frequently during the electron beam welding magnetic fields deflect the electron beam from the optical axis of the electron beam gun. The collimated X-ray sensor is used to monitor the beam deflection caused by the action of magnetic fields. Signal of X-ray sensor is processed by the method of synchronous detection. Analysis of spectral characteristics of the X-ray sensor showed that the displacement of the joint from the optical axis of the gun affects on the output signal of sensor. The authors propose dual-circuit system for automatic positioning of the electron beam on the joint during the electron beam welding in conditions of action of magnetic interference. This system includes a contour of joint tracking and contour of compensation of magnetic fields. The proposed system is stable. Calculation of dynamic error of system showed that error of positioning does not exceed permissible deviation of the electron beam from the joint plane.

  8. Effects of agricultural practices of three crops on the soil communities under Mediterranean conditions: field evaluation.

    NASA Astrophysics Data System (ADS)

    Leitão, Sara; José Cerejeira, Maria; Abreu, Manuela; Sousa, José Paulo

    2014-05-01

    Sustainable agricultural production relies on soil communities as the main actors in key soil processes necessary to maintain sustainable soil functioning. Soil biodiversity influences soil physical and chemical characteristics and thus the sustainability of crop and agro-ecosystems functioning. Agricultural practices (e.g.: soil tillage, pesticides and fertilizer applications, irrigation) may affects negatively or positively soil biodiversity and abundances by modifying the relationships between organisms in the soil ecosystem. The present study aimed to study the influence of agricultural practices of three crops (potato, onion and maize) under Mediterranean climate conditions on soil macro- and mesofauna during their entire crop cycles. Effects on soil communities were assessed at a higher tier of environmental risk assessment comprising field testing of indigenous edaphic communities in a selected study-site located in a major agriculture region of Central Portugal, Ribatejo e Oeste, neighbouring protected wetlands. A reference site near the agricultural field site was selected as a Control site to compare the terrestrial communities' composition and variation along the crop cycle. The field soil and Control site soil are sandy loam soils. Crops irrigation was performed by center-pivot (automated sprinkler that rotates in a half a circle area) and by sprinklers. Soil macro- and mesofauna were collected at both sites (field and Control) using two methodologies through pitfall trapping and soil sampling. The community of soil macro- and mesofauna of the three crops field varied versus control site along the crops cycles. Main differences were due to arachnids, coleopterans, ants and adult Diptera presence and abundance. The feeding activity of soil fauna between control site and crop areas varied only for potato and onion crops vs. control site but not among crops. Concentration of pesticides residues in soil did not cause apparent negative effects on the soil

  9. A wind tunnel for measuring selenium volatilization under field-like conditions

    SciTech Connect

    Dungan, R.S.; Stork, A.; Frankenberger, W.T. Jr.

    2000-04-01

    A wind tunnel was developed to measure the loss of volatile selenium (Se) from soil under field-like conditions. The wind tunnel consisted of a volatilization chamber made of Plexiglas (2.4 m long x 0.8 m wide x 1.2 m high), which was set above a stainless steel lysimeter (0.5 m{sup 2} surface area x 0.8 m deep). High air exchange rates (avg. 700 air changes h{sup {minus}1}) were used to simulate field-like environmental conditions inside the wind tunnel. To monitor the fate and transport of the Se, radiolabeled {sup 75}Se as sodium selenite (Na{sub 2}{sup 75}SeO{sub 3}) was incorporated into the top 5 cm of soil. Volatile Se was trapped on activated carbon filters and measured directly using gamma counting. A 135-d bare-soil experiment was carried out, during which 2.7% of the Se was released through volatilization without added C. The average flux rate of gaseous Se was 17 mg m{sup {minus}2} h{sup {minus}1}, with a high of 72 mg m{sup {minus}2} h{sup {minus}1} occurring on Day 6. After 135 d, 59 and 43% of the {sup 75}Se was located in the 0 to 5 and 5 to 10 cm soil layers, respectively. A total of 84.5% of all applied {sup 75}Se was recovered. The purpose of this study was to improve estimates on Se volatilization from seleniferous soils and help close the gap between previous laboratory and field experiments.

  10. Crop Type Mapping from a Sequence of Terrasar-X Images with Dynamic Conditional Random Fields

    NASA Astrophysics Data System (ADS)

    Kenduiywo, B. K.; Bargiel, D.; Soergel, U.

    2016-06-01

    Crop phenology is dynamic as it changes with times of the year. Such biophysical processes also look spectrally different to remote sensing satellites. Some crops may depict similar spectral properties if their phenology coincide, but differ later when their phenology diverge. Thus, conventional approaches that select only images from phenological stages where crops are distinguishable for classification, have low discrimination. In contrast, stacking images within a cropping season limits discrimination to a single feature space that can suffer from overlapping classes. Since crop backscatter varies with time, it can aid discrimination. Therefore, our main objective is to develop a crop sequence classification method using multitemporal TerraSAR-X images. We adopt first order markov assumption in undirected temporal graph sequence. This property is exploited to implement Dynamic Conditional Random Fields (DCRFs). Our DCRFs model has a repeated structure of temporally connected Conditional Random Fields (CRFs). Each node in the sequence is connected to its predecessor via conditional probability matrix. The matrix is computed using posterior class probabilities from association potential. This way, there is a mutual temporal exchange of phenological information observed in TerraSAR-X images. When compared to independent epoch classification, the designed DCRF model improved crop discrimination at each epoch in the sequence. However, government, insurers, agricultural market traders and other stakeholders are interested in the quantity of a certain crop in a season. Therefore, we further develop a DCRF ensemble classifier. The ensemble produces an optimal crop map by maximizing over posterior class probabilities selected from the sequence based on maximum F1-score and weighted by correctness. Our ensemble technique is compared to standard approach of stacking all images as bands for classification using Maximum Likelihood Classifier (MLC) and standard CRFs. It

  11. LSST summit facility construction progress report: reacting to design refinements and field conditions

    NASA Astrophysics Data System (ADS)

    Barr, Jeffrey D.; Gressler, William; Sebag, Jacques; Seriche, Jaime; Serrano, Eduardo

    2016-07-01

    The civil work, site infrastructure and buildings for the summit facility of the Large Synoptic Survey Telescope (LSST) are among the first major elements that need to be designed, bid and constructed to support the subsequent integration of the dome, telescope, optics, camera and supporting systems. As the contracts for those other major subsystems now move forward under the management of the LSST Telescope and Site (T and S) team, there has been inevitable and beneficial evolution in their designs, which has resulted in significant modifications to the facility and infrastructure. The earliest design requirements for the LSST summit facility were first documented in 2005, its contracted full design was initiated in 2010, and construction began in January, 2015. During that entire development period, and extending now roughly halfway through construction, there continue to be necessary modifications to the facility design resulting from the refinement of interfaces to other major elements of the LSST project and now, during construction, due to unanticipated field conditions. Changes from evolving interfaces have principally involved the telescope mount, the dome and mirror handling/coating facilities which have included significant variations in mass, dimensions, heat loads and anchorage conditions. Modifications related to field conditions have included specifying and testing alternative methods of excavation and contending with the lack of competent rock substrate where it was predicted to be. While these and other necessary changes are somewhat specific to the LSST project and site, they also exemplify inherent challenges related to the typical timeline for the design and construction of astronomical observatory support facilities relative to the overall development of the project.

  12. Toltrazuril treatment of cystoisosporosis in dogs under experimental and field conditions.

    PubMed

    Daugschies, A; Mundt, H C; Letkova, V

    2000-10-01

    Coccidia of the genus Cystoisospora cause mild to severe diarrhoea in dogs. The effects of toltrazuril treatment on cystoisosporosis were studied under experimental and field conditions. Twenty-four puppies were experimentally infected each with 4 x 10(4) oocysts of the Cystoisospora ohioensis group. Three groups of six puppies were treated 3 dpi with 10, 20 or 30 mg/kg body weight of toltrazuril suspension (5%); the remaining six puppies served as non-treated controls. Toltrazuril suspension or microgranulate were given once in a dose of 10 or 20 mg/kg body weight, respectively, to naturally infected puppies in conventional dog breeding facilities, depending on the coproscopical evidence of infection. Oocyst excretion and clinical data were recorded. Under experimental conditions, the non-treated puppies excreted oocysts beginning at 6 dpi and suffered from catarrhalic to haemorrhagic diarrhoea. On 12 dpi, four of six non-treated puppies died. Irrespective of the dose, toltrazuril treatment totally suppressed oocyst excretion and no diarrhoea or other signs of disease were observed in the treated groups. Natural Cystoisospora infections were regularly found during the 3rd or 4th week of age in dog breeding facilities although not always associated with diarrhoea. A single oral application of toltrazuril abrogated oocyst shedding and the treated puppies remained generally coproscopically negative during the following 2-4 weeks. Cystoisospora is pathogenic for puppies and can induce severe disease. Natural infections are common in conventional dog breeding facilities. Toltrazuril treatment is suitable for controlling cystoisosporosis under experimental and field conditions. A single oral treatment for puppies in the 3rd or 4th week of age is recommended.

  13. Directional orientation of birds by the magnetic field under different light conditions.

    PubMed

    Wiltschko, Roswitha; Stapput, Katrin; Thalau, Peter; Wiltschko, Wolfgang

    2010-04-06

    This paper reviews the directional orientation of birds with the help of the geomagnetic field under various light conditions. Two fundamentally different types of response can be distinguished. (i) Compass orientation controlled by the inclination compass that allows birds to locate courses of different origin. This is restricted to a narrow functional window around the total intensity of the local geomagnetic field and requires light from the short-wavelength part of the spectrum. The compass is based on radical-pair processes in the right eye; magnetite-based receptors in the beak are not involved. Compass orientation is observed under 'white' and low-level monochromatic light from ultraviolet (UV) to about 565 nm green light. (ii) 'Fixed direction' responses occur under artificial light conditions such as more intense monochromatic light, when 590 nm yellow light is added to short-wavelength light, and in total darkness. The manifestation of these responses depends on the ambient light regime and is 'fixed' in the sense of not showing the normal change between spring and autumn; their biological significance is unclear. In contrast to compass orientation, fixed-direction responses are polar magnetic responses and occur within a wide range of magnetic intensities. They are disrupted by local anaesthesia of the upper beak, which indicates that the respective magnetic information is mediated by iron-based receptors located there. The influence of light conditions on the two types of response suggests complex interactions between magnetoreceptors in the right eye, those in the upper beak and the visual system.

  14. Directional orientation of birds by the magnetic field under different light conditions

    PubMed Central

    Wiltschko, Roswitha; Stapput, Katrin; Thalau, Peter; Wiltschko, Wolfgang

    2010-01-01

    This paper reviews the directional orientation of birds with the help of the geomagnetic field under various light conditions. Two fundamentally different types of response can be distinguished. (i) Compass orientation controlled by the inclination compass that allows birds to locate courses of different origin. This is restricted to a narrow functional window around the total intensity of the local geomagnetic field and requires light from the short-wavelength part of the spectrum. The compass is based on radical-pair processes in the right eye; magnetite-based receptors in the beak are not involved. Compass orientation is observed under ‘white’ and low-level monochromatic light from ultraviolet (UV) to about 565 nm green light. (ii) ‘Fixed direction’ responses occur under artificial light conditions such as more intense monochromatic light, when 590 nm yellow light is added to short-wavelength light, and in total darkness. The manifestation of these responses depends on the ambient light regime and is ‘fixed’ in the sense of not showing the normal change between spring and autumn; their biological significance is unclear. In contrast to compass orientation, fixed-direction responses are polar magnetic responses and occur within a wide range of magnetic intensities. They are disrupted by local anaesthesia of the upper beak, which indicates that the respective magnetic information is mediated by iron-based receptors located there. The influence of light conditions on the two types of response suggests complex interactions between magnetoreceptors in the right eye, those in the upper beak and the visual system. PMID:19864263

  15. African-American Biography.

    ERIC Educational Resources Information Center

    Martin, Ron

    1995-01-01

    Suggests sources of information for African American History Month for library media specialists who work with students in grades four through eight. Gale Research's "African-American Reference Library," which includes "African-America Biography,""African-American Chronology," and "African-American Almanac,"…

  16. MECHANICAL STRENGTH RESPONSES OF POLED LEAD ZIRCONATE TITANATE UNDER EXTREME ELECTRIC FIELD AND VARIOUS TEMPERATURE CONDITIONS

    SciTech Connect

    Wang, Hong; Matsunaga, Tadashi; Zhang, Kewei; Lin, Hua-Tay; Wereszczak, Andrew A

    2016-01-01

    PZT (lead zirconate titanate), particularly PZT-5A, is used in a variety of critical actuation and sensing systems because of its high Curie temperature and large piezoelectric coefficients. However, PZT is susceptible to mechanical failure. The evaluation of the mechanical strength of the material under the target working conditions is very important. This study presents part of the recent experimental developments in mechanical testing and evaluation of PZT materials at Oak Ridge National Laboratory. Ball-on-ring and four-point bending testing setups were used, with modifications made to account for testing requirements from high-level electric field and elevated temperature. The poled PZT-5A or equivalent material was tested under various specimen and testing conditions. The parameters of the distribution of strengths (characteristic strength and Weibull modulus) are discussed in relation to the testing conditions. Fractographic results based on scanning electron microscopy are also presented and discussed. The related data can serve as input for the design of piezoceramic devices, not only those used in energy systems like fuel injectors in heavy-duty diesel engines, but also those used in structural health monitoring, energy harvesting, and other critical systems in aerospace and civil engineering.

  17. Conformal field theory of critical Casimir forces between surfaces with alternating boundary conditions in two dimensions

    NASA Astrophysics Data System (ADS)

    Dubail, J.; Santachiara, R.; Emig, T.

    2017-03-01

    Systems as diverse as binary mixtures and inclusions in biological membranes, and many more, can be described effectively by interacting spins. When the critical fluctuations in these systems are constrained by boundary conditions, critical Casimir forces (CCF) emerge. Here we analyze CCF between boundaries with alternating boundary conditions in two dimensions, employing conformal field theory (CFT). After presenting the concept of boundary changing operators, we specifically consider two different boundary configurations for a strip of critical Ising spins: (I) alternating equi-sized domains of up and down spins on both sides of the strip, with a possible lateral shift, and (II) alternating domains of up and down spins of different size on one side and homogeneously fixed spins on the other side of the strip. Asymptotic results for the CCF at small and large distances are derived. We introduce a novel modified Szegö formula for determinants of real antisymmetric block Toeplitz matrices to obtain the exact CCF and the corresponding scaling functions at all distances. We demonstrate the existence of a surface renormalization group flow between universal force amplitudes of different magnitude and sign. The Casimir force can vanish at a stable equilibrium position that can be controlled by parameters of the boundary conditions. Lateral Casimir forces assume a universal simple cosine form at large separations.

  18. Transgenic alteration of ethylene biosynthesis increases grain yield in maize under field drought-stress conditions.

    PubMed

    Habben, Jeffrey E; Bao, Xiaoming; Bate, Nicholas J; DeBruin, Jason L; Dolan, Dennis; Hasegawa, Darren; Helentjaris, Timothy G; Lafitte, Renee H; Lovan, Nina; Mo, Hua; Reimann, Kellie; Schussler, Jeffrey R

    2014-08-01

    A transgenic gene-silencing approach was used to modulate the levels of ethylene biosynthesis in maize (Zea mays L.) and determine its effect on grain yield under drought stress in a comprehensive set of field trials. Commercially relevant transgenic events were created with down-regulated ACC synthases (ACSs), enzymes that catalyse the rate-limiting step in ethylene biosynthesis. These events had ethylene emission levels reduced approximately 50% compared with nontransgenic nulls. Multiple, independent transgenic hybrids and controls were tested in field trials at managed drought-stress and rain-fed locations throughout the US. Analysis of yield data indicated that transgenic events had significantly increased grain yield over the null comparators, with the best event having a 0.58 Mg/ha (9.3 bushel/acre) increase after a flowering period drought stress. A (genotype × transgene) × environment interaction existed among the events, highlighting the need to better understand the context in which the down-regulation of ACSs functions in maize. Analysis of secondary traits showed that there was a consistent decrease in the anthesis-silking interval and a concomitant increase in kernel number/ear in transgene-positive events versus nulls. Selected events were also field tested under a low-nitrogen treatment, and the best event was found to have a significant 0.44 Mg/ha (7.1 bushel/acre) yield increase. This set of extensive field evaluations demonstrated that down-regulating the ethylene biosynthetic pathway can improve the grain yield of maize under abiotic stress conditions.

  19. African Trypanosomiasis

    DTIC Science & Technology

    2011-06-01

    infection by protozoan hemo- flagellates of the Trypanosoma brucei complex, 2 subspe- cies of which cause disease in humans: Trypanosoma bru- cei gambiense...public release; distribution unlimited 13. SUPPLEMENTARY NOTES See also ADA545141. Chapter 3 from e-book, Topics on the Pathology of Protozoan and...the brief ferry crossing. 2 3 • Topics on The paThology of proTozoan and invasive arThropod diseases Three severe epidemics of African trypanosomiasis

  20. Defining treatment conditions for pulsed electric field pasteurization of apple juice.

    PubMed

    Saldaña, G; Puértolas, E; Monfort, S; Raso, J; Alvarez, I

    2011-11-15

    The influence of temperature and the presence of N(α)-lauroyl ethylester (ethyl lauroyl arginate, LAE) on the inactivation caused by continuous pulsed electric field treatments (PEF) in Escherichia coli O157:H7 suspended in apple juice have been investigated to define treatment conditions applicable at industrial scale that promote an equivalent safety level when compared with thermal processing. In the range of experimental conditions investigated (outlet temperature: 20-40 °C, electric field strength: 20-30 kV, treatment time: 5-125 μs) at outlet temperatures equal or lower than 55±1 °C, the inactivation of E. coli O157:H7 treated in apple juice ranged from 0.4 to 3.6 Log₁₀ cycles reduction and treated in apple juice supplemented with LAE (50 ppm) ranged from 0.9 to 6.7 Log₁₀ cycles reduction. An empirical mathematical model was developed to estimate the treatment time and total specific energy input to obtain 5 Log₁₀ cycles reduction in the population of E. coli O157:H7 suspended in apple juice supplemented with 50 ppm of LAE at different electric field strengths and inlet temperatures. Treatment conditions established for E. coli O157:H7 were validated with other PEF resistant Gram-positive (Listeria monocytogenes, and Staphylococcus aureus) and Gram-negative (Salmonella enterica serovar Typhimurium) strains. When the treatment was applied to the apple juice, a treatment of 25 kV/cm for 63 μs corresponding with an outlet temperature of 65 °C and input energy of 125 kJ/kg was required to achieve more than 5 Log₁₀ cycles in the four strains investigated. The addition of LAE reduced the treatment time required to obtain an equivalent inactivation (>5 Log₁₀ cycles) in the four microorganisms to 38.4 μs, the outlet temperature to 55 °C, and the input energy to 83.2 kJ/kg.

  1. The effect of vaccination on the transmission of Mycoplasma hyopneumoniae in pigs under field conditions.

    PubMed

    Villarreal, I; Meyns, T; Dewulf, J; Vranckx, K; Calus, D; Pasmans, F; Haesebrouck, F; Maes, D

    2011-04-01

    This study investigated the effect of vaccination against Mycoplasma hyopneumoniae on its transmission in nursery pigs under field conditions. Seventy-two pigs were randomly allocated at weaning into vaccinated (V) and non-vaccinated (NV) groups. Animals in the V group were vaccinated at 3 weeks of age with a commercial M. hyopneumoniae bacterin vaccine. Broncho-alveolar lavage fluid taken at weaning and at the end of the nursery period was assessed for the presence of M. hyopneumoniae by nested PCR, and the reproduction ratio of infection (R(n)) was calculated. The percentage of positive pigs in the V and NV groups was 14% and 36% at weaning, and 31% and 64% at the end of the nursery period, respectively. The R(n)-values for the V and NV groups were 0.71 and 0.56, respectively (P>0.05). The study indicates that vaccination does not significantly reduce the transmission of this respiratory pathogen.

  2. Conditional random fields as classifiers for three-class motor-imagery brain-computer interfaces

    NASA Astrophysics Data System (ADS)

    Awwad Shiekh Hasan, Bashar; Gan, John Q.

    2011-04-01

    Conditional random fields (CRFs) are demonstrated to be a discriminative model able to exploit the temporal properties of EEG data obtained during synchronous three-class motor-imagery-based brain-computer interface experiments. The advantages of CRFs over the hidden Markov model (HMM) are both theoretical and practical. Theoretically, CRFs focus on modeling latent variables (labels) rather than both observation and latent variables. Furthermore, CRFs' loss function is convex, guaranteeing convergence to the global optimum. Practically, CRFs are much less prone to singularity problems. This property allows for the use of both time- and frequency-based features, such as band power. The HMM, on the other hand, requires temporal features such as autoregressive coefficients. A CRF-based classifier is tested on 13 subjects. Significant improvement is found when applying CRFs over HMM- and LDA-based classifiers.

  3. Electromechanical Breakdown of Barrier-Type Anodized Aluminum Oxide Thin Films Under High Electric Field Conditions

    NASA Astrophysics Data System (ADS)

    Chen, Jianwen; Yao, Manwen; Yao, Xi

    2016-02-01

    Barrier-type anodized aluminum oxide (AAO) thin films were formed on a polished aluminum substrate via electrochemical anodization in 0.1 mol/L aqueous solution of ammonium pentaborate. Electromechanical breakdown occurred under high electric field conditions as a result of the accumulation of mechanical stress in the film-substrate system by subjecting it to rapid thermal treatment. Before the breakdown event, the electricity of the films was transported in a highly nonlinear way. Immediately after the breakdown event, dramatic cracking of the films occurred, and the cracks expanded quickly to form a mesh-like dendrite network. The breakdown strength was significantly reduced because of the electromechanical coupling effect, and was only 34% of the self-healing breakdown strength of the AAO film.

  4. Symbiotic activity of pea (Pisum sativum) after application of Nod factors under field conditions.

    PubMed

    Siczek, Anna; Lipiec, Jerzy; Wielbo, Jerzy; Kidaj, Dominika; Szarlip, Paweł

    2014-04-29

    Growth and symbiotic activity of legumes are mediated by Nod factors (LCO, lipo-chitooligosaccharides). To assess the effects of application of Nod factors on symbiotic activity and yield of pea, a two-year field experiment was conducted on a Haplic Luvisol developed from loess. Nod factors were isolated from Rhizobium leguminosarum bv. viciae strain GR09. Pea seeds were treated with the Nod factors (10⁻¹¹ M) or water (control) before planting. Symbiotic activity was evaluated by measurements of nitrogenase activity (acetylene reduction assay), nodule number and mass, and top growth by shoot mass, leaf area, and seed and protein yield. Nod factors generally improved pea yield and nitrogenase activity in the relatively dry growing season 2012, but not in the wet growing season in 2013 due to different weather conditions.

  5. Suspicious activity recognition in infrared imagery using Hidden Conditional Random Fields for outdoor perimeter surveillance

    NASA Astrophysics Data System (ADS)

    Rogotis, Savvas; Ioannidis, Dimosthenis; Tzovaras, Dimitrios; Likothanassis, Spiros

    2015-04-01

    The aim of this work is to present a novel approach for automatic recognition of suspicious activities in outdoor perimeter surveillance systems based on infrared video processing. Through the combination of size, speed and appearance based features, like the Center-Symmetric Local Binary Patterns, short-term actions are identified and serve as input, along with user location, for modeling target activities using the theory of Hidden Conditional Random Fields. HCRFs are used to directly link a set of observations to the most appropriate activity label and as such to discriminate high risk activities (e.g. trespassing) from zero risk activities (e.g loitering outside the perimeter). Experimental results demonstrate the effectiveness of our approach in identifying suspicious activities for video surveillance systems.

  6. Optimization of operation conditions for extracting lithium ions from calcium chloride-type oil field brine

    NASA Astrophysics Data System (ADS)

    Yang, Hong-jun; Li, Qing-hai; Li, Bing; Guo, Feng-qin; Meng, Qing-fen; Li, Wu

    2012-04-01

    Al(OH)3 was prepared to extract lithium ions from calcium chloride-type oil field brine. The influences of four factors, namely temperature, Al3+/Li+ molar ratio, OH-/Al3+ molar ratio, and contact time between Al(OH)3 and the brine, on the yield of lithium ions were investigated. It is found that their optimal values are 35°C, 4.5, 2.6, and 6 h, respectively. In the course of the experiment, the apparent pH value was observed. The results reveal that the apparent pH value has no remarkable influence on the yield of lithium ions. Meanwhile, the effects of the concentrations of calcium ions and magnesium ions in the brine on lithium recovery were studied. The results indicate that calcium ions have minor negative influence on the yield of lithium ions under optimal conditions, and magnesium ions slightly influence the yield of lithium ions.

  7. Incorporating conditional random fields and active learning to improve sentiment identification.

    PubMed

    Zhang, Kunpeng; Xie, Yusheng; Yang, Yi; Sun, Aaron; Liu, Hengchang; Choudhary, Alok

    2014-10-01

    Many machine learning, statistical, and computational linguistic methods have been developed to identify sentiment of sentences in documents, yielding promising results. However, most of state-of-the-art methods focus on individual sentences and ignore the impact of context on the meaning of a sentence. In this paper, we propose a method based on conditional random fields to incorporate sentence structure and context information in addition to syntactic information for improving sentiment identification. We also investigate how human interaction affects the accuracy of sentiment labeling using limited training data. We propose and evaluate two different active learning strategies for labeling sentiment data. Our experiments with the proposed approach demonstrate a 5%-15% improvement in accuracy on Amazon customer reviews compared to existing supervised learning and rule-based methods.

  8. Extracting temporal constraints from clinical research eligibility criteria using conditional random fields.

    PubMed

    Luo, Zhihui; Johnson, Stephen B; Lai, Albert M; Weng, Chunhua

    2011-01-01

    Temporal constraints are present in 38% of clinical research eligibility criteria and are crucial for screening patients. However, eligibility criteria are often written as free text, which is not amenable for computer processing. In this paper, we present an ontology-based approach to extracting temporal information from clinical research eligibility criteria. We generated temporal labels using a frame-based temporal ontology. We manually annotated 150 free-text eligibility criteria using the temporal labels and trained a parser using Conditional Random Fields (CRFs) to automatically extract temporal expressions from eligibility criteria. An evaluation of an additional 60 randomly selected eligibility criteria using manual review achieved an overall precision of 83%, a recall of 79%, and an F-score of 80%. We illustrate the application of temporal extraction with the use cases of question answering and free-text criteria querying.

  9. SkipCor: Skip-Mention Coreference Resolution Using Linear-Chain Conditional Random Fields

    PubMed Central

    Žitnik, Slavko; Šubelj, Lovro; Bajec, Marko

    2014-01-01

    Coreference resolution tries to identify all expressions (called mentions) in observed text that refer to the same entity. Beside entity extraction and relation extraction, it represents one of the three complementary tasks in Information Extraction. In this paper we describe a novel coreference resolution system SkipCor that reformulates the problem as a sequence labeling task. None of the existing supervised, unsupervised, pairwise or sequence-based models are similar to our approach, which only uses linear-chain conditional random fields and supports high scalability with fast model training and inference, and a straightforward parallelization. We evaluate the proposed system against the ACE 2004, CoNLL 2012 and SemEval 2010 benchmark datasets. SkipCor clearly outperforms two baseline systems that detect coreferentiality using the same features as SkipCor. The obtained results are at least comparable to the current state-of-the-art in coreference resolution. PMID:24956272

  10. System for Detecting Potential Lost Person based on Conditional Random Field

    NASA Astrophysics Data System (ADS)

    Kusuma, R. S.; Saptawati, G. A. P.

    2017-01-01

    Global Positioning System (GPS) technology has been used widely in transsportation industry to help company in managing taxis. The most popular GPS utilization for taxi company is to identify the position of taxis and monitor theirs the mobility. Nowdays, data collected from GPS tracker is combined with data from taxi meter are analyzed to provide region information regarding potential passengers. Zicheng Liao’s proposed a system based on GPS taxi data to detect anomalous area/region which was then interpreted as region with to predict rare passengers. The system was developed based on conditional random field (CRF) method and features position, velocity, passenger loading information. Our research was aimed to develop tool based on GPS data to detect potential lost person. We motivated by Liao research and modified the algorithms and features of CRF. Our experiments showed that the system has precision of 98.86% and recall of 87.478%.

  11. Symbiotic Activity of Pea (Pisum sativum) after Application of Nod Factors under Field Conditions

    PubMed Central

    Siczek, Anna; Lipiec, Jerzy; Wielbo, Jerzy; Kidaj, Dominika; Szarlip, Paweł

    2014-01-01

    Growth and symbiotic activity of legumes are mediated by Nod factors (LCO, lipo-chitooligosaccharides). To assess the effects of application of Nod factors on symbiotic activity and yield of pea, a two-year field experiment was conducted on a Haplic Luvisol developed from loess. Nod factors were isolated from Rhizobium leguminosarum bv. viciae strain GR09. Pea seeds were treated with the Nod factors (10−11 M) or water (control) before planting. Symbiotic activity was evaluated by measurements of nitrogenase activity (acetylene reduction assay), nodule number and mass, and top growth by shoot mass, leaf area, and seed and protein yield. Nod factors generally improved pea yield and nitrogenase activity in the relatively dry growing season 2012, but not in the wet growing season in 2013 due to different weather conditions. PMID:24786094

  12. Chemical immobilization of crested porcupines with tiletamine HCl and zolazepam HCl (Zoletil) under field conditions.

    PubMed

    Massolo, Alessandro; Sforzi, Andrea; Lovari, Sandro

    2003-07-01

    The combination of tiletamine HCl and zolazepam HCl has been used on many species of wild mammals. Short induction time, low dosage, satisfactory safety margins, relatively constant immobilization time, and smooth recovery are benefits reported. This combination (Zoletil 100) was used during a study on behavioural ecology of the crested porcupine (Hystrix cristata) in a Mediterranean coastal area (Maremma Regional Park, Tuscany, Italy). We used this mixture 42 times on 31 individuals. Mean adult dose was (+/- SE) 7.24 +/- 0.37 mg/kg (74.0 +/- 3.0 mg/individual). Average adult induction time was 5.3 min (+/- 1.1) and average adult immobilization time was 22.6 min (+/- 6.0). One adult male porcupine died after chemical restraints. The use of tiletamine-zolazepam seems adequate for chemical immobilization of crested porcupines under field conditions, mainly because of its short induction time, small volume to be injected and wide safety margin.

  13. Dissipation rate and residue distribution of dufulin in tomato and soil under field conditions.

    PubMed

    Zhu, Huijun; Shi, Mengmeng; Hu, Deyu; Zhang, Kankan; Zhang, Yuping; Lu, Ping; Zeng, Song; Yang, Song; Song, Baoan

    2014-06-01

    Dissipation rate and residue distribution of dufulin in tomato and soil under field conditions were investigated in Guiyang, Tianjin, and Haikou during 2011-2012, using ultra-performance liquid chromatography. Average recoveries of dufulin in tomato and soil ranged from 91.03 % to 95.16 % and 94.35 % to 98.34 %, respectively, with relative standard deviations of 1.16 %-3.97 %. Dufulin dissipation followed first-order kinetics. Dufulin had half-lives of 2.8, 4.7, and 9.0 days in tomato and 6.1, 8.2, and 17.2 days in soil in Guiyang, Tianjin, and Haikou, respectively. At harvest, dufulin residues in tomato samples collected 5 days after the last application at 3 times recommended dosage applied every 5 days were below 1.0 mg kg(-1).

  14. Intercomparison of passive radon-detectors under field conditions in epidemiological studies

    SciTech Connect

    Kreienbrock, L. ); Poffijn, A. ); Tirmarche, M. ); Feider, M. ); Kies, A. ); Darby, S.C. )

    1999-05-01

    The Ardennes and Eifel region is a geologically distinct area covering parts of Germany, Belgium, France, and Luxembourg where enhanced concentrations of radon occur in some houses and other buildings. An international case-control study is being conducted to examine the role of radon in the etiology of lung cancer in this area. The radon detectors used are issued by different laboratories involving a variety of detector types and processes. A series of intercomparisons in houses was therefore conducted under similar conditions of exposure in the field. In most situations the different detectors gave similar results. Nevertheless, in some situations open and closed detectors yielded different results. Therefore, estimates of radon exposure have to be adjusted if results are to be pooled.

  15. Layout consistent segmentation of 3-D meshes via conditional random fields and spatial ordering constraints.

    PubMed

    Zouhar, Alexander; Baloch, Sajjad; Tsin, Yanghai; Fang, Tong; Fuchs, Siegfried

    2010-01-01

    We address the problem of 3-D Mesh segmentation for categories of objects with known part structure. Part labels are derived from a semantic interpretation of non-overlapping subsurfaces. Our approach models the label distribution using a Conditional Random Field (CRF) that imposes constraints on the relative spatial arrangement of neighboring labels, thereby ensuring semantic consistency. To this end, each label variable is associated with a rich shape descriptor that is intrinsic to the surface. Randomized decision trees and cross validation are employed for learning the model, which is eventually applied using graph cuts. The method is flexible enough for segmenting even geometrically less structured regions and is robust to local and global shape variations.

  16. Clutter sensitivity test under controlled field conditions Resonant Microstrip Patch Antenna (RMPA) sensor technology

    SciTech Connect

    1996-06-27

    Theoretical research, controlled laboratory tests, and these field test results show that nonmetallic (and metallic) shallowly buried objects can be detected and imaged with the Resonant Microstrip Patch Antenna (RMPA) sensor. The sensor can be modeled as a high Q cavity which capitalizes on its resonant condition sensitivity to scattered waves from buried objects. When the RMPA sensor is swept over a shallowly buried object, the RMPA fed-point impedance (resistance), measured with a Maxwell bridge, changes by tens of percent. The significant change in unprocessed impedance data can be presented in two-dimensional and three-dimensional graphical displays over the survey area. This forms silhouette images of the objects without the application of computationally intensive data processing algorithms. Because RMPA employed electromagnetic waves to illuminate the shallowly buried object, a number of questions and issues arise in the decision to fund or deny funding of the reconfiguration of the RMPA technology into a nonmetallic (metallic) land mine detector.

  17. Document page structure learning for fixed-layout e-books using conditional random fields

    NASA Astrophysics Data System (ADS)

    Tao, Xin; Tang, Zhi; Xu, Canhui

    2013-12-01

    In this paper, a model is proposed to learn logical structure of fixed-layout document pages by combining support vector machine (SVM) and conditional random fields (CRF). Features related to each logical label and their dependencies are extracted from various original Portable Document Format (PDF) attributes. Both local evidence and contextual dependencies are integrated in the proposed model so as to achieve better logical labeling performance. With the merits of SVM as local discriminative classifier and CRF modeling contextual correlations of adjacent fragments, it is capable of resolving the ambiguities of semantic labels. The experimental results show that CRF based models with both tree and chain graph structures outperform the SVM model with an increase of macro-averaged F1 by about 10%.

  18. Innovative tephra studies in the East African Rift System

    NASA Astrophysics Data System (ADS)

    WoldeGabriel, Giday; Hart, William K.; Heiken, Grant

    Geosciences investigations form the foundation for paleoanthropological research in the East African Rift System. However, innovative applications of tephra studies for constraining spatial and temporal relations of diverse geological processes, biostratigraphic records, and paleoenvironmental conditions within the East African Rift System were fueled by paleoanthropological investigations into the origin and evolution of hominids and material culture. Tephra is a collective, size-independent term used for any material ejected during an explosive volcanic eruption.The East African Rift System has become a magnet for paleoanthropological research ever since the discovery of the first hominids at Olduvai Gorge, in Tanzania, in the 1950s [Leakey et al., 1961]. Currently, numerous multidisciplinary scientific teams from academic institutions in the United States and Western Europe make annual pilgrimages for a couple of months to conduct paleoanthropological field research in the fossil-rich sedimentary deposits of the East African Rift System in Ethiopia, Kenya, and Tanzania. The field expedition consists of geological, paleontological, archaeological, and paleoenvironmental investigations.

  19. Sport Engagement by Accelerometry under Field Conditions in German Adolescents: Results from GINIPlus

    PubMed Central

    Smith, Maia; Berdel, Dietrich; Nowak, Dennis; Heinrich, Joachim; Schulz, Holger

    2015-01-01

    Introduction Sporting activities differ in their ability to promote moderate-to-vigorous physical activity (MVPA). To assess adolescents’ engagement in sport under field conditions we used accelerometers to measure their MVPA levels during sport. We pay special attention to differences between team and individual sport and between common sports. Methods Diary data and 7-day accelerometry from 1054 Germans ages 15–17 were combined to measure physical activity. 1373 diaried episodes of more than 40 common sports were identified from 626 participants and grouped into team and individual sport. We modeled the effect of team and individual sport, and described levels of MVPA and episodes of no MVPA for all recorded sports. Results German boys and girls averaged 43 (SD 21) and 37 (SD 24) minutes MVPA per day. Boys got 2.2 times as much MVPA per minute during team compared to individual sport (p<0.0001) but there was no significant difference for girls. Percent of time spent in MVPA during sport ranged from 6% for weight training to 74% for jogging, with individual sports averaging 10–30% and team sports 30–50%. 11% of sport episodes had no MVPA: half of episodes of cycling, 5% of jogging, and none for tennis or badminton. An episode of individual sport was 17 times more likely to have no MVPA than an episode of team sport (p<0.0001). Conclusion Under field condition, adolescents were active for only a fraction of diaried sporting time. As measured by accelerometry, individual sport often produced no MVPA. Characteristics of the sport, such as team vs. individual, were more predictive of MVPA than were characteristics of the participant, such as background activity levels. PMID:26291984

  20. Repellency of aerosol and cream products containing fennel oil to mosquitoes under laboratory and field conditions.

    PubMed

    Kim, Soon-Il; Chang, Kyu-Sik; Yang, Young-Cheol; Kim, Byung-Seok; Ahn, Young-Joon

    2004-11-01

    The repellency of fennel (Foeniculum vulgare Miller)-containing products (5% aerosol and 8% cream) against mosquitoes was compared with those of citronella oil, geranium oil and deet, as well as three commercial repellents, Baby Keeper cream containing IR3535, MeiMei cream containing citronella and geranium oils, and Repellan S aerosol containing 19% N,N-diethyl-m-toluamide (deet) under laboratory and field conditions. In a laboratory study with female Aedes aegypti (L), fennel oil exhibited good repellency in a release-in-cage test and repellency in skin and patch tests of the oil was comparable with those of citronella and geranium oils. In paddy field tests with five human volunteers, 5% and 8% fennel oil-containing aerosol and cream produced 84% and 70% repellency, respectively, at 90 min after exposure, whereas Baby Keeper cream and MeiMei cream gave 71% and 57% repellency at 90 min after exposure, respectively, and Repellan S aerosol gave 89% repellency at 210 min. The species and ratio of mosquitoes collected were the genera Culex (44.1%), Anopheles (42.2%), Aedes (7.8%) and Armigeres (5.9%). Fennel oil-containing products could be useful for protection from humans and domestic animals from vector-borne diseases and nuisance caused by mosquitoes.

  1. Effect of artificial electric fields on plants grown under microgravity conditions

    NASA Astrophysics Data System (ADS)

    Nechitailo, G.; Gordeev, A.

    2001-01-01

    Ionic and structural hetorogeneity of cells, tissues, and organs of plants are associated with a spectrum of electric characteristics such as bioelectric potentials, electrical conductance, and bioelectric permeability. An important determinant for the plant function is electric properties of the cell membranes and organelles which maintain energy and substance exchange with the environment. Enzymes and other biologically active substances have a powerful charge at the molecular level. Finally, all molecules, including those of water, represent dipoles, and this determines their reactive capacity. A major determinant is the bioelectric polarity of a plant is genetically predetermined and cannot be modified. It is an intrinsic structural feature of the organism whose evolution advent was mediated by gravity. An illustrative presentation of polarity is the downward growth of the roots and upward growth of stems in the Earth's gravitation field. However, gravity is a critical, but not the sole determinant of the plant organism polarization. Potent polarizing effects are exerted by light, the electromagnetic field, moisture, and other factors. It is known that plant cultivation in an upturned position is associated with impairment of water and nutrient uptake, resulting in dyscoordination of physiological processes, growth and developmental retardation. These abnormalities were characteristic when early attempts were made to grow plants in weightlessness conditions.

  2. Calcite precipitation dominates the electrical signatures of zero valent iron columns under simulated field conditions.

    PubMed

    Wu, Yuxin; Versteeg, Roelof; Slater, Lee; LaBrecque, Douglas

    2009-05-12

    Calcium carbonate is a secondary mineral precipitate influencing zero valent iron (ZVI) barrier reactivity and hydraulic performance. We conducted column experiments to investigate electrical signatures resulting from concurrent CaCO(3) and iron oxides precipitation under simulated field geochemical conditions. We identified CaCO(3) as a major mineral phase throughout the columns, with magnetite present primarily close to the influent based on XRD analysis. Electrical measurements revealed decreases in conductivity and polarization of both columns, suggesting that electrically insulating CaCO(3) dominates the electrical response despite the presence of electrically conductive iron oxides. SEM/EDX imaging suggests that the electrical signal reflects the geometrical arrangement of the mineral phases. CaCO(3) forms insulating films on ZVI/magnetite surfaces, restricting charge transfer between the pore electrolyte and ZVI particles, as well as across interconnected ZVI particles. As surface reactivity also depends on the ability of the surface to engage in redox reactions via charge transfer, electrical measurements may provide a minimally invasive technology for monitoring reactivity loss due to CaCO(3) precipitation. Comparison between laboratory and field data shows consistent changes in electrical signatures due to iron corrosion and secondary mineral precipitation.

  3. Calcite precipitation dominates the electrical signatures of zero valent iron columns under simulated field conditions

    SciTech Connect

    Wu, Yuxin; Versteeg, R.; Slater, L.; LaBrecque, D.

    2009-06-01

    Calcium carbonate is a secondary mineral precipitate influencing zero valent iron (ZVI) barrier reactivity and hydraulic performance. We conducted column experiments to investigate electrical signatures resulting from concurrent CaCO{sub 3} and iron oxides precipitation under simulated field geochemical conditions. We identified CaCO{sub 3} as a major mineral phase throughout the columns, with magnetite present primarily close to the influent based on XRD analysis. Electrical measurements revealed decreases in conductivity and polarization of both columns, suggesting that electrically insulating CaCO{sub 3} dominates the electrical response despite the presence of electrically conductive iron oxides. SEM/EDX imaging suggests that the electrical signal reflects the geometrical arrangement of the mineral phases. CaCO{sub 3} forms insulating films on ZVI/magnetite surfaces, restricting charge transfer between the pore electrolyte and ZVI particles, as well as across interconnected ZVI particles. As surface reactivity also depends on the ability of the surface to engage in redox reactions via charge transfer, electrical measurements may provide a minimally invasive technology for monitoring reactivity loss due to CaCO{sub 3} precipitation. Comparison between laboratory and field data shows consistent changes in electrical signatures due to iron corrosion and secondary mineral precipitation.

  4. Observation of high recombination occurrence of Porcine Reproductive and Respiratory Syndrome Virus in field condition.

    PubMed

    Franzo, Giovanni; Cecchinato, Mattia; Martini, Marco; Ceglie, Letizia; Gigli, Alessandra; Drigo, Michele

    2014-12-19

    Recombination in Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) is a well-documented phenomenon. A high recombination frequency has been reported in experimental conditions both in vitro and in vivo, and its role in driving viral evolution has been postulated by several authors. However field evidences are rare, mainly obtained from large-scale sampling and typically represented by single sequences rather than by groups of circulating "recombinant progenies". The present work was aimed to investigate the gray area between experimental studies and large-scale epidemiological investigations. The study was performed on ORF5, ORF7 and concatenated sequences obtained in our laboratory or available in GenBank collected between 2009 and 2012 in northern Italy. Six independent recombinant strains out of 66 concatenated sequences (∼9%) were found, demonstrating a high recombination frequency respect to previous field studies but comparable to in vitro experiments. In silico analysis let speculate that this new strain displayed physicochemical features diverse enough to potentially alter its immunological properties. Taken altogether, the results of our study support previous experimental evidences that depict PRRSV to be extremely prone to recombination. The limited temporal and geographical spread of recombinant strains however states in favor of a limited fitness of the recombinant progeny compared to parental strains and the marginal role of this phenomenon in PRRSV evolution.

  5. On the stability conditions for theories of modified gravity in the presence of matter fields

    NASA Astrophysics Data System (ADS)

    De Felice, Antonio; Frusciante, Noemi; Papadomanolakis, Georgios

    2017-03-01

    We present a thorough stability analysis of modified gravity theories in the presence of matter fields. We use the Effective Field Theory framework for Dark Energy and Modified Gravity to retain a general approach for the gravity sector and a Sorkin-Schutz action for the matter one. Then, we work out the proper viability conditions to guarantee in the scalar sector the absence of ghosts, gradient and tachyonic instabilities. The absence of ghosts can be achieved by demanding a positive kinetic matrix, while the lack of a gradient instability is ensured by imposing a positive speed of propagation for all the scalar modes. In case of tachyonic instability, the mass eigenvalues have been studied and we work out the appropriate expressions. For the latter, an instability occurs only when the negative mass eigenvalue is much larger, in absolute value, than the Hubble parameter. We discuss the results for the minimally coupled quintessence model showing for a particular set of parameters two typical behaviours which in turn lead to a stable and an unstable configuration. Moreover, we find that the speeds of propagation of the scalar modes strongly depend on matter densities, for the beyond Horndeski theories. Our findings can be directly employed when testing modified gravity theories as they allow to identify the correct viability space.

  6. Artificially decreased vapour pressure deficit in field conditions modifies foliar metabolite profiles in birch and aspen

    PubMed Central

    Lihavainen, Jenna; Keinänen, Markku; Keski-Saari, Sarita; Kontunen-Soppela, Sari; Sõber, Anu; Oksanen, Elina

    2016-01-01

    Relative air humidity (RH) is expected to increase in northern Europe due to climate change. Increasing RH reduces the difference of water vapour pressure deficit (VPD) between the leaf and the atmosphere, and affects the gas exchange of plants. Little is known about the effects of decreased VPD on plant metabolism, especially under field conditions. This study was conducted to determine the effects of artificially decreased VPD on silver birch (Betula pendula Roth.) and hybrid aspen (Populus tremula L.×P. tremuloides Michx.) foliar metabolite and nutrient profiles in a unique free air humidity manipulation (FAHM) field experiment during the fourth season of humidity manipulation, in 2011. Long-term exposure to decreased VPD modified nutrient homeostasis in tree leaves, as demonstrated by a lower N concentration and N:P ratio in aspen leaves, and higher Na concentration and lower K:Na ratio in the leaves of both species in decreased VPD than in ambient VPD. Decreased VPD caused a shift in foliar metabolite profiles of both species, affecting primary and secondary metabolites. Metabolic adjustment to decreased VPD included elevated levels of starch and heptulose sugars, sorbitol, hemiterpenoid and phenolic glycosides, and α-tocopherol. High levels of carbon reserves, phenolic compounds, and antioxidants under decreased VPD may modify plant resistance to environmental stresses emerging under changing climate. PMID:27255929

  7. Theory and generation of conditional, scalable sub-Gaussian random fields

    NASA Astrophysics Data System (ADS)

    Panzeri, M.; Riva, M.; Guadagnini, A.; Neuman, S. P.

    2016-03-01

    Many earth and environmental (as well as a host of other) variables, Y, and their spatial (or temporal) increments, ΔY, exhibit non-Gaussian statistical scaling. Previously we were able to capture key aspects of such non-Gaussian scaling by treating Y and/or ΔY as sub-Gaussian random fields (or processes). This however left unaddressed the empirical finding that whereas sample frequency distributions of Y tend to display relatively mild non-Gaussian peaks and tails, those of ΔY often reveal peaks that grow sharper and tails that become heavier with decreasing separation distance or lag. Recently we proposed a generalized sub-Gaussian model (GSG) which resolves this apparent inconsistency between the statistical scaling behaviors of observed variables and their increments. We presented an algorithm to generate unconditional random realizations of statistically isotropic or anisotropic GSG functions and illustrated it in two dimensions. Most importantly, we demonstrated the feasibility of estimating all parameters of a GSG model underlying a single realization of Y by analyzing jointly spatial moments of Y data and corresponding increments, ΔY. Here, we extend our GSG model to account for noisy measurements of Y at a discrete set of points in space (or time), present an algorithm to generate conditional realizations of corresponding isotropic or anisotropic random fields, introduce two approximate versions of this algorithm to reduce CPU time, and explore them on one and two-dimensional synthetic test cases.

  8. [Comparison of growth and field microclimate characteristics of broomcorn millet under different fertilization conditions].

    PubMed

    Zhang, Pan-pan; Zhou, Yu; Song, Hui; Qiao, Zhi-jun; Wang, Hai-gang; Zheng, Dian-feng; Feng, Bai-li

    2015-02-01

    A field experiment with two broomcorn millet varieties Longmi 8 (strong drought-resistant variety) and Jinmi 4 (drought-sensitive variety) was conducted to compare their differences in growth, field microclimate and photosynthetic capacity from anthesis to maturity under different fertility conditions. The results showed that, fertilization decreased canopy temperature, air temperature, soil temperature, illumination, but improved the relative humidity among broomcorn millet plants compared with the non-fertilization treatment. With an increase of the fertilizer level, the plant height, SPAD, LAI, net photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration in broomcorn millet showed an increasing trend, which of the high fertilization treatment were 9.2%, 15.1%, 56.6%, 17.8%, 24.6%, 14.2%, 29.7% higher than those of non-fertilization treatment, respectively. Compared with Jinmi 4, Longmi 8 showed a cold wet characteristic, with lower canopy temperature, air temperature, soil temperature; illumination, and higher plant height, LAI, SPAD and relative humidity during grain filling. Moreover, each photosynthetic index of Longmi 8 slowly decreased and extended the period of leaf photosynthetic function so as to accumulate more photosynthetic products.

  9. Evaluation of aerodynamic and rolling resistances in mountain-bike field conditions.

    PubMed

    Bertucci, William M; Rogier, Simon; Reiser, Raoul F

    2013-01-01

    Aerodynamic and rolling resistances are the two major resistances that affect road cyclists on level ground. Because of reduced speeds and markedly different tyre-ground interactions, rolling resistance could be more influential in mountain biking than road cycling. The aims of this study were to quantify 1) aerodynamic resistance of mountain-bike cyclists in the seated position and 2) rolling resistances of two types of mountain-bike tyre (smooth and knobby) in three field surfaces (road, sand and grass) with two pressure inflations (200 and 400 kPa). Mountain-bike cyclists have an effective frontal area (product of projected frontal area and drag coefficient) of 0.357 ± 0.023 m², with the mean aerodynamic resistance representing 8-35% of the total resistance to cyclists' motion depending on the magnitude of the rolling resistance. The smooth tyre had 21 ± 15% less rolling resistance than the knobby tyre. Field surface and inflation pressure also affected rolling resistance. These results indicate that aerodynamic resistance influences mountain-biking performance, even with lower speeds than road cycling. Rolling resistance is increased in mountain biking by factors such as tyre type, surface condition and inflation pressure that may also alter performance.

  10. Mosquitoes meet microfluidics: High-throughput microfluidic tools for insect-parasite ecology in field conditions

    NASA Astrophysics Data System (ADS)

    Prakash, Manu; Mukundarajan, Haripriya

    2013-11-01

    A simple bite from an insect is the transmission mechanism for many deadly diseases worldwide--including malaria, yellow fever, west nile and dengue. Very little is known about how populations of numerous insect species and disease-causing parasites interact in their natural habitats due to a lack of measurement techniques. At present, vector surveillance techniques involve manual capture by using humans as live bait, which is hard to justify on ethical grounds. Individual mosquitoes are manually dissected to isolate salivary glands to detect sporozites. With typical vector infection rates being very low even in endemic areas, it is almost impossible to get an accurate picture of disease distribution, in both space and time. Here we present novel high-throughput microfluidic tools for vector surveillance, specifically mosquitoes. A two-dimensional high density array with baits provide an integrated platform for multiplex PCR for detection of both vector and parasite species. Combining techniques from engineering and field ecology, methods and tools developed here will enable high-throughput measurement of infection rates for a number of diseases in mosquito populations in field conditions. Pew Foundation.

  11. Effect of artificial electric fields on plants grown under microgravity conditions.

    PubMed

    Nechitailo, G; Gordeev, A

    2001-01-01

    Ionic and structural hetorogeneity of cells, tissues, and organs of plants are associated with a spectrum of electric characteristics such as bioelectric potentials, electrical conductance, and bioelectric permeability. An important determinant for the plant function is electric properties of the cell membranes and organelles which maintain energy and substance exchange with the environment. Enzymes and other biologically active substances have a powerful charge at the molecular level. Finally, all molecules, including those of water, represent dipoles, and this determines their reactive capacity. A major determinant is the bioelectric polarity of a plant is genetically predetermined and cannot be modified. It is an intrinsic structural feature of the organism whose evolution advent was mediated by gravity. An illustrative presentation of polarity is the downward growth of the roots and upward growth of stems in the Earth's gravitation field. However, gravity is a critical, but not the sole determinant of the plant organism polarization. Potent polarizing effects are exerted by light, the electromagnetic field, moisture, and other factors. It is known that plant cultivation in an upturned position is associated with impairment of water and nutrient uptake, resulting in dyscoordination of physiological processes, growth and developmental retardation. These abnormalities were characteristic when early attempts were made to grow plants in weightlessness conditions.

  12. LES of the flow field around a 45 wing-wall abutment in different scour conditions

    NASA Astrophysics Data System (ADS)

    Bressan, Filippo; Armenio, Vincenzo; Ballio, Francesco

    2008-11-01

    Scouring process around bridge abutment is one of the main causes leading to the hydraulic structure failure, thus the determination of the maximum scour depth assumes a central role. Resolved LES of the turbulent flow field around a 45 wing wall abutment are carried out for three main scouring conditions: Initial phase (flat bed), logarithmic phase of scouring and equilibrium scour depth. The bathymetry and the flow parameters are taken from data of a laboratory experiment. Mean flow field, secondary flows and turbulent quantities such as Reynolds stresses and turbulent kinetic energy are calculated and compared for the three cases. The purpose of this study is to understand how the statistics of the wall stresses change with the increase of the scour depth. Preliminary results indicate that the bottom stresses decrease as the scour hole increases and that the bed deforms itself in order to minimize the effect of the obstacle on the Bernoulli trinomial. The results of this research will help in finding new erosion models based on the knowledge of turbulence-bed interaction.

  13. African American Educational Leadership in the School Superintendency

    ERIC Educational Resources Information Center

    Smith, Eva C.

    2013-01-01

    African American educational leadership has long been part of American education and African American activism to resist oppression. However, the field of educational leadership has rarely included the contributions of African American leaders, particularly women leaders, into mainstream leadership theory and practices. This omission is difficult…

  14. PREFACE: Quantum Field Theory Under the Influence of External Conditions (QFEXT07)

    NASA Astrophysics Data System (ADS)

    Bordag, M.; Mostepanenko, V. M.

    2008-04-01

    This special issue contains papers reflecting talks presented at the 8th Workshop on Quantum Field Theory Under the Influence of External Conditions (QFEXT07), held on 17 21 September 2007, at Leipzig University. This workshop gathered 108 physicists and mathematicians working on problems which are focused on the following topics: •Casimir and van der Waals forces—progress in theory and new experiments, applications at micro- and nano-scale •Casimir effect—exact results, approximate methods and mathematical problems •Vacuum quantum effects in classical background fields—renormalization issues, singular backgrounds, applications to particle and high energy physics •Vacuum energy and gravity, vacuum energy in supersymmetric and noncommutative theories. This workshop is part of a series started in 1989 and 1992 in Leipzig by Dieter Robaschik, and continued in 1995, 1998 and 2001 in Leipzig by Michael Bordag. In 2003 this Workshop was organized by Kimball A Milton in Oklahoma, in 2005 by Emilio Elizalde in Barcelona and in 2007 it returned to Leipzig. The field of physics after which this series of workshops is named is remarkably broad. It stretches from experimental work on the measurement of dispersion forces between macroscopic bodies to quantum corrections in the presence of classical background fields. The underlying physical idea is that even in its ground state (vacuum) a quantum system responds to changes in its environment. The universality of this idea makes the field of its application so very broad. The most prominent manifestation of vacuum energy is the Casimir effect. This is, in its original formulation, the attraction between conducting planes due to the vacuum fluctuations of the electromagnetic field. In a sense, this is the long-range tail of the more general dispersion forces acting between macroscopic bodies. With the progress in nanotechnology, dispersion forces become of direct practical significance. On a more theoretical side

  15. a Method to Estimate Temporal Interaction in a Conditional Random Field Based Approach for Crop Recognition

    NASA Astrophysics Data System (ADS)

    Diaz, P. M. A.; Feitosa, R. Q.; Sanches, I. D.; Costa, G. A. O. P.

    2016-06-01

    This paper presents a method to estimate the temporal interaction in a Conditional Random Field (CRF) based approach for crop recognition from multitemporal remote sensing image sequences. This approach models the phenology of different crop types as a CRF. Interaction potentials are assumed to depend only on the class labels of an image site at two consecutive epochs. In the proposed method, the estimation of temporal interaction parameters is considered as an optimization problem, whose goal is to find the transition matrix that maximizes the CRF performance, upon a set of labelled data. The objective functions underlying the optimization procedure can be formulated in terms of different accuracy metrics, such as overall and average class accuracy per crop or phenological stages. To validate the proposed approach, experiments were carried out upon a dataset consisting of 12 co-registered LANDSAT images of a region in southeast of Brazil. Pattern Search was used as the optimization algorithm. The experimental results demonstrated that the proposed method was able to substantially outperform estimates related to joint or conditional class transition probabilities, which rely on training samples.

  16. Control of environmental conditions at the lower boundary of field lysimeters

    NASA Astrophysics Data System (ADS)

    Schwärzel, Kai; Podlasly, Christian

    2014-05-01

    Lysimeters are vessels containing disturbed or undisturbed soil, embedded completely in soil with its top even to the soil surface. At the bottom of lysimeters, the soil is cut off from the parent soil, and the lower boundary of lysimeters is usually exposed to atmospheric pressure. For this reason, soil water conditions may be different than of the surrounding soil. This may affect the soil-water conditions throughout the soil profile in comparison to the surrounding soil. To avoid this problem, lysimeters with a construction depth much more than the expected rooting depth should be used or a suction-controlled drainage system needs to be installed at the bottom of lysimeters. Not only the water flow but also the heat flow in the lysimeter is affected by the isolation of the soil and by the fact that the soil at the bottom of the lysimeter is cut off from the surrounding area. However, since now only a few studies have dealt with this issue. This is surprising because the soil thermal regime controls both growth and function of roots and shoots. Therefore, a new design for an automatic control of soil temperature at the lower boundary of large, undisturbed field lysimeters was developed. The objective of the intended talk is to present and evaluate the design and functionality of this new setup.

  17. Conditional symmetries in axisymmetric quantum cosmologies with scalar fields and the fate of the classical singularities

    NASA Astrophysics Data System (ADS)

    Zampeli, Adamantia; Pailas, Theodoros; Terzis, Petros A.; Christodoulakis, T.

    2016-05-01

    In this paper, the classical and quantum solutions of some axisymmetric cosmologies coupled to a massless scalar field are studied in the context of minisuperspace approximation. In these models, the singular nature of the Lagrangians entails a search for possible conditional symmetries. These have been proven to be the simultaneous conformal symmetries of the supermetric and the superpotential. The quantization is performed by adopting the Dirac proposal for constrained systems, i.e. promoting the first-class constraints to operators annihilating the wave function. To further enrich the approach, we follow [1] and impose the operators related to the classical conditional symmetries on the wave function. These additional equations select particular solutions of the Wheeler-DeWitt equation. In order to gain some physical insight from the quantization of these cosmological systems, we perform a semiclassical analysis following the Bohmian approach to quantum theory. The generic result is that, in all but one model, one can find appropriate ranges of the parameters, so that the emerging semiclassical geometries are non-singular. An attempt for physical interpretation involves the study of the effective energy-momentum tensor which corresponds to an imperfect fluid.

  18. Expression of Low Molecular Weight Heat-Shock Proteins under Field Conditions.

    PubMed Central

    Hernandez, L. D.; Vierling, E.

    1993-01-01

    Heat-shock proteins (HSPs) are known to be expressed in plants experiencing high-temperature stress. We have examined the expression of class I cytoplasmic low molecular weight (LMW) HSPs and find that these HSPs also frequently accumulate in seeds, seed pods, and flowers during a normal growing season. We first examined the expression of class I cytoplasmic LMW HSPs by western blot analysis in a range of seed samples from both commercially grown and wild legumes. LMW HSPs were present in all seed samples, indicating that these HSPs are regularly expressed in these tissues. To examine more specifically conditions under which LMW HSPs were produced during an average growing season, additional studies of Medicago sativa were carried out during the fall season in Tucson, AZ. Plants were irrigated to avoid conditions of water stress, and canopy temperature was monitored throughout the study period. LMW HSP expression in leaves, flowers, and developing seed pods was analyzed by western blotting. Results show that in the field HSPs are frequently produced in flowers and seed pods, even in plants that show no HSP expression in leaves. Parallel greenhouse studies indicate that HSP expression in seeds is in part developmentally regulated. In total our data suggest a more widespread occurrence of HSPs in optimal growth environments and emphasize their potential role during reproduction. PMID:12231775

  19. Effect of soil water content on soil thermal conductivity under field conditions

    NASA Astrophysics Data System (ADS)

    Vico, G.; Daly, E.; Manzoni, S.; Porporato, A.

    2008-12-01

    Knowledge of the thermal properties of soils is required in many areas of engineering, meteorology, agronomy, and ecosystem and soil science. Soil thermal conductivity varies in time and space, since it is influenced by soil properties as well as soil temperature and moisture conditions. We use the one dimensional heat conduction equation in conjunction with two-year data measured in a grass-covered field in North Carolina Piedmont to estimate soil thermal conductivity and to investigate how it is impacted by water content. In agreement with laboratory experiments reported in the literature, our results suggest that under dry conditions soil thermal conductivity increases across a relatively narrow range of soil water contents, above which a further increase in water content does not significantly change thermal conductivity. However, when soil approaches saturation, heat transfer is further improved, a fact not previously noted. This nonlinear behavior is consistent with the formation at high water contents of a continuous film of liquid water in soil aggregates of mineral and organic matter.

  20. Field reversal effects on divertor plasmas under radiative and detached conditions in JT-60U

    NASA Astrophysics Data System (ADS)

    Asakura, N.; Hosogane, H.; Tsuji-Iio, S.; Itami, K.; Shimizu, K.; Shimada, M.

    1996-06-01

    Reversal effects of the toroidal field Bt on the principal divertor plasma parameters were investigated under radiative and detached divertor conditions in L mode discharges. The ion flux to the inboard separatrix strike point decreased before a MARFE occurred, irrespective of the ion Del B drift direction. The local electron temperature, Te, div, decreased to around 10 eV. The maximum fraction of power radiated in the divertor was comparable between the two directions of Bt. With the power flowing into the two divertor fans being slightly larger on the outboard than on the inboard, a nearly symmetric in-out heat load was observed for the ion Del B drift away from the target. This was due to the outboard enhanced asymmetries in the particle flux and radiation loss distributions. From the viewpoint of in-out symmetry in the target heat load and Te, div, operation with the ion Del B drift away from the target plate is desirable as long as the attached divertor condition is maintained. On the contrary, during the MARFE, although deterioration of the energy confinement as well as the increase in the fuelling efficiency were comparable, for the ion Del B drift towards the target the plasma did not detach completely, and the strong in-out asymmetry in the particle recycling was relaxed to a relatively symmetric distribution. From the viewpoint of particle exhaust to the divertor, operation with the ion Del B drift towards the target is favourable

  1. Assessment of sperm morphology in zebu bulls, under field conditions in the tropics.

    PubMed

    Chacón, J

    2001-04-01

    Sperm morphology was studied in 302 extensively managed Zebu bulls (aged 1.5-9 years), classified as sound (n=166) or unsound (n=136) for breeding, under field conditions in the dry tropics of Costa Rica. Single semen samples were collected by electro-ejaculation and fixed in formol-saline solution immediately after collection. Sperm morphology was determined in the field on wet smears using a microscope equipped with phase-contrast optics, and further determined in the laboratory on air-dried smears stained with carbol-fuchsin. The frequencies of sperm abnormalities (such as abnormal acrosome, head, neck, mid-piece, tail, and presence of cytoplasmic droplets) were recorded as a percentage of the total number of counted spermatozoa (400 cells). Zebu bulls considered unsound for breeding showed a higher mean prevalence (p < 0.05) of knobbed acrosomes (4.0 versus 0.9%), head defects [specifically, nuclear invaginations and heads with abnormal shapes and sizes (27.6 versus 4.0%)], abnormal tails (11.2 versus 4.7%), and proximal droplets (8.4 versus 1.6%), compared with bulls considered sound for breeding. In these latter bulls, the abnormality most commonly seen was the presence of single bent tails with an entrapped cytoplasmic droplet (3.0 +/- 3.7%). Young Zebu bulls (i.e. bulls under 2 years of age) showed a higher percentage of missing acrosomes, and proximal cytoplasmic droplets, than older sires (12.1 versus 2.4%, and 23.9 versus 3.6%, respectively; p < 0.05), interpreted as an indication of low ejaculation frequency and sexual immaturity, respectively. Bulls with a long scrotum and soft testicular consistency (TC) at palpation showed higher percentages of abnormal sperm heads in the ejaculate than bulls with a normal scrotal length (SL) and a normal TC (32.7 versus 12.8% and 30.7 versus 10.3%, respectively; p < 0.05). In addition, Zebu bulls with a scrotal circumference (SC) < or = 30 cm showed a higher prevalence of proximal cytoplasmic droplets than bulls

  2. Photochemical degradation of a brominated flame retardant (tetrabromobisphenol A) in ice under field and laboratory conditions

    NASA Astrophysics Data System (ADS)

    Waligroski, G.; Grannas, A. M.

    2013-12-01

    Studies of brominated flame retardants have raised awareness of their potential environmental impact as toxic compounds. Because these compounds are now globally distributed, including in the Polar Regions, it is important to assess their potential fate in the environment. It has been shown that active photochemistry occurs in sunlit snow and ice, but there is little information regarding potential photochemical degradation of brominated flame retardants in snow and ice. The purpose of this research is to investigate the direct and indirect photochemical transformation pathways of a widely used brominated flame retardant, tetrabromobisphenol A (TBBPA). We have conducted field-based experiments in Barrow, Alaska to investigate the potential photochemical degradation of TBBPA in snow and ice under environmentally-relevant conditions. Field-based results show that TBBPA is efficiently degraded under direct photolysis conditions in frozen aqueous samples under natural Barrow sunlight. In aqueous solution the light absorption properties of TBBPA are pH dependent. Therefore, the photodegradation of TBBPA in snow and ice will be highly pH dependent. Reactions that are pH dependent may be affected by the nature of the liquid-like layers in snow/ice as well as the presence of other solutes that may indirectly affect the local pH experienced by TBBPA in snow and ice samples. In order to establish how the effective pH of liquid-like regions in ice might impact the degradation of TBBPA, various salts (sodium chloride, sodium fluoride, sodium bromide, ammonium chloride, ammonium acetate and ammonium sulfate) were added to aqueous solutions of TBBPA. Upon freezing, these different salts will induce pH differences in the liquid-like regions of the sample due to a phenomenon known as the freezing potential. Observed reactivity differences upon addition of these salts will be evaluated and discussed. Additionally, the presence of natural dissolved organic matter (DOM), an effective

  3. Selecting Native Arbuscular Mycorrhizal Fungi to Promote Cassava Growth and Increase Yield under Field Conditions

    PubMed Central

    Séry, D. Jean-Marc; Kouadjo, Z. G. Claude; Voko, B. R. Rodrigue; Zézé, Adolphe

    2016-01-01

    The use of arbuscular mycorrhizal fungal (AMF) inoculation in sustainable agriculture is now widespread worldwide. Although the use of inoculants consisting of native AMF is highly recommended as an alternative to commercial ones, there is no strategy to allow the selection of efficient fungal species from natural communities. The objective of this study was (i) to select efficient native AMF species (ii) evaluate their impact on nematode and water stresses, and (iii) evaluate their impact on cassava yield, an important food security crop in tropical and subtropical regions. Firstly, native AMF communities associated with cassava rhizospheres in fields were collected from different areas and 7 AMF species were selected, based upon their ubiquity and abundance. Using these criteria, two morphotypes (LBVM01 and LBVM02) out of the seven AMF species selected were persistently dominant when cassava was used as a trap plant. LBVM01 and LBVM02 were identified as Acaulospora colombiana (most abundant) and Ambispora appendicula, respectively, after phylogenetic analyses of LSU-ITS-SSU PCR amplified products. Secondly, the potential of these two native AMF species to promote growth and enhance tolerance to root-knot nematode and water stresses of cassava (Yavo variety) was evaluated using single and dual inoculation in greenhouse conditions. Of the two AMF species, it was shown that A. colombiana significantly improved the growth of the cassava and enhanced tolerance to water stress. However, both A. colombiana and A. appendicula conferred bioprotective effects to cassava plants against the nematode Meloidogyne spp., ranging from resistance (suppression or reduction of the nematode reproduction) or tolerance (low or no suppression in cassava growth). Thirdly, the potential of these selected native AMF to improve cassava growth and yield was evaluated under field conditions, compared to a commercial inoculant. In these conditions, the A. colombiana single inoculation and the

  4. African (Black) Psychology: Issues and Synthesis.

    ERIC Educational Resources Information Center

    Baldwin, Joseph A.

    1986-01-01

    Reviews the recent attempts of Black psychologists and social scientists to formulate a conceptual-operational framework for the study of psychological phenomena as they bear on the cultural-survival conditions of Black-African people. Outlines issues and problems in the attempt to define African (Black) psychology and discusses its relation to…

  5. Genetics Home Reference: African iron overload

    MedlinePlus

    ... of a genetic condition? Genetic and Rare Diseases Information Center Frequency African iron overload is common in rural areas of central and ... more about the gene associated with African iron overload SLC40A1 Related Information What is a gene? What is a gene ...

  6. British African Caribbean Women and Depression

    ERIC Educational Resources Information Center

    Adkison-Bradley, Carla; Maynard, Donna; Johnson, Phillip; Carter, Stephaney

    2009-01-01

    Depression is a common condition among women in the United Kingdom. However, little is known about the context of depression among British African Caribbean women. This article offers a preliminary discussion regarding issues and information pertaining to depression among British African Caribbean women. Characteristics and symptoms of depression…

  7. Measurements of heat fluxes and soil moisture patterns in the field conditions

    NASA Astrophysics Data System (ADS)

    Sanda, M.; Snehota, M.; Haase, T.; Wild, J.

    2011-12-01

    temperature and soil salinity on the resulting values. The TMS2 sensors undergo present calibration process with implementation of new features, such as automated higher frequency data acquisition based on hydrological conditions and internal efficiency of the measurements as well. Soil database is to be build for use in different field conditions. The research is supported by the Technology Agency of the Czech Republic projects No. TA01021283

  8. Conditioning of a mesoscale hydrologic model with proxy soil moisture fields

    NASA Astrophysics Data System (ADS)

    Samaniego-Eguiguren, L. E.; Bardossy, A.; Kumar, R.

    2009-12-01

    variability range of the model outputs (e.g. discharge) as well as that of the calibrated global parameters. The transferability of these parameters to ungauged locations and different scales lead to an improvement in performance of at least 10% compared with those results obtained with a control experiment (i.e. parameters not conditioned with proxy soil moisture fields).

  9. Identification of Molecular and Cellular Responses of Desulfovibrio vulgaris Biofilms under Culture Conditions Relevant to Field Conditions for Bioreduction of

    SciTech Connect

    Wall, Judy D.

    2006-06-01

    Desulfovibrio vulgaris Hildenborough forms biofilms under stress and nutrient limitation conditions. Analysis of the transcriptional responses to acid exposure suggested that genes encoding arginine and polyamine biosynthesis were increased in expression. A literature search showed that polyamines had been suggested to stimulate biofilm formation in some bacteria. Therefore, biofilm formation by D. vulgaris was then examined. Two different assay methods were used to estimate the biofilm formation. First, the classical crystal violet stainable material attached to glass test tubes was measured. Second protein attached to the test tube sides and especially precipitated at the bottom was measured.

  10. Stem injection of Populus nigra with EDU to study ozone effects under field conditions.

    PubMed

    Bortier, K; Dekelver, G; De Temmerman, L; Ceulemans, R

    2001-01-01

    EDU or ethylenediurea (N-[2-(2-oxo-1-imidazolidinyl)ethyl]-N'-phenylurea) has been used in experiments to assess ozone effects on vegetation under field conditions because it provides protection against oxidative damage. Tests have mainly been conducted on crop plants, but for woody species only few reports have provided evidence that it can be used in long-term experiments. In this study we tested the technique of stem injection of EDU to study the effects of ozone exposure on Populus nigra cv. Wolterson over one growing season. Cuttings of Populus nigra were grown in pots in the field and between mid-July and early September plants were repeatedly injected with EDU solution (5 mg/plant) or with water at 14-day intervals. Significant differences were found between EDU- and water-injected plants: water-treated plants had more foliar injury, more chlorotic leaves, and shedding of leaves started earlier, suggesting EDU was effective in preventing visible ozone injury and acceleration of senescence. Photosynthetic rates, measured for one leaf age, showed no differences but were mostly higher for the EDU-treated plants. At the end of the growing season diameter increment was 16% higher and there was a non-significant trend for above-ground biomass to be increased by 9% for the EDU-treated plants. This experiment has provided evidence that for this clone serious ozone damage occurs at relatively low concentrations and that EDU can provide protection against visible injury, as well as against longer term growth reductions.

  11. Full-field predictions of ice dynamic recrystallisation under simple shear conditions

    NASA Astrophysics Data System (ADS)

    Llorens, Maria-Gema; Griera, Albert; Bons, Paul D.; Lebensohn, Ricardo A.; Evans, Lynn A.; Jansen, Daniela; Weikusat, Ilka

    2016-09-01

    Understanding the flow of ice on the microstructural scale is essential for improving our knowledge of large-scale ice dynamics, and thus our ability to predict future changes of ice sheets. Polar ice behaves anisotropically during flow, which can lead to strain localisation. In order to study how dynamic recrystallisation affects to strain localisation in deep levels of polar ice sheets, we present a series of numerical simulations of ice polycrystals deformed under simple-shear conditions. The models explicitly simulate the evolution of microstructures using a full-field approach, based on the coupling of a viscoplastic deformation code (VPFFT) with dynamic recrystallisation codes. The simulations provide new insights into the distribution of stress, strain rate and lattice orientation fields with progressive strain, up to a shear strain of three. Our simulations show how the recrystallisation processes have a strong influence on the resulting microstructure (grain size and shape), while the development of lattice preferred orientations (LPO) appears to be less affected. Activation of non-basal slip systems is enhanced by recrystallisation and induces a strain hardening behaviour up to the onset of strain localisation and strain weakening behaviour. Simulations demonstrate that the strong intrinsic anisotropy of ice crystals is transferred to the polycrystalline scale and results in the development of strain localisation bands than can be masked by grain boundary migration. Therefore, the finite-strain history is non-directly reflected by the final microstructure. Masked strain localisation can be recognised in ice cores, such as the EDML, from the presence of stepped boundaries, microshear and grains with zig-zag geometries.

  12. Temperature management during semen processing: Impact on boar sperm quality under laboratory and field conditions.

    PubMed

    Schulze, M; Henning, H; Rüdiger, K; Wallner, U; Waberski, D

    2013-12-01

    Freshly collected boar spermatozoa are sensitive to a fast reduction in temperature because of lipid phase transition and phase separation processes. Temperature management during semen processing may determine the quality of stored samples. The aim of this study was to evaluate the influence of isothermic and hypothermic semen processing protocols on boar sperm quality under laboratory and field conditions. In the laboratory study, ejaculates (n = 12) were first diluted (1:1) with Beltsville Thawing Solution (BTS) at 32 °C, then processed either with isothermic (32 °C) or hypothermic (21 °C) BTS, stored at 17 °C, and assessed on days 1, 3, and 6. Temperature curves showed that 150 minutes after the first dilution, semen doses of both groups reached the same temperature. Two-step hypothermic processing resulted in lower sperm motility on days 1 and 6 (P < 0.05). Concomitantly, hypothermally processed samples contained less membrane intact sperm on days 3 and 6 (P < 0.05). Using AndroStar Plus extender instead of BTS reduced the negative effect of hypothermic processing. In the field study, 15 semen samples from each of 23 European artificial insemination studs were evaluated as part of an external quality control program. Semen quality based on motility, membrane integrity, mitochondrial activity, and a thermoresistance test was higher for stations using one-step isothermic dilutions (n = 7) compared with artificial insemination centers using two-step hypothermic protocols (n = 16). Both studies show that chilling injury associated with hypothermic dilution results in lower quality of stored boar semen compared with isothermic dilution and that the type of semen extender affects the outcomes.

  13. Estrus induction and fertility response following different treatment protocols in Murrah buffaloes under field conditions

    PubMed Central

    Kumar, L.; Phogat, J. B.; Pandey, A. K.; Phulia, S. K.; Kumar, S.; Dalal, J.

    2016-01-01

    Aim: The aim of this study was to evaluate the efficacy of three different treatment protocols for estrus induction and conception rate in postpartum anestrus buffaloes during breeding season under field conditions. Materials and Methods: The 47 postpartum anestrus buffaloes of the 2nd to 6th parity were divided into three groups. Group 1 (n=16): Buffaloes received cosynch treatment, that is, buserelin acetate 10 µg on day 0 and 9, cloprostenol 500 µg on day 7 followed by fixed-time artificial insemination (FTAI) at the time of second buserelin acetate and 24 h later. Group 2 (n=15): Buffaloes received norgestomet ear implant subcutaneously for 9 days, estradiol benzoate 2 mg on the day of implant insertion (day 0), pregnant mare serum gonadotropin (PMSG) 400 IU and cloprostenol 500 µg on day 9 followed by AI at 48 and 72 h after implant removal. Group 3 (Cosynch-plus, n=16): Buffaloes received Cosynch protocol as per Group 1 except an additional injection of PMSG 400 IU (i.m.) was given 3 days before the start of protocol and FTAI done at the same time of Group 1. Pregnancy diagnosis was performed after 45 days of AI. Results: The estrus induction response following the treatment was 81.3%, 100%, and 93.7% in Group 1, 2, and 3, respectively. The buffaloes of Group 1, 2, and 3 expressed intense (38.4%, 60% and 46.6%, respectively) and moderate estrus (46.1%, 26.6%, and 40%, respectively). The conception rates in Group 1, 2, and 3, at FTAI and overall including subsequent estrus were 37.5% and 62.5%, 53.3%, and 66.6%, 56.3%, and 75%, respectively. Conclusion: All the three treatment protocols can be effectively used for induction of estrus with acceptable conception rate in postpartum anestrus buffaloes during breeding season under field conditions. However, Cosynch-plus (similar to Cosynch protocol except addition of PMSG, 400 IU 3 days before the start of first buserelin acetate administration) protocol results comparatively better pregnancy rate. PMID:28096623

  14. Use of a semi-field system to evaluate the efficacy of topical repellents under user conditions provides a disease exposure free technique comparable with field data

    PubMed Central

    2014-01-01

    Background Before topical repellents can be employed as interventions against arthropod bites, their efficacy must be established. Currently, laboratory or field tests, using human volunteers, are the main methods used for assessing the efficacy of topical repellents. However, laboratory tests are not representative of real life conditions under which repellents are used and field-testing potentially exposes human volunteers to disease. There is, therefore, a need to develop methods to test efficacy of repellents under real life conditions while minimizing volunteer exposure to disease. Methods A lotion-based, 15% N, N-Diethyl-3-methylbenzamide (DEET) repellent and 15% DEET in ethanol were compared to a placebo lotion in a 200 sq m (10 m × 20 m) semi-field system (SFS) against laboratory-reared Anopheles arabiensis mosquitoes and in full field settings against wild malaria vectors and nuisance-biting mosquitoes. The average percentage protection against biting mosquitoes over four hours in the SFS and field setting was determined. A Poisson regression model was then used to determine relative risk of being bitten when wearing either of these repellents compared to the placebo. Results Average percentage protection of the lotion-based 15% DEET repellent after four hours of mosquito collection was 82.13% (95% CI 75.94-88.82) in the semi-field experiments and 85.10% (95% CI 78.97-91.70) in the field experiments. Average percentage protection of 15% DEET in ethanol after four hours was 71.29% (CI 61.77-82.28) in the semi-field system and 88.24% (84.45-92.20) in the field. Conclusions Semi-field evaluation results were comparable to full-field evaluations, indicating that such systems could be satisfactorily used in measuring efficacy of topically applied mosquito repellents, thereby avoiding risks of exposure to mosquito-borne pathogens, associated with field testing. PMID:24767458

  15. The use of Poynting vector in wave-field decomposition imaging condition for reverse-time migration

    NASA Astrophysics Data System (ADS)

    Ren, Chiyuan; Song, Guojie; Tian, Xin

    2015-01-01

    An imaging condition based on cross-correlation is developed for prestack reverse-time migration. The imaging condition integrates the advantage of wave-field decomposition and Poynting vector and has powerful ability in artifacts removal. A truncation parameter is employed to balance imaging ability and artifacts removal in the imaging condition. The detail discussion has been done to verify the proposed imaging condition by lots of numerical simulation in a velocity model with vertical velocity gradient and Hess 2004 P-wave velocity model. The results show the proposed imaging condition works well to remove artifacts and improve imaging quality in these tests effectively.

  16. Quantifying atmospheric stability conditions at a swine facility and an adjacent corn field in Iowa, USA

    NASA Astrophysics Data System (ADS)

    Hernandez-Ramirez, Guillermo; Sauer, Thomas J.; Hatfield, Jerry L.; Prueger, John H.

    2011-10-01

    Atmospheric stability conditions in the atmospheric surface layer control the distance and direction of transport of air contaminants. Near confined animal facilities, transport processes significantly impact air quality as these sites typically act as point sources of dust and odor constituents; however, little information is available on atmospheric stability effects. This study was conducted to assess year-round temporal patterns of atmospheric stability at a swine production facility and an adjacent commercial corn field (CF) in the US Midwest. Two towers of 10 and 20 m heights for continuous micrometeorological measurements were deployed within a CF and between swine buildings (BSB), respectively. Each tower was equipped with an eddy-covariance system at 6.8 m height, infrared thermometers, and six cup anemometers with thermocouples installed at log-distributed heights. Overall results from gradient Richardson number and Monin-Obukhov (z/L) calculations revealed a greater prevalence of unstable conditions for BSB compared with CF. During the 13-month measurement period, unstable cases (z/L ranging from -1 to -0.01) occurred 1.4 times more frequently for BSB than CF (52 vs. 39%, respectively), while stable cases (0.011-0.2) were 1.8 times more frequent for CF than BSB (24 vs. 14%, respectively). These patterns were partly associated with higher surface radiometric temperatures for BSB. Relatively greater diurnal heat capture at BSB (ground and roof surfaces) and a cooling effect in CF through active canopy transpiration during the daytime explain these z/L and radiometric temperature results. Prevalent diurnal atmospheric instability at BSB suggests enhanced ascendant vertical transport of air pollutants perhaps causing greater mixing/dilution with the atmospheric layer and/or their facilitated transport over greater distances when sorbed onto particles. This enhanced understanding of the spatio-temporal patterns of atmospheric stability can be subsequently

  17. Inoculant of Arbuscular Mycorrhizal Fungi (Rhizophagus clarus) Increase Yield of Soybean and Cotton under Field Conditions.

    PubMed

    Cely, Martha V T; de Oliveira, Admilton G; de Freitas, Vanessa F; de Luca, Marcelo B; Barazetti, André R; Dos Santos, Igor M O; Gionco, Barbara; Garcia, Guilherme V; Prete, Cássio E C; Andrade, Galdino

    2016-01-01

    Nutrient availability is an important factor in crop production, and regular addition of chemical fertilizers is the most common practice to improve yield in agrosystems for intensive crop production. The use of some groups of microorganisms that have specific activity providing nutrients to plants is a good alternative, and arbuscular mycorrhizal fungi (AMF) enhance plant nutrition by providing especially phosphorus, improving plant growth and increasing crop production. Unfortunately, the use of AMF as an inoculant on a large scale is not yet widely used, because of several limitations in obtaining a large amount of inoculum due to several factors, such as low growth, the few species of AMF domesticated under in vitro conditions, and high competition with native AMF. The objective of this work was to test the infectivity of a Rhizophagus clarus inoculum and its effectiveness as an alternative for nutrient supply in soybean (Glycine max L.) and cotton (Gossypium hirsutum L.) when compared with conventional chemical fertilization under field conditions. The experiments were carried out in a completely randomized block design with five treatments: Fertilizer, AMF, AMF with Fertilizer, AMF with 1/2 Fertilizer, and the Control with non-inoculated and non-fertilized plants. The parameters evaluated were AMF root colonization and effect of inoculation on plant growth, nutrient absorption and yield. The results showed that AMF inoculation increased around 20 % of root colonization in both soybean and cotton; nutrients analyses in vegetal tissues showed increase of P and nitrogen content in inoculated plants, these results reflect in a higher yield. Our results showed that, AMF inoculation increase the effectiveness of fertilizer application in soybean and reduce the fertilizer dosage in cotton.

  18. Inoculant of Arbuscular Mycorrhizal Fungi (Rhizophagus clarus) Increase Yield of Soybean and Cotton under Field Conditions

    PubMed Central

    Cely, Martha V. T.; de Oliveira, Admilton G.; de Freitas, Vanessa F.; de Luca, Marcelo B.; Barazetti, André R.; dos Santos, Igor M. O.; Gionco, Barbara; Garcia, Guilherme V.; Prete, Cássio E. C.; Andrade, Galdino

    2016-01-01

    Nutrient availability is an important factor in crop production, and regular addition of chemical fertilizers is the most common practice to improve yield in agrosystems for intensive crop production. The use of some groups of microorganisms that have specific activity providing nutrients to plants is a good alternative, and arbuscular mycorrhizal fungi (AMF) enhance plant nutrition by providing especially phosphorus, improving plant growth and increasing crop production. Unfortunately, the use of AMF as an inoculant on a large scale is not yet widely used, because of several limitations in obtaining a large amount of inoculum due to several factors, such as low growth, the few species of AMF domesticated under in vitro conditions, and high competition with native AMF. The objective of this work was to test the infectivity of a Rhizophagus clarus inoculum and its effectiveness as an alternative for nutrient supply in soybean (Glycine max L.) and cotton (Gossypium hirsutum L.) when compared with conventional chemical fertilization under field conditions. The experiments were carried out in a completely randomized block design with five treatments: Fertilizer, AMF, AMF with Fertilizer, AMF with 1/2 Fertilizer, and the Control with non-inoculated and non-fertilized plants. The parameters evaluated were AMF root colonization and effect of inoculation on plant growth, nutrient absorption and yield. The results showed that AMF inoculation increased around 20 % of root colonization in both soybean and cotton; nutrients analyses in vegetal tissues showed increase of P and nitrogen content in inoculated plants, these results reflect in a higher yield. Our results showed that, AMF inoculation increase the effectiveness of fertilizer application in soybean and reduce the fertilizer dosage in cotton. PMID:27303367

  19. Diurnal photosynthesis, water use efficiency and light use efficiency of wheat under Mediterranean field conditions.

    PubMed

    Evrendilek, Fatih; Ben Asher, Jiftah; Aydin, Mehmet

    2008-05-01

    Photosynthesis and transpiration rates of wheat leaves (Triticum aestivum L.) were measured at 30 min intervals under Mediterranean field conditions, using Photosynthesis Monitor system (PM-48M). The dynamics of net photosynthetic rate (P(N)), transpiration rate (E(T)), water use efficiency (WUE), light use efficiency (LUE), stomatal conductance (g(s)), photosynthetically active radiation (PAR), air temperature (T), relative humidity (RH), and atmospheric CO2 concentration (Catm) were quantified at five rainfed wheat sites with the same stages of development (midflowering) along south-to-north and east-to-west transects for eight days in April. Diurnal P(N) (3.6 to 6.6 micromol m(-2) s(-1)), PAR (392 to 564 micromol m2 sec(-1)), LUE (0.006 to 0.015) and WUE (0.0001 to 0.011) did not vary significantly across all five wheat sites (p > 0.05). P(N) and E(T) were strongly coupled and highly correlated with PAR (p < 0.001). Best multiple linear regression (MLR) models accounted for 92% of variations in P(N) as a function of PAR and E(T), and 90% in E(T) as a function of PAR and RH (p < 0.001). P(N) exhibited a peak at mid-morning, and a photosynthetic midday depression under the limiting effects of high evaporative demand. Diurnal variations in WUE and LUE showed a bimodal behavior with the maximum values in early morning and late afternoon. As the impacts of global climate change become increasingly felt, continuous measurements of climate-crop-soil-managementinteractions under natural conditions play a pivotal role not only in exploring changes in ecophysiological properties of strategic crops for food security such as wheat but also in devising preventive and mitigative management practices to ensure sustained agricultural productivity.

  20. Revegetation processes and environmental conditions in abandoned peat production fields in Estonia

    NASA Astrophysics Data System (ADS)

    Orru, M.; Orru, H.

    2009-04-01

    As a result of peat extraction, peat production has been finished in Estonia at different times in 154 peat production areas and 9,500 ha (~1% of peatlands) are abandoned, although the peat reserves are not exhausted yet; besides, several areas are not properly recultivated. In addition 12,000 ha of fens (oligotrophic peat layers) are drained and used as grasslands. If the abandoned and non-recultivated peat production areas are not vegetated, their CO2 emission is considerable and peat mineralises in such areas. The aim of the study was to find out specific ecological and geological factors, which affect recovering of peatlands and influence the recultivation. During the revision the amount and quality of the remained reserves, as well as the state of water regime, drainage network and revegetation was assessed in all 154 abandoned peat production areas. The study showed that the state of them is very variable. Some of them are covered with forest, prevailingly with birches at former drainage ditches, later supplemented by pine trees. In the others predominate grasses among plants, and various species of moss (Cladonia rei, Bryum caespiticum, Sphagnum ripariuma, Sphagnum squarrosum) occur as well. Besides, some abandoned areas are completely overgrown with cotton grass. Open abandoned peat areas, which are not covered by vegetation, are much rarer. We found out, that water regime among the factors plays most important role. Moreover abandoned peat production fields, where the environmental conditions have changed - are appropriate for growth of several moss species, which cannot inhabit the areas already occupied by other species. The most interesting discovers were: second growing site of Polia elongata in West-Estonia and Ephemerum serratum, last found in Estonia in the middle of the 19th century, was identified in central Estonia. Also Campylopus introflexus, what was unknown in Estonia. However, the changes in environmental conditions influence the peat layers

  1. Compound specific isotope analysis to investigate pesticide degradation in lysimeter experiments at field conditions

    NASA Astrophysics Data System (ADS)

    Ryabenko, Evgenia; Elsner, Martin; Bakkour, Rani; Hofstetter, Thomas; Torrento, Clara; Hunkeler, Daniel

    2015-04-01

    The frequent detection of organic micropollutants such as pesticides, consumer care products or pharmaceuticals in water is an increasing concern for human and ecosystem health. Degradation analysis of these compounds can be challenging in complex systems due to the fact that metabolites are not always found and mass balances frequently cannot be closed. Many abiotic and biotic degradation pathways cause, however, distinct isotope fractionation, where light isotopes are transferred preferentially from the reactant to the product pool (normal isotope fractionation). Compound-specific isotope analysis (CSIA) of multiple elements is a particularly powerful method to evaluate organic micropollutant transformation, because it can even give pathway-specific isotope fractionation (1,2). Available CSIA field studies, however, have focused almost exclusively on volatile petroleum and chlorinated hydrocarbons, which are present in high concentrations in the environment and can be extracted easily from water for GC-IRMS analysis. In the case of micropollutants, such as pesticides, CSIA in more challenging since it needs to be conducted at lower concentrations and requires pre-concentration, purification and high chromatographic performance (3). In this study we used lysimeters experiments to analyze transformation of atrazine, acetochlor, metolachlor and chloridazone by studying associated isotope fractionation. The project combines a) analytical method development for CSIA, b) identification of pathways of micropollutant degradation and c) quantification of transformation processes under field condition. The pesticides were applied both, at the soil surface and below the top soil under field-relevant concentrations in May 2014. After typical irrigation of the lysimeters, seepage water was collected in 50L bottles and stored for further SPE and CSIA. Here we present the very first result of a) analytical method development, b) improvement of SPE methods for complex pesticide

  2. Plio-pleistocene African climate

    SciTech Connect

    deMenocal, P.B.

    1995-10-06

    Marine records of African climate variability document a shift toward more arid conditions after 2.8 million years ago (Ma), evidently resulting from remote forcing by cold North Atlantic sea-surface temperatures associated with the onset of Northern Hemisphere glacial cycles. African climate before 2.8 Ma was regulated by low-latitude insolation forcing of monsoonal climate due to Earth orbital precession. Major steps in the evolution of African hominids and other vertebrates are coincident with shifts to more arid, open conditions near 2.8 Ma, 1.7 Ma, and 1.0 Ma, suggesting that some Pliocene (Plio)-Pleistocene speciation events may have been climatically mediated. 65 refs., 6 figs.

  3. Plio-Pleistocene African Climate

    NASA Astrophysics Data System (ADS)

    Demenocal, Peter B.

    1995-10-01

    Marine records of African climate variability document a shift toward more arid conditions after 2.8 million years ago (Ma), evidently resulting from remote forcing by cold North Atlantic sea-surface temperatures associated with the onset of Northern Hemisphere glacial cycles. African climate before 2.8 Ma was regulated by low-latitude insolation forcing of monsoonal climate due to Earth orbital precession. Major steps in the evolution of African hominids and other vertebrates are coincident with shifts to more arid, open conditions near 2.8 Ma, 1.7 Ma, and 1.0 Ma, suggesting that some Pliocene (Plio)-Pleistocene speciation events may have been climatically mediated.

  4. Causal signal transmission by quantum fields. VI: The Lorentz condition and Maxwell's equations for fluctuations of the electromagnetic field

    NASA Astrophysics Data System (ADS)

    Plimak, L. I.; Stenholm, S.

    2013-11-01

    The general structure of electromagnetic interactions in the so-called response representation of quantum electrodynamics (QED) is analysed. A formal solution to the general quantum problem of the electromagnetic field interacting with matter is found. Independently, a formal solution to the corresponding problem in classical stochastic electrodynamics (CSED) is constructed. CSED and QED differ only in the replacement of stochastic averages of c-number fields and currents by time-normal averages of the corresponding Heisenberg operators. All relations of QED connecting quantum field to quantum current lack Planck's constant, and thus coincide with their counterparts in CSED. In Feynman's terms, one encounters complete disentanglement of the potential and current operators in response picture.

  5. Field experiments of beach scarp erosion during oblique wave, stormy conditions (Normandy, France)

    NASA Astrophysics Data System (ADS)

    Bonte, Yoann; Levoy, Franck

    2015-05-01

    A field-based experimental study of beach scarp morphodynamic evolution was conducted on the shoreface of a macrotidal sandy beach subject to storms combined with spring tide events (Luc-sur-Mer, France). Both video and in-situ measurements on an artificial berm are used to understand beach scarp evolution over one tide during stormy conditions. Image time stacks are used to analyze the swash action on the beach scarp and topographical data of the scarp are recorded with a terrestrial scanner laser to quantify the morphodynamic response of the beach scarp to wave action. This work provides a new and unique dataset about beach scarp changes and berm morphology in particular under rising tide and oblique wind-wave conditions. During one stormy event, the berm was completely destroyed. However, contrasting alongshore changes were measured during the erosive phase with different crest and foot scarp retreats and eroded volumes between the west and the east side of the berm. The beach in front of the scarp also shows a contrasting residual evolution, indicating an evident longshore sediment transport on the study area as a consequence of incident oblique wave conditions. A strong connection between beach evolution and beach scarp changes is clearly identified. The scarp erosion increases on the west side of the berm when the beach level is lowered and reduces when the beach surface rises on the east side. The beach slope and foreshore elevation as a result of a longshore sediment transport between east and west profiles, influence swash activity. Overall, water depth and swash activity became progressively different along the scarp during the experiment. Swash measurements indicate that the presence of the beach scarp strongly influences the swash motion. At high tide, the reflection of the uprush on the scarp front induces a collision between the reflected backwash and the following uprush dynamic. These collisions reduce and sometimes stop the motion of the following

  6. Measurement capability of field portable organic vapor monitoring instruments under different experimental conditions.

    PubMed

    Coffey, Christopher C; Pearce, Terri A; Lawrence, Robert B; Hudnall, Judith B; Slaven, James E; Martin, Stephen B

    2009-01-01

    The performance of field portable direct-reading organic vapor monitors (DROVMs) was evaluated under a variety of experimental conditions. Four of the DROVMs had photoionization detectors (ppbRAE, IAQRAE, MultiRAE, and Century Toxic Vapor Analyzer), one had a flame ionization detector (Century Toxic Vapor Analyzer), and one was a single-beam infrared spectrophotometer (SapphIRe). Four of each DROVM (two Century Toxic Vapor Analyzers and SapphIRes) were tested. The DROVMs were evaluated at three temperatures (4 degrees C, 21 degrees C, and 38 degrees C), three relative humidities (30%, 60%, and 90%), and two hexane concentrations (5 ppm and 100 ppm). These conditions were selected to provide a range within the operational parameters of all the instruments. At least four replicate trials were performed across the 18 experimental conditions (3 temperatures x 3 relative humidities x 2 concentrations). To evaluate performance, the 4-hr time-weighted average readings from the DROVMs in a given trial were compared with the average of two charcoal tube concentrations using pairwise comparison. The pairwise comparison criterion was +/-25% measurement agreement between each individual DROVM and the DROVMs as a group and the average charcoal tube concentration. The ppbRAE group performed the best with 40% of all readings meeting the comparison criterion followed by the SapphIRe group at 39%. Among individual DROVMs, the best performer was a SapphIRe, with 57% of its readings meeting the criterion. The data was further analyzed by temperature, humidity, and concentration. The results indicated the performance of some DROVMs may be affected by temperature, humidity, and/or concentration. The ppbRAE group performed best at 21 degrees C with the percentage of readings meeting the criterion increasing to 63%. At the 5 ppm concentration, 44% of the ppbRAE group readings met the criterion, while at 100 ppm, only 35% did. The results indicate that monitors can be used as survey tools

  7. Single image depth estimation based on convolutional neural network and sparse connected conditional random field

    NASA Astrophysics Data System (ADS)

    Zhu, Leqing; Wang, Xun; Wang, Dadong; Wang, Huiyan

    2016-10-01

    Deep convolutional neural networks (DCNNs) have attracted significant interest in the computer vision community in the recent years and have exhibited high performance in resolving many computer vision problems, such as image classification. We address the pixel-level depth prediction from a single image by combining DCNN and sparse connected conditional random field (CRF). Owing to the invariance properties of DCNNs that make them suitable for high-level tasks, their outputs are generally not localized enough for detailed pixel-level regression. A multiscale DCNN and sparse connected CRF are combined to overcome this localization weakness. We have evaluated our framework using the well-known NYU V2 depth dataset, and the results show that the proposed method can improve the depth prediction accuracy both qualitatively and quantitatively, as compared to previous works. This finding shows the potential use of the proposed method in three-dimensional (3-D) modeling or 3-D video production from the given two-dimensional (2-D) images or 2-D videos.

  8. Measurement of impulse peak insertion loss for four hearing protection devices in field conditions

    PubMed Central

    Murphy, William J.; Flamme, Gregory A.; Meinke, Deanna K.; Sondergaard, Jacob; Finan, Donald S.; Lankford, James E.; Khan, Amir; Vernon, Julia; Stewart, Michael

    2015-01-01

    Objective In 2009, the U.S. Environmental Protection Agency (EPA) proposed an impulse noise reduction rating (NRR) for hearing protection devices based upon the impulse peak insertion loss (IPIL) methods in the ANSI S12.42-2010 standard. This study tests the ANSI S12.42 methods with a range of hearing protection devices measured in field conditions. Design The method utilizes an acoustic test fixture and three ranges for impulse levels: 130–134, 148–152, and 166–170 dB peak SPL. For this study, four different models of hearing protectors were tested: Bilsom 707 Impact II electronic earmuff, E·A·R Pod Express, E·A·R Combat Arms version 4, and the Etymotic Research, Inc. Electronic BlastPLG™ EB1. Study sample Five samples of each protector were fitted on the fixture or inserted in the fixture's ear canal five times for each impulse level. Impulses were generated by a 0.223 caliber rifle. Results The average IPILs increased with peak pressure and ranged between 20 and 38 dB. For some protectors, significant differences were observed across protector examples of the same model, and across insertions. Conclusions The EPA's proposed methods provide consistent and reproducible results. The proposed impulse NRR rating should utilize the minimum and maximum protection percentiles as determined by the ANSI S12.42-2010 methods. PMID:22176308

  9. Biological Control of Alternaria Fruit Rot of Chili by Trichoderma Species under Field Conditions.

    PubMed

    Begum, Most Ferdousi; Rahman, M A; Alam, M Firoz

    2010-06-01

    Trichoderma strains were evaluated under field conditions to assay their efficacy in suppressing Alternaria fruit rot disease and promoting chili plant growth. The experiment was conducted at the Botanical Garden, Rajshahi University, Bangladesh from July 2006 to March 2007. Application of Trichoderma harzianum IMI 392432 significantly (p = 0.05) suppressed the disease compared to Alternaria tenuis (T2) treatment and improved both growth and yield. The treatment T4 (T. harzianum IMI-392432 + A. tenuis) was most effective in reducing disease percentage (72.27%) compared to A. tenuis (T1) treatment. The highest seed germination rate (85.56%) and the highest growth and yield (12.5 g/plant) was also recorded in the same treatment (T4), followed by T5 (T. harzianum IMI-392433 000000 + A. tenuis), T6 (T. harzianum IMI-392434 +A. tenuis), T2 (T. virens IMI-392430 + A. tenuis), and T3 (T. pseudokoningii IMI-392431 +A. tenuis) treatment, while single treatment with A. tenuis significantly decreased these values.

  10. An efficient conditional random field approach for automatic and interactive neuron segmentation.

    PubMed

    Uzunbas, Mustafa Gokhan; Chen, Chao; Metaxas, Dimitris

    2016-01-01

    We present a new graphical-model-based method for automatic and interactive segmentation of neuron structures from electron microscopy (EM) images. For automated reconstruction, our learning based model selects a collection of nodes from a hierarchical merging tree as the proposed segmentation. More specifically, this is achieved by training a conditional random field (CRF) whose underlying graph is the watershed merging tree. The maximum a posteriori (MAP) prediction of the CRF is the output segmentation. Our results are comparable to the results of state-of-the-art methods. Furthermore, both the inference and the training are very efficient as the graph is tree-structured. The problem of neuron segmentation requires extremely high segmentation quality. Therefore, proofreading, namely, interactively correcting mistakes of the automatic method, is a necessary module in the pipeline. Based on our efficient tree-structured inference algorithm, we develop an interactive segmentation framework which only selects locations where the model is uncertain for a user to proofread. The uncertainty is measured by the marginals of the graphical model. Only giving a limited number of choices makes the user interaction very efficient. Based on user corrections, our framework modifies the merging tree and thus improves the segmentation globally.

  11. Enantioselective degradation of (2RS,3RS)-paclobutrazol in peach and mandarin under field conditions.

    PubMed

    Wang, Xiangyun; Qi, Peipei; Yang, Guiling; Wang, Xinquan; Zhang, Hu; Xu, Hao; Wang, Zhiwei; Wang, Qiang

    2014-08-01

    In this study we investigated the enantioselective degradation of (2RS,3RS)-paclobutrazol in peach and mandarin fruits under field conditions after foliar treatment at 500 mg active ingredient/L using a Lux Cellulose-1 chiral column on a reverse-phase liquid chromatography-tandem mass spectrometry system. Degradations of paclobutrazol in both fruits followed first-order kinetics, with half-lives of about 9 days. Initial deposits were 1.63 mg/kg on peach and 1.99 mg/kg on mandarin; terminal concentrations were lower than 0.05 mg/kg, which was acceptable in most cases. As anticipated, paclobutrazol levels in peels of mature mandarin were about 6.3 times higher than in pulp, indicating the potential risk of peel consumption. We also observed that paclobutrazol degradation in mature mandarin was relatively slow, indicating it might not be efficient enough to hold mandarin fruits on trees for lowering paclobutrazol concentrations. Significant enantioselectivity was observed: the (2R,3R)-enantiomer was preferentially degraded in mandarin (whole fruit, peels, and pulp) but enriched in peach. Because of its more rapid degradation in mandarin and the lower levels observed in pulp compared with peels, potential endocrine-related side effects due to the (2R,3R)-enantiomer pose less of a risk in mandarin than in peach.

  12. Disease named entity recognition by combining conditional random fields and bidirectional recurrent neural networks.

    PubMed

    Wei, Qikang; Chen, Tao; Xu, Ruifeng; He, Yulan; Gui, Lin

    2016-01-01

    The recognition of disease and chemical named entities in scientific articles is a very important subtask in information extraction in the biomedical domain. Due to the diversity and complexity of disease names, the recognition of named entities of diseases is rather tougher than those of chemical names. Although there are some remarkable chemical named entity recognition systems available online such as ChemSpot and tmChem, the publicly available recognition systems of disease named entities are rare. This article presents a system for disease named entity recognition (DNER) and normalization. First, two separate DNER models are developed. One is based on conditional random fields model with a rule-based post-processing module. The other one is based on the bidirectional recurrent neural networks. Then the named entities recognized by each of the DNER model are fed into a support vector machine classifier for combining results. Finally, each recognized disease named entity is normalized to a medical subject heading disease name by using a vector space model based method. Experimental results show that using 1000 PubMed abstracts for training, our proposed system achieves an F1-measure of 0.8428 at the mention level and 0.7804 at the concept level, respectively, on the testing data of the chemical-disease relation task in BioCreative V.Database URL: http://219.223.252.210:8080/SS/cdr.html.

  13. Effect of swirling inlet condition on the flow field in a stenosed arterial vessel model.

    PubMed

    Ha, Hojin; Lee, Sang-Joon

    2014-01-01

    Blood flow in an artery is closely related to atherosclerosis progression. Hemodynamic environments influence platelet activation, aggregation, and rupture of atherosclerotic plaque. The existence of swirling flow components in an artery is frequently observed under in vivo conditions. However, the fluid-dynamic roles of spiral flow are not fully understood to date. In this study, the spiral blood flow effect in an axisymmetric stenosis model was experimentally investigated using particle image velocimetry velocity field measurement technique and streakline flow visualization. Spiral inserts with two different helical pitches (10D and 10/3D) were installed upstream of the stenosis to induce swirling flows. Results show that the spiral flow significantly reduces the length of recirculation flow and provokes early breakout of turbulent transition, but variation of swirling intensity does not induce significant changes of turbulence intensity. The present results about the spiral flow effects through the stenosis will contribute in achieving better understanding of the hemodynamic characteristics of atherosclerosis and in discovering better diagnosis procedures and clinical treatments.

  14. Dissipation of chlorpyrifos and residue analysis in rice, soil and water under paddy field conditions.

    PubMed

    Zhang, Xiao; Shen, Yan; Yu, Xiang-yang; Liu, Xian-jin

    2012-04-01

    The analytical method for the residues of chlorpyrifos in rice plants, water and soil was developed and dissipation of chlorpyrifos under field conditions was studied. The limit of detection (LOD) of chlorpyrifos was 0.006 mg kg(-1) and the limit of quantification (LOQ) was found to be 0.04 mg kg(-1) in rice plant (water) and 0.02 mg kg(-1) in the other substrates, respectively. The results showed that the initial residues of chlorpyrifos in Nanjing and Guangxi were 4.99 and 6.05 mg kg(-1) (rice plant), 1.35 and 1.58 mg kg(-1) (water) and 0.51 and 0.63 mg kg(-1) (soil), respectively. The half-lives of chlorpyrifos in rice plant, water and soil from Nanjing were 4.28, 0.58 and 1.35 day, respectively, and the half-lives of those from Guangxi were 3.86, 0.52 and 1.21 day, respectively. The husked rice, rice hull and straw samples were found to contain chlorpyrifos well below the maximum residue limit (MRL) following the recommended dosage, the residues of chlorpyrifos in soil were undetectable under all application levels and frequencies after 28 day of applications.

  15. Gene flow from GM glyphosate-tolerant to conventional soybeans under field conditions in Japan.

    PubMed

    Yoshimura, Yasuyuki; Matsuo, Kazuhito; Yasuda, Koji

    2006-01-01

    Natural out-crossing rates were evaluated for conventional soybeans (Glycine max (L.) Merr.) cultivated adjacent to genetically modified (GM) glyphosate-tolerant soybeans under field conditions during a four-year period in Japan. A total of 107 846 progeny of 2772 plants harvested from conventional varieties were screened for glyphosate herbicide tolerance. The highest out-crossing rates, 0.19% in 2001 and 0.16% in 2002, were observed in adjacent rows 0.7 m from the pollen source. The highest rate in 2004 was 0.052%, which was observed at 2.1 m. No out-crossing was observed in the rows 10.5 m from the pollen source over the four-year period. The farthest distances between receptor and pollen source at which out-crossing was observed were 7 m in 2001, 2.8 m in 2002, and 3.5 m in 2004. The greatest airborne pollen density during the flowering period, determined by Durham pollen samplers located between the rows of each variety, was 0.368 grains.cm(-2).day(-1), with the average value at 0.18 grains.cm(-2).day(-1), indicating that the possibility of out-crossing by wind is minimal. Thrips species and predatory Hemiptera visited the soybean flowers more frequently during the four-year period than any other common pollinators, such as bees.

  16. TECNAIRE winter field campaign: turbulent characteristics and their influence on air quality conditions

    NASA Astrophysics Data System (ADS)

    Yagüe, Carlos; Román Cascón, Carlos; Maqueda, Gregorio; Sastre, Mariano; Arrillaga, Jon A.; Artíñano, Begoña; Diaz-Ramiro, Elías; Gómez-Moreno, Francisco J.; Borge, Rafael; Narros, Adolfo; Pérez, Javier

    2016-04-01

    An urban field campaign was conducted at an air pollution hot spot in Madrid city (Spain) during winter 2015 (from 16th February to 2nd March). The zone selected for the study is a square (Plaza Fernández Ladreda) located in the southern part of the city. This area is an important intersection of several principal routes, and therefore a significant impact in the air quality of the area is found due to the high traffic density. Meteorological data (wind speed and direction, air temperature, relative humidity, pressure, precipitation and global solar radiation) were daily recorded as well as micrometeorological measurements obtained from two sonic anemometers. To characterize this urban atmospheric boundary layer (uABL), micrometeorological parameters (turbulent kinetic energy -TKE-, friction velocity -u∗- and sensible heat flux -H-) are calculated, considering 5-minute average for variance and covariance evaluations. Furthermore, synoptic atmospheric features were analyzed. As a whole, a predominant influence of high pressure systems was found over the Atlantic Ocean and western Spain, affecting Madrid, but during a couple of days (17th and 21st February) some atmospheric instability played a role. The influence of the synoptic situation and specially the evolution of the micrometeorological conditions along the day on air quality characteristics (Particulate Matter concentrations: PM10, PM2.5 and PM1, and NOx concentrations) are analyzed and shown in detail. This work has been financed by Madrid Regional Research Plan through TECNAIRE (P2013/MAE-2972).

  17. Disease named entity recognition by combining conditional random fields and bidirectional recurrent neural networks

    PubMed Central

    Wei, Qikang; Chen, Tao; Xu, Ruifeng; He, Yulan; Gui, Lin

    2016-01-01

    The recognition of disease and chemical named entities in scientific articles is a very important subtask in information extraction in the biomedical domain. Due to the diversity and complexity of disease names, the recognition of named entities of diseases is rather tougher than those of chemical names. Although there are some remarkable chemical named entity recognition systems available online such as ChemSpot and tmChem, the publicly available recognition systems of disease named entities are rare. This article presents a system for disease named entity recognition (DNER) and normalization. First, two separate DNER models are developed. One is based on conditional random fields model with a rule-based post-processing module. The other one is based on the bidirectional recurrent neural networks. Then the named entities recognized by each of the DNER model are fed into a support vector machine classifier for combining results. Finally, each recognized disease named entity is normalized to a medical subject heading disease name by using a vector space model based method. Experimental results show that using 1000 PubMed abstracts for training, our proposed system achieves an F1-measure of 0.8428 at the mention level and 0.7804 at the concept level, respectively, on the testing data of the chemical-disease relation task in BioCreative V. Database URL: http://219.223.252.210:8080/SS/cdr.html PMID:27777244

  18. Amaranthus hybridus can be pollinated frequently by A. tuberculatus under field conditions.

    PubMed

    Trucco, F; Jeschke, M R; Rayburn, A L; Tranel, P J

    2005-01-01

    Recent studies have confirmed that weedy Amaranthus species are capable of interspecific hybridization, and such hybridization may foster the evolution of herbicide resistance. However, the extent to which hybridization among these species occurs in nature is unknown. The purpose of this study was to determine the frequency under field conditions at which A. hybridus, a monoecious and predominantly self-pollinated species, would be pollinated by A. tuberculatus, a dioecious species. To do this, parents carrying different alleles at the ALS locus, which encodes a herbicide target site, were used. Male A. tuberculatus parents were homozygous for a dominant herbicide-insensitive allele, while A. hybridus parents were homozygous for a sensitive form. Hybrid progeny therefore could be detected via herbicide selection. Mean hybridization frequencies between 0.4 and 2.3% were obtained, depending on the proximity between parents (P=0.02). The robustness of the hybrid selection assay was verified using a molecular marker and DNA content analyses. Using these techniques, more than 99% of the progeny that survived the herbicide were confirmed to be hybrids. Frequencies obtained in this study were many times higher than the generally expected rate of mutation. Therefore, even minimal fertility in hybrid progeny would support the view that hybridization could play a role in adaptive evolution of weedy Amaranthus species.

  19. Influence of Chronic Heat Acclimatization on Occupational Thermal Strain in Tropical Field Conditions

    PubMed Central

    Brearley, Matt B.; Norton, Ian; Rush, Daryl; Hutton, Michael; Smith, Steve; Ward, Linda; Fuentes, Hector

    2016-01-01

    Objective: To examine whether non-heat acclimatized (NHA) emergency responders endure greater physiological and perceptual strain than heat acclimatized (HA) counterparts in tropical field settings. Methods: Eight HA and eight NHA men urban search and rescue personnel had physiological and perceptual responses compared during the initial 4 hours shift of a simulated disaster in tropical conditions (ambient temperature 34.0 °C, 48% relative humidity, wet bulb globe temperature [WBGT] 31.4 °C). Results: From the 90th minute through to end of shift, HA (38.5 °C) sustained a significantly higher gastrointestinal temperature than NHA (38.1 °C) (mean difference 0.4 ± 0.2 °C, 95% confidence interval [CI] 0.2 to 0.7 °C, P = 0.005) despite comparable heart rate (P = 0.30), respiratory rate (P = 0.88), and axilla skin temperature (P = 0.47). Overall, perception of body temperature was similar between cohorts (P = 0.87). Conclusions: The apparent tolerance of greater physiological strain by HA responders occurred in the absence of perceptual differences. PMID:27930487

  20. Automated torso organ segmentation from 3D CT images using conditional random field

    NASA Astrophysics Data System (ADS)

    Nimura, Yukitaka; Hayashi, Yuichiro; Kitasaka, Takayuki; Misawa, Kazunari; Mori, Kensaku

    2016-03-01

    This paper presents a segmentation method for torso organs using conditional random field (CRF) from medical images. A lot of methods have been proposed to enable automated extraction of organ regions from volumetric medical images. However, it is necessary to adjust empirical parameters of them to obtain precise organ regions. In this paper, we propose an organ segmentation method using structured output learning which is based on probabilistic graphical model. The proposed method utilizes CRF on three-dimensional grids as probabilistic graphical model and binary features which represent the relationship between voxel intensities and organ labels. Also we optimize the weight parameters of the CRF using stochastic gradient descent algorithm and estimate organ labels for a given image by maximum a posteriori (MAP) estimation. The experimental result revealed that the proposed method can extract organ regions automatically using structured output learning. The error of organ label estimation was 6.6%. The DICE coefficients of right lung, left lung, heart, liver, spleen, right kidney, and left kidney are 0.94, 0.92, 0.65, 0.67, 0.36, 0.38, and 0.37, respectively.

  1. Nonparametric Feature Matching Based Conditional Random Fields for Gesture Recognition from Multi-Modal Video.

    PubMed

    Chang, Ju Yong

    2016-08-01

    We present a new gesture recognition method that is based on the conditional random field (CRF) model using multiple feature matching. Our approach solves the labeling problem, determining gesture categories and their temporal ranges at the same time. A generative probabilistic model is formalized and probability densities are nonparametrically estimated by matching input features with a training dataset. In addition to the conventional skeletal joint-based features, the appearance information near the active hand in an RGB image is exploited to capture the detailed motion of fingers. The estimated likelihood function is then used as the unary term for our CRF model. The smoothness term is also incorporated to enforce the temporal coherence of our solution. Frame-wise recognition results can then be obtained by applying an efficient dynamic programming technique. To estimate the parameters of the proposed CRF model, we incorporate the structured support vector machine (SSVM) framework that can perform efficient structured learning by using large-scale datasets. Experimental results demonstrate that our method provides effective gesture recognition results for challenging real gesture datasets. By scoring 0.8563 in the mean Jaccard index, our method has obtained the state-of-the-art results for the gesture recognition track of the 2014 ChaLearn Looking at People (LAP) Challenge.

  2. Photochemical and Meteorological Conditions during the MCMA-2003 Field Measurement Campaign

    NASA Astrophysics Data System (ADS)

    Molina, L. T.; de Foy, B.; Molina, M. J.; Caetano, E.; Magana, V.; Zitacuaro, A.; Ramos, R.; Retama, A.; Cardenas, B.; Martinez, A.; Reyes, R.; Sosa, G.

    2004-12-01

    MCMA-2003 was a major field campaign of the atmospheric chemistry taking place in the Mexico City Metropolitan Area (MCMA) in April of 2003. April is in the transition from the dry to the wet season with predominant westerly synoptic winds and intense radiation heating leading to strong thermal mountain flows. Three basic types of meteorological conditions were identified: "Cold Surge", "O3-North" and "O3-South", corresponding to cloudy days associated with "Norte" events, peak ozone in the north of the city, and peak ozone in the south. The circulation associated with these is described both at the regional and local level, as high concentrations of both ozone and primary pollutants for each category make them equally relevant to chemical analyses of the basin. Modified wind roses (time roses) based on time of day categories instead of wind speed categories are used to identify shifts in wind directions associated with slope flows inside the basin and sea breeze flows outside of it. The photochemical episodes are compared with historical data from the RAMA monitoring network to assess the representativeness of MCMA-2003. The analysis of the episodes during the campaign shows the existence of one-day episodes where no build-up of pollutants is needed in order to attain very highly localized concentrations but where multi-day events lead to peaks covering a much larger geographic area.

  3. Evaluation of oral tilmicosin efficacy against severe cryptosporidiosis in neonatal kids under field conditions.

    PubMed

    Paraud, C; Pors, I; Chartier, C

    2010-05-28

    Many compounds have been screened for their potential anti-cryptosporidial activity in ruminants but none of them has been totally efficient in controlling the disease. Macrolide antibiotics have demonstrated some activity against Cryptosporidium spp. in humans. Tilmicosin is a macrolide antibiotic, available in France in an oral form (Pulmotil AC, Lilly France). The preventive efficacy of tilmicosin was evaluated in a goat farm experiencing severe clinical cryptosporidiosis in kids. Twenty-two kids were separated from their dams just after birth and placed in a separated pen. They were divided into 3 groups: an untreated group (10 kids), group 1 (6 kids) receiving tilmicosin at 25mg/kg BW/day and group 2 (6 kids) receiving tilmicosin at 50mg/kg BW/day. Tilmicosin was individually given by oral route from day 2 of age for 10 days. Three times a week, individual faecal samples were performed to assess the oocyst output. Clinical data, i.e. diarrhea and mortality, were recorded. In control kids, the highest prevalence and intensity of excretion were observed between day 6 and day 16 of age and mortality reached 90%. Excretion dynamic and clinical consequences were similar in both treated kid groups. Finally, tilmicosin did not demonstrate any activity against severe kid cryptosporidiosis in field conditions.

  4. Performance of certified wood stoves under field conditions. Report for August 1985-September 1987

    SciTech Connect

    Burnet, P.G.; McCrillis, R.C.; Morgan, S.J.

    1988-05-01

    This paper discusses the monitoring of wood-stove performance under field conditions in 34 Northeast U.S. houses for two heating seasons, and in 8 Northwest U.S. and 14 Whitehorse, Yukon, Canada, houses for one heating season. Stoves included models certified or capable of being certified to Oregon Department of Environmental Quality and U.S. EPA standards. Objectives of the studies were to evaluate the performance of advanced-technology stoves (catalytic, noncatalytic low emission, and catalytic add-on/retrofit devices) relative to conventional technology stoves. Stoves were monitored for particulate emissions, wood use, and creosote accumulation in flue systems. The new-technology stoves models showed the potential to reduce particulate emissions, fuel use, and creosote accumulation. Good performance in at least one installation for most of the stove models indicates that factors such as stove maintenance and fueling practices, as well as technology factors, are important in reducing emissions. Reducing firebox size appears to be a consistent factor in reducing emissions.

  5. Importance of Aerodynamic Resistance to Water Use Efficiency in Three Conifers under Field Conditions 1

    PubMed Central

    Smith, William K.

    1980-01-01

    The quantitative importance of aerodynamic resistance to H2O vapor and CO2 exchange was determined for shoots from saplings of three conifers (Abies lasiocarpa [Hook] Nutt., Pinus contorta Dougl., Juniperus communis L.) under natural conditions in the field. A combination of relatively low stomatal resistances (<300 seconds per centimeter) and low wind speeds (<30 centimeters per second) led to substantial contributions of the aerodynamic resistance (Rwva) to water use efficiency (WUE = photosynthesis/transpiration) for all three species. For A. lasiocarpa, transpiration was calculated to be 44% less and photosynthesis 17% less due to the presence of Rwva, which led to a predicted increase in WUE of 57% compared to the calculated WUE when Rwva was assumed negligible. Similar increases in WUE were computed for P. contorta (48%) with somewhat smaller values for J. communis (34%). These results are discussed in terms of the estimated importance of Rwva on water and photosynthetic relations of plants that have relatively low stomatal resistances and grow in microhabitats with low winds. PMID:16661128

  6. Modeled riparian stream shading: Agreement with field measurements and sensitivity to riparian conditions

    NASA Astrophysics Data System (ADS)

    Li, Guoyuan; Jackson, C. Rhett; Kraseski, Kristin A.

    2012-03-01

    SummaryShading by riparian vegetation and streambanks reduces incident solar radiation on channels, and accurate estimation of riparian shading through the sun's daily arc is a critical aspect of water temperature and dissolved oxygen modeling. However, riparian trees exhibit complex shapes, often leaning and growing branches preferentially over channels to utilize the light resource. As a result, riparian vegetation cast complex shadows with significant variability at the scale of meters. Water quality models necessarily simplify factors affecting shading at the expense of accuracy. All models must make simplifying assumptions about tree geometry. Reach-based models must average channel azimuth and riparian conditions over each reach, and GIS models must also accept errors in the channel-riparian relationships caused by the DEM grid detail. We detail minor improvements to existing shade models and create a model (SHADE2) that calculates shading ratio (%) by riparian canopy at any time and location for given stream characteristics including stream azimuth, stream width, canopy height, canopy overhang, and height of maximum canopy overhang. Sensitivity of simulated shade to these variables is explored. We also present a new field photographic technique for quantifying shade and use this technique to provide data to test the SHADE2 algorithm. Twenty-four independent shade measurements were made in eight channels with mature hardwood riparian trees at different times of the summer and at different times of the day. Agreement between measured and modeled shade was excellent, with r2 of 0.90.

  7. Biotite weathering in podzolic soil under conditions of a model field experiment

    NASA Astrophysics Data System (ADS)

    Sokolova, T. A.; Tolpeshta, I. I.; Topunova, I. V.

    2010-10-01

    The biotite changes in the 1-5 μm fraction after its occurrence in the F, H, AE, and E horizons of a pale-podzolic soil for five years under conditions of a model field experiment were assessed by X-ray diffraction analysis. It was found that the main changes of the biotite in all the horizons included the degradational transformation of its crystal lattice to interstratified mica-vermiculite structures and vermiculite. The intensity of this process gradually decreased from the F horizon down the profile in parallel with the decrease in the amount of roots and the abundance and activity of microbiota. Chloritized structures were present among the products of the biotite weathering in the H, AE, and E horizons; the degree of chloritization gradually increased from the H horizon to the E horizon. The main identified products of the biotite weathering in the AE and E horizons formed during the 5 years of the model experiment were identified in the clay and fine-silt fractions from these horizons of the native pale-podzolic soils. Therefore, the vermiculite, soil chlorite, and mixed-layer illite-vermiculite minerals in the soils studied could be considered as products of the recent soil functioning. The obtained results and literature data showed that the weathering of biotite resulted in the formation of K- and Al-buffer systems.

  8. Segmentation of anatomical branching structures based on texture features and conditional random field

    NASA Astrophysics Data System (ADS)

    Nuzhnaya, Tatyana; Bakic, Predrag; Kontos, Despina; Megalooikonomou, Vasileios; Ling, Haibin

    2012-02-01

    This work is a part of our ongoing study aimed at understanding a relation between the topology of anatomical branching structures with the underlying image texture. Morphological variability of the breast ductal network is associated with subsequent development of abnormalities in patients with nipple discharge such as papilloma, breast cancer and atypia. In this work, we investigate complex dependence among ductal components to perform segmentation, the first step for analyzing topology of ductal lobes. Our automated framework is based on incorporating a conditional random field with texture descriptors of skewness, coarseness, contrast, energy and fractal dimension. These features are selected to capture the architectural variability of the enhanced ducts by encoding spatial variations between pixel patches in galactographic image. The segmentation algorithm was applied to a dataset of 20 x-ray galactograms obtained at the Hospital of the University of Pennsylvania. We compared the performance of the proposed approach with fully and semi automated segmentation algorithms based on neural network classification, fuzzy-connectedness, vesselness filter and graph cuts. Global consistency error and confusion matrix analysis were used as accuracy measurements. For the proposed approach, the true positive rate was higher and the false negative rate was significantly lower compared to other fully automated methods. This indicates that segmentation based on CRF incorporated with texture descriptors has potential to efficiently support the analysis of complex topology of the ducts and aid in development of realistic breast anatomy phantoms.

  9. Stereoselective transformation of triadimefon to metabolite triadimenol in wheat and soil under field conditions.

    PubMed

    Liang, Hongwu; Li, Li; Qiu, Jing; Li, Wei; Yang, Shuming; Zhou, Zhiqiang; Qiu, Lihong

    2013-09-15

    Racemic triadimefon (TF) was applied to wheat and soil at three sites (Beijing, Huaibei, and Zhengzhou in China) under open field conditions. Its enantioselective degradation and stereoselective transformation to the major metabolite, triadimenol (TN), in wheat straw, grain and soil were investigated. At all sites, the degradation of TF enantiomers in straw and soil followed first-order kinetics. In soil from Beijing and Zhengzhou R-(-)-TF was preferentially degraded; however, preferential enantioselective degradations were not recorded in soil from Huaibei or in the straw from all sites. There were noticeable differences in the stereoselective formation of TN stereoisomers in all straw and soil samples. TN diastereomer A with high animal toxicity was preferentially produced via a reductive reaction in straw. In contrast, diastereomer B, was preferential in soil across the experimental period. Different TN concentrations were found in the order of SR-(-)-TN>RR-(+)-TN>RS-(+)-TN>SS-(-)-TN in straw, and RR-(+)-TN>SS-(-)-TN>SR-(-)-TN>RS-(+)-TN in soil. Neither TF nor TN was found in wheat grain at harvest. Because of differences in degradation, formation, and toxicity, the characterization of enantiomers and stereoisomers in this study contributes toward comprehensively assessing the fate and risk of chiral agrochemicals in the environment and food.

  10. Electronic and optical properties of a circular graphene quantum dot in a magnetic field: Influence of the boundary conditions

    NASA Astrophysics Data System (ADS)

    Grujić, M.; Zarenia, M.; Chaves, A.; Tadić, M.; Farias, G. A.; Peeters, F. M.

    2011-11-01

    An analytical approach, using the Dirac-Weyl equation, is implemented to obtain the energy spectrum and optical absorption of a circular graphene quantum dot in the presence of an external magnetic field. Results are obtained for the infinite-mass and zigzag boundary conditions. We found that the energy spectrum of a dot with the zigzag boundary condition exhibits a zero-energy band regardless of the value of the magnetic field, while for the infinite-mass boundary condition, the zero-energy states appear only for high magnetic fields. The analytical results are compared to those obtained from the tight-binding model: (i) we show the validity range of the continuum model and (ii) we find that the continuum model with the infinite-mass boundary condition describes rather well its tight-binding analog, which can be partially attributed to the blurring of the mixed edges by the staggered potential.

  11. Transcriptomic, proteomic and metabolomic analysis of maize responses to UV-B: comparison of greenhouse and field growth conditions.

    PubMed

    Casati, Paula; Campi, Mabel; Morrow, Darren J; Fernandes, John; Walbot, Virginia

    2011-08-01

    UV-B radiation from normal solar fluence elicits physiological and developmental changes in plants under fluctuating environmental conditions. Most UV photobiology studies in plants utilize controlled greenhouse and growth chamber environments in which few conditions vary except the brief presence of UV-B radiation. Our purpose was to compare responses to UV-B in irradiated and shielded maize organs in field (natural solar plus 2x solar supplementation for defined periods) and greenhouse (2x solar supplementation only) conditions during a 4 hour exposure. Three parameters were assessed--transcripts, proteins, and metabolites--to determine the degree of overlap in maize responses in field and greenhouse conditions. We assessed irradiated leaves, and both shielded leaves and immature ears. After comparing transcriptome, proteome and metabolome profiles, we find there are more differences than similarities between field and greenhouse responses.

  12. Effect of a Static Magnetic Field (1.5T) on Brain Oscillatory Activities in Resting State Condition.

    PubMed

    Formaggio, E; Avesani, M; Storti, S F; Milanese, F; Gasparini, A; Acler, M; Cerini, R; Pozzi Mucelli, R; Fiaschi, A; Manganotti, P

    2008-12-17

    The aim of the present study was to compare the EEG signal recorded outside and inside a 1.5T magnetic resonance (MR) scanner. The EEG was recorded in eyes open and eyes closed conditions using a digital recording MR-compatible system. To characterize how a static magnetic field induces changes in EEG signal, EEG data were analyzed using FFT frequency analysis. No significant difference between the alpha powers recorded outside and inside the magnetic field was observed in eyes closed conditions. However, in eyes open condition there was a significant increase in alpha power inside the magnet in comparison to the outside position. The changes in alpha power according to the eyes open/closed conditions could be inversely correlated to a subject's state of wakefulness and due to some physiological changes, rather than an effect of the magnetic field. This experiment suggests that subjects' state of wakefulness is of prime concern when performing functional MRI.

  13. African American Men in College

    ERIC Educational Resources Information Center

    Cuyjet, Michael J., Ed.

    2006-01-01

    This book is a much-needed resource that includes examples of real-world programs and activities to enhance academic success in the college environment for African American men. The examples are collected from a variety of institutions across the country. With contributions from leading practitioners and scholars in the field, this book explores…

  14. African Outreach Workshop 1974.

    ERIC Educational Resources Information Center

    Schmidt, Nancy J.

    This report discusses the 1974 African Outreach Workshop planned and coordinated by the African Studies Program at the University of Illinois at Urbana-Champaign. Its major aim was to assist teachers in developing curriculum units on African using materials available in their local community. A second aim was for the African Studies Program to…

  15. Africans in America.

    ERIC Educational Resources Information Center

    Hart, Ayanna; Spangler, Earl

    This book introduces African-American history and culture to children. The first Africans in America came from many different regions and cultures, but became united in this country by being black, African, and slaves. Once in America, Africans began a long struggle for freedom which still continues. Slavery, the Civil War, emancipation, and the…

  16. Modification of Pulsed Electric Field Conditions Results in Distinct Activation Profiles of Platelet-Rich Plasma

    PubMed Central

    Frelinger, Andrew L.; Gerrits, Anja J.; Garner, Allen L.; Torres, Andrew S.; Caiafa, Antonio; Morton, Christine A.; Berny-Lang, Michelle A.; Carmichael, Sabrina L.; Neculaes, V. Bogdan; Michelson, Alan D.

    2016-01-01

    presence of platelet-derived microparticles, platelets, and platelet aggregates whereas SMHEF pulses primarily resulted in platelet-derived microparticles. Microparticles and platelets in PRP activated with SMLEF bipolar pulses had significantly lower annexin V-positivity than those following SMHEF activation. In contrast, the % P-selectin positivity and surface P-selectin expression (MFI) for platelets and microparticles in SMLEF bipolar pulse activated PRP was significantly higher than that in SMHEF-activated PRP, but not significantly different from that produced by thrombin activation. Higher levels of EGF were observed following either SMLEF bipolar pulses or SMHEF pulses of PRP than after bovine thrombin activation while VEGF, PDGF, and PF4 levels were similar with all three activating conditions. Cell proliferation was significantly increased by releasates of both SMLEF bipolar pulse and SMHEF pulse activated PRP compared to plasma alone. Conclusions PEF activation of PRP at bipolar low vs. monopolar high field strength results in differential platelet-derived microparticle production and activation of platelet surface procoagulant markers while inducing similar release of growth factors and similar capacity to induce cell proliferation. Stimulation of PRP with SMLEF bipolar pulses is gentler than SMHEF pulses, resulting in less platelet microparticle generation but with overall activation levels similar to that obtained with thrombin. These results suggest that PEF provides the means to alter, in a controlled fashion, PRP properties thereby enabling evaluation of their effects on wound healing and clinical outcomes. PMID:27556645

  17. Identification of Molecular and Cellular Responses of Desulfovibrio vulgaris Biofilms under Culture Conditions Relevant to Field Conditions for Bioreduction

    SciTech Connect

    Fields, Matthew W.

    2006-06-01

    Desulfovibrio vulgaris ATCC29579 is a sulfate- reducing bacterium (SRB) that is commonly used as a model for direct and indirect heavy metal reduction, and can also be a causitative agent of metal corrosion. During growth with lactate and sulfate, internal carbohydrate levels increased throughout exponential-phase, and peaked as the cells transitioned to stationary-phase. The carbohydrate to protein ratio (C:P) peaked at 0.05 ug/ug as the cells transitioned to stationary-phase, and then declined to 0.02 ug/ug during extended stationary-phase. In contrast, a strain of D. vulgaris that does not contain the megaplasmid, maintained higher internal carbohydrate levels and the C:P ratio peaked at 0.1 ug/ug (2-fold increase compared to wild-type). Under the tested growth conditions, we observed biofilm formation in wild-type cells, but the plasmid-less strain formed less biofilm (2-fold decrease). We hypothesized that carbohydrate was re-allocated to the external cell proper for biofilm formation. However, biofilm contained relatively little carbohydrate (0.6 to 1.0 ug/ml) and had a similar C:P ratio compared to wild-type early stationary-phase cells. Staining with calcafluor white also indicated the presence of little external carbohydrate in D. vulgaris biofilms. Less biofilm was formed in the presence of protinease K, trypsin, and chymotrypsin, however, the growth of planktonic cells was not affected. In addition, when D. vulgaris biofilm was treated with a protease, less biofilm was observed. Electron micrographs suggested the presence of filaments between the biofilm cells, and filaments appeared to be susceptible to protease treatment. Biofilm filtrates contained soluble protein, and SDS-PAGE analysis suggested different polypeptide profiles between a filtrate, a planktonic, and a biofilm sample.

  18. Methods for conditioning anisotropic, operator-scaling, fractal random fields, and the effect on solute transport simulations

    NASA Astrophysics Data System (ADS)

    Revielle, J.; Benson, D. A.

    2008-12-01

    The fractal scaling of aquifer materials have been observed in many data sets. Typically, the scaling coefficient is different in different directions. To date, only unconditional realizations with these properties can be generated. We present and analyze two methods of creating conditional operator-scaling fractal random fields (OSFRF) which have the ability to condition any number and geometry of measurements into each realization. One method is based on the theory of Orthographic Projection (Feller, 1971) and requires the continuous checking of a conditional probability function. The other method uses a best linear unbiased estimate (i.e., a kriged mean surface between known points) and an unconditional realization to create each conditional field. These two methods are analyzed for computational difficulty and their ability to recreate the desired fractal scaling along different (eigenvector) directions. Finally these methods are applied to a transport experiment through a slab of Massillon sandstone to show the advantage of using conditional OSFRF in solute transport modeling.

  19. Leaf wetness duration measurement: comparison of cylindrical and flat plate sensors under different field conditions.

    PubMed

    Sentelhas, Paulo C; Gillespie, Terry J; Santos, Eduardo A

    2007-03-01

    In general, leaf wetness duration (LWD) is a key parameter influencing plant disease epidemiology, since it provides the free water required by pathogens to infect foliar tissue. LWD is used as an input in many disease warning systems, which help growers to decide the best time to spray their crops against diseases. Since there is no observation standard either for sensor or exposure, LWD measurement is often problematic. To assess the performance of electronic sensors, LWD measurements obtained with painted cylindrical and flat plate sensors were compared under different field conditions in Elora, Ontario, Canada, and in Piracicaba, São Paulo, Brazil. The sensors were tested in four different crop environments--mowed turfgrass, maize, soybean, and tomatoes--during the summer of 2003 and 2004 in Elora and during the winter of 2005 in Piracicaba. Flat plate sensors were deployed facing north and at 45 degrees to horizontal, and cylindrical sensors were deployed horizontally. At the turfgrass site, both sensors were installed 30 cm above the ground, while at the crop fields, the sensors were installed at the top and inside the canopy (except for maize, with a sensor only at the top). Considering the flat plate sensor as a reference (Sentelhas et al. Operational exposure of leaf wetness sensors. Agric For Meteorol 126:59-72, 2004a), the results in the more humid climate at Elora showed that the cylindrical sensor overestimated LWD by 1.1-4.2 h, depending on the crop and canopy position. The main cause of the overestimation was the accumulation of big water drops along the bottom of the cylindrical sensors, which required much more energy and, consequently, time to evaporate. The overall difference between sensors when evaporating wetness formed during the night was around 1.6 h. Cylindrical sensors also detected wetness earlier than did flat plates--around 0.6 h. Agreement between plate and cylinder sensors was much better in the drier climate at Piracicaba. These

  20. Intercomparison of fast response commercial gas analysers for nitrous oxide flux measurements under field conditions

    NASA Astrophysics Data System (ADS)

    Rannik, Ü.; Haapanala, S.; Shurpali, N. J.; Mammarella, I.; Lind, S.; Hyvönen, N.; Peltola, O.; Zahniser, M.; Martikainen, P. J.; Vesala, T.

    2014-08-01

    Four gas analysers capable of measuring nitrous oxide (N2O) concentration at a response time necessary for eddy covariance flux measurements were operated from spring till winter 2011 over a field cultivated with reed canary grass (RCG, Phalaris arundinaceae, L.), a perennial bioenergy crop in Eastern Finland. The instruments were TGA100A (Campbell Scientific Inc.), CW-TILDAS-CS (Aerodyne Research Inc.), N2O/CO-23d (Los Gatos Research Inc.) and QC-TILDAS-76-CS (Aerodyne Research Inc.). The period with high emission, lasting for about two weeks after fertilization in late May, was characterised by an up to two orders of magnitude higher emission, whereas during the rest of the campaign the N2O fluxes were small, from 0.1 to 1 nmol m-2 s-1. Two instruments, CW-TILDAS-CS and N2O/CO-23d, determined the N2O exchange with minor systematic difference throughout the campaign, when operated simultaneously. TGA100A produced cumulatively highest N2O estimates (with 29% higher value during the period when all instruments were operational). QC-TILDAS-76-CS obtained 36% lower fluxes than CW-TILDAS-CS during the first period, including the emission episode, whereas the correspondence with other instruments during the rest of the campaign was good. The reason for these episodic higher and lower estimates by the two instruments is not currently known, suggesting further need for detailed evaluation of instrument performance under field conditions with emphasis on stability, calibration and, in particular, simultaneous accurate determination of water vapour concentration due to its large impact on small N2O fluxes through spectroscopic and dilution corrections. The instrument CW-TILDAS-CS was characterised by the lowest noise level (std around 0.12 ppb at 10 Hz sampling rate), as compared to N2O/CO-23d and QC-TILDAS-76-CS (around 0.50 ppb) and TGA100A (around 2 ppb). Both instruments based on Continuous-Wave Quantum Cascade Lasers, CW-TILDAS-CS and N2O/CO-23d, were able to determine

  1. Do NERICA rice cultivars express resistance to Striga hermonthica (Del.) Benth. and Striga asiatica (L.) Kuntze under field conditions?

    PubMed

    Rodenburg, Jonne; Cissoko, Mamadou; Kayeke, Juma; Dieng, Ibnou; Khan, Zeyaur R; Midega, Charles A O; Onyuka, Enos A; Scholes, Julie D

    2015-01-01

    The parasitic weeds Striga asiatica and Striga hermonthica cause high yield losses in rain-fed upland rice in Africa. Two resistance classes (pre- and post-attachment) and several resistant genotypes have been identified among NERICA (New Rice for Africa) cultivars under laboratory conditions (in vitro) previously. However, little is known about expression of this resistance under field conditions. Here we investigated (1) whether resistance exhibited under controlled conditions would express under representative Striga-infested field conditions, and (2) whether NERICA cultivars would achieve relatively good grain yields under Striga-infested conditions. Twenty-five rice cultivars, including all 18 upland NERICA cultivars, were screened in S. asiatica-infested (in Tanzania) and S. hermonthica-infested (in Kenya) fields during two seasons. Additionally, a selection of cultivars was tested in vitro, in mini-rhizotron systems. For the first time, resistance observed under controlled conditions was confirmed in the field for NERICA-2, -5, -10 and -17 (against S. asiatica) and NERICA-1 to -5, -10, -12, -13 and -17 (against S. hermonthica). Despite high Striga-infestation levels, yields of around 1.8 t ha(-1) were obtained with NERICA-1, -9 and -10 (in the S. asiatica-infested field) and around 1.4 t ha(-1) with NERICA-3, -4, -8, -12 and -13 (in the S. hermonthica-infested field). In addition, potential levels of tolerance were identified in vitro, in NERICA-1, -17 and -9 (S. asiatica) and in NERICA-1, -17 and -10 (S. hermonthica). These findings are highly relevant to rice agronomists and breeders and molecular geneticists working on Striga resistance. In addition, cultivars combining broad-spectrum resistance with good grain yields in Striga-infested fields can be recommended to rice farmers in Striga-prone areas.

  2. Effect of milk composition and coagulation traits on Grana Padano cheese yield under field conditions.

    PubMed

    Pretto, Denis; De Marchi, Massimo; Penasa, Mauro; Cassandro, Martino

    2013-02-01

    The aim of this study was to assess the effect of chemical composition, coagulation properties, pH, and titratable acidity (TA, SH°/50 ml) of vat milk on Grana Padano cheese yield (CY) under field conditions. Twelve cheese-making sessions were carried out from February to December 2009 in a dairy cooperative of Grana Padano Consortium (Italy), for a total of 96 vats of milk processed. For each vat, samples of raw milk were collected and analysed for quality traits (fat, protein, and casein contents), pH, TA, and milk coagulation properties (MCP), measured as rennet coagulation time (RCT, min), curd-firming time (k(20), min), and curd firmness (a(30), mm). Cheese yield was expressed as kilograms of cheese per 100 kg milk transformed, and was measured after 2 d of drainage. Fat, protein, and casein contents were positively and strongly correlated with CY (coefficients of correlation, r = 0.72, 0.88, and 0.84, respectively; P < 0.001). Coagulation properties were moderately and significantly (P < 0.001) related to CY: milk that coagulated earlier and had stronger a(30) was associated to greater CY. Cheese yield was analysed with a model that accounted for fixed effects of cheese-making day, fat and protein content, TA, and a(30). Significance was found for all the effects (P < 0.05). Milk characterised by high values of a(30) resulted in higher CY than milk with low values of a 30, indicating that MCP could be used as indicators of cheese-making efficiency. Future research should investigate the relationships between MCP and quality of cheese, and explore the feasibility of including MCP in multiple component milk pricing system for Grana Padano cheese production.

  3. Production of carbon dioxide in a fattening pig house under field conditions. I. Exhalation by pigs

    NASA Astrophysics Data System (ADS)

    Ni, Ji-Qin; Hendriks, Jos; Coenegrachts, Jan; Vinckier, Christiaan

    Exhalation of carbon dioxide (CO 2) by pigs was investigated under field conditions in a mechanically ventilated commercial fattening house. The tranquil CO 2 exhalation rate (TCER) by pigs was defined and methodology was developed to study it. The experiments were conducted by moving groups of pigs in and out of one of the compartments in the house and comparing differences of measured CO 2 production rates. The measured TCERs ranged from 41.5 to 73.9 g CO 2 h -1 per pig for pigs from 32 to 105 kg. When pigs were very active, the CO 2 exhalation rate could be about 200% of the TCER but did not last for long time. A TCER mathematical model was developed based on 4 sets of experiments. It calculated the CO 2 exhalation by a pig at tranquil time as a function of its weight. Daily mean CO 2 exhalation rate (CER) by a pig was about 110% of the TCER. The TCER/CER model related the CO 2 exhalation to some aspects of pigs' behaviours and was the first reported model developed with direct measurement of CO 2 production rates. Five models of CO 2 exhalation in available literature were reviewed and the CER model was compared with them. There was a clear disparity among these models. The average CO 2 exhalation rate calculated with the "Ouwerkerk Model" was about three times as that obtained by the "Anderson Model" for pigs from 35 to 120 kg. The CER model produced the same CO 2 exhalation rate as the "Ouwerkerk Model" for a pig of 35 kg and a close rate to the "Klooster Model" for a pig of 85 kg.

  4. Assessment of metals bioavailability to vegetables under field conditions using DGT, single extractions and multivariate statistics

    PubMed Central

    2012-01-01

    Background The metals bioavailability in soils is commonly assessed by chemical extractions; however a generally accepted method is not yet established. In this study, the effectiveness of Diffusive Gradients in Thin-films (DGT) technique and single extractions in the assessment of metals bioaccumulation in vegetables, and the influence of soil parameters on phytoavailability were evaluated using multivariate statistics. Soil and plants grown in vegetable gardens from mining-affected rural areas, NW Romania, were collected and analysed. Results Pseudo-total metal content of Cu, Zn and Cd in soil ranged between 17.3-146 mg kg-1, 141–833 mg kg-1 and 0.15-2.05 mg kg-1, respectively, showing enriched contents of these elements. High degrees of metals extractability in 1M HCl and even in 1M NH4Cl were observed. Despite the relatively high total metal concentrations in soil, those found in vegetables were comparable to values typically reported for agricultural crops, probably due to the low concentrations of metals in soil solution (Csoln) and low effective concentrations (CE), assessed by DGT technique. Among the analysed vegetables, the highest metal concentrations were found in carrots roots. By applying multivariate statistics, it was found that CE, Csoln and extraction in 1M NH4Cl, were better predictors for metals bioavailability than the acid extractions applied in this study. Copper transfer to vegetables was strongly influenced by soil organic carbon (OC) and cation exchange capacity (CEC), while pH had a higher influence on Cd transfer from soil to plants. Conclusions The results showed that DGT can be used for general evaluation of the risks associated to soil contamination with Cu, Zn and Cd in field conditions. Although quantitative information on metals transfer from soil to vegetables was not observed. PMID:23079133

  5. Application of Pseudomonas fluorescens to Blackberry under Field Conditions Improves Fruit Quality by Modifying Flavonoid Metabolism

    PubMed Central

    Garcia-Seco, Daniel; Zhang, Yang; Gutierrez-Mañero, Francisco J.; Martin, Cathie; Ramos-Solano, Beatriz

    2015-01-01

    Application of a plant growth promoting rhizobacterium (PGPR), Pseudomonas fluorescens N21.4, to roots of blackberries (Rubus sp.) is part of an optimised cultivation practice to improve yields and quality of fruit throughout the year in this important fruit crop. Blackberries are especially rich in flavonoids and therefore offer potential benefits for human health in prevention or amelioration of chronic diseases. However, the phenylpropanoid pathway and its regulation during ripening have not been studied in detail, in this species. PGPR may trigger flavonoid biosynthesis as part of an induced systemic response (ISR) given the important role of this pathway in plant defence, to cause increased levels of flavonoids in the fruit. We have identified structural genes encoding enzymes of the phenylpropanoid and flavonoid biosynthetic pathways catalysing the conversion of phenylalanine to the final products including flavonols, anthocyanins and catechins from blackberry, and regulatory genes likely involved in controlling the activity of pathway branches. We have also measured the major flavonols, anthocyanins and catechins at three stages during ripening. Our results demonstrate the coordinated expression of flavonoid biosynthetic genes with the accumulation of anthocyanins, catechins, and flavonols in developing fruits of blackberry. Elicitation of blackberry plants by treatment of roots with P.fluorescens N21.4, caused increased expression of some flavonoid biosynthetic genes and an accompanying increase in the concentration of selected flavonoids in fruits. Our data demonstrate the physiological mechanisms involved in the improvement of fruit quality by PGPR under field conditions, and highlight some of the genetic targets of elicitation by beneficial bacteria. PMID:26559418

  6. Dissipation and runoff transport of metazachlor herbicide in rapeseed cultivated and uncultivated plots in field conditions.

    PubMed

    Mantzos, Nikolaos; Hela, Dimitra; Karakitsou, Anastasia; Antonopoulou, Maria; Konstantinou, Ioannis

    2016-10-01

    The environmental fate of metazachlor herbicide was investigated under field conditions in rapeseed cultivated and uncultivated plots, over a period of 225 days. The cultivation was carried out in silty clay soil plots with two surface slopes, 1 and 5 %. The herbicide was detectable in soil up to 170 days after application (DAA), while the dissipation rate was best described by first-order kinetics and its half-life ranged between 10.92 and 12.68 days. The herbicide was detected in the soil layer of 10-20 cm from 5 to 48 DAA, and its vertical movement can be described by the continuous stirred tank reactor (CSTR) in series model. Relatively low amounts of metazachlor (less than 0.31 % of the initial applied active ingredient) were transferred by runoff water. More than 80 % of the total losses were transferred at the first runoff event (12 DAA), with herbicide concentrations in runoff water ranging between 70.14 and 79.67 μg L(-1). Minor amounts of the herbicide (less than 0.07 % of the initial applied active ingredient) were transferred by the sediment, with a maximum concentration of 0.57 μg g(-1) (12 DAA), in plots with 5 % inclination. Finally, in rapeseed plants, metazachlor was detected only in the first sampling (28 DAA) at concentrations slightly higher than the limit of quantification; when in seeds, no residues of the herbicide were detected.

  7. Application of Pseudomonas fluorescens to Blackberry under Field Conditions Improves Fruit Quality by Modifying Flavonoid Metabolism.

    PubMed

    Garcia-Seco, Daniel; Zhang, Yang; Gutierrez-Mañero, Francisco J; Martin, Cathie; Ramos-Solano, Beatriz

    2015-01-01

    Application of a plant growth promoting rhizobacterium (PGPR), Pseudomonas fluorescens N21.4, to roots of blackberries (Rubus sp.) is part of an optimised cultivation practice to improve yields and quality of fruit throughout the year in this important fruit crop. Blackberries are especially rich in flavonoids and therefore offer potential benefits for human health in prevention or amelioration of chronic diseases. However, the phenylpropanoid pathway and its regulation during ripening have not been studied in detail, in this species. PGPR may trigger flavonoid biosynthesis as part of an induced systemic response (ISR) given the important role of this pathway in plant defence, to cause increased levels of flavonoids in the fruit. We have identified structural genes encoding enzymes of the phenylpropanoid and flavonoid biosynthetic pathways catalysing the conversion of phenylalanine to the final products including flavonols, anthocyanins and catechins from blackberry, and regulatory genes likely involved in controlling the activity of pathway branches. We have also measured the major flavonols, anthocyanins and catechins at three stages during ripening. Our results demonstrate the coordinated expression of flavonoid biosynthetic genes with the accumulation of anthocyanins, catechins, and flavonols in developing fruits of blackberry. Elicitation of blackberry plants by treatment of roots with P.fluorescens N21.4, caused increased expression of some flavonoid biosynthetic genes and an accompanying increase in the concentration of selected flavonoids in fruits. Our data demonstrate the physiological mechanisms involved in the improvement of fruit quality by PGPR under field conditions, and highlight some of the genetic targets of elicitation by beneficial bacteria.

  8. Tumor segmentation on FDG-PET: usefulness of locally connected conditional random fields

    NASA Astrophysics Data System (ADS)

    Nishio, Mizuho; Kono, Atsushi K.; Koyama, Hisanobu; Nishii, Tatsuya; Sugimura, Kazuro

    2015-03-01

    This study aimed to develop software for tumor segmentation on 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET). To segment the tumor from the background, we used graph cut, whose segmentation energy was generally divided into two terms: the unary and pairwise terms. Locally connected conditional random fields (LCRF) was proposed for the pairwise term. In LCRF, a three-dimensional cubic window with length L was set for each voxel, and voxels within the window were considered for the pairwise term. To evaluate our method, 64 clinically suspected metastatic bone tumors were tested, which were revealed by FDG-PET. To obtain ground truth, the tumors were manually delineated via consensus of two board-certified radiologists. To compare the LCRF accuracy, other types of segmentation were also applied such as region-growing based on 35%, 40%, and 45% of the tumor maximum standardized uptake value (RG35, RG40, and RG45, respectively), SLIC superpixels (SS), and region-based active contour models (AC). To validate the tumor segmentation accuracy, a dice similarity coefficient (DSC) was calculated between manual segmentation and result of each technique. The DSC difference was tested using the Wilcoxon signed rank test. The mean DSCs of LCRF at L = 3, 5, 7, and 9 were 0.784, 0.801, 0.809, and 0.812, respectively. The mean DSCs of other techniques were RG35, 0.633; RG40, 0.675; RG45, 0.689; SS, 0.709; and AC, 0.758. The DSC differences between LCRF and other techniques were statistically significant (p <0.05). In conclusion, tumor segmentation was more reliably performed with LCRF relative to other techniques.

  9. Analysis and prediction of the critical regions of antimicrobial peptides based on conditional random fields.

    PubMed

    Chang, Kuan Y; Lin, Tung-pei; Shih, Ling-Yi; Wang, Chien-Kuo

    2015-01-01

    Antimicrobial peptides (AMPs) are potent drug candidates against microbes such as bacteria, fungi, parasites, and viruses. The size of AMPs ranges from less than ten to hundreds of amino acids. Often only a few amino acids or the critical regions of antimicrobial proteins matter the functionality. Accurately predicting the AMP critical regions could benefit the experimental designs. However, no extensive analyses have been done specifically on the AMP critical regions and computational modeling on them is either non-existent or settled to other problems. With a focus on the AMP critical regions, we thus develop a computational model AMPcore by introducing a state-of-the-art machine learning method, conditional random fields. We generate a comprehensive dataset of 798 AMPs cores and a low similarity dataset of 510 representative AMP cores. AMPcore could reach a maximal accuracy of 90% and 0.79 Matthew's correlation coefficient on the comprehensive dataset and a maximal accuracy of 83% and 0.66 MCC on the low similarity dataset. Our analyses of AMP cores follow what we know about AMPs: High in glycine and lysine, but low in aspartic acid, glutamic acid, and methionine; the abundance of α-helical structures; the dominance of positive net charges; the peculiarity of amphipathicity. Two amphipathic sequence motifs within the AMP cores, an amphipathic α-helix and an amphipathic π-helix, are revealed. In addition, a short sequence motif at the N-terminal boundary of AMP cores is reported for the first time: arginine at the P(-1) coupling with glycine at the P1 of AMP cores occurs the most, which might link to microbial cell adhesion.

  10. Selenium and sulfur relationships in alfalfa and soil under field conditions, San Joaquin Valley, California

    USGS Publications Warehouse

    Severson, R.C.; Gough, L.P.

    1992-01-01

    Relationships between total Se and S or soluble SeO4 and SO4 in soils and tissue concentrations in alfalfa (Medicago sativa L.), under field conditions in the San Joaquin Valley of California, suggest that the rate of accumulation of Se in alfalfa may be reduced in areas where high Se and S concentrations in soils were measured. These data suggest that the balance between carbonate and sulfate minerals in soil may have a greater influence on uptake of Se by alfalfa than does the balance of SeO4 and SO4 in soil solution. Soil and alfalfa were sampled from areas representing a wide range in soil Se and S concentrations. Specific sampling locations were selected based on a previous study of Se, S, and other elements where 721 soil samples were collected to map landscape variability and distribution of elements. Six multiple-linear regression equations were developed between total and/or soluble soil chemical constituents and tissue concentrations of Se in alfalfa. We chose a regression model that accounted for 72% of the variability in alfalfa Se concentrations based on an association of elements in soil (total C, S, Se, and Sr) determined by factor analysis. To prepare a map showing the spatial distribution of estimated alfalfa Se concentrations, the model was applied to the data from the previously collected 721 soil samples. Estimated alfalfa Se concentrations in most of the study area were within a range that is predicted to produce alfalfa with neither Se deficiency nor toxicity when consumed by livestock. A few small areas are predicted to produce alfalfa that potentially would not meet minimum dietary needs of livestock.

  11. Detecting Hedge Cues and their Scope in Biomedical Literature with Conditional Random Fields

    PubMed Central

    Agarwal, Shashank; Yu, Hong

    2010-01-01

    Objective Hedging is frequently used in both the biological literature and clinical notes to denote uncertainty or speculation. It is important for text-mining applications to detect hedge cues and their scope; otherwise, uncertain events are incorrectly identified as factual events. However, due to the complexity of language, identifying hedge cues and their scope in a sentence is not a trivial task. Our objective was to develop an algorithm that would automatically detect hedge cues and their scope in biomedical literature. Methodology We used conditional random fields (CRF), a supervised machine-learning algorithm, to train models to detect hedge cue phrases and their scope in biomedical literature. The models were trained on the publicly available BioScope corpus. We evaluated the performance of the CRF models in identifying hedge cue phrases and their scope by calculating recall, precision and F1-score. We compared our models with three competitive baseline systems. Results Our best CRF-based model performed statistically better than the baseline systems, achieving an F1-score of 88% and 86% in detecting hedge cue phrases and their scope in biological literature and an F1-score of 93% and 90% in detecting hedge cue phrases and their scope in clinical notes. Conclusions Our approach is robust, as it can identify hedge cues and their scope in both biological and clinical text. To benefit text-mining applications, our system is publicly available as a Java API and as an online application at http://hedgescope.askhermes.org. To our knowledge, this is the first publicly available system to detect hedge cues and their scope in biomedical literature. PMID:20709188

  12. Rapid Microbiome Changes in Freshly Deposited Cow Feces under Field Conditions

    PubMed Central

    Wong, Kelvin; Shaw, Timothy I.; Oladeinde, Adelumola; Glenn, Travis C.; Oakley, Brian; Molina, Marirosa

    2016-01-01

    Although development of next generation sequencing (NGS) has substantially improved our understanding of the microbial ecology of animal feces, previous studies have mostly focused on freshly excreted feces. There is still limited understanding of the aging process dynamics of fecal microbiomes in intact cowpats exposed to natural environments. Fresh cowpats were sampled at multiple time points for 57 days under field conditions; half the samples were exposed to sunlight (unshaded) while the other half was protected from sunlight (shaded). The 16SRNA hypervariable region 4 was amplified from each sample and sequenced on an Illumina MiSeq Platform. While Clostridia, Bacteroidia, and Sphingobacteria were dominant classes of bacteria in fresh cowpats, Alphaproteobacteria, Betaproteobacteria, Actinobacteria, and Bacilli were the dominant classes by the end of the study, indicating a general shift from anaerobic to aerobic bacterial populations. This change was most likely influenced by the shift from cattle gut (anaerobic) to pasture ground (aerobic). Reduced moisture in cowpats may also contribute to the community shift since air can penetrate the dryer cowpat more easily. Twelve genera consisting pathogenic bacteria were detected, with Mycobacterium, Bacillus, and Clostridium being the most abundant; their combined abundance accounts for 90% of the total pathogenic genera. Taxonomic richness and diversity increased throughout the study for most samples, which could be due to bacteria regrowth and colonization of bacteria from the environment. In contrast to the high taxonomic diversity, the changes of PICRUSt inferred function profile were minimal for all cowpats throughout the study, which suggest that core functions predicted by PICRUSt may be too conserved to distinguish differences between aerobe and anaerobe. To the best of our knowledge, this is the first study demonstrating that cowpat exposure to air and sunlight can cause drastic microbiome changes soon

  13. Effects of transgenic Bt cotton on soil fertility and biology under field conditions in subtropical inceptisol.

    PubMed

    Singh, Raman Jeet; Ahlawat, I P S; Singh, Surender

    2013-01-01

    Although there is large-scale adoption of Bt cotton by the farmers because of immediate financial gain, there is concern that Bt crops release Bt toxins into the soil environment which reduces soil chemical and biological activities. However, the majorities of such studies were mainly performed under pot experiments, relatively little research has examined the direct and indirect effects of associated cover crop of peanut with fertilization by combined application of organic and inorganic sources of nitrogen under field conditions. We compared soil chemical and biological parameters of Bt cotton with pure crop of peanut to arrive on a valid conclusion. Significantly higher dehydrogenase enzyme activity and KMnO(4)-N content of soil were observed in Bt cotton with cover crop of peanut over pure Bt cotton followed by pure peanut at all the crop growth stages. However, higher microbial population was maintained by pure peanut over intercropped Bt cotton, but these differences were related to the presence of high amount of KMnO(4)-N content of soil. By growing cover crop of peanut between Bt cotton rows, bacteria, fungi, and actinomycetes population increased by 60%, 14%, and 10%, respectively, over Bt cotton alone. Bt cotton fertilized by combined application of urea and farm yard manure (FYM) maintained higher dehydrogenase enzyme activity, KMnO(4)-N content of soil and microbial population over urea alone. Significant positive correlations were observed for dry matter accumulation, dehydrogenase enzyme activity, KMnO(4)-N content, and microbial population of soil of Bt cotton, which indicates no harmful effects of Bt cotton on soil biological parameters and associated cover crop. Our results suggest that inclusion of cover crop of peanut and FYM in Bt cotton enhanced soil chemical and biological parameters which can mask any negative effect of the Bt toxin on microbial activity and thus on enzymatic activities.

  14. Wolbachia-Based Population Control Strategy Targeting Culex quinquefasciatus Mosquitoes Proves Efficient under Semi-Field Conditions

    PubMed Central

    Atyame, Célestine M.; Cattel, Julien; Lebon, Cyrille; Flores, Olivier; Dehecq, Jean-Sébastien; Weill, Mylène; Gouagna, Louis Clément; Tortosa, Pablo

    2015-01-01

    In mosquitoes, the maternally inherited bacterial Wolbachia induce a form of embryonic lethality called cytoplasmic incompatibility (CI). This property can be used to reduce the density of mosquito field populations through inundative releases of incompatible males in order to sterilize females (Incompatible Insect Technique, or IIT, strategy). We have previously constructed the LR[wPip(Is)] line representing a good candidate for controlling field populations of the Culex quinquefasciatus mosquito in the islands of the south-western Indian Ocean. The main purpose of the present study was to fill the gap between laboratory experiments and field implementation, i.e. assessing mating competitiveness of these incompatible males under semi-field conditions. In a first set of experiments, we analyzed crossing relationships between LR[wPip(Is)] males and La Réunion field females collected as larvae in 19 distinct localities throughout the island. This investigation revealed total embryonic mortality, confirming the strong sterilizing capacity of LR[wPip(Is)] males. Subsequently, mating competitiveness of LR[wPip(Is)] males was assessed under semi-field conditions in the presence of field males and females from La Réunion. Confrontations were carried out in April and December using different ratios of LR[wPip(Is)] to field males. The results indicated that the LR[wPip(Is)] males successfully compete with field males in mating with field females, displaying even higher competitiveness than field males in April. Our results support the implementation of small-scale field tests in order to assess the feasibility of IIT against Cx. quinquefasciatus in the islands of southwestern Indian Ocean where this mosquito species is a proven competent vector for human pathogens. PMID:25768841

  15. On the Question of the Causality Condition in Quantum Field Theory

    NASA Astrophysics Data System (ADS)

    Khokhlov, I. A.

    2017-01-01

    A mathematically correct generalization of the Bogoliubov microcausality condition to the case of arbitrary points in spacetime is given. The proposed generalized formulation of the microcausality condition is the basis for construction of a scattering matrix not containing ultraviolet divergences.

  16. Monitoring crop condition at field scale using multiple remote sensing data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop growth condition is affected by both environmental variables (climate, weather and soil condition etc.) and anthropogenic activities (fertilization and irrigation etc.). Crop condition varies by year and location and is critical for crop management and yield estimation. In the United States, cr...

  17. The Effects of Visual Field Conditions on Electromyography of the Lower Extremities during Reaching Tasks in Healthy Adults

    PubMed Central

    Park, Jun Hyuk; Lee, Kyeong Soon; Oh, Tae Young

    2014-01-01

    [Purpose] The purpose of this study was to identify the effects of visual field condition on electromyography of the lower extremities during arm reaching in healthy adults, and to compare differences in electromyography of the lower extremities between young and old adults according to visual fields condition. [Subjects and Methods] Twenty-nine young persons in their 20s and 19 elderly persons in their 60s, a total of 48 persons, participated in this study. Prior to participation in the study, each subject signed an informed consent form to comply with ethics guidelines dictated by the ethics committee for research at Silla University, Korea. We collected the muscle activation data for both of tibialis anterior and gastrocnemius muscle during reaching by subjects using electromyography. Data analysis with SPSS for Window Version 20.0 was performed using repeated one-way analysis of variance according to visual fields and age. [Results] There were no significantly differences between subjects in their 20s and 60s to visual field conditions except for left tibialis anterior muscle activation during left-side reaching. Left tibialis anterior muscle activation in subjects in their 60s was higher than in subjects in their 20s during left-side reaching. [Conclusion] We determined that tibialis anterior muscle activation in subjects in their 60s was higher than in subjects in their 20s. We suggest that visual field conditions are the important factor for physical therapy interventions to improve balance and priority of intervention . PMID:24764630

  18. a Study on the SAR Data Observation Time for the Classification of Planting Condition of Paddy Fields

    NASA Astrophysics Data System (ADS)

    Kimura, A.; Kondo, A.; Mochizuki, K.

    2016-06-01

    In recent years, cultivation methods of rice have been diversified due to the low cost of rice-growing techniques. For example, there is direct sowing of seed rice in paddy field in addition to the practice of usual paddy field to flooding at the time of planting. The yield of the usual paddy field and the direct sowing is different even though the same varieties are grown in the same area. It is necessary to grasp by performing classification for the usual paddy field or direct sowing for the management of agricultural crops. The main objective of this study was to select the observation time for the classification of paddy fields' planting conditions by utilizing Synthetic Aperture Radar TerraSAR-X satellite. The planting conditions included the usual planting of rice, the direct sowing of rice and the soybean. We selected the observation time by the statistical distance of the microwave backscattering in each paddy field for maximizing the planting condition classification. In addition, the satellite data observation timing considered the processing time of the analysis and the acquisition costs. The acquisition was performed 4 periods from 2 periods in the rice growing season and the planting phase. In the current study, we were able to classify the usual planting of rice, the direct sowing of rice and the soybean by TerraSAR-X data for the later planting of rice during mid-May and initial growth of rice in early June.

  19. Intercomparison of fast response commercial gas analysers for nitrous oxide flux measurements under field conditions

    NASA Astrophysics Data System (ADS)

    Rannik, Ü.; Haapanala, S.; Shurpali, N. J.; Mammarella, I.; Lind, S.; Hyvönen, N.; Peltola, O.; Zahniser, M.; Martikainen, P. J.; Vesala, T.

    2015-01-01

    Four gas analysers capable of measuring nitrous oxide (N2O) concentration at a response time necessary for eddy covariance flux measurements were operated from spring until winter 2011 over a field cultivated with reed canary grass (RCG, Phalaris arundinacea, L.), a perennial bioenergy crop in eastern Finland. The instruments were TGA100A (Campbell Scientific Inc.), CW-TILDAS-CS (Aerodyne Research Inc.), N2O / CO-23d (Los Gatos Research Inc.) and QC-TILDAS-76-CS (Aerodyne Research Inc.). The period with high emissions, lasting for about 2 weeks after fertilization in late May, was characterized by an up to 2 orders of magnitude higher emission, whereas during the rest of the campaign the N2O fluxes were small, from 0.01 to 1 nmol m-2 s-1. Two instruments, CW-TILDAS-CS and N2O / CO-23d, determined the N2O exchange with minor systematic difference throughout the campaign, when operated simultaneously. TGA100A produced the cumulatively highest N2O estimates (with 29% higher values during the period when all instruments were operational). QC-TILDAS-76-CS obtained 36% lower fluxes than CW-TILDAS-CS during the first period, including the emission episode, whereas the correspondence with other instruments during the rest of the campaign was good. The reasons for systematic differences were not identified, suggesting further need for detailed evaluation of instrument performance under field conditions with emphasis on stability, calibration and any other factors that can systematically affect the accuracy of flux measurements. The instrument CW-TILDAS-CS was characterized by the lowest noise level (with a standard deviation of around 0.12 ppb at 10 Hz sampling rate) as compared to N2O / CO-23d and QC-TILDAS-76-CS (around 0.50 ppb) and TGA100A (around 2 ppb). We identified that for all instruments except CW-TILDAS-CS the random error due to instrumental noise was an important source of uncertainty at the 30 min averaging level and the total stochastic error was frequently

  20. Decomposition of conifer tree bark under field conditions: effects of nitrogen and phosphorus additions

    NASA Astrophysics Data System (ADS)

    Lopes de Gerenyu, Valentin; Kurganova, Irina; Kapitsa, Ekaterina; Shorokhova, Ekaterina

    2016-04-01

    In forest ecosystems, the processes of decomposition of coarse woody debris (CWD) can contribute significantly to the emission component of carbon (C) cycle and thus accelerate the greenhouse effect and global climate change. A better understanding of decomposition of CWD is required to refine estimates of the C balance in forest ecosystems and improve biogeochemical models. These estimates will in turn contribute to assessing the role of forests in maintaining their long-term productivity and other ecosystems services. We examined the decomposition rate of coniferous bark with added nitrogen (N) and phosphorus (P) fertilizers in experiment under field conditions. The experiment was carried out in 2015 during 17 weeks in Moscow region (54o50'N, 37o36'E) under continental-temperate climatic conditions. The conifer tree bark mixture (ca. 70% of Norway spruce and 30% of Scots pine) was combined with soil and placed in piles of soil-bark substrate (SBS) with height of ca. 60 cm and surface area of ca. 3 m2. The dry mass ratio of bark to soil was 10:1. The experimental design included following treatments: (1) soil (Luvisols Haplic) without bark, (S), (2) pure SBS, (3) SBS with N addition in the amount of 1% of total dry bark mass (SBS-N), and (4) SBS with N and P addition in the amount of 1% of total dry bark mass for each element (SBS-NP). The decomposition rate expressed as CO2 emission flux, g C/m2/h was measured using closed chamber method 1-3 times per week from July to early November using LiCor 6400 (Nebraska, USA). During the experiment, we also controlled soil temperature at depths of 5, 20, 40, and 60 cm below surface of SBS using thermochrons iButton (DS1921G, USA). The pattern of CO2 emission rate from SBS depended strongly on fertilizing. The highest decomposition rates (DecR) of 2.8-5.6 g C/m2/h were observed in SBS-NP treatment during the first 6 weeks of experiment. The decay process of bark was less active in the treatment with only N addition. In this

  1. African horse sickness in naturally infected, immunised horses.

    PubMed

    Weyer, C T; Quan, M; Joone, C; Lourens, C W; MacLachlan, N J; Guthrie, A J

    2013-01-01

    To determine whether subclinical cases, together with clinical cases, of African horse sickness (AHS) occur in immunised horses in field conditions, whole blood samples were collected and rectal temperatures recorded weekly from 50 Nooitgedacht ponies resident in open camps at the Faculty of Veterinary Science, University of Pretoria, Onderstepoort, during 2008-2010. The samples were tested for the presence of African horse sickness virus (AHSV) RNA by a recently developed real-time RT-PCR. It was shown that 16% of immunised horses in an AHS endemic area were infected with AHSV over a 2 year period, with half of these (8%) being subclinically infected. The potential impact of such cases on the epidemiology of AHS warrants further investigation.

  2. Pre-Clinical Evaluation of a Real-Time PCR Assay on a Portable Instrument as a Possible Field Diagnostic Tool: Experiences from the Testing of Clinical Samples for African and Classical Swine Fever Viruses.

    PubMed

    Liu, L; Luo, Y; Accensi, F; Ganges, L; Rodríguez, F; Shan, H; Ståhl, K; Qiu, H-J; Belák, S

    2016-06-16

    African swine fever (ASF) and classical swine fever (CSF) are two highly infectious transboundary animal diseases (TADs) that are serious threats to the pig industry worldwide, including in China, the world's largest pork producer. In this study, a duplex real-time PCR assay was developed for the rapid detection and differentiation of African swine fever virus (ASFV) and classical swine fever virus (CSFV). The assay was performed on a portable, battery-powered PCR thermocycler with a low sample throughput (termed as 'T-COR4 assay'). The feasibility and reliability of the T-COR4 assay as a possible field method was investigated by testing clinical samples collected in China. When evaluated with reference materials or samples from experimental infections, the assay performed in a reliable manner, producing results comparable to those obtained from stationary PCR platforms. Of 59 clinical samples, 41 had results identical to a two-step CSFV real-time PCR assay. No ASFV was detected in these samples. The T-COR4 assay was technically easy to perform and produced results within 3 h, including sample preparation. In combination with a simple sample preparation method, the T-COR4 assay provides a new tool for the field diagnosis and differentiation of ASF and CSF, which could be of particular value in remote areas.

  3. Specially Conditioned EM Fields for Propellant-less Impulsion within Higher Dimensional Spacetimes

    NASA Astrophysics Data System (ADS)

    Froning, H. David

    2009-03-01

    A higher dimensional realm with room for both slower than light (STL) and faster-than-light (FTL) travel is defined, together with paths within this realm that enable: unlabored (momentum-conserving and energy-preserving) ship acceleration and deceleration between STL and FTL speeds. And it is shown that fields guiding ships on unlabored paths within this deeper realm must have components in more than the 3 spatial directions in which ordinary electromagnetic (EM) fields act. This is shown possible with EM fields that are transformed from lower U1 to higher SU2 Lie symmetry.

  4. Natural outcrossing rate of faba bean under Pullman field conditions and its implication to germplasm management and enhancement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The US faba bean (Vicia faba L.) germplasm collection is managed by the cool season food legume curator of the Western Regional Plant Introduction Station (WRPIS) in Pullman, Washington, USA. Knowledge of the natural outcrossing rate of this crop under Pullman field conditions will enable us to refi...

  5. Growing Opuntia (cactus) and Brassica species for the long-term remediation of selenium-contaminated soil under field conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Identifying alternative crops for planting in Se-containing agricultural soils of western central California will depend upon the plants’ ability to tolerate high salt and boron (B) conditions. Multi-year field studies were conducted on Se-laden soils with different cactus clones (Opuntia-ficus indi...

  6. Field Demonstration of Electro-Scan Defect Location Technology for Condition Assessment of Wastewater Collection Systems - Paper

    EPA Science Inventory

    A USEPA-sponsored field demonstration program was conducted to gather technically reliable cost and performance information on the electro-scan (FELL -41) pipeline condition assessment technology. Electro-scan technology can be used to estimate the magnitude and location of pote...

  7. The Validity and Utility of the California Family Risk Assessment under Practice Conditions in the Field: A Prospective Study

    ERIC Educational Resources Information Center

    Johnson, Will L.

    2011-01-01

    Objective: Analysis of the validity and implementation of a child maltreatment actuarial risk assessment model, the California Family Risk Assessment (CFRA). Questions addressed: (1) Is there evidence of the validity of the CFRA under field operating conditions? (2) Do actuarial risk assessment results influence child welfare workers' service…

  8. Equilibrium conditions and magnetic field rotation at the tangential discontinuity magnetopause

    NASA Astrophysics Data System (ADS)

    De Keyser, J.; Roth, M.

    1998-04-01

    De Keyser and Roth recently have developed a kinetic model of the tangential discontinuity magnetopause. This model predicts (1) that not all configurations of magnetic field vectors and magnetosheath velocity allow an equilibrium to exist and (2) that there is a preference for a particular magnetic field rotation sense across the magnetopause due to the different response of ions and electrons to the electric field in the current layer. In the present paper we extend the original model to allow for different magnetospheric and magnetosheath densities and temperatures, and we show that the conclusions remain essentially unchanged. Given the large-scale magnetosheath flow pattern around the magnetosphere, we also compute which regions of the dayside magnetopause may be in tangential discontinuity equilibrium for a given magnetosheath field orientation.

  9. Moving from the laboratory to the field: Adding natural environmental conditions to toxicology testing

    EPA Science Inventory

    While laboratory toxicology tests are generally easy to perform, cost effective and readily interpreted, they have been criticized for being unrealistic. In contrast, field tests are considered realistic while producing results that are difficult to interpret and expensive. To ...

  10. E-Field Conditioning and Charging Memory in Low Density Polyethylene

    NASA Astrophysics Data System (ADS)

    Brunson, Jerilyn; Dennison, J. R.

    2006-10-01

    Accurate measurement of electronic properties in extremely high resistivity materials must take into account a number of ways in which the measurements influence the materials properties being probed. These can include the strength of the applied electric field, the number of successive exposures to an applied field, the duration of exposure, and recovery time allowed during exposure cycles. An extensive series of constant voltage measurements of the resistivity of low density polyethylene samples were taken to determine consistency of measured resistivity results, the effects of varying electric field amplitude, and the extent of charging memory. Higher electric fields were found to lower the resistivity, as predicted by hopping conductivity models of polymers. Measurements at a particular voltage showed that the dark current resistivity approach successively lower values with repeated exposure.

  11. Some growth points in African child development research.

    PubMed

    Serpell, Robert; Marfo, Kofi

    2014-01-01

    We reflect on ways in which research presented in earlier chapters responds to challenges of generating an African child development field and identify additional issues calling for the field's attention. The chapters collectively display a variety of African contexts and reflexive evidence of the authors' African cultural roots. Connecting research with African audiences demands cooperative communication between educational practitioners and parents with low literacy, and cross-sector communication among professionals. Intracultural exploration of factors influencing the pattern of human development has begun to document the potential of indigenous African cultures as a fund of resources for enhancing child development. Priority topics for future African developmental research include multilingualism, musical performance, socially distributed caregiving, and the relation between adolescence and economic activity. Integration of multiple disciplines in the application of research-based principles to service delivery in the fields of community-based (re)habilitation and early childhood care and education calls for researcher collaboration with practitioners.

  12. Gradual conditioning of non-Gaussian transmissivity fields to flow and mass transport data: 2. Demonstration on a synthetic aquifer

    NASA Astrophysics Data System (ADS)

    Llopis-Albert, Carlos; Capilla, José E.

    2009-06-01

    SummaryIn the first paper of this series a methodology for the generation of non-Gaussian transmissivity fields conditional to flow, mass transport and secondary data was presented. This methodology, referred to as the gradual conditioning (GC) method, constitutes a new and advanced powerful approach in the field of stochastic inverse modelling. It is based on gradually changing an initial transmissivity ( T) field, conditioned only to T and secondary data, to honour flow and transport measured data. The process is based on combining the initial T field with other seed T fields in successive iterations maintaining the stochastic structure of T, previously inferred from data. The iterative procedure involves the minimization of a penalty function which depends on one parameter, and is made up by the weighted summation of the square deviations among flow and/or transport variables, and the corresponding known measurements. The GC method leads gradually to a final simulated field, uniformly converging to a better reproduction of conditioning data as more iterations are performed. The methodology is now demonstrated on a synthetic aquifer in a non-multi-Gaussian stochastic framework. First, an initial T field is simulated, and retained as reference T field. With prescribed head boundary conditions, transient flow created by an abstraction well and a mass solute plume migrating through the formation, a long-term and large scale hypothetical tracer experiment is run in this reference synthetic aquifer. Then T, piezometric head ( h), solute concentration ( c) and travel time ( τ) are sampled at a limited number of points, and for different time steps where applicable. Using this limited amount of information the GC method is applied, conditioning to different sets of these sampled data and model results are compared to those from the reference synthetic aquifer. Results demonstrate the ability and robustness of the GC method to include different types of data without

  13. Condition for adiabatic passage in the earth's-field NMR technique

    NASA Astrophysics Data System (ADS)

    Melton, B. F.; Pollak, V. L.

    2002-09-01

    The equation of motion d M/ dt=γ M× B(t) is solved for the case B(t)= jB p(t)+ kB e. The field Be is a small static field, typically the earth's field. The field Bp( t) decays exponentially toward zero with time constant T. This decay is produced by an overdamped switching transient that occurs near the end of the rapid cutoff of the coil current used to polarize the sample. It is assumed that Bp is initially large compared to Be, and that magnetization M is initially along the resultant field B. Exact solutions are obtained numerically for several decay time constants of Bp, and the motion of M is depicted graphically. It is found that for adiabatic passage, the final cone angle β of the precession in field Be is related to the decay time constant of Bp by β=2e -(π/2) ωeT. This is confirmed by measurements of the amplitudes of the ensuing free-precession signals for various decay rates of Bp. Near-perfect adiabatic passage (magnetization aligned within 2° of the earth's field) can be achieved for time constants T⩾2.6/ ωe. For the case of sudden passage, an approximate analytic solution is developed by linearizing the equation of motion in the laboratory frame of reference. For the adiabatic case, an approximate analytic solution is obtained by linearizing the equation of motion in a rotating frame of reference that follows the resultant field B= Bp+ Be.

  14. On the effects of grid ill-conditioning in three dimensional finite element vector potential magnetostatic field computations

    NASA Technical Reports Server (NTRS)

    Wang, R.; Demerdash, N. A.

    1990-01-01

    The effects of finite element grid geometries and associated ill-conditioning were studied in single medium and multi-media (air-iron) three dimensional magnetostatic field computation problems. The sensitivities of these 3D field computations to finite element grid geometries were investigated. It was found that in single medium applications the unconstrained magnetic vector potential curl-curl formulation in conjunction with first order finite elements produce global results which are almost totally insensitive to grid geometries. However, it was found that in multi-media (air-iron) applications first order finite element results are sensitive to grid geometries and consequent elemental shape ill-conditioning. These sensitivities were almost totally eliminated by means of the use of second order finite elements in the field computation algorithms. Practical examples are given in this paper to demonstrate these aspects mentioned above.

  15. Difference between the maximum empirical and field measured peak Watt values of thermal power system under highly sufficient solar conditions

    NASA Astrophysics Data System (ADS)

    Elhussain, O. A.; Abdel-Magid, T. I. M.

    2016-08-01

    Mono-Crystalline solar cell module is experimentally conducted in Khartoum, Sudan to study the difference between maximum empirical value of peak Watt and maximum value of thermal power produced in field under highly sufficient solar conditions. Field measurements are recorded for incident solar radiation, produced voltage, current and temperature at several time intervals during sun shine period. The thermal power system has been calculated using fundamental principles of heat transfer. The study shows that solar power for considered module could not attain the empirical peak power irrespective to maximum value of direct incident solar radiation and maximum temperature gained. A loss of about 6% of power can be considered as the difference between field measurements and the manufacturer's indicated empirical value. Solar cell exhibits 94% efficiency in comparison with manufacturer's provided data, and is 3'% more efficient in thermal energy production than in electrical power extraction for hot-dry climate conditions.

  16. Setting boundary conditions on the Khokhlov-Zabolotskaya equation for modeling ultrasound fields generated by strongly focused transducers

    NASA Astrophysics Data System (ADS)

    Rosnitskiy, P. B.; Yuldashev, P. V.; Vysokanov, B. A.; Khokhlova, V. A.

    2016-03-01

    An equivalent source model is developed for setting boundary conditions on the parabolic diffraction equation in order to simulate ultrasound fields radiated by strongly focused medical transducers. The equivalent source is defined in a plane; corresponding boundary conditions for pressure amplitude, aperture, and focal distance are chosen so that the axial solution to the parabolic model in the focal region of the beam matches the solution to the full diffraction model (Rayleigh integral) for a spherically curved uniformly vibrating source. It is shown that the proposed approach to transferring the boundary condition from a spherical surface to a plane makes it possible to match the solutions over an interval of several diffraction maxima around the focus even for focused sources with F-numbers less than unity. This method can be used to accurately simulate nonlinear effects in the fields of strongly focused therapeutic transducers using the parabolic Khokhlov-Zabolotskaya equation.

  17. African Americans and Glaucoma

    MedlinePlus

    ... Involved News About Us Donate In This Section African Americans and Glaucoma email Send this article to a ... glaucoma is the leading cause of blindness in African Americans. Half of those with glaucoma don't know ...

  18. Black African Traditional Mathematics

    ERIC Educational Resources Information Center

    Zaslavsky, Claudia

    1970-01-01

    Discusses the traditional number systems and the origin of the number names used by several African peoples living south of the Sahara. Also included are limitations in African mathematical development, and possible topics for research. (RP)

  19. Monosodium glutamate-associated alterations in open field, anxiety-related and conditioned place preference behaviours in mice.

    PubMed

    Onaolapo, Olakunle James; Aremu, Olaleye Samuel; Onaolapo, Adejoke Yetunde

    2017-03-29

    The present study investigated changes in behaviour associated with oral monosodium glutamate (a flavouring agent), using the open field, elevated plus maze and conditioned place preference (CPP) paradigms, respectively. Mice were assigned to two groups for CPP [monosodium glutamate (MSG)-naïve (n = 40) and MSG-pretreated (n = 40)] and two groups for open field (OF) and elevated plus maze (EPM) tests [n = 40 each], respectively. Animals in respective groups were then divided into four subgroups (n = 10) (vehicle or MSG (80, 160 and 320 mg/kg)). MSG-naïve mice were observed in the CPP box in three phases (pre-conditioning, conditioning and post-conditioning). Mice were conditioned to MSG or an equivalent volume of saline. The MSG pretreatment group received vehicle or respective doses of MSG daily for 21 days, prior to conditioning. Mice in the OF or EPM groups received vehicle or doses of MSG (orally) for 21 days, at 10 ml/kg. Open field or EPM behaviours were assessed on days 1 and 21. At the end of the experiments, mice in the OF groups were sacrificed and brain homogenates used to assay glutamate and glutamine. Results showed that administration of MSG was associated with a decrease in rearing, dose-related mixed horizontal locomotor, grooming and anxiety-related response and an increase in brain glutamate/glutamine levels. Following exposure to the CPP paradigm, MSG-naïve and MSG-pretreated mice both showed 'drug-paired' chamber preference. The study concluded that MSG (at the administered doses) was associated with changes in open field activities, anxiety-related behaviours and brain glutamate/glutamine levels; its ingestion also probably leads to a stimulation of the brain reward system.

  20. Major differences observed in transcript profiles of blueberry during cold acclimation under field and cold room conditions.

    PubMed

    Dhanaraj, Anik L; Alkharouf, Nadim W; Beard, Hunter S; Chouikha, Imed B; Matthews, Benjamin F; Wei, Hui; Arora, Rajeev; Rowland, Lisa J

    2007-02-01

    Our laboratory has been working toward increasing our understanding of the genetic control of cold hardiness in blueberry (Vaccinium section Cyanococcus) to ultimately use this information to develop more cold hardy cultivars for the industry. Here, we report using cDNA microarrays to monitor changes in gene expression at multiple times during cold acclimation under field and cold room conditions. Microarrays contained over 2,500 cDNA inserts, approximately half of which had been picked and single-pass sequenced from each of two cDNA libraries that were constructed from cold acclimated floral buds and non-acclimated floral buds of the fairly cold hardy cv. Bluecrop (Vaccinium corymbosum L.). Two biological samples were examined at each time point. Microarray data were analyzed statistically using t tests, ANOVA, clustering algorithms, and online analytical processing (OLAP). Interestingly, more transcripts were found to be upregulated under cold room conditions than under field conditions. Many of the genes induced only under cold room conditions could be divided into three major types: (1) genes associated with stress tolerance; (2) those that encode glycolytic and TCA cycle enzymes, and (3) those associated with protein synthesis machinery. A few of the genes induced only under field conditions appear to be related to light stress. Possible explanations for these differences are discussed in physiological context. Although many similarities exist in how plants respond during cold acclimation in the cold room and in the field environment, there are major differences suggesting caution should be taken in interpreting results based only on artificial, cold room conditions.

  1. Modulated systems in external fields: Conditions for the presence of reentrant phase diagrams

    NASA Astrophysics Data System (ADS)

    Mendoza-Coto, Alejandro; Billoni, Orlando V.; Cannas, Sergio A.; Stariolo, Daniel A.

    2016-08-01

    We introduce a coarse-grained model capable of describing the phase behavior of two-dimensional ferromagnetic systems with competing exchange and dipolar interactions, as well as an external magnetic field. An improved expression for the mean-field entropic contribution allows us to compute the phase diagram in the whole temperature versus external field plane. We find that the topology of the phase diagram may be qualitatively different depending on the ratio between the strength of the competing interactions. In the regime relevant for ultrathin ferromagnetic films with perpendicular anisotropy we confirm the presence of inverse-symmetry breaking from a modulated phase to a homogeneous one as the temperature is lowered at constant magnetic field, as reported in experiments. For other values of the competing interactions we show that reentrance may be absent. Comparing thermodynamic quantities in both cases, as well as the evolution of magnetization profiles in the modulated phases, we conclude that the reentrant behavior is a consequence of the suppression of domain wall degrees of freedom at low temperatures at constant fields.

  2. Influence of nonuniform magnetic fields on orientation of plant seedlings in microgravity conditions.

    PubMed

    Nechitailo, G S; Mashinsky, A L; Kuznetsov, A A; Chikov, V M; Kuznetsov, O A

    2001-01-01

    Experiments on the spatial behavior of the flax (Linum usitatissimum, L.) seedlings in a nonuniform magnetic field were conducted on the orbital space stations "Salut" and "Mir". This field can displace sensory organelles (statoliths) inside receptor cells and such displacement should cause a physiological reaction of the plant-tropistic curvature. Experiments were conducted in the custom-built "Magnetogravistat" facility, where seeds were germinated and grown for 3-4 days in a magnetic field with the dynamic factor grad (H2/2) approximately equal to 10(7) Oe2/cm, then fixed on orbit and returned to Earth for analysis. It was found, that 93% of the seedlings were oriented in the field consistently with curvature in response to displacement of statoliths along the field gradient by ponderomotive magnetic forces, while control seedlings grew in the direction of the initial orientation of the seed. This suggests, that gravity receptors of plants recognized magnetic forces on statoliths as gravity, and that gravity stimulus can be substituted for plants by a force of a different physical nature.

  3. Punctual Transcriptional Regulation by the Rice Circadian Clock under Fluctuating Field Conditions[OPEN

    PubMed Central

    Matsuzaki, Jun; Kawahara, Yoshihiro; Izawa, Takeshi

    2015-01-01

    Plant circadian clocks that oscillate autonomously with a roughly 24-h period are entrained by fluctuating light and temperature and globally regulate downstream genes in the field. However, it remains unknown how punctual internal time produced by the circadian clock in the field is and how it is affected by environmental fluctuations due to weather or daylength. Using hundreds of samples of field-grown rice (Oryza sativa) leaves, we developed a statistical model for the expression of circadian clock-related genes integrating diurnally entrained circadian clock with phase setting by light, both responses to light and temperature gated by the circadian clock. We show that expression of individual genes was strongly affected by temperature. However, internal time estimated from expression of multiple genes, which may reflect transcriptional regulation of downstream genes, is punctual to 22 min and not affected by weather, daylength, or plant developmental age in the field. We also revealed perturbed progression of internal time under controlled environment or in a mutant of the circadian clock gene GIGANTEA. Thus, we demonstrated that the circadian clock is a regulatory network of multiple genes that retains accurate physical time of day by integrating the perturbations on individual genes under fluctuating environments in the field. PMID:25757473

  4. A hyperbolic slicing condition adapted to Killing fields and densitized lapses

    NASA Astrophysics Data System (ADS)

    Alcubierre, Miguel; Corichi, Alejandro; González, José A.; Núñez, Darío; Salgado, Marcelo

    2003-09-01

    We study the properties of a modified version of the Bona Masso family of hyperbolic slicing conditions. This modified slicing condition has two very important features: in the first place, it guarantees that if a spacetime is static or stationary, and one starts the evolution in a coordinate system in which the metric coefficients are already time independent, then they will remain time independent during the subsequent evolution, i.e. the lapse will not evolve and will therefore not drive the time lines away from the Killing direction. Second, the modified condition is naturally adapted to the use of a densitized lapse as a fundamental variable, which in turn makes it a good candidate for a dynamic slicing condition that can be used in conjunction with some recently proposed hyperbolic reformulations of the Einstein evolution equations.

  5. East African ROAD

    NASA Astrophysics Data System (ADS)

    Tekle, Kelali

    2016-10-01

    In the developing world astronomy had been treated as the science of elites. As a result of this overwhelming perception, astronomy compared with other applied sciences has got less attention and its role in development has been insignificant. However, the IAU General Assembly decision in 2009 opened new opportunity for countries and professionals to deeply look into Astronomy and its role in development. Then, the subsequent establishment of regional offices in the developing world is helping countries to integrate astronomy with other earth and space based sciences so as to progressively promote its scientific and development importance. Gradually nations have come to know that space is the frontier of tomorrow and the urgency of preeminence on space frontier starts at primary school and ascends to tertiary education. For this to happen, member nations in east African region have placed STEM education at the center of their education system. For instance, Ethiopian has changed University enrollment strategy to be in favor of science and engineering subjects, i.e. every year seventy percent of new University entrants join science and engineering fields while thirty percent social science and humanities. Such bold actions truly promote astronomy to be conceived as gateway to science and technology. To promote the concept of astronomy for development the East African regional office has actually aligned it activities to be in line with the focus areas identified by the IAU strategy (2010 to 2020).

  6. Analysis of the linkages between rainfall and land surface conditions in the West African monsoon through CMAP, ERS-WSC, and NOAA-AVHRR data

    NASA Astrophysics Data System (ADS)

    Philippon, Nathalie; Mougin, Eric; Jarlan, Lionel; Frison, Pierre-Louis

    2005-12-01

    -vegetation water content over Guinea from winter to spring. Cross correlations and Granger causality analyses partly relate these winter to spring land surface anomalies to those recorded in precipitation during the previous autumn. Spring soil-vegetation water content anomalies strengthen the meridional gradient of soil-vegetation water content over the subcontinent. This gradient is thought to contribute to the gradient of entropy that drives the West African monsoon.

  7. Rossby normal modes in nonuniform background configurations. I Simple fields. II - Equinox and solstice conditions

    NASA Technical Reports Server (NTRS)

    Salby, M. L.

    1981-01-01

    An investigation is conducted regarding the influence of mean field variations on the realization of planetary normal modes, taking into account the mode response and structure in the presence of simple background nonuniformities. It is found that mean field variations have the combined effect of depressing, shifting, and broadening the characteristic response of Rossby normal modes. While nonuniformities in both the mean wind and temperature fields contribute to the reduction in peak response, the former are primarily responsible for translation and spectral broadening. An investigation is conducted to determine which modes may be realized in actual atmospheric configurations and which may be identified. For both the equinox and solstice configurations, response peaks corresponding to all of the first four modes of wavenumbers 1, 2, and 3 are readily visible above the noise.

  8. The African Connection

    ERIC Educational Resources Information Center

    Oguntoyinbo, Lekan

    2012-01-01

    From student and faculty exchanges to joint research projects, U.S. universities maintain a broad spectrum of collaborative relationships with African universities. It's unclear how many U.S. colleges and universities have partnerships with African universities. The African Studies Association, an organization of scholars, doesn't keep that kind…

  9. Cryogels for oil and gas field construction under the conditions of arctic zone

    NASA Astrophysics Data System (ADS)

    Altunina, L. K.; Manzhay, V. N.; Fufaeva, M. S.

    2016-11-01

    The results of investigation of elastic and thermal properties of cryogels filled with used mineral oil are presented. A new chemical-biological method for oil and gas field construction in the northern regions is proposed and tested. The field experiments carried out in the territory of Yamalo-Nenets Autonomous District are described. The formation of cryotropic polymer systems occurring at shallow freezing from 0 to -3°C and the impact of crystructured soil on the viability, enzymatic activity of native soil microflora and growth of perennial herbs have been investigated. Cryogels are harmless to humans and safe for the environment.

  10. Tests for the determination of the stress condition in tension fields

    NASA Technical Reports Server (NTRS)

    Lahde, R; Wagner, H

    1936-01-01

    The present experiments treat the stress of actual tension fields within the elastic range. They give the magnitude of the flexural stresses due to wrinkling. They also disclose, particularly by slightly exceeded buckling load, the marked unloading - as compared with the tension-field theory - of the uprights as a result of the flexural stiffness of the web plate. The test sheets were clamped at the edges and brought to buckling through shearing and compressive stresses applied in the direction of the long sides.

  11. The biology of Phymastichus coffea LaSalle (Hymenoptera: Eulophidae) under field conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The coffee berry borer, Hypothenemus hampei, was accidentally introduced into México in 1978, and rapidly became the main pest of coffee. As an exotic pest, its management has been based on biological control methods based on the introduction of parasitoids from Africa. In field studies conducted in...

  12. Growing Indian Fig Opuntia on selenium-laden agriculture drainage sediment under field conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Growing alternative crops for saline and selenium (Se) impacted lands in arid regions, e.g., Western United States, depends upon the plant’s ability to tolerate the presence of high salts and boron (B). In this field study, we planted 2-month old cacti plants on 30 x 1m beds and evaluated the abilit...

  13. Metabolite changes in nine different soybean cultivars grown under field and greenhouse conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Differences in the primary (amino acids, organic acids, and sugars) and secondary (isoflavones, fatty acid methyl esters) metabolites of nine soybean varieties grown in the field and in greenhouses were investigated by chemometric tools to identify the metabolic patterns associated with the growing ...

  14. FIELD OPERATIONS AND METHODS FOR MEASURING THE ECOLOGICAL CONDITION OF WADEABLE STREAMS

    EPA Science Inventory

    The methods and instructions for field operations presented in this manual for surveys of wadeable streams were developed and tested during 5 years of pilot and demonstration projects (1993 through 1997). These projects were conducted under the sponsorship of the U.S. Environment...

  15. FIELD OPERATIONS AND METHODS FOR MEASURING THE ECOLOGICAL CONDITION OF NON-WADEABLE RIVERS AND STREAMS

    EPA Science Inventory

    The methods and instructions for field operations presented in this manual for surveys of non-wadeable streams and rivers were developed and tested based on 55 sample sites in the Mid-Atlantic region and 53 sites in an Oregon study during two years of pilot and demonstration proj...

  16. Control of common bunt of wheat under field conditions with the biofumigant fungus Muscodor albus.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field experiments were conducted to evaluate the biological control potential of the fungus Muscodor albus, when applied as a seed treatment or an in furrow soil treatment, for control of common bunt (CB) of wheat caused by Tilletia caries. For seed treatments, dry rye grain culture of M. albus wa...

  17. Estimates of metabolic rate and major constituents of metabolic demand in fishes under field conditions: Methods, proxies, and new perspectives.

    PubMed

    Treberg, Jason R; Killen, Shaun S; MacCormack, Tyson J; Lamarre, Simon G; Enders, Eva C

    2016-12-01

    Metabolic costs are central to individual energy budgets, making estimates of metabolic rate vital to understanding how an organism interacts with its environment as well as the role of species in their ecosystem. Despite the ecological and commercial importance of fishes, there are currently no widely adopted means of measuring field metabolic rate in fishes. The lack of recognized methods is in part due to the logistical difficulties of measuring metabolic rates in free swimming fishes. However, further development and refinement of techniques applicable for field-based studies on free swimming animals would greatly enhance the capacity to study fish under environmentally relevant conditions. In an effort to foster discussion in this area, from field ecologists to biochemists alike, we review aspects of energy metabolism and give details on approaches that have been used to estimate energetic parameters in fishes. In some cases, the techniques have been applied to field conditions; while in others, the methods have been primarily used on laboratory held fishes but should be applicable, with validation, to fishes in their natural environment. Limitations, experimental considerations and caveats of these measurements and the study of metabolism in wild fishes in general are also discussed. Potential novel approaches to FMR estimates are also presented for consideration. The innovation of methods for measuring field metabolic rate in free-ranging wild fish would revolutionize the study of physiological ecology.

  18. Numerical Computation of Electric Field and Potential Along Silicone Rubber Insulators Under Contaminated and Dry Band Conditions

    NASA Astrophysics Data System (ADS)

    Arshad; Nekahi, A.; McMeekin, S. G.; Farzaneh, M.

    2016-09-01

    Electrical field distribution along the insulator surface is considered one of the important parameters for the performance evaluation of outdoor insulators. In this paper numerical simulations were carried out to investigate the electric field and potential distribution along silicone rubber insulators under various polluted and dry band conditions. Simulations were performed using commercially available simulation package Comsol Multiphysics based on the finite element method. Various pollution severity levels were simulated by changing the conductivity of pollution layer. Dry bands of 2 cm width were inserted at the high voltage end, ground end, middle part, shed, sheath, and at the junction of shed and sheath to investigate the effect of dry band location and width on electric field and potential distribution. Partial pollution conditions were simulated by applying pollution layer on the top and bottom surface respectively. It was observed from the simulation results that electric field intensity was higher at the metal electrode ends and at the junction of dry bands. Simulation results showed that potential distribution is nonlinear in the case of clean and partially polluted insulator and linear for uniform pollution layer. Dry band formation effect both potential and electric field distribution. Power dissipated along the insulator surface and the resultant heat generation was also studied. The results of this study could be useful in the selection of polymeric insulators for contaminated environments.

  19. Novel Applications of Magnetic Fields for Fluid Flow Control and for Simulating Variable Gravity Conditions

    NASA Technical Reports Server (NTRS)

    Ramachandran, N.

    2005-01-01

    Static and dynamic magnetic fields have been used to control convection in many materials processing applications. In most of the applications, convection control (damping or enhancement) is achieved through the Lorentz force that can be tailored to counteract/assist dominant system flows. This technique has been successfully applied to liquids that are electrically conducting, such as high temperature melts of semiconductors, metals and alloys, etc. In liquids with low electrical conductivity such as ionic solutions of salts in water, the Lorentz force is weak and hence not very effective and alternate ways of flow control are necessary. If the salt in solution is paramagnetic then the variation of magnetic susceptibility with temperature and/or concentration can be used for flow control. For thermal buoyancy driven flows this can be accomplished in a temperature range below the Curie point of the salt. The magnetic force is proportional to the magnetic susceptibility and the product of the magnetic field and its gradient. By suitably positioning the experiment cell in the magnet, system flows can be assisted or countered, as desired. A similar approach can be extended to diamagnetic substances and fluids but the required magnetic force is considerably larger than that required for paramagnetic substances. The presentation will provide an overview of work to date on a NASA fluid physics sponsored project that aims to test the hypothesis of convective flow control using strong magnetic fields in protein crystal growth. The objective is to understand the nature of the various forces that come into play, delineate causative factors for fluid flow and to quantify them through experiments, analysis, and numerical modeling. The seminar will report specifically on the experimental results using paramagnetic salts and solutions in magnetic fields and compare them to analytical predictions. Applications of the concept to protein crystallization studies will be discussed

  20. Evaluation of the Ott Hydromet Qliner for measuring discharge in laboratory and field conditions

    USGS Publications Warehouse

    McVay, Jason C.

    2015-01-01

    The U.S. Geological Survey, in collaboration with the University of Iowa IIHR – Hydroscience and Engineering, evaluated the use of the Ott Hydromet Qliner using laboratory flume tests along with field validation tests. Analysis of the flume testing indicates the velocities measured by the Qliner at a 40-second exposure time results in higher dispersion of velocities from the mean velocity of data collected with a 5-minute exposure time. The percent data spread from the mean of a 100-minute mean of Qliner velocities for a 40-second exposure time averaged 16.6 percent for the entire vertical, and a 5-minute mean produced a 6.2 percent data spread from the 100-minute mean. This 16.6 percent variation in measured velocity would result in a 3.32 percent variation in computed discharge assuming 25 verticals while averaging 4 bins in each vertical. The flume testing also provided results that indicate the blanking distance of 0.20 meters is acceptable when using beams 1 and 2, however beam 3 is negatively biased near the transducer and the 0.20-meter blanking distance is not sufficient. Field testing included comparing the measured discharge by the Qliner to the discharge measured by a Price AA mechanical current meter and a Teledyne RDI Rio Grande 1200 kilohertz acoustic Doppler current profiler. The field tests indicated a difference between the discharges measured with the Qliner and the field reference discharge between -14.0 and 8.0 percent; however the average percent difference for all 22 field comparisons was 0.22, which was not statistically significant.

  1. An energy absorbing far-field boundary condition for the elastic wave equation

    SciTech Connect

    Petersson, N A; Sjogreen, B

    2008-07-15

    The authors present an energy absorbing non-reflecting boundary condition of Clayton-Engquist type for the elastic wave equation together with a discretization which is stable for any ratio of compressional to shear wave speed. They prove stability for a second order accurate finite-difference discretization of the elastic wave equation in three space dimensions together with a discretization of the proposed non-reflecting boundary condition. The stability proof is based on a discrete energy estimate and is valid for heterogeneous materials. The proof includes all six boundaries of the computational domain where special discretizations are needed at the edges and corners. The stability proof holds also when a free surface boundary condition is imposed on some sides of the computational domain.

  2. A field test for differences in condition among trapped and shot mallards

    USGS Publications Warehouse

    Reinecke, K.J.; Shaiffer, C.W.

    1988-01-01

    We tested predictions from the condition bias hypothesis (Weatherland and Greenwood 1981) regarding the effects of sampling methods of body weights of mallards (Anas platyrhynchos) at White River National Wildlife Refuge (WRNWR), Arkansas, during 24 November-8 December 1985. Body weights of 84 mallards caught with unbaited rocket nets in a natural wetland were used as experimental controls and compared to the body weights of 70 mallards captured with baited rocket nets, 86 mallards captured with baited swim-in traps, and 130 mallards killed by hunters. We found no differences (P > 0.27) in body weight among sampling methods, but body condition (wt/wing length) of the birds killed by hunters was less (P 0.75 for differences > 50 g. The condition bias hypothesis probably applies to ducks killed by hunters but not to trapping operations when substantial (> 20 at 1 time) numbers of birds are captured.

  3. Wave-current interactions in deep water conditions: field measurements and analyses

    NASA Astrophysics Data System (ADS)

    Rougier, Gilles; Rey, Vincent; Molcard, Anne

    2015-04-01

    The study of wave - current interaction has drawn interest in oceanography, ocean engineering, maritime navigation and for tides or waves power device design. In the context of the hydrodynamics study along the French Mediterranean coast, a current profiler was deployed near Toulon at the south of the "Port Cros" island. This coastal zone is characterized by a steep slope, the water depth varying from tens meters to several thousand meters over few kilometers from the coast. An ambient current, the "Northern Current", coming from the Ligurian sea (area of Genoa, Italy) and following the coast up to Toulon, is present all over the year. Its mean surface velocity is of about 0.30 m/s, its flow rate of about 1.5 Sv. The region is exposed to two dominating winds: the Mistral, coming from North-West, and Eastern winds. Both generate swell and/or wind waves in either following or opposing current conditions with respect to the Northern Current. A current profiler equipped with a wave tracking system (ACPD workhorse from RDI) was deployed from July to October 2014 in deep water conditions (depth of about 500m). The mooring system allowed the ADCP to measure the current profile from the sea surface down to 25m depth, which corresponds more or less to the depth of influence of waves of periods up to 10s. The collected data include energetic wave conditions in either following or opposing current conditions. The current intensity and its vertical profiles have shown a significant temporal variability according to the meteorological conditions. Effects of the wave conditions on the current properties are discussed. ACKNOWLEDGEMENTS This work was supported by the program BOMBYX and the ANR grant No ANR-13-ASTR-0007.

  4. Low and Mid Level Tropical Atmosphere Characterization during African Dust Outbreaks Using Particle Size Distribution Data Retrieved from ICE-T and PRADACS Field Studies

    NASA Astrophysics Data System (ADS)

    Martínez-Sánchez, O.; Mayol-Bracero, O. L.; Sepulveda-Vallejo, P.; Heymsfield, A.

    2013-12-01

    Cloud formation in the tropical atmosphere is difficult to characterize when factors such as the Saharan Air Layer (SAL) play a role influencing the dynamic and thermodynamic processes. In order to characterize particle number size distribution across the Eastern Caribbean with the possible influence of African dust at low and mid levels, data collected during July 2011 from ground-based instruments and an aircraft platform were analyzed. Aerosol measurements from the ocean surface to ~8 km were performed below and in and around clouds by the National Center for Atmospheric Research (NCAR) C130 aircraft during the Ice in Clouds Experiment-Tropical (ICE-T) using the Passive Cavity Aerosol Spectrometer Probe (PCASP), while low-level measurements of aerosols were performed at the University of Puerto Rico-Rio Piedras Campus (UPRRP) during the Puerto Rican African Dust and Cloud Study (PRADACS) using an Optical Particle Counter (OPC) and a Scanning Mobility Particle Sizer (SMPS). Preliminary results using HYSPLIT back trajectories, flight tracks, SAL images and OPC/SMPS/PCASP time series all indicate peaks and troughs in aerosol concentrations at both low and mid levels over time, but the concentration was influenced by how strong the dust outbreak was as well as its horizontal travel speed. These and additional results regarding correlations between wind directions, cloud cover and atmospheric inversions will be presented.

  5. Impact of magnetic field in three-dimensional flow of Sisko nanofluid with convective condition

    NASA Astrophysics Data System (ADS)

    Hayat, T.; Muhammad, Taseer; Ahmad, B.; Shehzad, S. A.

    2016-09-01

    This communication addresses the magnetohydrodynamic (MHD) three dimensional flow of Sisko nanofluid bounded by a surface stretched bidirectionally. Nanofluid model includes the Brownian motion and thermophoresis. Heat transfer through convective condition is discussed. Developed condition with the zero nanoparticles mass flux at the surface is implemented. The governing problems subject to boundary layer approximations are computed for the convergent series solutions. Effects of interesting flow parameters on the temperature and nanoparticles concentration distributions are studied and discussed. Skin friction coefficients and the local Nusselt number are computed and analyzed.

  6. Flow field measurements around a Mars lander model using hot film anemometers under simulated Mars surface conditions

    NASA Technical Reports Server (NTRS)

    Greene, G. C.; Keafer, L. S., Jr.; Marple, C. G.; Foughner, J. T., Jr.

    1972-01-01

    Results are presented from a wind-tunnel investigation of the flow field around a 0.45-scale model of a Mars lander. The tests were conducted in air at values of Reynolds number equivalent to those anticipated on Mars. The effects of Reynolds number equivalent to those anticipated on Mars. The effects of Reynolds number, model orientation with respect to the airstream, and the position of a dish-type antenna on the flow field were determined. An appendix is included which describes the calibration and operational characteristics of hot-film anemometers under simulated Mars surface conditions.

  7. Cl constrains on shallow plumbing system and pre-eruptive conditions of the Phlegrean Fields.

    NASA Astrophysics Data System (ADS)

    Zdanowicz, Géraldine; Balcone-Boissard, Hélène; Boudon, Georges; Civetta, Lucia; Orsi, Giovanni; D'Antonio, Massimo

    2015-04-01

    The bay of Naples is known to concentrate several dangerous volcanoes that erupted a lot of times in prehistorical and historical periods: Vesuvius, Phlegrean Fields and Ischia Island. Phlegrean Fields produced voluminous high-magnitude eruptions including: the Campanian Ignimbrite (39 ka BP), one of the two largest explosive eruptions of the Mediterranean region during the last 200,000 years, with 300 km3 of magma emitted, and the Neapolitan Yellow Tuff (15 ka BP), the second major eruption (40 km3 of magma emitted). The Ischia Island is located in the Bay of Naples and its eruptive history has been recently detailed. We present a geochemical investigation of volatile components on the fallout products of the major explosive eruptions of Phlegrean Fields: the Campanian Ignimbrite (39 ka BP), the Neapolitan Yellow Tuff (15 ka BP), the Pomici Principali (10 ka BP; 0.38 km3 DRE magma), the Agnano Monte-Spina (4.1 ka BP; 0.60 km3 DRE magma); the Astroni 6 (3.8 ka BP; 0.70 km3 DRE magma); the Monte Nuovo (1,538 AD), which is the most recent eruption of the Phlegrean Fields (0.04 km3 DRE magma), and for comparison the Cretaio eruption of the Ischia Island (1,800 a BP; 0.02 km3 DRE magma). Volatiles of magmas (H2O, CO2, SO2, Cl, F) are informative not only because they play a key role in the eruptive dynamic but also because they, and especially chlorine, may allow estimating the pressure of localization of the magma storage and pre-eruptive water content (prior the eruption). In the alkaline magmas involved during the Phlegrean Fields eruptions, H2O is the main volatile species but Cl behaviour is particularly interesting to study. Experimentally, it has been demonstrated that in a pressure, temperature and composition domain a water-saturated magma may be in equilibrium with a fluid phase consisting of a water-rich vapor and a chlorine-rich brine. In that case, the Cl content in magma is buffered. This effect allows determining the pressure of localization of

  8. The Future of African-Americans to the Year 2000.

    ERIC Educational Resources Information Center

    Congressional Task Force on the Future of African-Americans, Washington, DC.

    This study considers the present condition of African-Americans and makes projections for the year 2000, emphasizing the relative conditions of European-Americans and African-Americans, and considering the public and private policy implications of these projections. Section 1, an overview of the subject, covers the following topics: (1) "The…

  9. Field and lab conditions alter microbial enzyme and biomass dynamics driving decomposition of the same leaf litter.

    PubMed

    Rinkes, Zachary L; Sinsabaugh, Robert L; Moorhead, Daryl L; Grandy, A Stuart; Weintraub, Michael N

    2013-01-01

    Fluctuations in climate and edaphic factors influence field decomposition rates and preclude a complete understanding of how microbial communities respond to plant litter quality. In contrast, laboratory microcosms isolate the intrinsic effects of litter chemistry and microbial community from extrinsic effects of environmental variation. Used together, these paired approaches provide mechanistic insights to decomposition processes. In order to elucidate the microbial mechanisms underlying how environmental conditions alter the trajectory of decay, we characterized microbial biomass, respiration, enzyme activities, and nutrient dynamics during early (<10% mass loss), mid- (10-40% mass loss), and late (>40% mass loss) decay in parallel field and laboratory litter bag incubations for deciduous tree litters with varying recalcitrance (dogwood < maple < maple-oak mixture < oak). In the field, mass loss was minimal (<10%) over the first 50 days (January-February), even for labile litter types, despite above-freezing soil temperatures and adequate moisture during these winter months. In contrast, microcosms displayed high C mineralization rates in the first week. During mid-decay, the labile dogwood and maple litters in the field had higher mass loss per unit enzyme activity than the lab, possibly due to leaching of soluble compounds. Microbial biomass to litter mass (B:C) ratios peaked in the field during late decay, but B:C ratios declined between mid- and late decay in the lab. Thus, microbial biomass did not have a consistent relationship with litter quality between studies. Higher oxidative enzyme activities in oak litters in the field, and higher nitrogen (N) accumulation in the lab microcosms occurred in late decay. We speculate that elevated N suppressed fungal activity and/or biomass in microcosms. Our results suggest that differences in microbial biomass and enzyme dynamics alter the decay trajectory of the same leaf litter under field and lab conditions.

  10. Strong IMF By-Related Plasma Convection in the Ionosphere and Cusp Field-Aligned Currents Under Northward IMF Conditions

    NASA Technical Reports Server (NTRS)

    Le, G.; Lu, G.; Strangeway, R. J.; Pfaff, R. F., Jr.; Vondrak, Richard R. (Technical Monitor)

    2001-01-01

    We present in this paper an investigation of IMF-By related plasma convection and cusp field-aligned currents using FAST data and AMIE model during a prolonged interval with large positive IMF By and northward Bz conditions (By/Bz much greater than 1). Using the FAST single trajectory observations to validate the global convection patterns at key times and key locations, we have demonstrated that the AMIE procedure provides a reasonably good description of plasma circulations in the ionosphere during this interval. Our results show that the plasma convection in the ionosphere is consistent with the anti-parallel merging model. When the IMF has a strongly positive By component under northward conditions, we find that the global plasma convection forms two cells oriented nearly along the Sun-earth line in the ionosphere. In the northern hemisphere, the dayside cell has clockwise convection mainly circulating within the polar cap on open field lines. A second cell with counterclockwise convection is located in the nightside circulating across the polar cap boundary, The observed two-cell convection pattern appears to be driven by the reconnection along the anti-parallel merging lines poleward of the cusp extending toward the dusk side when IMF By/Bz much greater than 1. The magnetic tension force on the newly reconnected field lines drives the plasma to move from dusk to dawn in the polar cusp region near the polar cap boundary. The field-aligned currents in the cusp region flow downward into the ionosphere. The return field-aligned currents extend into the polar cap in the center of the dayside convection cell. The field-aligned currents are closed through the Peterson currents in the ionosphere, which flow poleward from the polar cap boundary along the electric field direction.

  11. Mapping surface fluxes and moisture conditions from field to global scales using ALEXI/DisALEXI

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land-surface temperature (LST) maps derived from thermal infrared (TIR) satellite data convey valuable information for detecting moisture stress conditions and for constraining diagnostic surface flux estimates based on remote sensing. Soil surface and vegetation canopy temperatures rise as availab...

  12. Hydrogeological condition patterns of Kuznetsk Basin coalbed methane fields for estimating hydrodynamic calculations

    NASA Astrophysics Data System (ADS)

    Alexander, Gridasov; Konstantin, Kuzevanov; Anna, Bogdanova

    2016-09-01

    The paper describes the natural regional conditions and key formation factors of groundwater dynamics. Characteristic hydrogeological structure elements for Kuznetsk Basin coal were identified providing parameter-oriented hydrodynamic calculations and hydrogeological models in predicting coalbed methane mining impact on the regional groundwater.

  13. Field Validation of Molybdenum Accumulation as an Indicator of Hypoxic Water Conditions

    EPA Science Inventory

    Laboratory experiments have shown that the accumulation rate of authigenic molybdenum (Mo) in marine sediments may serve as a quantitative surrogate for direct measurement of hypoxic conditions in overlying waters: Mo accumulation in the top 1 cm of sediment is linearly related t...

  14. Non-Print Instructional Materials for the Air Conditioning and Refrigeration Maintenance Field.

    ERIC Educational Resources Information Center

    Golitko, Raymond L., Ed.; And Others

    This catalog contains a listing of air conditioning/refrigeration maintenance audiovisual training materials from the Houston Community College System library media collection. The material is organized by subject heading. The media titles are listed in alphabetical order by title under each subject heading in the catalog. The citation for each…

  15. Two beam energy exchange in hybrid liquid crystal cells with photorefractive field controlled boundary conditions

    NASA Astrophysics Data System (ADS)

    Reshetnyak, V. Yu.; Pinkevych, I. P.; Subota, S. I.; Evans, D. R.

    2016-09-01

    We develop a theory describing energy gain when two light beams intersect in a hybrid nematic liquid crystal (LC) cell with photorefractive crystalline substrates. A periodic space-charge field induced by interfering light beams in the photorefractive substrates penetrates into the LC layer and reorients the director. We account for two main mechanisms of the LC director reorientation: the interaction of the photorefractive field with the LC flexopolarization and the director easy axis at the cell boundaries. It is shown that the resulting director grating is a sum of two in-phase gratings: the flexoelectric effect driven grating and the boundary-driven grating. Each light beam diffracts from the induced gratings leading to an energy exchange between beams. We evaluate the signal beam gain coefficient and analyze its dependence on the director anchoring energy and the magnitude of the director easy axis modulation.

  16. Growth and decay of runaway electrons above the critical electric field under quiescent conditions

    SciTech Connect

    Paz-Soldan, C.; Eidietis, N. W.; Wesley, J. C.; Granetz, R.; Hollmann, E. M.; Moyer, R. A.; Zhang, J.; Crocker, N. A.; Austin, M. E.; Wingen, A.; Zhu, Y.

    2014-02-15

    Extremely low density operation free of error field penetration supports the excitation of trace-level quiescent runaway electron (RE) populations during the flat-top of DIII-D Ohmic discharges. Operation in the quiescent regime allows accurate measurement of all key parameters important to RE excitation, including the internal broadband magnetic fluctuation level. RE onset is characterized and found to be consistent with primary (Dreicer) generation rates. Impurity-free collisional suppression of the RE population is investigated by stepping the late-time main-ion density, until RE decay is observed. The transition from growth to decay is found to occur 3–5 times above the theoretical critical electric field for avalanche growth and is thus indicative of anomalous RE loss. This suggests that suppression of tokamak RE avalanches can be achieved at lower density than previously expected, though extrapolation requires predictive understanding of the RE loss mechanism and magnitude.

  17. [Return of African sleeping sickness].

    PubMed

    Stingl, Peter

    2006-09-14

    At present there is a steady rise in African sleeping sickness (trypanosomiasis) transmitted by the Tsetse fly, and which if left untreated, is fatal. Thanks to more than so years of neglect by research, our therapeutic repertoire is limited to medications with a high level of toxicity. Both WHO and international aid organizations are pushing hard for the development of new, more efficient drugs that can be readily applied in the field.

  18. Measurement of Energy Expenditure under Field Conditions Using Doubly Labeled Water

    DTIC Science & Technology

    1988-08-31

    nstitutes of Health . j ’PI Signature D ’ 1m TABLE OF CONTENTS Page IWTROUCTION 3 I Hypothesis 3 II Objectives 3 III Military Significance 3 VI Background 3...Surface water for use as drinking water was abundant during this field training exercise. The study was conducted in late September and October, with...8used to correct isotope abundances in subjects receiving H 0. These changes are quite close to the anticipated change. Although actual drinking water

  19. Complexities in using sentinel pigs to study Taenia solium transmission dynamics under field conditions.

    PubMed

    Devleesschauwer, Brecht; Aryal, Arjun; Tharmalingam, Jayaraman; Joshi, Durga Datt; Rijal, Suman; Speybroeck, Niko; Gabriël, Sarah; Victor, Bjorn; Dorny, Pierre

    2013-03-31

    The transmission dynamics of the pork tapeworm, Taenia solium, remain a matter of research and debate. In a longitudinal field study performed in southeastern Nepal, 18 sentinel pigs were serologically monitored to study the field kinetics of Taenia antigens and anti-T. solium antibodies. At the end of the twelve months' study period, necropsy was performed and suspected lesions were subjected to molecular identification of the Taenia species. The study generated new hypotheses on the transmission dynamics of Taenia spp. and exposed crucial complexities in the use of sentinel pigs in longitudinal field studies. Sentinel pigs can be useful epidemiological tools, but their use should be thoroughly planned before initiating a study and carefully monitored throughout the course of the study. Important aspects to be considered are those affecting the pig's susceptibility to infection, such as passive immunity, age, hormonal levels, and infection with competing Taenia species. In addition, serological test results should be interpreted considering possible cross-reactions and with proper understanding of the significance of a positive test result.

  20. A study on dynamic heat assisted magnetization reversal mechanisms under insufficient reversal field conditions

    SciTech Connect

    Chen, Y. J.; Yang, H. Z.; Leong, S. H.; Yu Ko, Hnin Yu; Wu, B. L.; Ng, V.; Asbahi, M.; Yang, J. K. W.

    2014-10-20

    We report an experimental study on the dynamic thermomagnetic (TM) reversal mechanisms at around Curie temperature (Tc) for isolated 60 nm pitch single-domain [Co/Pd] islands heated by a 1.5 μm spot size laser pulse under an applied magnetic reversal field (Hr). Magnetic force microscopy (MFM) observations with high resolution MFM tips clearly showed randomly trapped non-switched islands within the laser irradiated spot after dynamic TM reversal process with insufficient Hr strength. This observation provides direct experimental evidence by MFM of a large magnetization switching variation due to increased thermal fluctuation/agitation over magnetization energy at the elevated temperature of around Tc. The average percentage of non-switched islands/magnetization was further found to be inversely proportional to the applied reversal field Hr for incomplete magnetization reversal when Hr is less than 13% of the island coercivity (Hc), showing an increased switching field distribution (SFD) at elevated temperature of around Tc (where main contributions to SFD broadening are from Tc distribution and stronger thermal fluctuations). Our experimental study and results provide better understanding and insight on practical heat assisted magnetic recording (HAMR) process and recording performance, including HAMR writing magnetization dynamics induced SFD as well as associated DC saturation noise that limits areal density, as were previously observed and investigated by theoretical simulations.

  1. [Hygienic evaluation of the combined effect of electromagnetic fields and pesticides in experimental conditions].

    PubMed

    Chernykh, A M

    2003-01-01

    The paper deals with the evaluation of combined effects of some natural and anthropogenic factors that are typical of the Kursk magnetic anomaly region by means of dispersion analysis in the experiments on albino rats and mice. The resultant signs were the indices of animal deaths, nonspecific protective factors, immune responses, changes in body weight, etc. A higher geomagnetic field can modify the biological effects of exposure to agricultural chemicals. The combined effects of a static electromagnetic field with induction of 300 microT to 0.3 T and of chlorpyrifos at various concentrations (0.1, 1, 50, and 100 mg/kg) were found to potentiate the toxic properties of the pesticide. The proportion of the potentiation effects increased as the intensity of the studied factors rose. The dispersion analysis established a predominant role of chlorpyrifos in the combined effects of the factors on the death of animals, serum complementary activity, antibody- and rosette-forming cells of the spleen and other lymphoid organs. The role of a static electromagnetic field is prevalent in the formation of effects of the intensity and completeness of phagocytosis.

  2. Cyclic Variations of Near-Earth Conditions and Solar Magnetic Multipole Fields

    NASA Astrophysics Data System (ADS)

    Kim, B.; Lee, J.; Oh, S.; Yi, Y.

    2014-12-01

    We have investigated the cyclic variations of the magnetic multipole components of solar fields in comparison with various indices for the solar, interplanetary, and geomagnetic activities measured from 1976 to 2012 (from Solar Cycle 21 to the early phase of Cycle 24). The magnetic multipole components are calculated using the synoptic magnetic field data and the potential field source surface (PFSS) model of the Wilcox Solar Observatory (WSO). While most solar activity indices such as sunspot number, total solar irradiance, 10.7 cm radio flux, and solar flare occurrence rate are highly correlated with the flux of magnetic quadrupole component, the solar wind dynamic pressure and the geomagnetic activity index, AE, are rather correlated with the dipole and higher-order pole components, respectively. The cyclic variation of the dipole components is out of phase with the solar sunspot cycle and that of the quadrupole component is in phase. It is therefore argued that the temporal correlations of the activity indices with the individual multipole components as found in this study may clarify why some of the activity indices are seemingly out of phase with the sunspot cycle.

  3. Emissions of 1,3-Dichloropropene and Chloropicrin after Soil Fumigation under Field Conditions.

    PubMed

    Yates, Scott R; Ashworth, Daniel J; Zheng, Wei; Zhang, Qiaoping; Knuteson, James; van Wessenbeeck, Ian J

    2015-06-10

    Soil fumigation is an important agronomic practice in the production of many high-value vegetable and fruit crops, but the use of chemical fumigants can lead to excessive atmospheric emissions. A large-scale (2.9 ha) field experiment was conducted to obtain volatilization and cumulative emission rates for two commonly used soil fumigants under typical agronomic practices: 1,3-dichloropropene (1,3-D) and chloropicrin. The aerodynamic method and the indirect back-calculation method using ISCST3 and CALPUFF dispersion models were used to estimate flux loss from the treated field. Over the course of the experiment, the daily peak volatilization rates ranged from 12 to 30 μg m(-2) s(-1) for 1,3-D and from 0.7 to 2.6 μg m(-2) s(-1) for chloropicrin. Depending on the method used for quantification, total emissions of 1,3-D and chloropicrin, respectively, ranged from 16 to 35% and from 0.3 to 1.3% of the applied fumigant. A soil incubation study showed that the low volatilization rates measured for chloropicrin were due to particularly high soil degradation rates observed at this field site. Understanding and quantifying fumigant emissions from agricultural soil will help in developing best management practices to reduce emission losses, reducing adverse impacts to human and ecosystem health, and providing inputs for conducting risk assessments.

  4. Far-field condition of vortex methods on an impulsively started two-dimensional circular cylinder with rotation

    NASA Astrophysics Data System (ADS)

    Kida, Teruhiko; Nagata, Toshimi; Nakajima, Tomoya

    1994-08-01

    The far-field condition in the problem of the steady two-dimensional flow past a rotating circular cylinder is well known, but this condition is not clear in the problem of the two-dimensional unsteady flow past a rotating circular cylinder which is impulsively started. In the latter problem, the circulation around a contour of sufficient large radius surrounding the cylinder is dependent on initial conditions: (1) The circular cylinder is impulsively started with rotation from rest and (2) the rotating cylinder is impulsively started. The hybrid vortex method combined with a panel method is used for the flow of a slightly viscous, incompressible fluid around the rotating circular cylinder in the two initial conditions mentioned above. The numerical accuracy of this hybrid method is tested on the flow around an impulsively started cylinder without rotation. The detailed results of the flow around the rotating cylinder with a constant clockwise angular velocity show: (1) The initial shedding vortex is anticlockwise in the former initial case, but it is clockwise in the latter initial case. (2) The growth of the wake depends on the initial condition. (3) The time history of the aerodynamic force is dependent on the initial condition at the early stages of the development but it is almost independent of the initial condition after the early stages.

  5. Regulated expression of an isopentenyltransferase gene (IPT) in peanut significantly improves drought tolerance and increases yield under field conditions.

    PubMed

    Qin, Hua; Gu, Qiang; Zhang, Junling; Sun, Li; Kuppu, Sundaram; Zhang, Yizheng; Burow, Mark; Payton, Paxton; Blumwald, Eduardo; Zhang, Hong

    2011-11-01

    Isopentenyltransferase (IPT) is a critical enzyme in the cytokinin biosynthetic pathway. The expression of IPT under the control of a maturation- and stress-induced promoter was shown to delay stress-induced plant senescence that resulted in an enhanced drought tolerance in both monocot and dicot plants. This report extends the earlier findings in tobacco and rice to peanut (Arachis hypogaea L.), an important oil crop and protein source. Regulated expression of IPT in peanut significantly improved drought tolerance in both laboratory and field conditions. Transgenic peanut plants maintained higher photosynthetic rates, higher stomatal conductance and higher transpiration than wild-type control plants under reduced irrigation conditions. More importantly, transgenic peanut plants produced significantly higher yields than wild-type control plants in the field, indicating a great potential for the development of crops with improved performance and yield in water-limited areas of the world.

  6. Stress-energy distribution for a cylindrical artificial gravity field via the Darmois-Israel junction conditions of general relativity

    NASA Astrophysics Data System (ADS)

    Istrate, Nicolae; Lindner, John

    2014-03-01

    We design an Earth-like artificial gravity field using the Darmois-Israel junction conditions of general relativity to connect the flat spacetime outside an infinitesimally thin cylinder to the curved spacetime inside. In the calculation of extrinsic curvature, our construction exploits Earth's weak gravity, which implies similar inside and outside curvatures, to approximate the unit normal inside by the negative unit normal outside. The stress-energy distribution on the cylinder's sides includes negative energy density.

  7. A simple simulation approach to generate complex rainfall fields conditioned by elevation: example of the eastern Mediterranean region

    NASA Astrophysics Data System (ADS)

    Oriani, Fabio; Ohana-Levi, Noa; Straubhaar, Julien; Renard, Philippe; Karnieli, Arnon; Mariethoz, Grégoire; Morin, Efrat; Marra, Francesco

    2016-04-01

    Stochastically generating realistic rainfall fields is useful to study the uncertainty related to catchment recharge and its propagation to distributed hydrological models. To this end, it is critical to use weather radar images as training data, being the single most informative source for rainfall spatial heterogeneity. Generating realistic simulations is particularly important in regions like the eastern Mediterranean, where the synoptic conditions can lead to rainfall fields presenting various morphology, anisotropy and non-stationarity. The Direct Sampling (DS) technique [Mariethoz2010] is proposed here as a stochastic generator of spatial daily rainfall fields relying on the simulation of radar imagery. The technique is based on resampling of a training data set (in this case, a stack of radar images) and the generation of similar patterns to the ones found in the data. The strong point of DS, which makes it an attractive simulation approach for rainfall, is its capability to preserve the high-order statistical features present in the training image (e.g., rainfall cell shape, spatial non-stationarity) with minimal parameterization. Moreover, factors influencing rainfall, like elevation, can be used as conditioning variables, without the need of a complex statistical dependence model. A DS setup for radar image simulation is presented and tested for the simulation of daily rainfall fields using a 10-year radar-image record from the central region of Israel. Using a synoptic weather classification to train the model, the algorithm can generate realistic spatial fields for different rainfall types, preserving the variability and the covariance structure of the reference reasonably well. Moreover, the simulation is conditioned using the digital elevation model to preserve the complex relation between rainfall intensity and altitude that is characteristic for this region. [Mariethoz2010] G. Mariethoz, P. Renard, and J. Straubhaar. The direct sampling method to

  8. Heat Pump Water Heaters: Controlled Field Research of Impact on Space Conditioning and Demand Response Characteristics

    SciTech Connect

    Parker, Graham B.; Widder, Sarah H.; Eklund, Ken; Petersen, Joseph M.; Sullivan, Greg

    2015-10-05

    A new generation of heat pump water heaters (HPWH) has been introduced into the U.S. market that promises to provide significant energy savings for water heating. Many electric utilities are promoting their widespread adoption as a key technology for meeting energy conservation goals and reducing greenhouse gas emissions. There is, however, considerable uncertainty regarding the space conditioning impact of an HPWH installed in a conditioned space. There is also uncertainty regarding the potential for deployment of HPWHs in demand response (DR) programs to help manage and balance peak utility loads in a similar manner as conventional electric resistance water heaters (ERWH). To help answer these uncertainties, controlled experiments have been undertaken over 30 months in a matched pair of unoccupied Lab Homes located on the campus of the Pacific Northwest National Laboratory (PNNL) in Richland, Washington.

  9. Second-Order Far Field Computational Boundary Conditions for Inviscid Duct Flow Problems

    DTIC Science & Technology

    1990-03-01

    COMPUTATIONAL BOUNDARY CONDITIONS INTERNAL FLOW COMPUTATIONS EULER METHODS 19. ABSTRACT (Continue on reverse if necessary and identify by block number...SOLUTIONS OF THE LINEARIZED, SECOND-ORDER EULER EQUATIONS. THE EULER EQUATIONS ARE LINEARIZED ABOUT A CONSTANT PRESSURE, RECTILINEAR FLOW C)NDITION...THE BOUNDARY PROCEDURE CAN BE USED WITH ANY NUMERICAL EULER SOLUTION METHOD AND ALLOWS COMPUTATIONAL BOUNDARIES TO BE LOCATED EXTREMELY CLOSE TO THE

  10. Near-field acousto monitoring shear interactions inside a drop of fluid: The role of the zero-slip condition

    NASA Astrophysics Data System (ADS)

    Wang, Xiaohua; Fernandez, Rodolfo; Li, Nan; Hung, Hsien-Chih; Venkataraman, Anuradha; Nordstrom, Richard; La Rosa, Andres H.

    2016-05-01

    A full understanding of nanometer-range (near-field) interactions between two sliding solid boundaries, with a mesoscopic fluid layer sandwiched in between, remains challenging. In particular, the origin of the blue-shift resonance frequency experienced by a laterally oscillating probe when approaching a substrate is still a matter of controversy. A simpler problem is addressed here, where a laterally oscillating solid probe interacts with a more sizable drop of fluid that rests on a substrate, aiming at identifying interaction mechanisms that could also be present in the near-field interaction case. It is found that the inelastic component of the probe-fluid interaction does not constitute the main energy-dissipation channel and has a weak dependence on fluid's viscosity, which is attributed to the zero-slip hydrodynamic condition. In contrast, the acoustic signal engendered by the fluid has a stronger dependence on the fluid's viscosity (attributed also to the zero-slip hydrodynamic condition) and correlates well with the probe's resonance frequency red-shift. We propose a similar mechanism happens in near field experiments, but a blue-shift in the probe's resonance results as a consequence of the fluid molecules (subjected to the zero-slip condition at both the probe and substrate boundaries) exerting instead a spring type restoring force on the probe.

  11. Exploring correlation between redox potential and other edaphic factors in field and laboratory conditions in relation to methane efflux.

    PubMed

    Singh, S N

    2001-10-01

    Methane is primarily a biogenic gas, which is implicated in global warming. Although its production in the anoxic conditions is regulated by several edaphic factors, aquatic macrophytes also influence methane emission by providing aerenchyma to act as chimney for CH4 transport from the sediment to troposphere, by releasing root exudates to the sediment to serve as substrate for methanogenic bacteria and by transporting atmospheric O2 to rhizosphere, which stimulates CH4 consumption. Among the edaphic factors, redox potential (Eh) is the most important, which largely determines the action of methanogenic bacteria. Hence, a study was undertaken first to find out the correlation between CH4 emission and edaphic factors in the field conditions and then to understand the relationship between Eh and other edaphic factors. The field studies revealed that natural wetlands were the major source of CH4 emission, and the vegetation plays an important role in CH4 emission from the water bodies. However, it was very difficult to establish a strong relationship between the CH4 emission and the edaphic factors in the field conditions due to other limiting factors and their constant fluctuations. In this connection, the laboratory experiments exhibited that soil temperature, pH, moisture regime and incubation period were negatively correlated with Eh, which determines the initiation of methanogenic process. However, organic carbon and the water regime over the soil surface did not show any impact on Eh in this study.

  12. Data Mining and NIR Spectroscopy in Viticulture: Applications for Plant Phenotyping under Field Conditions

    PubMed Central

    Gutiérrez, Salvador; Tardaguila, Javier; Fernández-Novales, Juan; Diago, Maria P.

    2016-01-01

    Plant phenotyping is a very important topic in agriculture. In this context, data mining strategies may be applied to agricultural data retrieved with new non-invasive devices, with the aim of yielding useful, reliable and objective information. This work presents some applications of machine learning algorithms along with in-field acquired NIR spectral data for plant phenotyping in viticulture, specifically for grapevine variety discrimination and assessment of plant water status. Support vector machine (SVM), rotation forests and M5 trees models were built using NIR spectra acquired in the field directly on the adaxial side of grapevine leaves, with a non-invasive portable spectrophotometer working in the spectral range between 1600 and 2400 nm. The ν-SVM algorithm was used for the training of a model for varietal classification. The classifiers’ performance for the 10 varieties reached, for cross- and external validations, the 88.7% and 92.5% marks, respectively. For water stress assessment, the models developed using the absorbance spectra of six varieties yielded the same determination coefficient for both cross- and external validations (R2 = 0.84; RMSEs of 0.164 and 0.165 MPa, respectively). Furthermore, a variety-specific model trained only with samples of Tempranillo from two different vintages yielded R2 = 0.76 and RMSE of 0.16 MPa for cross-validation and R2 = 0.79, RMSE of 0.17 MPa for external validation. These results show the power of the combined use of data mining and non-invasive NIR sensing for in-field grapevine phenotyping and their usefulness for the wine industry and precision viticulture implementations. PMID:26891304

  13. Data Mining and NIR Spectroscopy in Viticulture: Applications for Plant Phenotyping under Field Conditions.

    PubMed

    Gutiérrez, Salvador; Tardaguila, Javier; Fernández-Novales, Juan; Diago, Maria P

    2016-02-16

    Plant phenotyping is a very important topic in agriculture. In this context, data mining strategies may be applied to agricultural data retrieved with new non-invasive devices, with the aim of yielding useful, reliable and objective information. This work presents some applications of machine learning algorithms along with in-field acquired NIR spectral data for plant phenotyping in viticulture, specifically for grapevine variety discrimination and assessment of plant water status. Support vector machine (SVM), rotation forests and M5 trees models were built using NIR spectra acquired in the field directly on the adaxial side of grapevine leaves, with a non-invasive portable spectrophotometer working in the spectral range between 1600 and 2400 nm. The ν-SVM algorithm was used for the training of a model for varietal classification. The classifiers' performance for the 10 varieties reached, for cross- and external validations, the 88.7% and 92.5% marks, respectively. For water stress assessment, the models developed using the absorbance spectra of six varieties yielded the same determination coefficient for both cross- and external validations (R² = 0.84; RMSEs of 0.164 and 0.165 MPa, respectively). Furthermore, a variety-specific model trained only with samples of Tempranillo from two different vintages yielded R² = 0.76 and RMSE of 0.16 MPa for cross-validation and R² = 0.79, RMSE of 0.17 MPa for external validation. These results show the power of the combined use of data mining and non-invasive NIR sensing for in-field grapevine phenotyping and their usefulness for the wine industry and precision viticulture implementations.

  14. Impact of integrated nutrient management on tomato yield under farmers field conditions.

    PubMed

    Pandey, S K; Chandra, K K

    2013-11-01

    Field trials were conducted in farmer's field of district Chandauli, Uttar Pradesh, India to assess the impact of integrated nutrient management (INM) on the performance of tomato crop during rabi (2008) and kharif (2009) season. Before conducting trials technological gap between actual and potential productivity were analyzed by interviewing growers to find out the major causes for low yield. Overall gap in use of fertilizers was recorded 64.90 % whereas overall mean gap in technology was 43.83%. On-farm experiments on INM were conducted by applying FYM (10t ha(-1)) + (NPK (150:80:60 kg ha(-1)) followed by dipping seedling roots in 1% Azotobacter solution for 15 min and foliar spray with 20 ppm ferrous ammonium sulphate after 30, 45 and 75 days of transplantation. The plant height, root length, number of primary branches, average fruit weight increased in INM plots as compared to farm practice. The increment in yield was found to be 28.84 and 33.86% during rabi and kharif season respectively. The maximum marketable yield obtained in INM plot during kharif and rabi seasons was 1025 q ha(-1) and 955 q ha(-1) respectively, whereas as farm practice yielded 740 q ha(-1) and 713 q ha(-1) during the same seasons. The percent loss from total production was recorded 8.5 % and 8.8 % in control plot and only 4.9 % and 5.7 % in INM plot during rabi and kharif seasons respectively. The higher fruit weight and lower incidence of disease and pest were observed in INM field in comparison to farm practice. The benefit cost ratio with INM treatment was recorded 4.25 and 4.23 in rabi and kharif season respectively against the benefit cost ratio of 2.98 and 2.82 in control plot during the same respective seasons.

  15. The effect of guide-field and boundary conditions on collisionless magnetic reconnection in a stressed X-point collapse

    SciTech Connect

    Graf von der Pahlen, J.; Tsiklauri, D.

    2014-01-15

    Works of Tsiklauri and Haruki [Phys. Plasmas 15, 102902 (2008); 14, 112905 (2007)] are extended by inclusion of the out-of-plane magnetic (guide) field. In particular, magnetic reconnection during collisionless, stressed X-point collapse for varying out-of-plane guide-fields is studied using a kinetic, 2.5D, fully electromagnetic, relativistic particle-in-cell numerical code. For zero guide-field, cases for both open and closed boundary conditions are investigated, where magnetic flux and particles are lost and conserved, respectively. It is found that reconnection rates, out-of-plane currents and density in the X-point increase more rapidly and peak sooner in the closed boundary case, but higher values are reached in the open boundary case. The normalized reconnection rate is fast: 0.10-0.25. In the open boundary case it is shown that an increase of guide-field yields later onsets in the reconnection peak rates, while in the closed boundary case initial peak rates occur sooner but are suppressed. The reconnection current changes similarly with increasing guide-field; however for low guide-fields the reconnection current increases, giving an optimal value for the guide-field between 0.1 and 0.2 times the in-plane field in both cases. Also, in the open boundary case, it is found that for guide-fields of the order of the in-plane magnetic field, the generation of electron vortices occurs. Possible causes of the vortex generation, based on the flow of decoupled particles in the diffusion region and localized plasma heating, are discussed. Before peak reconnection onset, oscillations in the out-of-plane electric field at the X-point are found, ranging in frequency from approximately 1 to 2 ω{sub pe} and coinciding with oscillatory reconnection. These oscillations are found to be part of a larger wave pattern in the simulation domain. Mapping the out-of-plane electric field along the central lines of the domain over time and applying a 2D Fourier transform reveal that

  16. Dispersal of Bacillus subtilis and its effect on strawberry phyllosphere microbiota under open field and protection conditions

    PubMed Central

    Wei, Feng; Hu, Xiaoping; Xu, Xiangming

    2016-01-01

    Using biological control agents (BCAs) is an essential component of integrated pest and diseases management. Despite much research on biocontrol of plant diseases, success in field crops has been limited with most successes being achieved in greenhouse cultivation. This lack of success is often attributed to the complex ecological processes involved in biocontrol. We used next generation sequencing (NGS) technology to study environmental fate of Bacillus subtilis, a widely used BCA, focusing on its dispersal aspect in open field and under protection. The dispersal of B. subtilis was very limited, particularly under protection. The reduction in the BCA population size was relatively small within 8 days; indeed, no overall reduction in the relative abundance was observed under the protected condition. These results suggested that limited dispersal is probably the main reason for its variable (and often low) control efficacy under field conditions. Thus to increase biocontrol efficacy, it is necessary to frequently apply this BCA with the application interval depending on the growth rate of target host tissues. Phyllosphere microbiota differed significantly between plants grown in open field and under protection but were not greatly affected by the introduced BCA. PMID:26936109

  17. Prenatal exposures to LTP-patterned magnetic fields: quantitative effects on specific limbic structures and acquisition of contextually conditioned fear.

    PubMed

    Whissell, P D; Tsang, E W; Mulligan, B P; Persinger, M A

    2009-01-01

    Weak (<1 microT) complex magnetic fields (CMFs) may exert their behavioral influences through the hippocampus by resonating by accident or design with intrinsic electrical patterns. Rats were exposed prenatally to one of four intensities of a CMF (either <5 nanoTesla [nT], 10-50 nT, 50-500 nT, or 500-1000 nT) designed to interact with the process of Long-Term Potentiation (LTP) in the hippocampus. Rats then underwent testing in the forced swim, open field, and fear-conditioning procedures. The cell densities of all amygdaloid nuclei, specific hypothalamic structures, and the major regions of the hippocampus were quantified. Results showed that acquisition of conditioned fear was strongly inhibited in animals exposed to LTP-CMFs. Rats exposed to intensities above 10 nT showed decreased cell density in the CA2 fields of the hippocampus; more neurons were present in the CA1 fields of rats exposed to the 10-50 nT intensities compared to all other groups. A decrease in cell density in the medial preoptic nucleus was linearly dependent on field intensity. In the forced-swim test, swimming was decreased in rats that had been exposed to low (10-50 nT) and medium intensity (50-500 nT) LTP-CMFs in a manner consistent with monoamine modulation. In the open field, exposed rats were indistinguishable from controls. These findings support the hypothesis that continuous exposure during prenatal development to CMFs designed to simulate intrinsic LTP within the hippocampus can affect adult behaviors specific to this structure and produce quantitative alterations in neuronal density.

  18. Towards Automated Large-Scale 3D Phenotyping of Vineyards under Field Conditions.

    PubMed

    Rose, Johann Christian; Kicherer, Anna; Wieland, Markus; Klingbeil, Lasse; Töpfer, Reinhard; Kuhlmann, Heiner

    2016-12-15

    In viticulture, phenotypic data are traditionally collected directly in the field via visual and manual means by an experienced person. This approach is time consuming, subjective and prone to human errors. In recent years, research therefore has focused strongly on developing automated and non-invasive sensor-based methods to increase data acquisition speed, enhance measurement accuracy and objectivity and to reduce labor costs. While many 2D methods based on image processing have been proposed for field phenotyping, only a few 3D solutions are found in the literature. A track-driven vehicle consisting of a camera system, a real-time-kinematic GPS system for positioning, as well as hardware for vehicle control, image storage and acquisition is used to visually capture a whole vine row canopy with georeferenced RGB images. In the first post-processing step, these images were used within a multi-view-stereo software to reconstruct a textured 3D point cloud of the whole grapevine row. A classification algorithm is then used in the second step to automatically classify the raw point cloud data into the semantic plant components, grape bunches and canopy. In the third step, phenotypic data for the semantic objects is gathered using the classification results obtaining the quantity of grape bunches, berries and the berry diameter.

  19. Physiological variables measured under field conditions according to age and state of training in French Trotters.

    PubMed

    Couroucé, A; Chrétien, M; Valette, J P

    2002-01-01

    We hypothesised that the derived physiological variables V2 and V4 (velocity to achieve a blood lactate concentration of 2 and 4 mmol/l, respectively), HR2 and HR4 (the corresponding heart rate) and V200 (the velocity for a heart rate of 200 beats/min) would improve with training state and age, in French Trotters. A total of 194 French Trotters from one training establishment were followed for 6 years and 1105 standardised field exercise tests performed on a sand training track. The horses were divided into 6 age groups (from 1 to > or = 6 years) and 4 training groups (beginning, endurance training, sprint training, racing). A 2-way analysis of variance was performed to evaluate the effects of age, training and the interaction of age and training on these physiological variables with the level of statistical significance set at 5%. The results showed that there was a significant influence of age on HR4, V2, V4 and V200, with these variables increasing with age. Also, there was a significant influence of training and both age and training on V2, V4 and V200, with these variables increasing with training and age. These results, obtained in a longitudinal study in a reproducible field environment, are consistent with previous laboratory-based experimental studies. We conclude that objective indices of fitness obtained on the training track can be useful in the commercial training environment.

  20. Towards Automated Large-Scale 3D Phenotyping of Vineyards under Field Conditions

    PubMed Central

    Rose, Johann Christian; Kicherer, Anna; Wieland, Markus; Klingbeil, Lasse; Töpfer, Reinhard; Kuhlmann, Heiner

    2016-01-01

    In viticulture, phenotypic data are traditionally collected directly in the field via visual and manual means by an experienced person. This approach is time consuming, subjective and prone to human errors. In recent years, research therefore has focused strongly on developing automated and non-invasive sensor-based methods to increase data acquisition speed, enhance measurement accuracy and objectivity and to reduce labor costs. While many 2D methods based on image processing have been proposed for field phenotyping, only a few 3D solutions are found in the literature. A track-driven vehicle consisting of a camera system, a real-time-kinematic GPS system for positioning, as well as hardware for vehicle control, image storage and acquisition is used to visually capture a whole vine row canopy with georeferenced RGB images. In the first post-processing step, these images were used within a multi-view-stereo software to reconstruct a textured 3D point cloud of the whole grapevine row. A classification algorithm is then used in the second step to automatically classify the raw point cloud data into the semantic plant components, grape bunches and canopy. In the third step, phenotypic data for the semantic objects is gathered using the classification results obtaining the quantity of grape bunches, berries and the berry diameter. PMID:27983669

  1. A quantitative health assessment index for rapid evaluation of fish condition in the field

    SciTech Connect

    Adams, S.M. ); Brown, A.M. ); Goede, R.W. )

    1993-01-01

    The health assessment index (HAI) is an extension and refinement of a previously published field necropsy system. The HAI is a quantitative index that allows statistical comparisons of fish health among data sets. Index variables are assigned numerical values based on the degree of severity or damage incurred by an organ or tissue from environmental stressors. This approach has been used to evaluate the general health status of fish populations in a wide range of reservoir types in the Tennessee River basin (North Carolina, Tennessee, Alabama, Kentucky), in Hartwell Reservoir (Georgia, South Carolina) that is contaminated by polychlorinated biphenyls, and in the Pigeon River (Tennessee, North Carolina) that receives effluents from a bleaches kraft mill. The ability of the HAI to accurately characterize the health of fish in these systems was evaluated by comparing this index to other types of fish health measures (contaminant, bioindicator, and reproductive analysis) made at the same time as the HAI. In all cases, the HAI demonstrated the same pattern of fish health status between sites as did each of the other more sophisticated health assessment methods. The HAI has proven to be a simple and inexpensive means of rapidly assessing general fish health in field situations. 29 refs., 5 tabs.

  2. Pressure-Water Content Relations for a Sandy, Granitic Soil Under Field and Laboratory Conditions

    NASA Astrophysics Data System (ADS)

    Chandler, D. G.; McNamara, J. M.; Gribb, M. M.

    2001-12-01

    A new sensor was developed to measure soil water potential in order to determine the predominant mechanisms of snowmelt delivery to streamflow. The sensors were calibrated for +50 to -300 cm for application on steep granitic slopes and deployed at three depths and 2 locations on a slope in a headwater catchment of the Idaho Batholith throughout the 2001 snowmelt season. Soil moisture was measured simultaneously with Water Content Reflectometers (Cambell Scientific, Logan, UT), that were calibrated in situ with Time Domain Reflectometry measurements. Sensor performance was evaluated in a laboratory soil column via side-by-side monitoring during injection of water with a cone permeameter. Soil characteristic curves were also determined for the field site by multi-step outflow tests. Comparison of the results from the field study to those from the laboratory experiment and to the characteristic curves demonstrate the utility of the new sensor for recording dynamic changes in soil water status. During snowmelt, the sensor responded to both matric potential and bypass-flow pore potential. Large shifts in the pressure record that correspond to changes in the infiltration flux indicate initiation and cessation of macropore flow. The pore pressure records may be used to document the frequency, timing and duration of bypass flow that are not apparent from the soil moisture records.

  3. Evidence against a mean field description of short-range spin glasses revealed through thermal boundary conditions

    NASA Astrophysics Data System (ADS)

    Machta, Jonathan; Wang, Wenlong; Katzgraber, Helmut

    2015-03-01

    A theoretical description of the low-temperature phase of short-range spin glasses has remained elusive for decades. It is not known if there is a single pair of pure states as predicted by the droplet model, or infinitely many pure states, as predicted by mean field theory. Here we study the three-dimensional Edwards-Anderson Ising spin glass in thermal boundary conditions using population annealing Monte Carlo. In thermal boundary conditions all eight combinations of periodic vs antiperiodic boundary conditions in the three spatial directions appear in the ensemble with their respective Boltzmann weights, thus minimizing finite-size corrections due to domain walls. From the relative weighting of the eight boundary conditions for each disorder instance a sample stiffness is defined, and its typical value is shown to grow with system size according to a stiffness exponent. An extrapolation to the large-system-size limit is consistent with a single pair of pure states in every volume but incompatible with the mean field, replica symmetry breaking picture. Supported in part by NSF DMR-1151387 and DMR-1208046.

  4. Evidence against a mean-field description of short-range spin glasses revealed through thermal boundary conditions

    NASA Astrophysics Data System (ADS)

    Wang, Wenlong; Machta, Jonathan; Katzgraber, Helmut G.

    2014-11-01

    A theoretical description of the low-temperature phase of short-range spin glasses has remained elusive for decades. In particular, it is unclear if theories that assert a single pair of pure states, or theories that are based on infinitely many pure states—such as replica symmetry breaking—best describe realistic short-range systems. To resolve this controversy, the three-dimensional Edwards-Anderson Ising spin glass in thermal boundary conditions is studied numerically using population annealing Monte Carlo. In thermal boundary conditions all eight combinations of periodic vs antiperiodic boundary conditions in the three spatial directions appear in the ensemble with their respective Boltzmann weights, thus minimizing finite-size corrections due to domain walls. From the relative weighting of the eight boundary conditions for each disorder instance a sample stiffness is defined, and its typical value is shown to grow with system size according to a stiffness exponent. An extrapolation to the large-system-size limit is in agreement with a description that supports the droplet picture and other theories that assert a single pair of pure states. The results are, however, incompatible with the mean-field replica symmetry breaking picture, thus highlighting the need to go beyond mean-field descriptions to accurately describe short-range spin-glass systems.

  5. An analysis of the pilot point methodology for automated calibration of an ensemble of conditionally simulated transmissivity fields

    USGS Publications Warehouse

    Cooley, R.L.

    2000-01-01

    An analysis of the pilot point method for automated calibration of an ensemble of conditionally simulated transmissivity fields was conducted on the basis of the simplifying assumption that the flow model is a linear function of log transmissivity. The analysis shows that the pilot point and conditional simulation method of model calibration and uncertainty analysis can produce accurate uncertainty measures if it can be assumed that errors of unknown origin in the differences between observed and model-computed water pressures are small. When this assumption is not met, the method could yield significant errors from overparameterization and the neglect of potential sources of model inaccuracy. The conditional simulation part of the method is also shown to be a variant of the percentile bootstrap method, so that when applied to a nonlinear model, the method is subject to bootstrap errors. These sources of error must be considered when using the method.

  6. Thermal comfort in the humid tropics: Field experiments in air conditioned and naturally ventilated buildings in Singapore

    NASA Astrophysics Data System (ADS)

    de Dear, R. J.; Leow, K. G.; Foo, S. C.

    1991-12-01

    Thermal comfort field experiments were conducted in Singapore in both naturally ventilated highrise residential buildings and air conditioned office buildings. Each of the 818 questionnaire responses was made simultaneously with a detailed set of indoor climatic measurements, and estimates of clothing insulation and metabolic rate. Results for the air conditioned sample indicated that office buildings were overcooled, causing up to one-third of their occupants to experience cool thermal comfort sensations. These observations in air conditioned buildings were broadly consistent with the ISO, ASHRAE and Singapore indoor climatic standards. Indoor climates of the naturally ventilated apartments during the day and early evening were on average three degrees warmer than the ISO comfort standard prescriptions, but caused much less thermal discomfort than expected. Discrepancies between thermal comfort responses in apartment blocks and office buildings are discussed in terms of contemporary perceptual theory.

  7. Seedling Emergence and Phenotypic Response of Common Bean Germplasm to Different Temperatures under Controlled Conditions and in Open Field

    PubMed Central

    De Ron, Antonio M.; Rodiño, Ana P.; Santalla, Marta; González, Ana M.; Lema, María J.; Martín, Isaura; Kigel, Jaime

    2016-01-01

    Rapid and uniform seed germination and seedling emergence under diverse environmental conditions is a desirable characteristic for crops. Common bean genotypes (Phaseolus vulgaris L.) differ in their low temperature tolerance regarding growth and yield. Cultivars tolerant to low temperature during the germination and emergence stages and carriers of the grain quality standards demanded by consumers are needed for the success of the bean crop. The objectives of this study were (i) to screen the seedling emergence and the phenotypic response of bean germplasm under a range of temperatures in controlled chamber and field conditions to display stress-tolerant genotypes with good agronomic performances and yield potential, and (ii) to compare the emergence of bean seedlings under controlled environment and in open field conditions to assess the efficiency of genebanks standard germination tests for predicting the performance of the seeds in the field. Three trials were conducted with 28 dry bean genotypes in open field and in growth chamber under low, moderate, and warm temperature. Morpho-agronomic data were used to evaluate the phenotypic performance of the different genotypes. Cool temperatures resulted in a reduction of the rate of emergence in the bean genotypes, however, emergence and early growth of bean could be under different genetic control and these processes need further research to be suitably modeled. Nine groups arose from the Principal Component Analysis (PCA) representing variation in emergence time and proportion of emergence in the controlled chamber and in the open field indicating a trend to lower emergence in large and extra-large seeded genotypes. Screening of seedling emergence and phenotypic response of the bean germplasm under a range of temperatures in controlled growth chambers and under field conditions showed several genotypes, as landraces 272, 501, 593, and the cultivar Borlotto, with stress-tolerance at emergence, and high yield

  8. Seedling Emergence and Phenotypic Response of Common Bean Germplasm to Different Temperatures under Controlled Conditions and in Open Field.

    PubMed

    De Ron, Antonio M; Rodiño, Ana P; Santalla, Marta; González, Ana M; Lema, María J; Martín, Isaura; Kigel, Jaime

    2016-01-01

    Rapid and uniform seed germination and seedling emergence under diverse environmental conditions is a desirable characteristic for crops. Common bean genotypes (Phaseolus vulgaris L.) differ in their low temperature tolerance regarding growth and yield. Cultivars tolerant to low temperature during the germination and emergence stages and carriers of the grain quality standards demanded by consumers are needed for the success of the bean crop. The objectives of this study were (i) to screen the seedling emergence and the phenotypic response of bean germplasm under a range of temperatures in controlled chamber and field conditions to display stress-tolerant genotypes with good agronomic performances and yield potential, and (ii) to compare the emergence of bean seedlings under controlled environment and in open field conditions to assess the efficiency of genebanks standard germination tests for predicting the performance of the seeds in the field. Three trials were conducted with 28 dry bean genotypes in open field and in growth chamber under low, moderate, and warm temperature. Morpho-agronomic data were used to evaluate the phenotypic performance of the different genotypes. Cool temperatures resulted in a reduction of the rate of emergence in the bean genotypes, however, emergence and early growth of bean could be under different genetic control and these processes need further research to be suitably modeled. Nine groups arose from the Principal Component Analysis (PCA) representing variation in emergence time and proportion of emergence in the controlled chamber and in the open field indicating a trend to lower emergence in large and extra-large seeded genotypes. Screening of seedling emergence and phenotypic response of the bean germplasm under a range of temperatures in controlled growth chambers and under field conditions showed several genotypes, as landraces 272, 501, 593, and the cultivar Borlotto, with stress-tolerance at emergence, and high yield

  9. Evaluating DEM conditioning techniques, elevation source data, and grid resolution for field-scale hydrological parameter extraction

    NASA Astrophysics Data System (ADS)

    Woodrow, Kathryn; Lindsay, John B.; Berg, Aaron A.

    2016-09-01

    Although digital elevation models (DEMs) prove useful for a number of hydrological applications, they are often the end result of numerous processing steps that each contains uncertainty. These uncertainties have the potential to greatly influence DEM quality and to further propagate to DEM-derived attributes including derived surface and near-surface drainage patterns. This research examines the impacts of DEM grid resolution, elevation source data, and conditioning techniques on the spatial and statistical distribution of field-scale hydrological attributes for a 12,000 ha watershed of an agricultural area within southwestern Ontario, Canada. Three conditioning techniques, including depression filling (DF), depression breaching (DB), and stream burning (SB), were examined. The catchments draining to each boundary of 7933 agricultural fields were delineated using the surface drainage patterns modeled from LiDAR data, interpolated to a 1 m, 5 m, and 10 m resolution DEMs, and from a 10 m resolution photogrammetric DEM. The results showed that variation in DEM grid resolution resulted in significant differences in the spatial and statistical distributions of contributing areas and the distributions of downslope flowpath length. Degrading the grid resolution of the LiDAR data from 1 m to 10 m resulted in a disagreement in mapped contributing areas of between 29.4% and 37.3% of the study area, depending on the DEM conditioning technique. The disagreements among the field-scale contributing areas mapped from the 10 m LiDAR DEM and photogrammetric DEM were large, with nearly half of the study area draining to alternate field boundaries. Differences in derived contributing areas and flowpaths among various conditioning techniques increased substantially at finer grid resolutions, with the largest disagreement among mapped contributing areas occurring between the 1 m resolution DB DEM and the SB DEM (37% disagreement) and the DB-DF comparison (36.5% disagreement in mapped

  10. Impact of radial magnetic field on peristalsis in curved channel with convective boundary conditions

    NASA Astrophysics Data System (ADS)

    Hayat, Tasawar; Tanveer, Anum; Alsaadi, Fuad; Mousa, Ghassan

    2016-04-01

    This paper addresses the peristaltic flow in curved channel with combined heat/mass transfer and convective effects. The channel walls are flexible. An imposed magnetic field is applied in radial direction to increase the wave amplitude (used in ECG for synchronization purposes). The pseudoplastic fluid comprising shear-thinning/shear thickening effects has been used in mathematical modeling. Small Reynolds number assumption is employed to neglect inertial effects. Half channel-width to wavelength ratio is small enough for the pressure to be considered uniform over the cross-section. The graphical results obtained are compared with planar channel. Results show the non-symmetric behavior of sundry parameters in contrary to the planar case. Additionally more clear results are seen when the curved channel is approached.

  11. Terahertz responsivity of field-effect transistors under arbitrary biasing conditions

    NASA Astrophysics Data System (ADS)

    Földesy, Péter

    2013-09-01

    Current biased photoresponse model of long channel field-effect transistor (FET) detectors is introduced to describe the low frequency behavior in complex circuit environment. The model is applicable in all FET working regions, including subthreshold, linear, saturated modes, includes bulk potential variations, and handles the simultaneous gate-source and drain-source detection or source-driven topologies. The model is based on the phenomenological representation that links the photoresponse to the gate transconductance over drain current ratio (gm/ID) and circuit theory. A derived method is provided to analyze the detector behavior, to characterize existing antenna coupled detectors, and to predict the photoresponse in a complex circuit. The model is validated by measurements of 180 nm gate length silicon and GaAs high electron mobility FETs.

  12. In vivo chlorophyll fluorescence study of hazardous waste site vegetation under field and controlled conditions

    SciTech Connect

    Mayasich, S.A.; Zygmont, N.J. CDM Federal Programs Corp., South Plainfield, NJ )

    1993-06-01

    Cattail (Typha sp.) and Arrow Arum (Peltandra virginica) were studied to determine the effects of cadmium and nickel contamination in a freshwater tidal marsh. An in vivo chlorophyll fluorescence instrument was used in the field to estimate photosynthetic capacity. No definitive effects on photosynthesis were observed. A laboratory study was then designed to determine whether fluorescence could detect sublethal impacts of cadmium and whether tolerant plants had developed in the contaminated area. Arrow Arum seeds collected from a reference wetland and from the contaminated wetland were grown in horticultural vermiculite with cadmium concentrations of 0, 1, 2, 5 and 10 mg/L. Results indicate that, regardless of seed origin, fluorescence can detect an effect at cadmium levels at which there are no visual signs of stress. However, the plants from the contaminated wetland exhibited reduced growth, and deformities in several individuals.

  13. Nonperturbative measurement of the local magnetic field using pulsed polarimetry for fusion reactor conditions (invited).

    PubMed

    Smith, Roger J

    2008-10-01

    A novel diagnostic technique for the remote and nonperturbative sensing of the local magnetic field in reactor relevant plasmas is presented. Pulsed polarimetry [Patent No. 12/150,169 (pending)] combines optical scattering with the Faraday effect. The polarimetric light detection and ranging (LIDAR)-like diagnostic has the potential to be a local B(pol) diagnostic on ITER and can achieve spatial resolutions of millimeters on high energy density (HED) plasmas using existing lasers. The pulsed polarimetry method is based on nonlocal measurements and subtle effects are introduced that are not present in either cw polarimetry or Thomson scattering LIDAR. Important features include the capability of simultaneously measuring local T(e), n(e), and B(parallel) along the line of sight, a resiliency to refractive effects, a short measurement duration providing near instantaneous data in time, and location for real-time feedback and control of magnetohydrodynamic (MHD) instabilities and the realization of a widely applicable internal magnetic field diagnostic for the magnetic fusion energy program. The technique improves for higher n(e)B(parallel) product and higher n(e) and is well suited for diagnosing the transient plasmas in the HED program. Larger devices such as ITER and DEMO are also better suited to the technique, allowing longer pulse lengths and thereby relaxing key technology constraints making pulsed polarimetry a valuable asset for next step devices. The pulsed polarimetry technique is clarified by way of illustration on the ITER tokamak and plasmas within the magnetized target fusion program within present technological means.

  14. Effects of different biochars and digestate on N2O fluxes under field conditions.

    PubMed

    Dicke, Christiane; Andert, Janet; Ammon, Christian; Kern, Jürgen; Meyer-Aurich, Andreas; Kaupenjohann, Martin

    2015-08-15

    Field studies that have investigated the effects of char materials on the emission of nitrous oxide (N2O) are still scarce. Therefore, we conducted a field trial with bio- and hydrochars and measured N2O emissions for one whole year. It was hypothesised that the incorporation of chars reduces the emissions of N2O. Chars were produced by pyrolysis and hydrothermal carbonisation (HTC) using either maize silage or wood residues as feedstock. In addition, after production chars were post-treated with digestate in order to accelerate the ageing process of the chars. Chars and digestate were applied to the soil to raise the C content. Emissions of N2O were measured weekly and soil samples for inorganic nitrogen (N) and soil water-content were taken once a month. Additionally, the abundance of functional marker genes from denitrification (nosZ) was determined in October 2012 and in June 2013. The treatment with pure digestate emitted the most N2O compared to the control and char treatments. However, this was significant only in one case. There were no great differences between the char treatments due to high spatial variability and gene abundance of nosZ did not differ between treatments. Overall, emissions of N2O were relatively low. This was attributed to the heterogeneous distribution of the chars and the sandy soils that did not favour the production of N2O. To conclude, the emissions of N2O were mainly influenced by temperature and precipitation and to a minor extent by the type of char and post-treatment.

  15. Influence of elevated ozone concentration on methanotrophic bacterial communities in soil under field condition

    NASA Astrophysics Data System (ADS)

    Huang, Y. Z.; Zhong, M.

    2015-05-01

    The open top chamber (OTC) method was used in combination with real-time quantitative PCR and terminal restriction fragment length polymorphism (T-RFLP) techniques in the wheat field to study the influence of different levels of O3 concentrations (ambient air filtered by activated carbons, 40 ppb, 80 ppb and 120 ppb) on the quantity and community structure of methanotrophic bacteria. O3 stress can influence the potential methane oxidation rate (PMOR) and potential methane production rate (PMPR) in the farmland soil. O3 treatment of 40 ppb improved significantly the 16S rRNA gene copy number in the total methanotrophic bacteria pmoA, and type I and type II methanotrophic bacteria in the soil depth of 0-20 cm. When the O3 concentration reached 120 ppb, the 16S rRNA gene copy number in the total methanotrophic bacteria pmoA and type I methanotrophic bacteria decreased significantly as compared to the control treatment in 10-20 cm layer. The 16s rRNA gene copy number of total methanotrophic bacteria pmoA and type I and type II methanotrophic bacteria were influenced by different O3 concentration and soil depth. The T-RFLP analysis indicated that O3 stress influenced significantly the community structure of the methanotrophic bacteria in soil, causing potential threat to the diversity of methanotrophic bacteria. It seems to imply that the rise of O3 concentration could produce an impact on the carbon cycling and the methane emission of the wheat field soil by changing the community structure and diversity of methanotrophic bacteria, which then influences the global climate change.

  16. Intra-plant Variation in Nectar Sugar Composition in Two Aquilegia Species (Ranunculaceae): Contrasting Patterns under Field and Glasshouse Conditions

    PubMed Central

    Canto, Azucena; Pérez, Ricardo; Medrano, Mónica; Castellanos, María Clara; Herrera, Carlos M.

    2007-01-01

    Background and Aims Intra-specific variation in nectar chemistry under natural conditions has been only rarely explored, yet it is an essential aspect of our understanding of how pollinator-mediated selection might act on nectar traits. This paper examines intra-specific variation in nectar sugar composition in field and glasshouse plants of the bumblebee-pollinated perennial herbs Aquilegia vulgaris subsp. vulgaris and Aquilegia pyrenaica subsp. cazorlensis (Ranunculaceae). The aims of the study are to assess the generality of extreme intra-plant variation in nectar sugar composition recently reported for other species in the field, and gaining insight on the possible mechanisms involved. Methods The proportions of glucose, fructose and sucrose in single-nectary nectar samples collected from field and glasshouse plants were determined using high performance liquid chromatography. A hierarchical variance partition was used to dissect total variance into components due to variation among plants, flowers within plants, and nectaries within flowers. Key Results Nectar of the two species was mostly sucrose-dominated, but composition varied widely in the field, ranging from sucrose-only to fructose-dominated. Most intra-specific variance was due to differences among nectaries of the same flower, and flowers of the same plant. The high intra-plant variation in sugar composition exhibited by field plants vanished in the glasshouse, where nectar composition emerged as a remarkably constant feature across plants, flowers and nectaries. Conclusions In addition to corroborating the results of previous studies documenting extreme intra-plant variation in nectar sugar composition in the field, this study suggests that such variation may ultimately be caused by biotic factors operating on the nectar in the field but not in the glasshouse. Pollinator visitation and pollinator-borne yeasts are suggested as likely causal agents. PMID:17259227

  17. Dissipation pattern of flubendiamide residues on capsicum fruit (Capsicum annuum L.) under field and controlled environmental conditions.

    PubMed

    Buddidathi, Radhika; Mohapatra, Soudamini; Siddamallaiah, Lekha; Manikrao, Gourishankar; Hebbar, Shibara Shankara

    2016-01-01

    This investigation was undertaken to compare the dissipation pattern of flubendiamide in capsicum fruits under poly-house and open field after giving spray applications at the recommended and double doses of 48 g a.i. ha(-1) and 96 g a.i. ha(-1). Extraction and purification of capsicum fruit samples were carried out by the QuEChERS method. Residues of flubendiamide and its metabolite, des-iodo flubendiamide, were analyzed by high-performance liquid chromatography-photodiode array, and confirmed by liquid chromatography-mass spectrometry/mass spectrometry. Limit of quantification of the method was 0.05 mg kg(-1), and recovery of the insecticides was in the range of 89.6-104.3%, with relative standard deviation being 4.5-11.5%. The measurement uncertainty of the analytical method was in the range of 10.7-15.7%. Initial residue deposits of flubendiamide on capsicum fruits grown under poly-house conditions were (0.977 and 1.834 mg kg(-1)) higher than that grown in the field (0.665 and 1.545 mg kg(-1)). Flubendiamide residues persisted for 15 days in field-grown and for 25 days in poly-house-grown capsicum fruits. The residues were degraded with the half-lives of 4.3-4.7 and 5.6-6.6 days in field and poly-house respectively. Des-iodo flubendiamide was not detected in capsicum fruits or soil. The residues of flubendiamide degraded to below the maximum residue limit notified by Codex Alimentarius Commission (FAO/WHO) after 1 and 6 days in open field, and 3 and 10 days in poly-house. The results of the study indicated that flubendiamide applied to capsicum under controlled environmental conditions required longer pre-harvest interval to allow its residues to dissipate to the safe level.

  18. Vasotocin/V2-type receptor/aquaporin axis exists in African lungfish kidney but is functional only in terrestrial condition.

    PubMed

    Konno, Norifumi; Hyodo, Susumu; Yamaguchi, Yoko; Matsuda, Kouhei; Uchiyama, Minoru

    2010-03-01

    The vasopressin/vasotocin (VT)-V2-type receptor (V2R)-aquaporin (AQP)-2 axis plays a pivotal role in renal water reabsorption in tetrapods. It is widely thought that this axis evolved with the emergence of the tetrapods, reflecting a requirement of water retention in terrestrial environment. Here we report that lungfish, the closest living relatives of tetrapods, already possess a system similar to the VT-V2R-AQP2 axis in the kidney, but the system is functional only in the terrestrial estivating condition. We cloned a novel AQP paralogous to AQP0. The water permeability of Xenopus oocytes was increased by injection with the AQP cRNA and was further facilitated by preincubation with cAMP. In the kidney of estivating lungfish, the AQP protein was localized on the apical plasma membrane of the late distal tubule and was colocalized with basolateral V2R. By contrast, we found only little expression of the AQP mRNA and protein in the kidney of lungfish in aquatic condition. The expression levels of mRNA and protein were dramatically increased during estivation and decreased again by reacclimation of estivating lungfish to water. The AQP mRNA levels positively correlated with the VT mRNA levels in the hypothalamus, suggesting that the AQP exerts tubular antidiuretic action under control of VT. Because the tetrapod AQP2/AQP5 lineage is considered to be evolved from duplication of an AQP0 gene, the paralogous AQP0 in the lungfish probably represents ancestral molecule for tetrapod AQP2.

  19. Demonstration and Validation of a Passive Flux Meter under Controlled Field Conditions

    NASA Astrophysics Data System (ADS)

    Sun, Q.; Hatfield, K.; Annable, M.; Cho, J.; Parker, B.; Cherry, J.

    2003-12-01

    Subsurface contaminant mass flows and fluxes are increasingly being viewed as critical information needed to address issues pertinent to aquifer and groundwater remediation. Theses issues include; source prioritization, risk prediction, compliance monitoring, remediation endpoint evaluation, and contaminant attenuation assessment. Field experiments were conducted to demonstrate and validate a passive flux meter (PFM), which is a down-hole monitoring technology that provides for simultaneous, direct, in situ, point measurements of cumulative or time-averaged contaminant mass flux and water flux. The experiments were conducted in a subsurface flume located at the Base Borden Test facility in Ontario, Canada. The sheet-pile enclosed flume was 15-m long and 2 m wide. Steady flow was established using four pumping wells located in the closed end of the flume. Flow rates and contaminant concentrations measured at the producing wells provided estimates of average groundwater and contaminant fluxes within the flume. Flux estimates were compared to direct measurements obtained from 6 flux meters and to calculated fluxes generated from multilevel samplers. Fuzzy analysis was used to characterize the uncertainty in MTBE mass flow and flux estimates generated from spatially integrating PFM measurements.

  20. Inbreeding depression in Solanum carolinense (Solanaceae) under field conditions and implications for mating system evolution.

    PubMed

    Kariyat, Rupesh R; Scanlon, Sarah R; Mescher, Mark C; De Moraes, Consuelo M; Stephenson, Andrew G

    2011-01-01

    The clonal weed Solanum carolinense exhibits plasticity in the strength of its self-incompatibility (SI) system and suffers low levels of inbreeding depression (δ) in the greenhouse. We planted one inbred and one outbred plant from each of eight maternal plants in a ring (replicated twice) and monitored clonal growth, herbivory, and reproduction over two years. Per ramet δ was estimated to be 0.63 in year one and 0.79 in year two, and outbred plants produced 2.5 times more ramets than inbred plants in the spring of year two. Inbred plants also suffered more herbivore damage than outbred plants in both fields, suggesting that inbreeding compromises herbivore resistance. Total per genet δ was 0.85 over the two years, indicating that S. carolinense is unlikely to become completely self-compatible, and suggesting that plasticity in the SI system is part of a stable mixed-mating system permitting self-fertilization when cross pollen limits seed production.

  1. Resistance of wild Solanum accessions to aphids and other potato pests in Quebec field conditions.

    PubMed

    Fréchette, B; Bejan, M; Lucas, E; Giordanengo, P; Vincent, C

    2010-01-01

    Two experiments were done to determine the susceptibility of six wild potato accessions to the aphids Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae) and Myzus persicae (Sulzer). Densities of aphid colonies were compared between caged Solanum pinnatisectum Dunal (Solanales: Solanaceae), S. polyadenium Greenmam, S. tarijense Hawkes, S. infundibuliforme Philippi, S. oplocense Hawkes, and S. stoloniferum Schlechted and Bouché, and the commercially cultivated potato plant S. tuberosum L. cv. Désirée. Moreover the susceptibility of S. polyadenium and S. tarijense to the Colorado potato beetle Leptinotarsa decemlineata (Say) (Coleoptera: Chrlysomelidae), the potato flea beetle Epitrix cucumeris (Harris), and the potato leafhopper Empoasca fabae (Harris) (Hemiptera: Cicadellidae) was compared to that of S. tuberosum cv. Désirée in the field. Results indicated that S. polyadenium and S. tarijense were more resistant to M. persicae than S. pinnatisectum and the commercially cultivated S. tuberosum cv. Désirée. Solanum polyadenium was more resistant to aphids than S. tarijense in 2004, but not in 2005. Moreover, S. polyadenium and S. tarijense were more resistant than S. tuberosum cv. Désirée to L. decemlineata, E. cucumeris and E. fabae.

  2. Resistance of Wild Solanum Accessions to Aphids and Other Potato Pests in Quebec Field Conditions

    PubMed Central

    Fréchette, B.; Bejan, M.; Lucas, É.; Giordanengo, P.; Vincent, C.

    2010-01-01

    Two experiments were done to determine the susceptibility of six wild potato accessions to the aphids Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae) and Myzus persicae (Sulzer). Densities of aphid colonies were compared between caged Solanum pinnatisectum Dunal (Solanales: Solanaceae), S. polyadenium Greenmam, S. tarijense Hawkes, S. infundibuliforme Philippi, S. oplocense Hawkes, and S. stoloniferum Schlechted and Bouché, and the commercially cultivated potato plant S. tuberosum L. cv. Désirée. Moreover the susceptibility of S. polyadenium and S. tarijense to the Colorado potato beetle Leptinotarsa decemlineata (Say) (Coleoptera: Chrlysomelidae), the potato flea beetle Epitrix cucumeris (Harris), and the potato leafhopper Empoasca fabae (Harris) (Hemiptera: Cicadellidae) was compared to that of S. tuberosum cv. Désirée in the field. Results indicated that S. polyadenium and S. tarijense were more resistant to M. persicae than S. pinnatisectum and the commercially cultivated S. tuberosum cv. Désirée. Solanum polyadenium was more resistant to aphids than S. tarijense in 2004, but not in 2005. Moreover, S. polyadenium and S. tarijense were more resistant than S. tuberosum cv. Désirée to L. decemlineata, E. cucumeris and E. fabae. PMID:21054161

  3. Response of different crop growth and yield to enhanced UV-B radiation under field conditions

    NASA Astrophysics Data System (ADS)

    Zheng, Youfei; Gao, Wei; Slusser, James R.; Grant, Richard H.; Wang, Chuanhai

    2004-10-01

    Enhanced UV-B radiation due to stratospheric ozone depletion may have impacts on the productivity of agricultural crops. Which crop will be more sensitive to increased UV-B has received little attention. This paper presents a comparative study of the effects of supplemental UV-B on plant height, leaf area, biomass and yield among soybean, cotton, corn and wheat which were cultivated in fields in Nanjing, China. The experimental results showed that the four crops response to enhanced UV-B irradiation was shortened plant height, decreased leaf area and reduced biomass and yield of crops. Using the same criteria, the response of soybean and cotton to elevated UV-B is bigger than that of wheat and corn. RI (response index) is an integrated index which is the accumulation of relative change in plant height, leaf area, biomass and yield, reflecting general impact of increased UV-B on crops. The results suggested that the RI for the four crops was minus, demonstrating a negative impact of enhanced UV-B on the crops. According to the RI, the soybean and cotton belong to the sensitive plants category, wheat is a moderately sensitive plant and corn is a tolerant plant.

  4. Physiological response of rice (Oryza sativa L.) genotypes to elevated nitrogen applied under field conditions.

    PubMed

    Singh, Hukum; Verma, Amit; Ansari, Mohammad Wahid; Shukla, Alok

    2014-01-01

    Field experiment was conducted at G.B.P.U.A.T. Pantnagar, Uttarakhand, India in rainy season of 2008 and 2009 to study the impacts of increased nitrogen doses on growth dynamics, biomass partitioning, chaffy grain and nitrogen use efficiency in 4 rice genotypes viz., Vasumati, Tulsi, Kasturi and Krishna Hamsa. Four doses (N(0), N(50), N(100) and N(200) kg N ha(-1)) of nitrogen in the form of urea were applied in 3 split. Increased trend in growth dynamics during active tillering and flowering stage, and biomass partitioning at the time of active tillering and flowering stage was observed with respect to nitrogen doses. Chaffy grain number and chaffy grain weight per 5 panicles was significantly increased with enhancing nitrogen doses and was highest for Vasumati. Nitrogen use efficiency (NUE) was increased up to N(100) kg N ha(-1) and it was declined with rising nitrogen doses (N(200) kg N ha(-1)). The highest values for NUE was achieved by rice genotype Krishna Hamsa whereas lowest by Vasumati. In addition to this, a significant correlation between nitrogen doses and growth dynamics, biomass partitioning and chaffy grain was observed. These findings suggest that growth dynamics, biomass partitioning, chaffy grain could be enhanced by the input of high rate of nitrogen fertilizer but not nitrogen use efficiency. Therefore, this study is useful to screen most N efficient genotypes which can be strongly suggested to rice growers to enhance crop yield irrespective of use of high dose of N fertilizers.

  5. Photochemical processing of aldrin and dieldrin in frozen aqueous solutions under arctic field conditions.

    PubMed

    Rowland, Glenn A; Bausch, Alexandra R; Grannas, Amanda M

    2011-05-01

    Organochlorine (OC) contaminants are transported to the Polar Regions, where they have the potential to bioaccumulate, presenting a threat to the health of wildlife and indigenous communities. They deposit onto snowpack during winter, and accumulate until spring, when they experience prolonged solar irradiation until snowmelt occurs. Photochemical degradation rates for aldrin and dieldrin, in frozen aqueous solution made from MilliQ water, 500 μM hydrogen peroxide solution or locally-collected melted snow were measured in a field campaign near Barrow, AK, during spring-summer 2008. Significant photoprocessing of both pesticides occurs; the reactions depend on temperature, depth within the snowpack and whether the predominant phase is ice or liquid water. The effect of species present in natural snowpack is comparable to 500 μM hydrogen peroxide, pointing to the potential significance of snowpack-mediated reactions. Aldrin samples frozen at near 0 °C were more reactive than comparable liquid samples, implying that the microenvironments experienced on frozen ice surfaces are an important consideration.

  6. Phytoextraction of heavy metals by willows growing in biosolids under field conditions.

    PubMed

    Laidlaw, W S; Arndt, S K; Huynh, T T; Gregory, D; Baker, A J M

    2012-01-01

    Biosolids produced by sewage treatment facilities can exceed guideline thresholds for contaminant elements. Phytoextraction is one technique with the potential to reduce these elements allowing reuse of the biosolids as a soil amendment. In this field trial, cuttings of seven species/cultivars of Salix(willows) were planted directly into soil and into biosolids to identify their suitability for decontaminating biosolids. Trees were irrigated and harvested each year for three consecutive years. Harvested biomass was weighed and analyzed for the contaminant elements: As, Cd, Cu, Cr, Hg, Pb, Ni, and Zn. All Salix cultivars, except S. chilensis, growing in soils produced 10 to 20 t ha(-1) of biomass, whereas most Salix cultivars growing in biosolids produced significantly less biomass (<6 t ha(-1)). Salix matsudana (30 t ha(-1)) and S. × reichardtii A. Kerner (18 t ha(-1)) had similar aboveground biomass production in both soil and biosolids. These were also the most successful cultivars in extracting metals from biosolids, driven by superior biomass increases and not high tissue concentrations. The willows were effectual in extracting the most soluble/exchangeable metals (Cd, 0.18; Ni, 0.40; and Zn, 11.66 kg ha(-1)), whereas Cr and Cu were extracted to a lesser degree (0.02 and 0.11 kg ha(-1)). Low bioavailable elements, As, Hg, and Pb, were not detectable in any of the aboveground biomass of the willows.

  7. Horizontal transmission of Beauveria bassiana in Anastrepha ludens (Diptera: Tephritidae) under laboratory and field cage conditions.

    PubMed

    Toledo, Jorge; Campos, Sergio E; Flores, Salvador; Liedo, Pablo; Barrera, Juan F; Villaseñior, Antonio; Montoya, Pablo

    2007-04-01

    The virulence of two products of the fungus Beauveria bassiana (LCPP and Bassianil) on adult Anastrepha ludens (Loew) (Diptera: Tephritidae) and their effect on the mating performance of infected males was evaluated in laboratory and field cage tests. The horizontal transmission capacity of the fungus during copulation or attempted copulation also was quantified using inoculated males as well as the impact of infection on female fecundity and longevity. Both fungal products were found to be highly virulent (LCPP, mortality = 98.7% at 1 x 10(8) conidia per ml, LT50 = 4.20 d, LC50 = 9.35 x 10(5) conidia per ml; Bassianil, mortality = 99.3% at 1 X 10(8) conidia per ml, LT50 = 4.04 d, LC50 = 2.69 x 10(7) conidia per ml). Mating success of inoculated males was not affected compared with the control group during the 3 d postinoculation. Horizontal transmission to females during the first day was 80.6 and 84.3% through mating and 15.4 and 21.6% through attempts to mate and contact during courtship for the LCPP and Bassianil products, respectively. The fertility of infected females was notably reduced, and longevity did not extend beyond 15 d. Our results suggest the possibility of using sterile flies as fungus vectors in sterile insect technique programs, but the potential benefits and shortcomings of this approach require further investigation.

  8. Spatial averaging of unsaturated flow equations under infiltration conditions over areally heterogeneous fields 2. Numerical simulations

    NASA Astrophysics Data System (ADS)

    Chen, Zhiqiang; Govindaraju, Rao S.; Kavvas, M. Levent

    1994-02-01

    Two models for horizontally averaged unsaturated flow have been developed from two different approaches in the first (Chen et al., this issue) of these companion papers. In this paper the results from both the spatially horizontally averaged Richards equation (SHARE) model and the averaged Green-Ampt model are compared with the results from a three-dimensional finite difference model of unsaturated flow which is perceived as the reference solution. The results of the averaged Green-Ampt model show very good agreement with the averaged results from the three-dimensional model, while SHARE model results are applicable only when fluctuations in soil parameters are small with respect to their mean values. It is also shown that methods of simple parameter averaging (arithmetic or geometric averages) with the local Richards equation does not yield meaningful results in heterogeneous soils. This study suggests that spatially horizontally averaged simplified models (such as the averaged Green-Ampt model) are attractive alternatives to perturbation models (such as the SHARE model) in heterogeneous fields. Due to their simplicity in formulation, accuracy in predicting average behaviors, and minimal requirement of computer effort, the spatially horizontally averaged simplified models can be easily implemented in large-scale models, such as atmospheric mesoscale models.

  9. The Neonicotinoid Insecticide Thiacloprid Impacts upon Bumblebee Colony Development under Field Conditions.

    PubMed

    Ellis, Ciaran; Park, Kirsty J; Whitehorn, Penelope; David, Arthur; Goulson, Dave

    2017-02-07

    The impacts of pesticides, and in particular of neonicotinoids, on bee health remain much debated. Many studies describing negative effects have been criticized as the experimental protocol did not perfectly simulate real-life field scenarios. Here, we placed free-flying bumblebee colonies next to raspberry crops that were either untreated or treated with the neonicotinoid thiacloprid as part of normal farming practice. Colonies were exposed to the raspberry crops for a two week period before being relocated to either a flower-rich or flower-poor site. Overall, exposed colonies were more likely to die prematurely, and those that survived reached a lower final weight and produced 46% fewer reproductives than colonies placed at control farms. The impact was more marked at the flower-rich site (all colonies performed poorly at the flower poor site). Analysis of nectar and pollen stores from bumblebee colonies placed at the same raspberry farms revealed thiacloprid residues of up to 771 ppb in pollen and up to 561 ppb in nectar. The image of thiacloprid as a relatively benign neonicotinoid should now be questioned.

  10. Inbreeding Depression in Solanum carolinense (Solanaceae) under Field Conditions and Implications for Mating System Evolution

    PubMed Central

    Kariyat, Rupesh R.; Scanlon, Sarah R.; Mescher, Mark C.; De Moraes, Consuelo M.; Stephenson, Andrew G.

    2011-01-01

    The clonal weed Solanum carolinense exhibits plasticity in the strength of its self-incompatibility (SI) system and suffers low levels of inbreeding depression (δ) in the greenhouse. We planted one inbred and one outbred plant from each of eight maternal plants in a ring (replicated twice) and monitored clonal growth, herbivory, and reproduction over two years. Per ramet δ was estimated to be 0.63 in year one and 0.79 in year two, and outbred plants produced 2.5 times more ramets than inbred plants in the spring of year two. Inbred plants also suffered more herbivore damage than outbred plants in both fields, suggesting that inbreeding compromises herbivore resistance. Total per genet δ was 0.85 over the two years, indicating that S. carolinense is unlikely to become completely self-compatible, and suggesting that plasticity in the SI system is part of a stable mixed-mating system permitting self-fertilization when cross pollen limits seed production. PMID:22174810

  11. Relationship of radon concentration to spacial and temporal variations of reservoir thermodynamic conditions in the Cerro Prieto Geothermal Field

    SciTech Connect

    Semprini, L.; Kruger, P.

    1982-08-10

    Measurements of radon concentration in produced fluids in Cerro Prieto are evaluated with respect to spacial and temporal variations in reservoir thermodynamic conditions and the rock mass to fluid mass ratio emanation. Observed higher concentration of radon at wells with higher fluid enthalpy can be attributed to the higher steam fraction in the wellhead fluid. Correlations of radon concentration to specific volume of pore fluid leads to improved correlations coefficients. The improvement results from the dependence of specific volume on both enthalpy and reservoir temperature. Temporal variations in radon concentration reflect changing phase conditions in the reservoir. Observations over a 2-year interval show significant changes in the producing zones. For example, the constant, low concentration along the western edge of the field indicates a fluid of low steam saturation. In the eastern area, radon concentrations have increased significantly suggesting an increase in the steam saturation in this part of the reservoir due to exploitation. Other areas, e.g., the southeast area, show decreased radon concentration, indicating a decrease in the vapor content of the field. Concurrent measurements of ammonia, a soluble component of the noncondensable gases, support the observation of partitioning of gas components, with wellhead concentration dependent on spacial variations in steam saturation over the field.

  12. Enhanced degradation of atrazine under field conditions correlates with a loss of weed control in the glasshouse.

    PubMed

    Krutz, L Jason; Zablotowicz, Robert M; Reddy, Krishna N; Koger, Clifford H; Weaver, Mark A

    2007-01-01

    Enhanced degradation of atrazine has been reported in the literature, indicating the potential for reduced residual weed control with this herbicide. Experiments were conducted to determine the field dissipation of atrazine in three cropping systems: continuous Zea mays L. (CC) receiving atrazine applications each year, Gossypium hirsutum L.-Z. mays rotation (CCR) receiving applications of atrazine once every 2 years and a no atrazine history soil (NAH). Subsequent laboratory and greenhouse experiments were conducted with soil collected from these cropping systems to determine atrazine degradation, mineralization and residual weed control. Field dissipation of atrazine followed first-order kinetics, and calculated half-life values for atrazine combined over 2003 and 2005 increased in the order of CC (9 d) = CCR (10 d) < NAH (17 d). Greenhouse studies confirmed that the persistence of atrazine was approximately twofold greater in NAH soil than in CC or CCR soil. Biometer flask mineralization studies suggested that enhanced degradation of atrazine was due to rapid catabolism of the s-triazine ring. Glasshouse efficacy studies revealed a loss of residual weed control in CC and CCR soil compared with NAH soil. These data indicate that, under typical Mississippi Delta field conditions and agronomic practices, the persistence of atrazine may be reduced by at least 50% if the herbicide is applied more than once every 24 months. Glasshouse studies suggest that under these conditions a loss of residual weed control is possible.

  13. Lack of glyphosate resistance gene transfer from Roundup Ready soybean to Bradyrhizobium japonicum under field and laboratory conditions.

    PubMed

    Isaza, Laura Arango; Opelt, Katja; Wagner, Tobias; Mattes, Elke; Bieber, Evi; Hatley, Elwood O; Roth, Greg; Sanjuán, Juan; Fischer, Hans-Martin; Sandermann, Heinrich; Hartmann, Anton; Ernst, Dieter

    2011-01-01

    A field